Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
Invention Title
TRANSMITTING/RECEIVING SYSTEM AND METHOD OF PROCESSING DATA IN
THE TRANSMITTING/RECEIVING SYSTEM
Field of the Invention
The present invention relates to a transmitting system for
transmitting a digital broadcasting signal, a receiving
system (or receiver) for receiving the digital broadcasting
signal transmitted from the transmitting system, and a method
of processing data in the transmitting system and the
receiving system (or receiving system).
Discussion of the Related Art
The Vestigial Sideband (VSB) transmission mode, which is
adopted as the standard for digital broadcasting in North
America and the Republic of Korea, is a system using a single
carrier method. Therefore, the receiving performance of the
receiving system may be deteriorated in a poor channel
environment.
Particularly, since resistance to changes in
channels and noise is more highly required when using
portable and/or mobile broadcast receivers, the receiving
performance may be even more deteriorated when transmitting
mobile service data by the VSB transmission mode.
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SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a
method of processing broadcast data in a broadcast transmitter, the method
comprising: performing, by a Reed Solomon (RS) frame encoder, RS encoding and
Cyclic Redundancy Check (CRC) encoding on mobile service data, thereby
generating an RS frame; mapping a portion of the RS frame into at least one
region
of a data group that has a plurality of regions, wherein the data group
further includes
known data sequences, a fast information channel (FIC) segment and
transmission
parameter channel (TPC) data; and transmitting a transmission frame including
the
data group, wherein an FIC chunk includes information for rapid mobile service
acquisition and comprises an FIC chunk header and an FIC chunk payload, the
FIC
chunk header including first protocol version information and second protocol
version
information, the first protocol version information indicating a major version
level of a
syntax of the FIC chunk, the second protocol version information indicating a
minor
version level of the syntax of the FIC chunk, wherein the FIC chunk is
segmented into
a plurality of FIC segment payloads, wherein the FIC segment being transmitted
in
the data group includes an FIC segment header and one of the plurality of FIC
segment payloads, wherein the FIC segment header includes third protocol
version
information that indicates a major version level of the syntax of the FIC
chunk and
has a same value as the first protocol version information, and wherein the
TPC data
comprise FIC version information for indicating a change of contents in the
FIC
chunk.
According to another aspect of the present invention, there is provided
a broadcast transmitter comprising: an RS frame encoder for performing RS
encoding and CRC encoding on mobile service data, thereby generating an RS
frame; a group formatting unit for mapping a portion of the RS frame into at
least one
region of a data group that has a plurality of regions, wherein the data group
further
includes known data sequences, an FIC segment and TPC data; and a transmitting
unit for transmitting a transmission frame including the data group, wherein
an FIC
chunk includes information for rapid mobile service acquisition comprises an
FIC
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chunk header and an FIC chunk payload, the FIC chunk header including first
protocol version information and second protocol version information, the
first
protocol version information indicating a major version level of a syntax of
the FIC
chunk, the second protocol version information indicating a minor version
level of the
syntax of the FIC chunk, wherein the FIC chunk is segmented into a plurality
of FIC
segment payloads, wherein the FIC segment being transmitted in the data group
includes an FIC segment header and one of the plurality of FIC segment
payloads,
wherein the FIC segment header includes third protocol version information
that
indicates a major version level of the syntax of the FIC chunk and has a same
value
as the first protocol version information, and wherein the TPC data comprise
FIC
version information for indicating a change of contents in the FIC chunk.
According to another aspect of the present invention, there is provided
a method of processing data in a transmitter, the method comprising: encoding
mobile service data for a service, channel information and table information;
and
transmitting the encoded mobile service data, channel information and table
information, wherein the channel information includes information for
indicating
whether the service is active or inactive, and wherein the table information
includes
access information for the mobile service data.
According to another aspect of the present invention, there is provided
a method of processing data in a receiver, the method comprising: receiving
mobile
service data for a service, channel information and table information; and
decoding
the received mobile service data, wherein the channel information includes
information for indicating whether the service is active or inactive, and
wherein the
table information includes access information for the mobile service data.
Some embodiments are directed to a transmitting/receiving system and
a data processing method that may substantially obviate one or more problems
due
to limitations and disadvantages of the related art.
Some embodiments may provide a transmitting/receiving system and a
data processing method that are highly resistant to channel changes and noise.
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2b
Some embodiments may provide a transmitting/receiving system and a
data processing method that can perform efficient channel setting by using
signaling
information.
Some embodiments may provide a transmitting/receiving system and a
data processing method that can also perform efficient channel setting by
using FIG
(fast information channel).
Additional advantages and features of some embodiments of the
invention will be set forth in part in the description which follows and in
part will
become apparent to those having ordinary skill in the art upon examination of
the
following or may be learned from practice of the invention. The objectives and
other
advantages of some embodiments of the invention may be realized and attained
by
the structure particularly pointed
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out in the written description and claims hereof as well as
the appended drawings.
In another aspect, a receiving system includes a
receiving unit, a first processing unit, and a second
processing unit. The
receiving unit receives a broadcast
signal including mobile service data from at least one slot.
Herein, a transmission frame is configured of a plurality of
sub-frames for receiving at least one ensemble and at least
one mobile service, and a sub-frame is configured of a
plurality of slots. The first processing unit acquires FIC
segments divided from an FIC chunk of at least one sub-frame.
Herein, each FIC segment comprises a 2-byte segment header
and a 35-byte segment payload. The segment header includes an
FIC type information, a number of a corresponding FIC segment,
and a number of a last FIC segment among the FIC segments
divided from the FIC chunk. The
second processing unit
obtains the FIC chunk including signaling information between
at least one ensemble and at least one mobile service from
respective payloads of the FIC segments, based upon the
acquired FIC type information, number of the corresponding
FIC segment, and number of the last FIC segment of each FIC
segment.
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Herein, the FIC chunk may be configured of a 5-byte chunk
header and a variable-length chunk payload, and the signaling
information between at least one ensemble and at least one
mobile service may be included in the chunk payload.
Also, a last FIC segment of the FIC chunk may include N
number of stuffing data bytes, wherein N is an integer and is
equal to or greater than 10' (PIO). And, the FIC segments
divided from an FIC chunk may be received through two or more
sub-frames. Also, the FIC segments divided from two or more
FIC chunks may be received through one sub-frame.
Furthermore, M number of null FIC segments may be received
through at least one sub-frame, wherein M is an integer and
is equal to or greater than '0' (Ad?...0). And each null FIC
segment may be identified by using an FIC type information
within a segment header of corresponding null FIC segment.
Finally, transmission parameter channel (TPC) data including
identification information from the received broadcast signal
may be acquired, wherein the identification information can
identify an update of a data structure of the FIC chunk.
According to another aspect, a
data processing method of a receiving system includes the
steps of receiving a broadcast signal including mobile
service data from at least one slot, wherein a transmission
frame is configured of a plurality of sub-frames for
receiving at least one ensemble and at least one mobile
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service, and wherein a sub-frame is configured of a plurality
of slots, acquiring FIC segments divided from an FIC chunk of
at least one sub-frame, wherein each FIC segment comprises a
2-byte segment header and a 35-byte segment payload, and
5 wherein the segment header includes an FIC type information,
a number of a corresponding FIC segment, and a number of a
last FIC segment among the FIC segments divided from the FIC
chunk, and obtaining the FIC chunk including signaling
information between at least one ensemble and at least one
mobile service from respective payloads of the FIC segments,
based upon the acquired FIC type information, number of the
corresponding FIC segment, and number of the last FIC segment
of each FIC segment.
It is to be understood that both the foregoing general
description and the following detailed description of some
embodiments of the present invention are exemplary and
explanatory and are intended to provide further explanation of
the invention as claimed.
The transmitting system and the receiving system and the
data processing method of the same according to some
embodiments may have the following advantages.
Some embodiments can signal mapping (or signaling)
information between at least one ensemble and at least one
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mobile service by using an FIC chunk, and can divide and
transmit the FIC chunk into FIC segment units, thereby
enabling a receiving, system to perform quick service
acquisition.
Furthermore, some embodiments can transmit multiple
FIC segments divided from an FIC chunk through a single sub-
frame or through multiple sub-frames, thereby preventing FIC
segments from being wasted, when a data size of the FIC chunk
is smaller or larger than the data size of the FIC segments
being transmitted through a single sub-frame.
In addition, some embodiments can transmit protocol
version information of an FIC chunk corresponding to an FIC
segment through a header of the FIC segment, thereby enabling
the receiving system to accurately recover the FIC chunk by
using the FIC segments configured of the corresponding
protocol version, even when FIC chunks of different protocol
versions co-exist in a single M/H frame.
Some embodiments also can transmit identification
information for identifying whether the signaling information
being transmitted to the payload of the' corresponding FIC
segment through the header of the FIC segment corresponds to
signaling information of the current M/H frame or to
signaling information of the next M/H frame, thereby enabling
the receiving sYstem to accurately recover the FIC chunk by
using the FIC segments of the corresponding M/H frame, even
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when an FIC chunk signaling ensemble configuration information of the current
M/H
frame and an FIC chunk signaling ensemble configuration information of the
next M/H
frame co-exist in a single M/H frame.
More specifically, some embodiments may be highly protected against
(or resistant to) any error that may occur when transmitting mobile service
data
through a channel. Some embodiments may also be highly compatible to the
conventional receiving system. Moreover, some embodiments may also receive the
mobile service data without any error even in channels having severe ghost
effect
and noise. Furthermore, by inserting known data in a particular position (or
place)
within a data region and transmitting the processed data, the receiving
performance
of the receiving system may be enhanced even in a channel environment that is
liable to frequent changes. Finally, some embodiments may be even more
effective
when applied to mobile and portable receivers, which are also liable to a
frequent
change in channel and which require protection (or resistance) against intense
noise.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and constitute a part
of this
application, illustrate
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embodiment(s) of the invention and together with the
description serve to explain the principle of the invention.
In the drawings:
FIG. 1 illustrates a block diagram showing a general
structure of a receiving system according to an embodiment of
the present invention;
FIG. 2 illustrates an exemplary structure of a data group
according to an embodiment of the present invention;
FIG. 3 illustrates an RS frame according to an embodiment
of the present invention;
FIG. 4 illustrates an example of an M/H frame structure
for transmitting and receiving mobile service data according
to an embodiment of the present invention;
FIG. 5 illustrates an example of a general VSB frame
structure;
FIG. 6 illustrates a data transmission structure in a
physical layer according to an embodiment of the present
invention;
FIG. 7 illustrates a hierarchical signaling structure
according to an embodiment of the present invention;
FIG. 8 illustrates a syntax structure of an FIC chunk
according to an embodiment of the present invention;
FIG. 9 illustrates a syntax structure of an FIC chunk
header according to an 'embodiment of the present invention;
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FIG. 10 illustrates an exemplary change in a minor protocol version of a
FIC chunk according to an embodiment of the present invention;
FIG. 11 illustrates an exemplary process of processing an FIC chunk,
when a minor protocol version of the FIC chunk is changed according to an
embodiment of the present invention;
FIG. 12 illustrates a syntax structure of an FIC chunk payload according
to an embodiment of the present invention;
FIG. 13 illustrates an example of segmentation process of a FIC chunk
according to an embodiment of the present invention;
FIG. 14 illustrates FIC segments transmitted according to an
embodiment of the present invention;
FIG. 15 illustrates FIC segments transmitted according to another
embodiment of the present invention;
FIG. 16 illustrates a syntax structure of an FIC segment header
according to an embodiment of the present invention;
FIG. 17 illustrates an example of recovering (or obtaining) one or more
FIC chunks by receiving FIC segments according to an embodiment of the present
invention;
FIG. 18 illustrates another example of recovering (or obtaining) one or
more FIC chunks by receiving FIC segments according to an embodiment of the
present invention;
FIG. 19 illustrates an example of errors that may occur when one or
more FIC chunks by receiving FIC segments is recovered according to an
embodiment of the present invention;
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FIG. 20 illustrates a syntax structure of an FIC segment header
according to another embodiment of the present invention;
FIG. 21 illustrates another example of recovering one or more FIC
chunks by receiving FIC segments according to an embodiment of the present
5 invention;
FIG. 22 illustrates an exemplary occurrence of reconfiguration of a FIC
chunk according to an embodiment of the present invention;
FIG. 23 illustrates an exemplary RS frame acquisition process by
performing an advanced signaling on a FIC chunk according to an embodiment of
the
10 present invention;
FIG. 24 illustrates another exemplary RS frame acquisition process by
performing an advanced signaling on a FIC chunk according to an embodiment of
the
present invention;
FIG. 25 illustrates another example of errors that may occur when one
or more FIC chunks by receiving FIC segments is recovered according to an
embodiment of the present invention;
FIG. 26 illustrates a syntax structure of an FIC segment header
according to another embodiment of the present invention;
FIG. 27 illustrates a syntax structure of a TPC data according to an
embodiment of the present invention;
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FIG. 28 illustrates another example of recovering one or
more FIC chunks by receiving FIC segments according to
an embodiment of the present invention; and
FIG. 29 and FIG. 30 illustrate flow-charts of recovering
one or more FIC chunks by receiving FIC segments according to
an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. Wherever possible,
the same reference numbers will be used throughout the
drawings to refer to the same or like parts. In addition,
although the terms used in the present invention are selected
from generally known and used terms, some of the terms
mentioned in the description of the present invention have
been selected by the applicant at his or her discretion, the
detailed meanings of which are described in relevant parts of
the description herein. Furthermore, it is required that the
present invention is understood, not simply by the actual
terms used but by the meaning of each term lying within.
Among the terms used in the description of the present
invention, main service data correspond to data that can be
received by a fixed receiving system and may include
audio/video (A/V) data. More specifically, the main service
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data may include A/V data of high definition (HD) or standard
definition (SD) levels and may also include diverse data
types required for data broadcasting. Also, the known data
correspond to data pre-known in accordance with a pre-
arranged agreement between the receiving system and the
transmitting system.
Additionally, among the terms used in the present
invention, "M/H" (or NH) corresponds to the initials of
"mobile" and "handheld" and represents the opposite concept
of a fixed-type system.
Furthermore, the M/H service data
may include at least one of mobile service data, and handheld
service data, and will also be referred to as "mobile service
data" for simplicity. Thereafter, the M/H, NH, and mobile is
used as the same meaning. Herein, the mobile service data not
only correspond to M/H service data but may also include any
type of service data with mobile or portable characteristics.
Therefore, the mobile service data according to the present
invention are not limited only to the M/H service data.
The above-described mobile service data may correspond to
data having information, such as program execution files,
stock information, and so on, and may also correspond to A/V
data.
Most particularly, the mobile service data may
correspond to A/V data having lower resolution and lower data
rate as compared to the main service data. For example, if
an A/V codec that is used for a conventional main service
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corresponds to a MPEG-2 codec, a MPEG-4 advanced video coding
(AVC) or scalable video coding (SVC) having better image
compression efficiency may be used as the A/V codec for the
mobile service.
Furthermore, any type of data may be
transmitted as the mobile service data.
For example,
transport protocol expert group (TPEG) data for broadcasting
real-time transportation information may be transmitted as
the main service data.
Also, a data service using the mobile service data may
include weather forecast services, traffic information
services, stock information services, viewer participation
quiz programs, real-time polls and surveys, interactive
education broadcast programs, gaming services, services
providing information on synopsis, character, background
music, and filming sites of soap operas or series, services
providing information on past match scores and player
profiles and achievements, and services providing information
on product information and programs classified by service,
medium, time, and theme enabling purchase orders to be
processed. Herein, the present invention is not limited only
to the services mentioned above.
In the present invention,
the transmitting system provides backward compatibility in
=the main service data so as to be received by the
conventional receiving system. Herein, the main service data
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and the mobile service data are multiplexed to the same
physical channel and then transmitted.
In the present invention, the transmitting system provides
backward compatibility in the main service data so as to be
received by the conventional receiving system.
Herein, the
main service data and the mobile service data are multiplexed
to the same physical channel and then transmitted.
Furthermore, the transmitting system according to the
present invention performs additional encoding on the mobile
service data and inserts the data already known by the
receiving system and transmitting system (e.g., known data),
thereby transmitting the processed data.
Therefore, when using the transmitting system according to
the present invention, the receiving system may receive the
mobile service data during a mobile state and may also
receive the mobile service data with stability despite
various distortion and noise occurring within the channel.
According to an embodiment of the present invention, the
transmitting system and the receiving system operate two
different types of data channels: an RS frame data channel
for transmitting contents and a fast information channel
(FIC) data channel for acquisiting service.
More specifically, the present invention can signal
mapping information between an ensemble and a mobile service
by using an FIC chunk, and can divide and transmit the FIC
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chunk into FIC segment units, thereby enabling a receiving
system to perform quick service acquisition.
Furthermore, the present invention can transmit multiple
FIC segments divided from an FIC chunk through a single sub-
frame or through multiple sub-frames, thereby preventing FIC
segments from being wasted, when a data size of the FIC chunk
is smaller or larger than the data size of the FIC segments
being transmitted through a single sub-frame..
In addition, the present invention can transmit protocol
version information of an FIC chunk corresponding to an FIC
segment through a header of the FIC segment, thereby enabling
the receiving system to accurately recover (or obtains) the
FIC chunk by using the FIC segments configured of the
corresponding protocol version, even when FIC chunks of
different protocol versions co-exist in a single M/H frame.
The present invention also can transmit identification
information for identifying whether the signaling information
being transmitted to the payload of the corresponding FIC
segment through the header of the FIC segment corresponds to
'signaling information of the current M/H frame or to
signaling information of the next M/H frame, thereby enabling
the receiving system to accurately recover the FIC chunk by
using the FIC segments of the corresponding M/H frame, even
when an FIC chunk signaling ensemble configuration
information of the current M/H frame and an FIC chunk
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signaling ensemble configuration information of the next M/H
frame co-exist in a single M/H frame.
Receiving System
FIG. 1 illustrates a block diagram showing a general
structure of a receiving system according to an embodiment of
the present invention. Referring to FIG. 1, the arrow shown
in dotted line indicates a data path, and the arrow shown in
slid line indicates a control signal path.
The receiving system according to the present invention
may include an operation controller 100, a tuner 111, a
demodulator 112, an equalizer 113, a known sequence detector
(or known data detector) 114, a block decoder 115, a primary
Reed-Solomon (RS) frame decoder 116, a secondary RS frame
decoder 117, a signaling decoder 118, and a baseband
controller 119. The receiving system according to the present
invention may further include an FIC handler 121, a service
manager 122, a service signaling handler 123, and a first
storage unit 124. The receiving system according to the
present invention may further include a primary RS frame
buffer 131, a secondary RS frame buffer 132, and a transport
packet (TS) handler 133. The receiving system according to
the present invention may further include an Internet
Protocol (IP) datagram handler 141, a descrambier 142, an
User Datagram Protocol (UDP) datagram handler 143, a Real-
.
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time Transport Protocol/Real-time Transport Control Protocol
(RTP/RTCP) datagram handler 144, a Network Time Protocol
(NTP) datagram handler 145, a service protection stream.
handler 146, a second storage unit 147, an Asynchronous
Layered Coding/Layered Coding Transport (ALC/LCT) stream
handler 148, an Extensible Mark-up Language (XML) parser 150,
and a Field Device Tool (FDT) handler 151. The receiving
system according to the present invention may further include
an Audio/Video (A/V) decoder 161, a file decoder 162, a third
storage unit 163, a middle ware (M/W) engine 164, and a
Service Guide (SG) handler 165. The receiving system
according to the present invention may further include an
Electronic Program Guide (EPG) manager 171, an application
manager 172, and an User Interface (UI) manager 173.
Herein, for simplicity of the description of the present
invention, the operation controller 100, the tuner 111, the
demodulator 112, the equalizer 113, the known sequence
detector (or known data detector) 114, the block decoder 115,
the primary RS frame decoder 116, the secondary RS frame
decoder 117, the signaling decoder 118, and the baseband
controller 119 will be collectively referred to as a baseband
processor 110. The FIC handler 121, the service manager 122,
the service signaling handler 123, and the first storage unit
124 will be collectively referred to as a service multiplexer
120. The primary RS frame buffer 131, the secondary RS frame
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buffer 132, and the TS handler 133 will be collectively
referred to as an IP adaptation module 130. The IP datagram
handler 141, the descrambler 142, the UDP datagram handler
143, the RTP/RTCP datagram handler 144, the NT? datagram
handler 145, the service protection stream handler 146, the
second storage unit 147, the ALC/LCT stream handler 148, the
XML parser 150, and the FDT handler 151 will be collectively
referred to as a common IP module 140. The A/V decoder 161,
the file decoder 162, the third storage unit 163, the M/W
engine 164, and the SG handler 165 will be collectively
referred to as an application module 160.
In addition, although the terms used in FIG. 1 are
selected from generally known and used terms, some of the
terms mentioned in the description of FIG. 1 have been
selected by the applicant at his or her discretion, the
detailed meanings of which are described in relevant parts of
the description herein. Furthermore, it is required that the
present invention is understood, not simply by the actual
terms used but by the meaning of each term lying within.
Referrfng to FIG. 1, the baseband controller 119 controls
the operation of each block included in the baseband
processor 110.
By tuning the receiving system to a specific physical
channel frequency (or physical transmission channel frequency,
,25 PTC), the tuner 111 enables the receiving system to receive
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main service data, which correspond to broadcast signals for
fixed-type broadcast receiving systems, and mobile service
data, which correspond to broadcast signals for .mobile
broadcast receiving systems. At this point, the tuned
frequency of the specific physical channel is down-converted
to an intermediate frequency (IF) signal, thereby being
outputted to the demodulator 112 and the known sequence
detector 114. The passband digital IF signal being outputted
from the tuner 111 may only include main service data, or
only include mobile service data, or include both main
service data and mobile service data.
The demodulator 112 performs self-gain control, carrier
recovery, and timing recovery processes on the passband
digital IF signal inputted from the tuner 111, thereby
modifying the IF signal to a baseband signal.
Then, the
demodulator 112 outputs the baseband signal to the equalizer
113 and the known sequence detector 114. The demodulator 112
uses the known data symbol sequence inputted from the known
sequence detector 114 during the timing and/or carrier
recovery, thereby enhancing the demodulating performance.
The equalizer 113 compensates channel-associated distortion
included in the signal demodulated by the demodulator 112.
Then, the equalizer 113 outputs the distortion-compensated
signal to the block decoder 115.
By using a known data
symbol sequence inputted from the known sequence detector 114,
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the equalizer 113 may enhance the equalizing performance.
Furthermore, the equalizer 113 may receive feed-back on the
decoding result from the block decoder 115, thereby enhancing
the equalizing performance.
5 The known sequence detector 114 detects known data place
(or position) inserted by the transmitting system from the
input/output data (i.e., data prior to being demodulated or
data being processed with partial demodulation).
Then, the
known sequence detector 114 outputs the detected known data
10 position information and known data sequence generated from
the detected position information to the demodulator 112, the
equalizer 113, and the baseband controller 119. Additionally,
in order to allow the block decoder 115 to identify the
mobile service data that have been processed with additional
15 encoding by the transmitting system and the main service data
that have not been processed with any additional encoding,
the known sequence detector 114 outputs such corresponding
information to the block decoder 115.
If the data channel-equalized by the equalizer 113 and
20 inputted to the block decoder 115 correspond to data
processed with both block-encoding of serial concatenated
convolution code (SCCC) method and trellis-encoding by the
transmitting system
data within the RS frame,
signaling data), the block decoder 115 may perform trellis-
decoding and block-decoding as inverse processes of the
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transmitting system. On the other hand, if the data channel-
equalized by the equalizer 113 and inputted to the block
decoder 115 correspond to data processed only with trellis-
encoding and not block-encoding by the transmitting system
(i.e., main service data), the block decoder 115 may perform
only trellis-decoding.
The signaling decoder 118 decodes signaling data that have
been channel-equalized and inputted from the equalizer 113.
It is assumed that the signaling data (or signaling
information) inputted to the signaling decoder 118 correspond
to data processed with both block-encoding and trellis-
encoding by the transmitting system.
Examples of such
signaling data may include transmission parameter channel
(TPC) data and fast information channel (FIC) data.
For example, among the data that are being inputted, the
signaling decoder 118 performs regressive turbo decoding of a
parallel concatenated convolution code (PCCC) method on data
corresponding to the signaling information region.
Subsequently, the signaling decoder 118 separates FIC data
and TPC data from the regressive-turbo-decoded signaling data.
Additionally, the signaling decoder 118 performs RS-decoding
as inverse processes of the transmitting system on the
separated TPC data, thereby outputting the processed data to
the baseband controller 119. Also, the signaling decoder 118
performs deinterleaving in sub-frame units on the separated
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FIC data, so as to perform RS-decoding as inverse processes
of the transmitting system on the deinterleaved FIC data,
thereby outputting the processed data to the FIC handler 121.
The FIC data being deinterleaved and RS-decoded from the
signaling decoder 118 and outputted to the FIC handler 121
are transmitted in units of FIC segments.
The FIC handler 121 receives FIC data from the signaling
decoder 118, so as. to extract signaling information for
service acquisition (i.e., mapping information between an
ensemble and a mobile service). In order to do so, the FIC
handler 121 may include an FIC segment buffer, an FIC segment
parser, and an FIC chunk parser.
The FIC segment buffer buffers FIC segment groups being
inputted in M/H frame units from the signaling decoder 118,
thereby outputting the buffered FIC segment groups to the FIC
segment parser. Thereafter, the FIC segment parser extracts
the header of each FIC segment stored in the FIC segment
buffer so as to analyze the extracted headers. Then, based
upon the analyzed result, the FIC segment parser outputs the
payload of the respective FIC segments to the FIC chunk
parser.
The FIC chunk parser uses the analyzed result
outputted from the FIC segment parser so as to recover the
FIC chunk data structure from the FIC segment payloads,
thereby analyzing the received FIC chunk data structure.
Subsequently, the FIC chunk parser extracts the signaling
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information for service acquisition.
The signaling
information acquired from the FIC chunk parser is outputted
to the service manager 122.
Meanwhile, the service signaling handler 123 consists of a
service signaling buffer and a service signaling parser.
Herein, the service signaling handler 123 buffers table
sections of a service signaling channel being transmitted
from the UDP datagram handler 143, thereby analyzing and
processing the buffered table sections.
Similarly, the
signaling information processed by the service signaling
handler 123 is also outputted to the service manager 122.
The service manager 122 uses the signaling information
collected from each of the FIC handler 121 and the service
signaling handler 123, so as to configure a service map.
Thereafter, the service manager 122 uses a service guide (SG)
collected from the service guide (SG) handler 165 so as to
draw up a program guide.
Then, the service manager 122
controls the baseband controller 119 so that a user can
receive (or be provided with) a user-requested mobile service
by referring to the se'rvice map and service guide.
Furthermore, the service manager 122 may also control the
receiving system so that the program guide can be displayed
on at least a portion of the dikplay screen based upon the
user's input.
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The first storage unit 124 stores the service map and
service guide drawn up by the service manager 122. Also,
based upon the requests from the service manager 122 and the
EPG manager 171, the first storage unit 124 extracts the
required data, which are then transferred to the service
manager 122 and/or the EPG manager 171.
The baseband controller 119 receives the known data place
information and TPC data, thereby transferring M/H frame time
information, information indicating whether or not a data
group exists in a selected parade, place information of known
data within a corresponding data group, power control
information, and so on to each block within the baseband
processor 110. The TPC data will be described in detail in a
later.
Meanwhile, according to the present invention, the
transmitting system uses RS frames by encoding units. Herein,
the RS frame may be divided into a primary RS frame and a
secondary RS frame. However, according to the embodiment of
the present invention, the primary RS frame and the secondary
RS frame will be divided based upon the level of importance
of the corresponding data.
The primary RS frame decoder 116 receives the data
outputted from the block decoder '115.
At this point,
according to the embodiment of the present invention, the
primary RS frame decoder 116 receives only the mobile service
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data that have been Reed-Solomon (RS)-encoded and/or cyclic
redundancy check (CRC)-encoded from the block decoder 115.
Herein, the primary RS frame decoder 116 receives only the
mobile service data and not the main service data.
The
primary RS frame decoder 116 performs inverse processes of an
RS frame encoder (not shown) included in the digital
broadcast transmitting system, thereby correcting errors
existing within the primary RS frame. More specifically, the
primary RS frame decoder 116 forms a primary RS frame by
grouping a plurality of data groups and, then, correct errors
in primary RS frame units.
In other words, the primary RS
frame decoder 116 decodes primary RS frames, which are being
transmitted for actual broadcast services. The primary RS
frame decoded by the primary RS frame decoder 116 outputs to
the primary RS frame buffer 131. The primary RS frame buffer
131 buffers the primary RS frame, and then configures an M/H
TP in each row unit. The M/H TPs of the primary RS frame
outputs to the TP handler 133.
Additionally, the secondary RS frame decoder 117 receives
the data outputted from the block decoder 115. At this point,
according to the embodiment of the present invention, the
secondary RS frame decoder 117 receives only the mobile
service data that have been RS-encoded and/or CRC-encoded
from the block decoder 115. Herein, the secondary RS frame
decoder 117 receives only the mobile service data and not the
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main service data. The secondary RS frame decoder 117
performs inverse processes of an RS frame encoder (not shown)
included in the digital broadcast transmitting system,
thereby correcting errors existing within the secondary RS
frame. More specifically, the secondary RS frame decoder 117
forms a secondary RS frame by grouping a plurality of data
groups and, then, correct errors in secondary RS frame units.
In other words, the secondary RS frame decoder 117 decodes
secondary RS frames, which are being transmitted for mobile
audio service data, mobile video service data, guide data,
and so on. The secondary RS frame decoded by the secondary RS
frame decoder 117 outputs to the secondary RS frame buffer
132. The secondary RS frame buffer 132 buffers the secondary
RS frame, and then configures an M/H TP in each row unit. The
M/H TPs of the secondary RS frame outputs to the TP handler
133.
The TP handler 133 consists of a TP buffer and a TP parser.
The TP handler 133 buffers the M/H TPs inputted from the
primary RS frame buffer 131 and the secondary RS frame buffer
132, and then extracts and analyzes each header of the
buffered M/H TPs, thereby recovering IP datagram from each
payload of the corresponding M/H TPs. The recovered IP
=
datagram is outputted to the IP datagram handler 141.
The IP datagram handler 141 consists of an IP datagram
buffer and an IF datagram parser. The IP datagram handler 141
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buffers the IP datagram delivered from the TP handler 133,
and then extracts and analyzes a header of the buffered IP
datagram, thereby recovering UDP datagram from a payload of
the corresponding IP datagram. The recovered UDP datagram is
outputted to the UDP datagram handler 143.
If the UDP datagram is scrambled, the scrambled UDP
datagram is descrambled by the descrambler 142, and the
descrambled UDP datagram is outputted to the UDP datagram
handler 143. For example, when the UDP datagram among the
received IP datagram is scrambled, the descrambler 142
descrambles the UDP datagram by inputting an encryption key
and so on from the service protection stream handler 146, and
outputs the descrambled UDP datagram to the UDP datagram
handler 143.
The UDP datagram handler 143 consists of an UDP datagram
buffer and an UDP.datagram parser. The UDP datagram handler
143 buffers the UDP datagram delivered from the IP datagram
handler 141 or the descrambler 142, and then extracts and
analyzes a header of the buffered UDP datagram, thereby
recovering data transmitted through a payload of the
corresponding UDP datagram. If the recovered data is an
RTP/RTCP datagram, the recovered data is outputted to the
RTP/RTCP datagram handler 144. If the recovered data is also =
an NTP datagram, the recovered data is outputted to the NTP
datagram handler 145. Furthermore, if the recovered data is a
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service protection stream, the recovered data is outputted to
the service protection stream handler 146. And, if the
recovered data is an ALC/LCT stream, the recovered data is
outputted to the ALC/LCT steam handler 148.
The RTP/RTCP datagram handler 144 consists of an RTP/RTCP
datagram buffer and an RTP/RTCP datagram parser. The RTP/RTCP
datagram handler 144 buffers the data of RTP/RTCP structure
outputted from the UDP datagram handler 143, and then
extracts A/V stream from the buffered data, thereby
outputting the extracted A/V stream to the A/V decoder 161.
The A/V decoder 161 decodes the audio and video streams
outputted from the RTP/RTCP datagram handler 144 using audio
and video decoding algorithms, respectively. The decoded
audio and video data is outputted to the presentation manager
170. Herein, at least one of an AC-3 decoding algorithm, an
MPEG 2 audio decoding algorithm, an MPEG 4 audio decoding
algorithm, an AAC decoding algorithm, an AAC+ decoding
algorithm, an HE AAC decoding algorithm, an AAC SBR decoding
algorithm, an MPEG surround decoding algorithm, and a BSAC
decoding algorithm can be used as the audio decoding
algorithm and at least one of an MPEG 2 video decoding
algorithm, an MPEG 4 video decoding algorithm, an H.264
decoding algorithm, an SVC decoding algorithm, and a VC-1
decoding algorithm can be used as the audio decoding
algorithm.
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The NTP datagram handler 145 consists of an NTP datagram
buffer and an NTP datagram parser. The NTP datagram handler
145 buffers data having an NTP structure, the data being
outputted from the UDP datagram handler 143. Then, the NTP
datagram handler 145 extracts an NTP stream from the buffered
data.
Thereafter, the extracted NTP stream is outputted to
the A/V decoder 161 so as to be decoded.
The service protection stream handler 146 may further
include a service protection stream buffer.
Herein, the
service protection stream handler 146 buffers data designated
(or required) for service protection, the data being
outputted from the UDP datagram handler 143.
Subsequently,
the service protection stream handler 146 extracts
information required for descrambling from the extracted data.
The information required for descrambling includes a key
value, such as SKTM and LKTM.
The information for
descrambling is stored in the second storage unit 147, and,
when required, the information for descrambling is outputted
to the descrambler 142.
The ALC/LCT stream handler 148 consists of an ALC/LCT
stream buffer and an ALC/LCT stream parser. And, the ALC/LCT
stream handler 148 buffers data having an ALC/LCT structure,
the data being outputted from the UDP datagram handler 143.
Then, the ALC/LCT stream handler 148 analyzes a header and a
header expansion of an ALC/LCT session from the buffered data.
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Based upon the analysis result of the header and header
expansion of the ALC/LCT session, when the data being
transmitted to the ALC/LCT session correspond to an XML
structure, the corresponding data are outputted to an XML
5 parser 150. Alternatively, when the data being transmitted
to the ALC/LCT session correspond to a file structure, the
corresponding data are outputted to a file decoder 162. At
this point, when the data that are being transmitted to the
ALC/LCT session are compressed, the compressed data are
10 decompressed by a decompressor 149, thereby being outputted
to the XML parser 150 or the file decoder 162.
The XML parser 150 analyses the XML data being transmitted
through the ALC/LCT session.
Then, when the analyzed data
correspond to data designated to a file-based service, the
15 XML parser 150 outputs the corresponding data to the FDT
handler 151.
On the other hand, if the analyzed data
correspond to data designated to a service guide, the XML
parser 150 outputs the corresponding data to the SG handler
165.
The FDT handler 151 analyzes and processes a file
20 description table of a FLUTE protocol, which is transmitted
in an XML structure through the ALC/LCT session.
The SG handler 165 collects and analyzes the data
designated for a service guide, the data being transmitted in
an XML structure, thereby outputting the analyzed data to the
25 service manager 122.
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The file decoder 162 decodes the data having a file
structure and being transmitted through the ALC/LCT session,
thereby outputting the decoded data to the middleware engine
164 or storing the decoded data in a third storage unit 163.
Herein, the middleware engine 164 translates the file
structure data (i.e., the application) and executes the
translated application.
Thereafter, the application may be
outputted to an output device, such as a display screen or
speakers, through the application presentation manager 170.
According to an embodiment of the present invention, the
middleware engine 164 corresponds to a JAVA-based middleware
engine.
Based upon a user-input, the EPG manager 171 receives EPG
data either through the service manager 122 or through the SG
handler 165, so as to convert the received EPG data to a
display format, thereby outputting the converted data to the
presentation manager 170.
The application manager 172 performs overall management
associated with the processing of application data, which are
being transmitted in object formats, file formats, and "so on.
Furthermore, based upon a user-command inputted through the
UI manager 173, the operation controller 100 controls at
least one of the service manager 122, the EPG manager 171;
the' application manager 172, and the presentation manager 170,
so as to enable the user-requested function to be executed.
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The UI manager 173 transfers the user-input to the operation
controller 100 through the UI.
Finally, the presentation manager 170 provides at least
one of the audio and video data being outputted from the A/V
decoder 161 and the EPG data being outputted from the EPG
manager 171 to the user through the speaker and/or display
screen.
Data Format Structure
Meanwhile, the data structure used in the mobile
broadcasting technology according to the embodiment of the
present invention may include a data group structure and an
RS frame structure, which will now be described in detail.
FIG. 2 illustrates an exemplary structure of a data group
according to the present invention. FIG. 2 shows an example
of dividing a data group according to the data structure of
the present invention into 10 M/H blocks (i.e., M/H block 1
(B1) to M/H block 10 (B10)). In this example, each M/H block
has the length of 16 segments. Referring to FIG. 2, only the
RS parity data are allocated to portions of the 5 segments
before the M/H block 1 (B1) and the 5 segments following the
M/H block 10 (B10).
The RS parity data are excluded in
regions A to D of the data group. More specifically, when it
is assumed that one data group is divided into regions A, B,
C, and D, each M/H block may be included in any one of region
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A to region D depending upon the characteristic of each M/H
block within the data group.
Herein, the data group is divided into a plurality of
regions to be used for different purposes. More specifically,
a region of the main service data having no interference or a
very low interference level may be considered to have a more
resistant (or stronger) receiving performance as compared to
regions having higher interference levels.
Additionally,
when using a system inserting and transmitting known data in
the data group, wherein the known data are known based upon
an agreement between the transmitting system and the
receiving system, and when consecutively long known data are
to be periodically inserted in the mobile service data, the
known data having a predetermined length may be periodically
inserted in the region having no interference from the main
service data (i.e., a region wherein the main service data
are not mixed). However, due to interference from the main
service data, it is difficult to periodically insert known
data and also to insert consecutively long known data to a
region having interference from the main service data.
Referring to FIG. 2, M/H block 4 (34) to M/H block 7 (B7)
correspond to regions without interference of the main
service data.
M/H block 4 (B4) to M/H block 7 (B7) within
the data group shown in FIG. 2 correspond to a region where
no interference from the main service data occurs.
In this
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example, a long known data sequence is inserted at both the
beginning and end of each M/H block. In the description of
the present invention, the region including M/H block 4 (B4)
to M/H block 7 (B7) will be referred to as "region A
(=B4+35+B6+B7)".
As described above, when the data group
includes region A having a long known data sequence inserted
at both the beginning and end of each M/H block, the
receiving system is capable of performing equalization by
using the channel information that can be obtained from the
known data. Therefore, the strongest equalizing performance
may be yielded (or obtained) from one of region A to region D.
In the example of the data group shown in FIG. 2, M/H
block 3 (B3) and M/H block 8 (B8) correspond to a region
having little interference from the main service data.
Herein, a long known data sequence is inserted in only one
side of each M/H block B3 and B8. More specifically, due to
the interference from the main service data, a long known
data sequence is inserted at the end of M/H block 3 (B3), and
another long known data sequence is inserted at the beginning
of M/H block 8 (B8). In
the present invention, the region
including M/H block 3 (B3) and M/H block 8 (B8) will be
referred to as "region B (=B3+B8)". As described above, when
the data group includes region B having a long known data
sequence inserted at only one side (beginning or end) of each
M/H block, the receiving system is capable of performing
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equalization by using the channel information that can be
obtained from the known data.
Therefore, a stronger
equalizing performance as compared to region C/D may be
yielded (or obtained).
5 Referring to FIG. 2, M/H block 2 (B2) and M/H block 9 (39)
correspond to a region having more interference from the main
service data as compared to region B.
A long known data
sequence cannot be inserted in any side of M/H block 2 (32)
and M/H block 9 (B9). Herein, the region including M/H block
10 2 (32) and M/H block 9 (39) will be referred to as "region C
(=B2+B9)".
Finally, in the example shown in FIG. 2, M/H
block 1 (B1) and M/H block 10 (B10) correspond to a region
having more interference from the main service data as
compared to region C. Similarly, a long known data sequence
15 cannot be inserted in any side of M/H block 1 (B1) and M/H
block 10 (B10).
Herein, the region including M/H block 1
(BI) and M/H block 10 (310) will be referred to as "region D
(=31+310)".
Since region C/D is spaced further apart from
the known data sequence, when the channel environment
20 undergoes frequent and abrupt changes, the receiving
performance of region C/D may be deteriorated.
Additionally, the data group includes a signaling
information area wherein signaling information is assigned
(or allocated). ' In the present invention, the signaling
25 information area may start from the 15t segment of the 4th M/H
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block (B4) to a portion of the 2nd segment. According to an
embodiment of the present invention, the signaling
information area for inserting signaling information may
start from the 15t segment of the 4' M/H block (B4) to a
portion of the 2nd segment.
More specifically, 276(=207+69)
bytes of the 4th M/H block (B4) in each data group are
assigned as the signaling information area. In other words,
the signaling information area consists of 207 bytes of the
1st segment and the first 69 bytes of the 2' segment of the
4' M/H block (B4). The
1st segment of the 4' M/H block (B4)
corresponds to the 17th or 173rd segment of a VSB field.
Herein, the signaling data transmitted through the
signaling information area may be identified by two different
types of signaling channel data: a transmission parameter
channel (TPC) data and a fast information channel (FIC) data.
Also, the TPC data includes parameters that are mostly
used in a physical layer module. And, since the TPC data are
transmitted without being interleaved, the TPC data may be
accessed by slot unit in the receiving system. The FIC data
are provided in order to enable the receiving system to
perform fast service acquisition.
Herein, the FIC data
include cross layer information between a physical layer and
= an upper layer. The FIC data are interleaved in sub-frame
units and then transinitted.
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For example, when the data group includes 6 known data
sequences, as shown in FIG. 2, the signaling information area
is located between the first known data sequence and the
, second known data sequence.
More specifically, the first
known data sequence is inserted in the last 2 segments of the
3rd M/H block (B3), and the second known data sequence in
inserted in the 2nd and 3rd segments of the 4th M/H block (34).
Furthermore, the 3rd to 6th known data sequences are
respectively inserted in the last 2 segments of each of the
io 4th, 5th, 6th, and 7th M/H blocks (34, 35, B6, and B7).
The 1st
and 3r1 to 6th known data sequences are spaced apart by 16
segments.
FIG. 3 illustrates an RS frame according to an embodiment
of the present invention.
The RS frame is received for each M/H frame in a condition
where the receiving system is switched to a time-slicing mode.
Each RS frame includes IF streams of each mobile service data
or signaling data, and service map table (SMT) section data
may exist in all RS frames. The SMT section data may be an
IF stream type, or a different data type. The RS frame data
is allocated to region corresponding to a plurality of data
groups, and transmitted to a receiving system.
The RS frame according to the embodiment of the present
invention consists of at least one M/H transport packet (TP).
Herein, the M/H TP includes an M/H header and an M/H payload.
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The M/H payload may include mobile service data as well as
signaling data.
More specifically, an M/H payload may
include only mobile service data, or may include only
signaling data, or may include both mobile service data and
signaling data. According to the embodiment of the present
invention, the M/H header may identify (or distinguish) the
data types included in the M/H payload. More specifically,
when the M/H TP includes a first M/H header, this indicates
that the M/H payload includes only the signaling data. Also,
when the M/H TP includes a second M/H header, this indicates
that the M/H payload includes both the signaling data and the
mobile service data.
Finally, when M/H TP includes a third
M/H header, this indicates that the M/H payload includes only
the mobile service data. In the example shown in FIG. 3, the
RS frame is assigned with an IP datagram (IP datagram 1) for
a SMT and IF datagrams (IP datagram 2 and IF datagram 3) for
two service types.
Data Transmission Structure
FIG. 4 illustrates a structure of an M/H frame for
transmitting and receiving mobile service data according to
the present invention.
In the example shown in FIG. 4, one
M/H frame consists of 5 sub-frames, wherein each sub-frame
includes 16 slots. In thi, case, the M/H frame according to
the present invention includes 5 sub-frames and 80 slots.
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Also, in a packet level, one slot is configured of 156 data
packets (i.e., transport stream packets), and in a symbol
level, one slot is configured of 156 data segments. Herein,
the size of one slot corresponds to one half (1/2) of a VSB
field. More specifically, since one 207-byte data packet has
the same amount of data as a data segment, a data packet
prior to being interleaved may also be used as a data segment.
At this point, two VSB fields are grouped to form a VSB frame.
FIG. 5 illustrates an exemplary structure of a VSB frame,
wherein one VSB frame consists of 2 VSB fields (i.e., an odd
field and an even field). Herein, each VSB field includes a
field synchronization segment and 312 data segments.
The
slot corresponds to a basic time unit for multiplexing the
mobile service data and the main service data.
Herein, one slot may either include the mobile service
data or be configured only of the main service data. If the
first 118 data packets within the slot correspond to a data
group, the remaining 38 data packets become the main service
data packets. In another example, when no data group exists
in a slot, the corresponding slot is configured of 156 main
service data packets.
Meanwhile, the mobile service data within one RS frame may
be assigned either to all of regions A/B/C/D within the
corresponding data group, or to at least one of regions
A/B/C/D. In
the embodiment of the present invention, the
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mobile service data within one RS frame may be assigned
either to all of regions A/B/C/D, or to at least one of
regions A/B and regions C/D. If the mobile service data are
assigned to the latter case (i.e., one of regions A/B and
5 regions C/D), the RS frame being assigned to regions A/B and
the RS frame being assigned to regions C/D within the
corresponding data group are different from one another.
According to the embodiment of the present invention, the
RS frame being assigned to regions A/B within the
10 corresponding data group will be referred to as a "primary RS
frame", and the RS frame being assigned to regions C/D within
the corresponding data group will be referred to as a
"secondary RS frame", for simplicity. Also, the primary RS
frame and the secondary RS frame form (or configure) one
15 parade.
More specifically, when the mobile service data
within one RS frame are assigned either to all of regions
A/B/C/D within the corresponding data group, one parade
transmits one RS frame. Conversely, when the mobile service
data within one RS frame are assigned either to at least one
20 of regions A/B and regions C/D, one parade may transmit up to
2 RS frames. More specifically, the RS frame mode indicates
whether a parade transmits one RS frame, or whether the
parade transmits two RS frames.
Such RS frame mode is
transmitted as the TPC data. Table 1 below shows an example
25 of the RS frame mode.
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Table 1
RS frame
= mode Description
(2 bits)
There is only one primary RS frame for
00
all group regions
There are two separate RS frames.
01 - Primary RS frame for group regions A and B
- Secondary RS frame for group regions C and D
Reserved
11 Reserved
Table 1 illustrates an example of allocating 2 bits in
5 order to indicate the RS frame mode. For example, referring
to Table 1, when the RS frame mode value is equal to '00',
this indicates that one parade transmits one RS frame. And,
when the RS frame mode value is equal to '01', this indicates
that one parade transmits two RS frames, i.e., the primary RS
10 frame and the secondary RS frame.
More specifically, when
the RS frame mode value is equal to '01', data of the primary
RS frame for regions A/B are assigned and transmitted to
regions A/B of the corresponding data group. Similarly, data
of the secondary RS frame for regions C/D are assigned and
transmitted to regions C/D of the corresponding data group.
As described in the assignment of ,data groups, the parades
are also assigned to be spaced as far apart from one another
as possible within the sub-frame. Thus, the receiving system
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can be capable of responding promptly and effectively to any
burst error that may occur within a sub-frame. Furthermore,
the method of assigning parades may be identically applied to
all M/H frames or differently applied to each M/H frame.
According to the embodiment of the present invention, the
parades may be assigned differently for each M/H frame and
identically for all sub-frames within an M/H frame.
More
specifically, the M/H frame structure may vary by M/H frame
units.
Thus, an ensemble rate may be adjusted on a more
frequent and flexible basis.
That is, the concept of an M/H ensemble is applied in the
embodiment of the present invention, thereby defining a
collection (or group) of services. Each M/H ensemble carries
the same QoS and is coded with the same FEC code. Also, each
M/H ensemble has the same unique identifier (i.e., ensemble
ID) and corresponds to consecutive RS frames.
FIG. 6 illustrates a data transmission structure in a
physical layer according to an embodiment of the present
invention. More specifically, FIG. 6 shows an example of FIC
data being included in each data group and transmitted. As
described above, an M/H frame for approximately 0.968 seconds
is divided into 5 sub-frames, wherein data groups
corresponding to multiple ensembles exist in combination
within each sub-frame.
Also, the data 'groups corresponding
to each ensemble are interleaved in M/H frame units, so as to
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configure an RS frame belonging to one ensemble. In FIG. 6,
2 ensembles (wherein NoG=4 and NoG=3) exist in each sub-frame.
Furthermore, a predetermined portion (e.g., 37 bytes/data
group) of each data group is used for the purpose of
separately delivering encoded FIC data apart from the RS
frame data channel.
The FIC region assigned to each data
group consists of one FIC segment. Herein, each of the FIC
segments is interleaved in sub-frame units. For example, RS-
encoding and SCCC encoding processes are applied to the RS
frame data, and RS encoding and PCCC encoding processes are
applied to the FIC data. Also, as well as the FIC data, the
RS encoding and PCCC encoding processes are applied to the
TPC data. More specifically, (187+P,187)-RS encoding process
is applied to the RS frame data, (51,37)-RS encoding process
is applied to the FIC data, and (18,10)-RS encoding process
is applied to the TPC. Herein, P is the number of parity
bytes.
Hierarchical signaling structure
20' FIG. 7 illustrates a hierarchical signaling structure
according to an embodiment of the present invention. As
shown in FIG. 7, the mobile broadcasting technology according
to the embodiment of the present invention adopts a signaling
method using FIC and SMT (Service Map Table).
In the
description of the present invention, the signaling structure
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will be referred to as a hierarchical signaling structure.
More specifically, FIG. 7 illustrates a hierarchical
signaling structure that provides data required for service
acquisition through an FIC chunk and a service map table
(SMT), among IP-level mobile service signaling channels. As
shown in FIG. 7, the FIC chunk uses its fast characteristic,
so as to deliver a mapping relation between a service and an
ensemble to the receiving system. More specifically, the FIC
chunk quickly locates (or finds) an ensemble that can deliver
a service requested by the receiving system, thereby
providing the receiving system with signaling data that can
enable the receiving system to swiftly receive RS frames of a
respective ensemble.
Fast information channel (FIC)
The receiving system according to the present invention
adopts the fast information channel (FIC) for a faster (or
swifter) access to a service that is currently being
broadcasted.
' More specifically, the FIC handler 121 of FIG. 1
configures an FIC chunk from the FIC segments. Then, after
parsing the FIC chunk, the FIC handler 121 outputs the parsed
result to the service manager 122.
FIG. 8 illustrates a syntax structure of an FIC chunk that
maps the relation between a mobile service and an ensemble
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through the FIC.
Herein, the FIC chunk consists of an FIC
chunk header and an FIC chunk payload.
FIG. 9 illustrates a syntax structure of an FIC chunk .
header according to an embodiment of the present invention.
5 Herein, the FIC chunk header signals a non-backward
compatible major protocol version change in a corresponding
FIC chunk and also signals a backward compatible minor
protocol version change.
Furthermore, .the FIC chunk header
also signals the length for an extension of an FIC chunk
10 header, the length for an extension of an ensemble loop
header, and the length for an extension of a mobile service
loop that can be generated by a minor protocol version change.
According to an embodiment of the present invention, a
receiver (or receiving system) that can adopt the
15 corresponding minor protocol version change may process the
corresponding extension field, whereas a legacy (or
conventional) receiver that cannot adopt the corresponding
minor protocol version change may skip the corresponding
extension field by using each of the corresponding length
20 infohnation. For example, in case of a receiving system that
can accept the corresponding minor protocol version change,
the directions given in the corresponding extension field may
be known. ' Furthermore, .the receiving system may perform
operations in accordance with the directions giVen in the
25 corresponding extension field.
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According to an embodiment of the present invention, a
minor protocol version change in the FIC chunk is performed
by inserting additional fields at the respective end portion
of the FIC chunk header, the ensemble loop header, and the
mobile service loop included in the previous minor protocol
version FIC chunk. According to an embodiment of the present
invention, in any other case, or when the length of the
additional fields cannot be expressed (or indicated) by each
extension length within the FIC chunk header, or when a
specific field within the FIC chunk payload is missing (or
cannot be found), or when the number of bits being assigned
to the corresponding field or the definition of the
corresponding field is changed (or altered), the major
protocol version of the corresponding FIC chunk is updated.
Also, the FIC chunk header signals whether the data of a
corresponding FIC chink payload carry mapping information
between an ensemble and a mobile service within the current
M/H frame, or whether the data of a corresponding FIC chink
payload carry mapping information between an ensemble and a
mobile aervice within the next M/H frame.
Furthermore, the
FIC chunk header also signals the number of transport stream
IDs of a mobile service through which the current FIC chunk
is being transmitted and the number of ensembles being
transmitted through the corresponding mobile service. '
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Accordingly, for this, the FIC chunk header may include an
FIC major protocol version field,
an
FIC minor protocol version field,
. an
FIC chunk header extension length field,
an
ensemble loop header extension length field,
an
M/H service loop extension length field,
a
current next indicator field, a transport stream id field,
and a num ensembles field.
The FIC_major_protocol_version field corresponds to a 2-
bit unsigned integer field that represents the major version
level of an FIC chunk syntax. A change in the major version
level shall indicate a change in a non-backward-compatible
level. When the FIC major protocol version field is updated,
legacy (or conventional) receivers, which can process the
prior major version of an FIC chunk protocol, shall avoid
processing the FIC chunk.
The FIC minor protocol version field corresponds to a 3-
bit unsigned integer field that represents the minor version
level of an FIC chunk syntax. When it is assumed that the
major version level remains the same, a change in the minor
version level shall indicate a change in a backward-
compatible level. More specifically, when
the
FIC minor protocol version field is updated, legacy (or
conventional) receivers, which can process the same major
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version of the FIC chunk protocol, may process a portion of
the FIC chunk.
The FIC Chunk header extension length field corresponds to
a 3-bit unsigned integer field identifying the length of FIC
chunk header extension bytes, which are generated by the
minor protocol version update of the corresponding FIC chunk.
Herein, the extension bytes are appended (or added) at the
end of the corresponding FIC chunk header.
The ensemble header extension length field corresponds to
a 3-bit unsigned integer field identifying the length of the
ensemble header extension bytes, which are generated by the
minor protocol version update of the corresponding FIC chunk.
Herein, the extension bytes are appended (or added) at the
end of the corresponding ensemble loop header.
Also, the M/H service loop extension length field
corresponds to a 4-bit unsigned integer field identifying the
length of the ensemble header extension bytes, which are
generated by the minor protocol version update of the M/H
service loop. Herein, the
extension bytes are appended (or
added) at the end of the corresponding M/H service loop.
The current next indicator field corresponds to a 1-bit
indicator, which, when set to '1', indicates that the
corresponding FIC ' chunk is currently
applicable.
Alternatively, when the current_next_indicator field is set
to '0', the current next indicator field indicates that the
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corresponding FIC chunk will be applicable for the next M/H
frame. Herein, when the current_next_indicator field is set
to '0', the most recent version of the FIC chunk being
transmitted with the current next indicator field set to '1'
shall be currently applicable. More specifically, when the
current next indicator field value is set to '1', this
indicates that the corresponding FIC chunk transmits the
signaling data of the current M/H frame.
Further, when the
current next indicator field value is set to '0', this
indicates that the corresponding FIC chunk transmits the
signaling data of the next M/H frame. When reconfiguration
occurs, wherein the mapping information between the ensemble
within the current M/H frame and the mobile service differs
from the ensemble within the next M/H frame and the mobile
service, the M/H frame prior to reconfiguration is referred
to as the current M/H frame, and the M/H frame following
reconfiguration is referred to as the next M/H frame.
The transport_stream_id field corresponds to a 16-bit
unsigned integer number field, which serves as a label for
identifying the cOrresponding M/H broadcast.
The value of
the corresponding transport_stream_id field shall be equal to
the value of the transport_stream_id field included in the
program association table (PAT) within the MPEG-2 transport
stream of a main ATSC broadcast.
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The num ensembles field corresponds to an 8-bit unsigned
integer field, which indicates the number of M/H ensembles
carried through the corresponding physical transmission
channel.
5 FIG. 10 illustrates an exemplary change in a protocol
version when using an FIC chunk syntax and a protocol
versioning structure according to an embodiment of the
present invention.
The structure shown in FIG. 10 includes 2 ensembles (i.e.,
10 ensemble 0 and ensemble 1). Herein, two mobile services are
transmitted through ensemble 0, and one mobile service is
transmitted through ensemble 1.
At this point, when the
minor protocol version of the FIC chunk is changed, the
FIC minor protocol version field value increases, and such
15 increase is indicated. Also, length information for each of
the extension bytes of the FIC chunk header, the extension
bytes of the ensemble loop header, and the extension bytes of
the mobile service loop, which are added by the corresponding
minor protocol version is respectively signaled through the
20 FIC chunk header extension length field,
the
ensemble loop header extension length field, and
the
M/H service loop extension length field of the FIC chunk
header.
More specifically, each length information is
signaled so that legacy receiver, which cannot adopt the
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change in the corresponding minor protocol version, can skip
the corresponding expansion bytes.
In case of FIG. 10, the FIC minor protocol version field
value of the FIC chunk is changed from '000' to '001'. And,
the FIC chunk header
extension length field, the
ensemble loop header extension length field,
and the
M/H service loop extension length field are
added (or
appended) to the FIC chunk header of the changed minor
protocol version. At this point, when the FIC chunk header
is expanded by 1 byte, the FIC_chunk_header_extension_length
field is marked as 1001'.
In this case, a 1-byte expansion
field (i.e., FIC_Chunk_header_extension_bytes field) is added
at the end of the FIC chunk header.
Also, the legacy
receiver skips the 1-byte expansion field, which is added at
the end of the FIC chunk header, without processing the
. corresponding expansion field.
Additionally, when the ensemble loop header within the FIC
chunk is expanded by 2 bytes,
the
ensemble loop header extension length field is marked as
'010'. In
this case, a 2-byte expansion field (i.e.,
Ensemble loop header extension bytes field) is respectively
added at the end of the ensemble 0 loop header and at the end
of the ensemble 1 loop header.
Also, the legacy receiver
skips the 2-byte expansion fields, which are respectively
added at the end of the ensemble 0 loop header and at the end
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of the ensemble 1 loop header, without processing the
corresponding 2-byte expansion fields.
Furthermore, when the mobile service loop of the FIC chunk
is expanded by 1 byte, the M/H_service_loop_extension_length
field is marked as '001'.
In this case, a 1-byte expansion
field (i.e., M/H_service_loop_extension_bytes field) is
respectively added at the end of 2 mobile service loops being
transmitted through ensemble 0 loop and at the end of 1
mobile service loop being transmitted through the ensemble 1
loop.
And, the legacy receiver skips the 1-byte expansion
fields, which are respectively added at the end of 2 mobile
service loops being transmitted through ensemble 0 loop and
at the end of 1 mobile service loop being transmitted through
the ensemble 1 loop, without processing the corresponding 1-
byte expansion fields.
FIG. 11 illustrates an exemplary process of processing an
FIC chunk, when a minor protocol version of the FIC chunk is
changed, as shown in FIG. 10. When the FIC_minor_protocol
version field is changed, a legacy (or conventional) receiver
(i.e., a receiver that cannot adopt the minor protocol
version change in the corresponding FIC chunk) processes the
fields apart from the extension field.
Thereafter, the
legacy receiver uses the FIC_chunk_header_extension_length
field, the ensemble loop header extension length field, and
the M/H service loop extension length field, so as to skip
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the corresponding expansion fields without processing the
corresponding fields. When using a receiving system that can
adopt the corresponding minor protocol version change of the
FIC chunk, each length field is used to process even the
corresponding expansion field.
FIG. 12 illustrates an exemplary syntax structure of an
FIC chunk payload according to an embodiment of the present
invention. . For each ensemble corresponding to the
num ensembles field value within the FIC chunk header of FIG.
9, the FIC chunk payload includes configuration information
of each ensemble and information on mobile services being
transmitted through each ensemble.
The FIC chunk payload
consists of an ensemble loop and a mobile service loop below
the ensemble loop.
The FIC chunk payload enables the
receiver to determine through which ensemble a requested (or
desired) mobile service is being transmitted.
(This process
is performed via mapping between the ensemble_id field and
the M/H service id field.) Thus, the receiver may receive RS
frames belonging to the corresponding ensemble.
In order to do so, the enemble loop of the FIC chunk
payload may include an ensemble id field,
an
ensemble structure major version field,
an
ensemble structure minor version field,
an
SZT ensemble indicator field, a GAT ensemble indicator field,
an M/H service configuration version field, and a
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num M/H services field, which are collectively repeated as
_ _
many times as the num_ensembles field value.
The mobile
service loop may include a multi_ensemble_service field, an
M/H service status field, and an SP indicator field, which
are collectively repeated as many times as the
num M/H services field.
_ _
The ensemble_id field corresponds to an 8-bit unsigned
integer field, which indicates a unique identifier of the
corresponding ensemble.
For example, the ensemble_id field
may be assigned with values within the range '0x00' to '0x7F'.
The ensemble_id field group (or associate) the mobile
services with the respective ensemble.
Herein, it is
preferable that the value of the ensemble_id field is derived
from the parade_id field carried (or transmitted) through the
TPC data. If
the corresponding ensemble is transmitted
through a primary RS frame, the most significant bit is set
to '0', and the remaining least significant bits are used as
the parade_id field value of the corresponding parade.
Meanwhile, if the corresponding ensemble is transmitted
through a secondary RS frame, the Most significant bit is set
to 10', and the remaining least significant bits are used as
the parade_id field value of the corresponding parade.
The ensemble major protocol version field corresponds to a
2-bit unsigned integer field, which represents the major
level version of the corresponding ensemble structure
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(particularly, the corresponding RS frame structure and
mobile service structure). Herein, a change in the major
protocol version level shall. indicate a change in a non-
backward-compatible level.
5 The
ensemble minor protocol version field corresponds to a
3-bit unsigned integer field, which represents the minor
level version of the corresponding ensemble structure
(particularly, the respective RS frame structure and the
respective M/H service signaling channel). Provided that the
10 major version level remains the same, a change in the minor
protocol version level shall indicate a change in a backward-
compatible level. Herein,
the
ensemble structure major version field and
the
ensemble structure minor version field may be omitted from
15 the FIC chunk payload.
The SLT ensemble indicator field corresponds to a 1-bit
indicator, which, when set to '1', shall indicate that the
service labeling table (SLT) is carried in the M/H service
signaling channel of the corresponding ensemble.
20 The GAT ensemble indicator corresponds to a 1-
bit
indicator, which, when set to '1', shall indicate that the
guide access table (GAT) is carried in the signaling stream
= =
of the corresponding ensemble.
The M/H service configuration version field corresponds to
25 a 5-bit field, which indicates the version number of the M/H
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service signaling channel respective of the corresponding M/H
ensemble. The value of the M/H service configuration version
field is 'modulo 32' and shall be incremented (or increased)
by 1, whenever a change is made in any of the tables carried
within the M/H service signaling channel of the corresponding
ensemble.
The num M/H services field corresponds to an 8-bit
_ _
unsigned integer field, which represents the number of M/H
services carried through the corresponding M/H ensemble. For
example, when the minor protocol version of the FIC chunk is
change, and if an expansion field is added to the ensemble
loop header, the expansion field is added after the
num M/H services field.
_ _
For example, when the minor protocol version within the
FIC chunk header is changed, and when an extension field is
added to the ensemble loop header, the extension field is
added immediately after the num M/H services
field.
_ _
According to anther embodiment of the present invention, if
the num M/H services field is included in the mobile service
_ _
loop, the extension field that is to be added in the ensemble
loop header is added immediately after. the
M/H service configuration version field.
The M/H service id field of the mobile 'service loop =
corresponds to a 16-bit unsigned integer number, which
identifies the corresponding M/H service. The value (or
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number) of the M/H_service_id field shall be unique within
the mobile (M/H) broadcast.
When an M/H service has
components in multiple .M/H ensembles, the set of IF streams
corresponding to the service in each ensemble shall be
treated as a separate service for signaling purposes, with
the exception that the entries for the corresponding services
in the FIC shall all have the same M/H service id field value.
.Thus, the same M/H_service_id field value may appear in more
than one num ensembles loop.
And, accordingly, the
M/H service id field shall represent the overall combined
service, thereby maintaining the uniqueness of the
M/H service id field value.
The multi ensemble service field corresponds to a 2-bit
enumerated field, which identifies whether or not the
corresponding M/H service is carried through more than one
M/H ensemble.
Also, the multi_ensemble_service field
identifies whether or not the M/H service can be rendered
meaningfully with only a portion of the M/H service being
carried through the corresponding M/H ensemble.
The M/H service status field corresponds to a 2-bit
enumerated field, which identifies the status of the
corresponding M/H service. For example, the most significant
bit of the M/H service status field indicates whether the
corresponding M/H service is active (when set to '1') or
inactive (when set to '0').
Furthermore, the least
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significant bit indicates whether the corresponding M/H
service is hidden (when set to '1') or not (when set to '0').
The SP indicator field corresponds to a 1-bit field, which,
when set to '1', indicates whether or not service protection
is applied to at least one of the components required for
providing a significant presentation of the corresponding M/H
service.
For example, when the minor protocol version of the FIC
chunk is change, and if an expansion field is added to the
mobile service loop, the expansion field is added after the
SP indicator field.
Also, the FIC chunk payload may include an
FIC chunk stuffing() field. Stuffing of
the
FIC chunk stuffing() field may exist in an FIC-Chunk, to keep
the boundary of the FIC-Chunk to be aligned with the boundary
of the last FIC-Segment among FIC segments belonging to the
FIC chunk. The length of the stuffing is determined by how
much space is left after parsing through the entire FIC-Chunk
payload preceding the stuffing.
At this point, the transmitting system '(not shown)
according to the present invention divides the FIC chunk into
multiple FIC segments, as shown in FIG. 13, thereby
outputting the divided FIC segments to the receiving system
in FIC segment units. The size of each FIC segment unit is
37 bytes, and each FIC segment consists of a 2-byte FIC
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segment header and a 35-byte FIC segment payload.
More
specifically, an FIC chunk, which is configured of an FIC
chunk header and an FIC chunk payload, as shown in FIG. 13(a),
is segmented by units of 35 bytes, as shown in FIG. 13(b).
Also, as shown in FIG. 13(c), an FIC segment is configured by
adding a 2-byte FIC segment header in front of each segmented
35-byte unit.
According to an embodiment of the present invention, the
length of the FIC chunk payload is variable.
Herein, the
length of the FIC chunk varies depending upon the number of
ensembles being transmitted through the corresponding
physical transmission channel and the number of mobile
services included in each ensemble.
Also, the FIC chunk payload may include stuffing data. In
this case, the stuffing data are used for the boundary
alignment of the FIC chunk and the last FIC-Segment, among
FIC segments belonging to the FIC chunk, according to the
embodiment of the present invention.
Accordingly, by
minimizing the length of the stuffing data, unnecessary
wasting of FIC segments can be reduced.
At this point, the number of stuffing data bytes being
inserted in the FIC chunk can be calculated by using Equation
1 below.
' Equation 1
The number of stuffing data bytes = 35 - j
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j = (5 + the number of signaling data bytes being inserted
in the FIC chunk payload) mod 35
For example, when the added total length of the 5-byte
header within the FIC chunk and signaling data, which is to
5 be inserted in the payload within the FIC chunk, is equal to
205 bytes, the payload of the FIC chunk may include 5 bytes
of stuffing data because j is equal to 30 in Equation 1.
Also, the length of the FIC chunk payload including the
stuffing data is equal to 210 bytes.
Thereafter, the FIC
10 chunk is divided into 6 FIC segments, which are then
transmitted. At this point, a segment number is sequentially
assigned to each of the 6 FIC segments divided from the FIC
chunk.
Furthermore, the present invention may transmit the FIC
15 segments divided from a single FIC chunk to a single sub-
frame, or may transmit the divided FIC segments to multiple
sub-frames, as shown in FIG. 14. If the FIC chunk is divided
and transmitted to multiple sub-frames, as in the latter case
shown in FIG. 14, signaling data, which are required even
20 when the amount of data that are to be transmitted through
the FIC chunk is larger than the amount of FIC segments being
transmitted through a single sub-frame (this case corresponds
to when multiple services having very low bit rates are being'
exeduted), may all be transmitted through the FIC chunk.
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FIG. 14 illustrates an example of the data of the FIC
chunk being transmitted through 4 FIC segments, when the TNoG
of the corresponding mobile broadcast is equal to '6'.
More specifically, FIG. 14 shows an example of the FIC
chunk being repeatedly transmitted two times.
Referring to
FIG. 14, all FIC segments divided from the FIC chunk are
transmitted through 2 sub-frames (subframe 1 and subframe 2),
and all FIC segments divided from the FIC chunk are
transmitted through only one (subframe 1) of the 2 sub-frames.
More specifically, the present invention indicates that
multiple FIC chunk can be transmitted through a single sub-
frame.
In FIG. 14, the content of the 2 FIC chunks may be
identical to one another or may be different from one another.
Herein, the FIC segment numbers indicated in FIG. 14
represent FIC segment numbers within each FIC chunk, and not
the FIC segment number within each sub-frame.
Thus, the
subordinate relation between the FIC chunk and the sub-frame
can be eliminated, thereby reducing excessive waste of FIC
segments.
Furthermore, the present invention may add a null E'IC
segment. Despite the repeated transmission of the FIC chunk,
and when stuffing is required in the corresponding M/H frame,
the null FIC segment is used for the purpose of processing
the reniaining FIC segments. For example, it is assumed that
TNoG is equal to '3' and that the FIC chunk is divided into 2
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FIC segments. . Herein, when the FIC chunk is repeatedly
transmitted through 5 sub-frames within a single M/H frame,
only 2.FIC segments are transmitted through one of the 5 sub-
frames (e.g., the sub-frame chronologically placed in the
last order). In this case, one null FIC segment is assigned
to the corresponding sub-frame, thereby being transmitted.
More specifically, the null FIC segment is used for aligning
the boundary of the FIC chunk and the boundary of the M/H
frame. At this point, since the null FIC segment is not an
FIC segment divided from the FIC chunk, an FIC segment number
is not assigned to the null FIC segment.
In the present invention, when a single FIC chunk is
divided into a plurality of FIC segments, and when the
divided FIC segments are included in each data group of at
least one sub-frame within the M/H frame, so as to be
transmitted, the corresponding FIC segments are allocated in
a reversed order starting from the last sub-frame within the
corresponding M/H frame. According to an embodiment of the
present invention, in case a null FIC segment exists, the
null FIC segment is positioned in the sub-frame within the
M/H frame, so that the corresponding null FIC segment can be
transmitted as the last (or final) segment.
FIG. 15 illustrates an example of the data of the FIC
chunk bein transmitted through 8 FIC segments, when the TNoG
of the corresponding mobile broadcast is equal to '6'. In
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this case, the amount of data that are to be transmitted
through the FIC chunk is larger than the amount of FIC
segments being transmitted through a single sub-frame.
Herein, since the FIC segments divided from the FIC chunk are
transmitted through 2 sub-frames, as shown in FIG. 15, all of
the required signaling data may be transmitted through a
single FIC chunk. Also, in this case, the number assigned to
each FIC segment corresponds to the number of each FIC
segment included in the FIC chunk. More specifically, even
when the amount of FIC chunk data is larger than the amount
of FIC segment data being transmitted through a single sub-
frame, all FIC chunk data are transmitted without leaving any
non-transmitted data portion.
At this point, in order to enable the receiving system to
discard the null FIC segment without having to process the
corresponding null FIC segment, identification information
that can identify (or distinguish) the null FIC segment is
required.
According to an embodiment of the present invention, the
present invention uses the FIC type field within the header
of the null FIC segment as the identification information for
identifying the null FIC segment.
In this embodiment, the
value of the FIC type field within the null FIC segment
header is set to 111', so as to identify the corresponding
null FIC segment. More specifically, when the FIC type field
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value within the null FIC segment header is set to '11' and
transmitted to the receiving system, the receiving system may
.discard the payload of the FIC segment having the FIC type
field value set to 111' without having to process the
corresponding FIC segment payload. Herein, the value '11' is
merely an exemplary value given to facilitate and simplify
the understanding of the present invention.
As long as a
pre-arrangement between the receiving system and the
transmitting system is established, any value that can
identify the null FIC segment may be given to the FIC type
field. Therefore, the present invention will not be limited
only to the example set presented herein.
Furthermore, the
identification information that can identify the null FIC
segment may also be indicated by using another field within
the FIC segment header.
FIG. 16 illustrates an exemplary syntax structure of an
FIC segment header according to an embodiment of the present
invention. Herein, the FIC segment header may include an
FIC type field, an error_indicator field, an FIC_segment_num
field, and an FIC last segment num field.
Each field will
now be described as follows.
The FIC_type field corresponds to a 2-bit field, which,
when set to '00' indicates that the corresponding FIC segment
is carrying a portion of an FIC chunk. Alternatively, when
the FIC type field is set to '11', the FIC_type field
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indicates that the corresponding FIC segment is a null FIC
segment, which transmits stuffing data. Herein, the
remaining values are reserved for future use.
The error indicator field corresponds =to a 1-bit field,
5 which indicates whether or not an error has occurred in the
corresponding FIC segment during transmission.
Herein, the
error indicator field is set to '1', when an error has
occurred. And, the error indicator field is set to '0', when
an error does not exist (or has not occurred).
More
10 specifically, during the process of configuring the FIC
segment, when a non-recovered error exists, the
error indicator field is set to '1'. More specifically, the
error indicator field enables the receiving system to
recognize the existence (or presence) of an error within the
15 corresponding FIC segment.
The FIC_segment_num field corresponds to a 4-bit unsigned
integer number field, which indicates a number of the
corresponding FIC segment. For example, if the corresponding
FIC segment is the first FIC segment of the FIC chunk, the
20 value of the FIC segment num field shall be set to '0x0'.
Also, if the corresponding FIC segment is the second FIC
segment of the FIC chunk, the value of the FIC_segment_num
field shall be set to '0x1'.
More specifically, the
FIC segment num field shall be incremented by one with each
25 additional FIC segment in the FIC chunk. Herein, if the FIC
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chunk is divided into 4 FIC segments, the FIC_segment_num
field value of the last FIC segment within the FIC chunk will
be indicated as '0x3'.
The FIC last segment num field corresponds to a 4-bit
unsigned integer number field, which indicates the number of
the last FIC segment (i.e., the FIC segment having the
highest FIC_segment_num field value) within a complete FIC
chunk.
In the conventional method, FIC segment numbers are
sequentially assigned (or allocated) for each FIC segment
within one sub-frame. Therefore, in this case, the last FIC
segment number always matches with the TNoG (i.e., the last
FIC segment number is always equal to the TNoG).
However,
when using the FIC number assignment method according to the
present invention, the last FIC segment number may not always
match with the TNoG. More specifically, the last FIC segment
number may match with the TNoG, or the last FIC segment
number may not match with the TNoG.
The TNoG represents a
total number of data groups that are allocated (or assigned)
to a single sub-frame.
For example, when the TNoG is equal
to '6', and when the FIC chunk is divided into 8 FIC segments,
the TNoG is equal to '6', and the last FIC segment number is
` 8 .
According to another embodiment of the present invention,
the null FIC segment may be identified by using the value of
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the FIC segment num field within the FIC segment header.
More specifically, since an FIC segment number is not
assigned to the null FIC segment, the transmitting system
allocates null data to the FIC segment num field value of the
null FIC segment, and the receiving system may allow the FIC
segment having null data assigned to the FIC_segment_num
field value to be recognized as the null FIC segment. Herein,
instead of the null data, data pre-arranged by the receiving .
system and the transmitting system may be assigned to the
FIC segment num field value, instead of the null data.
As described above, the FIC chunk is divided into a
plurality of FIC segments, thereby being transmitted through
a single sub-frame or being transmitted through multiple sub-
frames. Also, FIC segments divided from a single FIC chunk
may be transmitted through a single sub-frame, or FIC
segments divided from multiple single FIC chunks may be
transmitted through a single sub-frame. At this point, the
number assigned to each FIC segment corresponds to a number
within the corresponding FIC chunk (i.e., the FIC_seg_number
value), and not the number within the corresponding sub-frame.
Also, the null FIC segment may be transmitted for aligning
the boundary of the M/H frame and the boundary of the FIC
chunk. At this point, an FIC segment number is not assigned
to the null FIC segment.
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As described above, one FIC chunk may be transmitted
through multiple sub-frames, or multiple FIC chunks may be
transmitted through a single sub-frame.
However, according
to the embodiment of the present invention, the FIC segments
are interleaved and transmitted in sub-frame units.
FIG. 17 illustrates an example of the receiving system
receiving and recovering one or more FIC chunks, either when
a single FIC chunk is transmitted through multiple sub-frames,
or when multiple FIC chunks are transmitted through a single
sub-frame as shown in FIG. 13 to FIG. 15.
More specifically, the signaling decoder 118 of the
receiving system according to the present invention collects
FIC data of a signaling information region within a data
group for each sub-frame, so as to interleave the collected
data in sub-frame units.
Thereafter, the signaling decoder
118 performs RS-decoding on the deinterleaved FIC segment,
thereby outputting the RS-decoded data to the FIC handler 121.
The FIC segment buffer of the FIC handler 121 temporarily
stores the RS-decoded FIC segment and then outputs the
temporarily stored FIC segment to the FIC segment parser.
The FIC segment parser extracts and analyzes an FIC segment
header.
Subsequently, based upon the analyzed result, the
FIC segment parser collects FIC segments, which configure a
single FIC chunk. Thereafter, the FIC segment parser removes
(or discards) the FIC segment header of the collected FIC
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segments, thereby recovering (or configuring) a single FIC
chunk.
For example, the FIC segment parser uses the
FIC segment num field and the FIC last segment num field
within the FIC segment header in order to collect FIC
segments, which configure one FIC chunk. The recovered FIC
chunk is then outputted to the FIC chunk parser.
The FIC
chunk parser extracts and analyzes a header of the FIC chunk
that is being inputted. Then, based upon the analyzed result,
the FIC chunk parser extracts signaling data, which are
included in the payload of the corresponding FIC chunk,
thereby outputting the extracted signaling data to the
service manager 122.
More specifically, the FIC segment parser extracts and
analyzes a header of an FIC segment that is buffered and then
inputted.
Thereafter, the FIC segment parser searches for
(or locates) an FIC segment having the FIC_segment_num field
value of '0' (i.e., an FIC segment including a first byte of
the FIC chunk data). Once the FIC segment parser locates the
first FIC segment of the FIC chunk, the FIC segment parser
sequentially collects data starting from the first FIC
segment to the FIC segment having the same FIC_segment_num
field value and FIC last segment num field value. Thereafter,
the FIC segment parser removes the FIC segment headers of the
collected FIC segments, so as to configure an FIC chunk,
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thereby outputting the configured FIC chunk to the FIC chunk
parser.
For example, it is assumed that the TNoG of the
corresponding mobile broadcast is equal to '6', as shown in
5 FIG. 17, and that the FIC chunk is divided into 5 FIC
segments so as to be transmitted.
Referring to FIG. 17,
either the FIC segments of one FIC chunk are transmitted
through 2 sub-frames, or the FIC segments of 2 FIC chunks are
transmitted to one sub-frame. However, it is apparent that
10 the deinterleaving process is performed in sub-frame units.
Also, 5 FIC segments starting from the FIC segment having the
FIC segment num field value of '0' to the FIC segment having
the FIC segment num field value of '4' are collected.
Thereafter, when the FIC segment header of each FIC segment
15 is removed, one FIC chunk is recovered.
More specifically,
one FIC chunk is recovered (or configured), when the payloads
of all 5 FIC segments are collected. At this point, a null
FIC segment is identified by the FIC type field within the
corresponding null FIC segment header. However, the null FIC
20 segment is discarded without being used in the FIC chunk
recovery process.
FIG. 18 illustrates an example of the receiving system
' receiving FIC. segments so as to recover an FIC chunk, when
the FIC chunk is transmitted through 8 FIC segments, and when
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the TNoG of the corresponding mobile broadcast is equal to
'6'.
Also, in FIG. 18, although the FIC segments of one FIC
chunk are transmitted through 2 sub-frames, it is apparent
that the deinterleaving process is performed in sub-frame
units.
Since the FIC chunk recovery process of FIG. 18 is
the same as the FIC chunk recovery process of FIG. 17,
reference can be made to FIG. 17, and a detailed description
of the same will be omitted for simplicity.
More specifically, 8 FIC segments starting from the FIC
segment having the FIC_segment_num field value of '0' to the
FIC segment having the FIC_segment_num field value of 17' are
collected.
Thereafter, when the FIC segment header of each
FIC segment is removed, one FIC chunk is recovered.
More
specifically, one FIC chunk is recovered (or configured),
when the payloads of all 8 FIC segments are collected. At
this point, a null FIC segment is identified by the FIC type
field within the corresponding null FIC segment header.
However, the null FIC segment is discarded without being used
in the FIC chunk recovery process.
Meanwhile, it is assumed that multiple FIC chunks, each
having a different protocol version, are transmitted through
ohe M/H frame, and that the receiving system is capable of
processing all of the FIC chunks, each having a different
protocol version. At
this point, when the FIC segments
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divided from the multiple FIC chunks, each having a different
protocol version, are received normally without any error,
the receiving system may perform normal recovery on the
multiple FIC chunks each having a different protocol version.
However, if an error caused by burst noise occurs in the
multiple FIC chunks each having a different protocol version,
the receiving system may not be able to perform normal
recovery on the multiple FIC chunks each having a different
protocol version.
For example, it is assumed that an FIC chunk having a
major protocol version of '00' and an FIC chunk having a
major protocol version of '01' are simultaneously transmitted
to one FIC (i.e., one M/H frame).
And, it is also assumed
that, as shown in FIG. 19(a), FIC segment 4 to FIC segment 7,
which transmit the FIC chunk having the major protocol
version of '00', and that FIC segment 0 to FIC segment 3,
which transmit the FIC chunk having the major protocol
version of '01', are not received by the receiving system due
to an error caused by burst noise.
' In this case also, the receiving system uses the
FIC segment num field and the FIC last segment num field
within the FIC segment header, so as to collect 8 FIC
segments starting .from the FIC segment having the
FIC segment num field value of '0' to the FIC segment having
the FIC segment num field value of '7'. Thereafter, the FIC
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segment header of each of the 8 FIC segments is removed,
thereby configuring one FIC chunk, as shown in FIG. 19(b).
In this case, since the FIC segment having the
FIC segment num field value of 10' corresponds to an FIC
segment divided from the FIC chunk having the major protocol
version of '00', the receiving system recognizes the major
protocol version of the FIC chunk, which is configured as
shown in FIG. 19(b), as '00'.
However, in case of the FIC chunk shown in 19(b), FIC
segment 0 to FIC segment 3 correspond to FIC segment
transmitting data of the FIC chunk having the major protocol
version of '00', and FIC segment 4 to FIC segment 7
correspond to FIC segment transmitting data of the FIC chunk
having the major protocol version of '01'. Therefore, when a
loss occurs in the FIC segments due to burst noise, the
receiving system may recognize a set of FIC segments
transmitting an FIC chunk having 2 different protocol
versions as a set of FIC segments transmitting an FIC chunk
having a single protocol version, thereby causing a problem
of recovering the FIC chunk. Furthermore, when an error has
occurred in the FIC chunk recovery process, as described
above, the receiving system may not be able to recognize that
the FIC chunk recovery has not been performed correctly.
Accordingly, the receiving system may acquire an RS frame
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corresponding to an ensemble of a requested mobile service,
thereby causing a very critical problem.
In order to resolve the above-described problem, the .
present invention transmits protocol version information of
the FIC chunk through the FIC segment header of each FIC
segment.
According to the embodiment of the present
invention, the protocol version information of the FIC chunk
being transmitted through the FIC segment header corresponds
to at least one of a major protocol version information and a
minor protocol version information of the corresponding FIC
chunk.
FIG. 20 illustrates a syntax structure of an FIC segment
header according to another embodiment of the present
invention. Herein, an FIC Chunk major protocol version field
is further added to the syntax structure of the FIC segment
header shown in FIG. 16.
More specifically, the FIC segment header of FIG. 20 may
includes an FIC type field,
an
FIC Chunk major protocol version field, an error indicator
field; an FIC segment num field, and an FIC last segment num
field. With the exception of
the
FIC Chunk major protocol version field, the remaining fields
are identical to those described in FIG. 16.
Therefore,
detailed description of the same will be omitted ih FIG. 20
for simplicity.
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According to an embodiment of the present invention, the
FIC Chunk major protocol version field corresponds to a 2-bit
_ _ _ _
field, which indicates the major protocol version of the
corresponding FIC chunk. More specifically, the
5 FIC
Chunk major _ protocol _version field within the FIC segment
_ _
header has the same value as that of the
FIC major _ protocol _version field within the corresponding FIC
_
chunk header.
Reference may be made to the description of
the FIC chunk header in FIG. 9 for the major protocol version
10 of the FIC chunk syntax. Therefore, detailed description of
the same will be omitted herein for simplicity.
FIG. 21 illustrates an example of receiving FIC segments
having an FIC segment header as shown in FIG. 20 and
recovering the FIC chunk.
In this case also, it is assumed
15 multiple FIC chunks (e.g., 2 FIC chunks) are transmitted to
one FIC (i.e., one M/H frame), that each major protocol
version of the two FIC chunks is different from one another,
and that the receiving system can process both FIC chunks,
each having a different major protocol version.
20
More koecifically, it is assumed that an FIC chunk having
a major protocol version of '00' and an FIC chunk having a
major protocol version of '01' are simultaneously transmitted
to one FIC (i.e., one M/H frame), as shown in FIG. 21(a), and
that, due to an error caused by burst noise, the receiving
25 system has failed to receive FIC segment 4 to FIC segment 7,
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which transmit the FIC chunk having the major protocol
version of '00', and FIC segment 0 to FIC segment 3, which
transmit the FIC chunk having the major protocol version of
'01'.
At this point, the receiving system uses the
FIC segment num field, the FIC last segment num field, and
_ _ _ _ _
the FIC Chunk major protocol version within the FIC segment
_ _ _ _
header, so as to recover the FIC chunk.
More specifically, since
the
FIC Chunk major protocol version field values starting from
_ _ _ _
FIC segment 0 to FIC segment 3 are different from the
FIC Chunk major _ protocol _version field values starting from
_ _
FIC segment 4 to FIC segment 7, respectively, even though the
FIC segment numbers are consecutive, if the FIC chunk
protocol versions are different from one another, the data
cannot be configured as a single FIC chunk.
The FIC handler 121 of the receiving system according to
the present invention collects 4 FIC segments starting from
the FIC segment having the FIC_segment_num field value of '0'
to the FIC segment having the FIC_segment_num field value of
'3', as shown in FIG. 21(b).
Thereafter, the FIC segment
header of each of the 4 FIC segments is removed, thereby
configuring a FIC 'chunk having the major protocol version of
'00'. Additionally, the FIC handler 121 collects 4 FIC
segments starting from the FIC segment having the
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FIC segment num field value of '4' to the FIC segment having
the FIC segment num field value of 17'. Afterwards, the FIC
segment header of each of the 4 FIC segments is removed,
thereby configuring a FIC chunk having the major protocol
version of '01'.
Therefore, when a loss occurs in the FIC segments due to
burst noise, the problem of the receiving system recognizing
a set of FIC segments transmitting an FIC chunk having 2
different protocol versions as a set of FIC segments
transmitting an FIC chunk having a single protocol version
may be prevented.
More specifically, by allocating protocol version
information of the corresponding FIC chunk even in the FIC
segment header, even if a mixture of multiple FIC segments
corresponding to an FIC chunk having different protocol
versions within a single M/H frame are being received, the
present invention may collect only the FIC segments
corresponding to the same protocol version, thereby
recovering the FIC chunk.
At this point, when the FIC chunk is recovered, as shown
in FIG. 21, the FIC chink is not fully recovered.
For
example, an FIC chunk having a major protocol version of '00'
is missing 4 FIC segments starting= from the FIC segment
having the FIC_segment_num field value of '4' to the FIC '
segment having the FIC_segment_num field value of '7'.
_
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Furthermore, an FIC chunk having a major protocol version of
'01' is missing 4 FIC segments starting from the FIC segment
having the FIC_segment_num field value of '1' to the FIC
segment having the FIC_segment_num field value of '3'.
Therefore, according to an embodiment of the present
invention, the FIC chunk is not recovered in this case. More
specifically, when all FIC segments having the same major
protocol version are gathered, and when the number of
gathered FIC segments is smaller than the number of FIC
segments divided from the corresponding FIC chunk, then the
corresponding FIC chunk is not recovered.
At this point, the process of gathering FIC segments in
order to recover one FIC chunk may be performed in a single
sub-frame unit or in a single M/H frame unit.
This is
because the same FIC chunk may be repeated and then
transmitted within a single sub-frame, and also because the
same FIC chunk may be repeated and then transmitted within a
single M/H frame.
Moreover, the process of gathering FIC
segments may also be performed in a pre-determined (or pre-
designated) number Of sub-frame units or in a pre-determined
(or pre-designated) number of M/H frame units.
Furthermore, according to an embodiment of the present
invention, it is assumed that an FIC chunk having another
major protocol version co-exists within a single M/H frame,
and that the receiving system is capable of processing both
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FIC chunks, each having a different major protocol version.
In this case, a current FIC segment number, a last FIC
segment number, and a major protocol version of each FIC
segment are checked, so that FIC segments having the same
major protocol version as that of the receiving system can be
gathered, thereby configuring the FIC chunk.
Alternatively, when it is assumed that an FIC chunk having
another major protocol version co-exists within a single M/H
frame, and that the receiving system is capable of processing
only one of the two major protocol versions, the FIC chunk is
recovered from the FIC segments having their processable
major protocol version signaled.
Meanwhile, as described above, the present invention uses
the FIC chunk, so as to transmit the mapping (or
configuration) information between an ensemble and a mobile
service within an M/H frame.
Herein, when reconfiguration
occurs, wherein the mapping information between the ensemble
and the mobile service within a current M/H frame differs
from the mapping information between the ensemble and the
mobile service within a' next M/H frame, the present invention
may use at least one FIC chunk from the M/H frame prior to
the corresponding reconfiguration, in order to signal in
advance (or perform advanced signaling of) the mapping
information between the ensemble and the mobile service
within the M/H frame, wherein the reconfiguration occurs. In
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the description of the present invention, the M/H frame prior
to the occurrence of the reconfiguration will be referred to
as the current M/H frame, and the M/H. frame after the
occurrence of the reconfiguration will be referred to as the
next M/H frame.
Furthermore, according to the embodiment of the present
invention, the FIC chunk signaling the mapping information
between an ensemble and a mobile service within the current
M/H frame and the FIC chunk signaling the mapping information
between an ensemble and a mobile service within the next M/H
frame are alternately transmitted from a single M/H frame.
Herein, according to the embodiment of the present invention,
the FIC chunk signaling the mapping information between an
ensemble and a mobile service within the next M/H frame is
chronologically placed behind and transmitted after the FIC
chunk signaling the mapping information between an ensemble
and a mobile service within the current M/H frame.
More
specifically, the receiving system first receives the FIC
chunk signaling the mapping information between an ensemble
and a mobile service within the current M/H frame and, then,
receives the FIC chunk signaling the mapping information
between an ensemble and a mobile service within the next M/H
frame later on.
At this point, when the FIC chunk is received and
recovered, the FIC handler 121 of the receiving system uses
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the current next indicator field within the recovered FIC
chunk header, so as to determine whether the signaling
information included in the payload of the respective FIC
chunk corresponds to the mapping information between an
ensemble and a mobile service within the current M/H frame or
to the mapping information between an ensemble and a mobile
service within the next M/H frame. Hereinafter, the mapping
information between an ensemble and a mobile service within
an M/H frame will also be referred to as ensemble
configuration information of an M/H frame for simplicity.
FIG. 22 illustrates an exemplary occurrence of
reconfiguration, wherein the ensemble configuration
information of the current M/H frame differs from the
ensemble configuration information of the next M/H frame.
Referring to FIG. 22, the portions indicated as ,
k-1, k,
k+1, k+2, k+3, ...' represents a respective M/H frame. And,
in this example, the reconfiguration has occurred in the
(k+2)th M/H frame. As shown in FIG. 22, an M/H frame prior to
the occurrence of reconfiguration consists of two ensembles
and seven TNoGs. And, an M/H frame after the occurrence of
reconfiguration consists of three ensembles and seven TNoG.
As shown in FIG. 22, when reconfiguration occurs due to a
change in the number of ensembles being transmitted to the
respective M/H frame, the number of mobile service being
transmitted to each ensemble, and the number of TNoG of each
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sub-frame, the major protocol version information and the
minor protocol version information of the FIC chunk remain
unchanged.
However, the FIC version field value within the
TPC data is changed.
FIG. 22 shows an example of the FIC version field value
within the TPC data being updated to '6' after being
increased (or incremented) by '1' in the (k+l)th M/H frame and,
also, shows an example of the current_next_indicator field
value within the FIC chunk header being changed to '0' in the
(k+l)th M/H frame.
FIG. 23 illustrates an exemplary RS frame acquisition
process, when reconfiguration occurs in the (k+2)th M/H frame,
and when the ensemble configuration information of the
current M/H frame and the ensemble configuration information
of the next M/H frame are alternately transmitted from the
(k+1 th
) M/H frame.
Referring to the (k+l)th M/H frame of FIG. 23, the FIC
chunk signaling the ensemble configuration information of the
current M/H frame is received earlier than the FIC chunk
signaling the ensemble configura-Eion information of the next
M/H frame, thereby being recovered.
At this point, when tuning of a physical channel including
the requested ensemble is performed at a mid-portion of the
(k+l)th M/H frame, as shown in FIG. 23, the ensemble
th
configuration information of the (k+2) M/H frame may be
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acquired from the (k+l)th M/H frame. More specifically, when
reconfiguration occurs, wherein mapping information between
an ensemble and a mobile service within a mobile broadcast is
changed, by performing an advanced signaling of the ensemble
configuration information of a reconfiguration-occurred M/H
frame to an FIC chunk being transmitted to an M/H frame prior
to the corresponding reconfiguration, the present invention
may be able to quickly acquire the ensemble configuration
information of the -M/H frame having the corresponding
reconfiguration occurred therein (i.e., the corresponding
reconfiguration-occurred M/H frame).
Also, by using the
ensemble configuration information of the (k+2)th M/H frame,
which is acquired from the (k+l)th M/H frame, the present
invention may acquire the RS frame being transmitted to the
(k+2)th M/H frame, thereby being able to completely recover
the acquired RS frame.
Referring to FIG. 24, with the exception of the tuning of
the physical channel including the requested ensemble being
performed at an end-portion of the kth M/H frame, the rest of
the tuning process is the identical to the process steps
shown in FIG. 23.
At this point, when the receiving system
fails to receive an RS frame portion corresponding to
approximately 20% of the M/H frame, the entire RS frame may
be recovered by using RS-CRC decoding and SCCC decoding
processes. For example, it is assumed that the tuning of a
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physical channel including the requested ensemble is
performed at an end-portion of the kth M/H frame, and that
signaling information of the (k+1)th M/H frame is entirely (or
completely) acquired from the 1st FIC chunk of the (k+l)th M/H
frame.
In this case, while receiving the 1st FIC chunk of the
(k+l)th M/H frame, the RS frame being transmitted to the
( k+i) th M/H frame cannot be received. However, when the non-
received portion corresponds to approximately 20% of the
(k+l)th M/H frame, the entire RS frame being transmitted to
the (k+l)th M/H frame may be recovered by using RS-CRC
decoding and SCCC decoding processes. Furthermore, even if
reconfiguration occurs in the (k+l)th M/H frame, the present
invention may use the signaling information of the (k+2)th M/H
frame, which is acquired from the (k+l)th M/H frame, in order
to completely recover the RS frame being transmitted to the
( k+2 th
) M/H frame.
As described above, based upon a tuning point of the
physical channel and a FIC chunk data structure in an M/H
frame prior to the occurrence of the reconfiguration, the
present invention may quickly acquire and recover an RS frame,
thereby being able to service the required RS frame to the
user.
However, as described above, when an FIC chunk signaling
the mapping information between an ensemble and a mobile
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service within a current M/H frame and an FIC chunk signaling
the mapping information between an ensemble and a mobile
service within the next M/H frame co-exist in a single M/H
frame, the same problem that occurs when FIC chunks having
different protocol versions are received in a single M/H
frame may also occur in this case. More specifically, there
may occur an error, wherein one FIC chunk is recovered from
an FIC segment transmitting FIC chunk signaling the mapping
information between an ensemble and a mobile service within a
current M/H frame and an FIC segment transmitting FIC chunk
signaling the mapping information between an ensemble and a
mobile service within a next M/H frame. As described above,
when an error occurs during the recovery of an FIC chunk,
ensemble configuration information of a next M/H frame cannot
be appropriately acquired from the recovered FIC chunk.
Accordingly, the RS frame being transmitted to the next M/H
frame may also fail to be appropriately acquired and
recovered.
For example, when the FIC segments of the FIC chunk
signaling the mapping information between an ensemble and a
mobile service within a current M/H frame and the FIC
segments of the FIC chunk signaling the mapping information
between an ensemble and a mobile service within a next M/H
frame are received in a mixed order, the receiving system is
incapable of determining whether the corresponding FIC
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segment that is being received corresponds to an FIC segment
belonging to the FIC chunk signaling the mapping information
between an ensemble and a mobile service within a current M/H
frame or to an FIC segment belonging to the FIC chunk
signaling the mapping information between an ensemble and a
mobile service within a next M/H frame.
Therefore, the
above-described problem may occur.
Furthermore, when FIC segments have been lost due to an
error caused by burst noise, the receiving system may also be
incapable of determining whether the corresponding FIC
segment that is being received corresponds to an FIC segment
belonging to the FIC chunk signaling the mapping information
between an ensemble and a mobile service within a current M/H
frame or to an FIC segment belonging to the FIC chunk
signaling the mapping information between an ensemble and a
mobile service within a next M/H frame. Therefore, in this
case also, the above-described problem may occur.
Similarly, the above-described problem may also occur when
the TPC data and the FIC segment are being received, as shown
in FIG. 25. More specifically, as shown in CD of FIG. 25,
the FIC version field value within the TPC data is increased
by '1', in the 1st FIC segment of the FIC chunk signaling the
mapping information between an ensemble and a mobile service
within a next M/H frame. Accordingly, the receiving system
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may exit from the time-slicing mode, as shown in 0 of FIG.
25, thereby gathering (or collecting) the FIC segments.
Furthermore, as shown in ()of FIG. 25, the receiving
system uses the FIC segment num field and
the
FIC last segment num field within each FIC segment header of
the gathered FIC segments, so as to gather only the FIC"
segments configuring a single FIC chunk, thereby aligning
each of the FIC segments in the order of the respective FIC
segment numbers.
Thereafter, the receiving system removes
the header of from each of the aligned FIC segments.
Accordingly, a single FIC chunk is configured, as shown in (4)
of FIG. 25.
Then, the receiving system acquires ensemble
configuration information of the M/H frame from the
configured FIC chunk.
Subsequently, the receiving system
enters the time-slicing mode, as shown in CD of FIG. 25, in
accordance with the acquired ensemble configuration
information.
However, when referring to the FIC segments gathered as
shown in CD of FIG. 25, it is apparent that FIC segments of
an FIC chunk signaling the ensemble configuration information
within a current M/H frame and FIC segments of an FIC chunk
signaling the ensemble configuration information within the
next M/H frame are mixed (or co-exist). More specifically, CI =
of FIG. 25 shows an example of an incorrect gathering of the
25 FIC segments. This is because the
receiving system is
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incapable of determining whether a corresponding FIC segment
is an FIC segment belonging to the FIC chunk signaling the
ensemble configuration information within a current M/H frame
or an FIC segment belonging to the FIC chunk signaling the
ensemble configuration information within a next M/H frame.
Furthermore, when an FIC chunk is configured as shown in (4D
of FIG. 25, the receiving system determines that the
corresponding FIC chunk is signaling ensemble configuration
information of a next M/H frame.
However, the FIC chunk
includes a portion of the data included in the FIC chunk
signaling the ensemble configuration information within a
current M/H frame. More specifically, a) of FIG. 25 shows an
example of the FIC chunk being recovered while including
wrong (or incorrect) information. Accordingly, since the
ensemble configuration information that is acquired from an
incorrectly recovered FIC chunk corresponds incorrect
information, the RS frame being transmitted to the next M/H
frame may not be correctly acquired and recovered.
According to the embodiment of the present invention, in
order to resolve such problems, in transmitting M/H frame
identification information through the FIC segment header of
each FIC segment, the M/H frame identification information
notifies whether the corresponding FIC segment is an FIC
segment of the FIC chunk signaling the ensemble configuration
information of the current M/H frame or an FIC segment of the
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FIC chunk signaling the ensemble configuration information of
the next M/H frame.
According to the embodiment of the
present invention, the M/H frame identification information
being transmitted through the FIC segment header corresponds
to the current next indicator field.
FIG. 26 illustrates a syntax structure of an FIC segment
header according to another embodiment of the present
invention. More specifically, a current_next_indicator field
is additionally included in the syntax structure of the FIC
segment header shown in FIG. 20. According to the present
invention, the current_next_indicator field is assigned with
1 bit.
More specifically, the FIC segment header of FIG. 26 may
include an FIC type field,
an
FIC Chunk major _protocol version field, a
_
current next indicator field, an error indicator field, an
FIC segment num field, and an FIC last segment num field.
Since reference may be made to FIG. 16 for the description of
the FIC type field, the error indicator field,
the
FIC segment num field, and the FIC last segment num field,
detailed description of the same will be omitted for
simplicity.
The FIC Chunk major_protocol version field corresponds to
a 2-bit field, which indicates a major protocol version of
the corresponding FIC chunk. At this point, the value of the
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FIC Chunk major protocol version field should be the same as
the value of the FIC_major_protocol_version field within the
corresponding FIC chunk header. Since reference may be made
to the description of the FIC chunk header shown in FIG. 9, a
detailed description of the major protocol version of the FIC
chunk syntax will be omitted for simplicity.
The current next indicator field corresponds to a 1-bit
indicator, which, when set to '1', shall indicate that the
corresponding FIC segment is carrying a portion of the FIC
chunk, which is applicable to the current M/H
frame. Alternatively, when the value of
the
current next indicator field is set to '0',
the
current next indicator field shall indicate that the
corresponding FIC segment is carrying a portion of the FIC
chunk, which will be applicable for the next M/H frame. In
the former case, the most recent version of the FIC chunk
transmitted with the current next indicator field value set
to '1' shall be currently applicable.
Furthermore, in the signaling information region within
the data group, the TPC data being allocated along with the
FIC data and then transmitted include parameters that are
mostly used in a physical layer module. And, since the TPC
data are transmitted without being interleaved, the receiving
system is capable of accessing the TPC data by slot units.
According to the embodiment of the present invention, by
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using the property enabling the TPC data, which include the
FIC version field, to be received by slot units, when the FIC
chunk is updated, the receiving system may use the
FIC version field of the TPC data in order to determine the
update status of the corresponding FIC chunk. Also, when the
update status of the corresponding FIC chunk is detected, the
receiving system exits from the time-slicing mode, so as to
enable the FIC segments to be integrated (or combined).
FIG. 27 illustrates an example of a syntax structure of
TPC data.
The TPC data may include a sub-frame number field, a
slot number field, a parade id field, a starting_group_number
(SGN) field, a number _ of _groups
(NoG) field, a
parade_repetition_cycle (PRO) field, an RS_frame_mode field,
an RS code mode primary field, an RS code mode secondary
field, an SCCC block mode field, an SCCC outer code mode A
field, an SCCC outer code mode B field,
an
SCCC outer code mode C field, an SCCC outer code mode D field,
an FIC version field, a parade continuity_counter field, a
TNoG field, and a TPC_protocol_version field.
The Sub-Frame number field indicates the number of a
current sub-frame within a corresponding M/H frame and is
transmitted for M/H frame synchronization. A value of the
Sub-frame number field shall range from 0 to 4.
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The Slot number field is the current Slot number within
the Sub-Frame, which is transmitted for M/H Frame
synchronization. Its value shall range from 0 to 15.
The Parade id field identifies the Parade to which this
Group belongs. The value of this field may be any 7-bit value.
Each Parade in an M/H transmission shall have a unique
Parade id. In this case, communication of the Parade id
between the physical layer and the management layer shall be
performed by means of an ensemble_id formed by adding one bit
to the left of the Parade id. If the Ensemble id is for the
primary ensemble delivered through this Parade, the added MSB
shall be 10'. Otherwise, if it is for the secondary ensemble,
the added MSB shall be 11'.
The starting_Group_number (SGN) field shall be the first
Slot number for a Parade to which this Group belongs (after
the Slot numbers for all preceding Parades have been
calculated).
The
number _ of _Groups (NoG) field shall be the number of
Groups in a Sub-Frame assigned to the Parade to which this
Group belongs, minus 1, e.g., NoG = 0 implies that one Group
is allocated to this Parade in a Sub-Frame. A value of the
NoG field shall range from 0 to 7. Slot numbers assigned to
the corresponding parade can be calculated from SGN and NoG.
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=The Parade_repetition_cycle (PRC) field shall be the cycle
time over which the Parade is transmitted, minus 1, specified
. in units of M/H Frames.
The RS Frame mode field indicates whether a single parade
carries a single RS frame or two RS frames.
The RS code mode primary field indicates an RS code mode
for a primary RS frame.
The RS code mode secondary field indicates an RS code mode
for a secondary RS frame.
The SCCC Block mode field indicates how M/H blocks within
a data group are allocated to SCCC block.
The SCCC outer code mode A field indicates an SCCC outer
mode code for a region A within a data group.
The SCCC outer code mode B field indicates an SCCC outer
mode code for a region B within a data group.
The SCCC outer code mode C field indicates an SCCC outer
mode code for a region C within a data group.
The SCCC outer code mode D field indicates an SCCC outer
mode code for a region D within a data group.
The FIC version field indicates a version of FIC data.
More specifically, the FIC version field represents the
version of the FIC-Chunk data structure. The value of this
field shall be set equally to all the TPC data structure
delivered through one M/H frame and shall be incremented by
one whenever there is a FIC-Segment with
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current next indicator field set to '0' in the Sub frame,
where the TPC data structure is delivered. For example, when
. a number of mobile services included in ensemble 0 is changed
2 into 3, the value of the FIC version field is changed.
The Parade continuity_counter field is incremented to 0-15
and is incremented by 1 for each (PRC+1) M/H frame. For
instance, if PRC = 011, the Parade continuity_counter field
is incremented each fourth M/H frame.
The TNoG field indicates the total number of data groups
to be transmitted during a Sub-Frame. In other words, it is
the sum of NoGs of all Parades within a Sub-Frame. Its value
shall be in the range of 0 through 16 inclusive. The TNoG
field is used both for current M/H frame information and for
signaling in advance.
The tpc_protocol_version field corresponds to a 5-bit
unsigned integer and represents a version of the
corresponding TPC syntax structure. The 2 most-significant
bits are the major version level; the least-significant three
bits are the minor version level, to be interpreted as
follows: A change in the major version level shall indicate a
non-backward-compatible level of change. A change in the
minor version level, provided the major version level remains
the same, shall indicate a backward-compatible level of
change. The initial value for this field shall be '11111'. At
least one of the bits shall be changed so as to form a
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previously unused value of this field each time the TPC
structure is changed by a future version of this standard.
Other values of the version may be used in future to signal
use of the reserved bits or a change in the defined syntax.
The first such change shall be to '00' or '000', so that this
field inctements in the same manner as other fields for later
changes.
However, the information included in the TPC data
presented herein is merely exemplary. And, since the adding
or deleting of information included in the TPC may be easily
adjusted and modified by one skilled in the art, the present
invention will, therefore, not be limited to the examples set
forth herein.
Since the TPC data (excluding the Sub-Frame_number field
and the Slot number field) for each parade do not change
their values during an M/H frame, the same information is
repeatedly transmitted through all M/H groups belonging to
the corresponding parade during an M/H frame. This allows
very robust and reliable reception of the TPC data. Because
the Sub-Frame number and the Slot number are increasing
counter values, they also are robust due to the transmission
of regularly expected values.
FIG. 28 illustrates an example of receiving FIC segments
each having an FIC segment header shown in FIG. 26 and TPC
data having the structure shown in FIG. 27, thereby
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recovering an FIC chunk.
More specifically, when the
FIC version field value of the TPC data structure is
increased by '1', as shown in C) of FIG. 28, the receiving
system determines that the data structure of the
corresponding FIC chunk has been updated.
Then, the
receiving system exists from the time-slicing mode, as shown
in CD of FIG. 28, so as to gather (or collect) FIC segments.
Thereafter, as shown in CD of FIG. 28, the receiving .
system uses the FIC segment num field,
the
FIC last segment num field, and the current next indicator
field within each FIC segment header of the collected FIC
segments, so as to gather only the FIC segments that
configure one FIC chunk. Subsequently, the receiving system
aligns each of the gathered FIC segments in the order of the
respective FIC segment numbers. Then, the receiving system
removes the header of each FIC segment, thereby configuring
an FIC chunk, as shown in
of FIG. 28. Afterwards, the
receiving system acquires ensemble configuration information
of an M/H frame from the configured FIC chunk, so as to enter
the time-slicing mode based upon the acquired ensemble
configuration information, as shown in C) of FIG. 28.
In case of CD of FIG. 28, when gathering only the FIC
segments configuring one FIC chunk,
the
FIC Chunk major_protocol version field within the FIC segment
header may be additionally used.
More specifically, the
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receiving system may use the segment_num field, the
FIC last segment num field, the current next indicator field,
and the FIC Chunk major protocol version field, so as to
gather only the FIC segments of an FIC chunk signaling
ensemble configuration information of a next (or current) M/H
frame corresponding to the same protocol version.
Subsequently, the receiving system aligns each of the
gathered FIC segments in the order of the respective FIC
segment numbers.
Then, the receiving system removes the
header of each FIC segment, thereby configuring an FIC chunk.
When configuring an FIC chunk as described above, the FIC
chunk may be configured only of FIC segments corresponding to
an FIC chunk signaling ensemble configuration information of
a next M/H frame, as shown in C) of FIG. 28.
Therefore, the receiving system may prevent the problem of
configuring a single FIC chunk by gathering FIC segments
belonging to the FIC chunk signaling the ensemble
configuration information within a current M/H frame and FIC
segments belonging to the FIC chunk signaling the ensemble
configuration information within a next M/H frame.
More
specifically, the present invention allocates an M/H frame
identification information to each FIC segment header.
Herein, the M/H frame identification information may identify
whether the signaling information being transmitted to the
payload of a respective FIC segment corresponds to signaling
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information of the current M/H frame or to the signaling
information of the next M/H frame.
Thus, the receiving
system may be able to acquire the ensemble configuration
information of the next M/H frame from the FIC chunk without
any errors. Accordingly, the receiving system is capable of
properly acquiring and recovering an RS frame, which is to be
transmitted to the next M/H frame.
FIG. 29 and FIG. 30 respectively illustrate flow charts
showing the process of recovering an FIC chunk from FIC
segments according to an embodiment of the present invention.
Referring to FIG. 29 and FIG. 30, it is assumed that FIC
chunks having the same FIC chunk major protocol version are
received in a single M/H frame. It is also assumed that the
receiving system is capable of receiving and processing an
FIC chunk of the FIC chunk protocol version.
More specifically, when the receiving system tunes to a
physical transmission channel including a user-selected
mobile service (S501), the receiving system identifies a
mobile broadcast signal transmitting the user-selected mobile
service from the tuned physical transmission channel (S502).
Then, the receiving system finds out a sub-frame to which the
identified mobile broadcast signal is transmitted and a slot
that is allocated to the sub-frame (S503).
Subsequently, data groups, which are received through the
slots of the sub-frame found in step 503 gather (S504). Then,
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PCCC-decoding is performed on the FIC data, which is received
in each signaling information region of the gathered data
groups, deinterleaving is performed on the PCCC-decoded FIC
data in sub-frame units, thereby performing RS-decoding as an
inverse process of the transmitting system (S505).
Accordingly, the FIC segments may be recovered for each sub-
frame. At this point, deinterleaving is not performed on the
TPC data, which are received in the signaling information
region. However, PCCC-decoding and RS-decoding are performed
as inverse processes of the transmitting system.
After performing step 505, the header of the first
received FIC segment is analyzed, and, then, the first
received FIC segment is stored in the FIC segment buffer
within the FIC handler 121 (S506).
More specifically, an
FIC_segment_num field and an FIC_last_segment_num field
included in the header of the first received FIC segment are
parsed, thereby storing the FIC segment number, the last FIC
segment number, and a number of FIC segment divided from the
FIC chunk corresponding to the FIC segment are stored in FIC
segment buffer.
Thereafter, the receiving system grabs the next FIC
segment, so as to analyze the header of the grabbed next FIC
segment, thereby examining the FIC segment number (S507). In
other words, by parsing the FIC_segment_num field within the
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header of the next FIC segment, the receiving system extracts
the FIC segment number of the corresponding FIC segment.
Subsequently, the receiving system verifies whether or not
the FIC segment is already stored in the FIC segment buffer
(S508). This information may be known from the FIC segment
number (i.e., FIC_segment_num field) extracted in step 507.
When it is verified in step 508 that the corresponding FIC
segment is already stored in the FIC segment .buffer, the
corresponding FIC segment is discarded (or deleted) without
being stored (S509).
However, when it is verified in step
508 that the corresponding FIC segment is not stored in the
FIC segment buffer, the corresponding FIC segment is stared
in the FIC segment buffer (S510).
After performing step 509 or step 510, the receiving
system verifies whether the FIC segments of an FIC chunk are
all received and stored in the FIC segment buffer (S511).
This information can be verified by comparing the number of
FIC segments stored in the FIC segment buffer and the value
of the FIC last segment num field.
When it is verified in step 511 that not all of the FIC
segments of the FIC chunk are stored in the FIC segment
buffer, the receiving system step returns to step 507, so as
to repeat the process step corresponding to the next FIC
segment.
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On the other hand, when it is verified in step 511 that
all of the FIC segments of the FIC chunk are stored in the
FIC segment buffer, the receiving system aligns the FIC
segments stored in the FIC segment buffer in the order of the
FIC segment numbers and then sequentially removes the header
of each FIC segment (3512). Thus, one FIC chunk is recovered
(S513).
It will be apparent to those skilled in the art that
various modifications and variations can be made in the
present invention without departing from the scope
of the inventions. Thus, it is intended that the present
invention covers the modifications and variations of this
invention provided they come within the scope of the appended
claims and their equivalents.
Industrial Ap21icability
The embodiments of the method for transmitting and
receiving signals and the apparatus for transmitting and
receiving signals according to the present invention can be
used in the fields of broadcasting and communication.
=
