Note: Descriptions are shown in the official language in which they were submitted.
Description
Title of Invention: TRANSMITTING APPARATUS, RECEIVING
APPARATUS, AND CONTROL METHODS THEREOF
Technical Field
[1] Apparatuses and methods consistent with the exemplary embodiments of
the
present inventive concept relate to a transmitting apparatus, a receiving
apparatus,
and control methods thereof, and more particularly, to a transmitting
apparatus that
maps data onto at least one signal processing path and transmits the mapped
data, a
receiving apparatus, and control methods thereof.
Background Art
[2] In the information-oriented society of the 21st century, broadcasting
communication services are entering an era of digitization, multi-channel,
broadband,
and high quality. In particular, as high-quality digital televisions (TVs),
portable
multimedia players (PMP), and portable broadcasting apparatuses have been
increasingly used in recent years, even in digital broadcasting services, a
demand for
supporting various receiving methods has been increased.
[31 Thus, the broadcasting communication standard group has established
various
standards according to demands to provide various services to satisfy user's
needs.
Still, however, it is required to find methods for providing better services
having
improved performance.
Disclosure of Invention
Technical Problem
[4] Exemplary embodiments of the inventive concept may overcome the
above
disadvantages and other disadvantages not described above. Also, the exemplary
embodiments of the inventive concept are not required to overcome the
disadvantages described above, and may not overcome any of the problems
described
above.
[51 The exemplary embodiments provide a transmitting apparatus that
provides a
preamble including various types of information, a receiving apparatus, and
control
methods thereof.
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Solution to Problem
[6] According to an exemplary embodiment, there is provided a transmitting
apparatus
which may include: an LI signaling generator configured to generate LI
signaling
including first information and second information; a frame generator
configured to
generate a frame including a payload including a plurality of sub frames; and
a signal
processor configured to insert a preamble including the LI signaling in the
frame and
transmit the frame. The first information may include information required for
decoding a first sub frame among the plurality of sub frames.
[7] According to an exemplary embodiment, there is provided a receiving
apparatus
which may include: a receiver configured to receive a frame including a
preamble
including LI signaling including first information and second information and
a
payload including a plurality of sub frames; and a signal processor configured
to
signal-process the frame. The first information may include information
required for
decoding a first sub frame of the plurality of sub frames, and the signal
processor
may decode the first sub frame based on the information included in the first
information and decode the second information in parallel with the decoding
the first
sub frame.
[8] According to an exemplary embodiment, there is provided a method of
controlling
a transmitting apparatus. The method may include: generating LI signaling
including
first information and second information; generating a frame including a
payload
including a plurality of sub frames; and inserting a preamble including the LI
signaling in the frame and transmitting the frame. The first information may
include
information for decoding a first sub frame of the plurality of sub frames.
[9] According to an exemplary embodiment, there is provided a method of
controlling
a receiving apparatus. The method may include: receiving a frame including a
preamble including LI signaling including first information and second
information
and a payload including a plurality of sub frames; and signal-processing the
frame.
The signal-processing of the frame may include decoding a first sub frame
based on
information included in the first information and decoding the second
information in
parallel with the decoding the first sub frame.
[9a] According to an exemplary embodiment, there is provided a
transmitting apparatus
comprising: a layerl (LI) signaling generator configured to generate a first
signaling
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information and a second signaling information; and a frame generator
configured to
generate a frame comprising a preamble and a payload, wherein the preamble
comprises the first signaling information and the second signaling
information,
wherein the payload comprises at least one sub frame, wherein the first
signaling
information comprises information required to decode the second signaling
information and information required for an initial orthogonal frequency
division
multiplexing (OFDM) processing of a first sub frame among the at least one sub
frame, wherein the second signaling information comprises information for a
configuration of the at least one sub frame, and wherein the first signaling
information is used in a receiver to facilitate the initial OFDM processing of
the first
sub frame without waiting for decoding of the second signaling information.
[9b] According to an exemplary embodiment, there is provided a
transmitting method of
a transmitting apparatus, the method comprising: generating a first signaling
information and a second signaling information; and generating a frame
comprising a
preamble and a payload, wherein the preamble comprises the first signaling
information and the second signaling information, wherein the payload
comprises at
least one sub frame, wherein the first signaling information comprises
information
required to decode the second signaling information and information required
for an
initial orthogonal frequency division multiplexing (OFDM) processing of a
first sub
frame among the at least one sub frame, wherein the second signaling
information
comprises information for a configuration of the at least one sub frame, and
wherein
the first signaling information is used in a receiver to facilitate the
initial OFDM
processing of the first sub frame without waiting for decoding of the second
signaling
information.
[10] Additional and/or other aspects and advantages of the invention will
be set forth in
part in the description which follows and, in part, will be obvious from the
description, or may be learned by practice of the exemplary embodiments.
Advantageous Effects of Invention
[11] According to various exemplary embodiments, a processing delay in a
receiving
apparatus may be reduced.
Brief Description of Drawings
[12] The above and/or other aspects of the exemplary embodiments will be
described
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with reference to the accompanying drawings, in which:
[13] FIG. 1 is a diagram illustrating a hierarchical structure of a
transmitting system
according to an exemplary embodiment;
[14] FIG. 2 is a diagram illustrating a schematic configuration of a
broadcasting link
layer 1400 according to an exemplary embodiment;
[15] FIG 3A is a diagram illustrating a schematic configuration of a
transmitting system
(or a transmitting apparatus) according to an exemplary embodiment;
[16] FIGS. 38 and 3C are diagrams illustrating a multiplexing method,
according to
exemplary embodiments;
[17] FIG. 4 is a block diagram illustrating a detailed configuration of an
input formatting
block of FIG. 3A, according to an exemplary embodiment;
[18] FIGS. 5A and 5B are diagrams illustrating a detailed configuration of
a baseband
formatting block, according to exemplary embodiments;
[19] FIG. 6 is a block diagram illustrating a configuration of a
transmitting apparatus
according to an exemplary embodiment of the present invention;
[20] FIG. 7 is a diagram illustrating a configuration of a frame that is a
base for
describing the exemplary embodiments;
[21] FIG. 8 is a diagram illustrating a detailed configuration of the frame
of FIG. 7,
according to an exemplary embodiment;
[22] FIG. 9 is a diagram illustrating a start time for decoding a related
art payload;
[23] FIG. 10 is a diagram illustrating a start time for decoding a payload
according to an
exemplary embodiment;
[24] FIG. 11 is a diagram illustrating information included in Li basic
according to an
exemplary embodiment;
[25] FIG. 12 is a block diagram illustrating a configuration of a receiving
apparatus
according to an exemplary embodiment;
[26] FIG. 13 is a detailed block diagram illustrating a signal processor in
detail
according to an exemplary embodiment;
[27] FIG. 14 is a block diagram illustrating a configuration of a receiver
according to an
exemplary embodiment;
[28] FIG. 15 is a block diagram illustrating a demodulator in more detail
according to an
exemplary embodiment;
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[29] FIG. 16 is a flowchart illustrating a brief operation of a receiver
until an actually
selected service is played from a time when a user selects a service according
to an
exemplary embodiment;
[30] FIG. 17 is a flowchart illustrating a method of controlling a
transmitting apparatus
according to an exemplary embodiment; and
[31] FIG. 18 is a flowchart illustrating a method of controlling a
receiving apparatus
according to an exemplary embodiment.
Best Mode for Carrying out the Invention
[32] -
Mode for the Invention
[33] Hereinafter, various exemplary embodiments of the inventive concept
will be
described in detail with reference to the accompanying drawings. Further, in
the
following description, a detailed explanation of known related functions or
configurations may be omitted to avoid unnecessarily obscuring the subject
matter. In
addition, terms to be described below may vary according to a user's and an
operator's intentions, the convention, or the like as terms defined by
considering
functions. Therefore, the definition may be made according to the contents
throughout this specification.
[34] An apparatus and a method proposed in the exemplary embodiments may
be, of
course, applied to various communication systems including mobile broadcasting
services including a digital multimedia broadcasting (DMB) service, digital
video
broadcasting handheld (DVB-H), an advanced television systems committee
mobile/handheld (ATSC-M/H) service, an Internet protocol television (IPTV)
service,
and the like, communication systems including a moving picture experts group
(MPEG) media transport (MMT) system, an evolved packet system (EPS), a long-
term evolution (LTE) mobile communication system, a long-term evolution-
advanced (LTE-A) mobile communication system, a high speed downlink packet
access (HDSPA) mobile communication system, a high speed uplink packet access
(HSUPA) mobile communication system, a 3rd generation project partnership 2
(3GPP2) high rate packet data (HRPD) mobile communication system, a 3GPP2
wideband code division multiple access (WCDMA) mobile communication system, a
3GPP2 code division multiple access (CDMA) mobile communication system, an
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Institute of Electrical and Electronics Engineers (IEEE) 802.16m communication
system, a mobile Internet protocol (Mobile IP) system, and the like.
[35] FIG. 1 is a diagram illustrating a hierarchical structure of a
transmitting system
according to an exemplary embodiment.
[36] Referring to FIG. 1, a service includes media data 1000 and signaling
1050 for
transferring information required to acquire and consume the media data 1000
at a
receiver. The media data 1000 may be encapsulated in a format suitable for
transmission prior to the transmission. An encapsulation method may follow a
Media
Processing Unit (MPU) defined in ISO/IEC 23008-1 MPEG Media Transport (MMT)
or a DASH segment format defined in ISO/IEC 23009-1 Dynamic Adaptive
Streaming over HTTP (DASH). The media data 1000 and the signaling 1050 are
packetized according to an application layer protocol.
[37] FIG. 1 illustrates a case in which an MMT protocol (MMTP) 1110 defined
in the
MMT and a Real-Time Object Delivery over Unidirectional Transport (ROUTE)
protocol 1120 are used as the application layer protocol. In this case, a
method for
notifying information about an application protocol, in which a service is
transmitted,
by an independent method different from the application layer protocol is
required for
the receiver to know by which application layer protocol the service is
transmitted.
[38] A service list table (SLT) 1150 illustrated in FIG. 1 represents or
indicates a
signaling method and packetizes information about the service in a table for
satisfying the aforementioned object. Detailed contents of the SLT will be
described
below. The packetized media data and the signaling including the SLT are
transferred
to a broadcasting link layer 1400 through a user datagram protocol (UDP) 1200
and
an Internet protocol (IP) 1300. An example of the broadcasting link layer 1400
includes an ATSC 3.0 link-layer protocol (ALP) defined in the ATSC 3.0
standard
(hereafter, referred to as `ATSC 3.0'). The ALP protocol generates an ALP
packet by
using an IP packet as an input, and transfers the ALP packet to a broadcasting
physical layer 1500.
[39] I lowever, according to FIG. 2 to be described below, it is noted that
the
broadcasting link layer 1400 does not use only the IP packet 1300 including
the
media data and/or the signaling as the input, and instead, may use an MPEG2-TS
packet or general formatted packetized data as the input. In this case,
signaling
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information required to control the broadcasting link layer is also
transferred to the
broadcasting physical layer 1500 in the form of the ALP packet.
[40] The broadcasting physical layer 1500 generates a physical layer frame
by signal-
processing the ALP packet as the input, converts the physical layer frame into
a radio
signal, and transmits the radio signal. In this case, the broadcasting
physical layer
1500 has at least one signal processing path. An example of the signal
processing
path may include a physical layer pipe (PLP) of ATSC 3.0 or the Digital Video
Broadcasting - Second Generation Terrestrial (DVB-T2) standard, and one or
more
services or some of the services may be mapped to the PLP.
[41] FIG. 2 is a diagram illustrating a schematic configuration of the
broadcasting link
layer 1400, according to an exemplary embodiment.
[42] Referring to FIG. 2, the input of the broadcasting link layer 1400
includes the IP
packet 1300, and may further include link layer signaling 1310, an MPEG2-TS
packet 1320, and other packetized data 1330.
[43] Input data may be subjected to additional signal processing based on
the type of the
input data before ALP packetization 1450. As an example of the additional
signal
processing, the IP packet 1300 may be subjected to an IP header compression
process
1410 and the MPEG2-TS packet may be subjected to an overhead reduction process
1420. During the ALP packetization, input packets may be subjected to dividing
and
merging processes.
[44] FIG. 3A is a diagram illustrating a schematic configuration of a
transmitting system
or a transmitting apparatus, according to an exemplary embodiment. According
to
FIG. 3A, a transmitting system 10000 according to the exemplary embodiment may
include input formatting blocks 11000 and 11000-1, bit interleaved and coded
modulation (BICM) blocks 12000 and 12000-1, framing/interleaving blocks 13000
and 13000-1, and waveform generation blocks 14000 and 14000-1.
[45] The input formatting blocks 11000 and 11000-1 generate a baseband
packet from
an input stream of data to be serviced. Herein, the input stream may be a
transport
stream (TS), Internet packets (IP) (e.g., IPv4 and IPv6), an MPEG media
transport
(MMT), a generic stream (GS), generic stream encapsulation (GSE), and the
like. For
example, an ALP packet may be generated based on the input stream, and the
baseband packet may be generated based on the generated ALP packet.
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[46] The bit interleaved and coded modulation (BICM) blocks 12000 and 12000-
1
determine an forward error correction (FEC) coding rate and a constellation
order
according to an area (fixed PHY frame or mobile PHY frame) to which the data
to be
serviced will be transmitted, and perform encoding and time interleaving.
Meanwhile,
signaling information about the data to be serviced may be encoded through a
separate BICM encoder according to user implementation or encoded by sharing a
BICM encoder with the data to be serviced.
[47] The framing/interleaving blocks 13000 and 13000-1 combine the time-
interleaved
data with a signaling signal including the signaling information to generate a
transmission frame.
[48] The waveform generation blocks 14000 and 14000-1 generate an
orthogonal
frequency-division multiplexing (OFDM) signal in a time domain for the
generated
transmission frame, modulate the generated OFDM signal into an RF signal, and
transmit the RF signal to a receiver.
[49] The transmitting system 10000 according to the exemplary embodiment
illustrated
in FIG. 3A includes normative blocks marked with a solid line and informative
blocks marked with dotted lines. Herein, the blocks marked with the solid line
are
normal blocks, and the blocks marked with the dotted lines are blocks which
may be
used when informative multiple-input multiple-output (MIMO) is implemented.
[50] FIGS. 3B and 3C are diagrams illustrating a multiplexing method,
according to
exemplary embodiments.
[511 FIG. 38 illustrates a block diagram for implementing time division
multiplexing
(TDM), according to an exemplary embodiment.
[52] A TDM system architecture includes four main blocks (alternatively,
parts) of the
input formatting block 11000, the BICM block 12000, the framing/interleaving
block
13000, and the waveform generation block 14000.
[53] Data is input and formatted in the input formatting block 11000 and
forward error
correction is applied to the data in the BICM block 12000. Next, the data is
mapped
to a constellation. Subsequently, the data is time and frequency-interleaved
in the
framing/interleaving block 13000 and a frame is generated. Thereafter, an
output
waveform is generated in the waveform generation block 14000.
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[54] FIG. 3C illustrates a block diagram for implementing layered division
multiplexing
(LDM), according to an exemplary embodiment.
[55] An LDM system architecture includes several other blocks as compared
with the
TDM system architecture. In detail, two separated input formatting blocks
11000 and
11000-1 and the BICM blocks 12000 and 12000-1 for one of respective layers of
the
LDM are included in the LDM system architecture. The blocks are combined in an
LDM injection block before the framing/interleaving block 13000. And, the
waveform generation block 14000 is similar to the TDM.
[56] FIG. 4 is a block diagram illustrating a detailed configuration of the
input
formatting block illustrated in FIG. 3A, according to an exemplary embodiment.
[57] As illustrated in FIG. 4, the input formatting block 11000 includes
three blocks that
control packets distributed to PLPs. In detail, the input formatting block
11000
includes an encapsulation and compression block 11100, a baseband formatting
block
(alternatively, baseband framing block) 11300, and a scheduler block 11200.
[58] An input stream input to the encapsulation and compression block 11100
may be
various types. For example, the input stream may be a transport stream (TS),
an
Internet packets (IP) (e.g., IPv4 and IPv6), an MPEG media transport (MMT), a
generic stream (GS), a generic stream encapsulation (GSE), and the like.
[59] Packets output from the encapsulation and compression block 11100
become ALP
packets (generic packets) (also referred to as L2 packets). Herein, a format
of an ALP
packet may be one of the Type Length Value (TLV), the GSE, and the ALP.
[60] The length of each ALP packet is variable. The length of the ALP
packet may be
easily extracted from the ALP packet itself without additional information.
The
maximum length of the ALP packet is 64 kB. The maximum length of a header of
the
ALP packet may be 4 bytes. The ALP packet has a length of integer bytes.
[61] The scheduler block 11200 receives an input stream including the
encapsulated
ALP packets to form physical layer pipes (PLPs) in a baseband packet form. In
the
TDM system, only one PLP called a single PLP (S-PLP) or multiple PLPs (M-PLP)
may be used. One service may not use four or more PLPs. In the LDM system
constituted by two layers, one in each layer, that is, two PLPs are used.
[62] The scheduler block 11200 receives the encapsulated ALP packets to
designate
how the encapsulated ALP packets are allocated to physical layer resources. In
detail,
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the scheduler block 11200 designates how the baseband formatting block 1130
outputs a baseband packet.
[63] A function of the scheduler block 11200 is defined by a data size and
a time. A
physical layer may transmit some of data in the distributed time. The
scheduler block
generates a solution which is suitable in terms of a configuration of a
physical layer
parameter by using inputs and information such as constraints and
configuration from
an encapsulated data packet, the quality of service metadata for the
encapsulated data
packet, a system buffer model, and system management. The solution is targets
of a
configuration and a control parameter which are usable and an aggregate
spectrum.
[64] Meanwhile, an operation of the scheduler block 11200 is constrained to
a set of
dynamic, quasi-static, and static components. Definition of the constraint may
vary
according to user implementation.
[65] Further, a maximum of four PLPs may be used with respect to each
service. A
plurality of services which include a plurality of types of interleaving
blocks may be
implemented by up to a maximum of 64 PLPs with respect to a bandwidth of 6, 7,
or
8 MHz.
[66] The baseband formatting block 11300 includes baseband packet
construction
blocks 3100, 3100-1,..., and 3100-n, baseband packet header construction
blocks
3200, 3200-1, ..., and 3200-n, and baseband packet scrambling blocks 3300,
3300-
1, ..., and 3300-n, as illustrated in FIG. 5A. In an M-PLP operation, the
baseband
formatting block generates a plurality of PLPs as necessary.
[67] The baseband packet construction blocks 3100, 3100-1, ..., and 3100-n
construct
baseband packets. Each baseband packet 3500 includes a header 3500-1 and a
payload 3500-2 as illustrated in FIG. 5B. A baseband packet is fixed to a
length
Kpayload. ALP packets 3610 to 3650 are sequentially mapped to a baseband
packet
3500. When the ALP packets 3610 to 3650 do not completely fit in the baseband
packet 3500, these packets are distributed between a current baseband packet
and a
next baseband packet. The ALP packets are distributed in a unit of a byte.
[68] The baseband packet header construction blocks 3200, 3200-1, ..., and
3200-n
construct a header 3500-1. The header 3500-1 includes three parts, that is, a
base
field (also referred to as a base header) 3710, an optional field (also
referred to as an
option header) 3720, and an extension field (also referred to as an extension
header)
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3730, as illustrated in FIG. 5B. Herein, the base field 3710 is shown in every
baseband packet and the optional field 3720 and the extension field 3730 may
not be
shown in every baseband packet.
[69] A main function of the base field 3710 provides a pointer of an offset
value as bytes
to indicate a start of a next ALP packet in a baseband packet. When an ALP
packet
starts a baseband packet, the value of the pointer becomes 0. When there is no
ALP
packet that starts in the baseband packet, the value of the pointer may be
8191 and a
base header of 2 bytes may be used.
[70] The extension field 3730 may be used afterwards and for example, used
for a
baseband packet counter, baseband packet time stamping, additional signaling,
and
the like.
[71] The baseband packet scrambling blocks 3300, 3300-1, ..., and 3000-n
scramble the
baseband packet.
[72] As in a case where payload data mapped to constellations include
repetitive
sequences, the payload data is scrambled at all times before direction error
correction
encoding, so as not to be always mapped at the same point.
[73] FIG. 6 is a block diagram illustrating a configuration of a
transmitting apparatus
600, according to an exemplary embodiment.
[74] Referring to FIG. 6, the transmitting apparatus 600 includes an LI
signaling
generator 610, a frame generator 620, and a signal processor 630.
[75] The LI signaling generator 610 generates LI signaling. The LI
signaling generator
610 corresponds to a signaling unit 15000 illustrated in FIG. 3B. Also, as
described
above, Li signaling may be encoded through an additional BICM encoder or the
BCIM encoder which is for encoding data to be serviced. In particular, the LI
signaling includes a plurality of PLPs included in a payload configuring a
frame or
information about a data symbol.
[76] In detail, the LI signaling generator 610 generates the Li signaling
including first
information and second information.
[77] Here, as described above, the LI signaling includes information about
the plurality
of PLPs included in the payload configuring the frame or information about the
data
symbol, and may include LI basic and LI detail.
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[78] Herein, the first information and the second information configuring
the Ll
signaling will be described as respectively corresponding to the Ll basic and
the L I
detail.
[79] Also, the frame generator 620 generates a frame including a payload
including a
plurality of sub frames. In detail, the frame includes a bootstrap (BS), a
preamble,
and a payload. The BS includes information for processing an OFDM symbol
included in the preamble, and the preamble includes information for processing
the
OFDM symbol included in the payload. Here, the frame generator 620 corresponds
to
a framing/interleaving block 13000 of FIG. 3B.
[80] Also, the signal processor 630 includes the preamble including the LI
signaling in
the frame and then transmits the frame including the preamble. Here, the
signal
processor 630 corresponds to a waveform generation block 14000 of FIG. 3B.
[81] In detail, a configuration of the frame will now be described in
detail.
[82] FIG. 7 is a diagram illustrating a configuration of the frame 700 that
is a base for
describing the present invention.
[83] Referring to FIG. 7, the frame 700 may be represented as a combination
of three
basic components. In detail, the frame 700 may include a BS 710 located at a
start
part of each frame, a preamble 720 located next to the BS 710, and a payload
730
located next to the preamble 720.
[84] Here, the preamble 720 includes Ll signaling to be used for processing
data
included in the payload 730.
[85] Also, the payload 730 includes at least one sub frames 730-1, ..., and
730-n. If a
plurality of sub frames exist in the payload 730, the plurality of sub frames
are
connected to one another to be arranged based on a time axis illustrated in
FIG. 7.
[86] Each of the sub frames 730-1, ..., and 730-n has a Fast Fourier
Transform (FFT)
size, a GI length, a scattered pilot pattern, and the number of effective
carriers. The
FFT size, the GI length, the scattered pilot pattern, and the number of
effective
carriers are not changed in the same sub frame. However, FFT sizes, GI
lengths,
scattered pilot patterns, and the numbers of effective carriers may be
different
between different sub frames 730-1, ..., and 730-n of the frame 700.
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[87] In particular, the BS 710 may include a sync symbol located at a
start part of each
frame to detect signals, precisely synchronize the signals with one another,
estimate a
frequency offset, and perform an initial channel estimation.
[88] Also, the BS 710 may include control signaling required for
receiving and decoding
the other parts (i.e., the preamble 720 and the payload 730) excluding the BS
710
from the frame 700.
[89] In detail, the BS 710 uses a fixed sampling rate of 6.1.44 Ms/sec
and a fixed
bandwidth of 4.5 Mhz regardless of a channel bandwidth used for the other
parts
except the BS 710.
[90] The preamble 720 includes LI basic 720-1 and LI detail 720-2. In
detail, the LI
basic 720-1 includes information about an FEC-type required for decoding the
LI
detail 720-2, the number of symbols included in the preamble 720, a length of
the LI
detail 720-2, and the like.
[91] Also, the Ll detail 720-2 includes information about the number of
sub frames 730-
1, ..., and 730-n included in the payload 730, mod/cod (modulation/code rate)
of
symbols included in each of the sub frames 730-1, ..., and 730-n, and the
like.
[92] Here, the LI basic 720-1 according to the exemplary embodiment
includes
information required for decoding a first sub frame among a plurality of sub
frames
730-1, ..., and 730-n.
[93] In contrast, the LI detail 720-2 includes information required for
decoding the other
sub frames except the first sub frame among the plurality of sub frames 730-1,
...,
and 730-n.
[94] FIG. 8 is a diagram illustrating a configuration of the frame 700 of
FIG. 7 in detail.
[95] Referring to FIG. 8, the frame 700 includes the BS 710, the preamble
720, and a
plurality of sub frames 730-1, 730-2, ... configuring the payload 730. The
preamble
720 may include one LI basic (LIB) 720-1 and one or more LI details (LID) 720-
2,
and each of the sub frames 730-1, 730-2, ... may include a plurality of data
symbols
740.
[96] Here, the LI basic 720-1 includes information required for decoding
the first sub
frame 730-1 among the plurality of sub frames 730-1, 730-2.....
[97] For example, if the first sub frame 730-1 of the plurality of sub
frames 730-1, 730-
2, ... includes 10 data symbols from PO to P9, and the second sub frame 730-2
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includes 10 data symbols from P10 to P19, the LI basic 720-1 includes
information
required for decoding 10 data symbols from PO to P9.
[98] Also, the LI detail 720-2 includes information required for decoding
the other sub
frames 730-2, ... except the first sub frames 730-1 among the plurality of sub
frames
730-1, 730-2, ....
[99] For example, if the first sub frame 730-1 among the plurality of sub
frames 730-1,
730-2, ... includes 10 data symbols from PO to P9, and the second sub frame
730-2
includes 10 data symbols from P10 to P19, the Li detail 720-2 includes
information
required for decoding 10 data symbols from P10 to P19 included in the second
sub
frame 730-2 except the first sub frame 730-1.
[100] Even if a third sub frame, a fourth sub frame, or the like exists,
the LI detail 720-2
may include information required for decoding data symbols included in the
third sub
frame, the fourth sub frame, or the like.
[101] As described above, the LI signaling generator 610 of the
transmitting apparatus
600 generates LI signaling including the LI basic 720-1 including information
required for decoding the first sub frame 730-1 among a plurality of sub
frames and
the LI detail 720-1 including information required for decoding the other sub
frames
730-2, ... except the first sub frame 730-1 among the plurality of sub frames.
If the
signal processor 630 includes a preamble including the LI signaling in a
frame, and
then, transmits the preamble to a receiver, the receiver is capable of
accelerating a
start time for decoding a payload included in the frame by using information
required
for decoding the first sub frame 730-1 among a plurality of sub frames
included in
the LI basic 720-1. This will now be described in detail with reference to
FIGS. 9
and 10.
[102] FIG. 9 is a diagram illustrating a start time for decoding a related
art payload.
[103] Referring to FIG. 9, if a receiver receives a frame including a
payload including a
BS 910, Li basic (LIB) 920, three LI details (L1Ds) 930, 940, and 950, Pl, P2,
P3,
P4....., a time corresponding to 2 symbols (BS decoding) is delayed to decode
the
BS 910 to detect information 910' for decoding the LIB 920 included in the BS
910;
and a time corresponding to 1 symbol (FFT) and 6 symbols (LIB decoding), i.e.,
7
symbols, is delayed to decode the LIB 920 to detect information 920' for
decoding
the Lllls 930, 940, and 950.
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[104] Also, to respectively decode the LIDs 930, 940, and 950 to detect
information 930',
940', and 950' for decoding payloads included in the LI Ds 930, 940, and 950.
a time
corresponding to approximately 6 symbols (first L1D decoding) is delayed to
decode
the first Li D 930, and a time corresponding to approximately a total of 2
symbols
(second LID FFT and third LID FFT) is delayed to perform FFT with respect to
the
second LID 940 and the third LID 950.
[105] Thus, when a frame is received, a receiver may start decoding the
first data symbol
PO 960 after a time, corresponding to approximately 17 symbols, which is a sum
of a
time corresponding to 2 symbols (BS decoding) delayed to decode the BS 910 to
detect information 910' for decoding the Li B 920 included in the BS 910, a
time
corresponding to I symbol (FFT) and 6 symbols (L1 basic decoding) delayed to
decode the LIB 920 to detect information 920' for decoding the LI Ds 930, 940,
and
950 included in the LIB 920, a time corresponding to 6 symbols (first L1D
decoding)
delayed for decoding the first LID 930, and a time corresponding to a total of
2
symbols (second LID FFT and third L1D FFT) delayed for performing FFT with
respect to the second LID 940 and the third LID 950. Only when all of the LI
Ds 930,
940, and 950 are completely decoded, PO decoding 960' may be completed based
on
information required for decoding the first data symbol PO 960.
[106] Therefore, the receiver may be able to start decoding a first data
symbol included in
a payload after a time corresponding to approximately 17 symbols has passed
from a
time when the frame is received.
[107] FIG. 10 is a diagram illustrating a start time for decoding a payload
according to an
exemplary embodiment.
[108] Referring to FIG. 10, a frame according to an exemplary embodiment,
for example,
includes a payload including a BS 910, LI B 920, three LI Ds 930, 940, and
950, a
first sub frame 960 including a plurality of data symbols PO 960-1, Pl, P2,
P3, P4.....
and P10 960-10, and a second sub frame 970 including a plurality of data
symbols
P11, P12, P13, ..., and P19.
[109] Here, as described above, the LIB 920 includes information for
decoding the first
sub frame 960. In detail, the LIB 920 includes information for decoding P0960-
I, Pl,
P2, P3, P4, ..., and P10 960-10 included in the first sub frame 960.
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[110] Also, if such a frame is received by a receiver, a time corresponding
to 2 symbols
(BS decoding) is delayed to decode the BS 910 to detect information 910' for
decoding the Ll B 920 included in the BS 910, and a time corresponding to 1
symbol
(FFT) and 6 symbols (L1B decoding), i.e., 7 symbols, is delayed to decode the
LIB
920 to detect information 920' for decoding LlDs 930, 940, and 950 included in
the
L I B 920 at the receiver.
[111] Here, the LIB 920 includes information for decoding the first sub
frame 960.
Therefore, if decoding of the LIB 920 is completed, and thus information for
decoding the first sub frame 960 included in the L1B 920 is detected, the
receiver
according to an exemplary embodiment may immediately start decoding the first
sub
frame 960 without waiting a process of decoding the Ll Ds 930, 940, and 950
has
been finished. That is, the receiver may perform decoding of the first sub
frame 960
without information included in the Ll Ds 930, 940, and 950, and complete PO
decoding 960-1' as illustrated in FIG. 10.
[112] As a result, referring to FIG. 10, after delaying a time,
corresponding to 9 symbols,
which is a sum of a time corresponding to 2 symbols (BS decoding) delayed to
detect
information 910' for decoding the LI B 920 included in the BS 910, and a time
corresponding to 1 symbol (FFT) and 6 symbols (LI B decoding), i.e., 7
symbols,
delayed to decode the L1B 920 to detect information 920' for decoding the Ll
Ds 930,
940, and 950 included in the Ll B 920 from a time when a frame is received,
the
receiver according to the exemplary embodiment may start decoding the first
sub
frame 960.
[113] Therefore, in comparison between FIGS. 9 and 10, the Ll B 920
according to an
exemplary embodiment may include information for decoding P0960-I, P I , P2.
P3,
P4, ..., and P10 960-10 included in the first sub frame 960 to reduce a delay
by a
time corresponding to 8 symbols in comparison with a start time for decoding a
payload of the related art, thereby accelerating a start time for decoding a
payload.
[114] In other words, according to the exemplary embodiment, a start time
for decoding a
payload may be accelerated by a time taken for performing FFT with respect to
the
LIDs 930, 940, and 950 and decoding the LlDs 930, 940, and 950.
[115] Therefore, the receiver may reduce a processing delay of a received
stream, reduce
a capacity of a memory, and easily perform a fast change such as a channel
change.
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[116] FIG. 11 is a diagram illustrating information included in Ll basic
according to an
exemplary embodiment.
[117] Referring to FIG. 11, information included in the LI basic is
information for
decoding a first sub frame. The information for decoding the first sub frame
may be
information about an FFT size of the first sub frame, a length of a guard
interval, a
Peak to Average Power Ratio (PAPR), a scattered pilot pattern, a boundary
symbol
index, the number of OFDM symbols, the number of effective carriers, and a
length
of an additional guard interval.
[118] In detail, the information included in the Ll basic may be expressed
as
FIRST_ SUB _ FFT_ SIZE, FIRST_SUB_GUARD_INTERVAL, FIRST_SUB_PAPR,
FIRST_SUB_SP_PATTERN, FIRST_SUB_SBS_FIRST, FIRST_SUB_SBS_LAST,
FIRST_SUB_OFDM_SYMBOL, FIRST_SUB_NOC, and
FIRST_ SUB _EXCESS CP.
[119] Here, FIRST_SUB_FFT_SIZE refers to the FFT size of the first sub
frame,
FIRST_SUB_GUARD_INTERVAL refers to the length of the guard interval inserted
into the first sub frame, FIRST_SUB_PAPR refers to the PAPR of the first sub
frame,
FIRST_ SUB _ SP _PATTERN refers to the scattered pilot pattern inserted into
the first
sub frame, FIRST_SUB_SBS_FIRST refers to a boundary symbol index inserted into
a start end of the first sub frame, FIRST_SUB_SBS LAST refers to a boundary
symbol index inserted into a last end of the first sub frame,
FIRST_SUB_OFDM_SYMBOL refers to the number of OFDM symbols inserted
into the first sub frame, FIRST_SUB_NOC refers to the number of effective
carriers
of the first sub frame, and FIRST_SUB_EXCESS_CP refers to the length of the
additional guard interval inserted into the first sub frame.
[120] FIG. 12 is a block diagram illustrating a configuration of a
receiving apparatus
2000 according to an exemplary embodiment.
[121] Referring to FIG. 12, the receiving apparatus 2000 includes a
receiver 2100 and a
signal processor 2200.
[122] The receiver 2100 receives a frame including a preamble including Ll
signaling
including Li basic and Li detail and a payload including a plurality of sub
frames. A
detailed configuration of the frame has been described with reference to FIG.
7, and
thus a detailed description thereof is omitted.
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[123] Also, the signal processor 2200 signal-processes the frame.
[124] Here, the Li basic may include information required for decoding a
first sub frame
among the plurality of sub frames, and the signal processor 2200 may decode
the first
sub frame based on the information included in the LI basic and decode the LI
detail
in parallel.
[125] In detail, as described above with reference to FIG. 10, the signal
processor 2200
may start decoding the first sub frame 960 based on the information 920'
included in
the LIB 920, decode the first sub frame 960, and decode the LI Ds 930, 940,
and 950
in parallel with the decoding of the first sub frame 960.
[126] Also, the signal processor 2200 completes the decoding of the first
sub frame and
then decodes the other sub frames except the first sub frame based on the
decoded LI
detail.
[127] For example, as described above with reference to FIG. 10, the signal
processor
2200 may decode the first sub frame 960 based on the information 920' included
in
the LIB 920 and decode the LI Ds 930, 940, and 950 in parallel with the
decoding of
the first sub frame 960. Just when the decoding of the first sub frame 960 is
completed, the decoding of the LI Ds 930, 940, and 950 is completed.
Therefore, after
the decoding of the first sub frame 960 is completed, the signal processor
2200 may
start decoding of the other sub frame 970.
[128] Therefore, the signal processor 2200 according to the exemplary
embodiment may
accelerate a decoding start time of a payload as described above.
[129] FIG. 13 is a block diagram provided to explain in detail a signal
processor
according to an exemplary embodiment.
[130] Referring to FIG. 13, the signal processor 2200 includes a
demodulator 2210, a
signal decoder 2220, and a stream generator 2230.
[131] The demodulator 2210 performs demodulation according to OFDM
parameters
from received RF signals, performs sync-detection, and recognizes whether a
currently received frame includes necessary service data when the sync is
detected
from signaling information stored in a sync area. For example, the demodulator
831
may recognize whether a mobile frame for a mobile receiver is received or a
fixed
frame for a fixed receiver is received.
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[132] In this case, if OFDM parameters are not previously determined
regarding a
signaling area and a data area, the demodulator 2210 may perform demodulation
by
obtaining OFDM parameters regarding the signaling area and the data area
stored in
the sync area, and obtaining information about OFDM parameters regarding the
signaling area and the data area which are disposed right after the sync area.
[133] The signal decoder 2220 performs decoding of necessary data. In this
case, the
signal decoder 2220 may perform decoding by obtaining parameters of an FEC
method and a modulating method regarding the data stored in each data area
based on
the signaling information. Further, the signal decoder 2220 may calculate
positions of
necessary data based on the data information included in a configurable field
and a
dynamic field. Thus, it may calculate which positions of the frame a requested
PLP is
transmitted.
[134] The stream generator 2230 may generate data to be served by
processing a
baseband packet input from the signal decoder 2220.
[135] For example, the stream generator 2230 may generate an ALP packet
from the
baseband packet in which errors are corrected based on an ISSY mode, buffer
size
(BUFS), time to output (TTO) values, and input stream clock reference (ISCR)
values.
[136] Specifically, the stream generator 2230 may include de-jitter
buffers. The de-jitter
buffers may regenerate correct timing to restore an output stream based on the
ISSY
mode, BUFS, TTO values, and ISCR values. Thereby, a delay for sync between a
plurality of PLPs may be compensated.
[137] FIG. 14 is a block diagram of a receiving apparatus 4400 according to
an
exemplary embodiment.
[138] Referring to FIG. 14, the receiving apparatus 4400 may include a
controller 4410,
an RF receiver 4420, a demodulator 4430, and a service player 4440.
[139] The controller 4410 determines an RF channel and a PLP in which a
selected
service is transmitted. At this process, the RF channel may be defined by a
center
frequency and a bandwidth, and the PLP may be defined by a PLP identifier
(ID).
Certain services may be transmitted through more than one PLP belonging to
more
than one RF channel per component constituting services. However, it is
assumed in
the following descriptions that all data required for playing one service is
transmitted
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through one PLP with one RF channel for convenient explanation. Thus, services
are
provided with a unique data obtaining path to play services, and the data
obtaining
path is specified by an RF channel and a PLP.
[140] The RF receiver 4420 extracts RF signals from a selected RF channel
by the
controller 4410, and delivers OFDM symbols, extracted by performing signal-
processing of the RF signals, to the demodulator 4430. The signal processing
may
include synchronization, channel estimation, and equalization. Information
required
for the signal-processing is predetermined between a transmitting apparatus
and the
receiving apparatuses or transmitted to the receiving apparatus in a
predetermined
OFDM symbols among the OFDM symbols.
[141] The demodulator 4430 extracts a user packet by performing signal-
processing of
the OFDM symbols, and delivers the user packet to the service player 4440. The
service player 4440 plays and outputs the service selected by a user with the
user
packet. A format of the user packet may be different according to implementing
services. For example, a TS packet or an IPv4 packet may be the user packet.
[142] FIG. 15 is a block diagram describing the demodulator 4430 of FIG.
14, according
to an exemplary embodiment.
[143] Referring to FIG. 15, the demodulator 4430 may include a frame
demapper 4431, a
BICM decoder 4432 for LI signaling, a controller 4433, a BICM decoder 4434,
and
an output processor 4435.
[144] The frame demapper 4431 selects OFDM cells constituting FEC blocks
belonging
to a selected PLP from a frame constituted with OFDM symbols based on
controlling
information delivered from the controller 4433, and delivers the OFDM cells to
the
decoder 4434. Further, the frame demapper 4431 selects OFDM cells
corresponding
to more than one FEC block included in the LI signaling, and delivers the OFDM
cells to BICM decoder 4432 for the LI signaling.
[145] The BICM decoder 4432 for the LI signaling signal-processes the OFDM
cells
corresponding to the FEC blocks belonging to the LI signaling, extracts LI
signaling
bits, and delivers the LI signaling bits to the controller 4433. In this case,
the signal-
processing may include extracting log-likelihood ratio (LLR) values for
decoding low
density parity check (LDPC) codes in OFDM cells, and decoding the LDPC codes
by
using the extracted LLR values.
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[146] The controller 4433 extracts an Ll signaling table from the Ll
signaling bits, and
controls operations of the frame demapper 4431, the BICM decoder 4434, and the
output processor 4435 by using values of the Ll signaling table. FIG. 15
illustrates
that the BICM decoder 4432 for the LI signaling does not use controlling
information of the controller 4433 for convenient explanation. However, if the
Li
signaling includes a layer structure similar to Li pre-signaling and Ll post-
signaling
described above, the BICM decoder 4432 for the 1,1 signaling may be
constituted
with more than one BICM decoding block, and operations of the BICM decoding
blocks and the frame demapper 4431 may be controlled based on upper-layer LI
signaling information, as clearly understood in the above description.
[147] The BICM decoder 4434 signal-processes the OFDM cells constituting
FEC blocks
belonging to the selected PLP, extracts baseband packets, and delivers the
baseband
packets to the output processor 4435. The signal-processing may include
extracting
LLR values for coding and decoding LDPC codes in OFDM cells, and decoding the
LDPC codes by using the extracted LLR values. These two operations may be
performed based on the controlling information delivered from the controller
4433.
[148] The output processor 4435 signal-processes the baseband packets,
extracts a user
packet, and delivers the extracted user packet to the service player. In this
case, the
signal-processing may be performed based on the controlling information
delivered
from the controller 4433.
[149] According to an exemplary embodiment, the output processor 1235 may
include an
ALP packet processor (not illustrated) which extracts an ALP packet from a
baseband
packet.
[150] FIG. 16 is a flowchart provided to briefly explain an operation of a
receiving
apparatus from a time point when a user selects a service to a time point when
the
selected service is played.
[151] It is assumed that service information about all services that may be
selected at an
initial scan process of S4600 is obtained prior to a service select process at
S4610.
The service information may include information about an RF channel and a PLP
which transmits data required for playing a specific service in a current
broadcasting
system. One example of the service information may be Program-Specific
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Information/Service Information (PSI/SI) of an MPEG-2 TS, which may be usually
obtained through L2 signaling and upper layer signaling.
[152] When a user selects a service at S4610, the receiving apparatus
modifies a
frequency transmitting the selected service at S4620, and performs extracting
RF
signals at S4630. While performing S4620 modifying the frequency transmitting
the
selected service, the service information may be used.
[153] When the RF signals are extracted, the receiver performs S4640
extracting LI
signaling from the extracted RF signals. "[he receiving apparatus selects the
PLP
transmitting the selected service by using the extracted LI signaling at
S4650, and
extracts baseband packets from the selected PLP at S4660. At S4650 selecting
the
PLP transmitting the selected service, the service information may be used.
[154] Further, S4660 extracting the baseband packets may include selecting
OFDM cells
belonging to the PLP by demapping a transmission frame, extracting LLR values
for
coding/decoding LDPC, and decoding LDPC codes by using the extracted LLR
values.
[155] The receiving apparatus performs S4670 extracting an ALP packet from
the
extracted baseband packet by using header information about the extracted
baseband
packet, and performs S4680 extracting a user packet from the extracted ALP
packet
by using header information about the extracted baseband packet. The extracted
user
packet is used in S4690 playing the selected service. At S4670 extracting the
ALP
packet and at S4680 extracting the user packet, Li signaling information
obtained at
S4640 extracting the Li signaling may be used. In this case, a process of
extracting
the user packet from the ALP packet (restoring null TS packet and inserting a
TS
sync byte) is the same as described above. According to the exemplary
embodiments
as described above, various types of data may be mapped to a transmittable
physical
layer, and data processing efficiency may be improved.
[156] FIG. 17 is a flowchart illustrating a method of controlling a
transmitting apparatus,
according to an exemplary embodiment.
[157] Referring to FIG. 17, in operation S1710, LI signaling including LI
basic and LI
detail is generated.
[158] In operation S1720, a frame including a payload including a plurality
of sub frames
is generated.
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[159] In operation S1730, a preamble including the Li signaling is included
in the frame,
and then the frame is transmitted.
[160] Here, the Li basic includes information for decoding a first sub
frame of a plurality
of sub frames.
[161] Also, the Li detail includes information for decoding the other sub
frames except
the first sub frame.
[162] The information for decoding the first sub frame includes information
about an FFT
size of the first sub frame, a length of a guard interval, a PA PR, a
scattered pilot
pattern, a boundary symbol index, the number of OFDM symbols, the number of
effective carriers, and a length of an additional guard interval.
[163] FIG. 18 is a flowchart illustrating a method of controlling a
receiving apparatus,
according to an exemplary embodiment.
[164] Referring to FIG. 18, in operation S1810, the receiving apparatus
receives a frame
including a preamble including Ll signaling including Ll basic and Li detail
and a
payload including a plurality of sub frames.
[165] In operation S1820, the receiving apparatus signal-processes the
frame.
[166] Here, the signal-processing operation decodes the first sub frame
based on the
information included in the LI basic and decodes the Li detail in parallel
with the
decoding of the first sub frame.
[167] Also, the method of controlling the receiving apparatus may further
include
completing the decoding of the first sub frame and then decoding the other sub
frames except the first sub frame based on the decoded Li detail.
[168] There may be provided a non-transitory computer readable medium that
stores a
program sequentially performing a signal processing method.
[169] The non-transitory computer readable medium is a medium which does
not store
data temporarily such as a register, cash, and memory but stores data semi-
permanently and is readable by devices. More specifically, the aforementioned
applications or programs may be stored in the non-transitory computer readable
media such as compact disks (CDs), digital video disks (DVDs), hard disks, Blu-
ray
disks, universal serial buses (USBs), memory cards, and read-only memory
(ROM).
[170] At least one of the components, elements, modules or units
represented by a block
as illustrated in FIGs. 2 and 6-12 may be embodied as various numbers of
hardware,
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software and/or firmware structures that execute respective functions
described above,
according to an exemplary embodiment. For example, at least one of these
components, elements, modules or units may use a direct circuit structure,
such as a
memory, a processor, a logic circuit, a look-up table, etc. that may execute
the
respective functions through controls of one or more microprocessors or other
control
apparatuses. Also, at least one of these components, elements, modules or
units may
be specifically embodied by a module, a program, or a part of code, which
contains
one or more executable instructions for performing specified logic functions,
and
executed by one or more microprocessors or other control apparatuses. Also, at
least
one of these components, elements, modules or units may further include or may
be
implemented by a processor such as a central processing unit (CPU) that
performs the
respective functions, a microprocessor, or the like. Two or more of these
components,
elements, modules or units may be combined into one single component, element,
module or unit which performs all operations or functions of the combined two
or
more components, elements, modules or units. Also, at least part of functions
of at
least one of these components, elements, modules or units may be performed by
another of these components, elements, modules or units. Further, although a
bus is
not illustrated in the above block diagrams, communication between the
components,
elements, modules or units may be performed through the bus. Functional
aspects of
the above exemplary embodiments may be implemented in algorithms that execute
on one or more processors. Furthermore, the components, elements, modules or
units
represented by a block or processing steps may employ any number of related
art
techniques for electronics configuration, signal processing and/or control,
data
processing and the like.
[171] The foregoing exemplary embodiments and advantages are merely
exemplary and
are not to be construed as limiting the inventive concept. The inventive
concept can
be readily applied to other types of apparatuses. Also, the description of the
exemplary embodiments is intended to be illustrative, and not to limit the
scope of
the claims, and many alternatives, modifications, and variations will be
apparent to
those skilled in the art.
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