Note: Descriptions are shown in the official language in which they were submitted.
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Wireless and xDSL Residential Gateway and System
by
Thomas R. Eames
225 John Roberts Drive
Cotati, CA 94931
Cross Reference to Related Application
This application claims priority to provisional
application No. 60/142,778, filed July 8, 1999, the
entirety of which is incorporated herein by reference.
Background of the Invention
A number of different types of distribution systems
are utilized for transporting video signals to residences
including over-the-air-broadcasting, cable television
systems (also known as Community Access Television (CATV)
systems), wireless distribution systems including
Multichannel Microwave Distribution Systems (MMDS) and
Local Microwave Distribution Systems (LMDS), and Direct
Broadcast Systems (DBS) which are based on satellite
transmissions. These systems are broadcast in nature since
they transmit a number of channels to groups of
subscribers, with the channel selection being performed
locally at the subscriber television or television set-top
box. Broadcast systems have the advantage that they can
provide a large number of channels to a large number of
subscribers at the relatively low cost. The drawback of
broadcast systems is that although some broadcast systems
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can provide a substantial number of video selections, they
are ultimately limited in the number of channels which can
be transported.
DBS systems have another drawback in that they cannot
easily provide access to local television channels.
Transmitting local channels through the satellite would
involve sending the local stations to a set of subscribers
which is much larger than those in the local broadcast
area. Transmitting all of the local stations through the
satellite would require much more bandwidth than is
available in the satellite transponder.
Alternate architectures for the delivery of video
programming include Switched Digital Video (SDV)
architectures in which the subscriber channel selection is
transmitted to a central switching location, and an
individual channel is transmitted to the subscriber. The
SDV architecture has the advantage that any channel can be
provided to the subscriber, thus providing potentially
unlimited video selections.
One difficulty in implementing an SDV architecture is
that a high-speed digital connection to the subscriber
residence is required. Developments in digital
transmission technology allow high-speed data signals to be
transmitted over twisted wire pairs, either directly from a
telephone central office, or from a terminal in the
neighborhood. This technology, generically called Digital
Subscriber Line (DSL), allows for transmission at data
rates of up to an exceeding 25 Mb/s, but the transmission
rate which is achievable is heavily dependent on the length
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of the twisted wire pairs. Many DSL connections only
support data rates in the range of 5-7 Mb/s, and only
permit the transmission of a single, Standard Definition
Digital Television (SDTV) channel. This precludes
simultaneous reception of multiple channels at the home, as
well as the reception of multiple channels at the home, as
well as the reception of High Definition Television (HDTV)
signals.
For the foregoing reasons, there is a need for a video
transmission system and apparatus that supports SDV
functionality while simultaneously utilizing the benefits
of broadcast technology.
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Suamnary of the Invention
In the present invention broadcast signals are
received from a satellite, wireless, or other broadcast
source at a gateway device located in the residence. The
gateway device also has a connection to a twisted wire
pair, coaxial cable, or other transmission medium which
supports switched digital video services. Upon receiving a
channel request, the gateway determines if that channel is
available in the broadcast stream or if it must be
requested for transmission over the SDV network. In a
preferred embodiment, an authorization request is sent from
the gateway to a centralized control unit to determine if
the subscriber has authorization to receive the channel.
If the channel is available on the broadcast stream, the
gateway is sent an authorization message to permit decoding
the channel at the gateway for presentation to the
subscriber. If the channel is not available from the
broadcast stream, a request is made for the channel from
the SDV network, and the channel is transmitted over the
SDV transmission path.
In a preferred embodiment the DSL transmission system
is an Asymmetric Digital Subscriber Line (ADSL) connection
which supports data rates of up to 6 Mb/s over loop lengths
of 12,000 ft. This permits the ADSL modems to be located
in the telephone company central office or in an access
terminal which is remote from the neighborhood. Other DSL
systems include Very High-Speed Digital Subscriber Loop
(VDSL) transmission. Various DSL systems are often
collectively referred to as "xDSL."
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An advantage of the present invention is that local
channels can be provided over the SDV network, with
broadcast channels provided via satellite. This coupling
of the SDV network with the satellite distribution system
solves the long-standing issue of how to provide local
channels in DBS systems. Another benefit of this
architecture is that it does not burden the SDV system with
broadcast channels (such as popular network programming)
which can be readily provided by the satellite system. Yet
another advantage is that multiple channels can be
simultaneously received using the hybrid satellite/SDV
system, as opposed to a stand-alone SDV system using ADSL,
which has bandwidth limitations due to the use of twisted
wire pairs.
In the present system HDTV signals can be provided via
the satellite system, where a number of premium channels
can be broadcast in HDTV format. The DSL system is not
burdened with providing HDTV signals.
In an alternate embodiment the DSL system is HDTV
capable and HDTV signals can be received over the broadcast
or SDV network.
In the present invention data and telephone services
can be provided in conjunction with the broadcast video
system by using the SDV platform and associated telephone
plant for voice and data, while receiving broadcast signals
over the satellite, wireless, or cable network. This
allows display of data on the television without requiring
a two-way broadcast network. Low data rate DSL systems
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such as G.lite can be utilized for data services while
receiving video over the broadcast network.
In a preferred embodiment, the SDV system supports
channel authorizations, software downloads to the gateway,
and other data centric functions, freeing the broadcast
network from these requirements. This allows a simplified
security system to be utilized at the gateway, since
channel changes are authorized in the SDV system at a
centralized location.
In an alternate embodiment the gateway determines if
the requested channel is present in the broadcast stream
and obtains authorization locally at the gateway. This
allows use of a traditional satellite or wireless security
system.
Another feature of the present invention is that
bandwidth demands are reduced throughout the entire SDV
system including switching elements and fiber optic
transport, since many of the channels selected are
available from the broadcast stream.
In a preferred embodiment the present invention is
realized as a gateway processor on a single integrated
circuit which supports processing of multiple digital video
channels, independent of the media over which the signal is
received.
Another feature of the present invention is the
ability to distribute video signals from a gateway device
to remote receivers using existing in-home twisted wire
pairs. This permits transmission of signals to remote
devices without requiring the rewiring of the home.
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These and other features and objects of the invention
will be more fully understood from the following detailed
description of the preferred embodiments that should be
read in light of the accompanying drawings.
Brief Description of the Drawings
The accompanying drawings, which are incorporated in
and form a part of the specification, illustrate the
embodiments of the present invention and, together with the
description serve to explain the principles of the
invention.
In the drawings:
FIG. 1 illustrates a wireless and xDSL residential
gateway and system;
FIG 2. is a use case diagram illustrating the
functionality of the wireless and xDSL residential gateway;
FIG. 3 is a use case diagram illustrating the
functionality of the wireless and xDSL control system;
FIG. 4 illustrates a sequence diagram for channel
authorization in a wireless and xDSL residential gateway;
FIG. 5 illustrates an architecture for a wireless and
xDSL residential gateway;
FIG. 6 illustrates an architecture for a flexible
media gateway device; and
FIG. 7 illustrates an in-home distribution system
using a wireless and xDSL residential gateway with
distributed receiving devices.
Detailed Description of the Preferred Embodiment
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In describing a preferred embodiment of the invention
illustrated in the drawings, specific terminology will be
used for the sake of clarity. However, the invention is
not intended to be limited to the specific terms so
selected, and it is to be understood that each specific
term includes all technical equivalents that operate in a
similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and FIGS.
1 through 7 in particular, the apparatus of the present
invention is disclosed.
FIG. 1 illustrates one embodiment of the present
invention in which a DSL system is used in conjunction with
a satellite transmission system. Although the broadcast
system of FIG. 1 is a satellite based system, the invention
is not limited to satellite based broadcasts but can be
used with a variety of broadcast systems including over-
the-air transmission systems, MMDS or LMDS wireless
networks, cable networks, or any other broadcast system in
which multiple channels are simultaneously transmitted to a
plurality of subscribers.
In FIG. 1 satellite 192 transmits a signal which is
received by residence 100 using a satellite/wireless
antenna 120. A switched digital network is also in place
and is comprised of a Broadband Digital Terminal (BDT) 166,
which receives signals from an ATM network 172 through a
broadband interface 176, as well as receiving telephone
signals from a Public Switched Telephone Network (PSTN) 174
through a narrowband interface 178. In one embodiment the
BDT 166 is connected to a remotely located Universal
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Service Access Multiplexer (USAM) via an optional fiber
144. USAM 140 contains a Very High-Speed Digital
Subscriber Line (VDSL) modem 142 which connects to a
residence via outside plant twisted wire pairs 150. In
this embodiment the VDSL modem 142 supports data rates up
to an exceeding 25 Mb/s over loop lengths of up to 3,000
ft. The BDT 166 is capable of supporting multiple USAMs
140 using a plurality of optical fibers 144 or using a
passive optical network. USAM 140 supports a plurality of
subscriber connections and can accommodate multiple VDSL
models 142.
The switched digital network illustrated in FIG. 1 is
capable of providing voice, video and data services to
residence 100. In providing telephone services calls are
received via PSTN 174 at BDT 166 and are transmitted to CO
USAM 160 and through ADSL model 162 to residence 100. In a
preferred embodiment ADSL modem 162 contains circuitry for
generating an analog voice signal which is transmitted over
outside plant twisted wire pairs 150 and which his received
at NID 122 which separates out the voice signal and
transmits it to telephone 104. Data services are received
via ATM network 172 and are transmitted from BDT 166 to CO
USAM 160 through ADSL model 162 over outside plant twisted
wire pairs 150 and to a getaway 110 located in residence
100. Gateway 110 provides an interface to computer 114 via
a gateway-computer connection 116 which in a preferred
embodiment is Ethernet over twisted wire pairs. In this
way data services are provided to the residence.
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In the embodiment illustrated in FIG. 1 switched
digital services are provided directly from the central
office 130 to the residence 100 by an Asymmetric Digital
Subscriber Line (ADSL) modem 162 which is connected to a
Network Interface Device (NID) 122 at residence 100 via
outside plant twisted wire pairs 150. ADSL modem 162 is
located in a Central Office USAM (CO USAM) 160 which is
connected to BDT 166 via a BDT-CO USAM connection 180.
Central office 130 also contains an off-air antenna 190
which receives the over-the-air broadcasts including local
television channels. In alternate embodiments the local
programming is received at central office 130 via another
type of wireless connection, through a data network, or via
ATM network 172. As shown in FIG. 1 signals received from
the off-air antenna 190 are transmitted to an off-air
receiver/decoder 170 which converts the analog signals to
digital signals. In a preferred embodiment the off-air
signals are converted to Motion Pictures Expert Group
(MPEG) packets contained in an ATM transport stream.
Video services can be provide over the switched
digital network by receiving video programming either from
off-air receiver/decoder 170 or through ATM network 172 at
BDT 166. BDT 166 switches packets or cells containing
video to CO USAM 160 which transmits the requested video
channel over outside plant twisted wire pairs 150 to
gateway 110 through NID 122 and over in-home twisted wire
pairs 112.
Gateway 110 is capable of providing video to one or
more televisions and provides video programming to a first
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television 106 through a gateway to first television
connection 128. In a preferred embodiment the gateway to
first TV connection is an S-video connection operating over
an S-video cable. Gateway 110 is also capable of providing
video signals to other televisions, such as a second
television 108 and can do so via a gateway-splitter
connection 126, splitter 124 and splitter to second
television connection 127. A gateway which supports
multiple analog televisions from one received digital
stream is described in detail in US Patent Application
09/026,036 entitled "Video, Data and Telephone Gateway," of
which Thomas Eames and Charles Eldering are the inventors,
which is incorporated herein by reference.
Although the switched digital network illustrated in
FIG. 1 is based on the use of twisted wire pair connections
the invention is not limited to the use of a DSL based
switched digital platform. When used herein the term
switched digital refers to any type of local loop
communications system in which video or data services are
switched at a centralized location rather than being
broadcast simultaneously to a plurality of subscribers.
Switched digital platforms can be based on Fiber-to-the
Curb (FTTC), Fiber-to-the-Home (FTTH) or other types of
networks and can include coaxial, fiber-optic or other type
of connections to residence 100. Switched digital networks
are well understood by those skilled in the art.
In operation the system illustrated in FIG. 1 allows
the reception of a plurality of broadcast channels at
gateway 110 from the satellite/wireless antenna 120 via a
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satellite/wireless receiver connection 118. In a preferred
embodiment the satellite/wireless receiver connection 118
is a coaxial cable running from satellite/wireless antenna
120 to gateway 110.
Depending on the bandwidth provided by the DSL
connection in the switched digital platform data or data
and video services are available to gateway 110. In an
ADSL system operating at 6 Mb/s a limited number of video
channels can be transported simultaneously over the DSL
system. By providing access to broadcast programming
simultaneously with access to switched digital programming
the user can access either type of channels through gateway
110.
In operation a user selects a channel at residence
100, with the request being transmitted to gateway 110 via
an infrared, wireless, or coaxial signal originating from a
remote control. Methods for transmitting channel
selections to a gateway is described in detail in US Patent
Application 09/525,488 entitled "Method and Apparatus for
Transmitting Wireless Signals Over Media" and US Patent
Application 09/526,100 entitled "Optical Conversion
Device", which are both incorporated herein by reference.
Gateway 110 determines if that channel is part of the
broadcast lineup or needs to be requested from the switched
digital platform. In a preferred embodiment the channel
request is transmitted over the DSL connection to BDT 166
which contains software capable of authorizing or denying
the subscriber channel request. In addition to authorizing
or denying the subscriber request the BDT 166 can determine
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if the channel is already being received over ATM network
172, or if it must be requested from a video server. BDT
166 is capable of receiving a plurality of broadcast
channels via ATM network 172 but may also request
specialized programs in support of Video on Demand (VoD)
services. In this way the subscriber has access to both
broadcast and switched digital programming and can
simultaneously receive broadcast channels and one or more
switched digital channels.
In an alternate embodiment gateway 110 can determine
if a selected channel is part of the broadcast lineup, and
has authority to grant access to that channel locally
without transmitting the channel request to BDT 166. In
this embodiment traditional satellite based security can be
utilized to prevent unauthorized access to satellite or
other broadcast services. The security systems are based
on the use of transmitted keys which prevent gateway 110
from decoding unauthorized services. Security systems for
broadcast entertainment services are well known to those
skilled in the art.
FIG. 2 illustrates a use case diagram for a wireless
xDSL gateway such as gateway 110 illustrated in FIG. 1.
Use case diagrams are part of the Unified Modeling Language
(UML) and are useful in describing systems, software, and
methods of doing business. As shown in FIG. 2, a customer
200 interacts with this system which contains a receive
channel request function 218, a determine channel source
function 220, and a decoding and present channel function
222. The system also contains a demodulated
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satellite/wireless signal function 210 which is capable of
receiving and demodulating broadcast signals provided by a
satellite/wireless service provider 204. An xDSL service
provider 208 interacts with a request channel authorization
function 212 and a receive channel authorization function
214 for controlling which channels customer 200 is
authorized access to receive. The wireless xDSL gateway
system also contains a demodulate xDSL signal function 216.
FIG. 3 illustrates a use case diagram for a wireless
and xDSL control system. The wireless and xDSL control
system is the system and software which provides the entire
service functionality to customer 200. In a preferred
embodiment the wireless and xDSL control system is
distributed between gateway 110 and BDT 166. The wireless
and xDSL control system contains a generate authorization
tables function 316 which contains information relating to
which channels customer 200 is entitled to receive. This
information is frequently referred to as entitlement
information. The wireless and xDSL control system also
contains a receive channel request function 318, a transmit
authorization function 320, and a transmit channel function
322. The transmit channel function 322 transmits the
requested channel over the xDSL or other switched digital
platform to customer 200.
The wireless and xDSL control system also contains a
receive satellite/wireless channel lineup function 310
which enables satellite wireless service provider 204 to
transmit information regarding the broadcast channel
lineup. A receive xDSL channel lineup function 312
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receives a channel lineup from xDSL service provider 208
and contains the channels or video server access which are
provided by the switched digital system. A billing entity
300 can also communicate with a receive billing records
function 314 which indicates if a customer has been paying
for a service and can continue to receive a particular
channel or lineup of channels.
FIG. 4 illustrates a sequence diagram useful for
understanding the authorization sequence for the wireless
and xDSL gateway system. As shown in FIG. 4 a remote
control object entitled Remote:Tx 400 transmits a channel
change request message tx(c) 450 for channel c to a remote
control receive object Remote:Rx 410. Remote control
receive object Remote:Rx 410 is located in gateway 110 and
sends a gateway channel change request message tx(c) 452 to
a source object Source 420 in gateway 110 which is capable
of determining if the channel change request is for a
broadcast channel available locally or is for a channel
which must be delivered through the switched digital
platform. Source 420 transmits a request local channel
message requestL(c) 454 to an authorization gateway object
Authorization:GV~1 430 which can return an authorization
authorizeL(c) message 456 which permits the gateway 110 to
decode and present the channel to the subscriber.
If the channel is not part of the broadcast lineup a
request remote message requestR(c) 458 is sent to an
authorization object in the BDT entitled Authorization:BDT
440. Authorization:BDT 440 can return an authorize remote
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channel authorization signal in an authorizeR(c) message
460.
FIG. 5 illustrates an architecture for a preferred
embodiment of a wireless/xDSL residential gateway. As
shown in FIG. 5 the wireless/xDSL gateway has an input for
broadcast signals which may be received in a direct
broadcast satellite/digital video broadcast (DBS/DVB)
format, LMDS format, or other broadcast format. The
signals are received at a DBS triple tuner 510 which is
capable of tuning three separate frequency segments in the
broadcast spectrum. The output of DBS triple tuner 510 is
received by the DBS/LMDS/DVB format processor 512 which is
capable of receiving digital video in DBS/LMDS/DVB formats.
The output of DBS/LMDS/DVB format processor 512 is received
by an MPEG buffer 516 which stores digital video MPEG
packets until they can be decoded by MPEG decoder 530,
which is capable of supporting audio and video decoding.
The output of MPEG decoder 530 is received by an
audio/video input/output modulation device 534, which is
capable of presenting the video in a variety of formats
including RF modulated onto a known channel (e. g. channel
3), an National Television Standards Committee (NTSC)
baseband signal, or an S video signal. Audio/video input
output modulation device 534 can also generate audio
baseband signals and other specialized video and audio
output formats.
Data and graphics can also be received by DBS triple
tuner 510 and are processed by a Reduced Instruction Set
Computer (RISC) CPU 518 and subsequently processed by a
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graphics accelerator RISC engine 520. Graphics and data
signals are then sent to a graphics control device 532 and
passed on to the audio/video input/output modulator device
534 for presentation on the television or monitor.
The wireless/xDSL residential gateway depicted in FIG.
5 also receives xDSL signals from a twisted wire pair
connection at xDSL processor 514. The xDSL processor 514
can support cell reception in a variety of standardized
formats including G.lite, ADSL, and VDSL. The xDSL
processor 514 also contains an Asynchronous Transfer Mode
Segmentation And Reassembly (ATM SAR) processor which
allows for reconstruction of MPEG packets from the ATM
based xDSL signal. Although xDSL processor 514 has been
described as being based on standardized xDSL transmission
schemes, nonstandardized transmission formats can also be
utilized for transmission and reception of the xDSL signal,
and can be supported by specialized versions of xDSL
processor 514. As was the case for data and graphics
received over the broadcast channel, data and graphics
received over the xDSL line can be processed by the main
RISC CPU 518 and the graphics accelerator RISC engine 520.
The receivers, format processors, MPEG buffer 516 main
RISC CPU 518, and graphics accelerator RISC engine 520 are
all connected to an I/O control CPU 522 which supports
communication of gateway 110 with a variety of external
devices including derived Plain Old Telephony services
(POTS) devices which can provide analog telephony signals,
lOBaseT/Home Network Interface (HNI) connection, Universal
Serial Bus (USB), smart card, IDE or SCSI hard drive
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interfaces, Firewire (IEEE 1394), a front panel, IR
blaster, other devices known to one of skill in the art and
a wireless, infrared, or wired remote control. In
addition, a memory control until 524 is connected to the
various subsystems in the wireless/xDSL residential gateway
and supports use of a PCI card through a PCI bus.
As shown in FIG. 5, a plurality of MPEG decoders 530,
graphics control devices 532, and audio/video input/output
modulation devices 534 can be supported in the
wireless/xDSL residential gateway. In this way multiple
televisions in the residence can be supported from a
reception of a broadcast stream, a switched video stream,
or combination of the two. As shown in FIG. 5 not all of
the video formats need to be supported from the audio/video
input/output modulator device 534 and as a cost savings
measure some of the video modules may only support a
limited subset of interfaces.
In an alternate embodiment an FTTC system delivers
video signals across a coaxial cable which does not use an
xDSL format. In this case xDSL processor 514 is replaced
by a FTTC processor. Similarly, other types of input
processors can be used to support FTTH or other local loop
switched network architectures.
FIG. 6 illustrates a preferred embodiment of a gateway
device in the form of an integrated circuit gateway
processor (ICGP) 680 which can be used to realize many of
the function of the wireless/xDSL residential gateway shown
in FIG. 5. One of the advantages of the integrated circuit
gateway processor 680 shown in FIG. 6 is that it can
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provide the core functions for video and graphics
processing, independent of the external media and
transmission/reception technique. As shown in FIG. 6
external media dependent devices 690 can be utilized to
receive DVB, DBS, (or other xDSL) cable signals in the form
of digital cable signals or according to the Data Over
Cable System Interface Specification (DOCSIS), or MMDS/LMDS
signals. In a preferred embodiment the signals are
received over a standardized interface such as an ATM
UTOPIA interface 624 or a DOCSIS interface 622.
The ICGP 680 supports video functions by receiving a
demodulated signal containing MPEG packets, and decoding
the MPEG packets in an MPEG/ACTV decoder 608. MPEG/ACTV
decoder support a variety of digital video formats
including all of the standard definition and high
definition formats specified by the Advanced Television
Systems Committee (ATSC). The audio is processed in an
MPEG/AC-3 audio processor 610 and the graphics are
processed in a graphics engine 612. An integratable analog
system 606 supports the final conversion to an analog
signal. This analog signal is broadcast to the primary TV
through a primary TV interface subsystem 600. For the
second and third televisions an auxiliary TV1 interface
subsystem 602 and an auxiliary TV2 interface subsystem 604
are utilized. In this way a number of analog televisions
can be supported from one received digital video stream as
previously described.
ICGP 680 utilizes a RISC engine 620 in conjunction
with a RISC SAR 630 to process ATM cells containing MPEG
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packets. If the external media dependent devices 690
produce an MPEG stream as output, the stream is processed
directly by RISC engine 620. RISC engine 620 passes on the
MPEG cells for decoding by one of the MPEG decoders 608.
ICGP 680 supports an interface to a remote control device
through a remote control interface processor 650 which is
connection to an IR interface 652 or a UHF interface 654.
External receivers for the reception of the IR or radio
frequency radiation are used to convert the signal to an
electrical signal compatible with IR interface 652 or UHF
interface 654.
ICGP 680 also supports the processing of data and
permits data to be transmitted out of the ICGP 680 device
to external devices. This functionality is supported both
by it RISC SAR 630 which interfaces directly to an
isochronous port 648 for (POTS). An Ethernet/USB/Firewire
engine 640 supports transmission of data in a variety of
formats off the chip including interfaces to a 10/100BaseT
port 642, a USB port 644 and a Firewire port 646.
FIG. 7 illustrates an in-home distribution system
using a wireless and xDSL residential gateway with
distributed receiving devices that permits reception of
signals from a main host residential gateway 700 by a
plurality of in-home devices including full functionality
digital television set-tops, low-cost digital television
set-tops, and computers 114.
As illustrated in FIG. 7 a main host residential
gateway 700 is connected to a satellite/wireless antenna
120 which receives signals from a broadcast source which
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may be a satellite, LAN-based wireless transmitter or other
broadcast source. The broadcast source may be transmitting
a variety of services in different formats. These services
can include traditional broadcast channels, Near Video on
Demand (NVoD) services, ACTV or Advanced systems Television
(ATSC) format signals, or Standard Definition or High
Definition Digital Television (SD/HD TV) signals.
The main host residential gateway 700 also interfaces
to a switched network which may be a DSL network, FTTC,
FTTH or other switched infrastructure. In a preferred
embodiment the switched infrastructure is an ADSL network
in which signals are transmitted directly from a central
office over outside plant twisted wire pairs 150. DSL
signals are received at a diplex filters 702 which
separates out telephone signals 710 which are received by
logic block 712.
The digital signal is received by a DSL processor
which can be an ADSL processor 708 or a VDSL processor 706.
A RISC processor 720 is used in conjunction with
Synchronous Dynamic Random Access Memory (SDRAM) 722 and an
external memory 724 to generate decompressed MPEG signals
which are processed by a video/audio input/output processor
734. In a preferred embodiment RISC processor 720 is MAP-
CA device made by the Equator Corporation having a line
width of 0.18 um and operating at 300 MHz. Alternate RISC
processors including those manufactured by the MIPS
Corporation or ARM Ltd. can be utilized and are well known
to those skilled in the art. The output of video audio
input/output processor 734 is directed at a television 106.
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The second video audio processor 732 can be utilized for
additional video processing.
RISC processor 720 is able to support a large variety
of services using flexible software which can run on a
number of different operation systems. RISC processor 720
supports services including H.323 video conferencing,
display of graphics, and software based audio/video
functions. RISC processor 720 also connects to a telephone
line interface 780 which can support isochronous or
Internet protocol (IP) based telephone services. These
services are provided to derived POTS line interfaces 782.
Broadcast signals received from satellite/wireless
antenna 120 are processed by a broadcast signal receiver
704. The MPEG packets are subsequently processed by RISC
processor 720. A power supply 740 is used to power the
various devices in the main host gateway and is connected
to an external power source via an AC converter 742.
In the gateway system illustrated in FIG. 7 signals
can be distributed to devices in the home over inside
twisted wire pairs 112. This allows use of the existing
home wiring for the distribution of video signals and is
based on the use of a Home Network Interface (HNI) device
730. HNI devices 730 are based on the transmission of
digital signals over twisted wire pairs using a suitable
modulation format and standardized protocols. In a
preferred embodiment the digital signal is a 20 Mb/s signal
transmitted above the POTS spectrum in a VDSL like
modulation format and is based on Internet protocols in an
IEEE 802.3 compliant data format. A Quality of Service
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(QoS) functionality is supported such that video signals
can arrive at the remote devices uninterrupted.
At the remote devices the HNI signals are received at
a home network modem 750 or at an HNI network interface
card 752 which is plugged into computer 114. Remote
television decoders include a low-cost remote decoder 752
and a full ATSC compliant remote decoder 750. The full
ATSC compliant remote decoder 750 is capable of receiving
all digital television formats including HDTV formats,
while the low-cost remote decoder 752 only decodes a subset
of the ATSC digital formats. A home network interface
device 730 is used to receive data from the main host
residential gateway 700 over the in-home twisted wire pairs
112.
As shown in FIG. 7 the full ATSC compliant remote
decoder 750 contains the home network interface device 730
and a RISC processor 720. In a preferred embodiment RISC
processor 720 is an MAP-CA processor while in an alternate
embodiment the RISC processor is a SGS Thompson ST7000 RISC
processor. SDRAM 722 provides memory for reception of the
HNI signal as well as for MPEG decoding. A video/audio
input/output device 734 is used to generate a signal which
is compatible with an analog television.
The low-cost remote decoder 752 contains a home
network interface device 730, matching logic 754 and the
low-cost MPEG processor 756. In a preferred embodiment the
low-cost MPEG processor is an SGS Thompson 5505 MPEG
processor. SDRAM 722 is used to support the MPEG
processing and the resulting decoded video signal is sent
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to a video/audio input/output device 734 for converted to
analog format compatible with an analog television. Power
is provided by a power module 740 which is connected to an
external power source. In an alternate embodiment the low
cost remote decoder or ATSC compliant remote decoder 750
are powered by the television set.
One advantage of the present invention is that it can
be utilized to receive broadcast and DSL video signals and
can distribute those signals to a number of televisions or
computers in the home using existing twisted wire pairs in
the home. This permits reception of a variety of
television channels including local channels and allows
reception of multiple programs by televisions in different
locations of the home.
Referring to the preferred embodiment depicted in FIG.
7, a subscriber can have a second television 108 which is
connected to the main host residential gateway. In
addition to being connected to the second television, the
first television can receive the signal being sent to the
second television 108. This can be accomplished through
the use of a splitter 790 in conjunction with coaxial
cables 792. One advantage of this configuration is that a
subscriber can be viewing one program on first television
106 and receive programming directed at another television
on the first television 106. As an example, the subscriber
may be viewing an ADTV movie received from a satellite
(DBS) system on the first television 106, and can view
local channels received over the ADSL switched digital
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video network on both the second television 108 and the
first television 106.
As can be readily understood, viewers can watch
different or identical channels in different parts of the
house. The channels can be received over the switched
network or over the broadcast network. As an example, a
family may be viewing a movie which may be in a high
definition format received over the broadcast (e. g.,
satellite) network while someone is watching a local news
program upstairs. The present invention allows reception
of the local channel over the switched (e. g., DSL) network
while simultaneously permitting reception of the broadcast
programming over the satellite network. When the existing
wiring is utilized for the transmission of digital signals
in the home, low cost remote decoders can be used in the
secondary television locations.
Although this invention has been illustrated by
reference to specific embodiments, it will be apparent to
those skilled in the art that various changes and
modifications may be made that clearly fall within the
scope of the invention.
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