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Description  |
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TECHNICAL FIELD
The present invention relates to routing and access control and billing
functionalities in video distribution networks capable of providing
subscribers with access to multiple information service providers
utilizing wireless distribution in at least a portion of the network.
BACKGROUND ART
Distribution of full motion video data has evolved from early television
broadcasting to meet viewer demand. Earliest video distribution was by
point-to-point wiring between a camera and a video monitor. This was
followed by scheduled television broadcasting of programming over the
public air waves. In the 1960s, Community Antenna Television (CATV) was
chartered to provide off-air television signals to viewers in broadcast
reception fringe areas. Later, under FCC regulation, the CATV industry was
required to provide local access and original programming in addition to
off-air broadcast signal distribution.
In response, several sources of cable network programming were established.
Because of the wide bandwidth available on cable television systems,
additional channels were available for the new programming. However,
programming was generally prescheduled, with the viewer left to tune to
the designated channel at the appointed time to view a particular program.
To increase revenues, cable television systems have initiated distribution
of premium channels viewable only by subscribers having appropriate
descramblers. The subscriber tunes the descrambler to receive a premium
channel, descramble the video and audio information and supply a signal
capable of reception on a standard television set. Pay-per-view programs,
which evolved later, include recently released movies, live concerts and
popular sporting events. Subscribers wishing to view a pay-per-view
program place an order with the cable operator. At the designated time,
the subscriber's descrambler is activated by some control from the cable
operator to permit viewing of the pay-per-view programming. However, the
subscriber is still restricted to viewing the programming at the scheduled
time. There is no capability of delivering programming to a subscriber on
demand, that is, immediately or at a subscriber-specified time and date.
More recently, several different wideband digital distribution networks
have been proposed for offering subscribers an array of video services,
including true Video On Demand service. The following U.S. Patents
disclose representative examples of such digital video distributions
networks: U.S. Pat. Nos. 5,253,275 to Yurt et al., 5,132,992 to Yurt et
al., 5,133,079 to Ballantyne et al., 5,130,792 to Tindell et al.,
5,057,932 to Lang, 4,963,995 to Lang, 4,949,187 to Cohen, 5,027,400 to
Baji et al., and 4,506,387 to Walter. In particular, Litteral et al. U.S.
Pat. No. 5,247,347 discloses a digital video distribution network
providing subscribers with access to multiple Video On Demand service
providers through the public switched telephone network, as described in
more detail below.
U.S. Pat. No. 5,247,347 to Litteral et al., the disclosure of which is
hereby incorporated in its entirety into this disclosure by reference,
discloses an enhanced public switched telephone network which also
provides a video on demand service to subscribers over the public switched
telephone network. A menu of video programming information is displayed at
the subscriber's premises by a set-top terminal and a TV set. The
subscriber may transmit ordering information via the public switched
telephone network to the independent video information providers. Video
programming may be accessed and transmitted to the subscriber directly
from a video information provider (VIP) or through a video buffer located
at a central office (CO) serving the subscriber.
Connectivity between the central office and the subscriber for transmission
of video data is provided by an asymmetrical digital subscriber line
(ADSL) system. ADSL interface units at the central office multiplex
digital video information with voice information to be transmitted to the
subscriber and support two-way transmission between the subscriber's line
and the X.25 packet data network of one or more control channels. A
complementary ADSL interface unit at the subscriber's premises separates
downstream video control signals and voice telephone signals from the line
and multiplexes upstream control signals and voice telephone signals onto
the line.
A subscriber can request transmission of video data using a telephone
instrument by dialing a Voice Response Unit (VRU) of a video gateway
device, through the voice telephone switch and dialing in selection
information. Alternatively, the user can access the video gateway device
and select a video using a remote control device, the set-top terminal and
the control signalling channel through the network. The VIP's equipment
identifies the requested title and determines if the title is available.
If the title is found, the corresponding data file is opened and a reserve
idle communications port is identified for transmission of the video data
to an input node of a digital cross-connect switch (DCS). The video data
file is transmitted from the VIP's video storage device, through the DCS,
to the designated ADSL interfaces for transmission to the requesting
subscriber's premises. The ADSL interface on the subscriber premises
demultiplexes the broadband program transmission off of the subscriber
loop and applies the digital data stream to a decoder unit in the set-top
terminal. The decoder unit decompresses the audio and video data, and
converts the digital audio and video to corresponding analog signals. The
decoder can supply baseband analog audio and video signals to a television
receiver, or these analog signals can be modulated to a standard
television channel frequency for use by the television receiver.
While the foregoing patents deal with systems involving wired distribution
of the data, entertainment and information within the consumer premises, a
number of patents have proposed various schemes for wireless distribution
of information of one sort or another.
Robbins U.S. Pat. No. 4,509,211, issued Apr. 2, 1985, describes an
electrical system that utilizes an extended infrared radiation link for
remote control, such as a TV selector or for data communication.
Williams U.S. Pat. No. 4,882,747, issued Nov. 21, 1989, describes a
teleconferencing system including infrared communication apparatus that
provides simultaneous video control at a number of remote teleconferencing
sites from a central teleconferencing location.
Yasuoka et al. U.S. Pat. No. 4,885,766, issued Dec. 5, 1989, describes a
tele-controller system including a control device that receives and stores
incoming commands transmitted through a telephone line. The commands are
used to operate various apparatuses such as VCR, air conditioner, lamp,
etc., at pre-determined times.
Kameo et al. U.S. Pat. No. 4,899,370 issued Feb. 6, 1990, describes an
apparatus enabling remote control of electronic equipment such as a VCR
through the use of a remote telephone set. A remote controller will
provide wireless, line of sight operation of the VCR in response to a
signal from the telephone set.
Streck et al. U.S. Pat. Nos. 4,916,532, 5,012,350 and 5,023,931, issued
Apr. 10, 1990, Apr. 30, 1991, and Jun. 11, 1991, respectively, describe
the transmission of a wireless signal from a VCR to a TV. The output of
the VCR is fed into a transmitter and sent to the TV receiver. These
patents also describe several prior art arrangements for transmitting a
signal from a VCR to a TV set without linking wiring.
The above discussed media distribution systems provide varied approaches to
providing to business and residential premises numerous media services via
different types of delivery mechanisms. However, all systems known to have
been proposed to date have required a greater or lesser installation of
additional signal distribution wiring or cabling in the served premise. In
many instances, the installation of such facilities involves a major
construction project and significant expense.
DISCLOSURE OF THE INVENTION
The principal object of the present invention is to provide an efficient
system and method for providing wireless distribution of video and the
like wide band information services throughout a premise.
According to the present invention, interactive multimedia services are
provided to subscriber premises by any suitable multimedia distribution
and delivery system and then distributed through the subscriber premises
through a wireless distribution system particularly adapted to avoid
interference from wireless distribution systems which may be utilized in
adjoining or nearby premises of a different subscriber to the same or a
different service.
In an exemplary implementation of the present invention, real time encoders
receive video programs and encode the information for those programs into
packets of compressed digital data, e.g., in accord with the recognized
video compression standard. The head end may also receive previously
encoded video program material from other sources, such as a digital
server or a digital transmission media. Multiplexers combine digital data
for groups of programs into the multiplexed packet data streams. A digital
modulator, such as a 64 or 256 QAM modulator, modulates each digitally
multiplexed packet data stream for transport in one unique channel. A
combined spectrum signal containing these channels is delivered to the
subscribers premise through any suitable multimedia distribution and
delivery architecture.
The combined spectrum signal containing the above-described channels is
connected to a network interface at the subscriber premises where it is
up-converted to place the channels into available frequency channels,
preferably in the UHF range. The unique channel from each digital
modulator is fed to an up-converter synthesizer module which performs a
frequency hopping spread spectrum technique. The frequency synthesizer
uses an input frequency hopping spreading code to determine the particular
frequency from within the set of frequencies in the broad frequency band
at which to periodically generate the carrier wave. Frequency hopping
codes are input to the frequency synthesizer by a frequency hopping code
generator so that the carrier wave is frequency hopped. Each carrier is
assigned a different spreading code so that each occupies a different
channel during the same time period. The spreading codes are preferably
orthogonal to one another so that cross-correlation between the spreading
codes is approximately zero. The signals are fed to a suitable miniature
subscriber premise antenna for radiation throughout the premises.
At the receiver site within the premise a similar antenna receives a signal
which is then down-converted and supplied to a wireless signal processor.
The wireless signal processor, typically part of an interface module
connected by a cable to the down-converter, processes the received
wireless signal to select one of the channels. The wireless signal
processor effectively acquires a digital multiplexed data stream from the
selected channel and supplies that data stream to a digital signal
processor.
The digital signal processor selects packets of data relating to a selected
one of the programs. The digital processing section processes the
compressed, digitized data from those packets to produce signals
presentable to the subscriber. In the preferred embodiment, the digital
signal processor produces signals to drive a standard television set.
Particular transmitted signals are retrieved from the combined transmitted
signal by despreading with a frequency hopping spreading code
corresponding to the code for the particular transmitter antenna which is
to be retrieved. As will be understood by those skilled in the art the
transmitting and receiving codes are synchronized. When the spreading
codes are orthogonal to one another, the received signal can be correlated
with a particular spreading code such that only the desired signal related
to the particular spreading code is enhanced while the other signals are
not enhanced.
This system may use only one spreading code in the situation where the
subscriber uses only a single television set. However, the system is
uniquely adapted to provide interference free reception to multiple
television sets tuned to different programs within the same premises. In
like manner, the system provides prevention of interference from stray
signals which may enter the premise from adjoining or nearby premises of
other subscribers to the same or different multimedia distribution
systems.
According to the invention, interactive multimedia services are
particularly adapted to be provided to subscriber premises utilizing in
whole or in part the public switched telephone network. In one preferred
embodiment, the service is provided using an existing twisted wire pair
subscriber line with Asymmetrical Digital Subscriber Line (ADSL)
technology. The ADSL connection provides a 1.5 mbits/s downstream video
information channel, a two-way telephone connection, and a 16 kbits/s
control channel. This multiplexed signal is then separated and processed
on premise and distributed in a two-way fashion as a complex radio
frequency signal. Multiple television sets and telephone stations may be
simultaneously served and may conversely communicate commands upstream to
the multimedia network. A complete installation may be made in an entire
premise without the necessity for any significant installation of new
wiring. The system and methodology provide flexibility and are adapted to
serve as an integral termination for multiple multimedia distribution and
delivery architectures.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram of an example of a first Video Dial Tone Network
utilizing a Level 1 Gateway which may be utilized with the present
invention.
FIG. 2 is a block diagram of one example of an alternate network
architecture utilizing a Level 1 Gateway in a manner adapted to the
present invention.
FIG. 3 illustrates a hybrid fiber coax network architecture utilizing the
Level 1 Gateway in a manner adapted to the present invention.
FIG. 4 illustrates a digital entertainment terminal which may be utilized
with the present invention.
FIG. 5 illustrates the implementation of the invention according to one
embodiment utilizing the type of network illustrated in FIG. 1.
FIG. 6 illustrates another embodiment of utilization of the invention in a
network of the type illustrated in FIG. 1.
FIG. 7 shows a simplified block diagram of a translator or transponder
which may be utilized in the invention.
FIG. 8 illustrates another embodiment of implementation of the invention
utilizing the type of network illustrated in FIG. 3.
FIG. 9 illustrates a digital entertainment terminal which may be used with
the embodiment of FIG. 8.
FIG. 10 illustrates an on premise implementation of the embodiment of the
invention of FIG. 8.
BEST MODE FOR CARRYING OUT THE INVENTION
Architectural Overview of Video Dial Tone Network
FIG. 1 is a block diagram an exemplary broadband network for providing
interactive services, such as video on demand, home shopping or
purchasing, home banking, medical information, ticket ordering, gaming,
etc. In the network shown, the customer premises equipment (CPE) consists
of a set top terminal identified as "DET" (digital entertainment terminal)
100 and a telephone (POTS or ISDN). The connections to the central office
utilize Asymmetrical Digital Subscriber Line (ADSL) technology, typically
over twisted wire pair, similar to that disclosed in the above cited
Litteral et al. Patent. The ADSL connection provides a 1.5 mbits/s
downstream video information channel, a two-way telephone connection and a
two-way 16 kbits/s control channel. The illustrated Video Dial Tone
network architecture may use some form of fiber extension in the actual
subscriber loops, to provide services to subscribers located more than 1.5
kilo-feet from a central office (see e.g. U.S. patent application Ser. No.
08/233,579, in the name of Bruce Kostreski, filed Apr. 26, 1994 and
entitled "Extended Range Video On Demand System"). In the network
illustrated in FIG. 1, the drop to the subscriber's premises is a wired
ADSL loop.
As shown in FIG. 1, the network interface module in the DET 100 connects to
an ADSL multiplexer/demultiplexer 201 similar to the in-home ADSL unit in
the above discussed Litteral et al. Patent. As described in that patent,
the connection between the network interface module of the DET 100 and the
in-home ADSL unit 201 may consist of an RJ48C line and connectors. Such a
link comprises six wire pairs, two for the broadband data, two for
upstream signalling and two for downstream signalling. However, according
to the present invention, the distribution on the premise will differ in
the region indicated by the broken line rectangle, as is described in
detail hereinafter.
Each ADSL subscriber line 203 connects to an ADSL bay 205 located in or
associated with the subscriber's local central office. For each subscriber
line 203, the ADSL bay 205 includes an ADSL multiplexer/demultiplexer
similar to the central office ADSL unit in the above discussed Litteral et
al. Patent. The ADSL bay 205 provides transport for voice signals on the
subscriber loop to and from the associated voice switch 207. The ADSL bay
205 also connects to an access concentrator 209 for providing two-way
signalling connections through an X.25 type packet switched data network
211. The ADSL bay 205 also receives broadband digital signals for
downstream transport over the ADSL line 203 to each subscriber's premises
from a digital cross connect switch 213, labelled "Access DCS" in the
drawing. One ADSL line 203 to the home carries one channel of video
programming and provides a single output channel. The output channel can
provide a video signal to a VCR (not shown) or to the TV set 100'. The
various Access DCS switches throughout the network are controlled by
switch controller 212.
If the ADSL bay 205 is local, i.e. located in the same telephone company
central office as the cross connect switch DCS 213, the ADSL bay 205
connects to the Access DCS 213 via an appropriate number of local DS1
connections 215. In service areas where an ADSL bay does not carry enough
traffic to warrant an associated Access DCS, the ADSL bay will be located
in a remote central office facility. Such a remote ADSL bay connects to
the Access DCS 213 via a SONET type optical fiber link 217 providing an
appropriate number of multiplexed channels to service the number of
subscribers connected to the particular ADSL bay.
Video Information service Providers (VIP's) may access the downstream
broadband portion of the system at a hub location (not shown) within a
given LATA. The hub will not perform any switching. High capacity optical
fiber links are aggregated at the hub to provide each VIP with a number of
connections (e.g. one or more OC-3 links) from their respective video
server to each Access DCS within the LATA.
The Access DCS 213 provides both point-to-point connections and
point-to-multipoint connections. Individualized interactive services, such
as Video On Demand, home shopping/purchasing and banking, use
point-to-point connections wherein the Access DCS connects one broadband
input port from a VIP's server to one output port going to the
subscriber'sADSL line. Narrowcast and broadcast services utilize
point-to-multi-point connections of one input port to a plurality of
output ports.
The illustrated architecture of the Video Dial Tone network utilizes two
levels of gateways, both of which will communicate with subscribers' DET's
via the X.25 data network 211 and the signalling channel on the ADSL
subscriber loops 203.
The Level 1 Gateway 221 performs a variety of network connectivity related
functions, including communications port management of transmissions of
information between subscribers and servers, processing of billing
information and session management. Normally, each subscriber accesses the
Level 1 Gateway (e.g. to select and access a particular VIP's server) by
operation of a remote control device which causes the subscriber's DET 100
to transmit data signals to the Level 1 Gateway via the 16 kbits/s control
channel and the X.25 packet switched data network 211. The Level 1 Gateway
transmits one or more selection menus to the subscriber's DET 100 as
screens of text data carried by the same path back through the network.
In the present implementation, text or graphics information from the Level
1 Gateway is displayed as a page of data. Alternatively, the text or
graphics data could be overlaid on a video display received through the
broadband network, e.g. over one of the broadcast channels carried through
the more advanced networks discussed below.
In a typical scenario, the user would turn on the DET terminal 100, and in
response to data signals from the Level 1 Gateway 221, the terminal would
display an initial selection menu. The subscriber would input a selection,
and in response to an appropriate dat | | |
