Abstract:
A residential gateway for distributing video, data and telephony services is disclosed. The gateway has a MPEG bus connected from a network interface module to a first and a second video processors. A microprocessor controls the first and second video processors by sending control signals across a control bus.

Description:
CROSS-REFERENCE TO PRIOR APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/038,276 filed Feb. 19, 1997. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an apparatus for the distribution of video, data and telephony and other telecommunications services within a residence. 
     BACKGROUND OF THE INVENTION 
     Advances in the field of telecommunications allow large amounts of digital information to be delivered to residences. Inside the residence, devices will be connected to the network by twisted wire pairs which provide telephone services today, or by coaxial cable similar to that used by cable operators to provide cable TV services. 
     Because the majority of new video services will be digital, and because existing televisions are analog, there is a requirement for a device which converts the digital signals supplied by the network to analog signals compatible with existing televisions. Presently available television set-tops can perform this function, but are expensive. Many homes have more than one television, and will therefore require multiple television set-tops to receive digital programming at each location within the home. 
     A centrally located device can provide connectivity to the digital network as well as providing digital to analog conversion, but methods of distributing the signals around the home are required. In addition, methods of communicating with the centralized device from the different locations in the home are required. 
     It is also desirable to have data and telephony services in the home, and it is likely that these services will be required in more than one location in the home. In addition, there may be the need for communicating between devices in the home. 
     For the foregoing reasons, there is a need for a centralized unit in the home which can provide video, data, and telephony services, and methods for communicating with the centralized unit from different locations within the home. 
     SUMMARY OF THE INVENTION 
     In a preferred embodiment a centrally located gateway provides analog video services by receiving a digital data stream from a fiber-to-the-curb access system, and directing packets containing video signals to one or more digital video decompression processors. The video decompression processors generate analog video signals which are transmitted to televisions as S-video signals, or modulated onto carriers to produce broadcast type signals compatible with standard televisions. 
     In a preferred embodiment, the analog video signals which were generated from the digital network are combined with off-air or cable-TV broadcast signals for transmission to the televisions in the residence using a splitter and in-home coaxial cable wiring. The digitally originated signals are modulated onto unused television channels. A low pass filter can be used to insure that the off-air or CATV signal has unused channels in the UHF spectrum. 
     Return signaling from the televisions in the gateway is provided for by use of wireless remote controls which signal back to the gateway for channel changes and other video signal controls. 
     In a preferred embodiment an optional module can be inserted into the gateway to provide a standard signal for devices in the residence which are designed to be connected directly to the FTTC access system with coaxial drop cables. 
     A CATV module can be inserted and provides for the mapping of television channels from a CATV network or antenna for off-air broadcasts to a channel for transmission over the in-home coaxial network. By using the CATV module it is possible to map signals to new channels as well as equalizing signal levels to that there are no large signal differences between the signal levels from the CATV network or antenna and the gateway. 
     An optional module can be inserted to provide telephony services from the gateway. 
     Data services can be provided from the gateway, and an Ethernet port is used to connect data devices such as computers to the gateway. 
     In an alternate embodiment a centralized gateway is connected to televisions in the residence by point-to-point coaxial wiring. A main video decompression processor receives video packets and constructs multiple analog video channels. The multiple analog video channels are made available to inserted modules in the gateway through the use of analog video buses. Inserted video modules are used to modulate the video signals onto a channel which can be received by a television connected to the video module by point-to-point coaxial cable wiring. 
     In an alternate embodiment signaling from the remote locations in the home to the gateway is accomplished by use of an infrared transmitter and receiver. The receiver receives the infrared signals from the hand-held remote control and signals back the gateway via the in-home coaxial cable wiring. The infrared receiver can also be integrated into the television. 
     In an alternate embodiment the CATV module provides for the mapping of television channels from a CATV network or antenna for off-air broadcasts to a channel for transmission to an individual television. The CATV module places the analog television signal onto an analog video bus. Any one of the inserted TV modules can receive the signal from the bus and transmit that signal to a particular television. 
     These and other features and objects of the invention will be more fully understood from the following detailed description of the preferred embodiments which 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 fiber-to-the-curb access system with coaxial drop cables; 
     FIG. 2 illustrates a fiber-to-the-curb access system with a gateway used in the residence for the distribution of video, data and telephony signals; 
     FIG. 3 illustrates a fiber-to-the-curb access system with twisted wire pair drop cable to a residence having a gateway; 
     FIG. 4 illustrates an architecture for a video, data and telephony gateway which uses point-to-multipoint in-home coaxial wiring; 
     FIG. 5 illustrates a wireless method of signaling from remote locations in a home to a gateway; 
     FIG. 6 illustrates an architecture for a video, data and telephony gateway which uses point-to-point in-home coaxial wiring; 
     FIG. 7 illustrates a method for signaling from remote locations in the home to the gateway using the in-home coaxial wiring. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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 which 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. 
     Contents 
     I. Fiber-to-the-curb networks 
     II. Gateway with point-to-multipoint in-home coaxial wiring 
     III. Gateway with point-to-point in-home coaxial wiring 
     I. Fiber-to-the-curb Networks 
     FIG. 1 illustrates a Fiber-to-the-Curb (FTTC) network in which various devices in the residence  190  are connected to the Public Switched Telecommunications Network (PSTN)  100  or Asynchronous Transfer Mode (ATM) network  110 . The devices in the residence  190  can include telephone  194 , television (TV)  199  with a television set-top  198 , computer with Network Interface Card (NIC)  191 , and Premises Interface Device (PID)  196  connected to a telephone  194 . 
     The FTTC network illustrated in FIG. 1 works by connecting a Host Digital Terminal  130  to the PSTN  100  and ATM network  110 . The PSTN-HDT interface  103  is specified by standards bodies, and in the US are specified by Bellcore specification TR-TSY-000008, TR-NWT-000057 or TR-NWT-000303. The HDT  130  can also receive special services signals from private or non-switched public networks. The physical interface to the PSTN is twisted wire pairs carrying DS-1 signals, or optical fibers carrying OC-3 optical signals. 
     The interface to the ATM network-HDT interface  113  can be realized using an OC-3 or OC-12c optical interfaces carrying ATM cells. In a preferred embodiment, HDT  130  has two OC-12c broadcast ports, which can only receive signals carrying ATM cells, and one OC-12c interactive port which can receive and transmit signals. 
     An element management system (EMS)  150  is connected to HDT  130  and is used to provision services and equipment on the FTTC network, in the central office where the HDT  130  is located, in the field, or in the residences. The EMS  150  is software based and can be run on a personal computer in which case it will support one HDT  130  and the associated access network equipment connected to it, or can be run on a workstation in which case multiple HDTs and access networks are supported. 
     Optical Network Units (ONUs)  140  are located in the serving area and are connected to HDT  130  via optical fiber  160 . Digital signals in a Synchronous Digital Hierarchy (SDH)-like format at a rate of 155 Mb/s are transmitted to and from each ONU  140  over optical fiber  160 . In a preferred embodiment optical fiber  160  is a single-mode fiber and a dual wavelength transmission scheme is used to communicate between ONU  140  and HDT  130 . 
     A Telephony Interface Unit (TIU)  145  in ONU  140  generates an analog Plain Old Telephony (POTs) signal which is transported to the residence  190  via a twisted wire pair drop cable  180 . At the residence  190  a Network Interface Device (NID)  183  provides for high-voltage protection and serves as the interface and demarcation point between the twisted wire pair drop cable  180  and the in-home twisted pair wiring  181 . In a preferred embodiment TIU  145  generates POTs signals for six residences  190 , each having a twisted wire pair drop cable  180  connected to ONU  140 . 
     As shown in FIG. 1, a Broadband Interface Unit (BIU)  150  is located in ONU  140  and generates broadband signals which contain video, data and voice information. BIU  150  modulates data onto an RF carrier and transmits the data over a coaxial drop cable  170  to a splitter  177 , and over in-home coaxial wiring  171  to the devices in the residence  190 . 
     In a preferred embodiment  64  ONUs  140  are served by an HDT  130 . Each ONU serves 8 residences  190 . In an alternate embodiment, each ONU  140  serves 16 residences  190 . 
     As shown in FIG. 1, each device connected to the in-home coaxial wiring  171  will require an interface sub-system which provides for the conversion of the signal from the format on the in-home coaxial wiring  171  to the service interface required by the device. The PID  194  extracts time division multiplexed information carried on the in-home coaxial wiring  171  and generates a telephone signal compatible with telephone  194 . Similarly, the television set-top  198  converts digital video signals to analog signals compatible with TV  199 . The NIC card generates a computer compatible signal. 
     FIG. 2 illustrates the use of a gateway  200  to generate signals compatible with the devices in the home, which are connected to the gateway  200  via in-home twisted pair wiring  181  or in-home coaxial cable wiring  210  and a splitter  177 . The connection to the splitter  177  is made using a gateway-splitter connection, which in a preferred embodiment is coaxial cable. A direct connection to a television can be made using a gateway-television connection  205 , which in a preferred embodiment is a four conductor cable carrying an S-video signal. 
     FIG. 3 illustrates a FTTC network which relies on twisted wire pair drop cables  180  instead of coaxial drop cables  170 . This embodiment is preferable when it is cost prohibitive to install coaxial drop cables from ONUs  140  to residences  190 . 
     As shown in FIG. 3, a Universal Service Access Multiplexor (USAM)  340  is located in the serving area, and is connected to HDT  130  via optical fiber  160 . An xDSL modem  350  provides for the transmission of high-speed digital data over the twisted wire pair drop cable  180  to and from residence  190 . Traditional analog telephone signals are combined with the digital signals for transmission to the residence  190  and a NID/filter  360  is used to separate the analog telephone signal from the digital signals. The analog telephone signal is sent to telephone  194  over the in-home twisted pair wiring  181 . 
     The digital signals pass through the NID/filter  360  to the gateway  200 . The gateway  200  serves as the interface to the devices in the residence  190  including the television  199 , the computer  193 , and additional telephone  194 . 
     The central office configuration illustrated in FIG. 3 includes a Universal Service Access Multiplexor Central Office Terminal (USAM COT)  324  connected to HDT  130  via a USAM COT-HDT connection  325 , which in a preferred embodiment is an STS3c signal transmitted over a twisted wire pair. The PSTN-USAM COT interface  303  is one of the Bellcore specified interfaces including TR-TSY-000008, TR-NWT-000057 or TR-NWT-000303. 
     A Channel Bank (CB)  322  is also used in the central office to connect specials networks  310 , comprised of signals from special private or public networks, to the access system via the specials networks-CB interface  313 . In a preferred embodiment, the CB-USAM COT connection  320  are DS1 signals over twisted wire pairs. 
     When used herein the term subscriber network refers in general to the connection between the ONU  140  and the devices or gateway  200  in the residence  190  or the connection between USAM  340  and the devices or the gateway in the residence  190 . The subscriber network may be comprised of coaxial cable and a splitter, twisted wire pairs, or any combination thereof. 
     Although FIG.  2  and FIG. 3 illustrate the gateway  200  located inside the living area of residence  190 , the gateway can be located in the basement, in the garage, in a wiring closet, on an outside wall of the residence  190 , in the attic, or in any of the living spaces. For outside locations gateway  200  will require a hardened enclosure and components which work over a larger temperature range than those used for a gateway located inside the residence  190 . Techniques for developing hardened enclosures and selecting temperature tolerant components are known to those skilled in the art. 
     II. Gateway with Point-to-multipoint in-home Coaxial Wiring 
     FIG. 4 illustrates a gateway  200  which can be used with point-to-multipoint in-home wiring such as that created by the gateway-splitter connection  210 , the splitter  177 , and in-home coaxial wiring  171 , as illustrated in FIGS. 2 and 3. 
     Gateway  200  of FIG. 4 is comprised of a Network Interface Module (NIM)  410  which connects to the access network through network connection  460 . The access network may have a coaxial drop cable  170  for digital services as illustrated in FIG. 2, or may have a twisted wire pair drop cable  180 , as illustrated in FIG.  3 . NIM  410  will contain the appropriate modem technology for the access network. In a preferred embodiment, different types of NIMs are utilized for access networks having coaxial drop cables than for access networks having only twisted wire pair drops. 
     NIM  410  interfaces to a mother board  414  which provides the basic functionality of gateway  200 . Mother board  414  contains a microprocessor  434 , memory  436 , power supply  440  connected to an AC outlet via AC plug  476 , a main MPEG processor  430 , an Ethernet block  438  which connects to an Ethernet connector  478 , and a Remote control block  442 . 
     Within the main MPEG processor  430  there is a Video Segmentation and Reassembly (VSAR) section  432  which constructs MPEG packets from an ATM stream received from NIM  410 . VSAR section  432  can reduce jitter in MPEG packets which arises from transmission of those packets over the ATM network, as well as constructing a useable MPEG stream in spite of lost ATM cells which contain partial MPEG packets. 
     The main MPEG processor  430  has an interface to an S video connector  474  which provides connectivity for televisions having an S video port. 
     Remote control block  442  has an interface to an IR receiver  472  which can receive commands from a hand-held remote control which is operated within the vicinity of gateway  200 . Remote control block  442  also has an interface to a UHF receive antenna  470  which can receive commands from hand-held wireless remotes used anywhere in residence  190 . 
     A set of buses  429  is used to route information within gateway  200  and as illustrated in FIG. 4 includes a Time Division Multiplexing (TDM) bus  420 , a control bus  422 , a MPEG bus  424 , and an ATM bus  428 . 
     A number of optional modules can be inserted into gateway  200  including MPEG modules  450 , a DAVIC module  452 , and a telephony module  454 . All of the optional modules are connected to the control bus  422  in addition to being connected to at least one other bus which provides those modules with the appropriate types of data for the services supported by the module. 
     The MPEG modules  450  provide for decompression of MPEG packets which are constructed by the VSAR section  432 . The output of the MPEG module  450  is a signal which is compatible with present televisions, which in the US is the NTSC format. MPEG module  450  can modulate the decompressed analog format video signal onto an available channel for transmission to the televisions  199  in residence  190 . 
     The DAVIC module  452  transmits and receives ATM cells to devices in residence  190  over the in-home coaxial wiring  171 , in a format which is identical to that used by the access system with coaxial drop cables illustrated in FIG.  1 . The advantage of using DAVIC module  452  is that gateway  200  is compatible with in-home devices which connect directly to the access system as shown in FIG.  1 . 
     The MPEG modules  450  and the DAVIC module  452  are connected to combiner  418  which combines the RF signals from those modules, and can add other RF signals such as off-air broadcast television signals or Community Antenna Television (CATV) signals supplied by a cable television company. Signals from the antenna or cable system are coupled to the RE pass-through  464 , which in a preferred embodiment is an F-connector. A low pass filter  482  is used in combiner  418  to insure that the frequencies used by MPEG modules  450  are available. The output of combiner  418  is connected to in-home RF connector  466 , which in a preferred embodiment is an F-connector. The connection between the in-home RF connector  466  and splitter  177  is provided by the gateway-splitter connection  210 , which in a preferred embodiment is a coaxial cable. 
     An optional CATV module  480  can be inserted into gateway  200  and allow for mapping of off-air or cable video channels from their original frequencies to new frequencies for in-home distribution. Remote control unit  442  can control the channel selection and mapping via control bus  422  which is connected to CATV module  480 . Either a hand-held IR remote control or a wireless remote control can be used to change the channel mapping of CATV module  480 . 
     The front panel interface  462  provides for connectivity between the front panel controls (buttons) and the microprocessor  434 . Through the front panel control the user can make channel changes as well as changing the configuration of the channels transmitted on the in-home coaxial network. 
     Telephony module  454  transmits and receives information from TDM bus  420  and produces an analog telephone signal which is compatible with telephone  194 . The interface for the telephone is telephone jack  468 , which in a preferred embodiment is an RJ-11 jack. 
     FIG. 5 illustrates a method of controlling gateway  200  based on the use of a wireless remote  500  which transmits a UHF signal to the UHF receiver  470  illustrated in FIG.  4 . 
     III. Gateway with Point-to-point in-home Coaxial Wiring 
     FIG. 6 illustrates a gateway  200  which can be used in homes where there is point-to-point in-home coaxial cable wiring, and where the gateway can be located near the point where the coaxial wiring originates. 
     The gateway  200  shown in FIG. 6 has an main MPEG processor  430  which is capable of decompressing multiple MPEG streams. In a preferred embodiment, main MPEG processor  430  can decompress three video streams simultaneously, and generates three S-video signals which are available on S-video bus  620 . The TV modules  654  can receive any of the S-video signals from S-video bus  620 , and modulate the video signal onto an appropriate channel for reception by a television which is connected to that TV module  654  via coaxial cable and TV connector  630 . 
     An RF pass-through  464  and CATV module  480  are used to map off-air broadcast or CATV signals to S-video, which can subsequently be transmitted to any of the televisions connected to TV connectors  630  or S-video connector  474 . 
     In the embodiment illustrated in FIG. 6, control of the gateway  200  from locations in residence  190  is accomplished by means of return signals transmitted on the point-to-point in-home coaxial cable wiring. Return signals from remotes are received at TV connector  630 , and a diplexor  640  is used to separate the return signals from the forward signals. The return signals from TV #1 are transmitted on TV1 return line  642  to remote control block  442 , and return signals from TV #2 are transmitted on TV2 return line  644  to remote control block  442 . 
     FIG. 7 further illustrates a method of remote control using the coaxial cable return, in which an IR receiver  710  which is associated with a television  199  receives IR signals from an IR remote  700 , and converts the optical signal to an electrical signal which is transmitted over the coaxial cable to the remote control block  442  of FIG. 6 via the diplexor  640  and TV1 return  642  or TV2 return  644 . Only a simple signaling protocol between IR receiver  710  and the remote control block  442  is required, and the IR receiver functionality can be easily placed in the television  199 . 
     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 which clearly fall within the scope of the invention. 
     The invention is intended to be protected broadly within the spirit and scope of the appended claims.