Abstract:
In a residential environment with more than one analog television set a residential gateway has a network interface module which receives signals from a telecommunications network. The signals contain compressed digital video information which is routed within the gateway to a video module for the generation of an analog video signal for a television set located near the residential gateway, and to a wireless module for transmission to a remote receiver using spread spectrum communications.

Description:
CROSS-REFERENCE TO PRIOR APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/038,426 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 can 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. 
     However, it may not be possible to transmit high-speed digital data over the twisted wire pairs in the home, and coaxial cable wiring is not present in all homes. Furthermore, there may be neighborhoods in which some homes have coaxial cable wiring which will support devices for the reception and transmission of high-speed digital data, while some of the homes do not. Since devices for communication over the coaxial wiring will be made available to the residents by a telecommunications service provider, it would be advantageous to have a means for distributing high-speed digital data in those homes which do not have coaxial cable wiring which is compatible with the devices used in the homes with coaxial cable wiring. 
     For the foregoing reasons, there is a need for a means of distributing high-speed data signals within a residence which is connected to a broadband access system. 
     SUMMARY OF THE INVENTION 
     A wireless gateway located in a residence is connected to a broadband access system and transmits data received from the network to the devices in the residence using wireless transmission techniques, and receives data from the devices using wireless transmission techniques, and transmits that data onto the broadband access network. 
     In a preferred embodiment a downstream Time Division Multiplexed Quadrature Amplitude Modulated signal which is spectrally spread using a direct sequence signal in one or more 22 MHz wide channels in the 2.4 GHz range is transmitted from the wireless gateway to the devices in the residence at a data rate in the range of 10-30 Mb/s. An upstream signal which is Quadrature Amplitude Modulated and spectrally spread is transmitted from each device to the wireless gateway in one of eleven 22 MHz wide channels in the 2.4 GHz frequency range. In the upstream direction Time Division Multiple Access is used to permit each of the devices to access the upstream channel. Spreading of the spectrum is used in both the downstream and upstream directions to reduce interference between different residences which have wireless gateways. The 22 MHz channels available to the gateway are overlapping but centered at different frequencies. Different residences can use the same spectrum, but the different centering of the channels and spreading of the spectrum prevent interference between signals from the devices in one home and wireless gateway in an adjacent home and visa-versa. 
     In an alternate embodiment one 60.5 MHz wide channel is used for downstream communications from the wireless gateway to the devices at a data rate in the range of 10-30 Mb/s. The downstream signal is a Time Division Multiplexed signal which is Quadrature Amplitude Modulated onto a carrier centered at 2.430 GHz. The signal is spectrally spread using a code. In the upstream direction a 20.875 MHz channel centered at 2.473 GHz is used to transmit data a rate in the range of 2-6 Mb/s, using Quadrature Amplitude Modulation with spectral spreading. In the upstream direction Time Division Multiple Access is used to permit each of the devices to access the upstream channel. As in the downstream direction, codes are used to spread the spectrum. 
     In the alternate embodiment codes are used to reduce interference between homes. This is possible because the codes used by different homes are orthogonal or quasi-orthogonal, and gateways and devices in one home which receive signals from gateways or devices in another home are able to distinguish desirable from undesirable signals because the codes used in each home are different. 
     In the event that the codes used by adjacent homes are identical, the first gateway to determine that there is interference from another gateway will alter its code to one which is not subject to interference. 
    
    
     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 twisted wire pair drop cable to a residence having a wireless gateway; 
     FIG. 3 illustrates an architecture for a video, data and telephony gateway which uses wireless in-home distribution; 
     FIG. 4 illustrates a basic wireless gateway; 
     FIG. 5 a  illustrates a frequency plan for in-home wireless distribution using 11 channels in the 2.4 GHz band. 
     FIG. 5 b  illustrates a frequency plan for in-home wireless distribution using a downstream channel and an upstream channel. 
    
    
     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 5 in particular, the apparatus of the present invention is disclosed. 
     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  100  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 subsystem 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  196  extracts time division 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 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. 2, 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 serves as the interface to the devices in the residence  190  including the television  199 , the computer  210  and additional telephone  194 . 
     The central office configuration illustrated in FIG. 2 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 connection  320  are DS 1  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, splitter, or gateway 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 comprise of coaxial cable and a splitter, twisted wire pairs, or any combination thereof. 
     Although FIG.  2  and FIG. 3 illustrates, the wireless 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. 
     FIG. 3 illustrates a wireless gateway  200  which can be used with point-to-multipoint in-home wiring such as that created by the gateway-splitter connection, the splitter  177 , and in-home coaxial wiring  171 , but has the option for a wireless module  490  which can he used to transmit and receive data to devices within residence  190 . 
     Gateway  200  of FIG. 3 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 or may have a twisted wire pair drop cable  180 , as illustrated in FIG.  2 . 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. 3 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, 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 wireless module  490  transmits and receives ATM cells to devices in residence  190  using wireless signals transmitted and received via antenna  494 . After reception and demodulation of the wireless signal by the devices the information is in a format which is identical to that used by the access system with coaxial drop cables illustrated in FIG.  1 . 
     The MPEG modules  450  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 RF 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, 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. 
     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. 
     FIG. 4 illustrates an alternate embodiment for a wireless gateway  200  in which no coaxial or twisted wire pair connections are supported. As illustrated in FIG. 4 a NIM  410  connects to the network via a network connection  460 , and to a wireless module  510  which transmits and receives signals to and from the devices in the residence via antenna  494 . A power supply  440  provides power for the NIM  410  and wireless module  510  via an AC connector  476 . 
     FIG. 5 a  represents utilization of spectrum for in-home distribution using the 2.4 GHz frequency band. Eleven 22 MHz channels, channel #1 600 through channel #11 611, are available for use by the devices and the wireless gateway  200 . 
     FIG. 5 b  illustrates an alternate frequency plan in which one downstream channel  620  is used for communications between the gateway and the devices, and another smaller upstream channel  630  is used for communications between the devices and the gateway. 
     The invention is intended to be protected broadly within the spirit and scope of the appended claims.