Abstract:
A point-to-multipoint broadband local area network (BLAN) system comprising a local area modem controller (LAMC) and plurality of local area modems (LAMs) is capable of voice, video and data communications. The medium is capable of reliably supporting multiple downstream and upstream channels to meet the need of high-capacity and QoS of digital entertainment. Media-access-control (MAC) functions in the LAMC and the LAMs coordinate packet stream transmissions. The shared medium can be a tree-branch coaxial cable; the LAMs can be legacy DOCSIS or EuroDOCSIS cable modems or enhanced cable modems with multiple channels; the MAC can be a DOCSIS MAC or an enhanced multi-channel full-service MAC (fsMAC). The physical layer of each channel can be that of DOCSIS, wideband, or other technologies. Residential gateway and wide-area broadband modem functions can also be incorporated into the LAMC. Cable TV programming channels and the BLAN can shared the same cable spectrum.

Description:
[0001]     This application incorporates by reference the teachings of U.S. patent application Ser. No. 10/122,828 “FULL-SERVICE BROADBAND CABLE MODEM SYSTEM” filed by the same inventor of this application, published Feb. 20, 2003 for details of full-service cable modem (fsCM) systems and full-service media-access-control (fsMAC). 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field of the Invention  
         [0003]     This invention related to the field of multi-channel point-to-multipoint local area network communications method and apparatus supporting voice, video and data. It generally applies to shared wired-medium such as, but not limited to, coaxial cable.  
         [0004]     2. Prior Art  
         [0005]     There is an increasing need for a home backbone network with enough capacity and managed quality-of-service to serve multiple high-definition audio-visual streams as well as other voice, music, and data traffic generated by Internet appliances such as personal computers, printers, media servers, MP3 players, high-definition personal video recorders, wireless LAN (local area network) and wireless PAN (personal area network) access points.  
         [0006]     Broadband coax medium has the advantages of ubiquity and intrinsic high bandwidth (in Gbps), especially suitable for such a home backbone network, comparing to other “no new wire” media such as wireless, unshielded twisted-pair telephone wires, or power-line.  
         [0007]     Broadband point-to-multipoint multiple access networks using coaxial cable as a medium are described in [1 Dahod] U.S. Pat. No. 4,500,989 “DIGITAL COMMUNICATION SYSTEM” issued to Dahod, [2 Grobicki] U.S. Pat. No. 5,471,474 “COMMUNICATIONS HIGHWAY NETWORK SYSTEM” issued to Grobicki et al., [3 DOCSIS] CM-SP-RFlv2.0-108-050408 “DOCSIS 2.0 SPECIFICATION” available on www.cablemodem.com/downloads/specs/, [4 Terry] U.S. patent application Ser. No. 10/071,007 “MULTI-BAND COAX EXTENDER FOR IN-BUILDING DIGITAL COMMUNICATION SYSTEMS” filed by Terry et al., [5 Gurantz] U.S. patent application Ser. No. 09/910,412 “NETWORK INTERFACE DEVICE AND BROADBAND LOCAL AREA NETWORK USING COAXIAL CABLE” filed by Gurantz et al., [6 Morelli] U.S. patent application Ser. No. 10/852,002 “NETWORKING METHODS AND APPARATUS” filed by Morelli et al., [7 Ophir] U.S. patent application Ser. No. 10/935,963 “IMPLEMENTING A HYBRID WIRELESS AND COAXIAL CABLE NETWORK” filed by Ophir et al., [8 Robertson] U.S. patent application Ser. No. 10/924,077 “FULL DUPLEX WIDEBAND COMMUNICATIONS SYSTEM FOR A LOCAL COAXIAL NETWORK” filed by Robertson et al., [9 Eng] U.S. patent application Ser. No. 10/122,828 “FULL-SERVICE BROADBAND CABLE MODEM SYSTEM” filed by the same inventor of this invention, and [10 Lind] U.S. patent application Ser. No. 10/446,511 “WIDEBAND DOCSIS ON CATV SYSTEMS USING PORT-TRUNKING” filed by Lind et al., each of which is incorporated herein by reference.  
         [0008]     [1 Dahod][2 Grobicki] [6 Morelli] disclosed the using of a frequency translator at the root of the coaxial cable topology to reflect upstream transmissions to all stations. [5 Gurantz] disclosed a method of using a non-matching filter to reflect upstream transmissions back to all stations. [4 Terry][6 Morelli][7 Ophir] used spectrum above 750 MHz for upstream and downstream channels to avoid conflict with the spectrum used by conventional cable TV programming channels. [7 Ophir] disclosed a way to use coaxial cable to extend the reach of wireless LAN transmission. [8 Robertson] described a coaxial home network that used channels above 750 MHz for full-duplex point-to-point communications between two stations.  
         [0009]     [3 DOCSIS] disclosed the data-over-cable standards for a sub-split hybrid fiber-coaxial (HFC) cable infrastructure with a centralized controller (cable modem termination system, CMTS) residing at the root of the coaxial cable topology with a media-access-control (MAC) for coordinating the forwarding of packets to and from a plurality of cable modems. While [3 DOCSIS] has a robust MAC layer and the intelligence at the headend, and enjoys a consumer level pricing for the large volume of cable modems, it is nevertheless designed for metropolitan area operations for service providers; the CMTS is prohibitively expensive for residential consumer use. Moreover, the MAC is not scalable for providing the capacity for video operations.  
         [0010]     [9 Eng] disclosed a multi-channel MAC called fsMAC (full-service MAC) that scales the network capacity of a data-over-HFC network by adding multiple upstream and downstream channels, with a DCPC-UCC (downstream control and payload channel—upstream control channel) control channel-pair for efficient upstream multiple access and high network capacity in both upstream and downstream directions.  
         [0011]     [10 Lind] disclosed an enhancement to the DOCSIS MAC for adding wideband downstream and upstream channels to increase the capacity and burst rate of a DOCSIS HFC network.  
         [0012]     Using the spectrum above conventional cable TV channels requires changes to the coaxial network. It is not compatible with legacy cable modems and cable set-top boxes (STBs) and increases the complexity and cost to the home networking infrastructure.  
         [0013]     Therefore there is a need for an improved, reliable, high-capacity and low-cost broadband local area networking backbone for homes and premises to address the shortcomings of the prior art. It is desirable to take advantages of the legacy cable modem technology while providing the capacity and quality-of-service (QoS) required by multimedia communications of voice, video and data within the premises at consumer-level price.  
       BRIEF SUMMARY OF THE INVENTION  
       [0014]     According to the teachings of the present invention, a point-to-multipoint broadband local area network (BLAN) system comprising a shared medium, a local area modem controller (LAMC) located at the root of the medium topology, and one or more in-building local area modems (LAMs) is capable of voice, video and data communications. The medium is capable of reliably supporting multiple downstream and upstream channels for the high-capacity need of digital entertainment such as multiple high-definition television audio-visual packet streams. Media-access-control (MAC) functions in the LAMC and the LAMs coordinate the packet stream transmissions to meet the quality-of-service requirements of multimedia communications. The physical layer (PHY) of each of the channels can be the PHY of DOCSIS or EuroDOCSIS, wide-band, ultra-wideband, OFDM, SDM or other technologies.  
         [0015]     Other networking functions such as residential gateway (RG) can also be incorporated into the LAMC or provided externally. High-speed Internet access via a broadband modem including wide-area HFC cable modem, DSL modem, Fiber-to-the-Premises (FTTP) modem, two-way satellite modem, and fixed wireless modem, can be coupled to the LAMS via the external or internal RG.  
         [0016]     The shared medium can be a tree-branch in-premises coaxial cable. The LAMs can be legacy DOCSIS or EuroDOCSIS cable modems. The MAC implements the minimum functionality of a legacy DOCSIS MAC and other DOCSIS functionalities to initialize and register the DOCSIS or EuroDOCSIS cable modems. LAMs with multiple DOCSIS or EuroDOCSIS channels can be accommodated by enhancing the MAC with multi-channel features of a full-service MAC (fsMAC). Cable TV programming channels and the BLAN can shared the same cable spectrum.  
         [0017]     In its simplest form, each LAM has an Ethernet or USB outlet for interfacing to in-room Internet appliances or other CPE (customer premises equipment) devices. More advanced versions of the LAMs have other CPEs embedded.  
         [0018]     The QoS required by different applications such as voice, video and data can be easily accommodated by the LAMC because all transmissions to and from the LAMs are controlled and allocated by the LAMC according to the QoS needs of the applications. The capacity can be expanded according to need by adding the number of channels, limited only by the spectrum availability and cost of implementation.  
         [0019]     In accordance with still another further aspect of the present invention, if backward compatibility with legacy DOCSIS or EuroDOCSIS cable modems is not required, further simplification of the LAMC and LAMs are possible to reduce the cost and streamline the initialization and registration process. Furthermore, downstream channels can also be located beyond the DOCSIS or EuroDOCSIS frequency range for coexistence with conventional cable TV programming channels.  
         [0020]     The wide-area HFC cable modem and RG functionalities can be embedded into the LAMC so that the HFC cable modem downstream channels can be easily identified and be reused by the BLAN. Alternatively the LAMC downstream channels can be allocated by the cable operator, thus avoiding conflict with cable TV programming channels. The upstream spectrum is isolated by the wideband HFC cable modem and thus can be reused by the local area modems (LAMs).  
         [0021]     To preserve the cable TV programming channels, downstream channels identified to be used for the BLAN are filtered out before combining with the LAMC-generated downstream channels and the LAMs-generated upstream channels.  
         [0022]     Although this invention is described herein in terms of a coaxial cable medium, any other shared medium with point-to-multipoint topology in a local area environment such as wireless, power-line, or passive optical fiber can be benefited by the teachings of this invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a high-level block diagram of a broadband local area network system for a coaxial cable medium.  
         [0024]      FIG. 2  is a block diagram of the preferred embodiment of a broadband coaxial local area backbone network with a widearea HFC cable modem; it also shows the details of a local area modem controller (LAMC).  
         [0025]      FIG. 3  is a detailed diagram of an exemplary implementation a local area modem (LAM) embedded with CPE devices and networking interfaces.  
         [0026]      FIG. 4  shows the channel line-ups at various test points identified in  FIG. 2 ; it also shows how the downstream and upstream channels reuse the cable TV channels.  
         [0027]      FIG. 5  logically shows the coexistence of legacy cable modems and enhanced LAMs with various multi-channel capabilities. 
     
    
     DETAILED DESCRIPTION  
       [0028]     Referring to  FIG. 1 , a high level block diagram of a broadband local area network system based on coaxial cable is shown. A broadband service provider&#39;s access network  5  provides high-speed Internet access, digital video and voice-over-Internet Protocol (VoIP) services to the residence through a broadband modem  10  located on premises  900 . Entry for the broadband service is through wire  7  to a point-of-entry  101 . Examples of broadband modems include: DOCSIS/EuroDOCSIS cable modems for hybrid-fiber-coax (HFC), various versions of digital subscriber line (DSL) modems, fiber-to-the-premises (FTTP) modem, fixed or wideband wireless modem, and two-way satellite modem.  
         [0029]     The broadband modem  10  is typically connected to a Residential Gateway (RG)  15 , which is in turn connected to a coaxial cable broadband local area backbone network  1000 .  
         [0030]     The exemplary home backbone network  1000  comprises of a local area modem controller (LAMC)  100  and coaxial cable segments  180 ,  181 ,  182 , and  186 . The cable  186  is further split into cable segments  183  and  184  through a splitter  187 . Each of the cable segments  180 ,  181 ,  182 ,  183 , and  184  is respectively connected to a local area modem (LAM)  142 ,  144 ,  146 ,  148 , and  149  in each room (in this example, there are five rooms in the premises being networked). Each LAM  142  has at least an Ethernet interface available for interfacing to the Internet appliances or customer premises equipment (CPEs) in the room.  
         [0031]     In another embodiment, the broadband modem  10 , and/or RG can be embedded into the LAMC  100  (shown as block  2000  in  FIG. 1 ) to further optimize the performance, functionality and cost.  
         [0000]     Preferred Embodiment of Home Backbone with Cable TV and Cable Broadband Provider  
         [0032]      FIG. 2  is a preferred embodiment of the present invention for the broadband coaxial cable home network that also uses DOCSIS or EuroDOCSIS cable modem and cable TV programming services.  
         [0033]     Referring to  FIG. 2 , cable TV programming channels and DOCSIS or EuroDOCSIS cable modem channels enter coaxial cable part  101  of the wide-area HFC broadband access network  5  into the premises  900  through the point-of-entry  101  via the coaxial cable  7 . In the premises, the RF signal in the coax  7  is further split by splitter  105  into three paths: legacy coax  104 , coax to LAMC RF input  106 , and coax to wide-area HFC DOCSIS or EuroDOCSIS cable modem RF input  107 .  
         [0034]     The legacy coax  104  is further divided by splitter  151  to support legacy devices such as a legacy set-top box  152  and a legacy analog TV  154 . The coax path  104  is used to ensure full backward compatibility of existing legacy devices and no home network support is needed in that area of the premises. The coax path  104  is not essential to the operation of this broadband local area network, but is included for clarity and completeness.  
         [0035]     The coax path  107  is connected to a conventional wide-area HFC DOCSIS or EuroDOCSIS cable modem  10 , which is further connected to a residential gateway (RG)  15  via a network interface  12  such as an Ethernet CAT-5 cable or USB. The RG  110  performs packet filtering, NAT address translation, firewall, and other security and routing/bridging functions; and forwards the packets to and from the home backbone network  1000 , via a network cable  115 , to a network interface  120  coupled to a media-access-control (MAC) function  122 .  
         [0036]     The MAC  122  coordinates the forwarding of packets between multi-channel transmitter(s)  140  and multi-channel receiver(s)  130 . The MAC  122  also arbitrates upstream multiple-access packet transmissions from two or more of the local access cable modems (LAMs)  142 ,  144 ,  146 ,  148  and  149 ; and schedules packet transmissions downstream and upstream to achieve the quality of service required by applications.  
         [0037]     The MAC  122  can be implemented with both digital logic hardware, and/or software programs under the control of one or more microprocessors  102 .  
         [0038]     Each of the channels of the multi-channel transmitter(s)  140  and receiver(s)  130  can be, but not limited to, one of the following types: 
    Conventional DOCSIS/EuroDOCSIS downstream QAM channel,     Conventional DOCSIS/EuroDOCSIS upstream ATDMA/S-CDMA channel.     Wideband channel consisted of two or more DOCSIS/EuroDOCSIS channels being bonded or aggregated,     Wideband channel using channel bandwidth wider than conventional DOCSIS/EuroDOCSIS downstream or upstream channels,     Wideband channel that uses OFDM modulation scheme,     Wideband channel that uses carrier-less modulation schemes such as UWB (ultra-wideband) and SDM (Sub-band Division Modulation) with wavelet filters.    
 
         [0045]     These physical layer technologies are well-known in the art and will not be repeated here.  
         [0046]     One skill in the art will use various combinations of the number of channels and modulation types to optimize for Silicon cost, spectral efficiency and performance. In one example, a broadband LAN with two DOCSIS or EuroDOCSIS downstream and two upstream channels provides about 80 Mbps/60 Mbps in the downstream and upstream directions respectively, sufficient for most full-service multimedia audio-visual streaming, voice and data communications within a digital home.  
         [0047]     Depending on the advance of Silicon and DSP technology, the LAMC  100  can be scaled with many channels up to the entire upstream and downstream spectrum available for the broadband home network.  
         [0000]     Downstream Channels Insertion  
         [0048]     Since the downstream spectrum of a conventional HFC network is occupied by cable TV video programming channels and DOCSIS/EuroDOCSIS channels, and the upstream spectrum of a conventional sub-split HFC plant is occupied by DOCSIS/EuroDOCSIS upstream channels (and perhaps other reverse channels for applications such as plant monitoring and legacy pay-per-view), occupied channels must be freed up for use in the home backbone network.  
         [0049]     Channels can be made available (but not limited to) by one of the following methods: 
    (1) The cable service provider assigns downstream channel(s) for home networking. In this case, there is no conflict with the channel line-up. The downstream channels are tuned to the assigned channel frequencies and are inserted into the downstream spectrum. Notch filters  163  can be bypassed via RF path  162 .     (2) If no cable TV programming is subscribed, the entire cable TV downstream spectrum (54-870 MHz in DOCSIS, 65-870 MHz in EuroDOCSIS) can be used for home networking without conflict.     (3) Reuse the downstream channel(s) used for the DOCSIS/EuroDOCSIS cable modem  10 . The DOCSIS/EuroDOCSIS downstream channel profile(s) can be learned by either the cable modem  10  or LAMs, and are then communicated to the MAC  122  via signaling.     (4) Notch out the downstream channel(s) needed for home networking at channel frequencies not currently used for other in-premises cable-ready devices, which are also connected to the home network.     (5) Use channels outside the cable TV band (typically above 870 MHz depending on the HFC network). However, in this case, conventional DOCSIS/EuroDOCSIS cable modems cannot be used for LAMs.     (6) The upstream spectrum (5-42 MHz for DOCSIS or 5-65 MHz for EuroDOCSIS) is reused in the home network without interference because the upstream spectrum is isolated by the cable modem  10  and the high-pass filter  161 .    
 
         [0056]     Still referring to  FIG. 2 , cable TV programming channels will be notched out by the channel notch filters  163  (or filters if the channel used for home networking not contiguous) after filtering the programming channel RF signal  106  through the high-pass filter  161 . As described above, the notch filter(s)  163  can be bypassed by the RF path  162  if the channels are available for use without conflict to the programming channels.  
         [0057]     The output of the notch filter(s)  163  merges with the output from one or more transmitters  140  via path  141 , using a combiner  166 . The combined downstream signal is then amplified by RF amplifier  168 , and merged via path  170  with upstream receiver(s) path  132  in diplexer  134 .  
         [0058]     The output of the diplexer  134  is distributed to the rest of the premises via splitter  140  to F-connectors  600 ,  601 ,  602 , and  606 , which are connected to the in-premises coaxial cable segments (typically RG 59)  180 ,  181 ,  182 , and  186  respectively. Each cable segment typically has a length of up to 250 to 300 feet and each cable segment is typically terminated by a conventional F-type connector in a wall outlet (not shown).  
         [0059]     Each cable segment is coupled to a LAM for home networking operation. However, the cable segment can also be connected to a legacy set-top box or an analog TV.  
         [0000]     Preferred Embodiment of the Local Area Modem (LAM)  
         [0060]     There are typically three types of LAMs: 
        (1) Conventional DOCSIS/EuroDOCSIS cable modems with a single downstream-upstream channel-pair;     (2) Enhanced cable modems with multiple DOCSIS/EuroDOCSIS channels;     (3) Enhanced cable modems with a mix of DOCSIS/EuroDOCSIS channels, one or more wideband channels.        
 
         [0064]     Referring to  FIG. 3 , a preferred embodiment of one of the LAMs ( 142 ,  144 ,  146 ,  148  or  149  in  FIG. 1 ) is detailed. The incoming RF signal in the coaxial cable segment  180 ,  181 ,  182 ,  183 , or  184  enters the LAM via input F-connector  201 , and is then split by splitter  202 .  
         [0065]     One path  104  goes to output F-connector  262  for connection to an external legacy cable-ready device such as analog TV, legacy digital or analog set-top box  263 .  
         [0066]     The other path from the splitter  202  is coupled to a diplex filter  204 , which separates downstream spectrum from upstream spectrum.  
         [0067]     The downstream channels are coupled to multi-channel receiver(s)  206  that are tuned to the matching transmitter(s)  140 , for demodulation, decoding, error correction and formatting and other physical layer processing to recover packets transmitted. The packets are then forwarded to MAC  210  for further processing.  
         [0068]     Packets destined to the LAMC  100  are forwarded by the MAC  210  to multi-channel upstream transmitter(s)  208 , and are merged with the downstream RF in the diplex filter  204 . The transmitter(s)  208  performs formatting, encoding, modulation, up-conversion and other processing for transmitting to the matching receiver(s)  130  in the LAMC  100 .  
         [0069]     The MAC  210  can be implemented using one or more microprocessors  222  with control programs and other hardware to perform media access control (MAC) functions. The MAC  210  forwards packets, through a gateway function  220 , to and from embedded network functions  230 ,  244 ,  246 ,  240  and  242 , or CPE devices such as VoIP phone adapter  248 , or remote control receiver  250 .  
         [0070]     Note that in its simplest form, the LAM is implemented with at least one network interface such as the Ethernet interface  230 . Other embedded functions are implemented as required. The exemplary embedded network functions and CPEs in  FIG. 3  are listed below: 
        (1) The Ethernet bridge  230  connecting to an external Internet Protocol (IP) set-top box  232  for delivering audio-visual programs to a conventional television  233 , and connecting to a personal computer  235  for access to high-speed Internet;     (2) The USB Bridge  244  for connecting to popular USB peripherals;     (3) The IEEE 1394 Bridge  246  for connecting to IEEE 1394 enabled devices;     (4) The wireless LAN (Local Area Network) Access Point  240 , for in-premises communications;     (5) The wireless PAN (Personal Area Network) Access Point  242 , for in-room, short-range, ultra-high-speed communications;     (6) The voice-over-IP telephone adapter  248  that interfaces to a conventional telephone  247 ;     (7) The low-cost wireless remote control receiver  250 , working with a matching wireless remote control transmitter (not shown), useful for receiving video-on-demand commands for one way digital set-top boxes.        
 
         [0078]     The gateway  220  performs functions such as bridging, switching, routing, and filtering among the external network interface devices and the home backbone network. The gateway functions can be implemented in a separate microprocessor or in the microprocessor  222 .  
         [0000]     Exemplary Channel Plan for the Broadband Local Area Backbone Network  
         [0079]      FIG. 4  depicts an exemplary spectrum usage of the coaxial broadband home backbone network  1000  using multiple upstream and downstream DOCSIS/EuroDOCSIS, wide-band and ultra-wideband channels. Referring back to  FIG. 2 , RF signal test points A, B, C, D, E, and F correspond to the paths  7 ,  164 ,  141 ,  132 ,  170 , and  136  respectively.  
         [0080]     Referring to  FIG. 4 , the test point A shows the spectrum of the sub-split two-way HFC cable plant  5  comprising an upstream DOCSIS channel  310  and a downstream DOCSIS channel  304 . The sub-split spectrum has a cross-over frequency band  306  from 42 to 54 MHz. Upstream frequency band is from 5 to 42 MHz. Typically the downstream spectrum for the HFC (54 to 870 MHz) is divided into an analog video channels band  301  (typically from 54 to 550 MHz) and a digital video channels band  302 . A Satellite band  306  typically occupies frequencies greater than 950 MHz. A DOCSIS frequency band spans from 86 to 862 MHz.  
         [0081]     The test point B shows the downstream spectrum after removing the upstream channels via the high-pass filter  161 ; and removing the wide-area HFC DOCSIS downstream channel  304 , and removing another downstream channel  303  in the DOCSIS downstream frequency band  301  using the notch filters  163 . The notched-out channels  303  and  304  will be used by the broadband LAN.  
         [0082]     The test point C is the spectrum showing the LAMC  100 -generated DOCSIS downstream channels  322  and  320 , a wideband downstream channel  306 , and an ultra-wideband (UWB) downstream channel  350 . Note that UWB channel can span to frequencies beyond 1 GHz but can coexist with the carrier-based channels.  
         [0083]     The test point D is the spectrum showing the LAM-generated DOCSIS or upstream channels  331  and  332 , a wideband channel  334 , and an ultra-wideband upstream channel  341 .  
         [0084]     The test point E shows the combined downstream spectrum with the LAMC  100 -generated downstream channels  322 ,  320 ,  306  and  350 , the cable TV programming channels bands  301  and  302 , and the Satellite channels band  306 .  
         [0085]     Finally the test point F shows the combined spectrum with the LAMC  100 -generated downstream channels  322 ,  320 ,  306  and  350 , the LAMs-generated upstream channels  331 ,  332 ,  334  and  341 , the cable TV programming channels bands  301  and  302 , and the Satellite channels band  306 . This is the spectrum that each of the LAMs sees at its RF interface to the local area coaxial network.  
         [0000]     Coexistence of LAMs with Various Multi-Channel Capabilities  
         [0086]      FIG. 5  further illustrates how the LAMs with different channel capabilities coexist in the multi-channel broadband LAN environment. Logical channels connections are shown  FIG. 5 .  
         [0087]     The LAM  144  is a conventional DOCSIS cable modem that is tuned to the DOCSIS channels  322  and  332 .  
         [0088]     The LAM  142  is capable of supporting an additional DOCSIS channel-pair  320  and  331 , in additional to the DOCSIS channel-pair  322  and  332 .  
         [0089]     The LAM  148  is tuned to the ultra-wideband downstream channel  350  to provided extra throughput for fast download applications, in additional to the DOCSIS channel-pair  322  and  332 .  
         [0090]     LAM  146  is tuned to the ultra-wideband downstream channel  350 , and is tuned to transmit in the additional upstream channel  334 , in additional to the DOCSIS S channel-pair  322  and  332 , providing ultra-high speed in both the downstream and upstream directions.  
         [0091]     LAM  149  is tuned to the ultra-wideband downstream channel  350 , the wideband downstream channel  306 , and is tuned to transmit in the additional upstream channel  334  and the upstream ultra-wideband channel  341 , in additional to the DOCSIS channel-pair  322  and  332 , providing ultra-high speed in both the downstream and upstream directions.  
         [0092]     Note that the configuration shown in  FIG. 5  is exemplary only, many other combinations are possible. In any case, different types of LAMs can coexist in the multi-channel home network environment. Since all LAMs have a common DOCSIS channel-pair, they can be discovered and configured under the control of the multi-channel MAC  122  in the LAMC  100 .  
         [0000]     Multi-Channel Point-to-Multipoint MAC Protocol Operation  
         [0093]     The LAMC can implement minimal DOCSIS functionality to accommodate legacy DOCSIS or EuroDOCSIS cable modems with a single upstream and a single downstream channel. Additional functionality beyond DOCSIS needs to be added to accommodate LAMs with additional DOCSIS or EuroDOCSIS channels, wideband channels, UWB channels or channels with other physical layer technologies. There are many combinations and here are three exemplary scenarios:  
         [0094]     A) A LAMC with a single DOCSIS or EuroDOCSIS channel-pair and LAMs being legacy DOCSIS or EuroDOCSIS cable modems. Upon power-up or reset, the LAMC establishes a DOCSIS or EuroDOCSIS channel-pair and register all legacy DOCSIS or EuroDOCSIS LAMs using the procedure as described in reference [3 DOCSIS]. The LAMC must implement the necessary protocols such as DHCP server, TOD server, TFTP server and a valid DOCSIS cable modem Configuration File in order to register the DOCSIS or EuroDOCSIS cable modem before operational. The LAMC in this scenario will implement a subset of the DOCSIS MAC and other CMTS functionalities.  
         [0095]     B) LAMC with multiple DOCSIS or EuroDOCSIS channel-pairs and LAMs being legacy DOCSIS or EuroDOCSIS cable modems. Each legacy DOCSIS or EuroDOCSIS cable modem will initialize, range, and register on a DOCSIS or EuroDOCSIS channel-pair. The LAMC can distribute the load by moving the LAMs to different DOCSIS or EuroDOCSIS channel-pairs using DCC (dynamic channel change) protocol. In this scenario, the LAMC will implement a subset of the DOCSIS MAC and other CMTS functionalities. A typical LAMC startup sequence is as follows: 
        1) Establishes at least one DOCSIS or EuroDOCSIS downstream-upstream channel-pair by broadcasting in each of the downstream channels, a periodic SYNC MAC message, and a periodic UCD and a periodic MAP MAC messages for each of the upstream channels;     2) Performs initializing ranging and registering the DOCSIS or EuroDOCSIS cable modems and the multi-channel LAMs using one of the channel-pairs;     3) Distributes the downstream and upstream bandwidth to the local area modems by moving the cable modems to one of the specific DOCSIS or EuroDOCSIS channel-pairs using DCC MAC messages;     4) Arbitrates upstream multiple access transmissions according to DOCSIS MAC protocol; and     5) Schedule upstream and downstream transmissions according to the DOCSIS MAC protocol.        
 
         [0101]     C) LAMC and LAMs supporting multiple channels of DOCSIS or EuroDOCSIS and non-DOCSIS physical layer types. The channels can be a mix of DOCSIS or EuroDOCSIS channels, wideband channels, ultra-wideband channels, OFCM channels, and, but not limited to, SDM channels. The preferred embodiment is to use the fsMAC technology described in reference [9 Eng]. A typical startup sequence from the LAMC perspective is as follows: 
        (1) Establishes time synchronization among a LAMC and LAMs by broadcasting in a downstream-control-and-payload channel (DCPC), a periodic SYNC (time-stamp synchronization ) MAC Message;     (2) Establishes a fsMAC (full-service media-access-control) domain by broadcasting a periodic MDCD (fsMAC Domain Channels Descriptor) MAC message in the DCPC, thereby identifying the fsMAC domain, downstream channels and upstream channels, with the channel profiles and burst profiles supported by the LAMC;     (3) Initializes the upstream receivers using the channel profiles and burst parameters in step (2);     (4) Calibrates (including ranging, adjusting power, frequency, timing and equalization coefficients) upstream transmitters of the LAMs using MMAP (multi-channel MAP), CEQ (calibration Request), and CRSP (Calibration response) MAC messages;     (5) Initializes the downstream receivers in the LAMs by the channel profiles;     (6) Establishes one of the upstream channel as upstream-control-channel (UCC), designated by an indication in the MDCD message for communicating MAC messages to the LAMC;     (7) Registers the LAMs which now become operational;     (8) Schedules packet transmissions in one or more downstream channels simultaneously or sequentially;     (9) Arbitrates upstream bandwidth requests from one or more LAMs using bandwidth request (BREQ) MAC message; and schedules bandwidth grants using the MMAP messages; each of the grants including an amount of bandwidth granted to the LAM to transmit at a specific time, at one of the upstream channels, and with one of the burst profiles.        
 
         [0111]     If there is a mix of legacy DOCSIS or EuroDOCSIS cable modems and multi-channel LAMs, a designated DOCSIS or EuroDOCSIS channel-pair can be used to register all modems and served as DCPC and UCC channel-pair for MAC messages.  
         [0112]     The initialization can be simplified if legacy DOCSIS or EuroDOCSIS CM supported is not needed. A simpler layer-2 forwarding model can be used in the home backbone network. Provisioning servers such as DHCP, TFTP, TOD, and configuration files may be replaced by a simplified provisioning method.  
         [0113]     Alternatively, other point-to-multi-points MAC protocols similar to DOCSIS or fsMAC can be modified to use in the broadband local area network. Examples are: IEEE 802.16 fixed wireless protocol and IEEE 802.3ah Multi-Point Control Protocol.  
         [0114]     Although the invention has been disclosed in terms of the preferred and alternative embodiments disclosed herein, those skilled in the art will appreciate possible alternative embodiments and other modifications to the teachings disclosed herein which do not depart from the spirit and scope of the invention. All such alternative embodiments and other modifications are intended to be included with the scope of the claims append hereto.