IL160035A - Wideband subscriber interface device - Google Patents

Description

160035 p'Ji I 453476 τηκ A WIDEBAND SUBSCRIBER INTERFACE DEVICE 160035/2 A WIDEBAND SUBSCRIBER INTERFACE DEVICE RELATED APPLICATIONS The present application is generally related to co-pending PCT Publication No. WO 02/33968, entitled SYSTEM AND METHOD FOR EXPANDING THE OPERATIONAL BANDWIDTH OF A COMMUNICATION SYSTEM, filed 16 November 2000, to co-pending PCT Publication No. WO 03/94347 , entitled A WIDEBAND CATV SIGNAL SPLITTER DEVICE, filed 2 May 2002, to co-pending Israeli patent application serial number 157285, entitled A WIDEBAND CATV TAP DEVICE, filed 6 August 2003, and to co-pending Israeli patent application serial number 154673, entitled A WIDEBAND NODE IN A CATV NETWORK, filed 27 February 2003, which are incorporated herein by reference.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates generally to cable television distribution networks. More particularly the present invention relates to a wideband subscriber interface device for the processing of a wideband CATV signal. The device further relates to conversion of wideband signal to legacy frequencies.

DISCUSSION OF THE RELATED ART Traditionally, analog services providing cable television content have been carried over an electronic signal having a frequency range of about 75- 500MHz The recent advent of technology requires the suitable expansion of the transmission spectrum or the frequency bandwidth of carrier signals sent and received across the physical distribution path. Thus, new services can today be carried over a larger portion of the traditional spectrum, which typically spans the total frequency range of 5-860 MHz. Currently, the frequency range of about 5- 42 MHz is dedicated to the upstream traffic and is designed to be sent from the subscribers of the networks to a cable network head end. Cable television (CATV) operators must continue to provide analog contents within analog channels for economic, regulatory, and legal reasons. As a result the about 130-450 MHz or the 130-550 MHz frequency band remains dedicated to the transmission of the traditional analog channels.

In a modern CATV network implemented in the U.S.A. as well as in certain other countries, between 700 MHz and 800 MHz of bandwidth is generally available for downstream transmissions from the cable head end equipment to the subscriber, while in the US less than 40 MHz and in Europe less than 60 MHz are generally available for the return path. Until lately, this asymmetry had not been a concern due to the prevailing transmission needs of upstream traffic. Typically, upstream traffic comprised subscriber-submitted requests involving subscriber demands for the reception of video programs, music programs, live radio transmissions, data files, multi-media content, applications, and the like, in the downstream. The volume of these files has been typically much higher than the volume of the respective requests. As a result early proprietary cable modem systems and the subsequent DOCSIS releases called for spectrally efficient modulation schemes in the downstream path and relatively low-rate but robust schemes in the upstream. Recent trends suggest that data traffic over HFC networks is becoming gradually more symmetric as certain applications and services demand more upstream bandwidth. This upstream channel is extremely narrow and cannot supply the demand for upstream traffic even if such upstream traffic is compressed. The present alternatives such as fiber optic or ADSL UDSL service are expensive or lack the capacity to meet the demand. In addition, the utilization of the 5-42 MHz (or 5-65 MHz in some countries) frequency portion as the reverse path raises the problem of ingress noise. Ingress noise in a CATV network is typically generated by the operation of electric household devices as well as other EMI, RFI pick-ups in the vicinity of the drop system and the subscriber premises. Ingress is especially critical at the lower frequencies. Since, currently the only portion of the transmission spectrum 160035/2 for the reverse path spans the 5-42 MHz or the 5-65 MHz frequency range ingress is a dominant problem for the CATV operators attempting to implement two-way services. The result is that less than 20 MHz can be operatively used for efficient data transmission in the reverse path . This is because, in large part, of the noise funneling effect of the reverse path. It is becoming widely accepted that a large percent of ingress problems stem from the drop system (drop and subscriber premises) and only a small per cent of ingress originates in the trunk and feeder network. Also, the hard line of the feeder network is typically well-shielded and better maintained while the drop system is of lower shielding quality. In addition, the drop system is the least accessible, least controllable and least maintained portion of the network. In an effort to speed the activation of the reverse plant, many CATV operators are installing high-pass filters and windowed filters on every home. Although fairly effective and affordable, heavy reliance on filtering can be only a limited or temporary solution.

Persistent commercial competition among the different CATV operators requires the continuous improvement of the services provided to their subscribers, such as the addition of new video and audio channels, more flexible programming, symmetrical data services as required by telephony over cable, TI/EI type requiring guaranteed symmetric bandwidth, multi-user games over CATV networks, video telephony requiring symmetrical bandwidth, and other advanced services. The above-mentioned limitation concerning the availability of the bandwidth for digital services substantially hinders the ability of the CATV operators to compete successfully on today's extremely dynamic market where new cable network-related services are being developed and implemented continuously and new requests are made constantly by the increasingly sophisticated customer base concerning the enhancement of the desired programming mix PCT Publication No. WO 02/33968 titled SYSTEM AND METHOD FOR EXPANDING THE OPERATIONAL BANDWIDTH OF A COMMUNICATION SYSTEM, discloses a system and method for substantial extension in the bandwidth of a cable signal distribution network. The enhanced transmission capacity network is capable of transmitting a wideband signal of about 3 GHz.

It would be readily understood by one with ordinary skills in the art that there is a need for a device that provides a two-way interface between an enhanced transmission capacity CATV distribution network that is capable of transmitting a wideband signal of up to 3 GHz and between legacy Customer Premises Equipment (CPE) capable of handling a conventional CATV signal with a bandwidth of 5-860 MHz Preferably, the required device should also provide a solution for the minimization of noise and for increased signal to noise ratios in the reverse path.

SUMMARY OF THE PRESENT INVENTION It is an objective of the present invention to introduce a wideband subscriber interface apparatus designed to convert an extended frequency signal in the range of 1000-3000 MHz to or from legacy CATV signals in the range of 5-860 MHz such as to enable the processing of the additional extended signals by existing standard Customer Premises Equipment (CPE) devices.

It is a further objective of the present invention to introduce means that will not require installation and utilization of new CPE devices but use existing CPE units said means allow for the interfacing of the existing CPE devices to the wideband subscriber interface apparatus.

It is still another objective of the present invention to provide a method of operation of the wideband subscriber interface apparatus such as to allow the operation of an interface between the wideband subscriber interface apparatus and the existing CPE devices.

It is yet another objective of the present invention to provide means to modify the physical layer (level one) of a CATV network such that the support of any proprietary software and/or any protocol is maintained.

One aspect of the present invention regards a wideband subscriber interface apparatus in a cable signal distribution network. The wideband subscriber interface apparatus is operative in the division, frequency conversion, and multiplexing of signal sub-bands included in a wideband signal. The apparatus comprises the elements of a triplexer device to separate the wideband signal into a legacy signal, a high-frequency downstream signal, and a high-frequency upstream signal, and a downstream frequency converter device to down-convert the high-frequency downstream signal into a down-converted legacy signal for enabling the utilization of standard legacy Customer Premises Equipment (CPE) devices.

A second aspect of the present invention regards a wideband subscriber interface device in a cable signal distribution network. The wideband subscriber interface apparatus is operative in the division, frequency conversion, and multiplexing of signal sub-bands included in a wideband signal. The apparatus comprises the elements of a diplexer device to separate in the upstream direction the legacy signal into an upstream signal,; and an upstream frequency converter device to up-convert the upstream signal into a high frequency signal block having pre-defined frequency range limits within a high-frequency upstream signal sub-band.

A third aspect of the present invention regards a block division multiplexing method in a cable signal distribution network. The block division multiplexing method is operative in the division, frequency conversion and multiplexing of signal sub-bands included in a wideband signal. The method comprises the steps of separating the wideband signal into a legacy signal, into a high-frequency downstream signal, and into a high-frequency upstream signal, and down-converting the high-frequency downstream signal into a down converted legacy signal. - A fourth aspect of the present invention regards a block division multiplexing method in a cable signal distribution network. The block division multiplexing method is operative in the division, frequency conversion, and multiplexing of signal sub-bands included in a wideband signal. The method comprises the steps of separating in the upstream direction the legacy signal into an upstream signal, and up-converting the upstream signal into a high-frequency signal frequency block having pre-defined frequency range limits within a high-frequency upstream signal sub-band.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: Fig. 1A illustrates the frequency plan of the transmission spectrum of a legacy CATV signal with a frequency range of 5-860 MHz in a cable television distribution network; Fig. IB illustrates the frequency plan of the transmission spectrum of a CATV signal with a frequency range of about 5-3000 MHz in a cable television distribution network upgraded for the transmission of a wideband signal; Fig. 2 is simplified schematic block diagram of a cable television system (CATV) where the client premises equipment (CPE) includes a wideband subscriber interface device, in accordance with the preferred embodiments of the present invention; Fig. 3 illustrates the frequency plan of the transmission spectrum of the wideband signal of about 5-3000 MHz and the manipulation of the sub-bands included therein by the wideband subscriber interface device, in accordance with the preferred embodiments of the present invention; Fig. 4 is an electrical schematic illustration of the wideband subscriber interface device, in accordance with the first preferred embodiment of the present invention; Fig. 5A illustrates the frequency plan of the frequency spectrum of a conventional CATV signal with a frequency range of about 5-860 MHz in a legacy cable television distribution network; Fig. 5B illustrates the frequency plan of the transmission spectrum of a CATV signal with a frequency range of about 5-860 MHz in a legacy cable television distribution network; Fig. 6 is an electrical schematic illustration of the wideband subscriber interface device, in accordance with the second preferred embodiment of the present invention; Fig. 7A illustrates the frequency plan of the frequency spectrum of a conventional CATV signal with a frequency range of 5-860 MHz in a legacy cable television distribution network; Fig. 7B illustrates the frequency plan of the transmission spectrum of a wideband CATV signal in a cable television distribution network; Fig. 8 is an electrical schematic illustration of the wideband subscriber interface device, in accordance with the third preferred embodiment of the present invention; and Fig. 9 is schematic block diagram of the wideband subscriber interface device, in accordance with the fourth preferred embodiment of the present invention. 160035/2 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present application is generally related to co-pending PCT Publication No. WO 02/33968 entitled SYSTEM AND METHOD FOR EXPANDING THE OPERATIONAL BANDWIDTH OF A COMMUNICATION SYSTEM, filed 16 November 2000, to co-pending PCT Publication No. WO 03/94347 , entitled A WIDEBAND CATV SIGNAL SPLITTER DEVICE, filed 2 May 2002, to co-pending Israeli patent application serial number 157285, entitled A WIDEBAND CATV TAP DEVICE, filed 6 August 2003, and to co-pending Israeli application serial number 154673 entitled A WIDEBAND NODE IN A CATV NETWORK, filed 27 February 2003, which are incorporated herein by reference.

A novel wideband subscriber interface device to be used in a CATV network is disclosed. The wideband subscriber interface device is operative in the appropriate extension of the frequency plan and the frequency range of a CATV signal in order to enable the continued standard operation of legacy equipment. The subscriber inter face device is connectable to a standard set top box or a cable mode or like device. The subscriber interface device converts a first frequency band to a second frequency band that can be received or sent by the standard cable modem or set top box. The subscriber interface device allow the use of high band frequency within the cable TV plant while retaining the use of legacy equipment at the subscriber's location. To achieve these objectives, the present invention is operative in the division and in the modification of bandwidth blocks. The method is referred to as Block Division Multiplexing (BDM). The implementation of the BDM method enables the adding up of services (through the use of wide band signal) to the CATV network subscribers without changing the coaxial wires in the last mile physical infrastructure. The BDM method involves the translation of frequencies and associated signals from the extended frequency band into the legacy frequency band. The BDM method further involves the translation of frequencies and associated signals from the legacy frequency band into the extended frequency band The implementation of the BDM in the wideband subscriber interface device allows for the continued operation of the existing legacy equipment, such as set top boxes (STBs) and modems, without modifications. The principal objective of the present invention is to provide a device and method that would enable the continued utilization of existing legacy CPE devices and thereby negate the need for the addition of new CPE. This objective is achieved by interfacing the existing CPE devices to the wideband subscriber Interface device. The principal function of the wideband subscriber Interface device is to convert the extended frequency signals in the exemplary range of 1000-3000 MHz to or from the legacy CATV signals in the range of 5-860 MHz such as to enable the processing of the additional extended signals by the existing standard legacy CPE subscriber units, such as set top boxes and/or modems. The person skilled in the art will appreciate that while ranges of frequency are noted in the present application, these are exemplary and may be replaced with similar or alternative ranges.

The wideband subscriber interface allows the extension of the bandwidth from 1000 MHz and upwards to 3000 MHz thus providing additional upstream and downstream bandwidth. The invention enables the up and down conversion of transmissions such that legacy frequencies are up or down converted into bands made available by the wideband novel system. Thus, the apparatus of the present invention enables the up conversion of legacy spectra in the upstream of 5-42MHz to pre-defined agile sub-band between 2250-2750 MHz, and downstream down conversion of 1250-1950 MHz signals to the legacy 48-860 MHz, using the additional bandwidth made available by the use of the wideband subscriber interface. The wideband subscriber interface is preferably a self contained unit, which could be external or internal to any current standard set top box or modem designed to perform the up and down conversions in order to allow for the use of legacy equipment within a bandwidth environment in excess of 860MHz.

The wideband signal of about 5-3000 MHz consists of various frequency sub-bands is received from a wideband node device installed in a specifically adapted and upgraded network plant in accordance to the teaching of the referenced PCT Publication No. WO 02/33968 entitled SYSTEM AND METHOD FOR EXPANDING THE OPERATIONAL BANDWIDTH OF A COMMUNICATION SYSTEM, the referenced PCT Publication No. WO 03/94347 , entitled A WIDEBAND CATV SIGNAL SPLITTER DEVICE, filed 2 May 2002, the referenced Israeli patent application serial number 157285, entitled A WIDEBAND CATV TAP DEVICE, filed 6 August 2003, and the referenced co-pending Israeli patent application serial number 154673, entitled A WIDEBAND NODE IN A CATV NETWORK. The wideband signal is processed by the wideband subscriber interface device, such as to generate a signal with the legacy frequency range of 5-860 MHz to be fed to legacy CPE of a network subscriber, such as a residential subscriber, a small or medium-sized business (SMB), and the like. In the upstream, the legacy signal of about 5-860 MHz consists of various sub-bands is received from the CPE. The legacy signal is processed by the wideband subscriber interface device, such as to generate a wideband signal with a frequency region of about 2250-2750 MHz to be fed in the reverse path to the node device of the specifically adapted and upgraded cable distribution network. The wideband subscriber interface device is typically installed in the subscriber's premises between a wall outlet and a set-top box and/or a cable modem Thus, the wideband subscriber interface device is connected on the fust end to the wall outlet via which, in the downstream, a wideband CATV signal is fed from the CATV distribution network to the subscriber premises, and in the upstream the wideband CATV signal is fed to a CATV head-end via a node device The wideband subscriber interface device is connected at second end to an analog or a digital set-top box and/or a cable modem, such as a DOCSIS-compliant modem, installed on the subscriber's premises In the first preferred embodiment of the invention the wideband subscriber interface device (referred to hereinafter as the XTB) provides for the processing of a wideband CATV signal with a bandwidth of about 5-3000 MHz. The gener ation of the about 5-3000 MHz signal and the manner of upgrading the CATV distribution network in order to enable the generation, processing, maintenance, and transmission of the wideband signal is described in detail in the co-pending PCT patent application entitled SYSTEM AND METHOD FOR EXPANDING THE OPERATIONAL BANDWIDTH OF A COMMUNICATION SYSTEM. It would be easily understood by one with ordinary skills in the art that in other preferred embodiments the XTB could be utilized for the appropriate processing and manipulation of a signal with a wider bandwidth, such as having a frequency range with an upper limit which is substantially above 3000 MHz or with a narrower bandwidth, such as having a frequency range of with an upper limit of about 1000 MHz. In the preferred embodiments of the present invention the XTB is utilized for service-specific processing of the frequency regions or frequency sub-bands included in the wideband signal. Such processing includes the extraction of pre-defined signal sub-bands from pre-defined portions of transmission spectrum, the up-conversion and/or the down-conversion of pre-defined signal sub-bands extracted from predefined portions of the transmission spectrum and to the * overlaying of the extracted sub-bands into different pre-defined portions of the transmission spectrum. Performing these operations effects the modification of frequency plan and the frequency range of the wideband signal in order to enable the legacy equipment of the subscriber, such as cable modems, computing devices, set-top boxes, and TV devices to receive, process, and transmit a legacy CATV signal with a legacy frequency range of 5-860 MHz from/to the XTB. Thus, in the preferred embodiment of the invention, in the downstream, the XTB down-converts the downstream portion of the wideband signal into the legacy frequency range of 54-860 MHz in order to enable the appropriate operation of the CPE of a subscriber. In the upstream, the XTB up-converts the 5-42 MHz sub-band of the legacy signal, generated subsequent to the performance of specific operations of the network subscriber, into a pre-defined agile high-frequency sub-band.

Referring now to Fig. 1A that illustrates the frequency plan a legacy CATV signal typically generated, processed, maintained, and transmitted in a legacy CATV distribution network. The spectrum 10 is divided into an upstream portion 12 and a downstream portion 14. The upstream portion 12 of the signal spans a frequency region of about 5-42 MHz. The upstream sub-band 12 is typically used for data traffic and signaling from the CPE of a subscriber via the CATV plant to a head end. The upstream data is generated by the CPE consequent to diverse requests and/or demands and/or commands and/or data, submitted by the subscriber, such as the ordering of pay-per-view programs, the participation in various surveys, the playing of games, the requesting of the data files, and the like. The downstream portion 14 of the signal spans a frequency range of about 54-860 MHz. The downstream sub-band 14 is used for the transmission of the regular ubiquitous analog and digital TV channels to the subscriber from the head end. The downstream sub-band 14 could be further used for diverse other applications, such as for the transmission of data files, pay-per-view programs, voice transmission in telephony applications, and the like.

Referring to Fig. IB describes an upgraded, extended CATV spectrum enabling the transmission of signals having a considerably extended frequency range. The extended signals will be referred to herein after as the wideband signals. In the first preferred embodiment of the invention the wideband signals are modulated across a frequency range of about 5-3000 MHz or higher. The substantial extension of the frequency range enables the provision of a plurality of new digital services to the subscriber including but not limited to two-way, symmetrical or near-symmetrical applications. The term symmetrical refers to any system in which data speed or quantity is the same in both directions, averaged over time. The wideband signal 20 comprises a legaey upstream portion 22, a legacy downstream portion 24, an extended downstream portion 26, and an extended upstream portion 28. In order to maintain the existing legacy services (currently providing analog TV channels, digital TV channels, and the like) the legacy upstream sub-band 22 of about 5-42 MHz and the legacy downstream signal 24 of about 54-860 MHz are practically identical functionally and structurally to the upstream sub-band 12 of Fig. 1A and to the downstream sub- herein after as the new downstream) is allocated a frequency range of about 1250-1950 MHz. The sub-band 26 is designed to provide additional services to the subscriber, such as a video-on-demand, high-definition TV (HDTV), music-on-demand, Internet access, cable telephony, e-mail, video telephony, video conferencing, and the like. The sub-band 26 carries additional service-specific content from the head end to the subscriber. The extended upstream portion 28 (referred to herein after as the new upstream) is allocated a frequency range of about 2250-2750 MHz in one specific embodiment of the invention. The sub-band 28 may be operative in the carrying of DOCSIS-compliant data encoding additional-service-specific content in the reverse path from the subscriber to the head end. The sub-band 28 is typically divided into discrete frequency blocks 30, 32, 34, 36, 38, and 40 where each block having a bandwidth of about 30 MHz so as to be compatible with current standards, in order to provide for a considerable increase in the volume of the upstream traffic. A more detailed description of the functionality of the frequency blocks 30, 32, 34, 36, 38, 40 within the new upstream sub-band 28 will be set forth herein under in conjunction with the following drawings. The person skilled in the art will appreciate that the frequency ranges shown are exemplary and that other frequency ranges can be employed such that the extended portions of the frequency ranges are allocated different ranges.

Referring now to Fig. 2, in the preferred embodiments of the present invention the XTB is installed within a CATV distribution network 50. The CATV distribution network 50 includes, among other devices, a network head-end 52, a Cable Modem Termination System (CMTS) interface 54, a CATV network a wideband hub 60, a plurality of wideband tap devices 64, 66, 70, 72, 76, 78, a plurality of wideband line extension amplifiers 68, 74, and an infrastructure of cabling devices 58 in the trunk section of the network that could be fiber optic cables, coaxial cables or a combination thereof. The cabling devices connect the network head-end 52 with a network subscriber 82 operating a customer premises equipment complex 96. The CMTS 54 is installed typically in the head-end 52. The CMTS 54 is typically linked to a wide-area data communication network 56, such as the Internet, via a network browser (not shown). Two downstream CATV signals having a frequency range of about 100-800 MHz is fed, via the fiber 58, via the CATV network wideband hub device 60, via the distribution cable 62, via the wideband line extension amplifiers 68, 74 to the wideband tap devices 64, 66, 70, 72, 76, and 78. Note should be taken that the entire set of devices installed within the CATV network 50 infrastructure are suitably adapted/upgraded for the transmission of the wideband signal according to the teachings of the above-mentioned related co-pending patent applications. The wideband signal is fed from the wideband tap device 76 via the tap drop cable 80 to a CATV network subscriber 82. The subscriber 82 operates a complex of Customer Premises Equipment (CPE) devices 96. The CPE complex 96 devices include a wall outlet 84, an wideband subscriber interface unit (XTB) 86, a legacy set-top box 88, a legacy cable modem 94, such as a DOCSIS-compliant modem, a television set (TV device) 90, and a digital processor device 92, such as a desktop computer, a laptop computer, or the like. The wideband signal is relayed from the tap device 76 to the wall outlet 84.. The wideband signal is relayed from the wall outlet 84 to the XTB 86. In the downstream, the XTB 86 processes the downstream wideband signal by down-converting sub-bands contained within the extended frequency portion (about 1250-1950 MHz) of the signal to sub-bands contained within the legacy frequency range (about 54-860 MHz) and feeds the legacy frequency range signal containing the down-converted sub-bands to the to the cable modem 94. The legacy portion of the wideband signal is relayed directly to the legacy set-top box 88 without any modifications. The standard set-top box 88 passes the subscriber-selected sub-band of the legacy portion of the signal directly to the TV device 90, while the cable modem 94 feeds the suitable subscriber-selected sub-band of the down-converted signal to the computing device 92. In the upstream, consequent to specific requests submitted by the subscriber 82 by utilizing the appropriate input devices of the computing device 92 or the control devices of the TV device 90, a particularly generated subscriber-specific upstream signal is fed to the cable modem 94 and/or the standard set-top box 88 that- relays the subscriber-specific signal to the XTB 86. The XTB 86 up-converts the subscriber-specific signal to a pre-defined frequency block contained within the new upstream portion of the wideband signal within the 2250-2750 MHz range, and thereby overlaying the wideband signal with the up-converted sub-band. The XTB 86 then relays the wideband signal upstream via the wall outlet 84 and the drop cable 80 to the tap device 76, via the CATV network infrastructure 62, via the wideband node device 60 to the network head-end 52.

The structure and the functionality of the wideband node device 60 was described in detail in the related Israeli patent application serial number 154673, titled A WIDEBAND NODE IN A CATV NETWORK and dated 27 February 2003, the contents of which is incorporated herein by reference. The wideband node device as disclosed by the above-referenced patent application, enables the transmission of a wideband signal consisting of the legacy spectrum of about 5 - 860 MHz, a new downstream spectrum of about 1000 - 2000 MHz and a new upstream spectrum of about 2000 - 3000 MHz. The new upstream spectrum enables transfer of data in the upstream direction employing multiple upstream bands. The operation of the wideband node provides a method for the division, frequency conversion and multiplexing of a pre-defined number of signal sub-bands included in a high frequency upstream band signal of a combined wideband signal of about 5 to 3000 MHz. The wideband node separates in the upstream direction the wideband signal into the high frequency band signal and a CATV signal of about 50 to 860 MHz. Then the wideband node amplifies the high frequency band signal in the upstream direction, splits the amplified high frequency band signal into a pre-defmed number of reproduced signals in the upstream direction. The frequency sub-bands of the reproduced signals are down- converted into a pre-defined number of down-converted signals in the upstream direction. Then the down-converted signals are multiplexed into a combined signal in the upstream direction. The wideband node is further operative in the transmission of the legacy portions of the CATV signal in the downstream direction.

Still referring to Fig. 2 the appropriate portions of the signal are decoded and transmitted to the suitable network addresses of the data communications network 56 by the CMTS router interface 54. In response to a specific request carried by the transmitted signal the suitably addressed remote network unit downloads the requested information to the browser associated with the CMTS 54. The CMTS 54 encodes the received signal and inserts the encoded signal carrying the requested information to the wideband CATV signal in a predefined manner in order to be carried in the downstream via the CATV network infrastructure to the specific network subscriber 82. Note should be taken that although on the drawing under discussion only a limited number of tap devices and drop cable devices and only a single network subscriber and an associated CPE are shown, in a realistic environment a plurality of tap devices could be installed across the CATV network feeding a plurality of CPEs with the downstream signal. The plurality of the tap devices further receives upstream signals from the plurality of CPEs and transmitting the upstream signal back to the network head-end. Note should be taken that in other preferred embodiment of the invention the head end 52 could include diverse other devices. The head end could further include a satellite receiver/transmitter for applications involving satellite access.

Referring now to Fig. 3 the wideband CATV signal 112 is practically identical to the signal 20 of Fig. IB. In the first preferred embodiment of the invention the signal 112 is allocated a substantially extended frequency range of about 5-3000 MHz. Note should be taken that in other preferred embodiments the signal could be provided with a higher bandwidth, such as about 5-4000 MHz and even higher. In yet other embodiments a narrower bandwidth could be allocated, such as 5-1000 MHz. The wideband signal 112 includes several pre-defined sub-bands where each sub-band carries a functionally specific type of content information, such as a TV channel, a music channel, and the like. The legacy upstream sub-band 1 14 of about 5-42 MHz is reserved for the current legacy upstream content information, such as for example, encoded requests submitted by a network subscriber concerning the ordering of specific pay-per-view TV programs, residential Internet access, and the like. The requests are encoded into the CATV signal and sent upstream from the CPE complex 96 of Fig. 2 via the wideband hub device 60 to the head-end 52. The legacy downstream sub-band 116 of about 4—860 MHz carries legacy downstream content, such as analog and digital CATV channels provided for the network subscriber 82 in. order to be displayed selectively on the TV device 90 thereof. Then new downstream sub-band 118 located within the frequency range of about 1250-1950 MHz carries additional downstream content, such as multi-media content provided by the remote computers and/or services constituting the data communication network 56 of Fig. 1 in response to requests submitted by the network subscriber 82. The new upstream sub-band of about 2250-2750 MHz is allocated to carry the requests submitted by the network subscriber 82 concerning desired data, such as multi-media content from the data communication network 56. The frequency region of the new upstream sub-band 120 is sub-allocated into frequency blocks of about 30 MHz where each sub-allocated portion 122, 124, 126, and 128 carries data from a specific CPE complex associated with a specific network subscriber. The sub-allocation of the extended upstream sub-band 120 is pre-determined and performed by the suitable components of the XTB 86. Subsequent to the submittal of a communication request by the network subscriber 86 a subscriber-specific signal of about 12-42 MHz is generated, such as the signals 138, 140, 142, and 144. The subscriber-specific signals 138, 140, 142, and 144 are relayed to the specific XTB 86 of each respective subscriber. The signals 138, 140, 142, 144 are each up-converted by the respective XTBs 86 in a pre-programmed manner into specific blocks 130, 132, 134, and 136 respectively. Each signal 138, 140, 142, 144, associated with a given different subscriber, is up-converted to a different frequency range where the frequency limits are defined in a pre- determined manner and stored as parameters in a micro controller installed in the XTB 86. Thus, for example, the sub-band 138 of about 12-42 MHz is up-converted to a sub-band 130 of about 2250-2280 MHz, the sub-band 140 of about 12-42 MHz is up-converted to a sub-band 132 of about 2350-2380 MHz, the sub-band 142 of about 12-42 MHz is up-converted to a sub-band 134 of about 2350-2380 MHz, and the like. The up-converted sub-bands 130, 132, 134, 136, now capable of serving many more subscribers at substantially higher data speeds ,are spectrally overlaid on the new upstream sub-band 120 of about 2250-2750 MHz by the XTB 86. In the downstream, the XTB 86 is operative in the down-converting of the new downstream sub-band 118 to a sub-band 129 of about 100-860 MHz. A more detailed description of the structure, functionality and operation of the XTB 86 will be provided herein under in association with the following drawings. Note should be taken that the above-described frequency band allocations are exemplary only. In accordance with the operative requirements of the type of service provided to the network subscriber the limits of the sub-bands as well as the sub-allocation limits within a certain sub-band could differ. Further note should be taken that although on the drawing under discussion only four sub-allocation regions are shown the size and the number of the sub-allocated frequency regions could vary in accordance with the size of the new upstream sub-band.

The co-pending Israeli patent application serial No. 154673 entitled A WIDEBAND NODE IN A CATV NETWORK discloses a novel node device that enables transmission of a wideband signal in compliance with various acceptable transmission standards and protocols. The signal consists of a legacy spectrum of about 5-860 MHz as well as a new downstream spectrum of about 1000-2000 MHz and a new upstream spectrum of about 2000-3000 MHz or about 930-1100 MHz. The wideband node device enables transfer of data in the upstream and the downstream thus providing networking services to residential subscribers, as well as to small or medium-sized businesses (SMB), which may operate under existing DOCSIS protocols and controlled by standard DOCSIS routers.

Referring now to Fig. 4 the wideband subscriber interface device 200 includes a triplexer device 204, a diplexer device 222, a CPU (or microprocessor) 248, a first downstream amplifier 208, a first downstream variable attenuator 210, a first downstream mixer 212, a second downstream variable attenuator 214, a first downstream low pass filter 216, a second downstream amplifier 218, an upstream variable attenuator 230, a first phase upstream mixer 232, a first upstream SAW filter 234, a first upstream attenuator 236, an first upstream amplifier 238, a second upstream attenuator 240, a second phase upstream mixer 242, an first shutdown upstream amplifier 244, a second shutdown upstream amplifier 246, a first PLL controller 250, a second PLL controller 260, a second SAW filter 254, a control signal amplifier 256, a third PLL controller 262, and a frequency divider 258. The CPU 248 is programmed to control the first and second shutdown upstream amplifiers 246, 244, the first, second, third PLL controllers 250, 260, 262. The PLL controller 250 controls the mixer 242, the PLL controller 260 controls the signal source 252, and the PLL controller 262 drives the mixer 212. The first, second, and third PLL controllers 250, 260, 262 operate in accordance with control instructions delivered by the CPU 248 by a serial data bus. The triplexer 204 is connected to the wall outlet 84 via port 202. The diplexer 222 is connected to the legacy cable modem 94 of Fig. 1 via port 224. The port 228 is connected to the legacy set-top box 88 of Fig. 2.

Still referring to Fig. 4, first the structure, the functionality, and the operation of the XTB 200 will be described regarding the downstream direction. In the downstream, the extended wideband signal of about 5-3000 MHz is fed from the network head-end 52 of Fig. 2, via the CATV network cable infrastructure, via the wideband node device 60 of Fig. 2, via the specific wideband tap device 76 of Fig. 2, via the wall outlet 84 of Fig. 1, and via the port 202 to the triplexer 204. The frequency range and the frequency plan of the wideband signal are identical to the frequency range and frequency plan of the signal 112 of Fig. 3. Triplexer 204 is a filtering section that separates the wideband signal into the legacy sub-bands 114 and 116 of Fig. 3 of about 5-860 MHz, the new downstream sub-band 118 of Fig. 3 of about 1250-1950 MHz, and the new upstream band of about 2250-2750 MHz.. The legacy downstream sub-band 116 includes the frequency portion of the signal that carries the legacy components of the content provided by a typical CATV distribution network, such as analog and digital television channels. The legacy downstream sub-band signal 116 is fed directly to the legacy set-top box 88 of Fig. 2 via the port 228. Subsequently, the legacy downstream sub-band signal 116 is processed by the legacy set-top box 46 and relayed to the TV device 90 of Fig. 2. The legacy upstream portion 114 of the about 5-42 MHz is also handled by the legacy set top box 46. Thus, the legacy portion of the wideband signal is preserved and routed to the appropriate CPE components. In the first preferred embodiment of the invention the new downstream sub-band 118 of Fig. 3 with a frequency range of about 1250-1950 MHz carries data transmitted from the data network 56 of Fig. 2. The sub-band 118 is filtered by the triplexer 204 and amplified by the downstream amplifier 208, and attenuated by the first downstream variable attenuator 210. The signal is down-converted by the mixer 212 from the frequency range of about 1250-1950 MHz to the frequency range of about 100-800 MHz. Next, the down-converted signal is attenuated by the first downstream attenuator 214 and filtered by the first downstream low pass filter 216 to eliminate local oscillator high frequency harmonics. The signal is then amplified by the downstream amplifier 218 and following the amplifier 218 the down-converted, signal is fed into the diplexer 222. The diplexer 222 relays the signal to the legacy cable modem 94 of Fig. 2 via the port 224. The legacy cable modem 94 processes the signal and sends the signal to the computing device 92 of Fig. 2. The signal is appropriately decoded and the information carried therein is displayed, stored and enables interaction with by the network subscriber via the control devices of the computing device 92. The new downstream sub-band 118 includes a pilot signal at a frequency of about 1908 MHz. The function of the pilot signal is to maintain signal coherence. The mixer 212 down-converts the pilot signal to a frequency of about 140 MHz. The pilot signal is fed through the SAW control filter 254, and the control signal amplifier 256 into the PLL 260. The PLL 260 controls the crystal controlled frequency source 252 in accordance with the pilot signal frequency in order to determine the frequency limits of sub-allocated region in the extended upstream sub-band in the upstream. The PLL 262 controls the mixer 212 in accordance with pre-defined instruction received from the CPU 248.

Still referring to Fig. 4, in the upstream, the diplexer 222 receives from the cable modem 94 a subscriber-specific upstream signal 138 orl40 or 142 or 144 of Fig. 3 that were generated by various subscribers following specific requests and/or demands and/or commands submitted concerning controlled access and interaction with remotely located computing devices across the data network 56 of Fig. 2. The diplexer 222 is a filtering section that separates subscriber- having a frequency range of about 5-42 MHz . The variable attenuator 230 attenuates the subscriber-specific upstream signal, and the first phase upstream mixer 232 up-converts the upstream signal to an intermediate frequency range. The up-converted signal is filtered by the upstream SAW filter 234, attenuated by the first upstream attenuator 236, amplified by the first upstream amplifier 238, attenuated by the second upstream attenuator 240 and up-converted by the second phase upstream mixer 242. The frequency limits of the sub-allocated band into which the signal is up-converted is controlled by the PLL 250 that is controlled in turn by the instructions sent from the CPU 248 and by the signal generated by the frequency source 252 responding to the value of the pilot signal frequency. The up-converted signals 130, 132, 134, 136 are relayed optionally through an upstream shutdown section that includes a first upstream shutdown amplifier 244 and a second upstream shutdown amplifier 246. In accordance with the control instructions delivered from the CPU 248 via the serial data bus, the amplification of the signals could be disabled and thereby could cause the effective lowering of the signal strength in order to prevent data network access upon a fault condition. The CPU 248 initiates the shutdown option following the reception of a local access-lock detect signal. The up- converted signal sub-bands 130, 132, 134, 136 are respectively overlaid on the new upstream sub-band 120 of Fig. 3 of about 2300-2900 MHz. The new upstream signal 120 is fed into the triplexer 204. The triplexer 204 combines the new upstream signal 120, and the legacy upstream signal 114, and sends the combined signal to the network head-end 52 of Fig. 2 via the CATV cable infrastructure.

In the first preferred embodiment of the invention the functions of the wideband subscriber interface device are: a) receiving a wideband signal from the CATV distribution plant, b) separating the wideband signal into a legacy sub-band, a new downstream sub-band, and a new upstream sub-band, c) feed the legacy band directly to the legacy set-top box, d) down-converting the new downstream frequency band in order to enable appropriate handling by the legacy modem, e) feeding the down-converted frequency band to the legacy modem, f) receiving subscriber-specific upstream data from the legacy modem, h) up-converting the upstream data into a pre-defined frequency block within a new upstream sub-band, i) combining the legacy upstream sub-band, and the new upstream band, and j) feeding the combined new upstream wideband signal via the reverse path to the node device via the distribution part of the network.

The conversion of the frequency range and the frequency plan of the wideband signal enable the extension of the downstream and upstream bandwidth and thereby provides the option for the CATV operators of adding new channels associated with new services while negating the necessity of replacing the costly legacy CPE. In addition, since the upstream data is fed upstream from the CPE through the drop system within the high frequency portions of the signal the ingress noise (typically introduced into the lower frequency signal in the subscribers' premises and in the drop system) is substantially reduced. The carrying of the upstream data in high-frequency sub-bands further enables the use of high-order efficient modulation schemes in the upstream.

It would be readily perceived by one with ordinary skills in the art that the above description of the wideband subscriber interface device (XTB) is exemplary only. The same objectives could be accomplished using somewhat different components, alternative interconnections, different component values and the like. Diverse supplementary functions could be added to enhance the operation of the interface device and diverse advanced applications could be contemplated that could benefit from the concept underlying the operation of the device.

Referring now to Fig. 5A the second preferred embodiment of the invention allows for the addition several (6 to 8) upstream frequency blocks with considerably less CATV infrastructure modifications. The drawing under discussion illustrates variations of frequency range availability in the downstream in a current legacy CATV distribution network. The signal 300 is divided into an upstream portion 302 of 5-42 MHz, and a downstream portion 304, 306, 310 of 54-860 MHz. The downstream portion is divided into a first downstream portion 304 with an upper limit of 550 MHz, a second downstream portion 306 with an upper limit of 750 MHz, and a third downstream portion 310 with an upper limit of 860 MHz. The upper limit of the combined downstream portion is network-specific and is basically determined by the CATV operator taking into consideration the penetration of the last-mile upgrades. The upstream sub-band 302 is typically used for the carrying of data from the CPE of a network subscriber via the CATV plant to a head end. The upstream signal is generated by the CPE in response to the introduction of diverse requests and/or demands and/or commands and/or data by the subscriber. The downstream sub-band 304, 306, 310 is used for the transmission of the regular analog and digital channels to the subscriber from the head end. The downstream sub-band 304, 306, 310 could be further used for diverse other applications, such as for the transmission of additional data, pay-per-view programs, voice transmission in telephony applications and the like. Signal 312 includes a legacy upstream portion 314, a legacy downstream portion 316, 318, 320, and an extended upstream portion 322. In order to maintain the existing legacy services (currently provided analog and digital TV channels, and the like) the legacy upstream sub-band of 5-42 MHz and the legacy downstream signal 316, 318, 320 of 54-860 MHz are functionally and structurally identical to the upstream sub-band 302 of Fig. 5 A and to the downstream sub-band 304, 306, 310 of Fig. 5B respectively. The extended upstream portion 322 (referred to herein after as the new upstream) is allocated a frequency range of 950-1 150 MHz. The sub-band 322 is operative in the carrying of DOCSIS-compliant data encoding additional-service-specific content in the reverse path from the subscriber to the head end. The sub-band 322 is typically divided into several (6 to 8) blocks of frequencies 324, 326, 328, 330, 332 in order to increase the volume of the upstream traffic. Each block of frequencies provides for an upstream channel of 5-42 MHz. A more detailed description of the functionality of the frequency blocks 324, 326, 328, 330, 332 within the new upstream sub-band 322 will be set forth herein under in conjunction with the following drawings. It would be readily perceived by one with ordinary skills in the art that the addition of upstream or downstream channels or frequency bands is exemplary only. Other component values and frequency bands can be used in a similar fashion through the different allocation of bandwidth resources to suit the varying needs of CATV networks.

Referring now to Fig. 6 in the second preferred embodiment of the invention, the 1 GHz subscriber interface device 400 (referred to herein after as 1GHZ-XTB) is operative in providing the addition of , 6 up to 8 new upstream channels associated with new .upstream frequency blocks while keeping the infrastructure of the existing CATV plant intact. The number of the new upstream blocks that could be added is determined in accordance with the upper limit of the downstream region 316+318+320. The 1GHZ-XTB device 400 includes a first diplexer 404, a second diplexer 408, a splitter 460, an upstream poly-phase device 416, a first phase upstream mixer device 418, a first upstream amplifier device 420, a first upstream SAW filter 422, a second phase upstream mixer device 426, an upstream variable attenuator 424, a first upstream low-pass filter 428, a first shutdown upstream amplifier 430, a second shutdown upstream amplifier 432, a CPU (or microprocessor) 415, a first PLL controller 410, a second PLL controller 414, and a signal source 412, The CPU 415 is programmed to control the first and second shutdown upstream amplifiers 430, 432, the first PLL controller 410, and the second PLL controller 414. The PLL controller 410 drives the mixer 418, and the PLL controller 414 drives the mixer 426.; The first and second PLL controllers 410, 414 operate in accordance with control instructions delivered by the CPU 415 by a serial data bus. The first diplexer 404 is connected to the wall outlet 84 of Fig. 3 via the port 402. The second diplexer 408 is connected to the legacy cable modem 94 of Fig. 2 via the port 406. The splitter 450 is connected to first diplexer 404. The splitter 450 splits equally the legacy signal 5-860 MHz to the CATV port 451 and to the subscriber port 406.

Still referring to Fig. 6 first the structure, the functionality, and the operation of the 1GHZ-XTB 400 will be described regarding the downstream direction. In the downstream, the downstream signal is fed from the network head-end 52 of Fig. 2, via the CATV network cable infrastructure, via the node device 60 of Fig. 2, via the specific tap device 76 of Fig. 2, via the wall outlet 84 of Fig. 2, and via the port 402 to the diplexer 404. The frequency range and the frequency plan of the signal are identical to the frequency range and frequency plan of the signal 312 of Fig. 5B. Note should be taken that in the second preferred embodiment of the invention, the signal received has a frequency range of about 5-1150 MHz. Diplexer 404 is a filtering section that separates the wideband spectrum to the legacy spectrum of about 5-860 MHz and to the extended spectrum of about 950-1150 MHz that includes the frequency portions of the signal that carries the legacy content provided by a typical CATV distribution network, such as analog and digital television channels. The legacy downstream sub-band signal 316, 318, 320 is fed directly to the legacy set-top box 88 of Fig. 2 via the diplexer 408, and via the port 406. Subsequently, the legacy downstream sub-band signal 316, 318, 320 is processed by the legacy set-top box 88 of Fig. 2 and relayed to the TV device 90 of Fig. 2. Thus, the legacy portion of the signal is suitably preserved and routed to the appropriate CPE components Still referring to Fig. 6, in the upstream direction, the diplexer 408 receives from the cable modem 94 of Fig. 2 a subscriber-specific upstream signal that was generated following specific requests and/or demands and/or commands submitted the subscriber concerning controlled access and interaction with remotely located computing devices across the data network 56 of Fig. 2. The diplexer 408 is a filtering section that separates the subscriber-specific upstream signals each having a frequency range of about 5-42 MHz. The subscriber-specific upstream signals are fed from the diplexer 408 via an upstream path to the diplexer 404. The upstream path includes a first phase upstream mixer 418 to up-convert the upstream signal to an intermediate frequency range. The up-converted signal is amplified by the first upstream amplifier 420, filtered by the first upstream SAW filter 236, attenuated by the first upstream attenuator 424, up-converted by the second phase upstream mixer 426, and filtered by the first low pass filter 428. The frequency limits of the sub-allocated band into which the signal is up-converted is controlled by the PLL 414 that is controlled in turn by the instructions sent from the CPU 415 and by the signal generated by the frequency source 412. In a manner similar to the first preferred embodiment the subscriber-specific upstream signal of 5-42 MHz is up-converted to pre-defined frequency blocks of 30 MHz and overlaid on the new upstream sub-band 322 of 950-1150 MHz. The up-converted signals are fed optionally via an upstream shutdown section that includes a first upstream shutdown amplifier 430 and a second upstream shutdown amplifier 432. In accordance with the control instructions delivered from the CPU 415 via the serial data bus, the amplification of the signals could be disabled and thereby could cause the effective lowering of the signal strength in order to prevent data network access. The CPU 415 initiates the shutdown option following the reception of a local access-lock detect signal. The new upstream signal 312 is fed into the diplexer 404. The diplexer 404 combines the new upstream signal 322, the legacy downstream signal 316, 318, 320, and sends the combined signal to the network head-end 52 of Fig. 2 via the CATV cable infrastructure. Note should be taken that in the second preferred embodiment of the invention, the signal fed from the diplexer 404 to the CATV cable plant is having a frequency range of about 5-1150 MHz.

In the second preferred embodiment of the present invention the wideband subscriber interface device (1GHZ-XTB) has the following functionsf a) receiving an about 1.1 GHz signal from the CATV distribution plant, b) separating the received downstream signal into a legacy downstream sub-band, and a new upstream sub-band, c) feeding directly the legacy band to the legacy set-top box, d) receiving upstream data generated by the subscriber from the legacy modem, e) up-converting the upstream data a pre-defined frequency block within a new upstream sub-band, f) combining the legacy upstream sub-band, and the new upstream band into a wideband signal, g) feeding the signal via the reverse path to the wideband node device via the distribution part of the network. The modifications concerning the frequency range and the frequency plan of the signal enable the extension of the upstream bandwidth and thereby provides the option for the CATV operators of adding new two-way services while negating the necessity of replacing passive CATV infrastructure components, such as splitters, taps, and the like, nor legacy CPE components. In addition, since the upstream data is fed upstream from the CPE through the drop system within the high frequency portions of the signal the ingress noise (typically introduced into the signal in the subscribers' premises and in the drop system) is substantially reduced. The frequency conversion of the upstream data further enables the use of high-order modulation schemas in the upstream.

It would be readily perceived by one with ordinary skills in the art that the above description of the lGHz subscriber interface device (1GHZ-XTB) is exemplary only. The same objectives could be accomplished using somewhat different components, alternative interconnections, different component values and the like. Diverse supplementary functions could be added to enhance the operation of the interface device and diverse advanced applications could be contemplated that could benefit from the concept underlying the operation of the device.

Referring now to Fig. 7 A that illustrates the frequency plan of a legacy CATV signal typically generated, processed, maintained and transmitted in a legacy CATV distribution network. The signal 500 is divided into an upstream portion 502 and a downstream portion 503. The upstream portion 502 spans a frequency range of about 5-42 MHz. The upstream sub-band 502 is typically used for the carrying of data from the CPE of a network subscriber via the CATV plant to a head end. The upstream data is generated by the CPE consequent to diverse requests and/or demands and/or commands submitted by the subscriber, such as the ordering of pay-per-view programs, the performance of surveys, games, and the like. The downstream portion 503 spans a frequency range of about 54-860 MHz. The downstream sub-band 503 is divided into sub-bands where each sub-band carries specific media content. Thus, the sub-band 504 with 54-88 MHz carries a first audio channel, and the sub-band 506 with 88-108 MHz carries a second audio channel. The sub-bands 508, 510 with 108-400 MHz carry analog TV broadcast content while the sub-bands 512, 514, 516 with 400-750 or 400-860 MHz carry digital TV content and additional digital services. The analog TV content is kept at lower frequencies while digital video broadcasting starts around 400 MHz.

Referring to Fig. 7B in the third preferred embodiment of the invention the wideband signal is modulated across a frequency range of about 5-1500 MHz. The wideband signal 520 comprises a legacy upstream portion 522 of 5-42 MHz, a legacy downstream portion 521 of about 54-860 MHz, and an extended downstream portion 530 of about 1200-1500 MHz. The new downstream portion of 1200-1500 MHz is generated in the wideband node. The new downstream is detected by the wideband subscriber interface unit at the customer's premises. The downstream sub-band is down-converted to 100-400 MHz and is added to the legacy sub-band of 400-860 MHz carrying DVB programming. Since a digital set-top box is tunable to 120-860 MHz the digital set-top box can operate in full capacity adding numerous Video-On-Demand channels, HDTV channels and other digital broadcasts. The present programming of band frequency is illustrative as an alternative embodiment of the present invention may be used in order to supply digital video broadcasting since digital tuners are presently tunable to frequencies of 100-400Mhz.

Referring now to Fig. 8 in the third preferred embodiment of the invention, a low-cost DTV application-specific wideband subscriber interface device 600 (referred to herein after as XDTV-XTB) provides for the frequency conversion of the sub-bands included in a wideband signal of about 5-1500 MHz into sub-bands included in a legacy signal portion 'of about 5-860 MHz. The frequency conversion enables the legacy CPE components to handle the modified sub-bands within of the legacy frequency range of about 5-860 MHz. The XDTV-XTB 600 includes a first triplexer device 604, a second triplexer device 610, a first downstream band pass filter 620, a second downstream band pass filter 606, a third downstream band pass filter 612, a first upstream low pass filter 626, a first downstream amplifier 618, a second downstream amplifier 625, a mixer device 616, a signal generator device 626, a PLL device 624, and an MCU device 622. The XDTV-XTB 600 performs the following tasks: a) conversion of the about 1200-1500 MHz frequency band to the new about 100-400 MHz frequency band, and b) combining the new about 100-400 MHz band and the old about 400-860 MHz digital band. The first triplexer 604 receives the wideband signal from the port 602 and splits the pass band of the coaxial cable to three sub-bands: a) an about 400-860 MHZ downstream frequency range that carries the old digital channels, b) the about 1200-1500 MHz downstream frequency range that carries the new digital channels, and c) the about 5-42 MHz upstream frequency range utilized to preserve the upstream characteristics of the CATV plant. The about 1200-1500 MHz sub-band is down-converted by the PLL/VCO/Mixer 621 (controlled by a programmable micro-controller unit (MCU) 622) to about 100-400 MHz. The about 400-860 MHz sub-band is relayed to the second triplexer 610 directly. Consequently, the two downstream sub-bands are combined at the second triplexer 610 in order to create a complete pass band for the digital channels from about 100 MHz to about 860 MHz. The complete about 100-860 MHz band is fed to the subscriber's digital set top box via the port 608. The about 5-42 MHz upstream is relayed to the coaxial cable without being processed and therefore its characteristics is substantially preserved. It would be readily perceived by one with ordinary skills in the art that the above description of the XDTV-XTB is exemplary only. The same objectives could be accomplished using somewhat different components, alternative interconnections, different component values and the like. Diverse supplementary functions could be added to enhance the operation of the top box device and diverse advanced applications could be contemplated that could benefit from the concept underlying the operation of the device.

Referring now to Fig. 9 the fourth preferred embodiment of the present invention concerns a wideband subscriber interface unit (referred to herein after WXTB). The WXTB 700 enables the addition of 430 MHz of digital information or a full spectrum of 120-860 MHz. In a manner similar to the third preferred embodiment of the invention, the additional digital information is transmitted downstream from the head end in a frequency band of 1200-1600 MHz. The WXTB 700 performs the following tasks: a) conversion of the about 1200-1650 MHz frequency band to the new about 100-550 MHz frequency band, and b) combining the new about 100- 550 MHz band and the old about 550-860 MHz digital band. A first triplexer 706 at the port 708 splits the pass band of the coaxial cable to three sub-bands: a) an about 550-860 MHZ downstream frequency range that carries the old digital channels, b) the about 1200-1650 MHz downstream frequency range that carries the new digital channels, and c) the about 5-42 MHz upstream frequency range utilized to preserve the upstream characteristics of the CATV plant. The about 1200-1650 MHz sub-band is down- converted by the PLL/VCO/Mixer 702 (controlled by a programmable microcontroller unit (MCU) 730) to about 100-550 MHz. The about 550-860 MHz sub- band is relayed to the output triplexer 714 directly. Consequently the two downstream sub-bands are combined at the second triplexer 712 in order to create a complete pass band for the digital channels from about 100 MHz to about 860 MHz. The complete about 100-860 MHz band is fed to the subscriber's digital set top box) via the port 714. The about 5-42 MHz upstream is relayed to the coaxial cable without being processed and therefore its characteristics are substantially preserved. It would be readily perceived by one with ordinary skills in the art that the above description of the wideband subscriber interface device (WXTB) is exemplary only. The same objectives could be accomplished using somewhat different components, alternative interconnections, different component values and the like. Diverse supplementary functions could be added to enhance the operation of the top box device and diverse advanced applications could be contemplated that could benefit from the concept underlying the operation of the device.

The description of the preferred embodiment of the present invention is not meant to be limiting to other possible embodiments already contemplated of the present invention. For example in the future the substantially expended bandwidth of the signal could reach frequencies in the excess of 3 GHz. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims which follow. 160035/2

Claims (44)

1. An apparatus for connecting a subscriber device supporting a legacy frequency band, occupying the frequency range of 0-1 GHz, to a wideband distribution network supporting a wide frequency band including at least a legacy downstream frequency band and a legacy upstream frequency band comprised in said legacy frequency band, an extended upstream frequency band, occupying the frequency rage of 2-3 GHz, exterior to said legacy frequency band and not supported by said subscriber device, and an extended downstream frequency band occupying the frequency range of 1 -2 GHz, exterior to said legacy frequency band and not supported by said subscriber device; the apparatus comprising: an up-converter to up-convert a subscriber upstream signal within a subscriber upstream frequency band within said legacy frequency band supported by said subscriber device, into an up-converted upstream signal within an upstream sub-band of said extended upstream frequency band; and a down-converter to down-convert an extended downstream signal in said extended downstream frequency band into a down-converted downstream signal within a downstream frequency band supported by said subscriber device.

2. The apparatus of claim 1, wherein said up-converter is able to allocate said upstream sub-band based on a predetermined sub-band allocation scheme.

3. The apparatus of claim 1 comprising a multiplexer able to: selectively route said extended downstream signal to said down-converter; and selectively route said up-converted upstream signal to said network.

4. The apparatus of claim 3, wherein said multiplexer is further able to: 160035/2 selectively route a downstream signal in said legacy downstream frequency band from said network to another subscriber device supporting said legacy downstream frequency band; and selectively route an upstream signal in said legacy upstream frequency band from the other subscriber device to said network.

5. The apparatus of claim 3 comprising a diplexer to: selectively route said subscriber upstream signal to said up-converter; and selectively route said down-converted downstream signal to said subscriber device.

6. The apparatus of claim 1, wherein the downstream frequency band supported by said subscriber device comprises at least a sub-set of a frequency band of 100-800MHz.

7. The apparatus of claim 1 , wherein said extended downstream frequency band comprises at least a sub-set of a frequency band of 1250-1950MHz.

8. The apparatus of claim 1 comprising a network diplexer able to: selectively route a downstream signal in said legacy downstream frequency band from said network to said subscriber device; and selectively route said up-converted upstream signal to said network.

9. The apparatus of claim 8 comprising a subscriber diplexer to: selectively route said subscriber upstream signal to said up-converter; and selectively route the downstream signal in said legacy downstream frequency band to said subscriber device.

10. The apparatus of claim 9 comprising a splitter to split the downstream signal in said legacy downstream frequency band into first and second downstream signals in said legacy downstream frequency band to be provided to said subscriber diplexer and to another subscriber device, respectively. 160035/2

11. 1 1. The apparatus of claim 1, wherein the subscriber upstream frequency band comprises at least a sub-set of a frequency band of 5-60MHz.

12. The apparatus of claim 1, wherein said extended upstream frequency band comprises at least a sub-set of a frequency band of 2250-2750MHz or 1000-1 150MHz.

13. The apparatus of claim 1 , wherein said sub-band comprises at least a sub-set of a frequency band of 2250-2280 MHz, 2400-2430MHz, 2550-2580MHz, or 2600- 2630MHz.

14. The apparatus of claim 1, wherein said subscriber device comprises a customer- premises-equipment device.

15. The apparatus of claim 14, wherein said customer-premises-equipment device comprises a customer-premises-equipment device selected from the group consisting of a legacy set-top-box and a legacy modem.

16. The apparatus of claim 1 comprising a subscriber multiplexer to: selectively route an upstream signal in said legacy upstream frequency band from said subscriber device to a network multiplexer; selectively route said down-converted downstream signal to said subscriber device.

17. The apparatus of claim 16 comprising a network multiplexer is able to: selectively route said extended downstream signal to said down-converter; and selectively route the upstream signal in said legacy frequency band to said network.

18. The apparatus of claim 17, wherein said network multiplexer is able to selectively route a downstream signal in said legacy downstream frequency band from said network to said subscriber multiplexer, and wherein said subscriber multiplexer is able to selectively route the downstream signal in said legacy downstream frequency band to said subscriber device. 160035/2

19. The apparatus of claim 1 , wherein the subscriber downstream frequency band comprises at least a sub-set of a frequency band of 100-400MHz or 100-550MHz.

20. The apparatus of claim 1, wherein said extended downstream frequency band comprises at least a sub-set of a frequency band of 1200-1500MHz, or 1200- 1650MHz.

21. The apparatus of claim 1, wherein said legacy upstream frequency band and said legacy downstream frequency band comprise at least a sub-set of a legacy frequency band of 5-l OOOMHz.

22. A method of connecting a subscriber device supporting a legacy frequency band occupying the frequency range of 0-1 GHz, to a wideband distribution network supporting a wide frequency band including at least a legacy downstream frequency band and a legacy upstream frequency band comprised in said legacy frequency band, and an extended upstream frequency band, in the frequency range of 2-3 GHz, exterior to said legacy frequency band and not supported by said subscriber device, and an extended downstream frequency band, in the frequency range of 1-2 GHz, exterior to said legacy frequency band and not supported by said subscriber device, the method comprising: up-converting a subscriber upstream signal within a subscriber upstream frequency band within said legacy frequency band supported by said subscriber device, into an up-converted upstream signal within an upstream sub-band of said extended upstream frequency band; and down-converting an extended downstream signal in said extended downstream frequency band into a down-converted downstream signal within a downstream frequency band within said legacy frequency band supported by said subscriber device.

23. The method of claim 22 comprising allocating said upstream sub-band based on a predetermined sub-band allocation scheme. 160035/2

24. The method of claim 22 comprising: selectively routing said extended downstream signal to a down-converter; and selectively routing said up-converted upstream signal to said network.

25. The method of claim 24 comprising: selectively routing a downstream signal in said legacy downstream frequency band from said network to another subscriber device supporting said legacy downstream frequency band; and selectively routing an upstream signal in said legacy upstream frequency band from the other subscriber device to said network.

26. The method of claim 24 comprising: selectively routing said subscriber upstream signal to an up-converter; and selectively routing said down-converted downstream signal to said subscriber device.

27. The method of claim 22, wherein the downstream frequency band supported by said subscriber device comprises at least a sub-set of a frequency band of 100-800MHz.

28. The method of claims 22, wherein said extended downstream frequency band comprises at least a sub-set of a frequency band of 1250-1950MHz.

29. The method of claim 22 comprising: selectively routing a downstream signal in said legacy downstream frequency band from said network to said subscriber device; and selectively routing said up-converted upstream signal to said network.

30. The method of claim 29: selectively routing said subscriber upstream signal to an up-converter; and selectively routing the downstream signal in said legacy downstream frequency band to said subscriber device. 160035/2

31. The method of claim 30 comprising a splitting the downstream signal in said legacy downstream frequency band into first and second downstream signals in said legacy downstream frequency band to be provided to said subscriber diplexer and to another subscriber device, respectively.

32. The method of claim 22, wherein the subscriber upstream frequency band comprises at least a sub-set of a frequency band of 5-60MHz.

33. The method of claim 22, wherein said extended upstream frequency band comprises at least a sub-set of a frequency band of 2250-2750MHz or 1000-1150MHz.

34. The method of claim 22, wherein said sub-band comprises at least a sub-set of a frequency band of 2250-2280 MHz, 2400-2430MHz, 2550-2580MHz, or 2600- 2630MHz.

35. The method of claim 22 comprising: selectively routing an upstream signal in said legacy upstream frequency band from said subscriber device to a network multiplexer; selectively routing said down-converted downstream signal to said subscriber device.

36. The method of claim 35 comprising: selectively routing said extended downstream signal to a down-converter; and selectively routing the upstream signal in said legacy frequency band to said network.

37. The method of claim 36 comprising: selectively routing a downstream signal in said legacy downstream frequency band from said network to said subscriber device.

38. The method of claim 22, wherein the subscriber downstream frequency band comprises at least a sub-set of a frequency band of 100-400MHz or 100-550MHz. 160035/2

39. The method of claim 22, wherein said extended downstream frequency band comprises at least a sub-set of a frequency band of 1200-1500MHz, or 1200-1650MHz.

40. A system comprising: a wideband distribution network supporting a wide frequency band including at least a legacy downstream frequency band and a legacy upstream frequency band comprised in a legacy frequency band, occupying the frequency rage of 0-1 GHz, supported by a subscriber device, an extended upstream frequency band, in the frequency range of 2-3 GHz, exterior to said legacy frequency band and not supported by a subscriber device, and an extended downstream frequency band, in the frequency range of 1 -2 GHz, exterior to said legacy frequency band and not supported by said subscriber device; an apparatus for connecting said subscriber device supporting said legacy frequency band to said network, said apparatus comprising an up-converter to up-convert a subscriber upstream signal within a subscriber upstream frequency band within said legacy frequency band supported by said subscriber device, into an up-converted upstream signal within an upstream sub-band of said extended upstream frequency band; and a down-converter to down-convert an extended downstream signal in said extended downstream frequency band into a down-converted downstream signal within a downstream frequency band supported by said subscriber device.

41. The system of claim 40, wherein said apparatus comprises a network diplexer able to: selectively route a downstream signal in said legacy downstream frequency band from said network to said subscriber device; and selectively route said up-converted upstream signal to said network.

42. The system of claim 41, wherein said apparatus comprises a subscriber diplexer to: selectively route said subscriber upstream signal to said up-converter; and 160035/2 selectively route the downstream signal in said legacy downstream frequency band to said subscriber device.

43. The system of claim 40, wherein said apparatus comprises a subscriber multiplexer to: selectively route an upstream signal in said legacy upstream frequency band from said subscriber device to a network multiplexer; selectively route said down-converted downstream signal to said subscriber device.

44. The system of claim 40, wherein said apparatus comprises a network multiplexer is able to: selectively route said extended downstream signal to said down-converter; and selectively route the upstream signal in said legacy frequency band to said network. For the Applicant,