WO2003017529A1

WO2003017529A1 - Satellite tv and satellite internet for catv network

Info

Publication number: WO2003017529A1
Application number: PCT/IL2001/000781
Authority: WO
Inventors: Hillel Weinstein; Zeev Orbach
Original assignee: Xtend Networks Ltd.
Priority date: 2001-08-21
Filing date: 2001-08-21
Publication date: 2003-02-27
Also published as: EP1419593A1

Abstract

A method and system for the delivery of information from diverse content provider service networks to subscribers of a terrestrial CATV network is disclosed. The subscribers of the CATV network interact dynamically with the content provider networks by submitting requests for the delivery of data, video, services and other content information. The requests are suitably transmitted via the CATV cable plant to a content provider service network interface associated with the cable plant and are forwarded therefrom to the appropriate content provider service networks. The content information delivered by the appropriate service networks is received by the content provider service network interface and forwarded to the requesting subscribers. The request and content information is transmitted through the cable infrastructure at substantially high data rates. The high transfer rates are accomplished by the encoding of the information into a broadband signal having a substantially expanded bandwidth.

Description

SATELLITE TV AND SATELLITE INTERNET FOR CATV NETWORK

RELATED APPLICATIONS This application is related to PCT application No. PCT/IL00/00655 by Zeev Averbuch and Dr. Hillel Weinstein entitled "System and Method for Expanding the Operational Bandwidth of a Communication System", filed 16^th November 2000 which is incorporated by reference.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to communications networks, in general and to a method and system for enabling the subscribers of a terrestrial CATV network with the option of dynamically interacting with diverse content-providing communications networks via a flexible bi-directional signal path that includes terrestrial cables and communications satellites, in particular.

DISCUSSION OF THE RELATED ART In a relatively short time, communications satellites have become an essential part of global communication. A communications satellite is an electronics retransmission device serving as a repeater normally placed in orbit around the earth for the purpose of receiving and retransmitting electromagnetic signals. The signals are transmitted from terrestrial transmitters to the satellite and are re-transmitted ubiquitously by transponders deployed on board of the satellite, to terrestrial receivers disposed within a geographic receiving area (usually referred to as the satellite's footprint) within the area covered by the transmitting satellite. The signals are transmitted at very high frequencies typically in the microwave ranges. After being received by one or more antennas the transmitted signals are amplified and processed by satellite signal interfaces and are transmitted to end-user devices such as television sets or personal computers.

Communications satellite networks are unrestrained by the physical limitations of the infrastructure established on the ground, such as extensive land-transmission lines containing hundreds of miles of cables, a multitude of suitable connectors, and other diverse electronic components used to maintain the transmitted signal at the required stable characteristics. As a result, satellite systems are capable of transmitting signals across a substantially wider bandwidth than terrestrial communications systems are capable of distributing. Satellite networks also typically employ highly advanced state-of-art technologies such as digital transmission techniques, advanced QPSK modulation methods, real-time data compression routines, transmission path reuse via different polarization schemes, and the like. Higher power satellites have more recently been developed to broadcast signals to terrestrial cable systems or directly to the subscribers' houses. Advanced systems implementing direct delivery methods are referred to as Direct Broadcast Satellite (DBS) systems or Direct to Home (DTH) satellite systems.

Recently as a result of a series of technological developments the quantity of the video, audio, and data content distributed via satellite channels grew by a quantum increase. Literally thousands of channels are available through satellite broadcasting as a result of several significant advantages these networks now have in comparison with conventional land-based communications systems. The application of these technologies to the transmitted signals enables the satellite operators to deliver a multitude of channels to their subscribers. Currently an immense number of commercially available satellite channels exist that offer to the public a huge variety of diverse services, such as entertainment,, information, and communications. The extensive selection of programs and services made available to the public gives a substantial competitive advantage to the satellite networks over the existing land-based networks. The Internet is a large set of computer networks that communicate with each other, typically over telephone lines or wireless links. It enables companies, organizations, individuals, schools and governments to share information across the world. Recently a number of companies began to offer two-way satellite Internet access to customers desiring to access and interact with Internet information content stored within the network. Usually the service is referred to as the "satellite Internet".

The satellite Internet service is necessary for users living in geographically remote areas or in countries with little terrestrial infrastructure for broadband access to the data network while. Satellite Internet does not use telephone lines or cable systems but instead uses a satellite dish for two-way (up load and download) data communication. The download speed range is about 150-1200 Kbps depending on factors such as Internet traffic, the capacity of the server, and the sizes of downloaded files. Upload speed is about a tenth of the download speed. Terrestrial cable and DSL have higher download speeds but satellite systems are substantially faster than a typical modem. Satellite Internet uses Internet Protocol (IP) multicasting technology, which means up to 5,000 channels of communication can simultaneously be served by a single satellite. IP multicasting sends data from one point to many points simultaneously by sending data in compressed format thereby reducing the size of the data and the bandwidth. Typically, dial-up land-based terrestrial systems have bandwidth limitations that prevent multicasting of this magnitude.

A two-way satellite Internet service requires the installation of specific hardware devices at the subscribers' premises. Typically the hardware consists of a satellite dish antenna, a transceiver (transmitter/receiver), two modems (for downlink and uplink), and coaxial cables connecting the antenna with the modems. The hardware devices operate in the microwave portion of the radio spectrum. The satellite Internet connection is an arrangement in which the upstream (outgoing) and the downstream (incoming) data are sent from, and arrive at, a computer through a satellite. In a two-way satellite Internet connection, the upstream data is usually sent at a slower speed than the downstream data arrives. Thus, the connection is asymmetric. Satellite Internet systems are a rather expensive option for the subscribers due to the high cost of satellite interface units installation. Currently a number of firms offer or develop two-way satellite

Internet. For example, StarBand (Gilat) is a company that offers a two-way, high-speed satellite Internet service, which uses a single satellite dish antenna installed at the subscribers' premises for receiving and for sending information. Thus, no telephone connection is needed. An asymmetrical service, StarBand downloads data at faster speeds than it uploads. The download speeds average 500 Kbps at the maximum and 150 Kbps at busy access times. Upload speeds are slower, with StarBand claiming for a minimum 50 Kbps. Although for standard Internet access such as typical browsing an asymmetric service is quite satisfactory, there are many types of applications that require symmetrical transmission. Some exemplary applications that could benefit substantially from symmetrical transmissionare; full-motion video conferencing, FTP sessions, on-line gaming, peer-to-peer networking, virtual reality, and the like.

Satellite TV is the transmission of broadcast signals through artificial communications satellites. Typically positioned in geo-stationary orbit satellites have been used since the 1960's to relay television pictures around the world. Digital satellite TV channels are distributed by DBS systems that offer digital images that are better than those delivered by cable television, and provide hundreds of channels while analog cable distribution networks are capable of carrying only a few dozen. A great benefit of the DBS system as opposed to prior systems is that only a small dish-type antenna is required to receive_. the DBS signals and the alignment of the receiving dish is not critical. Thus, to enable individual households satellite reception, an outdoor unit including a small satellite dish assemblage associated with a Low Noise Block Converter (LNBC) unit, a polarizer element, and an indoor unit including a satellite tuner, and (whenever applicable) a descrambler component, are required. For an uplink segment a larger dish antenna and a costly microwave exciter transmitter are required.

In respect to the other satellite TV distribution networks DBS systems also have multiple drawbacks. One disadvantage of DBS systems is that the reception units have to be purchased or rented by the consumer and have to be installed individually at the consumers' premises at a considerable expense. Currently DBS systems also lack ancillary services, such as high-speed data streaming, telephone and two-way interactivity when accessing data communications networks. Another drawback of the satellite distribution systems concerns the geographical limitations of the receiving area or the satellite's footprint. To receive satellite broadcasts the installed antennas have to be disposed such as to be in the line-of-sight of the transmitting satellite's transponder. This requirement creates problems in high-rise housing complexes, apartment buildings, hospitals, schools, office buildings, multiple dwelling units, trailer parks, and the like where a significant portion of the residences or offices are not in the satellite's line-of-sight. To increase their effective footprints typically the satellites are inserted into a very high geo-synchronous orbit around the earth thereby effecting noticeable delays during two-way communications. Yet another drawback concerns the sensitivity of the satellite distribution system to environmental conditions. Heavy rainstorms, solar flares, periodic solar fades, and diverse other predictable or unpredictable physical phenomena could interfere substantially with the reception of the signals. In contrast land-based distribution systems are more stable in this respect. Furthermore, satellite TV comes up short on the number of local broadcast channels it is capable of delivering. Several solutions have been proposed to solve the above mentioned problems but all the solutions involve the addition of sophisticated hardware, such as larger antennas, or the creation of complex distribution sub-networks involving basic cabling, and the like. Naturally, the proposed solutions involve heavy expenses for both the satellite network operators and their subscribers. In order to balance the disadvantages of the satellite-based content distribution systems with the advantages of land-based distribution systems it would be highly advantageous to integrate the growing number of satellite channels into a conventional land-based distribution network such as a cable TV system. Cable TV (CATV) is the transmission of TV programs into the home and office via land-based conduits including optical fibers, coaxial cables, or hybrid-fiber optic/coaxial (HFC) lines. Although cable TV is not the only distribution and delivery solution to video broadcasts it has the greatest penetration in the television market. Cable TV organizations have tremendous potential for the addition of new services since they are already wired into so many homes. The enormous upsurge in the number of satellite channels caused cable network operators to begin a hard uphill struggle to upgrade the bandwidth of their cable plants and to insert digital channels in order to accommodate within the CATV networks the constantly growing number of satellite based channels. The expansion of the CATV service with the multiplication of the number of channels involves great difficulties as the severe infrastructure-related limitations establish a definitive limit to the channel capacity of the cable TV networks. In order to increase capacity higher level digital modulation schemes were introduced like 256QAM. The current standards define the bandwidth required for the transmission of a single video channel to be about 6 MHz in the U.S. and about 8 MHz in Europe. The maximum usable bandwidth of the existing cable networks is less than 1GHz. Therefore, the cable systems with their present infrastructure have the capacity of transmitting at most 150 distinct video channels to their subscribers. This limited channel capacity is insufficient to accommodate the growing number of available satellite channels. Thus, current CATV installations are not a viable alternative to the installation of the satellite dishes and associated indoor units needed for the reception of the new multiplicity of satellite channel at the consumers' premises.

It will be readily understood by one with ordinary skill in the art that in order to facilitate the integration of the ever-increasing number of new satellite channels into operative cable television distribution networks first and foremost the operational bandwidth of the cable plants must be substantially increased. There is thus a need for a satellite distribution system in association with a CATV distribution network equipped with a suitable satellite network connection interface having a sufficiently enhanced operational bandwidth.

SUMMARY OF THE PRESENT INVENTION One aspect of the present invention regards a communications network accommodating at least one subscriber linked via a communications network infrastructure to at least one communications network gateway unit, and a system for providing the delivery of request information and content information between the at least one network subscriber and at least one content provider service network. The system includes at least one subscriber equipment unit to enable the at least one network subscriber to submit request information to be transmitted to and to receive content information transmitted from the at least one content provider service network, a communications plant utilized as an information path to transmit a combined information stream including the request information and content information between the at least one subscriber equipment unit and the at least one content provider service interface unit, and at least one content provider service interface unit to format the information stream including the request information and the content information into specific formats suitable for the interfacing at least one content provider service network and the communications network.

A second aspect of the present invention regards a communications network accommodating at least one network subscriber connected via a communications network infrastructure to at least one communications network gateway unit, and a method for the delivery of request information and content information transmitted between the at least one network subscriber and at least one content provider service network. The method consists of submitting content request information by the at least one network subscriber to be delivered to the at least one content provider service network, accepting content information from the at least one content provider service network by the at least one network subscriber, communicating the request information and the content information via a communication network plant between the at least one network subscriber and the at least one content provider service network interface unit, and transmitting the request information from the at least one content provider service network interface to the at least one content provider service network, receiving the content information from the at least one content provider service network by the at least one content provider service network interface unit. All the above aspects of the present invention provide the subscribers of a communication network with the option of dynamically interact with content provider service networks via a flexible bi-directional information path.

All the above aspects of the present invention provide the controllable delivery of content and services from content provider networks via a terrestrial CATV infrastructure to subscribers of the terrestrial CATV network at substantially high data rates.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features of the present invention are set forth in the appended claims. The invention itself, as well as a preferred mode of usage, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

Fig. 1 illustrates the symmetrical configuration of the XBCS-CATV system, in accordance with the preferred embodiments of the present invention; and Fig. 2 is a simplified block diagram of a standard CATV data system; and

Fig. 3 is a simplified block diagram of the XBCS-CATV data system, in accordance with the first preferred embodiment of the present invention; and

Fig. 4 is a simplified block diagram of the XBCS-CATV data system bi-directional scheme, in accordance with the first preferred embodiment of the present invention; and

Fig. 5 is a simplified block diagram of the DOCSIS-compliant XBCS-CATV data system architecure; and

Fig. 6 shows the XBCS-CATV data network autonomous scheme, in accordance with the first preferred embodiment of the present invention; and

Fig. 7 shows the XBCS-CATV data network non-autonomous scheme, in accordance with the first preferred embodiment of the present invention; and

Fig. 8 illustrates the method of frequency hopping associated with the

XBCS-CATV data network, in accordance with the first preferred embodiment of the present invnetion; and

Fig. 9 shows the method of frequency band hopping associated with the XBCS-CATV data network, in accordance with the first preferred embodiment of the present invention; and

Fig. 10 is a schematic illustration of a combined communication environment, according to the second preferred embodiment of the present invention; and Fig. 11 shows the diagrams of the frequency bands structured by the satellite signal receiving and processing interface, according to the second preferred embodiment of the present invention; and

Fig. 12 shows the frequency band diagram of the integrated broadband signal, in accordance with the second preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

PCT Patent application Serial No. PCT/IL00/00655 by Zeev Averbuch and Dr. Hillel Weinstein entitled "System and Method for Expanding the Operational Bandwidth of a Communication System", within which a method and system for the substantial expansion of the usable bandwidth of a CATV network is disclosed, is incorporated herein by reference.

PCT Patent application Serial No. PCT/IL00/00655 teaches a method and system for the expansion of the functional bandwidth of a bi-directional symmetrical or asymmetrical multi-user communications system. Information units encoded into electronic signals having diverse content are received at a specific transmission center from a plurality of transmitting information sources. The received signals are suitably processed, frequency-mapped into predefined channels across a substantially expanded range of frequencies, multiplexed into a broadband signal modulated across a predefined portion of a substantially increased functional frequency range, and selectively distributed to a plurality of subscribers along a controlled transmission path. Transmission of encoded information units modulated across another predefined portion of the same substantially increased frequency range in the reverse direction, from a plurality of subscribers to the transmission center, is also provided. Along the transmission path diverse components (specifically developed for the proposed system) are operative in dynamically manipulating the required physical characteristics of the transmitted signal as well as in properly maintaining parameters operative to the integrity of the reproducible information encoded in the signal, are suitably upgraded by the addition of specifically developed add-up components in order to handle the signal modulated across the entire substantially increased transmission bandwidth. The present invention regards a novel method and system, which are functional in association with a cable communications network having a substantially expanded operational bandwidth. The method and system for the expansion of the operational bandwidth within the cable communications network will be referred to in the text of this document as the Extended Bandwidth Communications System (XBCS). XBCS could be implemented in association with diverse types of communications networks. Where implemented within the framework of cable television network the resulting system is referred to as an XBCS-CATV system

The present invention discloses a method and system for the distribution of a plurality of DBS channels via a satellite-HFC hybrid network. In the preferred embodiments of the present invention the terrestrial network is a CATV system and more specifically an XBCS-CATV system. In the first preferred embodiment of the present invention, the method and system proposed are used to provide a satellite Internet service. Subscribers of the XBCS-CATV system access and interact with content providing sites across the Internet by submitting suitable requests to Web browsers installed within personal computers (PCs) or business computers operatively connected to the XBCS-CATV system. The requests are transmitted upstream via the cable plant to hub units associated with the XBCS-CATV network. Subsequently the requests are up-linked via specific satellite-interface devices in the hub units and via appropriate satellite transmitters and dishes to satellite relay stations in earth orbit. The .requests are relayed to specific ground stations employed as gateway devices to the communications network (such as the Internet and the like). In response to the requests, suitable content information, transmitted from the gateway earth stations to the satellite relays and subsequently downlinked from the satellite relays, is received at the hub stations. The DBS channels are allocated at the hub units and delivered downstream via hybrid fiber-coaxial paths to groups of subscribers directly associated with the respective hub units. The proposed method and system eliminates the necessity for the installation of separate earth stations at the premises of individual subscribers and thereby can be implemented at a substantially lower expense. The method and system also provides the capability for uplink communications from the groups of subscribers via hybrid fiber-coaxial paths to the allocated satellite repeaters with single uplink installations at each hub unit. . It will be apparent to one skilled in the art that the following description is provided to facilitate a thorough understanding of the present invention and should not be construed as limiting to other possible embodiments and alternative uses that could be contemplated without departing from the spirit of the invention or the scope of the appended claims. In other preferred embodiments of the present invention diverse other services such as FM radio broadcasts, local, satellite or microwave TV stations, multi-channel TV programs, and video-on-demand services, could be distributed and delivered. Yet in another preferred embodiment of the present invention, a plurality of diverse channels having a variety of content, format, and purpose could be integrated into a programming package to be delivered and distributed by the cable communications system. Neither does the present disclosure intend to limit the type of the distribution network. In other embodiments of the invention, the distribution network could be a cellular communications network, or any other communication infrastructure operative in connecting diverse communication nodes located at separate remote or semi-remote geographical locations. Furthermore the proposed method and system could provide diverse other bi-directional symmetrical or asymmetrical services such as the deliverance of communications services by utilizing specific gateway devices to conventional or cellular telephone networks, and the like. The symmetrical configuration of the XBCS-CATV system operative in the implementation of the method and system will be described next. Fig. 1 shows the components of the XBCS-CATV data network. XBCS-CATV 110 provides channel control, data uplink, and data downlink from a hub unit 120 to a Customer Premises Equipment (CPE) 121, 121', 121", 121'". Hub unit 120 is linked to CPE 121,121',121",121'" via fiber and/or coaxial cable 123. Hub 120 contains a dish antenna 122, a satellite receiver/transmitter 124, a satellite modem 126, a demodulator 128, a controller 134, a modulator 136, a multiplexer 120, a hub multiplexer 132, and a hub XBCS amplifier 142. CPE 121 contains an XBCS set-top box 148, a data modem 150, a television set 152, a personal computer (PC) device 156, and remote controller device 138. CPE 121', 121", 121'" also contains an XBCS. set-top box (not shown), a data modem (not shown), a television set (not shown), a personal computer (PC) device (not shown), and remote controller device (not shown). Conventional CATV network 130 is linked to hub station 120 via an HFC infrastructure. Electronic signals carrying information content are received by dish 122 and satellite receiver/transmitter 124. The signals are processed by satellite modem 126 and fed into multiplexer 141 via modulator 136. The signals are modulated into channels allocated by controller 134 and multiplexed by multiplexer 141. The multiplexed channels are transmitted into hub multiplexer 132. The channels received from the satellite and a CATV signal from conventional CATV network 130 are multiplexed into a combined signal by hub multiplexer 132. The signal is selectively amplified by XBCS hub amplifier 142 and fed downstream via cable 123 to CPE 121, 121', 121", 121"'. Along the cable path XBCS amplifiers 144 and 146 selectively amplify the signal. The signal is fed into the XBCS set-top box 148. Set-top box

148 suitably separates and processes the broadband signal. The conventional

CATV channels are processed and displayed by the television set 152 while the satellite channels are sent via data modem 150 to PC device 156 for processing and display. The subscriber can select a specific CATV channel for display on the television set 152 or a desired satellite Internet channel for processing by the PC device 156 by activating the suitable controls on the XBCS set-top box 148 or by remotely manipulating the controls via remote controller unit 138. Where a satellite Internet channel is selected the subscriber is provided with the capability of transmitting information upstream from the PC 156. Thus, requests for specific information content is uplinked through data modem 150, set-top box 148, cable 123, hub multiplexer 132, multiplexer 141, demodulator 128, satellite modem 126, satellite receiver/transmitter 124, and dish 122, to the selected satellite relay station in orbit.

Although the first preferred embodiment of the present invention presents a method for integrating a satellite Internet service with a terrestrial CATV system and it is employed as a hybrid Internet providing service it should be clearly understood that in other embodiments diverse other services could be provided simultaneously. A plurality of specific audio, video, and data channels could be plugged into the satellite-XBCS-CATV interface to be distributed to the subscribers. For example, the second preferred embodiment of the present invention, discussed hereunder in association with the following drawings, presents a method and system for the selection, ordering, and respective delivery of digital movies to subscribers via a hybrid satellite-XBCS-CATV network.

Note should be taken that a particular sub-set of components within the set of operational components that constitutes the proposed XBCS-CATV system is uniquely novel. Thus, for example newly introduced passive components such as cable connections, circuits, filter assemblies, set-top box elements, wall outlets, splitters, and the like, which are necessary for the proper operation of the method are specifically designed and developed for this purpose. In other embodiments of the present invention, specific components deployed within the hub units in the currently discussed embodiment may be located within the cable plant head-end. Additional XBCS amplifiers could be deployed along the cable path in order to compensate for signal losses introduced into the system as a result of the cable plant topography. It should also be noted that although only a single hub unit connected to a single CPE is shown on the figure discussed, in a realistically configured system a plurality of hub units may be connected to a plurality of subscribers.

The configuration illustrated on Fig. 1 provides for bi-directional and symmetrical transmission. Thus, the transmission speeds will be identical for the both uplink connection and for the downlink connection. In contrast with the above-referred-to prior art, the data transfer rates of the XBCS-CATV network are the same for the delivery of the data downstream from the satellite relay through the XBCS-CATV network to the subscriber and in the reverse direction from the subscriber through the XBCS-CATV network and back to the satellite station. The substantially expended bandwidth provided by the XBCS system enables considerably higher data transfer rates in comparison with the currently operating systems.. The present method and system supports an extended bandwidth having a range of about 1050-3000 GHz and enables data transfer rates of up to about 10 Gbps. Note should be taken that in other embodiments of the present invention the XBCS-CATV network may operate as an asymmetrical service.

Presently, the bi-directional symmetric XCBS-CATV data network can be designed to operate in accordance with the Data Over Cable Service Interface Specifications (DOCSIS) standards. The proposed system and method is designed to be adaptable to further developments in the current standard and to new standards developed in the foreseeable future. DOCSIS specifies the schemes and the protocol for exchanging bidirectional signals over cable and defines the interface for cable modem, the devices that handle incoming and outgoing data signals between a cable TV operator and a personal or business computer or a television set.

Fig. 2 shows a simplified block diagram of a DOCSIS-compliant standard CATV data network. The network system 160 includes but not limited to a Hybrid Fiber-Coax plant (HFC) 162, and a Customer Premises Equipment

(CPE) 164. HFC 162 includes but not limited to a hub unit 166. CPE 164 includes but not limited to a Network Interface Card (NIC) 168. NIC 168 is can be a standard Ethernet card, such as the lOBaseT-Ethernet card installed within a computing device (not shown). NIC 168 is linked to a cable modem (CM) 170 which in turn communicates via the CATV physical layer 174 with a Cable Modem Termination System (CMTS) 172. CMTS 172 is a central device for connecting the cable TV network to a data network, such as the Internet. CMTS 172 is linked to hub 166. Hub 166 can be a hub unit or a cable head-end. Hub unit 166 is part of the HFC 162 through which data network packets are transmitted to the network 160. The network 160 is specified as an Internet Protocol (IP) forwarding system. The NIC 168 which is linked to the CM 170 and the CMTS 172 which is linked to the hub 166 function in a Local Area Network (LAN)-like manner in spite of the very large time delays between CM 170 and CMTS 172. Thus, CM 170 and CMTS 172 have to provide NIC 168 and the hub 166 with a virtual Local Area Network (LAN) environment. In order to provide the virtual enviromnent, DOCSIS is utilized and defined as the "virtualization" of the physical layer 176. Both CM 170 and the CMTS 172 must be able to capture LAN packets while ignoring the time delay in the transmission of the packets. Thus, the CM 170 and the CMTS 172 functions as if the packets were transmitted to the opposite terminal point of the system in an instantaneous manner, like in an actual LAN. After capturing the packet the CM 170 and the CMTS 172 transmit the packet to the available resource allocated to them.

In order to extend the performance of the DOCSIS, the XCBS method applies Frequency Domain Multiplexing (FDM) to the standard CATV band as well as to the additional portion of the substantially extended bandwidth. This extension requires in turn the formation of a different "virtualization" in respect to the CATV physical layer. Thus, in the XBCS-CATV network the bandwidth of the CATV physical layer is extended and the terminal equipment transmission is heterodyned accordingly. Fig. 3 shows an XBCS-CATV data network. The network 180 contains an HFC 182, and a CPE 184. HFC 182 contains a hub unit

186. CPE 184 contains a NIC 188. NIC 188 is linked to a CM 192, which in turn communicates via the XBCS physical layer 194 with a CMTS 190. CMTS 190 is linked to hub unit 186. Hub unit 186 is part of the HFC 182 through which data network packets are transmitted to the network 180. Satellite symmetrical data connection 187 is linked to HFC 182. The XBCS physical layer 194 includes additional components with respect to the LAN physical layer connecting the CM 192 with the CMTS 190. The enlargement of the LAN physical layer involves the addition of XBCS-CATV amplifiers, FDM devices, suitable band allocation and heterodyning devices.

The proposed system and method is not limited to a specific modulation method described above. The signal carrying the information could be modulated in diverse modulation techniques.

Referring now to Fig. 4 which is a simplified block diagram illustrating the architectural scheme of an XBCS-CATV asymmetrical data transmission system. The delivery of the data signals in the network is bi-directional; in the forward direction (downstream) from CMTS (cable modem termination system) 192 to CM (cable modem) 199 and in the reverse direction (upstream) from CM 199 to CMTS 192. CMTS 192 is linked to hub unit 194, which in turn is connected to the cable plant. Along the cable plant a predefined number of CATV amplifiers 196, 197 and associated XBCS amplifiers 195, 193 are deployed. The cable is linked to an XBCS set-top box 198, which in turn connected to CM 199. The portion of the diagram from hub unit 194 to XBCS set-top box 198 include the components associated with the XBCS-CATV physical layer, such the XBCS amplifier units, the FDM schemes, the appropriate band allocation modules and the terminal equipment heterodyning components. The CM 199 and the CMTS 192 include the conventional CM/CMTS physical layer which includes components for the handling of the MPEG packets, the TDM-related devices, the

64/256QAM schemes, and the TDMA channel allocation in the forward direction

(downstream). In the reverse direction (upstream) the components of the conventional CM/CMTS physical layer relate to the handling of the Ethernet packets, the FDMA scheme, QPSK/160AM schemes, and the FDMA channel access modules. The cables connecting the constituent components of the network are coaxial cable or HFC. The cables constitute the CATV physical layer. The hub unit 194 combines several CMTS 192 and super-heterodyne part of them between the CATV as the base-band and the extended portion XBCS band. The XBCS amplifiers 195, 193 separate the combined bandwidth between the CATV band and the XBCS band, pass the CATV band to the conventional CATV amplifiers 196, 197, amplify the XBCS band, and finally re-combine the separately amplified signals back to the combined band on the cable. The XBCS set-top box 198 serves the CM 199 by super-heterodyning between the CATV as the base-band and the extended portion of the XBCS band. Some architectural issues of the method and system proposed by the present invention will be discussed next. The major designs include the network management schemes, and the procedures used for the synchronization of the XBCS-CATV network with DOCSIS frequency hopping scheme.

NETWORK MANAGEMENT SCHEME

In cases when the transmission pipe breaks, the management system can no longer transfer assertions between the terminal points of the network. As a result the system looses the ability to manage the terminal equipment. The above-mentioned situation is called a deadlock. In order to recover from a deadlock a recovery process is required, which should include the reconstruction of the broken transmission pipe. Therefore, the LAN terminals (NIC and HUB) assume a steady physical layer and are provided with an autonomous management system for the avoidance of dependencies. Consequently the operative link can be re-established without the necessity of receiving assistance from a dependent system. In the same manner the DOCSIS terminals (CM and CMTS) assume a steady physical layer (CATV) and are provided with an autonomous management system.

Fig. 5 illustrates the DOCSIS architecture with a steady physical layer (CATV). Hub unit 206 within HFC 202 is linked to NIC 208 implemented within CPE 204 via CMTS 210, CATV physical link 214, and CM 212. CMTS 210, CATV physical link 214, and CM 212 are included within the Network Management System boundary 216. When the CM 212 loses connection it begins searching for a downstream channel to lock into and attempts to access an upstream channel through the downstream channel. The detailed description of the process can be found in the text of the document "DOCSIS RFI Radio Frequency Interface Specification" Chapter 9 "CM-CMTS Interaction" which is available on-line at http://www.cablelabs.com.

In the proposed method and system in order to form an autonomous management system both terminals incorporate modulated transceivers, such as a UART/FSK modem, a special protocol to communicate point to/from multi-point, and a special management protocol. Thus, the XBCS-CATV data network is independent of the higher level protocols and the avoidance of broken pipes and resulting deadlocks is accomplished. Fig. 6 illustrates the XBCS data network autonomous management system scheme. Hub unit 226 within HFC 222 linked to NIC 228, which is implemented within CPE 224, via CMTS 230, XBCS data network Manageable Physical Layer 236, and CM 232.

In order to simplify the XBCS data network, the management network may depend on the PC/business computer/work station and on the capability of the hub unit to communicate and interpret messages including processing of management software such as SNMP. In such a case the management system will not be autonomous. The monitoring and control signals to the terminal devices will be transmitted off-band in a higher hierarchy level (between the hub unit and the PC). Fig. 7 illustrates the XBCS data network non-autonomous management system scheme. Satellite connection 212 is connected to HFC 240. Hub unit 244 within HFC 240 linked to NIC 2246, which is implemented within CPE 242, via CMTS 248, XBCS data network Manageable Physical Layer 252, and CM 250. Hub unit 244 and NIC 246 are connected at a higher hierarchy level within sub-management boundary 258, 254, and 256.

Thus, a mechanism to avoid broken transmission pipes and the resulting deadlocks is established. The mechanism is activated upon the initialization of the CM 250. Irrespective of the frequency band the XCBS is set whether erroneous or correct the CM will search and find a channel to work with and will recover the broken transmission pipe to resume the proper operation of the management.

The are a number of problems relating to the operation of a non-autonomous management system. One problem concerns the diversity of the CPE equipment (both hardware and software). The solution proposed by the applicants is to connect the XBCS to the CPE via a serial connection, such as EIA RS-232, and developing specific drivers for different operating systems. The drivers may developed using off-the-shelf development packages of SNMP. Another problem of using a non-autonomous system is the lack of possibility to manage intermediate network elements, such as the XBCS amplifiers. The applicants propose to solve the problem by avoiding altogether the management of the intermediate network elements.

In spite of the potential difficulties involved with the use of a non-autonomous management system, the applicants prefer this approach as long as there is no real need to manage the XBCS amplifiers.

SYNCHRONIZATION OF THE XBCS NETWORKS WITH

DOCSIS FREQUENCY HOPPING While using standard DOCSIS CM and while the CM is connected via one specific frequency band, channels can be hopped with principal synchronization with the XBCS network band hopping and with the Operations

Support System (OSS). The XBCS network should hop bands, as for the CM the channel at the destination band is not expected to be the same as in the source band. Thus, both channel and band hop synchronously. The schematic diagram on Fig. 8 is provided as a useful aid in the understanding of the of the XBCS channel frequency hopping process. The steps involved in process are going to be described next.

1.1 CMTS instructs CM to hop from the current channel (262) to an aligned-waiting channel (260).

1.2 CM hops (268) to the aligned-waiting channel (260).

1.3 XBCS hub unit, or optical node, or satellite bi-directional facility instructs to the XBCS set-top box to hop to a new frequency band

1.4 XBCS set-top box hops (272) to next band (276) 1.5 CM finds virtual aligned-waiting channel (270) and locks thereon

1.6 CMTS instructs CM to hop from the virtual aligned-waiting channel (264) to the newly allocated channel (266)

1.7 CM hops (270) to the newly allocated channel (266).

Apart from frequency partitioning to channels in North America,

Europe, and other parts of the world it is assumed that the local service provider makes the channel allocation. Thus, for the purposes of the XBCS data network, the channel allocation map should be considered unknown and random. As a result a different procedure should be used. The schematic diagram on Fig. 9 is provided as a useful visual aid to the understanding of the of the XBCS channel frequency hopping procedure based on CM recovery. The steps involved in procedure are as follows:

2.1 XCBS hub unit, or optical node, or satellite bi-directional facility instructs the XBCS set-top box to hop to a new frequency band. 2.2 XBCS set-top box hops (288) to next band

2.3 CM loses communication link

2.4 CM enters re-initialization process (287) until a lock is achieved into a channel within the new band

2.5 CMTS instructs CM to hop to an allocated channel 2.6 CM hops (286) to an allocated channel and locks thereinto. As a result of the substantially expanded bandwidth of the XBCS-CATV network the system is capable of providing high-speed bi-directional asymmetric or bi-directional symmetric service. Consequently, in contrast with the similar satellite Internet services offered presently to subscribers, the present invention allows for the implementation of applications, such as full-motion videoconferencing, File Transfer Protocol sessions, on-line gaming, peer-to-peer networking, and the like, to which high-speed uplink connections are critical. Services currently offering satellite Internet services require the installation of the satellite receiving/transmitting equipment such as dish antennas, satellite modems, transceivers, and the like, at each and every subscriber's premises. According to the first preferred embodiment of the present invention, the satellite receiving/transmitting devices are deployed at a hub unit and the satellite channels are transmitted from the hub to the subscriber and in reverse direction from the subscriber to the hub via the existing CATV infrastructure. As a typical hub unit serves hundreds of subscribers the number of satellite receiving/transmitting devices to be installed will be reduced by an order of magnitude. As a result the method and system proposed by the present invention, can be implemented at a significantly lower cost for the subscribers.

The second preferred embodiment of the present invention, discloses a novel method and a system for a satellite connection interface to a CATV network and the expansion of the channel capacity of a CATV network in order to enable the incorporation of a multitude of direct satellite broadcast channels. The proposed solution makes available different options concerning the merging of diverse classes of useful content and services into the programming package provided by the CATV system. A plurality of video, audio, and data channels may be plugged in into a CATV distribution system having the sufficiently high operational bandwidth. Such newly introduced channels could have diverse formats and a variety of purposes such as Pay Per View entertainment and sporting events, Video on Demand systems providing recent movies in digital format, a multitude of high-quality FM radio broadcasts, and an abundance of data delivery channels to be utilized as means to access and to interact with information content providers in data networks such as the Internet. Advanced interactive features could be supported such as electronic program guides, e-mail, on-line shopping, banking services, and custom advertising. By virtue of a dramatically increased operational bandwidth XBCS-CATV networks could effectively function as the preferred carrier service for the distribution and delivery of multi-purpose, multi-content, multi-format information and services from content sources specializing in diverse domains, such as entertainment, education, information, commerce, advertising, and communication services. The distribution and delivery of the information content could be readily accomplished in both directions, e.g., upstream with the signal traffic containing requests and other data from the end-users to the content providing sources and downstream with signals transmitted carrying the requested content from the content providing sources to the end-users.

A plurality of pre-recorded or live video programs are carried by a plurality of radio frequency signals having multiple program content information digitally encoded thereon and being divided selectively into a plurality of transmission channels across a set of predefined microwave-range frequency bands. The channels are produced through the suitably selective modulation of carrier waves by base band signals with multiple video and audio program content information impressed thereupon. The resulting multiple signals are propagated in separate transmission paths through an unbounded medium, such as the atmosphere or the outer space, via artificial satellite-based transponder relays, or via terrestrial repeater stations, as required, to a satellite signal receiver interface of a land-based distribution network. The multiple satellite signals containing a plurality of digitally encoded video broadcast channels are appropriately received at the land-based distribution network satellite signal receiver interface and selectively input to a transmission center of the distribution network. The signals are suitably processed by the satellite signal interface modules of the distribution network. The signals are converted, filtered, divided into individual sets of channels, frequency-mapped across a substantially expanded frequency range, combined to form an integrated signal, and forwarded therewith via a bounded medium such as land-transmission conduits including coaxial cables, fiber optic lines, or hybrid- fiber optic/coaxial (HFC) lines to a plurality of end-user locations. The operative components along the physical delivery path of the distribution network are appropriately modified in order to enable the effective transmission of the integrated signal modulated across a substantially expanded frequency range. The end-user locations accommodate facilities designed to selectively decode the integrated signal modulated across a substantially expanded bandwidth in order to separate at least one distinct channel carrying distinct program content information and to display the extracted program content information on suitable user-interface devices, such as consumer television display units.

In the second preferred embodiment of the present invention the land-based distribution network is a cable television communications system (CATV) distributing audio, visual or digital information to paying subscribers. The distributed video programs are Digital Video Broadcast (DVB) wireless programs being delivered in the framework of Direct Broadcast Satellite (DBS) systems. These programs are transmitted from terrrestrial transmitter stations and delivered via artificial satellite networks. Television signals may be received from a satellite in geo-synchronous orbit in which it is stationary with respect to a geographic receiving area. Typically, the television signals are transmitted from a terrestrial transmitter to the satellite and then retransmitted from the satellite by a transponder device so that the signals can be received by terrestrial receivers within the geographic receiving area, that is, within the line of sight of the satellite. The satellites radiate microwave signal beams in the C-band, the

Ka-band, the Kb-band, and the Ku-band frequencies. Upon direct receipt at a consumer antenna, the satellite signals are initially down-converted to an intermediate frequency (IF) signal band of 950-1450 MHz before further down-conversion and detection at a lower detection frequency. To increase their number, DBS channels are typically grouped in two sets which each essentially span the same DBS band but each channel of one set is centered over a separating line between contiguous channels of the other set. In order to isolate further the sets, they are transmitted with different signal polarizations, such as vertical and horizontal polarizations or left-hand-circular and right-hand-circular polarizations. Once the transmitted signals are detected in the antenna, the polarization isolation is lost and the two intermediate frequency signal bands must either be carried on separate transmission lines, such as coaxial cables, or carried on a common transmission line after one channel set has been frequency offset from the other. In either case, DBS signals present distribution problems. If the two DBS channel sets are carried away from the antenna on separate cables, these cables must be continued all the way to the consumer's equipment, such as a television set. In multi-user installations it means that all the link portions of a satellite signal distribution system must be formed with pairs of cables.

Digital Video Broadcasting (DVB) is a set of international standards that define digital broadcasting using existing satellite, cable, and terrestrial infrastructures. Besides specifying how the audio and the video is interleaved, it is also specifies the format of channel identification, the interactive program guide format and the error correction algorithms. Numerous DVB broadcast services are available in Europe, North and South America, Africa, Asia, and Australia. For example, in the U.S. it is used by EchoStar's Dish Network and the Galaxy Network. The term digital television is sometimes used as a synonym for DVB. For compression of the audio and video signals the MPEG-2, one of a series of

MPEG standards for compression of audio and video signals is used. MPEG-2 reduces a single signal from 166 Mbits to 5 Mbits allowing broadcasters to transmit digital signals using existing cable, satellite, and terrestrial systems. DVB also uses conditional access (CA) systems to prevent external piracy by providing security modules that scramble and encrypt the content data. In the preferred embodiment of the present invention the distribution and delivery of DVB wireless channels transmitted in different signal polarizations, in compressed video and audio format, and carrying digital content information modulated by Quadrature Phase Key Shifting (QPSK) modulation scheme. Channels produced by alternative technologies, such as analog FM channels are received, processed and distributed. Note should be taken that in other preferred embodiments of the present invention alternative modulation schemes could be used. The proposed XCBS-CATV system and method is not limited to a specific modulation technology. Referring to Fig. 10 satellite platforms 10, 12, and 14 downlink satellite signals representing digital video programs uplinked from a terrestrial transmission center {not shown), to a satellite signal reception hardware which is associated with a cable headend 22, such as dish antennas 16, 18, and 20 and respective Low Noise Block Converters (LNBCs) 24, 26, and 28. Antennas 16, 18, and 20 convert the received radio frequency signals into the appropriate band to be processed by the operative components of cable headend 22. Headend 22 integrates and consolidates different signals carrying encoded content received from diverse satellite transmission sources into an combined signal representing and carrying an integrated programming package to be distributed via a cable plant 58 to the subscribers of the distribution system. Satellite signals picked up in the dish antennas 16, 18, and 20 feed the received signals via appropriate waveguides to the respective Low Noise Block Converters (LNBCs) 24, 26, and 28. LNBCs 24, 26, and 28 amplify the received signals and downconvert a block, a cluster, or a range of frequencies to an intermediate frequency range, typically in the 950 MHz to the 2150 MHz range. The IF signals are sent to active filters 30,

32, and 34 in order to be separated to different clusters containing sets of DVB channels. Filters 30, 32, and 34 are controlled by the Central Processing Unit

(CPU) 48, and 50. CPU 48 and 50 are preprogrammed microprocessors containing suitable program instructions and preset decision tables designed to select specific clusters of channels from the satellite signals. The programming 0^/017^29 instructions embedded into CPU 48, and 50 are operative in controlling filters 30, 32, and 34. CPU 48, and 50 utilize the preset block frequency range values stored in the decision tables in order to suitably feed the filters 30, 32, and 34 with the appropriate values associated with the respective frequency bands. Thus, CPU 48, and 50 effectuate the band passing of the clusters of assigned frequencies that represents predetermined DVB channels to be distributed within the cable network. The CPU 48, and 50 in association with the filter 30, 32, and 34 blocks non-assigned frequency ranges carrying other channels. The frequency-selected blocks of signals carrying clusters of channels are transmitted to converters 36, 38, and 40. The responsibility of converters 36, 38, and 40 is to upconvert or downconvert the frequencies of the assigned cluster of channels in order to fit the clusters and the channels therein into predetermined frequency slots in respective broadband signals. The CPU 48, and 50 control converters 36, 38, and 40. The CPU 48 and 50 are microprocessors preprogrammed with suitable programming instructions and preset cluster conversion tables. The CPU 48, 50 utilize the preset cluster conversion tables in order to feed the converters 36, 38, and 40 with suitable circuit values in order to correctly accomplish the frequency downconverting or frequency upconverting of specific clusters of channels to the predetermined frequency slots within the broadband signals. A detailed description of the conversion process will be set forth hereunder in association with the following drawings.

The signals outputted by converters 36, 38, and 40 are fed to active filters 42, 44, and 46. Filters 42, 44, and 46 are controlled by the CPU 48, and 50. CPU 48 and 50 are microprocessor containing programming instructions and cluster frequency range selection tables. CPU 48, and 50 are preprogrammed to utilize the cluster frequency range selection tables in order to feed active filters

42, 44, and 46 with the suitable circuit values to accomplish the precise filtering of the channel clusters. The processed signals are then combined into a broadband signal carrying the integrated waveforms of the received, frequency-shifted, and filtered clusters containing blocks of DVB channels by the multiplexer adder 52. The combined signal is further combined with a conventional CATV signal 56 by a second multiplexer 54 in order to output the completed signal carrying the integrated programming package. The conventional CATV signal 56 is constructed from a plurality of processed signals delivered by diverse information sources such as local programming sources, signals received from other terrestrial transmitters, from off-air television stations, from FM radio stations, from data network servers, and the like. The completed broadband signal is modulated across a substantially expanded frequency band having a range of about 3 GHz. The about 3 GHz broadband signal is feed from multiplexer 54 to the transmission lines of the cable plant 58 in order to drive the end-users equipment. Although a limited number of satellites, antennas, LNBCs, filter, converters, and CPUs appear in the associated drawing, in a practical application of the present invention, the number of operative components will be determined by the cable network operator only constrained by certain administrative or financial limitations. Thus, a plurality of satellite signals could be received by a plurality of satellite receiver hardware units. The number of channels received, processed, distributed, and forwarded to the end-users could be limited only by the amount of the available operational bandwidth of the cable plant.

Note should be made that specific hardware components such as power sources, amplifiers, and the like are not described in order to highlight only those components which are functional in the disclosure. The components illustrated within the cable head could be having diverse characteristics. For example, other types of antennas could be used instead of the dish antennas. In a practical application the antennas will have advanced reception elements such as the dual-band feed hom feature, in order to enable simultaneous reception of both horizontally and vertically polarized or both right-hand-circularly and left-hand-circularly polarized signals, and the simultaneous reception of both the C-band, the Ka-band, the Kb-band, and the Ku-band. O 03/017529

Referring now to Fig. 11 which illustrates exemplary frequency-band diagrams of typical polarized satellite signals carrying a plurality of digital video channels organized within sets of clusters after being converted to an intermediate frequency (IR) by specific LNBCs. In the preferred embodiment of the present invention as shown in Fig. 10, the LNBC 24 receives a satellite signal from the satellite platform 10 via the antenna 16. The first diagram 60 of Fig. 11 represents a signal received in the Ku frequency band and linearly polarized in the vertical plane. The converted signal carries three clusters of digital channels when the frequency band of each channel is about 6MHz. The first cluster contains three channels. LNBC converts the frequency of the first channel in the first cluster (62) to a frequency of about 1150 MHz. The frequency of the second channel in the first cluster (63) is converted to the frequency of about 1250 MHz and the third channel in the first cluster 64 is converted to the frequency of about 1350 MHz. The channels are separated with unused spectra referred to as band guards in order to prevent the adjacent communication signals to interfere with each other. The second cluster containing two channels is converted to the about 1500 MHz (68) and the about 1600 MHz (70) frequency range. The first channel (72) in the third cluster is converted to the about 1870 MHz range and the fourth channel (74) is slotted at about 2150 MHz. Still referring to Fig. 11 which illustrates an additional exemplary frequency-band diagram 76 of a typical polarized satellite signal carrying a plurality of digital video channels organized within sets of clusters after being converted to an intermediate frequency (IR) by a specific LNBC. In the preferred embodiment of the present invention, the LNBC 26 receives a satellite signal from the satellite platform 12 via the antenna 18. The second diagram 76 represent a signal received in the Kb frequency band and linearly polarized in the horizontal plane. The converted signal carries four clusters of DVB channels when the frequency band of each channel is about 6MHz. The first cluster contains four channels. LNBC converts the frequency of the first channel in the first cluster (78) to a frequency of about 950 MHz. The frequency of the second channel in the first O 03/017529 cluster (79) is converted to the frequency of about 1050 MHz, the frequency of the third channel (80) in the first cluster is converted to the frequency of about 1150 MHz, and the frequency of the fourth channel (81) is converted to the frequency of about 1250 MHz. The second cluster containing two channels (82, 84) is converted to the about 1400 MHz (82) and the about 1450 MHz (84) frequency range respectively. The frequency of the first channel (86) in the third cluster is converted to the about 1550 MHz range and the frequency of the second channel (78) is slotted at about 1600 MHz. The frequencies of the channels (90, 91, 92) within the fourth cluster are converted to the frequency ranges of about 1700 MHz, about 1750 MHz, and about 1850 MHz respectively. The channels are separated with unused spectra referred to as band guards in order to prevent the adjacent communication signals to interfere with each other. Signals outputted by the respective LNBCs are separated by the above-described frequency mapping operation. The separation of the channels performed within the given about 950-2150 MHz spectra represented by the frequency diagram 76 could be made in several alternative ways. Channels having different formats such as analog FM channels, and the like, could be integrated within the broadband signal represented by the frequency diagram 60, and 76.

Satellite signals are typically transmitted with different signal polarizations. Furthermore different polarization schemes could be used by different satellite delivery systems. The polarization attribute is lost in the receiving antenna and therefore the differently polarized signal sets have been frequency offset one from the other. If the antennas are designed to receive a signal with a particular polarity then the separation of the signals is made by the antennas and the output of the LNBC as was described in association with Fig. 11 is sufficient for the separation of the different channels. In contrast, if dual-band or dual-band and/or dual-feed antennas are used then the frequency mapping of the signals outputted by the associated LNBCs should frequency offset channels that were received with different polarities. For example, if the polarization is linear then the signal set having horizontal (HOR) polarization could be converted into the about 950-1450 MHz signal band and the signal set with a vertical (VER) polarization could be converted to the about 1550-2150 MHz signal band. If the polarization is circular then the signal set having Left Hand Circular Polarization (LHCP) will be converted into the about 950-1450 MHz signal band and the signal set with the Right Hand Circular Polarization (RHCP) will be converted to the about 1550-2150 MHz signal band. It should be noted, however, that the allocation of the respective frequency regions assigned as slots for signals having different polarities could be made in a number of alternative ways.

Fig. 12 illustrates the frequency diagram of the complete broadband signals outputted by multiplexer 54. The composite waveform includes the signals representing the entire set of the DVB channels received via the satellite signal reception interface units and the signals representing the entire set of other CATV channels collected or originated by the cable headend 22 of Fig. 10. The signals representing the combined set of channels are suitably frequency mapped into the broadband signal in two stages. In the first stage the DVB channels outputted by the satellite signals processing components are combined by multiplexer adder 52. In the second stage the signal containing the mix of the DVB channels, and the conventional CATV signal containing the combination of the regular CATV channels are fed to multiplexer 54 wherein the two signals are combined into the final broadband signal. The final broadband signal is created by selectively modulating the included signals representing different channels across a substantially expanded operational bandwidth within the about 5 MHz to the about 3000 MHz range. The expanded operational bandwidth is having a sufficiently wide scope to include hundreds of DVB channels in addition to the existing conventional CATV channels. The broadband signal is transmitted through the cable plant infrastructure 58 of Fig. 10 to the subscribers of the cable network.

Still referring to Fig. 12 the frequency-band diagram 94 includes a 5 -

35 MHz upstream region 96 for reverse communication originating by the subscribers and transmitted to the cable headend. A downstream portion 98 spanning about 50 - 750 MHz is utilized for the forward transmission of the conventional CATV channels from the headend to the subscribers. The frequency region 107 extending from the frequency of about 1GHz (114) up to the frequency of about 3 GHz (120) is utilized to the transmission of the DVB channels downstream to the subscribers. In the preferred embodiment of the present invention, the frequency region 107 includes signals representing hundreds of distinct DVB channels. For example, frequency region 100 with 200 MHz bandwidth spanning the about 1-1.2 GHz portion of the spectra could carry about 30 DVB channels selected from among the hundreds of DVB programs provided by the Hot Bird satellite distribution network. The frequency region 102 with 200 MHz bandwidth spanning the about 1.2 - 1.4 GHz portion of the spectra could carry another about -30 DVB channels selected from among the plurality of DVB channels delivered by the Astra satellite distribution network. The frequency region 104 with about 200 MHz bandwidth spanning the about 1.4 - 1.6 GHz portion of the spectra could carry yet another about 30 DVB channels selected from the set of channels provided by a similar satellite distribution network. The frequency regions 116, and 120 with a combined bandwidth of about 1.4 GHz spanning the about combined frequency portion of 1.6 - 3 GHz of the spectra could include about 200 DVB programs selected from among a set of one thousand DVB channels delivered by the Galaxy satellite distribution network. Thus, the cable network system having an operational bandwidth of about 3 GHz is capable of distributing about 300 DVB channels to the subscribers without interfering with the delivery of the conventional CATV channels or with the conventional reverse flow of information. The division of the spectra to specific functional frequency bands could be fashioned in a variety of ways. For example, still keeping within the total bandwidth of about 5 - 3000 MHz, a wider frequency range could be provided for the upstream communication region. In addition a higher upper frequency limit could be provided thus effecting a significant increase of the usable operational bandwidth. For example, further suitable enhancements _. to the operative components of the cable plant, such as amplifiers, filters, hubs, splitters, connectors, and the like could accomplish an operational bandwidth substantially above the about 3 GHz disclosed. Furthermore, a plurality of alternative combinations to the programming package could be accomplished by integrating diverse other channels with different formats, functionality and bandwidth. For example, a plurality of bi-directional asymmetrical or symmetrical channels dedicated to data communications could be inserted into the programming mix in place of or in addition to the DVB programs. Note should be taken also that the designations of specific satellites and satellite distribution networks were exemplary only. In a practical implementation of the present invention, a plurality of other satellite distribution networks could be connected to the proposed satellite signal interface in order to deliver a plurality of program channels.

Services currently offering satellite TV distribution require the installation of the satellite receiving/transmitting equipment such as dish antennas, satellite modems, transceivers, and the like, at each and every subscriber's premises. According to the second preferred embodiment of the present invention, the satellite receiving/transmitting devices are deployed at a hub unit and the satellite channels are transmitted from the hub to the subscriber and in reverse direction from the subscriber to the hub via the existing CATV infrastructure. As a typical hub unit serves hundreds of subscribers, the number of satellite receiving/transmitting devices to be installed will be reduced by an order of magnitude. Thus, the method and system proposed by the present invention can be implemented at a significantly lower cost for the subscribers.

The proposed system and method provides at least one bi-directional symmetrical or asymmetrical communication channels to be used for upstream/downstream transmission of content between the content providing source and the content user such as a subscriber.

Additionally, it is important to note that the set of operational components that constitutes the proposed system include uniquely novel elements. Thus, for example, newly introduced passive components, cable connections, _{. ,} _ like, which are necessary for the proper operation of the method are specifically designed and developed for this purpose.

While the present invention is described in the context of a fully operational communications network those skilled in the art will appreciate that the present invention is capable of being applied in a variety of forms and the method and system applies regardless of the particular type of network configuration used.

In view with the above description of the preferred embodiments of the present invention, many modifications and variations of the disclosed embodiments will be readily appreciated by those with skill in the art. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise that specifically described above.

Claims

WE CLAIM: 1. In a communications network accommodating at least one subscriber linked via a communications network infrastructure to at least one communications network gateway unit, a system for providing the delivery of request information and content information between the at least one network subscriber and at least one content provider service network, the system comprising the elements of: at least one subscriber equipment unit to enable the at least one network subscriber to submit request information to be transmitted to and to receive content information transmitted from the at least one content provider service network; and a communications plant utilized as an information path to a combined information stream including the request information and content information between the at least one subscriber equipment unit and the at least one content provider service interface unit; and at least one content provider service interface unit to format the information stream including the request information and the content information into specific formats suitable for the interfacing at least one content provider service network and the communication network.

2. The system of claim 1, wherein the at least one subscriber equipment unit comprises the elements of: a data modem device to modulate/demodulate the information stream including the request information generated by the at least one subscriber and the content information originated and delivered by the at least one content provider service network; and a set top box device to separate and to process the request, information submitted by the at least one network subscriber in order to be combined into the information stream and to separate and process the content information in order to be separated from the information stream; and 03/017529 at least one subscriber interface device to accept request information from the at least one network subscriber and to display content information for the at least one network subscriber.

3. The system of claim 1, wherein the communications plant comprises the elements of: a cable plant utilized as the transmission media for the delivery of the information stream; and at least one information stream processing device in order to maintain the required characteristics of the information stream including request information and content information.

4. The system of claim 3, wherein the cable plant comprises specifically developed passive components to provide for the suitable transmission of the information content carried by an electronic signal having a substantially expanded bandwidth.

5. The system of claim 1, wherein the at least one content provider service unit comprises the elements of: at least one multiplexing unit to insert the content information received from the at least one content provider service network into the combined information stream; and at least one controller unit to determine the manner of combining content information into and extracting request information from the information stream to be transmitted respectively to the at least one content provider service network and to the at least one network subscriber; and at least one modulator/demodulator unit to process the information stream including the request information extracted from the information stream and the content information to be combined into the information stream; and at least one receiver/transmitter unit to receive content information from the at least one content provider service network and to transmit request information to the at least one content provider service network.

6. The system of claim 1, wherein the communication network is a terrestrial cable television network (CATV).

7. The system of claim 1, wherein the content provider service network is a satellite network utilized for the delivery of at least one data network channel.

8. The system of claim 7, wherein the data network is the Internet

9. The system of claim 7, wherein the content provider service network is a satellite network for the delivery of at least one digital video broadcast (DVB) channel.

10. The system of claim 2, wherein the at least one subscriber interface device is a personal computer device (PC).

11. The system of claim 10, wherein the at least one subscriber interface device is a television device (TV).

12. The system of claim 3, wherein the at least one information stream processing device is an amplifier device.

13. The system of claim 1, wherein the cable plant comprises hybrid fiber optics (HFC) cables.

14. The system of claim 13, wherein the cable plant comprises optical cables.

15. The system of claim 13, wherein the cable plant comprises coaxial cables.

16. The system of claim 1, wherein the at least one content provider service interface unit further comprises an antenna device.

17. The system of claim 1, wherein the information stream comprises a broadband signal having a substantially expanded frequency range.

18. The system of claim 17, wherein the broadband signal is having a bandwidth of about 1050-3000 GHz.

19. The system of claim 18, wherein the expanded bandwidth of about 1050-3000 GHz provides data transfer rates up to about 10 Gbps. .

20. The system of claim 1, wherein the information content is delivered across the system by an exponentially modulated electronic signal.

21. The system of claim 1, wherein the information content is delivered across the system by a non-exponentially modulated electronic signal.

22. In a communications network accommodating at least one network subscriber connected via a communications network infrastructure to at least one communications network gateway unit, a method for the delivery of request information and content information transmitted between the at least one network subscriber and at least one content provider service network, the method comprising the steps of: submitting content request information by the at least one network subscriber to be delivered to the at least one content provider service network; and accepting content information from the at least one content provider service network by the at least one network subscriber; and communicating the request information and the content information via a communication network plant between the at least one network subscriber and the at least one content provider service network interface unit; and transmitting the request information from the at least one content provider service network interface to the at least one content provider service network; and receiving the content information from the at least one content provider service network by the at least one content provider service network interface unit.

23. The method of claim 22, wherein the step of communicating further comprises the step of maintaining the vital characteristics of the combined information stream.

24. The method of claim 22, wherein the step of receiving comprises the steps of: modulating the content information received from the at least, one content provider service network; and controllably multiplexing the modulated content information into a combined information stream; selectively amplifying the combined information stream; and feeding the information stream via the communication network plant to the at least one network subscriber.

25. The method of claim 24, wherein modulation of the received information content is accomplished by utilizing exponential modulation techniques.

26. The method of claim 25, wherein the modulation of the received content information is accomplished by utilizing non-exponential modulation techniques.

27. The method of claim 22, wherein the step of transmitting comprises the steps of: controllably de-multiplexing the forwarded information stream into request information units; and selectively modulating the de-multiplexed request information units; and processing the modulated request information units into an information stream suitable for inter-network transmission.

28. The method of claim 27, wherein modulation of the transmitted information content is accomplished by utilizing exponential modulation techniques.

29. The method of claim 28, wherein the modulation of the transmitted information content is accomplished by utilizing non-exponential modulation techniques. 3Q. The method of claim 22, wherein the transmission of the information between the at least one network subscriber and the at least one content provider service network is performed in a bi-directional symmetrical manner. 3 tf. The method of claim 22, wherein the transmission of the information between the at least one network subscriber and the at least one content provider service network is performed in a bi-directional asymmetrical manner. ABSTRACTOF THEDISCLOSURE

A method and system for the delivery of information from diverse content provider service networks to subscribers of a terrestrial CATV network is disclosed. The subscribers of the CATV network interact dynamically with the content provider networks by submitting requests for the delivery of data, video, services and other content information. The requests are suitably transmitted via the CATV cable plant to a content provider service network interface associated with the cable plant and are forwarded therefrom to the appropriate content provider service networks. The content information delivered by the appropriate service networks is received by the content provider service network interface and forwarded to the requesting subscribers. The request and content information is transmitted through- the cable infrastructure at substantially high data rates. The high transfer rates are accomplished by the encoding of the information into a broadband signal having a substantially expanded bandwidth.