Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
  • H04N7/17309—Transmission or handling of upstream communications

Definitions

• the present invention generally relates to the field of bidirectional broadband communications. More particularly, the present invention relates to communications networks which provide a secondary communication path for upstream and downstream transmissions.
• the signals carried over the broadband network are transmitted in a frequency spectrum of 5 MHz to 750 MHz (the "frequency spectrum").
• the bandwidth of the frequency spectrum is largely driven by the bandwidth limitations of coaxial cable, the transmission line most commonly used in broadband networks today. As fiber optic cable gets pushed deeper into the subscriber area, the available frequency spectrum is expected to increase to over 1 GHz to help satisfy growing bandwidth demands.
• Broadband networks were originally designed to distribute signals in the "downstream direction" only (i.e., from the headend to the subscriber locations, also referred to as the "forward" path). Therefore, the component equipment of many older broadband networks, which includes amplifiers and compensation networks, is typically adapted to deliver signals in the downstream direction only.
• the broadband network 124 delivers the decryption information 152 and the IPPV signals 146 to the end-user device 104. Once received, the end-user device 104 demodulates and uses the decryption information 152 to decode and convert the encrypted IPPV signals 146 into a form which can be displayed on a television set at the subscriber location. Finally, the subscriber views the decoded IPPV movie on a television set.
• the present invention overcomes the limitations discussed in the background by creating a "secondary communication path" for return signals in a commumcations network having a "primary communication path.”
• the primary communication path extends from a headend to an end-user device at a subscriber location.
• the secondary communication path is a bi-directional communication path between the end-user device at the subscriber location and the 13
• Figs. 2 and 2A illustrate an exemplary embodiment of the present invention.
• Fig. 2 is a functional block diagram of a communications network constructed in accordance with an exemplary embodiment of the present invention. Illustrated is a communications network 200 which provides bi-directional communications between a headend 202 (within the dashed line box) and an end-user device 204 at a subscriber location through the use of a secondary communication path (the "out-of-band" path) 239.
• FIG. 2A depicts a graphical representation of the frequency spectrum of the communications network 200 showing the relative positions of signals in the downstream band 222 (from 50 MHz to 750 MHz).
• Each block shown in Fig. 2 A represents the signals being transmitted in the particular frequency range subsumed by that block.
• the modulated signals 218 are shown being transmitted in the downstream band 222.
• the end-user device 204 In response, the end-user device 204 generates a return signal indicating that the subscriber desires to purchase the IPPV movie.
• the return signal can be a digital data packet containing information which enables the headend 202 to transmit the IPPV movie to the end-user device 204.
• the information can be a unique identifier associated with the end-user device 204 and an identifier for the IPPV movie.
• the end-user device 204 includes a baseband network interface 320 (Fig. 3) which supports the connection 228 between the end-user device 204 and the baseband gateway 232.
• the connection 228 can be any data transmission medium capable of transmitting signals between the end-user device 204 and the baseband gateway 232, such as coaxial cable, twisted-pair copper wire, fiber-optic cable or the like.
• the baseband gateway 232 can reside in a distribution component of the communications network 200 at the subscriber area, or in any other acceptable location.
• One example of an acceptable location for the baseband gateway 232 is within an optical network unit ("ONU") of a telecommunications system. 16
• ONU optical network unit
• the baseband gateway 232 receives the return signal from the end-user device 204 over the connection 228.
• the baseband gateway 232 transmits the return signal over the baseband network 238 to a host terminal 236 located at the headend 202.
• the baseband network 238 can be any acceptable network architecture, such as an ethernet network or the like.
• the transmission medium for the baseband network 238 can be any acceptable transmission medium, such as fiber optic cable, coaxial cable or the like.
• the host terminal 236 interfaces the transmission medium of the baseband network 238 to the data network electronics of the headend 202.
• the return signal is then forwarded to the network router 240.
• the network router 240 of the exemplary embodiment can be the same device as the network router 142 of the existing cable network 100, shown in Fig. 1.
• the network router 240 then forwards the return signals to the CMS 208 via the ATM 216 or other data networking connection.
• the CMS 208 directs the video server 212 to begin transmitting the IPPV movie. Also, the CMS 208 directs the ATM 216 to establish an appropriate connection to the broadband gateway 220. From the ATM 216, the IPPV movie is forwarded to the broadband gateway 220, which converts the IPPV movie to IPPV signals 248 for transmission over the broadband network 224. The broadband network 224 then distributes the downstream communications, including the IPPV signals 248, to the end-user device 204 at the subscriber location. Concurrently with the transmission of the IPPV signals
• the CMS 208 generates and transmits decryption information associated with the IPPV signals 248 to the ATM 216.
• the decryption information can include a decryption key and incoming channel information to allow the end-user device 204 to properly receive the IPPV signals 248.
• the ATM 216 forwards the decryption information to the network router 240.
• the network router 240 formats the 17
• the communications network 200 to service a subscriber's request for an IPPV movie.
• the present invention is not limited to the transmission of IPPV movies and those skilled in the art will appreciate that the communications network 200, including the secondary communication path 239, can be used to transmit other types of 18
• communications such as other cable television programming, Internet transmissions, audio programming, or the like.
• the communications network 200 of the exemplary embodiment differs from the cable network 100 shown in Fig. 1 in several ways.
• the secondary communication path 239 of the exemplary embodiment makes the demodulator 138 (Fig. 1) and the modulator 156 (Fig. 1) of the cable network 100 unnecessary.
• the exemplary embodiment uses the separate secondary communication path 239 between the headend 202 and the end-user device 204 for return signals and decryption information.
• the exemplary embodiment avoids the need to modulate and demodulate upstream communications. Eliminating the need to modulate and demodulate upstream communications can result in a decreased cost of communicating in the upstream direction.
• the secondary communication path 239 allows the exemplary embodiment to avoid transmitting return signals in the upstream band 244 of the broadband network 224. Consequently, the exemplary embodiment overcomes the problem in the art of multiple subscribers having to share the limited-bandwidth upstream band 244. Also, the exemplary embodiment eliminates the need for in-band signaling by providing the secondary communication path 239 for signaling. Removing the added burden of in-band signaling makes it possible to transmit additional downstream signals 256 in the downstream band 222.
• the secondary communication path could be supported by another networking architecture, such as asynchronous transmission mode, 19
• the interface 302 demultiplexes the downstream signals 324 into individual channels or bands of information on multiple carrier frequencies.
• the demultiplexed downstream signals 324 are then demodulated by the QAM demodulator 306 to remove the carrier frequencies and otherwise prepare the downstream signals 324 for use at baseband by the end-user device 204.
• the video display terminal 314 transforms the signals into output signals 328 which can be displayed on a television set.
• the output signals 328 can also be music signals for transmission to a stereo, digital signals for transmission to a computer, or any other form of output signal.
• the baseband network interface 320 connects the end- user device 204 to the connection 228 (Fig. 2) of the secondary communication path 239 (Fig. 2).
• the baseband network interface 320 is a bi-directional communications interface capable of transmitting and receiving data signals 332 to and from the headend 202.
• the data signals can be downstream signals or decryption information received from the headend 202 (Fig. 2), or return signals transmitted to the headend 202 (Fig. 2).
• the baseband network interface 320 includes an auxiliary connector 336 to allow a subscriber or field technician to make a second connection to the baseband network interface 320. In this manner, a subscriber or field technician can connect a laptop or desktop computer to the end-user device 204 and make use of the end-user device 204 as a gateway to the secondary communication path 239.
• the controller 310 converts the subscriber's instruction into a return signal containing the request for the IPPV movie.
• the controller 310 then forwards the return signal to the baseband network interface 320 which transmits the return signal over the connection 228 (Fig. 2) as data signals 332 to the baseband gateway 232 (Fig. 2).
• the controller 310 also receives data signals 332 from the baseband network interface 320.
• the received data signals 332 can include decryption information associated with the IPPV movie requested by the subscriber.
• the controller 310 can extract the decryption information from the data signals 332, allowing the controller 310 to decode the IPPV movie transmitted in the downstream signals 324. In this manner, the end-user device 204 is able to transmit return signals to and receive signals from the headend 202 without burdening the broadband network 224 (Fig. 2).
• the exemplary end-user device 204 eliminates some of the components in use in set-top boxes and broadband networks today, such as a modulator/demodulator pair for return signals.
• the secondary communication path created by the exemplary embodiment eliminates the existing need for multiple subscribers to share the upstream or downstream bands of the broadband frequency spectrum for return signals.
• the exemplary embodiment does not require additional electronics in the downstream direction to accumulate, parse out, and redirect return signals back to the headend 102, as is used in certain existing communications networks.
• Fig. 4 is a flow chart illustrating the steps performed by a communications network, for example, the communications network 200 illustrated in Fig. 2, having a secondary communication path for communicating between a service provider and an end-user device.
• a communications network for example, the communications network 200 illustrated in Fig. 2, having a secondary communication path for communicating between a service provider and an end-user device.
• a method 400 proceeds from beginning step 401 to block 404.
• the communications network transmits a first downstream signal containing multiple options, such as a listing of IPPV movies available to a subscriber for purchase.
• the first downstream signal is broadcast "out- of-band" over a secondary communication path to the end-user device.
• the secondary communication path is a bi-directional communication path, separate from a primary communication path, between an end-user device and a service provider.
• the secondary communication path can be a data communications network, such as an Ethernet wide area network, between the end-user device and the service provider.
• the primary communication path may be a broadband network from the service provider to the end-user device.
• the method then proceeds to block 408.
• the service provider When received, the service provider acts upon the return signal in two ways, illustrated in the flow chart by a branched arrow.
• the service provider generates a second downstream signal, such as the video content of the particular IPPV movie selected by the subscriber.
• the service provider may transmit the second downstream signal to the end-user device over the primary communication path.
• the service provider concurrently with the steps at blocks 422 and 426, the service provider generates a third downstream signal, such as decryption information relating to the IPPV movie.
• the service provider transmits the third downstream signal to the end-user device over the secondary communication path. By transmitting the third downstream signal over the secondary communication path, the bandwidth of the primary communication path is not reduced by the third downstream signal.
• the present invention provides a "secondary communication path" for return signals in a communications network having a "primary communication path.”
• the primary communication path extends from a headend to an end-user device at a subscriber location and delivers downstream signals to the end-user device.
• the secondary communication path is a bi-directional communication path between the end-user device at the subscriber location and the headend.
• the secondary communication path is capable of carrying return signals from the end-user device to the headend without consuming bandwidth in the primary communication path of the communications network.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Cited By (1)

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• 1999
  • 1999-03-12 MX MXPA00010621A patent/MXPA00010621A/es unknown
  • 1999-03-12 WO PCT/US1999/005489 patent/WO1999056468A1/en not_active Application Discontinuation
  • 1999-03-12 AU AU30024/99A patent/AU3002499A/en not_active Abandoned
  • 1999-03-12 EP EP99911372A patent/EP1075763A1/en not_active Withdrawn
  • 1999-03-12 CA CA002330031A patent/CA2330031A1/en not_active Abandoned
  • 1999-03-29 TW TW88104936A patent/TW468345B/zh not_active IP Right Cessation

Non-Patent Citations (1)

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