摘要:
A digital video, audio and data distribution system which enables a set-top terminal (STT) associated with a customer's television set or other information presentation device to request interactive digital video, audio and data services from a service provider (SP) through the use of control system messages transmitted via a hi-directional signalling path. The requested interactive service is transmitted from the service provider over a portion of the bandwidth of a broadband transmission network which is dedicated to interactive digital services. A Video Session Connection (VSC) is provided for setting up and maintaining interactive sessions between the set-top terminal and a video service provider during the time the interactive programming is provided to the customer. The set-top terminal and service provider establish the Video Session Connection via a two-way signalling path within the bandwidth of the transmission medium into the customer's home. Applications of the system of the invention include "movie on demand" services where the set-top terminal not only requests a movie to be transmitted from the service provider for immediate transmission, but also the bi-directional command channel permits the set-top terminal to control the video presentation by sending commands such as Play, Pause, Fast-Forward and the like to the Service Provider while the movie is being transmitted. Other applications of the invention include on-line data retrieval services, shop at home services and other services which require the use of an interactive connection.
摘要:
Packets of data, some of which may carry a timestamp value, are transmitted through an Asynchronous Transfer Mode (ATM) network. Prior to transmission, each packet of data is encapsulated in a respective convergence sublayer protocol data unit (CS-PDU) having a header portion and a payload portion. The header portion of each CS-PDU contains a time correction indicator (TCI), which indicates whether the CS-PDU carries a packet of data having a timestamp value that may require correction after the CS-PDU passes through the network, and a time reference correction (TRC) field. Each CS-PDU is then segmented into a plurality of successive segments; a first one of the segments of each CS-PDU contains the CS-PDU header. Each segment is then inserted into the payload section of a respective ATM cell for transmission through the network. At each node in the network, cells are examined to determine if they contain a CS-PDU header. If a cell contains a CS-PDU header, any variable delays imposed upon that cell as it passed through the node are measured and added to the TRC field in the CS-PDU header prior to sending the cell to the next node. At a destination node, the accumulated TRC value may be added to the time stamp value of the packet carried in the CS-PDU in order to compensate for the variable delays imposed upon that packet as the cells carrying the packet traversed the network.
摘要:
A method is disclosed for providing packet error indication in a multi-hop communications system in which packets of data are transmitted from a transmission site to a reception site via a plurality of successive physical links. According to the method, at the transmission site, a pre-defined bit in a packet to be transmitted is set to a first value, the first value indicating that no errors are present in the packet. Then, at each successive physical link in the communication system, after transmission of the packet over that physical link, the following steps are performed: (a) detecting whether any uncorrectable errors occurred in the packet during transmission over that physical link; (b) if an uncorrectable error is detected, setting the pre-defined bit in the packet to a second value wherein the second value is indicative of an uncorrectable error in the data of the packet; and (c) relaying the packet to the next successive physical link for transmission over that next link. A decoder at the reception site may, upon receiving a given packet, examine the value of the pre-defined bit to determined the integrity of the data contained in that packet.
摘要:
A method for transferring DHCT settings includes receiving by a first digital home communication terminal (DHCT) a request for transmitting a DHCT setting from the first DHCT to a second DHCT, and transmitting the DHCT setting from the first DHCT to the second DHCT. Systems and other methods for transferring DHCT settings are also provided.
摘要:
A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances,” or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are partially-encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.
摘要:
A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances,” or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are partially-encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.
摘要:
Systems and method for partial encryption are disclosed. One example method comprises: creating a program association table to include a first program number which identifies a program encrypted in accordance with a first encryption scheme, and a second program number which identifies the same program encrypted in accordance with a second encryption scheme; and creating a program map table for the same program to include first audio and video identifiers associated with the first encryption scheme and second audio and video identifiers associated with the second encryption scheme.
摘要:
Systems and methods are disclosed for providing objects to a remote digital home communication terminal (remote DHCT) via a gateway device located at a customer premises. One such method, among others, includes receiving a message from a remote DHCT requesting a carousel object, receiving the carousel object from a server device, and transmitting the carousel object to the remote DHCT.
摘要:
The present invention is directed towards providing a partial dual-encrypted stream in a conditional access overlay system. The headend equipment includes an aligner, identifier, and remapper (AIR) device (615) that receives a clear stream and one or two encrypted streams, where the two encrypted streams have been encrypted by two different encryption schemes. The AIR device (615) identifies critical packets associated with the clear stream and subsequently allows two encrypted streams to pass and drops the critical packets of the clear stream. A multiplexer (640) then combines a percentage of the non-critical packets of the clear stream and the critical packets of the two encrypted streams to provide the partial dual-encrypted stream.
摘要:
A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances”, or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.