Abstract: 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.

Abstract: 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.

Abstract: 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.