Abstract: A cellular radio communication system for transmitting blocks of data over transmission links in which the quality of the transmission links are monitored. The system comprises a data storage means for storing sets of modulation scheme and forward error correction coding level pairs to give an optimum data rate at a predetermined bit error rate and a predetermined symbol rate for different quality transmission links. The database is interrogated and a modulation scheme and forward error correction coding level pair is allocated and applied to the blocks of data transmitted over a transmission link dependent on the monitored quality of the transmission link.

Abstract: This invention provides a communication network with a method and apparatus for interrupting the transmission of an existing stream of data to insert interrupting packets which may have a higher priority than the existing data stream. The interrupting packets are inserted in the data stream by making use of unused pointer values in common transmission schemes known as the Data Over Cable Service Interchange Specification (DOCSIS) or the Asynchronous Transfer Mode (ATM) adaptation layer 2 (AAL2) format of the International Telecommunications Union (ITU) recommendation I363.2. Advantageously, the scheduling of packets is significantly simplified and the packet jitter is better controlled which results in a significant improvement in transmission performance.