DBP-M: a technique for meeting end-to-end (m, k)-firm guarantee requirement in point-to-point networks

A real time message stream is said to have an (m, k) firm guarantee requirement if at least m out of any k consecutive messages from the stream must meet their deadlines to ensure adequate quality of service. M. Hamdaoui and P. Ramanathan (1995) recently proposed a scheduling policy called Distance based Priority Assignment (DBP) to better service multiple real time streams, each with its own (m, k) firm guarantee requirement. The key assumption in the DBP technique is that all messages reach their destination in one hop. This assumption, however, is not valid in most networks because there is often no direct connection between the source and the destination nodes of a real time stream. The DBP scheme is extended to deal with streams in which the messages traverse more than one hop in reaching their destination. Through empirical evaluation, it is also shown that this extended DBP scheme, called DBP-M, performs better than existing policies in reducing the probability of not meeting the (m, k) firm guarantee requirement