A primary-backup channel approach to dependable real-time communication in multihop networks

Many applications require communication services with guaranteed timeliness and fault tolerance at an acceptable level of overhead. We present a scheme for restoring real-time channels, each with guaranteed timeliness, from component failures in multihop networks. To ensure fast/guaranteed recovery, backup channels are set up a priori, in addition to each primary channel. That is, a dependable real-lime connection consists of a primary channel and one or more backup channels. if a primary channel fails, one of its backup channels is activated to become a new primary channel. We propose a protocol which provides an integrated solution for dependable real-time communication in multihop networks. We also present a resource sharing method that significantly reduces the overhead of backup channels. Good coverage (in recovering from failures) is shown to be achievable with about 30 percent degradation in network utilization under a reasonable failure condition. Moreover, the fault tolerance level of each dependable connection can be controlled, independently of other connections, to reflect its criticality.