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 multi-hop networks. To ensure fast/guaranteed recovery, backup channels are set up a priori in addition to each primary channel. That is, a dependable real-time 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 multi-hop networks. We also present a resource sharing method that signiicantly reduces the overhead of backup channels. Good coverage (in recovering from failures) is shown to be achievable with about 30% 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 reeect its criticality.