A PRIMARY-BACKUP CHANNEL APPROACH TO DEPENDABLE REAL-TIME COMMUNICATION IN MULTIHOP NETWORKS

Many applications require communication services with guaranteed timel iness and fault tolerance at an acceptable level of overhead. We prese nt a scheme for restoring real-time channels, each with guaranteed tim eliness, 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 co nsists of a primary channel and one or more backup channels. if a prim ary channel fails, one of its backup channels is activated to become a new primary channel. We propose a protocol which provides an integrat ed solution for dependable real-time communication in multihop network s. We also present a resource sharing method that significantly reduce s the overhead of backup channels. Good coverage (in recovering from f ailures) is shown to be achievable with about 30 percent degradation i n network utilization under a reasonable failure condition. Moreover, the fault tolerance level of each dependable connection can be control led, independently of other connections, to reflect its criticality.