DIVERSITY TRANSMISSIONS IN A COMMUNICATION NETWORK WITH UNRELIABLE COMPONENTS.

Abstract

The effect of sending redundant copies of each message in a point-to-point communication network with unreliable components is studied. To increase the probability of success, it is desirable to send the copies along link-disjoint or vertex-disjoint paths. The mean network delay is used as the basis of comparison of a two-copy scheme with a single-copy scheme. The effects of network routing and retransmission due to failures are analyzed. The environment in which the two-copy scheme achieves smaller network delay is discussed. The loop-freedom property of memoryless routing is briefly discussed. For the optimal two-copy scheme which minimizes the mean network delay, one solution that does not satisfy the constaint of sending along vertex-disjoint paths is found. Some heuristics to find two-copy routing schemes that satisfy this constraint are proposed.