A multicriteria handoff decision scheme for the next generation tactical communications systems

In this paper a novel handoff decision algorithm for the mobile subsystem of tactical communications systems is introduced. In this algorithm, handoff decision metrics are: received signal strength measurements from the access points, the ratio of the used capacity to the total capacity for the access points, and relative directions and speeds of the mobiles to the access points. We use a fuzzy inference system to process these metrics. We also introduce a ‘‘membership value’’ to represent the degree of membership of a mobile to an access point and ‘‘membership value threshold’’ to represent the minimum membership value before a mobile considers handing off to another access point. We compare our algorithm with the received-signal strength-based handoff decision algorithms. Our tests have shown that the proposed scheme, with the lowest membership value threshold, achieves the minimum number of handoffs, and the proposed scheme with the highest membership value threshold achieves the minimum call blocking rate. 2004 Elsevier B.V. All rights reserved.