Effects of interference between co-located frequency-hopping ad hoc networks

Traffic in military ad hoc networks are often broadcast or multicast traffic. A robust and efficient way to handle this type of traffic is the multi-point-relay (MPR) method. Furthermore, frequency spectrum is a scarce resource and must often be shared by several networks resulting in a risk for internetwork interference. The objective of this paper is to analyze the effects from internetwork interference in frequency-hopping (FH) ad hoc networks. Earlier work show that performance on a communication link can be degraded by interference between FH systems sharing the same spectrum resource. Results in this paper show that ad hoc networks are robust against FH interference in terms of a maintained high delivery ratio, but it is achieved at the cost of reduced capacity in the network. This reduction can in some scenarios be severe resulting in two networks with interference being less efficient than time-sharing between the networks.