Enhancing mobile adhoc networks through node placement and topology control

Mobile adhoc networks (MANETs) provide a means of communication when infrastructure is not available. Due to the interference caused through the sharing of a common frequency the capacity of such networks decreases as the number of users increase. This paper investigates how the insertion of additional nodes at strategic points coupled with control of nodes´ transmission powers can decrease the interference and power consumption within the network. This is known to cause an increase in both network capacity and the lifetime of the network. A simplified particle swarm optimisation is used to analyse network structures and find the optimum placement for additional nodes. The work in this paper first validates the use of swarm optimisation by comparing its results to those of an exhaustive search. It then compares the benefits achieved when using additional nodes as opposed to the use of topology control alone; the use of additional nodes results in an average reduction in interference of 18% and an average power reduction per node of 60% over all network configurations tested.