Test-Bed Evaluation of Ingress Queuing for Improved Packet Delivery

In addition to bit errors and packet collisions, packets in ad hoc networks are lost due to missing routes and unreachable next hop nodes. The latter is costly, since these packets consume scarce network resources as they are retransmitted up to transmission-threshold times before being discarded. In this paper we demonstrate, through experimental test beds and simulation, the advantage of ingress queuing. By comparing the experimental results with the simulation we illustrate the difference between actual behaviour and the behaviour of the system abstraction. The latter has value in itself, since simulation by far is the preferred methodology in ad hoc networks.