The modeling of packet disordering in multi-stage wireless sensor networks

Packet disordering is a common problem in many industrial applications where wireless sensor nodes, interconnected with an ad hoc network, are used to monitor a certain event. In such systems, packets will have to be resequenced at the receiving nodes because they would have been disordered while traversing different paths over the ad hoc network. In this paper we investigate analytically and by simulation the disordering and the resequencing delay in n-stage wireless sensor networks where ALOHA and CSMA are implemented as possible MAC protocols. The results we develop in this paper indicate that the disordering is highly dependent on the MAC protocol and the number of stages crossed by the packets.