Applying time-reversal technique for tracking the mobility in opportunistic networks with random fading channels

Opportunistic network (ON) is particular type of delay-tolerant network. ON takes advantages of the broadcast nature of wireless medium to improve the transmission quality and range. In GPS-free environments, positioning is resolved by solutions basing on self-positioning, cooperative localization... However, major disadvantage of these methods lies in requiring strict synchronization between each pair of sender and receiver. In this paper, we propose a novel tracking the mobility scheme of nodes based on Time-Reversal (TR) technique without requiring strict synchronization and a new forwarding strategy is inferred. We simulate the processes in operation of new forwarding strategy basing on proposed mobility tracking. The simulation results show that applying TR technique for tracking mobility of nodes is efficient in finding forwarding nodes. And these results also indicate that there is a predicted duration time which the probabilities of sending packets to destinations has high value. Therefore, we can anticipate the optimal size of packets is used for the current state of the network.