Abstract: Opportunistic network which employs store-carry-and-forward pattern doesn’t consider encounter possibility of destination nodes and passing nodes during message transmission,leading to a large deviation for the estimation on message transmission status.This paper proposed an encounter interval based buffer management strategy.It facilitates the characteristic of exponential distribution for the encounter intervals between nodes,and the number of message co-pies is also considered.So the average delivery probability is estimated.All messages stored in the buffer are sorted according to the average delivery probability when the buffer is overflow,and the messages with low delivery probability will be dropped first for buffer management intent.Simulation results show that the proposed strategy achieves better performance compared to existing schemes in respect of the delivery ratio,average latency and overhead ratio.

Key words: Average delivery probability, Buffer management, Encounter interval, Opportunistic networks