On Exploring Data Forwarding Problem in Opportunistic Underwater Sensor Network Using Mobility-Irregular Vehicles

Data forwarding techniques in opportunistic underwater sensor networks (OUSNs) are significantly different from those of wireless sensor networks or delay-tolerant networks, due to the irregular mobility of nodes. To this end, an Opportunistic Forwarding Algorithm based on Irregular Mobility (OFAIM) is proposed hereby, which intermittently computes and chooses the appropriate paths of an end-to-end data session. In OFAIM, the contacting probabilities among nodes are estimated according to current nodes statuses. OFAIM is particularly suitable for heterogeneous networks composed of nodes with different communication and movement ranges. The performance of OFAIM is also analyzed through simulations, which indicate that OFAIM achieves a satisfactory delivery ratio (larger than 67% at the worst case) within a limited duration, while the message cost is largely reduced (the number of forwarding copies at every slot is restricted to two or three) compared with epidemic forwarding, motion vector forwarding, and predict and spread forwarding.