Optimal Packet Length in Delay-Tolerant Networks under Mobile-to-Mobile Fading Channel

The performance of Delay-Tolerant Networks (DTN) is deeply affected by the node mobility and time-variant wireless channel, by which the joint influence has not been investigated in depth. We analyze the optimal packet length to maximize the effective data throughput, measured by the time spent in successfully transmitting payload data with constant bit rate (CBR) during a given period, by jointly considering the impact of node mobility and wireless channel. Based on a designed simulation model which resembles the environment of mobile nodes under mobile-to-mobile fading channel, we formulate a packet length optimization mechanism to resist packet loss due to channel fading and improve the efficiency of data transmission between mobile DTN nodes, which makes significant sense in multi-hop DTN communication. Theoretically optimal packet lengths for nodes under both environment with fixed velocity and the Random Waypoint (RWP) mobility model with variable velocity are thoroughly deduced and validated by simulation results.