Research On Throughput Capacity And Delay Performance In Mobile Ad-hoc Networks With Correlated Mobility

Wireless ad hoc network is a temporary self-organizing multi-hop wireless net-work with no center. Compared with traditional wireless networks, the ad hoc network can be dynamically deployed anytime and anywhere without any infrastructure, and thus provides an effective solution for communication needs of special occasions with temporary communications, such as military communications, disaster recovery, etc.The capacity and delay are important parameters to measure the performance of wireless ad hoc networks. The throughput capacity is defined as the number of bits per second that can be transmitted by every node to its destination in the network. Due to the limited bandwidth of wireless transmission and the dynamic topology of ad hoc networks, the throughput capacity of wireless ad hoc networks is very low. Thus, how to improve network capacity has become a hot research topic in the field of wireless ad hoc networks. The packet delay refers to the average time needed for a packet to reach its destination node from the source node. Due to the inherent contradictions between network capacity and packet delay, the optimization solution of the trade-off between capacity and delay is a technical difficulty faced by the related research works.Based on the study of current works, this paper makes a research on the through-put capacity and delay performance of mobile ad hoc networks with correlated mobility and packet redundancy. We propose a routing algorithm with packet redundancy, and derive the expressions of throughput capacity and end-to-end delay on the basis of a Markov chain model. Through the analysis of theoretical results, we reveal the signif-icant influence of packet redundancy on the throughput capacity and delay. The main contributions of this paper are summarized as follows:(1) By applying the idea of f-cast transmission to the group mobility model, we propose a multi-hop routing scheme with packet redundancy, and derive the scaling laws of network capacity. We show the effect of packet redundancy on the throughput capacity by theoretical analysis.(2) In order to improve the packet transmission efficiency, we propose a 3HR-f routing algorithm in the correlated mobility model, which is a 3-hop routing scheme with at most f copies of a packet. We construct the Markov chains for the packet distri-bution and reception processes, and derive the closed-form expressions of the network capacity and end-to-end delay. We also verify the theoretical analysis of capacity and delay through simulation results.