Interference Range-Reduced Cooperative Multiple Access with Optimal Relay Selection for Large Scale Wireless Networks

Abstract

Cooperative communication improves the link throughput of wireless networks through spatial diversity. However, it reduces the frequency reuse of the entire network due to the enlarged link interference range introduced by each helper. In this paper, we propose a cooperative medium access control (MAC) protocol with optimal relay selection (ORS-CMAC) for multihop, multirate large scale networks, which can reduce the interference range and improve the network throughput. Then, we investigate the performance gain achieved by these two competitive factors, i.e., the spatial frequency reuse gain and spatial diversity gain, in large scale wireless networks. The expressions of maximum network throughput for direct transmissions and cooperative transmissions in the whole network are derived as a function of the number of concurrent transmission links, data packet length, and average packet transmission time. Simulation results validate the effectiveness of the theoretical results. The theoretical and simulation results show that the helper can reduce the spatial frequency reuse slightly, and spatial diversity gain can compensate for the decrease of the spatial frequency reuse, thereby improving the network throughput from the viewpoint of the whole network.

Performance Analysis of Cooperative Multiple Access With Minimum Interference Range for Large Scale Wireless Networks

“…The value taken by p is related to link distance d. p=1, 2, 3, 4, 5 when d>R2, and p=1, 2, 3 when R3<d≤R2. Pcp and PcD depend on λH and d, which can be calculated according to [6].…”

“…Most research work focuses on throughput for the performance analysis of CMAC protocols in a fully-connected or two-hop network. Specifically, the throughput performance is analyzed in connection with the reliability of link transmission [6], but without considering the process of channel access among neighboring links and handshake between source and destination nodes.…”

“…dp is the distance between ip H and '' ip H . The calculation of these two variables is given in [6]. ( , )= ( , ) ( , ) P i j P i j P i j  (26) Finally, the probability that link Li is not interfered and the probability that link Lj is not interfered can be derived as follows respectively…”

Review of MAC Protocols for Vehicular Ad Hoc Networks

“…The principle of selecting a local manager is to minimize the impact of communication link interruptions on network stability and communication sessions, and maximize the efficiency of message transmissions. Cooperative communication can solve resource constraint [ 76 ]. The cluster-based structure also defines relay vehicles to forward the packets among different clusters, and forms a powerful network architecture for the clusters and for the vehicles within each cluster.…”