Node-Block based Topology Control Algorithm for Mobile Optical Wireless Communication Networks

Abstract

Topology control is an efficient strategy to improve robustness and connectivity in networks. The mobility of nodes, the limited node degree and fragile links in optical wireless communication (OWC) networks make topology control a great challenge. In this paper, the node-block (NB) based topology control algorithm is proposed. Firstly, the proposed algorithm forms a stable tree structure, named node-block, using the predicted contact time between nodes as link weights. Secondly, quantized value based on GammaGamma channel model is used as the link weight to enable the establishment of multi-link connections between any two node-blocks. Finally, a connected graph is formed. The performance evaluation parameters, such as topological stability, algebraic connectivity and average node degree are discussed, and their expressions are given. Simulations are carried out, and a comparison with Minimum Spanning Tree (MST) algorithm is shown. The results indicate that our proposed topology control algorithm can ensure the connectivity and stability of the OWC networks. Meanwhile, the available node degree reserved is capable of large-scale networks.