Unidirectionality in ad-hoc networks: a simulation study

This paper is to study the impact on performance on using unidirectional links, in addition to bidirectional links, in ad-hoc networks. The study offers a better understanding on the future routing protocol design for ad-hoc networks. By using unidirectional links in addition to bidirectional links, the routing performance will improve greatly. To accurately evaluate the use of unidirectional links, both unidirectional and bidirectional links in the random graph and the Euclidean graph approaches are investigated. The random graph approach, where node connection and link direction are the only concerns, serves as a theoretical benchmark for the study. The Euclidean graph approach, where the dynamics of the wireless network are captured, examines the ability of the networks to transmit messages to most, if not all, of the nodes within a small number of hops on the provision of the minimal network connectivity. The simulation results show the presence of a significant proportion of unidirectional links and the improvement of network performance by increasing network connectivity and reducing path length.