Using hybrid AOA/TOA information for distributed topology control in VANETs

In a vehicular ad-hoc network (VANET), the network topology may change frequently. Consequently, the key design issue is how to organize nodes effectively such that the topology can be stabilized quickly. In order to balance the load among the nodes and govern the topology change, a group formation scheme using localized criterions is implemented. The proposed distributed topology control method focuses on reducing the rate of group member change and avoiding the unnecessary information exchange. Two phases are sequentially applied to choose the group members of each node using hybrid angle-of-arrival (AOA) and time-of-arrival (TOA) information. The operation of Phase I is based on the concept of the cone-based method, which can exclude a lot of nodes quickly. Afterwards, the proposed time-slot method is further applied to stabilize the network topology. Given the network structure in Phase I, the routing group member is determined by Phase II operation. The proposed scheme is simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithm provides efficient network topology management and achieves high scalability in VANETs.