Disseminating Fair Emergency Messages to Prevent Broadcast Storms by Selecting a Relay Node at a Cross-Sectional Road in VANETS

Abstract

Vehicular ad-hoc networks are ad hoc network that takes vehicles as communicating node which enables frequent topological change and link disconnectivity concerning other ad hoc networks. They are network-connected nodes in which they can exchange safety or non-safety messages within themselves or other infrastructures such as V2V or V2X. In vehicular communication, emergency messages are safety messages those should be disseminated yet to all nodes to inform others about some issues. To disseminate basic safety messages different types of broadcasting approaches such as single-hop, multi-hop, and flooding were used. In urban areas disseminating any messages is a challenging task as many nodes interrupt the communication. The main issues are packet broadcast storms, packet collision, and end-to-end delays. When many nodes are rebroadcasting the message, packet redundancies happen which affect the performance and stability of the network. To prevent broadcast storms this study depends on the urban scenario at a cross-sectional road and proposed a solution that selects a single relay node within a single transmission range. The node with the maximum time to leave, high density, and medium signal strength was selected as the relay node. Through this approach, a fair safety message was disseminated to all nodes. Besides it, the real scenario was generated with a SUMO traffic generator and the proposed algorithm was simulated with NS2 tools to consider the proposed solution as scientific. The output of the proposed solution (SMD) was compared with a fast broadcasting approach to evaluate its performance. It has enhanced E2ED by 0.54% for 20 and 60 nodes at different simulation times, PLR by 4%, and PDR by 17.5%. As the quantity of vehicles and simulation times increases E2ED and PLR increased proportionally; while PDR decreased. The proposed solution improved the number of broadcast storms with a high proportion in urban scenarios