A Cluster-Based QoS-OLSR Protocol for Urban Vehicular Ad Hoc Networks

This paper proposes a cluster-based routing pro-tocol for urban Vehicular Ad Hoc Networks (VANETs) using Optimized Link State Routing (OLSR). In OLSR, MultiPoint Relays (MPRs) used for routing, are selected at each node using neighbors' reachability resulting in a high percentage of MPRs. Quality-of-Service (QoS) was introduced to improve MPRs' quality in VANETs while clustering was introduced to reduce MPRs' percentage in dense areas. Relay selection in urban VANETs routing protocols incorporates vehicle mobility metrics, velocity and position whose significance is lowered by abrupt topology change. Our proposed clustering protocol extends the street-centric QoS-OLSR protocol for urban VANETs. QoS and current street are used for cluster head and MPR selection to improve network connectivity, stability, and performance. Simulations conducted using SUMO and NS3 demonstrate that the proposed protocol improves percentage of MPRs, percentage of stability, throughput, packet delivery ratio, hop count and end-to-end delay compared to OLSR and street-centric QoS-OLSR in urban VANET.