Tham khảo tài liệu 'mobile ad hoc networks applications part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 96 Mobile Ad-Hoc Networks Applications position-based routing and map-based routing show an improvement in its performances when used for dynamic vehicular networks. This improvement is due to real-time traffic consideration that makes routing decisions adapted to network conditions. Nevertheless this procedure generates an additional overhead to maintain the freshness of the topology information. More adapted and suitable schemes for providing the connectivity information should be used to improve the scalability of RBVT protocols. In the rest of this chapter we introduce a new routing approach which is well adapted to vehicular ad hoc networks called Road Connectivity-based Routing RCBR . Based on the fact that the density of vehicles moving along one road is not an accurate indicator of its connectivity RCBR defines the concept of road connectivity to provide real-time view of the network topology. In addition to providing a good support for delay sensitive applications RCBR has the advantage of performing well under sparse networks. A detailed description of the proposed scheme is given on the following section. 4. New approach road connectivity-based routing protocols RCBR routing approach combines information about the real-time vehicular traffic and the road-topology to select more stable routing paths. The idea is mainly based on the concept of road connectivity describing the state of each road segment whether it is connected or disconnected. In this context a road is defined as connected if it has enough vehicular traffic which allows the transmission of the packet through multi-hop communications between its two adjacent intersections. For that we define an algorithm predicting the connectivity duration over each road segment. We designed two variants of RCBR protocols a source routing protocol S-RCBR and a dynamic version of D-RCBR. S-RCBR computes the route using a global connectivity graph of the real-time state of the road segments and includes them
