Optimized Handoff Strategy for Vehicular Ad-hoc Network based Communication
The dissertation titled ???Optimized Handoff Strategy for Vehicular Ad-hoc Network based Communication??? is the compilation of all efforts taken and tasks completed in order to implement an optimal handoff method in Vehicular Ad-hoc Network communication.Wireless communication technologies have been improving exponentially. Ad-hoc networks can form a network of wireless nodes anywhere and they are not bound by the limitations of a static infrastructure. This enhances the ability of mobile nodes to communicate with each other even in situations where a defined architecture is absent. Vehicular Ad-hoc Networks (VANETs) has its applications in dynamic environments that involve nodes with high mobility. The nodes frequently move between the coverage areas of different access points. This increases the chance of link breakage and new link formation in communication network. Handoff is a process that helps in transferring the session details between one access point to another whenever the node is about to move away from a currently serving access point. Many handoff methods have been proposed but a majority of them utilize just a particular attribute of a network to employ the channel selection process. This process of network selection would be skewed as other attributes of a network play important roles in improving its overall efficiency. Multiple Attributes Decision Making (MADM) methods make use of different attributes in order to perform the network selection process. Use of MADM methods help in selecting optimal access points that can provide services to the nodes for a longer duration. In the proposed system, MADM methods have been utilized to modify existing protocols in order to optimize their approach for handoff operations. Various scenarios involving vehicular nodes and different access points have been considered in order to improve the efficiency of the proposed system across applications. The proposed handoff mechanism follows a proactive approach where the target access points are selected before the mobile node reaches the edge of its coverage area. This leads to a seamless transition of the communication channels. Based on the client/access point information stored in the data log, optimal access points which are situated along the direction of the node???s movement can be selected. NS2 and SUMO have been implemented to simulate mobile environments that accommodate handoff operations.