A Markov chain model for securing link layer in mobile ad hoc networks

The increased usage of wireless ad-hoc networks (MANET), which is a collection of wireless mobile nodes that form a dynamic network without the need for infrastructure or centralized points, in many different applications has opened the door for many security challenges. In recent years, securing and protecting communications between mobile nodes in MANETs have become an active research field. The vast majority has only focused on providing authenticity of the route and mostly ignored the availability of malicious nodes in the environment. The aim of this work is to explore the effectiveness of the Request-to-Send (RTS) / Clear-to-Send (CTS) protocol in securing MANETs by avoiding such a node´s communication with malicious nodes. It is assumed that a certain node is not listening to any RTS messages until it has a specific number of nodes within its range, and, it will have a fixed period of time before it replays a CTS message. In this paper, specific attention was paid to the security issues of a mobile single hop ad hoc network. We propose a general Markov chain model that satisfies the basic mobility requirements of a MANET and define the requirements for securing communication in this model. We perform MATLAB analysis for RTS/CTS handshake in IEEE 802.11 in order to secure link layer, which would protect the networks from malicious nodes. Our results show that the probability for a node to communicate with pernicious nodes is low.