Throughput Capacity And Security In Wireless Sensor Networks

In recent years, with the rapid development of wireless sensor network andwireless ad hoc network, improvement of network capacity and security becomes a keyissue in morderm wireless communication systems. Although many approaches havebeen proposed to address these issues, many basic problems in wireless networksremain unresolved. Recently, information theory researchers have provided a novelconcept-capacity scaling laws, which attracted much attention since they quantifiednetwork capacity. This thesis concentrates on throughput capacity in the wirelesssensor network and wireless ad hoc netword. Also, an efficient and secure userauthentication protocol in wireless sensor network was given. The main achievementsand results of this thesis are listed as follows:1. Some works have been done in analyzing and improving the throughputcapacity of sensor networks, by exploiting the properties of physical constraints suchas mutual interference, limited bandwidth, characteristics of nodes’ distribution and soon. In particular, scaling laws have received the most attention as they quantify thecapacity of sensor wireless networks. In dense WSNs, throughput capacity andavailable throughput per node are of great importance performance metrics due to thelimited energy of WSN sensor node. However, it is hard to formulate the capacity ofspecific WSNs accurately because of the changing of the network topology. Thus,previous researches mainly focus on modeling the throughput scaling law, whichdescribes how the throughput capacity varies when the number of nodes approachestoward infinity. We propose the general throughput scaling law expressions that isappropriate for both mobile and static wireless sensor network models. Throughanalyzing the throughput capacity of the dense WSNs, we find that the strategy ofindividual nodes in the network determined the throughput capacity. Based on theproposed uniform description, we confirm the existence of optimal strategies thatmaximize the throughput capacity of WSNs. Using a game theoretic approach, wefurther illustrate that the optimal strategies can achieve Nash equilibria and maintainevolutionarily stable.2. Typically, a wireless sensor network consists of many individual, low-cost, low-power and resource-limited sensor nodes. The purpose of wireless sensor networksis to provide users access to the information gathered by the spatially distributedsensors. WSNs are becoming more and more popular in everyday life as they offereconomically viable, real time monitoring solutions. In real-time, it is necessary tocontrol that is accessing the information and whether he/she is allowed to do so.Access control provides the service to protect the data from access by unauthorizedparties. In general, user authentication is considered as one of the basic solutions forthe access control issue. Moreover, a key problem to design user authenticationprotocol for wireless sensor networks is to prolong the lifetime of the WSNs whileguaranteeing the security. In this paper, we proposed a strong and efficient userauthentication protocol for WSNs using smart card. Performance analysis shows thatour proposed protocol is more secure against many popular attacks and achieves highefficiency.3. We analyze the security of LEACH protocol and point out it is easilyvulnerable to selective forwarding, Sybil and Hello floods attacks. We propose asecure routing protocol based on LEACH. It improves cluster head node chosen andcluster generation, and introduces authentication mechanism to enhance routingprotocol security.