Routing Protocol In Wireless Sensor/Actuator Networks For Indoor Environment Control And Monitoring

Reducing energy consumption and increasing user comfort propose new challenges to indoor environment control and monitoring system. Wireless Sensor/Actuator Network (WSAN) has the potential to solve many of the problems associated with indoor environment control and monitoring system. WSAN characterized with low cost, high density and widespread can be used to manage energy consumption and provide information related to decision-making. However, there are no routing protocols which meet the characteristics and requirements of indoor environment control and monitoring system integrated with WSAN. Design of such a routing protocol is the main task of this dissertation.In this dissertation, we first analyzed the characteristics of indoor environment control and monitoring system integrated with WSAN. Such system comprises of a large number of sensor nodes and a few actuator/controller nodes. Sensor nodes are usually battery powered and have limited computing power. Actuator/controller nodes have enhanced computing power and are usually main-powered. Static nodes and mobile nodes coexist in this system and most nodes are static. Anther important characteristic of such system is the link instability. Based on the characteristics analyzed above, we proposed a location based on demanded routing protocol named RPWSAHA which comprises of "routing discovery phase", "location service phase" and "routing maintenance phase". RPWSAHA has the advantage of simple, energy efficiency and high reliability."Routing discovery phase" is the main part of RPWSAHA in which we designed two routing discovery strategies: space restricted flooding and time restricted flooding. In space restricted flooding, the broadcasted routing request packets are limited into a small area which is calculated by using static nodes' location information. This is a localization-free location-based routing discovery strategy in which mobile node's location is referred by its static neighbors. It also support multi-path. In time restricted flooding, energy efficiency and static nodes have the priority to forward routing request packets. By this way, the route established is energy efficiency and stable. Time restricted flooding can reduce the time of routing discovery thus reduce routing overhead. In the "location service phase", static sensor nodes maintain all the location information for static sensor and actuator nodes. Actuator nodes maintain location information for all nodes. This is based on the fact that the traffic involved in frequently updating mobile node location information could be restricted to actuator nodes that are not battery-powered and are not sensitive to energy consumption issues. In "routing maintenance phase", PRWSAHA routing protocol only support non-localized algorithm for it can reduce routing overhead further when the size of network is small or intermediate and multi-paths exist. Compared with AODV which is supported by ZigBee specification, PRWSAHA only introduces extra time complexity and communication complexity in "location service phase" which are still low.We developed the source code of RPWSAHA routing protocol using NS simulator and analyzed its ratio of packet received and routing overhead in three networks with different scale. The simulation result showed that RPWSAHA routing protocol has similar performance with AODV when the network has 30 nodes. In the network with 60 nodes or 90 nodes, RPWSAHA can increase the ratio of packet received by 40% and reduce routing overhead by 70% in comparing with AODV.