Research And Implementation Of Routing Protocol In Wireless Sensor Networks Based On 6LoWPAN

With the rapid development of computer, communication and network, it is more and more important to connect the wireless sensor networks to the Intetnet using IPv6. The Internet Engineering Task Force (IETF) establish a working group called "6LoWPAN" in 2004, whose aim is to solve the problems that block the integration of IPv6 and WSN. In this paper, we add an adaptation layer between network layer and MAC layer according to the drafts and RFCs of 6LoWPAN. The adaptation layer is responsible for fragmentation and reassembly, head compression and decompression. With the help of the adaptation layer, IPv6 datagrams can be transmitted over IEEE 802.15.4 so that the IPv6 and WSN are connected.Another important achievement of this paper is adding routing function to the WSN. We can divide the routing schemes in 6LoWPAN into two categories:the mesh-under and the route-over, based on the routing decision taken on adaptation layer or network layer respectively. After analyzing the advantages and disadvantages of the two routing scheme, this paper selects the mesh-under routing scheme. As to the routing algorithm, we use a simplified AODV routing protocol called "AODVjr", which is energy-saving and easy to implement.The implementation of the 6LoWPAN and AODVjr routing is based on the driver of the CC2420, which is the transceiver chip of the Imote2 nodes. After the implementation, a series of tests are carried out. Both the adaptation layer and AODVjr routing work well according to the results of the tests.Finally, a WSN monitor website is built with the LAMP technology, so that the Internet client could acquire information about the WSN. The main functions of the website are history data, real-time data and remote controlling. The history data function will show the data either in a table or in a graph according to the choice of the user. The real-time data function will show the real-time states of nodes. The remote controlling function could gather instructions from user, and then send them to the nodes so that the nodes will work according to the instructions.