The Research On Bluetooth Based Ad Hoc Network Topology Formation Protocols

Mobile Ad hoc network is a special multihop wireless network without centralized administration and can be deployed without any infrastructure. For it is widely used in different fields, mobile Ad hoc network has become a research hotspot internationally in recent years. Bluetooth which is a global standard for short-range wireless communication is considered as one of the promising technologies to be used in Ad hoc networks. However, before it becomes reality, many challenging issues caused by the constraints and some characteristics of Bluetooth technology itself should be addressed, including network formation. Bluetooth specification hasn't addressed this issue in detail yet and there are some theoretical and practical significance of studying on this problem.In this thesis, the characteristic of Ad hoc networks based on Bluetooth, the topology models of Bluetooth networks, and the problem space of Bluetooth topology formation are introduced at first. And then, previous research on Bluetooth-based Ad hoc network formation is outlined, and several representative protocols are described in detail and compared qualitatively. In the following, the mechanism of Bluetooth device discovery is analyzed and simulated. By setting up a mathematical model for the probability of the discovered devices, the optimized value of the key parameter which improves the efficiency of the device discovery procedure is pointed out. The simulation further shows the great impact of the parameter on the efficiency of device discovery. Last, after some improvements on the device discovery procedure and the protocol's control message of the tree topology protocol-Law, a new ring Bluetooth network topology formation protocol is proposed. The new protocol is implemented in the Bluetooth module based on Ns-2. The theoretic analysis and simulation experiments evaluate the performance of the protocol, which validate the protocol has the properties of less topology formation latency, less control messages and forming a network with less piconets number and lower nodes degree.