Research On Improved Routing Algorithm And Communication Protocol For Low Voltage Power Line Communication

Because of characteristics of wide distribution, no new line and low cost, low voltage power line technology has been widely used in street lamp control, intelligent home and building automation, remote automatic meter reading system. However, the changeable physical topology, frequency selective fading and strong channel interference, restrict its communication distance and communication reliability. To set up relay network is a common strategy to satisfy the need of scale expansion. Most existing routing algorithms and communication protocols that can be used for power line network can not maintain a balance between algorithm complexity and communication reliability. This paper, aiming at improving communication reliability and stability, oriented to the automatic meter reading system, researched improvement schemes of routing algorithms and communication protocols for low voltage power line communication.Firstly, by the study of low voltage power line network characteristics, this paper summed up the requirements for networking. Based on strengths and weaknesses analysis of three main routing algorithms, an improved routing model was proposed. By the comparison of communication success rate with non-overlapping clustering model, it is showed that improved model has unparalleled advantages over the former in the communication reliability and stability.Based on the proposed routing model, routing algorithm was designed. And algorithm principles and case analysis were made by Matlab simulation tool. The results showed that improved routing algorithm, taking advantage of the non-overlapping clustering algorithm and single artificial cobweb algorithm, achieved networking requirements of simplification, high effiency and high reliability.Then, this paper described a typical communication protocol based on non-overlapping clustering routing model — PRIME standard. A thorough and detailed analysis of contents and characteristics of the physical layer and MAC layer protocol was conducted. In terms of some of its shortcomings, using the improved routing model, corresponding improvement schemes were designed, which improved flexibility, reliability and efficiency of communication.As the complexity, high demanding for node storage space and computing power, of PRIME standard, a four-layer communication protocol in line with DL/T645 specification in our country — CCMR protocol, was put forward. Detailed algorithms and programs of its data link layer and network layer protocol were designed. And the characteristics and advantages of the protocol were analyzed.Finally, a low-voltage power line network simulation mode l was built by True Time toolbox. Program design and simulation verification of PRIME protocol, improved PRIME protocol and CCMR protocol were conducted. Performances of the three protocols were compared and analyzed quantitatively. The results showed that compared with PRIME protocol, communication protocols based on improved routing model and algorithms, had shorter networking time, smaller routing overhead, and higher packet delivery rate, which met the requirements of efficient and reliable communication, and would have good market values and application prospects.