Research On Fairness Algorithm For Resilient Packet Rings

The Resilient Packet Ring (RPR), standardized by the IEEE 802.17 work group, is a new topology technology for bidirectional packet-switched metropolitan backbone networks. The key objective of RPR is to achieve high bandwidth utilization, optimum spatial reuse and fairness simultaneously. RPR technology is at the stage of research and exploration, attracting a large number of scientific research institutes to study and research. One of the key technologies is the bandwidth allocation algorithm which can be devised to achieve these objectives.In this paper, the RPR network technology was discussed and researched. First, a variety of solutions to the next generation MAN,reference model for RPR's hierarchical,the structure and operation of RPR node,MAC entity structure and frame structure was described, then, the key technologies for RPR network such as topology discovery mechanism and protection switching mechanism was discussed. Secondly, the fairness bandwidth allocation algorithm in the RPR network was conducted an in-depth study. Some existent fairness algorithms were given briefly analyzing. A specific analysis and a comparison between two modes of operation for the RPR fairness algorithm were given. Meanwhile, a theoretical analysis for the mathematical model of the reference model RIAS fairness definition was given. Finally, a new dynamic bandwidth allocation algorithm with low computational complexity and time complexity was presented, and the performance of ORABD and comparisons with others based on simulation platform were studied.In this paper, dichotomy was introduced to the design of fairness algorithm firstly. Dichotomy is a simple mechanism and is the speediest convergent method for information inquiring in ordered set. Dichotomy was used in the new fairness algorithm to achieve the dynamic bandwidth allocation in distributed network environment because of the low computational complexity and time complexity of the dichotomy. Meanwhile, the fairness bandwidth allocation of the network was ensured maximally among all the ingress nodes'traffic without bias to spatial location.In this paper, a network model for RPR was established by network simulation platform and language C. The results were compared between existing fairness algorithms and the new algorithm. The results show that compared with some other algorithms, the new algorithm was an effective method in reducing the oscillation in RPR and had low computational complexity and time complexity, each node can be allocated with an ideal fair rate approximately, and the whole ring can be obtained the maximum spatial reuse and converged quickly.