Design novel weighted rating of multiple attributes scheme to enhance handoff efficiency in heterogeneous wireless networks

摘要

With the availability of multiple access interfaces, mobile device users can move between heterogeneous wireless networks. Service providers now must try harder to satisfy their users by ensuring connection service quality. The vertical handoff scheme plays an important role in this endeavor. We propose a novel handoff scheme that features two operating processes: attributes rating and network ranking. A self-developed WRMA (Weighted Rating of Multiple Attributes) method is used to rate attributes. TOPSIS is employed to rank networks. The WRMA-based handoff scheme, as we shall call it hereafter, select an AHP-SAW handoff model to compare with. The WRMA, which rates attributes directly, is relatively simple to use. Further, TOPSIS was found to be more precise than SAW in ranking networks. We also compared our handoff scheme with the traditional NIST signal handoff model. Four Key Performance Indicators of packet drop ratio, delay, jitter and throughput were applied in our experiments. Results demonstrate our handoff scheme outperformed the NIST model in lowering packet drop ratio for all four traffic types. Higher average throughput is achieved. Experiments also show improvements on packet delay and jitter. Such improvements can significantly enhance link service quality, making it more suitable for voice and video traffic applications.