An Enhanced Multi-path Scheme for QoS Guarantee in Wireless Sensor Network

A sensor network consists of a large number of sensor nodes that are densely deployed. The large scale sensor network is generally used for applications such as target tracking and emergency response rather than common data. The applications have real-time requirements that sensed data must be exactly delivered to a destination node within a given time. In this paper, we propose a multi-path scheme, which utilizes the virtual grid, to meet the real-time requirements. In order to select one of multi-paths depending on the service differentiation, the proposed scheme uses several information such as the size and transfer period of sensed data. In addition to an existing path, the proposed algorithm dynamically selects an alternative path according to multi-path environments. Moreover, it assigns the shortest path to the sensed data with most strict time restriction. Therefore, our scheme can guarantee the transmission reliability since sensed data is transmitted two or more routes by using the dualized multi-path on the virtual grid. In this paper, we introduce some realistic scenarios and propose an analytical model. Then performance of the proposed scheme is evaluated by numerical analysis. Our results show that the proposed scheme significantly outperforms the SPEED and MMSPEED.