A Proposal of Forwarding Method for Urgent Messages on an Ubiquitous Wireless Sensor Network

Recent advancement in wireless communications and electronics has enabled the development of low-cost wireless sensor networks. Early deployment of wireless sensor networks assumes homogeneous devices and adopts application-dependant routing. However, in many prototypical systems today, there are a variety of sensor nodes with different battery resource, communications capability, computation capability, and so on. Consequently, in the near future, wireless sensor networks need to support a variety of different devices and a multiple of applications. We call such sensor networks ubiquitous wireless sensor network. In this paper, we propose a forwarding method for urgent messages on the ubiquitous wireless sensor network. To realize the forwarding method for urgent messages, we resolve two problems. First one is a problem caused by the fact that most of existing routing protocols for ad hoc networks are designed without explicitly considering QoS control. And second one is a problem by the transmission quality of error-prone wireless channel. We also evaluate the message's loss rate on the ubiquitous wireless sensor network and the average number of packets sent by nodes to transfer a single urgent message by using computer simulation.