| Wireless sensor networks have emerged as an important new technology [1]. New addressed routing algorithms and medium access arbitration have been proposed for sensor network for saving energy [1][13][31][33][41]. However, little research has been done on supporting QoS in wireless sensor networks. In particular, research on QoS supporting data-centric routing algorithm in wireless sensor networks is rare although there has been some research on QoS routing for mobile ad hoc networks (MANETs). Directed diffusion is a typical data-driven communication paradigm for sensor networks. The paradigm, however, does not prioritize transmission. In this work, we extended the directed diffusion, a representative of data-centric routing methods, so that the user is allowed to specify the priority of queries on events. We propose the DCPS (Data Centric Priority Scheduling), which prioritizes the transmission of packets based on users' requested preferences. A high priority packet should be delivered in preference to other packets with lower priorities using data aggregation if there is duplicated data on packets. This characteristic enables a user to get events sent from the source nodes more which prioritizes the transmission of packets based on users' requested preferences. A high priority packet should be delivered in preference to other packets with lower priorities using data aggregation if there is duplicated data on packets. This characteristic enables a user to get events sent from the source nodes more effectively according to event priority, which results in more reliable events-report. We compare our scheme with standard directed diffusion and present simulation results. |
