earticle

영어

This paper presents a more efficient method for medium access in a real-time ubiquitous sensor network. To reduce the latency for the delivery of event data from sensor nodes, a fixed-size contention window with a non-uniform probability distribution of transmitting in each slot is selected. Through a simulation using ns-2, a widely used network simulation package, it is shown that the proposed method can reduce the latency considerably as compared to conventional IEEE 802.11 MAC protocols for a sensor network with up to 256 nodes. It is also shown that the proposed MAC scheme realizes a latency similar to that realized by a decentralized CSMA-based MAC protocol for real-time ubiquitous sensor networks that are sensitive to latency.