Abstract
Wireless Sensor Network typically assimilates various real time applications that must meet some QoS requirements (e.g. delay, jitter, throughput, packet loss) under severe resource limitations. Hence, quality-of-service (QoS) management in Wireless Sensor Network is an important issue yet to be investigated. Due to the high data rate and burst traffic for real time applications, occurrence of congestion is very common. Ensuring the QoS requirements under congested scenario is quite challenging. As an attempt to this direction, in this paper we propose a hop-by-hop dynamic rate control algorithm which controls the congestion as well as ensures that the real time traffic will meet the soft QoS requirements. We have introduced per-hop deadline miss ratio as the congestion indication metric and performed the rate control when this ratio goes above to a certain level. Thus by per-hop rate adjustment, soft QoS is being met locally which in turns meets the end-to-end soft QoS. Finally, simulation has demonstrated the effectiveness of our approach.