IEEE 802.15.4 Based QoS Support Slotted CSMA/CA MAC for Wireless Sensor Networks

In wireless sensor network, IEEE 802.15.4 should operate in beacon-enabled mode in order to schedule periodic sleep and wake up to minimize energy consumption. In beacon enabled mode QoS is supported by using guaranteed time slots(GTS). However maximum number of GTS node cannot exceed seven, and the number is not sufficient for wireless sensor network which have high node density. In this paper, we present QoS support mechanism in beacon enabled mode using CSMA/CA back-off time. Our algorithm have compatibility with IEEE 802.15.4 Standard, which means that there is no need to change hardware to support QoS on existing network. We will analysis the performance of our algorithm to design QoS parameters.