Implementation analysis of the IEEE 802.15.4 MAC for wireless sensor networks

IEEE 802.15.4 is the dominant Medium Access Control protocol in wireless sensor networks. To implement this protocol on such severely resource constraint devices, several trade-offs have to be considered. This paper presents an analysis of IEEE 802.15.4 software implementations available for typical sensor node systems, such as the MSP430 from Texas Instruments. We discuss the available implementations concerning the supported features, flexibility issues and the efficiency of the implementations. The latter is based on a static code analysis that allows to measure and compare the number of clock cycles, needed to execute specific MAC functionalities. The result of the study is that the performance of the implementations does not correlate with the number of supported features but rather inversely with the implementation flexibility. The results do not only support integrators of 802.15.4-based networks but help identifying key aspects of future implementations of the protocol.