  IEEE 802.15.4 standard is designed for low power and low data rate
applications with high reliability. It operates in beacon enable and non-beacon
enable modes. In this work, we analyze delay, throughput, load, and end-to-end
delay of nonbeacon enable mode. Analysis of these parameters are performed at
varying data rates. Evaluation of non beacon enabled mode is done in a 10 node
network. We limit our analysis to non beacon or unslotted version because, it
performs better than other. Protocol performance is examined by changing
different Medium Access Control (MAC) parameters. We consider a full size MAC
packet with payload size of 114 bytes. In this paper we show that maximum
throughput and lowest delay is achieved at highest data rate.
