Extended airtime fair scheduling method for a Zigbee network

In a Zigbee network, when many nodes simultaneously send data packets to a Zigbee coordinator through routes (branches), the Zigbee coordinator cannot deal with all signals. Interference and noises are existed during data transmission. This problem is still one of challenges in the network communication. In this paper, we propose an extended airtime fair algorithm in which throughput of a Zigbee network is maximized and fractions of airtime are taken into account. We adapt a utility function that is proposed by Kelly (1997) in maximizing the network throughput; nevertheless, throughput of each branch is multiplied by a fraction of airtime. Fractions of airtime play a role in creating a balance of throughputs of branches: the throughput and fairness of each branch is guaranteed. Moreover, the usefulness of our proposed algorithm for a Zigbee network is presented; simulation results show that the throughput and fairness are better than those of a case of not using airtime fair.