Resource Management for Improving Performance of IEEE 802.15.4-Based Home Automated Systems

Recently, renewed interest has been given to improving energy efficiency of automated home systems for which Zigbee (over IEEE 802.15.4) is a potential technology. The IEEE 802.15.4 standard supports both contention-free and contention-based services. Contention-free services can be provided via guaranteed time slots (GTS) in beacon mode. However, directly applying GTS scheduling in IEEE 802.15.4 for resource management is not efficient in improving network performance. First, the improvement of GTS scheduling requires adding more bits and fields to IEEE 802.15.4 frames or more layers to Zigbee network stacks, this results in incompatibility problems with deployed products. Second, the network coordinator fails to assess the exact bandwidth demand from sensors for optimal resource management; resulting in the waste of network resources. This paper therefore proposes a resource management approach for improving the performance of IEEE 802.15.4-based automated home systems. The solution includes four extensions of the IEEE 802.15.4 standard. First, sensors specify data size they have to transmit instead of number of GTSs in their GTS command frames. Second, the coordinator handles two separate queues: a GTS allocation queue and a GTS deallocation one. Third, the coordinator runs the optimal GTS scheduling algorithm and fourth, the sensor operates according to the optimal power- saving algorithm. Extensive simulations show that the proposed approach significantly improves network performance in terms of power efficiency, bandwidth utilization and throughput while guaranteeing delay requirements for home automation applications.