Throughput, power and cost comparison of Zigbee-based and ISM-based WSAN implementations

This study intends to contribute to the growing pool of knowledge on WSAN especially in the design for novel applications such as image or video over WSANs, and solar energy and RF energy harvesting for the WSAN nodes. Two basic scalable wireless sensor and actuator networks were implemented and characterized in terms of throughput and power consumption. The two WSANs are the Zigbee-based WSAN which is based on the IEEE 802.15.4 protocol, and the ISM-based Zigbee which makes use of the industrial, scientific and medical (ISM) radio bands. The throughput is quantified with varied factors including distance from node to node, obstructions in between nodes and co-channel interference. As distance and obstructions between nodes are increased, the throughput for both networks decreases with varying degrees. The ISM-based WSAN network is weak in dealing with co-channel interference and error rate as compared to the Zigbee-based WSAN, thus requiring it to have a better data encryption. Power consumption is generally larger for the ISM-based WSAN as compared to its Zigbee-based counterpart. However, the ISM-based nodes consume the same power even up to a few hundreds of meters distance and are thus practical for covering large distances. Therefore, the Zigbeebased WSAN system is more appropriate for closed environment, such as in room automation and home automation applications where distance from node to node is relatively shorter. The ISM-based WSAN prototype, on the other hand, can be developed further for applications in larger areas such as deployment in fields and cities, since transmission is not generally limited by distance and obstructions.