ACPT Is Cognitive Radio an Opportunity to Improve the Performance of the IEEE 802.15.4 in Mobile e-Health Scenarios?

Abstract

In the last decade, the number of wireless devices in the 2.4 GHz band has grown rapidly, such as WiFi, Bluetooth, ZigBee and IEEE 802.15.4. This scenario increases the probability of spectrum saturation. The implementation of the Cognitive Radio proposes an alternative to reuse spectrum, in order to guarantee a peaceful coexistence with the other technologies operating in the same frequency band. The contribution of this paper can be listed as follows: i) Proposes a study to verify the performance of the IEEE 802.15.4 standard in mobile e-Healthscenarios and its capacity with multiple mobile source nodes in the network to evaluate its capacities to support Cognitive Radio directives, through an OMNeT++simulation and a testbed of physical embedded devices, results from both studies show a high correlation. The novelty of this study is the introduction of mobile nodes (which simulate mobile patients inside one hop Wireless Sensor Networks topology). ii) Results show that in the best case a 14.5% of packet lost by collisions was obtained with five mobile source nodes, which is 13.5% greater than the 1% allowed by the standard. In addition, the percentage of packets lost by the backoff algorithm has an important increase from eight up to ten mobile source nodes, demonstrating the impact of the number of nodes has on the performance of the network. iii) Concluding, the implementation of Cognitive Radio will improve the performance in IEEE 802.15.4 Wireless Sensor Networks, through dynamic multichannel operation avoiding the spectrum saturation problem.