An Enhanced Channel Access Method to Mitigate the Effect of Interference Among Body Sensor Networks for Smart Healthcare

Wireless body sensor networks (WBSNs) are exposed to interferences such as intrabody and interbody interferences. Intrabody interference exists within a WBSN and interbody interference occurs between the WBSNs, which degrades the overall system performance. The impact of interference becomes more intense with the increase in the number of nodes. The most popular standard for WBSNs, the IEEE 802.15.4 standard, is very well suited for short-range communication and low-power wireless sensor networks. However, this standard is not robust enough to handle the interferences when multiple nodes/WBSNs come in close to each other. In this paper, a new scheme that can mitigate the effect of interference called the interference reduction channel access mechanism (IR-CAM) is proposed. In this mechanism, the coordinator adjusts the contention window size and frame length adaptively to reduce the effect of interference. The simulations are carried out for both static and mobile nodes. The simulation results prove the efficacy of the new scheme by comparing with the existing schemes in terms of normalized throughput, average end-to-end delay, average energy consumption, packet drop rate, and packet delivery ratio. In static, the proposed method outperforms the IEEE 802.15.4e standard and the transmission model by 33% and 10% in terms of throughput and a 3% drop in the average end-to-end delay when compared with the IEEE 802.15.4e standard. In mobility, the proposed method has 53% and 27% reduction in average energy consumption when compared to the IEEE 802.15.4e and transmission model. The simulation also includes the performance analysis for multiple WBSNs.