Integrating ultra-wideband and free space optical communication for realizing a secure and high-throughput body area network architecture based on optical code division multiple access

Nodes in a body area network (BAN) are miniature wearable or implantable battery-powered wireless sensors which continuously transmit real-time vital physiological data of a patient to remote health-care center while remaining in close proximity to the human body. Therefore, BAN nodes should have the features of high data rates and low transmit powers to protect the human body, environment and bio-medical equipment from harmful exposure of electromagnetic radiations and electromagnetic interference (EMI). Ultra-wideband (UWB) signals have low allowable transmission power and high data rates. Therefore, we propose a low cost, low powered and secure optical body area network (OBAN) composed of four UWB-BAN nodes each transmitting at a data rate of 30 Mbps. At the control node, UWB signals from UWB-BAN nodes are encoded using spectral amplitude coding-optical code division multiple access (SAC-OCDMA) scheme and the combined signal is transmitted over free space optics (FSO) channel towards remote health-care center. At the health-care center, the combined signal is decoded and UWB signal of each UWB-BAN node is photo-detected for analysis of patient’s data. Log-normal channel model is considered between control node and the health-care center. The signal received from each UWB-BAN after propagation through the FSO channel is analyzed through Bit error rate (BER) results. Similarly, cost efficiency of the proposed architecture is also evaluated through a detailed cost analysis. It was observed that the proposed architecture requires the UWB-BAN nodes to have low receiver sensitivities with the added benefits of cost-efficiency and data security.