Dual-band cognitive radio for wearable sensors in hospitals

Wireless communication technology has the potential to impact beneficially modern medical practice through the use of biomedical sensors combined with small intercommunicating radio transceivers. This development will enable cost-effective continuous monitoring of patients in hospitals and other healthcare centers. It is anticipated that a large number of medical body area networks (MBANs) will soon operate in unlicensed frequency bands, a fact that will create a coexistence problem with legacy medical equipment. This situation is particularly challenging in small indoor areas like intensive care units (ICUs) and operating rooms (ORs). Electromagnetic interference (EMI) from wireless devices can disrupt the performance of non-communication electronic medical equipment located in ICUs and ORs. Cognitive radio (CR) is a promising technology that can ease the coexistence of the aforementioned systems. In this work we present an EMI-aware CR protocol for e-health applications. This protocol protects noncommunication medical equipment from harmful interference while maintaining low outage probability for wireless communication devices and MBANs. We propose the use of an additional emergency channel in a different frequency band for control/data transmission, which exploits indoor propagation conditions to lower the outage probability. Performance evaluation of the proposed protocol through numerical simulations with realistic indoor propagation conditions is presented.