Performance enhancement of wireless body area networks

Abstract

Wireless Body Area Networks (WBANs) or Wireless Body Sensor Networks (WBSNs) are becoming popular in the field of human healthcare to monitor and manage day-to-day activities. The recent developments in the field of semiconductor devices and wireless communication technologies have made WBAN a promising platform for medical and non-medical applications. The medical applications of WBSN include real-time patient monitoring, rehabilitation of elderly, ambient assisted living, early disease prediction, etc. WBAN is a subset of Wireless Sensor Network (WSN) that includes a number of tiny sensor nodes worn on the human body or implanted within the body to collect the patient health vital signs. The measured physiological data are sent to the physician to monitor the clinical conditions of the patient. The major challenges for real-time medical Body Area Networks (BANs) are in terms of energy consumption, reliability, and delay. These factors are found to be necessary because, in a critical situation, the information has to be sent on time with higher reliability for immediate medication. Also, the network should be energy efficient to avoid the frequent charging of patient-worn sensor node batteries. The IEEE 802.15.4 MAC (Medium Access Control) standard is better suitable for in-hospital patient monitoring scenario due to its low power and low data rate characteristics. However, it has inherent drawbacks, like non-adaptive superframe structure, MAC unreliability and lack of emergency handling capability for medical-WBAN applications. In the superframe duration, the slots are assigned either by random channel access called Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) method or by limited reservations. If an emergency happens in any of the nodes in a WBSN, it has to wait for its assigned slot or its own Contention Free Period (CFP). newline