A Wireless Sensor Network for Hospital Security: From User Requirements to Pilot Deployment

Abstract

Increasing amount of Wireless Sensor Network (WSN) applications require low network delays. However, current research on WSNs has mainly concentrated on optimizing energy-efficiency omitting low network delays. This paper presents a novel WSN design targeted at applications requiring low data transfer delays and high reliability. We present the whole design flow from user requirements to an actual pilot deployment in a real hospital unit. The WSN includes multihop low-delay data transfer and energy-efficient mobile nodes reaching lifetime of years with small batteries. The nodes communicate using a low-cost low-power 2.4 GHz radio. The network is used in a security application with which personnel can send alarms in threatening situations. Also, a multitude of sensor measurements and actuator control is possible with the WSN. A full-scale pilot deployment is extensively experimented for performance results. Currently, the pilot network is in use at the hospital.