Intra-Mobility Support Solutions for Healthcare Wireless Sensor Networks–Handover Issues

At present, several solutions are available for monitoring patient health using body sensors. In hospitals, healthcare wireless sensor networks (HWSNs) offer support to access these sensors to allow for continuous patient monitoring. To improve the quality-of-life of the hospitalized patients, it is important to let them walk around the monitored area. This ability brings several challenges to HWSNs with mobility support. Because of the crucial importance of the sensed parameters, the HWSNs must be in continuous communication with the body sensors. The connection between body sensors and a HWSN is performed through an access point. Indoor communications are limited in terms of signal propagation and, therefore, several access points to cover large areas are deployed. To maintain the sensors´ accessibility, these should frequently change their point of attachment by performing a mechanism known as a handover. Handover mechanisms are able to support the intra-mobility of sensors in networks within the same domain. This paper surveys the most recent intra-mobility solutions with special focus on handover approaches that can be used in HWSNs. An in depth review of the related literature is performed in order to present the state of the art on this paper, to discuss the available solutions, and to point out open issues for further research.