An enhanced MAC protocol of wireless LAN for wireless health monitoring systems

Abstract

This dissertation introduces a health monitoring system for seniors in retirement community/nursing home with integrated Bluetooth and wireless LAN technologies. It also addressed the technical requirements and challenges that may affect the deployment such as power efficiency and quality of service (QoS), real-time location system (RTLS) for tracking senior, handoff for seamless connectivity, and coexistence issues in Industrial, Scientific and Medical (ISM) bands. Existing techniques in literature are thoroughly reviewed. Numerous configurations and parameters are computed and the performances of existing techniques are simulated in the wireless health monitoring system to satisfy the scenario specifications and required technologies. This work analyzes the power consumption in a multi-radio monitoring system, and shows that a simple power saving operation can provide power efficiency with QoS support. It also explored and evaluated the existing methods for RTLS and compared the trade-off between accuracy, performance and cost. For cases where existing schemes failed to satisfy the objective of this health monitoring system, new and enhanced scheme is proposed and its performance is compared with previous work. This work proposes a simple handoff scheme for the health monitoring applications. Enhancement of performance is achieved at the expense of doze mode time, in that a station will collect Access Point (AP) information by AP probe during idle time, instead of falling into doze mode. Modified coexistence mechanism is also proposed to prevent performance degradation due to mutual interference and to guarantee the required throughput. Based on channel number information and activity information (channel utilization value), the WLAN station or Bluetooth master in the controller operates the comprehensive coexistence mechanism using packet arbitration by handshaking signals and a probabilistic adaptive scheduling method. For wireless health monitorin...