Coexistence of ZigBee-Based WBAN and Wi-Fi for Health Telemonitoring Systems

Abstract : The development of telemonitoring via wireless body area networks (WBANs) is an evolving direction in personalized medicine and home-based mobile health. A WBAN consists of small, intelligent medical sensors which collect physiological parameters such as EKG (electrocardiogram), EEG (electroencephalography) and blood pressure. The recorded physiological signals are sent to a coordinator via wireless technologies, and are then transmitted to a healthcare monitoring center. One of the most widely used wireless technologies in WBANs is ZigBee because it is targeted at applications that require a low data rate and long battery life. However, ZigBee-based WBANs face severe interference problems in the presence of WiFi networks. This problem is caused by the fact that most ZigBee channels overlap with WiFi channels, severely affecting the ability of healthcare monitoring systems to guarantee reliable delivery of physiological signals. To solve this problem, we have developed an algorithm that controls the load in WiFi networks to guarantee the delay requirement for physiological signals, especially for emergency messages, in environments with coexistence of ZigBeebased WBAN and WiFi. Since WiFi applications generate traffic with different delay requirements, we focus only on WiFi traffic that does not have stringent timing requirements. In this paper, therefore, we propose an adaptive load control algorithm for ZigBee-based WBAN/WiFi coexistence environments, with the aim of guaranteeing that the delay experienced by ZigBee sensors does not exceed a maximally tolerable period of time. Simulation results show that our proposed algorithm guarantees the delay performance of ZigBee-based WBANs by mitigating the effects of WiFi interference in various scenarios.

 EXISTING SYSTEM :

 ? It is very important to facilitate patients' access to healthcare professionals without saturating the available resources, and this is one of main expected outcomes of the wireless health remote monitoring approach. ? Moreover, adaptive frequency hop spread spectrum allows BLE to co-exist with Wi-Fi. ? The wireless link used for body sensors should reduce the interference and increase the coexistence of sensor node devices with other network devices available in the environment. ? This is especially important for large scale implementation of WBAN systems. ? Non-existent support for massive data collection and knowledge discovery.

 DISADVANTAGE :

 ? In this several issues need to be resolved by both networks operators and hardware manufacturer for a better support to mobile health services. ? To avoid this problem, the authors in propose interference mitigation algorithms that are applied when ZigBee and WiFi devices operate on the same channels. ? Although the authors in consider coexistence of ZigBeebased WBANs and WiFi devices for health telemonitoring, none of them specifies a solution to the interference problem. ? However, this process results in the same problems that arise from the channel allocation algorithms (i.e., additional delay and limited number of channels).

 PROPOSED SYSTEM :

 • The proposed system is highly customizable vital signal monitoring system based on Wireless Body Area Networks (WBAN). • The proposed system allows the incorporation of diverse medical sensors via wireless connections and the live transmission of the measured vital signals over public wireless networks to healthcare providers. • We propose a wireless BAN composed of off-the-shelf sensor platforms with application-specific signal conditioning modules. • The purpose of this scenario is to evaluate whether use of mobile communications can improve quality of care and decrease lag-time between the accident and the intervention.

 ADVANTAGE :

 ? In extensive efforts have been made to enhance the performance of ZigBee in coexistence environments. ? In the presence of WiFi traffic on the shared channel, however, ZigBee-based WBANs can suffer significant degradation in delay performance due to WiFi interference. ? We aim to improve the delay performance of the ZigBee network by controlling only the WiFi traffic generated from delay-tolerant applications so that delay-sensitive WiFi traffic remains uninterrupted. ? We demonstrate that the delay performance for the ZigBeebased WBAN is guaranteed by the proposed algorithm. ? To see the effects of considering the patient’s mobility on the performance of our algorithm and the Bridging approach, we compare the performance of the two approaches.