Development of Zigbee-Wifi-Wimax Hybrid Wireless Sensor Network based Telemedicine System

This paper is an outcome of an on-going research project sponsored by department of (DST), Ministry of Science and Technology, Government of India, in which a wireless sensor network based on ZigBee-WiFi-Wi-Max hybrid wireless sensor network (WSN) has been developed. This system has been used for implementing telemedicine system as an information gateway between old age homes and nearby hospitals, for the purpose of transmitting health data wirelessly over a distance of about 20 km range. This system is developed in two separate modules, one consisting of ZigBee based WSN which is applied for wireless data transmission up to a distance of two kilometres, and the other comprises of WiFi-Wi-Max based WSN used to transmit data up to a distance of twenty kilometres. The hybrid wireless network has been tested for distance range, speed of data transfer and time delays for bulk data transfer. Several observations were collected and it has been proved experimentally that the developed system is low cost, consumes relatively low power, and transmits data efficiently without significant time delay in bulk data transmission. Another solution which has been designed and validated is to transfer all data to a database residing on web. This database can be accessed via 3G – GRPS connection on PDA, Mobile phones at any location across the globe. For areas without pre-existing physical cable or landline telephone networks, wireless application protocol (WAP) may be a viable alternative for broadband access between remote ZigBee networks and hospital information centre that has been economically unavailable. In the ZigBee-Wi-Max hybrid system first low distance information (within old age home) is transmitted wirelessly using ZigBee technology. Then this information is transferred to Web server and it can be assessed on Laptops/ Computers having internet connection, mobile phones, personnel digital assistant (PDAs) using GPRS connection. The performance of the hybrid system has been evaluated based on numeric result of testing.