A new distributed localization algorithm for zigbee wireless networks

Node localization becomes an exciting research area for recently large emergence of ZigBee based wireless applications, where received signal strength indication is adopted as a coarse but simple method on range measurement. Compared with the centralized approach, distributed algorithm that nodes locally calculate their own position coordinates can significantly reduce location-related network traffic; however, this is an intensive process. Unlike commercial digital-hardware-block based method used in CC2431, we propose a novel distributed algorithm that can be implemented based on common 8-bit MCU. In this algorithm, instead of 'log-normal', 'piecewise linear' path loss model was established, which let only linear operation when estimating range from RSSI. Besides, min-max method, other than maximum likelihood estimation method, was used to simplify coordinate calculation. Furthermore, ZigBee compatible sensor node modules were developed to carry out the contrast experiments, and results demonstrate the new method has close or even better precision compared with basic algorithm, but with lower cost.