Location based service has been recently increasing with the rapid development of wireless Internet and mobile devices, therefore, many applications are requiring location tracking systems. GPS is a favoured location measuring system for tracking the target location in the outdoor environment. Because GPS is not supported a communication function, many location tracking devices use a communication module such as Wi-Fi with GPS. The handoff method of IEEE 802.11 standard is not enough considering power consumption. This thesis analyzes the previous location tracking systems and proposes low-power system. The proposed handoff method resolve power problem by using the location information and behavior model minimize power consumption of tag through power-saving mode and the concept of duty cycle. To evaluating proposed methods and system performance, we perform simulations and experiments in a real environment. And then, we calculate tag's power consumption based on the actual measured current consumption of each operation. In simulation results, the proposed behavior model and handoff method reduced about 98%, 59% than the standard's handoff and default behavior model.
Sanghyun SonJong-Chan BaikYunju Baek
Sanghyun SonTae‐Wook KimYunju Baek
Byung Ki KimHo Min JungJae‐Bong YooWan Yeon LeeChan-Young ParkYoung Woong Ko