Recently, Location Based Service(LBS) that require the location information is increasing with mobile device. So, many applications are requiring location tracking system.
Location tracking system using short range communication technology has high positioning accuracy but, has the disadvantage that should build the infrastructure. For this reason, the 802.11-based location tracking system that has a lot of infrastructures is used recently.
Location tracking system to obtain the location information of a moving target is an important element of energy. It is because of the battery-operated for portability. However, location tracking system that conforms to the 802.11 standard scan all channels when collecting Receive Signal Strength(RSS) and therefore unnecessary scanning is occurred. Also, tag and Access Point(AP) are connected to a data transfer even if they are not needed can cause unnecessary power consumption.
This thesis analyzes the problems of the previous location tracking systems and proposes power aware system. First, we designed and implemented the tag optimized for the low-power location tracking system. Next, we proposed an adaptive channel scanning method to minimize the number of scanning and low-power behavior model in implemented tag. The proposed adaptive channel scanning method and low-power behavior model resolve problem of power by using the AP’s information and behavior minimize the power of the tag through sleep mode and action if needed connection.
To evaluate the proposed methods and system performance, we perform simulations and experiments in real environment. And then, we have calculated and measured tag’s power consumption. According to the result, the proposed methods reduced the number of channel scan and power consumption than IEEE 802.11 standard method. In a simulation result, The proposed method reduced the number of channel scan and a power consumption for about 41%, 46% than IEEE 802.11 channel scan method and default behavior model.