In-network location estimation using collaborative ranging technique in wireless sensor network

In the application of ubiquitous healthcare, wireless sensor network used for tracking user’s location is more restricted in design. For example, it must reserve sufficient resources for the normal operation of body’s signal monitoring. Therefore, the location estimation system must be simple and robust. This paper presents novel approach for in-network location estimation that reduces the use of communication bandwidth and computational capability. In stead of using PC, this approach estimates fine-grained location coordinates of user locally within a network. With this, only the processed small size data is sent through the network and terminal. To ensure the minimum usage of computational power, new location algorithm: collaborative ranging is used in sensor node. This algorithm is able to estimate large area of location in centimeter without exceeding bit limit. The results show that the average accuracy of location estimation is better than trilateration approach.