Date Added: Jul 2010
In recent years, the wireless sensor network is getting more and more popular and applied into many applications. Depending on different requirements, people usually use more than one sensor in their application since the sensor is cheap, low power consuming and easy to carry. Besides, most applications require identifying the positions of sensor nodes to locate where the events occur. There are already many existing methodologies which can locate the accurate position of sensors. However, their algorithms are complicated and take more computing power which means more energy consumption. In some situations, the authors simply need rough position. For example, in the bio-sensing project, they only need to know in which sickroom the patient stays.