Characterization of Geographic Distribution of Sensor Data by Opportunistic Network

In addition to blog and schedule sharing, sharing physical data, such as noise or temperature values, and event data, such as information recorded when purchasing at a shop, with other nodes located in a distributed manner enables new applications using geographic distribution. Geographic distribution of physical data of noise allows a user to see geographic trends, such as the location of quiet areas, and geographic distribution of event data of shop purchases allows a user to estimate the route for the shop. However, due to the immature ubiquity of dedicated sensor nodes used to detect physical and event data, it is not easy for a user to share physical and event data. In this paper, we propose a new characterization method to provide geographic distribution of physical and event data, by using a mobile phone as a sensor node, since mobile phones have gained wide acceptance. In this method, a mobile phone can share physical and event data with other mobile phones by using opportunistic networks, which may be composed of other mobile phones incidentally located within the transmission range of short distance wireless communication. Furthermore, we define new indicators to take the freshness of physical and event data into account, so that a user can grasp geographic trends in real time. We conducted a computer simulation to show how valuable geographic distribution can be characterized by the proposed method.