Design of mobility functionality in IP-based bluetooth sensor network

In the conventional sensor network, different sensor node (SN) uses different channel to transmit wireless signal to the access point (AP), and therefore, the remote Data Center (DC) identifies the data source by checking the data packet's channel number. That is to say the channel number identifies the sensor node. In the case of fixed-position sensor network, this solution does not present any problem, but in case of the mobile sensor network, it is prone to errors. In order to solve this problem, we propose changing signal transmitted between the access point and sensor node from the channel-based fashion into IP-based fashion, using Bluetooth (BT) [1] as the wireless link. However, the wireless IP-based Bluetooth sensor network technologies using Point-to-Point Protocol (PPP) 121 could encounter problems during handover, even though the mobility support is at the IP layer. A new method to carry IP packets over Bluetooth, named middleware, is designed as a protocol layer between IP and L2CAP, and is implemented in the form of a network driver in Linux [3]. This solution is able to overcome the problems in the Point-to-Point Protocol to integrate well with Mobile IP for providing a better sensor mobility support for seamless handover between neighboring access points.