Design of Micro Mobility Support in Bluetooth Sensor Network

The mobile application represents a class of sensor network application. A sensor node (SN) roaming across several access points (AP) will bring in new technical challenges. The current sensor network uses channel number, which is indicated by certain bits in sent datagram, to identify the source sensor node. Such mechanism can not fit well into the mobile applications. In order to solve this problem, we propose another approach, which changes the signal transmission style from the channel-based into IP-based, and the wireless link uses Bluetooth (BT). However, the IP-based sensor network technologies using PPP could create problems during handover, even though 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 a form of network driver in Linux. This solution is able to overcome the problems in PPP, to integrate well with Cellular IP for providing a better sensor mobility support for seamless handover between neighboring APs.