A simple neighbour discovery procedure for Bluetooth ad hoc networks

Bluetooth was designed to replace cables between electronic devices, but it can also be used to build ad hoc networks. In the cable replacement scenario nodes can discover each other using the inquiry procedure. This has been designed to satisfy the requirements of cable replacement applications so that it discovers all neighbours in a fixed amount of time. On the other hand, the inquiry procedure is not well suited for nodes in a Bluetooth ad hoc network, where we found three main weaknesses. First, inquiry takes a lot of time and therefore it requires too much overhead if used regularly. Second, it is very inefficient to transmit data simultaneously with the inquiry. Third, the inquiry assumes asymmetric roles, which is not well suited to an ad hoc network of peer nodes. To resolve these problems we propose the simple neighbour discovery (SND) procedure. We evaluate it using analytical and simulation methods and show that it is configurable in the trade-off between discovery time and overhead. The results show that the SND procedure is more efficient in an ad hoc network of peer Bluetooth nodes than the inquiry procedure.