Neighbor Discovery with Dynamic Spectrum Access in Adhoc Networks

In this paper, different discovery methods are considered for adhoc networks without fixed spectrum allocations where discovery of neighboring nodes may need to occur over a large frequency range (e.g., tens of MHz to a few GHz). In such systems, co-existance policies or dynamic spectrum access protocols may also introduce temporal variability in the availability of neighbor discovery thus making it challenging to discover neighbors in a short period of time and with low energy consumption. In this paper, we analyze the performance of a baseline scheme (representative of current techniques) where nodes perform discovery by transmitting and receiving beacons randomly across a large frequency range. We also propose and analyze a family of fast, energy-efficient neighbor discovery techniques that use pseudo-random frequency hopping sequences for beacon transmission and reception. For the cases considered, these techniques provide substantial improvements in discovery time and energy consumption relative to the baseline.