Performance Comparison of Unstructured Content Discovery Techniques over Ad Hoc Networks

The performance of several unstructured peer-to- peer (P2P) content discovery techniques over ad hoc networks was analyzed in this work. They include: query flooding, expanding ring search, random walk and Bloom filter(BF)-based probabilistic routing. The chosen performance metrics are the query success rate, the route stretch and the search cost. Mathematic analysis is conducted to predict their behavior in static ad hoc networks. Finally, extensive computer simulations is performed to validate our analytical results in the ad hoc network. It is concluded that the BF-based probabilistic routing outperforms flooding-based and random walk schemes in finding a good balance among various performance metrics. Its only potential disadvantage is that the control packet size increases as the number of shared objects increases, which may not impose a severe constraint on a middle-sized ad hoc network.