Making Dense Networks Work for You

The increased contention and collisions in dense networks trigger excessive scans for finding AP. The collective effect of simultaneous probes from all devices create even more contention in the network. Eventually, the devices start continuous cycles of probing since network condition does not improve after the handoff. Traces we have collected during Infocom 2012 and at busy airport terminals show this impact of probing on dense networks. In this paper, we propose Dynamo-Probing that obtains AP information from nearby active scan using its novel scan mode, Opp-Scan, and by switching to active scan when such opportunities are not available. By avoiding sending probes for each device in the network, Dynamo-Probing reduces the network overload due to probing and thus improves communication quality. Results from our ns-2 simulations capture a 78% improvements in network association time and up to an 82% improvements in throughput for very dense networks. By being adaptive to network density and interoperable with legacy devices, Dynamo-Probing provides an appropriate scan solution that ensures survival in dense networks and good performance in sparse networks.