Publish/Subscribe (pub/sub) for Mobile Environments 

Publish/Subscribe (pub/sub) middleware architecture proliferates loose coupling and leverages reconfigurability and evolution. Supporting mobility in pub/sub systems requires allowing for roaming clients so that existing applications can seamlessly be used in mobile environments. Courier, a group communication tool based on the pub/sub principle, exploits the location and velocity of roaming nodes to provide multicasting communications between publishers and subscribers in mobile environments.

Routing in Asymmetric Ad-Hoc Networks

Link conditions in realistic wireless networks vary drastically from the ideal disk model and a substantial percentage of links are asymmetric. Existing Geographic Forwarding (GF) algorithms fail to consider asymmetric links in neighbor discovery and thus discount a substantial number of potentially stable routes with good one-way reliability. Asymmetric Geographic Forwarding (A-GF) protocol discovers asymmetric links in the network and exploits them for efficient routing. Toward that end, A-GF results in decrease in hop count/latency and increase in successful routing, with only a small increase in overheads.

Stability Aware Routing in Mobile Ad Hoc Networks

Dynamic Power Management (DPM) schemes in Wireless Ad-Hoc Networks often puts wireless nodes into a sleep state when the node is not transmitting or receiving data. Such sleep states can lead to loss of network connectivity and hence lower the packet delivery ratio. Stability Aware Dynamic Source Routing (SA-DSR) exploits the transient availability of the intermittently sleeping nodes by introducing DPM-awareness in the routing decisions. It finds stable routes as predicted by a ‘DPM-aware Route Stability Prediction Algorithm’ and thus ensures acceptable network connectivity.