Reducing Latency in Rendezvous-Based Publish-Subscribe Systems for Wireless Ad Hoc Networks

To ensure decoupling between publishers and subscribers, most publish-subscribe systems route notifications through intermediate message brokers. A byproduct of this practice is that notifications often follow suboptimal paths that are much longer than a direct path. Hence, in this paper, we propose a publish-subscribe architecture called GeoRendezvous which aims to reduce the latency experienced by end clients in the delivery of notifications. We base our system on a position-based distributed hash table (DHT) that supports rendezvous points where the interests of publishers and subscribers match. Leveraging from previous work, we replicate the rendezvous points to give multiple choices of paths to the subscribers. We show that in this way, the subscriber is able to achieve latencies comparable to a direct publisher-subscriber path without breaking the decoupling assumptions of the publish-subscribe model. Additionally, we show that scalability is one of the most prominent features of GeoRendezvous, as the number of rendezvous points scales with the network size.