Ekta: an efficient DHT substrate for distributed applications in mobile ad hoc networks

Distributed hash tables (DHTs) have proven to be a novel and efficient platform for building a variety of scalable and robust distributed applications like content sharing and location in the Internet. Similar to those in the Internet, distributed applications and network services in mobile ad hoc networks (MANETs) can potentially benefit from the deployment of a DHT. However, bandwidth limitations, node mobility, and multi access interference pose unique challenges to deploying such DHTs in MANETs. In this paper, we first study how to efficiently implement DHTs in MANETs. We explore two disparate design options: the simple approach of directly overlaying a DHT on top of a MANET multi-hop routing protocol, and Ekta which integrates a DHT with a multi-hop routing protocol at the network layer. Second, we examine the efficiency of DHT substrates in supporting applications in MANETs by examining the performance of a resource discovery application built on top of Ekta with one that directly uses physical layer broadcast. Such a study answers the fundamental question of whether a DHT substrate can be more efficient in supporting applications than a physical layer broadcast-based protocol, since in MANETs, DHT protocols effectively rely on physical layer broadcast to discover and maintain routes.