Improving performance in delay/disruption tolerant networks through passive relay points

Abstract

In this paper, we study the case of a limited number of mobile nodes trying to communicate in a large geographic area, forming a delay/disruption tolerant network (DTN). In such networks the mobile nodes are disconnected for significantly long periods of time. Traditional routing protocols proposed for mobile ad hoc networks or mesh networks, which assume at least one path between each source and destination, are ineffective in DTNs. One approach to improve communication is through gossip based protocols because these protocols do not rely on a fixed path. Another approach is to control the movement of the mobile nodes and/or use special mobile nodes called ferry nodes. Others try to employ a fixed infrastructure including stationary relay points. One scheme in stationary relay point approach is to use base stations as relay points which need their own power supply. In this paper, we study a passive approach where mobile nodes deposit/retrieve messages to/ from known stationary locations in the geographic region. Messages are delivered from a source by being deposited at one or more locations that are later visited by the destination. A proposed implementation of our approach using read/writable passive Radio Frequency Identification (RFID) tags, one per point location, is considered in this work. Passive RFID technology is desirable because it operates wirelessly and without the need for attached power. Our simulation results indicate that our approach can achieve competitive message delay and delivery rates. We also demonstrate several techniques for optimizing the stationary relay node placement, namely relay pruning, probability based relay distribution and a genetic algorithm; the genetic algorithm is shown to provide the best solutions to this problem.

Homing spread: Community home-based multi-copy routing in mobile social networks

“…Moreover, these throwboxes are randomly placed, and usually they are physical storage devices. In addition, some other works also use the stationary relays to improve the routing performance, such as [19]. The network model and routing scheme are different from this paper.…”

Dynamic Rendezvous Based Routing Algorithm on Sparse Opportunistic Network Environment

“…The concept of passive relay node can be found on several recent research proposals such as throwbox [48–51], FINs (fixed infrastructure nodes) [12], fixed point [52], or passive relay points [53]. These relay nodes are stationary wireless devices injected into the infrastructure of network in order to create additional contact opportunities and increase the connectivity between mobile nodes.…”

Information dissemination dynamics in delay tolerant network

“…In [22], the authors show that, use of such relay devices effectively decreases the data delivery latency as well as increases the data delivery ratio. However, the existing modeling or analysis related works on DTN do not consider the presence of such message buffers.…”