We consider the problem of routing in intermittently connected networks. In such networks there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts. We propose a probabilistic routing protocol for such networks.

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Probabilistic routing in intermittently connected networks

In this paper, we address the problem of routing in intermittently connected networks. In such networks there is no guarantee that a fully connected path between source and destination exists at any time, rendering traditional routing protocols unable to deliver messages between hosts. There does, however, exist a number of scenarios where connectivity is intermittent, but where the possibility of communication still is desirable. Thus, there is a need for a way to route through networks with these properties. We propose PRoPHET, a probabilistic routing protocol for intermittently connected networks and compare it to the earlier presented Epidemic Routing protocol through simulations. We show that PRoPHET is able to deliver more messages than Epidemic Routing with a lower communication overhead.

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Probabilistic Routing in intermittently connected networks

n the last few years, there has been much research activity in mobile, wireless, ad hoc networks (MANET). MANETs are infrastructure-less, and nodes in the networks are constantly moving. In MANETs, nodes can directly communicate with each other if they enter each others' communication range. A node can terminate packets or forward packets (serve as a relay). Thus, a packet traverses an ad hoc network by being relayed from one node to another, until it reaches its destination. As nodes are moving, this becomes a challenging task, since the topology of the network is in constant change. How to find a destination, how to route to that destination, and how to insure robust communication in the face of constant topology change are major challenges in mobile ad hoc networks. Routing in mobile ad hoc networks is a well-studied topic. To accommodate the dynamic topology of mobile ad hoc networks, an abundance of routing protocols have recent-For all these routing protocols, it is implicitly assumed that the network is connected and there is a contemporaneous end-to-end path between any source and destination pair. However, in a physical ad hoc network, the assumption that there is a contemporaneous end-to-end path between any source and destination pair may not be true, as illustrated below. In MANETs, when nodes are in motion, links can be obstructed by intervening objects. When nodes must conserve power, links are shut down periodically. These events result in intermittent connectivity. At any given time, when no path exists between source and destination, network partition is said to occur. Thus, it is perfectly possible that two nodes may never be part of the same connected portion of the network. Figure 1 illustrates the time evolving behavior in intermittent-ABSTRACT Recently there has been much research activity in the emerging area of intermittently connected ad hoc networks and delay/disruption tolerant networks (DTN). There are different types of DTNs, depending on the nature of the network environment. Routing in DTNs is one of the key components in the DTN architecture. Therefore, in the last few years researchers have proposed different routing protocols for different types of DTNs. In this article we capture the state of the art in routing protocols in DTNs. We categorize these routing protocols based on information used. For deter-ministic time evolving networks, three main approaches are discussed: the tree approach, the space and time approach, and the modified shortest …

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Routing in intermittently connected mobile ad hoc networks and delay tolerant networks: overview and challenges

In this paper, we describe AntHocNet, an algorithm for routing in mobile ad hoc networks. It is a hybrid algorithm, which combines reactive path setup with proactive path probing, maintenance and improvement. The algorithm is based on the nature-inspired ant colony optimisation framework. Paths are learned by guided Monte Carlo sampling using ant-like agents communicating in a stigmergic way. In an extensive set of simulation experiments, we compare AntHocNet with AODV, a reference algorithm in the field. We show that our algorithm can outperform AODV on different evaluation criteria. AntHocNet's performance advantage is visible over a broad range of possible network scenarios, and increases for larger, sparser and more mobile networks. Copyright © 2005 AEIT.

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AntHocNet: an adaptive nature-inspired algorithm for routing in mobile ad hoc networks

https://www.eecs.ucf.edu/~turgut/Research/Publications/Download/Boukerche-2011-ComputerNetworks.pdf

Survey Paper: Routing protocols in ad hoc networks: A survey

ANSI: a swarm intelligence-based unicast routing protocol for hybrid ad hoc networks

In recent years, a number of P2P systems, for instance, Gnutella, KaZaA, Napster, and BitTorrent, have been proposed for the wired Internet. However, these protocols are not immediately applicable to the mobile ad hoc networks (MANETs) owing to the extreme conditions MANETs operate under. Of the above protocols, although BitTorrent has several features which make it an ideal candidate for adapting to MANETs, the current specification of BitTorrent has several drawbacks which make a straightforward implementation of BitTorrent for MANETs an undesirable solution. In this paper, we investigate a straightforward implementation of BitTorrent in MANETs, termed BTI, and compare its performance with a cross-layer adaptation of BitTorrent for MANETs, termed BTM. We resolve the issues of centralized control and single point of failure in BTI by proposing mechanisms to decentralize the BitTorrent model for MANETs and provide resource/data redundancy to improve the protocol performance. In addition, the cross-layer model of BTM is more suited for use in a MANET. Our performance comparison studies show that BTM is able to outperform BTI in terms of goodput, and the number of pieces delivered, in the context of amortizing the client download expenses over more connections (that is, BTM has a higher average peer degree)

A Cross-layer Decentralized BitTorrent for Mobile Ad hoc Networks

Future Earth and space science missions are envisioned to be implemented using a flexible, distributed architecture consisting of a constellation of dynamically deployed or configured satellites that are networked together into an integrated information system. These satellites form an ad hoc network characterised by a frequently changing topology and potentially sparse and intermittent connectivity, which pose unique challenges to routing. We propose interrogation-based relay routing for ad hoc satellite networks, where the satellites interrogate each other to learn more about network topology and nodal capacity to make intelligent routing decisions. Simulations have been conducted to study the effects of satellite density and orbital patterns on throughput and delivery ratio.

Interrogation-based relay routing for ad hoc satellite networks

Ad hoc networks consist of mobile nodes that autonomously establish connectivity via multihop wireless communications. Swarm intelligence refers to complex behaviors that emerge from very simple individual behaviors and interactions. In this paper, we describe the ANSI project that adopts swarm intelligence as an adaptive distributed control mechanism to design multicast routing, topology control, and energy conservation protocols for mobile ad hoc networks.

/pdf/ad-hoc-networking-with-swarm-intelligence-5oufscuose.pdf

Sundaram Rajagopalan

Papers

ANSI: a swarm intelligence-based unicast routing protocol for hybrid ad hoc networks

A Cross-layer Decentralized BitTorrent for Mobile Ad hoc Networks

Interrogation-based relay routing for ad hoc satellite networks

Ad Hoc Networking with Swarm Intelligence

A flexible routing architecture for ad hoc space networks