Cross-Layer Routing for Outage Minimization in Multihop Ad-Hoc Networks

In this study, cross-layer approach for joint routing and power allocation problem is formulated in an optimization framework for end-to-end outage minimization under the constraint of total permissible transmission power. A closed form solution for optimal transmission power is obtained following the extraction of routing metric. The scheme is referred as minimum end-to-end outage probability (MEO) strategy. A distributed implementation of the proposed strategy is also presented. Simulation results prove that our proposed MEO routing and power allocation strategy succeeds in achieving significant improvement of end-to-end outage probability over MEO routing and equal power allocation scheme.

Ad Hoc Network as a Solution in Disaster Management

Whenever some natural disaster occurs, the immediate and most dreadful impact is a communication failure. It can easily be understood that communication systems can make a significant difference between survivals for life and death for those affected areas. Due to the potential for existing telecommunication infrastructure to be damaged, disasters are one of the most difficult implementations of multihop ad hoc networks Following a natural disaster, the deployed cellular network system could be partially or entirely lost. Multihop ad hoc contact is an intriguing option for dealing with a lack of communication in crisis situations. In many situations, ad hoc networks have been used for recovery or communication links. The main reason behind the concept is that they are infrastructure less and can adopt any topology. Though in the research arena disaster situations are one of the challenging areas. The situation can be disastrous in many ways, in this paper underwater situation like flood etc. have been considered as a case study. It has been observed that a significant gain in the signal strength ranges from 50–70% have been achieved which is quite respectable in disaster situations. The performance has been evaluated in terms of energy and signals gained. The research has been carried out and promising results were evident from the simulation. The new scheme performs better in certain cases and minor delay can be acceptable in the disastrous situations. We present criteria for ad hoc networks used in disaster for emergency response, with a focus on delay, packet delivery ratio, size, speed, and providing network status awareness through the network's nodes.

Ingress Throttling and its Applications in IEEE 802.11 Based MANETs

One of the stumbling blocks which prevents multihop ad hoc networks from wide deployment is a known problem of unfair bandwidth distribution between competing data sessions. Practically, a combination of the current IEEE 802.11 technology and the standard TCP protocol allows only a couple of up to three hops connections co-exist simultaneously while providing fairly stable and acceptable service to end users. In this article we describe ingress throttling, a resource protection layer which restores fair bandwidth sharing between plain TCP as well as arbitrary UDP sources. We summarize analytical as well as simulation studies of our solution and demonstrate itsapplications for determining scaling limits of ad hoc specificsimulations and evaluating the effect of ad hoc routing onperformance of data communications.