Load distribution and energy awareness in manets using multipath routing

• Main Author: Tachtatzis, Christos
• Published: University of Strathclyde 2008
• Subjects: 621.382
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501793

Wireless ad-hoc networks are characterised by lack of infrastructure and frequent topological changes. Traditional routing protocols seek only single paths to the desired destinations, while multipath routing obtains multiple paths for only marginal additional overhead. This work argues that multipath routing is advantageous, even allowing for the additional overheads, because of the improved network load distribution. The merits of multipath routing are shown through extensive performance evaluation considering packet delivery ratio, average end-to-end delay and routing efficiency, for both mobile and static scenarios. The second aspect of the thesis addresses energy awareness. When a single connection is considered, multipath routing can potentially consume more total energy compared to its unipath counterparts because some traffic can traverse longer (in terms of hop count) paths. On the other hand, unipath routing concentrates nodal traffic over the same single path; resulting in unfairness for the intermediate hops and uneven energy consumption which, in turn, can result in network partitioning. Here, it is argued that multipath routing extends the network lifetime, because the routing protocol can make more sophisticated decisions to avoid node exhaustion. Two novel energy aware routing schemes, which select optimal paths to homogenise the energy map of the network, are presented. A range of performance evaluation techniques are employed to demonstrate the merits of the proposed schemes, and it is shown that the approach of homogenising the network energy map mitigates against the effects of inevitable node outages cause by energy exhaustion and prolongs network lifetime.