Fault Tolerance and Congestion Control in Mobile AD – HOC Networks: A Survey

Abstract

MANET is dynamic collection of nodes that communicate with each other using wireless connections. The
nodes are independent of each other so it is expected that they deviate from their usual behavior. This leads to fault.
Fault-Tolerance is an important design issue in the construction of a reliable mobile ad hoc network. Many types of
faults can occur in mobile AD – HOC networks such as link failure, end to end delay, node failure, routing overhead,
misbehaving nodes, network failure, power and energy consumption etc. Congestion in a network can occur at any
interval, it occurs due to traffic in the network. When the number of packets coming to a node is more than buffer
capacity, then the node becomes congested and starts dropping packets. Ad – hoc mobile networks are composed of
mobile nodes that communicate through wireless medium and they do not have any fixed backbone infrastructure. In
these networks, congestion occurs in any intermediate node when data packets travel from source to destination. The
network suffers high packet loss and long delay due to traffic, which causes performance degradations of the network. In
this paper, we surveyed various methods to provide fault tolerance and congestion control in Mobile AD - HOC
Networks. We also compared EDAODV, EDOCR, EDCSCAODV, AODV and DCDR on the basis of packet delivery
ratio, end-to-end delay and routing overhead.