Performance evaluation of roll/RPL protocol in Delay Tolerant Networks (DTN)

Abstract

Delay-Tolerant Networks (DTNs) are a type of emerging networks characterized by very long delay paths, frequent network partitions and high loss rates. The nodes are sparsely deployed and intermittently connected. The presenting network is used in a variety of environments including military, disaster situations and for long distance communications. Although it is used in critical sectors, the communication support lacks the high end technology usually found in important networks. The nodes participating in this network do not have stable end-to-end connections. They can communicate to each other only occasionally, through the opportunistically available links. Thus, routing becomes one of the most challenging problems. On the other hand, the Ripple Routing protocol (RPL) was introduced by a working group called Routing Over Low and Lossy Networks (ROLL) and aimed to be used as a routing protocol over Low and Lossy Networks (LLN). This thesis aims to find a suitable protocol that can be applied to Delay tolerant Networks in order to improve and optimize the routing and to lower the delay and loss of packets between the nodes. Since the ROLL/RPL protocol is specialized for the Low power and Lossy Networks; therefore it could include Delay Tolerant Networks as well. However, the ROLL/RPL protocol was mainly designed for dense wireless networks. On the other hand, a mobile DTN does not have much in common with a dense "always on" network. Therefore, we decided in this thesis to investigate the applicability of the ROLL/RPL on a DTN, and to calculate its efficiency depending on the network density. This thesis shall provide recommendations on how this protocol could be upgraded to suit sparse Low and Lossy Networks (LLNs).