An Analysis Optimal Buffer Management Policy to Improve QOS in DTN Routing Protocol

Abstract

Abstract—Network architectures like TCPIP, AODV, OSPF perform communication in environments where end-to-end path must exist before the start of transmission and is not devisable in most of advanced wireless applications for example military networks , vehicular ad hoc networks, pocket switched networks, deep space communication. Delay Tolerance network (DTN) build communication infrastructure through intermittently connected mobile nodes where each node store the message in its buffer, carries the message while moving and forward it when encounter with other nodes. To maximize the delivery probability, a node while moving replicate message copies to all encounters nodes. This iterative replication and storage of message produce congestion which is override by dropping message(s). An efficient buffer management policy to improve quality of service is required to decide which message will be dropped, when buffer run out of its capacity.In this paper we proposed a new buffer management policy which drops the message from congested buffer only if size of existing queued message(s) falls in Threashhold range (T).This technique is called as T-Drop. We prove through simulations that propose T-Drop policy minimize the message drop, hop count average, overhead while increase the delivery probability as compared to existing DOA.