31-05-2012, 12:25 PM
Improving performance of Adhoc TCP in MANETS
Improving performance of Adhoc TCP in MANETS.doc (Size: 75 KB / Downloads: 81)
Introduction
Purpose
Modifying transmission control protocol (TCP) to improve its performance in wireless networks has
been a long-standing research problem. Many methods have been proposed improve TCP performance in mobile ad hoc networks (MANETS).
Project Scope
This paper proposes Improved- ADTCP (I-ADTCP) an improvement on ADTCP. To improve the performance of ADTCP we consider following: ensure sufficient bandwidth utilization of the sender-receiver path; avoid the overloading of network by limiting TCP’s congestion window below the Upper Bound of Bandwidth Delay product (BDU-UB) of the path; check for incipient congestion by calculating inter-packet delay difference and short term throughput using Relative Sample Density(RSD) technique. In an incipient congestion condition, we reduce Congestion Window Limit (CWL) to half, which limits the packets send by the sender and does not allow the congestion to build up. Results of simulation using NS-2 show that I-ADTCP performance is superior to that of ADTCP for all the levels of traffic intensity in the network.. The good put performance is improved by 10%-30% in I-ADTCP.
Product Perspective
The product perspective is to improve the TCP performance in mobile ad hoc networks (MANETS) over ad hoc TCP. Results of simulation using NS-2 show that I-ADTCP performance is superior that of ADTCP for all the levels of traffic intensity in the networks. We propose the algorithm to improve performance of ADTCP. For this we tune the maximum congestion window considering network status adaptively; detect and react to incipient congestion. we discuss CWL for ADTCP and evaluates performance of proposed algorithm, and finally gives conclusion.
Product Features
Our solution does not rely on energy expensive overhearing techniques, or communication intensive acknowledgement schemes. We adopt a reactive approach where a random audit process is initiated only after a performance degradation is observed, thus significantly reducing the associate resource overhead. Based on storage an communication efficient representation of the packets forwarded by each intermediate node, we construct a publicly verifiable proof of node misbehavior.
User Classes and Characteristics
In this project there is no involvement of user. MANET’s itself act as user. MANETs are the collection of independent mobile nodes that can communicate each other via radio waves. The mobile nodes that are in radio range of each other can directly communicate, where as other needs the aid of intermediate nodes to route their packets. These networks are fully distributed, and can work at any place without the help of any infrastructure.
Design and Implementation Constraints
The study of the algorithms and to improve the TCP performance in MANETS is being simulated through the Network Simulator (NS-2.33) available. In the simulation, all the characteristics like the packet dropping, packet losses and packets received have been analyzed using the Xgraphs available in the simulator. This simulation is shown in the Network Animator (NAM). This animator gives the real time environment of the mobile ad-hoc network and the real time packet transfer and droppings by the mobile nodes in the network. The details about the simulation, simulation goals and the introduction about the simulation purpose are given below. The simulation is completely done under the Windows environment by creating a virtual Linux environment in the Windows working space, so as to feel the Linux environment in Windows, for this purpose, Cygwin has been used to provide the required environment in Windows.