Wireless Multi-path TCP Westwood+ Modification to Achieve Fairness in HSDPA

Multi-path is a technique to increase the reliability of the internet connection in IP network. The implementation of this technique can be described as a host with two TCP paths work together, when one of them fails the other will back up the connection. Since TCP does not support multi-homing, the right term for this technique is multi-path. The fairness problem arises when multi-path host uses the same bottleneck link with another single-path host. This problem can be solved by scaling down each sub-flow on the multi-path by modifying the Congestion Control on Westwood+. This paper will design a Multi-path protocol which will use the same weighing method on BMC and a few modification on weight calculation by exploiting the Bandwidth Estimation on Westwood+ congestion control, this multi-path protocol will be mentioned as Normalize Uniform High-Adaptability (NUHA) TCP. The simulation will be conducted on HSDPA air interface to represent the wireless condition using network simulator 2. The results show that the multi-path protocol NUHA TCP works well in high loss network without violating the fairness.