An Interference-Aware Admission Control Design for Wireless Mesh Networks

In this paper, we present IAC, an interference aware admission control algorithm for use in wireless mesh networks. The core concept of IAC is to use a low overhead dual threshold based approach to share the bandwidth information with its neighbors in the interfering range. As a result, IAC guarantees that the shared wireless bandwidth is not overutilized and the quality of all existing flows are preserved. Moreover, IAC takes into account the intraflow interference effect to estimate the bandwidth consumption of the flow in a multihop path. We have further proposed two approaches of bandwidth allocation, FCFS and MCU, and demonstrated that proper tuning of thresholds can lead to high performance of both schemes. Simulation results illustrate that IAC effectively limits the overutilization of channel resources which in turn results in high throughput, low delay and low packet loss rate for all admitted flows

Improving the performance of TCP in the presence of interacting UDP flows in ad hoc networks

In this paper, we study how fairness affects the performance of TCP over ad hoc networks with IEEE 802.11 at the MAC layer. The problem addressed is that the throughput of TCP flows degrades severely in the presence of heavily loaded UDP flows. Our contribution is twofold. First, we identify the factors affecting the TCP throughput by providing a micro-analysis of the performance at a level of detail that is not seen in previous studies. The intuition obtained from the first part leads us to our second contribution. We propose and study the use of per flow fairness through a mechanism we call backpressure. Backpressure improves the performance of TCP flows in the presence of heavy UDP flows. In fact, in some cases, this increased TCP throughput does not affect the throughput of UDP flows. We find that backpressure can increase the TCP throughput by as much as 95%. An advantage of backpressure is that it does not require any changes to the existing TCP or IEEE 802.11 protocols

Testing Applications in MANET Environments through Emulation

Mobile Ad Hoc Network solution testing is typically done using simulation. The simulated code is generally a simplified version of the real code, and thus code porting to actual operating systems lacks a strong validation. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for real ad hoc network environments using low-cost, off-the-shelf devices and open source software. Castadiva is also compatible with the ns-2 simulator, allowing a combined and more complete evaluation. In this work we present our tool and the results obtained when evaluating videocalls in different scenarios, both static and dynamic