Characterizing Interference in Wireless Mesh Networks

of thesis entitled: Characterizing Interference in Wireless Mesh Networks Submitted by HUI, Ka Hung for the degree of Master of Philosophy at The Chinese University of Hong Kong in August 2007 The relationship between interference and capacity has been a main focus in the study of wireless mesh networks. To find out the capacity of a wireless mesh network, we have to accurately model the interference among the wireless links. Then we can design traffic engineering algorithms to allocate flows on each link to achieve the capacity. Existing traffic engineering algorithms were designed based on the celebrated interference model protocol model, and the existence of a perfect scheduler. However, these assumptions only help simplify the problem, and may not be achieved in reality. Therefore, these works may have little value in current wireless mesh networks. In this thesis, we first introduce a new interference model partial interference, predicting the result of a transmission in a wireless network to be probabilistic based on the corresponding signal-to-noise ratio (SNR) and the modulation scheme used. We illustrate there is a gain in terms of capacity by considering partial interference. Second, towards designing traffic engineering algorithms in wireless random access networks, we study the stability regions of 802.11 and slotted ALOHA networks under partial interference. The results show that the protocol model is not accurate