Fast Link Assessment in Wireless Mesh Networks by Using Non-Constant Weight Code

The wireless mesh network is experiencing tremendous growth with the standardization of IEEE 802.11 and IEEE 802.16 technologies. Compared to its wired counterpart, the resource (e.g., capacity) of the wireless mesh network is limited. Worst yet, the wireless link quality is time and space varying, depending on the environment and interference. In order to make efficient use of the scarce channel resource during topology formation, scheduling and routing, it is vital to understand the quality of the links in the wireless mesh network (in terms of, e.g.,probability of successful transmission, or signal to noise ratio). The existing approaches for link assessment consume substantial amount of time and thus introduce significant delay and overhead. In this paper, we propose a novel link assessment scheme where the link assessment packets are transmitted efficiently according to a set of non-constant weight codes, which achieves low collision probability within a short link assessment period. In our proposed approach, each node considers the actual nodal degree while choosing the codeword for its link assessment. In this work, we design the link assessment procedure and establish a set of theorems that provide the necessary condition for successful link assessment. Extensive simulations are carried out, showing that our proposed approach reduces link assessment delay by over 70% compared to the orthogonal optical code OOC-based approach.