Abstract— 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...