The ns-2 simulator has limited support for simulating 802.11based wireless mesh networks. We have added the following new features at the MAC and PHY layer of ns-2: (i) cumulative interference in SINR (Signal to Interference and Noise Ratio) computation, (ii) an accurate and combined shadowfading module, (iii) multi-SINR and multi-rate link support, (iv) auto rate fallback (ARF) for rate adaptation, and (v) a framework for link probing and link quality estimation as required by most mesh routing protocols. We have made these modules publicly available. In this paper, we present an overview of these new features. Categories and Subject Descriptors C.2.1 [Network Architecture and Design]: Wireless communication; C.2.5 [Computer-Communication Networks]: Local and Wide-Area Networks; I.6 [Computing Methodologies]: Simulation and Modeling General Terms Design Keywords Wireless network, Wi-Fi, 802.11, mesh network, network simulation