Analysis of SoftToken: a coordinated Medium Access Control (MAC) for IEEE 802.11 based wireless mesh networks

摘要

Wireless Mesh Networks (WMNs) which can be integrated to other types of networks at a reasonable cost are good candidates to facilitate the efficient and flexible deployment of Next Generation Networks (NGNs). Due to the widespread presence of IEEE 802.11Wireless Local Area Networks (WLANs) most of current WMNs are based on this technology. However, IEEE 802.11 is primarly designed for one-hop networks and its random access protocol (CSMA/CA) is problematic in multi-hop environments due to collisions, which decrease efficiency and service quality. To alleviate these problems a novel approach, SoftToken, was proposed to provide a coordinated Medium Access Control (MAC) for WLANs whose goal is to add a token-passing mechanism on top of the standard IEEE 802.11 in a way that collisions can be avoided. In this thesis, we present an analysis and evaluation of SoftToken in various scenarios. We also develop some functions to integrate this protocol into the architecture designed by the CARrier grade MEsh Networks (CARMEN) project. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------