Improving mesh-agnostic client announcement in B.A.T.M.A.N.-advanced

Research in Wireless Mesh Networking has been very active in the past years, with the birth of several new ideas and the protocols that implement them. Most common implementations rely on Layer-3 addressing and routing; however 802.11s and other successful protocols suggest that Mesh Networking on Layer-2 address space is more efficient, does not mingle with the global IP routing, and provides easier ways to support micro-mobility as well as client management. This paper focuses on the client announcement protocol, i.e., the functionality, somewhat embedded between Layer-2 and Layer-3, that allows routers in a mesh network to announce the clients they are serving and that in practice makes the entire routing protocol work correctly. In particular, it focuses on B.A.T.M.A.N.-Advanced, analyses the shortcomings of the simple implementation of this functionality present until v.2011.2.0 and defines the new protocol and algorithms that we have implemented and are part of the distribution starting from v.2011.3.0. Experiments in controlled scenarios show how performance increases dramatically even in scenarios designed specifically to stress the new protocol. The new mechanism and improved performance make it possible to design new features for B.A.T.M.A.N.-Advanced, most notably the support for fast and seamless handover, which is currently under testing.