A Hybrid Cross Layer Architecture For Wireless Protocol Stacks

Many architectures to support multiple cross-layer optimizations have been proposed. Most of them can be categorized as either signaling-based or function-call based. The signaling approaches use messages to propagate the information in the protocol stack, while the function-call uses application programming interface (API) for direct access to variables. The signaling approach complies with the layered protocol stack architecture but introduces latency in the information propagation and additionally increases the packet size. The function- call approaches are more efficient but highly operating system dependent. Even a slight protocol modification requires the function-call middleware to be updated. We previously proposed an infrastructure for cross-layer designs interaction (ICDI) based only on the signaling approach. In this paper, we first provide in-depth analysis of the two main schemes. Thereafter we propose a hybrid version of the ICDI architecture that combines the advantages of both approaches. According to our simulation results, the packet size overhead is reduced by around 75% (in bytes) and the propagation latency is reduced by more than 60%. The proposed hybrid system remains operating system independent.