On the Implementation of a Cross-Layer SDN Architecture for 802.11 MANETs

The adoption of the Software Defined Networking (SDN) paradigm is aggressively expanding from traditional datacenter networks to 5G and IoT deployments due to its flexibility in network management and routing. Mobile Ad-Hoc Networks (MANETs), with their unique characteristics and requirements stemming from the mobility and volatile wireless medium conditions, have not yet realized the benefits of the SDN approach. Adoption has been hampered by technical challenges and the contradiction between the centralized concept of SDN and the distributed one of traditional MANET routing schemes. In this paper, we present our implementation of a fully-fledged SDN framework, which attempts to bridge the gap by combining the benefits of both worlds. Our developed prototype integrates with 802.11 Ad-Hoc networks and offers a) fault tolerance for the SDN controller by recovering from failures with the (re)-election of a new controller, b) dynamic network topology discovery, and c) a cross-layer approach in routing based on 802.11 MAC layer statistics that more accurately characterize link quality and capacity. We validated the applicability and performance benefits of our method by evaluating our proposed SDN architecture in a proof-of-concept scenario.