Po-Fi: Facilitating innovations on WiFi networks with an SDN approach

Most of softwareized WiFi networks rely on dedicated softwares for realizing novel wireless functionalities. However, such an approach is not flexible enough, and introduces management complexity. On the other hand, the programmable forwarding pipeline, which models packet processing as multiple stages of forwarding rules, exhibits great flexibility in facilitating network innovations, and has been recognized as a consensus for abstracting SDN data plane. In this paper, we present Po-Fi, an architecture for software-defined WiFi networks. Based on Protocol-Oblivious Forwarding (POF), Po-Fi follows the SDN consensus by abstracting WiFi AP as a programmable forwarding pipeline, and provides a rich and unified programmability to enable user to realize novel wireless functionalities with forwarding rules. Comparing with previous approaches, Po-Fi is highly flexible in facilitating WiFi innovations. To show this, we realize a wide range of use cases with Po-Fi, including per-client virtual AP (VAP), seamless mobility, multi-AP MPTCP data transmission, smooth remote AP switching for wireless backhaul, and TDMA MAC scheduling. We implement a Po-Fi prototype with commodity hardware, and evaluate the use cases with real-world experiments. The results show that the Po-Fi facilitated innovations can effectively improve the WiFi network services.