Managing Programmable Low-End Wireless Networks through Distributed SDN Controllers
Andre Scheibe, Luciano Paschoal Gaspary, Weverton Luis Da Costa Cordeiro · 2021
Low Power Wide Area Network (LPWAN) have recently attracted attention as a potential alternative to power affordable internet access to remote communities and help bridge the digital divide. Nevertheless, realizing the full potential of LPWAN devices as an alternative to bring remote communities to the internet requires addressing two technical challenges. The first one is making LPWAN devices suitable for exchange of data flows running under standard protocols like TCP/IP. The second one is devising a fully distributed management approach tailored for a network composed of autonomous LPWAN devices that are reachable only through unstable and unreliable wireless links. We addressed the first challenge in a prior work, with a conceptual solution for programmable low-end devices, i.e., LPWAN devices whose behavior can be redefined using programming languages for the data plane like P4. In this paper, we address the second challenge by presenting an algorithmic approach for SDN-based distributed management for programmable low-end networks. In summary, we consider that each programmable low-end device in a community network is autonomous and has its independent SDN controller. For coordinated management, they use control messages transmitted over unreliable and constrained links (up to 300 kbps), hence the need for a lightweight and fault-tolerant management approach. We experiment our SDN-based distributed approach with LTP (Lightweight Tunnel Protocol), a proof-of-concept protocol written in P4 for powering programmable low-end networks. We provide evidence, through a series of experiments, that our algorithmic approach for fully distributed SDN-based management is capable of maintaining stable network connectivity despite running over unstable and unreliable links.