Multi-Armed Bandit in Action: Optimizing Performance in Dynamic Hybrid Networks

Abstract: Today's home networks are often composed of several technologies such as Wi-Fi or power-line communication (PLC). Yet, current network protocols rarely fully harness this diversity and use each technology for a specific, pre-defined role, for example, wired media as a backbone and the wireless medium for mobility. Moreover, a single path is generally employed to transmit data; this path is established in advance and remains in use as long as it is valid, although multiple possible paths offer more robustness against varying environments. We introduce HyMAB, an algorithm that explores different multipaths and finds the best one in a mesh hybrid network, while keeping congestion under control. We employ the multi-armed-bandit framework and prove that HyMAB achieves optimal throughput under a static scenario. HyMAB design also accounts for real-network intricacies and dynamic conditions; it adapts to varying environments and switches multipaths when needed. We implement HyMAB on a PLC/Wi-Fi test bed. This is, to the best of our knowledge, the first implementation on a real test bed of multi-armed-bandit strategies in the context of routing. Our experimental results confirm the optimality of HyMAB and its ability to adapt to dynamic network conditions, as well as the gains provided by employing multi-armed-bandit strategies.