Harmony: Saving Concurrent Transmissions from Harsh RF Interference

• Published in: IEEE INFOCOM 2020 - IEEE Conference on Computer Communications pp. 1024 - 1033
• Main Authors: Ma, Xiaoyuan, Zhang, Peilin, Liu, Ye, Boano, Carlo Alberto, Kim, Hyung-Sin, Wei, Jianming, Huang, Jun
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.07.2020
• Subjects: Data collection; Electromagnetic interference; Protocols; Radio frequency; Reliability; Synchronization
• ISSN: 2641-9874
• DOI: 10.1109/INFOCOM41043.2020.9155423

The increasing congestion of the RF spectrum is a key challenge for low-power wireless networks using concurrent transmissions. The presence of radio interference can indeed undermine their dependability, as they rely on a tight synchronization and incur a significant overhead to overcome packet loss. In this paper, we present Harmony, a new data collection protocol that exploits the benefits of concurrent transmissions and embeds techniques to ensure a reliable and timely packet delivery despite highly congested channels. Such techniques include, among others, a data freezing mechanism that allows to successfully deliver data in a partitioned network as well as the use of network coding to shorten the length of packets and increase the robustness to unreliable links. Harmony also introduces a distributed interference detection scheme that allows each node to activate various interference mitigation techniques only when strictly necessary, avoiding unnecessary energy expenditures while finding a good balance between reliability and timeliness. An experimental evaluation on real-world testbeds shows that Harmony outperforms state-of-the-art protocols in the presence of harsh Wi-Fi interference, with up to 50% higher delivery rates and significantly shorter end-to-end latencies, even when transmitting large packets.