WiLongH: A Custom Hand-Held Platform for Long-Range HaLow Mesh Networks in Human-to-Human Communication

Abstract

Over the past 25 years, IEEE 802.11 (Wi-Fi) has played a vital role in last-mile Internet connectivity. The Wi-Fi HaLow (802.11ah) standard marks a significant leap, offering long-range, low-power connectivity, particularly suited for Internet of Things (IoT) applications. Operating in sub-1 GHz frequencies, Wi-Fi HaLow extends coverage up to 1 km. However, deploying multi-hop HaLow mesh networks for ground-level Human-to-Human (H2H) communication presents unique challenges, as the standard primarily supports star and tree topologies. This paper introduces the WiLongH hand-held platform, designed for long-range Wi-Fi HaLow mesh networks aimed at H2H communication at ground level. Utilizing commercial hardware, open-source software, IEEE 802.11s mesh, and the B.A.T.M.A.N. Advanced Routing Protocol (batman-adv) with custom radio profiles, the platform was tested across various environments, including indoor, outdoor, urban, and multi-level parking settings. Results demonstrate that the platform supports voice call ranges exceeding 1 km and video call ranges up to 800 m in line-of-sight conditions, with throughputs of 420 Kbps and 700 Kbps, respectively. In complex urban environments (300-700 m), it achieved up to 64% success for voice calls and 30% for video calls using a 1 MHz channel bandwidth with two nodes. Connectivity across 3-4 floors in basement parking revealed the need for additional mesh nodes. The platform’s multicast audio performance showed near-optimal forwarding, outperforming traditional flooding techniques, with 4-node multi-hop performance tested in outdoor and indoor settings. A dense mesh network setup of 14 nodes in an indoor arena further validated the scalability of the platform. Moreover, the use of a SAW filter in the US band (902-928 MHz) significantly reduced cellular interference, enhancing voice and video call performance by 15-20% and 7-10%, respectively. Additionally, the WiLongH platform demonstrated a 33% improvement in battery life compared to conventional long-range Wi-Fi mesh systems.