Real-Time Digital Video Streaming at Low-VHF for Compact Autonomous Agents in Complex Scenes

Abstract

This paper presents an experimental investigation of real-time digital video streaming in physically complex Non-Lineof-Sight (NLoS) channels using a low-power, low-VHF system integrated on a compact robotic platform. Reliable video streaming in NLoS channels over infrastructure-poor ad-hoc radio networks is challenging due to multipath and shadow fading. In this effort, we focus on exploiting the near-ground low-VHF channel which has been shown to have improved penetration, reduced fading, and lower power requirements (which is critical for autonomous agents with limited power) compared to higher frequencies. Specifically, we develop a compact, low-power, low-VHF radio test-bed enabled by recent advances in efficient miniature antennas and off-the-shelf software-defined radios. Our main goal is to carry out an empirical study in realistic environments of how the improved propagation conditions at low-VHF affect the reliability of video-streaming with constraints stemming from the limited available bandwidth with electrically small low-VHF antennas. We show quantitative performance analysis of video streaming from a robotic platform navigating inside a large occupied building received by a node located outdoors: bit error rate (BER) and channel-induced Peak Signalto-Noise Ratio (PSNR) degradation. The results show channeleffect-free-like video streaming with the low-VHF system in complex NLoS channels.

Low Frequency Multi-Robot Networking

“…Short range video webcam streaming experiments were conducted at 40 MHz using software defined radios, with the transmitter mounted on a small UGV navigating inside a building and communicating to an outdoor receiver [87]. Transmit power was limited to < 20 dBm.…”