Implementation of video data transmission protocol for a narrow sewer pipe screening system using drifting wireless cameras

Saving the cost for inspecting old sewer pipe is a key issue for keeping cities sustainable. To this end, we have been working on developing a low-cost sewer screening method by drifting small capsules with a camera and a wireless LAN function. We have developed a protocol for transmitting video data recorded by multiple camera-capsules drifting in the same pipe and have been investigating the performance of wireless LAN communication in narrow underground pipes. In this paper, we report the improvement of the video data transfer protocol considering the frame aggregation function of IEEE 802.11n Wireless LAN to improve the reliability, also report the measured performance of IEEE 802.11n in a narrow reinforced concrete sewer pipe.