Design of a Wireless Sensor Network for Open Ocean Aquaculture Based on 802.11 ac Wireless Bridge and LoRa™ Technology

This paper presents the design of a remote monitoring system for open ocean aquaculture, which is based on the integration of two long-range wireless communication technologies: the IEEE 802.11ac wireless bridge and the LoRa-Android embedded system. The system is composed of sensors and underwater camera that can measure the seawater quality and observe the fish behavior in aquaculture cages in real time. The sensor and video electrical cables were connected to the watertight control unit attached to the upper frame of the cage with stainless steel brackets and wire rope. The sensor data and video recorded in control unit were sent to the remote data center located on land by LoRa wireless module and IEEE 802.11ac wireless bridge, respectively. Finally, all these data were uploaded to NTOU (National Taiwan Ocean University) Cloud center. To extend the system run time for the daily operation period under the fixed battery capacity, a remote relay controller has been used in the watertight control unit. The entire system can be shut down by remote commands except the relay itself and the wireless subsystem. In addition, the wireless subsystem can be turned off by setting a periodic wake-up time in the relay controller for power saving. The preliminary experiment was performed at Gongliao in New Taipei City to test the proposed system. After successful testing, the whole system has been setup at the fish farm at Pingtung for long-term testing. The experiment results show that the proposed wireless sensor network has good suitability and sustainability when applied in the field of open ocean aquaculture.