Remotely Operated VoIP Radio for Drones

Sammanfattning: Nowadays, search and rescue organizations are considering using drones to aid in rescue missions. To ensure the drones work properly, we need to design a reliable and stable systems. One of these systems is the communication system, which creates a link between the drone and the operator. There are many communication technologies used in rescue missions, such as Voice over Internet Protocol (VoIP). VoIP uses the Internet to send and receive traditional telephony services such as voice, video, and other media sessions. In this project, we investigate the performance of Software Defined Radio (SDR) in implementing the VoIP technology on the drones to stream video by using Fourth Generation of Telecommunication Systems (4G) Long-Term Evolution (LTE). In addition, the SDR should also communicate in the sea using marine Very High Frequency (VHF) voice-radio for sea rescue missions. To verify and evaluate the system, we used BladeRF xA4 to run Qradiolink and srsLTE to simulate the communication system as the hardware platform. In this experiment, we use a BladeRF SDR as a base station. The test procedure is designed to evaluate the performance of the 4G LTE and marine VHF links. We conducted tests in three different environments to evaluate the performance of the system and show the impacts of different environments. In the 4G LTE measurements we evaluate the Signal to Noise Ratio (SNR), Reference Signal Received Power (RSRP), jitter, delay, and packet loss. In the marine VHF measurement we evaluate the Received Signal Strength Indicator (RSSI). The experimental result shows that it is possible to use SDR to implement the suggested communication system. However, there are some restrictions that are related to the power source and the BladeRF xA4 hardware design. Based on the experimental results, we create a scaling graph to show the base­line of the hardware specifications to achieve the desired performance. We also discussed in details the cost to implement this communication system. Finally, we conclude that it is cost-effective to use SDR as the communication system if there are no off-the-shelf products that cost 15000 SEK.