Low Latency Bandwidth Control Algorithms for Unreliable Networks

Abstract: Real-time multimedia streaming is an extensively researched topic. The possibility of streaming video over the internet in real time requires smart solutions on many levels at the player and streamer side, as well as along the intermediate network. There are many different methods used to achieve this, but not all of them are suitable for the low latency real-time streaming needed for remote operations of vehicles. This thesis focuses on the bit-rate control at the streamer side to achieve low latency, meaning how the video quality is changed to adapt to the changes in the network. A literature study was conducted, in order to find what algorithms are currently being used for real-time streaming. It investigated both what control methods are used, as well as what feedback metrics are feed to these controllers. These approaches where then evaluated from a theoretical standpoint for real-time low latency streaming on 4G networks together with the rest of the assumed system. Using these discovered methods, two new algorithms were created. They were tested against an already existing benchmark controller, both in simulation and on a real network. As the benchmark algorithm proved to already be using all suitable feedback metrics, only small control alterations where done to the existing benchmark algorithm. The goal for the new algorithms was to increase the total throughput of the video stream, without decreasing the robustness and causing a higher latency.  Simulation and real network tests proved that the new algorithms are unable to provide a higher throughput without increasing the latency. The conclusion is that the benchmark controller is well designed and explicitly configured to work for the goal of low latency video streaming. This being the case with many controllers in the industry, as they are well designed and extensively trimmed for their specific task.