Achieving Low Latency and High Throughput over Cellular Internet Connections2023-06-22
Mobile networks are constantly evolving to enable improved throughput and low latency for applications. However, it has been shown that current standard congestion control algorithms can cause long delays in mobile networks due to over-allocation of buffers. In his thesis, Habtegebreil Kassaye Haile has investigated the performance of two possible solutions to this problem.
The Internet is constantly evolving. This evolution is driven by the need to support new application requirements and improve the performance of existing applications. The layered architecture of the Internet enables this evolution to take place at a specific layer without having to make changes to components at other layers. However, upgrades limited to a specific layer or component are often not sufficient to achieve the desired performance of the application. When upgrading mobile networks, performance and latency issues can simply be moved to another layer.
The thesis evaluates congestion control for mobile broadband services and possibilities to improve transport protocols to support the features required for improved congestion control algorithms (CCAs) that go beyond loss-based congestion control.
Parameters that have been investigated include the methods used in the protocols to achieve high bandwidth and low latency, traceability and accurate estimation of delivery rates to detect possible bottlenecks.
- The main findings are that the latency, and to some extent the throughput, of some CCAs can experience poor performance under some common cellular network conditions, and that those issues can be mitigated with the solutions proposed in the thesis, says Habtegebreil Kassaye Haile .
Using a proposed rate estimation method and additions to the transport layer protocol QUIC, modifications to two prominent modern CCAs, BBR and Copa, are proposed. Through extensive evaluation, this thesis shows that the modified BBR results in lower packet delays, and the modification of Copa provides a more consistent and predictable delay performance.
Habtegebreil Kassaye Haile recently presented the sixth paper of the thesis at the global telecommunications conference 2023 EuCNC & 6G Summit.
Habtegebreil Kassaye Haile defended his PhD in Computer Science at Karlstad University on 29 May 2023. Opponent was Markku Kojo, University of Helsinki, Finland. Habtegebreil Kassaye Haile previously studied at Åbo Akademi University. He currently works at a consulting company with various projects in the field of networking.