The Electronics Research Group (ERG) operates as a part of the School of Engineering at the University of Aberdeen and has a recognised research capability in designing new protocols, testing and the evaluation of network performance, especially over challenging Internet paths. Research across the group favours a blend of simulation and practical investigation, ranging from architectural design, research into new protocol techniques, open source implementation and evaluation using Internet testbeds. ERG is active at the Internet Engineering Task Force (IETF), with a range of published standards over the years and important publications on dedicated journals.
The proposed research addresses the problem of low performance of IP transport connections over highly variable mobile channels. New radio-frequency techniques in 5G will soon allow significant improvements in available bandwidth, an increase of transmission efficiency and reduction of latency. This paves the way to a vast class of bandwidth-demanding applications not possible in previous generations of cellular networks.
To boost the responsiveness of Internet transport, this studentship will study a new form of congestion control based on explicit congestion signalling. The design concept will be inspired by new Internet L4S (Low-Latency Low Loss Scalable) architecture, which is currently being standardised at the IETF . L4S proposes that multiple congestion control signals coexist in the future Internet. Internet nodes need to maintain a balance among flows applying different treatments to flow with different congestion control behaviour.
This research addresses the important problem of low performance of IP transport connections over highly variable mobile channels. Although radio-frequency techniques are able to adapt their transmission modes faster than earlier generations, current Internet transport protocols do not possess the agility and responsiveness necessary to respond fast enough to take advantage of the additional capacity. Current congestion control scheme requires that, after a loss or an explicit congestion signal, the source resumes increasing its congestion window at a rate of one segment per round-trip. This procedure can take several seconds to fully utilise new capacity, far too slow to track the capacity variations expected with new mobile links. Initial tests show a transport may only able to exploit part (e.g. less than 50%) of total available cellular capacity. Unless tackled, this deficiency poses a significant hurdle to the development of new video applications being able to use capacity made available by 5G.
This programme of research aims to design new congestion control methods that target low latency and the ability to rapidly accelerate to high speeds. At a time when Advanced Queue Management (AQM) is reshaping our approach to design the packet forwarding, our first goal is to bolster the cooperation of the transport protocol and the network utilising explicit congestion notification signals at the transport layer made available through the new L4S (Low-Latency Low-Loss Scalable) framework .
Candidates should have (or expect to achieve) a UK honours degree at 2.1 or above (or equivalent) in Electrical Engineering, Electronic Engineering or Computer Science.
It is essential that the successful candidate has a background in EEE subjects and be familiar with Internet protocols and understand the basics of Internet networking.
The candidate should provide evidence of their experience with internetworking, citing examples of software developed, participation to projects and communities, awards and achievements.
The ideal candidate must have, or willing to develop, expertise in using tools for network analysis and performance evaluation, including data traffic analysis tools (e.g. tcpdump), programming/configuring network devices (e.g. Linux boxes network interfaces), and/or simulation (e.g. ns2/ns3).
Additional research cost will be required to cover travel costs to conferences/meetings.
• Apply for Degree of Doctor of Philosophy in Engineering
• State name of the lead supervisor as the Name of Proposed Supervisor
• State ‘Self-funded’ as Intended Source of Funding
• State the exact project title on the application form
When applying please ensure all required documents are attached:
• All degree certificates and transcripts (Undergraduate AND Postgraduate MSc-officially translated into English where necessary)
• Detailed CV
Informal inquiries can be made to Dr R Secchi ([email protected]
) with a copy of your curriculum vitae and cover letter. All general enquiries should be directed to the Postgraduate Research School ([email protected]
 B. Briscoe, K. De Schepper, M. Bagnulo, “Low Latency, Low Loss, Scalable Throughput (L4S) Internet Service Architecture”, draft-ietf-tsvwg-l4s-arch-03, Oct 2018.
 G. Fairhurst et al., “Reducing Internet Latency: A Survey of Techniques and their Merits”, IEEE Commun. Survey and Tutorials, 18(3), pp 2149-2196.