Informed Access Network Selection (IANS)

My Ph.D. thesis, Informed Access Network Selection to Improve Application Performance, is available here. I defended it on 5. November 2019.

Often, end-user devices have multiple access networks available, such as as WiFi or cellular. While devices have the potential to select between these networks or use them in parallel, this potential is not always explored yet. Therefore, Informed Access Network Selection (IANS) enables end-user devices to select the best suitable access network(s) based on application needs and network performance characteristics. To this end, we design Socket Intents as an abstraction for application needs, collect network performance characteristics, and design IANS policies for Web browsing and HTTP Adaptive Streaming (HAS). We implement IANS within the Socket Intents prototype, which enables applications to communicate their needs through an enhanced networking API. Using the Socket Intents prototype, we evaluate the performance benefits of IANS for Web browsing and HAS compared to using a single access network and using MPTCP.


The initial Socket Intents paper, Socket Intents: Leveraging Application Awareness for Multi-Access Connectivity, has been published at CoNEXT 2013. In it, we describe the idea of Socket Intents and our initial prototype, as well as present an initial evaluation.

In the paper Metrics for access network selection, which appeared as a poster in the Applied Networking Research Workshop 2018, we study in more detail how to get good performance estimates of the available access networks.

I evaluated the benefits of Informed Access Network Selection for Web performance and published the results in the paper Informed Access Network Selection: The Benefits of Socket Intents for Web Performance at the 15th International Conference on Network and Service Management (CNSM 2019).

Finally, I evaluated the benefits of Informed Access Network Selection for HTTP Adaptive Streaming (HAS). The results are published in the paper Using Informed Access Network Selection to Improve HTTP Adaptive Streaming Performance at the ACM Multimedia Systems Conference 2020 (MMSys 2020). This paper comes with artifacts to reproduce results (code and data).

Socket Intents Prototype

The Socket Intents Prototype is a research software prototype available on Github.

You can watch me give a presentation about this project at the Linux low-level user-space conference “All Systems Go” 2017: Recorded Talk.

I also put more technical details in an Internet-Draft about the Socket Intents Prototype.

I wrote about the first version of the Socket Intents abstraction and prototype in my Master thesis, Socket Intents: Extending the Socket API to Express Application Needs

Web Performance Pitfalls

In order to evaluate the Socket Intents Prototype, I need to understand whether it improves the performance for applications such as Web browsing and video streaming. Accordingly, I took a deep dive into Web performance evaluation. In the process I discovered several pitfalls, i.e., things that can go wrong when trying to measure load times or other Web-related performance metrics.

My findings are being published in a paper at Passive and Active Measurement Conference 2019 (PAM 2019). A personal copy of the paper is available here. My Web measurement tools are available on Github.

OpenFlow in Wireless Networks

Authentication, Authorization and Mobility in Openflow-enabled Enterprise Wireless Networks (September 2011)
A study project, supervised by Ruben Merz.
I looked at the possibility to use OpenFlow in a larger wireless network, e.g. on a campus, and how it plays together with some aspects of 802.11.
Bottom line: It would be a lot of work to develop something useful here.