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5G networks are used for everything, from browsing funny videos to running medical software and payment traffic. The use of Network Slicing – dividing one physical network into multiple virtual ones – is increasingly used by network operators. Using slices ensures enough bandwidth for devices and applications that require low latency or are used at crowded events. 

Nokia, too, saw the need to expand internal testing coverage of network slicing. From this, a topic for a master's thesis took shape. It required a strong understanding of 5G Radio Access Networks (RAN) and 5G Core technologies, as well knowledge of the slicing process and the UE Routing Selection Policy (URSP) – application-specific slicing process which allows a device to use several network slices simultaneously. 

The challenge was accepted by Riina Kostiainen, who studied Human-Computer Interaction and Communications Engineering at Aalto University. Kostiainen was familiar with these technologies, as her summer internships and a part-time internship during her studies were done at Nokia. During these, she gained strong knowledge in parametrisation and configuration of 5G base stations, as well as experience in field testing mobile networks alongside several teams. 

‘Riina had gained experience with network slicing during her internships at Nokia, so this developed into a suitable topic for her master’s thesis,’ says Jesse Kruus, Principal Test Architect at Nokia. 

From plan to action – testing the 5G Network Slicing 

To kick things off, Kostiainen and Nokia’s representatives held a comprehensive meeting regarding the thesis work and defining Nokia’s needs for the end result. The goal was to implement 5G network slicing and application-specific URSP slicing within Nokia’s test network, and examine how these technologies can benefit the end user. The thesis itself was sliced into suitable blocks and tailored to fit the schedules of both parties. 

For the theoretical part of the thesis, Kostiainen conducted a literature review on 5G network structures. This helped her gain insight on potential network issues and their fixes. 

‘The testing took place in Nokia’s testing environment, which features physical 5G radios, as well as 5G-capable phones and Nokia’s 5G 360 camera. The data on network traffic was collected using Nokia’s internal measurement tools,’ Koistainen describes. 

Over the course of the project, Koistainen designed and implemented 23 new network slices, and tested out two new slices. 

‘The largest and most time-consuming part of the work was designing the structure and properties of the network slices, so that these could meet the needs of specific applications,’ says Kostiainen. 

During the process, Kostiainen and Kruus regularly reviewed the work, and planned goals and schedules for the next stages. The collaboration went well – Kostiainen did a lot of independent work, but received guidance and technical support from Nokia to help finish her work. On the Aalto side, thesis advisor Gopika Premsankar actively supported the writing process.

Increasing expertise in 5G Network Slicing 

According to Kruus, the end result lived up to Nokia’s expectations: ‘We received significant help with future network slice configuration of base stations, as well as useful guidance on various other radio interface parametrisations.’ 

‘In addition, our team gained strong expertise in slicing Nokia’s 5G test network and associated end user configurations, as well as insight into various measurement methods for mobile network performance in different slices,’ he continues. 

Kostiainen is also happy with her thesis. She feels that the process has increased her know-how of communications networks and prepared her for working with these technologies. She’s looking forward to growing as a professional – possibly in this area of technology. 

‘Network Slicing is seen as one of the most important innovations in 5G technologies. It has a lot of potential use cases, so I think it’s important to understand how it works,’  Kostiainen says. 

Tips for smooth collaboration 

Kruus sees that collaborating on a thesis project is a useful way for companies to gain both information and employees. 

‘Companies should regularly consider potential thesis topics, especially if a certain case could be explored by a thesis worker,’ he says. 

Writing a thesis is a requirement for graduating, but Kruus sees that a collaborative thesis is also a great opportunity to get acquainted with working life and an organisation’s operating methods. A company providing the thesis topic also has a high chance of employing a fresh graduate already familiar with the environment. 

Kruus also has a tip for the students: a suitable topic should be interesting and motivating, but it has to be precisely defined. It’s worth breaking the thesis work into smaller parts and drawing up a schedule for it – with enough time reserved for research, writing, and possible testing. 

‘Once the plan is done, you can jump into action,’ Kruus says. 

He says the overall plan can be adjusted over the course of the work – but that the schedule should hold, so graduating doesn’t get unnecessarily delayed.