Towards future mobile networks from an operational perspective

My research work focuses on future mobile networks, and the challenges involved in the successful operation of such networks. In this regard, my work is structured into three "pillars".

The first pillar focuses on the novel design of the core of mobile networks. In a mobile network, the core is responsible for managing and facilitating access to the network. Studies have demonstrated the increasing strain on the core due to the increase in the number of connected devices and changing device patterns, particularly those of Internet of Things (IoT) devices.

In previous work I have demonstrated that hosting the core in the cloud has the potential to solve these issues. This was demonstrated through a novel, cloud-based design of a core that remains complaint with the standard radio access network (RAN) interfaces. However, due to the novelty of this work, the question remains as to whether this radically different paradigm can be successfully adopted by network operators.

Key questions that remain unanswered include whether moving to the cloud will impact the security of the core, whether the multi-vendor approach pioneered with the Open-RAN initiative can be adapted to a cloud-based core, and whether the resilience and upgradable of the core can be improved upon in a cloud environment. I will answer these questions by studying the performance, security, resilience and upgradability of the core design in real operational environments, focusing on the perspective of the mobile network operator.

This study will result in both modifications to the novel core design, and perspectives beneficial for other critical infrastructure that is deployed in cloud environments.

The second pillar of my work expands the focus beyond the core and into the RAN. Existing mobile devices have limited ability to seamlessly switch between different networks. This includes networks using the same radio access technology (RAT), such as moving between a public and a private 5G network, and multi-RAT networks (e.g: moving from 5G to WiFi).

The increasing proliferation of RATs (WiFi, 4G, 5G, light-based Li-Fi, and new non-terrestial technologies such as Starlink and OneWeb) has resulted in the need for a new approach to managing seamless roaming between different networks. Key questions include how to adopt seamless roaming from a standards-based approach, where is the optimal part of the network to modify to achieve this (on the mobile network operator side, or on the user side, or both), and what additional technologies are needed to ensure this vision.

I will answer this from a mobile network operator perspective, focusing, as with my work on the mobile network core, on the operational aspects including the deployment and management of potential solutions. This research will be achieved through (a) a study of existing roaming technologies and (b) the design and evaluation of new roaming technologies to address the limitations of existing solutions.

A planned campus-scale private 5G network, integrating with an existing campus-scale WiFi deployment, will assist in the study and evaluation of multi-RAT networks while single-RAT networks will be studied through roaming between public 5G networks and the private 5G deployment.

The final pillar of my work focuses on developing tools and infrastructure for research that will be used to achieve the first two pillars. Software tools include frameworks necessary to develop, test and evaluate core networks, and tools to emulate real-world networks which are necessary for simulations of roaming scenarios. Physical infrastructure includes lab-scale and campus-scale mobile networks.

Key questions include: what tools are required for research into mobile core networks and roaming, how should physical infrastructure be setup to best enable this research, and how should the tools and knowledge gained from the infrastructure be disseminated to best enable future research, additional studies and reproducibility