Who hasn’t experienced losing signal on their phone? Everyone has faced this situation when moving away from urban areas, for instance, while in the middle of the mountains. This happens because our phone cannot find a nearby base station to connect to via radio, and thus loses signal. Deploying a cellular network involves placing these base stations on the ground, which is not always feasible in hard-to-reach areas, such as mountainous or maritime regions. This scenario is also common in emergency or natural disaster situations where the terrestrial network has collapsed, and a new one cannot be rapidly deployed. The new sixth-generation mobile communication standard, 6G, aims to provide solutions to these issues. To achieve this, it leverages Non-Terrestrial Networks (NTN) and the concept of the Edge-Cloud Continuum. In this article, we’ll explain what these systems consist of and how they contribute to the 6G standard.
Satellites Enabling Global Coverage
NTN networks are based on extending terrestrial network coverage using a non-terrestrial platform, typically a satellite. This would allow users to have global coverage on their devices without needing a nearby ground base station. However, one of the main challenges with this type of network is the delay caused by the distance between the satellite and Earth. A high-orbit satellite (referred to as GEO or geostationary) offers wider coverage due to its height, as it can cover a larger area of the Earth’s surface. However, the signal will take longer to travel between the ground communication point and the satellite, leading to longer response times.
On the other hand, low-orbit satellites (known as LEO satellites) are closer to Earth’s surface, offering less coverage but shorter response times.
As a middle ground, medium-orbit satellites (MEO satellites) provide a compromise between latency and coverage. In NTN networks, it’s essential to identify the communication needs of applications and, if available, use the NTN infrastructure that best fits those needs.
Roaming: Managing Device Movement Between Networks
Integrating satellite networks into the current network architecture is a key aspect under investigation. One area of focus is managing the movement of a device between networks, a process known as handover (roaming). This is what allows our devices to maintain connectivity as we move between base stations. This process is not straightforward in NTN networks and is currently a highly interesting research focus. The goal is to enable users to seamlessly transition between terrestrial and satellite networks.
Edge-Cloud Continuum
Alongside NTN networks, we at 6GDIFERENTE are also working with the innovative concept of the Edge-Cloud Continuum. One could say that Cloud Computing (or Edge Computing) are paradigms already integrated into our daily lives. However, the goal of this continuum is to merge the different elements of each layer into a unified distributed architecture. That is, the Edge-Cloud Continuum is an innovative concept that describes an infrastructure connected from the edge to the cloud, integrating computing devices so that applications and services can be deployed by leveraging the capacities of the entire continuum. This allows various tasks to be orchestrated across the network, gaining flexibility, efficiency, and speed compared to isolated deployment on each layer.
The Connection of Autonomous Vehicles
In this context, the continuity of resources between the Edge and the Cloud plays a crucial role in NTN networks. By integrating satellite base stations with resources available in the Edge-Cloud Continuum, users can access applications or information processing ubiquitously and seamlessly. Additionally, there’s no penalty in terms of connectivity or task execution.
For example, imagine an autonomous vehicle traveling on a road connected to a 6G network, communicating with the nearest edge for critical data processing needed for driving. In the continuum, this processing will migrate between different edge centers to ensure the vehicle remains safe for driving. But what happens if we enter an area without terrestrial coverage and the vehicle’s connectivity shifts to a satellite network? Thanks to the Edge-Cloud Continuum, we could migrate the loads to the infrastructure closest to the satellite base station, while maintaining the vehicle’s needs according to the latency between the satellite and the base station.
In Summary
The integration of NTN networks with the innovative Edge-Cloud Continuum concept provides an intelligent, adaptable, and connected environment where resources can be managed seamlessly. This makes the vision of universal coverage possible, supported by a network of networks being researched under the 6G umbrella.
At 6GDIFERENTE, we explore the implications and challenges of combining these technologies. In this state initiative, we support research in each field by implementing a mobility use case where users experience transitions between terrestrial and non-terrestrial networks.
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