Challenges and Innovations of Transport Networks to Support 6G Use-Cases

The sixth generation (6G) of mobile networks will greatly impact the way we work and communicate as well as our interaction with the surrounding environment. 6G will extend the capabilities of 5G to introduce new use-case categories based on the prominent role of AI, the integration between sensing and communication, and the omnipresent connectivity, which, for the fixed part of the network, is translated as fiber-to-the-everything (FTTE). To realize this vision, new technologies and network capabilities need to be conceived to support the highly demanding 6G use-case requirements, which are latency (0.1-1 ms), peak data rate (up to hundreds of Gb / s), reliability (10^-5. to 10^-7) and spectrum efficiency (1.5-3 times greater than 5G), among others. For the fixed part of the network, these challenging requirements accelerate the progress across many areas, including the evolving fixed Internet Protocol (IP)/Optical transport network (known as x-haul) connecting the Radio Access Network (RAN), mobile Core Network (CN), and the Internet. In this work, we discuss possible 6G innovations that need to be introduced to meet the 6G requirements, such as the implementation of Flexible Functional Splits (FFS), the development of network components such as ultra-low energy transceivers and the intelligent control plane for resource allocation optimization. All the above are seen from the viewpoint of evolved x-haul networks that are based on novel and energy-efficient optical communications systems and network technologies.