Network Digital Twins of MEC Servers in 6G Systems: Models, Functions and Interfaces

The operation and management of upcoming sixth generation (6G) networks will be heavily challenged by a variety of increasingly complex and sophisticated services and of their stricter and unprecedented requirements. The Digital Twin (DT) concept, especially consolidated in the industrial domains, is gaining momentum as a key enabler of 6G. By interacting in real time with the paired physical network components (e.g., end-devices, routers, base stations, edge servers), Network DTs (NDTs) can monitor, predict and optimize their performance, without affecting their actual behaviour. In particular, in recent years, NDTs have been devised to be coupled with MEC servers to track their state and assist, among others, in resource allocation, task offloading and service migration optimization policies. Notwithstanding, to the best of our knowledge, it is unclear how the DT of a MEC server should be built, in terms of data models, functions and interfaces, and where it should be placed. In order to fill this gap, in this work we design a reference architecture for MEC NDTs along with the relevant components needed to support the main MEC operations and identify possible guidelines for the placement of such NDTs.