Flexible transport networks for future C-RAN [Invited]

The rapid growth of artificial intelligence and digital services is generating a vast amount of data, imposing tight performance requirements, and raising concerns about energy efficiency and sustainability. This paper introduces and reports a concrete deployment of a flexible transport network for future Cloud Radio Access Network (C-RAN) to support three key use cases such as metropolitan-scale elastic load balancing, local statistical multiplexing, and multi-operator infrastructure sharing. The Innovative Optical and Wireless Network Global Forum initiative is proposing the deployment of optical technology in future C-RAN architectures, thanks to its ability to ensure deterministic latency and reduce power consumption. Integrating optical technology with packet technology can enhance wavelength usage efficiency and resource optimization through dynamic resource allocation, efficient infrastructure sharing, and stringent performance standards. However, several challenges arise when combining packet and optical technologies such as congestion control in packet networks and efficient integration between the two technologies. Two models of supporting multi-operator infrastructure are presented for the three use cases, and a solution is proposed and assessed through simulations and a proof-of-concept demonstrator.