Lecture Description:

With the increase of user traffic, mobile networks are transforming into more software-driven, virtualized, flexible, intelligent and energy efficient systems. Traditionally, RAN components such as radio transceivers and baseband were implemented on proprietary hardware, and these components typically used vendor-specific protocols for communications. The software and interfaces between different RAN components were customized for optimal performance of the proprietary hardware. Disaggregated base station architecture with open interfaces was introduced in 5G to allow multi-vendor solutions while ensuring interoperability of various components. A key challenge arising from the migration toward open RAN architectures is the scale and flexibility of deployment, optimization, security, management and orchestration of the network.

RAN cloudification was one of the fundamental tenets of the open RAN architecture. Cloud-RAN architecture addressed capacity, flexibility and coverage issues, while supporting mobile fronthaul and/or backhaul solutions as well as network self-organization, self-optimization, configuration, and adaptation with software control and management through SDN and NFV techniques. Cloud-RAN has also provided advantages in managing operational costs, improving network security, network controllability, network agility and flexibility. Considering the migration of the networks toward virtualization and SDN control, the use of programmable and fully configurable cloud-RAN components is essential, in order to minimize operators’ CAPEX and OPEX when deploying networks in different scenarios and geographies.

Massive MIMO, as one of the key enablers of 5G new radio, requires scalable, adaptable, optimized partitioning and integration of complex digital and RF signal processing functions. New architectures will leverage the latest innovations to better utilize existing spectrum and improve the capacity of networks using techniques like carrier aggregation and beam forming to implement adaptive active arrays. The cost associated with moving data between these new RF frontends and the digital frontend is one of the major issues that must be resolved to make these new technologies commercially viable. Another key requirement is increased adaptability and programmability of the RF frontend to reduce time to market and to provide a platform that addresses the wide range of emerging radio requirements. A new generation of semiconductor technology which combines programmable logic with integrated radio frequency data converters would allow design of radio units based on direct RF sampling radio transceiver architecture.
In this presentation, we describe a scalable, modular, programmable, and SDN-configurable radio unit reference design, which can provide various connectivity options toward the baseband unit including the open fronthaul interface specified by Open RAN Alliance, support flexible functional splits and deliver a platform for supporting massive MIMO operation using an integrated or discrete array of active antennas.