RAN as a service: Challenges of designing a flexible RAN architecture in a cloud-based heterogeneous mobile network

Small cell deployment is one of the most promising technology trends to cope with the rising need for very high data rates foreseen in future mobile networks. Nevertheless, it has the side effect of introducing more complex interference scenarios, needing to be properly managed by means of coordination mechanisms. The recently introduced Cloud-RAN architecture, based on centralized processing, enables the implementation of efficient interference prevention and cancelation algorithms across multiple cells. However, it struggles with the need of high-capacity front-haul links and cost-intensive deployments. This paper introduces the novel concept of RANaaS (Radio Access Network-as-a-Service) as a flexible architecture based on centralized processing, capable of handling the increasing interference in very dense networks, reducing energy consumption, cost-efficiently deploying and managing cellular networks.