What is Open RAN?

Traditional wireless networks have been based on an integrated RAN with the network towers containing both the Radio Frequency, (RF), transmission equipment and the baseband processing functionality. 

5G requires both a significant densification of the radio access network and smaller cells, leading to issues with real estate and power consumption. The RAN is also the most expensive component of a mobile network and densification drives an increase in both capex and opex. By disaggregating the RAN, effectively separating the RF transmission from the baseband processing functionality, operators can share base-station functionality across multiple Radio Units deployed in towers or access points, saving capex, opex and reducing power requirements.

This centralisation of radio resource processing and management is known as virtualised RAN, (vRAN), and has the advantage of enabling network operators to decouple hardware from software and also to run modularised network functions on Commercial Off-the-Shelf, (COTS), servers. Taking this one step further, standardising key interfaces in the vRAN – opening and disaggregating the RAN – removes the traditional barriers to entry raised by vertically-integrated RAN networks. Open vRAN standards, such as O-RAN Alliance, support a new eco-system of smaller suppliers bringing innovation to the RAN, further reducing costs, and increasing flexibility. This trend is of ever-increasing importance in the 5G era, where mobile operators are struggling to deploy 5G networks in indoor and shared spaces. Lower cost, standardised RAN equipment enables a new breed of service providers, such as neutral hosts, to offer shared services in locations which would otherwise be underserved by mobile operators.