The Essential Guide for Understanding O-RAN

INTRODUCTION

O-RAN based radio access networks represent the mobile communication industry’s move toward an open, virtualized, and disaggregated architecture. O-RAN revolutionizes how mobile network operators (MNOs) can build their radio access networks (RANs) using a multivendor, interoperable, and autonomous supply ecosystem. RAN deployment for 4G and earlier generations of cellular technology relied on a single-vendor model. These networks used proprietary hardware and software systems, not compatible with other vendors’ products, creating a closed and uncompetitive environment. O-RAN breaks down the traditional hardware-centric RAN into building blocks (radios, hardware, and virtualized functions) using open and standardized interfaces. Network vendors can focus on specific building blocks rather than building an entire RAN. Operators gain the ability to mix and match components from multiple vendors. In this new model, you must perform testing to ensure multivendor components work together seamlessly and without compromising performance. 

O-RAN Basics

The mission of an open radio access network (O-RAN) is to create an open, virtualized, and intelligent radio access network (RAN) architecture to enable a multivendor, interoperable, and competitive ecosystem. The O-RAN Alliance is a worldwide community with its members developing a unified roadmap for future O-RAN standards and specifications, a reference architecture, and the interfaces between the various components of the network. Understanding the O-RAN architecture and the benefits it can deliver are key to helping you assess if this model is right for you.

Architecture

A 5G O-RAN architecture includes the following key components: 

• O-RAN radio unit (O-RU) for processing the lower part of the physical layer 

• O-RAN distributed unit (O-DU) for baseband processing, scheduling, radio link control, medium access control, and the upper part of the physical layer 

• O-RAN central unit (O-CU) for the packet data convergence protocol layer 

• O-RAN intelligent controller (O-RIC) to gather information from the network and perform the necessary optimization tasks

Benefits

The O-RAN architecture addresses traditional RAN challenges by creating a disaggregated and virtualized network with standard interfaces. In doing so, it delivers four key benefits: 

Transformation

• Enabling more open, virtualized, and fully interoperable radio access networks. 

Innovation 

• Choose from the latest and best 5G RAN components with access to a wide variety of product, service, and feature options across vendors. 

• Prepare for the future by adopting an architecture that supports 4G and 5G, and even 6G. 

Agility 

• Gain the flexibility to mix and match RAN components from more than one vendor to construct a 5G network that works best for you. 

• Deploy and upgrade your 5G network at a faster pace with help from multiple specialized vendors. 

Capital expenditure savings 

• Reduce your 5G network deployment costs with a competitive supplier ecosystem.

Chapter 2

O-RAN Interface Conformance and Interoperability

Next-generation 5G new radio (NR) RAN equipment design, validation, and production teams face new test challenges. O-RAN standardized fronthaul architectures and gNB disaggregation are driving the need for testing gNB components in isolation, flexible peer emulation, and conformance and interoperability testing of new O-RAN devices. These tasks require multidomain test solutions with O-RAN protocol generation and measurement capabilities spanning all O-RAN interfaces.