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ICT 5G

5G technology devices for an O-RAN

wireless solution

Brad Brannon, Systems Engineer

O-RAN was created as a catalyst to transform the wireless community, to enable new channels of
wireless equipment, and to enable innovation to fulfill the promises made by 3GPP about 5G.
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To be successful and cost-effective, open sources of radio equipment and optimised 5G
technology devices must be available. This article will review one of those solutions for designing
and building a power efficient solution.

What are the 5G challenges? provides reference designs for the O-CU, O-DU, and O-RU (Open
There are several techniques that radio and network engineers Centralised Unit, Open Distributed Unit, and Open Radio Unit,
are using to achieve these goals. In addition to moving data respectively—as defined by O-RAN). Together these will enable
services to the edge of the network, utilisation of both massive standardisation of fronthaul and baseband processors to further
MIMO and small cell technology aids in increasing both capacity reduce solution cost. Together with other integrated 5G devices
and throughput. Massive MIMO technology utilises numerous like integrated radios, these can serve to define what small cells
radios in an array to achieve not only capacity but also coverage are to become, as well as enable the implementation of those
for a central location. Like its predecessor the macrocell, a standards. The work of these bodies is a critical step.
massive MIMO radio would provide relatively broad coverage Third, radio technology has rapidly evolved in the last few
around that location. However, massive MIMO radios are placed years. High performance radios are now available in several
at higher frequencies, typically 2.6 GHz and above, that do not formats, capable of meeting the required performance standards
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penetrate buildings very well. To service indoor locations and demanded by 3GPP in 38.104 and related documents. These
other difficult-to-reach outdoor areas, small cells will be utilised. radios are highly integrated and include not only the analogue and
Given the number of indoor and outdoor locations ranging from RF components, but critical algorithms like DPD and crest factor
households to enterprise installations to commercial shopping reduction (CFR). While these radios are built on fine-line CMOS,
areas and even arenas, small cell utilisation will be vital to the other evolutions have taken place in the RF front ends where
success of 5G. Also, given the vast numbers of small cells and low-cost RF processes (SiGe, SOI, GaN, GaAs, etc.) are turning
diversity of deployments required in a network, they must be out highly integrated LNAs and high power, high performance PAs
inexpensive to install and operate; this will be a key enabler of 5G. that can meet the challenges these standards demand.
Finally, highly integrated and efficient power solutions,
What technologies are available? including power over ethernet (PoE), standard power device,
Over the last few years, multiple technologies have evolved in a supervisory and monitoring, and protection solutions, are
direction that enables solutions for 5G. Firstly, from a baseband available that can provide compact power delivery. These
perspective, Moore’s law continues to not only reduce the cost solutions offer very high efficiency and very low noise in the radio
of silicon per gate but enable more complex functionality to be environment and include options that provide protection of key
integrated into radio technology. It is now possible to integrate devices like power amplifiers.
many of the control algorithms required directly into the radio, Together, these technologies are enabling low cost, high
including functionality like digital predistortion (DPD). Many other performance small cell platforms that can effectively be deployed
possibilities exist as new generations of radios become available. throughout an operator’s network for both low and high power
Second, industry alliances like O-RAN are working across the systems.
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wireless industry to enable economies of scale not only to reduce
cost, but to improve supply chain security and to offer new ways
to monetise these wireless networks. Specifically, “the O-RAN O-RAN ALLIANCE https://www.o-ran.org
alliance was founded by operators to clearly define requirements Empowered by principles of intelligence and openness,
and help build a supply chain eco-system to realise its objectives”. the O-RAN architecture is the foundation for building the
To accomplish these objectives, the O-RAN alliance’s work will virtualised radio access network (RAN) on open hardware and
embody the principles of openness and intelligence. As such,
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their activities focus on defining the physical interfaces specified cloud, with embedded AI-powered radio control. The architecture
by 3GPP so that they can be standardised and implemented is based on standards defined by O-RAN ALLIANCE, which are
across the industry as inter-operable white box solutions. fully supporting and complementary to standards promoted by
Additionally, O-RAN also defines the hardware requirements and 3GPP and other industry standards organisations.

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