WHITEPAPER

Executive Summary
TABLE OF CONTENTS
Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
State of the Open RAN Ecosystem . . . . . . . . . . . . . . . . . . . 2
5G RAN Virtualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Open RAN Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Supermicro RAN Optmized Systems . . . . . . . . . . . . . . . . . . 9
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

The Open RAN landscape has matured significantly,
reaching a pivotal stage where Tier 1 Mobile Network
Operators (MNOs) are poised for large-scale deployment.
This transition is underscored by major endorsementsfrom industry giants like AT&T and Vodafone, reflecting
the growing confidence in Open RAN technology. While
initially led by greenfield operators, mainstream adoption
has expanded to include legacy Tier 1 suppliers,
showcasing the technology's broader applicability.

From a technological standpoint, Intel® played a crucialrole in establishing the viability of 5G base stations on
general-purpose processors. However, the ecosystem has diversified, with alternatives from AMD, ARM, and NVIDIA
offering a range of solutions. The benefits of Open RAN and virtualization are driving industry objectives,promoting innovation, supplier diversity, and cost-effectiveness. The shift to cloud-native 5G architectures, while
presenting challenges, brings scalability, agility, and significant operational benefits.
As the industry achieves performance parity with legacy solutions, attention turns to energy efficiency, dynamic
workload management, and the ability to adapt to changing network traffic loads. Supermicro's optimized
systems, ranging from Cloud RAN servers to cell site servers, enable operators to streamline Open RAN
deployments with increased efficiency, scalability, and a lower total cost of ownership (TCO).

1

1© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

1

State of the Open RAN Ecosystem
Following a lengthy and tortuous gestation, Open RAN is considered ready for scale deployment by Tier 1 MNOs.
This achievement was validated by AT&T's announcement and endorsement towards the end of 2023 andVodafone's 2023 announcement of its intent to run a global RFP with around 30,000 cell sites intended to be Open
RAN. Verizon has also reported having over 15,000 virtualized Cloud RAN sites, a close cousin of Open RAN. Notably,
all these also involve legacy Tier 1 incumbent suppliers. While Open RAN reporting has tended to focus on the US
and European markets, Japan has been a pioneer in Open RAN, with NTT DoCoMo and KDDI having earlyinteroperable deployments.
Prior to this, greenfield operators, namely Rakuten and Dish Networks, have led the Open RAN charge. The
pioneering work was done by new supplier entrants—Mavenir, Parallel Wireless, and Altiostar (later acquired by
Rakuten)—although the primary standards steering body, the O-RAN Alliance, itself a merger of the xRAN Forum with
the C-RAN Alliance, has always had heavy representations by industry stalwarts like Ericsson. The intent is for output
from the O-RAN Alliance, as an operator-led body, to feed into the 3GPP standards organization.
From a technology perspective, Intel was the clear proponent and standards bearer. Intel advocated strongly that a
5G base station could be implemented in virtualized software running on standard general-purpose processors(GPPs). Here, a GPP is defined as an industry-standard, generally available processor that is also used for generalcomputing applications. While meeting the required performance was clearly a stretch at the outset, thanks to some
optimizations, initial hardware assists, and the inevitable performance gains from the march of Moore's law, we areat a point where GPPs can quickly implement 4G and lower-order 5G with acceleration and on the brink ofsupporting full Massive MIMO. Intel implemented a processor roadmap with the requisite enhancement thatdelivered the required performance. Intel also developed their FlexRAN™ software stack as a usable reference toimplement Open RAN DU (Distributed Unit).
A key criticism of Open RAN has been that Intel was the only silicon supplier. Alternate COTS (commercial off-theshelf) GPP processors for Open RAN are now available from AMD, ARM, and NVIDIA’s GPU-based solutions. One of
the key optimizations was to add matrix vector processing. Intel has this with AVX-512, which AMD eventually also
added. ARM has followed with its own version, the Scalable Vector Extension, or SVE2. GPUs that NVIDIA uses are
inherently vector-processing capable.
Another contentious accelerator is one for FEC encoding, as this is the most compute-intensive processing task
requiring hardware assist, especially for massive MIMO. This need led to an industry-wide debate about lookasideversus inline accelerators. Lookaside accelerators, as developed by Intel, accelerate just the FEC function, leaving
the rest of the L1 processing to the CPU. In contrast, inline accelerators typically perform the complete Layer 1 DU
functionality and are not perceived as COTS General Purpose Processors. In servers with the requisite PCIe
expansion slots, inline processors can be mated with a GPP for Layer 2. The latest 5th Gen Intel® Xeon® processors
with Intel vRAN Boost have integrated dedicated hardware FEC encoding acceleration within the CPU. Looking
ahead, it is likely that either (1) FEC encoding can be done on the processor itself, as processors get more cores, or(2) a hardware abstraction driver will be developed, allowing software to call on different hardware accelerator
implementations, even those from a different chipset vendor, in a standardized way.
In short, we are entering a phase where GPP performance has been validated as adequate for 5G DU implementation.
Solutions are now available from multiple chipset suppliers for both GPPs (Intel, AMD, NVIDIA, and ARM) and Inline
2(Qualcomm, Marvell, NXP, and EdgeQ), enabling a broad ecosystem of hardware and software solution providers.

2© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

2

From an operator's perspective, the emphasis is now on cost, performance, and power efficiency, as these are all
CapEx and OpEx drivers. There is a particular focus on energy consumption and the ability to dynamically match
power consumption with network traffic loading.
Supermicro is uniquely positioned in that it has server offerings with all of the aforementioned chipset vendors in avariety of platform configurations, which can be optimally selected based on the operator's deployment scenario.
All products have PCIe expansion slots and can optionally be provisioned with inline or other accelerators, such as
AI modules for radio management and MEC applications. Supermicro is also an active participant in the O-RAN
Alliance and an editor of WG7: The White-box Hardware Work Group.

Open RAN Recap
Before diving deeper into products and applications, it is worth a short recap on Open RAN and industry objectives.
Open RAN is defined by the O-RAN Alliance in Figure 1. The key is that the RAN had been segregated into discrete
functional blocks (RIC, CU, DU, RU, AU) with industry standard interfaces between them. An often-understatedchange in Open RAN is separating the RIC (RAN Intelligent Controller) into its own entity with support for 3rd party
apps that will allow for innovation in RAN resource management.

Figure 1 - O-RAN architecture. Image used courtesy of the O-RAN Alliance33© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

3

One of the most critical interfaces is the front-haul interface and the split between DU and RU. The industry had
defined various splits and primarily settled on 7.2x. However, Ericsson raised objections related to massive MIMO
CAT-B radio uplink performance and is a proponent of putting the equalizer and channel estimation in the Radio
Unit. Recently, an agreement was reached within the O-RAN Alliance for a Class A and Class B option that addresses
the issue, and with that change, the industry now has full buy-in from the major system suppliers.

Figure 2- Open RAN Functional Splits

RAN “Openness”
When discussing Open RAN, various terms like Open RAN, OpenRAN, O-RAN are used. In general, Open RAN is the
movement in wireless telecommunications to disaggregate hardware and software and to create open interfaces
between them. The intention is to avoid vendor lock-in, diversify supply, and create more innovation.
Per Figure 3, there are two dimensions to Open RAN, leading to four quadrants,
The first openness is horizontal disaggregation, as defined by the O-RAN Alliance. Here, the NodeB (radio basestation) is disaggregated into separate CU (Centralized Unit), DU (Distributed Unit), RU (Radio Unit), and RIC (RANIntelligent Controller) Network Functions (NF) with standardized interfaces between them, allowing a mix-andmatch of suppliers.
Note that the O-RAN Alliance does not mandate the implementation of the RAN architecture or require virtualization;
it is primarily concerned with the disaggregation of the Base Station and standardizing the interfaces between parts.
44© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

4

Integrated

DisaggregatedVirtualized

OpenRAN
vRAN

O-RAN
vDU

Non-virtualized

The second is vertical openness through virtualization, where to align with the cloud-native 5G core and adopt thesame operating model, it is desirable to virtualize the RAN Network Functions. OpenRAN comes from the Telecom
Infra Project group, an initiative to define and build 2G, 3G, and 4G RAN solutions based on general-purpose, vendorneutral hardware and software-defined technology. The NFs are virtualized into software running on COTS servers.
This creates a software-defined RAN that benefits from cloud native DevOps agility and CI/CD (continuous
integration and continuous deployment).

LegacyNodeB

O-RAN
Appliance

Figure 3 - Open RAN Implementations

These quadrants can be explained as follows:
1. Legacy NodeB: the traditional appliance base station is neither virtualized nor disaggregated. It uses
proprietary firmware on custom silicon.
2. O-RAN Appliance: the legacy base station is disaggregated to conform to the O-RAN Alliance architectureand standard interface between components. Each component (CU, DU, RU) can be based on proprietary
solutions, but units from different suppliers can be mixed and matched. This model was validated by NTT
Docomo in their initial Open RAN deployments.
3. OpenRAN vRAN: virtualized but not disaggregated, often referred to as Open vRAN, with the emphasis on DU
virtualization running on general purpose processors. These systems can still have proprietary5 interfaces
and RAN architecture. Some early all-G implementations also fell into this category.

5© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

5

4. O-RAN vDU: disaggregated, virtualized, and O-RAN Alliance interface compliant. This combination is the holygrail. While there is some debate on how open CPUs with accelerators are, it can apply to both look-aside
and inline acceleration, if the inline accelerator card is a commercially available, standardized card withsupported software from multiple suppliers. The NVIDIA GPU card, which supports virtualization, would also
fit here.

5G Virtualization and Cloud-native Benefits
A pertinent question is: “What are the benefits of Open RAN and virtualization?” as these are the industry’s driving
objectives.
An important goal of Open RAN is to stimulate greater innovation and supplier diversity. RAN is the most complex
and costly part of the network, and operators look to reduce dependencies on a single supplier and avoid supplierlock-in. By disaggregating the base station system into separate components, different suppliers, both at the device
and chipset level, could compete for a position in the network. Standardized interfaces would make it easier tosubstitute one supplier for another, or suppliers could focus on a subset of the total solution. Pulling the RIC out andcreating an API for 3rd party applications brings real innovation to the RAN management and operation, including
the ability to apply AI. In traditional appliance-based systems, the RIC functionality was not separately specified andwas the secret sauce of the RAN vendor. The operator was dependent on the capabilities of their supplier.
Virtualization brings a related set of benefits. The 5G architecture was defined as a cloud-native service-basedarchitecture (SBA), adopting the same principles as hyperscalers operating on cloud-like infrastructure. This means
using containerized network functions running on standard COTS servers, with a high degree of DevOps styleautomation utilizing continuous integration and continuous deployment (CI/CD).
With virtualization, the need for customized hardware appliances was eliminated. Using standard COTS servers, thehardware could be sourced from volume server manufacturers, benefiting from industry scale and rate of evolution.
The complexity of high-reliability hardware was replaced with resilience at the software level, and systems could
scale seamlessly as network load increased.
Notwithstanding the many benefits, cloud-native 5G is not without its challenges, even more so on the RAN. These
challenges include:
•

•

•
•

Moving from a traditional, appliance-based network to a true cloud-native network requires a sizeableorganizational mindset, cultural change, and a reskilling of the workforce. This shift has been one of thebiggest hurdles to full standalone 5G deployment.
In a legacy procurement model, a single vendor provided the solution, although, for business continuity,
operators would typically have more than one supplier. With an open solution, especially if best-of-breed
components are sourced from multiple suppliers, there is a need for a system integrator. Many operators
are finding this a role that they best undertake and are part of the organizational transformation. However,in time, this can also be their best competitive differentiator.
The technology is immature and going through a maturation and hardening process.
Legacy procurement practices need to be reassessed. These typically call for long equipment lifecycles,
whereas with cloud-native, servers are refreshed more frequently to take advantage of the superior
performance and enhanced efficiency each new generation brings. Being GPP COTS, the servers6 can often
be easily redeployed to different parts of the network, utilized for different workloads, or sold off.

6

© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

6

5G RAN Virtualization
While the 5G core lent itself to cloud-native architecture, and an SBA (Service-Based Architecture) for the core hadalready been validated with 4G LTE EPC—albeit based on Virtual Machines (VMs)—to garner the same benefits, there
was a desire to extend this to the RAN part of the network. However, the RAN has stringent real-time performanceand latency requirements and utilizes complex Digital Signal Processing (DSP). These implementations traditionallyrequired custom logic, embedded processors, and proprietary firmware.
Spearheaded by Intel with FlexRAN, it was proven that the DU RAN signal processing can be implemented onstandard GPP, and this has now been further validated by AMD and ARM. NVIDIA has implemented their L1 Aerial
RAN stack on the GPU, where any excess capacity can be used for AI and MEC applications.
Initial developments by both Mavenir and Parallel Wireless and Dish Networks and Rakuten deployments havevalidated that virtualized RAN can match appliance-based systems and operate cost effectively at scale.
The benefits of cloud-native for RAN have been extensively documented by Rakuten Symphony, running on
Supermicro hardware. For more background information about automation in Open RAN, visit this TelecomTV
webinar.
The benefits include:•••

Fast-tracking development and testing new applications and updates, streamlining build, testing in staging,
and advancement to production, contributing to agility.
Software-based and policy-driven monitoring and actioning based on real-time insights, resulting in a moreagile and reliable network.
An automation framework that enables efficient lifecycle management for workloads, further increasing
network agility.

The benefits span cost reduction, mitigation of errors when accepting new builds from vendors, and the ability to
rapidly spin up new services in days or even hours versus months.
Now that performance parity with legacy solutions is in range and will improve with new-generation chipsets, andthe spotlight has moved to energy efficiency. Arguably, at full network load, a custom silicon solution will be more
power efficient, but networks only operate at full capacity for a small percentage of the time. With containerized
Virtualized Network Functions, there is scope to vary the number of processor cores dynamically with network load.
There is also consideration for deploying idle cores—say at night—for other purposes, thereby offsetting costs
apportioned to the RAN workload.
The benefits of a virtualized Open RAN solution can be assessed by considering the Huawei case. Westerngovernments determined Huawei equipment to be a security risk and required that it be removed, which
necessitated a costly rip-and-replace of all installed equipment. Had the Huawei RAN been deployed using avirtualized, disaggregated Open RAN architecture, with industry standard interfaces, it would likely have beenpossible to keep the Radio Units (RUs), which make up the most expensive part of mobile network, as these primarily
perform RF Signal processing. The DUs now being COTS GPP servers would simply require a different supplier’s vDU
7 a central
container software stack to be ported and deployed, and this could potentially all be automated fromlocation.

7© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

7

Open RAN Topologies
One of the complexities of the RAN is that the deployment topologies vary depending on the operator and whether
it’s urban or rural. A major determinant is the availability of fiber in the access network between the core and thecell tower. The topologies are shown in Figure 4 and fall into two distinct categories.

Figure 4 Open RAN Topologies

88© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

8

1. Distributed – DU at the cell site or access network.
The primary challenges with the DU at the cell site are the extended temperature, vibration environmental
requirements, and the form factor. Many cell-site cabinets, especially European ones, are very short in depth,
requiring servers with sub-300mm depth. For cell-site deployments, eliminating the cell-site router or fronthaul
gateway is a significant cost benefit. This setup requires the DU to have 6 to 12 RU optical connections anddirectly support 5G GNSS and IEEE 1588 Precision Time Protocol (PTP) Grand Master timing.
If the DU is placed in the access network, a high-speed front-haul port connection and PTP support is required.
Form factors and environmental requirements may be more relaxed and, depending on how many cell sites areserved from the DU Node, multiple 1U or multi-node DU servers may be deployed.
2. Centralized – DU in a central office or edge data center
C-RAN (Cloud RAN; also referred to as Centralized-RAN) deployments are typically resident in a refurbished telco
central office or a modern data center. The form factor requirements are more relaxed, allowing for larger
servers. With a C-RAN, many cell sites will feed to a common aggregation node. This situation allows for more
complex and dynamic workload scheduling, e.g., when the network load is light, the workload can beconcentrated on fewer servers. As this requires that containers be dynamically moved between servers without
traffic interruption, it also lends itself to fault protection, where workloads on a failing server can simply bereassigned to another. Depending on the deployment, the traffic load will vary by time of day, such as a nodethat spans a residential neighborhood and business park so that the server capacity can be scaled to theaggregate peak workload rather than the sum of the workloads. For a lightly loaded network, any unused corescan be used to run other workloads.

Supermicro RAN Optimized Systems
Supermicro delivers the industry’s broadest portfolio of workload-optimized solutions for Open RAN topologies anddeployment scenarios. Additionally, Supermicro server options span all major CPU chipsets, allowing for further
optimization depending on the technical or business requirements.
Supermicro offers 5G servers that scale from the cloud core and BSS/OSS to RAN, private 5G, and MEC applications.
The servers are available in a variety of form factors to meet all operator’s environmental requirements.
Cloud RAN Servers include:•••

High core-count single processor and dual processor servers with PCIe Gen 5, supporting up to 400Gbps
SmartNIC and DPU network cards. These systems have extensive SSD drive support and are ideal for CU,
core, and OSS/BSS applications.
Multi-node systems for Cloud RAN DU.
NVIDIA MGX™ systems, which simultaneously support RAN, AI, and MEC applications.

Cell site servers include:••

Edge optimized multi-node systems for central office and access network feeding into a front haul network.
Highly integrated extended-temperature systems situated at the cell site with direct connection to the RU.
99© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

9Figure 5 – Supermicro Systems for Open RAN Deployments

New All-in-One RAN-Optimized DU Server
Supermicro introduces a new server for the next generationof Open RAN deployments, designed for deployment at scaleand reduction in both OpEx and CapEx. The SYS-211EFRN(D)N13P is an all-in-one COTS DU server featuring a 5th/4th
Gen Intel® Xeon® Scalable processor with Intel vRAN Boost.
The server has an onboard network interface and 12 SFP25G
ports, eliminating the need for add-on cards and breakout
cables, fully integrated timing support with eight hours ofholding time, and a compact, long-life design. The
Supermicro SYS-211E systems deliver a fully integrated
server optimized for cost, size, and power usage, handlinglarge volumes of traffic at the edge across multiple cell site configurations, including massive MIMO streams.
Visit Supermicro’s website to learn more about the new X13 RAN-optimized Server.

10

10© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

10

Overview of Supermicro Systems for Open RAN
X13 1U
Edge/Telco
Server

X13 2U
Edge/Telco
Server

X13
SuperEdge

X13 Hyper-E

H13 1U
Edge/Telco
Server

SYS-111EF(D)WTR

SYS-211EFR(D)N2T

SYS-211SE31A/D

SYS-221HEFTNR(D)AS -1115SF(D)WTRT

ARS-211ME-FNR

ARS-111GLNHRKey Features

High-density 1U
system for 5G
networking

Ultra shortdepth form
factor for telcoand edge
deployments

Versatile,
compact edge
platform withthree
independent
nodesPowerful dual
processor
system incompact form
factorHigh-density 1U
system for 5G
Networking

Short-depth
system for highsingle-thread
performance

High-density
1U GPUsystem withintegrated
H100

Processor

5th/4th Gen
Intel® Xeon®
Scalable
processor

5th/4th Gen
Intel® Xeon®
Scalable
processor

5th/4th Gen
Intel® Xeon®
Scalable
processor per
node

Dual 5th/4th
Gen Intel®
Xeon® Scalable
processor

AMD EPYC™
8004 Series
processor

Ampere®
AmpereOne™
processor

NVIDIA GH200
Grace
Hopper™
Superchip

RU

1U

2U

2U

2U

1U

2U

1U

SystemDepth

429mm / 16.9”299mm / 11.8”

430mm / 16.9”574m / 22.6”

429mm / 16.9”432mm / 17”940mm / 37”

Connectivity

2x 10GbE

2x 10GbE

1x 1GbE (1)Up to 2x 100
GbE
or 4x 10 GbE

2x 10GbE

2x 25GbE

1x 1GbE

MemoryUp to 2 TB
DDR5-5600

Up to 2 TB
DDR5-5600

Up to 2 TB
DDR5-5600 (1)Up to 8 TB of
DDR5-5600

Up to 576GB
DDR5-4800

Up to 4 TB
DDR5-4800

Up to 480GB
LPDDR5X and
96GB of HBM3

Expansion
Slots

2x PCIe 5.0 x16
FHFL
1x PCIe 5.0 x16
LP

Up to 6x PCIe
5.0 slots (mixed
sizes)

2x PCIe 5.0
FHHL
1x PCIe 5.0
HHHL (1)Up to 8 PCIe 5.0
slots (mixed
sizes)

2x PCIe 5.0 x16
FHFL
1x PCIe 5.0 x16
LP

6x PCIe 5.0 slots(mixed sizes)

2x PCIe 5.0 x16
FHFL

Power Supply

Redundant
800W AC or
redundant
600W DC PSU

Redundant
800W AC or
redundant
600W DC PSU

Redundant
2000W AC or
redundant
2000 DC PSU

Redundant
2000W DC or
redundant
1300W DC PSU

Redundant
800W AC or
redundant
600W DC PSU

Redundant
1000W AC PSU

Redundant
2000W AC PSU

and

RAN

(1)

R13
Edge/Telco
Server

G1 Highdensity GPU
systemPer Node

For more information aboutwww.supermicro.com/5g.

Supermicro’s

systems

for

5G

Open

deployments,

1111© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 2024

11

visit

Glossary:
Cloud RAN
A virtualized RAN built on cloud-native properties, including microservices, CI/CD, and containerization.
Open RAN
Generic term for Open Radio Access Network architecture with disaggregated functionality, software-definedtechnology, and open, community-developed standards.
OpenRANAn initiative based on TIP’s (Telecom Infra Project) OpenRAN Project group.
O-RAN
O-RAN refers to the O-RAN Alliance Community and the specifications defined in their framework and interfaces.
vRAN
Refers to virtualized radio access networks, a way to run baseband functions as software.

About Supermicro
As a global leader in high performance, high efficiency server technology, and innovation, we develop and provide
end-to-end green computing solutions to the data center, cloud computing, enterprise IT, big data, HPC, andembedded markets. Our Building Block Solutions® approach allows us to provide a broad range of SKUs, andenables us to build and deliver application-optimized solutions based upon your requirements.
For more information, visit www.supermicro.com.

1212© 2024 Copyright Super Micro Computer, Inc. All rights reserved

January, 202412