Industrial Automation Wireless Networks
Update – Ever More Relevant for CIP
Communications
David Brandt, Paul Didier Bob Voss
Principal Engineer, Solution Architect, Distinguished Engineer
Rockwell Automation, Cisco, Panduit
Presented at the ODVA
2023 Industry Conference & 22nd Annual Meeting
October 18, 2023
El Vendrell, Spain
Abstract
Wireless is no longer just an extension of the Enterprise Wi-Fi. Industrial wireless use cases are
increasing in industrial operations: AR/VR assistance for personnel, location services, highspeed SW
downloads to products and mobile machinery and assets. The wireless technology choices are also
growing: Wi-Fi, 5G/Private 5G, sensor networks, Bluetooth, ultra-wideband and other reliable wirelesstechnologies. The technologies are making enhancements for industrial use cases. All offer opportunities
to enhance safety, security, and efficiency. This session will explore the wireless options providing key
considerations around Use Case, Spectrum, Distance, Reliability, Speed, Latency, Management andTotal Cost of Ownership. Additionally, the session will consider how ODVA may be able to help users andvendors integrate wireless technologies for use in CIP communications.

Keywords
Wi-Fi, Private 5G, Industrial Wireless

Use Cases
Industrial Wireless technologies are ever improving and evermore utilized in industrial operations. The
technology improvements are meeting more and more of the industrial requirements, including:•High-Bandwidth and throughput to bandwidth intensive applications such as video streaming,
Augmented/virtual reality and tele-remote support•

Low latency to support tighter Industrial Automation and Control applications, including CIP
Safety.

•High-availability via improved interference avoidance, faster roaming and lower packet-loss rates

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Key use cases where industrial wireless play key roles include:
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Smart devices – such as smart phones and tablets
Automated Guided Vehicles – autonomous robots and vehicles moving product and parts aroundproduction facilities
Surveillance Cameras – streaming video for surveillance and vision control
Human Machine Interface – mobile HMIs keep operational personnel connected
Remote Expert – integrated remote engineers and support for deployment and problem resolution
Augmented Reality/Virtual Reality – mobile AR/VR headsets to improve personnel effectivenessSensors, Actuators – wireless sensors and actuators where wired connectivity is challenging
Wireless Tooling – More effectiveness and efficient tooling when not tethered
Mobile Work-Cell – flexible, nomadic production equipment and assets
Product Downloads – download Software and data to intelligent products.

Technologies – Current State
This section will provide an overview of key standard wireless technologies: Wi-Fi (a.k.a. IEEE 802.11)
and Cellular 5G (managed by the 3GPP standards organization).

Wi-Fi – Current State
Currently, the most recent available Wi-Fi technology is based on Wi-Fi 6/6E technology. Wi-Fi 6
technology (IEEE 802.11ax) is currently shipping where much of the infrastructure is ready to support theadditional spectrum allocation referred to as Wi-Fi 6E. As of the writing of this paper, Wi-Fi 6E isavailable in a number of countries, including the US, although only a limited set of devices support it yet.
Specifically, low-power indoor (LPI) devices support 6E. Most industrial Wi-Fi 6 devices must disable
support for 6E because they do not have integral antennas and/or have enclosures that could be used
outdoors (even if they are intended to be used indoors, but must withstand washdown).

Wi-Fi 6/6E - Update
The following summarizes the key enhancements in Wi-Fi 6/6E:
Figure 1 – Wi-Fi 6/6E enhancements

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For more information see: https://www.cisco.com/c/en/us/products/collateral/wireless/white-paper-c11740788.html.
In addition to these features, Wi-Fi 6E grants additional access to 1200 MHz of relatively clean spectrum
in the newly-opened unlicensed 6 GHz band that significantly increases the available spectrum (roughly@200% increase in the US, @100% increase in EU) , improving data rates, lowering interference andsupporting more applications.
Figure 2 – Wi-Fi 6/6E available spectrum diagram

Wi-Fi 7 - Update
As of the writing of this paper, the Wi-Fi Alliance is working on Wi-Fi 7 and is expected to be ratified in
2024. The IEEE IEEE is still working on IEEE 802.11be.
Wi-Fi 7 continues the improvements in resiliency, bandwidth and denser deployments of devices. Wi-Fi 7
currently includes enhancements for industrial applications around resiliency and priority.
Figure 3 - Enhancements expected in Wi-Fi 7

For more information see: https://wballiance.com/road-to-wi-fi-7/

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5G - Update
3GPP is the organization that creates 5G standards. The standards cover the complete 5G architecture –UE (User Equipment) end-devices, RAN (Radio-Access Network) and Mobile Packet Core. The standards
are delivered in releases. Here are some considerations about 3GPP standards:
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•

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•

•

Feature release for telecom providers remains 5G vendor priority
There is significant lag between 3GPP specification release and commercial availability (particularlyof “industrial” features not needed by telecom)– Release 16 completed in 2020
– No infrastructure supporting Release 16 features (e.g., time sync support) until end of 2023 /early 2024
5G modems more closely follow 3GPP releases– Some updates are via firmware, but many require new silicon– More likely to see 5G modems advertised as “Release 16-compliant”
Infrastructure adds features from future 3GPP releases incrementally– Typically via software update– Follows vendor internal roadmaps– Features from lower-numbered 3GPP releases are generally added first– Some features (e.g., localization) may require special hardware support in basebands
Even though the standards are released groups, UE, RAN and MPC vendors can pick and choose
what features and functions to deliver.

Below is a table of features relevant to industrial communications and the release that they were included.
Table 1: 5G Feature Release
FeatureRelease 15(2018/2019)

Release 16(2020)

Release 17 (2022)

URLLC (Ultra-Reliable
Low-LatencyCommunication)

All basic features(for IMT-2020
compliance)

Adds redundanttransmissions, QoS
monitoring

No new features

Ethernet PDU

No

Yes

Yes

Time Sync Support

None

IEEE 802.1AS gPTP
only

IEEE 1588 PTP (CIP
Sync)

Positioning< 50 m<3m<1m

Network Slicing

Basic slicing
features (similar to
VLAN)

Adds network slicebased authentication(NSSAA)

Adds slice groups(NSSRG), enhanced
RAN support

IIoT

Relies on LTE

5G core support for
NB-IoT

NR RedCap(replacement for LTE
Cat 1)

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5G and CIP
The good news is that 5G natively carries EtherNet/IP traffic, as it is based on TCP/IP. A few other notes
about 5G and industrial networks:
•
•
•
•
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Support for Ethernet frames was added in 3GPP Release 16, specifically Ethernet protocol data unit
(PDU) sessions– Most existing 5G equipment on the market today does not support Ethernet PDU
EtherNet/IP is carried by TCP and UDP, so EtherNet/IP can run on any 5G!
– Most industrial protocols need special tunneling (e.g., VXLAN) or Ethernet PDU support
Special support is needed for:– Time synchronization (motion)– Multiple devices behind a UE
5G typically requires UEs to request a schedule to send data uplink which may disrupt low-latency
communications, which can be mitigated via Grant-Free Scheduling
Along these lines, typical 5G systems are configured to prioritize downlink data (e.g., video
streaming) over uplink, whereas industrial communication creates nearly symmetric uplink anddownlink traffic. This can be mitigated with 1:1 slot ratios.

Each of the above are covered below.
Figure 4 – 3GPP 5G support stack in Releases 15 through 17.

5G and Precision Time Protocol (PTP)
5G base stations must be synchronized to a GPS-derived clock to avoid interference with neighboring
cells. GPS time is distributed to UEs via a system information block (SIB), specifically SIB 9 forstandalone networks and SIB 16 for non-standalone networks that rely on LTE. The distribution of GPS
clock data, combined with a method such as timing advance (TA) to correct for signal time of flight, allows
all elements of the 5G system to remain synchronized.
3GPP has added features to support industrial PTP protocols (IEEE 802.1AS gPTP in Release 16 andstandard PTP / CIP Sync in Release 17) as depicted below.

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Figure 5 – 3GPP PTP support as of Release 17

While details may be vendor-specific, the basic mechanism to support PTP works as follows:• A 5G system (5GS) supporting Release 16+ will correct residence time via TSN Translators(TTs)• There are two types of TTs: device-side TT (DS-TT; TSN master), and network-side TT (NW-TT)• Ingress traffic into the 5G system is timestamped; on egress, the TTs subtract the current timefrom the ingress timestamp to compute residence time, which is added to a correction field• In essence, the 5G system acts like a single switch implementing a PTP transparent clock• The PTP Grandmaster may be internal or external to the 5G system; at most one NW-TT can be
a TSN slave

Support for Multiple Devices Behind Single UE
Cellular was originally designed for phone and eventually smart phone use, where all traffic was to/from asingle end device. As such, it is still developing “bridging” functions similar to Work-Group Bridges foundin Wi-Fi networks.
Figure 6 – Industrial Use Case – multiple devices behind a UE connection

Remote I/O
5G Industrial
Router
https://www.industrialnetworking.com/pdf/HMS-anybus-wireless-bolt.pdf

Safety I/O
PLC / PAC

A few points about support for multiple devices behind a single 5G user equipment (UE):• It is advantageous if a single UE can support multiple automation devices– 5G UEs (modules or routers) are expensive– Many automation devices are located in metal cabinets that block RF, so it often doesn’t
make sense to integrate 5G radios in these devices• Tunneling / VXLAN can be used to support multiple devices behind a single UE– May need an “extra box” behind UE to act as a tunnel endpoint2023 ODVA Industry Conference

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••– Some UEs have tunneling support or can run containers (e.g., with OpenVPN)
5G also supports “framed routing” (3GPP TS 23.501 §5.6.14)– Originally developed as part of RADIUS (RFC 2865)– 5G vendors may call this feature “Routing Behind Mobile Station” or “Routing BehindUE”, but it is typically implemented using framed routing
Example of how framed routing works:– Allocate small subnet (/27 or smaller) behind UE– This subnet is associated with a user name and password, stored in the 5G core

– When a 5G UE initially connects (attaches) to a network, it authenticatesusing SIM credentials (primary authentication)––

A 5G UE may also authenticate to a specific data network using EAP (typically via PAP
or CHAP) with a user name and password; this is called secondary authentication
When the UE performs secondary authentication, a route is created in the core to thesubnet associated with the secondary authentication credentials

Grant-Free Scheduling
5G UEs typically must request permission (a grant) to send uplink data. This adds delay and increases
inter-packet delay variation (colloquially called jitter), both of which are problematic for CIP protocols. The
added delay from this scheduling procedure also generally precludes very low-latency applications.
Figure 7 – 5G Scheduling Procedurehttps://www.rfwireless-world.com/5G/5G-NR-Scheduling-Request-Procedure.html
Grant-free scheduling (also called transmission without grant, TWG) avoids the added delay and packet
delay variation caused by uplink scheduling. It works as follows:• The 5G base station reserves resources for uplink for each UE; the UE can transmit on thesereserved uplink resources at any time
• The periodicity of the grant-free uplink resources is adjustable; ideally this period would be thesame as the CIP packet interval, but synchronization may not be possible• In general, grant-free schedule reduces latency at the expense of throughput since reserved
uplink resources may not be used

1:1 Slot Ratios
EtherNet/IP typically has approximately equal traffic in each direction. Typical cellular use cases aredownlink heavy (e.g., streaming video). In fact, most 5G equipment initially only supported a few fixed
downlink to uplink ratios with at best a 4:1 downlink to uplink ratio.
This downlink uplink asymmetry creates several problems for EtherNet/IP traffic. First, it creates abottleneck in the uplink direction, which may cause extra queuing delay for CIP connections in thisdirection. A second, less-obvious effect is that it also increases the time required for physical-layer retries
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when the uplink slots are fewer and farther apart. This adds delay and increases inter-packet delay
variation.
Therefore, usage of slot ratios as close to 1:1 as possible is advantageous for EtherNet/IP traffic. A few
points about 1:1 slot ratios:
•
•

•

•

5G divides resources in time into frames, subframes, slots, then symbols– Individual symbols can be allocated for downlink, uplink, or flexible
With time-division duplexing, slots (each containing 14 symbols) are typically allocated as downlink(D), uplink (U), or special (S; mix of symbols)– It takes time to switch radios between transmitting and receiving, so blocks of downlink or
uplinks slots allows higher throughput
Slot patterns sets ratio of uplink to downlink traffic, as well as retry delay– 5G base stations and UEs initially offered only a few fixed slot ratios– Closest to symmetric was 4:1 downlink to uplink, such as DDDSUUDDDD– Current 5G equipment may offer nearly 1:1 slot ratio, e.g., DDSUU
Even with an exactly 1:1 slot ratio, downlink throughput is typically better due to MCS differences,such as higher-order QAM in downlink

Key Industrial Considerations
The key considerations when choosing wireless communications include:
1. What are the devices to connect? Cranes, AGVs, tablets, sensors etc.
2. What are the applications requirements? Latency, reliability, nomadic/stationary, etc.
3. What are the deployment Scenarios? Regional regulations, spectrum, indoor/outdoor,
access/backhaul
4. What are the potential technology options?
• Wired: Ethernet, serial, DSL• Wireless: Wi-Fi and Ultra-Reliable Wireless Backhaul, 5G Cellular,
Wi-SUN, LoRaWAN,• Spectrum: Unlicensed, Licensed: Private,
Public, Shared
5. What are the CapEx and OpEx Implication?

Wireless Architectures
Below is a depiction of wireless architectures for WiFi and 5G:

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Figure 7 – Wi-Fi and 5G architecturesODVA Impact
As stated above, CIP and EIP are already well suited for both Wi-Fi and 5G communications with a few
noted caveats, especially around time synchronization and motion applications. Both technologies aredesigning improvements for industrial control applications.

*********************************************************************************************************************The ideas, opinions, and recommendations expressed herein are intended to describe concepts of the author(s) for the possible use of ODVA
technologies and do not reflect the ideas, opinions, and recommendation of ODVA per se. Because ODVA technologies may be applied in many
diverse situations and in conjunction with products and systems from multiple vendors, the reader and those responsible for specifying ODVA
networks must determine for themselves the suitability and the suitability of ideas, opinions, and recommendations expressed herein for intended
use. Copyright ©2023 ODVA, Inc. All rights reserved. For permission to reproduce excerpts of this material, with appropriate attribution to theauthor(s), please contact ODVA on: TEL +1 734-975-8840 FAX +1 734-922-0027 EMAIL odva@odva.org WEB www.odva.org. CIP, Common
Industrial Protocol, CIP Energy, CIP Motion, CIP Safety, CIP Sync, CIP Security, CompoNet, ControlNet, DeviceNet, and EtherNet/IP aretrademarks of ODVA, Inc. All other trademarks are property of their respective owners.

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