IoT Congestion is
Challenging Engineers
to a ‘Dual’
The Importance of Dual-Band
Wi-Fi for the Next Wave of
IoT Growth
Dan Kephart,
Sr. Product Manager of Laird Connectivity
Engineers working on IoT design and
deployment are being challenged to
a “dual,” but this has little to do with
battles of honor like the one that
involved Alexander Hamilton and
Aaron Burr. This challenge may not
be worthy of a Broadway musical,
but the stakes are high for people
designing IoT devices and building
out IoT networks that rely on Wi-Fi
connectivity.
Because IoT networks in a range
of industries rely so heavily on WiFi networks, the resulting network
congestion and RF complexity too
often lead to degraded performance
and reliability. The dueling demands of
so many Wi-Fi-based IoT devices push
Wi-Fi-based networks to their limits.
As a solution, engineers can resolve all
of these demands with the adoption
of dual-band Wi-Fi. This provides
dramatically higher performance and
more reliable connections, even in
highly-congested IoT environments
such as industrial settings, hospitals,
and manufacturing plants.
This white paper provides an overview
of the role that dual-band Wi-Fi
can play in IoT deployments. It also
provides a number of practical design
considerations that engineers can use
as they begin integrating dual-band
Wi-Fi into their product development
pipeline and IoT deployment plans.
Before discussing dual-band Wi-Fi in
depth, however, I should mention that
this is the newest in an ongoing series
of Laird Connectivity white papers
and other resources for engineers
designing with Wi-Fi. The following
prior materials provide practical
information and best practices:
• Testing Wi-Fi Functionality in
Medical Devices: This white paper
maps out a proven strategy for
successfully testing and optimizing
Wi-Fi-based IoT devices in hospital
settings – a complex wireless
environment where Wi-Fi has
proven to be an effective wireless
platform for connected medical
devices.
• 802.11n and Medical Devices: This
white paper discusses why WiFi performs well in hospital and
medical settings and provides
design considerations for futureproofing Wi-Fi devices for these
environments.
• Bluetooth and Wi-Fi Coexistence:
This white paper provides technical
guidance to engineers who are
designing and deploying Bluetooth
and Wi-Fi devices alongside one
another. This ensures that reliability
is maximized in an environment
populated by numerous devices
utilizing each of the wireless
technologies.
• FCC Opens 6 GHz Frequency,
Opening the Future of Wi-Fi: This
blog post provides a look ahead to
the future of Wi-Fi technologies,
with a focus on key features
and attributes that engineers
should begin planning for in their
development roadmaps.
For other resources about IoT
design, please visit: https://www.
lairdconnect.com/resources.
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Why Dual-Band
Wi-Fi Makes
Sense for IoT
For examples of the benefits of
dual-band Wi-Fi for increasing
performance and reliability, you don’t
have to look far. The nearest family
room will do. The use of dual-band WiFi is extensive in residential settings,
with adoption that has been far faster
by consumers than in the enterprise,
industrial, and medical fields. The
devices being used may be different,
but many of the drivers and benefits
are similar to IoT deployments.
At one point in time, single-band WiFi on the 2.4 GHz frequency was more
than adequate for a household, but as
the number of Wi-Fi enabled devices
increased and as the demands of
those devices intensified, families
experienced the limits of how much
traffic a single band of Wi-Fi could
support. A smart tv playing Netflix
shows, gaming systems running
Gears of War, and tablets playing
YouTube videos would often lead
to arguments about which member
of the family was hogging the Wi-Fi
due to the performance issues. These
challenges are even more acute in the
era of COVID-19, with online learning,
at-home work, Zoom calls, and other
applications demanding even more of
the Wi-Fi network.
Dual-band
residential
routers
have helped alleviate that network
congestion, particularly when certain
devices are dedicated to each band.
For example, gaming and Netflix
that are sensitive to latency might be
dedicated to the 5 GHz signal, while
other devices use the 2.4 GHz signal.
Yes, IoT networks in settings like
hospitals are very different than the
nearest family room, but the same
principles for use of dual-band WiFi apply. One of the ways that dualband allows organizations to relieve
congestion and dramatically improve
performance is by adding another
signal for devices to connect with. But
dual band also gives organizations
the ability to manage traffic and
performance by assigning specific
devices to specific bands and
prioritizing which of these devices get
different levels of connectivity.
Design Considerations and Success
Factors for Dual-Band Wi-Fi IoT
Below is an outline of key principles
that should steer how you integrate
dual-band Wi-Fi into your IoT
strategy. Also included is a number
of best practices and caveats based
on the extensive work that the Laird
Connectivity team has done with
customers on these projects.
• Design Dual-Band Flexibility into
Your IoT Devices – IoT networks
are not static. Over time your
organization may want flexibility in
how wireless devices are utilized and
how connectivity is shared by those
devices. For example, a device that
you initially plan to solely use the 2.4
GHz spectrum may later need to be
reassigned to the higher band or vice
versa. As network traffic evolves over
time, your organization might need
to shift some devices to the higher
or lower band in order to optimize
performance and manage traffic.
For that reason, it is best to design
devices with both versions of Wi-Fi in
order to have future flexibility. Using
dual-band modules and antennas
ensures flexibility without impacting
the complexity and cost-structure of
a device in a substantive way.
• Assign Bands Based on Criticality
of the Devices – One of the most
important principles to follow in
deploying dual-band Wi-Fi devices is
to utilize one band as mission critical
and the other band as less critical. In
the same way that the hypothetical
family in the previous section reserved
the 5 GHz band for “performance
apps” like gaming, organizations like
hospitals typically opt to reserve the
higher band for critical devices such
as medical devices that track patient
vitals or are directly related to patient
care. In that scenario, the 2.4 GHz
band becomes the home for lessvital devices including the personal
smart devices of patients and their
families. This same assigning of
bands to critical/non-critical devices
is a general guideline to consider in
other industries where the stakes
may not be life and death but where
some devices are more important
than others. This guideline can also
allow engineering teams to begin
modeling what level of demand each
Wi-Fi band will experience, enabling
them to anticipate how to optimize
deployments before the switch is
flipped on for an IoT network.
p. 3
• Take Advantage of Lesser Traffic
and Interference with 5 GHz – As
a postscript to the section above, I
should note that the 2.4 GHz band
is less ideal for mission critical
devices not only because of the
demands already on that band but
also because of its susceptibility
to interference. In a complex RF
environment, the 2.4 GHz band
can experience interference from
a number of sources including the
proliferation of devices tuned to that
frequency, the number of nearby
gateways broadcasting on that
band, and even nearby devices like
microwave ovens. The 5 GHz band is
far less susceptible to any of those
challenges, underscoring how it is
ideal for supporting critical devices.
• Also Take Advantage of Channels to
Further Improve Performance and
Reliability – For engineers who have
not worked with dual-band Wi-Fi in
the past, one of the key capabilities
to be aware of is the number of
channels that the 5 GHz band offers.
Engineering teams can tune the
performance of their devices and
networks by assigning 5 GHz devices
to specific channels within the band
that enable even more precise
control of performance, traffic
control, and latency. For this reason, I
recommend that engineering teams
not only create a strategy for how
to segment devices between 2.4
GHz and 5 GHz, but also strategize
how to segment devices across the
channels on the higher band.
• You Get What You Pay for with
Modules – As with so much other
technology in the wireless world,
things that are inexpensive upfront
often cost much more in the long run
than if you had chosen something of
higher quality. This general principle
holds true when it comes to dualband Wi-Fi modules. Choosing a
low-quality module can lead to a
much higher TCO in a number of
ways. It can lead to higher costs in
terms of supplemental engineering
that needs to be done to shore up
missing elements where corners
were cut. It can lead to higher costs in
terms of certifications that were not
completed by the manufacturer. Not
to mention the opportunity costs
caused by delays when modules
do not work as advertised, require
augmentation, or cause teams to
go back to the drawing board on
module selection. In our experience,
a quality dual-band module always
has a lower TCO and is a faster path
to completing projects. Excellent
documentation,
readily-available
technical
support,
guidance
about module mounting, and
comprehensive
pre-certifications
are all key selection criteria for a
high-quality module.
• Focus on Future-Proofing Your
Module Choice – One of the most
important design considerations for
these projects is to anticipate how
long a device may be in the field
and factor that device lifespan into
the radio and module. Some devices
have a relatively short lifespan given
the pace of turnover with which
devices are replaced. But for use
cases that have devices in the field
for three years, five years, or more,
the  engineering team should
ensure that the radio and module
they have selected will likely still
be viable throughout that life cycle
based on information available from
industry groups and manufacturers.
With that said, I believe it is too
early for most engineering teams to
be factoring 6 GHz Wi-Fi into their
product roadmap. For most IoT
applications, it will likely be several
years before that newest release of
the Wi-Fi protocol becomes widely
adopted.
• Antenna Selection and Placement
Can Make or Break Your Project – One
of the biggest pitfalls for dual-band
Wi-Fi design projects is related to
antenna selection. Antenna selection
is fraught with difficulty no matter
what technologies are involved, due
to the number of antennas on the
market, the confusion created by
their marketing-driven data sheets,
and the often dramatic difference
between reported performance and
actual performance. Dual-band WiFi devices require antennas that are
well-designed, have successfully
optimized performance of both
bands, and avoid the detuning
that is possible with 5 GHz signal.
Engineering teams should not rely
on data sheets and RF modeling
for antenna selection. That is also
true for antenna placement of both
internal and external antennas.
Testing is critical to ensure that your
team selected the right antenna and
installed it in a manner that optimizes
performance. Extensive testing is a
wise time investment up front in the
process that saves time and prevents
design headaches later on. This is
particularly true for IoT deployments
in complex RF environments such
as those in healthcare, industrial,
and manufacturing settings. It is
also important to note that working
with an antenna provider that is
committed to being a partner in the
process provides the engineering
team with invaluable guidance and
technical support which lowers the
risks involved in this critical decision.
p. 4
Laird Connectivity’s Sterling-LWB5+ 802.11ac and 60
Series of Wi-Fi + Bluetooth 5 modules answer the call
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CYW4373E silicon, the SterlingLWB5+ is purpose-built for
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ruggedness are required to deliver
reliable wireless connectivity. The
Sterling-LWB5+ offers significant
value to developers by providing
an unmatched breadth of options
including SMT and M.2 module
form factors, certifications, optional
antenna diversity, Linux backport
packages, and personal support and
design services, which altogether
provide greater flexibility to meet
the challenging requirements of
many wireless designs.
The 60 Series 60-2230, powered
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achieves the best possible
connectivity and performance
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industry-leading software, broad
OS support, and M.2 form factor,
the 60 Series 60-2230 offers
flexibility to meet your needs. The
60 Series introduces 802.11ac, 2x2
MU-MIMO, and Bluetooth 5.1 on
one low-power module, delivering
future-ready cutting edge
technology for your product.
Pairing embedded modules with
a pre-certified RF antenna saves
both certification
time and costs.
New, exclusive, flexible antenna
solutions from Laird Connectivity,
the antenna authority, provide
unmatched flexibility to help
you solve your real-world design
challenges.
For more information about
Laird Connectivity’s Wi-Fi
solutions, visit: https://www.
lairdconnect.com/wirelessmodules/wifi-modules-bluetooth
Learn more about
Laird Connectivity antennas at:
www.lairdconnect.com/rfantennas
p. 5
About the Author:
Dan Kephart, Senior Product Manager, IoT Platforms, Laird Connectivity
Dan manages the Wi-Fi, SOM, and gateway product lines to enable customers
to create IoT solutions that are reliable, secure, and use industry leading
connectivity. Dan has over 15 years of industry experience including 12 years
in wireless focused products.
About Laird Connectivity:
Laird Connectivity simplifies the enablement of wireless technologies with
market-leading wireless modules and antennas, integrated sensor and
gateway platforms, and customer-specific wireless solutions. Our best-inclass support and comprehensive engineering services help reduce risk and
improve time-to-market. When you need unmatched wireless performance to
connect electronics with security and confidence, Laird Connectivity delivers
— no matter what.
Learn more at www.lairdconnect.com.
For the latest news or more
information, visit:
Lairdconnect.com
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lairdconnectivity
linkedin.com/company/
lairdconnectivity
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