Designing for the IoT: How to Choose Between Bluetooth and LoRaWAN
Wireless technologies all have their own unique features and advantages as well as limitations. Choosing the right standard is about really understanding what your application needs, as well as what it doesn’t.
Published on September 7, 2023
Finding the Right Wireless for IoT
In today’s cutting-edge connected applications, especially
in the industrial sector, the businesses that succeed are integrating wireless
connectivity into their processes and using the data around them to drive
results. These businesses are using the IoT to capture machine status, automate
checks and verifications, harvest sensor data for cloud processing, and more.
Wireless devices make these solutions easier than ever to prototype and integrate,
solving challenges inherent in large facilities with countless machines,
vehicles and tools. Untethered by cables and mountable on many surfaces,
wireless sensors are a flexible and scalable way to start gathering and using
the information available across one or many industrial facilities.
Not all wireless technologies are the same, obviously, and
when it comes to protocols that are well suited for industrial IoT, their
differences are meaningful. Laird Connectivity provides modules, sensors, and
gateways that support many wireless types. But for Industrial IoT, our
portfolio is mostly focused on Bluetooth Low Energy and LoRaWAN. The two share
some similarities: They’re both highly suitable for sharing intermittent data
in short bursts, configurable for long sleep windows if needed, and both are
designed not to interfere with other infrastructure protocols, such as
facility-wide Wi-Fi. But here, many of the similarities end. Bluetooth Low
Energy and LoRaWAN are distinctly different technologies, not just in terms of
their frequency utilization and their underlying mechanics, but also their
position in the marketplace and their behavior in complex environments.
In this post, we’ll take a look at Bluetooth Low Energy and
LoRaWAN, discussing what makes them each unique, as well as the considerations
you should make when deciding which is right for your IoT application.
Bluetooth Low Energy
There are many reasons that Bluetooth is a great fit for all
kinds of wireless applications, not just in the industrial or IoT spaces. For
one, it’s almost ubiquitous: In the last 20+ years, Bluetooth has exploded into
countless applications and enjoys practically universal interoperability with
smartphones, laptops, and other personal devices. When talking about wireless,
it’s impossible not to talk about Bluetooth. And with the introduction of
Bluetooth Low Energy in the last decade, the potential applications for
Bluetooth have grown well beyond its original scope and scale.
Bluetooth Low Energy allows short bursts of data
transmission via Bluetooth, a new use case that goes beyond Bluetooth’s initial
popularity for audio, HID, and serial port transfer. Bluetooth Low Energy
devices send data as needed and configured by OEMs to communicate
intermittently, dramatically cutting power consumption. This also makes
Bluetooth Low Energy a particularly good fit for battery-powered applications,
such as sensors that must be mounted in places that cannot be easily cabled or
serviced by technicians. A long battery life means less time between
maintenance of sensor devices, freeing up time for other maintenance tasks. One
example is our BT510
sensor, which can be adhesive mounted on nearly any surface to capture
temperature, humidity, door open/close or vibration data, and can last for
years on a single coin cell battery (see
our website to estimate battery life in your application).
Additionally, Bluetooth Low Energy benefits from long-established
and improved pairing mechanisms, common availability in personal devices, and
familiarity from hardware engineering teams. It’s a long-proven wireless
technology that OEMs love, and it continues to improve for wider use cases. For
example, the introduction of LE Coded PHY in Bluetooth 5.0 allows for much
greater range than was previously possible in Bluetooth LE. Alternately, longer
range can be traded away for higher data rates via 2M PHY.
New features like Auracast allow audio to be broadcast over
Bluetooth Low Energy as well, with lower power consumption and with an
unlimited number of receivers to connect to a broadcast. Bluetooth Low Energy
continues to grow and evolve to new applications, and to serve existing
applications with greater and greater ease, power efficiency, and reliability.
While much newer than Bluetooth Low Energy, LoRaWAN has
rapidly emerged as a top-tier contender for IoT applications, and with some
unique properties that perfectly suit difficult industrial environments.
LoRaWAN operates in the sub-GHz band, which puts it well outside of the
frequency designated for Wi-Fi and Bluetooth, and therefore doesn’t require
coexistence schemes to avoid interference with those protocols. Additionally,
those low frequencies lend to much longer range: LoRaWAN is capable of
connecting over distances up to 10-15 km.
Additionally, thanks to many characteristics including its
chirp spread spectrum technique, LoRaWAN is able to maintain an exceptionally
robust connection, even in metallic or noisy environments that can cause other
wireless signals to scatter or attenuate. For this reason, LoRaWAN can
outperform competing technologies in factories and refineries full of pipes and
tanks, or in kitchen type environments blanketed in stainless steel paneling.
And still, with all of this, it operates with very low power
consumption. Our RS1xx
Sensors, which come in internal temp/humidity, external RTD temp probe, or
door open/closed configurations, run on 2x replaceable AA batteries and can do
so for years without replacement. They’re configurable via Bluetooth and our
Android/iOS app, and communicate for miles to a LoRaWAN gateway (such as our RG1xx
gateway). They transmit data with full end-to-end encryption, highly
valuable for sensitive data, which protects your data from unauthorized access
or interception over the air.
Making the Call: Which is Right For You?
Bluetooth and LoRaWAN are both established, reliable, and
capable wireless protocols with many uses in industrial IoT. But to decide
which to adopt, you’ll want to focus on the following factors:
- How much range do you need? If your sensors and gateways are likely to be within 30 meters of each other on average, Bluetooth Low Energy might suit your needs – especially if your data rates are likely to be low. If you need coverage to the tune of 2, or 4, or 8 miles, you’ll need to seriously consider LoRaWAN. Bluetooth Low Energy simply doesn’t provide this much range, even with features like LE Coded PHY.
- Where are you mounting your wireless hardware? If you want to place a sensor inside a large metallic hood, or inside a machine enclosure, or somewhere else that is inherently challenging for RF, LoRaWAN might be more effective at reliably transmitting that signal. If your device can be mounted in open air on a wall, outside of a reflective enclosure and possible line of sight, Bluetooth Low Energy probably won’t be negatively impacted by these materials.
- How important is it to keep your power consumption and maintenance to a minimum? Bluetooth Low Energy offers, by comparison, the lowest power usage over the longest amount of time. If your sensors are going to be mounted somewhere that requires downtime and stoppage to maintain and replace batteries, and especially if those sensors require more frequent communication, Bluetooth Low Energy will enable the greatest uptime and the best regular throughput for its power usage. Our BT510 sensor can last for over 11 years while sending temperature data every 15 minutes, all of this on a single coin cell battery. Understanding your application’s actual requirements can help you begin to estimate your power needs and which sensor or module might be right for you.
It’s worth noting that these technologies are evolving all
the time, and there are development efforts at hand to expand what LoRaWAN is
capable of. Currently, LoRaWAN is being used by some to transmit data into
satellite networks for data backhaul in low earth orbit. New implementations of
LoRaWAN operate in the 2.4 GHz range as well, decreasing range but increasing
data rates. Look to hear more from Laird Connectivity as these wireless trends
grow and become more broadly available to customers.
A Comprehensive Portfolio for Industrial IoT
Laird Connectivity provides packaged sensors and gateways,
as well as individual module offerings, to integrate IoT sense and control into
industrial applications. We’re wireless experts with over 30 years of
experience in bringing connected products to market. Our large portfolio of
modules, packaged products, system-on-modules, and embedded antennas provides
connectivity via Wi-Fi, Bluetooth, LTE, LoRaWAN, ultra-wideband, proprietary
RF, and more.
We’re an experienced wireless designer AND design partner,
with in-house capabilities in wireless testing, EMC compliance, product design,
and more. Whether you’re looking for off-the-shelf solutions to augment your
existing designs or looking to integrate wireless and processing in the next
generation of your product, Laird Connectivity has all the expertise under one
roof to bring your IoT applications to life.