How to choose an IoT radio network

If you’ve been tasked with developing an IoT project, here’s a look at the latest communications technologies currently available and on their way

How to choose an IoT radio network
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Cellular, short range Wi-Fi (good for WAN gateways) and Bluetooth (good for wearables) aren’t the only wireless technologies IoT development has available. Some newer networks are being developed specifically for the Internet of Things.

Here’s what you need to know.

Ultra-narrowband Sigfox, beginning its roll-out in the U.S., says its low-power wide-area network (LPWAN) has the lowest subscription costs (digging at expensive LTE) and that its communications proffer “radically lower energy consumption.” 

The European company, along with Microchip, recently launched a radio transceiver development kit for building IoT solutions with its license-free Industrial, Scientific and Medical (ISM) two-way network. Sigfox says its 12-byte-per-message network is suited to “small quantities of data over long distances.”

Long-range, long endpoint battery-life Semtech is another LPWAN provider worth exploring. One thing to be aware of with both Sigfox and Semtech is that they aren’t and won’t be available everywhere.

Semtech is behind the the LoRa Alliance, a non-profit organization attempting to open-standardize IoT-based LPWAN. Its technology is called LoRaWAN.

Random Phase Multiple Access (RPMA), created by Ingenu, is a form of LPWAN, but it’s distinct from LoRaWAN in that it has its bandwidth available at 2.4 GHz in the ISM band. One reason that can be an advantage is that 2.4 GHz ISM is a global band, and radios don’t have to be modified depending on region—frequencies in lower-down ISM are inconveniently 915 MHz in the U.S. and 433 MHz and 868 MHz in Europe, for example.

Range can also be better than other LPWAN solutions Ingenu claims in a compellingly argued comparison in it ebook. Its RPMA access points can cover 176 square miles in the Americas and Australia. It claims to be able to receive 535,117 messages an hour.

Mobile network operators (MNOs)

Traditional MNOs, such as Vodafone, are eager to be part of the race to ubiquitous IoT connectivity.

Narrowband IoT (NB-IoT), also known as LTE Cat, is the cellular industry’s version of LPWAN. It’s geared towards utilizing the LTE bands and providing deep-building penetration. As it’s released, it will give MNOs a chance to offer services through their own, expensively-fought-for existing spectrum.

Vodafone, which operates in 26 countries, claims it will be the first to launch NB-IoT markets (Germany, Ireland, the Netherlands and Spain). It is expected to be live in Q1 2017. They’re doing the job by simply performing a software upgrade on existing base stations.

Vodafone argues that using licensed spectrum improves reliability, and that’s why one should pay for IoT communications subscriptions. Indeed, Verizon, in the U.S. has been marketing for some time what it calls a Private Network Traffic Management quality of service system for its plain-old 4G LTE IoT customers. 

Power saving

As with all of the M2M and IoT-specific networks, NB-IoT touts abstemious battery use as a primary benefit.

With any network, power saving—through battery efficiency, radio efficiency or chip design—means devices need less onerous maintenance and costs are reduced. That’s a big deal if billions of sensors are deployed. Twenty-year battery life is a goal. “Existing cellular standards don’t support power saving capabilities,” says Ublox, an NB-IoT radio vendor known too for its high-end GPS modules on its website.

Older cellular technology shouldn’t necessarily be written off as an IoT option, some incumbents say, though.

“Broadband cellular connectivity has dominated the IoT landscape for more than a decade,” AT&T says. Advantages include “global reach, scalability, diversity and high bandwidth capabilities,” the company claims of its traditional 3G and 4G LTE networks.

However, bear in mind that 2G cellular is being sun-setted in many places. The reason for that is the claim that 100 times the “spectral efficiency” can be achieved by replacing the aging system with LTE, Ingenu explains in its ebook.

Interestingly, satellite can also be a good choice for IoT. AT&T discusses that in its guide to choosing WAN technology for IoT. Notably, satellite is the least geographically limiting choice of communications.

“Connecting remote assets” such as facility monitoring and asset management at “unmanned sites” are where satellite excels, explains satellite M2M provider Thuraya on its website. Satellite can also be combined with cellular through roaming agreements. Thuraya has been using AT&T Mobility, Alltel and T-Mobile in the U.S., for example.

And hopping mesh networks such as 802.15.4 Zigbee are also in play. Those kinds of networks can provide distance gains through a lattice of radios piggybacking on each other. Utility companies are trying mesh networks for their smart meters, for example. One radio sends the message to another and so on.

Future IoT networks

The future of IoT networks may well turn out to be decentralized ad hoc networks—one step beyond mesh. Sensors strewn around an IoT network are created on the fly and don’t have routers or central hand-offs. They figure out for themselves what to communicate with through sampling. It's a bit like how an ant colony finds out where ants are—they randomly bump into each other and learn who else is around, scientists claim of the insects.

High-bandwidth, but technically difficult Millimeter band will also be in the future. Known now as 5G, it’s expected to become a usable product by 2020.

And some experts say 5G will gain its use case from IoT.

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