IoT wireless networks are evolving to help meet the needs of a wide variety of connected devices — from connected cars and smart homes to intelligent lighting and infrastructure. Low-power wide area (LPWA) networks are particularly well-suited for IoT systems that need low power consumption and extended battery life with carrier-grade security.
Several different technologies are being developed and deployed — including LTE-M and Narrownand IoT (NB-IoT) — to support such IoT requirements. As LPWA is expected to have a significant impact on the growth rate of future IoT innovation, here are some things you need to know.
Selecting the right IoT network
Building a successful IoT system is all about matching connectivity needs to the right technology or mix of technologies. Depending on the IoT application, businesses may choose to weigh the importance of six key decision criteria differently: coverage, data throughput, mobility, latency, battery life and cost.
Take throughput, for example, which represents the rate (or speed) at which data can be exchanged over a network. For smart city parking meters, tolls, lighting management or other scenarios where data exchange is minimal and may be managed using controlled time intervals, data throughput may be a lower priority. If, however, an application is targeted at streaming media, telemedicine or scenarios that involve video, then a higher-throughput, low-latency network is essential.
Benefits of LPWA technology
Lower cost and increased battery life have long been top considerations for IoT system architectures. LTE-M and NB-IoT are uniquely suited to address these factors — and more — but I’ll focus on these two.
LPWA technology has clear advantages over traditional IoT cellular connectivity options. Thanks to wide area coverage and the anticipated high endpoint capacity per cell, overall connectivity costs are expected to be lower than traditional broadband cellular service.
Additionally, LTE-M and NB-IoT can offer extended battery life up to 10 years for many IoT-enabled devices. While 12 to 24 hours of battery life may be enough for devices like consumer wearables, remote asset monitoring devices need much more. For example, autonomous, rechargeable devices that are tracking assets in the supply chain may need anywhere from seven to 30-plus days depending on the transit time or whether the device is traveling by land, sea or air. Simple on-off or full-empty use cases such as monitoring trash cans or liquid storage containers will require years of service in the field on a single battery charge.
Licensed vs. unlicensed spectrum LPWA
There are two primary categories of LPWA technologies: licensed and unlicensed.
Licensed LPWA utilizes mobile network operators’ existing wireless spectrum holdings. Mobile network operators have long held licenses to operate within dedicated spectrum specifically for the use of wireless communication. It’s how they provide the highly reliable, scalable and secure environments that large enterprises have come to expect. Both NB-IoT and LTE-M are supported in licensed spectrum with carrier-grade security.
Unlicensed LPWA technologies can be used without a permit in designated frequency bands, provided they comply with rules associated with the frequency bands. Wi-Fi routers, cordless telephones and other communication devices also access unlicensed spectrum, which can cause interference — thereby degrading performance. In addition, unlicensed spectrum technologies typically offer limited coverage availability, lack carrier-grade security and don’t always support two-way communications. Therefore, most unlicensed LPWA technologies do not support firmware and software over-the-air updates.
LTE-M and NB-IoT momentum
According to GSMA, mobile operators have commercially launched 58 mobile IoT networks worldwide across both NB-IoT and LTE-M. GSMA forecasts 1.8 billion licensed LPWA connections by 2025. At AT&T, we launched our LTE-M network last year in the U.S. and Mexico and recently announced that we expect to launch NB-IoT in the U.S. early next year and in Mexico in 2019.
LTE-M and NB-IoT are complementary LPWA IoT technologies. NB-IoT is ideally suited to meet very basic data requirements for use cases with limited data needs, while LTE-M supports more robust capabilities requiring higher bandwidth, mobility and Voice over LTE. They both ease direct connection to the cellular network without the need for Wi-Fi login or Bluetooth pairing.
NB-IoT is best for supporting simple on-off devices that could include smart parking meters, smart agriculture sensors, electric meters, industrial monitors and building automation. LTE-M, on the other hand, is best for supporting asset trackers, fleet tracking, smart watches, alarm panels, pet trackers, smart home appliances, patient monitors, utility meters and point-of-sale devices.
There is some overlap, though. For example, both can support smart metering depending on the specific needs and requirements. Modules and devices are increasingly appearing in the market built for dual use of the two technologies.
A look ahead
NB-IoT and LTE-M are expected to become part of the industry’s massive IoT standards. Investment toward both NB-IoT and LTE-M helps businesses ensure their technologies are future-ready.
As LPWA accelerates IoT innovation and spurs even higher volume device deployments, building a broad base of ecosystem partners, devices and applications for global markets will be key to increasing adoption.
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