All three LPWAN technologies hit lower power consumption targets

A trio of announcements were made in the LPWAN (low power wide area network) industry last week, as it chases new lows in power consumption.

The first came from Semtech, the owner of the LoRa  technology, which announced what it said was the first disposable LoRa-enabled nanotag. The reference design is aimed at applications that require long range connectivity, and uses an “ultra-thin printed battery” that should enable it to be easily integrated into packaging designs, or simply fixed to an object.

The target industries include logistics, shipping, healthcare, pharmaceutical, and asset tracking, as well as general purpose compliance. Semtech says it will be available in 2018, and is undergoing trials with LoRa Alliance members. It can be built using both flexible tape and paper substrates.

The first pilot partner is machineQ, US cable provider Comcast’s IoT division, which is currently building out coverage in the US – starting with its HQ in Philadelphia. Notably, Comcast is not currently using its massive reach through in-home consumer premises equipment (CPE) to roll out a quick and dirty LoRa footprint, but is sticking with the tried-and-trusted tower model.

“As we continue to work with customers across a wide range of use cases, the innovative service made possible by coupling Semtech’s new nanotag on machineQ’s dense IoT network opens a whole new set of use cases, across multiple industries, that were not commercially or technically viable using existing technologies,” said Alex Khorram, general manager of machineQ.

Over in the rival Sigfox ecosystem, Fujitsu claimed the world’s smallest LPWAN sensor device, boasting a multi-kilometer range in a form factor measuring 82mm x 24mm x 6mm. The design is an evolution of Fujitsu’s solar-powered Bluetooth beacon, which has been modified to support Sigfox – able to send temperature readings over a range of seven kilometers.

The breakthrough, according to the designer, came from a new technology that allows Fujitsu to accommodate changing temperatures and their impact on power efficiency (for both generation and consumption). Fujitsu says this let it half the energy storage elements in the design, leading to the tiny design – but adds that the LPWAN message sending can require significantly more power than BLE (up to 1,500 times, apparently).

Fujitsu is positioning its K5 IoT platform-as-a-service (PaaS) as the ideal destination for the data generated by these sensors, which already has Sigfox Ready Program certification, after the readings have been transported over the local Sigfox Network Operator’s (SNO) infrastructure. In Fujitsu’s domestic market, that SNO would be Kyocera – a ceramics and electronics manufacturer.

The third low power announcement came from the cellular LPWAN market, from Riot Micro, which announced an NB-IoT and LTE-M baseband chip that it says draws less than 20 milliamps. Emerging from stealth mode, Riot Micro says the RM1000 will be cheap enough to achieve the much-vaunted $5 module target that the 3GPP ecosystem is aiming for, in order to compete with LoRa and SIgfox in a wider range of ultra-low power use cases.

Speaking to EETimes, CEO Peter Wong explained that the chip supports either NB-IoT or LTE-M, and not simultaneous transmission. Instead of using software to run the baseband functions, Wong says the RM1000 has used hardware-based Fourier transforms and filters in its PHY block, and stripped down the LTE software stack to its bare essentials.

Consequently, the RM1000 claims to support the two low power protocols using just a 26 MHz ARM Cortex-M0 microcontroller and a tiny amount of SRAM – a fraction of the resources required by rival designs, according to Wong. The claimed power consumption for the baseband of 20 milliamps is drawn from a 3.7V battery, when sending 23dBm transmissions.

However, when added to a complete chipset, the relative savings are not so apparent, thanks to all those other components. However, Wong believes that the improvements will bring the cost of NB-IoT and LTE-M close to that of Bluetooth. A notable drawback of the hardware-based approach is that Riot can’t just reprogram the firmware should something go wrong, as those mistakes would be baked into the silicon itself.