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  • The IoT Pendulum Swings from LPWAN to Cellular with NB-IoT

    Will cellular connectivity become the dedicated wireless technology for the huge Internet of Things (IoT) market that’s being predicted by nearly everyone in the technology industry today? The naysayers argue that non-cellular, low-power wide-area (LPWA) network technology, promoted by providers such as SigFox and the LoRa Alliance, will win this tug of war since LPWA has been building market share (at the expense of the cellular industry) while 3GPP and the cellular operators have haggled over how to adapt their LTE standard for IoT uses.

    Granted, it has taken the cellular standards org, 3GPP, a lot of valuable time to finalize its cellular standards for IoT. But despite a slow start, 3GPP recently finalized in June 2016 its LTE-based IoT standards (Release 13), with the NB-IoT standard – the new IoT narrowband radio technology – gaining wide support among the mobile operators. (Even before the standard was finalized, AT&T, China Mobile, China Unicom, Deutsche Telekom, Orange, and Telefonica all had been conducting NB-IoT test trials.)

    So the future for cellular-based IoT, buttressed by the new NB-IoT technology, seems to be smelling as sweet as a rose given its support by mobile network operators. But they aren’t the only ones touting the promise of cellular IoT. ABI Research predicts that by 2021 NB-IoT radio node shipments will account for more than 33% of all cellular IoT shipments – an amount that's greater than legacy M2M or current Cat-1 shipments. Now, how sweet is that!

    But the debate persists even though the IoT pendulum appears to be swinging from LPWA technology to cellular connectivity thanks to NB-IoT. On the one hand, some people believe non-cellular LPWA technology will overwhelm cellular as the standard for IoT wireless connectivity, and on the other hand we have a few saying cellular will be the winner at the end of the day. More than likely, these competing technologies will split market share. NB-IoT won't be perfect for everyone, but it does provide a competitive alternative to LPWA. Let's explore this some more and start by answering the question: What’s the big deal about NB-IoT?

    What's the Big Deal about NB-IoT?

    The NB-IoT standard is the specification for cellular-based, low-power, wide area (LPWA) networking technology produced by 3GPP for IoT uses. It is one of several licensed-spectrum technologies (e.g., Cat-M1, LTE-MTC) designed to provide low throughput, deep coverage, and low power consumption for very long battery life (10-20 years) that was not possible with the traditional cellular standards (i.e., 2G, 3G, 4G). As a result, NB-IoT technology makes cellular connectivity a viable alternative to non-cellular LPWA technologies.

    The NB-IoT standard has been optimized for low throughput and supports a very large number of devices transferring small, intermittent blocks of data, which is common to a lot of IoT applications. It can also provide indoor coverage for nodes (e.g., utility meters) located deep in basements.

    NB-IoT supports uplink and downlink rates of around 200kbps. And since it requires only 200 kHz of bandwidth, it can run along with existing cellular networks. What this means is NB-IoT devices can benefit from carrier grade reliability, privacy and security, including support for user identity confidentiality, entity authentication, confidentiality, data integrity, and mobile equipment identification.

    Another advantage of NB-IoT technology is that by operating in the licensed spectrum, it isn't as affected by interference, as opposed to LPWA devices in the unlicensed spectrum. An even bigger advantage over non-cellular LPWA is that NB-IoT can be configured on an LTE network with only a software upgrade. Plus, the capacity of NB-IoT is huge. 3GPP puts the number of devices that can connect to a single cell at 50,000; some vendors puts it up to 100,000. Best of all, since NB-IoT devices are low complexity, they will be competitively priced, especially as demand increases.

    Table 1: NB-IoT Specifications

    3GPP Release13
    Downlink Peak Rate250 kbps
    Uplink Peak Rate250 kbps (multi-tone)
    20 kbps (single-tone)
    Duplex ModeHalf Duplex
    No. of Antennas1
    Device Receive Bandwidth180 kHz
    Receiver Chains1 (Single In / Single Out)
    Device Transmit Power23 dBm
    Coverage 164 dB

    Chipset Makers Prepare for the NB-IoT Market

    It didn’t take long after 3GPP completed the NB-IoT specification (i.e., weeks to be exact) for chipset makers to roll out NB-IoT products in anticipation for the projected demand for NB-IoT modems. Here are three early market entries:

    u-blox SARA‑N2 NB-IoT module

    u-blox SARA‑N2 NB-IoT module

    u-blox: In June 2016 the company introduced its SARA‑N2 NB-IoT module, which is the first cellular radio module compliant to the 3GPP Release 13, Narrowband IoT (LTE Cat. NB1) standard. The SARA‑N2 module provides secure, private communications over licensed spectrum with guaranteed quality of service. It supports peak downlink rates of up to 227 kbps and uplink rates of up to 21 kbps. Simultaneous support for three RF bands means that the same module may be used in most geographic regions. The module will operate for between 10 and 20 years from a single-cell primary battery.

    Sequans Communications’ LTE Cat M1/NB1 Chip

    Sequans Communications’ LTE Cat M1/NB1 Chip

    Sequans Communications S.A.: In February 2016, prior to the completion of the NB-IoT standard, the company introduced the Monarch, a single-chip LTE Cat M1/NB1 solution designed specifically for narrowband IoT applications, including sensors, wearables, and other low data, low power M2M and IoT devices. Monarch complies with the ultra-low-power and reduced complexity feature requirements of the 3GPP release 13 LTE Advanced Pro standard. The Monarch is highly integrated with baseband, RF transceiver, power management, and RAM memory all in a tiny 6.5 x 8.5 mm package, running Sequans’ carrier-proven LTE protocol stack, an OMA lightweight M2M (LWM2M) client for over-the-air device management, and a rich set of AT commands.

    Altair Semiconductor FourGee-1160 chipset

    Altair Semiconductor FourGee-1160 chipset

    Altair Semiconductor: In August 2016, the company introduced the FourGee-1160 chipset which is certified to run on AT&T's LTE network and currently supports LTE Cat-1 connectivity and but will support the newer Cat-M1 standard via an upgrade. The CAT-M1 standard is designed to boost module performance for Internet of Things (IoT) applications, offering enhanced coverage and extended battery life.

    Is NB-IoT Technology in Your Future?

    LPWA technology is used for applications that require small amounts of data that need to be transferred (often times infrequently) over very broad geographic territories. It has been ideal for this kind of application since it could do the job with very low power consumption, promising a long battery life. But can’t NB-IoT devices do the same thing? What do you think?

    Do you think cellular IoT is ready to take market share away from non-cellular LPWA technologies? Or has NB-IoT technology come too late, and well after IoT engineers and product designers have decided to opt for non-cellular LPWA technology such as SigFox or LoRa? Are you looking at NB-IoT technology for a future project? Take part in the discussion and share your thoughts!