The 5 biggest misconceptions about NB-IoT

The term interim solution is misleading and therefore incorrect, precursor is more appropriate. As early as 2016, the 3rd Generation Partnership Project (3GPP) presented the criteria for the new NarrowBand IoT mobile standard. The international committee is responsible for mobile communications standards and by coming up with the specifications for NB-IoT it was responding to a growing demand for Industry 4.0: How can millions of machines and devices be quickly and cost-effectively networked and integrated into the Internet of Things (IoT) in the future to develop new business models?

For example, three years before 5G was introduced, there was already a mobile technology available that offered a new solution for several applications in the Industrial Internet of Things (IIoT) (see box). Not only that: NB-IoT will become an integral part of the future 5G network. This will meet three requirement profiles:

• even faster mobile Internet (enhanced Mobile Broadband / eMBB) for broadband data connections,
• reliable networking with extremely short reaction times (Ultra-Reliable Low-Latency Communications / URLLC), for example for robotics or autonomous driving, and
• networking of billions of IoT devices worldwide (massive Machine Type Communications / mMTC).

And NB-IoT was specifically developed for the last of these scenarios. 5G is not only designed as a new mobile communications standard, but also as a comprehensive network structure. This network of the future will be so intelligent that it will automatically provide the right connection technology for every application – whether 3G, 4G or 5G mobile telephony, fixed network, WiFi, LTE-M or NB-IoT.

The data throughput at NB-IoT – i.e. the rate of successfully transmitted data – can be limited on the one hand by external factors. Restrictions arise, for example, from the battery of the radio module, which has to provide the necessary energy for the transmission of the information, the data volume included in the tariff, or structural challenges that might prevent a good connection. On the other hand, the bandwidth of NB-IoT is limited to 200 kilohertz, which only allows data rates of up to 250 kilobits per second.

However – and this is the crucial point: this limitation of the bandwidth is intentional. The NB-IoT machine and sensor network was specifically designed for the transmission of small data packets. If, for example, the meter reading of a smart meter is queried once a week, only minimal data sizes are generated. Also, the measurement data of a sensor on a machine does not have to be transmitted continuously for predictive maintenance in production, but only in the case of defined deviations. The limitation of the functional scope to the bare essentials makes NB-IoT modules significantly more energy-saving and also cheaper to manufacture than conventional radio modules – and that’s a decisive advantage especially for small and medium-sized companies.

A second advantage of the limited bandwidth: NB-IoT technology combines a narrow-band, robust modulation method with repeated transmission of the small data packets, achieving unbeatable high building penetration. The technology even achieves reliable connections from basements – the preferred location for energy meters – as shown in a large-scale measurement test conducted by T-Systems and the real estate service provider ista.

While it’s correct that the devices don’t have a removable SIM like a smartphone, SIM functions are still necessary, since NarrowBand IoT operates in the licensed LTE spectrum of mobile phone providers. With NB-IoT modules, the SIM is permanently integrated into the device: as an eSIM (embedded Subscriber Identity Module) soldered onto the circuit board. Deutsche Telekom will offer companies a further development specifically for NB-IoT applications with the nuSIM from spring 2020. With the nuSIM, the SIM functions are integrated directly into the modem chip. It also dispenses with functions such as SMS and voice. This makes it more energy-efficient and less expensive than the eSIM.

This prejudice stems from the fact that NB-IoT does not support handover. For smartphones this uninterrupted change from cell to cell is essential – but it’s not necessary for many IoT devices. A tracking module on a container, for example, does not have to transmit its position continuously during the journey, so it can simply dial into the next cell after leaving one without any loss of data. Even roaming is now possible: Telekom's NB-IoT network, for example, allows mobile use across national borders in Germany, Austria, Hungary, the Czech Republic, Slovakia and the Netherlands; other countries will follow.

NB-IoT naturally offers a reliable downlink channel for firmware updates over the air (FOTA). This allows, for example, important security updates – just like on a smartphone – in steps and in groups. Devices in sleep mode are updated immediately after "waking up."

Conclusion: The alleged weaknesses of NarrowBand IoT turn out, on closer inspection, to be a necessary focus on the essentials in order to elicit the particular advantages for which the mobile standard was developed.