narrowband IoT (NB-IoT)

What is narrowband IoT (NB-IoT)?

Narrowband IoT (NB-IoT) is a wireless internet of things (IoT) protocol that uses low-power wide area network (LPWAN) technology. It was developed by the 3rd Generation Partnership Project (3GPP) for cellular wireless communication to enable a wide range of new NB-IoT devices and services. NB-IoT is one of the three main 3GPP LPWAN standards.

The NB-IoT communication standard lets IoT devices operate via carrier networks, either within an existing Global System for Mobile (GSM) communication carrier wave, in an unused guard band between Long-Term Evolution (LTE) channels or independently.

One of the goals of NB-IoT is to boost the coverage extension beyond what existing cellular technologies offer. To do that, NB-IoT offers transmission repetitions and different bandwidth allocation configurations in uplink transmission.

NB-IoT can enable a broad range of new IoT devices and services. It reduces the power consumption of connected devices while increasing system capacity and bandwidth efficiency, particularly in locations that aren't easily covered by traditional cellular technologies. NB-IoT-connected devices can have a battery life of more than 10 years for many use cases.

How does NB-IoT work?

NB-IoT is a data transmission standard designed to enable devices to operate in mobile carrier networks. It uses low-bandwidth signals to communicate within existing LTE and GSM technologies. The NB-IoT standard uses a small radio band of 200 kilohertz (kHz), specifically designed to support IoT use cases.

Specially designed devices and sensors are also used as basic components in NB-IoT systems. These devices collect information from their surroundings and transmit it to NB-IoT base stations or transmission nodes. Individual base stations are connected to an IoT gateway and IoT cloud application servers for centralized monitoring and data analysis.

NB-IoT employs a new physical layer with signals and channels to meet the requirements of extended coverage in rural areas and deep indoors while enabling low device complexity. The underlying technology is much less complex than that of GSM/General Packet Radio Services modules.

Supported by all major mobile equipment, chipset and module manufacturers, NB-IoT can exist along with 2G, 3G, 4G, LTE-M and 5G mobile networks.

What are the benefits of NB-IoT?

NB-IoT offers the following benefits:

• Ubiquitous coverage and connectivity. NB-IoT can help support massive numbers of devices by establishing NB-IoT networks that can connect to billions of nodes. Designed for extended coverage indoors, the lower complexity of the devices provides long-range connectivity and communication.
• Bandwidth. NB-IoT is designed with bandwidth efficiency in mind. It uses a small portion of the spectrum, meaning multiple NB-IoT networks can coexist in the same area without any interference.
• Strong signals. NB-IoT signal strengths are typically strong, designed to penetrate multiple layers of brick.
• Low power consumption. NB-IoT doesn't need to run a heavy operating system, such as Linux, or do a lot of signal processing, making it more power-efficient compared to other cellular technologies.
• Low cost of devices. Because it's easier to create devices with lower complexity, the devices cost significantly less.
• Multiyear battery life. The enhanced power consumption capability enables NB-IoT to support a multiyear battery life for devices.
• Security. NB-IoT is secured using methods such as data encryption, secure authentication and signaling protection.

Examples of NB-IoT applications

NB-IoT can be used for the following applications:

• Smart metering. NB‑IoT works well for monitoring water and gas meters via regular and small data transmissions. Network coverage is a major problem in rolling out smart metering, as meters are often installed deep underground, in cellars or in remote rural areas. NB‑IoT coverage and penetration can address this issue.

• Energy savings. Sensors can be used to save on devices that are often active, such as using automatic light-dimming motion sensors connected to an NB-IoT system in an office building.

• Water conservation. NB-IoT water flow sensors can monitor water consumption in buildings.
• Supply chain management (SCM). NB-IoT is a good fit in SCM, as its wide and consistent coverage can be used in a variety of ways, including customer data management and inventory tracking.
• Monitoring temperature levels or optimizing store layouts. NB-IoT sensors can be used to monitor temperature for perishable goods or to optimize a store's layout to receive an ideal ROI.
• Smart cities. Through smart city deployments, NB‑IoT can help local governments control street lighting, determine when trash bins must be emptied, identify free parking spaces, monitor environmental conditions and survey road conditions.
• Smart buildings. NB‑IoT-connected sensors can send alerts to facilities managers regarding building maintenance issues. They can also be used for indoor temperature monitoring systems. NB‑IoT can serve to back up a building's broadband connection.
• Tracking. NB‑IoT provides a secure, inexpensive way to track people, animals and assets when continuous tracking isn't necessary. NB-IoT is good for tracking objects that aren't moving all the time.
• Smart farming. NB‑IoT connectivity enables farmers and cities to capture data from environmental sensors containing NB‑IoT modules that can send alerts if anything out of the ordinary happens. These sensors can be used to monitor the temperature and humidity of the soil, as well as to track the attributes of land, pollution, noise and rain.

NB-IoT vs. Cat-M1

NB-IoT and Category M1 (Cat-M1) are the two major technologies that support massive IoT deployments. While these are both 3GPP standardized technologies, they address different types of use cases based on the strengths of their capabilities.

NB-IoT supports ultra-low complexity devices with a narrow bandwidth of 200 kHz. Because of its narrow bandwidth, the data rate peaks at about 250 kilobits per second (Kbps).

Cat-M1, on the other hand, operates at 1.4 megahertz (MHz) bandwidth with higher device complexity and at a greater cost than NB-IoT. However, with the wider bandwidth, Cat-M1 can achieve lower latency, data rates up to 1 megabit per second (Mbps) and more accurate device positioning capabilities.

NB-IoT and Cat-M1 devices can sleep for extended periods of time with extended discontinuous reception, a method used in mobile communication to conserve the battery life of a mobile device. Both NB-IoT and Cat-M1 also support enhanced signal coverage per base station.

NB-IoT vs. LTE-M

NB-IoT and LTE-M are both LPWAN technology standards introduced by 3GPP. LTE-M, or LTE Machine-Type Communications, supports 1.4 MHz bandwidth with data rate peaks at 1 Mbps.

LTE-M supports simplified device complexity, low device power consumption, massive connection density and low latency. LTE-M also provides extended coverage and enables the reuse of the LTE installed base.

LTE-M deployment can be done in-band within a standard LTE carrier or standalone in a dedicated spectrum. It uses the free LTE spread spectrum technology. Device manufacturers that want to deploy on current cellular networks can use LTE-M. On the other hand, NB-IoT uses direct-sequence spread spectrum modulation technology for connectivity versus LTE spread technology. NB-IoT can also be implemented in an LTE carrier's guard band.

As NB-IoT is very flexible, it can operate in 2G, 3G, 4G and 5G bands, and it removes the need for a gateway which ultimately saves money.

NB-IoT offers improved indoor coverage, supports massive numbers of low throughput devices, low delay sensitivity, low device power consumption, optimized network architecture and is cost-effective.

LTE-M, however, is more expensive because several large carriers have patents on the underlying technologies, and LTE-M users pay royalties to these companies for their intellectual property.

NB-IoT vs. LoRa

Long Range (LoRa), which is used as a WAN technology, is a noncellular modulation technology for LoRaWAN, the standard protocol for WAN communications.

LoRa is a low-power, long-range wireless communication protocol developed by the LoRa Alliance, a nonprofit organization dedicated to standardizing LPWAN technologies as a secure, energy-efficient IoT standard.

LoRa is a modulation technology for LoRaWAN, an LPWAN specification intended for long-range communications. LoRa and NB-IoT both operate within LPWAN technology.

Although NB-IoT and LoRa are both LPWAN technologies created for low-power devices, NB-IoT has a lower latency compared to LoRa because of the higher device output power, which can offer higher data rates.

NB-IoT operates in the licensed spectrum. However, it can be deployed in-band within a normal LTE carrier or standalone for deployments in a dedicated spectrum. Because the channel width is small, it allows the NB-IoT signal to bury itself inside a larger LTE channel, replace a GSM channel or exist in the guard channels of regular LTE signals.

LoRaWAN is a spread spectrum modulation technique designed to facilitate communication between low-power devices and IoT applications. The LoRa wireless system uses unlicensed frequencies available worldwide to communicate with a network. LoRaWAN also uses radio frequency bands between 433 and 923 MHz. Its peak data rate is 50 Kbps per channel and has bandwidths of 125, 250 and 500 kHz.

Barriers to NB-IoT becoming a norm

The NB-IoT market is expected to grow 31% by 2027, according to market research firm Technavio. But there are still a few barriers to using NB-IoT, including the following:

• Limited device mobility. NB-IoT devices only remain connected within a finite environment and only to one network operator. This could mean limitations for such uses as wearables that leave specific perimeters. If a person with a wearable device, for example, enters another country, the device could become inoperable if the operator doesn't have a local presence.
• Limited data transmission. Voice or video transmission isn't an option because NB-IoT can only transmit less than a kilobyte of data per day, about equal to a text message. The NB-IoT data upload rate is around 20 Kbps, low compared to competing technologies. Its bandwidth is about 200 KHz.
• Limited support for roaming. Roaming enables LTE-M and NB-IoT users to connect to their IoT devices across countries and mobile networks. However, the network must be supported in each country a user plans to connect through.
• Limited large data transfers. NB-IoT has a slower data rate, so large quantities of data can't be transferred quickly.

Learn how NB-IoT is being used in large healthcare applications.