Internet of Things (IoT) has transformed the way smart devices connect, communicate, and share data. However, as the number of IoT devices continues to grow into the billions, traditional mobile networks face challenges in handling massive connectivity with low power and wide coverage needs. This is where Narrowband IoT (NB-IoT) comes into play.
Narrowband IoT (NB-IoT) is a standards-based Low-Power Wide-Area Network (LPWAN) technology developed by 3GPP to support large-scale IoT deployments. It enables reliable, energy-efficient, and secure communication for low-data-rate devices such as smart meters, environmental sensors, wearables, and smart city infrastructure.
Unlike conventional cellular technologies, NB-IoT operates over licensed spectrum using a 200 kHz bandwidth, offering extended indoor coverage, multi-year battery life, and low device cost. These features make it ideal for applications in smart agriculture, utilities, logistics, and healthcare.
In this article, you’ll learn everything about what NB-IoT is, how it works, its architecture, operation modes, security framework, advantages, and key applications. You’ll also discover how NB-IoT compares with LTE-M, and why it’s becoming a foundational technology for the next generation of connected systems.
What is Narrowband IoT?
A standards-based LPWA (low power wide area) technology like NB-IoT is mainly developed to allow a broad range of IoT devices as well as services. This technology utilizes a spectrum within the low MHz range through 200kHz bandwidth by offering more channels as compared to Wi-Fi or LTE. NB-IoT network has many benefits as compared to other mobile networks like; entity authentication, user identity confidentiality, data integrity, mobile equipment identification & confidentiality. This technology applies to stationary devices that transmit small amounts of data, have longer wavelengths & operate wherever other technologies struggle to obtain a signal.
NB-IoT extensively improves user devices’ power consumption, spectrum efficiency, and system capacity, particularly in deep coverage. It supports >10 years of battery life for a broad range of use cases. The initial price of the NB-IoT is similar to GPRS or GSM. It is supported by major mobile equipment, module manufacturers, and chipsets. It can co-exist through 2G to 4G mobile networks.
This technology is used in wearable devices for fitness and health monitoring by providing valuable data to healthcare professionals & individuals. It can be utilized in home ecosystems for security cameras, door locks & thermostats to provide security & better control for homeowners. These can be deployed to verify air quality for contamination levels and execute measures for development.
Narrowband IoT Working
The NB-IoT network works based on LTE Technology which offers connections with good coverage and less interference because it can work on frequencies not utilized by existing communication networks.
The connected systems are arranged with sensors & devices that are designed to gather data from the surroundings and send it to NB-IoT nodes or base stations. The main benefit of this is, that it operates with extremely low transmission power because IoT device’s battery life is much longer due to their low power consumption and their coverage is extremely wide.
NB-IoT is a low-cost technology that allows various small businesses & public organizations to have the right of entry to long-range coverage. So in this manner, even hard-to-reach and rural areas can also be connected to numerous IoT-connected devices
NB-IoT Architecture
NB-IoT Architecture according to the 3GPP LTE-NB specifications is shown below which describes different elements utilized within the LTE NB-IoT architecture.
3GPP has launched specifications mainly for LTE-NB (or) NB-IoT known as narrowband cellular IoT solution which uses 200 KHz BW. It has been released in Rel.15, Rel.14, and Rel.13. NB-IOT is called as Low Power Wide Area Network (LPWAN) technology which focuses mainly on enhancing indoor coverage, long battery life, low cost, and number of connected devices.
Narrowband IoT Architecture
In the above NB-IoT architecture, there are mainly two significant parts available; access network & core network. So, UEs are simply connected to base stations (eNBs) with the UU interface. These base stations are connected mutually through the X2 interface. Here, eNBs are simply connected using the S1 interface to the Core network side where this interface carries either data packets or NB-IoT control packets. X2-interface is utilized to allow quick resume from UE IDLE state, although NB-IoT does not support handover.
Data Transmission and Reception
The data transmission and reception diagram is shown below. There are mainly two optimizations utilized in Cellular IoT (CIoT) based architecture like NB-IoT. Here red color indicates the control plane and the blue color is the user plane. Here, SCEF’s new code in NB-IoT is designed mainly to handle machine-type data which is used for transmitting non-IP data above the control plane. So it also provides an abstract interface mainly for the network services like; authorization, authentication, discovery & access network capabilities.
Data Transmission & Reception
UL data is transmitted to MME from eNB. After that, it may follow either the SGW path to PGW otherwise to SCEF path. So from this node, it will be forwarded to the application server mainly for CIoT services.
DL data can be transmitted above similar paths although in reverse direction.
So this LTE NB-IoT architecture does not need a data radio bearer setup, so, instead, data packets can be sent on a signaling radio bearer. Therefore this architecture is best for infrequent & tiny data packet transmission.
Operation Modes
NB-IoT works in three different modes for mainly very efficient spectrum utilization like in band guard and stand-alone operation modes.
- In-band operation mode uses resource blocks in a standard LTE carrier signal
- Guard operation uses the guard bands’ unused resource blocks in the LTE carrier signal.
- The stand-alone operation uses spectrum presently being utilized by GSM systems like minimum one or above GSM carrier signals replacement.
Narrowband IoT Security
Narrowband-IoT uses the verified security framework which is defined for LTE networks by 3GPP. So this mainly includes mutual authentication between the network and device, above-the-air data encryption through session keys & signed firmware updates. Extra device-level strategies such as tamper-proofing & anomaly detection further harden safety.
NB-IoT can also support both current security protocols utilized across cellular networks & any new features included in the future. Whenever no technology is protected from hacking or tampering, NB-IoT provides strong standardized security measures on equality with present mobile networks to guard against a variety of cyber threats that expand right down toward the IoT edge devices.
Specifications:
The Narrowband IoT specifications include the following.
- Standardization is 3GPP.
- Frequency is licensed.
- Its data throughput is less than 250kbps.
- It has extended coverage.
- Its bandwidth is 200 KHz.
- It has medium latency.
- There is no possibility of private networks.
- Power consumption is medium-low or higher as compared to LoRa.
Difference between NB-IoT and LTE-M
The differences between NB-IoT and LTE-M are discussed below.
|
NB-IoT |
LTE-M |
| NB-IoT or Narrowband IoT is a radio technology arranged above mobile networks that are particularly suitable for low cost, indoor coverage, long battery life & a large number of devices. | LTE-M or long-term evolution for machines is an LPWAN (low power wide area network) technology that allows the reutilization of an LTE installed base through extended coverage. |
| It can be deployed on both GSM (2G) and LTE (4G) networks. | LTE-M is exclusively for LTE (4G) networks. |
| It uses OFDM modulation for downlink & SC-FDMA for mainly uplink communications. | It uses 16QAM or QPSK in both downlink and uplink based on signal quality. |
| Its low-up link and high-up link speed is Kbit/sec. | Its low-up link & high-up link speed is Mbit/sec. |
| It is cheaper. | It is expensive. |
| This is suitable for only static devices. | This is suitable for both static & mobile devices. |
| It consumes less power. | It consumes more power. |
| NB-IoT has limited coverage. | LTE-M has extensive coverage in remote areas. |
| NB IoT utilizes a narrow bandwidth. | LTE-M uses a wider bandwidth. |
| It is mainly designed for massive device connectivity so it is suitable for applications that need a high density of devices. | LTE-M is suitable in applications with less device density like asset tracking. |
Advantages & Disadvantages
The advantages of Narrowband IoT include the following.
- It has ubiquitous connectivity and coverage.
- It has less power consumption, and it does not need a powerful OS or wide signal processing to make it very power-efficient.
- The device’s cost is lower because it is simple to make devices with decreased complexity.
- It has a multiyear battery life
- It is very secure with full encryption & SIM-based authentication.
- It has very efficient utilization of BW.
- Connectivity is reliable.
The disadvantages of Narrowband IoT include the following.
- It has limited data transmission and device mobility.
- It is optimized for slow-moving or stationary IoT devices like smart meters, environmental sensors, or certain asset trackers.
- It doesn’t support highly mobile or higher-speed devices. In addition, it is restricted in terms of roaming and handover capabilities.
- It provides less data rate as compared to LTE Cat-M1.
- Its bandwidth is about 200 KHz, so it is perfect to use only for stationary devices.
- It does not support VoLTE for speech transmission. Therefore, voice transmission cannot be supported.
- It does not support roaming.
Applications
The applications of Narrowband IoT include the following.
- Narrowband IoT in a smart city functions perfectly for mainly device-to-device communication, which includes smart meters, pollution monitoring systems & intelligent parking systems.
- It is suitable for a wide range of IoT-based applications.
- It allows parking space monitoring by providing real-time data regarding the availability of parking so that traffic flow and congestion can be reduced.
- It is used in street lighting systems by allowing remote monitoring & controlling so that it optimizes energy consumption & improves public security.
- NB-IoT is used for waste bins for smart waste collection so that municipal authorities can easily plan routes to decrease costs.
- It plays a fundamental role in real-time location tracking & asset condition.
- NB-IoT can be used on industrial machinery to detect potential failures, program maintenance, & reduce downtime.
- It is used in agricultural fields to monitor soil conditions, crop health & humidity levels so that farmers can make data-driven decisions regarding irrigation, pest control & fertilization.
- NB-IoT devices track and monitor livestock activities by providing data on location, behavior & health.
- It can be used with smart metering systems for real-time and accurate energy, gas, and water consumption monitoring.
FAQs
1. How does NB-IoT improve energy efficiency in IoT devices?
NB-IoT is designed with Power Saving Mode (PSM) and Extended Discontinuous Reception (eDRX) features, which allow IoT devices to stay in deep sleep for long periods without losing network connection. These features reduce the frequency of communication with the base station, resulting in battery life of over 10 years on small-capacity batteries—ideal for remote or hard-to-reach IoT sensors.
2. Can NB-IoT be integrated with existing 4G and 5G networks?
Yes. One of the biggest strengths of NB-IoT is that it can coexist with 2G, 3G, 4G, and 5G networks. It can operate in-band (within LTE), in guard-band, or stand-alone mode (using GSM spectrum). This allows mobile network operators to reuse their existing cellular infrastructure, minimizing deployment cost while gradually evolving toward full 5G IoT integration.
3. What challenges are faced in deploying NB-IoT networks?
Some of the key challenges include:
- Limited roaming support across different operators
- Firmware updates and device management in large-scale deployments
- Network congestion in dense IoT environments
- Integration complexity with legacy IoT platforms
- Despite these, advancements like over-the-air device management (OTA) and cloud-based NB-IoT platforms are addressing most of these issues effectively.
4. How does NB-IoT support smart agriculture and environmental monitoring?
NB-IoT enables farmers and environmental scientists to deploy low-power sensors that can operate for years in the field. These sensors collect real-time data on soil moisture, crop health, humidity, and air quality. The data is transmitted over NB-IoT networks to analytics platforms that use AI to optimize irrigation, reduce water wastage, and improve crop yield. It is especially valuable in rural and remote areas where traditional broadband is unavailable.
5. What is the future outlook for NB-IoT in industrial and satellite communication?
The next generation of NB-IoT will integrate with Non-Terrestrial Networks (NTN), including satellite IoT systems, to provide global coverage for industries like logistics, mining, and maritime operations. Additionally, NB-IoT will play a critical role in Industry 4.0 for connecting low-cost sensors in manufacturing plants to predictive maintenance platforms. With 3GPP Release 17 and 18, NB-IoT is evolving into a key component of 5G Massive IoT ecosystems.
The Narrowband IoT (NB-IoT) technology represents a major advancement in connecting low-power, low-bandwidth IoT devices over wide areas. With its strong network reliability, low energy consumption, and enhanced indoor coverage, NB-IoT is accelerating the growth of smart cities, precision agriculture, industrial automation, and connected healthcare.
By leveraging existing LTE infrastructure and the 3GPP standardized security framework, NB-IoT provides a cost-effective, scalable, and future-ready solution for massive IoT connectivity. While it has limitations in mobility and data rate, its advantages in coverage, battery life, and simplicity make it a key enabler of large-scale IoT ecosystems. As the world moves toward 5G and beyond, NB-IoT will continue to evolve and integrate with next-generation networks, supporting billions of smart devices that power a truly connected world. Here is a question for you: What is LoRa?