NB-IoT: Reliable, power-efficient IoT for challenging locations

NB-IoT offers long battery life, deep signal penetration, and scalable connectivity for devices transmitting small amounts of data infrequently. Supported by the GSMA Mobile IoT initiative and standardized by 3GPP, NB-IoT is now widely recognized as one of the most robust LPWAN technologies available for industrial and utility-grade IoT applications

At Com4, we enhance NB-IoT by combining it with a multi-mode IoT SIM that enables seamless switching between NB-IoT, LTE-M, 4G, 3G, and 2G networks under a single price plan. This flexibility ensures service continuity across borders, even in markets where NB-IoT roaming is not yet available.

Table of Contents

What is NB-IoT?

Technical overview of NB-IoT

Architecture & Components

NB-IoT vs LTE-M vs 2G/3G/4G

Key advantages of NB-IoT

Limitations of NB-IoT

Com4 NB-IoT coverage

Example use cases

Security in NB-IoT

Why choose Com4 for NB-IoT deployments

What is NB-IoT and why it matters

NB-IoT is a Low Power Wide Area Network (LPWAN) standard developed specifically for IoT applications. Built on licensed LTE spectrum, it is designed to connect stationary devices that need to operate for years without maintenance and are often placed in areas where coverage is limited, such as basements, underground utility rooms, remote rural areas, or deep inside industrial complexes. By using a narrow frequency band and advanced signal repetition techniques, NB-IoT achieves exceptional indoor and underground penetration—something that traditional cellular networks like 2G, 3G, and even 4G LTE often cannot match.

The technology is particularly valuable for devices that transmit small amounts of data periodically rather than continuously, such as water meters that send usage data once a day or environmental sensors that report readings every few hours. This efficiency is achieved through advanced power-saving modes like Power Saving Mode (PSM) and Extended Discontinuous Reception (eDRX), which allow devices to “sleep” for extended periods without consuming significant battery power.

Technical overview of NB-IoT

NB-IoT is a 3GPP Release 13 specification designed for stationary, low-power, low-data-rate IoT applications. Unlike unlicensed LPWAN technologies, it operates in licensed LTE spectrum, ensuring predictable performance and carrier-grade security.

Table 1: Technical characteristics of NB-IoT

Source: GSMA Mobile IoT initiative, 3GPP Release 13 specifications

Architecture & Components

NB-IoT relies on a layered structure that simplifies deployment while supporting long-term, low-power IoT services.

Device/Module Layer

• Small, embedded modules used in meters, sensors, and static equipment.
• Designed for low data needs and minimal energy consumption.
• Often include basic processing and integrated antennas.
• Built to operate reliably in fixed, unattended environments.

SIM & Identity

• Devices use SIM, eSIM or iSIM to authenticate and connect.
• Each SIM provides a secure, unique device identity.
• iSIM enables tighter integration and smaller device footprints.
• Supports remote provisioning and lifecycle management.

Network & Coverage Planning

• Operates on licensed LTE spectrum using narrow 200 kHz bandwidth.
• Planning focuses on reaching indoor, basement, or rural zones.
• Signal repetition and high link budget improve coverage reach.
• Network density can be high, with thousands of devices per cell.

Platforms & APIs

• Devices transmit data to cloud platforms via standard APIs.
• APIs handle device provisioning, data routing, and alerts.
• Support for automation, dashboards, and third-party integrations.
• Scales easily across regions or application types.

Comparing NB-IoT with Other Network Options

NB-IoT is one of several connectivity options used in the IoT space. Choosing the right one depends on your device's mobility, power limits, and data needs. Below are simple comparisons to help understand how it stacks up against other popular technologies.

NB-IoT vs LTE-M

LTE-M is another cellular IoT standard developed alongside NB-IoT. It is better suited for mobile devices and applications that require voice or larger data packets.

NB-IoT vs 2G/3G/4G

Traditional mobile networks offer higher speeds but are not optimised for low-power IoT. Many of these networks are also being phased out.

NB-IoT vs LoRaWAN and Sigfox

LoRaWAN and Sigfox are low-power networks using unlicensed spectrum. They allow private network setups but can face interference and lower reliability.

NB-IoT in the 5G Era

NB-IoT is officially part of the 5G family under the massive Machine-Type Communication (mMTC) category. It will continue to coexist with newer 5G standards and is expected to support even wider use cases through satellite and terrestrial coverage.

Key advantages of NB-IoT

Narrowband IoT was built to serve a very specific need in the IoT landscape: reliable connectivity for devices that operate quietly in the background, often in hard-to-reach locations. Its benefits go beyond just signal strength or battery life.

Here are the 6 key benefits of Narrowband IoT (NB-IoT) technology:

Strong Coverage in Difficult Environments

NB-IoT performs well in places where standard cellular signals struggle. This includes underground facilities, remote rural areas, and buildings with dense construction. Its improved link budget delivers up to 20 dB more coverage than GSM, helping devices stay connected in harsh conditions.

Battery Life Measured in Years

One of NB-IoT’s biggest advantages is energy efficiency. Devices can run for five to ten years on small batteries without needing regular maintenance. This is especially useful in large-scale deployments where manual servicing is costly or difficult.

Scalable and Cost-Efficient

NB-IoT modules are less complex than full LTE or 5G modems, which helps reduce hardware costs. A single network cell can support tens of thousands of devices at once. This makes the technology suitable for city-wide or national-scale IoT projects.

Reliable and Secure

Operating on licensed spectrum, NB-IoT benefits from managed network environments. It uses SIM-based authentication and standard LTE-grade encryption. These features protect against signal interference and unauthorised access.

For global or multi-site deployments, managed connectivity solutions like Com4’s Global IoT SIM Cards support secure, flexible coverage.

Minimal Network Interference

Because it operates in dedicated licensed bands, NB-IoT avoids the noise and congestion often found in unlicensed networks. This leads to more stable performance, especially in high-density areas where many IoT devices may be transmitting simultaneously.

Designed for Simplicity and Longevity

NB-IoT removes many of the features found in traditional mobile technologies that are not needed for basic IoT. This streamlined approach lowers power demands and extends the operational life of both the hardware and the network itself. It is built to last, not to be replaced frequently.

Limitations of NB-IoT

NB-IoT is well suited for low-power, fixed-location IoT applications, but like any technology, it comes with trade-offs that need to be considered during planning.

• Low data rates: NB-IoT is designed for small and infrequent data transmissions. It is not suitable for use cases that require video, large file transfers, or frequent updates.
• Latency: Typical latency ranges from 1.6 to 10 seconds. This makes it less suitable for time-sensitive or real-time applications such as emergency alerts or remote control systems.
• Limited mobility: It is best for stationary or low-movement devices. It does not support handover between cell towers, which means mobile devices may lose connection or use more power when attempting to reconnect.
• No native voice or SMS: Most NB-IoT deployments do not support SMS or VoLTE. This can limit troubleshooting options, especially when SMS is used as a fallback to reach devices in the field.
• Roaming limitations: Seamless international roaming is not widely supported. While some operators are testing roaming agreements, global NB-IoT connectivity still lags behind legacy networks.
• Firmware updates can be slow: NB-IoT’s narrow bandwidth makes over-the-air (OTA) firmware updates slower than on broadband networks. This could affect how frequently and efficiently devices can be updated in large fleets.

Com4 NB-IoT coverage

Com4 provides dedicated NB-IoT access across Europe, with strong footprints in:

• Norway and Sweden – National NB-IoT deployments from major operators, enabling coverage even in rural and indoor environments.
• Germany – Nationwide NB-IoT through partnerships with Deutsche Telekom, ensuring carrier-grade service quality.
• Pan-European support – NB-IoT coverage extended through multiple partner networks across Central and Eastern Europe.

Table 3: Com4 coverage for NB-IoT and multi-mode SIM

This dual approach ensures that IoT deployments remain future-proof and globally scalable, while still taking advantage of NB-IoT’s unique characteristics in markets where it is available.

Common Use Cases for NB-IoT

NB-IoT is ideal for applications where data traffic is low and battery efficiency is key. Some examples include:

• Smart metering: Utility meters can send daily readings without the need for constant power or technician visits. Devices installed in underground areas benefit from NB-IoT’s strong signal penetration.
• Environmental monitoring: Sensors tracking air quality, noise, or soil moisture often operate in remote or crowded areas. These sensors benefit from NB-IoT’s ability to operate for years on battery power and maintain stable connectivity in challenging locations.
• Agriculture: It supports crop monitoring and irrigation control systems in rural fields. Its long-range connectivity and power-saving features reduce the need for wired networks or frequent battery changes.
• Smart cities: From parking sensors to bin level monitors, city systems often rely on stable, low-power connectivity. NB-IoT allows these devices to function with low maintenance, supporting the long-term rollout of smart urban infrastructure.
• Building automation: Devices like smoke detectors, temperature controls, and door sensors require minimal data and long operating time. It ensures consistent performance even in areas where standard cellular signals may be weak.
• Industrial use: Factories and infrastructure sites use NB-IoT to monitor tanks, machines, or remote pipelines. It helps reduce manual inspections and supports long-term data logging in places that are hard to reach or power.
• Healthcare: Medical devices in care homes or clinics often need low-bandwidth data links with consistent uptime. NB-IoT supports these devices by offering secure and reliable connectivity without draining battery life.

Security in NB-IoT

Security is one of the most critical considerations in any IoT deployment. Many NB-IoT applications handle sensitive or business-critical data: from smart meters reporting household energy usage to industrial sensors monitoring pipelines or infrastructure. Protecting this data from interception, manipulation, or unauthorized access is essential not only for compliance but also for customer trust and operational reliability.

NB-IoT is built on the 3GPP cellular security standards, which are the same frameworks that have safeguarded mobile networks for decades. Unlike unlicensed LPWAN technologies such as LoRaWAN or Sigfox, NB-IoT benefits from operator-managed infrastructure and licensed spectrum, which provide higher levels of reliability and protection. At its core, NB-IoT uses SIM-based authentication, where each device is equipped with a unique, tamper-resistant identity. This enables strong, hardware-based authentication that prevents device spoofing or cloning. The standard also ensures mutual authentication, meaning that both the device and the network must verify each other before communication begins, effectively reducing the risk of man-in-the-middle attacks. In addition, data is encrypted during transmission, typically with 128-bit algorithms, and signaling integrity protection ensures that messages cannot be altered without detection.

The GSMA IoT Security Guidelines provide further direction for implementing best-in-class protection in IoT deployments. These guidelines recommend a layered approach to security, beginning with unique device identity management through SIM, eSIM, or iSIM technology, and extending to end-to-end encryption that secures data from the device all the way to the application server. GSMA also highlights the importance of secure lifecycle management, ensuring that devices can be safely provisioned, updated, and eventually decommissioned without introducing vulnerabilities. Regular testing and monitoring are also emphasized, since IoT deployments often run for 10 to 15 years and need to remain secure in the face of evolving threats and regulatory changes.

While the 3GPP framework provides a strong foundation, Com4 enhances NB-IoT deployments with additional layers of security tailored for enterprise and mission-critical applications. One such option is the use of Private APNs (Access Point Names), which create closed user groups within the cellular network, effectively isolating IoT devices from public internet exposure. Com4 also supports VPN and IPsec tunneling, which establish secure and encrypted channels between the customer’s backend systems and Com4’s core network. 

For organizations requiring advanced segmentation, traffic can be separated by device groups or applications, ensuring that no single compromise can affect an entire fleet. In addition, Com4 customers benefit from the possibility of implementing end-to-end encryption on the application layer, ensuring that sensitive information remains protected beyond the cellular transport level.

For customers planning NB-IoT deployments, Com4 recommends following a set of best practices to maximize security. The use of IoT-optimized SIM, eSIM, or iSIM credentials ensures that device identities remain tamper-resistant and hardware-secure. Private APNs or VPNs should be deployed whenever possible to reduce exposure to the public internet. For particularly sensitive deployments, end-to-end encryption is advised, so that even if traffic is intercepted outside the operator’s control, the information remains inaccessible. Organizations should also implement device monitoring and anomaly detection, since unusual traffic patterns can often signal an attempted compromise. Finally, it is critical to design for secure updates, ensuring that devices deployed for long lifecycles can be patched and protected against newly discovered vulnerabilities.

In summary, NB-IoT provides one of the most secure environments for IoT connectivity by leveraging the robust 3GPP cellular security framework. When combined with the GSMA’s recommended best practices and Com4’s enterprise-grade enhancements such as Private APNs, VPNs, and end-to-end encryption, enterprises gain a connectivity solution designed for the highest levels of trust and resilience. This makes Com4 NB-IoT an ideal choice for mission-critical applications where data integrity, privacy, and long-term reliability cannot be compromised.

Why Choose Com4 for NB-IoT Deployments

With more than 14 years of IoT connectivity experience, Com4 ensures NB-IoT deployments are:

• Backed by expert guidance on device selection and module compatibility.
• Supported by predictable pricing models.
• Enabled by partnerships with leading European operators for coverage and reliability.
• Future-proofed with multi-mode connectivity for international projects.

NB-IoT represents one of the most reliable and cost-effective solutions for connecting stationary, low-data IoT devices in coverage-challenged environments. Supported by GSMA-backed standards and commercial operator rollouts worldwide, it enables deep penetration, long device lifetimes, and large-scale deployments at low cost.

When combined with Com4’s multi-mode IoT SIM and global coverage, NB-IoT becomes a versatile connectivity option for industries such as utilities, agriculture, manufacturing, and smart cities.

For more details on NB-IoT and global Mobile IoT deployments, visit the GSMA’s dedicated resources on NB-IoT and the Mobile IoT Deployment Map.