Complete Guide to GSM, LTE, NB-IoT and GNSS Modules for IoT Projects

 

Wireless connectivity has become one of the most important requirements in modern embedded systems. Whether it is an EV charger, smart energy meter, asset tracker, agricultural monitoring system, industrial controller, vehicle telematics unit, or remote weather station, the ability to transmit data over a cellular network has made Internet of Things (IoT) solutions more practical and scalable than ever before.

Although Wi-Fi and Bluetooth are suitable for short-range communication, they depend on the availability of local infrastructure. Cellular communication, on the other hand, enables devices to remain connected over large geographical areas using mobile operator networks. This makes GSM, LTE, CAT-M1, and NB-IoT modules indispensable in applications where long-distance connectivity and remote monitoring are required.

Another increasingly common requirement in IoT systems is location tracking. For applications such as fleet management, logistics, vehicle security, and asset tracking, Global Navigation Satellite System (GNSS) receivers are integrated into cellular modules to provide accurate positioning data.

Today, manufacturers offer a wide variety of communication modules ranging from legacy 2G GSM devices to advanced LTE Cat-4 modules capable of high-speed internet access. Choosing the right module depends on factors such as network availability, power consumption, cost, data rate, ease of development, and future network support.

This article provides a comprehensive comparison of the most popular cellular modules available for IoT development, discussing their features, advantages, disadvantages, ease of use, and practical applications.

 

Understanding Cellular Technologies

Before selecting a module, it is important to understand the different cellular technologies currently available. Below is the list of common technologies available over time. The most common technologies include:

·         GSM (2G)

·         GPRS

·         EDGE

·         LTE Cat-1

·         LTE Cat-4

·         LTE Cat-M1

·         NB-IoT

·         GNSS

Each technology is designed for different communication requirements.

 

GSM (2G)

GSM remains one of the easiest technologies for beginners because it supports SMS, Voice Calls, GPRS Internet, TCP/IP Communication, HTTP and FTP.

Modules such as the SIM800 series became extremely popular due to their low cost and simple AT command interface. However, many countries have already started shutting down 2G networks, making GSM unsuitable for new long-term commercial products.

 

LTE Technologies

LTE provides much higher communication speed and improved network coverage.

Different LTE categories exist like

·         LTE Cat-1

·         LTE Cat-4

·         LTE Cat-M1

·         LTE Cat-6

For IoT applications, Cat-1 and Cat-M1 are the most widely used.

 

NB-IoT

Narrowband IoT is specifically designed for battery-operated devices transmitting small amounts of data. Its advantages includes:

·         Extremely low power consumption

·         Excellent indoor coverage

·         Long battery life

·         Lower communication cost

It is ideal for Smart meters, Agriculture, Water monitoring and Environmental sensors.

 

GNSS

GNSS refers to satellite navigation systems such as:

·         GPS

·         GLONASS

·         Galileo

·         BeiDou

·         QZSS

Many modern cellular modules include integrated GNSS receivers, eliminating the need for a separate GPS module.

 

Major Cellular Module Manufacturers

The IoT market is dominated by several manufacturers.

These include:

·         SIMCom

·         Quectel

·         u-blox

·         Fibocom

·         Ai-Thinker

·         Neoway

·         Telit

·         Sierra Wireless

Each manufacturer offers products targeting different applications.

 

SIMCom Modules

SIMCom is perhaps the most popular manufacturer among hobbyists and embedded developers. Its modules are inexpensive, well documented, and supported by numerous Arduino and ESP32 libraries.

Popular products from SIMCom include:

SIM800L

Technology:

·         GSM/GPRS (2G)

Features:

·         SMS

·         Voice

·         GPRS

·         TCP/IP

Advantages:

·         Extremely inexpensive

·         Huge online community

·         Easy AT commands

·         Ideal for beginners

Disadvantages:

·         2G network shutdown in many countries

·         Limited internet speed

Applications:

·         Home automation

·         SMS alert systems

·         Remote switching

Ease of Use:

★★★★★

Availability:

★★★★★

 

SIM900A

Although older, the SIM900A is still widely used for educational projects.

Advantages:

·         Very low cost

·         Excellent documentation

Disadvantages:

·         Regional network limitations

·         Legacy technology

 

SIM7600 Series

The SIM7600 series represents one of the most versatile LTE modules available today.

Supports:

·         LTE Cat-4

·         GSM fallback

·         GNSS

·         Voice

·         USB

·         TCP/IP

·         MQTT

·         HTTPS

Advantages:

·         Integrated GPS

·         High-speed internet

·         Excellent software support

Disadvantages:

·         Higher power consumption

·         More expensive than GSM modules

Ideal Applications:

·         Vehicle tracking

·         Industrial gateways

·         EV chargers

·         Video transmission

Ease of Use:

★★★★☆

Availability:

★★★★★

 

SIM7670 Series

A newer LTE Cat-1 module designed for modern IoT devices.

Advantages:

·         Lower power than Cat-4

·         Better future support

·         Compact size

Recommended for new designs.

 

Quectel Modules

Quectel is one of the world’s largest IoT module manufacturers. Its products are widely used in industrial equipment.

Popular modules include:

EC200U

Technology:

·         LTE Cat-1

Advantages:

·         Excellent India support

·         Stable firmware

·         Industrial reliability

Applications:

·         Smart POS

·         Industrial automation

·         Energy monitoring

Ease of Use:

★★★★☆

Availability:

★★★★★

 

EC25

One of the industry’s most popular LTE Cat-4 modules.

Supports:

·         GNSS

·         USB

·         PPP

·         MQTT

·         HTTPS

Advantages:

·         Industrial-grade quality

·         Extensive documentation

Disadvantages:

·         Slightly expensive

 

BG95

Technology:

·         LTE Cat-M1

·         NB-IoT

·         GNSS

Advantages:

·         Ultra-low power

·         Battery-operated applications

Applications:

·         Smart agriculture

·         Asset tracking

·         Water meters

 

BG96

One of the most widely deployed NB-IoT modules.

Supports:

·         LTE-M

·         NB-IoT

·         GNSS

Excellent for commercial IoT products.

 

u-blox Modules

u-blox is known for high-quality industrial modules.

Popular products:

·         SARA-R4

·         LARA-R6

·         TOBY-L4

Advantages:

·         Excellent firmware

·         Industrial certifications

·         High reliability

Disadvantages:

·         Higher cost

Used extensively in:

·         Automotive

·         Medical equipment

·         Industrial automation

 

Fibocom Modules

Fibocom modules are gaining popularity because of their competitive pricing.

Popular modules include:

·         L610

·         NL668

Applications:

·         Smart terminals

·         Industrial IoT

·         Retail automation

 

Ai-Thinker Modules

Ai-Thinker manufactures affordable IoT modules.

Examples include:

·         A9G

Features:

·         GSM

·         GPRS

·         GPS

Advantages:

·         Low cost

·         Integrated GPS

Disadvantages:

·         Limited documentation

Suitable for educational projects.

 

Modules with Integrated GNSS

If your application requires location tracking, choosing a module with built-in GNSS significantly simplifies the hardware design.

Popular integrated GNSS modules include:

·         SIM7600

·         BG95

·         BG96

·         EC25

·         A9G

Advantages:

·         One antenna connector for cellular and one for GNSS

·         Reduced PCB area

·         Lower BOM cost

·         Simplified software

 

Comparison Table

Module	Network	GNSS	Voice	Power Consumption	Ease of Use	Availability	Recommended For
SIM800L	2G	No	Yes	Medium	★★★★★	★★★★★	Learning GSM
SIM900A	2G	No	Yes	Medium	★★★★★	★★★★☆	Educational Projects
SIM7600	LTE Cat-4	Yes	Yes	High	★★★★☆	★★★★★	Industrial IoT
SIM7670	LTE Cat-1	Optional	Yes	Medium	★★★★☆	★★★★☆	Modern IoT
EC200U	LTE Cat-1	Optional	Yes	Medium	★★★★☆	★★★★★	Commercial Products
EC25	LTE Cat-4	Yes	Yes	High	★★★★☆	★★★★★	Vehicle Tracking
BG95	LTE-M/NB-IoT	Yes	No	Very Low	★★★☆☆	★★★★☆	Battery Devices
BG96	LTE-M/NB-IoT	Yes	No	Very Low	★★★☆☆	★★★★☆	Smart Metering
SARA-R4	LTE-M	Optional	No	Low	★★★★☆	★★★★☆	Industrial Applications
A9G	GSM	Yes	Yes	Medium	★★★☆☆	★★★☆☆	Student Projects

 

Choosing the Right Module

For beginners:

Choose SIM800L if a 2G network is still available in your deployment region and the project is for learning or prototyping.

For modern commercial products:

Choose LTE Cat-1 modules such as SIM7670 or EC200U, which offer a good balance between cost, performance, and long-term network support.

For industrial gateways and applications requiring higher bandwidth:

The SIM7600 or EC25 are excellent choices because they support high-speed LTE, GNSS, voice, and advanced networking protocols.

For battery-operated sensors that send small amounts of data:

Modules such as BG95 and BG96 are ideal because they support LTE-M and NB-IoT with very low power consumption.

For fleet management and asset tracking:

Select a module with integrated GNSS, such as SIM7600, EC25, or BG95, to reduce hardware complexity and improve positioning accuracy.

 

Advantages of Cellular Modules

Cellular modules provide several benefits:

·         Long-range communication

·         No dependence on local Wi-Fi

·         Support for SMS and data services

·         Global network availability

·         Secure communication using TCP/IP, MQTT, and HTTPS

·         Easy integration with cloud platforms

 

Limitations

Despite their advantages, cellular modules also have some drawbacks:

·         SIM card requirement

·         Network subscription costs

·         Higher power consumption than short-range wireless technologies

·         RF design considerations

·         Cellular certification requirements for commercial products

 

Future Trends

The IoT industry is rapidly transitioning away from legacy 2G networks toward LTE Cat-1, LTE-M, and NB-IoT. These technologies provide improved coverage, lower power consumption, and better long-term support.

Designers starting new projects should avoid selecting 2G-only modules unless they are certain that the target deployment region will continue to support GSM services for the expected product lifetime.

 

Conclusion

Selecting the appropriate cellular module is one of the most important decisions in an IoT project. While GSM modules such as the SIM800L remain popular for educational purposes due to their simplicity and low cost, modern commercial designs increasingly rely on LTE Cat-1, LTE Cat-4, LTE-M, and NB-IoT modules for their superior performance and future network compatibility.

When location tracking is required, choosing a module with integrated GNSS simplifies both hardware and firmware development. For developers beginning with IoT, starting with a simple GSM module can be an excellent learning experience, but for products intended for long-term deployment, investing in a modern LTE-based solution is strongly recommended.