When discussing the device ecosystem, particularly for cellular connectivity, it’s essential to understand the key components involved—modems and modules—because each plays a critical role in the functionality and performance of connected devices. Let’s explore the differences between them and their respective roles in the ecosystem.
Modems
A modem, short for modulator-demodulator, is a device that converts digital data from a computer or other device into a format suitable for a transmission medium and vice versa. In the context of cellular connectivity, modems are responsible for enabling communication over cellular networks.
Examples of Cellular Modems
- Sony: Known for its high-performance LTE and 5G modems, Sony provides reliable solutions for various IoT applications.
- Qualcomm: A leader in cellular technology, Qualcomm’s modems support advanced features like multi-gigabit LTE, 5G NR, and global multi-mode compatibility.
- Nordic Semiconductor: Specializes in low-power LTE-M and NB-IoT modems, ideal for IoT applications requiring extended battery life and reliable connectivity.
Band Support: Global, Regional, and Carrier-Specific
Each modem supports different frequency bands, which determine where and how the device can connect to cellular networks. Understanding band support is essential to ensure a device can operate effectively in its intended environment.
- Global Modems: These modems support a wide range of bands that are used worldwide, making them suitable for devices that need to operate in multiple countries, making them ideal for global IoT deployments.
- Regional Modems: These modems support bands specific to certain regions, such as North America, Europe, or Asia, and are optimized for performance and compliance within those regions.
- Carrier-Specific Modems: Some modems are designed to support the bands used by specific carriers. These modems ensure optimal performance and compatibility with the carrier’s network, often required for carrier certification.
Understanding the band support of a modem helps you select the right modem for your application—whether it needs to work globally, in a specific region, or with a particular carrier.
Modules
A module is a pre-assembled unit containing a modem along with additional components such as memory, power management, and sometimes even an application processor. Modules simplify the integration process for device manufacturers, since they are pre-certified and tested, reducing the time and effort required for development.
Examples of Cellular Modules
- Telit: Offers a wide range of modules supporting various cellular technologies, from 2G to 5G, with a focus on IoT and M2M (machine-to-machine) communication.
- Sierra Wireless: Known for its robust and reliable modules, Sierra Wireless provides solutions for industrial, automotive, and consumer IoT applications.
- Murata: Provides compact and high-performance modules suitable for applications where space and power consumption are critical factors.
- u-blox: Offers versatile modules that support a broad range of cellular technologies, with a focus on positioning and wireless communication.
- Quectel: Known for its extensive portfolio of cellular modules, Quectel caters to a wide range of applications, from automotive to smart metering and beyond.
Understanding IMEI
The International Mobile Equipment Identity (IMEI) is a unique, 15-digit identifier assigned to each cellular device that ensures devices connect securely and reliably. Since IMEIs are structured depending on the module, and are critical for identifying and tracking devices on cellular networks, it’s important to understand how they’re formed.
Structure of IMEI
- TAC (Type Allocation Code): The first eight digits of the IMEI, which identify the manufacturer and model of the device.
- Serial Number (SNR): The next six digits, which are unique to each device.
- Check Digit (CD): The final digit, used for error-checking.
Example: Decoding a Murata IMEI Consider the IMEI: 351521106948474.
- TAC (Type Allocation Code): 35152110
- This code identifies the manufacturer and model of the device. For instance, 35152110 is assigned to Murata.
- SNR (Serial Number): 694847
- This is a unique number assigned to each individual device by the manufacturer.
- CD (Check Digit): 4
- This digit is used to verify the integrity of the IMEI.
Integrating Components on the Printed Circuit Board
A significant part of developing a cellular-connected product involves embedding the module, SIM card, and antenna onto the Printed Circuit Board (PCB). The PCB supports various components necessary for the device’s operation:
- Module Integration: The module, containing the modem and additional components, is mounted onto the PCB, allowing it to interface with other parts of the device, such as sensors, processors, and power management units.
- SIM Card: The SIM card slot is also integrated onto the PCB, providing the necessary interface for network authentication and connectivity.
- Antenna: The antenna, crucial for signal transmission and reception, is embedded or connected to the PCB in a manner that optimizes performance and minimizes interference.
- Power Management: The PCB includes circuits for managing power distribution, ensuring that all components receive the appropriate voltage and current. This includes connections to the device’s battery or external power supply.
- Switches and Buttons: Input devices like switches and buttons are mounted on the PCB and connected to the control circuitry, allowing users to interact with the device.
- LEDs and Lights: LEDs and other light indicators are embedded on the PCB to provide visual feedback to the user. These can indicate power status, connectivity, notifications, and more.
- Displays: Screens or displays, such as LCDs or OLEDs, are connected to the PCB, providing a user interface for the device. The PCB includes the necessary connectors and drivers to control the display.
- Sensors: Various sensors, such as temperature, humidity, motion, and more, can be integrated onto the PCB. These sensors provide data to the device, enabling it to perform specific functions or respond to environmental changes.
- Communication Interfaces: The PCB includes interfaces for additional communication methods, such as USB, Bluetooth, Wi-Fi, and others, allowing the device to connect and interact with other devices or networks.
Certification: Ensuring Compliance and Performance
Before a cellular device can be deployed, it must undergo various certifications to ensure it meets regulatory and performance standards. These certifications verify that the device can operate safely and effectively on cellular networks worldwide.
FCC Certification
The Federal Communications Commission (FCC) certification is required for any electronic device intended to be sold or used in the United States. This certification ensures that the device complies with the FCC’s regulations for radio frequency (RF) emissions, which are designed to prevent interference with other electronic devices and communication systems.
CE Certification
The CE (Conformité Européenne) mark is mandatory for products sold within the European Economic Area (EEA). It indicates that the device meets the EU’s safety, health, and environmental protection requirements. For cellular devices, this often includes compliance with the Radio Equipment Directive (RED).
Carrier Certification
In addition to regulatory certifications, many cellular devices must also obtain carrier certification from mobile network operators. This certification process ensures that the device can operate reliably on the carrier’s network and complies with their specific technical requirements. Each carrier has its own certification process, which can vary significantly in complexity and duration.
Monogoto Support
Monogoto is here to help customers navigate the carrier certification process by conducting audits and providing the necessary guidance to guarantee compliance and successful certification. This support can streamline the certification process, reducing your project’s time to market.
