Selection Guide for Cellular Modems: From Scenario Requirements to Professional Solutions, PUSR Provides Precise Matching

What is the Function of a Cellular Modem?

As the core hub of the Internet of Things (IoT) and industrial automation, a cellular modem (data transmission unit) holds its core value in breaking down data silos and achieving efficient collaboration between devices and the cloud. Taking a chemical industrial park as an example, by deploying the USR-DR154-E rail-mounted cellular modem, data from over 200 pressure sensors, thermometers, and other devices within the park can be collected in real-time and transmitted to a monitoring platform. Managers can view key parameters such as pipeline network pressure and storage tank temperature via their mobile phones. When the temperature of a certain storage tank exceeds a threshold, the cellular modem immediately triggers an SMS alarm and simultaneously activates the sprinkler system to automatically cool down, preventing accidents. This closed loop of "sensing - transmission - decision-making - execution" is precisely the core value of a cellular modem.

From a technical perspective, a cellular modem needs to possess three key capabilities:

• Protocol Conversion: Support industrial protocols such as Modbus and MQTT, and be compatible with devices like PLCs and sensors.
• Data Transparent Transmission: Convert serial port data into IP data to achieve seamless connection between devices and the cloud.
• Edge Computing: Complete data preprocessing locally to reduce cloud load and improve response speed.
  For example, the USR-G786 4G cellular modem has built-in data filtering rules that can automatically eliminate outliers and only upload valid data to the platform, reducing traffic costs while enhancing data quality.

Who Needs a Cellular Modem?

The application scenarios of cellular modems cover four major fields: "energy, manufacturing, environmental protection, and transportation," with specific requirements as follows:

• Energy Industry: Power grid monitoring, oil and gas pipeline inspection, and photovoltaic power plant operation and maintenance. For instance, an oil field achieved real-time monitoring of pumping unit status through the USR-DR771-E Cat-1 cellular modem, reducing fault diagnosis time from 2 hours to 10 minutes.
• Smart Manufacturing: Industrial automation, assembly line monitoring, and equipment predictive maintenance. A car factory adopted the USR-DR504 rail-mounted 4G LTE cellular modem to connect over 100 AGV (Automated Guided Vehicle) trolleys, enabling path planning and task scheduling, and improving production efficiency by 15%.
• Environmental Monitoring: Water quality monitoring, air quality monitoring, and noise pollution warning. An environmental protection bureau collected river water level data through the USR-DR154-E, combined it with AI algorithms to predict the risk of waterlogging, and scheduled drainage equipment in advance.
• Smart Transportation: Intelligent streetlight control, traffic signal optimization, and shared parking space management. A city connected 5,000 streetlights through the USR-G786 4G cellular modem, achieving on-demand lighting and saving 30% of annual electricity consumption.

What Scenarios Are 4G Cellular Modems and Cat-1 Cellular Modems Suitable for, Respectively? What Are Their Advantages and Disadvantages?

4G Cellular Modems: High-Speed and Stable, Suitable for High Real-Time Scenarios

Typical Scenarios: Video surveillance, remote control, and large data transmission. For example, a logistics warehouse connected high-definition cameras through the USR-G786 4G cellular modem to monitor cargo stacking in real-time and trigger alarms immediately when cargo topples over.

Advantages:

• High Speed: The theoretical downlink rate reaches 150Mbps, meeting the demand for high-definition video transmission.
• Low Latency: The end-to-end latency is less than 50ms, suitable for remote control scenarios.
• Wide Coverage: Relying on operator networks, it has a wide signal coverage range.

Limitations: High power consumption (approximately 3W under full load), requiring continuous power supply; and higher cost compared to Cat-1.

Cat-1 Cellular Modems: Low Power Consumption and Low Cost, Suitable for Small Data Volume Scenarios

Typical Scenarios: Environmental monitoring, equipment status reporting, and smart electricity meters. For example, an agricultural greenhouse collected soil moisture data through the USR-DR771-E Cat-1 cellular modem, uploading only 10 records per day, with an annual traffic cost of less than 10 yuan.

Advantages:

• Low Power Consumption: The sleep current is less than 1mA, suitable for solar-powered scenarios.
• Low Cost: The module price is 30% lower than that of 4G, and the data plan is more flexible.
• Long Battery Life: The built-in battery can support continuous device operation for more than 3 years.

Limitations: The uplink rate is only 5Mbps, not suitable for video transmission; and the signal coverage is weaker than that of 4G.

How to Select a Cellular Modem from PUSR

PUSR provides a "scenario-based selection tool" that allows users to precisely match their needs through the following steps:

Clarify Communication Requirements:

• If high-speed transmission (such as video surveillance) is required, choose the USR-G786 4G cellular modem.
• If low-cost and long battery life are required (such as environmental monitoring), choose the USR-DR771-E Cat-1 cellular modem.
• If compact installation is required (such as inside distribution cabinets), choose the USR-DR154-E rail-mounted cellular modem.
• If multi-network redundancy is required (such as monitoring critical equipment), choose the USR-DR504 rail-mounted 4G LTE cellular modem.

Evaluate Interface Types:

• Sensor Interface: The USR-DR154-E supports RS485/RS232/TTL, compatible with most industrial devices.
• Control Interface: The USR-G786 provides 2 DO (Digital Output) channels, which can directly link to alarms.
• Storage Expansion: The USR-DR504 supports TF card storage, which can cache data when the network is interrupted.

Consider Environmental Adaptability:

• Wide Temperature Design: The USR-DR771-E has an operating temperature range of -40℃ to 85℃, suitable for cold regions in the north.
• Lightning Protection and Moisture Resistance: The USR-DR504 has passed IP65 protection certification and can withstand heavy rain.
• Electromagnetic Compatibility: The USR-G786 has passed CE/FCC certification and is suitable for strong electromagnetic environments.

Submit the Form to Obtain Expert Consultation

If you still have questions about the selection, you can click here to submit a requirement form, and the PUSR technical team will contact you within 2 hours to provide:

• A free scenario analysis report;
• A customized networking solution;
• Device compatibility testing services.

The selection of a cellular modem is not only a technical decision but also a long-term investment in production efficiency and safety. With the philosophy of "scenario-driven and technology-empowered," PUSR helps you build reliable and efficient IoT infrastructure.