In the IIoT field, the stability and reliability of data transmission are crucial. As a wireless data terminal for the Internet of Things, the cellular modems plays a key role in transmitting remote device data to the data center through wireless networks. However, there are manycellular modemsproducts on the market, how to judge which product is trustworthy?

1. Overview and importance of cellular modems

Cellular modems is a device that uses public operator networks to provide users with wireless long-distance data transmission capabilities. It uses high-performance industrial-grade communication processors and industrial-grade wireless modules, and is widely used in remote monitoring, data collection, automation control, and other scenarios. In the industrial Internet of Things, the stability of thecellular modemsis directly related to the continuity and accuracy of data transmission, which in turn affects the operational efficiency and decision-making quality of the entire system.

2. Introduction to USR-G771 product

USR-G771 is a high-performancecellular modemslaunched by the PUSR brand. It is equipped with a Cat-1 network and supports 10Mbps download and 5Mbps upload rates, which can meet 80% of data transmission application scenarios. In addition, USR-G771 also has the characteristics of low latency, multi-standard, wide coverage, and no need for special cards. It supports network transparent transmission, KEEPALIVE mechanism, and multiple parameter setting methods, providing strong support for industrial IoT applications.

3. Cellular modemsstability and reliability testing methods

● Online idle test
Test purpose:
To verify the ability ofcellular modemsto maintain the established link when there is no data transmission.

Test method:
Connectcellular modemsto the data center and observe how long it can maintain the link without sending any data. USR-G771 should be able to maintain an average link duration of at least 1 hour without disconnection or reconnection.

Judgment criteria: 

At the end of the test, send several data packets to the data center andcellular modemsto verify whether the idle link is truly available.

● Signal recovery test

Test purpose: To verify the rapid recovery capability ofcellular modemsafter data center recovery.
Test method: Shut down the data center for a short period of time, such as 1 minute, and then restore it to observe whether the USR-G771 can quickly connect.

Judgment criteria: The recovery time should be within 5 minutes, and after repeated testing, the USR-G771 must be able to restore the connection 100% of the time.

● Frequent small data packet receiving and transmitting test

Test purpose: to verify the ability ofcellular modemsto frequently send and receive small data packets.
Test method: In the data center and on the USR-G771 side, send a data packet of approximately 100 bytes to each other every 10 seconds for 10 minutes.

Judgment criteria: Determine whether the statistical network has disconnection or data packet loss. The best result is that there is no disconnection or reconnection, and no data packets are lost.

● Stress test of large data volume

Test purpose: To verify the stability and reliability ofcellular modemsin large data transmission.
Test method: In the data center and the USR-G771 terminal, a data packet of about 1000 bytes is sent to each other every 2 seconds for 30 minutes.

Judgment criteria: whether there are network disconnections and packet losses in statistics. Generally speaking, the number of disconnection and reconnection should not exceed 10 times, and the smaller the number, the better.

● Go to antenna test

Test purpose: To verify the automatic recovery ability ofcellular modemsafter temporary signal interruption.
Test method: Unplug the antenna of USR-G771 to simulate signal interruption, and then observe whether it can automatically connect after the signal returns to normal.
Judgment criteria: USR-G771 should automatically reconnect after the signal is restored.

The performance of USR-G771 in practical applications

The USR-G771 has been widely used in the industrial IoT field due to its excellent stability and reliability. For example, in scenarios such as remote sewage site monitoring and distribution automation station terminals, USR-G771 can stably transmit remote data to the monitoring center through 4G networks, providing real-time and accurate data support for decision makers. At the same time, USR-G771 also supports multiple parameter setting methods and indicator light status judgment, which facilitates user configuration and troubleshooting of the device.

In the field of industrial Internet of Things, the stability and reliability ofcellular modemsare important indicators to measure its performance. Through online idle testing, signal recovery testing, frequent small packet transmission and reception testing, large data volume stress testing, and antenna removal testing, we can comprehensively evaluate the performance of thecellular modems. As a high-performancecellular modemsproduct, USR-G771 has demonstrated excellent stability and reliability in practical applications, providing strong support for industrial IoT applications. In the future, with the continuous development of industrial IoT technology, we believe that high-performancecellular modemsproducts such as USR-G771 will play an important role in more fields and promote the in-depth development of industrial IoT applications.