RF Drive Test in Telecom: Measurements and Tools

RF drive testing is a critical process in the telecommunications industry, used to evaluate and optimize network performance. It involves collecting real-time data on signal strength, coverage, and quality using specialized tools and equipment while a technician drives along a predetermined route.

In this guide, we’ll explore what an RF drive test entails, its significance in the telecom industry, and the tools commonly used for effective measurements.

Basics of RF Drive Testing

RF drive testing is the procedure used to evaluate the performance of a wireless modem or system while in motion (usually driving). The wireless modem or system being tested may support any wireless standard, such as GSM, WCDMA, HSPA, UMTS, LTE, WiMAX, or WLAN. The test helps to perform various measurements.

RF Drive Test Measurements

RF drive test measurements may include, but are not limited to, the following:

• Dropped calls
• Handover within the same Radio Access Technology (RAT), for example, GSM to GSM.
• Handover between two RATs, for example, between GSM and WCDMA.
• Verification of different call quality levels by changing various parameters.
• RF signal strength measurement.
• Sector swapping (full or partial).
• EDGE and GPRS testing with short and long PS (Packet Switched) calls.
• Short and long duration CS (Circuit Switched) calls.
• Idle and connected mode tests.
• Checking RLC (Radio Link Control) throughput according to system requirements.

RF Drive Test Planning

For RF drive testing, a particular route and a proper SIM card with multiple or single RAT support are required. (Common RATs are GSM, WCDMA, and LTE.) GPS support is needed in the setup to track the route during the RF drive test.

RF Drive Test Setup

Below is a typical setup:

Image showing a UE (User Equipment) with an antenna connected to a laptop running RF drive test software. GPS functionality is incorporated for route tracking. An external hard drive is connected for long-term data storage.

As shown in the figure, a UE (User Equipment) with an antenna is connected to a laptop running RF drive test software. GPS functionality is incorporated to support driving along the planned route. An external hard disk is used to store large amounts of data for long duration tests to avoid data loss.

RF Drive Test Data Analysis

After acquiring the data for short and long call durations, the logs need to be analyzed by domain experts (specializing in GSM, LTE, or WCDMA) to find the root cause of any issues observed or recorded during the drive tests.

Typical problems observed can be call drops, handover failures, coverage limit issues, quality limit failures, blocked calls, and data link failures.

Engineers often use software tools like MapInfo to prepare thematic diagrams representing received signal level, dropped calls, receiver quality, blocked calls, and handover failures.

Conclusion

RF drive testing plays a vital role in enhancing network performance and user experience. By using advanced measurement tools, telecom engineers can effectively identify and address network issues, ensuring optimal connectivity for end users.

RF Drive Test Tools

• TEMS Investigation: This drive test solution is used for initial tuning, site acceptance (especially for 5G), verifying software upgrades, feature validation, and network troubleshooting.

Refer to resources on RF drive test tools for various RF tools used for RF drive testing and network optimization.