7 Simple Steps: Field Guide to Drive Test Analysis

Drive testing is a method used by telecommunication operators to measure and analyze the coverage, capacity, and Quality of Service (QoS) of a mobile network in a specific geographical area. The term 'drive test' comes from the fact that engineers literally drive a vehicle equipped with specialized measurement receivers, test phones, and GPS devices along selected roads to collect radio frequency (RF) data in real time.

During a drive test, the equipment continuously performs voice calls, web browsing sessions, and file transfers to simulate real-world subscriber behavior. At the same time, it records radio metrics such as Reference Signal Received Power (RSRP), Signal-to-Interference-plus-Noise Ratio (SINR), block error rates, and Layer 3 signaling messages. These measurements help RF engineers identify network issues like coverage holes, weak coverage boundaries, pilot pollution, and call drops.

For beginners, the most important aspect of drive testing is understanding the hardware and software stack. Typically, a drive test kit consists of multiple smartphones connected to software like TEMS Investigation, Nemo Outdoor, or Rohde & Schwarz ROMES. The phones are locked to specific frequencies or technologies (like 4G LTE or 5G NR) to capture raw radio layers. A GPS receiver tracks the vehicle's exact latitude and longitude, allowing engineers to map the radio signal strength across a visual map (often represented by green, yellow, and red dots).

Once the drive test is complete, the collected log files are loaded into post-processing software like TEMS Discovery or Actix Analyzer. RF Optimization Engineers analyze this data to troubleshoot specific failures. For example, if a call drops at a certain intersection, the engineer examines the Layer 3 signaling log (e.g. check for missing neighbor definitions, delayed handover commands, or sudden increases in uplink interference). Based on these findings, they adjust physical antenna parameters (tilt and azimuth) or logical radio settings to resolve the problem.