TEMS Investigation

TEMS Investigation is one of the long-standing workhorses of drive and walk testing — originally an Ericsson product, now under Infovista. You connect supported test phones and scanners to a laptop running it, and it gives you a live, on-screen view of what each device sees as you move: RSRP, RSRQ, SINR, throughput, plus the decoded RRC and NAS signalling so you can watch attaches, handovers, and drops happen in real time rather than only in post-processing.

Two things make it a field staple. First, the live view — being able to see a handover fail or SINR collapse as it happens on the route lets you react and re-test on the spot. Second, the device support: vendors put effort into chipset access so you get layer-3 messages and detailed metrics that a normal handset won't expose. The logfiles it produces then feed into analysis tools (TEMS Discovery and others) for the heavier post-processing. One operational catch to plan for: the supported-device list moves with the software version, so a brand-new handset or a fresh band may not be loggable until TEMS catches up — check compatibility before you build a campaign around a specific phone. What to do with the logs afterwards — and the parsers that read vendor exports directly — is covered in the 5G drive test guide.