Signal testing matters. Choosing the wrong operator, positioning an antenna incorrectly, or leaving a router configured with default settings are mistakes that generate support calls, repeat site visits and unhappy customers. Getting it right requires accurate data at the point of installation. The problem is that the tools available to most installers make accurate data difficult to obtain.
The 4G ceiling
The most widely used handheld signal testers were designed when 4G LTE was the leading cellular technology. They report 2G, 3G and 4G signal strength. They do not support 5G NR, 5G SA, NB-IoT, LTE Cat-M or 5G RedCap.
EE, Vodafone, Three and O2 all have live 5G SA networks covering significant portions of the UK. NB-IoT is the dominant technology for smart metering and low-power sensor deployments. 5G RedCap (Release 17) is entering the market for mid-tier IoT devices. An installer using a 4G-only tester has no visibility of the technology their router is actually connecting on or what the 5G signal quality looks like at the site.
The wrong modem problem
Handheld signal testers contain their own cellular modem. That modem is different from the modem in the router being installed. Different antenna, different chipset, different radio performance characteristics.
A reading from a handheld tester tells you what signal is available to that device, held in that orientation, at that moment. It does not tell you what signal the installed router will receive with its antenna mounted in its final position. The data is indicative at best. An installation decision made on indicative data is a guess made with extra steps.
No speed testing
Most signal testers report signal strength metrics - RSRP, RSSI, sometimes SINR. Very few run speed tests. None run speed tests on multiple operators automatically.
Signal strength is a necessary but not sufficient indicator of network performance. Two sites can have identical RSRP and very different throughput depending on cell loading, interference, and the modulation scheme in use. For applications with minimum bandwidth requirements - CCTV, video telemetry, industrial data logging - a speed test is the only way to confirm the network can support the application.
No documentation
Signal testers store readings internally or export to CSV via USB. Generating a professional commissioning record requires manual effort - transcribing readings, creating a document, printing or emailing it.
A commissioning certificate is proof of quality at the time of installation. If signal performance degrades six months after installation, a certificate establishes what was measured at commissioning and whether the issue is with the installation or the network. Without documentation, the installer has no protection and the customer has no baseline.
Cost and accessibility
5G-capable signal analysers with full feature sets exist. They cost thousands of pounds. That price point is viable for network operators and large enterprises. It is not viable for most IoT installation businesses.
The result is that most IoT and CCTV installers are making installation decisions with tools that do not match the technology being deployed, using hardware that does not represent what is being installed, and producing no documentation that proves the work was done correctly.