The GSM (Global System for Mobile Communications) cellular network provides a simple and reliable feedback channel for transmitting data from measuring devices being used in the field.
The TV usage measuring box Audience Tracker AT08 also relies on GSM technology, making complicated WLAN connection password setups or high support costs to remedy error-prone household telephone lines a thing of the past.
Modern energy-efficient GSM modules even allow for mobile use without a plug-in power supply, for instance to track car radio usage. Modern Smartphones, run with software applications like Mobility Tracker or Audience Tracker Mobile make the out-of-home use of market research tools possible. The SIM chips utilized are simple to swap out but well-protected against abuse. Today's low cellular rates for machine-to-machine communication are meanwhile helping to lower costs even further.