All PPM data is sent to one location in the Nielsen organization for all 48 PPM markets.
Each meter gets docked "at home" for recharging and data collection. Currently, it uses Telco lines to send data back to the home base, using the charger as a data collection point. The data shows the encoder number and the codes recorded throughout the period from the last upload.
New meters, soon to be rolled out, don't need to be docked as they can upload the data themselves and only need periodic charging:
After years of development and lab testing, Nielsen is finally ready to take its sleek, lightweight wearable PPM devices out for a test spin with real ratings panelists. In what
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This has been delayed by the pandemic and the shortage of specialized CPUs for such devices.
In any case, every stream, AM, FM, LPFM, translator, etc., is encoded with a unique code. No matter where the meter is, it registers the codes of the stations it hears and saves them.
The purpose of ratings is to show what residents of each metro hear or listen to, no matter where they are. In the diary, you only participated for a week. But with the PPM, a person may be on the panel more than 2 years. During that time they may be away from home many times, registering stations heard on vacation or on work-related trips.