In this measurement setup, no auxiliary hardware components are involved, but instead two PCs are used, each of which has a mobile phone connected. The AQM computation is done on the PCs.

VoIP calls are controlled by the same Service Control activities as CS voice calls, and the audio quality measurement is governed by the Voice Quality activity. Everything about the Service Control mechanisms is covered in section "Voice Activities". For a comprehensive treatment of PC-based VoIP testing, including AQM, please turn to the document "VoIP Testing with TEMS Investigation PC-based Clients", found in the TEMS Investigation documentation package.

A quick overview of the measurement setup follows below:

The calling device is connected to one PC and the called device to the other. Audio is sent in semi-duplex fashion between the parties, that is, in both directions but only in one direction at a time. Each instance of TEMS Investigation has a built-in VoIP client; the VoIP clients thus reside in the PCs and not in the mobile devices.