Optimizing Your GSM Network - Using Drive Testing to Estimate Downlink Speech Quality
Drive test notes--Golden Rules for collecting Data during drive test - Introduction--
This application note is a guide to understanding the air interface quality parameters of GSM (global system for mobile communications) networks and their relationship to downlink speech quality. These parameters are first defined and then the impact of network settings on their values is examined. Finally, the note shows which
parameters and methods are best for estimating the speech quality of a GSM network under different operation conditions. Tools and methods for estimating uplink speech quality are not covered in this note. Also not covered are the basics of GSM technology; for information on this topic please refer to Application Note 1344, Using Drive Testing to Troubleshoot Coverage, Interference, Handover Margin, and Neighbor Lists (literature number, 5980-0218E).
The measurements described in this note are made using phone-based drive test tools that measure air interface parameters (figure 1) instead of specialized MOS scoring systems. (Refer to the ‘Product Literature’ section at the end of this document for more information on automated uplink and downlink voice quality MOS-scoring solutions from Agilent.)