Efficient evaluation of voice quality in GERAN (GSM EDGE Radio Access Network)

The transport of multimedia application is now a key feature of the future radio access networks. The evolution of GSM networks is also able in principle to take benefit from end-to-end transfer of such applications. However, careful attention has to be taken regarding the quality perceived by the end user. Indeed, for voice services, mobile subscribers are familiar with a given quality. The introduction of IP services should not decrease this quality. Besides, the introduction of such feature on the radio links should also enable the operators to increase their network capacity. In this context, this paper analyses the perceived voice quality when voice frames are transported on existing packet radio bearers of GSM/EDGE Radio Access Networks. In this situation, the benefit for the operator should be maximal. The quality is evaluated with an objective method that relies on comparison of reference speech sequence with the same sequence that is passed through GERAN radio links. This methodology of evaluation if by far more consistent than simply considering radio link level performance like the bit error rate