Terminals used for MTSI shall conform to the minimum performance requirements on the acoustic characteristics of 3G terminals specified in TS 26.131. The codec modes and source control rate operation (DTX) settings shall be as specified in TS 26.132. Furthermore, the test point (Point-of-Interconnect (POI)) specified in TS 26.131 shall be a reference terminal capable of receiving digital speech data at the send side and producing a digital output of the received signal (see Figure 11.1). During the testing, the radio conditions should be error free and the jitter and packet loss in the IP transport shall be kept to a minimum.