03.503GPPTransmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) systemTS
3.13.1 Near and far end crosstalk
The near end or far end crosstalk ratio between two complete PLMN connections should not be less than 65 dB.
3.13.2 Go/return crosstalk
The crosstalk ratio between the go and return channels of a single PLMN connection should not be less than 55 dB. This is to avoid nullifying the effect of the electrical echo canceller at the MSC. The requirement applies for an acoustic input signal at the MRP with a measurement being made at the UPCMI in the opposite direction of transmission.