Abstract: Methods and systems for estimating Supervisory Audio Tone (SAT) strength during data transfer and for a short time period thereafter. The SAT during this period is regarded as being identical to the strength measured just before the data transfer was started. In an alternative embodiment, a probabilistic algorithm can be used wherein previous measurements are used to predict the SAT strength during and for a period after data transfer. Where the present invention is used in a mobile radio telecommunications system of the type in which analog information is transmitted between at least one base station and a number of mobile stations, a method for supervising the quality of a connection between the base station and a mobile station includes transmitting data between the base station and the mobile station during which a SAT is not transmitted and using pre-data transfer SAT measurement for radio transmission quality supervision during at least a time period of said data transmitting step.

Abstract: Methods and systems allowing for the following two Supervisory Audio Tone-Signalling Tone (SAT-ST) qualifications: (1) when detecting a ST as being on, the signalling tone signal is accepted if the SAT strength value indicates that the SAT is on, in accordance with the IS-54-B standard; and (2) when detecting the ST as being on and a momentary or instantaneous SAT strength value indicates that the SAT is off, the signalling tone signal is not accepted at this stage. However, should the instantaneous SAT strength subsequently be detected as being on while the signalling tone is still on, the signalling tone signal is accepted, which is a deviation from the IS-54-B standard. In one embodiment, the measurements of the ST duration are not started until SAT and ST both on.