14 Receiver In this clause on receiver measurements, the procedures to test equipment which is fitted with a permanent antenna connector, and the procedures to test equipment which is designed to only be used with an integral antenna, are in bined into one single test description. Tests on Mobile Stations fitted with an integral antenna and having no means of connecting an external antenna are specified in terms of received field strength. In order to perform tests on such Mobile Stations without the need for separated access to a calibrated test site a temporary antenna connector is used as defined in annex 1 subclause (General Conditions). In practice the temporary antenna connector may be used for transmitter measurements described in clause 3, but the calibration factors determined in annex 1 will not be directly usable. The detailed calibration, when needed, for transmission tests are described in the relevant subclauses of 3. Wherever in this subclause, for H tests, the SS is required to send a Layer 3 message not requiring a Layer 3 response from the MS the message can be a TEST INTERFACE message or a STATUS message, possibly with an unknown Protocol Discriminator. Testing philosophy Certain assumptions concerning the functional mechanisms of GSM receivers have been made in order to define tests that will verify the receiver performance without excessive redundancy and excessive test times. The receiver functions can be divided into: - Analogue RF and IF stages that are affected by input levels, temperature and power supply levels. - Demodulator that is affected by input levels and interfering signals. - Decoders that are affected by the different logical channels and input levels. The tests are designed to stress each of these blocks with a minimum of redundancy. Statistical testing of receiver BER/FER performance Error Definition 1) Frame Erasure Ratio (FER) A frame is defined as erased if the error detection functions in the receiver,
