Error ratios used in conjunction with GSM speech channels:

· Frame Erasure Rate, FER, is defined as the amount of swept speech frames (260 bits each)

divided by the amount of transmitted speech frames. The speech frame is swept if even one of

its most important 50 bits is observed not to be correct. The three parity bits following the 50

class Ia bits are used for error detection.

· Bit Error Rate, BER, is the ratio of erroneously received bits to all received bits. It is

important to notice that BER is evaluated before channel decoding, i.e. after equaliser. BER is

used for defining the RXQUAL value