Method and apparatus for transmission error characterization

A method of measuring the transmission error characteristics of a channel employing frame based transmission, in which a frame classification indicator is generated for an expected frame, according to data received via said channel, comprising the steps of

• a) generating frame classification data relating to the expected frame;
• and
• b) updating a statistical representation of the transmission error characteristics according to said frame classification data, wherein steps a) and b) are performed at least twice,
• in which the frame classification data comprises one of a plurality of possible classifications and said statistical representation comprises a first set of one or more members, each member of the first set relating to an associated classification;
• and
• a member of the first set comprises a sample distribution representing the distribution of the number of consecutive frames which are classified as having the frame classification associated with said sample distribution and in which said frame classification is used to update the sample distribution of the first set related to said frame classification.