Validation and verification methodology of GSM network call duration measurement system

The article deals with the validation and verification methodology of the GSM network measurement system, as these systems performing call duration measurements fall within the scope of legal metrology. Because the number of calls in the GSM networks is very large, the test call sample size determination algorithm proposed in the paper. Correctly chosen sample size allows to take statistically significant decision about communication network call duration measurement system measurement error with chosen confidence level. The sample representativity issue is also discussed in the paper. The proposed methodology was tested experimentally.