Previous network transmission model standards and bulletins for evaluating modem
performance (e.g. TSB-37A, TIA/EIA 3700, TIA/EIA 793 and TIA 876) have been statistical
models in which likelihood of occurrence (LOO) values were assigned to all network elements
and impairments. Test results using these statistical models were expressed in terms of
Network Model Coverage (NMC). These NMC results were unconditional – not dependent on
the a priori specification of any network elements or impairments. This is an example of a
Statistical Model. Testing to a comprehensive Statistical Model suggests how communications
devices may perform over an IP network in terms of Network Model Coverage.