RES535 – 338 – These default values should be used by the Bureau for its compatibility analyses. The times for which a compatibility analysis is made should be user selectable, the default values being: – 30 min past the hour in which the requirement starts; – 30 min past each successive hour until the hour in which the requirement ends. These default values should be used by the Bureau for its compatibility analyses. Software output data For rapid assessment of the performance of a requirement, the software should calculate: – the overall service reliability for the relevant test points from the set of 911 test points; – the overall area reliability for the relevant test points from the set of 911 test points. In order to provide information about the geographic distribution of wanted and unwanted signal values for a given requirement, additional results should be available from the software: – a listing should be available giving the overall circuit reliability for each of the relevant test points from the set of 911 test points. In some cases, a graphical display of the coverage achieved throughout a required service area may be desirable. These values will need to be calculated by the user (with the supplied software and on the user’s own computer hardware) at test points at 2° intervals of latitude and longitude throughout the required service area. The values should be displayed graphically as a set of coloured or hatched pixels in steps of 10%. It should be noted that: – reliability values relate to the use of a single frequency; – reliability values are a function of the desired RF signal-to-noise and RF protection ratios (both user selectable); – the field-strength values for the test points (from the set of 911 test points) inside the required service area should be calculated by the Bureau. The software supplied should calculate the relevant reliability values based on these pre-calculated field-strength values and the user-supplied desired signal-to-noise and signal-to-interference values; – the field-strength values for the test points at 2° intervals should be calculated using the supplied software on the user’s own computer hardware. The software supplied should calculate the relevant reliability values based on these field-strength values and the user-supplied desired signal-to-noise and signal-to-interference values.