No. is important only when the system has several base stations. In such case every base station has a site number allocated. Control channel index is a number sent by the base station and used by the mobile stations to determine the base allocation frequency and jump to the appropriate channel when necessary. Control channel frequency is the frequency corresponding to the control channel index. This value is useful when the decoder is working in 'Single Receiver Mode'.
Accepted frames indicates the percentage of correctly received frames.
To improve this figure, finely tune the receiver frequency until the number of accepted frames reaches the maximum value and only then adjust the receiver or sound card volume for maximum performance. Channel step initially used by the SmartNet protocol was 12.5kHz below 300MHz and 25kHz above. Nowadays, the system administrator decides the channel spacing, depending on the type of the mobile stations used by the system. As the software cannot detect automatically which channel spacing is used, this value needs to be set manually. If you don t know which channel spacing is used, just select one to start with - if it doesn t work out, you can change it later.