User manual

Using the RDS SECTION (FM version ONLY) ENG
Page 75
As mentioned earlier, Method B is used with high numbers of alternative frequencies and/or when the transmitter also
has frequencies that broadcast different radio program at various times of day (splitting, local programming, etc.).
In the latter instance, the mobile receiver should check whether the AF is broadcasting the same content before selecting
another frequency.
Each list begins with the tuning frequency (for which the list is valid) and then contains up to 12 pairs of frequencies in
sequence, each containing the tuning frequency and an alternate. If there are more than 12 possible alternative
frequencies, the list continues in other lists in the same manner.
The order of the frequencies in each pair follow the rules below:
- If the order is increasing, the alternative frequency broadcasts the same programming as the tuning frequency.
- If the order is decreasing, the two frequencies have different programming.
Returning to the example of transmitters B, D and E in the previous paragraph (in which the coverage areas of D and E
do not overlap), two more lists will be assigned to transmitter B, sorted according to the above criteria to take into
account any different programming by some of the AFs.
AF1 AF2
f Tx B f Tx D
f Tx B f Tx D
Tx B
(tuning frequency: f Tx B)
f Tx D f Tx B
Notice that the tuning frequency f Tx B is
repeated twice in list 1: in the first position,
then paired with f Tx D. Tx B broadcasts the
same program as D if
f Tx B < f Tx D, and different programs if f Tx
B > f Tx D.
The AF lists for the other transmitters are compiled according to the same criteria, alternating the frequency pairs. NOTE:
if the same tuning frequency is used by more than one transmitter within the same network, the corresponding AF lists
must not be consecutive (for instance AF 1 and AF 2). Lists for different tuning frequencies must be placed between
them.