Type 0 Extension 19 - mattpascoe135/dab GitHub Wiki

#Extension 19 - Announcement switching The announcement switching description is encoded in Extension 19 of FIG type 0 (FIG 0/19). Figure 51 shows the structure of the announcement switching field which is part of the Type 0 field (see also figure 4).

The following definitions apply:

###Cluster Id: this 8-bit field shall identify the announcement cluster, for which the announcement is intended. Cluster Id = "0000 0000" shall be used for signalling an announcement forming a programme item within the same service. Cluster Id = "1111 1111" shall be used for Alarm announcements and shall be directed to all programme services carried in the ensemble. It shall not be used for any other announcement type.

###ASw (Announcement switching) flags: this 16-bit field shall specify the announcement types which apply to the announcement. The individual bits indicate whether or not a particular announcement type is signalled. The interpretation of the flags shall be as defined in TS 101 756 [16], table 14. The flags shall be coded as follows:

bi (i = 0 to 15);

0: Announcement type not valid;

1: Announcement type valid.

###New flag: this 1-bit flag shall indicate whether the announcement is newly introduced, as follows:

0: repeated announcement;

1: newly introduced announcement.

###Region flag: this 1-bit flag shall indicate whether a region is specified or not, as follows:

0: last byte (the 2-bit Rfa field and the RegionId Lower part field) absent. The announcement concerns the whole service area;

1: last byte (the 2-bit Rfa field and the RegionId Lower part field) present.

###SubChId: this 6-bit field shall identify the sub-channel which contains the audio service component carrying the announcement.

###Rfa: this 2-bit field shall be reserved for future additions. These bits shall be set to zero until they are defined.

###RegionId Lower part: this 6-bit field shall identify the region to which the announcement is targeted. It uses the lower part of the Region Identifier. The upper part of the Region Identifier shall be set to "00000" (see clause 8.1.16).