Type 0 Extension 2 - mattpascoe135/dab GitHub Wiki

#Extension 2 - Basic service and service component definition The Extension 2 of FIG type 0 (FIG 0/2) defines the basic service organization. All the service descriptions applying to a service shall be contained within one field (service k) carried in a single FIG. Figure 24 shows the structure.

The following definitions apply: ###SId (Service Identifier): this 16-bit or 32-bit field shall identify the service. The length of the SId shall be signalled by the P/D flag, see clause 5.2.2.1.

Service Identifier description:

• Country Id (Identification): this 4-bit field shall be as defined in TS 101 756 [16], tables 3 to 7.
• Service reference: this field shall indicate the number of the service.
• ECC (Extended Country Code): this 8-bit field shall be as defined in TS 101 756 [16], tables 3 to 7.

###Local flag: this 1-bit flag shall indicate whether the service is available over the whole, or only a partial area served by the ensemble, as follows:

0: whole ensemble service area

1: partial ensemble service area.

###CAId (Conditional Access Identifier): this 3-bit field shall identify the Access Control System (ACS) used for the service. The definition is given in TS 102 367 [15]. A non-CA capable DAB receiver shall not interpret this field. If no ACS is used for the service, CAId is set to zero.

###Number of service components: this 4-bit field, coded as an unsigned binary number, shall indicate the number of service components (maximum 12 for 16-bit SIds and maximum 11 for 32-bit SIds), associated with the service. Each component shall be coded, according to the transport mechanism used.

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##Service component description: ###TMId (Transport Mechanism Identifier): this 2-bit field shall indicate the transport mechanism used, as follows:

b15 - b14

0 0: MSC - Stream mode - audio;

0 1: MSC - Stream mode - data;

1 0: FIDC;

1 1: MSC - Packet mode - data.

###ASCTy (Audio Service Component Type): this 6-bit field shall indicate the type of the audio service component. The following types are defined (the remaining types are reserved for future use):

b13 - b8

0 0 0 0 0 0: foreground sound (MPEG I or II (Layer II or reserved) coding);

0 0 0 0 0 1: background sound (MPEG I or II (Layer II or reserved) coding);

0 0 0 0 1 0: multi-channel audio extension (MPEG II (Layer II or reserved) coding).

###SubChId (Sub-channel Identifier): this 6-bit field shall identify the sub-channel in which the service component is carried.

###P/S (Primary/Secondary): this 1-bit flag shall indicate whether the service component is the primary one, as follows:

0: not primary (secondary);

1: primary.

###CA flag: this 1-bit field flag shall indicate whether access control applies to the service component, as follows:

0: no access control or access control applies only to a part of the service component;

1: access control applies to the whole of the service component.

Every DAB receiver shall check the "CA flag". A non-CA capable DAB receiver shall not try to decode the service component if the "CA flag" is set to 1.

###DSCTy (Data Service Component Type): this 6-bit field shall indicate the type of the data service component. The interpretation of this field shall be as defined in TS 101 756 [16], table 2.

For the FIDC (TMId=10), only entries which have an associated FIG Type 5 coding description shall be permitted - see clause 8.2).

###FIDCId (Fast Information Data Channel Identifier): this 6-bit field shall identify the service component carried in the FIDC. It is organized as shown in figure 25 and the TCId and extension fields are described in clause 5.2.2.3.

###SCId (Service Component Identifier): this 12-bit field shall uniquely identify the service component within the ensemble.