- Service Description Channel 2 -
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Service Description Channel (SDC)

 

region definition data entity - type 7

 

A frequency group can be given a geographical area. The area is defined in terms of multiples of 1 × 1 degree ‘squares’. It therefore gives a resolution of (EW × NS) 111 km × 111 km (at equator) or 31 km × 111 km at 70° latitude (e.g. Scandinavia, Canada). The coding provided allows for the signalling of squares of up to about 4 000 km × 4 000 km for < 73° latitude. The area may in addition be defined in terms of CIRAF zones. Up to seven zones may be specified per group. Latitude and longitude are specified as a 2's complement number. 

 

region id

4 bits

up to 15 regions can be defined

latitude

8 bits

specifies the southerly point of the area in degrees.

longitude

9 bits

specifies the westerly point of the area in degrees.

longitude extent

7 bits

longitude extent: this field specifies the size of the area to the east, in 1 degree steps

n CIRAF zones

n x 8 bits

coded as an 8 bit unsigned binary number in the range 1 to 85, gives one CIRAF zone.

 

 

 

 

 

 

 

 

 

 

 

time and date information data entity - type 8

 

The current time and date can be specified to allow a receiver to follow frequency schedules, etc. When the time and date are signalled, this data entity shall be sent in the first SDC block after the minute's edge.

 

Modified Julian Date

17 bits

this field indicates the date in MJD format

UTC (hours and minutes)

11 bits

UTC: this field specifies the current time expressed in hours (5 bits) and minutes (6 bits)

 

 

 

 

 

 

audio information data entity - type 9

 

Each audio service needs a detailed description of the parameters needed for audio decoding.

 

short id

2 bits

indicates the short id for the service concerned.

stream id

2 bits

indicates the stream id that carries the service concerned

audio coding

2 bits

00:  AAC

01:  CELP

10:  HVXC

11:  reserved

SBR flag

1 bit

0:   SBR not used

1:   SBR used

audio mode

2 bits

this field depends upon the value of the audio coding field:

00

 

 

 

00: mono

01: parametric stereo

10: stereo

11: reserved

01

rfa 1 bit

0: CELP CRC not used

1: CELP CRC used

10

HVXC rate 1 bit

0: 2 kbit

1: 4 kbit

 

HVXC CRC 1 bit

0: CRC not used

1: CRC used

audio sampling rate

3 bits

000: 8 kHz

001: 12 kHz

010: 16 kHz

011: 24 kHz

100: reserved

101: 48 kHz

110: reserved

111: reserved

text flag

1 bit

0: no text message is being carried

1: text message is being carried

enhancement flag

1 bit

0: no enhancement available

1: enhancement is available

coder field

5 bits

depends upon the value of the audio system coding system field:

00 (AAC)

3 bits MPEG Surround mode

000: no MPEG

001: reserved

010: MPEG Surround 5.1

011: MPEG Surround 7.1

100 – 110: reserved

111: other mode

2 bits rfa

01 (CELP)

5 bits CELP bit rate index

10 (HVXC)

5 bits rfa

 

 

rfa

1 bit

reserved for future addition and set to zero until defined.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FAC channel parameters data entity - type 10

 

This data entity permits the next configuration FAC channel parameters to be specified in advance for service following reconfigurations. If the DRM transmission is being discontinued at the reconfiguration, then this data entity shall be sent with the length field of the header set to 0, and the first four bits of the body field set to 0.

 

base/

enhancement flag

1 bit

0: base layer

1: enhancement layer

robustness mode

2 bits

robustness mode of the new configuration:

00: mode A

01: mode B

10: mode C

11: mode D

RM flag

1 bit

flag = 0: as above

flag = 1: 00: mode E

spectrum occupancy

4 bits

0000:  4.5kHz

0001:  5.0kHz

0010:  9.0kHz

0011:  10kHz

0100:  18kHz

0101:  20kHz

0110:  not defined

::::::::

1111:  not defined

interleaver depth flag

1 bit

0: 2 s (long interleaving)

1: 400 ms (short interleaving)

MSC modulation mode

2 bits

00: 64-QAM, no hierarchical

01: 64-QAM, hierarchical on I

10: 64-QAM, hierarchical on I&Q

11: 16-QAM, no hierarchical

SDC modulation mode

1 bit

0: 16-QAM

1: 4-QAM

number of services

4 bits

0000: 4 audio services

0001: 1 data service

0010: 2 data services

0011: 3 data services

0100: 1 audio service

0101: 1 audio service and 1 data service

0110: 1 audio service and 2 data services

0111: 1 audio service and 3 data services

1000: 2 audio services

1001: 2 audio services and 1 data service

1010: 2 audio services and 2 data services

1011: reserved

1100: 3 audio services

1101: 3 audio services and 1 data service

1110: reserved

1111: 4 data services

rfa

4 bits

reserved for future additions set to zero until defined.

rfu

1 bits

reserved for future use and set to zero until defined.

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

linkage data entity - type 11

 

The linkage data entity allows the connections between alternative sources of the same service to be signalled. 

   

short id announcement

1 bit

0: short ID

1: announcement ID

short id announcement

2 bit

short id for the service concerned.

region/

schedule flag

1 bit

0: no restriction

1: region and/or schedule applies

same service flag

1 bit

0: alternative service

1: same service

rfa

2 bit

system ID

5 bits

00000: DRM service

00001: AM service with AMSS service

00010: AM service

00011: FM-RDS service (Europe and North America grid)

00100: FM-RDS service (Europe and North America grid) PI code only

00101: FM service (Europe and North America grid) PI code not specified

00110: FM-RDS service (Asia grid)

00111: FM-RDS service (Asia grid)

(PI code only).

01000: FM service (Asia grid)

(PI code not specified).

01001: DAB service

01010: DAB service

01011: DAB service

all other values: reserved for future definition.

region/

schedule field

8 bits

4 bits region ID

4 bits schedule ID

other service ID

16 bits

n frequencies

n x (8 or 16) bits

00000 DRM frequency

00001, 00010 AM frequency

00011, 00100, 00101 FM1

00110, 00111, 01000 FM2

01001, 01010, 01011 DAB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

language and country data entity - type 12

 

The language and country data entity allows addition language and country information to be signalled. 

 

short id

2 bits

short id for the service concerned

rfu

2 bits

set to zero until they are defined

language code

24 bits

language of the target audience of the service using three characters as specified by ISO 8859-1

If the language is not specified, field contains "-" characters

country code

16 bits

country of origin of the service (studio) according to ISO 3166 using two lower case characters as specified by ISO 8859-1.

If the country code is not specified, the field contains "-" characters

 

 

 

 

 

 

 

 

 

 

 

 

alternative frequency signalling: detailed region definition data entity - type 13

 

packet stream FEC parameters data entity - type 14

 

Data entity 15 has not yet been defined.

 

DRM background
COFDM
FAC
SFN
MSC
SDC data 1
Multimedia
Bandplan
DRM future
DRM audio
FAC sync
DRM multiplex
DRM modes
SDC data 2