The DAB+ system is an upgrade to DAB (Digital Audio Broadcasting) to enable it to transmit mobile phone quality moving pictures. To do this it DAB+ uses AAC+ V2 audio compression which is also used by DRM. DAB uses MPEG level 2 compression. DAB+’s use of AAC+ v2 leaves enough capacity for moving pictures. Its coverage areas are likely to be similar to high powered FM.
There are a total of 32 possible DAB+ channels between band 3’s 174 and 230 MHz. Unfortunately for DAB+ radio, digital and analog TV also use this frequency range containing channels 6. 7. 8, 9, 9A, 10, 11 and 12. In capital cities 4 channels are used for digital TV and 3 for analog TV leaving only channel 9A.
There are 4 DAB+ channels per TV channel. Labelled. for example 6A, 6B, 6C & 6D
DAB+ can also use the 1.4 GHz band (L band) either for local and fill in transmitters or satellite. 1.452 - 1.492 GHz is divided into 23 channels. Channels LA - LP are or ground based transmitters and LQ - LW for satellite based transmitters.
A DAB+ channel is 1.712 MHz wide and can carry around 1 Mbit/s
Multiple radio programs will be multiplexed together and sent as one digital signal using a DAB+ radio channel. Data including pictures can be added to this multiplex. A typical multiplex will contain around 20 stereo radio programs.
Source: DVT Forum Australia
Digital Radios - Related Articles Worth Reading:
- New Generation Radio Broadcasting - Digital Radio
- Dab + Radios Benefits Motorists Take Note
- DAB+ Radio Station Broadcasting in Australia Update