The VHF frequency band
The VHF band ranges from 30 to 300MHz. It includes different broadcast bands, amateur radio bands, and aviation bands.
- VHF Band I ranges from 41 MHz up to 68 MHz Rev. Geneva 2006 (GE06)
- VHF Band II ranges from 87.5 MHz up to 108 MHz. It includes the entire FM Broadcasting band in Europe Geneva 1984 (GE84)
- VHF Band-III ranges from 174 MHz to 230 MHz for the VHF television band. This 56MHz for analog TV was reallocated to DAB/DAB+ (see Geneva 2006 (GE06)).
In Europe, most countries divided the 56 MHz bandwidth into 8 television channels of 7 MHz (Channel 5 to 12). Some countries did also use 8 Mhz per channel for their analog TV.
The DAB+ frequency band
The GE06 (Geneva 2006) agreement reallocated the band for DAB/DAB+.
Each 7 MHz TV channel was divided by 4 to deliver a 1,75 MHz bandwidth for 4 terrestrial DAB/DAB+ blocks (A, B, C, and D).
People have kept the designation of the former TV channel for the DAB+ channels. The old analog TV channel numbers still identify the MUX. Thus, channel 5A stands true for the former TV channel 5 and A for the first of the four muxes available in the TV channel (A, B, C, D). The DAB+ band possesses a total of 32 frequency blocks for DAB+ MUXes.
In countries such as Norway and Denmark, the additional 10 MHz of channel 13 (230 MHz up to 240 MHz for DAB/DAB+. This extra 10 MHz results in 6 DAB/DAB+ blocks (13A to 13F).
DAB+ band versus FM band
As radio stations, we need to be aware of the possibilities offered by the system. DAB+ allows 12 stations (in FEC 3A) of 96kbps or even 18 stations of 64 kbps in a MUX. Given they are broadcast simultaneously by a digital system, they are all within the same bandwidth of 1.54 MHz. So very close together without interfering with each other. It would be impossible with FM!
Moreover, the frequency band for DAB+ is more than double, with a capacity of 56 MHz compared to 20.5 MHz for FM. Unlike FM, DAB+ is suitable for SFN (Single Frequency Network). It means broadcasters can always use the same frequency over a large area (country). Thus, DAB+ is pre-eminently the solution to the current limitations on the FM band. As local radio, we need to start realizing and embracing this.