The old analogue television services, for example 鶹Լ 1 or 鶹Լ 2, were broadcast from a transmitter using separate frequencies. Digital television allows us to bundle a number of television services into what is known as a multiplex and to broadcast them all on one frequency from a transmitter. Your television, or set- top box, then pulls out each individual service in the multiplex and allows you to watch it.
A number of multiplexes can be transmitted from each transmitter site, allowing a wider range of stations to be broadcast.
Freeview multiplexes
There are three public service broadcast (PSB) multiplexes. The 鶹Լ runs two of them and they are known as PSB1 and PSB3 or sometimes 鶹ԼA and 鶹ԼB. There is also a set of commercially-operated multiplexes, known as COM4, COM5, COM6. Plus, in some areas, there are local television multiplexes which usually start with LTV.
We keep an updated list of all our services on the various multiplexes
Why do we use multiplexes?
Using a multiplex enables us to broadcast a number of television channels at once using just a single frequency. This allows broadcasters to use the spectrum allocated to television to the maximum, giving you more stations to choose from. We are able to do this using technology that allows the television channels to be compressed together into a multiplex and then fed to the distribution network for transmission.
We can also add in radio stations, Red Button data services, subtitles and audio description into a multiplex. Each multiplex also carries the service information which includes the data needed for EPGs.
Digital transmission needs less power than analogue, so it is more cost-effective and environmentally friendly.
How many multiplexes can I get where I live?
The 鶹Լ’s two multiplexes (PSB1 and PSB3) are broadcast from over a thousand transmitters across the UK, along with PSB2, which carries services such as ITV, Channel 4 and FIVE. Between them they cover over 98.5% of the population. Only PSB1 and PSB3 are funded by the licence fee.
The commercial multiplexes (COM4, COM5 and COM6) are broadcast from a much smaller number of transmitters and cover 90% of the population.There is also COM7 multiplex which broadcasts from even fewer sites and cover about 63% of the population.
In some cities and surrounding areas, one or more Local TV multiplexes may be available. These carry a channel dedicated to the local area, plus some additional commercial services.
Use our transmitter checker tool to find out which transmitters you can tune to and the multiplexes available on those transmitters.
Reception Problems
If you have a reception problem with one service in a multiplex, you will also have problems with all the other services in that multiplex. It is also possible for the signal strength and quality of one multiplex to be different from another. This could be due to the different frequencies used, the power of the transmitter and that not all multiplexes are broadcast from the same antenna on the site.
The our transmitter checker tool can give you an indication of the expected quality of the multiplex signal you can receive at your location.
