A new record for the number of channels being broadcast simultaneously on a Freeview multiplex has been broken.
Multiplex operator SDN, owned by ITV plc has been recorded carrying 18 channels at the same time, beating their previous record set last month of 17 simultaneous streams.
The record for a UK DVB-T multiplex was broken when shopping channel Create and Craft made a frequency change at lunchtime today to join the SDN multiplex, also known as COM4.
Multiplexes contain bundles of channels broadcast from transmitter masts such as the one pictured above. How many videostreams they can carry determines the number of Freeview channels a viewer can receive at any one time. New encoders have made it possible to increase the number of simultaneous streams over the past decade. However, there can be a trade-off with regards picture quality. All services use the lower 544×576 standard definition resolution. Parameters used to transmit the signal to viewers can also impact on the amount of bandwidth available for TV channels, with a further trade-off between number of channels and ease of reception.
For comparison, as of 12 noon today, the Arqiva-operated COM5 carried 14 channels simultaneously and COM6 15 channels.
The 18 channels currently being broadcast on the SDN multiplex are:
- CBS Reality
- Channel 5+1
- Create & Craft
- Horror Channel
- Paramount Network
- Sony Movies Action^^
* Timeshares with TCC and the Blaze+1 placeholder channel.
** Timeshares with ITV3+1 and Studio 66.
*** 7am-7pm only.
^ Timeshares with the ITV4+1 and ITVBe+1 placeholder channels.
^^ in Wales: E4. Sony Movies Action is not broadcast from welsh transmitters.