9
DMHD04D/C
5 - Adding services (programmes) to the modulator:
In the list of programmes, you will find two or four
columns with a GREEN ‘+’ symbol or a RED ‘-’ symbol.
The columns indicate the output channels of the
modulator. If a green ‘+’ symbol appears besides a
certain programme, this means that this programme is added to that specific channel in the
modulator. The status can be changed by double clicking the activation symbol besides the
requested programme. In the far right columns you can add a LCN number or HDLCN number
for channel numbering.
6 - Using High Definition HD LCN
In some systems you may want to broadcast a version of a programme in Standard Definition
(SD) at the same time as High Definition (HD). With HD LCN numbering, you can force HD
Television sets to follow the HD LCN numbering and SD Television sets to follow the LCN
numbering for those programs which are transmitted in duplicate.
For example: You want to broadcast a BBC television programme in SD version as well
as in HD. Application of HD LCN would be:
BBC1
LCN: 5
HDLCN: 55
BBC1HD
LCN: 55
HDLCN: 5
Television sets with the HD tuner will now put BBC1 HD on number 5 and BBC1 on channel 55
Television sets without the HD tuner will now put BBC1 HD on number 55 and BBC1 on
channel 5
7 - Occupied Bandwidth
The terrestrial Aerial symbol features a number beneath that signifies the total occupied
bandwidth of the modulator. This number should not exceed the maximum available
bandwidths of the modulator. The maximum available bandwidth is calculated on the maximum
available bandwidth per channel x the number of channels. The maximum available bandwidth
per channel is depending on the modulation parameters (Constellation / Bandwidth / F.E.C. /
Guard interval). (See technical specification list)
For example: for a DMHD04D/C modulator, the maximum available bandwidth is 4 x 31.6Mbit/s =
approx. 126.4Mbit/s.
The occupied bandwidth of each channel in the modulator is
showed by bar graphs in the modulator window.
The occupied bandwidth will increase as the number of programmes added to that channel
is increased. It also depends on the bandwidth of each individual programme. Please avoid
overloading a channel as this will lead to defects in the programmes.