Channel of terrestrial digital broadcasting
As for the terrestrial digital broadcasting, a physical channel that shows the broadcast physical frequency becomes another to the channel number of remote control unlike the analog broadcasting.
Number of physical channel and remote control
A physical channel is a channel number (channel 13-62) corresponding to the frequency of UHF actually transmitted. Moreover, the number of remote control is a number of the channel automatically allocated when the channel is set.
It is necessary to know this for the trader who sets up the antenna though a physical channel is trivial for a general user.
Next, a physical channel and the remote control number for a typical Kinkouzan transmission place in Okayama Prefecture are shown as an example.
Physical channel at transmitting station in Okayama and number of remote control
- Remote control number---1 and physical channel---32 (The analogue is 5ch.)
- Remote control number---2 and physical channel---45 (The analogue is 3ch.)
- West Japan broadcasting
- Remote control number---4 and physical channel---20 (The analogue is 9ch.)
- Setonaikai broadcasting
- Remote control number---5 and physical channel---30 (The analogue is 25ch.)
- San-yo broadcasting
- Remote control number---6 and physical channel---21 (The analogue is 11ch.)
- Television Setouchi
- Remote control number---7 and physical channel---18 (The analogue is 23ch.)
- Television Okayama
- Remote control number---8 and physical channel---27 (The analogue is 35ch.)
There is a channel that doesn't see the television even if the electric wave is sent from the same transmission place.
Naturally, the electric wave of broadcasting is different the frequency because of the channel. What is being broadcast from a separate transmission antenna by the broadcasting station is abundant though the transmission antenna is broadcast from the position where any channel is almost the same.
Therefore, it is natural that strength of the electric wave is individually different because of the channel received even if it is possible to receive it usually and well.
The signal strength by which the terrestrial digital broadcasting is received well is in the range of 35dB-90dB[μV]. It becomes impossible to receive only the channel when the electric wave weakens and it weakens more than 35dB.
The screen might not reflect by the change of strength of a little electric wave because digital broadcasting is in the screen at all the difference and is seen in case of the range with strength of the electric wave.
Moreover, it is necessary to note it because it is not likely to be able to receive it well according to the quality of a signal peculiar to digital as follows.
The signal quality (BER and MER) is also important in the reception of the terrestrial digital broadcasting.
The signal quality (BER and MER) is important matters to receive the terrestrial digital broadcasting excellently for the digital signal though the signal strength is also as important as the above-mentioned.
BER Bit Error Rate abbreviation
It is the one to show whether the digital signal of the television transmitted by the broadcasting station doesn't receive the influence of the noise etc. in the radio propagation and how much it was possible to receive it accurately. If BER is 2.00E-4 or less (2.0010-4), it is possible to receive it.
MER Modulation Error Ratio abbreviation
It is the one that the ratio of the error margin of the amplitude of the digital modulation transmitted by the broadcasting station, the phase, the amplitude actually received, and the phase was shown. It is a standard that the reception becomes excellent 25dB or more MER.