Carriers And Channels; Aspects Of Infra-Red Distribution Systems; Directional Sensitivity Of The Receiver; The Footprint Of The Radiator - Bosch INTEGRUS Installation And Operating Manual

INTEGRUS | Installation and Operating Manual | System description and planning

1.2.4 Carriers and channels

The Integrus system can transmit up to 8 different car-
rier signals (depending on the transmitter type). Each
carrier can contain up to 4 different audio channels.
The maximum number of channels per carrier is
dependent on the selected quality modes. Stereo sig-
nals use twice as much bandwidth as a mono signals,
premium quality uses twice as much bandwidth as
standard quality.
Per carrier a mix of channels with different quality
modes is possible, as long as the total available band-
width is not exceeded. The table below lists all possible
channel combinations per carrier:
Mono
Standard
4
2
Possible
2
number of
channels
per carrier
1.3 Aspects of infra-red
distribution systems
A good infra-red distribution system ensures that all
delegates in a conference venue receive the distributed
signals without disturbance. This is achieved by using
enough radiators, placed at well planned positions, so
that the conference venue is covered with uniform IR-
radiation of adequate strength.
There are several aspects that influence the uniformity
and quality of the infra-red signal, which must be con-
sidered when planning an infra-red radiation distribu-
tion system. These are discussed in the next sections.

1.3.1 Directional sensitivity of the receiver

The sensitivity of a receiver is at its best when it is
aimed directly towards a radiator. The axis of maxi-
mum sensitivity is tilted upwards at an angle of 45
degrees (see figure 1.4). Rotating the receiver will
decrease the sensitivity. For rotations of less than
+/- 45 degrees this effect is not large, but for larger
rotations the sensitivity will decrease rapidly.
Bosch Security Systems | 2003-02 | 3122 475 22011en
Channel quality
Mono Stereo Stereo
Premium Standard Premium
1
1
1 1
2
2
1
45
Figure 1.4 Directional characteristics of the receivers
Bandwidth
4 x 10 kHz
2 x 10 kHz and 1 x 20 kHz
2 x 10 kHz and 1 x 10 kHz (left) and 1 x 10 kHz (right)
1 x 20 kHz and 1 x 10 kHz (left) and 1 x 10 kHz (right)
2 x 10 kHz (left) and 2 x 10 kHz (right)
2 x 20 kHz
1 x 20 kHz (left) and 1 x 20 kHz (right)

1.3.2 The footprint of the radiator

The coverage area of a radiator depends on the num-
ber of transmitted carriers and the output power of the
radiator. The coverage area of the LBB 4512 radiator is
twice as large as the coverage area of the LBB 4511.
The coverage area can also be doubled by mounting
two radiators side by side. The total radiation energy
of a radiator is distributed over the transmitted carriers.
When more carriers are used, the coverage area gets
proportionally smaller. The receiver requires a strength
of the IR signal of 4 mW/m2 per carrier to work with-
out errors (resulting in a 80 dB S/N ratio for the audio
channels). The effect of the number of carriers on the
coverage area can be seen in figure 1.5 and figure 1.6.
The radiation pattern is the area within which the radi-
ation intensity is at least the minimum required signal
strength.
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