Devolo dLAN 200 AVpro - Page 43

devolo dLAN® 200 AVpro Project Manual
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and use devolo Informer or even better devolo dLAN AVpro manager and Iperf as
network tools to check whether both devices connect, and, if so, with what
bandwidth. A minimum of 50 Mbit/s. should be achieved here at the physical level.
If both dLAN adaptors succeed in connecting, high through rates of around
200 Mbit/s are normally achieved as well. It is only seldom that low
bandwidths are achieved (e.g. low, two figure rates). If that is the case,
high-performance services such as IP-TV cannot be realised where they are
stable.
Before and after connecting the additional d
LAN adaptors, check the visual quality of
TV reception on the top and ground floors, in all hotel wings and at a point where
there is poor TV reception.
If you have not already done so, connect the low-pass filter included to the
output on the devolo dLAN 200 AVpro.
The follow
ing faults may occur:
 Connection failed: other booster amplifiers on the leg (line amplifiers) are
usually the case here. This need to be located and bridged. Further
information on this is available in Chapter 3. In rare cases, booster
amplifiers are installed covered and hence difficult to find. You can
modulate a RF beam on the screen with a professional device in order to
detect the cable guide. The fact that the amplifier is connected to the power
supply, means that a cable leads to it, which you can locate as well.
 Lines or moiré patterns: these effects can be caused by poor shielding
attenuation on the antenna sockets or coax cable resulting from cheap
material being used. An other explanation could be that the devolo dLAN
200 AVpro adaptor is located too close to the TV set (near-field coupling ).
You should move the adapter to a better location further away in this case.
 Graininess or pixeling: negative effects like graininess or pixeling on the
TV picture usually means that the antenna network level is too low. You
would need to just this somewhat in this case. Professionally designed
broad communication networks usually have enough level reserve to
compensate for the approx. 4 dB of attenuation that occurs as a result of
decoupling on the main distribution for a leg.
You can quickly and easily transform the availability and throughput rate test into a
small demonstration of dLAN technology. Connect a notebook which has a
streaming server setup on it to the master (cf. Section 7.2 in this Manual). Start the
streaming client on the client laptop.
Technical
demonstrations
For demonstration purposes,
it is perfectly adequate to use a stream with a
low bandwidth, because you only want to clarify the functioning principle
of dLAN technology and its practicability o the customer at this point.