29 Jul
2009
29 Jul
'09
10:08 p.m.
Hi Dieter.
If you want to connect the BTS and an MS directly, you
have to use
an attenuator to reduce the signal to some "reasonable" level. To
give you some numbers about "reasonable": The maximum RF output level
of two different GSM tester which are intended for direct connection
to an MS are -14 dBm for one of them and -40 dBm for the other. To be
on the safe side I would make sure that the level is below -40 dBm,
this is more than enough for good receiption (poor receiption is around
-100 dBm). If the signal is too strong, you can damage the MS and/or BTS.
Please note that I have not tried to connect a BTS and an MS yet, my
experience comes from the GSM testers only.
Good to know. Maybe this helps to calculate the attenuation rates.
One problem I see with this approach is how to handle
the separate
RX and TX connectors of the BS-11.
Where is the problem? RX and TX are connected over at least one attenuator.
I you can't make sure that no RF signal is
emitted, you can at least try
to cause as little trouble as possible:
I know that but i would sleep much better if BTS and MS were connected
directly by a shielded cable. The network operators will not accept a
pirate signal even if it causes no harmful effects to the network.
There is another problem that comes in my mind: I don't think that every
MS will have 50 Ohms impedance on its antenna connection. There might be
any impedance since an MS is normaly not made for beeing connected to
external antennas/cabeling ect...
I think i will try the second way first because there is nothing that
can go wrong. The only risk it that it does not work, but it can not
damage the BTS or MS.
regards.
Philipp