Technical description and operating manual ST 167 and ST167W5
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6.11 BLOCKER (JAMMER) DETECTION
When the «J» sign is selected, the unit detects operating blockers of cellular GSM,
GPS and GLONASS receivers. The GSM cellular blockers are detected by blocker
broadband radiation in at least two different frequency ranges (900 and 1800MHz) of the
base stations.
GPS and GLONASS blockers are detected by the analysis of the radiation in the receivers
frequency range.
Separate selection of GSM or GPS blocking detection is provided in manual mode.
By successive pressing
, the level of the GSM signal blocker is displayed first, then GPS.
6.12 EXTERNAL DEVICES CONTROL (only for devices with external device control option)
For external devices control built-in relay with control circuit is designed. Relay contacts are connected
to the socket, which is located on the side of device. Setup is in subMENU «System..» - «Relay..».
There are two options for using this option:
External indication devices control
Blockers/jammers control
External indication devices control is done in «AUTOMATIC» mode. Wherein, relay contact closure is
done immediately when threshold excess is done by one of the signals and shortcut of this signal will be backlighted
by red (see 6.3).
Blockers/jammers control starts with celullar and wireless standards selection,
which should be blocked (In case of possibility to it by blocker itself). GSM 900, 1800 and
3G standards can be seen on fig. 30
To suppress unwanted communication session blocker should have the following properties:
With separate channel transmission and reception (GSM, 3G, 4G) interference signal is done in base station
frequency range, which match receiving frequency of mobile devices. In case of lack of frequency separation
(DECT, WI FI) signal of suppressing should be cover all frequency range of this signal.
Signal level should be higher than suppressed signal level on determined level.
Blockers/jammers control is done by chosen standards analysis on presence of radio signals in a frequency
range of remote terminals (phones). In case of signal presence ST167R relay contacts closes, that provides blocker
activation and suppresion signal in frequency band of receiving channel will appear.
In case if blockers frequency range captures external terminals transmitting frequency range or in case of lack
of frequency separation (DECT, WI FI) blocker will be permanently activated. To prevent this situation additional
option is designed – mandatory periodic shut down of the blocker on time, needed for radio environment analysis.
Time value can be selected in submenu «System..» - «Relay..» - «Relay timer..». Shut down time depends on
blocker signal entering speed in receiving channel of the ST167R,
turn on – choosing between blocker excess radio
emission and turn on periodicity. By default, shut down time – 5sec, turn on – 2 min.
Fig.30
Fig.29
