24. RF Interference detection, does it exists on Wireless Alarm System ?

[-pull@shoot]

Everybody knows that wireless alarm systems are unreliable during
Radio Frequency Interference (RFI) because the transmission path of
signals between sensors and wireless receiver is muzzled by an
external transmitter causing RFI.
 Wireless is unreliable during RFI, and there are a tremendous number
of sources who generate it, theyre number increases day by day..
    YOU WILL NOT BE WARNED THAT YOUR WIRELESS SYSTEM is DEAD.

Is RFI detected?
Let's see what "so called" professionals say about the lack of the
sensor data reception detection circuit.

All wireless alarm systems have tamper and battery low detection.
 The presence of an extra bit(s) in the coded sensor transmitted
signal stream allow the control panel to identify the occurrence of
tamper or battery low.
 Some of the so called pro's attempt to convince you and say that this
is also useable and effective for RFI detection..
 Everybody knows that no valid signal reaches the wireless receiver
during RFI.. how can that work when transmitted signal and there
detection just fail because RFI jeopardize the RF loop signal
validity???
 Forget it, its sellers talk.

In some new and recent systems each sensor transmit on a regular basis
to the panel an "I'm here" signal. The panel takes note if all are
received correctly within a certain timespan. Some systems have a
signal strength indication to.
 This design feature is used to check validity of the sensor reception
signal at installation.It allow to see if all sensors are located at a
receiver signal reachable place.

Note:
      If this feature is always left ON, it detects continuously
      sensor transmission failures and sensor position problems caused
      after installation due to the displacement of conductive objects
     (statues, car and other metal objects).
       The displacements of a conductive object alter the RF signal
      path by masking completely or partially (attenuation) the
      transmitted signal to the receiver, the signal decoding of the
      system fails.

Most of the time the installers "disable and put OFF this feature"
because it don't identify typically RFI from sensor "transmission
path" failure, both occult signal reception validity.
 There is a way around the problem, metal object obstruction is
usually for a rather relative long timespan before it is removed
(statue, car), by tuning up the time delay the system can warn lack of
sensor signal and +/- avoid false alarms.
 This works and is effective for long (hours) time delays before
warning occur, unusable to detect intruder generated RFI.

Until now, according to pro's, no interference warning has been
received at central stations during 20+ years..
 Conclude yourself of the efficiency of that RFI detection...

Why doesn't the most recent developed systems not detect typically
interference situation?
 Because there are several interference sources, situations,
impossible to identify them (see diversity of sources i described) and
during that time, the wireless systems are muzzled, dead.


Conclusion:
Assume that there is some kind of detection that really works(?), it
don't solve the muzzling and intruder "detection" during
interferences.
 You think there are systems who detect RFI, well try it out with a
RFI generating transmitter preferably in a crowded wireless users area
at night and see how many nightmares it will cause, police adventures,
and more..
 Good luck