Re: 30. Regardless the wireless brand..

[Crash Gordon® <webmaster@xxxxxxxxxxxxxxxxxxxxx>]

Yes dear I totally agree, now take your little yellow pill and this nice =
glass of warm milky and go sleepy-bye for a few weeks, ok honey? Thats a =
nice boy.


<-pull@shoot> wrote in message =
news:vr3ua118h74moapin54vsvmf4g7dsumt0d@xxxxxxxxxx
|=20
| Regardless the brand, wireless alarm systems ARE unreliable whatever
| the "so called low level electrician" pro's attempt to let you
| believe.
|=20
| Its brand independent because radio waves behave alike in all
| country's and the Radio Frequency (RF) receivers undergo the same
| nuisances.
|=20
| If you like to purchase an alarm system "GO WIRED".
|=20
| What is the basic difference between wired and wireless alarm systems?
|  It boils down to the "connections link" between sensors and control
| panel of both systems, besides that sensor data connection link both
| systems are alike.
|=20
| The comparison is easy:
| - the WIRED WIRES
|  versus
| - a WIRELESS data link between sensors and the control panel.
|=20
| WIRED:
| - Each sensor has "hiss own" cabling, hiss own data transmission link.
|  All attempts to tamper sensor boxes, short or cut sensor wires are
| detected without any ambiguity an with no delay.
|=20
| - At a first glance the wired links are of the non-frequency selective
| type and as such are more prone to capture a greater Radio Frequency
| (RF) spectrum range of signals.
|  The data transmitted on sensor wired lines are of the low frequency
| type and as such can easily be filtered at all inputs entering the
| control panel, the line receiver module.
|  This makes the system data link low frequency selective by
| attenuating the eventual High Frequencies reaching the equipment by
| huge power transmitters.
|=20
| - The level of the transmitted signals on the wired lines are around
| "2Volt" to switch from on to off (to be more precise, 400mV
| interference free immunity for TTL circuits).
|=20
| WIRELESS:
| - All the sensor data is vehicle via ONE wireless data link composed
| of a low power transmitter in the sensors and a sensitive receiver at
| the input who has around 4 micro volt input sensitivity (wired 400
| millivolt (mV) / wireless 4 micro volt (uV) =3D ratio 100 000 times =
less
| power required to disturb wireless systems)
|=20
| - The wireless data link contains all the information required to have
| a reliable connection as long as there are "no other transmissions"
| present who block the data communication.
|  The wireless RF receiver collect in normal circumstances the data and
| decode it. This data contains an ID (rolling code), alarm, tamper
| attempt, battery low and more information. When the signal is
| disturbed, EVERYTHING is, ID can't be recognized...
|=20
| The receiver:
|   The receiver is made as much as possible frequency selective and
| sensitive at signals on the frequency in order to capture the week
| signals emanating from the sensors (see below).
|  They "attenuate" more or less, depending on the quality of the
| receiver, the frequencies beside that privileged frequency, its called
| the bandpass attenuation range (essential quality comparison data not
| provided and published by the manufacturers in order to mask how bad
| the bandpass is).
|=20
| The sensor transmitters:
|   In wireless alarm systems the transmitting power is limited by law
| and by reasonable battery live time.
|   The RF transmitter power of the sensors is of the order of 10
| milliWatt (mW), low, very low.
|=20
| COMPARISON:
| - The receive end is 100,000 times more sensitive to signals in
| wireless versus wired (4uV / 400mV);
|  The ratio is even higher because the high frequencies, where
| disturbing transmissions occurs, are attenuated by low pass filters at
| the input of the wired lines.
|=20
| - The link in wired systems are wires who can be filtered/shielded
| against RF interferences (and by location of the wires); in wireless
| it is the open air reachable by everybody, no shielding possible.
|=20
| CONCLUSION:
| - An external RF transmitter can disturb both systems but the power
| required to do this is much higher in wired systems (>100,000 times).
| - In wireless systems, the power required to interfere and disturb the
| system is similar to the sensor power (10mW) when generated at the
| same distance, RFI power should be increased if the distance is
| increased.
| - Wireless alarm systems are not reliable, they can be interfered and
| disturbed/muzzled due too and by an outside transmission.
|=20
| FINAL NOTE:
| - Don't forget that in order to interfere wireless alarm systems that
| the RF disturbing signal source should satisfy some frequency
| requirements.
| - Wireless alarm systems are unreliable when there is a Transmitters
| in the vicinity operating:
| - ON the wireless frequency
| - Saturating the receiver
| - provoking intermodulation
| - having harmonics
| - Falling aside in the receiver bandpass
| - On the IF frequency
| - and more...
| In essence the problems caused can be defined as a "Radio Frequency
| Interference (RFI)" and is the fact that by no way two (or more)
| systems can use simultaneously the same receiver input.
|  THIS RFI muzzle and jeopardize completely the normal operation you
| expect from an alarm system.
|=20
|  For example; cell phones with theyre 2 watt power don't satisfy that
| frequency dependent requirement and as such don't disturb normally.
|=20
| If the above don't convince you to "GO WIRED", well...
|  Will seller talk without reliability measurement tools and required
| electronic and radio technical knowledge and manufacturer support
| about theyre wireless performance and reliability warranty clause
| convince you, well be Happy, your ON.
|=20
|=20
|