18 Feb 2008 04:53:24 | Max Penn
Prevent phone monitoring with digital spread spectrum
If you are using an analog cordless or cellular telephone,
someone is listening to your conversations!
You'll notice I did not say someone might be listening to your
telephone conversations, or there is a possibility that your
telephone conversations can be overheard.
Simply put, your telephone conversations are being monitored!
Radio hobbyists, with their scanners being used as spy
equipment, have the capability to listen to telephone
conversations and we must assume that a small percentage do from
time to time.
Beyond these hobbyists, however, is an underground culture of
scanner users who make specific efforts to monitor telephone
conversations. This underground culture ranges from individuals
wanting nothing more than to satisfy their personal curiosity,
to news reporters lookng for leads, to private eyes gathering
information for a case, to criminals listening for credit cards
numbers, SSN's, or other information to be used in the
furtherance of a crime. Beyond this, various law enforcement and
security agencies may monitor telephones for their own purposes.
But wait, you say--it's illegal to monitor telephone
conversations. It's even illegal for the police to do so without
a warrant. True, it's illegal to monitor telephone
conversations, but do you really think that noone's listening? A
law is nothing more than words and, in and of itself, does
nothing to prevent that which it proscribes. The chance of
getting caught doing phone monitoring are almost nil, and when
have you heard of anyone being prosecuted for monitoring a
cordless phone?
HOW TO PREVENT IT One way to prevent monitoring of your
telephone conversations is through the use of digital spread
spectrum technology. To understand this, we first need to be
aware that telephones are either analog or digital. Analog
telephones are nothing more than radio transmitters sending
signals between the telephone and the cell site in the case of
cellular phones and between the handset and the base plugged in
the wall socket in the case of cordless phones.
Any radio scanner can be programmed to receive the cordless
telephone frequencies. Newer scanners have the cellular
telephone frequencies block, but these frequencies can be
unblocked by anyone with a basic knowledge of radio electronics.
Digital telephones are also radio transmitters, but a digital
signal is unintelligible when heard on an analog receiver. Of
course, a digital receiver would receive a digital telephone
signal were it programmed to the appropriate frequency. However,
here is where spread spectrum technology comes in.
Spread spectrum was first used during World War II as a method
to prevent torpedos being jammed en route to their target.
Digital spread spectrum uses a signal spread over a number of
frequencies. These signals are difficult to intercept and
demodulate and are resistant to jamming or interference. This
provides for a clearer and cleaner telephone signal, as well as
preventing monitoring of the signal itself. It is also worth
noting that cordless telephones are now available with an
operating frequency of 2.4 GHz. Since most scanners do not
receive into the gigahertz range, this gives additional
protection against interception and phone monitoring of your
telephone signal as it is transmitted between the handset and
the base.
About Author :
Max Penn is the man behind the respected Spy equipment
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