Hi on I am only going to post this one time here it go's.
        C e l l u l a r    T e l e p h o n y
        by
        B r i a n   O b l i v i o n
               A  -=Restricted -=Data -=Transmission
        The benefit of a mobile transceiver has been the wish of
experimentors         since the late 1800's.  To have the ablility to
be reached by another         man despite location, altitude, or depth
has had high priority in         communication technology throughout
its history.  Only until the late         1970's has this been
available to the general public.  That is when         Bell Telephone
(the late MaBell) introduced the Advanced Mobile         Phone Service,
AMPS for short.
        Cellular phones today are used for a multitude of different
jobs.         They are used in just plain jibber-jabber, data
transfer(I will         go into this mode of cellular telephony indepth
later), corporate         deals, surveillance, emergencies, and
countless other applications.         The advantages of cellular
telephony to the user/phreaker are         obvious:
                1.  Difficulty of tracking the location of a transciever
                    (especially if the transciever is on the move) makes
                    it very difficult to locate
                2.  Range of the unit within settled areas
                3.  Scrambling techniques are feasible and can be made
to                     provide moderate security for most transmissions.
                4.  The unit, with modification can be used as a bug,
being                     called upon by the controlling party from
anywhere on                     the globe.
                5.  It with the right knowledge one can modify the
cellular                     in both hardware and software to create a
rather diverse-                     iffied machine that will scan,
store and randomly change                     ESN's per call there by
making detection almost impossible.
        I feel it will be of great importance for readers to understand
the         background of the Cellular phone system, mainly due to the
fact that         much of the pioneering systems are still in use
today.  The first         use of a moblie radio came about in 1921
(remember prohibition?)         by the Detroit police department.  This
system operated at 2Mhz.  In         1940, frequencies between 30 and
40Mhz were made available to and         soon became overcrowded.  The
trend of overcrowding continues today.
        In 1946, the FCC declared a 'public corresponence system'
called,         or rather classified as "Domestic Public Land Mobile
Radio Service"         (DPLMRS) at 35 - 44 Mhz band that ran along the
highway between         New York and Boston.  Now the 35-44MHz band is
used mainly by Amateur         radio hobbiest's due to the bands
susceptibility to skip-propogation.
        These early mobile radio systems were all PTT(push-to-talk)
systems         that did not enjoy todays duplex conversations.  The
first real         mobile 'phone' system was the 'Improved Mobile
Telephone Service'         or the IMTS for short, in 1969.  This system
covered the spectrum         from 150 - 450MhHz, sported automatic
channel selection for each         call, eliminated PTT, and allowed
the customer to do thier own         dialing.  From 1969 to 1979 this
was the mobile telephone service         that served the public and
business community, and it is still         used today.
        IMTS frequencies used(MHz):
        Channel         Base Frequency          Mobile Frequency
        VHF Low Band
        ZO              35.26                   43.26
        ZF              35.30                   43.30
        ZH              35.34                   43.34
        ZA              35.42                   43.32
        ZY              34.46                   43.46
        ZC              35.50                   43.50
        ZB              35.54                   43.54
        ZW              35.62                   43.62
        ZL              35.66                   43.66
        VHF High Band
        JL              152.51                  157.77
        YL              152.54                  157.80
        JP              152.57                  157.83
        YP              152.60                  157.86
        YJ              152.63                  157.89
        YK              152.66                  157.92
        JS              152.69                  157.95
        YS              152.72                  157.98
        YA              152.75                  158.01
        JK              152.78                  158.04
        JA              152.81                  158.07
        UHF Band
        QC              454.375                 459.375
        QJ              454.40                  459.40
        QO              454.425                 459.425
        QA              454.45                  459.45
        QE              454.475                 459.475
        QP              454.50                  459.50
        QK              454.525                 459.525
        QB              454.55                  459.55
        QO              454.575                 459.575
        QA              454.60                  459.60
        QY              454.625                 459.625
        QF              454.650                 459.650
        VHF High frequencies are the most popular frequencies of all
        the IMTS band.  VHF low bands are used primarily in rural areas
        and those with hilly terrain.  UHF bands is primarily used in
cities         where the VHF bands are overcrowded.  Most large cities
will find         at least one station being used in their area.
        ADVANCED MOBILE PHONE SYSTEM
        The next step for Mobile telephone was made in 1979 by Bell
        Telephone, again (gee.. where was the competition?), introducing
        the Advanced Mobile Phone Service.  This service is the focus
        of this document, which has now taken over the mobile telephone
        industry as the standard.   What brought this system to life
        were the new digital technologies of the 1970's.  This being
        large scale integrated custom circuits and microprocessors.
        Without these technologies, the system would not have been
        economically possible.
        The basic elements of the cellular concept have to do with
        frequency reuse and cell splitting.
        Frequency reuse refers to the use of radio channels on the same
        carrier frequency to cover different areas which are seperated
by         a signifigant distance.  Cell splitting is the ability to
split         any cell into smaller cells if the traffic of that cell
requires         attitional frequencies to handle all the area's calls.
 These two         elements provide the network an opportunity to
handle more simul-         taneous calls, decrease the
transmitters/receivers output/input         wattage/gain and a more
universal signal quality.
        When the system was first introduced, it was allocated 40mHz in
--- GOMail v2.0 [DEMO] 04-03-38
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