ANALOG
The
first cellular networks, introduced in the early 1980’s, were built on analog
technology. Analog networks were rapidly deployed in the country, providing
coverage from almost any calling area within the United States. The following
are characteristics of Analog:
·
The
earliest and most widely used cellular technology.
·
Its
extensive network has made it popular as a backup service available with
dual-mode phones since analog offers coverage areas that are without digital
coverage.
·
Phones
are typically less expensive than digital phones.
The
analog phone service operates in the following ways:
Base
station frequencies are 869-894 MHz.
Mobile
station frequencies are 824-849 MHz.
Number
of channels is 832 with 21 x 2 control channels.
Radiation
radius coverage is 2-20 Km.
Audio
signal modulation is Frequency Modulation (FM).
Frequency
deviation is +/- 12 kHz.
Control
signal modulation is Frequencies shift keying (FSK).
Frequencies
deviation is +/- 8 kHz.
Data
transmission rate is 10 kb/s.
DIGITAL
As
cellular technology evolved, digital technology entered the scene. Digital
technology transmits signals and data differently than the analog technology,
allowing for more efficient transmissions and enhanced sound quality. Digital
technology also enables additional calling service. However, because these
newer digital networks are still being built, they do not yet match the breadth
of coverage of analog networks. One reason behind the proliferation of
dual-mode phones, which offer digital service where available, and analog
service as a backup when digital is not available. The following are the
characteristics of digital technology:
·
Newer
technology offers a wide range of features from call waiting to e-mail
access
and more.
·
Digital
service costs less to provide, offers high quality sound and is less draining
on
battery life.
·
Digital
phones offer lots of features, from display screens to e-messaging
capabilities, but typically cost more to make.
·
Network
coverage is not yet as extensive as the analog network. Dual-mode phones
can
switch between analog and digital.
* For even
greater coverage flexibility, digital dual mode phones can operate on two
bandwidths or frequencies of 800 MHz
and 1900 MHz.
We
transmit TDMA @ 1.930 to 1.990 Giga Hz’s with 60 channels. The output power
is
Bursts
of Differential Quadrature Phase Shift Keying of pulsating modulating of digital data.
We
transmit GSM @ 1.930 to 1.990 Giga Hz’s with 124 channels with Pulsating
Digital
TDMA
data, which uses Gaussian minimum shift
keying modulation.
We
transmit CDMA @ 1.930 to 1.990 Giga Hz’s with 64 channels of pulsating digital data Using Spread
Spectrum modulations of Convolutional Encoding.
We
transmit IDen @ 800, 900, and 1.5 GHz with TDMA modulations. In the 900 MHz
band IDen combines a pair of 12.5 kHz channels to create a 25 kHz channel.
Using TDMA, the paired channels will be split into six time slots, effectively
tripling the RF capacity of each 900 MHz
Channels.