▲Uniden Data 2000Wireless CDPD PC Card
1-2What is CDPD?
CDPD or Cellular Digital Packet Data is a wireless, public access, pack-
et data standard designed to operate over existing analog cellular
phone systems. Since it is designed to use existing cellular phone sys-
tems, CDPD provides a large coverage area, low service pricing, and
fast transaction execution. CDPD’s primary benefit is quick, inexpen-
sive, and efficient transmission of data packets over the existing cellu-
lar network. Additional benefits include built-in encryption for security
(where applicable); a billing structure which charges for message size
rather than on-line time (depending on individual service provider’s
service plans); forward error correction methods that reduce the effects
of noise and interference on the airlink; and availability.
1.3What is the PCMCIA Standard for PC Cards?
Over the past several years, mobile computers have experienced
explosive growth. While prices have fallen sharply, features are becom-
ing more advanced and reliability has been greatly improved. One of
the most notable features of today’s mobile computers is the PC Card
slot. Over the last four years, the personal computer industry has rapid-
ly adopted the PC Card slot feature, and today nearly 75 percent of lap-
tops include a PC Card slot. This has been the driving force in the
innovation and development of PC Card technology.
In 1989, an international standards body and trade association was
founded, called the PCMCIA (Personal Computer Memory Card
International Association.). This organization was founded in order to
establish standards for Integrated Circuit cards and to promote inter-
changeability among mobile computers where ruggedness, low power,
and small size are critical.
Even though PCMCIA is a rather young technology, it has been quickly
adopted by every major personal computer manufacturer in the world.
Since it’s inception, PCMCIA has published a PC Card Standard which
contains all of the physical, electrical and software specifications for
PC Card technology. This standard is in a constant state of improve-
ment by the PCMCIA technical committee.
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