Digital Packet Data
Cellular Digital Packet Data (CDPD) systems offer what is currently one of the
most advanced means of wireless data transmission technology. Generally used as
a tool for business, CDPD holds promises for improving law enforcement communications
and operations. As technologies improve, CDPD may represent a major step toward
making our nation a wireless information society. While CDPD technology is more
complex than most of us care to understand, its potential benefits are obvious
even to technological novices.
In this so-called
age of information, no one need to be reminded of speed but also accuracy in the
storage, retrieval and transmission of data. The CDPD network is a little one
year old and already is proving to be a hot digital enhancement to the existing
phone network. CDPD transmits digital packet data at 19.2 Kbps, using idle times
between cellular voice calls on the cellular telephone network.
represent a way for law enforcement agencies to improve how they manage their
communications and information systems. For over a decade, agencies around the
world have been experimenting with placing Mobile Data Terminals(MDT) in their
vehicles to enhance officer safety and efficiency.
Early MDT's transmits
their information using radio modems. In this case data could be lost in transmission
during bad weather or when mobile units are not properly located in relation to
transmission towers. More recently MDT's have transmitted data using analog cellular
telephone modems. This shift represented an improvement in mobile data communications,
but systems still had flaws which limited their utility.
the mid-1990's, computer manufacturers and the telecommunication industry have
been experimenting with the use of digital cellular telecommunications as a wireless
means to transmit data. The result of their effort is CDPD systems. These systems
allow users to transmit data with a higher degree of accuracy, few service interruptions,
and strong security. In addition CDPD technology represent a way for law enforcement
agencies to improve how they manage their communications and information systems.
This results in the capacity for mobile users to enjoy almost instantaneous access
WHAT IS CDPD?
is a specification for supporting wireless access to the Internet and other public
packet-switched networks. Data transmitted on the CDPD systems travel several
times faster than data send using analog networks
and modem providers that offer CDPD support make it possible for mobile users
to get access to the Internet at up to 19,2 Kbps. Because CDPD is an open specification
that adheres to the layered structure of the Open Systems Interconnection (OSI)
model, it has the ability to be extended in the future. CDPD supports both the
Internet's Connectionless Network Protocol (CLNP).
also supports IP multicast (one-to-many) service. With multicast, a company can
periodically broadcast company updates to sales and service people on the road
or a news subscription service can transmit its issues as they are published.
It will also support the next level of IP, IPV6. With CDPD we are assigned our
very own address. With this address, we are virtually always connected to our
host without having to keep a constant connection.
are currently two methods for sending data over cellular networks: cellular digital
packet data (CDPD) and cellular switched-circuit data (CSCD). Each has distinct
advantages depending on the type of application, amount of data to send or receive,
and geographic coverage needs.
Blu Ray Disc
Bluetooth Based Smart Sensor Networks
Bluetooth Network Security
Boiler Instrumentation and Controls
Wireless Integrated Network Sensors
Buffer Overflow Attack
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