Overview
The PCX5000 provides you with high-speed data communications over the television cable network
by following the widely accepted DOCSIS standard. This standard, as defined by CableLabs™,
offers a combination of high performance and interoperability among all major cable system
operators in North America.
How does the PCX5000 work?
Digital signals are represented by high and low electrical voltage levels. The speed of how fast these
levels can switch and still be transmitted is determined by the "bandwidth" of the transmission
system. The pair of wires used in a telephone connection has a greatly limited bandwidth because of
their electrical characteristics. When a device called a modem is connected between the computer
output and the phone line, it generates an electrical wave whose strength and phase change in step
with the highs and lows of the computer's digital output. It is because of the "smoothness" of the
resultant signal that a higher data rate can be transmitted.
A cable modem “ modulates” and “demodulates” electrical signals in the same way that the telephone
modem does. However, since coaxial cable can transmit much higher frequencies, cable modems
are far more complex. None of the activity caused by the PCX5000 disturbs your regular cable TV
reception.
How does the PCX5000 connect to a computer?
The 10/100 Ethernet connection, USB connection and 802.11b wireless connection used in this
device are emerging as the most popular means of networking computers together and to the
Internet.
How does the PCX5000 differ from a stand-alone DOCSIS
cable modem?
The standalone cable modem is designed to connect one computer. The PCX5000 is designed to
connect multiple computers using 10/100 Ethernet, USB and 802.11b wireless interface. For
standalone cable modems, you typically need to purchase an additional networking device called a
router to connect more than one computer to the cable modem. With the PCX5000, all of your
computers can share your high-speed connection.
The PCX5000 also includes advance security features such as a Stateful Inspection firewall that can
protect your personal information and your equipment from malicious damage by hackers. The
PCX5000 Stateful Inspection firewall is intelligent enough to know what applications should be
allowed to access your network, and those that should be excluded.
What is DOCSIS?
D
ata
O
ver
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able
S
ervice
I
nterface
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pecifications. DOCSIS defines interface requirements for cable
modems involved in high-speed data distribution over a cable television network. On November 17,
1997, Cable Television Laboratories, Inc. (CableLabs) and its members established a formal path of
certification for cable modem equipment suppliers to obtain an interoperability seal for their products
based on the DOCSIS specification. This certification process provides cable modem equipment
suppliers with a fast, market-oriented method for attaining cable industry acknowledgment of
compliance with DOCSIS.
