Configuration Files; Downstream And Upstream Transmissions; Cable Frequencies; Modulation - Hitron CVE-30360 User Manual

HITRON CVE-30360 USER'S GUIDE
When the CVE-30360 is not in routing mode, the service provider assigns an IP
address to each computer connected to the CVE-30360 directly. The CVE-30360
does not perform any routing operations, and traffic flows between the computers and
the service provider.
Routing mode is not user-configurable; it is specified by the service provider in the
CVE-30360's configuration file.
2.1.7

CONFIGURATION FILES

The CVE-30360's configuration (or config) file is a document that the CVE-30360
obtains automatically over the Internet from the service provider's server, which
specifies the settings that the CVE-30360 should use. It contains a variety of settings
that are not present in the user-configurable Graphical User Interface (GUI) and can
be specified only by the service provider.
2.1.8

DOWNSTREAM AND UPSTREAM TRANSMISSIONS

The terms "downstream" and "upstream" refer to data traffic flows, and indicate the
direction in which the traffic is traveling. "Downstream" refers to traffic from the
service provider to the CVE-30360, and "upstream" refers to traffic from the CVE-
30360 to the service provider.
2.1.9

CABLE FREQUENCIES

Just like radio transmissions, data transmissions over the cable network must exist
on different frequencies in order to avoid interference between signals.
The data traffic band is separate from the TV band, and each data channel is
separate from other data channels.
2.1.10

MODULATION

Transmissions over the cable network are based on a strong, high frequency periodic
waveform known as the "carrier wave." This carrier wave is so called because it
"carries" the data signal. The data signal itself is defined by variations in the carrier
wave. The process of varying the carrier wave (in order to carry data signal
information) is known as "modulation." The data signal is thus known as the
"modulating signal."
Cable transmissions use a variety of methods to perform modulation (and the
"decoding" of the received signal, or "demodulation"). The modulation methods
defined in DOCSIS 3 are as follows:

QPSK: Quadrature Phase-Shift Keying

QAM: Quadrature Amplitude Modulation

QAM TCM: Trellis modulated Quadrature Amplitude Modulation
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CABLE