Cisco Model GS7000 4-Port Node 1 GHz with 42 54 Split インストールガイド
Glossary
56
4024769 Rev A
PWB
printed wiring board.
Q
QAM
quadrature amplitude modulation. A phase modulation technique for representing digital
information and transmitting that data with minimal bandwidth. Both phase and amplitude
of carrier waves are altered to represent the binary code. By manipulating two factors, more
discrete digital states are possible and therefore larger binary schemes can be represented.
information and transmitting that data with minimal bandwidth. Both phase and amplitude
of carrier waves are altered to represent the binary code. By manipulating two factors, more
discrete digital states are possible and therefore larger binary schemes can be represented.
R
RCVR
receiver.
reverse path
Signal flow direction toward the headend.
RF
radio frequency. The frequency in the portion of the electromagnetic spectrum that is above
the audio frequencies and below the infrared frequencies, used in radio transmission systems.
the audio frequencies and below the infrared frequencies, used in radio transmission systems.
RFI
radio frequency interference.
RMA
return material authorization. A form used to return products.
router
A data communications device which examines a packet and routes the packet to an output
port appropriate to the packet destination. On the Internet, a router is a device or, in some
cases, software in a computer that determines the next network point to which a packet
should be forwarded toward its destination. The router is connected to at least two networks
and decides which way to send each information packet based on the router’s current
understanding of the state of the networks it is connected to. A router creates or maintains a
table of the available routes and their conditions and uses this information along with
distance and cost algorithms to determine the best route for a given packet.
port appropriate to the packet destination. On the Internet, a router is a device or, in some
cases, software in a computer that determines the next network point to which a packet
should be forwarded toward its destination. The router is connected to at least two networks
and decides which way to send each information packet based on the router’s current
understanding of the state of the networks it is connected to. A router creates or maintains a
table of the available routes and their conditions and uses this information along with
distance and cost algorithms to determine the best route for a given packet.
RX
receive or receiver.
S
S/N or SNR
signal-to-noise ratio. The ratio, in decibels, of the maximum peak-to-peak voltage of the video