Black Box LMC7004A-R4 User Manual
BLACK BOX
®
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05/14/2010
#20400
Single-strand fiber WDM.
Traditional fiber optic media converters perform a useful func-
tion but don’t really reduce the amount of cable needed to send
data on a fiber segment. They still require two strands of glass to
send transmit and receive signals for fiber media communications.
Wouldn’t it be better to combine these two logical communica-
tion paths within one strand?
data on a fiber segment. They still require two strands of glass to
send transmit and receive signals for fiber media communications.
Wouldn’t it be better to combine these two logical communica-
tion paths within one strand?
That’s exactly what single-strand fiber conversion does. It
compresses the transmit and receive wavelengths into one single-
mode fiber strand.
mode fiber strand.
The conversion is done with Wavelength Division Multiplexing
(WDM) technology. WDM technology increases the information-
carrying capacity of optical fiber by transmitting two or more sig-
nals simultaneously at different wavelengths on the same fiber.
The way it usually works is that one unit transmits at 1550 nm and
receives at 1310 nm. The other unit transmits at 1310 nm and
receives at 1550 nm. The two wavelengths operate independently
and don’t interfere with each other. Wavelength-sensitive filters
are used at the receiving end to separate the wavelengths.
carrying capacity of optical fiber by transmitting two or more sig-
nals simultaneously at different wavelengths on the same fiber.
The way it usually works is that one unit transmits at 1550 nm and
receives at 1310 nm. The other unit transmits at 1310 nm and
receives at 1550 nm. The two wavelengths operate independently
and don’t interfere with each other. Wavelength-sensitive filters
are used at the receiving end to separate the wavelengths.
This bidirectional traffic flow effectively converts a single fiber
into a pair of “virtual fibers,” each driven independently at differ-
ent wavelengths.
ent wavelengths.
WDM on single-strand fiber is most often used for point-to-
point links on a long-distance network. It’s also used to increase
network capacity or relieve network congestion.
network capacity or relieve network congestion.
Although the WDM used in media converters typically offers
two channels on single-strand fiber at 10-, 100-, or 1000-Mbps
speeds, WDM is a rapidly evolving techology that’s increasing the
capacity of fiber infrastructure by leaps and bounds.
speeds, WDM is a rapidly evolving techology that’s increasing the
capacity of fiber infrastructure by leaps and bounds.
Coarse wavelength-division multiplexing (CWDM) uses wave-
lengths between 1310 nm and 1610 nm and usually multiplexes
signals across eight channels, although some versions support
up to 16 channels. The relatively new 10GBASE-LX4 Ethernet
standard achieves its 10-Gigabit speeds by using CWDM to divide
the data stream into four separate 3.125-Gbps channels for trans-
mission over fiber cable.
signals across eight channels, although some versions support
up to 16 channels. The relatively new 10GBASE-LX4 Ethernet
standard achieves its 10-Gigabit speeds by using CWDM to divide
the data stream into four separate 3.125-Gbps channels for trans-
mission over fiber cable.
Dense wavelength-division multiplexing (DWDM) uses the
1550-nm band and increases channel density even more. It can
achieve as many as 64 channels on a single fiber strand. With
DWDM it’s possible to achieve speeds of hundreds of Gbps across
a single fiber. Its ability to handle vast amounts of traffic — even
different kinds of traffic moving at different speeds — makes
DWDM the technology of choice for metropolitan area networks.
Companies that offer TV, Internet, and phone service on fiber use
this technology.
achieve as many as 64 channels on a single fiber strand. With
DWDM it’s possible to achieve speeds of hundreds of Gbps across
a single fiber. Its ability to handle vast amounts of traffic — even
different kinds of traffic moving at different speeds — makes
DWDM the technology of choice for metropolitan area networks.
Companies that offer TV, Internet, and phone service on fiber use
this technology.
technically Speaking