ITU grid Flashcards
How many channels in the ITU grids
72
Name three kinds of spacing in the ITU grid
50 ghz 100ghz 200 ghz
Where does the red band start?
1546.12 nm and higher.
Where does the blue band start?
1546.12 nm and lower
What times what equals the speed of light
Terra hertz frequency of the wave times the ITU designation.
192.1 x 1550.92 = speed of light
1550.92 is an example of what kind of spacing
Red wave
How many channels in the L band?
?
How many channels are in the C band?
72
What is the acronym for the different channels
Our Excellent soldiers can lick yours ??
Channel 1531 is in which band?
?
1550.92 is in which band
?
1625 is in which band?
?
How fast is the speed of light?
?
How many channels are in the C band?
?
How many channels in the L band?
?
What does ITU stand for?
?
What is the range of the L band?
L-Band: 1571nm to 1611nm
What is the range of the C band?
C-Band:1531nmto 1570nm
Name all of the bands.
O, E, S, C, L
What does the C in CWDM stand for?
Coarse
What is the channel spacing in nm for the C band?
The spacing is 20nm
1270nm -> 1610nm
What is the usual span limit for CWDM?
around 60km for a 2.5Gb circuit.
Why can’t CWDM use EDFA amplifiers?
the signals are not spaced appropriately for amplification by EDFAs.
EDFAs are effective for what wavelengths in the C band?
effective for wavelengths between approximately 1525–1565 nm (C band)
EDFAs are effective for what waves in the L band?
effective for wavelengths between 1570–1610 nm (L band).
What is an OSC Channel used for?
Optical Supervisory Channel (OSC). This is data channel which uses an additional wavelength usually outside the EDFA amplification band (at 1,510 nm, 1,620 nm, 1,310 nm or another proprietary wavelength). It can carry data, orderwire, network management, etc.
Why do DWDMs have to maintain a more stable and tighter tolerance frequency than CWDM
The spacing is very close in DWDM systems, and a precision temperature control will help eliminate drift off of a very narrow frequency window.
What does 3R mean?
Retime, Reshape, Retransmit.
Whats a muxponder?
(Multiplexed Transponder) - It can do some simple time-division multiplexing of lower-rate signals into a higher-rate carrier within the system (a common example is the ability to accept 4 OC-48s and then output a single OC-192 in the 1,550 nm band).
What does ROADM stand for?
Reconfigurable Optical Add Drop Multiplexer.
Transceiver vs Transponder
A transponder can be made up of two transceivers placed after each other: the first transceiver converting the 1550 nm optical signal to/from an electrical signal, and the second transceiver converting the electrical signal to/from an optical signal at the required wavelength.
What is a PhotoDiode?
It is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the photodiode.
What is the OTU2 rate?
10.70Gbps
What is the OTU2e rate?
11.09Gbps -
Transports a 10 Gigabit Ethernet local area network (LAN) PHY coming from IP/Ethernet switches and routers at full line rate (10.3 Gbit/s). This is specified in G.Sup43.
What is OTU4 rate?
112Gbps -
Transports a 100 Gigabit Ethernet signal
What is OTU3 rate?
43Gbps
Transports an OC-768 or STM-256 signal or a 40 Gigabit Ethernet signal.[2]
What are the typical signals an OTN at the Optical channel layer processes?
OTN
SONET/SDH
Ethernet/FibreChannel
Packets
Whats a key feature of OTN?
Offer transparent service delivery.
Does OTN introduce Jitter or latency into the network?
OTN is an optical technology that introduces virtually no latency or jitter into the network.
This increases application throughput, eliminates the need for constant network tuning and improves overall network performance.
PMD stands for what?
Polarization Mode Dispersion.
Describe PMD.
its a form of modal dispersion where TWO different polarizations of light in a waveguide, which normally travel at the same speed, travel at different speeds due to random imperfections and asymmetries, causing random spreading of optical pulses.
