TTM 1: Access and core networks, advanced:
“Optical access and transport networks”
Info and Intro
Autumn 2014
Info overview• Tutors:
– Adjunct assoc. professor Steinar Bjørnstad– Possible Guest lecture– The students
• Assistant: Katina Kralevska• Presentations, write name and e-mail on list
– What is the area of your project work? (2-3 keywords are sufficient)
– What do you know about optical networks?
• Working methods in colloquiums (..discuss..)• Curriculum overview• Tentative schedule
Form of lectures
• Based on colloquium form:– Some material is presented by Steinar and
guests – Some material is presented by students .. any
volunteers?– Hopefully we all learn something …
• Organised as 2 X 2 hour seminars in “Savannen and Arthur”, ITEM
Theme overview• Course Info & Intro – 1 hour (Steinar)• Optical components / transmission – 2 hours (Steinar)• Transmission continued, Core & Metro networks, Optical
circuit switching (OCS)– 2 hours (Steinar)
• Optical Transport Network (OTN) – 3 hours (Steinar,Tesfaye)
• Carrier Ethernet switching (Steinar, Jarle)• Protection switching - 3 hours (Steinar, Tewelde)• Control and Traffic management - 3 hours (Steinar, Alfredo)• Access networks - 3 hours (Steinar, Joakim, Haakon)• Optical burst / packet switching (OBS/OPS) - 3 hours
(Steinar, Halvard, Sonal)• Repetition – Greatest hits, Steinar• Total: 21 hours (+ repetition)
Tentative schedule• See web-pages
Curriculum / Info / Contacts
• Curriculum:Conference papers and Journal articles (Mostly ready, some to be decided)
• Info on web:http://www.ntnu.no/telematikk/academics/courses/ttm1/start
• [email protected], (Room….)– Tlf: 90081033– Katina Kralevska
Intro overview
• Growth rates
• Wavelength division multiplexing (WDM)
• Optical switching- circuit/wavelength- packet
• Some facts/observations
Internet growth• Moores law (CPU)
– Double performance every 18 months, from 1975-> • Computer performance
– Doubles every 21 months• Router performance
– Doubles every 21 months• Optical link performance
– WDM gave a period with cost reduction of two every 12 months
• Internet traffic trends• Growth trends Internet versus telephone
Internet traffic trends
1
1) Prediction made in 2000; believe the last years have not been that fast
What do you think will make the traffic grow in the future?
Link capacity growth trend• Example of overoptimistic prognosis:
Internet traffic forces routers to become ”wire speed”
Internet traffic > Voice traffic
(?)
Capacity increase in systems• Fiber based transport/core networks• Switching of high bitrates, Gb/s and Tb/s
V e i k a r t f o r o p t i s k e s y s t e m e r : K a p a s i t e t d o b l e s h v e r t å r ! !
0 . 0 1
0 . 1
1
1 0
1 0 0
1 0 0 0
1 0 0 0 0
1 0 0 0 0 0
1 9 8 0 1 9 8 5 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5Y e a r
Single
fiber c
apacity
(Gb/s)
2 x p e r y e a r
K i l d e :
V e r d e n s r e k o r di l a b o r a t o r i u m 1 0 , 9 2 T b / s !
Introduction of Wavelength Division Multiplexing (WDM)
World record in lab:2002
Currently 32 Tb/sOCF 2009
Wavelength division multiplexing
• Large capacity increase in optical fibers • Makes optical networking possible/interresting
Earlier
11 11
11 1111 1144 44
11
22
33
44
11
22
33
44
Tidligere utbygging
RegeneratorTerminalFiber
Før: 1 kanal pr fiber
Optiskforsterker
MultiplekserDemultiplekser
2,5 Gb/s =30000
Opptil20 000 000
WDM: 4-128 kanaler
pr fiberNåværende utbygging
Wavelength Division Multiplexing(WDM), mangedobler kapasitet i fiber
Electronic/electrooptical
Now
Optical amplifier
WDM: 4-128 channelspr fiber
1 channel pr fiber
Up to
Optical switches• Circuit switching
– Switches signals between fibers and/or wavelengths.
• Wavelength conversion– To avoid collision on wavelengths (in same fiber)
Optisk krysskopler
BølgelengdeKonverter
I1
I2
I3
I4
U1
U2
U3
U4Wavelengthconverter
Optical crossconnect
Packet switching• More complicated in the optical domain:
– Higher speeds needed in switches– Not (currently) available technology for optical processing
of headers etc.– The payload information is switched optically– Optical buffering is difficult
O X C C ontroller
N ode C ontro ller (e .g ., M PL S)
D elay <= header length+ processing tim e
H eader processor
To O XC -contro l
Skiller header og n yttelast
D M U X’er W D M signal
O ptiske buffere
O ptisk krysskopler
M U X’er signaler til W D M signal
Optical crossconnect (with or without wavelength conversion)
Optical buffers (to handle contention on output)
Mux of signals to a WDM signal
Separates header and payload
Demux of WDM signals
Some key facts
• Optical switching:– Optical circuit switches are available
• Switches fibers or wavelengths in fibers• Optical wavelength converters are not commercially
widely available• Optical packet switches in labs• Optical buffers/memory is a problem
• Rapid development in optical transmission:– Systems with more than 1 Tb/s are available– Higher than 30 Tb/s is demonstrated in the lab