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

• Steinar.Bjornstad@item.ntnu.no, (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