ANALYSIS AND SYNTHESIS OF OPTICAL BURST SWITCHED NETWORKS Li 1. shuo Supervisor: Prof. Moshe Zukerman Co-supervisor: Dr Eric W. M. Wong Further Credits: Dr V Abramov, Dr. Meiqian Wang and Zhang Jianan Jan.06,2014
ANALYSIS AND SYNTHESIS OF OPTICAL BURST SWITCHED NETWORKS Li, Shuo Supervisor: Prof. Moshe Zukerman Co-supervisor: Dr. Eric W. M. Wong Further Credits: Dr. V. Abramov, Dr. MeiqianWang and Zhang Jianan Jan. 06, 2014 1
Outline B ackoround: Optical burst switching (OBS Bounds for blocking probability obtained by Overflow Priority Classification Approximation(OPCA)in OBS networks with deflection routin o Effective and ineffective utilizations in obs networks EBSL-a combination of Emulated-OBS(E-OBS) segmentation and least remaining hop-count first ( LRHF .Q&a
Outline Background: Optical burst switching (OBS) Bounds for blocking probability obtained by Overflow Priority Classification Approximation (OPCA) in OBS networks with deflection routing Effective and ineffective utilizations in OBS networks EBSL – a combination of Emulated-OBS (E-OBS), segmentation and least remaining hop-count first (LRHF) Q & A 2
Outline Background: Optical burst switching(ObS) o Bounds for blocking probability obtained by Overflow Priority Classification Approximation(OPCA) in OBS networks with deflection routing Effective and ineffective utilizations in OBS networks EBSL-a combination of Emulated-OBS(E-OBS segmentation and least remaining hop-count first (RHF) ●Q&A
Outline Background: Optical burst switching (OBS) Bounds for blocking probability obtained by Overflow Priority Classification Approximation (OPCA) in OBS networks with deflection routing Effective and ineffective utilizations in OBS networks EBSL – a combination of Emulated-OBS (E-OBS), segmentation and least remaining hop-count first (LRHF) Q & A 3
Optical networks Ever-increasing demand for higher bandwidth o Bandwidth intensive applications-voice over IP, video-on-demand Fast increasing number of Internet users Internet Users In the World Growth1995-2010 Solution: Optical data communication 1093 Use circuit switching( CS)& packet switching(PS) 248 Drawbacks 1990 0002005201 2015 Year CS: low bandwidth efficiency PS: buffer high energy consuming
Optical networks 4 Ever-increasing demand for higher bandwidth Bandwidth intensive applications – voice over IP, video-on-demand Fast increasing number of Internet users Solution: Optical data communication Use circuit switching (CS) & packet switching (PS) Drawbacks: CS: low bandwidth efficiency PS: buffer & high energy consuming 16 36 70 147 248 361 513 587 719 817 1018 1093 1262 1400 1530 1650 0 200 400 600 800 1000 1200 1400 1600 1800 1990 1995 2000 2005 2010 2015 Millions of Users Year Internet Users In the World Growth 1995-2010
Optical Burst Switching(OBS) OXC: optical cross-connect Packets Core Trunk a group of fibers Network Packet 2 connecting two OXCs Packet 4 Network A trunk Access Network Packet 1 Packet 2 ● Network Packet 3 Packet 4 Netw Packets with the same destination are aggregated at ingress nodes to form bursts A control packet is sent ahead of a burst to reserve wavelength channels along the transmission path hop b pp by hop ) Bursts may be dumped before reaching their destinations
Optical Burst Switching (OBS) OXC: optical cross-connect • Packets with the same destination are aggregated at ingress nodes to form bursts • A control packet is sent ahead of a burst to reserve wavelength channels along the transmission path hop by hop • Bursts may be dumped before reaching their destinations A trunk 5 Trunk: A group of fibers connecting two OXCs
Outline Background: Optical burst switching (OBS o Bounds for blocking probability obtained by overflow Priority Classification Approximation(OPCA) in OBS networks with deflection routin Effective and ineffective utilizations in Obs networks EBSL-a combination of Emulated-OBS (E-OBS segmentation and least remaining hop-count first (RHF o&A
Outline Background: Optical burst switching (OBS) Bounds for blocking probability obtained by Overflow Priority Classification Approximation (OPCA) in OBS networks with deflection routing Effective and ineffective utilizations in OBS networks EBSL – a combination of Emulated-OBS (E-OBS), segmentation and least remaining hop-count first (LRHF) Q & A 6
Network model PA e Independent poisson process of arriva Holding times Independently, exponent 17 distributed with unit mean Full wavelength conversion MA G The offered load to each GA source-destination(SD) is identical S ource WA CAl CAl CA2 TX GA Destination MD MA CD NY MA Source MD IL MA CD NY MA DestinationWA CAI CAl CA2 TX GA
Network model 7 Source WA CA1 CA1 CA2 TX GA Destination MD IL MA CD NY MA Source MD IL MA CD NY MA Destination WA CA1 CA1 CA2 TX GA Independent Poisson process of arrivals Holding times - independently, exponentially distributed with unit mean Full wavelength conversion The offered load to each source-destination (SD) pair is identical
One Contention Resolution method Deflection routing A B C Reservation of burst 1 B C - Reservation of burst 2 Performance study of OBS networks with deflection routing Blocking probability no. of lost bursts blocking probabili no. of sent bursts 8
One Contention Resolution Method Blocking probability 8 Performance study of OBS networks with deflection routing Deflection routing no of sent bursts no of lost bursts Blocking probability . . =
Erlang Fixed Point Approximation(EFPA) decouple a given system into independent trunks o traffic offered to each trunk follows an independent poisson process Overflow Error Path Error Poisson error underestimate overestimate Independence error underestimate overestimate Overflow error--ignore high variance of deflected traffic and dependence Path error--ignore the effect of traffic smoothing, and the positive correlation of trunk occupancy alons the th that increases the probability to admit bursts
Erlang Fixed Point Approximation (EFPA) 9 Overflow error -- ignore high variance of deflected traffic and dependence Path error-- ignore the effect of traffic smoothing, and the positive correlation of trunk occupancy along the path that increases the probability to admit bursts decouple a given system into independent trunks traffic offered to each trunk follows an independent Poisson process
Overflow Priority classification Approximation(OPCA) o Define a surrogate model based on classifying the traffic into different layers(priorities) ayer i for traffic deflected i times Strict priority regime o Junior bursts- higher priori Senior bursts -lower priority The surrogate is without inter-layer mutual dependence (but may still have intra-layer mutual dependence) Solve the surrogate system by applying EFPA-like algorithm in each layer
10 Overflow Priority classification Approximation (OPCA) Define a surrogate model based on classifying the traffic into different layers (priorities) Layer i for traffic deflected i times Strict priority regime Junior bursts – higher priority Senior bursts –lower priority The surrogate is without inter-layer mutual dependence (but may still have intra-layer mutual dependence) Solve the surrogate system by applying EFPA-like algorithm in each layer
