Lambda Networks DWDM Vara Varavithya Department of Electrical Engineering King Mongkut s Institute of Technology North Bangkok vara@kmitnb.ac.th
Treads in Communication Information: High Speed, Anywhere, Anytime, Everyone. Optical Networking Research has been conducted over the past 20 years. Optical WDM technology has been emerged in the marketplace.
Fiber-optic Technology Huge bandwidth-- 50Tbps Low material usage Low cost Low signal attenuation-- 0.2 db/km Low Space requirements, and
Bandwidth Demand Single Computer-- PCI Express: 133MHz--64 bits with peak transfer of 8.512 Gbps Electronic speed is limited to a few Gbps While Fiber has four orders of magnitude more in capacity (50Tbps)
Bandwidth Demand The demand is much higher than high speed ATM can offer. Newly adopt applications Voice Video Conferencing, Movie on Demand WWW, JAVA Applications
How to make use of fiber bandwidth? Code division multiplexing (CDM) Time division multiplexing (TDM) Both CDM and TDM are limited by electronic speed. Wave-length division multiplexing (WDM) current favorite multiplexing techniques
C band (1520-1565nm) L band (1565-1625nm) S band (1460-1530nm) 10.92 Tbps has been demonstrated using this combination O band (1260-1360nm)
WDM End-user equipment needs to operate at the bit rate of a WDM Channel. The optical transmission spectrum is divided into a number of nonoverlapping wavelength. Multiplexing large numbers of wavelengths (lambdas) onto a single fiber Coarse Wave Division Multiplexing (CWDM) 20nm Dense Wave Division Multiplexing (DWDM) 1.6nm
From: Overview of Wideband Optical Fiber Amplification Technologies, Makoto Yamada
Erbium-Doped FiberAmplifer DWDM over long distances EDFA: enabling technology 120km between amplifier
WDM It is easier to create WDM device because it operate only at electronic speed. Now deploy mainly in backbone networks End user s aggregate activities can be used close to the peak electronic transmission rate. Each fiber can carry 100s of parallel wavelength
Point to Point WDM In some case, WDM is more economical than lay down more fiber. OC-n -- n * 51.84 Mbps OC-48: 2.5 Gbps, OC-192: 10Gbps, OC-768: 40Gbps OC-768 is the next step of electronic communication speed
Point to Point WDM From WDM Optical Communication Networks: Progress and Challenges, B. Mukherjee
Point to Point WDM
Wave-length Add/Drop MUX the signal on the corresponding wavelength is dropped. a new data stream can be added. From WDM Optical Communication Networks: Progress and Challenges, B. Mukherjee
Fiber and wavelength Crossconnects Passive Star Broadcast Device, no power needed Passive Router Static Route, allow wavelength reuse, no power needed Active Switch Allow wavelength reuse Dynamic Route- Wide area network, electronic control, need power, less fault tolerant Wavelength Convertor
Passive Star From WDM Optical Communication Networks: Progress and Challenges, B. Mukherjee
Passive Router
Passive Star is used to build Local WDM Network Tunable Transmitters and Receivers Support Multicast Active Switch is for WAN Environment
Active Switch
Optical Switch Fabric 2D 3D
From WDM Optical Communication Networks: Progress and Challenges, B. Mukherjee Wavelength-Routed
Wavelength Route Each node has a set of transmitters and receivers, tunable Lightpath: All optical communication between two nodes. may span more than on fiber links Without wavelength-conversion: same wavelength channels
WDM Problems All optical lightpaths Circuit Switching Wavelength Allocation We target for all optical networks
Electro-Optical Networks Transport plane: Data plan, covey user information between location. Control plane: performs the call control and connection control functions Management Plane: performs management Functions From: Optical Networks--the electro-optic reality, Andrzej Jajszczyk
Interconnection Model Overlay: no routing information exchange between IP and Optical Pear Model: Using single control plan, common addressing schemes Augmented Model: Compromise between the overlay and the peer From: Optical Networks--the electro-optic reality, Andrzej Jajszczyk
IP over Fiber IP ATM IP IP SONET ATM SONET IP OPTICAL OPTICAL OPTICAL OPTICAL
Protocol Control Planes SONET Based IP Overlay Approach IP ATM IP ATM SONET IP Direct Lambda SONET WDM IP Physical Optic Layers
GROOMING Traffic Grooming: efficient multiplexing/ demultiplexing low-speed traffic streams onto/from high speed trunk Wavelength utilization Assign low rate circuit to wavelength
Optical Packet Switching Normally employ circuit switching Connections in switching nodes are set up by external control signal from management of control plane Not match with packet-oriented Traffic From: Optical Networks--the electro-optic reality, Andrzej Jajszczyk
Packet Switch in WDM Switching time require in order of nano second Can use an optical switch with electronic header processing Using fiber delay line From: Optical Networks--the electro-optic reality, Andrzej Jajszczyk
Case Study: OptIputer, Quatzite, and Starlight Projects Dedicate optical connections versus shared internet connection Begining of the use private 1 Gbps or 10 Gbps light pipe create deterministic network between laboratory Using Lambda connect Linux clusters
OptIPuter: create interactive visualization as easy as Web Quartzite: connects over 300 cluster nodes at UCSD, moving toward packet switching only... apart from optical-circuit-only Using packet switch that tightly coupled with MEM passive optical switch
Plug lab instrument of cluster to fiber uplink core Backbone carries multiple standby allocatable lambda in addition to the common shared Internet Target 100s of 10Gbps bisection bandwidth Now Quartzite core handle up to 32 ten- Gbps
Conclusions Overview of DWDM Key enabling technologies Next level of bandwidth Dedicate light path between end points Barebone optical networks