OM4 Multimode Fibers for the Next Generation of Enterprise Networks by linzhengnd

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									          OM4 Multimode Fibers for the
          Next Generation of Enterprise
                   Networks


                   John Kamino
          Product Manager, Multimode Fiber
                       OFS

Slide 1
            Fiber Optics LAN Section

  •  Part of the Telecommunications Industry
     Association (www.tiaonline.org)
  •  Formed 17 years ago
  •  Mission: to educate users about the benefits of
     deploying fiber in customer-owned networks
  •  FOLS provides vendor-neutral information




Slide 2
                      Fiber Optics LAN Section
          •  Current Members
             –    AFL Telecommunications
             –    Berk-Tek
             –    CommScope
             –    Draka Communications
             –    OFS
             –    Ortronics
             –    Panduit
             –    Sumitomo Electric Lightwave
             –    ADC
             –    Corning Incorporated
             –    Fluke Networks
             –    Tyco Electronics


Slide 3
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 4
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 5
                   IP Traffic Growth
  •  Global IP traffic will quadruple from 2009 to
     2014 – in other words, the Internet will be 4
     times larger!
  •  It will take 72 million years to watch the
     amount of video traffic that will cross Global IP
     networks in 2014
  •  Mobile data traffic will double every two years
     through 2014
                                 Cisco Visual Networking Index:
                                 Forecast and Methodology, 2009-2014
                                 June 10, 2010



Slide 6
          CAGR

          108%

          29%




          34%




Slide 7
                            Internet Applications
    •  Drivers:
          –  March 2010 – YouTube – 24 hours of video uploaded
             every minute 1
          –  May 2010 – YouTube hits 2 billion views/day 1
          –  February 2010 – Apple iTunes hits 10 billion song sales 2
          –  June 2010 – Facebook has 400 million active users,
             spending 500 billion minutes per month on site 4
          –  June 2010 – Apple reports 600,000 iPhone 4 sales in 1st
             day of presales 3


               1 http://mashable.com/2010/05/17/youtube-2-billion-views/
               2 http://www.apple.com/pr/library/2010/02/25itunes.html
               3 http://www.apple.com/pr/library/2010/06/16iphone.html
               4 http://www.facebook.com/press/info.php?statistics




Slide 8
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 9
              Two Basic Optical Fiber Types

           1. Multimode                        2. Single-mode
62.5 micron          50 micron                   ~8 micron


                                                               125 micron




              850 nm          Operating           1310 - 1625 nm
             & 1300 nm       Wavelengths
            50 um MMF (with its large core and low operating
             wavelength) drives source and systems costs
                                  down
Slide 10
                           Multimode Fiber
  •  Has large Numerical Aperture (NA), or cone of acceptance of light.
  •  Light entering outside of cone escapes out of core.
  •  Large NA allows for easier, less precise transmitter & connector
     alignment.
  •  Lowers cost of transmitter, connectors, and installation.


NA – Cone of
Acceptance of Light

                      θ


                                NA = 0.275 for 62.5 um
                                NA = 0.200 for 50 um
Slide 11
                   Singlemode Fiber
                          Small NA
  •  Requires precise alignment of transmitter & connectors;
     drives up cost of components, installation.




                         NA ~ 0.1 for SM


Slide 12
           Multimode or Singlemode?




Slide 13
                                  Multimode Fiber
                       •  Light Signal (pulse) travels along many modes, or paths.
                       •  Pulse spreading occurs due to Modal Dispersion,
                          or DMD (Differential Mode Delay)
                       •  Pulse spreading limits Bandwidth (transmission carrying capacity)




Input Pulse                                                                     Output Pulse



               1   0     1    0    1                      1    ?    ?    ?      ?
                                                         Excessive Pulse Spreading =
                                                        Intersymbol Interference (ISI) =
    Slide 14                                                       Bit Errors
             Refractive Index Profile in MMF
                    Cladding

                      Core




                                              An optimized Refractive
                                              Index Profile minimizes
                                                DMD and maximizes
                                                    Bandwidth
                                    n

  Refractive                                  Equalizes arrival times
 Index Profile                                   of all the modes

(Graded Index)
                                               n = c/vg

                               a
        r

 Slide 15
           Pulses of Light Traveling Through
                Multimode Optical Fiber

                    10 
Gb/s
              10 
Gb/s

                    Bit Period
            Bit Period





Fiber
Core





              Excessive              Minimal
            Modal Dispersion      Modal Dispersion

Slide 16
           LEDs vs. Vertical Cavity Surface Emitting Lasers



                                       Overfills core (large spot size)
                                          Excites all modes.
                                       Bandwidth performance
                                        dependant on all modes.
                                       Uniform, consistent power
                                        profile. Repeatable.

    Encircled Power   3D Power map


                                       Underfills core (small spot size)
                                          Excites fewer modes
                                       Bandwidth dependant on which
                                        modes happen to carry power.
                                       Non-uniform, fluctuating, non-
                                        repeatable power profile.


Slide 17
                LEDs vs. VCSELs
  LED         VCSEL 1   VCSEL 2   VCSEL 3
  All Modes




Slide 18
            Different VCSELs give Different
           Bandwidth, even on the same fiber
VCSEL A




                                     Output Pulse
                     Same Fiber
VCSEL B




                                     Output Pulse

Slide 19
                    DMD Measurement Provides a Means to
                     Assess Bandwidth for Specific Modes
                            (per TIA FOTP-220 or IEC 60793-1-49)

      DMD Scanning Process                      DMD Scan Example
                               High                          DMD

                               Speed
                               Detector
SM 850 nm Laser



SM 850 nm Laser
                    Core


SM 850 nm Laser




                   DMD = Difference in delay between
                  the earliest and latest arriving pulses
      Slide 20
                      DMD Specifications - Mask Method
                                (TIA-492AAAC-A or IEC 60793-2-10)
                                                                         Radius
                                                 DMD Scan Example         (um)

                                                                             23

DMD Templates
  Each template has Inner and Outer Mask
                                                                             18
  Fiber must meet at least one template




                                                               Sliding
                                                        mask
  Inner mask floats temporally in outer mask




                                                               Sliding
                                                        mask
Sliding Mask
  “Smooth” DMD in critical 7-19 um region                                       5
  DMD < 0.25 ps/m over any 6 um window

                                                                                 0




Slide 21
                        DMD Mask to Encircled Flux
                        Tight inner mask matches region carrying bulk of power

               Industry Standard
                  DMD Specs                                            50 um
                23                                                     Fiber
                18                                                      Core
Outer Mask                                       Bulk
Inner Mask                                        of
                                                Power
                 5
   Radial                                        4.5
  Position       0
    (µm)
                -5

                                                        19

               -18

               -23
    Slide 22
                     DMD
           Effective Modal Bandwidth Calculated (EMBc)
                     (TIA-492AAAC, TIA-492AAAD, IEC 60793-2-10)



 Calculated based on DMD
   DMD of fiber measured per TIA FOTP-220 or IEC 60793-1-49

   Bandwidth calculated from interaction of the DMD with ten
    simulated VCSELs (weighting functions)

   Ten VCSELs that represent the range of compliant VCSEL
    specifications

   The lowest of the 10 calculated bandwidths is minEMBc

   minEMBc is multiplied by 1.13 for EMB




Slide 23
           Multimode Fiber Types




Slide 24
                  Multimode Fiber Types,
                   Performance Grades

                                                 OFL BW = Overfilled Launch
                                                               Bandwidth

                                                 EMB = Effective Modal
                                                            Bandwidth
                                                    (also known as “Laser” BW)

                                                   EMB met by meeting:
                                                     a)  DMD specifications, or
                                                     b)  minEMBc
                                                   as outlined in TIA-492AAAC
                                                   and TIA-492AAAD
OM1, OM2, OM3,OM4 = ISO/IEC 11801 designations




Slide 25
                                              Multimode Fiber Types,
                                               Performance Grades
                                   Reach & Bandwidth by MM Fiber Type

                                                               

                                              Reach (at 10 Gb/s)        Bandwidth (at 850nm)   

                                          
                                                   





                                                                                                   Bandwidth

                                       600                                                5000




                                                                                                           

               





                                                                                                                (MHz-km, at 850nm)
                (meters, at 10 Gb/s)




                                       500
                                               4000

           Reach




                                       400

                                                                                          3000

                                       300

                                                                                          2000

                                       200

                                       100
                                               1000


                                         0
                                               0

                                              62.5 um
 50 um
          50 um
    50 um

                                               OM1   
    OM2      
   OM3  
    OM4  

                                                 Fiber Type ( ISO Grade )


Slide 26
           Multimode Link Distance Support




                   1Mode    Conditioning Patch-cords required
                   2With   1.0dB connector loss


Slide 27
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 28
                Why is the OM4 standard
                       important?

       Gives IEEE 802.3, Fibre Channel and
         Infiniband input on how a standards
       defined multimode fiber will operate with
                next generation systems




Slide 29
                    OM4 Standardization

Specifications agreed upon in both TIA
 and IEC
      –  TIA-492AAAD
      –  IEC 60793-2-10, Fiber Type A1a.3


           General agreement to harmonize with
           TIA-492AAAD


Slide 30
                           OM4 Specifications

 •  Effective Modal Bandwidth (EMB) >/= 4700 MHz-km
           –  Allows 2 methods for verification– DMD Masks or
              minEMBc

 •  OFL Bandwidth at 850nm >/= 3500 MHz-km
           –  Ensures performance with sources that launch more power into
              outer modes

 •  OFL Bandwidth at 1300nm >/= 500 MHz-km
           –  Ensures backward compatibility with OM1, OM2, OM3 fibers for
              applications such as FDDI, 100BASE-FX, 1000BASE-LX, etc.


Slide 31
                            Why is OM4 important?
Fiber dominates in Access to Distribution and Distribution to Core links.





                           Alan Flatman – Principal Consultant, LAN Technologies, UK
                           “Long Data Center Links vs. Length”
                           IEEE802.3ba, Jan. 2008, Flatman_01_0108




Slide 32
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 33
                                          IEEE802.3ba
                     40 Gb/s Ethernet Reach Objectives

  Servers, Access, SANs, HPC

   –  10 km over single-mode fiber (1310 nm)            40GBASE-LR4
   –  1501 m over OM4 multimode fiber (850 nm)          40GBASE-SR4
   –  100 m over OM3 multimode fiber (850 nm)           40GBASE-SR4
   –           7 m over copper                          40GBASE-CR4
   –           1 m over backplane                       40GBASE-KR4

           1   – Connector loss budget of 1.0 dB



Slide 34
                                          IEEE802.3ba
                     40 Gb/s Ethernet Reach Objectives

  Switching, Routing, Aggregation

   –  40 km over single-mode fiber (1310 nm)       100GBASE-ER4
   –  10 Km over single-mode fiber (1310 nm)       100GBASE-LR4
   –  1501 m over OM4 multimode fiber (850 nm)     100GBASE-SR10
   –  100 m over OM3 multimode fiber (850 nm)      100GBASE-SR10
   –           7 m over copper                     100GBASE-CR10

           1   – Connector loss budget of 1.0 dB



Slide 35
                    40G & 100G Ethernet – MDI Recommendations
                          References MPO interface req’s/specs of IEC 61754-7.




             40GBASE-SR4
                                           Left 4 pins are Tx
                                          Right 4 pins are Rx
                                        (inner 4 pins unused)


      100GBASE-SR10




Inner 10 pins, Top Row are Rx         Inner 10 pins, Left Side are Tx       Inner 10 pins, Top are Rx
Inner 10 pins, Bot Row are Tx        Inner 10 pins, Right Side are Rx       Inner 10 pins, Bot are Tx
(outermost pins both rows unused)     (outermost pins each side unused)
                                                                          (outermost pins Top & Bot unused)
        Option A                              Option B                             Option C
     (recommended)

  Slide 36
                                 IEEE802.3ba
                             Reach Objectives
 •  Reduced reach compared to 10G is due to relaxation of
    transmitter spectral width:
       –  from 0.45 to 0.65 nm

 •  Proposal for extended reach on OM4 accepted in
    January 2010 IEEE meeting
       –  150 meter link distance
       –  Addresses links greater than 100 m that would otherwise
          require singlemode fiber
       –  Increased link margin for higher reliability



Slide 37
                High Speed Short Reach Technologies:
                Multiple Fiber Parallel Systems on MMF


            for 40G:

•  One 12-fiber cable
     –  duplex link
     –  8 active fibers
•  4 x 10 Gb/s
•  12 Fiber MPO connector
•  One wavelength per fiber



Slide 38
               High Speed Short Reach Technologies:
               Multiple Fiber Parallel Systems on MMF
           for 100G:

•  Two 12 Fiber Cables, or
   24 fiber Cable
    –  20 Active
    –  Duplex link
•  10 x 10 Gb/s
•  MPO connector
    –  2 x 12 fiber
    –  1 x 24 fiber
•  One wavelength per fiber

Slide 39
               High Speed Long Reach Technologies:
              Wavelength Division Multiplexing on SMF

4 Different                                         4 Detectors
  Lasers
                 Combiner                Splitter




                                         Cladding
                            For 100G
              •  2 Fiber Cable
              •  Multiple Lasers and Detectors
              •  4 x 25 Gb/s
 Slide 40
               Cost Comparison between Single-
              mode and Multimode Fiber Systems

     Traditionally, optoelectronics have driven the cost
       difference between single-mode and multimode

•  Single-mode CWDM system
      –  Pro: Lower cabling cost
      –  Con: Significantly higher transceiver cost


•  OM3 and OM4 multimode parallel systems
      –  Pro: Much lower transceiver cost using existing 10Gb/s VCSELS
      –  Con: Higher cabling cost



Slide 41
                 Cost Comparison between Single-mode
                   and Multimode Fiber - 40G Systems



                                     > 3x


                                                          Paul Kolesar
                                                          CommScope
                                                          “The Case for Extended Reach
                                                          Multimode Objectives”
                                                          IEEE 802.3ba
                                                          September 2008
                                                          Kolesar_01_0908




           •  Single-mode cabling costs less than multimode,
              but total link cost over 3x higher!
Slide 42
            Cost Comparison between Single-mode
             and Multimode Fiber - 100G Systems



                             > 10x !


                                                     Paul Kolesar
                                                     CommScope
                                                     “The Case for Extended Reach
                                                     Multimode Objectives”
                                                     IEEE 802.3ba
                                                     September 2008
                                                     Kolesar_01_0908




   •  Cabling costs insignificant compared to optoelectronics
       –  Single-mode total cost over 10x multimode system!
Slide 43
                  Power Consumption
•  Lower power consumption critical as link density
   and speed increase
       –  10G SFP Fiber transceivers consume <1 watt
       –  10GBASE-T copper transceivers can consume
          10 watts or more.


•  Savings ~ 9 watts/transceiver
•  Cooling – another 9 watts/transceiver


Slide 44
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 45
               Bend Optimized Multimode Fiber
•  Newest development in multimode fiber
      –  Provides better bending performance than standard
         50um fiber
      –  Improved optical reliability under tightly bent
         conditions
      –  Bend radius down to 7.5mm – smaller than a dime!
           •  0.2dB added loss @ 850nm with 2 turns
           •  0.5dB added loss @ 1300nm with 2 turns
      –  NOT a substitute for proper cable management
           •  Mechanical reliability unchanged from standard fiber



Slide 46
                        Outline
 •  Market Drivers
 •  Optical Fiber Overview
 •  OM4 Fiber Standards & Specifications
 •  Role of OM4 fiber in 40G & 100G Ethernet
 •  Bend Optimized Multimode Fiber
 •  Conclusions



Slide 47
                   Conclusions
•  Bandwidth demand is continuing to grow
   at a high rate
•  OM3/OM4 multimode fiber is the right
   choice for high speed networks in the
   short reach environment
•  Development work continues on
   multimode fiber to support next generation
   requirements

 Slide 48
                         Thank you… 



      
 
           
Visit     www.fols.org

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Slide 49

								
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