Shielded Systems for 10G on Copper

Agenda

IEEE/ISO/TIA StandardsTransmission BasicsShielded vs. Unshielded Electrical PerformanceInstallation and Structure Issues

IEEE/ISO/TIA Standards

What is 10 Gigabit Ethernet

The latest standard from the IEEE for an Ethernet protocolIt represents a 10 fold increase over existing Ethernet protocols It represents a data rate of 10,000,000,000 bits per secondThe channel performance requirements for this standard drive the performance parameters for cabling specifications to support it.

Ethernet Adoption

Source: Dell Oro 2006

020406080

100120140160180

Mill

ions

of P

orts

1997 1999 2001 2003 2005 2007 2009

Year

Ethernet Adoption - history & projections

100MbpsTotal GigTotal 10Gig

Clearing Up the Mystery

IEEE 10GBaseT – vs. -– EIA/TIA-568-B.2.10 Augmented Category 6– ISO/IEC 11801:2002 Class EA

EIA/TIA – vs. – ISO/IECWhat the EIA/TIA and ISO/IEC standards say about Unshielded Media – vs. – Shielded Media

TIA/EIA Cat 6A vs. ISO Class EA

Two Standards – TIA/EIA Cat 6A vs. ISO Class EA

Characteristics ISO Class EA TIA Cat6APSNEXT Loss 24.8dB 23.2dBNEXT Loss 27.9dB 26.1dBPSANEXT Loss 49.5dB 49.5dBReturn Loss 8.0dB 6.0dBInsertion Loss 49.3dB 49.3dB

Extrapolated Test Limits for NEXT and PSNEXT to 500Mhz

Yes No

The ISO Class EA System has– More stringent Return Loss– More stringent NEXT– More stringent PSNEXT

IEEE Standards and Applications

Reference Source – The Ethernet Alliance

IEEE Standard

Date Standard Released

Description Designation Data Rate Media Distance Limitation Common Applications

802.3ab 1999 Gigabit Ethernet over UTP 1000Base-T 1000Mb/s Category 5 Cable 100 meters Desktop Computing802.3z 1998 Gigabit Ethernet over Fiber 1000Base-SX 1000Mb/s 220-550 meters Enterprise Backbone

1000Base-LX 5 Kilometers WAN,MAN802.3an 2006 10Gigabit Ethernet over copper 10GBase-T 10Gb/s Category 6A Cable 100 meters Data center, R & D, Computing

Category 6 Cable 37 - 55 meters High Resolution VideoAdvanced Desktop Computing

802.3ae 2002 10 Gigabit Ethernet over Fiber 10GBase-SR/SW 10Gb/s Singlemode fiber 300 meters Data center & Enterprise Backbone10GBase-LR/LW 10Gb/s Singlemode fiber 10 Kilometers WAN,MAN10GBase-ER/EW 10Gb/s Singlemode fiber 40 Kilometers WAN,MAN10GBase-LX-4 10Gb/s Multimode fiber 300 meters Data center & Enterprise Backbone10GBase-LX-4 10Gb/s Singlemode fiber 10 Kilometers WAN,MAN

802.3ak 2004 10 Gigabit Ethernet over short range copper 10GBase - CX4 10Gb/s screened 4 pair cable 15 meters Data center links

International Standards – Copper Cabling

Cabling StandardsEIA/TIA ISO/IEC CENELEC

Category 5 EIA/TIA-568 A - Category 5 11801:1995 Class D EN50173-1:1995 Class DCategory 5e EIA/TIA-568-B.2 - Category 5e 11801:2002 Class D EN50173-1:2002 Class DCategory 6 EIA/TIA-568-B.2 - Category 6 11801:2002 Class E EN50173-1:2002 Class EAugmented Category 6 EIA/TIA-568-B.2.10 Augmented Category 6 11801:2002 Class EA EN50173-2:200x Class EA

Standards for 10G Ethernet over Copper

International Standards for 10GBase-T Status

ISO/IEC 11801 A1.1 Channel specificationsThe International Standard organization approved the category 6A Channel specification for 10GBASE-T in February 2009

ISO/IEC 11801 A1.2 Component specifications Expected October 2009

EIA/TIA-568-B.2-10 Transmission performance specifications for 100 Ohm Augmented Category 6 Cabling

The American Telecommunications Industry Association (TIA) published the full standard in April 2008

EIA/TIA and ISO/IEC

Unshielded Media: – Acceptable copper cabling media for EIA/TIA-568-

B.2.10 Augmented Category 6– Acceptable copper cabling media for ISO/IEC

11801:2002 Class EA

Shielded Media– Acceptable copper cabling media for EIA/TIA-568-

B.2.10 Augmented Category 6– Acceptable copper cabling media for ISO/IEC

11801:2002 Class EA

Transmission Basics

Copper Cabling for 10 Gigabit

10GBase-T (802.3an) requirements– Each of the 4 pairs supports a data rate of

2500 MB/s bi-directionally & simultaneously– Star topology

Encoding Schemes

100Base-Tx– PAM5

1000BaseT– PAM5

10GBase-T– PAM 16

Encoding Schemes

Cat 6A Unshielded vs. Cat 6A Shielded and Electrical

Performance

IEEE 802.3an Unshielded vs. Shielded

Which media type does 802.3an suggest– It does not care– It cares that the minimum transmission channel

characteristics are available over CAT6 UTP, CAT6 FTP, CAT6A UTP or CAT6A FTP.

The big problem with 10GBase-T is dealing with an external noise source generated by….transmission over surrounding cables in a bundle of cables. This is known as Alien Crosstalk (AXT).

Alien Crosstalk

10GBase-T Public Enemy #1 is AXTAlien crosstalk is unwanted coupling of signals between adjacent cablesAlien crosstalk cannot be cancelled by Digital Signal Processing (DSP)Alien crosstalk can only be mitigated only with a shield or space separation

Category 6A Unshielded Cable

Strategies – Space between cables– Variable AWG & twist

schemes– Core to jacket

separators, fluted jackets, air injected plastics and non-round shape

Category 6A UTP cables can be as large as .9mm (.35”) OD– Larger cable diameter

provide better AXT but creates issues for routings & pathways Gap A > Gap B

A

B

CAT6A

CAT6

Category 6A Shielded Cable

Specifically designed for 10G performanceANEXT of 15dB headroom or higher Shields significantly reduces EMI including ANEXTSmaller cable OD (7mm vs. 9mm)

Shielded ANEXT

Shielded PS-ANEXT 15 to 30 dB of Headroom!

Interoperability between Unshielded Horizontal Cables

On July 2007 JEITA (Japan Electronics and Information Technology Industries Association) submitted to TIA TR 42.7 a short report (TR42.7-2007-07-076) showing that 3 different CAT 6A U/UTP cables bundled together failed the TIA ANEXT limits.

These cables comply to the TIA ANEXT limits when bundled to identical (=same vendor) cables, but when 3 different cables (= made by different vendors, having different constructions) were bundled together, two of them failed miserably.

The Shielded Advantage

Superior, most effective design for eliminating Alien Crosstalk NoiseThe most simple design for eliminating Alien Crosstalk NoiseThe most mechanically robust designMost able to survive installation stresses100% shield barrier throughout the entire cabling channel

Installation and Structure Issues

Cat 6A – Pathways & Routing

Cable diameter increasedCable weight increaseIncreased bend radii considerationsIncreased cabling space requirements for ducts, trays, racks, raceway, and cable managementMore space needed in Equipment room and Telecommunications roomIt may be harder to install Category 6A into existing buildings which were not designed with this in mind

Cable Bundle Comparison

Cable Nom. OD ~ 9mm Cable Nom. OD ~ 7mm Cable Nom. OD ~6 mm Cable Nom. OD ~5mm

Cables Cat6a U/UTP Cat6A F/UTP Cat6 U/UTP Cat5e U/UTP

Approx. Diameter (mm) 48 cables Bundle 65mm 55mm 45mm 40mm

Approx. Weight (g) 48 cables bundle 500mm long 1750g 1300g 1050g 750g

Quick comparison of Category Cabling Systems

Cabling Relative Price Tested PathwaysType Bandwidth 24 x 4 inches

No of CablesCategory 5e 100% 100 MHz 1400Category 6 135 - 150% 250MHz 1000

Category 6A 165-180% 500MHz 700

Source: Ethernet Alliance

This is a major issue!

Cat 6A Unshielded Installation

Increased installation time to lay containment, lay cabling & terminate connecting hardwareCannot mix Cat6 or Cat5e UTP cables with Cat6A UTP cables due to AXT– Options:

• New containment system• Clear existing containment system

– Not an issue for Cat6A shielded systems

Field Testing Cat 6A Unshielded

Increased time required for field testing – Not addressed in standards but a major concern for

Cat6A UTP systems– Costly and time consuming sample based testing

• 3 – 10 min per victim pair• Cat 6 testing on Level 3 tester less 20 sec per

link– Not an issue for Cat6A shielded systems

Shielded Cabling Solution for 10GbEMolex’s PowerCat 6A Shielded System is specifically designed to support 10GBASE-T applications. – Minimizes alien crosstalk– Improved insertion loss performance– 15dB ANEXT headroom or higher– Superior electromagnetic interference (EMI) protection– No interoperability problems

Superior installation and testing to UTP systemsLeast impact on existing structureMeets the requirements of both the ratified TIA and draft ISO 10GBASE-T standardsCovered by Molex 25 year product and application assurance warranty