Gigabit Ethernet PMD ECE135 Group 2 – Presentation 2 Andrew Meyerson February 3, 2005

Gigabit Ethernet: Progress Summary Updated Gantt chart Made initial assignment of group responsibilities Reviewed IEEE 802.3z Standard regarding the PMD module Started researching VCSELs Test eval board Preliminary optical link budget Select VCSELs and PDs/ROSAs Complete optical link budget Build practice board Revise Gantt chart Order parts? Completed TasksNext Week’s Tasks

Group Responsibilities Andrew Meyerson – Administration, ordering, soldering Clifton Kerr – Layout, design, testing Vinh Nguyen – Webpage, report writing Bryan Justice – Optical link budget, design, testing, report writing

Gantt Chart

IEEE 802.3z PMD Initial Research We will be building a Physical Medium Dependent (PMD) sublayer board PMD should conform to the IEEE 802.3z specifications for type 1000BASE-SX (Short Wavelength Laser)

802.3z Standard PMD block diagram as found in the 802.3z standard

802.3z Cont. Transmit characteristics (from 802.3z standard)

802.3z Cont. Receive characteristics (from 802.3z Standard)

802.3z Cont. The standard also defines a worst case link power budget and penalties This will probably be needed for determining the optical link budget

802.3z Cont. The standard also specifies how to test the PMD to ensure compliance For example, the extinction ratio must be measured with a repeating K28.7 data pattern The standard also specifies test values corresponding to the minimum level of compliance For example, maximum high frequency optical jitter is specified

VCSEL Research Started looking at VCSELs Performed 4 Corner Analysis of: – Advanced Digital Optics – Roithner Lasertechnik – Appointech – ThorLabs Briefly examined:

Four Corners Analysis for Roithner Lasertechnik TTR-D1

Four Corners Analysis for Advanced Digital Optics HFE438x-521

Four Corners Analysis for Appointech 850nm VCSEL Module

Four Corner Analysis for ThorLabs VCSEL 780

Four Corner Analysis for TechLabs VCSEL 850

Other VCSEL Vendors Lasermate – Link to datasheet for VCSEL with SC connector is dead Optek – Does not appear to have VCSEL model with SC connectors

Summary of VCSELs The Roithner Lasertechnik TTR-D1 appears to be the best VCSEL so far in performance terms – Potential problems Delivery time Currency costs The most affordable with good performance appears to be the ThorLabs 850 option – Is it connecterized?

PDs and ROSAs Preliminary research has begun for selecting an appropriate PD or ROSA Delay due to questions regarding which will be used ROSAs are readily available online and it is just a function of finding a cheap one with the right connecters

Evaluation Board Testing

Evaluation Board Testing (cont) Tested both PRBS7 and K285 – Using the clock, found the eye diagram of both signals with and without attenuation – Used the Bit Error Rate tester to find the BER of the PRBS7 pattern

Evaluation Board Testing (cont) K285 with proper attenuation (above) Triggering itself (below) PRBS7 with attenuation (above) without (below)

Evaluation Board Testing (cont) With attenuation, the BER of PRBS7 was measured to be 0E-9 With no attenuation, the BER of PRBS7 was measured to be 6.9E-2

Next Week Research and select parts – Look at more VCSELs – Look at PDs/ROSAs – Call vendors for more information about price, availability, and whether the components are connecterized Finalize optical link budget Build evaluation board Revise Gantt chart as necessary Order parts?

References IEEE Computer Society (2003). IEEE Standard. New York: The Institute of Electrical and Electronics Engineers, Inc. Retrieved Thursday, January 20, 2005, from ECE website: ECE164 Group 1 Presentations. (April 26, 2004). ECE164 Group 1 Website. Retrieved January 20, 2005 from ECE164 Group 2 Presentations. (April 17, 2004). ECE164 Group 2 Website. Retrieved January 20, 2005 from