Gigabit Ethernet PMD ECE 135 Group 2 Presentation

Gigabit Ethernet PMD ECE 135 Group 2 – Presentation 2 Andrew Meyerson February 3, 2005

Gigabit Ethernet: Progress Summary Completed Tasks l l l Updated Gantt chart Made initial assignment of group responsibilities Reviewed IEEE 802. 3 z Standard regarding the PMD module Started researching VCSELs Test eval board Preliminary optical link budget Next Week’s Tasks l l l Select VCSELs and PDs/ROSAs Complete optical link budget Build practice board Revise Gantt chart Order parts?

Group Responsibilities l l 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. 3 z PMD Initial Research l l We will be building a Physical Medium Dependent (PMD) sublayer board PMD should conform to the IEEE 802. 3 z specifications for type 1000 BASE-SX (Short Wavelength Laser)

802. 3 z Standard l PMD block diagram as found in the 802. 3 z standard

802. 3 z Cont. l Transmit characteristics (from 802. 3 z standard)

802. 3 z Cont. l Receive characteristics (from 802. 3 z Standard)

802. 3 z Cont. l l The standard also defines a worst case link power budget and penalties This will probably be needed for determining the optical link budget

802. 3 z Cont. l l The standard also specifies how to test the PMD to ensure compliance For example, the extinction ratio must be measured with a repeating K 28. 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 l l Started looking at VCSELs Performed 4 Corner Analysis of: – – l Advanced Digital Optics Roithner Lasertechnik Appointech Thor. Labs Briefly examined:

Four Corners Analysis for Roithner Lasertechnik TTR-D 1

Four Corners Analysis for Advanced Digital Optics HFE 438 x-521

Four Corners Analysis for Appointech 850 nm VCSEL Module

Four Corner Analysis for Thor. Labs VCSEL 780

Four Corner Analysis for Tech. Labs VCSEL 850

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

Summary of VCSELs l The Roithner Lasertechnik TTR-D 1 appears to be the best VCSEL so far in performance terms – Potential problems l l l Delivery time Currency costs The most affordable with good performance appears to be the Thor. Labs 850 option – Is it connecterized?

PDs and ROSAs l l l 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) l Tested both PRBS 7 and K 285 – – 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 PRBS 7 pattern

Evaluation Board Testing (cont) K 285 with proper attenuation (above) Triggering itself (below) PRBS 7 with attenuation (above) without (below)

Evaluation Board Testing (cont) l l With attenuation, the BER of PRBS 7 was measured to be 0 E-9 With no attenuation, the BER of PRBS 7 was measured to be 6. 9 E-2

Next Week l Research and select parts – – – l l 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 l l l IEEE Computer Society (2003). IEEE 802. 3 Standard. New York: The Institute of Electrical and Electronics Engineers, Inc. Retrieved Thursday, January 20, 2005, from ECE 164. 02 website: http: //www. ee. duke. edu/~mbrooke/EE 164. 02/Spring_2004/group_2/index_files/8023. pdf ECE 164 Group 1 Presentations. (April 26, 2004). ECE 164 Group 1 Website. Retrieved January 20, 2005 from http: //www. ee. duke. edu/~mbrooke/EE 164. 02/Spring_2004/group_1/downloads. html ECE 164 Group 2 Presentations. (April 17, 2004). ECE 164 Group 2 Website. Retrieved January 20, 2005 from http: //www. ee. duke. edu/~mbrooke/EE 164. 02/Spring_2004/group_2/presentations. html