Optical Specification Progress ============================== Del Hanson, Hewlett Packard Corporation Stan Swirhun, Vixel Corporation Jonathan Thatcher, IBM Corporation (presenting) June 8, 1996 Overall Status/Summary ---------------------- o Theoretical analysis and experimental measurements demonstrated that we were are not able to meet the current 802.3 HSSG multimode-based link distance objectives (500 meters with 62.5 micron fiber) at 1.25 Gbaud. o Further analysis and data demonstrate operation at the following distances: + 50 micron fiber: 450 meters. + 62.5 micron fiber: 200 meters. o The focus to date has been on E-to-O, fiber, and O-to-E (no attention to the SERDES). o It is still unclear what combination of FC0, "10b" Specification, FC Jitter Working Group output, and potential simplifications will be applied. o A great deal of future work lies ahead. o In the meantime, we should be able to create interoperable links with existing hardware prior to the completion of the specification. Optical "PHY" Layer Elements ---------------------------- o The FC-0 Specification is based on this simple, point-to-point link. <<< Graphic of simple point-to-point link defining graphic symbols >>> Optical "PHY" Typical Packaging ------------------------------- o History has presented a variety of "PHY" layer package options. o This has created a need for multiple specification/measurement points. <<< Graphic shows packaging combinations for Serializer; Laser Driver/Laser; Receiver/Amplifier; and Deserializer >>> FC0 Optical "PHY" Measurement/Specification Points -------------------------------------------------- o It is assumed that the "b" and "c" measurement points are in fact points.! o FC-0 specifies only "b" to "c"; the "10b" Specification specifies some parallel data I/O. o FC-AL broke this assumption while expanding the number of elements in the link. o The net result was that minor specification problems became unbearable. o Therefore, the creation of the FC Jitter Working Group. <<< Graphic of point-to-point link showing "b, S, R, c" >>> Link Budget Comparisons ----------------------- =============================================================================== Description Unit ANSI FC IEEE 802.3 Status ----------------------- --------- ---------- ------------- -------------------- General Bit Rate MBaud 1063 1250 Agreed Tolerance PPM 100 100 Agreed Bit Error Rate E-12 E-12 Agreed; see note 3 Transmitter (Point "S") Type Laser Laser Agreed Wavelength (l) nm min 770 770 Agreed max 860 860 Agreed Spectral Width (RMS) nm 4 4 Agreed; work required Maximum Launch Power dBm, avg @ 780 nm -5 -5 Agreed @ 850 nm -5 -4 Agreed Minimum Launch Power dBm, avg -10 -10 Agreed Extinction Ratio dB 9 9? Agreed RIN (max) dB/Hz -116 -117? More work required Eye Opening %p-p 57 n/u Agreed; see note1 Deterministic Jitter % 20 n/u Agreed; see note1 Optical Rise/Fall ns 0.45 n/u Agreed; see note1 Receiver (Point "R") -------------------- Minimum Receiver Power dBm, avg -16 -17 Agreed Maximum Receiver Power dBm, avg 0 ? See Note 2 Return Loss dB, min 12 12? More work required Optical Rise/Fall ns 0.6 n/u More work required; see note 1 Fiber ("S to R") ---------------- Operating Range m Agreed 50 mm core fiber 2 - 500 2 - 450 62.5 mm core fiber 2 - 300 2 - 200 Maximum Attenuation dB/km @ Lamda More work required 50 mm core fiber 4.0 3.5? 62.5 mm core fiber 4.5 4? Modal Bandwidth MHz*km, min More work required 50 mm core fiber 400 400 62.5 mm core fiber 160 160 Dispersion Slope ps/km*nm**2 More work required 50 mm core fiber n/u ? 62.5 mm core fiber n/u ? Dispersion Minimum mm More work required 50 mm core fiber n/u ? 62.5 mm core fiber n/u ? =============================================================================== Note 1: We have tentatively agreed that it is sufficient to specify the transmit eye mask alone. This allows the implementor to make trade-offs regarding rise-time, fall-time and jitter. Note 2:HP would like to see the Maximum Receiver Power match the Maximum Launch Power. IBM would like to see the Maximum Receiver Power match the other standards. Note 3: FC is "looking" at the problem of having all subcomponents specified to E-12 BER while having the entire link also specified as E-12. =============================================================================== Transmit Eye Mask Definition (Point "S" only) --------------------------------------------- This transmit eye mask definition is taken directly from Fibre Channel. <<< Graphic of eye mask definition >>> Challenges/Gates Remain ----------------------- o Not clear how much this specification should be leveraged from the FC Jitter Working Group. + Complete specification of the serializer. + Specification of the receiver. + Complete specification of the deserializer o Input will be required from the fiber industry to help resolve a variety of specifications: + Fiber Bandwidth/Attenuation + RIN + Return Loss + Chromatic Dispersion o Direction is needed from IEEE 802.3 + Are the distances recommended here acceptable? + Do we need to add single mode to this work? + Do we need to leave open the option for gigabit, serial, copper? + Do we need to expand this effort to include the SERDES and higher logic (where is the partition)?