[10GMMF] TP3 meeting Notes, Oct 26
Here are my notes from Tuesday's Meeting
Dial in Details for Next Meeting
Next Meeting Tuesday November 2nd at 9am SJ, 5pm UK, 6pm Germany
Dial in (650) 599-0374, Meeting ID: 136169
Meeting Notes, October 26th
1. List Attendees
Van Schyndel, Andre
2. Review meeting notes from last week
No comments ... other than those from Tom which have already been put on the reflector
3. Agenda additions/changes?
4. Static Channel Methodology
- Noise loading - review calculations from Lew
Lew had sent out some calculations for how to compute the required OSNR in support of appropriate noise adders for modal noise and RIN.
There was a question about the assumption of using Gaussian noise for RIN given that we know it peaks around the resonant frequency of the laser. The point was made that this peaking is outside the bandwidth of the filtering effect of the channel, so we probably dont need to be too concerned about it.
The calculations were only sent out just prior to the meeting.
ACTION: Everyone to review Lew's work and give him feedback and propose changes where necessary
ACTION: Lew to summarise where this work is at our next meeting
- Channel types and exact characteristics
o review comments from Tom reference rise and fall time
Tom made the point that we need to separate the rise/fall times that we are describing when we talk either about how we are fitting to the Cambridge IPR or how we are representing the Tx within the TP3 test.
- Petre kindly agreed to evaluate jitter testing requirements and the need for a high frequency
Petre presented his work which argues that we need to include the following jitter tests:-
- Tx clock random jitter - represented by high pk-pk amplitudes and low freq (within PLL b/w)
- Laser random jitter - represented by low pk-pk amplitudes over a wide frequency range
- Channel jitter - arising form channel ISI
He cited pattern dependency as another source of jitter, but argued that it was small compared with the channel jitter.
In our previous meeting we had explored having channel jitter only. Petre's work brought us back to a discussion on how we represent the low and high frequency jitter. An argument was made that testing to multiple frequencies against a mask definition was not practical. I dont think the group had agreement on this point. The discussion concluded with 3 choices for us to investigate:-
i) define mask and leave it to the implementor to determine what testing is required
ii) define mask and give the characteristics for sinusoidal interferer (pk-pk, frequency)
- this would likely be a high frequency interferer with a separate test for tracking low freq jitter
iii) use an approach similar to CEI. Here they use a PN sequence to phase modulate the signal. This in effect produces a signal which includes a "comb" of frequencies which are all stressing the Rx at the same time. Key question around availability of the phase modulating component.
Tom has some experience of iii) and feels the approach warrants attention.
ACTION: For all to investigate the different choices for jitter testing and form their opinion on preffered options.
6. Link Budget
No discussion except to raise the work TP2 is doing to characterise the impact of different transmitter choices on the link budget.
7. OMA Measurement methodology
No discussion on this topic.