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Measurements >> Phase Noise and Jitter Measurements >> Questions about the SONET OC-192
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Message started by iccc on Jul 10th, 2007, 10:48pm

Title: Questions about the SONET OC-192
Post by iccc on Jul 10th, 2007, 10:48pm

Hi,all

As we know the OC 192 SONET specification applies to 10 Gbit/s data rates, and specifies three benchmark specifications that must be met by CDR circuits -jitter generation, jitter tolerance, and jitter transfer.

1 Is the jitter bandwith as narrow as 120kHz?

2 Where can i download the the OC 192 SONET specifications?

3 How to solve the problem between jitter tolerance and jitter transfer as mentioned at the end of chap.9 in Behzad Razavi'book "the design of integrated circuits for optical communications"?

Any good papers are greatly appreciated.

thanks

Title: Re: Questions about the SONET OC-192
Post by smlogan on Nov 16th, 2007, 8:50am


iccc wrote on Jul 10th, 2007, 10:48pm:
Hi,all

As we know the OC 192 SONET specification applies to 10 Gbit/s data rates, and specifies three benchmark specifications that must be met by CDR circuits -jitter generation, jitter tolerance, and jitter transfer.

1 Is the jitter bandwith as narrow as 120kHz?

Yes. The ITU and ANSI standards specify this. There is a long history and some controversy concerning the 120 kHz bandwidth requirement.

2 Where can i download the the OC 192 SONET specifications?

The standards must be purchased from either ITU (intenational standard) or ANSI. They are not in the public domain. Your company may have a membership that will allow you to download the documents.


3 How to solve the problem between jitter tolerance and jitter transfer as mentioned at the end of chap.9 in Behzad Razavi'book "the design of integrated circuits for optical communications"?

I do not have Razavi's book, but the issue relates, I believe to the trade-off between jitter tolerance requirements and the narrow loop bandwidth requirement of an OC-192 data recovery system.  Careful design and the use of a high Q based CDR or phase-locked loop is one means of approaching the design. An alternative approach involves cascading a high bandwidth loop with a low bandwidth loop to provide the necessary tolerance, jitter generation and jitter transfer performance.

It is a challenge none the less.

Shawn

Any good papers are greatly appreciated.

thanks


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