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[802.3_NGEPON] Link channel model



Dear colleagues,

 

As promised, I am sharing the link channel model for NG-EPON, with updates from 10G-EPON to accommodate higher data rates and potentially different operating windows for upstream and downstream channels. The document has macros – please make sure they are enabled, when the file opens. Macros are used to calculate fiber dispersion and attenuation curves, as well as a bunch of other parameters later on filled into respective fields.

 

When using the spreadsheet, note that NOT all fields are supposed to be used accessible. Most of the fields are populated automatically, based on user input. A simple rule should be followed: fields that you cannot select are not expected to be user modifiable.

 

The usage is relatively simple: set the transmission wavelength by providing min and max ranges for the transmission window (cells B11 and B12), set the Extinction Ratio parameter in B4 (defaults to 9dB), and then min and max launch power (B5 and B6). Data rate is already set to 25 Gbps (we can tweak it later on more if needed). The link parameter section provides options to set the minimum and maximum channel loss for calculation (B31 and B32, respectively) together with example link length (B23) and split (B25). Fibre attenuation curve can be selected in B18 and PSC loss curve can be selected in B26 – for the purpose of link model design, I would suggest these remain as they are (they are worst case values right now).

 

Non-linear loss can be accommodated in field B28, set to 1dB right now – thus value might need to be further tweaked depending on launch power of the digital signal and presence of any co-propagating and counter-propagating analog signals.

 

Finally, cell B40 provides TDP (transmitter dispersion penalty) entry, which defaults to 1.5dB at this time.

 

The Receiver parameters (expressed in a number of ways, including IEEE and ITU nomenclature) are shown at the bottom of the spreadsheet. These are the values that are critical for the receiver definition for our future PHYs.

 

The following materials can be used for reference:

-          Fiber attenuation and dispersion model: http://www.ieee802.org/3/av/public/2007_03/3av_0703_anslow_1.pdf

-          EPON link budget in a graphical form: http://www.ieee802.org/3/av/public/2007_09/3av_0709_effenberger_3.pdf

 

I would like to suggest that we start working on the specific wavelength allocation proposals, together with power budget (Tx and Rx) proposals based on the spreadsheet. At the same time, if there are any suggestion of changes, improvements, modifications, etc. please let me know and I will be happy to discuss this on the next call. If a presentation of the operation of the spreadsheet is needed, let’s put it on the agenda for the first consensus call after this F2F meeting.

 

Regards

Marek Hajduczenia, PhD, CCNA CSCO12874393
Network Architect, Principal Engineer
Bright House Networks
Office +1-813-295-5644
Cell +1-813-465-0669

ccna_routerswitching_sm

 

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