Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

[802.3_SPEP2P] Another solution to the long-reach encoding problem



Hello P802.3dg,

I would like to share another solution to the long-reach encoding problem [1,2].
[1] https://www.ieee802.org/3/dg/public/May_2024/Lo_3dg_01a_0724.pdf
[2] https://www.ieee802.org/3/dg/public/May_2024/Lo_3dg_02_0924.pdf


Compared to the current solution [1,2], the new solution has the following features:

=) operates over a span of 16 transfer units: treats on 16 MII input cycles, outputs a 65-bit block
=) a single transfer unit can represent a data nibble = choice one-of-16 per nibble
=) a couple of two adjacent transfer units can represent a control symbol = choice one-of-8 per octet

+) constant encoding delay of two nibble periods
+) both singles (of data) and couples (of control) are located arbitrarily, with precision of a single transfer unit
+) singles and couples are independent: no dribble nibbles are required
+) every period on MII corresponds to a transfer unit period in a span, as 1 to 1: no tx compressions/rx decompressions

-) information about control symbols may be shared between two adjacent spans, uses AUX bit to avoid such sharing between FEC frames

?) best fits when used with explicit delimiters: SSD, ESD/STILL_IDLE at "background" of data/dummy nibbles
?) (maybe useful) side effect: extra means for "immediate" signaling with 48 user-defined bits per span ("forced output")


Despite I found this as a hobby, I gave it a formal definition (see in attachment).

Because 17-bit blocks are more redundant, the low-latency problem can be solved just mimicking this solution (see also in attachment).

Thanks,

A. Ivanov

To unsubscribe from the STDS-802-3-SPEP2P list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-SPEP2P&A=1

Attachment: p802dot3dg-64b65b-longreach.pdf
Description: Adobe PDF document

Attachment: p802dot3dg-16b17b-lowlatency.pdf
Description: Adobe PDF document