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Re: [8023-10GEPON] [FEC] upstream lock status



Dear Marek, 

To answer your question, the distances shown on the right hand side of the
graph are not important to the searching for the pattern.  This is because
once we find the pattern, we stop looking.  It was just something that Glen
did to make the graph interesting, I guess.

Anyway, I've done some studies of different lengths.  
For delimiters of N=8, 12, 16, and 20, I can always find several golden
patterns that have distance N/2-1 from all shifts.  This is what suggested
that the N/2-1 formula rule was generally valid.  

But, when we all have been looking at patterns of 64 and 66, we seem to top
out at 29 and 30 (instead of the 31 and 32 that the 'rule' would suggest.)
This could be caused by the rule being not generally true, or because the
number space is just too large to search effectively.  

So, I looked at delimiters of size 24, which is only moderately larger than
20.  Search as I might, I can't find a delimiter with distance 11, the best
I found was 10.  This was done with a random searching method, and not an
exhaustive scheme, so I can't say anything for sure.  But, the trends
suggest that the rule is not generally valid, and that as the delimiter size
gets bigger, there is a larger deviation from the 'ideal' N/2 value.  

Bottom line, a distance of 31 may not be obtainable... but I don't know.  

As a practical matter, the distance of 30 is plenty big enough for our
needs.  

Regards, 
Frank E. 


-----Original Message-----
From: Hajduczenia, Marek [mailto:marek.hajduczenia@SIEMENS.COM] 
Sent: Wednesday, December 20, 2006 11:40 AM
To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
Subject: Re: [8023-10GEPON] [FEC] upstream lock status

Dear all, 
I am currently running more extensive analysis of the potential FEC
delimiters. 
So far I identified two 66bit wide sequences which have the minimum Hamming
distance of 30, run length of 3 and 32/34 (1/0) DC balance.

010010001110001001001110100101010110001100101110100101100101101011
111001001001101011010100101010101010100010001001110001011100101101

There is also a number of sequences with the Hamming distance of 28 (the
first column is the binary sequence of 66 bits, the second column has the
maximum run length for 1/0s and the third column contains the DC balance
where: 0 = 33/33, 2 = 34/32 and -2 = 32/34 for 1/0 respectively). I assume
that sequences with smaller Hamming distance are of no importance.  

000100010111011011010011011101000110101101100011000111000111011000;	3
0
000100011011101100100111000101100100111011011011001000110110100111;	3
2
000100100010011011100011101101011000111000101011100101001110011010;	3
-2
000100101101110101110100010101001011001110011011010100011010101100;	3
0
000100110010011010110111011100010011101010110100100101100110001010;	3
-2
000100110110010100101001001000110001001101110101100110101101110101;	3
-2
000101011010011000100011100101100110111000100101101110111010001100;	3
-2
000101011010101011010110101011011101100101001011010010011010011010;	3
2
000101100011011100011101100010010101101011100010101011010100011010;	3
-2
000101110010111000100110010100010010101101101010001110100110110110;	3
-2
000101110011001011101001110110001001101110001101100011010101001000;	3
-2
000110001100010110110101101010010111010101010011010101011100101110;	3
2
000110001101010001100011100011101101110100010011011011011100011010;	3
0
000110010010101001110001001100111010111001011011100110110100100011;	3
0
000110010101000100110100110101001001110001101101011101101010100101;	3
-2
000110010110110010101010100010110111001101100101011010001101010010;	3
-2
000110100010011000101001001010011011000111001101110110110110001011;	3
-2
000110100010011011100010010110111011101101001100011001101001010010;	3
-2
000110100010110101100101101101001110100011011100111001101010101010;	3
2
000110101000111001110110111011000110110001110010100011011010010010;	3
0
000110101011010001101101101101001110001110100101101100010101011001;	3
2
000110110001010101100011100110001011000110100110110110010110011101;	3
0
000110110010010011010100010001010111011011011011100011101100111000;	3
0
000110110101000100110100101101011011010110011100010100111010111010;	3
2
000111000101101001011000100101110011010011101100110101101100101011;	3
2
000111010001011010101100011011001010010001011001011101110010100110;	3
-2
000111010101100011001000101000111000100110110110101101010110110010;	3
-2
000111010101101110101110010010010100100100010100100110010110101101;	3
-2
000111011100010010001101010110011010010010110110110101101101011100;	3
2
000111011100100011001001110110100111011010110110101011001001000101;	3
2
001000100110011101110101101001010011100100100010110101010100101011;	3
-2
001000100111011010001011101011001101000110111001011010010010101110;	3
0
001000101001011010011101010011100011010110001010011010001101101101;	3
-2
001000110111011101010011011000101010111000101011010010110110010110;	3
2
001001001101101110001010001001110110010001110011011010010110101100;	3
-2
001001010100110011011010011101100110101000101001010011100111011100;	3
0
001001010101100100011101100101001010010001101010111001010101011101;	3
-2
001001010101101101010101001100101101000111010100101110101110101001;	3
2
001001011011001000110101010001010111010101011010100110010110011001;	3
-2
001001100011010101011101010011011010111011000101001011000110001101;	3
0
001001110111010011010110111001100101101010001001100101010100110100;	3
0
001010010010110110001010111011101001010010101001101110001110011001;	3
0
001010010100111011011000110011001110100100110101011101101001100100;	3
0
001010100101010110110110110001101110001011001011010001100011100011;	3
0
001010110001100100111010011101101100110001011011001001101011101001;	3
2
001010110010011011000101010101011010110001011000111011100100110101;	3
0
001010111011010100010011001001010010011011001001110111001110100100;	3
-2
001011000101101110001010100111011011011000110011100011100110001110;	3
2
001011001010101100011001011000100101011100101010101100101110111011;	3
2
001011010001001110101101001110100010001101011100100011100110110101;	3
0
001011010001101001101010101110001101011010010011011100101011100100;	3
0
001011010001110010011101100100100110010101110100100100101011100110;	3
-2
001011010101101110010111010100111010100100101001011000101010100010;	3
-2
001011011010011010101101010001101010101101011011010100010001011101;	3
2
001011100100011000110111011010100100100101110101110010110110001101;	3
2
001011101110010110010001001101001000110100110101110101101101010100;	3
0
001100100100101010100111010100110101101100110001011001110101011010;	3
0
001100110101110111001011101010011001001011100011000100100111010010;	3
0
001100110111001100100110100100110110101110110001001001010010001110;	3
-2
001100111010010110011100100010001110101100010001110011010111001101;	3
0
001100111011000110101101011010111010011011001011010011010010101000;	3
2
001101001001011101000110001110011011101101110010001011001100110101;	3
2
001101010001101100011100111010011011010001010110011011011000110110;	3
2
001101010011101001010111001101110100100100101110011100101001001010;	3
0
001101100100110011101101010010111010100010001101101001011100011101;	3
2
001101101000111001011010011010100011101000110001101100100111011001;	3
0
001101101011001000111010001110001001011001010011010111001110010100;	3
-2
001101101101110011001011101010111001001010111001001100101010010100;	3
2
001101110101101010110110110110001100100010001001101101001110010100;	3
0
001110001110110100100010110110100100101101100010001110010111001101;	3
0
001110011000100111001001000110001010110111011011101101001100100100;	3
-2
001110011011010010110110100110001110111011001001010100101011010010;	3
2
001110100010110011001100011010110101011100100010100011011101001110;	3
0
001110100110111010100010001001010001001001100111010110010110101101;	3
-2
001110101001000101101101010110111010011001000101110100101101001101;	3
2
001110101100011001100011101010010010111000101011011001010001101100;	3
-2
001110110010010010010111010010011000101010111011001000111011100101;	3
0
001110110110101010001010001001011001110101100010001011101100011100;	3
-2
010001001000111001001100011001110010110111001010100011010111010110;	3
-2
010001001010110010111000101011100010010110010110111010110111000100;	3
-2
010001001101010111011010110101000101100011011001100011001010010101;	3
-2
010001011001010010101001011101010110110011101000101001010111001110;	3
0
010001100011101010001101100111001011100110010011001010010110111010;	3
0
010001100110111001010001101001001011001101100011010101101011011011;	3
2
010001101000110101100010100100101101110111011011001010100011010111;	3
2
010001101101011100110010110101101010100010010111011010011000111010;	3
2
010001110001101010111011100110001101100101100010010001011101001011;	3
0
010001110110010001011001110100100010110011100010110111011101010010;	3
0
010010010010110101110001001110010110101000111000110101010110011101;	3
0
010010010100110010110101010100010011101110100011010010101101011101;	3
0
010010011011010101001010011010101101110001001011001110111010010100;	3
0
010010100011011000101010011011010001101011001011101101001110010100;	3
-2
010010101010111011010001010101101000100101100100101011101101101110;	3
2
010010101011000110111001010001001011011000101101010010110010111001;	3
-2
010010101011001100110100101011101010011101110001010111001011000110;	3
2
010010110010011001000110101011001101011100011000111001110100101100;	3
-2
010010110110011101110010101001000100101101101100110010010001110101;	3
0
010011000101101110101000110100011101110100110111000111011100010010;	3
2
010100011010011101010101011011001010111000111010110100011100100101;	3
2
010100011100100111001010100010110001110111010110010001010011011001;	3
-2
010100100101110001100111011011001010010111010011101000101101000100;	3
-2
010100110101101011010001011010100111010011010100011001011011100110;	3
2
010100111010001011010110001000101011101000111001000101100100111011;	3
-2
010101000110101110101011100100010100010110110101110100100010011011;	3
0
010101001001011011100011100110111001010110111010001101011001101000;	3
2
010101001011010110010011010101101001001001100011101001010111010010;	3
-2
010101010010010011100100010010010110101100101101110100111001010101;	3
-2
010101011000101010100010100011100011010010100011001110110111011011;	3
0
010101100100100101101101110011001000110011101011000101100110101100;	3
0
010101100101101110001001110110111001010110010011100101000110010101;	3
2
010101101110011101010101100101100101010010001010001010110100110111;	3
2
010110010110100010110001101011010100010010001101001011001011101110;	3
-2
010110010110100101011010101101010010001010011001110011011000110100;	3
-2
010110100100110111011001110100111010100011001101101100011100010100;	3
2
010110100101001001011001100110011010011001110011101100110111010100;	3
2
010110100101001011001110001101100110011001001001110101000110001110;	3
-2
010110101001010110110100011101101001101011011101000101100010110100;	3
2
010110101110100011101101001000110010110101101000101110011101101000;	3
2
010111000100011101110110101000110001001011011100010101101001110100;	3
0
010111001001110010010001001110001010001010101100110110100110111011;	3
0
010111001010110110110001110001000101011010111001000101011001101100;	3
0
010111001101001010010111010100110001001010001001011001101101100110;	3
-2
010111010010101101000101101100100010010001101101100011011100010101;	3
-2
010111011011101011011101011010011100011100100010001010011101001000;	3
2
010111011100010001010011011011011101101110100100010111000111001000;	3
2
010111011100011001101110100010010110101000110110100011101000100011;	3
0
011000100111010101101011010011101010010010110001100100010111000101;	3
-2
011000101010001001101011101010011010100111011100010110010110111001;	3
2
011000101100101011100110001010100101001100101011011010110110011101;	3
2
011000101101011100100010010010110100010001101110101110011100011101;	3
0
011000101101100011001011101011100111001101100010010110010110101000;	3
0
011000101110010010001011101001011011010111000101010100110010101010;	3
-2
011000110101010111011011010110010001110010010110011010100101001000;	3
-2
011000110101110110101011001010101110100010010011101110010011101000;	3
2
011000110111001101100110010100110110110010100010100110110101100011;	3
2
011000111010111001100110001001110100100110100101011100110100010100;	3
-2
011001000111010001001001101010111011010001110010110100111010100101;	3
0
011001001001001100010011101110110100101001001110101010011100011001;	3
-2
011001001010011001110101101100010111001011001110011100010010010001;	3
-2
011001100011001011001010001010101101011010100010101101010111011100;	3
0
011001100011011000101101110111010100110010110010110100101100101001;	3
2
011001101001000111001110110101001101010011001101011001100010011011;	3
2
011001110100100100100011101110010100101110110010001101100011010011;	3
0
011001110110101010110011001101001010011101000100100101011011001010;	3
0
011010001010100011001010100111001101011100110001001011011010111010;	3
0
011010001100010100100010111001011001100110111000101110111000101101;	3
0
011010010100111001110010110011011001011000100100110110111001001110;	3
2
011010010111010001110101101100100110111000100101101010100101100110;	3
2
011010010111011001010010011010011010110001001100011100101101010001;	3
-2
011010011000110110001010101110010100110100010110111011011001100100;	3
0
011010011101001010001010101010110110100011011101101010001101001110;	3
2
011010100111001110010110001010111001001010100101110001010010010110;	3
-2
011010101011101110011010110001010010110001001011100010001101110001;	3
0
011010101101100011001010001001010001001101100110001101110110110101;	3
0
011010110001000110101100101010011100100110101110101010101010010100;	3
-2
011010110100011101011100101011101101001000100100100111000111001001;	3
0
011010110101010111001001010100010110101001101011000111011001000100;	3
-2
011010110110001000101101011000101110010010010100111010010111000110;	3
-2
011010111000110111000100101101110110001110001000101110100111010001;	3
2
011011010011001010101011010001011001110010011101010101001101110100;	3
2
011011010100011101001010110100111000110111010110110001100100110010;	3
2
011011010111000110010010001100110111000100101011000110110110111001;	3
2
011011011010101000110100110011101000110010101110011101001010010101;	3
2
011011011100010101001110101110100010001100011100111001010101001011;	3
2
011011101011010110010001011011000110101110001001101010001001010010;	3
-2
011100011010100110110110110110001101100110001101010100011000110101;	3
2
011100011011100011101001110110101001101100101100100100101001010110;	3
2
011100110010010100111001011011011101010101001010010010100010101010;	3
-2
011101000100100011010100111000110011010110101110001010110110011000;	3
-2
011101001001001110010101001101101011010010101100010010101100111010;	3
0
011101001101101010010011011001101011100110011100110101001001010001;	3
2
011101001110001010111010010010100101101011100101110001101001010101;	3
2
011101010100101011010100110110110111011010011010010110001100010010;	3
2
011101100011000101110110001011000100100101010110110001101001011100;	3
-2
011101100011101001110110110011010100011100100010111000110010001000;	3
-2
011101100110011010011100110111000101001001000101101000110101101000;	3
-2
011101100111010100011011001011010010111001010001110001011011100100;	3
2
011101101001110110001010110010011001100100101001011011101000101001;	3
0
011101101110100010011010101011101001110110010001010010100110111000;	3
2
011101101110100111011101010010011101101011010001010010001010001000;	3
0
011101110011010001100010110011010110111000101010010100100110100100;	3
-2
100010001001010101110101011101110001110110110110010100101101010100;	3
2
100010010101010011100110010010110110111011000101001110111010001110;	3
2
100010011001010101101011101100010100100100011101001101110010010111;	3
0
100010011010110010010101101000101001000110010101101101110110100111;	3
0
100010011011010100100011100010110111010101000101110100010100101101;	3
-2
100010101010010011101011100110010100100100101110110101100011010001;	3
-2
100010101011010110101001011011001010110100100010011010110011010010;	3
-2
100010101110100111001000110100010110111010101010001001101001100111;	3
0
100010101110111001000101101011001000101010100100011101101001010111;	3
0
100010110111010011100011011000111010101010100011011000110100100111;	3
2
100010111011010010010101110101011011000101001110001001001011000111;	3
0
100011000111010100011010110001011000100100100111010101110110011100;	3
-2
100011001101011010001010001011011100011010110110100100111011001011;	3
2
100011010001110100110111000101110110011001011001010010100111010011;	3
2
100011010100111010011011100101011101100101000111001100011101100100;	3
2
100011101100010110111010100101100101101010011100101001100010001011;	3
0
100011101100100110011001000110101110001001011001101110010101101001;	3
0
100100010111010001001011011100111001100110010101100110010110100101;	3
0
100100101011010010100101100110101100111011101001110001001001011101;	3
2
100100110100011011010001000110100110101010111011010110110010100111;	3
2
100100110110100101100011100010101010100101110011001001010001110111;	3
0
100100111010001010010100011001011000110111001110011101010110110100;	3
0
100100111011011100011101010101110101000100100100101001101101011000;	3
0
100101000100011011101100011100111011011001000111000110001100110110;	3
0
100101001001100111011010110100111011010001110001100110010010011011;	3
2
100101001010001010111000100011010101100101101101011100010011011001;	3
-2
100101011000110101010010101100110111010100110111001100010100100111;	3
2
100101011000111010111011000100010001100101110010011001011100110110;	3
0
100101011010101000111010011011000110101110010010110100011100010011;	3
0
100101100110100011010110110110100010001110110001110100101101010101;	3
2
100101100111010111000100101011011011010001100010111001101001011001;	3
2
100101101011001001101100010011100101000110110110110001100010101101;	3
0
100101101011011001010010001000111011010001011011100111001001100011;	3
0
100101110010010111010101001010101011101110110100101000101100110010;	3
2
100110010001101011011011101100010101011000111001110001101010110100;	3
2
100110011000101101010010101010101010100100110101100011101001110001;	3
-2
100110101101001100110001100010101100111000110110111000110011011100;	3
2
100110101110110101100110110101011001001010101100101110001100011000;	3
2
100110111001101010111010011010001101010110010010111001001001001000;	3
-2
100110111010010100010100100110110101011101010100010001101010100111;	3
0
100111010100011100011010001010100111001010111011000110001010110010;	3
-2
100111010111011101001011000110110011000101101001101011000100010011;	3
2
100111011000101101010011100011001100101110011001101010100010110101;	3
2
101000101000101011101100100110100011010111010100101011011000100111;	3
0
101000101001011100010111011001001101100011100110100100011100110011;	3
0
101000110001010010001100101011001001110011001011101101101110110110;	3
2
101000111001001100101010101001001101110011011011010010100011010011;	3
0
101001001101110100010001110011101010010101100010011101010110101001;	3
0
101001010001100100101101110110101110001001101100110001101001011011;	3
2
101001011100110010100101100100111011101000101100010110010001011001;	3
-2
101001011101011010010100101011100010001010111011100101010101101001;	3
2
101001101001011100111011010010110011010001110011001001000100010110;	3
-2
101001101100010111001100110011100111010100011000110100100100110111;	3
2
101001101110001100101110010111010110100110001110010100011010010011;	3
2
101010001101001011001110110010110010101011010011010111001110010100;	3
2
101010001101110001001110101110010010111000110001100101100010011001;	3
-2
101010010101010100100101110001101001010111000111001001001001100111;	3
-2
101010010110011000100010101011011001110110110001101101001010100100;	3
-2
101010010111011011011000101001110001110001110110001000101010011001;	3
0
101010011011011100111010001101101110001001100010101100101001110100;	3
2
101010100010111001011011001101110110010100101100011010001000110100;	3
-2
101010101010110111010111001001010011010010101010001101001110111000;	3
2
101010101011000111001011001110100101010010101100100101101101101000;	3
0
101010101101000101110011011011010111000100101011001100101001101100;	3
2
101010101110111001001001110001010011010100101100011010101101100100;	3
0
101010110010101100011001101010001110110010110110010010001100110100;	3
-2
101011001110011010010101110111010001010011100011011001010100100110;	3
2
101011011010001011100110010011001110011001100101000101001011010011;	3
0
101100011000101110111000101011010100110101011011010001100010100100;	3
-2
101100011010110110100010101010001100010101110011011101011000111000;	3
0
101100011101100110100110001001000101100111011010001110101010101101;	3
2
101100100011101011001011001010001101011011101000111011100101001000;	3
0
101100100110101100010010010100010001101001110111010101010111000110;	3
-2
101100101011101100010010011001010011100111001011010001001101010001;	3
-2
101100101101001101000110110111011000110011101100010100100101000110;	3
0
101100110011010111010100011001001110010100100010110100110110101101;	3
2
101100110100110010100101001101010001101101100110010101000110011101;	3
0
101100110101010001100100100100110101101000111000110110011010100111;	3
0
101100111001011000100011010111001100110110001110001010101011010010;	3
0
101101000100010101010100101000100101100110001011010001110101110111;	3
-2
101101000101010010110001110100010011100101101100010011101100101101;	3
0
101101000110010001010001010101110011011001010010110011011010101001;	3
-2
101101000110010010001110100010111011101110110100010101101011010100;	3
2
101101001001001100010001101110101010110010101100010101110001010011;	3
-2
101101001011101101101010001100110101010010001011000111001100010101;	3
0
101101001100101010101100111010001001101100101010010101001001110111;	3
2
101101010101101101000110101110011100101110010001100100011000111010;	3
2
101101011101001001010100100110010111000110100110010101000110100111;	3
0
101101011101011011100110100101110100101000101101101010001000100110;	3
2
101101100010010101011000110101110011101011000101011001001010101110;	3
2
101101100010110011010100010111010010001101010001110100011011100110;	3
0
101101101010110010101011010001001110001001001101010100100011011101;	3
0
101110001001100101001100111010011001101011100010001011010010010101;	3
-2
101110001110001010011100100010100101100110101100010111010101001001;	3
-2
101110010111000111001110010100010011101000100101110001001000110101;	3
-2
101110010111010001001010100010001010110100111000101110001001100111;	3
-2
101110010111010010001010001010101100111010011101000110101100111001;	3
2
101110101011010001101101010001110001011011010011010100011000111010;	3
2
101110101101001110110001010010011000100011001010110111011001001001;	3
0
101110101110010101010010010010101100101101011011000100010001110011;	3
0
101110110010001110100110001010110101101001101011100101000101101010;	3
2
110001001110101001011100111010110010101110010011000101001001010101;	3
0
110001011011011010111011001101100010010001110101010001010110001011;	3
2
110001100110001100100100101011101001110010011011100110101101110001;	3
2
110001100110010110001000101101110100101010010001011000110111001101;	3
-2
110001101000101100100100010111000101010101110001001101101011000111;	3
-2
110001101100111000100100010101001101110010110011101011010010101101;	3
2
110001101101001010001001010101001110110011100011011011001100010110;	3
0
110001110001100010111011010110100111010010101010010101110100010110;	3
2
110010001101011100100011101010011101100011001001001010110110110110;	3
2
110010010011000111001011100100010100111010101101100010011101101011;	3
2
110010011000100110101101001011010110101110011101010010100010110110;	3
2
110010011011000110111011001001110001110010100101100011000110010111;	3
2
110010101101110001010011100111000101100100110100011001001100101101;	3
0
110010101110101001110011100100010001011101010110101010010111010001;	3
2
110010110001101001101100011001100011010001010110101101011001101101;	3
2
110010110110111001101010001100011100010111010100100110011011001000;	3
0
110010111010110110001110010001011001000100110110100011010111010011;	3
2
110011000100110100101110010101110111010100101100111001001010110100;	3
2
110011001001110011100011000101101110001010101011000110100010010011;	3
-2
110011001100101110101110100110101001010001101001010011010101101010;	3
2
110011010101010110101110110011010010001001001011101100011000110110;	3
2
110011011010011101101001001100010001011001000101001100111010011101;	3
0
110011100010101001100010110111001011000101010111001011101001101000;	3
0
110011100111010111001010010010001001101100111001001011101101001001;	3
2
110100010110100011001110110001001011010111001010001101011001100101;	3
0
110100011001011001001011011010101100110011101100011001010101001010;	3
0
110100011011010001010101110101100010100110111011100010110001011000;	3
0
110100100011001011010101001001101110100101101100011101010110001000;	3
-2
110100100011101011001110110001000101001010101101101001100010111010;	3
0
110100100100110111000100101100011010110110110001110101101010011001;	3
2
110100101100110001101011001101110101000110001101100010110001100111;	3
2
110100110100100110010011001010100010101110111011010001101010100100;	3
-2
110100110101010100010010110110010011001100101101001110010110011011;	3
2
110101001010101011101010101010010001100011101100010100110100111010;	3
0
110101001100010011101110110110110100110001101010100011000100101100;	3
0
110101001101000110001100011001001110111010110010110101001101110100;	3
2
110101010110101101000101110010100101100100010110101110110001001101;	3
2
110101100100110101010011100100011011101001101010010100010110110010;	3
0
110101100111010100110111001010110011000101000110110100101000100101;	3
0
110101101110011100010110100010111010010001011010110001011001000110;	3
0
110101110001101101001001100100101100010111001101000100010010110101;	3
-2
110101110001101101101100010001110100101000101101000110010101100010;	3
-2
110101110001110101110010110001010010100101100100101011101011010100;	3
2
110110001001100101001001000101100101110111011001011000111010010011;	3
0
110110001101001110011100101001101101101110110001011001000110101000;	3
2
110110001110011101010011011100101000110010001011101010010100010010;	3
-2
110110010101001011000101001101100110101110001101001110110001010110;	3
2
110110011011010011011100101100011001110011000111011010100010011000;	3
2
110110011101101101011010011101000111001001001000101000100010100111;	3
0
110110100010011010111000110101110010001001010111001001110011001011;	3
2
110111001100101001001001000110011010101011100010100111000110110110;	3
0
110111001101010001101110010110101010001100011011001101101101001000;	3
2
110111010100110001011100110010110001101101001000110101100010100111;	3
2
110111011000100100100110001011010111001110001001101001011101011100;	3
2
111000100010100011101001001011011010010011101011100100110110100111;	3
2
111000100011010001010001110110011010011101011010101011001001001110;	3
0
111000100011101010100011001000110110011011100010110101010011101001;	3
0
111000100110101010111010011000110001110010111000110101110101000110;	3
2
111000101000110001010011101100101010010011011010010011001011100011;	3
-2
111000110110110010111010011010010100011000101010111001001010100100;	3
-2
111001001001101100110010100011010111010001110001110001001001010110;	3
-2
111001011000110100100100010100011100110101001110100011101100111000;	3
-2
111001011000110101010111010100110111001010001011010001100010010111;	3
2
111001011010011001000100010111011011100110001001110100010110001011;	3
0
111001011100010001010110110011000110001010011001110001110100010011;	3
-2
111001110111000100110010110010100101101011001001011100101110001001;	3
2
111010001110011011010100011000101010111010100101101100011000100111;	3
2
111010011100111010101010010001011000111000111001010001000110010111;	3
0
111010100110110111010100101001010010010100011101010110001011001110;	3
2
111010101010111000111011000101101101001101101010100100101101001000;	3
2
111010101101010110001011011100110101011001011101000101010010001100;	3
2
111010101110100110001101101001100010001100100100101010010111001001;	3
-2
111010110011010001110011010111001011010101011000100010010001100111;	3
2
111010110100100100100100011000110111000111011001100111001010001010;	3
-2
111010111000101101011011001010111001010001101101100100110001101000;	3
2
111010111001100100010100101110010101100011100100101110011001000111;	3
2
111010111011010001100110101001010001010001010101110001011000110110;	3
0
111011001010001101000100010110001000110101101011011001011101001011;	3
0
111011010010101001101011010110011011001000100010110001100110010001;	3
-2
111011011001100110100101000100101100011010100110001110111010001110;	3
2
111011011001110100011011010010011101001110011100011100100010100010;	3
2
111011011010100101011000101101010001011011001001110010110100111000;	3
2
111011100010001110100011100011000101100011010010101110010101100010;	3
-2
111011100101011010011010010100011010100010001010110011011001001001;	3
-2

I would also like to try to have a shot at the Golden sequences but I need
an answer from Glen regarding the last sentence from his previous email:

"As we move past the comparator, the distance stays high initially, but
starts to decline. This decline is due to my attempt to capture worst case,
where the first scrambled block that follows the golden block happens to
match a suffix portion of the golden block."
Does that mean that after the sequence G8 we expect a scrambled block with
G1 (accidental match) ??

0x5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 G1 G2 G3 G4 G5
G6 G7 G8
                          | | | | | | | |
                      <-- G1G2G3G4G5G6G7G8 -->

Thank You and best wishes

Marek Hajduczenia (141238)
SIEMENS Networks S.A. - IC COM D1 R
Rua Irmãos Siemens, 1
Ed. 1, Piso 1
Alfragide
2720-093 Amadora
Portugal
* Marek.Hajduczenia@siemens.com
http://marekhaj.easyisp.pl/index.php
(+351.21.416.7472  4+351.21.424.2082
 

-----Original Message-----
From: Glen Kramer [mailto:glen.kramer@TEKNOVUS.COM] 
Sent: segunda-feira, 18 de Dezembro de 2006 20:19
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [FEC] upstream lock status



> -----Original Message-----
> From: Jeff Mandin [mailto:Jeff_Mandin@PMC-SIERRA.COM]
> Sent: Monday, December 18, 2006 8:42 AM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: [8023-10GEPON] [FEC] upstream lock status
> 
> All,
> 
> Thanks to everyone for the productive and beneficial efforts in the FEC
> framing telecon and reflector discussions last week.
Jeff and all,

> One point for clarification: we have one proposal which says that finding
> a 64bit sequence with more than 29bits Hamming Distance is difficult.
> Another proposal says finding one with the 30bits is straightforward.
> Is this discrepancy due to having a slightly different objective - or
> perhaps a different set of assumptions?


Frank and I were looking at different things. I was searching for code that
would give max distance for any shift of itself.

Frank's scheme requires finding of a Hamming distance of golden block
(denoted GGGGGGGG) with a pattern 0x55, followed by GGGGGGGG.

0x555555555555555555555555555555GGGGGGGG
                          ||||||||
                      <-- GGGGGGGG -->


In Frank's scheme there also exist MANY golden blocks that give a minimum
Hamming distance of 30 for any shift.

But out of ~5000 such blocks, I only found 2 blocks that do not exceed
running distance of 3, which is pretty good, I think.

111011010101101101001001000100101010101110110001000100111000110101
111011010101101101001001001100101010101110010001000100111000110101

See the attached chart for illustration.  Hamming distance stays at or above
30 as golden block approaches the comparator. As golden block coincides with
comparator, the distance jumps to 0 (of course, it assumes no bit errors
here).

As we move past the comparator, the distance stays high initially, but
starts to decline. This decline is due to my attempt to capture worst case,
where the first scrambled block that follows the golden block happens to
match a suffix portion of the golden block. 


Please, let me know if there are any questions.

Glen



> The following seems to be where things stand vis-a-vis upstream lock.
> Please let me know if something is mischaracterized:
> 
> One point for clarification: we have one proposal which says that finding
> a 64bit sequence with more than 29bits Hamming Distance is difficult.
> Another proposal says finding one with the 30bits is straightforward.
> Is this discrepancy due to having a slightly different objective  - or
> perhaps a different set of assumptions?
> 
> - Jeff Mandin
> PMC-Sierra
> 
> 
> Issue 1.   Sync Pattern (for Gain Control and Clock Recovery at OLT):
> --------------------------------------------------------------------------
> --------------------------
> 
> 
>     option A:    Repeated 0x55 (ie. alternating 1s and 0s)
> 
>     option B:    Repeated newly specified 66b control block that will also
> be used for aligning OLT receiver to 66b boundary.  This codeword is DC
> balanced for smooth AGC and scrambling is not employed.  The control block
> has maximum run length of 3, but CDR is might still in some manner be less
> effective than with repeated 0x55.  The sync pattern has Hamming distance
> of at least 30 from all shifts of itself.
> 
> 
> 
> Issue 2.  Burst Delimiter
> -----------------------------------
> 
>     option A:    64 bit "golden block" pattern (has Hamming Distance of 31
> [or 29 anyway] from any shift of itself)
> 
>     option B:    66 bit codeword with high Hamming Distance from Sync
> pattern (eg. 64bit payload logically inverted)
> 
>     option C (suggested on reflector): shorter "golden block" pattern
> (similar to GPON) to reduce implementation complexity at OLT (if shorter
> pattern meets system requirements).
> 
> 
> Issue 3. Transport (ie. "framing") of sync pattern and delimiter)
> --------------------------------------------------------------------------
> -----------------
> 
>     option A: "leader frame" scheme -> pretty much ruled out by the adhoc
> 
>     option B: sync pattern and delimiter words are carried in a datastream
> of 66b blocks in which FEC and scrambling are disabled.  FEC and
> scrambling
> 	      are activated in the transmitted datastream following
> transmission of the FEC Codeword Delimiter 66b control block.
> 
>     option C (from "superframe.ppt" proposal): Burst begins with Sync
> Pattern and Burst Delimiter transmitted in unadorned manner.  FEC and
> scrambling
> 	      are activated in the transmitted datastream immediately
> following transmission of the FEC Codeword Delimiter pattern.
> 
> 
> Issue 4.  OLT frame synchronization sequence
> --------------------------------------------------------------------
> 
>     option A: One-step locking in the following sequence:
> 
> 	   * ONU transmits multiply repeated sync pattern on the upstream
> 
> 	   * OLT performs automatic gain control
> 
> 	   * OLT performs clock and data recovery sequence
> 
> 	   * zero or more bits from the multiply repeated sync pattern are
> received by the FEC/PCS layer at the OLT
> 
> 	   * OLT PCS layer performs bit-by-bit correlation to compare the
> received datastream to the FEC Codeword Delimiter pattern.  When the
> 	     Hamming Distance between the received datastream and the FEC
> Codeword Delimiter is less than "Threshold", then FRAME LOCK is declared.
> 
> 	    * OLT expects the next received bit to be the first bit of the
> first scrambled 66b block of a FEC Codeword
> 
> 
> 
>     option B: Two-step locking in the following sequence:
> 
> 	   * ONU transmits sync pattern blocks on the upstream
> 
> 	   * OLT performs automatic gain control
> 
> 	   * OLT performs clock and data recovery sequence
> 
> 	   * One or more instances of the entire sync pattern block is
> received by the FEC/PCS layer at the OLT
> 
> 	   * OLT PCS layer performs bit-by-bit correlation to compare the
> received datastream to the sync pattern block.  When the
> 	     Hamming Distance between the received datastream and the sync
> pattern block is less than "Threshold", then BLOCK LOCK is declared.
> 
> 	   * OLT expects the next received bit to be the first bit of an
> unscrambled 66b block
> 
> 	   * OLT PCS layer performs block-by-block correlation to compare
> the received datastream to the FEC Codeword Delimiter pattern.  When the
> 	     Hamming Distance between the received datastream and the FEC
> Codeword Delimiter is less than "Threshold", then FRAME LOCK is declared.
> 
> 	   * OLT expects the next received bit to be the first bit of the
> PCS data (putting aside the scrambler init issue for the moment)