adsl2+ slower than adsl2 on some lines, here is why.

I decided to check my bitloading on adsl2+ vs adsl2 to see why adsl2+ is much slower on my line.

The comparitive sync speeds on equal settings is.
adsl2 - 7.9mbit
adsl2+ 4.9mbit
settings - 4db noise margin, coding gain 7 (most agressive), reduced upstream power and fast path.

here is the adsl2 bitloading.

Bin 32 = 8 8 8 8 9 9 10 9 9 11 12 12 12 13 9 13
Bin 48 = 13 14 14 2 13 14 14 14 14 13 13 10 11 13 13 14
Bin 64 = 13 14 14 14 14 14 14 14 14 14 14 14 14 14 14 10
Bin 80 = 13 13 14 14 14 14 14 13 14 13 13 13 13 13 13 13
Bin 96 = 13 13 13 10 13 13 13 13 13 13 13 13 13 13 12 12
Bin 112 = 13 12 12 12 12 12 12 10 12 12 12 12 12 12 12 12
Bin 128 = 12 12 12 12 12 12 11 11 11 11 11 10 11 11 11 11
Bin 144 = 11 11 9 10 10 10 10 9 9 8 8 8 7 6 5 4
Bin 160 = 2 0 3 5 6 7 7 8 8 9 9 8 9 8 9 9
Bin 176 = 9 9 8 9 8 8 9 8 8 8 8 8 7 7 7 6
Bin 192 = 5 3 0 0 2 4 4 5 6 6 5 5 2 2 4 5
Bin 208 = 5 5 5 2 5 5 5 5 5 5 5 2 0 4 6 5
Bin 224 = 5 5 5 5 5 5 2 3 2 5 4 4 4 4 4 5
Bin 240 = 4 4 3 2 0 1 2 2 2 1 2 2 1 0 2 1

and here is the adsl2+ bitloading

Bin 32 = 3 3 4 4 4 5 6 6 6 6 7 7 7 7 7 8
Bin 48 = 8 8 8 8 9 9 9 9 9 9 10 9 10 10 10 10
Bin 64 = 10 10 11 11 11 11 11 11 11 11 11 11 11 11 11 10
Bin 80 = 11 11 11 11 2 11 11 11 11 11 11 11 11 11 11 11
Bin 96 = 11 11 11 10 11 11 11 11 11 11 11 11 11 11 11 11
Bin 112 = 11 11 11 11 11 11 11 10 11 11 11 11 11 10 10 10
Bin 128 = 10 10 10 10 10 9 9 9 9 9 9 9 9 9 9 9
Bin 144 = 9 8 8 8 8 8 8 7 7 7 7 6 6 5 5 3
Bin 160 = 0 0 2 4 5 5 5 6 6 6 6 6 6 6 6 6
Bin 176 = 6 6 6 6 6 6 6 5 5 5 5 5 5 4 4 3
Bin 192 = 2 0 0 1 2 2 3 3 3 3 3 3 2 2 3 3
Bin 208 = 3 3 3 1 3 3 3 3 3 3 3 1 3 2 2 2
Bin 224 = 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
Bin 240 = 1 1 1 1 0 0 1 1 1 1 1 1 0 0 1 1
Bin 256 = 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

my thoery in previous posts on this forum about adsl2+ supplying less power to each tone seems to be true as each tone seems to have 3-4bits lesser loading, the noise margin was not higher on adsl2+. As you can see also my sync only utilised a single bit on a single tone above the adsl 1/2 frequency.

for the curious here is the bitloading after a night, many higher tones on 0 now after been disabled. some bitloading moved to the first tones so not all bandwidth lost. sync speed now 7.28mbit (SRA dynamic) and had fell to about 6.9mbit during the night.

Bin 32 = 9 9 9 9 10 10 11 9 9 12 12 13 13 13 9 14
Bin 48 = 14 2 14 14 14 14 14 14 14 13 13 9 11 13 13 14
Bin 64 = 14 14 13 13 13 13 14 14 14 13 14 13 13 13 13 10
Bin 80 = 13 13 13 14 14 13 13 13 13 13 13 13 13 12 13 13
Bin 96 = 13 13 13 10 13 12 12 13 12 12 12 13 12 12 12 12
Bin 112 = 12 12 12 12 12 12 12 11 12 12 12 12 12 12 12 12
Bin 128 = 12 12 12 12 12 12 11 11 11 11 11 10 11 11 11 11
Bin 144 = 11 10 9 10 10 10 9 9 9 8 8 7 7 6 5 4
Bin 160 = 0 0 3 5 6 0 7 8 8 9 9 8 9 0 9 9
Bin 176 = 9 9 8 8 8 9 9 9 8 8 8 8 0 7 7 6
Bin 192 = 5 0 0 0 3 4 0 5 0 6 0 0 0 0 0 5
Bin 208 = 5 0 0 0 4 0 6 0 6 0 5 0 0 5 5 0
Bin 224 = 0 0 5 0 0 4 0 0 0 0 0 3 0 5 0 0
Bin 240 = 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Edited by Chrysalis (Sat 10-Apr-10 10:01:19)