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[digitalnemesis]

Let's say one achieves 50 Mbps at 6 db, what's the formula to calculate sync at 3 db?

(50 / 6) x 3 + 50 = 75 Mbps at 3db?

[William Grimsley]

Let's say one achieves 50 Mbps at 6 db, what's the formula to calculate sync at 3 db?

(50 / 6) x 3 + 50 = 75 Mbps at 3db?

WOW, I'd be happy with that! :O

I'm pretty sure it's 5 Mbps per 3 dB but it may be more.

[digitalnemesis]

Let's say one achieves 50 Mbps at 6 db, what's the formula to calculate sync at 3 db?

(50 / 6) x 3 + 50 = 75 Mbps at 3db?

WOW, I'd be happy with that! :O

I'm pretty sure it's 5 Mbps per 3 dB but it may be more.

I did (50 / 6) to calculate dB per Mb but this doesn't seem correct. I'm sure there is a better formula based on attenuation?

[S.Stephenson]

old rule-of-thumb data I had calculated a year ago...

My rule of thumb for what an extra 3dB of noise margin is worth in the downstream direction:
- For speeds around 20Mbps, 3dB is worth 3Mbps
- For speeds around 40Mbps, 3dB is worth 6Mbps
- For speeds of 60Mbps or more, 3dB is worth 11Mbps.

The figures comes from using the 3dB to buy one extra bit on each tone. If that can happen across all downstream tones (about 2750 tones), it buys 11Mbps.

I made a graph based on this below.

[William Grimsley]

So, if my attainable rate is currently 44 Mbps at 10 dB, then at 6 dB I'd be looking at 52 Mbps and I'd sync at that speed? :O

[S.Stephenson]

So, if my attainable rate is currently 44 Mbps at 10 dB, then at 6 dB I'd be looking at 52 Mbps and I'd sync at that speed? :O

Probably in the 51-55mbps region I would imagine with 3dB, so the new Infinity 1 is ideal for you.

[digitalnemesis]

old rule-of-thumb data I had calculated a year ago...

My rule of thumb for what an extra 3dB of noise margin is worth in the downstream direction:
- For speeds around 20Mbps, 3dB is worth 3Mbps
- For speeds around 40Mbps, 3dB is worth 6Mbps
- For speeds of 60Mbps or more, 3dB is worth 11Mbps.

The figures comes from using the 3dB to buy one extra bit on each tone. If that can happen across all downstream tones (about 2750 tones), it buys 11Mbps.

I made a graph based on this below.

What formula did you use?

[licquorice]

So, if my attainable rate is currently 44 Mbps at 10 dB, then at 6 dB I'd be looking at 52 Mbps and I'd sync at that speed? :O

No, your attainable rate assumes 6dB. You have snrm of 10dB because you are capped at 35M

[William Grimsley]

So, if my attainable rate is currently 44 Mbps at 10 dB, then at 6 dB I'd be looking at 52 Mbps and I'd sync at that speed? :O

No, your attainable rate assumes 6dB. You have snrm of 10dB because you are capped at 35M

That's interesting. Because when I had 6 dB before, it was at 52 Mbps...

[S.Stephenson]

I used the age old method of using the rules and doing a rough approximation, best way to work on a formula would be to look into the "using the 3dB to buy one extra bit on each tone. If that can happen across all downstream tones (about 2750 tones), it buys 11Mbps"

[Ronski]

That's interesting. Because when I had 6 dB before, it was at 52 Mbps...

If you was interleaved it used to over estimate your attainable, that may be an explanation. Although I see you are on a Huawei cabinet, so unless it was around a year ago you are unlikely to have been interleaved as Huswei's have had G.inp for some time.

[William Grimsley]

That's interesting. Because when I had 6 dB before, it was at 52 Mbps...

If you was interleaved it used to over estimate your attainable, that may be an explanation. Although I see you are on a Huawei cabinet, so unless it was around a year ago you are unlikely to have been interleaved as Huswei's have had G.inp for some time.

Bum, I was hoping to get nearer 50 Mbps with the new package...

[renluop]

I found something called Increase Broadband Speed in a Google Search. From that I'd guess +~14% per 3dB reduction in margin, which is not dissimilar to WWW's estimates above.