5 Upstream channels
 

Hey all,

Haven't seen this posted anywhere, but apologies if i'm behind the curve...

Seem to have 5 upstream channels in Gateshead after a reboot overnight, no change in config but suspect it's related to the incoming 500/35 package

https://www.cableforum.uk/images/local/2019/03/5.png

Re: 5 Upstream channels
 

I think someone on here a week or so ago said they had 5 upstreams.

Edit

Martin had 32 Downstreams and 6 upstreams which settled on 5 up streams.

https://www.cableforum.uk/board/show...6&postcount=12

Re: 5 Upstream channels
 

Ah I did scan that thread but didn't spot it.

On 30 down here, never had an issue with up or down speeds but it's good to see they're investing before it's 'needed'!

Re: 5 Upstream channels
 

How much bandwidth do they allocate per (16QAM??) channel?

I'm sure you could calculate it with the symbol rate and modulation - But I'll de damned if I can remember how :D

Tom

Re: 5 Upstream channels
 

I wonder what the maximum transmit would be for 5 upstreams

Re: 5 Upstream channels
 

I am also on 4 16QAM, i have only ever seen 1 64 & 32 for a few days before i went to 4 channels.

Re: 5 Upstream channels
 

I used to have 3x 64QAM but they dropped to 16 when they upgraded the area to 4x up streams, expected the standard to be 64 but apparently not

Re: 5 Upstream channels
 

I'm on 4 64QAM and channel ID's show up to 30 downstream available.

Re: 5 Upstream channels
 

And back to 4 today...

Re: 5 Upstream channels
 

How weird same

1 32600000 4.025 5120 64 qam 5
2 39400007 4.125 5120 64 qam 4
3 46199998 4.225 5120 64 qam 3
4 53700002 4.475 5120 64 qam 2

Re: 5 Upstream channels
 

Weird indeed, looks like they're testing something in various areas

Re: 5 Upstream channels
 

it is probably in preparation for the 500mbit tier

Re: 5 Upstream channels
 

The other day we went from 16 downstream channels to 24 we are in area 18

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 683000000 0 35 256 qam 31
2 475000000 0.5 37 256 qam 9
3 483000000 0.5 37 256 qam 10
4 491000000 0.5 37 256 qam 11
5 499000000 0.5 37 256 qam 12
6 507000000 0.5 37 256 qam 13
7 515000000 0.7 37 256 qam 14
8 523000000 0.7 36 256 qam 15
9 531000000 0.7 37 256 qam 16
10 539000000 0.5 37 256 qam 17
11 547000000 0.7 36 256 qam 18
12 555000000 0.4 36 256 qam 19
13 563000000 0 36 256 qam 20
14 571000000 0.2 36 256 qam 21
15 579000000 -0.2 35 256 qam 22
16 587000000 -0.5 35 256 qam 23
17 595000000 -1 35 256 qam 24
18 635000000 -0.5 35 256 qam 25
19 643000000 -0.2 35 256 qam 26
20 651000000 -0.2 35 256 qam 27
21 659000000 -0.4 34 256 qam 28
22 667000000 -0.2 35 256 qam 29
23 675000000 0 35 256 qam 30
24 691000000 -0.4 35 256 qam 32

Upstream has stayed a 4 channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 25799994 4.3 5120 64 qam 4
2 46199976 4.425 5120 64 qam 1
3 39400000 4.4 5120 64 qam 2
4 32600053 4.35 5120 64 qam 3

Re: 5 Upstream channels
 

Well I did finally join the 4 upstream channels club (4 x 64 qam).

According to this site, thats 6 bits per symbol, and my symbol rate is 5120k
So I guess 5120 x 1024 x 6 is my max upstream bps (31,457,280) = 30Mbps per channel.

Assuming this maths is [now ]correct, four channels allows for 120M upload (five would max at 150M).


*Note: My knowledge of qam and bit rates is limited, so the above could easily be completely wrong.

Re: 5 Upstream channels
 

You forgot to multiply by 4 for the 4 channels.

And just to be accurate, you should multiply by 1000, not 1024. Bit rates always come in thousands.