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iansltx
join:2007-02-19
Austin, TX

iansltx

Member

[Wideband] Service is up, but modem is overkill

Got my 50/5 connection installed a little over an hour ago. Speeds are consistent so far at advertised levels, maybe a little above. Latency is reasonable to the first hop, and on out from there.

The modem that I'm leasing, however, is a bit overkill for the current state of TWC's plant in my apartment complex. I can't complain about downstream signals...dBmV values are between -1 and -3.5 and SNRs on all DS channels are in the 42 dB range. Upstream may be okay as well, though the return path is being pushed pretty hard (49.5 dBmV).

But, back to the overkill argument. The modem I left in Colorado with Comcast was a Moto SB6120 (4 down, 4 up). In that area I was bonding all four downstreams and two upstreams. Here, with an 8x4 modem, I'm bonding four down (543, 549, 555, 561 MHz) as well, but upstream bonding is nowhere to be found. Heck, I'll bet the channel is still running at only 16QAM (I know it's a narrow channel, at 2.56 MSym/sec, AKA 3.2MHz). The channel ID is 1 and it's located at 38 MHz, with a channel type of "TDMA and ATDMA" according to the gateway (which is now bridged to my own wireless router).

In short, TWC will have to do some plant upgrades in my area if they want to offer more upload speed than 5 Mbps...which is sad, because I want more upload speed than 5 Mbps! I could try ordering a second cable modem/line, and bonding that way, but at that point I'd probably be monopolizing the entire upstream channel if I wanted to go at full speed...which wouldn't work too well. So yeah, hopefully TWC can figure out how to add a 6.4MHz wide, 64QAM modulated upstream channel here, because capacity-wise they don't have room to grow right now.

DocDrew
How can I help?
Premium Member
join:2009-01-28
SoCal

DocDrew

Premium Member

Being that the channel you see is on the high end of the upstream band, I'd say that there is guaranteed to be other channels lower in the band. They just aren't bonded.

motorola870
join:2008-12-07
Arlington, TX

motorola870 to iansltx

Member

to iansltx
said by iansltx:

Got my 50/5 connection installed a little over an hour ago. Speeds are consistent so far at advertised levels, maybe a little above. Latency is reasonable to the first hop, and on out from there.

The modem that I'm leasing, however, is a bit overkill for the current state of TWC's plant in my apartment complex. I can't complain about downstream signals...dBmV values are between -1 and -3.5 and SNRs on all DS channels are in the 42 dB range. Upstream may be okay as well, though the return path is being pushed pretty hard (49.5 dBmV).

But, back to the overkill argument. The modem I left in Colorado with Comcast was a Moto SB6120 (4 down, 4 up). In that area I was bonding all four downstreams and two upstreams. Here, with an 8x4 modem, I'm bonding four down (543, 549, 555, 561 MHz) as well, but upstream bonding is nowhere to be found. Heck, I'll bet the channel is still running at only 16QAM (I know it's a narrow channel, at 2.56 MSym/sec, AKA 3.2MHz). The channel ID is 1 and it's located at 38 MHz, with a channel type of "TDMA and ATDMA" according to the gateway (which is now bridged to my own wireless router).

In short, TWC will have to do some plant upgrades in my area if they want to offer more upload speed than 5 Mbps...which is sad, because I want more upload speed than 5 Mbps! I could try ordering a second cable modem/line, and bonding that way, but at that point I'd probably be monopolizing the entire upstream channel if I wanted to go at full speed...which wouldn't work too well. So yeah, hopefully TWC can figure out how to add a 6.4MHz wide, 64QAM modulated upstream channel here, because capacity-wise they don't have room to grow right now.

if your modem is reporting TDMA-ATDMA mixed the channel is running QAM16/QAM64 on the same upstream it will be either QAM16 or QAM64 on your modem depending on the noise level.

North Texas has 4 upstreams with QAM16 and QAM64 enabled on all four:

24.5MHz
29.5MHz
33MHz
36.5MHz