[c-nsp] Ubr Docsis 2.0 Question

[Justin Shore]

I'm not a RF expert by any means but I'm pretty sure this is how we're 
actually doing it on our Arris C3s.  We've built 2 main modulation 
profiles, one ATDMA and on TDMA and associated them with different 
sub-interfaces of the upstreams.  The modems train up on the correct 
sub-interfaces.  This works like a champ for us.  I'm assuming that the 
uBR has a similar capability.

Justin



Paul Stewart wrote:
> Following up...
> 
> I'm pretty sure you can run mixed-mode though with QPSK upstream on the 1.x
> modems and then 64QAM modulation for Docsis 2.0 modems on the same
> upstream/downstreams?  This would be ideal even with the 3.2Mhz channel size
> until we get a chance to swap out hundreds of cable modems...
> 
> Thanks,
> 
> Paul
> 
> 
> -----Original Message-----
> From: Michel Renfer [mailto:michel.renfer at finecom.ch] 
> Sent: Monday, March 05, 2007 10:39 AM
> To: cisco-nsp at puck.nether.net
> Cc: Paul Stewart
> Subject: RE: [c-nsp] Ubr Docsis 2.0 Question
> 
> Hi Paul
> 
> No, of course not. Your DOCSIS 1.x (TDMA) modems will only support
> channel-widths up to 3.2 MHz. If you want use the benefits of a 6.4 MHz
> channel-width you need to use DOCSIS 2.0 modems (ATDMA).
> 
> cheers,
> michel
> 
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp- 
>> bounces at puck.nether.net] On Behalf Of Paul Stewart
>> Sent: Monday, March 05, 2007 4:02 PM
>> To: cisco-nsp at puck.nether.net
>> Subject: [c-nsp] Ubr Docsis 2.0 Question
>>
>> Hi there...
>>
>> I'm pretty sure there's some Ubr experts on here ;)
>>
>> We are migrating a Cisco Ubr7114 up to Ubr7246VXR - so during this 
>> we'll be changing to Docsis 2.0 ... this will also involve changing 
>> the channel bandwidth from 3.2 to 6.4 Mhz....
>>
>> My question is in regards to Docsis1.1 modems - if we change the 
>> channel size to 6.4 is there a way to support modems that only work 
>> with 3.2 channel width (therefore Docsis 1.x)??