Kitz Forum

Broadband Related => Broadband Technology => Topic started by: Weaver on April 08, 2017, 03:27:41 AM

Title: Downstream on low bins and TDM
Post by: Weaver on April 08, 2017, 03:27:41 AM
I read that an ADSL system has been proposed (or maybe even implemented, I don't know, it didn't say) in which all the bins from 138 kHz down to 25 kHz can be used for downstream, but no more details were given. Presumably TDM is used to give upstream a share of certain bins. Sounds cool. I wonder why they didn't go for it?

Is this like G.Fast?
Title: Re: Downstream on low bins and TDM
Post by: ejs on April 08, 2017, 07:52:43 AM
I believe you are talking about the downstream "overlapped spectrum operation" described in the ITU-T ADSL documents. I have not given it much thought because it's not what we use in this country, I don't know about elsewhere. I don't think it's TDM, it's usually described as Echo Cancellation.
Title: Re: Downstream on low bins and TDM
Post by: Weaver on April 08, 2017, 08:01:08 AM
So they just subtract the Tx from the Rx and pray? Very efficient then if they can get it right.