That's interesting, I dug around and found some stuff, this being one of the best I came up with:
http://www.broadcom.com/collateral/wp/XDSL-WP101-R.pdfMy initial impression is that it's basically a more efficient error-correction mechanism involving physical layer retransmissions, so providing a lower BER.
If it's based on physical layer ReTX, it's safe to assume it would need a co-operating DSLAM.
It seems to targeted at IPTV which apparently requires a lower BER (ie fewer physical layer errors) compared to more conventional internet traffic, which can rely on TCP/IP protocols for recovery from physical layer error. I know nothing about IPTV, but if it can't benefit from TCP's error recovery then I can well speculate that it wouldn't work over normal DSL or, at least, it would require a more generous SNRM and hence a degradation of data rate.
I'd need to understand the document a lot better before speculating whether PhyR provides any benefit for users of applications that use TCP/IP, who don't need IPTV.
And in order to consume the document properly I'll need daylight, strong coffee, and a degree of motivation and attention span that I find hard to sustain these days, so perhaps I never will
- 7LM
