I should clarify: Distance x loss/km + splitter loss. = link loss.
On Fri, Feb 1, 2013 at 3:03 PM, Jason Baugher <ja...@thebaughers.com> wrote: > I disagree. Loss is loss, regardless of where the splitter is placed in > the equation. Distance x loss + splitter insertion loss = total loss for > purposes of link budget calculation. > > The reason to push splitters towards the customer end is financial, not > technical. > > > On Fri, Feb 1, 2013 at 2:29 PM, Scott Helms <khe...@zcorum.com> wrote: > >> Owen, >> >> You're basing your math off of some incorrect assumptions about PON. I'm >> actually sympathetic to your goal, but it simply can't work the way you're >> describing it in a PON network. Also, please don't base logic for open >> access on meet me rooms, this works in colo spaces and carrier hotels but >> doesn't in broadband deployments because of economics. If you want to >> champion this worthy goal you've got to accept that economics is a huge >> reason why this hasn't happened in the US and is disappearing where it has >> happened globally. >> >> >> > Bottom line, you've got OLT -> FIBER(of length n) -> splitter -> >> > fiber-drops to each house -> ONT. >> > >> >> So far you're correct. >> >> >> > >> > All I'm proposing is making n really short and making "fiber-drops to >> each >> > house" really long. >> > I'm not proposing changing the fundamental architecture. Yes, I >> recognize >> > this changes the economics and may well make PON less attractive than >> other >> > alternatives. I don't care. That's not a primary concern. The question >> is >> > "can PON be made to work in this environment?" It appears to me that it >> can. >> > >> >> >> Here is where you're problems start. The issue is that the signal *prior >> to being split* can go 20km if you're splitting it 32 ways (or less) or >> 10km if you're doing a 64 way split. AFTER the splitter you have a MAX >> radius of about 1 mile from the splitter. >> >> Here is a good document that describes the problem in some detail: >> >> http://www.ofsoptics.com/press_room/media-pdfs/FTTH-Prism-0909.pdf >> >> >> Also, here is a proposed spec that would allow for longer runs post >> splitter with some background on why it can't work in today's GPON >> deployments. >> >> >> http://www.ericsson.com/il/res/thecompany/docs/publications/ericsson_review/2008/3_PON.pdf >> >> -- >> Scott Helms >> Vice President of Technology >> ZCorum >> (678) 507-5000 >> -------------------------------- >> http://twitter.com/kscotthelms >> -------------------------------- >> > >
