Adam, Olt goes down the road, then open up ~16 strands in either direction. Simply do a 1:32 per FSA. This way there isn't any math, there's one uniform light source to customer method, etc.
In practice with our 1:32 splits we're getting 15-20 route miles. Look here: https://preseem.com/2024/09/ont-receive-power-fiber-length/ Class C is 60km. See Calix info: 100-05071 GPON SFP OIM, Class C+, 60Km, 1490/1310nm Single Fiber Transceiver, I-Temp, AXOS On Tue, Aug 19, 2025 at 12:13 PM Adam Moffett <[email protected]> wrote: > Oddly, I find the opposite. The distance limitation is a differential > between the nearest and farthest ONT, not a maximum total distance. I > think with our Nokia GPON it's 20km. With the XGS-PON transceivers it's > 20km by default and you can raise it higher....I want to say 60km? > > If I went 20km to the first splitter I've lost 4dB from distance (@ > 0.2dB/km). Starting from +6 tx power, if you place a 1x4 top level > splitter and four 1x16's you're at about -19 or so at the splitter ports. > In a suburban neighborhood there's no way we're going 20km from the first > splitter to the last one. You can still add a 1x2 or 1x4 at the house if > it's needed. The max differential distance is almost never an issue for me. > > Are you running down rural roads perchance? > > ------------------------------ > *From:* AF <[email protected]> on behalf of Chuck McCown < > [email protected]> > *Sent:* Monday, August 18, 2025 6:11 PM > *To:* 'AnimalFarm Microwave Users Group' <[email protected]> > *Subject:* Re: [AFMUG] how is underground FTTH done? > > > When you work out a 32:1 GPON, the timing distance limitations are > exhausted before you run out of light. Splits are a 3 dB loss. A good > splice will be .02dB. So don’t worry about splices. > > > > *From:* AF [mailto:[email protected]] *On Behalf Of *Dev > *Sent:* Monday, August 18, 2025 9:56 AM > *To:* AnimalFarm Microwave Users Group <[email protected]> > *Subject:* Re: [AFMUG] how is underground FTTH done? > > > > The thing with PON is that every time the light hits a splitter it loses a > bit of strength, so you sort of have to plan to use a little hotter SFP in > your OLT sometimes. Luckily, those are getting way cheaper nowadays, so > it’s not the end of the world, but you do have to plan for that. > > > > Plus, each splice you do cuts down the signal a bit more. Fusion splicers > only lose a tiny bit, but a physical connector can lose a bunch more, like > the equivalent of a mile or more of distance, and a piece of crud on an > uncleaned connector can lose 5 miles distance, so make sure you clean them > with those cheap cleaner tools. > > > > On Aug 18, 2025, at 8:39 AM, Josh Luthman <*[email protected] > <[email protected]>*> wrote: > > > > Splitters are waaay small. Smaller than a standard house key. > > > > What you are looking at is an MST terminal, looks like 8 ports. There can > be a splitter inside of that yes. You can have the MST with 8 fibers > splice to another 8 fibers or you can have what is in your picture have 1 > fiber in, split 1x8, and then have 8 ports out for the installers to simply > plug in to. > > > > If that MST is a 1x8, you can have a 1x4 before it, between the MST and > OLT. That makes for OLT -> 1x4 splitter -> 1x8 splitter/MST. That is > still a 1x32 split. > > > > On Mon, Aug 18, 2025 at 11:34 AM Ken Hohhof <*[email protected] > <[email protected]>*> wrote: > > I thought PON used like 16:1 or 32:1 splitters, and in this photo, I > assumed that’s what the black boxes were. > > > > *From:* AF <*[email protected] <[email protected]>*> *On > Behalf Of *Josh Luthman > *Sent:* Monday, August 18, 2025 10:16 AM > *To:* AnimalFarm Microwave Users Group <*[email protected] > <[email protected]>*> > *Subject:* Re: [AFMUG] how is underground FTTH done? > > > > Don't assume that about aerial. That's not how it works. Don't think > about it in terms of taps. > > > > Generally speaking, installations are PON. What we do is design the fiber > so we can hook up 100% of homes. We assign a color to every house. > > > > The first thing to think about is that you have to access the individual > strand out of the cable, be it 12/24/48/144/etc. That is done with a > SpliceCase or you splice on an MST for an ez mode plug. At Imagine we only > splice - no connectors, no MST, no plugs, etc. > > > Second thing is that when there's a cable up and down the road, you just > need access to it through the case/MST from the house. This can be from > the house to the handhole (concrete box in the ground) or you can run it > from the house to the handhole through some 1.25" duct to the next handhole > where there is one case. > > > > I can show you what it looks like if you don't get it yet. > > > > On Mon, Aug 18, 2025 at 11:11 AM Ken Hohhof <*[email protected] > <[email protected]>*> wrote: > > The fiber train left without me, so maybe someone here can help me > understand how the physical installation is typically done. > > > > I’ve seen aerial fiber and it’s pretty straightforward, I see splitters up > on poles maybe at each intersection, and to hook up a customer, they run a > drop wire from the nearest splitter to the house. If take rate is better > than expected or a new house is built, worst case I assume they just add a > splitter. > > > > But I also see FTTH deployments going in where they are boring for duct in > the ROW and putting a little handhole in front of every house. How does > this work? Are they using taps instead of splitters? If not, when they > get a customer install order, do they pull his drop cable through all the > handholes to a splitter? That doesn’t seem feasible. Are they dedicating > a strand to each house and pulling the main cable out each time and > splicing to that strand? And what if they estimate the take rate wrong, or > a new house is built? > > > > There’s probably a simple explanation and once someone enlightens me it > will be a Duh! moment. > > -- > AF mailing list > *[email protected] <[email protected]>* > *http://af.afmug.com/mailman/listinfo/af_af.afmug.com > <http://af.afmug.com/mailman/listinfo/af_af.afmug.com>* > > -- > AF mailing list > *[email protected] <[email protected]>* > *http://af.afmug.com/mailman/listinfo/af_af.afmug.com > <http://af.afmug.com/mailman/listinfo/af_af.afmug.com>* > > -- > AF mailing list > *[email protected] <[email protected]>* > *http://af.afmug.com/mailman/listinfo/af_af.afmug.com > <http://af.afmug.com/mailman/listinfo/af_af.afmug.com>* > > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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