From: invalid@see.sig.telecom-digest.org   
      
   On 10/22/2020 9:28 PM, Bill Horne wrote:   
   > On Thu, Oct 22, 2020 at 09:43:21AM -0400, Fred Goldstein wrote:   
   >   
   >> This does lead to a push to use more private microwave solutions.   
   >> We've replaced Verizon repeater backhauls with a mix of licensed and   
   >> unlicensed microwave here. You'd be amazed what you can do unli-   
   >> censed if you know what you're doing, though you really do have to   
   >> know what you're doing or at least run it by someone who does, since   
   >> some vendors will happily sell you a bill of goods. And unlicensed   
   >> links need maintenance to check that they're not being clobbered by   
   >> interference -- you may sometimes want to change frequency,   
   >> especially on the popular 5 GHz band.   
   >   
   > Is interference a common problem? Can low-beamwidth antennas help?   
      
   Yes, interference is a problem. Unlicensed frequencies have all sorts   
   of users coming and going. Comcast's home "wireless gateway" puts an   
   80 MHz signal on the 5 GHz band, for instance, and there's a ton of   
   Wi-Fi, but if the cellco uses LAA (license assisted access), it's the   
   worst. That's a supplementary LTE downlink on unlicensed 5 GHz while   
   the uplink is licensed, guaranteeing that the cellco gets through   
   while unlicensed users suffer from the noise. Very nasty but legal   
   since it's unlicensed.  Of course if you're in a remote location,   
   there won't be LAA or much Wi-Fi. The better radios have decent   
   spectrum analyzer functions built in.   
      
   >> The Wireless ISP industry has come a long way in 20 years. Its   
   >> vendors have gone through multiple generations (not the same as   
   >> mobile G's!) of technology. Fixed outdoor (WISP) gear is not the   
   >> same as fixed indoor (WLAN, like Wi-Fi) or mobile. It's a category   
   >> of its own. The biggest unlicensed-band equipment vendors in the US   
   >> market are probably Cambium Networks (spun out of Motorola almost a   
   >> decade ago), Ubiquiti, and Mimosa. MikroTik is a major radio-gear   
   >> player in, uh, developing countries, but mainly a major router and   
   >> switch player in the US.   
   >   
   > Which vendor do you recommend for short (1-3 miles) and for longer   
   > routes? How are the prices? How much time and effort goes into aiming   
   > the dishes?   
      
   I'm not going to recommend one specific vendor since they all have   
   advantages and disadvantages. I do like Mimosa B5 (built-in 25 dB   
   antenna) and B5c (external antenna, so you can choose a big dish, like   
   from KP Performance) radios for 1-15 mile high-capacity shots (two   
   parallel 20-80 MHz carriers); their C5x (metal body) has a nice set of   
   screw-on dish options for smaller applications (up to 25 dB antenna).   
   The IgniteNet MetroLinq radios are cute 60 GHz radios that do gigabit+   
   for shorter shots (up to a mile or so) with perfect line of sight.   
   Ubiquiti sells a Powerbeam ISO which has a dish with an isolation ring   
   to improve side-lobe rejection, good for urban applications.   
      
   The Ubiquiti radios and most similar one-channel non-sync'd radios are   
   under $200. Radios with GPS sync, like Mimosa B5 (very useful for   
   keeping them from interfering with each other if you have a bunch of   
   them), are generally in the $500-1000 range. IgniteNet is under $200   
   for the 1G radio, more like $500 for 2.5Gbps, but - pro tip - remember   
   to buy the more expensive optional mount and you need the scope for   
   alignment. Aligning 5 GHz is easier and usually only takes a few minutes   
   per end as these are usually 5-10 degree beams, vs. 1 degree or so on on   
   60 GHz.   
      
   >> Point to point and point to multipoint are different too -- with   
   >> PtP, both ends have a highly directional antenna, while PtMP   
   >> typically pairs a highly directional client radio with a sector. On   
   >> 5 GHz, power limits for PtP use are highest, so you can easily shoot   
   >> 10 miles with a pair of 2-foot dishes, if you have line of sight. If   
   >> there's clutter (trees or buildings) in the way, though, all bets   
   >> are off -- 5 GHz gets through a little bit of wood but not a lot. I   
   >> do blast it through clutter on some short links though.   
   >   
   > There used to be a couple of sites that would let me lookup the Tower   
   > Height needed for a given route, without charge: do they still exist?   
      
   I use the program RadioMobile to do most path calculations, but it can   
   be hard to set up and has a steep learning curve so you wouldn't use   
   it for a one-of. Mimosa, Ubiquiti, and I think Cambium all have free   
   online path tools. (So do some licensed microwave vendors like Aviat.)   
   I'm not sure how good they are with locating clutter, though. I   
   generally use Google Earth "measure" to see the potential path and   
   then I can see what's under it, to see if tall trees or buildings are   
   in the way. Its path profile helps see if there are terrain   
   obstructions.   
      
   > Thanks for the info: there's always another way to get it done, but   
   > knowing how and who makes all the difference.   
   >   
   > Bill   
      
      
   - -   
   Fred R. Goldstein      k1io     fred "at" ionary.com   
     +1 617 795 2701   
      
   ***** Moderator's Note *****   
      
   A very wise man once said something to me that I've never forgotten:   
      
   "If you want to find the really sharp people, you have to go to the cutting   
   edge!"   
      
   Thank you, Fred: you're the best.   
      
   Bill Horne   
   Moderator   
      
   --- SoupGate-Win32 v1.05   
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