Attenuation in 3.5ghz is on average 15db per 100meters of foliage.  I got that number from a Telrad engineer, and it seemed to hold up experimentally.  Whether it's Wimax, LTE, etc, there's no reason that would be different.

LTE can connect with almost nothing for a signal.  So a person testing with a single base station and a single UE might run around and say "wow I've got 5 megs here and No LOS!", but I think they forget that the entire base station's capacity is 5meg when it's talking to that single UE at 5mbps.  It's impressive that it worked, but is that actually useful as a fixed ISP?

Another thing I noticed is that Telrad could turn the Tx Power all the way to +30dbm, and people were actually doing it, and Telrad support seemed to be encouraging them to do it.  At a training session someone in Telrad support told me, "Adam, if you're worried about the legal EIRP limit then you're the only one worried about it."  So if you're 8-10db stronger than the legally operating product, and you can technically connect with a signal too weak for the other product, that certainly makes people feel like there's better penetration.

There may also be some "magic" in how LTE allocates resource blocks and gets feedback from the UE's (CQI) on which resource blocks are working best for each unit, but I think that's a matter of getting the most value possible out of a trashy signal.  If you're a fixed operator building for capacity and performance then you hopefully won't be installing with a trashy signal anyway.

My biggest issue of all is that all of the WISP priced LTE stuff is clunky and buggy.  Frankly, that was true of WiMax too.  It seemed like Telrad's bridging modes never quite worked right for example.  You were better off building an L2 tunnel on your own box behind the UE.

-Adam


On 9/14/2020 12:19 AM, Ken Hohhof wrote:

Ever since I got bamboozled into deploying a WiMax basestation, I have been skeptical of tree penetration hype.

We have been deploying Cambium 450 in 3.5 GHz / CBRS and it’s great, but it doesn’t “penetrate” trees. OK, an SM within a mile can go through 1 or 2 trees, depending on the size/density/type of tree.  And with the usual caveat that trees near the customer are more problematic than trees in the middle of the path.

Some people say otherwise, but there were all sorts of glowing testimonials for the WiMax equipment as well.

Maybe LTE has magic properties.  I doubt it, but I haven’t tried it, I don’t want to repeat the WiMax fiasco.  So I could be wrong.  But when I’m wrong, usually it’s because I wasn’t pessimistic enough and things are even worse than I feared.  Only on rare occasions do I expect a lion behind the door and there’s a beautiful lady.  Usually there’s 2 lions.

Certainly turning on CBRS made all our 3.5 GHz Cambium stuff work better, we got several dB higher xmt power, and usually cleaner spectrum.  But the cleaner spectrum thing is only true until other operators fire up their stuff in 3550-3650.  Even if you get a PAL, it’s not like nobody can use that frequency in the whole county.  The interference at the edge of your PAL protection zone should be below some level that the SAS uses when authorizing nearby operators to transmit.  But that level isn’t -99 dBm.

LTE gear may be designed with better receiver sensitivity, that will help if the noise floor is really really low.  On the other hand, does most LTE gear use the highest allowed EIRP?  What about the CPE?  That was another problem with the WiMax stuff, the CPE was 3rd party stuff that typically had kind of wimpy xmt power and not particularly high antenna gain.  Maybe that’s not true of LTE gear, I haven’t looked into it.  But pull out a Cambium 3 GHz 450b high-gain SM spec sheet and compare to the LTE CPE.

*From:* AF <af-boun...@af.afmug.com> *On Behalf Of *Trey Scarborough
*Sent:* Sunday, September 13, 2020 4:43 PM
*To:* af@af.afmug.com
*Subject:* Re: [AFMUG] LTE vendors

Has anyone done a comparison or know of a whitepaper between LTE and Cambium? I am mainly looking at tree penetration or lower DB signals to actual throughput comparison. I have been told that LTE gets a little better tree penetration but if that is at a low rate that really doesn't help any.

On 9/12/2020 10:03 AM, Darin Steffl wrote:

    It comes down to complexity. Ericsson, Nokia, etc are all cellular
    brands and to run and manage those complex LTE networks, you need
    full time engineers to manage, debug, and optimize things.

    Cambium is so easy, in comparison, there's very little extra
    learning to do in order to get it running great. Ericsson LTE
    probably would require months of training and needing to hire
    someone just to run the gear or hire expensive consultants to do
    it for you.

    On Sat, Sep 12, 2020, 9:49 AM Kurt Fankhauser
    <lists.wavel...@gmail.com <mailto:lists.wavel...@gmail.com>> wrote:

        450m is the only way to do, especially if your already using
        the 450 platform in other parts of your network, there is an
        operator in my area with the Ericson system and they had a ton
        of issues with getting it up and running, not even sure if
        they ever got it all resolved.

        On Fri, Sep 11, 2020 at 9:00 PM Sean Heskett <af...@zirkel.us
        <mailto:af...@zirkel.us>> wrote:

            Yup what josh said lol.

            We tried the LTE thing and glad we switch to 450m...much
            easier.

            -Sean

            On Fri, Sep 11, 2020 at 4:43 PM Josh Luthman
            <j...@imaginenetworksllc.com
            <mailto:j...@imaginenetworksllc.com>> wrote:

                Having done one LTE vendor and 450m the only mistake I
                made was not buying the 450m sooner.


                Josh Luthman
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                Direct: 937-552-2343
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                On Fri, Sep 11, 2020 at 5:54 PM Adam Moffett
                <dmmoff...@gmail.com <mailto:dmmoff...@gmail.com>> wrote:










                    And yeah, 450m might be expensive, but so is all
                    the LTE stuff.

                    You'll max out the legal EIRP with 450m, and get
                    8x8 MIMO.  I think

                    part of the magic with LTE is that it will connect
                    with ridiculously

                    low signal, but on a fixed system you probably
                    won't really want the

                    trashy signals anyway.

                    Cambium also has LTE for whatever it's worth.  The
                    CBRS version

                    is supposed to be available relatively soon
                    (though I forget

                    precisely when).

                    I don't know if I state it as "fewer issues since
                    there is no

                    EPC", but definitely fewer complexities and fewer
                    things to worry

                    about.  The connection from eNB to EPC has to be
                    /pristine/,

                    and the EPC comes with its own set of new
                    terminology and new

                    concepts to figure out.



                    On 9/11/2020 4:06 PM, Darin Steffl

                    wrote:







                        I have seen lots to people doing 450M in CBRS

                        stating coverage is nearly the same as LTE but
                        way better speeds

                        and triple the aggregate capacity due to mu-mimo.



                        Way fewer issues too since there is no EPC. Just

                        straight layer 2 with no bullshit.





                        On Fri, Sep 11, 2020, 2:39 PM

                        David Coudron <david.coud...@advantenon.com
                        <mailto:david.coud...@advantenon.com>>

                        wrote:

                            We are looking at a new area to

                            expand out network that has a lot more
                            tree cover than

                            our current footprint.   We are thinking
                            with the

                            combination of CBRS and LTE, that we might
                            be able to

                            offer better coverage than with
                            traditional fixed

                            wireless options.   We have started
                            conversations with

                            the following vendors, wondering if anyone
                            has any hands

                            on experience with any of them and what their

                            impressions were:

                            Blinq

                            Airspan

                            Baicells

                            Ericsson

                            The Ericsson equipment is in a class

                            by itself price wise, but the others are
                            similarly

                            priced, and somewhere around double the
                            price of PMP 450

                            stuff.   Normally we would add more tower
                            sites for

                            better coverage, but this project will
                            need to be done

                            before the end of the year and building
                            towers isn’t an

                            option.   We have good enough spread on
                            the towers that

                            we think we can do this with PMP 450 APs,
                            but are

                            thinking we’d get even better coverage out
                            of LTE.   Any

                            opinions on the reliability and the
                            manageability of the

                            four vendors above?   Sorry for such an
                            open ended

                            question, but not sure what to ask to be more

                            specific.   We know that we will have the
                            LTE stuff to

                            deal with like access to an EPC and so on,
                            so not so

                            much worried about that as more the
                            manufacturers

                            themselves.   Baicells concerns us as they
                            may get

                            lumped in with Huawei.

                            Thoughts?

                            Regards,

                            David Coudron



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VP Engineering
3DS Communications LLC
p:9729741539

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