The 4x4 uses TM4 (Transmit Mode 4) https://www.youtube.com/watch?v=JiNYEQKXAAk
Part of this is the reflections through trees, if you don't have NLOS (Trees) then you lose the reflections and therefore speed. I have shutoff 4x4TM4 on all sites. I have one site with a mix of LOS and NLOS and really would like 4x4TM4 on, but I saw a large decrease in performance. UE's there were NLOS had better SINR/CINR and therefore better speeds. Matt Carpenter Amarillo Wireless On Mon, Jan 2, 2017 at 2:12 PM, Adam Moffett <[email protected]> wrote: > In drive testing we had best overall throughput with 2x4, so we came out > of the gate with 2x4 everywhere. > > 4x4 was only circumstantially helpful, and often made throughput worse. > That's what tech support advised me, and our testing seemed to confirm it. > > > Interesting if confusing. Doesn't make sense to me that this is only > usable if ALL CPE are NLOS. What if you have a handful of NLOS CPE you > want to improve performance of? You can't do that without negatively > impacting the performance of LOS ones? Sounds like a feature with very > limited usefulness. > > > > Are your experiences with 2x4 good and do you find that it helps? > > > > -- Nathan > > > > *From:* [email protected] [mailto:[email protected] > <[email protected]>] *On Behalf Of *Adam Moffett > *Sent:* Saturday, December 31, 2016 9:19 AM > *To:* [email protected] > *Subject:* Re: [Telrad] More CPE8K woes > > > > I was advised not use 4x4 unless all the CPE were NLOS. The explanation I > was given was that in 4x4's current form the CPE will have difficulty > differentiating between all 4 chains. > > In our drive testing we found 4x4 performed worse than 2x2 in most cases, > but it was better for weak/NLOS CPE, which jives with what I was told. Try > 2x4 as a middle ground. I also believe I was told that 4x4 is going to > work better when MU-MIMO hits the street. > > -Adam > > So, an update on this for those who are interested: > > > > VERY preliminary results so far, and I'm not even sure I am willing to > hang my hat on them yet they are so "late-breaking", but: > > > > - Upgrading Compacts on 6.5r1 to 6.6 *seems* to have largely mitigated > this issue for CPE8Ks attached to such Compacts. > > - CPE8Ks attached to Compacts already running 6.6 that exchibited similar > symptoms *seem* to be fixed...after turning 4x4TM4 off on the Compact. :-( > > > > The CPE8Ks on the 6.6 Compacts in 4x4 mode showed other weirdness in > addition to the constant detaches, such as extremely low downlink > throughput (CPE7Ks on the same Compact continued to perform just fine). > Once 4x4 was disabled, throughput issue cleared right up, as did the CPE > detaches. > > > > grrr. > > > > So I guess we continue to run without 4x4. > > > > It wasn't like we seemed to be getting much benefit from it anyway. We > didn't see the SINRs budge at all on any of the CPEs. Maybe we are doing > something wrong? The only thing I did to enable it was 'set deployment > topology SingleCarrier4X4TM4', commit, and reboot. > > > > -- Nathan > > > > *From:* Nathan Anderson > *Sent:* Wednesday, December 21, 2016 3:27 PM > *To:* [email protected] > *Subject:* RE: [Telrad] More CPE8K woes > > > > To be more precise, I should say that a CPE8K that didn't have the problem > suddenly started experiencing it, and this coincided with the firmware > upgrade of the eNB he attaches to. I can't definitively say that the eNB > upgrade actually caused it. It's just an interesting data point that we > definitely have CPE8Ks experiencing this issue across multiple eNB firmware > versions. > > > > -- Nathan > > > > *From:* [email protected] [mailto:[email protected] > <[email protected]>] *On Behalf Of *Nathan Anderson > *Sent:* Wednesday, December 21, 2016 3:23 PM > *To:* [email protected] > *Subject:* Re: [Telrad] More CPE8K woes > > > > EPC is 6.6 0729 > > > > We admittedly still have some ENB 6.5r1 (2616) running out there; when 6.6 > came out, it wasn't soon after (2-3 months maybe?) we had managed to stop > banging our heads into our desks trying to get everything to run smoothly > and with good performance. We saw some reports of troubles with 6.6 > shortly after release, esp. with 4x4 mode, which we didn't have to use if > we upgraded, true, but it was one of the major draws of the release, so if > we were going to hold off on implementing that, why rush to upgrade? It > was nice to be able to have things run smoothly for a time and sit back and > take a breath. > > > > But 6.5 ENB code doesn't seem to be to blame here; in fact, last night, I > pushed 6.6 out to one ENB, which caused a CPE8K that previously was not > exhibiting these symptoms to suddenly begin doing so today! > > > > -- Nathan > > > > *From:* [email protected] [mailto:[email protected] > <[email protected]>] *On Behalf Of *Jeremy Austin > *Sent:* Wednesday, December 21, 2016 3:12 PM > *To:* [email protected] > *Subject:* Re: [Telrad] More CPE8K woes > > > > > > On Wed, Dec 21, 2016 at 2:08 PM, Nathan Anderson <[email protected]> wrote: > > > Is anybody else out there seeing their CPE8000s randomly drop off the > network > > > I only saw this on a 1xxx revision of EPC code, and it might have not been > the same precise behavior. What ENB/EPC code are you running? > > > > -- > > Jeremy Austin > > > > (907) 895-2311 > > (907) 803-5422 > > [email protected] > > > > Heritage NetWorks > > Whitestone Power & Communications > > Vertical Broadband, LLC > > > > Schedule a meeting: http://doodle.com/jermudgeon > > > > > _______________________________________________ > > Telrad mailing list > > [email protected] > > http://lists.wispa.org/mailman/listinfo/telrad > > > > > _______________________________________________ > Telrad mailing > [email protected]http://lists.wispa.org/mailman/listinfo/telrad > > > > _______________________________________________ > Telrad mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/telrad > > -- *Matthew Carpenter* *806-316-5071 office* *806-236-9558 cell*
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