Usually Mu-MIMO is used when you have four or eight chains talking to multiple 2 chain clients.
----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Midwest Internet Exchange http://www.midwest-ix.com ----- Original Message ----- From: "Adam Moffett" <[email protected]> To: [email protected] Sent: Wednesday, May 13, 2015 8:58:48 PM Subject: Re: [AFMUG] FCC 3.5 GHZ and Cambium 450 Patrick, I can envision how MU-MIMO could increase efficiency . I don't understand how it could double capacity . If a spatial stream has capacity "X", then two spatial streams could have capacity 2X. If We're sending one stream each to two users, or two streams to one user, we still only have maximum capacity of 2X. I see an increase in efficiency because if one of the two users was connected at a lower data rate, then we're devoting only half the access point's capacity to that low speed user during that time frame, whereas in single user MIMO we'd be devoting all of our resources to the low speed user. With clever scheduling you'd certainly get more out of the access point with MIMO, possibly even double if you have a wide spread of high and low speed users....but a 50mbps channel wouldn't become 100mbps channel. Rather, you'd be able to use a higher proportion of the possible 50mbps. Unless there's something about MU-MIMO that escapes me (which is completely possible). Can you explain? Thanks, Adam As I understand it, the SAS will only be required to "try" to keep those owning two 10 MHz PALs in one census areas contiguous, and even then will not be required to do so. I think it will be tough to do carrier agg in 3.55-3.7 GHz given the new rules, even as a PAL licensee, much less as a GAA user. Further, I'm uncertain of the technical complexity in getting a base station to be have dynamic flexibility in frequency assignment in it carrier aggregation feature. I would suspect such a thing would not be easy to implement -- seems easy enough in a none aggregating set of spectrum or a fixed set of aggregated spectrum, but to have multiple carriers, with each set potentially dynamic AND aggregated? I'm very doubtful. What would be much better is MU-MIMO. That will still give you the doubling of capacity, but enables you to do that within the same 10 or 20 MHz channel. Patrick Leary M 727.501.3735 From: Af [ mailto:[email protected] ] On Behalf Of Mike Hammett Sent: Saturday, April 18, 2015 9:47 AM To: [email protected] Subject: Re: [AFMUG] FCC 3.5 GHZ and Cambium 450 I don't see why you couldn't have 20 MHz. There haven't been technical enough rules put out to know if you can do ABAB. I'm guessing not as the SAS will tell you what frequency to use, but maybe they'll be able to support common systems. ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Image removed by sender.Image removed by sender.Image removed by sender.Image removed by sender. ----- Original Message ----- From: "Matt" <[email protected]> To: [email protected] Sent: Saturday, April 18, 2015 7:42:36 AM Subject: [AFMUG] FCC 3.5 GHZ and Cambium 450 Has anyone heard how the Cambium 450 gear will work with the new 3.5Ghz FCC rules and additional spectrum? Will he still have 20Mhz channels and ABAB capability? How will this all work? ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************ ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************
