wifi_guy wrote: Cambium Pros? So far you haven't mentioned anything about performance between the two. Just features which really can be work-arounds.
Hi Wifi_guy. Yes, I was just commenting on your three points, more as input & suggestions for Cambium. One of top things is that 'test mode' thing... we really need that for sure.
As for Cambium Pros - many, many. Let me sum them up to this though, SELF INTERFERENCE MITIGATION. In the unlicensed band, there will be interference. So, real world performance largely comes down to how well a radio can deal with interference, AND how well you can mitigate your own interference from your own towers.
So...
1) GPS Sync is HUGE. That, all by itself will syncronize your ePMP AP's so that they will all broadcast at the same instant, and all go into receive mode at the same instant. That alone is huge, becuase the #1 cause of interference is your network - your other AP's. If AP#1 is listening for one of it's clients 5 miles away, and at that same instant AP#2 started broadcasting... welll, AP#1 has no chance. It's listening for a -73 client and the nearby AP is -38. So, GPS Syncing is huge and all by itself, it'll syncronize all your AP's to TX at the same instant, and RX at the same instant and virtually eliminate self AP to AP interference.
Of course, I say ''virtually'', because there are ways that you can design things incorrectly and still manage to screw up Cambium's hard work, but more on that later. Sufice it to say for now, that the #1 PRO is GPS.
2) Cambium's scheduler. When the CPE's (SM's) register to the AP, the AP does all the scheduling for every SM and when they should listen and talk. Unlike other systems, where the other SM's on the same AP will interfere with each other. It's always chaos to some degree or other, and SM#6 might ask for permission to talk while SM#13 is currently talking, and neither of their messages get through. With Cambium, the AP transmits a highly organized and efficient scheule to all the SM's letting them know when they need to be quiet and when they should talk. Likelise, rather than each packet having an ''ack'' packet coming back, which means that further away CPE's will affect performance of the nearly CPEs - with Cambium all the SM's will send in their 'acks' at the end of the frame, in an oranized way, so that performance over distance stays more consistent.
The organized scheduler also results in MANY many WISPs being able to put twice as many SM's on a sector with Cambium vs UBNT. There are ton's of WISP's with 40 or 50 or 60 or 80 SM's on a sector, and with good performance. It's not unusual for other companies gear to fall apart at 20 or 30 CPE's per sector, and (other's can comment) it's fairly common to have 50 or 60 SM's working great.
NOW - the GPS Syncing and scheduler does come at a bit of a cost... if all the AP and SM's are told to ''wait for their turn'', that translates into a bit more latency. Obviously, any system that is 'first come, first serve' can have lower latency (at the cost of chaos) and any system with a ''you wait your turn scheduler" can have more performance (at the cost of more latency). ePMP can be configured with your choice of 'Fixed' or 'Flexible' frames, and so you can choose to have higher or lower levels of latency, but some of these features are mutually exclusive. So, if you want the best level of self-interference mitigation and performance, then you'll want to select a Fixed Frame Ratio, and that'll allow all Cambium's magic, but at the expense of a few extra ms of latency.
3) ATPC - the AP not only schedules each SM, but it can also tell each SM to turn itself up or down in transmit power, in order to have a well balanced signals on the AP. One of the many many problems with other brands of gear can be that a close customer might be a -42 signal, while a distant one may be -75. Sure you can turn the -42 down to get him to a -60, but then on a humid day, or when there are leaves on the trees, or whatever.. that CPE that you've manually turned down will drop off the map. With ePMP, you can tell the AP that you'd like all your CPE's to be a -60 or a -55 or a -63 or whatever you choose, and they will turn themselves up or down to try to achieve that. That means that you can safely overpower your antennas on the SM side, and you've got built in fade margin, without blasting all the time. The power can only come up when it's needed. Also, that -42 CPE will be (of course) not only defening the AP, but it'll also be interfering with your other tower 8 miles further on where it still might be heard at -75 maybe. If that -42 can automatically be turned down to a -60 on the fly, then it'ss only be interfering at a -93 to your other tower.
4) Air Fairness, not Bandwidth fairness. Cambium's scheduler is ''Air Time Fairness'', where as other psudo-TDMA will do a QOS type fairness. So, if you have a client who's turned in the wind or whatever, and is a -80 signal... that guy starts to use his internet and he can totally dominate the AP at the expense of everyone else. With Cambium, that -80 guy will still have funky performance, BUT he'll only get his fair share of the airtime scheduled to him. To a MUCH greater degree, the Cambium scheduler will help prevent one SM in distress from impacting other SM's.
The list goes on and on and on... And I haven't even started on the 2000 AP, with it's digital filter and it's Beamforming antenna.
Here's a good thread to read.
http://community.cambiumnetworks.com/t5/ePMP-2000-and-1000/Convince-me-to-switch-from-Ubiquiti/m-p/55747#U55747
Here's a thread from a while ago talking about the performance results we've had. This is with 2.4ghz gear, but much of it still applies. This focused on 2.4ghz gear because we just replace a non-Cambium 2.4ghz gear was struggling to even function. We replaced 17 clietns from non-Cambium to ePMP, and 'vive la différence'!
http://community.cambiumnetworks.com/t5/ePMP-2000-and-1000/ePMP-2-4Ghz-Performance/m-p/56574#U56574
And then in the 'STORIES' forum, there are likely lots that you could read there too.
http://community.cambiumnetworks.com/t5/ePMP-Stories/Transition-from-UBNT-to-Cambium/m-p/55801
http://community.cambiumnetworks.com/t5/ePMP-Stories/bd-p/ePMP_Stories