Is there a required distance that 2 SMs collocated on the same building should be apart?
They are 5.2 GHz Advantage SMs, by the way.
as long as they are connecting to the same AP then they can be right next to each other.
if they are connecting to different APs then i’d put as much space as possible.
the canopy system is timed so that the AP broadcasts to all the SMs at the same time and then switches to listening mode and each SM transmits at it’s scheduled time. If the SMs are talking to the same AP then they’ll be transmitting at a different scheduled time and therefore won’t interfere with each other. if they are talking to different APs then they could try to transmit at the same time and cause interference.
I have to disgree with seano. As long as the whole system is sync’d properly two SMs can be at the same location right next to each other regardless of what AP they are connected to.
If you put two SMs next to each other and they are synced up to different APs, there are specific scenarios where they can interfere with each other.
If the APs are both in the same band, are using overlapping channels, and are using different timing parameters (such as control slots, % up/down, etc…) then the SMs are almost certain to interfere with each other.
If the APs are both in the same band–but synchronized with the same settings–then you are less likely to self interfere. But if the channels overlap, you could still have interference because either SM may see signals from both APs at the same time. This is only a problem if the SM picks up both APs at a similar signal level. If one AP is 15dB from the other, then no problem. if one AP is 3dB from the other, then neither will work very well, regardless of the SMs being next to each other. This is just an issue of two APs with overlapping channels in the same space.
twinkletoes wrote:
If the APs are both in the same band--but synchronized with the same settings--then you are less likely to self interfere. But if the channels overlap, you could still have interference because either SM may see signals from both APs at the same time. This is only a problem if the SM picks up both APs at a similar signal level. If one AP is 15dB from the other, then no problem. if one AP is 3dB from the other, then neither will work very well, regardless of the SMs being next to each other. This is just an issue of two APs with overlapping channels in the same space.
I did forget about the same frequency problem. If you are going to point to two different APs who have overlapping frequencies make sure that each SM sees its AP at least 11db better than the other AP. 15db as twinkletoes says would be even better if this is 900.
Guys, am I missing something? When would you put two SM’s at the same location on different AP’s?
Jerry Richardson wrote: Guys, am I missing something? When would you put two SM's at the same location on different AP's?
Network redundancy.
Especially if both AP's are fed differently.
The other scenario is where you have two SM's pointed at the same cluster, but they associate to two different AP's - but in that case it shouldn't be a problem.
Just to add to what others have said... collocating SM's generally isn't a problem except in the following two situations:
1) The AP's they are pointing at are not synchronized properly with each other.
2) The SM's are on overlapping channels AND each SM cannot hear their AP at least 10 db (in 2x mode) louder than the other SM's ap.
-forrest
For Network redundancy i would use diferent frecuency band or diferent node…
We have 2 sm next to each other(same ap, diferent custumers)