has any one out there gotten two ap’s to work of one sm
i have a use to light up a new neighbour hood on one side of a highway and use the one sm - ap that is already in place
the hop is working fine but i would like to use the same sm to provide signal to both ap’s
i would assume that i would paralell the timming ports and use a switch for the data packets.
has any one out there gotten two ap’s to work of one sm
i’m not getting what you are trying to do?
You have 2 Access Points, and 1 Subscriber?.
Do you mean 1 AP, and 2 SM’s ?
Think I got you.
1 sm feeding 1 ap on the same tower and you want to put up a second ap on the same tower?
If that’s what you are doing then you should be fine as long as your gps cable lengths total isn’t to long.
We did that setup on one of our towers. Didn’t work with 2 ap’s at 450 ft. but did work one 2 bh’s at 285 ft.
We bring the gps cables to the base of the tower in case we need to default on the ground.
Ok, so basically you have 1 SM that is receiving a signal from an AP that is not located close to the SM.
Then, from the SM, you want to physically connect another AP to Repeat a signal or create a new AP ?..
So yes… it will work.
What you need to remember is that your Maximum upload and download will always be AT BEST what your SM is performing at.
We have some of these setup.
I recommend you put the AP that is feeding the SM to a 50% / Download upload ratio. This way, you get good up and download speeds.
thanks for the reply’s
i guess i should fill in more details
1 ap cluster located 6 miles away from the recieving sm that is on it’s own tower
we already have the bounce setup to service the one ap that is gaining signal from the sm that is on the same tower.
2 i do not want to put up a cmm or gps to get the sync so we are using software on the bounce to the other sm’s.
3 what i want to do is parallel the ap sync cable from the one sm that is already
providing sync and connection to our network to the other ap so i can service some customers that are in the oposite direction of the existing ap
of course you could just put up a “cyclone ap” from lastmilegear.com
We use the six ap cluster’s and the single cyclone ap throughout our newtwork
Both work great depending on population of the area you offer service to.
You can pass GPS sync from the SM to the AP’s however it isnt recommended. If you do decide to do this I highly recommend that you make sure that the SM is a different band than the AP’s. For instance you shouldnt have a 5.7 SM feeding the tower if you are using 5.7 AP’s on the same tower.
We have done the same.
cyclones work fine, but even better in Hardware Scheduling.
If you need help, let us know.
Does creating a new cluster like this via the timing port of an SM add latency to the network? If so, how much vs. the use of a CMM?
Canopy_Support wrote: You can pass GPS sync from the SM to the AP's however it isnt recommended. If you do decide to do this I highly recommend that you make sure that the SM is a different band than the AP's. For instance you shouldnt have a 5.7 SM feeding the tower if you are using 5.7 AP's on the same tower.
The question I have is, "Why?"
If I have an 900 AP generating sync to an 900 SM and that 900 SM is passing sync to a second 900 AP, why isn't the second 900 AP in proper sync with the first 900 AP? Why does Moto say we can pass sync thru an SM, but we can't pass sync to a second AP in the same band? Why would we want to pass sync at all if we couldn't pass sync to a second AP in the same band?
Look at it like this:
1) If I have two colocated APs operating on DIFFERENT bands, I don't care if they are in sync because they can't interfere with each other.
2) Now if I have an SM and an AP colocated and they are on different bands they can't interfere with each other either.
3) If I have two SMs colocated and they are on different bands, they can't interfere with each other.
In all cases if I have two colocated nodes operating on different bands I do not care if they are synchronized because they can't interfere with each other.
The only time that I have a need to synchronize units is when those units are on the same bands and can hear each other. Now an AP sends sync to it's SMs no matter how it gets that sync in the first place. Once the SM has the clock, why pass the clock along, except to synchronize a second AP which IS on the same band?
This confuses me no end. Help, obviously there is something I am missing here.
Here is the simple answer…because the 900 MHz SM will be in TX mode when the 900 MHz AP next to it is in RX mode. So the AP will be getting blasted by the SM on the same tower.
The reason you want two colocated AP’s on different bands using GPS sync is because we opperate in the unlicensed spectrum and there is nothing to stop a competitor from firing up the same band just a few blocks away. If you want to properly engineer this then you should have GPS sync and you shouldnt have AP’s and SM’s of the same band on the same tower.
Does that help?
Canopy_Support wrote: Here is the simple answer.....because the 900 MHz SM will be in TX mode when the 900 MHz AP next to it is in RX mode. So the AP will be getting blasted by the SM on the same tower.
Perhaps, but WHY? If they are on the same clock they can't clobber each other. Unless one AP handles sync differently fron another, which I would think highly unlikely. Perhaps the answer is because you have to set the maximum distance in the AP and that information is not passed along thru the subscriber module when it forwards sync?
You see if everyone were on the same sync and there were a constant timing stream everything would work fine. Motorola doesn't hire idiots, so there must have been something which was NOT explained in the manual. The thing which is not explained in the manual is that the second AP in the chain has no way of knowing the actual timing of the first AP. It simply knows the clock. It does not know the actual scheduling.
This is a long way of saying, "The APs have no means of synchronizing themselves." Which does appear in the manual. We KNOW that two APs have no means of synchronizing themselves. There is NO reason given in the manual that explains why a subscriber module feeding sync to a second AP on the same band won't properly sync that AP.
The reason you want two colocated AP's on different bands using GPS sync is because we opperate in the unlicensed spectrum and there is nothing to stop a competitor from firing up the same band just a few blocks away.
So? GPS sync is not going to be helpful if a competitor fires up on the same band a few blocks away unless he is using Canopy hardware (which rumor suggests is going the way of the dodo anyway, right?). Now if I have understood the problem with passing sync thru an SM properly, there is NO assurance that that competitor is going to have the same scheduling and he could hammer you anyway.
IF being on a CMM ensures that two completely unrelated networks can not clobber each other, then if follows that the sync pulse is handled identically in all APs and that an AP following an SM and on the same band will schedule properly because everyone is on the same clock in both cases.
If you want to properly engineer this then you should have GPS sync and you shouldnt have AP's and SM's of the same band on the same tower.
Does that help?
No, that does not tell me anything I can't get out of the manual for myself. I want TECHNICAL information that explains WHY I can't have an SM push the clock to an AP on the same band. I don't need someone to read the manual to me.
I don't mean to be difficult with you, but I have yet to receive an answer from you with respect to ANYTHING I have asked in six weeks, which I did not obtain from the manual or by experimentation by myself.
Motorola needs to wake up and realize just how valuable this forum COULD be and start treating it that way...
I will bet dollars to donughts that the truth is that they WILL sync correctly IF you set the maximum ranges the same.
If you have an SM at 915 MHz sitting next to an AP at 924 MHz you will have an issue. Canopy uses 2 & 4-level FSK which is NOT the same as OFDM. The reason I would like to explain the difference is because you will not see a steep drop off of the 8MHz channel and instead you will see a gradual drop off of the signal strength. That said, if you have an SM transmitting at 915 MHz it will interfere with the AP at 924 that is trying to listen to its associated SM’s. Vice versa, when the SM is receiving on 915 MHz it will be over powered by the AP on 924 MHz that is transmitting. If this was an OFDM system then the signal would have a direct drop off at the edges of the 8 MHz signal and depending on the saw filters you might have a better chance at getting away with the collocation.
You need to understand GPS timing and that when the AP’s sends the SM’s listen. It has nothing to do with having to set the maximum distance; it has everything to do with RF.
You are missing the point on how the clock is being passed. The clock comes out of the SM sync port and then a ‘Y’ cable is custom made to pass the sync to both AP’s. As I stated, this is NOT recommended. We never said it wouldn’t properly sync the AP, we just said that you shouldn’t collocate SM’s and remote AP’s of the same band due to potential interference issues.
When a competitor fires up the same band a few blocks away it is evident that Canopy out performs due to the GPS timing have implemented.
I didn’t quote a manual to you, I told technically why you shouldn’t (not couldn’t) push the clock from an SM to an AP on the same band. Understand that this forum is NOT formal technical support. There are many people who have benefited from the forum and will disagree with your comments. If you are not benefiting then you should call your reseller and technical support and discontinue use of the forum.
Again, I never said you COULDNT but instead said you SHOULDNT collocate the same band when performing a remote AP scenario. It has nothing to do with your max range settings.
Ok, I got it finally. Thanks for your patience.
I can be incredibly obtuse at times. The simple answer for me is that "All APs on the same clock ARE synchronized to transmit at the same time."
What was not registering for me was that fact. You said it, but I was not grasping it. Since the AP generating sync is talking at the same time as the AP receiving sync, and the AP receiving sync is colocated with the SM passing sync. The collision is inevitable.
Sorry I made you work so hard for that one. I get it now.
wow what a buzz that is created by a simple quesiton.
a good question mind you but simple.
thanks for all of the info.