What needs to match on all APs for Sync to work ?

Products ePMP
1

On the PMP100 gear we have to match  3 settings Downlink Data, Control Slots  and Max Range.  What settings need to match on the ePMP ?

2
@brubble1 wrote:

On the PMP100 gear we have to match  3 settings Downlink Data, Control Slots  and Max Range.  What settings need to match on the ePMP ?

Hi, 

You will need to match the Downlink/Uplink Ratio and Frame Size. You should also set the "Front" and "Back" sectors when deploying back-to-back APs in a frequency reuse scenario. Refer to the eMP User Guide and supporting documents @https://support.cambiumnetworks.com/files/epmp/ for more details. 

Thanks,
Sriram

1 Like
3

Sriram,

    I'm not doing back to back reuse at this time so my only interest in GPS sync is for APs on different towers that can see each other.  Does the sync work well enough to prevent AP's on different towers from seeing each other or is this something that only works on AP's that are right next to each other ? 

4
@brubble1 wrote:

Sriram,

    I'm not doing back to back reuse at this time so my only interest in GPS sync is for APs on different towers that can see each other.  Does the sync work well enough to prevent AP's on different towers from seeing each other or is this something that only works on AP's that are right next to each other ? 

Hi, 

If APs on different towers are seeing each other, then it does not matter if you are GPS Syn'd or not. If it happens that you have two APs on neighboring towers using the same frequency and they are facing each other, then the first AP will be interfering with the SMs registered to the second AP. This is an undesirable situation and GPS sync does not play a role or help. In the User Guide and a couple of documents (titled "ePMP ABAB frequency reuse deployment" and "ePMP Configuration in a Frequency Reuse Deployment") on our support site (https://support.cambiumnetworks.com/files/epmp/) there is some guidance on how to frequency plan your network/neighboring towers using GPS sync. Have a look to see if it helps. 

Or if you'd like to expand on on how these APs are deployed (i.e. orientation with respect to each other, frequencies they are using, approximate locations where the SMs are deployed with respect to each other etc.) I will be able to better provide suggestions. 

Thanks,

Sriram

5

I just don't whant the AP's to see each other. We are in very hill / tree covered terrain.  We have very very few situations where a SM can see more than one tower and I don't know of a single instance where a SM can see two towers running the same frequency. So SM to AP interferrence is pretty much non-existant for us.  Every single AP we have ( 24 in 5Ghz and right now 6 in 2.4Ghz across 12 towers)  is LOS to every other AP we have.  All of our AP's are LOS to each other.

6
@brubble1 wrote:

I just don't whant the AP's to see each other. We are in very hill / tree covered terrain.  We have very very few situations where a SM can see more than one tower and I don't know of a single instance where a SM can see two towers running the same frequency. So SM to AP interferrence is pretty much non-existant for us.  Every single AP we have ( 24 in 5Ghz and right now 6 in 2.4Ghz across 12 towers)  is LOS to every other AP we have.  All of our AP's are LOS to each other. 

Hi, 

If none of the SMs can see an interfering AP and your concern is only about APs seeing each other, then you should GPS sync them. When the APs on neighboring towers are sync'd they will not hear each other as their TX and RX will be sync'd. 

Edit: I would like to add that since none of the SMs can hear an interfering AP, your deployment is a very well thought out smart deployment. Well done!

Thanks,

Sriram

7

>I would like to add that since none of the SMs can hear an interfering AP, your deployment is a very well thought out smart deployment. Well done!

I would love to take credit for it but terrain and the trees get most of the credit  :) 

8
@brubble1 wrote:

>I would like to add that since none of the SMs can hear an interfering AP, your deployment is a very well thought out smart deployment. Well done!

I would love to take credit for it but terrain and the trees get most of the credit  :) 

Well, using the terrain and trees to your advantage is a part of planning your deployment. So take full credit! :)