Client disconnecting in PMP450


I currently own two PMP450i 900mhz panels with about 60 clients on top of one of them. As customers started complaining about throughput, I decided to activate another panel at another frequency allowed in my country and set up half of the clients on top.

The problem is that even activating the second panel at another frequency, the moment I turn it on the clients in the other panel start to disconnect.

What am I doing wrong? It follows the screens of the client settings and the PMP 450.

Thank you!

Client ConfiguratationPMP 450 1PMP450 2

Are both APs receiving GPS sync?

I checked your frames. Based on the screenshots you provided they do look to be compatible.

Also what firmware are both APs on?

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Hi Seth!

I am not using CMM or uGPS, I am using internal synchronization.

They are in different versions of FW.

Ok...unfortunately that is likely the problem.

Without a sync source you need very large guard bands to prevent interference. (I would guess as least 20MHz in your case.)

With GPS Sync we ensure that all APs are transmitting at the same time and then all SMs are transmitting at the same time. And there is never an instance where an AP is transmitting while a SM is transmitting.

In your situation it is likely that the AP cannot "hear" the SMs that are miles away because there is an AP a few inches or feet away transmitting at the same time. Even though they are on different channels there is a bleed over effect that is magnified the closer the radios are together.

I hope this helps.



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Seth, thank you so much!

I'll look to get a uGPS module or even try to increase the space between the channels.

Thank you!

Synchronization is nearly impossible to live without in the 900 MHz band, as there is not a lot of guard band to be had... because the total band is so narrow.  I would highly recommend getting a GPS sync source, and synchronizing the network.  This should eliminate the issues you're seeing.