General insight on timing/wifi/tdd

Just a little background. We started out 15 years ago with Canopy 100 gear. We still have a few over 100 2.4 SMs in the field. The majority of our subs are 5 GHz using the other guys. We are testing the epmp 1000 2 GHz now to replace the existing Canopy users and maybe 2.4 from the other guys.

Our current ptmp 100 sites are timed over timing port. From what I can tell most of the co-location is geared for for 5 GHz, correct? Am I just better to run them in WiFi and make the best of it? Our sites now are 4 90 degree sectors running ACAC. Right now they are fairly off loaded and most towers involved are using either 2 or 3 sectors, but doesnt really leave alot of spectrum open

My thinking is if we can get the signal and the distance we now have with the ptmp 100 gear with the epmp gear, we shoudl be able to better service those customers. We do a fair amount of LTE, but I would rather be more cost effective, plus have a much stronger network offering as well



So the ePMP GPS AP's (in both 5ghz and 2.4 flavors) come with an external GPS puck, or can use an internal GPS patch antenna, OR can use internal timing, OR you can use an external ethernet pulse timing, like from a PacketFlux device. So, lots of different ways to sync on ePMP. One way that ePMP can't sync that differs from PXP100 is the AUX/timing port... can't use that on ePMP. If you wish to sync PXP100 and ePMP you will need to use something like a PacketFlux, LastMile, or CMM and ditch the internal timing.

I would strongly recommend NOT using WiFi mode on your ePMP AP's... it will perform worse then using TDD mode, even under interference or when conflicting with out-of-sync sources, like your PXP100 radios. If you do decide to get a common sync running between PXP100 and ePMP, Cambium has provided resources for helping get the proper settings in place (2.5ms timing method, along with a handy timing calculator located HERE).

Lastly, ePMP allows for channel sizes as small as 5MHz, which gives you some options for running an AP in between your PXP100 radios to give you some breathing room to transition from one to the other.


 I really appreciate the insight. The one spot I want to test badly I kind of planned on hanging the epmp pointing the same direction and potentially killing the original ptmp100 and testing each subs site. We would have a slight down time for those few users but they are understanding and have been with me for a while. I have never seen anything good with 2.4 GHz pointing the same direction, or even close. But maybe with the 5 MHz we might be able to tweak it out. I dont know but if it works we will turn off the old AP completely and just run door to door swapping gear!

But from my experience with 2.4 sectors in the past, I will want to definitely look for a sync timing source. I had used 2 packet flux devices almost a decade ago, but they both died out on me on an extremely hot day. Im sure alot has changed since those days

Looks like I have more testing and thinking to do. If I can get anywhere close to the dependability, signal and distance with epmp as the ptmp 100, I think I will have a solid offering! Thanks again!



The gps antenna enclosed with the APs can be used to time with the pmp100 gear. Follow the guide eric shared and you’ll be set. You won’t break your pmp100 gear while doing the change over, and depending on your situation, you may be able to use a 10 or 20mhz channel.

Wifi mode, and wifi modified modes from vendors x y and z are no where near as organized and efficient as the epmp. The epmp runs much more like the cambium pmp gear and not just kinda modified wifi like some of the other products out there.