We have recently shifted 4 of our 900MHz sites within 3-5 miles of each other to “Transmit Frame Spreading Enabled”.
Once we did this, we noted an increase in the short term in the number of re-reg’s we observed on the sessions pages of the APs.
Has anyone else observed this? Is it a “normal” artifact of TFS? If so, is there any real impact? We don’t like to see re-reg’s at the best of times…
Are there any other parameters anyone is aware of that might help mitigate this behaviour?
We are running 7.3.6 on all devices, all AP sites are running 1W EIRP omni’s on the same frequency (920MHz, due to the Australian band plan), HW scheduling, synchronised with each other and using identical AP channel parameters (apart from Color code).
I’m pretty sure the moto recommendation is, if you have Hardware Scheduling on, turn Transmit Frame Spreading off.
In my experience with our own 900s, that’s why you are having re-registrations.
I checked the latest edition of the Canopy user guide (issue 2, covering 7.3.6) and it mentions that TFS is do-able when hardware scheduling is enabled, as long as you use software releases at 7.0 or later.
I am puzzled that no-one else has seen this issue - the field behaviour with TFS really does seem to replace one problem (beacon “capture” or de-sense) with another, namely the greatly increased number of re-regs we now get on the affected sites.
Anyone else out there with a success story on how to use Transmit Frame Spreading?
Transmit Frame Speading changes the beacons to a random number per second, instead of the normal 200 or 400. You supposedly lose 10% of bandwidth right off the top when this is enabled, but it’s supposed to help SMs that try to sync and register but can’t. That’s strange that you’re seeing even more re-registrations. :? Sorry that I don’t have any success story on this.
This will happen when you are causing self interferance.