Any Negatives to using 5ms Frames?


I'm curious if there are any negatives to changing from 2.5ms frames, to 5ms frames.

I saw this in an old forum post, and from what I've been able to find, it seems like a crewd but accurate description...

5ms frames:

-little more throughput

-little longer latency

2.5 ms frames:

-more stability

-little less latency

-little less throughput

My questions are whether the 5ms frame has any effect on NLOS performance?  Is it more susceptible to interference?  What stability is lost by using a 5ms frame over a 2.5ms?

Basically, I'm wondering what the overall negatives of a 5ms frame are, because if there really aren't any serious negatives, I'd be quick to change for the frame utilization and throughput improvements.  Just have to make sure I won't be lowering RF performance by doing so...

We've done exactly this and have done a lot of tests between 2.5 and 5ms frames and I can comfortably say:

- Neither have an effect on nNLOS, no benefits, no downsides. They're the same

- Neither have an effect on interference, good or bad.

- Neither have stability issues (I've never read or heard of 2.5ms being more stable then 5ms, this makes no sense to me)

About a year ago we changed our entire network from 2.5 to 5ms frames and never looked back. We got about a 10% increase in performance at a cost of a few extra ms of latency. Not one customer complaint.

If you're taking the time to make this jump, you should also enable auto contention slots on every AP... another excellent new feature that can help squeeze some more performance out of 450.


Thanks for the info Eric.

Do you mind my asking what frequencies you are running? 

Or which Platform? PMP450 or ePMP?

Just curious if I should be worried about a difference between what we are both doing, because I use pretty much every frequency Cambium has a product for, aside from 3.65Ghz (which will likely be added to the sauce later this year when the 450b is available).

Thanks in advance.

We use it all… PMP450/450i/450m on 5/3/2.4GHz, 900MHz, and ePMP on 5 and 2.4GHz. All of our Cambium gear is set to 5ms.