Anyone Using 4.4.1; 2.4Ghz Network?

I am guessing 4.4.1 will allow short GI on a 2.4Ghz network to squeeze an extra 10% of throughput out of sectors. Has anyone tried 4.4.1?  Does it allow a short GI for 2.4Ghz? Most importantly, is 4.4.1 stable at 2.4Ghz?

People are reporting 10-15% performance gains using 4.4.1 w/Short GI enabled on ePMP 2.4. I'd say it's very stable if you're using all Cambium radios. There are issues if you're using elevated radios... but these are typically when moving from earlier 4.X builds to 4.4.1. ALSO, some elevated radios don't support short GI.

At the moment 100% of our ePMP network is running 4.4.1 and we have about a dozen e1k 2.4GHz AP's using it and it's working very well.


Thanks for the info. I had a feeling some brave sole had put several 2.4 AP's on 4.4.1. I have twelve 2.4Ghz sectors to upgrade. We are 100% Cambium down to our backhauls. Guess I will schedule a cnMaestro upgrade on our least subscribed tower for very early in the morning and pray all is well when I wake. 


How is your experience with the ePMP 2.4GHz?   Are you using the Cambium sectors for example?  Bandwidth, throughput as expected or better?  What's your typical speed? 

@Lincs_Chel wrote:


How is your experience with the ePMP 2.4GHz?   Are you using the Cambium sectors for example?  Bandwidth, throughput as expected or better?  What's your typical speed? 

We've had excellent results with ePMP 2.4... similar performance to ePMP on 5GHz... although typically there's more noise. We almost always have to use a 10MHz channel, and we use GPS sync at every site to we can squeeze more out of the spectrum by using back to back frequency reuse and smaller 5MHz guard bands between channels.

To give an example... we have a 2.4GHz AP using a 20MHz channel with 35 clients on it, hitting peaks as high as 75mbps download, and 6mbps upload during busy hours.

We really like Cambium's OEM ePMP 2.4GHz Sector... it's very high quality, and has an excellent front to back ratio, making it good for frequency reuse situations... I think the antenna is made by MTI. We've also used some of KP's dual band antennas (5+2.4GHz) with mixed results. I think if you're just wanting to deploy 2.4 or have the tower space, then the OEM antenna *feels* like it works better. If tower space is at a premium, then the dual band KP's can save you some serious money in terms of tower rent.

With the new 4.4.1 firmware we're seeing about 10% performance increase over 3.5.6 firmware, due to short GI and LDPC optimizations. Some other people are reporting up to 15% performance increase. We now run 4.4.1 on 100% of our ePMP network... for both AC and N based radios.


Hi Eric;

Thank you very much for sharing your setup and results.  This really helped. 

I was tossed between the GPS and the non-GPS versions primarily because of the cost of entry to deployment and testing.  We also had a pair of the Ubiquiti AirMax 2.4GHz 90deg sectors available which we never got deployed.  They were originally meant to be deployed and test with the Mikrotik APs.  Then ePMP came out and became a possibility.  

It also appears that the ePMP 2.4GHz series was being given very little attention to by Cambium, so investing in this platform would leave you in a bind.   For example, even their current product brochures/datasheets seems to elude the 2.4GHz series (

Whereas if you had the Mikrotik APs for instance, you can just continue to roll-out with whichever standard 2.4GHz WiFi stuff is on the market.   Which we've had to do before.  Going through products such as Tranzeo, SmartBridges are just a few for example.  I hope that they continue to support and enhance the ePMP 2.4GHz platform.  They don't even have case studies or brochures to promote the performance and reliability of the 2.4GHz platform.

Your performance using the Cambium's 2.4GHz antenna sounds very positive.  I've been researching to see what this platform is doing before taking an expensive plunge.


Hi, this reply will be a little bit off topic, because your question was specifically about 4.4.1, and this reply is more generally about epmp in 2.4ghz.

The first thing I’ll say, is I’ve been also a little bit disappointed about the seemingly lack of development ongoing in 2.4ghz by Cambium.

However, to be fair to Cambium, the primary differences between the epmp1000 and the epmp2000 in 5ghz basically boil down to the digital filter, and the beam steering antenna. Cambium has said that neither of those technologies would be particularly useful in 2.4, due to less spectrum and wider propogation inherent in 2.4ghz. I’m not sure I 100% agree with them, but that is Cambium’s reasoning for not having a 2.4Ghz ePMP2000.

And then, with the ePMP3000, it is based on an AC Wave2 chipset, and the chipset manufacturers really don’t make that in 2.4 - so again, Cambium says there is no viable option for a ePMP3000 flavour at 2.4Ghz.

The good news is that the next generation (presumably the 4000) is apparently based around a chipset which contains both 2.4 and 5Ghz frequencies, so I expect we will see future development. I don’t know that for sure, but it seems to make sense based on what we know at this point.

And the final piece of info I can give you is that we also initially struggled with our decision on whether to go cambium or to continue struggling with our non-cambium deployments. We had frankly almost given up on the 2.4ghz spectrum, just thinking it was too polluted to be useful. We finally took the plunge, and this thread from 3 years ago tells you our results switching from the other brand, to Cambium at 2.4ghz.

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