B5C Link Problems and Firmware issues


Has anyone else had issues with the B5C? We see a number of links that run fine, on clean channels and then drop to a low 5-10mbps of throughput? We also have had extensive issues with updating the links. Moving to any firmware past 1.4.1 makes the Ethernet not talk to our mikrotik routers. Having to travel out to get a link back up and going is very frustrating. Would love to deploy more mimosa equipment, though the stability issues have prevented that from coming to fruition.


I have a B5 link that I downgraded to firmware 1.4.1 for two reasons.

They did something to “fix” compatibility with some switches, but things got worse. Speed negotiation with the switch is very unpredictable, and speed fallback don’t work with my Cisco switches. Works OK with 1.4.1 but not with newer versions.

Power output is lower by about 3dB with firmware 1.4.4 and newer. My link is 1.5 miles and very stable with 1.4.1 but not working as good with newer version since the signal to noise ratio decreases with 3dB.

Have not seen a drop in throughput in my case with 1.4.1


We have experienced a number of issues with the B5c that we don’t have with the B5 or B5-Lite products. I would like answers as well but nothing from the support folks. We are never ordering another Mimosa B5c radio.



We’re talking about several different topics on this thread.

Benjamin, the Ethernet-related firmware changes did resolve several known interoperability issues with other vendors routers and switches. We know about some new ones now, so we will be issuing more updates soon to resolve them. Which model and firmware do you have? We’ll test it in our labs.

Tom, the B5 and B5c share the same hardware design, so there may be a different problem if you only experience an issue on a B5c but not a B5.

Mats, firmware 1.4.4 and later have improved dynamic IQ calibration to stabilize EVM and modulation in situations where there are large interference swings. We found that radios were selecting aggressive (unsustainable) modulation, and then dropping dramatically in the other direction. This change dampened those swings. The rate adaptation controls in 1.4.1 and later provide the option to accept more aggressive modulation if you don’t have noise. Try “PER Aggressive” or “EVM Aggressive”.


That is what version we are using is the 1.4.1, it seems to be the most stable/useable in our network. To get the B5 to work we have to update them and physically power cycle the units to get the Ethernet adapter back up and running. So I suppose our solution is putting a web power switch in everywhere that the mimosa BH is located.

Some kudos are in order though. We did try to replace the B5’s with AF5X’s and the mimosa;s did outperform the UBNT’s in a the noisy environment.