450sm 5GHZ frequency selection issue

Hello Guys

Did not find any info on this one.

We have found an issue between 5.x 450a and 450b sm's frequency and channel selection. Issue being we have a 450 1st gen AP on 5480 with a 20 mhz channel. the 450a sm can use this no problem, the 450b sm cannot. 450b shows 5480 is in the 15 mhz channel. both sm's running 16.1.1.1. Why would these be different? Selecting the 15 mhz channel did make the 20 mhz AP show up in the evaluation.

I see that you're in the United States. The most likely answer is that regulations have tightened over the years, especially in the 5.2/5.4 GHz band (U-NII-2). What was once permissible may no longer be under the current rules (or more specifically, the regulations at the time of applying for the FCC Grant). The 450b is a newer model (approved in 2018) than the original 450 SM (approved in 2012).

Out of band emission rules have tightened since then, as have DFS radar detection schemes and patterns. Hopefully, you can still find adequate usable spectrum, even if this causes some headaches in replanning.