ePMP 2000 can not operate at a frequency of 4920 MHz

The equipment ePMP 1000 with Sync and Force 180 may to work in frequency band 4920 MHz - 5865 MHz. But the AP ePMP 2000  operate in frequency band 5150 MHz - 5970 MHz.
On the other hand, the sector antenna is designed to operate in the frequency range of 4900 - 5970 MHz.
Why is equipment ePMP 2000 can not operate at a frequency of 4920 MHz?

Hi Leonid,

When designing ePMP 2000, we focused on 5 GHz performance because we had not seen many 4.9 GHz ePMP deployments that were suffering from the same interference conditions seen in 5 GHz that ePMP 2000 is built to address. We are however considering other frequency bands for future ePMP 2000 development.

Thanks,

Alex