We all know Lumia 810′s Firmware variant is RM-878. But on FCC there is one recent entry with name RM-878X and it has passed test for LTE 1700 Frequency (T-Mobile’s LTE frequency). This devices has a final action date of December.The original
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RM-878X with LTE 1700 Frequency at FCC. LTE enabled Lumia 810 from June or some new device?