Hi,
As Chris suggested, please feel free to checkout our webinar archive. There should be a few of them that will give you a nice overview of the custom technology behind ePMP.
Some notes:
1. ePMP uses ARQ and not FEC
2. The frame is a TDD frame and can be configured as 5ms or 2.5ms in length. The frame contains the Tx portion and a Rx portion. Unlike WiFi, where there may be several gaps in the frame for timing advance to different subscribers, there is only a single gap for transition from TX <-> Rx to account for timing advance. This allows for efficient use of the frame. Some of the webinars may cover this.
3. #2 applies when the AP is in TDD or TDD PTP mode and they allow frequency reuse via GPS sync. There is a third mode called ePTP mode and that is low latency non TDD mode of operation. You cannot sync in ePTP mode.
Sriram