When an AP triggers the NAV timeout it should try to trigger a DIFS before resuming the backoff.
However, if the DIFS cannot be trigger because the primary channel is occupied, when free again, it should just wait a DIFS, not an EIFS.
The EIFS must be triggered only after detecting a packet time out (after sending an RTS, not receiving a CTS or after sending a DATA packet, not receiving the ACK).
When an AP triggers the NAV timeout it should try to trigger a DIFS before resuming the backoff. However, if the DIFS cannot be trigger because the primary channel is occupied, when free again, it should just wait a DIFS, not an EIFS.
The EIFS must be triggered only after detecting a packet time out (after sending an RTS, not receiving a CTS or after sending a DATA packet, not receiving the ACK).