What statements are true concerning the use of Orthogonal Frequency Division Multiplexing (OFDM) in IEEE 802.11 WLANs? Choose 2

A.
Six (6) "pilot" sub-carriers are used as a reference to disregard frequency and phase shifts of the signal during transmission.

B.
UNII band OFDM channels have 20 MHz spacing between center frequencies

C.
16QAM modulation is used at the 54 Mbps data rate.

D.
The OFDM PHY is divided into two sub-layers, the LLC and PLCP.

E.
Forty-eight (48) sub-carriers are used as parallel symbol transmission paths.