ofdm_phy_hdr
D11A_PHY_HDR_SRATE((struct ofdm_phy_hdr *) plcp, rate_signal);
D11A_PHY_HDR_GRATE((struct ofdm_phy_hdr *) plcp) :
(struct ofdm_phy_hdr *) rts_plcp) :
((struct ofdm_phy_hdr *) plcp)->rlpt[0]);
((struct ofdm_phy_hdr *) plcp)->rlpt[0]);