wpi_plcp_signal
static uint8_t wpi_plcp_signal(int);
tx->rate = wpi_plcp_signal(rate);
wpi_plcp_signal(12) : wpi_plcp_signal(2);
wpi_plcp_signal(12) : wpi_plcp_signal(2);
hdr->cmd.rate = wpi_plcp_signal(12);
hdr->cmd.rate = wpi_plcp_signal(2);
node.rate = wpi_plcp_signal(2);