ural_txtime
dur = ural_txtime(pktlen, rate, ic->ic_flags) +
ural_txtime(RAL_ACK_SIZE, ackrate, ic->ic_flags) +
dur += ural_txtime(RAL_CTS_SIZE, ural_ack_rate(ic,
uint16_t ural_txtime(int, int, uint32_t);
dur = ural_txtime(RAL_ACK_SIZE, ural_ack_rate(ic, rate),