[ns] Help with Radio states of 802.15.4 implementation (Ankur Garg)

[ankur garg]

Hi!,

I am working on the 802.15.4. I am tweaking up things to implement a new
protocol. Can any body tell me why a transition of radio state TX_ON to
RX_ON is not done immediately. this has been done  using a turn
_around_state with a delay of turn_around and two times a confirmation goes:

1. from this plme_set_trx_state_confirmation with state as p_SUCCESS
2. when the TRXhandler is called it confirms the state as TX_ON/RX_ON.

Is this because of RFC of 802.15.4 or just done for simulation or a
limitation of radio that it takes a turnaorund time for switching.

I am also posting here the code section from file wpan/phy802_15_4.cc
--------------------------------------------------
CODE
-------------------------------------------------
        {
            t_status = p_SUCCESS;
            if (((state == p_RX_ON)&&(trx_state == p_TX_ON))
              ||((state == p_TX_ON)&&(trx_state == p_RX_ON)))
            {
                trx_state_turnaround = state;
                delay = true;
            }
            else
                trx_state = state;
        }
        //we need to delay <aTurnaroundTime> symbols if Tx2Rx or Rx2Tx
        if (delay)
        {
            trx_state = p_TRX_OFF;    //should be disabled immediately
(further transmission/reception will not succeed)
            TRXH.start(aTurnaroundTime/getRate('s'));
        }
        else
            mac->PLME_SET_TRX_STATE_confirm(t_status);