How to change radio mode in inet 3.5 ?

[Jack]

Hi! I want to use a radio in inet 3.5 in omnet++5.1

the tadio type is

radioType = default("Ieee80211ScalarRadio");

when I want to transmit packets out, the events says

radio is not in transmitter or transceiver mode, dropping frame。

I was confused, and then I am going to change the mode by set:

        string opMode @enum("a","b","g","n","p") = default("g");     /  /"a","b","g","n","p"

        double bitrate @unit("bps") = default(opMode == "b" ? 11Mbps : opMode == "p" ? 27Mbps : 54Mbps);

        **.opMode = opMode;

        **.bitrate = bitrate;

but still dose not work. when I set opMode to "a","n","p",there is a error like 

I want to change the mode to transceiver. 

How to realize that?

Thank you.