[ns] How to change transmission power of a specific node in the middle of simulation run time or in protocol?

[Mahshid Rahnama]

Hi all,

I am try to change transmission power of each node according to some
parameters in my protocl,
How can I set and adjust a node transmission power in simualtion run time?

I know threshold -m <propagation-model> [other-options] distance
 and Phy/WirelessPhy set RXThresh_ <value>
 ....
 But I think it just work when creating a node,
but What should I do to change transmission power of for example
mobilenode(4) after 5 seconds ?

Thanks for any help,
--Mah