/**
* Return initial backoff time before attempting to send message m. The
* units are radio dependent.
+ * @param 'message_t* ONE m'
* @return Initial backoff time
*/
async event uint16_t initial(message_t* m);
/**
* Return backoff time after message m could not be send due to congestion.
* The units are raio dependent.
+ * @param 'message_t* ONE m'
* @return Backoff time after congestion
*/
async event uint16_t congestion(message_t* m);