A method for transmitting data from a sender node to a receiver node in a wireless network including (a) sampling a main network frequency and at least one backup frequency, (b) transmitting a message on the main network frequency without using a multiple access protocol, (c) transmitting the message on the main network frequency, using the multiple access protocol exchange, if an acknowledgement is not received, (d) transmitting the message on at least one backup frequency, using a multiple access protocol, if the main network frequency is busy after (c), (e) repeating (c) and (d) for a predefined number of time slots, until an acknowledgement is received, (f) transmitting the message on each backup frequency, using the multiple access protocol, until an acknowledgment is received, and (g) performing an exponential backoff and subsequent transmission of the message if an acknowledgement is still not received after (a) through (f).