Method for determining an operational radio channel out of a set C of radio channels, of a communication network, said communication network comprising at least two potential proxies (ZGPP1, ZGPP2) for an energy-restricted device (ZGPD) to join the network, said at least two potential proxies being in commissioning mode, the method comprising the following steps: - the energy-restricted device (ZGPD) attempting to join the network, wherein for each attempt i, - the energy-restricted device (ZGPD) transmits in MAC broadcast a beacon message (Beacon GPDF) on a channel c i of the set C, and switches to receiving mode on channel listen(c i), wherein listen is an arithmetical function, from C to C, - wherein the next channel on which the energy-restricted device will transmit the next beacon message for the next attempt i + 1 is c i + 1 =succ(c i), wherein succ is arithmetical function, from C to C; - at least one of the proxies (ZGPP1, ZGPP2) receiving a first beacon message (Beacon GPDF) sent on the operational radio channel c _ op, - applying a mechanism for determining a temporary master device (ZGPP1) among the at least two potential proxies, - the temporary master device (ZGPP1) switching its radio receiver to channel succ m (c_op), m being a non-zero positive integer, wherein succ m denotes that the function succ is applied m times, such that succ m (c) = succ(succ m-1 (c)), - the energy-restricted device (ZGPD) transmitting a further beacon message on radio channel succ m (c_op) and switching to receiving mode on channel listen(succ m (c_op)), - upon receipt of the further beacon message, the temporary master device transmitting a response (Beacon Rsp GPDF) on a channel listen(succ m (c_op)), - the energy-restricted device (ZGPD) receiving the beacon response on a channel listen(succ m (c_op)), determining that c_op is the operational channel. - the energy-restricted device (ZGPD) attempting to join the network, wherein for each attempt i, - the energy-restricted device (ZGPD) transmits in MAC broadcast a beacon message (Beacon GPDF) on a channel c i of the set C, and switches to receiving mode on channel listen(c i), wherein listen is an arithmetical function, from C to C, - wherein the next channel on which the energy-restricted device will transmit the next beacon message for the next attempt i + 1 is c i + 1 =succ(c i), wherein succ is arithmetical function, from C to C; - the energy-restricted device (ZGPD) transmits in MAC broadcast a beacon message (Beacon GPDF) on a channel c i of the set C, and switches to receiving mode on channel listen(c i), wherein listen is an arithmetical function, from C to C, - wherein the next channel on which the energy-restricted device will transmit the next beacon message for the next attempt i + 1 is c i + 1 =succ(c i), wherein succ is arithmetical function, from C to C; - at least one of the proxies (ZGPP1, ZGPP2) receiving a first beacon message (Beacon GPDF) sent on the operational radio channel c _ op, - applying a mechanism for determining a temporary master device (ZGPP1) among the at least two potential proxies, - the temporary master device (ZGPP1) switching its radio receiver to channel succ m (c_op), m being a non-zero positive integer, wherein succ m denotes that the function succ is applied m times, such that succ m (c) = succ(succ m-1 (c)), - the energy-restricted device (ZGPD) transmitting a further beacon message on radio channel succ m (c_op) and switching to receiving mode on channel listen(succ m (c_op)), - upon receipt of the further beacon message, the temporary master device transmitting a response (Beacon Rsp GPDF) on a channel listen(succ m (c_op)), - the energy-restricted device (ZGPD) receiving the beacon response on a channel listen(succ m (c_op)), determining that c_op is the operational channel.