A wireless network system with at least - a network device (1, 1', 1") comprising at least - a communication interface for transmitting and receiving data over a wireless medium, - network identification information, - a network configuration memory, the wireless network system further comprising - a joining device (21, 81, 91, 101, 111) comprising at least - a communication interface for transmitting and receiving data over the wireless medium, - a predefined address and - a device configuration memory, - said network device (1, 1', 1") and said joining device (21, 81, 91, 101, 111) being configured for communicating in a commissioning mode, in which - said network device (1, 1', 1 ") being configured to broadcast said network identification information, - said joining device (21, 81, 91, 101, 111) being configured upon reception of said broadcast to send a request to join the network comprising said predefined address to said network device (1, 1', 1"), - said network device (1, 1') being configured to respond said request by assigning a network address to said joining device (21, 81, 91, 101, 111), to store data corresponding to said network address in said network configuration memory and to send joining information comprising at least said network address to said joining device (21, 81, 91, 101, 111) using said predefined address and - said joining device (21, 81, 91, 101, 111) being configured to receive said joining information and to store said joining information in said device configuration memory, so that said joining device (21, 81, 91, 101, 111) is addressable in the network system (30, 60) using said network address, characterized in that - said network device (1, 1', 1 ") comprises predetermined code data and a secondary signal transmitter configured for sending a signal corresponding to said predetermined code data to said joining device (21, 81, 91, 101, 111), - said joining device (21, 81, 91, 101, 111) comprises a secondary signal receiver, configured to receive said signal, said joining device being further configured to, upon reception of said signal, send corresponding verification information over said wireless medium to said network device (1, 1', 1") and - said network device (1, 1', 1") being configured to determine whether said verification information corresponds to said code data and to send joining information to the joining device (21, 81, 91, 101, 111) only if the verification information corresponds to said code data. - a network device (1, 1', 1") comprising at least - a communication interface for transmitting and receiving data over a wireless medium, - network identification information, - a network configuration memory, - a joining device (21, 81, 91, 101, 111) comprising at least - a communication interface for transmitting and receiving data over the wireless medium, - a predefined address and - a device configuration memory, - said network device (1, 1', 1") and said joining device (21, 81, 91, 101, 111) being configured for communicating in a commissioning mode, in which - said network device (1, 1', 1 ") being configured to broadcast said network identification information, - said joining device (21, 81, 91, 101, 111) being configured upon reception of said broadcast to send a request to join the network comprising said predefined address to said network device (1, 1', 1"), - said network device (1, 1') being configured to respond said request by assigning a network address to said joining device (21, 81, 91, 101, 111), to store data corresponding to said network address in said network configuration memory and to send joining information comprising at least said network address to said joining device (21, 81, 91, 101, 111) using said predefined address and - said joining device (21, 81, 91, 101, 111) being configured to receive said joining information and to store said joining information in said device configuration memory, so that said joining device (21, 81, 91, 101, 111) is addressable in the network system (30, 60) using said network address, - said network device (1, 1', 1 ") comprises predetermined code data and a secondary signal transmitter configured for sending a signal corresponding to said predetermined code data to said joining device (21, 81, 91, 101, 111), - said joining device (21, 81, 91, 101, 111) comprises a secondary signal receiver, configured to receive said signal, said joining device being further configured to, upon reception of said signal, send corresponding verification information over said wireless medium to said network device (1, 1', 1") and - said network device (1, 1', 1") being configured to determine whether said verification information corresponds to said code data and to send joining information to the joining device (21, 81, 91, 101, 111) only if the verification information corresponds to said code data.