A configuration system arranged to configure a first set (112, 114, 116, 118, 117, 119) of wireless network devices to form a first stand-alone wireless network with regard for existing further stand-alone wireless networks, the system comprising - a portable configuration device arranged to - connect to a configuration manager and transmit a configuration request for the first set of wireless network devices, and - wirelessly connect with the first set of wireless network devices for configuring the first set of wireless network devices to form a first stand-alone wireless network, and - a configuration information storage arranged to store configuration parameters of further sets of wireless network devices (122, 124, 126, 128) configured to form the existing further stand-alone wireless networks, the configuration parameters include the radio frequencies on which the further stand-alone wireless networks operate, and - the configuration manager arranged to - receive the configuration request for the first set of wireless network devices from the portable configuration device, - determine in the further sets of wireless network devices a second set of wireless network devices configured to form an existing second stand-alone wireless network, spatially located so that it may be merged with the first set of wireless network devices into a single wireless network in future, and obtain second configuration parameters of the second stand-alone wireless network from the configuration information storage, the second configuration parameters including the radio frequency on which the second stand-alone wireless network operates, - determine first configuration parameters for the first set of wireless network devices for forming the first set into a first stand-alone wireless network, the first configuration parameters including the radio frequency on which the second stand-alone wireless network operates for operating the first stand-alone wireless network on the same radio frequency as the second stand-alone wireless network. - a portable configuration device arranged to - connect to a configuration manager and transmit a configuration request for the first set of wireless network devices, and - wirelessly connect with the first set of wireless network devices for configuring the first set of wireless network devices to form a first stand-alone wireless network, and - connect to a configuration manager and transmit a configuration request for the first set of wireless network devices, and - wirelessly connect with the first set of wireless network devices for configuring the first set of wireless network devices to form a first stand-alone wireless network, and - a configuration information storage arranged to store configuration parameters of further sets of wireless network devices (122, 124, 126, 128) configured to form the existing further stand-alone wireless networks, the configuration parameters include the radio frequencies on which the further stand-alone wireless networks operate, and - the configuration manager arranged to - receive the configuration request for the first set of wireless network devices from the portable configuration device, - determine in the further sets of wireless network devices a second set of wireless network devices configured to form an existing second stand-alone wireless network, spatially located so that it may be merged with the first set of wireless network devices into a single wireless network in future, and obtain second configuration parameters of the second stand-alone wireless network from the configuration information storage, the second configuration parameters including the radio frequency on which the second stand-alone wireless network operates, - determine first configuration parameters for the first set of wireless network devices for forming the first set into a first stand-alone wireless network, the first configuration parameters including the radio frequency on which the second stand-alone wireless network operates for operating the first stand-alone wireless network on the same radio frequency as the second stand-alone wireless network. - receive the configuration request for the first set of wireless network devices from the portable configuration device, - determine in the further sets of wireless network devices a second set of wireless network devices configured to form an existing second stand-alone wireless network, spatially located so that it may be merged with the first set of wireless network devices into a single wireless network in future, and obtain second configuration parameters of the second stand-alone wireless network from the configuration information storage, the second configuration parameters including the radio frequency on which the second stand-alone wireless network operates, - determine first configuration parameters for the first set of wireless network devices for forming the first set into a first stand-alone wireless network, the first configuration parameters including the radio frequency on which the second stand-alone wireless network operates for operating the first stand-alone wireless network on the same radio frequency as the second stand-alone wireless network.