A system for communication of sensor data and/or control data within a predetermined space, said system comprising a base unit arranged to communicate wirelessly using an open network, wherein the base unit has stored therein settings for network communication with units intended to be connected to the system using said open network, said settings being unique for one or more manufacturers of units of and/or intended for use with the system for communication of sensor data and/or user control data and comprising a first encryption key and a predetermined scheme for network communication between devices having the first encryption key, wherein the predetermined scheme defines time slots for network communication, at least one node (102; 103, 104) comprising a sensor unit and/or a user control unit intended to be connected to the system, said node having stored therein said settings for network communication and a unit ID identifying the node, and wherein the base unit and the at least one node (102; 103, 104) are arranged to find each other based on said settings for network communication, and communicate over an entry network using said first encryption key and in accordance with said predetermined scheme for network communication, whereby the encryption and the predetermined scheme defining time slots for network communication, both contribute to making it difficult for an intruder to access the entry network and/or to listen to the communications between the base unit and the node(s) and wherein the base unit is arranged to initiate a pairing procedure with at least one of the found nodes of the entry network, said pairing procedure involving transmitting of additional settings for communication over a secure network to the at least one of the found nodes (102; 103, 104), said additional settings including at least one second, unique encryption key for use in secure communication over the secure network, and wherein each paired node (102; 103, 104) is added to the secure network upon completion of the pairing procedure. a base unit arranged to communicate wirelessly using an open network, wherein the base unit has stored therein settings for network communication with units intended to be connected to the system using said open network, said settings being unique for one or more manufacturers of units of and/or intended for use with the system for communication of sensor data and/or user control data and comprising a first encryption key and a predetermined scheme for network communication between devices having the first encryption key, wherein the predetermined scheme defines time slots for network communication, at least one node (102; 103, 104) comprising a sensor unit and/or a user control unit intended to be connected to the system, said node having stored therein said settings for network communication and a unit ID identifying the node, and wherein the base unit and the at least one node (102; 103, 104) are arranged to find each other based on said settings for network communication, and communicate over an entry network using said first encryption key and in accordance with said predetermined scheme for network communication, whereby the encryption and the predetermined scheme defining time slots for network communication, both contribute to making it difficult for an intruder to access the entry network and/or to listen to the communications between the base unit and the node(s) and wherein the base unit is arranged to initiate a pairing procedure with at least one of the found nodes of the entry network, said pairing procedure involving transmitting of additional settings for communication over a secure network to the at least one of the found nodes (102; 103, 104), said additional settings including at least one second, unique encryption key for use in secure communication over the secure network, and wherein each paired node (102; 103, 104) is added to the secure network upon completion of the pairing procedure.