A communication system comprising a plurality of local wireless networks corresponding to a predetermined plurality of wireless cells, each local wireless network in the plurality of local wireless networks (110, 120, 130, 140, 150) including a wireless master device (111; 121; 131; 141; 151) and at least one wireless slave device that are installed in each wireless cell (101, 102, 103, 104, 105) of the plurality of wireless cells (101, 102, 103, 104, 105), wherein the wireless slave device includes: a wireless communication unit for receiving a plurality of network management packets transmitted by a plurality of wireless master devices (111, 121, 131, 141, 151) corresponding to the plurality of wireless cells (101, 102, 103, 104, 105); an installation position recognition unit for obtaining information indicating an intra-wireless-cell slave device's position which is an installation position of the wireless slave device in the wireless cell (101; 102; 103; 104; 105), in which the wireless slave device is installed, of the plurality of wireless cells (101, 102, 103, 104, 105); a received-signal-strength measurement unit for obtaining, from the plurality of network management packets, information indicating intra-communication-system cell positions that are positions, in the communication system, of the plurality of wireless cells (101, 102, 103, 104, 105) in which each wireless master device (111, 121, 131, 141, 151) of the plurality of wireless master devices (111, 121, 131, 141, 151) are installed, of the plurality of wireless cells (101, 102, 103, 104, 105) and obtaining, in association with the information each indicating the intra-communication-system cell positions, measured values of received signal strengths of the plurality of network management packets; a received-signal-strength predicted-value provision unit for providing predicted values of the received signal strengths of the plurality of network management packets at the intra-wireless-cell slave device's position; a connection-wireless-master-device determination unit for performing a comparison of the predicted values provided by the received-signal-strength predicted-value provision unit with the measured values obtained by the received-signal-strength measurement unit, and designating, as a connection-destination wireless master device to be connected by the wireless slave device, a wireless master device inferred, on a basis of a result of the comparison, installed in the wireless cell (101; 102; 103; 104; 105) in which the wireless slave device is installed; and a connection processor for carrying out processing to connect with the connection-destination-wireless master device designated by the connection-wireless-master-device determination unit. a wireless communication unit for receiving a plurality of network management packets transmitted by a plurality of wireless master devices (111, 121, 131, 141, 151) corresponding to the plurality of wireless cells (101, 102, 103, 104, 105); an installation position recognition unit for obtaining information indicating an intra-wireless-cell slave device's position which is an installation position of the wireless slave device in the wireless cell (101; 102; 103; 104; 105), in which the wireless slave device is installed, of the plurality of wireless cells (101, 102, 103, 104, 105); a received-signal-strength measurement unit for obtaining, from the plurality of network management packets, information indicating intra-communication-system cell positions that are positions, in the communication system, of the plurality of wireless cells (101, 102, 103, 104, 105) in which each wireless master device (111, 121, 131, 141, 151) of the plurality of wireless master devices (111, 121, 131, 141, 151) are installed, of the plurality of wireless cells (101, 102, 103, 104, 105) and obtaining, in association with the information each indicating the intra-communication-system cell positions, measured values of received signal strengths of the plurality of network management packets; a received-signal-strength predicted-value provision unit for providing predicted values of the received signal strengths of the plurality of network management packets at the intra-wireless-cell slave device's position; a connection-wireless-master-device determination unit for performing a comparison of the predicted values provided by the received-signal-strength predicted-value provision unit with the measured values obtained by the received-signal-strength measurement unit, and designating, as a connection-destination wireless master device to be connected by the wireless slave device, a wireless master device inferred, on a basis of a result of the comparison, installed in the wireless cell (101; 102; 103; 104; 105) in which the wireless slave device is installed; and a connection processor for carrying out processing to connect with the connection-destination-wireless master device designated by the connection-wireless-master-device determination unit.