Wireless system, relay method, and communication terminal

A relay method performed by a wireless system including:

• a closed network-side communication terminal that is a communication terminal to be connected to a closed network on a public line;
• a LAN-side communication terminal that is a communication terminal to be connected to a local area network;
• a gateway device to relay voice communication between the closed network-side communication terminal and the LAN-side communication terminal;
• a closed network-side control server to perform communication control in the closed network;
• and
• a LAN-side control server to perform communication control in the local area network,
• the relay method comprising:
• by the closed network-side communication terminal, when the closed network-side communication terminal is started, acquiring network information for performing communication with the LAN-side control server, which serves as a destination of the registration, from the closed network-side control server;
• by the closed network-side control server, performing communication control in the closed network;
• by the LAN-side control server, performing communication control on the closed network-side communication terminal via encapsulation/decapsulation performed by the gateway device in the local area network;
• by the LAN-side control server, performing communication control on the LAN-side communication terminal in the local area network directly;
• by the gateway device, receiving LAN data conforming to a communication standard of the local area network from the local area network, generating closed network data conforming to a communication standard of the closed network by performing encapsulation by adding a header for communication in the closed network to the received LAN data, and transmitting the generated closed network data to the closed network;
• and
• by the gateway device, receiving the closed network data from the closed network, generating the LAN data by performing decapsulation by removing a header for communication in the closed network from the received closed network data, and transmitting the generated LAN data to the local area network,
• connecting the closed network-side communication terminal to the LAN-side control server using the network information,
• registering the closed network-side communication terminal to the LAN-side control server, and
• by the closed network-side communication terminal, acquiring, from the LAN-side control serve, provisioning data that are information for enabling communication with another communication terminal.

A communication terminal connectable to a closed network on a public line and configured to communicate with a communication terminal to be connected to the closed network or a communication terminal to be connected to a local area network that is connected to the closed network via a gateway device, the communication terminal comprising:

• a terminal-side interface circuit connected to the closed network and configured to perform transmission and reception of closed network data conforming to a communication standard of the closed network;
• a data generator to generate LAN data conforming to a communication standard of the local area network, based on data for transmission and generate the closed network data by performing encapsulation by adding a header for communication in the closed network to the LAN data;
• and
• a data extractor to generate the LAN data by performing decapsulation by removing a header for communication in the closed network from the closed network data received by the terminal-side interface circuit and extract received data from the LAN data, wherein
• the data generator and the data extractor are embodied with a processing circuit contained in the communication terminal,
• the terminal-side interface circuit transmits the closed network data generated by the data generator to the closed network,
• the communication terminal connectable to the closed network is subjected to communication control by a LAN-side control server via encapsulation/decapsulation performed by the gateway device,
• the communication terminal to be connected to the local area network is subjected to direct communication control by the LAN-side control server,
• when the communication terminal connectable to the closed network is started, the communication terminal to be connected to the local area network acquires network information for performing communication with the LAN-side control server, which serves as a destination of the registration, from a closed network-side control server, and
• the communication terminal to be connected to the local area network
• is connected to the LAN-side control server using the network information,
• is registered in the LAN-side control server, and
• acquires, from the LAN-side control serve, provisioning data that are information for enabling communication with another communication terminal.