Patent ID: 6993005

Claim:
An information transfer method for transferring information regarding an AV control protocol in a radio system for carrying out data transfer after establishing a logical connection between radio terminals or gateways prior to data transfer between the radio terminals or gateways, the method comprising the steps of: exchanging signaling packets for signaling at a datalink layer between the radio terminals or gateways prior to an exchange of data packets on which the information regarding the AV control protocol is loaded, each signaling packet containing a channel identifier indicating a logical channel that is set up for transferring the data packets and a protocol identifier indicating the AV control protocol, such that a signaling packet transmitted from each radio terminal or gateway indicates a channel identifier that is set up for the each radio terminal or gateway and a signaling packet received from a correspondent radio terminal or gateway indicates a channel identifier that is set up for the correspondent radio terminal or gateway; storing at the each radio terminal or gateway a correspondence information obtained through an exchange of the signaling packets, the correspondence information indicating a correspondence among the protocol identifier, the channel identifier that is set up for the each radio terminal or gateway; and the channel identifier that is set up for the correspondent radio terminal or gateway; transferring the data packets between the radio terminals or gateways, according to the correspondence information; and giving a received AV control command to a Subunit corresponding to a message type contained in a data packet on which the received AV control command is loaded.