Radio communication system realizing extended MPDU format having large number of data bytes

A radio transmission system in accordance with a network protocol forming an IP layer handling an IP packet, a MAC layer handling a MAC packet including the IP packet, and a physical layer having a MAC protocol data unit including the MAC packet, for transmitting the MAC protocol data unit having a predetermined data amount, formed in the physical layer, by time-division radio transmission, between a transmitting-side transmission terminal and a receiving-side transmission terminal among a large number of transmission terminals through a local area network,

• wherein a part of the large number of transmission terminals uses an extended network protocol capable of forming an extended MAC protocol data unit having a larger data amount than the predetermined data amount, as the network protocol, and
• wherein when the part of transmission terminals become the transmitting-side transmission terminal, if it is determined through the local area network that the receiving-side transmission terminal is the part of transmission terminals applicable to the extended network protocol, the transmitting-side transmission terminal forms the extended MAC protocol data unit in the physical layer in accordance with the extended network protocol, and transmits the extended MAC protocol data unit through the local area network to the receiving-side transmission terminal.