All Products for US Patent 4797879 - Packet switched interconnection protocols for a star configured optical lan

Inventor(s): Habbab; Isam M. I. (Aberdeen, NJ), Kavehrad; Mohsen (Holmdel, NJ), Sundberg; Carl-Erik (Hazlet, NJ)

Owner: American Telephone and Telegraph Company AT&T Bell Laboratories (Murray Hill, NJ)

Filing Date: June 5, 1987

Issue Date: January 10, 1989

Abstract: The present invention relates to packet switched interconnection protocols for use in high-speed optical Star-configured Local Area Networks (LANs). In the present Star LAN, a plurality of N+1 wavelength division multiplexed (WDM) channels are provided for use by M transceivers connected to the Star coupler, where preferably M>N. N of the N+1 WDM channels are used for transmission of data packets, and the remaining WDM channel is used by all transceivers for transmitting control packets only. In the present protocols, a transmitter in an active transceiver first send a control packet over the control channel using a first protocol such as, for example, ALOHA or CSMA. The control packet includes (1) the transmitter's unique address, (2) the destined receiver's address, and (3) the address of the data channel to be used in transmitting the associated data packet. Immediately after the control packet is sent, the associated data packet is transmitted over the chosen one of the N data channels using a second protocol such as, for example, ALOHA, CSMA or N-Server Switch. In the Star network, the transceivers receive their own transmissions and detect if a collision or not has occurred, and if a collision is detected the transmission procedure is repeated until successful.