Patent ID: 6952533

Claim:
A network structure for IP-over-WDM comprising: a plurality of sub-rings each for accommodating n number of terminals (where n is a positive integer); a main ring having m number of connection nodes (where m is a positive integer), each of the connection nodes connected to a sub-ring via a sub-ring controller; a sub-ring controller for connecting an associated sub-ring to said main ring through the connection node, and controlling the flow of packets inside said sub-ring and the flow of packets between said sub-ring and said main ring; and a main ring controller for controlling the flow of packets inside said main ring, wherein all the sub-ring controllers share information on IP addresses of all the terminals connected to the entire network and a wavelength allocated to the sub-ring to which its IP address belongs and communicate with the main ring controller that manages the sub-ring controllers using different wavelengths wherein all the terminals connected to a given sub-ring communicate with corresponding sub-ring controllers using different wavelengths, respective terminals communicate via the sub-ring controllers each of which is connected to the sub-rings, respectively, wherein said terminals and connection nodes each add/drop only their own unique wavelengths, said sub-ring controller configured to drop all wavelength division multiplexed signals flowing in the sub-ring itself to de-multiplex the signals, a) to load each of said signals on a unique wavelength assigned to its terminal by using a destination address that is included in the packet, and then multiplex again said signal to transmit to said sub-ring when the destination terminal is located on the sub-ring of itself, and b) to add an identifying code (which is called a λ-tag) designating the sub-ring having a destination terminal of the packet, load the packet on its unique wavelength assigned between said sub-ring controller and the main-ring controller, and then transmit it to the connection node of said main ring when the destination terminal is located on the sub-ring other than the sub-ring having the source terminal of the packet, said main ring controller configured to drop all the wavelength division multiplexed signals flowing in the main ring itself, extract the λ-tag information, switch incoming packets based on the λ-tag information, load packets on their unique wavelengths assigned to the respective sub-ring controller, and then transmit packets to the main ring, wherein said main ring controller switches the packets extended by an wavelength socket scheme in which a buffer storing the packet, a lead frame framing the packet to be suitable for being transmitted and a transmitter converting the packets into optical signals are provided for each wavelength, and each sub-ring controller and the main ring controller configured to transmit signals only in a uniquely defined direction.