Optical-inclusive dWDM local area network

• US 7,496,295 B2
• Filed: 10/10/2002
• Issued: 02/24/2009
• Est. Priority Date: 10/10/2001
• Status: Active Grant

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Baldine, Ilia, Jackson, Laura
• Primary Examiner(s): Leung; Christina Y
• Application Number:
  US10/268,424
• Publication Number:
  US 20040071469A1
• Time in Patent Office: 2,329 Days
• Field of Search: 398 58- 64, 398/68, 398/69, 398/70, 398/71
• US Class Current: 398/69
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0228 Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths
• CPC Class Codes: H04J 14/0238 Wavelength allocation for communications one-to-many, e.g. multicasting wavelengths
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0018 using tunable transmitters or receivers
• CPC Class Codes: H04Q 2011/0064 Arbitration, scheduling or medium access control aspects
• CPC Class Codes: H04Q 2011/0086 Network resource allocation, dimensioning or optimisation
• CPC Class Codes: H04Q 2011/0088 Signalling aspects
• CPC Class Codes: H04Q 2011/0094 Star

Abstract

An optical-inclusive, dWDM local area network and the accompanying signaling protocol necessary to facilitate communication between nodes in a network. This network architecture provides for a packet-oriented network, independent of the number of nodes and the number of supported wavelengths, and provides for scheduled access to the medium, which guarantees higher utilization.

Claims

1. An optical-inclusive dense wavelength division multiplexing network, the network comprising:

a passive star coupler that serves as a network hub;

one or more candidate nodes in optical communication with the passive star coupler, the one or more candidate nodes including a fast tunable transmitter and a slowly tunable receiver for receiving and transmitting optical signals, the one or more candidate nodes implementing an election algorithm to elect a scheduling entity from amongst the one or more candidate nodes; and

a master node in optical communication with the passive star coupler and selected from amongst the one or more candidate nodes to serve as the scheduling entity, the master node implementing a scheduling algorithm that schedules the transmission of at least two service classes of data frames allocated between different candidate wavelengths throughout the network based on scheduling constraints imposed by at least one of the service classes for delivery of the data frames,

said scheduling algorithm determining a priority for transmission of scheduled data frames from the one or more candidate nodes by

     1) calculating for each candidate node a total number of data frames regardless of wavelength to be transmitted and

     2) calculating for each candidate wavelength a total number of data frames regardless of node to be transmitted,

wherein the node with the highest total number of data frames regardless of wavelength determines node transmission priority and the highest total number of data frames regardless of node determines wavelength transmission priority.

2. The network of claim 1, wherein the fast tunable transmitter is further defined as a transmitter having tuning times of less than about 1 microsecond and the slowly tunable receiver is further defined as a receiver having tuning times greater than about 100.0 micro-seconds.

3. The network of claim 1, further comprising one or more slave nodes that are in optical communication with the passive star coupler and receive scheduling data from the master node.

4. The network of claim 1, wherein the scheduling algorithm is further defined as a one-pass greedy scheduling algorithm.

5. The network of claim 1, wherein the at least two service classes comprise at least two of:

an expedited forwarding class;

an assured forwarding class; and

a best-efforts class.

6. The network of claim 1, wherein the constraint comprises a quality of service guarantee.

7. The network of claim 1, wherein wavelength resources are allocated among the candidate nodes such that excess bandwidth is distributed among network flow of the data frames throughout the network.

8. The network of claim 1, wherein the scheduling algorithm comprises a traffic matrix in which rows of the traffic matrix are associated with respective ones of the candidate nodes, columns of the traffic matrix are associated with respective ones of the candidate wavelengths, and entries in the traffic matrix show for each node and each wavelength the number of the scheduled data frames to be transmitted, and

the scheduling algorithm determines 1) respective row summations for each of the candidate nodes of all scheduled data frames to be transmitted for a particular node and 2) respective column summations for each of the candidate wavelengths of all scheduled data frames to be transmitted for a particular wavelength, and

wherein the highest row summation determines said node transmission priority and the highest column summation determines said wavelength transmission priority.

9. A node within an optical-inclusive dense wavelength division multiplexing network, the node comprising:

a fast tunable transmitter for optically transmitting data frames to a slowly tunable receiver for optically receiving data frames;

a plurality of queues that buffer the data frames, prior to transmission, on a per-wavelength basis;

a queue manager that controls which frames are transmitted from the plurality of queues in accordance with a scheduling algorithm; and

an election module that implements an election routine to elect a scheduling node from a plurality of predetermined nodes within the network with the scheduling node being elected configured to schedule the transmission of at least two service classes of data frames allocated between different candidate wavelengths throughout the network based on scheduling constraints imposed by at least one of the service classes for delivery of the data frames,

said scheduling algorithm determining a priority for transmission of scheduled data frames from the one or more candidate nodes by

     1) calculating for each candidate node a total number of data frames regardless of wavelength to be transmitted and

     2) calculating for each candidate wavelength a total number of data frames regardless of node to be transmitted,

wherein the node with the highest total number of data frames regardless of wavelength determines node transmission priority and the highest total number of data frames regardless of node determines wavelength transmission priority.

10. The node of claim 9, further comprising a first look-up table that enables a network node to perform Internet Protocol to Medium Access Control (IP-to-MAC) address resolution.

11. The node of claim 10, further comprising a second look-up table that enables a network node to perform MAC-to-receive wavelength resolution.

12. The node of claim 9, further comprising a join algorithm that is implemented to allow additional nodes to join the network.

13. The node of claim 9, wherein the scheduling algorithm is implemented by an elected scheduling node and calculates data packet delivery schedules for all nodes in the network.

14. The node of claim 9, further comprising a scheduling management module that manages the scheduling of data transmission.

15. The node of claim 9, further comprising a synchronization module that provides synchronization of transmissions between the node and a passive star coupler.

16. The node of claim 9, wherein the fast tunable transmitters are further defined as transmitters having tuning times of less than about 1 microsecond.

17. The node of claim 9, wherein the slowly tunable receivers are further defined as receivers having tuning times greater than about 100 microseconds.

18. The node of claim 9, wherein the at least two service classes comprise at least two of:

an expedited forwarding class;

an assured forwarding class; and

a best-efforts class.

19. The node of claim 9, wherein the constraint comprises a quality of service guarantee.

20. The node of claim 9, wherein wavelength resources are allocated among the candidate nodes such that excess bandwidth is distributed among network flow of the data frames throughout the network.

21. The node of claim 9, wherein the scheduling algorithm comprises a traffic matrix in which rows of the traffic matrix are associated with respective ones of the candidate nodes, columns of the traffic matrix are associated with respective ones of the candidate wavelengths, and entries in the traffic matrix show for each node and each wavelength the number of the scheduled data frames to be transmitted, and

the scheduling algorithm determines 1) respective row summations for each of the candidate nodes of all scheduled data frames to be transmitted for a particular node and 2) respective column summations for each of the candidate wavelengths of all scheduled data frames to be transmitted for a particular wavelength, and

wherein the highest row summation determines said node transmission priority and the highest column summation determines said wavelength transmission priority.

22. A method for electing a scheduling node in an optical-inclusive dense Wavelength Division Multiplexing (dWDM), Local Area Network (LAN), the method comprising:

failing to detect, at one or more candidate nodes, the presence of a scheduling node within the network;

tuning the one or more candidate node receivers and transmitters to an election wavelength;

announcing to the network that one or more candidate nodes are available as candidates for scheduling node election; and

electing one of the one or more announced candidate nodes as the scheduling node.

23. The method of claim 22, wherein the step of electing one of the one or more announced candidate nodes as the scheduling node further comprises electing one of the one or more announced candidate nodes as the scheduling node based on the timing of the announcements to the network that the candidate nodes are available for election.

24. The method of claim 22, wherein the step of electing one of the one or more announced candidate nodes as the scheduling node further comprises electing one of the one or more announced candidate nodes as the scheduling node based on highest Media Access Control (MAC) Identifier (ID) of one or more announced candidate nodes.