Method, System and Node for Implementing Automatic Protection Switching in Optical Burst-switching Ring

• US 20160156410A1
• Filed: 06/19/2014
• Published: 06/02/2016
• Est. Priority Date: 07/16/2013
• Status: Active Grant

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Guo, Hongxiang, Zhang, Dongxu, Chen, Xue, Wu, Jian, AN, Gaofeng
• Granted Patent: US 9,998,212 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 10/032 using working and protection systems H04J14/0287 takes precedence
• CPC Class Codes: H04B 10/07955 Monitoring or measuring power
• CPC Class Codes: H04B 10/275 Ring-type networks
• CPC Class Codes: H04L 12/437 Ring fault isolation or reconfiguration for SDH/SONET ring networks H04J3/085
• CPC Class Codes: H04L 41/0668 by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0092 Ring

Abstract

Provided are a method, a system and a node for implementing APS in an OBRing network. The method comprises: a master node and a slave node separately perform optical power monitoring on respective channels, and aggregate monitoring results to the master node; when determining, according to the monitoring results, that a fault occurs, the master node sends a switching operation instruction to the slave node; and the slave node performs a switching operation and enters a protection working state. With the disclosure, a protection switching mechanism is introduced to the OBRing, which implements the processing on fault and ensures the communication quality of the OBRing.

Claims

1. A method for implementing Automatic Protection Switching (APS) in an Optical Burst-switching Ring (OBRing) network, comprising:

performing separately, by a master node and a slave node, optical power monitoring on respective channels, and aggregating monitoring results to the master node;

when determining, according to the monitoring results, that a fault occurs, sending, by the master node, a switching operation instruction to the slave node; and

performing a switching operation and entering a protection working state, by the each slave node.

2. The method according to claim 1, wherein the optical power monitoring comprises real-time monitoring of optical power states of a control channel and a data channel.

3. The method according to claim 2, wherein aggregating the monitoring results to the master node comprises:

transmitting, by the slave node, the monitoring result carried in a control frame or a new fault report message to the master node through the control channel;

the monitoring result of the master node comprises a real-time monitoring result that the master node monitors the optical power states of the control channel and the data channel and the monitoring result reported by the slave node through the control channel.

4. The method according to claim 2, wherein the determining, according to the monitoring results, that the fault occurs comprises:

when the monitoring results show that there is only one ring having a node reporting optical loss on both control channel and data channel, determining that the fault is a single-fibre single-point line fault;

when the monitoring results show that there are two rings respectively having a node, which is adjacent to each other, reporting optical loss on both control channel and data channel, determining that the fault is a double-fibre single-point line fault;

when the monitoring results show that there is only one node reporting optical loss on the control channel, determining that the fault is a control channel transmitter fault;

when the monitoring results show that both rings have an exception in receiving of control frames, determining that the fault is a non-master node paralysis.

5. The method according to claim 4, wherein when the fault indicates that there is a wavelength fault in a data channel which does not affect an operation of an entire network, the method further comprises:

notifying, by the master node, related nodes to avoid the data channel with an unavailable wavelength, and reporting, by the master node, a condition to a network management system.

6. The method according to claim 3, further comprising:

feeding back, by the slave node, a control frame indicating a successful switching operation to the master node;

or, feeding back a fault report response message indicating a successful switching operation corresponding to the fault report message.

7. The method according to claim 1, wherein based on that the master node is located at one end of a fault point, the method further comprises:

performing a switching operation by the master node itself, and triggering, by the master node, a protection switch to enter a protection state;

otherwise, directly entering the protection working state by the master node.

8. The method according to claim 7, wherein before the slave node performs the switching operation, the method further comprises:

after the slave node receives a switching operation instruction, judging, by the slave node, whether the slave node is one of the nodes located at two ends of the fault point;

based on that the slave node is not one of the nodes located at two ends of the fault point, the slave node directly entering the protection working state and waiting the master node to reallocate bandwidth;

based on that the slave node is one of the nodes located at two ends of the fault node, entering the protection working state according to the switching operation instruction after performing a switching operation on the protection.

9. The method according to claim 8, wherein performing the switching operation on the protection switch to enter the protection working state comprises:

switching the protection switch from a bar state which is a normal working state to a cross state;

or,

scheduling the control channel from one ring to another ring in an electrical domain.

10. The method according to claim 7, wherein after entering the protection working state, the method further comprises:

sharing one control channel, by all transceivers of the master node and each slave node;

dividing each node into an upper node and a lower node logically, which correspond to transceivers on the original inner ring and outer ring respectively, wherein the upper node extracts from a control frame the bandwidth configuration information of an upper link and performs OB transceiving according to the bandwidth configuration information of the upper link, and the lower node extracts, from a control frame, bandwidth configuration information of a lower link and performs OB transceiving according to the bandwidth configuration information of the lower link.

11. The method according to claim 10, wherein the master node is divided into an upper master node and a lower master node logically and the method further comprises:

when the control frame flows through the upper master node, all bandwidth request information of the lower link is aggregated to the upper master node, and the upper master node calculates a corresponding bandwidth configuration policy according to a bandwidth allocation algorithm and fills the corresponding bandwidth configuration policy into a control frame;

when the control frame flows through a first node on the lower link, the carried bandwidth allocation policy of the lower link begin to take effect;

correspondingly, when the control frame flows through the lower master node, all bandwidth requests of the upper node are submitted and a corresponding bandwidth allocation policy of the upper link is updated according to the bandwidth allocation algorithm.

12. The method according to claim 1, further comprising:

ranging by the master node, and fine tuning, by the master node, a ring length according to a ranging result.

13. The method according to claim 12, further comprising:

recovering normal transmission of services on the master node and each slave node.

14. The method according to claim 13, wherein after the fault is recovered, the method further comprises:

transmitting, by a network, an instruction through the network management system to notify the master node and the slave node to enter a normal dual-ring working state from the protection working state.

15. The method according to claim 14, wherein entering to the normal dual-ring working state comprises:

after the master node receives the instruction from the network management system, sending, by the master node, a control frame carrying a network recovery indication on the control channel, wherein the control frame is processed and forwarded at all approached nodes;

suspending all services and waiting a new restart by the approached nodes, meanwhile,

when the nodes at two ends of the fault section terminates service transmission, switching back the protection switch from the cross state to the bar state which is the normal working state, or, stopping the cross-ring forwarding of the control channel in an electrical domain, and recovering to the normal working state.

16. The method according to claim 15, wherein after the master node sends the control frame carrying the network recovery indication, the method further comprises:

enabling a new turn of ranging, bandwidth allocation and restart by the master node immediately or after receiving a response indicating waiting from the slave node.

17. A node, which is applied to an Optical Burst-switching Ring (OBRing) network of a two-fibre reverse ring network, characterized by comprising:

a control channel processing component, a data channel receiving component, a data channel sending component and a protection switch, wherein

the control channel processing component comprises;

a first power monitoring component configured to detect an optical signal power state of a control channel and to output a control frame to a control frame parsing component after performing photoelectrical conversion;

a control frame parsing component configured to;

parse the control frame, transmit a corresponding instruction to the data channel receiving component and the data channel sending component according to bandwidth reservation information indicated in the control frame, transmit a data frame on an upper link and a lower link normally, and notify a control frame generation component to generate a new control frame according to a processing condition of the current node;

a control frame generation component configured to;

receive a notification from the control frame parsing component or a fault notification from the data channel receiving component, generate a new control frame according to the notification, and send the new control frame to a control frame sending component;

a control frame sending component configured to send the new control frame sent from the control frame generation component to a fibre line to transmit to a downstream node;

the data channel receiving component comprises;

a second power monitoring component configured to monitor each wavelength and to notify a monitoring result to the control frame generation component via a control interface;

a quick selection switch configured to receive, via the control interface, the control frame sent from the control channel processing component, and to receive, according to the bandwidth reservation information contained in the control frame, an OB signal transmitted on the lower link, wherein the received OB optical signal is sent to a user end after photoelectrical conversion and local electrical domain cache.

18. The node according to claim 17, wherein based on that the control frame received by the node is to indicate the node to perform a protection switching operation,

the control frame parsing component is further configured to notify the protection switch to perform a switching action after finishing parsing the control frame.

19. The node according to claim 17, wherein the node is a master node and the node further comprises a fault judgement component and a bandwidth allocation component, wherein

the fault judgement component is configured to:

collect monitoring results on the node, acquire optical power monitoring results of other nodes in a network from the information, which is parsed from a control frame in the control channel processing component by the control frame parsing component, determine, according to the monitoring results, whether there is a fault in the network, and a fault type and a fault location, and output the obtained fault result to the control frame generation component in the control channel processing component;

the control frame generation component in the control channel processing component is further configured to;

receive a bandwidth allocation result from the bandwidth allocation component and convert the bandwidth allocation result to corresponding control frame data, receive a fault result from the fault judgement component, generate corresponding signalling information according to the fault result and filling the signalling information into a new control frame, and send the new control frame to the control frame sending component.

20. A system for implementing Automatic Protection Switching (APS) in an Optical Burst-switching Ring (OBRing) network, wherein the system is an OBRing network of a two-fibre reverse ring network;

in the OBRing network, a control channel occupies a physical channel individually;

nodes in the OBRing network comprises a master node and a plurality of slave nodes;

each of the nodes comprises a control channel processing component, a data channel receiving component, a data channel sending component and a protection switch.

21. (canceled)