Optical-layer multipath protection for optical network
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsMing Xia, Stefan Dahlfort
Life of this patent
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Abstract
A multi-path provisioning scheme is provided to ensure full protection while reducing or minimizing resource overbuild. A signal to be provisioned is divided at a source node into a plurality of sub-signals that are independently routed from the source node to a destination node. Bandwidth for back-up traffic B is allocated in addition to bandwidth for primary traffic T. In some embodiments, the initial bandwidth B of the backup traffic equals the bandwidth of the primary traffic. The T+B traffic is initially distributed so that no link carries more than B traffic. The traffic distribution pattern is then iteratively revised to reduce the bandwidth requirements for the backup traffic while still meeting requirements for protection.
Claims13
A method of determining a traffic distribution pattern in an optical network having a plurality of links, said method comprising:
- dividing, in an optical module, a signal into a plurality of sub-signals;
- determining, by a processing circuit associated with the optical module, a distribution pattern such that each sub-signal traverses one or more of said plurality of links between a same beginning node and a same ending node;
- and
- iteratively revising, by the processing circuit, the distribution pattern to reduce backup traffic load by:
- identifying one or more critical links in the distribution pattern;
- determining a first set of sub-signals that each traverse at least one critical link;
- reallocating a primary traffic load from the first set of sub-signals to one or more link-disjoint sub-signals, further comprising the steps of:
- determining a reference link in a link-disjoint sub-signal that has the highest traffic load;
- and
- reallocating a portion of the primary traffic load equal to the difference between a total traffic load on the one or more critical links and a total traffic load on the reference link;
- and
- reducing backup traffic on one or more of the link-disjoint sub-signals by an amount equal to the total reallocated primary traffic load.
A system module for an optical network comprising one or more links, said system module comprising:
- an optical module configured to transmit and receive signals;
- and
- a processing module connected to said optical module and configured to:
- divide a transmitted signal into a plurality of sub-signals;
- determine a distribution pattern for the sub-signals such that each sub-signal traverses one or more of said links between the same beginning node and the same ending node;
- and
- iteratively revise the distribution pattern by:
- identifying one or more critical links in the distribution pattern;
- determining a first set of sub-signals, each sub-signal in said first set traversing at least one critical link;
- reallocating a primary traffic load from the first set of sub-signals to one or more link-disjoint sub-signals;
- by determining a reference link in a link-disjoint sub-signal that has the highest traffic load;
- and
- reallocating a portion of the primary traffic load equal to the difference between a total traffic load on the one or more critical links and a total traffic load on the reference link;
- and
- reducing backup traffic on one or more of the link-disjoint sub-signals an amount equal to the total reallocated primary traffic load.
Dependencies are inferred from the claim text.