ES2401274B1 - SYSTEM AND METHOD FOR PERFORMING SPECTRUM ASSIGNMENT IN AN OPTICAL NETWORK - Google Patents

Abstract

System and method for performing spectrum allocation in an optical network. # In the system of the invention, said spectrum allocation is performed according to a control plane, said spectrum allocation comprises a provision of resources and trajectories and further comprises an optimization of the spectrum. The system is characterized in that said optical network is a flexible optical network comprising a plurality of flexible optical nodes and in that it comprises: # - at least one flexible optical node controller in each of said flexible optical nodes for said provision of resources and paths , said provision of resources and paths comprising at least the reservation of resources and the establishment of a connection link between at least part of said plurality of flexible optical nodes; # - protocol extensions for said control plane in order to perform the less such provision of resources and trajectories; and # - an optical spectrum manager that provides said spectrum optimization, connected to said plurality of flexible optical nodes, comprising adapting the use of the spectrum according to traffic measurements carried out by means of a monitoring tool in said flexible optical network. # The method is arranged to carry out said provision of resources and trajectories and said spectrum optimization.

Description

SYSTEM AND METHOD FOR PERFORMING SPECTRUM ASSIGNMENT IN A OPTICAL NETWORK

Technical field

The present invention relates, in general, in a first aspect, to a system for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, said spectrum allocation comprising a provision of resources and trajectories and further comprising spectrum optimization, and more particularly to a system in which said optical network is a flexible optical network comprising a plurality of flexible optical nodes, said system comprising a flexible optical node controller in each of said flexible nodes for said provision of resources and paths, protocol extensions for said control plane and an optical spectrum manager that provides said spectrum optimization.

A second aspect of the invention relates to a method arranged to carry out said provision of resources and trajectories and said spectrum optimization.

Prior art

High-definition video distribution services, high-speed broadband and cloud computing technologies, which need to connect emerging advanced technology computers, clustered data stores, scalable adaptive graphical environment, and scientific instruments, require connections High speed flexible. Therefore, future networks will need to transport a wide variety of traffic that ranges from several gigabits per second to several terabits per second in an economical and scalable way.

Transport networks provide reliable data transport between two endpoints. However, current transport networks can only provide fixed bandwidth connections. For example, today's most advanced transport network is based on the wavelength switching paradigm and offers connections from 1 gigabit to 100 gigabit / second. The main advantage of optical wavelength switching networks (WSON) is the elimination of expensive OEO regenerators (optical electric optical) that consume power and take up space and the automated remote provision of optical paths. However, it still has a drawback with respect to the lost bandwidth due to its large rigid granularity. It goes without saying that the effective utilization of the capacity of the deployed network is one of the main concerns of network operators. Despite this, the optical path networks routed by current wavelengths require full capacity of wavelength assignment for an optical path between a pair of end nodes even when the traffic between the nodes is not sufficient to fill the entire wavelength capacity

In order to address the problem of the existing transport network and provide an economical flexible solution, the concept of flexible optical networks (EON) has been proposed by Jinno et al. [one]. An EON provides transport services adjustable to scale and with spectral efficiency of 100 Gb / s and more through the introduction of flexible granular conditioning in the optical frequency domain. The EON provides arbitrary contiguous concatenation of the optical spectrum that allows the creation of a custom size bandwidth. The concept of EON is to assign the appropriate optical bandwidth, unlike a fixed size, to an end-to-end optical path. The assignment is made according to the volume of traffic or user request in an adjustable way to scale and with great spectral efficiency. This spectral efficiency can be estimated as 50% of new free bandwidth including EON technology.

Unlike the rigid bandwidth of the conventional fixed bandwidth optical path, an optical path in EON, if necessary, expands and contracts according to the volume of traffic and user request. The flexible term in EON comes from its ability to expand and contract in contrast to the conventional rigid optical path.

In summary, EON makes it possible to adapt directly with spectral efficiency to mixed transmission rates of data bits in the optical domain due to flexible spectrum allocation. This efficient use consists in adapting the use of the optical spectrum to the really necessary one, on the contrary, the current optical networks with fixed grid can lead to the loss of optical bandwidth due to the excess of spacing between frequencies for transmission rate signals of lower bits.

A transport network is made up of network elements that enable the transport of data between two points. In this context, the set of elements that enable physical connectivity is usually called the data plane. In the particular case of optical networks, they will comprise transmitters (lasers) and receivers (photodiodes) that can be grouped into transceivers. It also includes intermediate switching equipment such as optical interconnections. As an example, WSON networks are defined by equipment that can multiplex wavelengths and lead to different destinations in the network. These wavelengths are located on a fixed grid and implies that, regardless of the bandwidth required, the spectrum usage will be fixed.

On the contrary, in a transport network, the control plane is the software (network protocols, routing algorithms, resource allocation algorithms, ...) that is responsible for the automatic operation of the network devices. For example, the control plane is responsible for the signaling process whereby the physical resources of the data plane are reserved for that connection. Current transport networks mainly use the RSVP protocol (resource reservation protocol) [RFC4974] to reserve network resources through the network elements and establish new connections.

Resource reservation protocols are not sufficient to complete a connection due to the information they need to provide services throughout the network. The information that these protocols need refers to the technology used in the network (OTN / WSON / ...), the available link capacity and other necessary information is closer to the routing information, interface / node identification and others. This information must be exchanged between network equipment. The preferred protocol for the topology and exchange of traffic engineering information is based on OSPF [RFC4230].

The control plane is also used for self-recovery purposes, which refers to the ability of the network to automatically recover connectivity when failures occur. In that case, both RSVP and OSPF protocols can be mixed to allow the network to recover from failures. It is also on the side of the control plane to ensure the efficiency of the network as much as possible with the technology present in the network control plane.

In order to generalize all network technologies and adapt to different transport networks, the GMPLS (generalized multiprotocol label switching) is born as a control plane protocol and allows the switching of labels in multiple technologies in transport networks. This fact makes extensions of both OSPF [RFC 4230] and RSVP [RFC 4974] necessary to adapt to this new framework.

EON transport networks need their own data and control plans, which are currently not complete.

The changes in technology that are pushing EON networks to become a new transport network focus on variable bandwidth transceivers and switching equipment that can adapt to the signal of the variable transceivers and lead it to the correct destination in the net. A flexible grid is allowed in this network technology which, compared to current WSON networks, is a great advantage in terms of spectral efficiency. This difference is reflected in parameters that have to be configured in the equipment, such as:

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 Wavelength to tune the transmitter and receivers.

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 Multiple subcarriers to be used (number of them).

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Modulation that each subcarrier should use.

Currently, there are several patents on flexible optical networks that focus exclusively on the photonic components required for the implementation of the data plane, such as:

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US 2010/023925: This patent proposes a variable bandwidth transponder that can dynamically adapt to both data transmission rates and optical spectrum consumption according to remote control orders.

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US 2009/0226173): This patent proposes a wavelength interconnection (WXC) of variable bandwidth that can dynamically adapt to the width of optical filters according to remote control orders.

Current patents on the optical control plane mainly focus on WSON (optical networks switched by wavelengths) and OTN (optical transport network). An example is “Path Computation Element Method to Support Routing and Wavelenght Assignment in Wavelenght Switched Optical Networks (US 2009/0110395)”. However, such patents do not address flexible optical spectrum allocation.

An example of the architecture of an EON network will be shown in Figure 1. The figure reflects the components of both the data plane and the control plane, which are listed below:

Data plane:

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Variable Bandwidth Transponder (BVT) (Element 102): The variable bandwidth transponder generates an optical signal using only sufficient spectral resources to transmit the client signal while minimizing the separation between adjacent optical paths. A technological option to implement a variable bandwidth transponder, without excluding others, may be based on using optical orthogonal frequency division multiplexing (OFDM) as the variable bandwidth modulation format (US 2010/023925).

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Variable bandwidth interconnection (BVXC) (element 101): each WXC (wavelength interconnection) of variable bandwidth in the path of the optical path assigns an interconnection with the corresponding spectral bandwidth to create an optical path from end to end of appropriate size. When utilization increases, the transmitter increases the line capacity and each WXC in the route expands the switching window, raising the bandwidth of the flexible optical path. Variable bandwidth interconnections can be based, for example and without excluding other techniques, on adaptive optical filters (US 2009/0226173).

Control plane:

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Flexible optical node controller (element 108): This element will include software to regulate the behavior of the node in an EON network. All control plane extensions must be included in this one. You will configure your own data plane components internally (BVXC switching configuration and BVT transmission and reception settings). Externally, you will have to inform the rest of the network about your own BVXC and BVT configuration. It will also configure itself through RSVP messages sent from other nodes in the network.

Although it promises high spectral efficiency and scalability for future optical transport networks, the EON concept presents new challenges. The flexible spectrum allocation scheme, non-uniform spectrum allocation and routing algorithm, network management and control scheme, etc. They have not been defined yet. Also, in addition to the wavelength continuity restriction of the current wavelength allocation and routing (RWA) algorithms, spectrum continuity must be incorporated into EON.

Description of the invention

It is necessary to offer an alternative to the state of the art that covers the gaps found therein, particularly in relation to the lack of proposals that really define a control plane for flexible optical networks. One option could be the creation of new protocols for exchanging equipment information, resource reservation, connectivity recovery and behavior optimization. The second option, chosen in the present invention, is to extend the existing protocols to allow all the operations necessary to regulate the EON networks.

To this end, the present invention provides, in a first aspect, a system for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, and said spectrum allocation comprising a provision of resources and paths and comprising also a spectrum optimization.

Unlike the known proposals, in the method of the invention said optical network is a flexible optical network comprising a plurality of flexible optical nodes, and in a characteristic manner comprises:

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at least one flexible optical node controller in each of said flexible optical nodes for said provision of resources and paths, said provision of resources and paths comprising at least the reservation of resources and the establishment of a connection link between at least part of said plurality of flexible optical nodes;

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protocol extensions for said control plane in order to make at least said provision of resources and paths; Y

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an optical spectrum manager that provides said spectrum optimization, connected to said plurality of flexible optical nodes, which comprises adapting the use of the spectrum according to traffic measurements carried out by means of a monitoring tool in said flexible optical network.

Other embodiments of the system of the first aspect of the invention are described according to the attached claims 2 to 16, and in a subsequent section relating to the detailed description of various embodiments.

A second aspect of the present invention comprises a method for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, and said spectrum allocation comprising a provision of resources and paths and further comprising spectrum optimization. .

Unlike the known proposals, the method of the invention, in a characteristic manner, comprises that said optical network is a flexible optical network comprising a plurality of flexible optical nodes with at least one flexible optical node controller in each of said flexible optical nodes in charge of making said provision of resources and paths, and a variable bandwidth transponder, or BVT, placed in each of said plurality of optical nodes, and an optical spectrum manager that provides said spectrum optimization, being said optical spectrum manager connected to said plurality of flexible optical nodes, said method comprising the following steps:

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informing, said flexible optical node controller, about the status of said BVT to said optical spectrum manager and / or to different flexible optical node controllers through an external interface and OSPF-TE extensions;

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correlating, said optical spectrum manager, information received from said flexible optical node controller and / or from other flexible optical node controllers;

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 deciding, said optical spectrum manager, to perform a spectrum optimization according to said correlation;

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sending, said optical spectrum manager, RSVP-TE extensions to said flexible optical node controller and / or to said other flexible optical node controllers if said spectrum optimization should be performed, according to said decision; Y

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configuring, said flexible optical node controller and / or said other flexible optical node controllers, said BVT according to the reception of said RSVP-TE extensions.

Brief description of the drawings

The foregoing and other advantages and features will be more fully understood from the following detailed description of embodiments, with reference to the attached drawings (some of which have already been described in the prior art state section), which they should be considered in an illustrative and non-limiting manner, in which:

Figure 1 shows an example of current flexible optical networks.

Figure 2 shows the procedure followed by the optical spectrum manager to perform a spectrum optimization, according to an embodiment of the present invention.

Figure 3 schematically shows the control plane modules, according to an embodiment of the present invention.

Figure 4 shows a flexible optical network with the control plane modules proposed in the present invention.

Figure 5 shows a switching capacity descriptor sub-TLV, according to an embodiment of the present invention.

Figure 6 shows a sub-TLV of available frequency band, according to an embodiment of the present invention.

Figure 7 shows a sub-TLV of unreserved wavelength band, according to an embodiment of the present invention.

Figure 8 shows a TLV of flexible optical node property, according to an embodiment of the present invention.

Figure 9 shows a sub-TLV of variable bandwidth transponder information, according to an embodiment of the present invention.

Figure 10 shows a sub-TLV of variable bandwidth transponder status, according to an embodiment of the present invention.

Figure 11 shows an OSPF-TE announcement workflow, according to an embodiment of the present invention.

Figure 12 shows a generalized label request object, according to an embodiment of the present invention.

Figure 13 shows a sender TSPEC, included in the PATH sender descriptor, according to an embodiment of the present invention.

Figure 14 shows a flow SPEC, included in the RESV flow descriptor construct, according to an embodiment of the present invention.

Figure 15 shows a reserve workflow of RSVP-TE, according to an embodiment of the present invention.

Figure 16 shows a flexible optical network according to a preferred embodiment of the present invention.

Figure 17 and Figure 18 show the consumption of bandwidth in the case of fixed grid and flexible grid, respectively, according to an embodiment of the present invention.

Detailed description of various embodiments

The present invention proposes a novel control plane architecture that enables a new provision of resources and paths as well as optimization of the optical and dynamic spectrum in flexible optical networks.

The provision of resources and trajectories in EON networks means the reserve of resources "on demand" that allows the establishment of connections between different flexible optical nodes throughout the network. In this context, the invention provides all the elements of the control plane (flexible optical node controller, element 108, and control plane protocol extensions) that are needed to create these paths regardless of how they are performed or who performs them ( network management systems, network operators, directly client nodes ...).

The optimization of the optical spectrum is to adapt the use of the optical spectrum to the needs or requirements of the operator (maximize the total network capacity, minimize the most expensive links, ...). The spectrum optimization is implemented by the optical spectrum manager (item 104) and will be performed by measuring the current network demand (traffic monitoring system, item 106, and which is outside the scope of the invention) and with respect to the network demands requested by customers (it is not defined how to gather this data, it can be by storing resource requests or by consulting IP layer NMS or by other means).

These new features added by this invention are in the context of the proposed new architecture that allows the network operator to achieve efficient use of network resources, obtaining all the benefits of flexible optical networks. The invention assumes the flexible optical network data plane architectures, as shown in Figure 1, which can be based on photonic components such as those described in US patents US 2010/023925 or US 2009/0226173.

The procedure for the provision of resources and trajectories follows the procedures for the provision of the transport network standardized in GMPLS RFCs for reservation and provision of resources. There is no need to change these procedures since the procedures that are defined fit perfectly to the EON networks.

As the optical spectrum manager is one of the main points of the invention, the procedure that allows the optimization of the optical spectrum is defined and explained below:

The optical spectrum optimization process basically consists of three stages:

1. Measurement

The optimization will use traffic measurements to best adjust the spectrum assigned to the necessary one. This stage is performed periodically by measuring the traffic generated by the client nodes of the optical network (for example, IP routers). The measurements generated from average traffic will have to be sent to a new element called “optical spectrum manager” that will process them. The network traffic information will be obtained from the monitoring tool (item 106). The control plane will provide the utilization information of the optical network spectrum to the optical spectrum manager.

2. Measurement processing

The optical spectrum manager interprets the traffic measurements and correlates them by observing whether the use of the current network optical spectrum is optimal for meeting traffic demands. The OSM takes into account both the end-to-end path and each optimal channel spectrum allocation to meet the demands of the client nodes and optimizes the full consumption of the network optical spectrum.

If the OSM through optical network resource optimization algorithms understands that the current optical spectrum is not optimal, it will activate the network reconfiguration to optimize it. These algorithms will have all the necessary information to work provided by the EON network control plane (current transmitter and receiver configurations, free and busy spectrum, modulations).

3. Network reconfiguration

Stage 2 resulted in different paths with different spectrum utilization in the optical network, so that, acting accordingly, the OSM will reconfigure the BVTs of client nodes (which are supposed to have variable bandwidth transponders available) with the desired parameters increasing the optical spectral efficiency.

The described procedure can be triggered due to different reasons such as changes in the traffic demand matrix, network failures and the inclusion of new network equipment.

As shown in Figure 3, the proposed invention defines the following control plane modules, protocols and interfaces:

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Control plane extensions for flexible optical networks: new signaling and routing protocols adapted to the optical spectrum for flexible optical networks.

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 A control module called "optical spectrum manager" (element 104): this module is responsible for calculating both the path and the optical spectrum resources required by each optical channel on an EON.

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Communication interfaces between the “optical spectrum manager” and the following network elements:

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Network traffic monitoring system (item 106): The optical spectrum manager will initiate the network reconfiguration processes according to the information provided by the traffic monitoring tools. Traffic monitoring tools are beyond the scope of this invention.

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Variable bandwidth transponder (BVT) (item 102): The optical spectrum manager will configure the BVT optical transmission parameters according to the optimization criteria of the optical spectrum. BVTs are outside the scope of this invention.

• Flexible optical node controller

The flexible optical node controller (EONC) (item 108) handles communication with the optical spectrum manager (item 104) and with other EONC. For communication between these elements, interface 105 is defined.

Each optical network node will have to include an EONC in order to work with the EON. The EONC will communicate in two ways with the network equipment:

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Externally (105): The EONC will communicate with the OSM and other EONC on other optical nodes.

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Internally (109): the EONC will communicate with the BVTs to configure them as desired,

The internal communication is responsible for the configuration and information gathering of data plane equipment in the node. In particular, to configure the BVTs in the desired way (tune the wavelength, select the number of subcarriers, ...) and adapt to the current configuration states and maximum capacities of each existing BVT in the node. Internal communication is also responsible for the BVXC switching configuration (what data has to be sent by what port, if the node is the end of the path it will have to send the data to the client ...).

External communication is responsible for exchanging control plane information between nodes and the OSM. The exchange of resource reservation information will be done through RSVP-TE extensions and internal node information messages using OSPF-TE extensions.

The workflow that explains the intervention of EONC is as follows:

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Each EONC reports on the status of its BVTs to the OSM and other EONC (OSPF-TE). (External through 105)

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 The OSM correlates the information of each EONC and decides whether a spectrum optimization should be performed.

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In case of optimization of the spectrum, the OSM will send RSVP-TE messages to the EONC to effectively reserve the spectrum. (External through 105) -When an RSVP-TE message reaches an EONC, it will configure, as indicated by the RSVP-TE message, its BVT. (Internal through 109).

As explained throughout the document, extensions of the control plane protocols must be made to support the new EON technologies. OSPF-TE extensions are related to the capabilities and configuration information present in the EON nodes.

The extensions allow exchange of reachability information as well as specific TE information. The traffic engineering information needed for an EON is:

Node Level:

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Specific link capabilities (interface switching capability descriptor).

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 Total frequency band available (frequency band available).

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Free frequency bands defined. Bandwidth and central wavelength. (Wavelength band not reserved).

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Inform in the LSA that an EON node is present (TLV owned by

flexible optical node) Interface level:

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Information on specific BVT capabilities such as adjustable wavelength, number of subcarriers, ... (sub-TLV of variable bandwidth transponder information).

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BVT utilization status (sub-TLV of variable bandwidth transponder status).

Interface switching capacity descriptor

First, the interface switching capability descriptor sub-TLV (190) [rfc4203] already defined, as shown in Figure 5, must be reused to inform about specific EON link capabilities:

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Type of sub-TLV (191): 15

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 Length (192): Variable

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 Switching capacity (193): 500

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Specific switching capacity information (194): variable length field that informs about the variable transmission rate capabilities.

Frequency band available

Total frequency bands available. It is defined by a MIN_WAVELENGTH and a MAX_WAVELENGTH. Note that, due to the flexible approach, no predefined channels are defined.

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MIN_WAVELENGTH is the minimum wavelength that can be used, measured in nm.

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MAX_WAVELENGTH is the maximum wavelength that can be used, measured in nm.

In order to reflect this information in OSPF extensions, the new sub-TLV (202), available frequency band, as shown in Figure 6, has been defined as follows:

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Type of sub-TLV (203): 27

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 Length (204): 12 octets

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Minimum wavelength (205): 4 octets using the IEEE floating point format with the minimum wavelength in nanometers.

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Maximum wavelength (206): 4 octets using the IEEE floating point format with the maximum wavelength in nanometers.

Wavelength band not reserved

It is defined by CENTRAL_WAVELENGTH and USED_SPECTRUM. Wavelength bands are created dynamically. Note that the CENTRAL_WAVELENGTH minus half of the USED_SPECTRUM must be greater than the MIN_WAVELENGTH of the available frequency band field.

In order to reflect the unreserved wavelength bands in the OSPF extensions, the new sub-TLV (207), unreserved wavelength band, as shown in Figure 7, has been defined from the Following way:

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Type of sub-TLV (208): 28

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 Length (209): 12 octets

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Central wavelength (210): 4 octets using the IEEE floating point format with the central wavelength.

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Spectrum used: 4 octets using the IEEE floating point format with the spectrum width used in nanometers.

It should be noted that unreserved wavelength band sub-TLVs can be associated with the same TLV due to the granularity of EON interfaces.

TLV owned by flexible optical node

EON nodes have special properties that also suggest OSPF extensions to send and gather the information required for correct network behavior.

Each EON node has different BVTs with particular information. All BVT information must be sent through the network reflected in the OSPF extensions as the flexible optical node property TLV.

Document [RFC 3630] defines the OSPF TE LSA using an opaque LSA. This proposal adds a new higher level TLV for use in the OSPF TE LSA: TLV (221) owned by flexible optical node, as shown in Figure 8.

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TLV Type (222): 4, refers to the new type of EON TLV.

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 Length (223): Variable

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SubTLV (224): Multiple associated sub-TLVs that reflect any existing BVT present in the node.

Variable bandwidth transponder information subTLV

There are two types of information related to BVT, on the one hand the basic information that is invariable and remains constant in the life of each BVT. On the other hand, the current status information will reflect how the BVT is using the spectrum. This information will be found in the following sub-TLVs.

Sub-TLV (231) of variable bandwidth transponder information presents the basic BVT information listed below:

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Subcarrier modulation format: The subcarrier modulations available that are suitable to use.

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Maximum number of subcarriers: The maximum subcarriers that the BVT can use.

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Bandwidth per subcarrier: The relationship between modulation and the bandwidth occupied by each subcarrier.

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Allowed center wavelengths: The range of wavelengths in which the BVT can tune its laser.

The definition of the corresponding sub-TLV, as shown in Figure 9, is as follows:

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Type of sub-TLV (232): 41, refers to the sub-TLV of EON BVT information.

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 Length (233): 24 octets.

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Subcarrier modulation format (234): 4 octets, IEEE floating point format number with available subcarrier modulations that are suitable for use. For its definition in the future:

1- QPSK 2- BPSK 3- DQPSK 4- 8QAM 5- 16QAM 6- 64QAM

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Maximum number of subcarriers (235): 4 octets, IEEE floating point format number with the maximum subcarriers that the BVT can use.

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Bandwidth per subcarrier (236): 4 octets, IEEE floating point format number with the relationship between modulation and bandwidth occupied by each subcarrier.

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First allowed wavelength (237): 4 octets, IEEE floating point format number with the first wavelength at which the BVT can tune its laser to nanometers.

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Last allowed wavelength (237): 4 octets, IEEE floating point format number with the last wavelength at which the BVT can tune its laser to nanometers.

All fields must be present to fully define a BVT.

Variable Bandwidth Transponder Status SubTLV

The current status information of BVT is composed of the following properties:

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BVT Status: The status of the transponder. The following are defined: busy / free / unavailable.

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Current spectrum utilization: Current spectrum width used.

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 Current central wavelength used: Current central wavelength used.

The sub-TLV (241) of variable bandwidth transponder status is the extension to include the particularities of BVT status, as shown in Figure 10. It is defined as follows:

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Type of sub-TLV (242): 42, refers to the sub-TLV of BVT status of EON.

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 Length (243): 20 octets.

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 Status (244): 4 octets, using the IEEE floating point format number with the BVT status which can be:

1- Busy

2- Free

3- Not available

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Current spectrum utilization (245): 4 octets, using the format number

of floating point of IEEE with the width of use of the spectrum in nanometers. 0 nm in the case of free state.

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 Current center wavelength (246): 4 octets, using the IEEE floating point format number with the current central wavelength in nanometers. 0 nm in the case of free state.

GMPLS RSVP-TE enhancements to support flexible optical networks will be described below. The extensions allow the reservation of trajectories in an EON that includes specific information relevant to both the source and the destination, such as information on the number of carriers and the modulation format, and relevant information for all nodes in the path, such as the frequency band that must be reserved for the path.

With respect to the path reservation problem, the BVT configuration parameters must be sent to the path endpoints to configure them in the correct way to get the OSM suggestions to obtain the optimal network behavior.

The GMPLS RSVP-TE trajectory reservation mechanism [RFC 3473] consists of two messages that are the PATH message and the RESV message. The PATH message is sent by the source node where the LSP wishes to start and ends at the destination node where the LSP must end. If there is no resource / node problem, the destination node sends a RESV message to the source node confirming

the resources to be reserved and the path selected to direct the LSP from end to end. The parameters that have to be included to allow the reservation of EON resources are listed below: 5 - The number of subcarriers to be used.

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 The subcarrier modulation to be used.

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 The central wavelength to be used in nanometers.

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 The bandwidth of LSP in bytes per second.

To reflect this in GMPLS RSVP-TE, this information must be included in both PATH and RESV messages in the following fields and objects.

MESSAGE

MANDATORY OBJECTS OPTIONAL OBJECTS

PATH

SESSION, RSVP_HOP, TIME_VALUES, LABEL REQUEST, sender descriptor INTEGRITY, EXPLICIT_ROUTE, MESSAGE_ID_ACK / NACK, MESSAGE_ID, PROTECTION, LABEL_SET, SESSION_ATTRIBUTE, NOTIFY_REQUEST, ADMIN_STATUS, POLICY_DATA

RESV

SESSION, RSVP_HOP, TIME_VALUES, STYLE, flow descriptor INTEGRITY, EXPLICIT_ROUTE, MESSAGE_ID_ACK / NACK, MESSAGE_ID, RESV_CONFIRM, SCOPE, NOTIFY_REQUEST, ADMIN_STATUS, POLICY_DATA

CONSTRUCTS

MANDATORY OBJECTS OPTIONAL OBJECTS

sender descriptor

SENDER_TEMPLATE, SENDER_TSPEC ADSPEC, RECORD_ROUTE, SUGGESTED_LABEL, RECOVERY_LABEL

flow descriptor RFC (3209)

FLOW_SPEC, FILTER_SPEC, LABEL RECORD_ROUTE

Generalized label request object

The generalized label request object [RFC 3473 and 3471] must be included in the path message and its purpose is to indicate the characteristics required for the network to support the requested LSP.

The generalized label request object (301) is the GMPLS extension of the RSVP-TE label request object. Your information, as shown in Figure 12, is contained in the following fields:

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 Length (302): 2 octets. The object length is 8 octets.

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Class number (303): 1 octet. The object class identifier that allows the protocol to identify these tag request objects. It should be set to 19.

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Type c (304): 1 octet. The object identifier that informs about the type of label request object. As it is the object of generalized label request should be set to 4.

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Type of LSP coding (305): 1 octet. Indicates the coding of the requested LSP. This field must refer to the type of EON LSP switching. The extension defines 18 as the flexible switching type value.

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Switching type (306): 1 octet. The switching to be performed on a particular link. The extension defines 300 as the flexible switching capacity (ESC) value.

-G-PID (307): 2 octets. An identifier of the payload carried by an LSP (the client layer of that LSP). The extension defines 100 as the fiber spectrum value with EON technology.

The generalized label request object extension indicates the EON path switching capability necessary to allow an EON end-to-end reservation. To get the reservation, the specific BVT configuration must be carried in both PATH and RESV messages to confirm and configure the desired BVTs to create the requested LSP.

The RSVP-TE includes this information in the sender descriptor construct of the PATH message and the RESV message does so in the flow descriptor construct. Specifically, the information is carried in the sender TSPEC and flow SPEC objects.

The extension required by the invention consists in defining two particular emitter TSPEC and flow SPEC objects that include the information necessary to establish a flexible LSP.

Issuer TSPEC

The sender TSPEC object (311), included in the PATH sender descriptor will include the following fields with the information to support EON resource reservation, as shown in Figure 13:

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 Length (312): 2 octets. The object length is 20 octets.

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Class number (313): 1 octet. The object class identifier that allows the protocol to identify these sender TSPEC objects. It must be set to 12 [RFC 2205].

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Type C (314): 1 octet. The object identifier that informs about the type of sender TSPEC. This invention defines this field value at 10 to identify it as an EON emitter TSPEC.

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Number of subcarrier (315): 4 octets. The number of subcarriers to be used in the LSP reserve.

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 Subcarrier modulation (316): 4 octets. The modulation selected by each subcarrier.

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Central wavelength (317): 4 octets. The central wavelength to be used.

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Bandwidth (318): 4 octets. The LSP bandwidth in bytes per second using the IEEE floating point format.

Flow specification

The flow specification object (321) that is included in the RESV flow descriptor construct will include the following fields to support the EON resource reservation, as shown in Figure 14:

-

 Length (322): 2 octets. The object length is 20 octets.

-

Class number (323): 1 octet. The object class identifier that allows the protocol to identify these flow SPEC objects. It must be set to 9 [RFC 2205].

-

Type C (324): 1 octet. The object identifier that informs about the type of flow TSPEC. This invention defines this field value at 10 to identify it as EON flow SPEC.

-

Number of subcarriers (325): 4 octets. The number of subcarriers that should be used in the LSP reserve.

-

 Subcarrier modulation (326): 4 octets. The modulation selected by each subcarrier.

-

Central wavelength (327): 4 octets. The central wavelength to be used.

-

Bandwidth (328): 4 octets. The LSP bandwidth in bytes per second using the IEEE floating point format.

This extension forces OSM spectrum utilization messages and RSVP PATH messages to include explicit path objects (EROs) that reserve the path ordered by the OSM. It means that both OSM requests and PATH RSVP messages must include the ERO with the specific associated LABEL object. These LABEL objects must be WAVEBAND SWITCHING objects as defined in RFC documents 3473 and 3471.

• Optical spectrum manager

The optical spectrum manager (104) is a new element that will play an important role in this workflow of section 2 of the document (spectrum optimization process). The OSM will receive and process OSPF-TE messages that include the configuration of current network elements and resource allocation. Going deeper into the messages, correlating resource information and through optimization algorithms that are outside the scope of this invention, the OSM will issue a response in the following terms:

-

If spectrum optimization should be performed, then the OSM will initiate an optimization process based on reallocating current resource reserves. This new reservation will be communicated to the EON nodes by means of the RSVP-TE protocol through the BVXC interface (105).

-

If optimization is not needed, then the OSM will continue measuring the network.

The location of OSM is not defined in this invention, it can be located in certain network nodes or it can be centralized in a single element such as the ITEF standardized path calculation element.

• Case of use This section describes a possible use case of the proposed invention:

Adaptation to multiple data transmission rates.

The use case of adaptation to multiple data rates focuses on the use of the optical spectrum efficiently. The current WSON fixed grid networks are not as effective as they could be because they use an inflexible grid. In contrast, EON networks can adjust the grid used to the required bandwidth in order to achieve higher spectral efficiencies.

Figure 16 represents a network in which the optical layer (SW x nodes) carries the data between all network routers (R x nodes). To compare the current WSON against EON networks, we will assume the following traffic demands:

-

 100 Gbs from R1 to R3.

-

 50 Gbs of R2 to R3.

-

 100 Gbs from R1 to R4.

-

Variable data transmission rate (20 - 40 Gbs) from R2 to R5.

SW1 will add all the traffic from R1 and R2 to drive it through the topology. Current WSON networks will need to use the full example spectral grid to service all demands due to their fixed granularity (10, 40 or 100 Gbs per lambda) even if it is used completely or not.

In the case of an EON network, the optical spectrum manager will optimize the use of the spectrum by consulting ITMS to obtain the current optical network status. This information will allow the OSM to make a decision to configure the network efficiently by means of wavelength and wavelength techniques. The techniques of adaptation of both sub and wavelengths adapt the bandwidth reserved to that really necessary, obtaining a higher spectral efficiency.

In the use case network, the use of the spectrum suggested by OSM for node SW1 can be as shown in Figure 17. Figure 18 shows obtaining a higher spectral efficiency thanks to the adequacy of the data of a Flexible spectrum allocation in EON networks.

Once the decision has been made, the OSM will have to configure the variable bandwidth interconnections using the standardized interface (IBVXC) indicating the necessary parameters to achieve the desired spectrum, then the BVXC through the standardized interface (IBVT ) will perform the configuration. These parameters are listed below:

-

 The main subcarrier wavelength.

-

 Number of subcarriers.

-

 Subcarrier Modulation

As a result of this entire process, additional free spectrum is obtained that will be used with different objectives such as postponing investments in network equipment or increasing availability using these additional resources to restore failures.

One skilled in the art can make changes and modifications to the described embodiments without departing from the scope of the invention as defined in the appended claims.

ACRONYM

ASE

Amplified Spontaneous Emissions; amplified spontaneous emissions

BVT

Bandwidth Variable Transponder; bandwidth transponder

variable

BVXC

Bandwidth Variable Cross Connect; bandwidth interconnection

variable

CSNRZ

Carrier-Suppressed NonReturn-to-Zero; carrier suppressed without return

to zero

DPSK

Differential Phase Shift Keying; phase shift modulation

differential

EON

Elastic Optical Network; flexible optical network

EONC

Elastic Optical Node Controller; flexible optical node controller

ERO

Explicit Route Object; explicit route object

GMPLS

Generalized Multiprotocol Label Switching; tag switching

generalized multiprotocol

IP

Internet Protocol; internet protocol

LSA

Link Status Advertisement; link status ad

LSP

Label Switched Path; tag-switched path

MPLS

Multi Protocol Label Switching; multi-protocol tag switching

NMS

Network Management System; network management system

OEO

Optical-Electrical-Optical; optical electric optical

OFDM

Orthogonal Frequency Division Multiplexing; division multiplexing

orthogonal frequency

OSM

Optical Spectrum Manager; optical spectrum manager

OSNR

Optical Signal to Noise Ratio; signal to optical noise ratio

OSPF

Open Shortest Path First; open the shortest path first

OTN

Optical Transport Network; optical transport network

RFC

Request For Comments; Request for comments

ROADM

Reconfigurable Optical Add Drop Multiplexer; optical multiplexer of

reconfigurable extraction insert

RSVP

Resource Reservation Protocol; resource reservation protocol

RWA

Routing and Wavelenght Assignment; wavelength assignment and

routing

SPEC

Specification; specification

TEA

Traffic Engineering; traffic engineering

TSPEC

Traffic Specification; traffic specification

TLV

Type Length Value; length value type

Wxc

Wavelenght Cross Connect; wavelength interconnection

WSON

Wavelenght  Switched Optical Network;  net optic switched by

wavelength

BIBLIOGRAPHY

[1] M. Jinno; H. Takara; B. Kozicki, Y. Tsukishima, Y. Sone, S. Matsuoka, “Spectrum-efficient and scalable elastic optical path network: architecture, benefits, and enabling technologies”, IEEE Communications Magazine, volume: 47 Issue 11, pages 66 - 73 November 2009

[2] E. Mannie "Generalized Multi-Protocol Label Switching (GMPLS) Architecture, RFC 3945", October 2004

[3] IETF Internet Engineering Task Force www.ietf.org

[4] D. Papadimitriu. “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control, RFC 4328”, January 2006

[5] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS and PCE Control of Wavelenght Switched Optical Networks (WSON) draft-ietf-ccamp-rwa-wsonmarco-06.txt", April 2010

Claims (18)

1. System for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, said spectrum assignment comprising a provision of resources and paths and further comprising spectrum optimization, characterized in that said optical network is a flexible optical network comprising a plurality of flexible optical nodes and because it comprises:

-

at least one flexible optical node controller in each of said flexible optical nodes for said provision of resources and paths, said provision of resources and paths comprising at least the reservation of resources and the establishment of a connection link between at least part of said plurality of flexible optical nodes;

-

protocol extensions for said control plane in order to make at least said provision of resources and paths; Y

-

an optical spectrum manager that provides said spectrum optimization, connected to said plurality of flexible optical nodes, which comprises adapting the use of the spectrum according to traffic measurements carried out by means of a monitoring tool in said flexible optical network.

2. System according to claim 1, wherein said optical spectrum manager is responsible for:

-

retrieve information from said traffic measurements using said control plane;

-

 process said traffic measurements;

-

check whether the use of the current optical spectrum is adequate to meet traffic demands, according to said processing; Y

-

reconfiguring a variable bandwidth transponder, or BVT, placed in each of said plurality of flexible optical nodes of said flexible optical network according to said check.

3.

System according to claim 2, wherein it comprises an external interface through which said flexible optical node controller communicates with said optical spectrum manager and other flexible optical node controllers and an internal interface that provides communication with said BVT and / or interconnection of variable bandwidth, or BVXC.

Four.

System according to claim 3, wherein the communication through said external interface is carried out by means of engineering extensions of

resource reservation protocol traffic, or RSVP-TE extensions, for at least said provision of resources and paths and / or through traffic engineering extensions to first open the shortest path, or OSPF-TE extensions, for at least the exchange of internal messages between said optical nodes.

5.

System according to claim 4, wherein the fields of the interface switching capability descriptor sub-TLV of said OSPF-TE extensions are filled in as follows:

-type of sub-TLV: 15;

-

 length: variable;

-

 switching capacity: 500; and

-specific information - switching capacity: variable, according to the transmission rate capabilities.

6.

System according to claim 5, wherein the frequency band available in at least part of said optical network is expressed by a sub-TLV of available frequency band of said OSPF-TE extensions and the fields and values of said sub- Available frequency band TLVs are defined as follows:

-type of sub-TLV: 27; - length: 12 octets;

-

minimum wavelength: 4 octets using the IEEE floating point format with the minimum wavelength in nanometers; Y

-

maximum wavelength: 4 octets using the IEEE floating point format with the maximum wavelength in nanometers.

7.

System according to claim 6, wherein the unreserved wavelength bands are expressed by a sub-TLV of unreserved wavelength band of said OSPF-TE extensions and the fields and values of said sub-TLV of Unreserved wavelength band are defined as follows:

-type of sub-TLV: 28; - length: 12 octets; - central wavelength: 4 octets using the IEEE floating point format with the central wavelength in nanometers; and -spectrum used: 4 octets using the IEEE floating point format with the spectrum used in nanometers.

8.

System according to claim 7, wherein the special properties of said flexible optical node controller are expressed by a flexible optical node property TLV of said OSPF-TE extensions, said special properties comprising BVT information to be sent to through said optical network and the fields and values of said flexible optical node property TLV are defined as follows:

-

 TLV type: 4;

-

 length: variable; Y

-sub-TLV: multiple associated sub-TLVs that reflect the BVTs present in said plurality of optical nodes.

9.

System according to claim 8, wherein the spectrum information that a given BVT is using is expressed by a sub-TLV of variable bandwidth transponder information of said OSPF-TE extensions, said information sub-TLV containing of variable bandwidth transponder at least the following information: available subcarrier modulations suitable for use by said given BVT, maximum subcarriers that said given BVT can use, ratio between modulation and bandwidth occupied by each subcarrier and length range waveform in which said given BVT can tune its laser.

10.

System according to claim 9, wherein the fields and values of said sub-TLV of variable bandwidth transponder information are defined as follows:

-type of sub-TLV: 41; - length: 24 octets; - Subcarrier modulation format: 4 octets using the IEEE floating point format number; -maximum number of subcarriers: 4 octets using the IEEE floating point format number; - bandwidth per subcarrier: 4 octets using the IEEE floating point format number; - first allowed wavelength: 4 octets using the IEEE floating point format number with the first wavelength at which said given BVT can tune its laser to nanometers; Y - Last wavelength allowed: 4 octets using the IEEE floating point format number with the last wavelength at which said given BVT can tune its laser into nanometers.

eleven.

System according to claim 10, wherein the current status information of BVT is expressed by a variable bandwidth transponder sub-TLV of said OSPF-TE extensions and the fields and values of said sub-TLV of Variable bandwidth transponder status are defined as follows:

-type of sub-TLV: 42; - length: 20 octets; -state: 4 octets using the IEEE floating point format number indicating the status of a BVT, expressing said status if said BVT is busy, free or unavailable; - use of the current spectrum: 4 octets using the IEEE floating point format number that indicates the spectrum utilization width in nanometers; Y - Current central wavelength: 4 octets using the IEEE floating point format number with the current central wavelength in nanometers.

12.

System according to claim 11, wherein a resource node of said plurality of optical nodes and a destination node of said plurality of optical nodes are adapted to perform a generalized multiprotocol label switching, or GMPLS, a path reserve mechanism of RSVP-TE, said RSVP-TE path reservation mechanism comprising sending, said resource node, a path message to said destination node and sending, said destination node, a reservation message to said source node, making said path message and said reservation message using said RSVP-TE extensions and said source node and said destination node being a tag-switched path, or LSP.

13.

System according to claim 12, wherein the characteristics required for said optical network to support said LSP are expressed by means of a generalized label request object of said RSVP-TE extensions, said generalized label request object included in said message. of trajectory and the fields and values of said request object of

Generalized label, according to the label request objects defined in RSVP-TE, are defined as follows:

-

 Length: 2 octets;

-

 class: 1 octet, set to 19;

-

type c: 1 octet, set to 4;

-

LSP coding type: 1 octet, set to 18;

-

switching type: 1 octet, set to 300; Y

-G-PID: 2 octets, set to 100. 14. System according to claim 13, wherein said path message is included in a sender traffic specification object, or sender TSPEC, of said RSVP-TE extensions, the field of said sender TSPEC object being filled as follows:

-

 Length: 2 octets;

-

 class number: 1 octet, set to 12;

-

type c: 1 octet, set to 10;

-

number of subcarriers: 4 octets indicating the number of subcarriers to be used in said path reservation;

-

subcarrier modulation: 4 octets indicating the modulation selected by each subcarrier;

-

 center wavelength: 4 octets; Y

-

bandwidth: 4 octets using the IEEE floating point format number that indicates the bandwidth of said LSP in bytes per second.

15. System according to claim 14, wherein said reservation message is included in a flow specification object, or flow SPEC, of said RSVP-TE extensions, the field of said flow SPEC object being filled in with the Following way:

-

 Length: 2 octets;

-

 class number: 1 octet, set to 9;

-

type c: 1 octet, set to 10;

-

number of subcarriers: 4 octets indicating the number of subcarriers to be used in said path reservation;

-

subcarrier modulation: 4 octets indicating the modulation selected by each subcarrier;

-

 center wavelength: 4 octets; and - bandwidth: 4 octets using the IEEE floating point format number that indicates the bandwidth of said LSP in bytes per second.

16.

System according to claim 15, wherein said RSVP-TE extensions sent from said optical spectrum manager to said flexible optical node controller and / or to said other flexible optical node controllers and said path message include explicit route objects with an associated specific tag object, said associated specific tag object being a frequency band switching object as defined in document Request for Comments 3473 and 3471.

17.

Method for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, said spectrum allocation comprising a provision of resources and paths and further comprising spectrum optimization, characterized in that said optical network is an optical network flexible comprising a plurality of flexible optical nodes with at least one flexible optical node controller in each of said flexible optical nodes responsible for making said provision of resources and paths, and a variable bandwidth transponder, or BVT, placed in each of said plurality of optical nodes, and an optical spectrum manager that provides said spectrum optimization, said optical spectrum manager being connected to said plurality of flexible optical nodes, said method comprising the following steps:

-

informing, said flexible optical node controller, about the status of said BVT to said optical spectrum manager and / or to different flexible optical node controllers through an external interface and OSPF-TE extensions;

-

correlating, said optical spectrum manager, information received from said flexible optical node controller and / or from other flexible optical node controllers;

-

 deciding, said optical spectrum manager, to perform a spectrum optimization according to said correlation; - sending, said optical spectrum manager, RSVP-TE extensions to said flexible optical node controller and / or to said other flexible optical node controllers if said spectrum optimization must be performed, according to said decision; and -configuring, said flexible optical node controller and / or said other flexible optical node controllers, said BVT according to the reception of said RSVP-TE extensions.

SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201131579 SPAIN Date of submission of the application: 30.09.2011 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: H04J14 / 02 (2006.01) RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

X

RAÚL MUÑOZ et al .: "Dynamic Distributed Spectrum Allocation in GMPLS controlled Elastic Optical Networks", September 18, 2011 (09/18/2011), XP055048021, Entire document; Returned from the Internet: URL: // http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6066001&tag=1 1-17

X

XIN WAN et al .: "Dynamic routing and spectrum assignment inflexible optical path networks", OPTICAL FIBERCOMMUNICATION CONFERENCE, 2011. TECHNICAL DIGEST.OFC / NFOEC, IEEE, March 6, 2011 (06.03.2011), pages 1-3, the whole document ); XP031946099, ISBN: 978-1-4577-0213-6 URL: // http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5875148 1-3.17

Y

4

TO

5-16

X

KOZICKI B et al .: "Enabling technologies for adaptive source allocation in elastic optical path network (SLICE)", COMMUNICATIONS AND PHOTONICS CONFERENCE AND EXHIBITION (ACP), 2010 ASIA, IEEE, PISCATAWAY, NJ, USA, December 8, 2010 (08.12. 2010), pages 23-24; XP031845403, ISBN: 978-1-4244-7111-9 URL: // http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5682852 1-3.17

TO

4-16

Y

SONE Y et al .: "Highly survivable restoration scheme employing optical bandwidth squeezing in spectrum-sliced elastic optical path (SLICE) network", OPTICAL FIBERCOMMUNICATION -INCUDES POST DEADLINE PAPERS, 2009. OFC2009. CONFERENCE ON, IEEE, PISCATAWAY, NJ, USA, March 22, 2009 (2009-09-22), pages 1-3, XP031467830, ISBN: 978-1-4244-2606-5 URL: // http://ieeexplore.ieee. org / xpls / abs_all.jsp? arnumber = 5032701 4

TO

CHRISTODOULOPOULOS K et al .: "Elastic Bandwidth Allocation in Flexible OFDM-Based Optical Networks", Article by LIGHTWAVE TECHNOLOGY, IEEE SERVICE CENTER, NEW YORK, NY, US, vol. 29, no. 9, 1 May 2011 (01.05.2011), pages 1354-1366, XP011353989, ISSN: 0733-8724, DOI: 10.1109 / JLT.2011.2125777; URL: // http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5727897 1-16

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 07.10.2013

Examiner B. Pérez García Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE Application number: 201131579 Minimum documentation sought (classification system followed by classification symbols) H04B, H04J Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC, WPI, INSPEC State of the Art Report Page 2/5  WRITTEN OPINION Application number: 201131579 Date of Completion of Written Opinion: 07.10.2013 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-17 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-17 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/5  WRITTEN OPINION Application number: 201131579 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

RAÚL MUÑOZ et al .: "Dynamic Distributed Spectrum Allocation in GMPLS controlled Elastic Optical Networks". 09-18-2011

D02

XIN WAN et al .: "Dynamic routing and spectrum assignment inflexible optical path networks". 06.03.2011

D03

KOZICKI B et al .: "Enabling technologies for adaptive source allocation in elastic optical path network (SLICE)". 12/08/2010

D04

SONE Y et al .: "Highly survivable restoration scheme employing optical bandwidth squeezing in spectrum-sliced elastic optical path (SLICE) network”. 03/22/2009

D05

CHRISTODOULOPOULOS K et al .: "Elastic Bandwidth Allocation in Flexible OFDM-Based Optical Networks". 05.01.2011

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement D01 is the document found in the state of the art closest to the object of the invention. Following the wording of the first claim, D01 describes a system for performing spectrum allocation in an optical network, said spectrum allocation being performed according to a control plane, said spectrum allocation comprising a provision of resources (spectrum resources) and trajectories ( path computation) and which also includes spectrum optimization (performing efficient spectrum allocation), characterized in that said optical network is a flexible optical network (GMPLS-controlled Elastic Optical Network) comprising a plurality of flexible optical nodes and because it comprises: -al less a flexible optical node controller (stateless PCE) in each of said flexible optical nodes for the provision of resources and paths, said provision of resources and paths comprising at least the reservation of resources and the establishment of a connection link between the less part of said plurality of flexible optical nodes (stateless PCE maintains its own network status information, eg spectrum topology and resources, collected in a local repository, the TDE database); - protocol extensions (OSPF-TE) for said control plane in order to make at least said provision of resources and trajectories; There is a difference between D01 and the first claim. The first claim indicates the existence of an optical spectrum manager that provides spectrum optimization according to traffic measurements carried out by means of a monitoring tool and which is connected to the flexible optical nodes. The technical effect that produces this difference is that in the first claim the allocation of the spectrum is done in the optical spectrum manager (since it has a centralized point), while in document D01, which focuses especially on a distributed architecture , is performed on the destination node. The objective technical problem is how to perform spectrum allocation optimally. However, the solution is contained in D01 itself (section 1) where two possible types of architecture are presented in flexible optical networks that allow dynamic spectrum allocation: a centralized architecture (using stateful PCE) and a distributed architecture (using stateless PCE ). The first claim actually details a mixture of both, since there is a flexible optical node controller in each node (it could be equivalent to a stateless PCE) and an optical spectrum manager (it could be equivalent to a stateful PCE). That is, a network architecture is created that mixes the two types of architectures disclosed in D01. For its part, D01 not having a centralized control point, performs the allocation of the spectrum at the destination, although if you incorporate a manager equivalent to a stateful PCE you could make the assignment in that manager. The mere combination of two known architectures is not considered to be an inventive effort for an expert in the field and therefore, this claim does not meet the requirement of inventive activity, according to Art. 8 of Law 11/1986. The second claim specifies the functions of the optical spectrum manager: retrieving information from said traffic measurements using said control plane; process said traffic measurements; check whether the use of the current optical spectrum is adequate to meet traffic demands according to said processing; and reconfiguring a variable bandwidth transponder, or BVT, placed in each of said plurality of flexible optical nodes of said flexible optical network according to said check. State of the Art Report Page 4/5  WRITTEN OPINION Application number: 201131579 In D01 it is described that “in a centralized routing control, a single entity (eg a network management system with a stateful PCE) maintains a complete, global and unique view of the network topology, availability of resources from the spectrum and physical matching parameters… ”It is known in the state of the art that a stateful PCE includes two BDs: TED (Traffic Engineering Database), which includes information on the topology and use of the network; and LSP (Label Switched Paths), which indicates the group of calculated paths and the resources used in the network. That is, this entity has of the management and control capacity to measure existing traffic and reconfigure traffic allocation. Without activity inventiveness. Claim number three specifies that the flexible optical node communicates with an external interface with the manager of optical spectrum and other flexible optical node controllers and with an interface with the bandwidth transponder BVT variable and / or variable bandwidth interconnection, or BVXC. D01 (section 2.1) specifies that a new connection capacity (the external one) is added to the standard interface (the internal one). It has no inventive activity. The fourth claim clarifies that communication through the external interface is carried out by means of extensions of traffic engineering of resource reservation protocol, or extensions of RSVP-TE, for at least said provision of resources and trajectories and / or through traffic engineering extensions to first open the shortest path, or OSPF-TE extensions, for at least the exchange of internal messages between said optical nodes. This is quoted verbatim in document D01 (GMPLS RSVP-TE and GMPLS OSPF-TE). It lacks inventive activity. Claims 5-11 add ways to fill in fields and define information of a sub-TLV in OSPF extensions. TEA. These are specific characteristics that determine possible ways of carrying out the invention, without contributing to the technical result of the same (section 2.2 of D01). They have no inventive activity. Claims 12-16 do the same for the RSVP-TE protocol, which, as in the previous case, also does not have inventive activity (see section 2.3 of D01). Claim 17 corresponds to the method that uses the system of the preceding claims to fulfill its function. Following the previous reasoning, and like the system, it does not present inventive activity. In summary, the application presented has no inventive activity for an expert in the field, according to Art. 8 of the Law Spanish Patent. State of the Art Report Page 5/5