The present disclosure relates to a method for managing a microwave network comprising a plurality of microwave nodes. The present disclosure also relates to a controller for managing a microwave network and to a computer program product configured, when run on a computer, to carry out a method for managing a microwave network.
The production, build and expansion of microwave links is a key part of the telecom industry. Current microwave nodes realise wireless point-to-point connections employing passive or active repeaters and providing connectivity up to 10 Gbit/s over up to tens of km. The IETF draft “A framework for Management and Control of microwave and millimeter wave interface parameters” draft-ietf-ccamp-microwave-framework-06 (Reference 1) indicates that the main application for microwave networks is providing backhaul for mobile broadband. Backhaul networks will continue to be modernised in the coming years using a combination of microwave and fiber technologies.
Current microwave networks are composed of links having a fixed geographical orientation. A link therefore connects the same two nodes for all of its working life. Fault tolerance for such links is achieved through redundant hardware, with associated costs for installation, power and maintenance. The fixed nature of microwave links imposes significant advance planning and resourcing to accommodate future connectivity requirements. A microwave link may for example be over resourced in an initial deployment to accommodate an expected evolution in traffic patterns. Even with such forward planning and resourcing, changes in network traffic may require adjustment of microwave links, requiring manual intervention at the individual microwave nodes. Manual intervention imposes time delays and increased costs for the microwave network to evolve with the connectivity requirements of the network traffic it is required to service.
It is an aim of the present invention to provide a method, apparatus and computer readable medium which at least partially address one or more of the challenges discussed above.
According to a first aspect of the present disclosure, there is provided a method for managing a microwave network comprising a plurality of microwave nodes, wherein a microwave node is associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal. A microwave path of at least some of the microwave nodes in the microwave network is reconfigurable. The method, performed at a domain controller of the microwave network, comprises exposing, on an interface of the domain controller, a link topology of the microwave network, wherein the link topology comprises, for a microwave node in the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
For the purposes of the present specification, a microwave path of a microwave node is reconfigurable if its geographical orientation may be adjusted by the microwave node during the operational life of the node, that is after the initial deployment phase during which the path of the node may be established according to a desired topology of the microwave network. A geographical orientation of a microwave path refers to the direction in which the path travels, represented for example by azimuth and elevation angles at an end point of the path, or by coordinates of the path's end points. Reconfiguration of a microwave path is thus distinguished from reconfiguration of a signal transmitted or received over the path, including for example a change in the bit-rate, the modulation format or the digital framing of a signal transmitted or received over the path. A path may be reconfigurable owing to actuators installed at an antenna of the node and operable to change the orientation of the antenna, and/or owing to beamforming techniques applied at the node.
According to examples of the present disclosure, a microwave node may be associated with a single path, which may be serviced by a single antenna or by a group of antennas operated together, for example operable to provide Multiple In Multiple Out (MIMO) functionality. Multiple nodes may therefore be co-located at the same geographical site, with different nodes associated with microwave paths connecting the site to a range of other sites in different locations, each path serviced by one or more antennas.
According to examples of the present disclosure, the domain controller which may perform the method may comprise an SDN controller such as a Provisioning Network Controller in an ACTN hierarchy.
According to examples of the present disclosure, the interface may comprise a northbound interface.
According to examples of the present disclosure, the parameter quantifying the extent to which the microwave path associated with a microwave node is reconfigurable may comprise at least one of a maximum azimuth for the path of the node, a minimum azimuth for the path of the node, a maximum elevation for the path of the node and/or a minimum elevation for the path of the node.
According to examples of the present disclosure, the link topology of the microwave network may further comprise, for a microwave node in the microwave network, a parameter quantifying the current microwave path of the microwave node.
According to examples of the present disclosure, the parameter quantifying the current microwave path of a microwave node may comprise at least one of current configured azimuth for the path of the node, current actual azimuth for the path of the node, current configured elevation for the path of the node and/or current actual elevation for the path of the node.
According to examples of the present disclosure, current configured azimuth and elevation may comprise values of azimuth and elevation that the microwave node is configured to apply, and current actual azimuth and elevation may comprise values of azimuth and elevation that are currently captured by the network for the microwave node.
According to examples of the present disclosure, current actual values may be captured by the network through measurement readings and/or reporting, and a difference between current configured and current actual values may arise owing to self-optimisation at the node or to error.
According to examples of the present disclosure, the link topology of the microwave network may further comprise, for a microwave node in the microwave network, a microwave link budget parameter.
According to examples of the present disclosure, the microwave link budget parameter may comprise at least one of a terrain factor and/or a climate factor.
According to examples of the present disclosure, the link topology of the microwave network may further comprise, for a microwave node in the microwave network, geographic coordinates for the microwave node.
According to examples of the present disclosure, the method may further comprise, for a microwave node in the microwave network, receiving from the microwave node the parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the method may further comprise, for a microwave link in the link topology of the microwave network, storing, as a backup microwave link in a data store, current configured values of azimuth and elevation for the microwave paths associated with the microwave nodes forming endpoints of the link.
According to examples of the present disclosure, the method may further comprise, for the backup microwave link, storing, in the data store, current actual values of azimuth and elevation for the microwave paths associated with the microwave nodes forming endpoints of the link.
According to examples of the present disclosure, the method may further comprise indexing, in the data store, the stored values of azimuth and elevation for the backup microwave link with an identifier comprising identifiers of the microwave nodes forming endpoints of the link.
According to examples of the present disclosure, the method may further comprise storing in the data store at least one of a date or a time at which the backup microwave link has been used in the microwave network.
According to examples of the present disclosure, the method may further comprise using the parameter quantifying, for a microwave node in the microwave network, the extent to which the microwave path associated with the microwave node is reconfigurable, to evaluate the feasibility of a potential new path between microwave nodes in the microwave network.
According to examples of the present disclosure, the method may further comprise using the parameter to evaluate the feasibility of a potential new path between microwave nodes in the microwave network in the event of a change in the link topology of the microwave network.
According to examples of the present disclosure, using the parameter quantifying, for a microwave node in the microwave network, the extent to which the microwave path associated with the microwave node is reconfigurable, to evaluate the feasibility of a potential new path between microwave nodes in the microwave network may comprises identifying a change in the link topology of the microwave network. Using the parameter may further comprise identifying a path between first and second microwave nodes in the microwave network, which path is impacted by the change in topology, the path comprising at least one microwave link, identifying a potential new path between the first and second microwave nodes, which path maintains connectivity between the first and second nodes in the changed link topology, and evaluating the feasibility of the potential new path on the basis of parameters quantifying the extent to which the microwave paths associated with the first and second microwave nodes are reconfigurable.
According to examples of the present disclosure, the method may further comprise, if the potential new path between the first and second microwave nodes is evaluated as feasible, instructing the first and second microwave nodes to reconfigure their associated microwave paths to form the potential new path.
According to examples of the present disclosure, instructing the first and second microwave nodes to reconfigure their associated microwave paths to form the potential new path may comprise configuring the first and second microwave nodes with azimuth and elevation values corresponding to microwave paths that will form the potential new path.
According to examples of the present disclosure, the method may further comprise checking the data store for backup microwave links having the first or second microwave nodes as endpoints, determining whether the potential new path can be formed from stored backup links, and, if the potential new path can be formed from stored backup links, identifying the stored backup links required to form the potential new path and instructing the first and second microwave nodes to reconfigure their associated microwave paths to match the microwave paths of the identified backup links.
According to examples of the present disclosure, the method may further comprise checking, for example, weather or traffic conditions at a date and/or time associated with the backup links in order to determine whether the backup links are appropriate for use in the current weather and/or traffic conditions.
According to examples of the present disclosure, the method may further comprise, if the potential new path cannot be formed from stored backup links, proceeding to evaluate the feasibility of the potential new path on the basis of parameters quantifying the extent to which the microwave paths associated with the first and second microwave nodes are reconfigurable.
According to examples of the present disclosure, identifying a change in the link topology of the microwave network may comprise identifying a microwave node in the microwave network that has become at least partially unavailable. According to examples of the present disclosure, identifying a path between first and second microwave nodes in the microwave network, which path is impacted by the change in topology, the path comprising at least one microwave link, may comprise identifying a path comprising a microwave link that terminates at the at least partially unavailable node. According to examples of the present disclosure, identifying a potential new path between the first and second microwave nodes, which path maintains connectivity between the first and second nodes in the changed link topology, may comprise identifying a path comprising a single microwave link between the first and second microwave nodes.
According to examples of the present disclosure, identifying a microwave node in the microwave network that has become at least partially unavailable may comprise identifying a microwave node in the microwave network that has become at least partially unavailable owing to at least one of a failure affecting the microwave node and/or a programmed downtime for the microwave node.
According to examples of the present disclosure, programmed downtime may include scheduled repairs or maintenance work, or scheduled downtime during periods of low traffic load, for example scheduled overnight downtime for energy saving.
According to examples of the present disclosure, identifying a change in the link topology of the microwave network may comprise identifying a microwave node in the microwave network that has become newly available. According to examples of the present disclosure, identifying a path between first and second microwave nodes in the microwave network, which path is impacted by the change in topology, the path comprising at least one microwave link, may comprise identifying a path the capacity of which may be increased by passing via the newly available node. According to examples of the present disclosure, identifying a potential new path between the first and second microwave nodes, which path maintains connectivity between the first and second nodes in the changed link topology, may comprise identifying a path comprising a microwave link that terminates at the newly available node.
According to examples of the present disclosure, identifying a microwave node in the microwave network that has become newly available may comprise identifying a microwave node in the microwave network that has become newly available owing to at least one of a new microwave node installation and/or a node becoming available after a failure or programmed downtime.
According to examples of the present disclosure, the method may further comprise determining a difference in capacity between the identified path and the potential new path, and engineering traffic on the potential new path to accommodate the difference in capacity. For example, if the potential new path has reduced capacity compared to the identified path, engineering traffic on the potential new path to accommodate the difference in capacity may comprise filtering traffic on the path according to a priority level of the traffic, so as to ensure that low priority traffic is dropped or diverted and high priority traffic is delivered over the potential new path.
According to another aspect of the present disclosure, there is provided a method for operating a microwave node in a microwave network, the microwave node being associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal. The method, performed at the microwave node, comprises reporting, to a domain controller of the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the parameter quantifying the extent to which the microwave path associated with a microwave node is reconfigurable may comprise at least one of a maximum azimuth for the path of the node, a minimum azimuth for the path of the node, a maximum elevation for the path of the node and/or a minimum elevation for the path of the node.
According to examples of the present disclosure, the method may further comprise reporting, to the domain controller of the microwave network, a parameter quantifying the current microwave path of the microwave node.
According to examples of the present disclosure, the parameter quantifying the current microwave path of a microwave node may comprise at least one of current configured azimuth for the path of the node, current actual azimuth for the path of the node, current configured elevation for the path of the node and/or current actual elevation for the path of the node.
According to examples of the present disclosure, current configured azimuth and elevation may comprise values of azimuth and elevation that the microwave node is configured to apply and current actual azimuth and elevation may comprise values of azimuth and elevation that are currently captured by the network for the microwave node.
According to another aspect of the present disclosure, there is provided a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out a method according to any one of the preceding aspects or examples of the present disclosure.
According to another aspect of the present disclosure, there is provided a carrier containing a computer program according to the preceding aspect of the present disclosure, wherein the carrier comprises one of an electronic signal, optical signal, radio signal or computer readable storage medium.
According to another aspect of the present disclosure, there is provided a computer program product comprising non transitory computer readable media having stored thereon a computer program according to a preceding aspect of the present disclosure.
According to another aspect of the present disclosure, there is provided a domain controller for managing a microwave network comprising a plurality of microwave nodes, wherein a microwave node is associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal, and wherein a microwave path of at least some of the microwave nodes in the microwave network is reconfigurable. The domain controller comprises a processor and a memory, the memory containing instructions executable by the processor such that the domain controller is operable to expose, on an interface of the domain controller, a link topology of the microwave network, wherein the link topology comprises, for a microwave node in the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the domain controller may be further operable to carry out a method according to any one of the preceding aspects or examples of the present disclosure.
According to another aspect of the present disclosure, there is provided a domain controller for managing a microwave network comprising a plurality of microwave nodes, wherein a microwave node is associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal, and wherein a microwave path of at least some of the microwave nodes in the microwave network is reconfigurable. The domain controller is adapted to expose, on an interface of the domain controller, a link topology of the microwave network, wherein the link topology comprises, for a microwave node in the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the domain controller may be further adapted to carry out a method according to any one of the preceding aspects or examples of the present disclosure.
According to another aspect of the present disclosure, there is provided a microwave node in a microwave network, the microwave node being associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal. The microwave node comprises a processor and a memory, the memory containing instructions executable by the processor such that the microwave node is operable to report, to a domain controller of the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the microwave node may be further operable to carry out a method according to any one of the preceding aspects or examples of the present disclosure.
According to another aspect of the present disclosure, there is provided a microwave node in a microwave network, the microwave node being associated with a physical microwave path over which the microwave node is operable to transmit or receive a microwave signal. The microwave node is adapted to report, to a domain controller of the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable.
According to examples of the present disclosure, the microwave node may be further adapted to carry out a method according to any one of the preceding aspects or examples of the present disclosure.
For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the following drawings in which:
Microwave links are currently an active topic in Software Defined Networking (SDN). SDN of transport networks is increasing in popularity, with operators beginning to deploy SDN based solutions for single domain management in transport networks. Abstraction of network resources is a technique that can be applied to a single network domain or across multiple domains to create a single virtualized network that is under the control of a network operator or the customer of the operator. Abstraction and Control of Traffic Engineered Networks (ACTN) is an initiative standardised in various IETF drafts with the aim of facilitating resource abstraction in multi technology and multi-vendor transport networks. In ACTN terminology, an SDN based solution for single domain management in transport networks is referred to as a Physical Network Controller (PNC) controlled domain. The driver for the introduction of SDN in transport networks is to provide network operators with Traffic Engineering (TE) capabilities in terms of constraints to be applied to the routing of traffic in the network. Such capabilities may include for example computing paths with minimum delay, minimum cost etc. SDN promises greater automation and operational efficiency by decoupling forwarding from control/management and introducing much higher abstraction and programmability than was previously available.
Reference 1 describes use cases for controlling microwave systems with the SDN approach, and states that “One of the main drivers for applying SDN from an operator perspective is simplification and automation of network provisioning as well as end to end network service management”. Use cases for SDN control of microwave networks include: Understand the capabilities and limitations, Initial configuration, and Radio link re-configuration and optimization.
The IETF draft “A YANG Data Model for Microwave Radio Link” draft-ietf-ccamp-mw-yang-05 (Reference 2) defines a data model for “management and control of the radio link interface(s) and the relationship to packet (typically Ethernet) and/or TDM interfaces in a microwave/millimeter wave node”. YANG (Yet Another Next Generation) is a data modelling language for the definition of data sent over the NETCONF network configuration protocol. YANG models are defined in Reference 2 for the air interface and for the packet side. The IETF draft “A YANG Data Model for Microwave Topology” draft-ye-ccamp-mw-topo-yang-00 (Reference 3) proposes a YANG data model to describe the topology of a microwave network. It is an augmentation of the TE topology model and addresses use cases of improved network planning, adaptive bandwidth configuration and capturing microwave-link specific information like the availability to drive path computation. It will be appreciated that the above noted YANG models, developed by the Internet Engineering Task Force (IETF), are referenced and discussed below for the purposes of illustration. The methods and apparatus of the present disclosure are equally applicable to YANG models developed by other organisations, including for example those developed by the Open Networking Foundation (ONF), as set out in: https://github.com/OpenNetworkingFoundation/CENTENNIAL/blob/master/models/yanq/microwave-model.yang.
In a transport network including a microwave domain and controlled according to the ACTN hierarchy of
It is anticipated that as a part of the continuing development of microwave networks, the following capabilities will become increasingly available in microwave nodes within PNC controlled microwave domains in the near future:
1) Configurable capacity: this can be achieved by means of configurable modulation formats and symbol rate, by using multiple carriers, multiple antennas etc. How the actual capacity is modulated to achieve the desired maximum capacity is left to the nodes (as is the case for most current deployments) and is outside the scope of this disclosure. For example, a microwave link could be configured for 1024 QAM maximum capacity but due to heavy rain only 256 QAM ensures the desired quality of transmission for short time intervals.
2) Reconfigurable microwave path: the microwave path over which a microwave node sends or receives a signal can be redirected on the horizontal plane to point to a new location described in terms of azimuth (angle on the Earth surface with respect to the North) and can be redirected on the vertical plane by changing its elevation angle (angle between the Earth surface and the microwave path). Microwave paths may also be described in terms of the latitude, longitude and elevation of an end point. The reconfiguration of a microwave path may be achieved in a relatively coarse manner using high precision DC motors and/or with a finer control using beamforming.
3) Operations and Maintenance (O&M) out-of-band channel which is always available for communicating with microwave nodes in all operating conditions and during reconfiguration of capacity and direction. The O&M channel may be realised for example via low-bandwidth commercial radio, fixed access or satellite network.
Some of the above capabilities are already available in certain microwave network deployments. Others are anticipated to become available as part of the ongoing evolution of microwave networks.
Aspects of the present disclosure provide a method for managing a microwave network that exploits some of the anticipated future capabilities of microwave nodes to provide redundancy, adaptability and energy savings in the microwave network.
As noted above, for the purposes of the present specification, a microwave path of a microwave node is reconfigurable if its geographical orientation may be adjusted by the microwave node during the operational life of the node, that is after the initial deployment phase during which the path of the node may be established according to a desired topology of the microwave network. A geographical orientation of a microwave path refers to the direction in which the path travels, represented for example by azimuth and elevation angles at an end point of the path, or by coordinates of the path's end points. Reconfiguration of a microwave path is thus distinguished from reconfiguration of a signal transmitted or received over the path, including for example a change in the bit-rate, the modulation format or the digital framing of a signal transmitted or received over the path. A path may be reconfigurable owing to actuators installed at an antenna of the node and operable to change the orientation of the antenna, and/or owing to beamforming techniques applied at the node.
Also as noted above, a microwave node may be associated with a single path, which may be serviced by a single antenna or by a group of antennas operated together, for example operable to provide Multiple In Multiple Out (MIMO) functionality. Multiple nodes may therefore be co-located at the same geographical site, with different nodes associated with microwave paths connecting the site to a range of other sites in different locations, each path serviced by one or more antennas.
Referring again to
With reference to
In step 310, the domain controller exposes, on an interface of the domain controller, a link topology of the microwave network, wherein the link topology comprises, for one or more microwave node(s) in the microwave network, the parameter quantifying the extent to which the microwave path associated with the microwave node(s) is reconfigurable. Thus in step 310, the domain controller may expose some or all of the parameters received in step 302. The domain controller may receive a parameter for all nodes in the microwave network, or may in some examples only receive the parameter for those nodes having a microwave path that is reconfigurable. The domain controller may expose the link topology on the northbound interface of the controller. Thus for an example controller comprising a PNC in an ACTN hierarchy, the controller may expose the link topography on the MPI interface. As will be understood by those skilled in the art, “a northbound interface” is an interface from a lower-layer device, node or entity (in the illustrated example, a PNC) to a higher-layer device, node or entity (in the illustrated example, an MDSC). The northbound interface may conceptualize the details used by the lower-layer device, node or entity.
As illustrated at 310a, the parameter quantifying the extent to which the microwave path associated with a microwave node is reconfigurable comprises at least one of a maximum azimuth for the path of the node, a minimum azimuth for the path of the node, a maximum elevation for the path of the node and/or a minimum elevation for the path of the node. Examples of these parameters are discussed in further detail below.
As illustrated at 310b, the link topography exposed in step 310 may further comprise, for a microwave node in the microwave network, a parameter quantifying the current microwave path of the microwave node, which parameter may also have been received from the microwave node in step 302. As illustrated at 310b, the parameter quantifying the current microwave path of a microwave node comprises at least one of current configured azimuth for the path of the node, current actual azimuth for the path of the node, current configured elevation for the path of the node and/or current actual elevation for the path of the node. Current configured azimuth and elevation may comprise values of azimuth and elevation that the microwave node is configured to apply and current actual azimuth and elevation may comprise values of azimuth and elevation that are currently captured by the network for the microwave node. Current actual values may be captured by the network through measurement readings and/or reporting, and a difference between current configured and current actual values may arise owing to self-optimisation at the node or to error.
As illustrated at 310c, the link topology exposed in step 310 may further comprise, for a microwave node in the microwave network, a microwave link budget parameter, which may for example comprise at least one of a terrain factor and/or a climate factor.
As illustrated at 310d, the link topology exposed in step 310 may further comprise, for a microwave node in the microwave network, geographic coordinates for the microwave node.
In step 312, the domain controller stores, for a microwave link in the link topology of the microwave network, current configured values of azimuth and elevation for the microwave paths associated with the microwave nodes forming endpoints of the link. This information is stored as a backup microwave link in a data store. The data store may be hosted at the domain controller or may be remotely hosted and accessible to the domain controller. As illustrated in step 314, the domain controller also stores in the data store, for the backup microwave link, current actual values of azimuth and elevation for the microwave paths associated with the microwave nodes forming endpoints of the link.
In step 316, the domain controller indexes, in the data store, the stored values of azimuth and elevation for the backup microwave link with an identifier comprising identifiers of the microwave nodes forming endpoints of the link.
Referring now to
The domain controller then proceeds to use the parameter quantifying, for a microwave node in the microwave network, the extent to which the microwave path associated with the microwave node is reconfigurable, to evaluate the feasibility of a potential new path between microwave nodes in the microwave network. The use may be conditional upon a change in the link topology of the microwave network taking place or being detected or identified. Steps 320 to 324 and 336 described below illustrate examples of how the domain controller may use the indicated parameter to evaluate the feasibility of a potential new path between microwave nodes in the microwave network
In step 320, the domain controller identifies a change in the link topology of the microwave network. This may comprise identifying a microwave node in the microwave network that has become at least partially unavailable, as illustrated at 320a. A microwave node may become at least partially unavailable owing to one or more of a failure affecting the microwave node or a programmed downtime for the microwave node. Programmed downtime for a microwave node may include scheduled repairs or maintenance work, or scheduled downtime during periods of low traffic load, for example scheduled overnight downtime for energy saving.
In other examples, identifying a change in the link topology of the microwave network may comprise identifying a microwave node in the microwave network that has become newly available, as illustrated at 320b. A microwave node may become newly available owing to one or more of a new microwave node installation or a node becoming available after a failure or programmed downtime.
In step 322, the domain controller identifies a path between first and second microwave nodes in the microwave network, which path is impacted by the change in topology, the path comprising at least one microwave link. As illustrated at 322a and 322b, a path between first and second microwave nodes in the microwave network, which path is impacted by the change in topology, may include for example a path comprising a microwave link that terminates at an at least partially unavailable node, or a path the capacity of which may be increased by passing via a newly available node
In step 324, the domain controller identifies a potential new path between the first and second microwave nodes, which path maintains connectivity between the first and second nodes in the changed link topology. As illustrated at 324a and 324b, a potential new path between the first and second microwave nodes, which path maintains connectivity between the first and second nodes in the changed link topology, may comprise a path comprising a single microwave link between the first and second microwave nodes, or may comprise a path comprising a microwave link that terminates at the newly available node.
In step 326, the domain controller checks the data store for backup microwave links having the first or second microwave nodes as endpoints and, in step 328 as illustrated in
If the potential new path can be formed from stored backup links (Yes at step 330), the domain controller identifies the stored backup links required to form the potential new path in step 332 and instructs the first and second microwave nodes to reconfigure their associated microwave paths to match the microwave paths of the identified back links in step 324. The domain controller then proceeds directly to step 342 as discussed below.
If the potential new path cannot be formed from stored backup links (No at step 330), the domain controller proceeds to evaluate the feasibility of the potential new path on the basis of parameters quantifying the extent to which the microwave paths associated with the first and second microwave nodes are reconfigurable. This may comprise determining whether the parameters exposed as part of the link topology in step 320 for the first and second microwave nodes indicate that the microwave paths associated with the first and second microwave nodes can be reconfigured to form the potential new path (checking maximum and minimum azimuth, elevation, etc.). The domain controller may be aware of geographical characteristics of the region where the microwave network is deployed and may take these into account to determine feasibility of the link from established rules accounting for distance, chosen carrier frequency, margins for obstructions, atmospheric variations etc.
If the potential new path between the first and second microwave nodes is evaluated as feasible (yes at step 338), the domain controller instructs the first and second microwave nodes at step 340 to reconfigure their associated microwave paths to form the potential new path. As illustrated at 340a, this comprises configuring the first and second microwave nodes with azimuth and elevation values corresponding to microwave paths that will form the potential new path.
In step 342, the domain controller determining a difference in capacity between the identified path and the potential new path, and in step 344, the domain controller engineers traffic on the potential new path to accommodate the difference in capacity. This may comprise for example prioritising certain classes of traffic, if the capacity of the new path is less than that of the identified path.
As illustrated at 410a, the parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable comprises at least one of a maximum azimuth for the path of the node, a minimum azimuth for the path of the node, a maximum elevation for the path of the node and/or a minimum elevation for the path of the node. Examples of these parameters are discussed in further detail below.
As illustrated at 410b, the microwave node may additionally report to the domain controller a parameter quantifying the current microwave path of the microwave node, which parameter may be at least one of current configured azimuth for the path of the node, current actual azimuth for the path of the node, current configured elevation for the path of the node and/or current actual elevation for the path of the node. Current configured azimuth and elevation may comprise values of azimuth and elevation that the microwave node is configured to apply and current actual azimuth and elevation may comprise values of azimuth and elevation that are currently captured by the network for the microwave node. Current actual values may be captured by the network through measurement readings and/or reporting, and a difference between current configured and current actual values may arise owing to self-optimisation at the node or to error.
In step 412, the microwave node may receive an instruction from the domain controller to reconfigure its microwave path. This instruction may for example comprise new configured values of azimuth and elevation. The microwave node may then proceed, in step 414, to reconfigure its microwave path in accordance with the received instruction. This may for example comprise using actuators to physically change the alignment of one or more antennas at the node, and/or using beamforming techniques applied at the node to shift the microwave path associated with the node in accordance with the received instruction.
Additional details and example use cases of methods according to the present disclosure are discussed below, in the context of an example microwave network 500 illustrated in
As discussed above with reference to
It will be appreciated that the above parameters may be added to the link topology for both microwave nodes having fixed microwave paths in addition to reconfigurable microwave nodes, so maintain backwards compatibility. Microwave nodes having fixed microwave paths will simply indicate maximum and minimum values for azimuth, elevation etc. that are essentially same, encompassing only a small margin for self-optimization at the node.
Referring again to the example microwave network of
It will be appreciated that the parameters discussed above may be stored manually (e.g. via a Graphical User Interface) or automatically using sensors. It will also be appreciated that the manner in which self-optimization of azimuth and elevation is performed at the microwave nodes, in addition to the manner in which self-configuration of the modulation format at the microwave nodes is performed, may be selected according to the requirements of a particular implementation or deployment.
Use Case 1: Protection without Extra Hardware
Referring to
Use Case 2: Cost-Effective First-In Deployment
Referring to
Use Case 3: Energy-Efficient Networking
Referring to
Use Cases 1 and 3 can be conveniently paired to an automatic system for the forecasting of traffic and/or link conditions, which may for example run in the cloud. For example, the SDN domain controller can be instructed by another application which is able to extrapolate traffic patterns or weather conditions. As a result, the controller anticipates a node reconfiguration to serve a predicted scenario.
The following examples demonstrate how the YANG model set out in Reference 3 may be amended to include a parameter according to examples of the present disclosure. Additions to the model are indicated in bold type.
A corresponding JSON-encoded GET of the microwave topology for the node Erzelli-1 in example network 500 would be:
As discussed above, a new data store may be introduced to manage microwave backup links. Backup links may be addressed by an index and by a date/time value to capture different configurations used at different date/times of the year (e.g. corresponding to different climate conditions which may affect the optimal azimuth and/or elevation).
A JSON-encoded GET on the backup links data store for the example network 500 is illustrated below. There are two instances of the Beigua-2-Fasce-2 links and one instance of the Beigua-2-Erzelli-1 link:
It will be appreciated that the above YANG model examples are provided for the purposes of illustration, and methods according to the present disclosure may be implemented using YANG models developed by organisations other than the IETF, or using other data modelling languages.
As discussed above, the methods 200, 300 may be performed by a domain controller, which may be an SDN domain controller such as a PNC. The domain controller may be a physical node or may be a Virtualised Network Function, which may for example be run in a cloud environment exploiting associated benefits of computing capability, high availability, and scalability.
Referring to
The method 400 may be performed by a microwave node, a microwave path of which may or may not be reconfigurable.
Referring to
Aspects of the present disclosure thus provide methods for managing a microwave network, according to which a domain controller may expose on an interface a link topology of the microwave network which includes, for a microwave node in the microwave network, a parameter quantifying the extent to which the microwave path associated with the microwave node is reconfigurable. The interface may be a north bound interface such as the MPI (MDSC to PNC Interface) in the IETF ACTN, but may also or alternatively comprise other interfaces including NETCONF/RESTCONF interfaces defined by other standardization bodies. In some examples of the present disclosure, “backup” microwave topologies in the form of backup links may be stored at installation time or created during system life and subsequently applied when needed, so reducing the time, computation and checking required to implement an alternative path on the fly. Examples of the methods disclosed herein may enable the exploitation of reconfigurable microwave links, offering both cost and energy savings.
Examples of the present disclosure may be implemented as a NETCONF/RESTCONF Protocol/YANG model extension for a network controller controlling microwave nodes where air interfaces can be software reconfigured to realize new microwave paths and/or implement backup links. The extension may include the communication of the steering capabilities of microwave nodes in terms of azimuth and elevation and the configured and operational values of azimuth and elevation.
The methods of the present disclosure may be implemented in hardware, or as software modules running on one or more processors. The methods may also be carried out according to the instructions of a computer program, and the present disclosure also provides a computer readable medium having stored thereon a program for carrying out any of the methods described herein. A computer program embodying the disclosure may be stored on a computer readable medium, or it could, for example, be in the form of a signal such as a downloadable data signal provided from an Internet website, or it could be in any other form.
It should be noted that the above-mentioned examples illustrate rather than limit the disclosure, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim, “a” or “an” does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims. Any reference signs in the claims shall not be construed so as to limit their scope.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/085477 | 12/18/2018 | WO | 00 |