Abstract: A method of abstracting network resources in a mobile communications network includes: determining a service coverage area for a class of service, the class of service defined by service parameters; determining a set of tracking areas that fall at least partly within the service coverage area; selecting available network resources for tracking areas of the set of tracking areas, for providing the class of service in the tracking areas; defining an abstraction view of the selected network resources for the class of service in the service coverage area, the abstraction view having deliverable values of the service parameters within the set of tracking areas; and outputting a communication signal having an indication of the abstraction view.

Abstract: Resource provisioning in a virtualized network Within a network comprising a plurality of domains, an end-to-end route for a required service is computed by setting a respective parameter value for each of a plurality of paths in a domain. Each parameter value is based on resources that are available for the required service, and the parameter value is dependent on a priority given to said service. The end-to-end route for the required service is selected based on said parameter values.

Abstract: A method of monitoring performance of a network using network tomography comprises obtaining (102) information indicative of topology of the network and computing (104) a plurality of paths for monitoring the network. Further the method comprises instructing (110) source nodes of the computed paths to send probing packets towards destination nodes of the computed paths, wherein said probing packets undergo segment routing in said network and instructing (114) the destination nodes of the computed paths to carry out network performance measurements based on probing packets received by the destination nodes. Finally the method comprises receiving (116) the performance measurements from the destination nodes and inferring (118) information about performance of nodes in the network using network tomography, wherein the inference process includes correlating the performance measurements of the computed paths.

Abstract: A method for providing support for elasticity in network virtualisation of a heterogeneous, multi-domain network comprising receiving (802) from network domains information about elasticity capability of physical paths in said network domains; summarising (804) physical paths in said network domains into virtual links; and producing (806) a topology of a virtual network overlaying the multi-domain network by associating elasticity parameters with the virtual links, wherein the elasticity parameters are inferred from the physical paths.

Abstract: Resource provisioning in a virtualized network Within a network comprising a plurality of domains, an end-to-end route for a required service is computed by setting a respective parameter value for each of a plurality of paths in a domain. Each parameter value is based on resources that are available for the required service, and the parameter value is dependent on a priority given to said service. The end-to-end route for the required service is selected based on said parameter values.

Abstract: A method (400) for providing support for elasticity within a domain of a multi-domain network. The method comprises receiving (401) information for a requested virtual link forming part of an end-to-end path across the multi-domain network; wherein the information of the virtual link comprises a service parameter and an elasticity parameter. The method further comprises selecting (402) a physical path (150) corresponding to the virtual link on which to send traffic. The physical path is selected based on a service parameter and an elasticity parameter of the physical path.

Abstract: A multi-domain network (5) has a Hierarchical Path Computation Element, H-PCE, architecture comprising a Parent Path Computation Element, P-PCE (31) and a Child Path Computation Element, C-PCE, (21-25) at each of the domains (11-15). A C-PCE (21-25) determines summarised domain topology information about the domain (11-15). The summarized domain topology information comprises at least one of: an indication of whether the domain (11-15) is capable of supporting Point-to-Multi-Point services; an indication of whether a node of the summarised domain topology is capable of supporting a branch point for Point-to-Multi-Point services. The summarised domain topology information is sent to a P-PCE (31) via a communication interface (35). The P-PCE (31) computes an end-to-end Point-to-Multi-Point tree using a topology based on summarised domain topology information (32) received from the Child Path Computation Elements.

Abstract: A method of monitoring performance of a network using network tomography comprises obtaining (102) information indicative of topology of the network and computing (104) a plurality of paths for monitoring the network. Further the method comprises instructing (110) source nodes of the computed paths to send probing packets towards destination nodes of the computed paths, wherein said probing packets undergo segment routing in said network and instructing (114) the destination nodes of the computed paths to carry out network performance measurements based on probing packets received by the destination nodes. Finally the method comprises receiving (116) the performance measurements from the destination nodes and inferring (118) information about performance of nodes in the network using network tomography, wherein the inference process includes correlating the performance measurements of the computed paths.

Abstract: A method for providing support for elasticity in network virtualisation of a heterogeneous, multi-domain network comprising receiving (802) from network domains information about elasticity capability of physical paths in said network domains; summarising (804) physical paths in said network domains into virtual links; and producing (806) a topology of a virtual network overlaying the multi-domain network by associating elasticity parameters with the virtual links, wherein the elasticity parameters are inferred from the physical paths.

Abstract: A method of calculating a path in a first layer of a multi-layer network comprises receiving information corresponding to one or more parameter from a second layer of the multi-layer network. The one or more parameter relates to a summarization of links between edge nodes of the second layer connected with the first layer. The method further comprises calculating a path in the first layer using the received information from the second layer.

Abstract: A node 800 of a multi-layer communication is capable of routing a message signal via one or more different layers (for example a PSC layer, TDM layer, LSC layer) in the multi-layer communication network. The node 800 comprises a first interface 801 for receiving a path message 803 containing routing information for routing an associated message signal through the multi-layer communication network. One or more second interfaces 805i to 805N are provided for transmitting a message signal to one or more respective layers in the multi-layer communication network. A processing unit 807 is adapted to determine if the path message 803 contains protection information 40 indicating that protection switching is to be performed in one or more different layers of the multi-layer communication network, and if so, establish a protection switching mechanism in the one or more different layers using the protection information 40 provided in the path message 803.

Abstract: A path computation element for a communications network, receives link advertisements from hybrid nodes (10) of the network and selects paths for new traffic flows based on the received link advertisements. The hybrid node has switching matrices (20, 30) operable using different protocols, and has internal links between the switching matrices. The link advertisements indicate a maximum and in a minimum bandwidth on any one of the internal links for a new traffic flow. The element can select a path via the hybrid node for a new traffic flow according to the bandwidth of the requested new traffic flow and according to the maximum and the minimum bandwidth indicated by the link advertisements. Advertising the maximum and minimum bandwidths available for a single new traffic flow for the internal links can enable more efficient path computation with little additional cost and hence maintain scalability of the link advertisements for larger networks.

Abstract: A multi-domain network (5) has a Hierarchical Path Computation Element, H-PCE, architecture comprising a Parent Path Computation Element, P-PCE (31) and a Child Path Computation Element, C-PCE, (21-25) at each of the domains (11-15). A C-PCE (21-25) determines summarised domain topology information about the domain (11-15). The summarised domain topology information comprises at least one of: an indication of whether the domain (11-15) is capable of supporting Point-to-Multi-Point services; an indication of whether a node of the summarised domain topology is capable of supporting a branch point for Point-to-Multi-Point services. The summarised domain topology information is sent to a P-PCE (31) via a communication interface (35). The P-PCE (31) computes an end-to-end Point-to-Multi-Point tree using a topology based on summarised domain topology information (32) received from the Child Path Computation Elements.

Abstract: A node 800 of a multi-layer communication is capable of routing a message signal via one or more different layers (for example a PSC layer, TDM layer, LSC layer) in the multi-layer communication network. The node 800 comprises a first interface 801 for receiving a path message 803 containing routing information for routing an associated message signal through the multi-layer communication network. One or more second interfaces 805i to 805N are provided for transmitting a message signal to one or more respective layers in the multi-layer communication network. A processing unit 807 is adapted to determine if the path message 803 contains protection information 40 indicating that protection switching is to be performed in one or more different layers of the multi-layer communication network, and if so, establish a protection switching mechanism in the one or more different layers using the protection information 40 provided in the path message 803.

Abstract: Computing working paths and recovery paths in a telecommunications network having nodes capable of supporting different recovery schemes, is based on traffic demands having an indication of a desired recovery service level, for that demand. A path computation is carried out to select a working path through the network for each of the traffic demands and to select which of the different recovery schemes to use according to the service level. The selected working paths and their associated recovery schemes are then set up in the network. By leaving the selection of the recovery scheme to the path computation stage, network resources can be used more efficiently, and operators can specify resiliency in terms of needs rather than in terms of the technology of the network. Thus operators can be insulated from the detailed knowledge of the network.

Abstract: A path computation element for a communications network, receives link advertisements from hybrid nodes (10) of the network and selects paths for new traffic flows based on the received link advertisements. The hybrid node has switching matrices (20, 30) operable using different protocols, and has internal links between the switching matrices. The link advertisements indicate a maximum and in a minimum bandwidth on any one of the internal links for a new traffic flow. The element can select a path via the hybrid node for a new traffic flow according to the bandwidth of the requested new traffic flow and according to the maximum and the minimum bandwidth indicated by the link advertisements. Advertising the maximum and minimum bandwidths available for a single new traffic flow for the internal links can enable more efficient path computation with little additional cost and hence maintain scalability of the link advertisements for larger networks.