A method of generating a network slice, comprising: determining, by a network slice manager, NWSM, that a service requested by a service provider cannot be accommodated on an existing network slice; receiving (1610, 240), by a network slice orchestrator, NWSO, from the NWSM, a request for a new network slice, the request including a parameter; assigning, by the NWSO, a network slice descriptor, NWSD, to the new network slice which is to accommodate a new service from the parameter included in the request, the NWSD including a network slice ID; wherein the assigning a NWSD for the new network slice comprises: adding a new network slice forwarding graph, NWSFG, ID, Common network service descriptor and slice specific network service descriptor to a new NWSFG information element, IE, for the new network slice; and referencing the NWSFG IE in a new NWSD for the network slice; the method further comprising: transmitting, by the NSWO, a request to a resource orchestrator, RO, for an instantiation of the network slice using enhanced network function virtualization management and orchestration, E-MANO, system, the RO being part of the E-MANO, wherein the request for an instantiation of the network slice comprises the NWSD of the new network slice, wherein the E-MANO instantiates new functions onto the resources allocated for the new network slice, wherein the E-MANO sends a Create Network Slice Response to the NWSO, and wherein the NWSO sends an NWSO response to the NWSM; and transmitting, by the NWSM, an acknowledgement including the network slice ID to the service provider. determining, by a network slice manager, NWSM, that a service requested by a service provider cannot be accommodated on an existing network slice; receiving (1610, 240), by a network slice orchestrator, NWSO, from the NWSM, a request for a new network slice, the request including a parameter; assigning, by the NWSO, a network slice descriptor, NWSD, to the new network slice which is to accommodate a new service from the parameter included in the request, the NWSD including a network slice ID; wherein the assigning a NWSD for the new network slice comprises: adding a new network slice forwarding graph, NWSFG, ID, Common network service descriptor and slice specific network service descriptor to a new NWSFG information element, IE, for the new network slice; and referencing the NWSFG IE in a new NWSD for the network slice; the method further comprising: transmitting, by the NSWO, a request to a resource orchestrator, RO, for an instantiation of the network slice using enhanced network function virtualization management and orchestration, E-MANO, system, the RO being part of the E-MANO, wherein the request for an instantiation of the network slice comprises the NWSD of the new network slice, wherein the E-MANO instantiates new functions onto the resources allocated for the new network slice, wherein the E-MANO sends a Create Network Slice Response to the NWSO, and wherein the NWSO sends an NWSO response to the NWSM; and transmitting, by the NWSM, an acknowledgement including the network slice ID to the service provider. transmitting, by the NSWO, a request to a resource orchestrator, RO, for an instantiation of the network slice using enhanced network function virtualization management and orchestration, E-MANO, system, the RO being part of the E-MANO, wherein the request for an instantiation of the network slice comprises the NWSD of the new network slice, wherein the E-MANO instantiates new functions onto the resources allocated for the new network slice, wherein the E-MANO sends a Create Network Slice Response to the NWSO, and wherein the NWSO sends an NWSO response to the NWSM; and transmitting, by the NWSM, an acknowledgement including the network slice ID to the service provider.