A user equipment, UE, comprising: means (37, 43) for determining whether a new Protocol Data Unit, PDU, session is compatible or incompatible with an established PDU session based on all of: a) at least one of a value of a first Slice Service Type, SST, of a first Single-Network Slice Selection Assistance Information, S-NSSAI, for the established PDU session on the UE and a value of a first Service Descriptor, SD, of the first S-NSSAI for the established PDU session on the UE, b) a first incompatibility attribute value for indicating restriction of at least one of the value of the first SST and the value of the first SD for simultaneous use of the new PDU session and the established PDU session, c) at least one of a value of a second SST of a second S-NSSAI for the new PDU session and a value of a second SD of the second S-NSSAI, and d) a second incompatibility attribute value for indicating restriction of at least one of the value of the second SST and the value of the second SD for simultaneous use of the new PDU session and the established PDU session, and means for receiving an incompatibility attribute value for indicating restriction of at least one of a value of a SST and a value of a SD per S-NSSAI in a Registration Accept message, from a core network node for mobility management; wherein the means for receiving is configured to receive the incompatibility attribute value per S-NSSAI in a case where the UE sends capability information for indicating that the UE is configured to understand the Attribute value per S-NSSAI. means (37, 43) for determining whether a new Protocol Data Unit, PDU, session is compatible or incompatible with an established PDU session based on all of: a) at least one of a value of a first Slice Service Type, SST, of a first Single-Network Slice Selection Assistance Information, S-NSSAI, for the established PDU session on the UE and a value of a first Service Descriptor, SD, of the first S-NSSAI for the established PDU session on the UE, b) a first incompatibility attribute value for indicating restriction of at least one of the value of the first SST and the value of the first SD for simultaneous use of the new PDU session and the established PDU session, c) at least one of a value of a second SST of a second S-NSSAI for the new PDU session and a value of a second SD of the second S-NSSAI, and d) a second incompatibility attribute value for indicating restriction of at least one of the value of the second SST and the value of the second SD for simultaneous use of the new PDU session and the established PDU session, and a) at least one of a value of a first Slice Service Type, SST, of a first Single-Network Slice Selection Assistance Information, S-NSSAI, for the established PDU session on the UE and a value of a first Service Descriptor, SD, of the first S-NSSAI for the established PDU session on the UE, b) a first incompatibility attribute value for indicating restriction of at least one of the value of the first SST and the value of the first SD for simultaneous use of the new PDU session and the established PDU session, c) at least one of a value of a second SST of a second S-NSSAI for the new PDU session and a value of a second SD of the second S-NSSAI, and d) a second incompatibility attribute value for indicating restriction of at least one of the value of the second SST and the value of the second SD for simultaneous use of the new PDU session and the established PDU session, and means for receiving an incompatibility attribute value for indicating restriction of at least one of a value of a SST and a value of a SD per S-NSSAI in a Registration Accept message, from a core network node for mobility management; wherein the means for receiving is configured to receive the incompatibility attribute value per S-NSSAI in a case where the UE sends capability information for indicating that the UE is configured to understand the Attribute value per S-NSSAI.