Methods and nodes for facilitating a pdu session procedure in interworking networks

Abstract

A method at an Access and mobility Management Function (AMF) for facilitating a Protocol Data Unit (PDU) session procedure for a User Equipment (UE) in a 5th Generation System (5GS) network, wherein the 5GS network is interworking with an Evolved Packet System (EPS) network, and a Packet Data Network Gateway Control plane Function+Session Management Function (PGW-C+SMF) supporting the interworking is selected for managing the PDU session. The method comprises determining whether the PDU session supports interworking with the EPS network, based on at least one of a capability of the UE and a subscription data of the UE; and sending an indication which indicates whether the PDU session supports interworking with the EPS network to the PGW-C+SMF.

What is claimed is: 
     
         1 . A method at a Packet Data Network Gateway Control plane Function+Session Management Function (PGW-C+SMF) for facilitating a procedure for a Protocol Data Unit (PDU) session for a User Equipment (UE) in a 5th Generation System (5GS) network, wherein the 5GS network interworks with an Evolved Packet System (EPS) network, and the PGW-C+SMF, that supports interworking of the 5GS network with the EPS network, is selected for managing the PDU session, the method comprising:
 receiving an indication from an Access and mobility Management Function (AMF) indicating whether the PDU session supports interworking with the EPS network, wherein the indication is determined based on a capability of the UE, a subscription data of the UE, or both the capability of the UE and the subscription data of the UE, wherein a value of the capability of the UE comprises S1 mode supported, or a value of the subscription data of the UE comprises core network type restriction to the EPS network, or both; and   determining whether the PDU session supports interworking with the EPS network according to the indication.   
     
     
         2 . The method of  claim 1 , wherein whether the PDU session supports interworking with the EPS network comprises whether the PDU session can be moved to the EPS network. 
     
     
         3 . The method of  claim 1 , wherein procedure for the PDU session is a PDU session establishment procedure. 
     
     
         4 . The method of  claim 1 , further comprising sending a request to the AMF to allocate resources for the PDU session in the EPS network. 
     
     
         5 . The method of  claim 4 , further comprising receiving a response to reject the request to allocate resources for the PDU session in the EPS network from the AMF. 
     
     
         6 . The method of  claim 4 , wherein the resources comprise EPS bearer identity. 
     
     
         7 . The method of  claim 4 , further comprising sending a request to allocate an identity of a bearer in the EPS network for the PDU session to the AMF, when the indication indicates a N26 interface between the 5GS network and the EPS network is to be used for interworking of the PDU session. 
     
     
         8 . A Packet Data Network Gateway Control plane Function+Session Management Function (PGW-C+SMF) for facilitating a procedure for a Protocol Data Unit (PDU) session for a User Equipment (UE) in a 5th Generation System (5GS) network, wherein the 5GS network interworks with an Evolved Packet System (EPS) network, and the PGW-C+SMF, that supports interworking of the 5GS network with the EPS network, is selected for managing the PDU session, the PGW-C+SMF comprising:
 a processor; and   a memory containing instructions which, when executed by the processor, cause the PGW-C+SMF to:
 receive an indication from an Access and mobility Management Function (AMF) indicating whether the PDU session supports interworking with the EPS network, wherein the indication is determined based on a capability of the UE, a subscription data of the UE, or both the capability of the UE and the subscription data of the UE, wherein a value of the capability of the UE comprises S1 mode supported, or a value of the subscription data of the UE comprises core network type restriction to the EPS network, or both; and 
 determine whether the PDU session supports interworking with the EPS network according to the indication. 
   
     
     
         9 . The PGW-C+SMF of  claim 8 , wherein whether the PDU session supports interworking with the EPS network comprises whether the PDU session can be moved to the EPS network. 
     
     
         10 . The PGW-C+SMF of  claim 8 , wherein procedure for the PDU session is a PDU session establishment procedure. 
     
     
         11 . The PGW-C+SMF of  claim 8 , further to send a request to the AMF to allocate resources for the PDU session in the EPS network. 
     
     
         12 . The PGW-C+SMF of  claim 11 , further to receive a response to reject the request to allocate resources for the PDU session in the EPS network from the AMF. 
     
     
         13 . The PGW-C+SMF of  claim 11 , wherein the resources comprise EPS bearer identity. 
     
     
         14 . The PGW-C+SMF of  claim 11 , further to send a request to allocate an identity of a bearer in the EPS network for the PDU session to the AMF, when the indication indicates a N26 interface between the 5GS network and the EPS network is to be used for interworking of the PDU session. 
     
     
         15 . A non-transitory computer-readable storage medium comprising instructions which, when executed by at least one processor of a Packet Data Network Gateway Control plane Function+Session Management Function (PGW-C+SMF) for facilitating a procedure for a Protocol Data Unit (PDU) session for a User Equipment (UE) in a 5th Generation System (5GS) network, wherein the 5GS network interworks with an Evolved Packet System (EPS) network, and the PGW-C+SMF, that supports interworking of the 5GS network with the EPS network, is selected for managing the PDU session, are capable of causing the PGW-C+SMF to perform operations comprising:
 receiving an indication from an Access and mobility Management Function (AMF) indicating whether the PDU session supports interworking with the EPS network, wherein the indication is determined based on a capability of the UE, a subscription data of the UE, or both the capability of the UE and the subscription data of the UE, wherein a value of the capability of the UE comprises S1 mode supported, or a value of the subscription data of the UE comprises core network type restriction to the EPS network, or both; and   determining whether the PDU session supports interworking with the EPS network according to the indication.   
     
     
         16 . The non-transitory computer-readable storage medium of  claim 15 , wherein whether the PDU session supports interworking with the EPS network comprises whether the PDU session can be moved to the EPS network. 
     
     
         17 . The non-transitory computer-readable storage medium of  claim 15 , wherein the instructions further to perform operations comprising sending a request to the AMF to allocate resources for the PDU session in the EPS network. 
     
     
         18 . The non-transitory computer-readable storage medium of  claim 17 , wherein the instructions further to perform operations comprising receiving a response to reject the request to allocate resources for the PDU session in the EPS network from the AMF. 
     
     
         19 . The non-transitory computer-readable storage medium of  claim 17 , wherein the resources comprise EPS bearer identity. 
     
     
         20 . The non-transitory computer-readable storage medium of  claim 17 , wherein the instructions further to perform operations comprising sending a request to allocate an identity of a bearer in the EPS network for the PDU session to the AMF, when the indication indicates a N26 interface between the 5GS network and the EPS network is to be used for interworking of the PDU session.