Enhancement of feature support after interworking
A method of enhancing IP packet forwarding feature support after interworking is proposed. When a PDU session in 5GS is transferred to a PDN connection in EPS, the UE shall assume the feature is supported after inter-system change from 5GS to EPS. When a PDN connection is established in EPS, the network indicated that the feature is not supported, and the network provided 5GSM parameters for ESM/5GSM interworking for this PDN connection, then UE shall assume the feature is supported after inter-system change from EPS to 5GS, the UE shall also assume the feature is supported after inter-system change from 5GS back to EPS. The IP packet forwarding features include PS data off and local IP address in TFT.
1. A method, comprising:
maintaining a Protocol data unit (PDU) session by a user equipment (UE) in a 5G system (5GS) of a mobile communication network, wherein the UE supports a packet-switched data-off (PS_Data_Off) feature for the PDU session;
performing an inter-system change and thereby switching from 5GS to an evolved packet system (EPS);
converting the PDU session to a packet data network (PDN) connection in EPS, wherein the UE assumes that the PS_Data_Off feature is supported for the PDN connection after performing the inter-system change from 5GS to EPS; and
monitoring a PS_Data_Off status change and in response initiating a Bearer Resource Modification procedure with a 3GPP PS_Data_Off UE Status.
2. The method of claim 1 , wherein the PDN connection is associated with a PS_Data_Off Support Indication indicating whether the PS_Data_Off feature is supported.
3. The method of claim 1 , wherein the 3GPP PS_Data_Off UE status is changed between “activated” or “deactivated” in the UE when the PS_Data_Off feature is supported.
4. The method of claim 1 , wherein the 3GPP PS_Data_Off UE status is included in an extended Protocol Configuration Options (ePCO)/PCO information element (IE) of a Bearer Resource Modification Request message.
5. The method of claim 1 , wherein the UE performs inter-system change from EPS to 5GS, wherein the UE assumes that the PS_Data_Off feature is supported in 5GS after performing the inter-system change.
6. The method of claim 1 , wherein the UE performs inter-system change from EPS to 5GS and then back to EPS, wherein the UE assumes that the PS_Data_Off feature is supported for the same PDN connection.
7. A User Equipment (UE), comprising:
a Protocol data unit (PDU) session handling circuit that maintains a PDU session in a 5G system (5GS) of a mobile communication network, wherein the UE supports a packet-switched data-off (PS_Data_Off) feature for the PDU session;
a mobility management circuit that performs an inter-system change and thereby switching from 5GS to an evolved packet system (EPS), wherein the UE converts the PDU session to a packet data network (PDN) connection in EPS, wherein the UE assumes that the PS_Data_Off feature is supported for the PDN connection after performing the inter-system change from 5GS to EPS; and
a control circuit that monitors a PS_Data_Off status change and in response initiating a Bearer Resource Modification procedure with a 3GPP PS_Data_Off UE Status.
8. The UE of claim 7 , wherein the PDN connection is associated with a PS_Data_Off Support Indication indicating whether the PS_Data_Off feature is supported.
9. The UE of claim 7 , wherein the 3GPP PS_Data_Off UE status is changed between “activated” or “deactivated” in the UE when the PS_Data_Off feature is supported.
10. The UE of claim 7 , wherein the 3GPP PS_Data_Off UE status is included in an extended Protocol Configuration Options (ePCO)/PCO information element (IE) of a Bearer Resource Modification Request message.
11. The UE of claim 7 , wherein the UE performs inter-system change from EPS to 5GS, wherein the UE assumes that the PS_Data_Off feature is supported in 5GS after performing the inter-system change.
12. The UE of claim 7 , wherein the UE performs inter-system change from EPS to 5GS and then back to EPS, wherein the UE assumes that the PS_Data_Off feature is supported for the same PDN connection.