Enhancement of DSCP-based paging policy differentiation

Abstract

A method performed by a session management function (SMF) for facilitating paging policy differentiation is provided. The method includes determining a user plane function (UPF) (325) support paging policy differentiation characteristic. The method includes transmitting, to the UPF (325), a message indicating that the UPF (325) inserts a paging policy indicator (PPI) value (110) into a downlink packet based on a differential service code point (DSCP) value (106). The message includes DSCP to PPI control information.

Description

[0001] This application is a divisional application of the Chinese patent application “Enhancement of differentiated paging strategy based on DSCP” with application number 202380020961.6 (filing date is January 31, 2023). Technical Field

[0002] The present disclosure is directed to enhancing DSCP-based paging policy differentiation. Background Art

[0003] Paging Policy Differentiation (PPD) is a feature that allows the Access and Mobility Management Function (AMF) to apply different paging policies to different services or service types provided within the same Protocol Data Unit (PDU) session based on operator configuration. When the 5G System (5GS) supports the PPD feature, the Differentiated Services Code Point (DSCP) value (Type of Service (ToS) in IPv4 / Traffic Class (TC) in IPv6) is set by the application to indicate to the 5GS which paging policy should be applied to a certain Internet Protocol (IP) packet.

[0004] For UEs in radio resource control (RRC) inactive state, the next generation radio access network (NG-RAN) can enforce a specific paging policy in the case of NG-RAN paging based on the 5G quality of service (QoS) identifier (5QI), allocation and retention priority (ARP), and paging policy indicator (PPI) associated with the incoming downlink (DL) PDU. To this end, the session management function (SMF) instructs the user plane function (UPF) to detect the DSCP in the ToS (IPv4) / TC (IPv6) value in the IP header of the DL PDU (by using the DL packet detection rule (PDR) with the DSCP for the service) and transmit the corresponding PPI in the core network (CN) tunnel header (by using the QoS enforcement rule (QER) with the PPI value). The NG-RAN can then utilize the PPI received in the CN tunnel header of the incoming DL PDU to apply the corresponding paging policy for the case where the UE needs to be paged when it is in the RRC inactive state. Operators should be able to configure the SMF so that the paging policy differentiation feature applies only to certain Home Public Land Mobile Networks (HPLMNs), Data Network Names (DNNs) and 5QIs.

[0005] In the case of home routed roaming, the visited SMF (V-SMF) is responsible for controlling the UPF settings of the PPI. In a PDU session with an intermediate SMF (I-SMF), the I-SMF is responsible for controlling the UPF settings of the PPI.

[0006] like Figure 1As shown, UPF 102 may have an incoming DL PDU 104 that includes a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer 104a and a GTP-U payload 104b. Within the IP header of the GTP-U payload 104b is a user data DSCP value 106. This value 106 may be mapped to a PPI 110 within the DL PDU session information 108.

[0007] Section 5.4.3.2 “Paging policy differentiation” of the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.501 V17.3.0 (2021-12) and section “Transmission of DL PDU session information” of TS 38.415 V16.6.0 (2021-12) provide more information. Summary of the invention

[0008] As per the existing Packet Forwarding Control Protocol (PFCP) protocol, the SMF shall provide the PPI in the QER and therefore the UPF shall set the PPI for the DL service matching the PDR associated with the QER. The PDR will be provided to detect (one or more) DSCP codes, i.e. the SMF will be configured with (one or more) DSCP code to PPI mapping tables. This may work when the SMF knows which DSCP code will be set by the application server, for example, it may work for I / V-UPF where service level detection is not required. For example, in the case where the PDU Session Anchor (PSA) UPF is directly connected to the NG-RAN, it will have problems since the SMF does not know which DSCP code will be set by the application server for a specific service data flow (SDF). Therefore, in order to comply with the standard, it seems that the SMF must blindly provide all possible DSCPs to the same SDF, especially in the following cases: (1) Application ID is used to match incoming packets; (2) Lists of SDF filters with different DSCP values ​​(ToS / TC) are associated with the same PDR; or (3) The SMF is unaware of the DSCP value of the SDF (e.g., not defined as a match condition for DL ​​packets by the Policy Control Function (PCF)). Therefore, in order to support the PPI function, the SMF should create different DL PDRs corresponding to all possible DSCP values ​​to match incoming packets. But this is not realistic considering the number of DSCP values ​​as shown below: {af11|af12|af13|af21|af22|af23|af31|af32|af33|af41|af42|af43|be|cs1|cs2|cs3|cs4|cs5|cs6|cs7|ef}.

[0009] Therefore, under the existing PFCP protocol, the SMF needs to provide additional SDF filters to address all possible DSCP values ​​for each SDF. This may mean that up to 64 SDF filters per SDF (corresponding to 64 possible DSCP values) may need to be provided. The SMF needs to provide those additional PDR / QERs for each SDF. This may mean that up to 8 PDR / QERs per SDF (corresponding to 8 possible PPI values) may have to be provided to address the SA2 requirement of enabling (one or more) DSCPs to be mapped to (one or more) PPIs.

[0010] Figure 2 The relationship between PDR and QER (indicating PPI) is shown. Figure 2 As shown, in the SDF filter, the DSCP value (ToS / TC) is defined as a matching condition for an incoming packet (such as DL PDR 200), and the PPI in the QER is used to indicate the corresponding PPI in the CN tunnel header of the incoming packet.

[0011] Another problem is that since NG-RAN uses PPI value to apply corresponding paging policy for the case that UE needs to be paged when it is in RRC inactive state, while PPI value is not needed when UE is in RRC connected state. However, SMF / UPF is not aware of RRC state and will set PPI value for all DL packets in DL PDU, which is too costly for performance considering that PPI value is mapped from DSCP in ToS(IPv4) / TC(IPv6) value in IP header of each DL PDU.

[0012] If the PPD feature is enabled in the SMF for certain HPLMN, DNN and / or 5QI, the SMF instructs the UPF to detect the DSCP in the ToS (IPv4) / TC (IPv6) value in the IP header of the DLPDU and transmit the corresponding PPI in the CN tunnel header. The instruction can be per PFCP session or 5QI or service. The UPF marks the PPI mapped from the DSCP of the transmitted packet. The DSCP to PPI mapping can be configured in the UPF or can be indicated by the SMF. The SMF can instruct the UPF to transmit the corresponding PPI in the first few DL packets (e.g., the first 10 packets) only after a time period without uplink (UL) payload and DL payload (during which it can be assumed that the UE has entered an RRC inactive state) exceeds a threshold.

[0013] Advantages of the embodiments disclosed herein include that such embodiments allow operators to fully support the PPD functionality as defined in TS23.501V17.3.0 (December 2021).

[0014] According to some embodiments, a method for facilitating paging policy differentiation performed by a session management function (SMF) is provided. The method includes determining that a user plane function (UPF) supports a paging policy differentiation feature and that the paging policy differentiation feature is applicable to a protocol data unit (PDU) session. The method includes sending a message to the UPF instructing the UPF to insert a paging policy indicator (PPI) value into an outgoing packet based on a differentiated services code point (DSCP) value. The message includes DSCP to PPI control information.

[0015] In some embodiments, the message instructs the UPF to insert a PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet, and the DSCP value is in an IP header of the payload packet. In some embodiments, the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more Quality of Service (QoS) flow identifiers (QFIs), and a timer. In some embodiments, the timer is configured so that the UPF inserts the corresponding PPI value into a fixed number of outgoing packets only after a time period determined by the timer when there are no incoming or outgoing packets. In some embodiments, the one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for insertion of the PPI based on the DSCP to PPI mapping information. In some embodiments, the DSCP to PPI mapping information includes one of the following: (1) enabling the UPF to select an index of a DSCP to PPI mapping table pre-configured in the UPF, and (2) mapping the DSCP of the payload packet to a table of corresponding PPIs. In some embodiments, the message is a Packet Forwarding Control Protocol (PFCP) session message. In some embodiments, the PFCP message is one of a PFCP session establishment request or a PFCP session modification request.

[0016] According to another embodiment, a method for facilitating paging policy differentiation performed by a user plane function (UPF) is provided. The method includes receiving a message containing DSCP to PPI control information from a session management function (SMF), the message requesting the UPF to insert a paging policy indicator (PPI) value into an outgoing packet. The method includes retrieving a differentiated services code point (DSCP) value in an Internet Protocol (IP) header of an incoming payload packet. The method includes determining a PPI value for an outgoing packet based on the DSCP value and the DSCP to PPI mapping information. The method includes inserting the PPI value into the outgoing packet.

[0017] In another aspect, there is provided a computer program comprising instructions which, when executed by a processing circuit, cause the processing circuit to perform any of the methods disclosed herein.

[0018] In another aspect, a carrier containing the computer program disclosed herein is provided. The carrier may be one of an electronic signal, an optical signal, a radio signal and a computer-readable storage medium.

[0019] In another aspect, an apparatus configured to perform any of the methods disclosed herein is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The relationship between the DSCP value and the PPI value in the DL PDU is depicted.

[0021] Figure 2 DL PDR is depicted.

[0022] Figure 3 Describes the reference architecture of 5G communication system.

[0023] Figure 4 is a message flow diagram illustrating message flow according to some embodiments.

[0024] Figure 5 is a message flow diagram illustrating message flow according to some embodiments.

[0025] Figure 6 is a message flow diagram illustrating message flow according to some embodiments.

[0026] Figure 7 is a flow chart illustrating a process according to some embodiments.

[0027] Figure 8 is a flow chart illustrating a process according to some embodiments.

[0028] Fig. 9 is a block diagram of a physical machine according to some embodiments. DETAILED DESCRIPTION

[0029] Figure 3 A reference architecture of a communication system 300 according to one embodiment is depicted. In the example shown, the system 300 is a 5G system. More specifically, Figure 3A UE 301 is depicted connected to an access network (AN) 303, which may be a radio access network (RAN). The AN 303 is connected to an access and mobility management function (AMF) 326 via an N2 reference point, and the AN is also connected to a user plane function (UPF) 325 via an N3 reference point. The UPF 325 is adapted to be connected to a session management function (SMF) 327 via an N4 reference point, and to be connected to a data network (DN) 320 via an N6 reference point. The DN may be, for example, an operator service, an Internet access, or a third party service. The UE 301 is also connected to the AMF 326 via an N1 reference point. As in Figure 3 As further shown in FIG. 3 , the system 300 also includes the following additional network functions: an authentication server function (AUSF) 328, a network slice selection function (NSSF) 329, a network open function (NEF) 330, an NRF 331, a policy control function (PCF) 332, a unified data management (UDM) 333, and an application function (AF) 334. Each network function 326 to 334 exposes a service-based interface. For example, the service-based interface exposed by NSSF 329 is referred to as "Nnssf". Similarly, the service-based interface exposed by AMF 326 is referred to as "Namf".

[0030] UE 301 may be any mobile or fixed communication device that is capable of communicating with an access point (e.g., a base station) of an AN via a wireless channel (e.g., a radio channel). For example, UE 301 may be a mobile phone, a smart phone, a sensor, a meter, a vehicle, an appliance (home, medical, etc.), a media player, a camera, a machine-to-machine (M2M) device, or any type of consumer electronic device, such as, but not limited to, a television, a radio, a lighting device, a tablet, a laptop, or a personal computer (PC). UE 301 may be portable, pocket-storable, handheld, composed of a computer, or vehicle-mounted, and may be enabled to communicate voice and / or data with another entity (such as another UE or a server) via a radio access network. AN 303 may include an access point (in Figure 1 3GPP access network (not shown), such as NodeB, eNodeB, gNB, Wi-Fi access point or any other access point capable of communicating with UE 301 through a radio carrier. The abbreviations AN and RAN can be used interchangeably. AN can include both 3GPP radio access networks and non-3GPP access networks. A typical non-3GPP access network is a Wi-Fi network.

[0031] As mentioned above, under the current specification for PPD, it is unclear how to address all requirements in the PFCP protocol, which may result in additional PDR provisioning, for example. Consider an example. When the requirement to set PPI is not considered, for the SDF corresponding to application 1, the SMF can provide PDR to identify the DL application service:

[0032] PDR1: Packet Detection Information (PDI) is set with App-ID=1, UE IP address, together with Forwarding Action Rule (FAR) FAR1 for forwarding traffic to NG-RAN, and QER for QoS;

[0033] Now consider the requirement that the SMF instructs the UPF to set the PPI based on the DSCP code. For the purpose of this example, the DSCP code to PPI mapping is configured as per the operator's paging policy, for example, as shown below. This mapping is required here because there are 64 DSCP code points and there are 8 PPI values, and this mapping can be configured per DNN / Single Network Slice Selection Auxiliary Identifier (S-NSSAI).

[0034] DSCP to PPI mapping: - Up to 8 per index

[0035] Paging policy indicator = 1

[0036] DSCP=EF

[0037] DSCP=AF42

[0038] DSCP to PPI mapping:

[0039] Paging policy indicator = 2

[0040] DSCP=AF11

[0041] DSCP=AF12

[0042] DSCP=AF13

[0043] And for any other DSCP code, the PPI will be set to 3.

[0044] Using the above DSCP to PPI mapping, the SMF shall provide the following PDR and QER:

[0045] PDR1: PDI is set with App-ID=1&DSCP EF&DSCP AF42 together with QER 1, and PPI=1 is set;

[0046] PDR1: PDI is set with App-ID=1&DSCP AF11&DSCP AF12&AF13 together with QER 2, and PPI=2 is set;

[0047] PDR1: PDI is set with App-ID=1 together with QER 3, and PPI=3 is set;

[0048] Therefore, for each SDF, the SMF needs to provide: (1) an additional PDR with the same application detection logic but different DSCP codes (which are mapped to different PPIs); and (2) an additional QER with the same QoS requirements for different PPIs.

[0049] Furthermore, since the PPI is intended to be used by the NG-RAN only in case of NG-RAN paging, there is no need to set the PPI for all DL packets, which would add additional processing load on the UPF.

[0050] Therefore, embodiments provide an enhanced provision of PPI. For example, in embodiments:

[0051] 1. This DSCP to PPI mapping should be configured per PFCP session, because different DNN / S-NSSAI may have different paging policies. Therefore, SMF can indicate to UPF whether this DSCP to PPI mapping is required; if necessary, SMF can provide a DSCP to PPI mapping table;

[0052] 2. Since such DSCP to PPI mapping is only required for NG-RAN paging when the UE is in RRC Inactive state, the SMF may provide a timer to the UPF so that the UPF should insert the PPI for the first few DL packets after a period of no UL and DL payload (during which it can be assumed that the UE may enter RRC Inactive state).

[0053] 3. Optionally, add a QoS Flow Identifier (QFI) list, i.e., apply this DSCP to PPI mapping only to packets related to the requested QoS flow.

[0054] For example, the SMF instructs the UPF to detect the DSCP in the ToS (IPv4) / TC (IPv6) value in the IP header of the DL PDU and transmit the corresponding PPI in the CN tunnel header. The instruction can be per PFCP session or 5QI or service. The UPF marks the PPI mapped from the DSCP of the incoming packet, and the DSCP to PPI mapping can be configured in the UPF or can be indicated by the SMF. The SMF can instruct the UPF to transmit the corresponding PPI only in the first few downlink packets (e.g., the first 10 packets) after a period of time without uplink and downlink payload (during which it can be assumed that the UE enters the RRC inactive state).

[0055] Figure 4A flow chart according to an embodiment is shown. As shown, the SMF enables the paging policy per application for all services of the entire session or the services of 5QI. The SMF indicates to the UPF that the PPD function is enabled for all incoming packets. For example, in the PFCP session establishment (or modification) request 410, the SMF 327 may include DSCP to PPI control information. The UPF 325 may confirm this in the returned PFCP session establishment (or modification) response 412.

[0056] Example details of the information elements (IEs) are shown in Tables 1-4 below.

[0057] Table 1: PFCP session establishment request

[0058]

[0059] Table 2: DSCP to PPI control information in PFCP session establishment request

[0060]

[0061] Table 3: DSCP to PPI mapping information

[0062]

[0063]

[0064] The PPI value in octet 5 shall be encoded as a value between 0 and 7 as specified in clause 5.5.3.7 of 3GPP TS 38.415.

[0065] Table 4: PFCP Session Modification Request

[0066]

[0067] Figure 5 4 shows a flow chart according to an embodiment. As shown in the figure, the SMF enables the paging policy per application. The SMF instructs the UPF to enable the PPD function for all incoming packets. For example, in the PFCP session establishment (or modification) request 510, the SMF 327 may include DSCP to PPI control information (such as Figure 4 The UPF 325 may confirm this in the returned PFCP session establishment (or modification) response 512.

[0068] Example details of the information element (IE) are shown in Tables 5-6 below.

[0069] Table 5: Creating QER

[0070]

[0071] Table 6: Update QER

[0072]

[0073] Figure 6 A flow chart according to an embodiment is shown. As shown, the DSCP to PPI mapping information may be configured in the UPF, or may be indicated by the SMF at the node level if it is provided from the SMF. For example, in a PFCP session establishment (or modification) request or response 610, the SMF 327 may include the DSCP to PPI mapping information.

[0074] Figure 7 A flow chart illustrating a process 700 according to some embodiments is shown. The process 700 may start at step s702 and is a method for facilitating paging policy differentiation, performed by a session management function (SMF), such as SMF 327.

[0075] Step s702 includes determining that the user plane function (UPF) (325) supports the paging policy differentiation feature and that the paging policy differentiation feature is applicable to the protocol data unit (PDU) session.

[0076] Step s704 comprises sending a message to the UPF (325) instructing the UPF (325) to insert a Paging Policy Indicator (PPI) value (110) into outgoing packets based on a Differentiated Services Code Point (DSCP) value (106).

[0077] Step s706 includes: wherein the message includes DSCP to PPI control information.

[0078] In some embodiments, the message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet, and the DSCP value is in an IP header of the payload packet. In some embodiments, the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more Quality of Service (QoS) flow identifiers (QFIs), and a timer. In some embodiments, the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a time period determined by the timer when there are no incoming or outgoing packets.

[0079] In some embodiments, one or more QFIs indicate to the UPF a QoS flow to which the payload packet belongs that is eligible for insertion of a PPI based on the DSCP to PPI mapping information. In some embodiments, the DSCP to PPI mapping information includes one of: (1) enabling the UPF to select an index to a DSCP to PPI mapping table preconfigured in the UPF, and (2) a table that maps the DSCP of the payload packet to a corresponding PPI. In some embodiments, the message is a packet forwarding control protocol (PFCP) session message. In some embodiments, the PFCP message is one of a PFCP session establishment request or a PFCP session modification request.

[0080] Figure 8 A flow chart illustrating a process 800 according to some embodiments is shown. The process 800 may start at step s802 and is a method for facilitating paging policy differentiation, performed by a user plane function (UPF), such as the UPF 325.

[0081] Step s802 comprises receiving a message from a Session Management Function (SMF) (327) containing DSCP to PPI control information requesting the UPF (325) to insert a Paging Policy Indicator (PPI) value (110) into outgoing packets.

[0082] Step s804 comprises retrieving a Differentiated Services Code Point (DSCP) value in an Internet Protocol (IP) header of the transmitted payload packet.

[0083] Step s806 comprises determining a PPI value for outgoing packets based on the DSCP value and the DSCP to PPI mapping information.

[0084] Step s808 comprises inserting the PPI value into the outgoing packet.

[0085] In some embodiments, the message requests the UPF (325) to insert the PPI value into an outgoing General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) packet encapsulating the payload packet in a GTP-U layer extension header. In some embodiments, the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more Quality of Service (QoS) flow identifiers (QFIs), and a timer. In some embodiments, the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a time period determined by the timer when there are no incoming or outgoing packets, and further includes: determining based on the timer that there have been no incoming or outgoing packets within the time period; and as a result of determining based on the timer that there have been no incoming or outgoing packets within the time period, inserting the PPI value into the fixed number of outgoing packets.

[0086] In some embodiments, one or more QFIs indicate to the UPF a QoS flow to which the payload packet belongs, which QoS flow is eligible for insertion of a PPI based on the DSCP to PPI mapping information; and also includes: determining that the outgoing packet matches a QFI in the one or more QFIs before inserting the PPI value into the outgoing packet. In some embodiments, the DSCP to PPI mapping information includes one of the following: (1) enabling the UPF to select an index to a DSCP to PPI mapping table pre-configured in the UPF, and (2) a table that maps the DSCP of the payload packet to the corresponding PPI. In some embodiments, the message is a packet forwarding control protocol (PFCP) session message. In some embodiments, the PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

[0087] Summary of various embodiments

[0088] A1. A method for facilitating paging policy differentiation performed by a session management function (SMF) (327), the method comprising:

[0089] Determining that a user plane function (UPF) (325) supports a paging policy differentiation feature and that the paging policy differentiation feature is applicable to a protocol data unit (PDU) session; and

[0090] sending a message to the UPF (325) instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into outgoing packets based on a differentiated services code point (DSCP) value (106),

[0091] The message includes DSCP to PPI control information.

[0092] A2. A method according to embodiment A1, wherein the message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet, and the DSCP value is in the IP header of the payload packet.

[0093] A3. A method according to any one of embodiments A1-A2, wherein the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more quality of service (QoS) flow identifiers (QFIs), and a timer.

[0094] A4. A method according to embodiment A3, wherein the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a period of time determined by the timer without incoming or outgoing packets.

[0095] A5. A method according to any one of embodiments A2-A4, wherein one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for PPI insertion based on DSCP to PPI mapping information.

[0096] A6. A method according to any one of embodiments A2-A5, wherein the DSCP-to-PPI mapping information includes one of the following: (1) enabling the UPF to select an index of a DSCP to PPI mapping table pre-configured in the UPF, and (2) a table that maps the DSCP of the payload packet to the corresponding PPI.

[0097] A7. A method according to any one of embodiments A1-A6, wherein the message is a packet forwarding control protocol (PFCP) session message.

[0098] A8. A method according to embodiment A7, wherein the PFCP message is one of a PFCP session establishment request or a PFCP session modification request.

[0099] B1. A method for facilitating paging policy differentiation performed by a user plane function (UPF) (325), the method comprising:

[0100] receiving a message from a session management function (SMF) (327) containing DSCP to PPI control information requesting a UPF (325) to insert a paging policy indicator (PPI) value (110) into outgoing packets;

[0101] retrieving a Differentiated Services Code Point (DSCP) value in an Internet Protocol (IP) header of an incoming payload packet;

[0102] determining a PPI value for outgoing packets based on the DSCP value and the DSCP-to-PPI mapping information; and

[0103] Insert the PPI value into outgoing packets.

[0104] B2. A method according to embodiment B1, wherein the message requests the UPF (325) to insert the PPI value into a GTP-U layer extension header of an outgoing General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) packet encapsulating the payload packet.

[0105] B3. A method according to any one of embodiments B1-B2, wherein the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more quality of service (QoS) flow identifiers (QFIs), and a timer.

[0106] B4. The method of embodiment B3, wherein the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a time period determined by the timer when there are no incoming or outgoing messages, and the method further comprises:

[0107] Based on the timer, determining that there have been no incoming or outgoing packets for a time period; and

[0108] As a result of determining based on the timer that there have been no incoming or outgoing packets for a period of time, the PPI value is inserted into a fixed number of outgoing packets.

[0109] B5. A method according to any one of embodiments B3-B4, wherein one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for PPI insertion based on DSCP to PPI mapping information; and the method also includes: before inserting the PPI value into the outgoing packet, determining that the outgoing packet matches a QFI in one or more QFIs.

[0110] B6. A method according to any one of embodiments B3-B5, wherein the DSCP to PPI mapping information includes one of the following: (1) enabling the UPF to select an index of a DSCP to PPI mapping table pre-configured in the UPF, and (2) a table that maps the DSCP of the payload packet to the corresponding PPI.

[0111] B7. A method according to any one of embodiments B1-B6, wherein the message is a packet forwarding control protocol (PFCP) session message.

[0112] B8. A method according to embodiment B7, wherein the PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

[0113] C1. A computer program (943) comprising instructions (944) which, when executed by a processing circuit (902), cause the processing circuit (902) to perform the method of any one of embodiments A1-A8 and B1-B8.

[0114] C2. A carrier containing the computer program of claim 17, wherein the carrier is one of an electronic signal, an optical signal, a radio signal and a computer-readable storage medium (942).

[0115] D1. A device (900) configured to execute the method described in any one of the above embodiments A1-A8 and B1-B8.

[0116] E1. A session management function (SMF) (327) node, the node being configured to:

[0117] Determining that a user plane function (UPF) (325) supports a paging policy differentiation feature and that the paging policy differentiation feature is applicable to a protocol data unit (PDU) session; and

[0118] sending a message to a UPF (325) instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into an outgoing packet based on a differentiated services code point (DSCP) value (106);

[0119] The message includes DSCP to PPI control information.

[0120] E2. A node according to embodiment E1, wherein the message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet, and the DSCP value is in the IP header of the payload packet.

[0121] E3. A node according to any one of embodiments E1-E2, wherein the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more quality of service (QoS) flow identifiers (QFIs), and a timer.

[0122] E4. A node according to embodiment E3, wherein the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a period of time determined by the timer without incoming or outgoing messages.

[0123] E5. A node according to any one of embodiments E3-E4, wherein one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for PPI insertion based on DSCP to PPI mapping information.

[0124] E6. A node as in any one of embodiments E3-E5, wherein the DSCP to PPI mapping information comprises one of: (1) an index enabling the UPF to select a DSCP to PPI mapping table pre-configured in the UPF, and (2) a table mapping the DSCP of the payload packet to the corresponding PPI.

[0125] E7. A node according to any one of embodiments E1-E6, wherein the message is a packet forwarding control protocol (PFCP) session message.

[0126] E8. A node according to embodiment E7, wherein the PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

[0127] F1. A user plane function (UPF) (325) node, configured to:

[0128] receiving a message from a session management function (SMF) (327) containing DSCP to PPI control information requesting a UPF (325) to insert a paging policy indicator (PPI) value (110) into outgoing packets;

[0129] retrieving a Differentiated Services Code Point (DSCP) value in an Internet Protocol (IP) header of an incoming payload packet;

[0130] determining a PPI value for outgoing packets based on the DSCP value and the DSCP-to-PPI mapping information; and

[0131] Insert the PPI value into outgoing packets.

[0132] F2. A node according to embodiment F1, wherein the message requests the UPF (325) to insert the PPI value into a GTP-U layer extension header of an outgoing General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) packet encapsulating the payload packet.

[0133] F3. A node according to any one of embodiments F1-F2, wherein the DSCP to PPI control information further includes one or more DSCP to PPI mapping information, one or more quality of service (QoS) flow identifiers (QFIs), and a timer.

[0134] F4. A node according to embodiment F3, wherein the timer is configured to cause the UPF to insert the corresponding PPI value into a fixed number of outgoing packets only after a period of time determined by the timer without incoming or outgoing messages, and the node is further configured to:

[0135] Based on the timer, determining that there have been no incoming or outgoing packets for a time period; and

[0136] As a result of determining based on the timer that there have been no incoming or outgoing packets for a period of time, the PPI value is inserted into a fixed number of outgoing packets.

[0137] F5. A node according to any one of embodiments F3-F4, wherein one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for PPI insertion based on DSCP to PPI mapping information; and the node is also configured to: before inserting the PPI value into the outgoing packet, determine that the outgoing packet matches a QFI in one or more QFIs.

[0138] F6. A node as in any one of embodiments F3-F5, wherein the DSCP to PPI mapping information comprises one of: (1) an index enabling the UPF to select a DSCP to PPI mapping table pre-configured in the UPF, and (2) a table mapping the DSCP of the payload packet to the corresponding PPI.

[0139] F7. A node according to any one of embodiments F1-F6, wherein the message is a packet forwarding control protocol (PFCP) session message.

[0140] F8. A node according to embodiment F7, wherein the PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

[0141] G1. A device (900) configured to perform the method described in any one of the above embodiments A1-A8 and B1-B8.

[0142] Fig. 9 9 is a block diagram of a physical machine (or "device") 900 that may be used to run any of UPF 325 and SMF 327, according to some embodiments. Fig. 9As shown, the device 900 may include: a processing circuit (PC) 902, which may include one or more processors (P) 955 (e.g., a general-purpose microprocessor and / or one or more other processors, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc.), which may be co-located in a single housing or a single data center, or may be geographically distributed (i.e., the device 900 may be a distributed computing device); a network interface 948, which includes a transmitter (Tx) 945 and a receiver (Rx) 947, for enabling the device 900 to send and receive data to other machines connected to a network 910 (e.g., an Internet Protocol (IP) network) to which the network interface 948 is directly or indirectly connected (e.g., the network interface 948 may be wirelessly connected to the network 110, in which case the network interface 948 is connected to an antenna device); and a local storage unit (also referred to as a "data storage system") 908, which may include one or more non-volatile storage devices and / or one or more volatile storage devices. In an embodiment where the PC 902 includes a programmable processor, a computer program product (CPP) 941 may be provided. The CPP 941 includes a computer readable medium (CRM) 942 storing a computer program (CP) 943 including computer readable instructions (CRI) 944. The CRM 942 may be a non-transitory computer readable medium, such as a magnetic medium (e.g., a hard disk), an optical medium, a storage device (e.g., a random access memory, a flash memory), etc. In some embodiments, the CRI 944 of the computer program 943 is configured so that when executed by the PC 902, the CRI causes the device 900 to perform the steps described herein (e.g., the steps described herein with reference to the flowcharts). In other embodiments, the device 900 may be configured to perform the steps described herein without requiring code. That is, for example, the PC 902 may consist solely of one or more ASICs. Thus, the features of the embodiments described herein may be implemented in hardware and / or software.

[0143] Although various embodiments are described herein, it should be understood that they are presented by way of example only, not limitation. Therefore, the breadth and scope of the present invention should not be subject to any limitation of the above-mentioned exemplary embodiments. In addition, any combination of the above-mentioned elements in all possible variations thereof is included in the present disclosure, unless otherwise stated herein or clearly contradicted by the context.

[0144] In addition, although the processes described above and shown in the accompanying drawings are shown as a sequence of steps, this is for illustration only. Therefore, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be rearranged, and some steps may be performed in parallel.

Claims

1. A method for facilitating paging policy differentiation, performed by a session management function (SMF) (327), the method comprising: Determining that the user plane function UPF (325) supports paging strategy differentiation characteristics; as well as sending a message to the UPF (325), the message instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into a downlink packet based on a differentiated services code point (DSCP) value (106), The message includes DSCP to PPI control information.

2. The method according to claim 1, wherein: The message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet.

3. The method according to any one of claims 1 to 2, wherein: The DSCP to PPI control information further includes one or more DSCP to PPI mapping information and / or one or more quality of service QoS flow identifiers QFI.

4. The method according to any one of claims 1 to 3, further comprising: Prior to sending a message to the UPF (325) instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into a downlink packet based on a differentiated services code point (DSCP) value (106), determining that the paging policy differentiation feature is applicable to a protocol data unit (PDU) session.

5. The method according to any one of claims 2 to 4, wherein: The one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, the QoS flow being eligible for PPI insertion based on the DSCP-to-PPI mapping information.

6. The method according to any one of claims 2 to 5, wherein: The DSCP-to-PPI mapping information includes a table that maps the DSCP of a payload packet to a corresponding PPI, the table including one or more DSCP identifiers corresponding to a PPI identifier.

7. The method according to any one of claims 1 to 6, wherein: The message is a Packet Forwarding Control Protocol PFCP session message.

8. The method according to claim 7, wherein: The PFCP message is one of a PFCP session establishment request or a PFCP session modification request.

9. A method for facilitating paging strategy differentiation performed by a user plane function (UPF) (325), the method comprising: receiving a message containing DSCP to PPI control information from a session management function SMF (327), the message requesting the UPF (325) to insert a paging policy indicator PPI value (110) into a downlink packet; Retrieving a Differentiated Services Code Point (DSCP) value in an Internet Protocol (IP) header of an incoming payload packet; determining a PPI value for a downlink packet based on the DSCP value and the DSCP-to-PPI mapping information; as well as The PPI value is inserted into the downlink packet.

10. The method according to claim 9, wherein: The message requests the UPF (325) to insert the PPI value into a GTP-U layer extension header of a downlink General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) packet encapsulating a payload packet.

11. The method according to any one of claims 9 to 10, wherein: The DSCP to PPI control information further includes one or more DSCP to PPI mapping information and / or one or more quality of service QoS flow identifiers QFI.

12. The method according to claim 4, wherein: The message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet.

13. The method according to any one of claims 11 to 12, wherein: The one or more QFIs indicate to the UPF a QoS flow to which a payload packet belongs, the QoS flow being eligible for insertion of a PPI based on the DSCP to PPI mapping information; And the method further includes, before inserting the PPI value into the downlink packet, determining that the downlink packet matches a QFI among the one or more QFIs.

14. The method according to any one of claims 11 to 13, wherein: The DSCP-to-PPI mapping information includes a table that maps the DSCP of a payload packet to a corresponding PPI, the table including one or more DSCP identifiers corresponding to a PPI identifier.

15. The method according to any one of claims 9 to 14, wherein: The message is a Packet Forwarding Control Protocol PFCP session message.

16. The method according to claim 15, wherein: The PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

17. A computer program (943) comprising instructions (944) which, when executed by a processing circuit (902), cause the processing circuit (902) to perform the method of any one of claims 1 to 16.

18. A carrier comprising the computer program according to claim 17, wherein: The carrier is one of an electronic signal, an optical signal, a radio signal and a computer-readable storage medium (942).

19. An apparatus (900) configured to perform the method of any one of claims 1 to 16.

20. A session management function (SMF) node (327), the node being configured to: Determining that the user plane function UPF (325) supports paging strategy differentiation characteristics; and sending a message to the UPF (325), the message instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into a downlink packet based on a differentiated services code point (DSCP) value (106), in, The message includes DSCP to PPI control information.

21. The node according to claim 20, wherein: The message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet.

22. A node according to any one of claims 20 to 21, wherein: The DSCP to PPI control information further includes one or more DSCP to PPI mapping information and / or one or more quality of service QoS flow identifiers QFI.

23. The node according to claim 20 is further configured to: determine that the paging policy differentiation characteristic is applicable to a protocol data unit (PDU) session before sending a message to the UPF (325) instructing the UPF (325) to insert a paging policy indicator (PPI) value (110) into a downlink packet based on a differentiated services code point (DSCP) value (106).

24. A node according to any one of claims 21 to 23, wherein: The one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, the QoS flow being eligible for PPI insertion based on the DSCP-to-PPI mapping information.

25. A node according to any one of claims 21 to 24, wherein: The DSCP-to-PPI mapping information includes a table that maps the DSCP of a payload packet to a corresponding PPI, the table including one or more DSCP identifiers corresponding to a PPI identifier.

26. A node according to any one of claims 20 to 25, wherein: The message is a Packet Forwarding Control Protocol PFCP session message.

27. The node according to claim 26, wherein: The PFCP message is one of a PFCP session establishment request or a PFCP session modification request.

28. A user plane function (UPF) node, the node being configured to: receiving a message containing DSCP to PPI control information from a session management function SMF (327), the message requesting the UPF (325) to insert a paging policy indicator PPI value (110) into a downlink packet; Retrieving a Differentiated Services Code Point (DSCP) value in an Internet Protocol (IP) header of an incoming payload packet; determining a PPI value for a downlink packet based on the DSCP value and the DSCP-to-PPI mapping information; as well as The PPI value is inserted into the downlink packet.

29. A node according to claim 28, wherein: The message requests the UPF (325) to insert the PPI value into a GTP-U layer extension header of a downlink General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) packet encapsulating a payload packet.

30. A node according to any one of claims 28 to 29, wherein: The DSCP to PPI control information further includes one or more DSCP to PPI mapping information and / or one or more quality of service QoS flow identifiers QFI.

31. The node according to claim 23, wherein: The message instructs the UPF (325) to insert the PPI value into a General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTP-U) layer extension header of a GTP-U packet encapsulating a payload packet.

32. A node according to any one of claims 30 to 31, wherein: The one or more QFIs indicate to the UPF the QoS flow to which the payload packet belongs, which QoS flow is eligible for PPI insertion based on the DSCP to PPI mapping information; and the node is also configured to: before inserting the PPI value into the downlink packet, determine that the downlink packet matches a QFI in the one or more QFIs.

33. A node according to any one of claims 30 to 32, wherein: The DSCP-to-PPI mapping information includes a table that maps the DSCP of a payload packet to a corresponding PPI, the table including one or more DSCP identifiers corresponding to a PPI identifier.

34. A node according to any one of claims 28 to 33, wherein: The message is a Packet Forwarding Control Protocol PFCP session message.

35. A node according to claim 34, wherein: The PFCP session message is one of a PFCP session establishment request or a PFCP session modification request.

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