Communication methods and systems, session management function network elements and storage media

Abstract

The present disclosure relates to a communication method, a network and a system, a session management function network element and a storage medium. The method includes: when the protocol data unit session anchor point PSA changes, the session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller. The present disclosure uses the SDN controller to change the routing direction of the DN switch, thereby achieving that when the PSA UPF changes, the PDU session IP address always remains fixed.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communications, and in particular to a communication method and system, a session management function network element, and a storage medium. Background Art

[0002] The 5G system supports three SSC (Session and Service Continuity) Modes (types), among which: SSC Mode1: PSA (PDU Session Anchor) remains unchanged; SSC Mode2: PSA changes, and the UE (User Equipment) immediately initiates a new PDU session establishment process after releasing the PDU (Protocol Data Unit) session; SSC Mode3: PSA changes, and the UE first establishes a new PDU session and then releases the old session. Summary of the invention

[0003] Through research, the inventors found that in SSC Mode 2 / 3, there is a situation where PSA is changed. When the PSA UPF (UserPlane Function) changes, the IP address of the UE will change according to the current core network standard. However, if the edge application does not support the client's IP address change, there will be a technical problem that the edge application cannot access the network.

[0004] In view of at least one of the above technical problems, the present disclosure provides a communication method and system, a session management function network element and a storage medium, so that when the PSA UPF changes, the 5G core network can keep the UE IP address unchanged.

[0005] According to one aspect of the present disclosure, there is provided a communication method, comprising:

[0006] When the protocol data unit session anchor point PSA changes, the session management function network element keeps the IP address of the user terminal unchanged through the software-defined network controller.

[0007] In some embodiments of the present disclosure, the session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller, including:

[0008] When the protocol data unit (PDU) session of the user terminal is switched from the first PSA to the second PSA, the session management function network element sends the IP address of the second PSA to the software defined network controller so that the software defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

[0009] In some embodiments of the present disclosure, the session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller, including:

[0010] When a protocol data unit (PDU) session of a user terminal is switched from a first PSA to a second PSA, the session management function network element sends a session establishment message to the second PSA;

[0011] The session management function network element sends the IP address of the second PSA to the software defined network controller, so that the software defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA;

[0012] After the PDU session of the second PSA is established, the session management function network element sends a session deletion message of the first PSA to cancel the PDU session of the first PSA.

[0013] In some embodiments of the present disclosure, the session management function network element sending the IP address of the second PSA to the software defined network controller includes: the session management function network element sending the IP address of the second PSA to the software defined network controller through the network development function network element.

[0014] In some embodiments of the present disclosure, the session establishment message is a packet switched control protocol session establishment message.

[0015] In some embodiments of the present disclosure, the session deletion message is a packet switching control protocol session deletion message.

[0016] According to another aspect of the present disclosure, a session management function network element is provided, wherein:

[0017] The session management function network element is configured to keep the IP address of the user terminal unchanged through the software defined network controller when the protocol data unit session anchor point PSA changes.

[0018] In some embodiments of the present disclosure, the session management function network element includes:

[0019] The address sending module is configured to send the IP address of the second PSA to the software-defined network controller when the protocol data unit (PDU) session of the user terminal is switched from the first PSA to the second PSA, so that the software-defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

[0020] In some embodiments of the present disclosure, the session management function network element includes:

[0021] A session establishment message sending module, configured to, when a protocol data unit (PDU) session of a user terminal is switched from a first PSA to a second PSA, a session management function network element sends a session establishment message to the second PSA;

[0022] An address sending module is configured to send the IP address of the second PSA to the software defined network controller, so that the software defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA;

[0023] The session deletion message sending module is configured to, after the PDU session of the second PSA is established, send a session deletion message of the first PSA by the session management function network element to cancel the PDU session of the first PSA.

[0024] In some embodiments of the present disclosure, the address sending module is configured to send the IP address of the second PSA to the software defined network controller through the network development function network element.

[0025] In some embodiments of the present disclosure, the session establishment message is a packet switched control protocol session establishment message.

[0026] In some embodiments of the present disclosure, the session deletion message is a packet switching control protocol session deletion message.

[0027] According to another aspect of the present disclosure, a session management function network element is provided, including:

[0028] a memory configured to store instructions;

[0029] The processor is configured to execute the instructions so that the session management function network element performs operations to implement the communication method described in any of the above embodiments.

[0030] According to another aspect of the present disclosure, a communication network is provided, comprising a software defined network controller and a session management function network element as described in any of the above embodiments.

[0031] In some embodiments of the present disclosure, the communication network further includes a first PSA, a second PSA, and a switch in the data network, wherein:

[0032] The software defined network controller is configured to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA;

[0033] The switch in the data network is configured to add a new routing entry in the routing table, wherein in the routing entry, the next hop points to the second PSA, and the host IP address of the user terminal is still the IP address allocated from the IP address pool of the first PSA.

[0034] In some embodiments of the present disclosure, the switch in the data network is configured to query the routing table and send the downlink data to the user terminal through the second PSA when the downlink data of the user terminal arrives at the data network.

[0035] In some embodiments of the present disclosure, a switch in a data network is configured to aggregate multiple adjacent routing entries by routing aggregation when a newly added routing table entry is a plurality of adjacent routing entries.

[0036] According to another aspect of the present disclosure, a communication system is provided, including a user terminal and a communication network as described in any one of the above embodiments.

[0037] According to another aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, the communication method described in any of the above embodiments is implemented.

[0038] The present disclosure adopts an SDN controller to change the routing direction of the DN switch, thereby ensuring that when the PSA UPF changes, the PDU session IP address always remains fixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 It is a schematic diagram of the SSC mode 2 process in the related art.

[0041] Figure 2 It is a schematic diagram of the SSC mode 3 process in the related art.

[0042] Figure 3 The following are schematic diagrams of some embodiments of the communication method disclosed herein.

[0043] Figure 4 Schematic diagrams of other embodiments of the communication method disclosed herein.

[0044] Figure 5 Schematic diagram of some embodiments of the communication system disclosed herein.

[0045] Figure 6 Schematic diagrams of some further embodiments of the communication system and the communication network disclosed in the present invention.

[0046] Figure 7 The present invention is a schematic diagram of the structure of some embodiments of the session management function network element.

[0047] Figure 8 It is a schematic diagram of the structure of some other embodiments of the session management function network element disclosed in the present invention. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0049] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

[0050] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0051] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0052] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0053] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0054] The inventors have discovered through research that in the scenario of edge computing of the related technology, there may be a UPF that is closer to the user, so the original PDU session of the UE may undergo a PSA UPF switch.

[0055] Figure 1 FIG. 2 is a schematic diagram of the SSC mode 2 process in the related art. Figure 1As shown in Figure 2, in SSC mode 2, the PSA changes and the UE immediately initiates a new PDU session establishment process after releasing the PDU session. Figure 1 As shown, the SSC mode 2 process may include: step 10, the user terminal accesses UPF1 through RAN (Radio Access Network) or AN (Access Network), and AMF (Access and Mobility Management Function), and the UE interacts with UPF1 for uplink data and downlink data; step 11, SMF (Session Management Function) determines UPF relocation needs to be performed (determines that UPF relocation is needed); step 11a, SMF1 sends Nsmf_PDUSession_SMContextStatusNotifyRequest / Response (PDU session context status notification request or response) message to AMF; step 12, SMF1 executes the release process of the PDU session between UE and UPF1; step 13, SMF2 executes the establishment process of the PDU session between UE and UPF2; step 14, uplink data and downlink data are interacted between UE and UPF2.

[0056] Figure 2 FIG. 3 is a schematic diagram of the SSC mode 3 process in the related art. Figure 2 As shown in Figure 2, in SSC mode 3, the PSA changes, and the UE first establishes a new PDU session and then releases the old session. Figure 2As shown, the SSC mode 3 process may include: step 20, the user terminal accesses UPF1 through RAN or AN and AMF, and the UE interacts with UPF1 for uplink data and downlink data; step 21, SMF determines that UPF / SMF relocation is required; step 21a, SMF1 sends a PDU session context status notification request or response message to AMF; step 22, SMF1 calls Namf_Communication_N1N2MessageTransfer (communication message transmission) to AMF; step 23a, AMF sends a PDU session modification command (PDU Session ModificationCommand) to the user terminal; step 23b, the user terminal returns a PDU session modification command confirmation message to AMF; step 23c, AMF requests SMF to update the PDU session through the Nsmf_PDUSession_UpdateSMContext service; step 23c, SMF returns a PDU session update response message (Nsmf_PDUSession_UpdateSMContext to AMF Response); Step 24, the terminal initiates the process of establishing a PDU session with UPF2, that is, UE-initiated PDU Session establishment procedure (with UPF2); Step 25, uplink data and downlink data are exchanged between UE and UPF2; Step 26, SMF1 executes the release process of the PDU session between UE and UPF1.

[0057] The inventors discovered through research and development that since different UPFs allocate different IP address pools, the switching of the PSA UPF in the related art will cause the UE IP address to change.

[0058] In view of at least one of the above technical problems, the present disclosure provides a communication method and system, a session management function network element and a storage medium. The present disclosure is described below through specific embodiments.

[0059] Figure 3 Schematic diagram of some embodiments of the communication method of the present disclosure. Preferably, the present embodiment can be executed by the session management function network element of the present disclosure or the communication network of the present disclosure or the communication system of the present disclosure. The method includes step 30, wherein:

[0060] Step 30: When the protocol data unit session anchor point PSA changes, the session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller.

[0061] In some embodiments of the present disclosure, step 30 may include: when the protocol data unit PDU session of the user terminal is switched from the first PSA to the second PSA, the session management function network element sends the IP address of the second PSA to the software defined network controller, so that the software defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

[0062] In some embodiments of the present disclosure, step 30 may include at least one of steps 31 to 33, wherein:

[0063] Step 31: When the protocol data unit (PDU) session of the user terminal is switched from the first PSA to the second PSA, the session management function network element sends a session establishment message to the second PSA.

[0064] In some embodiments of the present disclosure, the session establishment message is a PFCP (Packet Forwarding Control Protocol) session establishment message.

[0065] In some embodiments of the present disclosure, PSA1 and PSA2 may be implemented as UPF.

[0066] In step 32, the session management function network element sends the IP address of the second PSA to the software defined network controller so that the software defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to the switch in the data network, wherein the host IP address of the user terminal is still the IP address allocated from the IP address pool of the first PSA.

[0067] In some embodiments of the present disclosure, in step 32, the step of the session management function network element sending the IP address of the second PSA to the software defined network controller may include: the session management function network element sends the IP address of the second PSA to the software defined network controller through the NEF (Network Exposure Function) network element.

[0068] Step 33: After the PDU session of the second PSA is established, the session management function network element sends a session deletion message of the first PSA to cancel the PDU session of the first PSA.

[0069] In some embodiments of the present disclosure, the session deletion message is a packet switching control protocol session deletion message.

[0070] After switching the PSA UPF in the above embodiment of the present disclosure, the SMF sends the IP address of the new PSAUPF to the AF (SDN controller) through the NEF, and the SDN controller sends the UE host route pointing to the new PSA UPF to the switch in the DN, so that the DN can reach the new PSA UPF through the route.

[0071] Figure 4 Schematic diagrams of other embodiments of the communication method of the present disclosure. Preferably, this embodiment can be performed by the communication network of the present disclosure or the communication system of the present disclosure. The method includes at least one step of steps 40-46, wherein:

[0072] In step 40, the user terminal UE accesses PSA1 through the RAN or AN and the AMF. The UE interacts with the DN (Data Network) through PSA1 for uplink data (UL Data) and downlink data (DL Data), and is allocated IP1 from the IP address pool of PSA1.

[0073] In some embodiments of the present disclosure, PSA1 and PSA2 may be implemented as UPF.

[0074] In some embodiments of the present disclosure, the UE is serving PSA1 and exchanging uplink and downlink data with the DN.

[0075] Step 41: The session management function network element determines that UPF Relocation (reconfiguration) is required.

[0076] In some embodiments of the present disclosure, step 41 may include: when the PSA serving the user terminal needs to be changed, the session management function network element modifies the anchor point from the first PSA to the second PSA.

[0077] In some embodiments of the present disclosure, step 41 may include: when an event (such as edge computing) triggers the SMF to change the PSA, the SMF determines the UPF serving the UE based on the event trigger, for example: the SMF determines to change the anchor point from PSA1 to PSA2.

[0078] Step 42, SMF releases the PDU session via PSA1.

[0079] Step 43, SMF informs AF (SDN controller) of the new anchor point PSA2 IP address through NEF.

[0080] Step 44, the DN controller sends the UE host route containing the next hop pointing to PSA2 to the switch in the DN through its southbound interface.

[0081] Step 45: PSA2 establishes a new PDU session with the UE.

[0082] Step 46, when DN has downlink traffic of UE, since the routing table is queried and there is a UE host route pointing to PSA2, the downlink traffic will be sent to UE through PSA2, thus achieving the goal of changing PSA while keeping the UE IP address unchanged.

[0083] In the above embodiment of the present disclosure, when DN has downlink traffic of UE, since the routing table is queried and there is a UE host route pointing to PSA2, the downlink traffic will be sent to UE through PSA2, thereby achieving the goal of changing PSA while keeping the UE IP address unchanged.

[0084] The related art SSC Mode 2 / 3 must change the PDU session IP address, but after using the method of the above embodiment of the present disclosure, when the PSA UPF changes, the PDU session IP address always remains fixed.

[0085] Figure 5 Schematic diagram of some embodiments of the communication system disclosed in the present invention. Figure 5 As shown, the communication system of the present disclosure may include a user terminal 50 and a communication network 60 .

[0086] Figure 5 Schematic diagrams of some embodiments of the communication network disclosed in the present invention are also provided. Figure 5 As shown, the communication network 60 of the present disclosure may include a software defined network controller 61, a session management function network element 62 and a data network 63, wherein:

[0087] The session management function network element 62 is configured to keep the IP address of the user terminal unchanged through the software defined network controller 61 when the protocol data unit session anchor point PSA changes.

[0088] In some embodiments of the present disclosure, the session management function network element 62 is configured to send the IP address of the second PSA to the software defined network controller when the protocol data unit PDU session of the user terminal is switched from the first PSA to the second PSA.

[0089] The software defined network controller 61 is configured to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network 63 .

[0090] In some embodiments of the present disclosure, the communication network may further include a data network 63 wherein:

[0091] The software defined network controller 61 is configured to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA;

[0092] The switch in the data network 63 is configured to add a new routing entry in the routing table, wherein in the routing entry, the next hop points to the second PSA, and the host IP address of the user terminal is still the IP address allocated from the IP address pool of the first PSA.

[0093] In some embodiments of the present disclosure, the switch in the data network 63 is configured to query the routing table and send the downlink data to the user terminal through the second PSA when the downlink data of the user terminal arrives at the data network.

[0094] In some embodiments of the present disclosure, the switch in the data network 63 is configured to aggregate the multiple adjacent routing entries by routing aggregation when the newly added routing table entry is a plurality of adjacent routing entries.

[0095] Figure 4 Schematic diagrams of other embodiments of the communication system and communication network disclosed in the present invention are also provided. Figure 4 As shown, Figure 4 The embodiment communication network may include a software-defined network controller 61, a session management function network element 62, a data network 63, a radio access network (RAN) or an access network (AN) 64, an access and mobility management function network element (AMF) 65, a first PSA (PSA1) and a second PSA (PSA2), and a NEF (network open function network element) 66.

[0096] Figure 6 Schematic diagrams of some other embodiments of the communication system and communication network disclosed in the present invention. Figure 6 As shown, the communication system of the present disclosure may include a user terminal (UE) 50 and a communication network. Figure 6 As shown, the communication network of the present disclosure may include an access network (AN) 64, an access and mobility management function network element (AMF) 65, a software defined network controller 61, a session management function network element (SMF) 62, a data network (DN) 63 and three UPFs, wherein:

[0097] like Figure 6 As shown, Figure 6 There are three UPFs, including one BP (Branching Point) and two PSAs, namely, PSA1 (PDU Session Anchor 1) and PSA2 (PDU Session Anchor 2). PSA1 and PSA2 access the same DN through local access.

[0098] In some embodiments of the present disclosure, Figure 6As shown, UE and AMF communicate through the N1 interface, AN and AMF communicate through the N2 interface, AN and UPF communicate through the N3 interface, SMF communicates with three UPFs (BP, PSA1 and PSA2) through the N4 interface, DN communicates with PSA1 and PSA2 through the N6 interface, BP communicates with PSA1 and PSA2 through the N9 interface, and SMF and AMF communicate through the N11 interface.

[0099] Assume that IP allocation is completed by UPF, the IP address pool of PSA1 is IP_POOL_1, and that of PSA2 is IP_POOL_2. There will be two routes in the routing table of the DN switch, as shown in Table 1. Table 1 is the routing table of the DN switch, where Dest IP is the destination IP address and Next hop is the next hop IP address.

[0100] Table 1

[0101] Dest IP Next hop IP_POOL_1 PSA1 IP_POOL_2 PSA2

[0102] Assume that the UE is allocated IP1 from IP_POOL_1 of PSA_1, and the UE is connected to the DN through BP and PSA1.

[0103] Then, for the downlink data sent from DN, the switch in DN will look up the routing table and forward the traffic to PSA1, and finally reach the UE.

[0104] When the PDU session switches to PSA2, SMF sends a PFCP session establishment message to PSA2 and sends the IP address of PSA2 to AF through NEF, where AF is the SDN controller; after establishment, it sends a PFCP session deletion message to PSA1 to cancel the PDU session of PSA1.

[0105] The SDN controller sends a host route with the next hop of PSA2 IP to the switch in the DN through its southbound interface, and a new routing entry will be added to the routing table of the DN, which becomes Table 2. Table 2 is the DN switch routing table of this method after the PSA changes.

[0106] Table 2

[0107] Dest IP Nexthop IP_POOL_1 PSA1 IP_POOL_2 PSA2 IP1 PSA2

[0108] When the downlink data of the UE reaches the DN, the DN switch will query the routing table and send the traffic to PSA2. Since PSA2 has received the PFCP message sent by SMF, the message can finally reach the UE through the PDR (message detection rule) and FAR (forwarding operation rule) in PFCP.

[0109] In some embodiments of the present disclosure, if the newly added routing table entries are batch adjacent routing entries, the adjacent routing entries can be aggregated by routing aggregation to reduce the number of routing entries. For example, IP 10.1.1.1 / 32~10.1.1.31 / 32 can be aggregated into 10.1.1.0 / 24.

[0110] The above embodiment of the present disclosure provides a method and device for keeping the IP address of the user terminal unchanged based on the SDN (Software Defined Network) controller, which is used for keeping the IP address of the user terminal unchanged when the PDU session anchor (PSA) changes. The communication core of the above embodiment of the present disclosure mainly includes UE, SMF, UPF, NEF, AF (SDN controller) and DN. The UE accesses the DN through UPF1 and is assigned IP1; when the PSA UPF switches (from PSA1 to PSA2), the SMF will send the IP address of PSA2 to the AF (SDN controller) through NEF, and the SDN controller will publish the host route pointing to the IP1 of PSA2 to the switch in the DN through its southbound interface, so that the downlink message from the DN is changed to enter from UPF2. Therefore, the above embodiment of the present disclosure can complete the PSA switching when the UE IP has never changed. The method of the above embodiment of the present disclosure can effectively solve the demand for fixed IP in edge computing.

[0111] Figure 7 FIG. 1 is a schematic diagram of the structure of some embodiments of the session management function network element disclosed in the present invention. Figure 7 As shown, the session management function network element (eg Figure 4-Figure 6 The session management function network element 62 of any embodiment may include a memory 71 and a processor 72 .

[0112] The memory 71 is used to store instructions. The processor 72 is coupled to the memory 71. The processor 72 is configured to execute and implement any of the above embodiments (for example, Figure 3 or Figure 4 Embodiment) described communication method.

[0113] like Figure 7 As shown, the session management function network element further includes a communication interface 73 for information exchange with other devices. At the same time, the session management function network element further includes a bus 74, through which the processor 72, the communication interface 73, and the memory 71 communicate with each other.

[0114] The memory 71 may include a high-speed RAM memory, and may also include a non-volatile memory (Non-volatile Memory), such as at least one disk memory. The memory 71 may also be a memory array. The memory 71 may also be divided into blocks, and the blocks may be combined into virtual volumes according to certain rules.

[0115] In addition, the processor 72 may be a central processing unit CPU, or may be a fourth integrated circuit ASIC, or may be configured to implement one or more integrated circuits of the embodiments of the present disclosure.

[0116] Figure 8 FIG. 1 is a schematic diagram of the structure of some other embodiments of the session management function network element disclosed in the present invention. Figure 8 As shown, the session management function network element (eg Figure 4-Figure 6 The session management function network element 62 of any embodiment may include an address sending module 81, wherein:

[0117] The address sending module 81 is configured to send the IP address of the second PSA to the software-defined network controller when the protocol data unit PDU session of the user terminal is switched from the first PSA to the second PSA, so that the software-defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

[0118] In some embodiments of the present disclosure, the address sending module 81 may be configured to send the IP address of the second PSA to the software defined network controller through a network development function network element.

[0119] In some embodiments of the present disclosure, Figure 8 As shown, the session management function network element may further include a session establishment message sending module 82 and a session deletion message sending module 83, wherein:

[0120] The session establishment message sending module 82 is configured to, when the protocol data unit PDU session of the user terminal is switched from the first PSA to the second PSA, the session management function network element sends a session establishment message to the second PSA.

[0121] In some embodiments of the present disclosure, the session establishment message is a packet switched control protocol session establishment message.

[0122] The address sending module 81 is configured to send the IP address of the second PSA to the software-defined network controller so that the software-defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to the switch in the data network, wherein the host IP address of the user terminal is still the IP address allocated from the IP address pool of the first PSA.

[0123] The session deletion message sending module 83 is configured to, after the PDU session of the second PSA is established, send a session deletion message of the first PSA by the session management function network element to cancel the PDU session of the first PSA.

[0124] In some embodiments of the present disclosure, the session deletion message is a packet switching control protocol session deletion message.

[0125] In the edge computing scenario, there may be a UPF that is closer to the user, so the UE's original PDU session may undergo PSA UPF switching; in the relevant technical standards, since different UPFs allocate different IP address pools, the switching of PSA UPF in the relevant technology will cause the UE IP address to change.

[0126] The above-mentioned embodiments of the present disclosure solve this problem based on the method of software-defined network, so that when the PSA UPF changes, the 5G core network can keep the UE IP address unchanged.

[0127] According to another aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, any of the above embodiments (for example Figure 3 or Figure 4 Embodiment) described communication method.

[0128] In some embodiments of the present disclosure, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

[0129] The advantages of the above embodiments of the present disclosure over the related art are:

[0130] 1. There is no method for keeping the UE IP address fixed in the relevant technical standards. The above embodiments of the present disclosure realize for the first time that the 5G core network can keep the UE IP address unchanged when the PSA UPF changes.

[0131] 2. The above embodiments of the present disclosure can achieve seamless switching. In the above embodiments of the present disclosure, when the PDU session performs PSA UPF switching in the core network, the UE and the application cannot perceive the change at all.

[0132] 3. The above-mentioned embodiments of the present disclosure are simple and feasible.

[0133] 4. The above embodiments of the present disclosure facilitate application identification and management. The UE address remains unchanged, which is more friendly to edge computing, firewall and other applications, making it easier for them to identify and manage users.

[0134] 5. The above embodiments of the present disclosure may be implemented using an SDN method.

[0135] 6. The above embodiments of the present disclosure may reduce the number of routing entries by adopting a routing aggregation method.

[0136] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, devices, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a fourth computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0138] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0139] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0140] The software-defined network controller, session management function network element, address sending module, session deletion message sending module, session establishment message sending module, first protocol data unit session anchor point, second protocol data unit session anchor point, user plane function network element, data network and user terminal described above can be implemented as a general-purpose processor, a programmable logic controller (), a digital signal processor (DSP), a fourth integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component or any appropriate combination thereof for performing the functions described in this application.

[0141] So far, the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0142] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing the relevant hardware through a program, and the program may be stored in a non-transitory computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0143] The description of the present disclosure is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the present disclosure to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present disclosure, and to enable those of ordinary skill in the art to understand the present disclosure and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A communication method, comprising: In the case of a change in the protocol data unit session anchor point PSA, the session management function network element keeps the IP address of the user terminal unchanged through the software-defined network controller; The session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller, including: When a protocol data unit (PDU) session of a user terminal is switched from a first PSA to a second PSA, the session management function network element sends a session establishment message to the second PSA; The session management function network element sends the IP address of the second PSA to the software defined network controller, so that the software defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA; After the PDU session of the second PSA is established, the session management function network element sends a session deletion message of the first PSA to cancel the PDU session of the first PSA.

2. The communication method according to claim 1, wherein: The session management function network element keeps the IP address of the user terminal unchanged through the software defined network controller, including: When the protocol data unit (PDU) session of the user terminal is switched from the first PSA to the second PSA, the session management function network element sends the IP address of the second PSA to the software defined network controller so that the software defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

3. The communication method according to claim 1 or 2, wherein: The session management function network element sending the IP address of the second PSA to the software defined network controller includes: the session management function network element sending the IP address of the second PSA to the software defined network controller through the network development function network element; and / or, The session establishment message is a packet switching control protocol session establishment message; and / or, The session deletion message is a packet switching control protocol session deletion message.

4. A session management function network element, wherein: The session management function network element is configured to keep the IP address of the user terminal unchanged through the software defined network controller when the protocol data unit session anchor PSA changes; A session establishment message sending module, configured to, when a protocol data unit (PDU) session of a user terminal is switched from a first PSA to a second PSA, a session management function network element sends a session establishment message to the second PSA; An address sending module is configured to send the IP address of the second PSA to the software defined network controller, so that the software defined network controller is used to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA; The session deletion message sending module is configured to, after the PDU session of the second PSA is established, send a session deletion message of the first PSA by the session management function network element to cancel the PDU session of the first PSA.

5. The session management function network element according to claim 4, wherein: The address sending module is configured to send the IP address of the second PSA to the software-defined network controller when the protocol data unit (PDU) session of the user terminal is switched from the first PSA to the second PSA, so that the software-defined network controller is used to send the user terminal host route containing the next hop pointing to the second PSA to the switch in the data network.

6. The session management function network element according to claim 4 or 5, wherein: An address sending module is configured to send the IP address of the second PSA to the software defined network controller through the network development function network element; and / or, The session establishment message is a packet switching control protocol session establishment message; and / or, The session deletion message is a packet switching control protocol session deletion message.

7. A session management function network element, comprising: a memory configured to store instructions; The processor is configured to execute the instruction so that the session management function network element performs the operation of implementing the communication method according to any one of claims 1 to 3.

8. A communication system comprising a software defined network controller and a session management function network element as claimed in any one of claims 4 to 7.

9. The communication system of claim 8, further comprising the first PSA, the second PSA, and a switch in the data network, wherein: The software defined network controller is configured to send a user terminal host route containing a next hop pointing to the second PSA to a switch in the data network, wherein the host IP address of the user terminal is still an IP address allocated from the IP address pool of the first PSA; The switch in the data network is configured to add a new routing entry in the routing table, wherein in the routing entry, the next hop points to the second PSA, and the host IP address of the user terminal is still the IP address allocated from the IP address pool of the first PSA.

10. The communication system according to claim 8, wherein: The switch in the data network is configured to query the routing table and send the downlink data to the user terminal through the second PSA when the downlink data of the user terminal arrives at the data network.

11. The communication system according to claim 9 or 10, wherein: The switch in the data network is configured to aggregate the multiple adjacent routing entries in a routing aggregation manner when the newly added routing table entry is a plurality of adjacent routing entries.

12. The communication system according to claim 9 or 10, further comprising a user terminal.

13. A computer-readable storage medium, wherein: The computer-readable storage medium stores computer instructions, and when the instructions are executed by a processor, the communication method according to any one of claims 1 to 3 is implemented.

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