KR20190133622A - Method and apparatus for allocating mptcp address for 5g network - Google Patents

Abstract

Provided is user equipment comprising a processor and a memory, which performs the steps of: receiving, from an interworking function device in a non-cellular network, a first address of a multi-path transmission control protocol (MPTCP) proxy generated by a session management function (SMF) by executing a program stored in the memory; and transmitting uplink data to the MPTCP proxy using the first address.

Description

METHOD AND APPARATUS FOR ALLOCATING MPTCP ADDRESS FOR 5G NETWORK}

The present disclosure relates to an address allocation method and apparatus for MPTCP in a 5G network.

5G systems include Access Traffic Steering, Switching and Splitting (ATSSS) for unified traffic control between 3GPP (Cellular Network) and Non-3GPP Access Networks (Non-Cellular Network). Included. Traffic steering is the transmission of new data traffic through a new access network, traffic switching is the transmission of all of the data traffic currently in transit through another access network, and traffic splitting is the transmission of one data traffic to multiple accesses. Distributed transmission over the network.

For this ATSSS, a multi-access (MA) protocol data unit (PDU) session for distributing traffic between user equipment (UE) and user plane function (UPF) Multi-Access PDU Session) is required. The MA PDU session may be established, modified, or released. In addition, there are various techniques related to traffic distribution for multi-access between UE and UPF in a MA PDU session, and the protocol (Multi-Path Transmission Control Protocol, MPTCP) is one of several techniques.

One embodiment provides user equipment for receiving an address of an MPTCP proxy.

According to one embodiment, user equipment is provided. The user equipment includes a processor, a memory, and a communication device, wherein the processor executes a program stored in the memory, and is generated by a session management function (SMF). Receiving a first address of a Path Transmission Control Protocol (MPTCP) proxy from the interworking function device of a non-cellular network using the communication device, and using the first address, uplink data to the MPTCP proxy. And the first address is different from the second address of the MPTCP proxy received from the radio access network device of the cellular network.

The data subflow between the MPTCP Client and the MPTCP Proxy can be divided based on a plurality of MPTCP Proxy addresses corresponding to each access network. That is, when the MPTCP-based ATSSS function through the multi-access between the UE and the UPF is provided, MPTCP subflows may be distinguished through different MPTCP proxy addresses instead of the UE addresses. Therefore, within the MA-PDU session having one UE address, the ATSSS function using the MPTCP proxy can be easily implemented without additional allocation of the UE address.

1 is a conceptual diagram illustrating a 5G architecture including an MTPCP proxy according to an embodiment.
2 is a flowchart illustrating a procedure for establishing an MTPCP PDU session according to an embodiment.
3 is a flowchart illustrating a procedure of establishing an MTPCP PDU session according to another embodiment.
4 is a block diagram illustrating a wireless communication system according to an exemplary embodiment.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present disclosure. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout the specification, user equipment (UE) includes a terminal, a mobile station (MS), a mobile terminal (MT), an advanced mobile station (AMS), a high reliability mobile station. (high reliability mobile station, HR-MS), subscriber station (SS), portable subscriber station (PSS), access terminal (AT), machine type communication device, MTC device) and the like, and may include all or a part of functions of the UE, MS, MT, AMS, HR-MS, SS, PSS, AT, and the like.

1 is a conceptual diagram illustrating a 5G architecture including an MTPCP proxy according to an embodiment.

Referring to Figure 1, MPTCP Proxy is included in the 5G architecture to support the ATSSS function. Functions for the ATSSS are included in the UE, user data management (UDM), session management function (SMF), policy control function (PCF), and UPF. The MPTCP Client is also included in the UE. The MPTCP proxy may be included in the UPF or standalone in the 5G architecture.

According to a conventional MPTCP technique using a proxy server, data subflows through a plurality of access networks are classified based on a plurality of UE addresses and one MPTCP proxy address. That is, data subflows through different access networks may be divided into a plurality of MPTCP client addresses.

2 is a flowchart illustrating a procedure of establishing an MTPCP PDU session according to an embodiment.

In FIG. 2, the MPTCP subflow may be divided based on a plurality of UE addresses and one MPTCP proxy address. Referring to FIG. 2, the UE transmits a PDU session establishment request to the AMF (S101). The UE may also initiate a PDU session establishment procedure for an untrusted non-3GPP connection. Upon receiving the PDU session establishment request, the AMF selects an SMF that supports the MTPCP procedure (S102). The AMF transmits an Nsmf_PDUSession_CreateSMContext request to the selected SMF (S103). Receiving the Nsmf_PDUSession_CreateSMContext request, the SMF retrieves subscription information from the UDM and registers the UE (S104a). At this time, the SMF may update the subscriber information of the UDM (S104b).

The SMF sends an Nsmf_PDUSession_CreateSMContext response to the AMF (S105), after which authentication of a PDU session and authorization for a UE may be selectively performed (secondary authorization / authentication) (S106).

If dynamic policy and charging control (PCC) is applied, the SMF performs PCF selection (S107a). The SMF may perform session management policy establishment or session management policy modification (S107b).

The SMF selects the UPF including the MTPCP proxy functionality (S108). Thereafter, the SMF may perform a session management policy modification procedure (S109).

Steps S110 to S117 relate to a method for the UE to transmit and receive data subflows through a 3GPP connection. In step S110 to step S117 the user plane of the PDU session over the 3GPP connection is set, the UE may transmit and receive the first MTPCP subflow through the 3GPP connection. In FIG. 2, the address of the UE generated per MA PDU session for services other than the MPTCP application is not mentioned. 2, the SMF and the UPF transmit and receive requests and responses of N4 Session Establishment / Modification (S110a and S110b). The SMF instructs the AMF through the Namf_Communication_N1N2MessageTransfer to the MTPCP proxy address and the MPTCP UE address (the first UE address for the MPTCP) (S111). The MTPCP proxy address and the UE address for MPTCP are delivered via NAS messages (N2 PDU session requests) that are forwarded from AMF to the NG-RAN (Next Generation Radio Access Network) (S112), and the UE receives the NG-RAN (Next Generation Radio Access). A PDU session establishment accept message including an MTPCP proxy address is received from the network (S113). Accordingly, the UE may determine that the MTPCP PDU session over the 3GPP connection is established. The NG-RAN transmits an N2 PDU session request ACK to the AMF (S114), and the first uplink data of the MPTCP application of the UE may be delivered to the MTPCP proxy via the NG-RAN (first MTPCP sub with the MTPCP proxy). Generation of flows).

The AMF sends an Nsmf_PDUSession_UpdateSMContext request message to the SMF (S115). The SMF and the MTPCP proxy exchange N4 session modification request / response (S116a, S116b), and the MTPCP proxy may transmit the first downlink data to the UE via the NG-RAN. After the exchange of the N4 signal, the SMF transmits an Nsmf_PDUSession_UpdateSMContext response message to the AMF (S117).

Steps S119 to S127 relate to a method for the UE to transmit and receive data subflows over a non-3GPP connection. In step S119 to S127 the user plane of the PDU session through the untrusted non-3GPP access is set, the UE can send and receive additional MTPCP subflows through the untrusted non-3GPP access. In FIG. 2, steps S110 to S117 may be executed in parallel with steps S119 to S127.

Referring to FIG. 2, firstly, the UE establishes an IPSec Security Association (SA) with a Non-3GPP Inter-Working Function (N3IWF) device (S118). The SMF and the UPF transmit and receive requests and responses of N4 Session Establishment / Modification (S119a and S119b). The SMF transmits another MPTCP client UE address (second UE address for MPTCP) to the AMF through Namf_Communication_N1N2MessageTransfer (S120). Thereafter, the N2 PDU session request including the NAS message is delivered from the AMF to the N3IWF (S121), and the UE sets the N3IWF and the IPSec child SA (S122). The UE receives a PDU Session Establishment Accept message from the N3IWF (S123). Thereafter, the N3IWF transmits an N2 PDU session request ACK to the AMF (S124), and the first uplink data of the UE may be delivered to the MTPCP proxy via the N3IWF (generation of a second MTPCP subflow with the MTPCP proxy).

AMF sends Nsmf_PDUSession_UpdateSMContext request message to SMF (S125), SMF and UPF exchange N4 session modification request / response (S126a, S126b), and UPF that exchanges N4 message with SMF to non-3GPP to UE through MTPCP proxy The first downlink data through the access can be transmitted. The SMF having exchanged the N4 message with the MTPCP proxy transmits an Nsmf_PDUSession_UpdateSMContext response message to the AMF (S127).

The address allocation scheme between the MTPCP client (eg, UE) and the MTPCP proxy shown in FIG. 2 is suitable for a general IP network. However, in ATSSS technology, the UE can use one common IP address for each multi access (MA) PDU session. At this time, the address of the MTPCP proxy is transmitted to the UE in the network in the MA-PDU session establishment procedure. If the UE uses only one address allocated per MA PDU session, there is a limitation in the method of classifying data MPTCP subflows using one MTPCP proxy address shown in FIG. 2.

Referring to FIG. 2, an address of the MTPCP proxy is transmitted from the network to the UE between steps S110 to S113 regarding the first access of the UE. In steps S118 to S122 regarding the second access of the UE, the address of the MTPCP proxy is not transmitted to the UE in the network, only the client address for MPTCP is transmitted. That is, if a UE uses one IP address per MA-PDU session to deliver data subflows over multiple access networks, the addresses of the MTPCP Client and the MTPCP Proxy have an N: 1 relationship, and over multiple access networks Subflows sent are separated within the MA-PDU session, but require additional address management for MPTCP.

3 is a flowchart illustrating a procedure of establishing an MTPCP PDU session according to another embodiment.

Referring to FIG. 3, the UE transmits a PDU session establishment request to the AMF (S201). The UE may also initiate a PDU session establishment procedure for an untrusted non3GPP connection. Upon receiving the PDU session establishment request, the AMF selects an SMF that supports the MTPCP procedure (S202). The AMF transmits an Nsmf_PDUSession_CreateSMContext request to the selected SMF (S203). Receiving the Nsmf_PDUSession_CreateSMContext request, the SMF retrieves subscriber information from the UDM and registers the UE (S204a). At this time, the SMF may update the subscriber information of the UDM (S204b).

The SMF sends an Nsmf_PDUSession_CreateSMContext response to the AMF (S205), after which authentication of a PDU session and authorization for a UE may be performed (secondary authorization / authentication) (S206).

When the dynamic PCC is applied, the SMF performs PCF selection (S207a). The SMF may perform session management policy establishment or session management policy modification (S207b).

The SMF selects a UPF including MTPCP proxy functionality (S208). Thereafter, the SMF may perform a session management policy modification procedure (S209).

Steps S210 to S217 relate to a method for the UE to transmit and receive data subflows through a 3GPP connection. In steps S210 to S217, the user plane of the PDU session over the 3GPP connection is set, and the UE may transmit and receive the first MTPCP subflow through the 3GPP connection.

Referring to FIG. 3, the SMF and the UPF transmit and receive requests and responses of N4 Session Establishment / Modification (S210a and S110b). The SMF indicates the MA PDU session UE address and the first MTPCP proxy address to the AMF through Namf_Communication_N1N2MessageTransfer (S211). The first MTPCP proxy address is delivered with an N2 PDU session request message including a NAS message destined for the Next Generation Radio Access Network (NG-RAN) from AMF (S212), and the UE establishes a PDU session including the first MTPCP proxy address. A PDU Session Establishment Accept message is received from the NG-RAN (S213). Accordingly, the UE may determine that the MTPCP PDU session over the 3GPP connection is established. The NG-RAN transmits an N2 PDU session request ACK to the AMF (S214), and the first uplink data of the UE may be delivered to the MTPCP proxy via the NG-RAN (generation of a first MTPCP subflow with the MTPCP proxy). ). The AMF sends an Nsmf_PDUSession_UpdateSMContext request message to the SMF (S215). The SMF and the UPF exchange N4 session modification request / response (S216a, S116b), and the MTPCP Proxy may transmit the first downlink data to the UE via the NG-RAN. After the exchange of the N4 signal, the SMF transmits an Nsmf_PDUSession_UpdateSMContext response message to the AMF (S217).

Steps S219 through S227 relate to a method for the UE to generate a data subflow over a non-3GPP connection. In steps S219 to S227, a user plane of a PDU session that has passed through an untrusted non-3GPP connection is set, and the UE may transmit and receive additional MTPCP subflows through an untrusted non-3GPP access. In FIG. 3, steps S210 to S217 may be executed in parallel with steps S219 to S227.

Referring to FIG. 3, a UE first establishes an IPSec Security Association (SA) with a Non-3GPP Inter-Working Function (N3IWF) device (S218). The SMF and the UPF transmit and receive requests and responses of N4 session establishment / modification (S219a and S219b). The SMF transmits Namf_Communication_N1N2MessageTransfer including the second MPTCP proxy address to the AMF (S220). That is, according to one embodiment, the SMF may generate an address of the MPTCP proxy (second MPTCP proxy address) even when the UE connects via a non-3GPP (ie, a non-cellular network) and deliver it to the UE. That is, since the address relationship between the UE and the MPTCP proxy is 1: N, the ATSSS function for data traffic can be efficiently implemented. That is, the IP of the UE for the additional MPTCP function is not assigned.

Thereafter, the AMF transfers the second MPTCP proxy address to the N3IWF through an N2 PDU session request message including a NAS message (S221), and the UE receives a PDU Session Establishment Accept message from the N3IWF (S223). . The UE may receive the second MPTCP proxy address through the PDU session establishment accept message. An IPSec child SA between the UE and the N3IWF is also set (S222). Thereafter, the N3IWF transmits an N2 PDU session request ACK to the AMF (S224), and the UE may transmit the first uplink data to the MTPCP proxy via the N3IWF using the second MPTCP proxy address (having the second MPTCP proxy address). Generation of a second MTPCP subflow with an MTPCP proxy).

The AMF sends an Nsmf_PDUSession_UpdateSMContext request message to the SMF (S225), the SMF and the MTPCP Proxy exchange N4 session modification request / response (S226a, S226b), and the MTPCP Proxy that exchanges the N4 message with the SMF provides the UE with a non-3GPP access. The first downlink data can be transmitted. The SMF exchanging the NF message with the UPF transmits an Nsmf_PDUSession_UpdateSMContext response message to the AMF (S227).

As described above, the data subflow between the MPTCP Client (UE) and the MPTCP Proxy can be divided based on a plurality of MPTCP Proxy addresses corresponding to each access network, so that MPTCP within a MA-PDU session with one UE address ATSSS function using a proxy can be easily implemented.

4 is a block diagram illustrating a wireless communication system according to an exemplary embodiment.

Referring to FIG. 4, a wireless communication system according to an embodiment includes a network function device 410 and user equipment 420.

The network function device 410 may perform a function of AMF, SMF, PCF, UDM, NG-RAN, or N3IWF of a 5G network. The network function device 410 includes a processor 411, a memory 412, and a radio frequency unit (RF unit) 413. The memory 412 may be connected to the processor 411 to store various information for driving the processor 411 or at least one program executed by the processor 411. The wireless communication unit 413 may be connected to the processor 411 to transmit and receive wireless signals. The processor 411 may implement a function, process, or method proposed in the embodiments of the present disclosure. In this case, in the wireless communication system according to the exemplary embodiment of the present disclosure, the air interface protocol layer may be implemented by the processor 411. The operation of the network function device 410 according to an embodiment may be implemented by the processor 411.

User equipment 420 includes a processor 421, a memory 422, and a wireless communication unit 423. The memory 422 may be connected to the processor 421 and store various information for driving the process 421. The wireless communication unit 423 may be connected to the processor 421 to transmit and receive a wireless signal. The processor 421 may implement the functions, steps, or methods proposed in the embodiments of the present disclosure. In this case, in the wireless communication system according to the exemplary embodiment of the present disclosure, the air interface protocol layer may be implemented by the processor 421. Operation of the user equipment 420 according to one embodiment may be implemented by the processor 421.

In an embodiment of the present disclosure, the memory may be located inside or outside the processor, and the memory may be connected to the processor through various known means. The memory is various types of volatile or nonvolatile storage media, and for example, the memory may include read-only memory (ROM) or random access memory (RAM).

Although the embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts defined in the following claims also belong to the scope of rights.

Claims (1)

As user equipment,
A processor, a memory, and a communication device, the processor executing a program stored in the memory,
A first address of a Multi-Path Transmission Control Protocol (MPTCP) proxy, generated by a session management function (SMF), is obtained from an interworking function device of a non-cellular network. Receiving by using, and
Transmitting uplink data using the communication device to the MPTCP proxy using the first address
And wherein the first address is a different address than the second address of the MPTCP proxy received from a radio access network device of a cellular network.

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