Method and apparatus for connection establishment

Abstract

Various embodiments of the present disclosure disclose a method and apparatus for connection establishment. According to one embodiment, a first network node receives, from a terminal device, a first request to establish a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The first network node sends a second request to the second network node to establish the first connection. The second request includes a first indication. The first network node receives, from the second network node, a second indication as to whether the second connection is supported by the second network node. And the first network node sends a second indication to the terminal device.

Description

[0001] This application is a divisional application of the patent application with application number 201980092259.4 filed on July 9, 2019 and invention name “Method and device for connection establishment”. Technical Field

[0002] Embodiments of the present disclosure relate generally to communications, and more particularly to methods and apparatus for connection establishment. Background Art

[0003] This section introduces aspects that may facilitate a better understanding of the present disclosure. Therefore, the statements in this section should be read in this sense, and should not be understood as an admission of what is or is not prior art.

[0004] For the Evolved Packet System (EPS), according to the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.401 v16.1.0, a Packet Data Network (PDN) connection can have a PDN type of IP (i.e., IPv4, IPv6, IPv4v6) or non-IP (but no Ethernet), as described below. The term IP refers to the Internet Protocol. The term IPv4 refers to IP version 4, the term IPv6 refers to IP version 6, and the term IPv4v6 refers to IP version 4 / version 6.

[0005] 3.1 Definition

[0006] PDN connection: The association between a PDN represented by an APN and a UE, represented by an IPv4 address and / or an IPv6 prefix (for IP PDN types) or by a UE identity (for non-IP PDN types).

[0007] Default bearer: An EPS bearer that is first established for a new PDN connection and remains established throughout the lifetime of the PDN connection.

[0008] According to 3GPP TS23.401v16.1.0, a PDN contains a default bearer and optionally one or more dedicated bearers. A default bearer is a non-guaranteed bit rate (non-GBR) bearer. GBR-related network resources can only be implemented through dedicated bearers.

[0009] 4.7.2.1 Common EPS bearer ...

[0011] In this release of the specification, dedicated bearers are only supported for IP PDN connection services. ...

[0013] When a UE connects to a PDN, an EPS bearer is established and remains established throughout the lifetime of the PDN connection to provide the UE with an always-on IP connection to the PDN. This bearer is called the default bearer. Any additional EPS bearers established for the same PDN connection are called dedicated bearers. ...

[0015] If dedicated network resources related to the guaranteed bit rate (GBR) value associated with an EPS bearer are permanently allocated (e.g. by the admission control function in the eNodeB) at bearer establishment / modification time, then the EPS bearer is called a GBR bearer. Otherwise, the EPS bearer is called a non-GBR bearer. ...

[0017] A dedicated bearer can be a GBR or non-GBR bearer. A default bearer should be a non-GBR bearer.

[0018] According to 3GPP TS 23.401 v16.1.0, dedicated bearers for PDN connections of non-IP PDN types (eg, GBR dedicated bearers) are not supported.

[0019] 4.3.17.8 Support for Non-IP Data Delivery (NIDD)

[0020] 4.3.17.8.1 Overview ...

[0022] For non-IP data, dedicated bearers are not supported.

[0023] For the fifth generation system (5GS), according to 3GPP TS23.501v15.4.0, a protocol data unit (PDU) session can be of type IP (v4, v6, v4v6), Ethernet, or unstructured.

[0024] 3.1 Definition ...

[0026] PDU Session: An association between a UE and a data network that provides PDU connection services.

[0027] PDU Session Type: The type of PDU session, which can be IPv4, IPv6, IPv4v6, Ethernet, or Unstructured.

[0028] According to 3GPP TS23.501v15.4.0 and 3GPP TS23.503v15.4.0, GBR Quality of Service (QoS) flows are also supported for Ethernet type PDU sessions. An excerpt from 3GPP TS23.501v15.4.0 is as follows:

[0029] 3.1 Definition ...

[0031] 5G QoS flow: The finest granularity for QoS forwarding processing in the 5G system. All services mapped to the same 5G QoS flow receive the same forwarding processing (e.g. scheduling policy, queue management policy, rate shaping policy, RLC configuration, etc.). Providing different QoS forwarding processing requires separate 5G QoS flows.

[0032] 5.7.1.1 QoS Flow

[0033] The 5G QoS model is based on QoS flows. The 5G QoS model supports both QoS flows that require guaranteed flow bit rates (GBR QoS flows) and QoS flows that do not require guaranteed flow bit rates (non-GBR QoS flows). ....

[0034] An excerpt from 3GPP TS23.503v15.4.0 is as follows:

[0035] 4.3.3.2QoS control requirements

[0036] 4.3.3.2.1 QoS control at the service data flow level

[0037] It should be possible to apply QoS control on a per-service data flow basis in SMF, applicable to both IP-type and Ethernet-type service data flows. ...

[0039] 4.3.3.2.2 QoS Control at the QoS Flow Level ...

[0041] For the PCC architecture, it should be possible to support QoS control for packet services of PDU sessions. ...

[0043] The PCC architecture should be able to handle both QoS flows requiring a guaranteed bit rate (GBR bearers) and QoS flows without a guaranteed bit rate (non-GBR bearers). Summary of the invention

[0044] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0045] One of the objects of the present disclosure is to provide an improved solution for connection establishment.

[0046] According to a first aspect of the present disclosure, a method implemented at a terminal device is provided. The method includes sending a first request to a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The method also includes receiving a response to the first request from the first network node. The response includes a second indication of whether the second connection is supported by a second network node.

[0047] In an embodiment of the present disclosure, the method further includes determining, based on the second indication, whether both the terminal device and the second network node support the second connection. The method further includes, when it is determined that both the terminal device and the second network node support the second connection, sending a second request to the first network node for switching from the first connection to the second connection.

[0048] In an embodiment of the present disclosure, the first type is an Ethernet type.

[0049] In an embodiment of the present disclosure, the first technology is 5th Generation (5G) and the second technology is Long Term Evolution (LTE).

[0050] In an embodiment of the present disclosure, the first connection is a protocol data unit (PDU) session of Ethernet type, and the second connection is a packet data network (PDN) connection of Ethernet type.

[0051] In an embodiment of the present disclosure, the first network node is an access and mobility management function (AMF). The second network node is a session management node that supports both 5G and LTE in a home network or a visited network.

[0052] According to a second aspect of the present disclosure, a method implemented at a first network node is provided. The method includes receiving a first request from a terminal device for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The method also includes sending a second request to a second network node for establishing the first connection. The second request includes the first indication. The method also includes receiving a second indication from the second network node as to whether the second connection is supported by the second network node. The method also includes sending the second indication to the terminal device.

[0053] In an embodiment of the present disclosure, the second request is sent to the second network node via a third network node, and the second indication is received from the second network node via the third network node. Alternatively, the first request is from the terminal device via a third network node, and the second indication is sent to the terminal device via the third network node.

[0054] In an embodiment of the present disclosure, the method further includes, in response to a requirement to switch from the first technology to the second technology, sending a third indication to the second network node regarding whether a fourth network node supports the second connection. The method further includes receiving a fourth indication from the second network node regarding whether the second connection or a third connection is to be used, the third connection being a second type of connection according to the second technology. The method further includes sending the fourth indication to the fourth network node.

[0055] In an embodiment of the present disclosure, the first type is an Ethernet type.

[0056] In an embodiment of the present disclosure, the first technology is 5G and the second technology is LTE.

[0057] In an embodiment of the present disclosure, the first connection is an Ethernet type PDU session, and the second connection is an Ethernet type PDN connection.

[0058] In an embodiment of the present disclosure, the first network node is an AMF. The second network node is a session management node that supports both 5G and LTE in a home network or a visited network. The third network node is an SMF in a visited network.

[0059] In an embodiment of the present disclosure, the first network node is an SMF in a visited network. The second network node is a session management node that supports both 5G and LTE in a home network or a visited network. The third network node is an AMF.

[0060] In an embodiment of the present disclosure, the fourth network node is a Mobility Management Entity (MME).The second type is a non-IP type.

[0061] According to a third aspect of the present disclosure, a method implemented at a second network node is provided. The method comprises receiving a second request from a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology for a terminal device. The first request comprises a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The method further comprises determining a second indication of whether the second connection is supported by the second network node. The method further comprises sending the second indication to the first network node.

[0062] In an embodiment of the present disclosure, the second indication is about whether the second connection is supported by both the terminal device and the second network node.

[0063] In an embodiment of the present disclosure, the second request is received from the first network node via a third network node, and the second indication is sent to the first network node via the third network node.

[0064] In an embodiment of the present disclosure, the method further includes receiving a third indication from the first network node regarding whether a fourth network node supports the second connection. The method further includes determining, based on the first indication and the third indication, a fourth indication regarding whether the second connection or a third connection is to be used for the terminal device, the third connection being a second type of connection according to the second technology. The method further includes sending the fourth indication to the first network node.

[0065] In an embodiment of the present disclosure, determining the fourth indication includes determining that the second connection will be used for the terminal device when the terminal device, the second network node, and the fourth network node support the second connection. Determining the fourth indication also includes determining that the third connection will be used for the terminal device when the fourth network node supports the third connection but does not support the second connection.

[0066] In an embodiment of the present disclosure, the first type is an Ethernet type.

[0067] In an embodiment of the present disclosure, the first technology is 5G and the second technology is LTE.

[0068] In an embodiment of the present disclosure, the first connection is an Ethernet type PDU session, and the second connection is an Ethernet type PDN connection.

[0069] In an embodiment of the present disclosure, the first network node is an AMF. The second network node is a session management node that supports both 5G and LTE in a home network or a visited network. The third network node is an SMF in a visited network.

[0070] In an embodiment of the present disclosure, the fourth network node is an MME. The second type is a non-IP type.

[0071] According to a fourth aspect of the present disclosure, a terminal device is provided. The terminal device comprises at least one processor and at least one memory. The at least one memory contains instructions executable by the at least one processor, whereby the terminal device is operable to send a first request to a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request comprises a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The terminal device is further operable to receive a response to the first request from the first network node. The response comprises a second indication as to whether the second connection is supported by the second network node.

[0072] In an embodiment of the present disclosure, the terminal device may be operable to execute the method according to the first aspect above.

[0073] According to a fifth aspect of the present disclosure, a first network node is provided. The first network node includes at least one processor and at least one memory. The at least one memory contains instructions executable by the at least one processor, whereby the first network node is operable to receive a first request from a terminal device for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The first network node is also operable to send a second request to a second network node for establishing the first connection. The second request includes the first indication. The first network node is also operable to receive a second indication from the second network node as to whether the second connection is supported by the second network node. The first network node is also operable to send the second indication to the terminal device.

[0074] In an embodiment of the present disclosure, the first network node may be operable to execute the method according to the second aspect above.

[0075] According to a sixth aspect of the present disclosure, a second network node is provided. The second network node comprises at least one processor and at least one memory. The at least one memory contains instructions executable by the at least one processor, whereby the second network node is operable to receive a second request for establishing a first connection from a first network node, the first connection being a connection of a first type according to a first technology for a terminal device. The first request comprises a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The second network node is further operable to determine a second indication as to whether the second connection is supported by the second network node. The second network node is further operable to send the second indication to the first network node.

[0076] In an embodiment of the present disclosure, the second network node may be operable to execute the method according to the third aspect above.

[0077] According to a seventh aspect of the present disclosure, a computer program product is provided, wherein the computer program product comprises instructions, and when the instructions are executed by at least one processor, the at least one processor executes the method according to any one of the first to third aspects.

[0078] According to an eighth aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium contains instructions, and when the instructions are executed by at least one processor, the at least one processor executes the method according to any one of the first to third aspects.

[0079] According to a ninth aspect of the present disclosure, a terminal device is provided. The terminal device includes a sending module, configured to send a first request to a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The terminal device also includes a receiving module, configured to receive a response to the first request from the first network node. The response includes a second indication of whether the second connection is supported by a second network node.

[0080] According to a tenth aspect of the present disclosure, a first network node is provided. The first network node includes a first receiving module, configured to receive a first request for establishing a first connection from a terminal device, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The first network node also includes a first sending module, configured to send a second request for establishing the first connection to a second network node. The second request includes the first indication. The first network node also includes a second receiving module, configured to receive a second indication from the second network node as to whether the second connection is supported by the second network node. The first network node also includes a second sending module, configured to send the second indication to the terminal device.

[0081] According to an eleventh aspect of the present disclosure, a second network node is provided. The second network node includes a receiving module, configured to receive a second request for establishing a first connection from a first network node, the first connection being a connection of a first type for a terminal device according to a first technology. The first request includes a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The second network node also includes a determining module, configured to determine a second indication of whether the second connection is supported by the second network node. The second network node also includes a sending module, configured to send the second indication to the first network node.

[0082] According to some embodiments of the present disclosure, the connection establishment process can be facilitated. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of illustrative embodiments of the present disclosure, which is to be read in connection with the accompanying drawings.

[0084] Figure 1 Shows the mapping between PDU session type and PDN type;

[0085] Figure 2 is a flowchart illustrating a method implemented at a terminal device according to an embodiment of the present disclosure;

[0086] Figure 3 is a flowchart illustrating a method implemented at a terminal device according to another embodiment of the present disclosure;

[0087] Figure 4 is a flow chart illustrating a method implemented at a first network node according to an embodiment of the present disclosure;

[0088] Figure 5is a flowchart illustrating a method implemented at a first network node according to another embodiment of the present disclosure;

[0089] Figure 6 is a flow chart illustrating a method implemented at a second network node according to an embodiment of the present disclosure;

[0090] Figure 7 is a flow chart illustrating a method implemented at a second network node according to another embodiment of the present disclosure;

[0091] Figure 8 is a diagram illustrating an exemplary process according to an embodiment of the present disclosure;

[0092] Fig. 9 is a diagram illustrating an exemplary process according to an embodiment of the present disclosure;

[0093] Fig.10 is a diagram illustrating an exemplary process according to an embodiment of the present disclosure;

[0094] Fig.11 is a diagram illustrating an exemplary process according to an embodiment of the present disclosure; and

[0095] Fig.12 is a block diagram illustrating apparatus suitable for use in practicing some embodiments of the present disclosure. DETAILED DESCRIPTION

[0096] For purposes of explanation, certain details are set forth in the following description in order to provide a thorough understanding of the disclosed embodiments. However, it is apparent to one skilled in the art that the embodiments may be practiced without these specific details or with an equivalent configuration.

[0097] Currently, according to 3GPP TS23.501 and TS23.502, the mapping between PDU session type and PDN type is Figure 1 In the case of 5GS to EPS mobility, PDU session types "Ethernet" and "Unstructured" are mapped to non-IP PDN types, and the UE and PGW-C+SMF will remember the original PDU session type, and when the UE moves back to 5GS, the original Ethernet PDU session type or unstructured PDU session type will continue to be used.

[0098] A mobile operator has proposed to support dedicated bearers for Ethernet services in EPC, see document S2-1813344, which was approved in the 3GPP SA2#129bis meeting. The rationale for this proposal is as follows:

[0099] 3GPP’s ecosystem continues to expand beyond smartphones;

[0100] Many places in the world may not be covered by the 5G core network;

[0101] Small / medium-sized enterprises in developed countries may not be able to obtain dedicated in-building cells;

[0102] A reasonable number of applications (machines) are expected to use Ethernet only (no IP);

[0103] Many machines require some guaranteed QoS, such as GBR bearers.

[0104] In document S2-1813344, two solution options are mentioned as follows:

[0105] Option 1: Introduce a new PDN type "Ethernet" in EPS;

[0106] Option 2: Use non-IP PDN type in EPS and allow dedicated bearers for PDN connections of non-IP PDN type.

[0107] Under the assumption that a new PDN type "Ethernet" will be introduced into EPS (i.e., adopting option 1 above), when the UE moves from 5GS to EPS, there is no mechanism for the UE and the network to know whether EPS supports PDN type "Ethernet", and therefore the PDU session type cannot be mapped to PDN type "Ethernet". As a result, QoS requirements with some guarantees for Ethernet services in EPS are not possible.

[0108] The present disclosure proposes a solution for connection establishment. Figures 2 to 12 Describe the solution in detail.

[0109] As used herein, the term "communication system" refers to a system that complies with any suitable communication standard (such as first generation (1G), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, and / or any other protocols currently known or developed in the future). In addition, communication between terminal devices and network functions in the communication system can be carried out according to any suitable generation of communication protocols (including but not limited to 1G, 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, and / or any other protocols currently known or developed in the future).

[0110] In the following, different terms may refer to the same or similar network functions or network nodes with the same or similar functionality in different communication systems. Therefore, the specific terms used in this article do not limit the present disclosure to the communication system associated with the specific terms, but these specific terms may also be more generally applicable to other communication systems.

[0111] The term "terminal device" may also be referred to as, for example, an access terminal, a user equipment (UE), a mobile station, a mobile unit, a user station, etc. It may refer to any end device capable of accessing a wireless communication network and receiving services therefrom. By way of example and not limitation, the terminal device may include a portable computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback device, a mobile phone, a cellular phone, a smart phone, a tablet computer, a wearable device, a personal digital assistant (PDA), etc.

[0112] In the Internet of Things (IoT) scenario, a terminal device may refer to a machine or other device that performs monitoring and / or measurement and transmits the results of such monitoring and / or measurement to another terminal device and / or network device. In this case, the terminal device may be a machine-to-machine (M2M) device, which in the 3GPP context may be referred to as a machine type communication (MTC) device. Specific examples of such machines or devices may include sensors, metering devices such as power meters, industrial machinery, bicycles, vehicles, or household or personal appliances (e.g., refrigerators, televisions), personal wearable devices (such as watches), and the like.

[0113] Figure 2 201 is a flowchart illustrating a method implemented at a terminal device according to an embodiment of the present disclosure. At box 202, the terminal device sends a first request to a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of a first type according to a second technology. For example, the first network node may be an access and mobility management function (AMF). The first type may be an Ethernet type. The first technology may be 5G, and the second technology may be LTE. Therefore, the first connection may be an Ethernet type PDU session, and the second connection may be an Ethernet type PDN connection. As an illustrative example, the first request may be a PDU session establishment request. The first indication may take any suitable form.

[0114] At block 204, the terminal device receives a response to the first request from the first network node. The response includes a second indication of whether the second connection is supported by the second network node. For example, the second network node may be a session management node that supports both 5G and LTE in a home network or a visited network. Similar to the first indication, the second indication may take any suitable form. As an illustrative example, the response to the first request may be a PDU session establishment accept message.

[0115] Figure 3is a flowchart illustrating a method implemented at a terminal device according to another embodiment of the present disclosure. As shown in the figure, the method includes blocks 202-204, 306 and 308. At block 306, the terminal device determines whether both the terminal device and the second network node support the second connection based on the second indication. At block 308, when it is determined that both the terminal device and the second network node support the second connection, the terminal device sends a second request to the first network node for switching from the first connection to the second connection. The second request can be sent in the case of 5GS to EPS mobility. As an illustrative example, the second request can be an initial attachment request message with switching.

[0116] Figure 4 4 is a flowchart illustrating a method implemented at a first network node according to an embodiment of the present disclosure. For example, the first network node may be an AMF, or an SMF in a visited network, as described later. At box 402, the first network node receives a first request from a terminal device to establish a first connection, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of a first type according to a second technology. For example, the first type may be an Ethernet type. The first technology may be 5G, and the second technology may be LTE. Therefore, the first connection may be an Ethernet type PDU session, and the second connection may be an Ethernet type PDN connection. As an illustrative example, the first request may be a PDU session establishment request. The first indication may take any suitable form. In a first option in which the first network node is an AMF, the first request is received directly from the terminal device. In a second option in which the first network node is an SMF in a visited network, the first request is received indirectly from the terminal device via a third network node, which may be an AMF.

[0117] At box 404, the first network node sends a second request to establish a first connection to the second network node. The second request includes a first indication. For example, the second network node may be a session management node that supports both 5G and LTE in a home network or a visited network. In the first option above, the second request is indirectly sent to the second network node via a third network node, which may be an SMF in a visited network. As an exemplary example, the second request may be a PDUSession_CreateSMContext (PDU Session_Create SM (Session Management) Context) request. In the second option above, the second request may be sent directly to the second network node. As an exemplary example, the second request may be a PDUSession_Create (PDU Session_Create) request.

[0118] At block 406, the first network node receives a second indication from the second network node as to whether the second connection is supported by the second network node. Similar to the first indication, the second indication may take any suitable form. In the first option above, the second indication is received indirectly from the second network node via a third network node, which may be an SMF in a visited network. In the second option above, the second indication is received directly from the second network node.

[0119] At block 408, the first network node sends a second indication to the terminal device. In the first option above, the second indication is sent directly to the terminal device. In the second option above, the second indication is sent indirectly to the terminal device via a third network node, which may be an AMF.

[0120] Figure 5 is a flowchart showing a method implemented at a first network node according to another embodiment of the present disclosure. As shown, the method includes blocks 402-408, 510, 512, and 514. At block 510, in response to a requirement to switch from a first technology to a second technology, the first network node sends a third indication to the second network node about whether the fourth network node supports the second connection. For example, the third indication can be sent in a context request message. Similar to the first indication and the second indication, the third indication can take any suitable form. The fourth network node can be a mobility management entity (MME). At block 512, the first network node receives a fourth indication from the second network node about whether the second connection or the third connection is to be used, the third connection being a second type of connection according to the second technology. For example, the fourth indication can be received in a context response message. The second type can be a non-IP type. Therefore, the third connection can be a non-IP type PDN connection. Similar to the first indication to the third indication, the fourth indication can take any suitable form. At block 514, the first network node sends a fourth indication to the fourth network node.

[0121] Figure 66 is a flowchart illustrating a method implemented at a second network node according to an embodiment of the present disclosure. For example, the second network node may be a session management node that supports both 5G and LTE in a home network or a visited network. At box 602, the second network node receives a second request from a first network node to establish a first connection, the first connection being a connection of a first type according to a first technology for a terminal device. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of a first type according to a second technology. Box 602 corresponds to box 404 and its details are omitted here. At box 604, the second network node determines a second indication as to whether the second connection is supported by the second network node. Optionally, the second indication may be as to whether the second connection is supported by both the terminal device and the second network node. At box 606, the second network node sends a second indication to the first network node. Box 606 corresponds to box 406 and its details are omitted here.

[0122] Figure 7 7 is a flowchart illustrating a method implemented at a second network node according to another embodiment of the present disclosure. As shown in the figure, the method includes blocks 602-606, 708, 710 and 712. At block 708, the second network node receives a third indication from the first network node about whether the fourth network node supports the second connection. Block 708 corresponds to block 510 and its details are omitted here. At block 710, the second network node determines a fourth indication about whether the second connection or the third connection will be used for the terminal device based on the first indication and the third indication, and the third connection is a second type of connection according to the second technology. For example, the second type may be a non-IP type. Therefore, the third connection may be a non-IP type PDN connection. If the terminal device, the second network node and the fourth network node support the second connection, it can be determined that the second connection will be used for the terminal device. However, if the fourth network node supports the third connection but does not support the second connection, it can be determined that the third connection will be used for the terminal device. At block 712, the second network node sends a fourth indication to the first network node.

[0123] Now, several embodiments will be further described to explain the solution of the present disclosure. As a first embodiment, negotiation of EPS Ethernet capability is performed when the UE establishes a PDU session in 5GS. When the UE establishes an Ethernet type PDU session in 5GS, the UE also provides the SMF with EPS Ethernet capability (i.e., whether the UE supports the PDN type "Ethernet" in EPS). If the SMF supports the PDN type "Ethernet" in EPS, the SMF provides back to the UE: the network is able to support the EPS Ethernet PDN type.

[0124] As a second embodiment, in the case of 5GS to EPS mobility with N26, if the MME, UE and PGW-C+SMF support Ethernet PDN type, the PGW-C+SMF maps the PDU session of Ethernet type to the PDN connection of Ethernet PDN type. If the UE and PGW-C+SMF support Ethernet PDN type, but the MME only supports non-IP type (but not Ethernet PDN type), the PGW-C+SMF will use the non-IP type as in the traditional scheme (i.e., the network behavior described in 3GPP Release 15). In this way, for Ethernet services, the guaranteed QoS (if any) in 5GS can also be maintained when the UE moves to EPS.

[0125] As a third embodiment, in the case of 5GS to EPS mobility without N26, if the UE knows that the network also supports Ethernet PDN type in EPS, the UE uses Ethernet PDN type in the initial attach request with handover to move the Ethernet type PDU session to EPS. In this way, for Ethernet services, the guaranteed QoS (if any) in 5GS can also be maintained when the UE moves to EPS.

[0126] Figures 8 to 9 is a diagram showing an exemplary process according to the first embodiment described above. The process assumes that a new PDN type "Ethernet" will be introduced into EPS. In order to enable the PDU session type "Ethernet" to be mapped to the PDN type "Ethernet" in the case of 5GS to EPS mobility, the UE and the network negotiate the EPS Ethernet capability at the time of PDU session establishment, such as Figure 8 (for non-roaming or local breakout roaming) and Fig. 9 It should be noted that for ease of understanding, only relevant steps are shown in the figure.

[0127] for Figure 8, at step 1, when the UE establishes a PDU session of Ethernet type, the UE includes a new indication of whether EPS Ethernet is supported in the UE in the NAS message PDU Session Establishment Request. Optionally, the new indication of supporting EPS Ethernet can be sent as a new 5GSM (session management) capability, or can be sent in a PCO (protocol configuration option). At step 2, the new indication is sent from the AMF to the PGW-C / SMF in the N1 SM container of the Nsmf_PDUSession_CreateSMContext request. At step 3, if both the PGW-C+SMF and the UE support EPS Ethernet, the PGW-C+SMF also returns to the UE: "EPS Ethernet" is supported. At step 4, the "EPS Ethernet" support indication is sent from the PGW-C+SMF to the AMF in the N1N2Transfer request. At step 5, the "EPS Ethernet is supported in the network" indication is sent from the AMF to the UE. At step 6, the PGW-C+SMF can store the information whether EPS Ethernet is supported for later use (i.e., for 5GS to EPS mobility). At step 7, the UE may store the information whether EPS Ethernet is supported for later use (ie, for 5GS to EPS mobility).

[0128] for Fig. 9 , in the case of home router roaming, Figure 8 Compared to the non-roaming case in , the EPS Ethernet capability is handled by PGW-C+H-SMF (not V-SMF). The new indication of supporting EPS Ethernet is transparent to V-SMF.

[0129] Based on the above process, the following updates are recommended for the current technical specification 3GPP TS23.502V15.4.1.

[0130] 4.11.5 Impact on the 5GC process

[0131] 4.11.5.3 UE-requested PDU session establishment process

[0132] The following impacts apply to clause 4.3.2.2 (UE-Requested PDU Session Establishment Procedure) to support interworking with EPS:

[0133] - Step 1: In the PDU Session Establishment Request message, the UE also includes "UE Capabilities Supported by Ethernet in EPS" Provided to SMF (or H-SMF in home routing roaming);

[0134] - Step 3: AMF also includes the EPS interworking indication in the Nsmf_PDUSession_CreateSMContext request message sent to SMF.

[0135] The AMF determines the indication based on, for example, UE radio capabilities (e.g., "support S1 mode") and UE subscription data (e.g., core network type restrictions for EPS). The AMF includes the EPS interworking indication in the Nsmf_PDUSession_CreateSMContext or Nsmf_PDUSession_UpdateSMContext request to indicate whether the UE supports EPS interworking.

[0136] - Step 4: If the EPS interworking indication received from the AMF indicates that the UE supports EPS interworking, and the SMF determines, for example, based on UE subscription data (e.g. whether EPS interworking is allowed for this DNN and S-NSSAI)

[0137] If it is determined that the PDU session supports EPS interworking, the PGW-C+SMF FQDN for the S5 / S8 interface is included in the Nudm_UECM_Registraion request.

[0138] - Step 13: In the PDU Session Establishment Accept message, the SMF (or H-SMF in home routed roaming) also includes The SMF and UE store the information on whether the Ethernet PDN type is supported so that the SMF and UE can It is then used when the UE moves from 5GS to EPS.

[0139] Fig.10is a diagram showing an exemplary process according to the above-mentioned second embodiment. At step 2, (corresponding to step 2 of TS23.502 clause 4.11.1.2.1 "5GS to EPS handover using N26 interface", or step 5a of TS23.502 clause 4.11.1.3.2 "5GS to EPS idle mode mobility using N26 interface"), when the AMF uses the Nsmf_PDUSession_Context request to retrieve the SM context from the SMF, in addition to the target MME capability provided by the AMF whether the non-IP PDN type is supported, the AMF also provides the target MME capability whether the Ethernet PDN type is supported. At step 3, if the MME, UE and PGW-C+SMF support the Ethernet PDN type, the PGW-C+SMF maps the PDU session of the Ethernet type to the PDN connection of the Ethernet PDN type. If the UE and PGW-C+SMF support Ethernet PDN type, but the MME only supports non-IP type (but not Ethernet PDN type), the PGW-C+SMF will use the non-IP type and include all bearers in the PDN connection. At step 5, the AMF may include an Ethernet type PDN connection or a non-IP type PDN connection. At step 6, the MME shall accept multiple bearers in a PDN connection for Ethernet type. The MME may accept multiple bearers for non-IP PDN type. At step 8, if a Policy Control and Charging (PCC) rule with Ethernet packet filter is received and a dedicated bearer is to be established, the MME and SGW may accept the dedicated bearer creation even if the PDN type indicates a non-IP type.

[0140] Fig.11 is a diagram showing an exemplary process according to the third embodiment described above. At step 2, if the UE knows that the network also supports the Ethernet PDN type in EPS, the UE uses the Ethernet PDN type in the initial attach request with handover. It should be noted that two consecutively shown blocks in the accompanying drawings may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved.

[0141] Based on the above process, the following updates are recommended for the current technical specification 3GPP TS23.502V15.4.1.

[0142] For 5GS-EPS Mobility with N26:

[0143] 4.11.1.2.1 5GS to EPS Handover Using N26 Interface

[0144] The procedure involves handover to the EPC and establishment of the default EPS bearer in the EPC and dedicated bearers for GBR QoS flows in steps 1-16, and reactivation (if required) of dedicated EPS bearers for non-GBR QoS flows in step 17. The procedure may be triggered, for example, due to new radio conditions, load balancing, or in the presence of QoS flows for normal voice or IMS emergency voice, the source NG-RAN node may trigger handover to the EPC.

[0145] When PDN type Ethernet is not supported in EPS, the following applies:

[0146] For Ethernet and Unstructured PDU Session Types, the PDN type "Non-IP" is used in EPS (when it is supported). Therefore, in these cases, the SMF shall set the PDN type of the EPS bearer context to Non-IP. After switching to EPS, the PDN connection will have PDN type "Non-IP", but it shall be locally associated to PDU Session Type "Ethernet" or "Unstructured" in the UE and SMF, respectively.

[0147] When PDN type "Ethernet" is supported in EPS, use Ethernet type and only PDU session type "Unstructured "Non-IP" PDN type needs to be transferred to EPC as a "non-IP" PDN type (when it is supported by the UE and the network). ...

[0149] 2. The AMF determines from the "Target eNB Identifier" IE that the type of handover is a handover to E-UTRAN. The AMF selects the MME as described in TS 23.401

[13] clause 4.3.8.3.

[0150] In case of HR roaming, the AMF requests the V-SMF to provide the SM context, which also includes the mapped EPS bearer context, by using the Nsmf_PDUSession_Context request. The AMF provides the target MME capabilities to the SMF in the request to allow the V-SMF to determine whether to include the Ethernet PDN type or EPS bearer context of non-IP PDN type. For a PDU Session with PDU Session Type "Ethernet", If the target MME supports Ethernet PDN type, the SMF provides If the target MME does not support Ethernet type but supports non-IP type, the SMF provides a SM context for non-IP type. For SM contexts with PDU session type IP PDN. “Unstructured” PDU Session , SMF provides SM context for non-IP PDN types.

[0151] In the case of non-roaming or LBO roaming, the AMF requests the PGW-C+SMF to provide the SM context by using the Nsmf_PDUSession_Context request. The AMF provides the target MME capabilities to the PGW-C+SMF in the request to allow the PGW-C+SMF to determine whether to include the Ethernet type orEPS bearer context of non-IP PDN type. For a PDU Session with PDU Session Type "Ethernet", If the target MME supports Ethernet PDN type, the SMF provides SM for Ethernet PDN type context, otherwise if the target MME does not support Ethernet but supports non-IP PDN types, the SMF provides For SM contexts with PDU session type “Unstructured” PDU Session , SMF provides SM context for non-IP PDN type. PGW-C+SMF sends N4 Session Modification to PGW-U+UPF to establish CN tunnel for each EPS bearer and provide EPS bearer context to AMF as described in step 8 of clause 4.11.1.4.1. PGW-U+UPF prepares to receive uplink packets from E-UTRAN.

[0152] This step is performed by all PGW-C+SMFs corresponding to the UE's PDU Sessions that are associated with 3GPP access and have EBIs assigned to them.

[0153] Note 2: AMF knows whether MME capabilities are supported through local configuration Ethernet PDN type and / or Non-IP PDN type.

[0154] 19. If necessary, the PGW-C+SMF initiates a dedicated bearer activation procedure for non-GBR QoS flows by mapping the parameters of the non-GBR flows to the EPC QoS parameters. This establishment may be triggered by the PCF, if PCC is deployed. This procedure is specified in TS 23.401

[13] clause 5.4.1, with modifications as embodied in clause 4.11.1.5.4. This step applies It is applicable to PDN types "IP" or "Ethernet", but not applicable to non-IP PDN types.

[0155] 4.11.1.2.2 EPS to 5GS Switching Using N26 Interface

[0156] NOTE 1: If a non-IP PDN type is locally associated to a PDU Session Type "Ethernet" in the UE and SMF, then Meaning that Ethernet PDN type is not supported in EPS.

[0157] Note 2: If the PGW-C+SMF in the HPLMN does not provide mapped QoS parameters, IP address continuity cannot be supported.

[0158] 7.PGW-C+SMF (V-SMF only in the home route roaming scenario) sends Nsmf_PDUSession_CreateSMContext response (PDU session ID, S-NSSAI, N2 SM information (PDU session ID, S-NSSAI, QFI, QoS profile, EPS bearer establishment list, mapping between EBI and QFI, CN tunnel information, reason code)) to AMF.

[0159] For the home route roaming scenario, you need to first execute step 8. The CN tunnel information provided to the AMF in the N2 SM information is the V-CN tunnel information.

[0160] The SMF includes the mapping between the EBI and the QFI as part of the N2 SM information container. If the P-GW-C+SMF (H-SMF in the case of home routing scenario) determines that seamless session continuity from EPS to 5GS is not supported for a PDU session, then it does not provide SM information for the corresponding PDU session, but includes an appropriate reason code for rejecting the PDU session transfer in the N2 SM information. If the direct forwarding flag indicates indirect forwarding and there is no indirect data forwarding connection between the source and the target, the SMF shall also include a "data forwarding not possible" indication in the N2 SM information container. In the case of home routing roaming, the S-NSSAI included in the N2 SM information container is the S-NSSAI received in step 4.

[0161] AMF stores the association of PDU session ID, S-NSSAI and SMF ID.

[0162] If the PDN type of the PDN connection in EPS is non-IP and is locally associated to the PDU Session Type "Ethernet" in the SMF, the PDU Session Type in the 5GS shall be set to Ethernet. In case the PDN type of the PDN connection in EPS is non-IP and is locally associated to the PDU Session Type "Unstructured" in the UE and SMF, the PDU Session Type in the 5GS shall be set to Unstructured.

[0163] NOTE X: If a non-IP PDN type is locally associated in the SMF to a PDU Session Type "Ethernet", this means This means that Ethernet PDN type is not supported in EPS.

[0164] 4.11.1.3.2 5GS to EPS Idle Mode Mobility using N26 Interface 5a.AMF verifies the integrity of the TAU Request message and requests the PGW-C+SMF to provide the SM context using the Nsmf_PDUSession_Context request which also includes the mapped EPS bearer context. The AMF provides the target MME capabilities to the SMF in the request to allow the SMF to determine whether to include use For Ethernet PDN type or EPS bearer context of non-IP PDN type. This step is performed by all PGW-C+SMFs corresponding to the UE's PDU sessions that are associated with 3GPP access and have EBIs assigned to them. In this step, if the AMF correctly authenticates the UE, the AMF starts a timer.

[0165] Note 1: AMF knows whether the MME capability is supported through local configuration Ethernet PDN type and / or Non-IP PDN type.

[0166] 5b. For non-roaming or roaming with local breakout scenarios, if the CN tunnel information is allocated by PGW-U+UPF, the SMF sends an N4 session modification request to the PGW-U+UPF to establish a tunnel for each EPS bearer, and the PGW-U+UPF provides the PGW-U tunnel information for each EPS bearer to the PGW-C+SMF.

[0167] NOTE 2: In the home routed roaming case, the CN tunnel information for each EPS bearer has been prepared by the PGW-C+SMF and provided to the V-SMF as specified in clause 4.11.1.4.1.

[0168] 5c.SMF returns the mapped EPS bearer context, which includes the PGW-C control plane tunnel information of the PDN connection corresponding to the PDU session, the EBI for each EPS bearer, the PGW-U tunnel information for each EPS bearer, and the EPS QoS parameters for each EPS bearer. For a PDU session with PDU session type "Ethernet", If the target MME supports Ethernet If the target MME does not support Ethernet PDN type, the SMF provides an SM context for the Ethernet PDN type. Otherwise, if the target MME does not support Ethernet PDN type, the SMF provides an SM context for the Ethernet PDN type. For a PDU session type with PDU session type 1, but supporting non-IP types, the SMF provides an SM context for non-IP PDN types. “Unstructured” PDU Session , SMF provides SM context for non-IP PDN types.

[0169] 4.11.1.3.3 EPS to 5GS Mobility Registration Procedure Using N26 Interface (Idle and Connected States)

[0170] NOTE: For connected state mobility registration, the release of the CN tunnel for the EPS bearer and the UDM registration for the session corresponding to the PDU session are performed in the handover execution phase.

[0171] If the PDN type of the PDN connection in EPS is non-IP and it is initially established as an Ethernet PDU session when the UE resides in 5GS (based on local context information in the UE and SMF set to PDU session type "Ethernet"), the PDU session type in 5GS shall be set to Ethernet by the SMF and the UE.

[0172] In case the PDN type of the PDN connection in EPS is non-IP and is locally associated to PDU Session Type "Unstructured" in the UE and SMF, the PDU Session Type in 5GS shall be set to Unstructured by the SMF and UE.

[0173] NOTE X: If a non-IP PDN type is initially established as an Ethernet PDU session, this means that the EPS does not support the Ethernet PDU session. Ethernet PDN type.

[0174] For 5GS-EPS Mobility without N26:

[0175] 4.11.2.4 Impact on EPS Process

[0176] 4.11.2.4.1 E-UTRAN Attach

[0177] -Step 1:

[0178] The UE constructs the Attach Request message according to the following principles:

[0179] - if the UE is operating in single registration mode, the UE indicates that it is moving from the 5GC and provides the original 4G-GUTI (if available), or the 4G-GUTI mapped from the 5G GUTI (indicated as the original GUTI), otherwise the IMSI, or

[0180] - if the UE is operating in dual registration mode, the UE indicates that it is moving from 5GC and provides the original 4G-GUTI, or

[0181] - If the UE sent a TAU in step 2 and the TAU was rejected because the MME could not derive the UE identity, the UE provides the IMSI.

[0182] If the UE wishes to transfer a PDU Session to the EPC as part of the attach procedure, the UE includes a PDN Connection Request message in the Attach Request and provides the request type "Handover", the DNN / APN, and the PDU Session ID of the PDU Session (TS23.401

[13] , clause 5.3.2.1). The UE provides the PDU Session ID in the PCO as described in clause 4.11.1.1. For Ethernet type PDU Session, if the UE and the network support Ethernet PDN type in EPS (this is in PDU Session as described in clause 4.11.5 If the PDN type is not set as “Ethernet”, the UE includes the PDN type “Ethernet” in the PDN Connection Request message.

[0183] Fig.12 1 is a block diagram showing an apparatus suitable for use in practicing some embodiments of the present disclosure. For example, any of the terminal device, the first network node, and the second network node described above may be implemented by the apparatus 1200. As shown in the figure, the apparatus 1200 may include a processor 1210, a memory 1220 storing programs, and an optional communication interface 1230 for data communication with other external devices via wired and / or wireless communication.

[0184] The program includes program instructions that, when executed by the processor 1210, enable the device 1200 to operate according to the embodiments of the present disclosure, as discussed above. That is, the embodiments of the present disclosure may be implemented at least in part by computer software executable by the processor 1210, or by hardware, or by a combination of software and hardware.

[0185] The memory 1220 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The processor 1210 may be of any type suitable for the local technical environment and may include, as non-limiting examples, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture.

[0186] As another embodiment, a terminal device includes a sending module and a receiving module. The sending module may be configured to send a first request for establishing a first connection to a first network node, the first connection being a connection of a first type according to a first technology. The first request includes a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The receiving module may be configured to receive a response to the first request from the first network node. The response includes a second indication of whether the second connection is supported by a second network node.

[0187] As another embodiment, the first network node includes a first receiving module, a first sending module, a second receiving module, and a second sending module. The first receiving module may be configured to receive a first request for establishing a first connection from a terminal device, the first connection being a connection of a first type according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The first sending module may be configured to send a second request for establishing the first connection to a second network node. The second request includes the first indication. The second receiving module may be configured to receive a second indication as to whether the second connection is supported by the second network node from the second network node. The second sending module may be configured to send the second indication to the terminal device.

[0188] As another embodiment, the second network node includes a receiving module, a determining module and a sending module. The receiving module may be configured to receive a second request for establishing a first connection from the first network node, the first connection being a connection of a first type for a terminal device according to a first technology. The first request includes a first indication as to whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology. The determining module may be configured to determine a second indication as to whether the second connection is supported by the second network node. The sending module may be configured to send the second indication to the first network node. The above modules may be implemented by hardware, software, or a combination of both.

[0189] In general, various exemplary embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, although the present disclosure is not limited thereto. Although various aspects of the exemplary embodiments of the present disclosure may be shown and described as block diagrams, flow charts, or using some other graphical representations, it should be well understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers, or other computing devices, or some combination thereof.

[0190] Thus, it should be understood that at least some aspects of the exemplary embodiments of the present disclosure may be practiced in various components such as integrated circuit chips and modules. Thus, it should be understood that the exemplary embodiments of the present disclosure may be implemented in a device embodied as an integrated circuit, wherein the integrated circuit may include circuits (and possibly firmware) for embodying at least one or more of a data processor, a digital signal processor, a baseband circuit, and a radio frequency circuit that may be configured to operate according to the exemplary embodiments of the present disclosure.

[0191] It should be understood that at least some aspects of the exemplary embodiments of the present disclosure may be embodied in computer executable instructions executed by one or more computers or other devices, such as embodied in one or more program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., which perform specific tasks or implement specific abstract data types when executed by a processor in a computer or other device. Computer executable instructions may be stored on a computer readable medium, such as a hard disk, an optical disk, a removable storage medium, a solid-state memory, a RAM, etc. It will be appreciated by those skilled in the art that the functions of the program modules may be combined or distributed as needed in various embodiments. In addition, the functions may be embodied in firmware or hardware equivalents (such as integrated circuits, field programmable gate arrays (FPGAs), etc.) in whole or in part.

[0192] References in this disclosure to "one embodiment," "an embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0193] It should be understood that, although the terms "first", "second", etc. can be used in this article to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element without departing from the scope of this disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0194] The terms used herein are only used to describe the purpose of specific embodiments, and are not intended to limit the present disclosure. As used herein, the singular "a, an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will also be understood that the terms "include", "have" and / or "comprise" when used herein refer to the existence of stated features, elements and / or components, and do not exclude the existence or addition of one or more other features, elements, components and / or their combinations. The term "connection" used herein covers the direct and / or indirect connection between two elements.

[0195] The present disclosure includes any novel feature or feature combination disclosed herein, either explicitly or in any generalized form thereof. When read in conjunction with the accompanying drawings, various modifications and adaptations to the above exemplary embodiments of the present disclosure will become apparent to those skilled in the relevant art in view of the above description. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of the present disclosure.

[0196] Abbreviations

[0197] AMF Access and Mobility Management Function

[0198] EPS Evolved Packet System

[0199] GBR Guaranteed Bit Rate

[0200] H-SMF Home Session Management Function

[0201] MME Mobility Management Entity

[0202] PGW-C Packet Gateway - Control Plane

[0203] PDN Packet Data Network

[0204] PDU Packet Data Unit

[0205] QoS Quality of Service

[0206] SGW Service Gateway

[0207] UE User Equipment

[0208] V-SMF Visiting Site Session Management Function

[0209] 5GS Fifth Generation System.

Claims

1. A method in a terminal device, comprising: sending a first request to a first network node for establishing a first connection, the first connection being a connection of a first type according to a first technology, the first request comprising a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology; and wherein the first type is an Ethernet type; and wherein the first technology is the 5th generation 5G, and the second technology is the Evolved Packet System EPS.

2. The method according to claim 1, further comprising: A response to the first request is received from the first network node, the response comprising a second indication of whether the second connection is supported by a second network node.

3. The method according to claim 2, further comprising: determining, based on the second indication, whether both the terminal device and the second network node support the second connection; as well as When it is determined that both the terminal device and the second network node support the second connection, a second request for switching from the first connection to the second connection is sent to the first network node.

4. The method according to any one of claims 1 to 3, wherein: The first connection is a protocol data unit, PDU, session of Ethernet type and the second connection is a packet data network, PDN, connection of Ethernet type.

5. The method according to claim 2 or 3, wherein: The first network node is an Access and Mobility Management Function (AMF); and The second network node is a session management node that supports both 5G and EPS in a home network or a visited network.

6. A method in a first network node, comprising: receiving, from a terminal device, a first request to establish a first connection, the first connection being a connection of a first type according to a first technology, the first request comprising a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology; wherein the first type is an Ethernet type; and wherein the first technology is the 5th generation 5G, and the second technology is the Evolved Packet System EPS.

7. The method according to claim 6, further comprising: sending a second request for establishing the first connection to a second network node, the second request including the first indication; receiving a second indication from the second network node as to whether the second connection is supported by the second network node; as well as Send the second indication to the terminal device.

8. The method according to claim 7, wherein: The second request is sent to the second network node via a third network node, and the second indication is received from the second network node via the third network node; or The first request comes from the terminal device via a third network node, and the second indication is sent to the terminal device via the third network node.

9. The method according to claim 7 or 8, further comprising: In response to a request to switch from the first technology to the second technology, sending a third indication to the second network node regarding whether a fourth network node supports the second connection; receiving a fourth indication from the second network node as to whether the second connection or a third connection is to be used, the third connection being a second type of connection according to the second technology; as well as The fourth indication is sent to the fourth network node.

10. The method according to any one of claims 6 to 9, wherein: The first connection is a protocol data unit, PDU, session of Ethernet type and the second connection is a packet data network, PDN, connection of Ethernet type.

11. The method according to claim 8, wherein: The first network node is an access and mobility management function AMF; The second network node is a session management node supporting both 5G and EPS in a home network or a visited network; and The third network node is a session management function SMF in a visited network; or Wherein, the first network node is an SMF in a visited network; The second network node is a session management node supporting both 5G and EPS in a home network or a visited network; and Wherein, the third network node is AMF.

12. The method according to claim 9, wherein: The fourth network node is a mobility management entity MME; and The second type is a non-IP type.

13. A method in a second network node, comprising: receiving, from the first network node, a second request to establish a first connection, the first connection being a connection of a first type according to a first technology for a terminal device, the second request comprising a first indication of whether the terminal device supports a second connection, the second connection being a connection of the first type according to a second technology; wherein the first type is an Ethernet type; and wherein the first technology is the 5th generation 5G, and the second technology is the Evolved Packet System EPS.

14. The method according to claim 13, further comprising: determining a second indication of whether the second connection is supported by the second network node; as well as The second indication is sent to the first network node.

15. The method according to claim 14, wherein: The second indication is about whether the second connection is supported by both the terminal device and the second network node; and / or wherein the second request is received from the first network node via a third network node; and wherein the second indication is sent to the first network node via the third network node.

16. The method according to claim 15, further comprising: receiving, from the first network node, a third indication of whether a fourth network node supports the second connection; determining, based on the first indication and the third indication, a fourth indication as to whether the second connection or a third connection is to be used for the terminal device, the third connection being a second type of connection according to the second technology; as well as The fourth indication is sent to the first network node.

17. The method according to claim 16, wherein: Determining the fourth indication includes: When the terminal device, the second network node, and the fourth network node support the second connection, determining that the second connection is to be used for the terminal device; and When the fourth network node supports the third connection but does not support the second connection, it is determined that the third connection is to be used for the terminal device.

18. The method according to any one of claims 13 to 17, wherein: The first connection is a protocol data unit, PDU, session of Ethernet type and the second connection is a packet data network, PDN, connection of Ethernet type.

19. The method according to claim 16, wherein: The first network node is an access and mobility management function AMF; The second network node is a session management node supporting both 5G and EPS in a home network or a visited network; and The third network node is a session management function SMF in a visited network; and The fourth network node is a mobility management entity MME; and The second type is a non-IP type.

20. A terminal device, comprising: at least one processor; as well as At least one memory, the at least one memory containing instructions executable by the at least one processor, whereby the terminal device is operable to implement the method according to any one of claims 1 to 5.

21. A first network node, comprising: at least one processor; as well as At least one memory, the at least one memory containing instructions executable by the at least one processor, whereby the first network node is operable to implement the method according to any one of claims 6 to 12.

22. A second network node, comprising: at least one processor; as well as At least one memory containing instructions executable by the at least one processor, whereby the second network node is operable to implement the method according to any one of claims 13 to 19.

Images