Method and related network entity / node for providing anchor change for Ethernet PDU session

Abstract

To provide a method of operating a session management function (SMF) entity of a wireless communication network and a method of operating user plane function (UPF) entity of a wireless communication network.SOLUTION: A method comprises receiving an Ethernet (ETH) context for a wireless terminal (UE) from a source user plane function (UPF) entity. The ETH context is provided for an Ethernet Protocol Data Unit (PDU) Session for the UE using the source UPF entity and includes a Medium Access Control (MAC) address for the UE. The method also comprises transmitting the Ethernet context including the MAC address for the UE to a target UPF entity.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to communications, and more particularly to wireless communications and related communication entities and / or nodes.

Background Art

[0002] The 5G system defines several session and service continuity (SSC) modes for mobile wireless terminals (UEs). These modes may enable the use of a PDU session anchor (PSA) close to the UE's current attachment point to the network in the RAN. SSC modes 1, 2, and 3 are defined in 3GPP TS23.501 section 5.6.9. The currently defined SSC modes are as follows. · SSC mode 1 applies a PSA that does not change even when the UE moves. This may reduce / avoid issues and / or complexities associated with PSA changes, but the distance between the PSA and the UE may increase, which may increase end-to-end latency and also increase network traffic in the operator's network. · SSC mode 2 applies the break-before-make principle when setting up a new PDU session. When the UE moves far away from the UE's original PSA, the old PDU session is released and the UE is instructed to establish a new PDU session where a PSA close to the UE's new location is selected. · SSC mode 3 applies the make-before-break principle when setting up a new PDU session. When the UE moves far away from the UE's original PSA, the UE is instructed to establish a new PDU session where a PSA close to the UE's new location is selected. The UE may prefer to use the new PDU session for the UE's network traffic. The old session coexists with the new session for a temporary period of time. After a while, the old session is released.

[0003] SSC modes 2 and 3 can only be applied to PDU session types IPv4 / v6, and SSC mode 1 can be applied to any type of PDU session. The reason is that SSC modes 2 and 3 may imply that the UE will obtain a new IP address allocated for the UE's new PDU session. A new IP address may be required because the IP address can carry the topological significance in the data network, and thus, the PSA in the new location may require an IP address in the case of IP routing. Existing solutions may not adequately address the mobility issues related to Ethernet PDU sessions. SUMMARY OF THE INVENTION

[0004] According to some embodiments of the inventive concept, a method of operating a session management function (SMF) entity of a wireless communication network may be provided. An Ethernet context for a wireless terminal may be received from a first user plane function (UPF) entity, the Ethernet context being provided for an Ethernet protocol data unit (PDU) session for the wireless terminal using the first UPF entity, and the Ethernet context including a media access control (MAC) address for the wireless terminal. The Ethernet context including the MAC address for the wireless terminal may be transmitted to a second UPF entity.

[0005] According to some embodiments of the inventive concept, the complexity in handling Ethernet PDU sessions can be reduced in both the network and the user equipment, and the need for PDU session release and re-establishment can be reduced / avoided. Moreover, by using a nearby PSA, a shorter delay can be provided without affecting the operation of the user equipment.

[0006] Included to provide a further understanding of the present disclosure, incorporated in the present application and constituting a part of this application, the accompanying drawings illustrate some non-limiting embodiments of the inventive concept.

Brief Description of the Drawings

[0007]

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DETAILED DESCRIPTION OF THE INVENTION

[0008] Next, the inventive concept will be described in more detail below with reference to the accompanying drawings that illustrate examples of embodiments of the inventive concept. However, the inventive concept may be embodied in many different forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. It should also be noted that these embodiments are not mutually exclusive. Components from one embodiment may be implicitly assumed to be present / used in another embodiment.

[0009] The following description presents various embodiments of the disclosed subject matter. These embodiments are presented as illustrative examples and should not be construed as limiting the scope of the disclosed subject matter. For example, some details of the described embodiments may be modified, omitted, or extended without departing from the scope of the described subject matter.

[0010] FIG. 5 is a block diagram showing elements of a mobile terminal UE (also referred to as a wireless device, wireless communication device, wireless terminal, wireless communication terminal, user equipment, user equipment node / terminal / device, etc.) configured to provide wireless communication according to an embodiment of the inventive concept. As illustrated, the mobile terminal UE may include an antenna 707 and a transceiver circuit 701 (also referred to as a transceiver) configured to provide uplink wireless communication and downlink wireless communication with one or more base stations of a wireless access network. The mobile terminal UE may also include a processor circuit 703 (also referred to as a processor) coupled to the transceiver circuit and a memory circuit 705 (also referred to as a memory) coupled to the processor circuit. The memory circuit 705 may include computer-readable program code that, when executed by the processor circuit 703, causes the processor circuit to perform operations according to the embodiments disclosed herein. According to other embodiments, the processor circuit 703 may be defined to include memory such that a separate memory circuit is not required. The mobile terminal UE may also include an interface (such as a user interface) coupled to the processor 703, and / or the mobile terminal UE may be incorporated into a vehicle.

[0011] As described herein, the operations of the mobile terminal UE may be performed by the processor 703 and / or the transceiver 701. For example, the processor 703 may control the transceiver 701 to transmit communications through the transceiver 701 on a wireless interface to another UE and / or receive communications through the transceiver 701 on a wireless interface from another UE. Additionally, modules may be stored in the memory 705, and these modules may provide instructions such that when the instructions of the modules are executed by the processor 703, the processor 703 performs respective operations (such as the operations described below with respect to exemplary embodiments).

[0012] FIG. 6 is a block diagram illustrating elements of a Node B base station (also referred to as a network node, base station, eNode B, eNB, gNode B, gNB, etc.) of a radio access network (RAN) configured to provide cellular communications. As shown, the Node B base station may include a transceiver circuit 801 (also referred to as a transceiver) configured to provide uplink and downlink radio communications with mobile terminals. The Node B base station may include a network interface circuit 807 (also referred to as a network interface) configured to provide communications with other nodes of the RAN (e.g., with other base stations and / or other entities). The Node B base station may also include a processor circuit 803 (also referred to as a processor) coupled to the transceiver circuit and a memory circuit 805 (also referred to as a memory) coupled to the processor circuit. The memory circuit 805 may include computer-readable program code that, when executed by the processor circuit 803, causes the processor circuit to perform operations in accordance with the embodiments disclosed herein. According to other embodiments, the processor circuit 803 may be defined to include memory such that a separate memory circuit is not required.

[0013] As described herein, the operation of the Node B base station can be performed by the processor 803, the network interface 807, and / or the transceiver 801. For example, the processor 803 can control the transceiver 801 to transmit communications to one or more mobile terminals UE over the radio interface through the transceiver 801 and / or receive communications from one or more mobile terminals UE over the radio interface through the transceiver 801. Similarly, the processor 803 can control the network interface 807 to transmit communications to one or more other network nodes / entities through the network interface 807 and / or receive communications from one or more other network nodes / entities through the network interface. Moreover, modules can be stored in the memory 805, and these modules can provide instructions such that when the instructions of the modules are executed by the processor 803, the processor 803 performs the respective operations.

[0014] According to some other embodiments, the elements of the Node B base station can be implemented as a control node without a transceiver. In such embodiments, the transmission to the mobile terminal can be initiated by the control node such that the transmission to the radio terminal is provided through a network node including a transceiver, for example, through a base station. According to embodiments where the control node is a base station including a transceiver, initiating the transmission can include transmitting through the transceiver.

[0015] FIG. 7 is a block diagram showing elements of a network entity (e.g., a UPF entity, an AMF entity, an SMF entity, or any other control entity of a radio access network (RAN) or a core network (CN)) configured to support cellular communication. Such a network entity may also be referred to as a network node. As shown, the network entity may include a network interface circuit 907 (also referred to as a network interface) configured to provide communication with other network entities / nodes (e.g., with a base station and / or with another network entity of the RAN and / or the CN). The network entity may also include a processor circuit 903 (also referred to as a processor) coupled to the network interface circuit 907 and a memory circuit 905 (also referred to as a memory) coupled to the processor circuit. The memory circuit 905 may include computer-readable program code that, when executed by the processor circuit 903, causes the processor circuit to perform operations according to the embodiments disclosed herein. According to other embodiments, the processor circuit 903 may be defined to include memory such that a separate memory circuit is not required.

[0016] As described herein, the operation of the network entity may be performed by the processor 903 and / or the network interface 907. For example, the processor 903 may control the network interface 907 to send communications to one or more other network nodes / entities through the network interface 907 and / or receive communications from one or more other network nodes / entities through the network interface. Additionally, modules may be stored in the memory 905, and these modules may provide instructions such that when the instructions of the modules are executed by the processor 903, the processor 903 performs the respective operations. As described above, the structure of the network entity in FIG. 7 may be used to implement, for example, a UPF entity, an AMF entity, and / or an SMF entity to perform the operations of a UPF entity, an AMF entity, and / or an SMF entity, as will be described in more detail below. The operation of the network entity in FIG. 7 may be performed, for example, by one network server or may be distributed across multiple network servers having the structure of FIG. 7, and multiple such distributed servers may be collectively referred to as servers.

[0017] SSC modes 2 and 3 may enable the use of a nearby PSA, but these modes may have limitations. SSC modes 2 and 3 may only be applicable to PDU sessions of type IPv4 / v6, and Ethernet PDU sessions, although they may also benefit from a nearby PSA, may not be applicable to Ethernet PDU sessions. SSC mode 2 may interrupt data traffic by session release and re-establishment. SSC mode 3 may, in principle, reduce / avoid interruptions, but implementing SSC mode 3 may require UE support, which may involve complexities that are not always reasonable.

[0018] According to some embodiments of the inventive concept, an SSC mode may be provided for an Ethernet PDU session and / or SSC mode 1 may be specially adjusted for an Ethernet PDU session. In the case of an Ethernet PDU session, the PSA may be moved without releasing the session. Such embodiments may change the PSA of an ongoing session in combination with updating forwarding in a data network.

[0019] Thereby, simplified handling may be possible in both the network and the terminal, especially since there may be no need for PDU session release and re-establishment. This also means that the process may be faster. This mechanism may not affect the UE except that the UE may enjoy the benefit of a shorter delay by a nearby PSA.

[0020] The result of this approach may be that it becomes easier to support a deployment where the PSA is collocated with the RAN node (i.e., the PSA and the RAN node are at the same site or even running on the same platform). This may simplify the deployment in, for example, a small-scale local industrial deployment.

[0021] Some embodiments of the inventive concept are shown in the figure of FIG. 1. The embodiments of FIG. 1 may be applied in a 5G system, but the same / similar embodiments may be equally applied in a 4G system, 3G system, 2G system, and / or other mobile / wireless communication systems with appropriate adjustments.

[0022] In Figure 1, the wireless terminal UE is initially connected via a RAN node source gNB (also called the source base station) and a CN node source UPF acting as the PSA. The CN control plane entities AMF and SMF may assist in establishing the session. Figure 1 also shows the control plane entities UDM, NRF, PCF, NEF, which may not be essential for the following description. The 5G system is connected to an Ethernet data network, shown as an ETH subnet.

[0023] The source UPF may maintain an Ethernet context (ETH context), which contains information related to the Ethernet network to which the source UPF is connected. More specifically, the Ethernet context includes the MAC address used by the wireless terminal UE for Ethernet traffic. The Media Access Control (MAC) address can be determined by the UPF, for example, by learning the Media Access Control (MAC) address based on ongoing traffic or by explicit configuration. In some cases, there may be multiple MAC addresses corresponding to a PDU session due to the wireless terminal UE having multiple addresses or other Ethernet devices connecting through that UE (in which case the Ethernet context may include multiple MAC addresses).

[0024] The Ethernet context is copied from the source UPF to the SMF. When a change to the Ethernet context for the wireless device UE is made, the change is also updated in the SMF's copy. The Ethernet context may be stored in the SMF so that the SMF can provide the current Ethernet context to the new / target UPF when a new PSA is established.

[0025] In the case of wireless terminal UE mobility, the wireless terminal UE moves to a target gNB (also referred to as the target base station). The CN, or more specifically, the SMF, may determine to establish a new PSA. In the example of FIG. 1, the target UPF that will act as the new PSA. Tunneling is updated from the source gNB-source UPF tunnel before handover to the target gNB-target UPF after handover. The SMF installs the Ethernet context in the target UPF. Thereafter, the target UPF updates the forwarding in the Ethernet subnetwork. This can be done in several ways depending on which operating mode is used. · When MAC learning is applied in the Ethernet subnetwork, the target UPF may generate an Ethernet frame with the MAC address stored in the Ethernet context, and the target UPF may send that Ethernet frame as a flooded frame in the Ethernet subnetwork. Such a frame can be, for example, a broadcast frame. It is possible to include a data payload in such a frame, but it is not necessarily required to include a data payload. Sending such a frame will update the Ethernet forwarding in the subnetwork. It may be possible to send multiple flooded frames to protect against drop or transient behavior. · When the central controller sets the forwarding table of the Ethernet subnetwork, the target UPF may contact the central controller to notify the central controller that a given MAC address is now reachable at the new location (target UPF).

[0026] In addition to the two methods described above, additional methods may be possible. · According to some embodiments, it may be possible to trigger the UE (e.g., by sending a signaling message to the UE) to send an Ethernet frame that updates the forwarding in the subnet. · According to some embodiments, it may be possible to not immediately update the forwarding in the Ethernet subnet. In such a case, the frame may be sent to the old PSA, and the old PSA may forward downlink packets to the UE for a temporary time period. A new uplink frame via the new PSA can update the Ethernet forwarding. · According to some embodiments, it may be possible to not immediately update the forwarding in the Ethernet subnet. The old PSA (knowing that it can no longer reach the UE at a given MAC address) may flood downlink frames in the local subnet, such that the downlink frames also reach the new PSA and are ultimately forwarded to the UE. Eventually, and an uplink frame from the UE can update the forwarding in the subnet.

[0027] If the Ethernet context includes multiple MAC addresses, the operations described above can be repeated for all MAC addresses of the Ethernet context for the UE. According to some embodiments, it may be possible that the Ethernet handling function is not incorporated in the UPF, in which case the UPF may use a signaling protocol to instruct the Ethernet handling function to perform the necessary operations.

[0028] The signaling diagram of FIG. 2 shows some embodiments of the inventive concept for an Xn-based handover from a source gNB 253 to a target gNB 255 in a 5G system. In FIG. 2, the Xn-based handover can be updated.

[0029] First, an Ethernet PDU session is established by user data proceeding (at 200a) via source gNB 253 and source UPF 257. The source UPF 257 acts as the PSA.

[0030] 201. The source UPF 257 sends an N4 report to inform the SMF 263 of the Ethernet context (i.e., the maintained information related to the Ethernet network to which the source UPF 257 interfaces). Specifically, the N4 report may include the media access control (MAC) address for UE 251 that the source UPF 257 learned from the UE side. If there is a change in the Ethernet context, the change is updated to the SMF 263 such that the SMF 263 maintains the latest copy of the Ethernet context at the source UPF 253 for UE 251. This signaling may be realized using the N4 reporting procedure.

[0031] 202. The SMF 263 acknowledges the source UPF report of operation 201, for example, using an N4 report confirmation response (Ack) sent from the SMF 263 to the source UPF 257.

[0032] 203. An Xn handover is prepared in the RAN (including source gNB 253 and target gNB 255), and then downlink data forwarding from the source gNB to the target gNB (at 200b) continues.

[0033] 204. The handover is executed in the radio access network (RAN) (including source gNB 253 and target gNB 255), and the UE 251 connects to the target gNB 255. Thereafter, uplink data can pass (at 200c) via the target gNB 255 and the source UPF 257.

[0034] 205. The target gNB 255 starts sending a path switch request to the AMF 261 to effect a user plane switch in the CN.

[0035] 206. The path switch is signaled from the AMF 261 to the SMF 263, for example, by sending an Nsmf_PDUSession_UpdateSMContext request.

[0036] 207. The SMF 263 determines that the PSA should be changed for the Ethernet PDU session and selects a new UPF that will act as the target UPF 259.

[0037] 208. A target UPF N4 session is established, including the tunnel endpoint of the RAN node to be used between the target gNB 255 and the target UPF 259. The Ethernet context is also sent from the SMF 263 to the target UPF 259, for example, by sending an N4 session establishment request.

[0038] 209. The establishment of the new N4 session is acknowledged from the target UPF 259 to the SMF 263, for example, by sending an N4 session establishment response.

[0039] 210. Ethernet forwarding is updated in the Ethernet subnetwork. This can be done by the target UPF259 generating a new Ethernet frame with the MAC address for the UE251 as the source when the Ethernet network uses MAC learning, or, when a central controller in the Ethernet network is used to set the forwarding table of the Ethernet network, by instructing the central controller of the Ethernet network that a given MAC address is reachable at a new location. In the case of multiple MAC addresses for the UE251, this process can be repeated for each MAC address. From this point on, the downlink frame for the UE251 (at 200d) can be forwarded towards the target gNB259. Further explanations / options for updating Ethernet forwarding were described above.

[0040] 211. The path switch can be acknowledged from the SMF263 to the AMF261 using the Nsmf_PDUSession_UpdateSMContext response. This signaling can also include the tunnel endpoint at the target UPF259 for the tunnel between the target gNB255 and the target UPF259. If an end marker is not provided for the target gNB255, the Nsmf_PDUSession_UpdateSMContext response of operation 211 can include a no end marker flag indicating that there will be no end marker for the Ethernet PDU session.

[0041] 212. The path switch can be acknowledged from the AMF 261 to the target gNB 255 using the N2 path switch request Ack. This signaling also includes the tunnel endpoint at the target UPF 259 for the tunnel between the target gNB 255 and the target UPF 259. From this point on, uplink frames from the UE 251 (at 200e) can pass through the target gNB 255 and the target UPF 259. As described above with respect to operation 211, in response to the Nsmf_PDUSession_UpdateSMContext response of operation 211 that includes the end markerless flag, the N2 path switch request Ack may include an end markerless flag indicating that there will be no end marker for the Ethernet PDU session. Thus, the target gNB will know that there will be no end marker based on receiving the end markerless flag.

[0042] 213. The N4 session is released at the source UPF 257, for example, using an N4 session release request. This triggers the source UPF 257 to send an end marker to the target gNB 255 via the source gNB 253 (at 200f), helping the target gNB 255 to deliver frames in order. After this, the target gNB 255 knows that it does not need to expect further frames from the source gNB 253. Next, the user plane is switched (at 200g), and user data is then communicated via the target gNB 255 and the target UPF 259 in both the uplink and downlink directions.

[0043] 214. The N4 session release is acknowledged from the source UPF 257 to the SMF 263 using an N4 session release response. Note that operations 213-214 can be performed early, for example, immediately after operation 209. Alternatively, operations 213-214 can be performed later, and during a temporary time period, it is also possible that downlink frames are forwarded from the source UPF 257 to the target gNB 259.

[0044] Note that the end marker sent after operation 213 (in 200f) may be optional according to some embodiments and may be omitted according to some embodiments. If the end marker is omitted, the target gNB 259 may not reorder the downlink frames, or alternatively, the target gNB 259 may wait during a timeout period in which the target gNB 259 sends only the forwarded frames to the UE 251, and after the timeout, the target gNB 259 stops sending the forwarded frames and delivers only the downlink frames from the target UPF 259. Whether to use the end marker or not can be established based on a setting that should be consistent in the system for a given UE, regardless of whether the end marker is expected to be used.

[0045] As described above regarding anchor change for an Ethernet PDU session, the end marker can be omitted / skipped in this way in the case of UPF change. Different options are described below regarding how the RAN node (e.g., the target gNB 255) can be made aware that it should not expect the arrival of an end marker packet in the case of UPF change for an Ethernet PDU session. · The RAN node can be preconfigured not to anticipate an end marker. In a given deployment, the RAN node can be configured not to anticipate the arrival of an end marker for any PDU session. This option can be suitable for local (e.g., factory) deployments. · The RAN node can be configured not to anticipate an end marker for a set of network slices identified by the S-NSSAI provided for a given UE. · The RAN node can be configured not to anticipate an end marker for a specific PDU session type. The PDU session type can be provided to the RAN node. · The RAN node can be configured not to anticipate an end marker for a set of RAT / Frequency Selection Priority (RFSP) indices. The RFSP indices are provided to the RAN node by the AMF and are applied per UE. · The RAN node can be configured not to anticipate an end marker for a PDU session having a flow with a 5QI from a predefined set of 5G (5th Generation) QoS (Quality of Service) indicators (5QIs). · New PDU session parameters indicating whether an end marker should be anticipated can be defined at the RAN node and at the AMF entity / node 261. When the "no end marker" flag is indicated to the RAN node for a given PDU session, the RAN node knows that it should not anticipate an end marker for that session. (Alternatively, a per-UE flag can be defined.) The AMF can determine the flag based on a subscription or local configuration, the AMF can maintain the result in its own UE context, and the AMF can provide the flag to the RAN node when the RAN context is established.

[0046] Of course, the above combinations can also be used. For example, for a given combination of slice identifier and PDU type, the RAN node can be configured not to expect an end marker.

[0047] As another embodiment, whether the RAN node should expect an end marker can be indicated individually in each change of the UPF, together with the signaling to update the N3 tunnel endpoint in the UPF. This can be done during a handover procedure, but UPF changes without handover may also be possible. Examples of UPF changes with handover and examples of UPF changes without handover are shown in Figure 6.11.2-1 of section 6.11 of 3GPP TR 23.725 v2.0.0 (2018-12) (cited below).

[0048] Within the procedures of Figure 6.11.2-1 of 3GPP TR 23.725, operation 9 and operation 10 in the case of handover, and optionally operation 11 in the case of no handover, may include an additional flag indicating to the RAN node whether the RAN node should expect an end marker when the UPF endpoint of the N3 tunnel is changed. In the embodiment of Figure 2, such an end markerless flag may be included in the messages of operation 211 and operation 212.

[0049] When the RAN node is informed (using any of the above methods) that the RAN node should not expect an end marker, the RAN node can deliver the downlink packet when the downlink packet arrives, regardless of whether the downlink packet arrives directly from the new (target) UPF or from the source UPF (either directly or, in the case of handover, forwarded via the source RAN node). In contrast, the RAN node can buffer new downlink packets coming directly from the source UPF (up to a threshold time period) until the end marker (forwarded via the source RAN node) arrives on the old path.

[0050] If the RAN node cannot determine whether an end marker is expected, the RAN node may decide to wait for the end marker for a short time period and buffer new downlink packets coming directly from the UPF. That is, in case of uncertainty regarding the end marker, a threshold time period for waiting for the end marker may be reduced / decreased so that the RAN node does not wait too long for an end marker that may never arrive. In case of uncertainty, it may also be possible to not wait for the end marker at all and deliver all downlink packets without reordering when the downlink packets arrive.

[0051] Figures 3A - 3B and 4A - 4B show embodiments of the inventive concept in a dual connectivity (DC) setting where dual connectivity features are used in the RAN and a single UE 351 is connected to both an MgNB 353 (master gNB) and an SgNB 355 (secondary gNB). International Application No. PCT / IB2017 / 058517 describes a situation where a UE maintains two PDU sessions in parallel for redundancy in both the RAN and the CN.

[0052] This signaling diagram of FIGS. 3A and 3B shows some embodiments applicable to dual connectivity where a new secondary gNB 355 is added. In the embodiments of FIGS. 3A - 3B, the UE 351 initially has two PDU sessions, namely, a first PDU session via the MgNB and UPF1 in 300a, and a second PDU session via the MgNB and UPF2A (referred to as the secondary source UPF 359) in 300b. As will be described below, the second PDU session can be handed over from the MgNB 353 and the secondary source UPF 359 to the SgNB 355 and the secondary target UPF 361 (UPF2B). The operation of the secondary source UPF 359 can be similar to the operation described above for the source UPF 255, and the operation of the secondary target UPF 361 can be similar to the operation described above for the target UPF 259.

[0053] 301. The secondary source UPF 359 sends an N4 report to inform the SMF 367 of the Ethernet context (i.e., the maintained information related to the Ethernet network to which the secondary source UPF 359 interfaces). Specifically, the N4 report may include the media access control (MAC) address for the UE 351 that the secondary source UPF 359 learned from the UE side. If there is a change in the Ethernet context, the change is updated to the SMF 367 so that the SMF 367 maintains the latest copy of the Ethernet context at the secondary source UPF 359 for the UE 351. This signaling can be realized using the N4 reporting procedure.

[0054] 302. The SMF 367 acknowledges the source UPF report of operation 301, for example, using an N4 report confirmation response (Ack) sent from the SMF 367 to the secondary source UPF 359.

[0055] 303. The MgNB 353 may send a secondary node (SN) addition request to the SgNB 355 to initiate the addition of the secondary node SgNB to be used for PDU session 2.

[0056] 304. The SgNB 355 responds to the SN addition request with an SN addition request confirmation response.

[0057] 305. Radio Resource Control (RRC) reconfiguration and / or Random Access (RA) may be performed to add the secondary node SgNB 355 for PDU session 2. Then, downlink (DL) data forwarding is performed (at 300c), and downlink data from the secondary source UPF 359 may be forwarded from the MgNB 353 to the SgNB 355 for downlink (DL) transmission to the UE 351 for PDU session 2. (At 300d), uplink (UL) data may be transmitted from the UE 351 through the SgNB 355 to the secondary source UPF 359 for PDU session 2.

[0058] 306. The MgNB 353 starts sending an N2 path switch request to the AMF 363 to perform switching of the user plane in the CN.

[0059] 307. The path switch is signaled from the AMF 363 to the SMF 367, for example, by sending an Nsmf_PDUSession_UpdateSMContext request.

[0060] 308. The SMF 367 determines that the PSA should be changed for Ethernet PDU session 2 and selects a new UPF that will act as the secondary target UPF 361.

[0061] 309. A secondary target UPF N4 session is established that includes the tunnel endpoint of the RAN node to be used between the SgNB 355 and the secondary target UPF 361. The Ethernet context is also sent from the SMF 367 to the secondary target UPF 361, for example, by sending an N4 session establishment request.

[0062] 310. The establishment of a new N4 session is acknowledged from the secondary target UPF 361 to the SMF 367, for example, by sending an N4 session establishment response.

[0063] 311. Ethernet forwarding is updated in the Ethernet subnetwork. This can be done by the secondary target UPF 361 generating a new Ethernet frame with the MAC address for the UE 351 as the source, if the Ethernet network uses MAC learning, or, if a central controller in the Ethernet network is used to set the forwarding table of the Ethernet network, by instructing the central controller in the Ethernet network that a given MAC address is reachable at a new location. In the case of multiple MAC addresses for the UE 351, this process can be repeated for each MAC address. From this point on, downlink frames for the UE 351 using PDU session 2 (in 300e) can be forwarded towards the SgNB 355. Further explanations / options for updating Ethernet forwarding were described above.

[0064] 312. The path switch can be acknowledged from the SMF 367 to the AMF 363 using the Nsmf_PDUSession_UpdateSMContext response. This signaling may also include the tunnel endpoint at the secondary target UPF 361 for the tunnel between the SgNB 355 and the secondary target UPF 361.

[0065] 313. The path switch can be acknowledged from the AMF 363 to the MgNB 353 using the N2 path switch request Ack. This signaling includes the tunnel endpoint at the secondary target UPF 361 for the tunnel between the SgNB 355 and the secondary target UPF 361.

[0066] 314. MgNB353 may send a secondary node (SN) modification request to SgNB355.

[0067] 315. SgNB355 may reply with a SN modification request confirmation response. From this point on, uplink frames from UE351 (at 300f) can pass through SgNB355 and the secondary target UPF361 via PDU session 2.

[0068] 316. The N4 session is released at the secondary source UPF359, for example, using an N4 session release request. This triggers the secondary source UPF359 to send an end marker to SgNB355 via MgNB353 (at 300g), helping SgNB355 to deliver frames in order. After this, SgNB355 knows that it does not need to expect further frames from MgNB353. Next, (at 300h) the user plane for PDU session 2 is switched, and user data is then communicated via SgNB355 and the secondary target UPF361 in both the uplink and downlink.

[0069] 317. The N4 session release is acknowledged from the secondary source UPF359 to SMF367 using an N4 session release response. Note that it may be possible to perform operations 316 - 317 earlier, for example, immediately after operation 310. Alternatively, it may also be possible to perform operations 316 - 317 later and have downlink frames forwarded from the secondary source UPF359 to SgNB355 for a temporary time period.

[0070] In the diagrams of FIGS. 3A - 3B, operations 306 - 313 and operations 316 - 317 may be similar to operations 205 - 214. However, in operations 314 and 315 from the diagrams of FIGS. 3A - 3B, since SgNB 355 is the node terminating the tunnel, the uplink tunnel endpoint in the new PDU session anchor UPF 2 (secondary target UPF 361) is sent from MgNB 353 to SgNB 355.

[0071] The signaling diagrams of FIGS. 4A and 4B illustrate some embodiments applicable to a combined dual connectivity handover in which both the MgNB and the SgNB are changed (and, if the change of the SgNB is not performed, it may be regarded as a special case of this scenario). The handover itself in the case of dual connectivity may be performed in accordance with section 10.7.2 of 3GPP TS 37.340. As shown, according to international application No. PCT / IB2017 / 058517, a first PDU session is set up (at 400a) via a source MgNB 453 and a source primary UPF 461, and a second PDU session is set up (at 400b) via a source SgNB 455 and a source secondary UPF 465. Embodiments of the present disclosure may thus be implemented for both the first PDU session and the second PDU session as described below with respect to FIGS. 4A and 4B.

[0072] 401. The source primary UPF 461 transmits an N4 report to notify the SMF 471 of the Ethernet context (i.e., the maintained information related to the Ethernet network to which the source primary UPF 461 interfaces). Specifically, the N4 report may include the media access control (MAC) address for the UE 451 that the source primary UPF 461 has learned from the UE side. If there is a change in the Ethernet context, the change is updated to the SMF 471 so that the SMF 471 maintains the latest copy of the Ethernet context at the source primary UPF 461 for the UE 451. This signaling may be realized using the N4 reporting procedure.

[0073] 402. The SMF471 responds to the source primary UPF report of operation 401, for example, by using an N4 report confirmation response (Ack) sent from the SMF471 to the source primary UPF461.

[0074] 403. The source secondary UPF465 sends an N4 report to inform the SMF473 of the Ethernet context (i.e., the maintained information related to the Ethernet network with which the source secondary UPF465 interfaces). Specifically, the N4 report may include the media access control (MAC) address for the UE451 that the source secondary UPF465 learned from the UE side. If there is a change in the Ethernet context, the change is updated to the SMF473 so that the SMF473 maintains the latest copy of the Ethernet context at the source secondary UPF465 for the UE451. This signaling can be realized using the N4 report procedure.

[0075] 404. The SMF473 responds to the source secondary UPF report of operation 403, for example, by using an N4 report confirmation response (Ack) sent from the SMF473 to the source secondary UPF465.

[0076] 405. The source MgNB453 sends a handover request to the target MgNB459.

[0077] 406. The target MgNB459 sends a secondary node (SN) addition request to the target SgNB457

[0078] 407. The target SgNB457 sends an SN addition request confirmation response (ACK) to the target MgNB459.

[0079] 408. The target MgNB459 sends a handover request confirmation response (ACK).

[0080] 409. The source MgNB453 sends an SN release request to the source SgNB455.

[0081] 410. The source SgNB455 sends an SN release request confirmation response (ACK).

[0082] 411. Radio Resource Control (RRC) reconfiguration and / or Random Access (RA) may be performed to add the target MgNB for the first PDU session and add the target SgNB457 for the second PDU session. (In 400c) Downlink (DL) data forwarding is performed, and the downlink data from the source 1st UPF461 may be forwarded from the source MgNB453 to the target MgNB459 for downlink (DL) transmission to the UE451 for the first PDU session. (In 400d) Downlink (DL) data forwarding is performed, and the downlink data from the source 2nd UPF465 may be forwarded from the source SgNB455 to the target SgNB457 for downlink (DL) transmission to the UE451 for the second PDU session. (In 400e) Uplink (UL) data may be sent from the UE451 through the target MgNB459 (in 300d) to the target 1st UPF463 for the first PDU session and through the target SgNB457 to the target 2nd UPF467 for the second PDU session.

[0083] 412. The target MgNB459 may send an SN reset completion message to the target SgNB457 to complete the radio handover. Accordingly, the target MgNB459 adds the target SgNB457, and the source MgNB453 releases the source SgNB455. However, it should be noted that the source SgNB455 and the target SgNB457 may occur simultaneously in some cases. Data forwarding may be performed both from the source MgNB453 to the target MgNB459 and, as a new feature, from the source SgNB455 to the target SgNB457, as described in TS37.340.

[0084] 413. The target MgNB459 starts sending an N2 path switch request to the AMF469 to perform the switching of the user plane in the CN. The path switch request of operation 413 may initiate a PSA change for both PDU sessions, as described for operations 414 - 419 for the first PDU session and operations 420 - 425 for the second PDU session.

[0085] 414. The path switch is signaled from the AMF469 to the SMF471, for example, by sending an Nsmf_PDUSession_UpdateSMContext request.

[0086] 415. The SMF471 determines that the PSA should be changed for the first Ethernet PDU session and selects a new UPF that will act as the target primary UPF463.

[0087] For the first PDU session, a target first UPF N4 session is established that includes the tunnel endpoints of the RAN node to be used between the target MgNB 459 and the target first UPF 463. An Ethernet context is also sent from the SMF 471 to the target first UPF 463, for example, by sending an N4 session establishment request (including the Ethernet context).

[0088] 417. The establishment of the new N4 session is acknowledged from the target first UPF 463 to the SMF 471, for example, by sending an N4 session establishment response.

[0089] 418. Ethernet forwarding is updated in the Ethernet subnetwork for the first PDU session. This can be done by the target first UPF 463 generating a new Ethernet frame with the MAC address for the UE 451 as the source if the Ethernet network uses MAC learning, or by the central controller in the Ethernet network being instructed to make a given MAC address reachable at a new location if the Ethernet network's forwarding table is set. In the case of multiple MAC addresses for the UE 451, this process can be repeated for each MAC address. From this point on, the downlink frame for the UE 451 (at 400f) can be forwarded towards the target MgNB 459. Further explanations / options for updating Ethernet forwarding were described above.

[0090] 419. The path switch can be acknowledged from SMF 471 to AMF 469 using the Nsmf_PDUSession_UpdateSMContext response. This signaling may also include the tunnel endpoint at the target primary UPF 463 for the tunnel between the target MgNB 459 and the target primary UPF 463.

[0091] 420. The path switch is signaled from AMF 469 to SMF 473 by sending, for example, the Nsmf_PDUSession_UpdateSMContext request (which is abbreviated to the UpdateSMContext request in Figure 4B).

[0092] 421. SMF 473 determines that the PSA should be changed for the second Ethernet PDU session and selects a new UPF that will act as the target secondary UPF 467.

[0093] 422. A target secondary UPF N4 session for the second PDU session is established, including the tunnel endpoint of the RAN node to be used between the target SgNB 457 and the target secondary UPF 467. The Ethernet context is also sent from SMF 473 to the target secondary UPF 467, for example, by sending an N4 session establishment request (including the Ethernet context).

[0094] 423. The establishment of the new N4 session is acknowledged from the target secondary UPF 467 to SMF 473, for example, by sending an N4 session establishment response.

[0095] 424. Ethernet forwarding is updated in the Ethernet subnetwork for the second PDU session. This can be done by the target secondary UPF 467 generating a new Ethernet frame with the MAC address for the UE 451 as the source if the Ethernet network uses MAC learning, or by the central controller in the Ethernet network instructing the central controller in the Ethernet network that a given MAC address is reachable at the new location if the Ethernet network's forwarding table is set using the central controller in the Ethernet network. In the case of multiple MAC addresses for the UE 451, this process can be repeated for each MAC address. From this point on, the downlink frame for the UE 451 (at 400g) can be forwarded towards the target SgNB 457. Further explanations / options for updating Ethernet forwarding were described above.

[0096] 425. The path switch can be acknowledged from the SMF 473 to the AMF 469 using the Nsmf_PDUSession_UpdateSMContext response. This signaling can also include the tunnel endpoint at the target secondary UPF 467 for the tunnel between the target SgNB 457 and the target secondary UPF 467.

[0097] 426. The path switch can be acknowledged from the AMF 471 to the target MgNB 459 using the N2 path switch request Ack. The path switch request Ack carries tunnel endpoint information for both PDU sessions. Thus, this signaling includes, for the first PDU session, the tunnel endpoint at the target first UPF 463 for the tunnel between the target MgNB 459 and the target first UPF 463, and for the second PDU session, the tunnel endpoint at the target second UPF 467 for the tunnel between the target SgNB 457 and the target second UPF 467. From this point on, (at 400h) uplink frames from the UE 451 can pass through the target MgNB 459 and the target first UPF 463.

[0098] 427. For the second PDU session, the target SgNB 457 is informed of the tunnel endpoint using the SN modification request.

[0099] 428. The target SgNB 457 responds with an SN modification request Ack. From this point on, (at 400i) uplink frames from the UE 451 can pass through the target SgNB 457 and the target second UPF 467.

[0100] 429. The first N4 PDU session is released at the source first UPF 461, for example, using the N4 session release request. This may trigger the source first UPF 461 to send an end marker to the target MgNB 459 via the source MgNB 453 (at 400j), helping the target MgNB 459 to deliver frames in order. After this, the target MgNB 459 knows that it does not need to expect further frames from the source MgNB 453. Next, (at 400k) the user plane is switched, and user data is now communicated via the target MgNB 459 and the target first UPF 463 in both the uplink and downlink.

[0101] 430. The N4 session release is acknowledged from the source primary UPF 461 to the SMF 471 using the N4 session release response. It should be noted that operations 429 - 430 can be carried out early, for example, immediately after operation 417. Alternatively, operations 429 - 430 can be carried out later, and during a temporary time period, downlink frames can also be forwarded from the source primary UPF 461 to the target MgNB 459. Operations 429 and 430 can thus be carried out in a different order, and these operations can overlap with the previous operations. End markers can optionally be sent for the purpose of rearrangement.

[0102] 431. The second N4 PDU session is released at the source secondary UPF 465, for example, using the N4 session release request. This can trigger the source secondary UPF 465 to send an end marker to the target SgNB 457 via the source SgNB 455 (at 400L), which can help the target SgNB 457 to deliver the frames in order. After this, the target SgNB 457 knows that it does not need to expect further frames from the source SgNB 455. Next, (at 400m) the user plane is switched, and user data is then communicated via the target SgNB 457 and the target secondary UPF 467 in both the uplink and downlink.

[0103] 432. The N4 session release is acknowledged from the source secondary UPF 465 to the SMF 473 using an N4 session release response. Note that operations 431-432 can be performed early, for example, immediately after operation 423. Alternatively, operations 431-432 can be performed later, and during a temporary time period, downlink frames can also be forwarded from the source secondary UPF 465 to the target SgNB 457. Operations 431 and 432 can thus be performed in a different order, and these operations can overlap with the previous operations. An end marker can optionally be sent for rearrangement purposes. Eventually, the user plane is reset for both the first and the second PDU sessions.

[0104] According to some embodiments of the inventive concept, an Ethernet PDU session can · have the core network (CN) control plane establish a new PSA, · have the new PSA be informed by the CN control plane of an Ethernet context including the UE's MAC address, and the CN control plane collect this Ethernet context from the old PSA, · have the new PSA update Ethernet forwarding in the Ethernet subnet either by sending Ethernet frames in the local subnet or by informing a central controller, and / or · have the tunnel endpoint of the new PSA, which switches tunnels to the new PSA, be signaled to the RAN node to change the PDU session anchor (PSA) of the Ethernet PDU session.

[0105] Next, the operation of the Session Management Function (SMF) entity (also referred to as the SMF node / server) of the wireless communication network (e.g., the SMF entity 263 in FIG. 2) will be described with reference to the flowchart of FIG. 8. For example, the SMF entity may be implemented using the structure of FIG. 7, where the modules are stored in the memory 905, such that the modules provide instructions for the processor 903 to perform respective operations when the instructions of the modules are executed by the processor 903. Thus, the processor 903 of the SMF entity may transmit and / or receive communications to / from one or more other network nodes / entities / servers of the wireless communication network through the network interface 907.

[0106] In block 851, the processor 903 may receive an N4 report including an Ethernet context for the wireless terminal UE (e.g., the wireless terminal 251 in FIG. 2) from the first User Plane Function (UPF) entity (e.g., the source UPF entity 257 in FIG. 2) through the network interface 907. The Ethernet context may be provided for the Ethernet protocol data unit (PDU) session for the wireless terminal using the first UPF entity, and the Ethernet context may include a media access control (MAC) address for the wireless terminal UE. The operation of block 851 may be implemented as described above with respect to, for example, operation 201 in FIG. 2, operation 301 in FIG. 3A, operation 401 in FIG. 4A, and / or operation 403 in FIG. 4A.

[0107] In block 853, the processor 903 may transmit an N4 report confirmation response (ACK) to the first UPF entity through the network interface 907. The operation of block 853 may be implemented as described above with respect to, for example, operation 202 in FIG. 2, operation 302 in FIG. 3A, operation 402 in FIG. 4A, and / or operation 404 in FIG. 4A.

[0108] In block 855, the processor 903 may receive a request to switch an Ethernet PDU session for a wireless terminal from an AMF entity (e.g., AMF entity 261 in FIG. 2) through the network interface 907. The operation of block 855 may be implemented as described above with respect to, for example, operation 206 in FIG. 2, operation 307 in FIG. 3A, operation 414 in FIG. 4A, and / or operation 420 in FIG. 4B.

[0109] In block 857, in response to receiving a request to switch an Ethernet PDU session for a wireless terminal, the processor 903 may select a second UPF entity (e.g., target UPF entity 259 in FIG. 2). The operation of block 857 may be implemented as described above with respect to, for example, operation 207 in FIG. 2, operation 308 in FIG. 3A, operation 415 in FIG. 4A, and / or operation 421 in FIG. 4B.

[0110] In block 859, the processor 903 may send an N4 session establishment request including an Ethernet context including a MAC address for a wireless terminal to the second UPF entity through the network interface 907. The N4 session establishment request may be sent in response to selecting the second UPF entity. The operation of block 859 may be implemented as described above with respect to, for example, operation 208 in FIG. 2, operation 309 in FIG. 3B, operation 416 in FIG. 4A, and / or operation 422 in FIG. 4B.

[0111] In block 861, the processor 903 may receive an N4 session establishment response through the network interface 907. The operation of block 861 may be implemented as described above with respect to, for example, operation 209 in FIG. 2, operation 310 in FIG. 3B, operation 417 in FIG. 4B, and / or operation 423 in FIG. 4B.

[0112] In block 863, after selecting the second UPF entity, the processor 903 may send a confirmation response of the request to switch to the AMF entity through the network interface 907, and this confirmation response may include the identification information of the second UPF entity. The operation of block 863 may be implemented as described above with respect to, for example, operation 211 in FIG. 2, operation 312 in FIG. 3B, and / or operation 425 in FIG. 4B.

[0113] In block 865, in response to selecting the second UPF entity, the processor 903 may send a session release request for the wireless terminal to the first UPF entity (source UPF) through the network interface 907. The operation of block 865 may be implemented as described above with respect to, for example, operation 213 in FIG. 2, operation 316 in FIG. 3B, operation 429 in FIG. 4B, and / or operation 431 in FIG. 4B.

[0114] In block 867, the processor 903 may receive a session release response from the first UPF entity through the network interface 907. The operation of block 867 may be implemented as described above with respect to, for example, operation 214 in FIG. 2, operation 317 in FIG. 3B, operation 430 in FIG. 4B, and / or operation 432 in FIG. 4B.

[0115] The Ethernet context may be provided for the Ethernet PDU session for the wireless terminal using the first UPF entity and using the first base station (e.g., source gNB 253), and the request to switch the Ethernet PDU session for the wireless terminal may include the identification information of a second base station different from the first base station (e.g., target gNB 255), and selecting the second UPF entity (e.g., target UPF 259) includes selecting the second UPF entity based on the identification information of the second base station.

[0116] The Ethernet context in block 851 may include a plurality of MAC addresses for the wireless terminal, and transmitting the Ethernet context in block 859 may include transmitting an Ethernet context including a plurality of MAC addresses.

[0117] The various operations in FIG. 8 may be optional with respect to some embodiments of the inventive concept. For example, operations 853, 855, 857, 861, 863, 865, and / or 867 in FIG. 8 may be optional with respect to exemplary embodiment 1 described below.

[0118] Next, the operation of a user plane function entity (e.g., UPF entity 259 in FIG. 2, also referred to as a UPF node / server) of a wireless communication network is described with reference to the flowchart of FIG. 9. For example, the UPF entity may be implemented using the structure of FIG. 7, where modules are stored in memory 905, such that the modules provide instructions for processor 903 to perform respective operations when the instructions of the modules are executed by processor 903. Accordingly, the processor 903 of the UPF entity may transmit and / or receive communications to / from one or more other network nodes / entities / servers of the wireless communication network through network interface 907.

[0119] In block 951, the processor 903 may receive a request to establish an Ethernet protocol data unit (PDU) session for a wireless terminal (e.g., the wireless terminal UE251 in FIG. 2) using an Ethernet network. The request to establish an Ethernet PDU session may include a media access control (MAC) address for the wireless terminal. The request may be received from an SMF entity (e.g., the SMF entity 263 in FIG. 2) through the network interface 907 as an N4 session establishment request. Moreover, the request may include an Ethernet context for the wireless terminal, and the Ethernet context may include a MAC address for the wireless terminal. The operation of block 951 may be implemented as described above with respect to, for example, operation 208 in FIG. 2, operation 309 in FIG. 3B, operation 416 in FIG. 4A, and / or operation 422 in FIG. 4B.

[0120] In block 953, the processor 903 may send an N4 session establishment response to the SMF entity through the network interface 907. The operation of block 953 may be implemented as described above with respect to, for example, operation 209 in FIG. 2, operation 310 in FIG. 3B, operation 417 in FIG. 4B, and / or operation 423 in FIG. 4B.

[0121] In block 955, in response to receiving a request, the processor 903 may update the forwarding for the wireless terminal in the Ethernet network using the MAC address of the wireless terminal. According to some embodiments, updating the forwarding for the wireless terminal may include flooding the Ethernet network with a frame including the MAC address of the wireless terminal as the source of the frame. According to some other embodiments, updating the forwarding for the wireless terminal may include sending an instruction to the controller of the Ethernet network to forward the downlink traffic for the wireless terminal through the UPF entity. The operation of block 955 may be implemented as described above with respect to, for example, operation 210 of FIG. 2, operation 311 of FIG. 3B, operation 418 of FIG. 4B, and / or operation 424 of FIG. 4B.

[0122] In block 957, in response to a request, the processor 903 may establish an Ethernet PDU session for the wireless terminal to support data communication between the wireless terminal and the Ethernet network through a base station (e.g., target gNB 255 of FIG. 2) and a UPF entity. In block 959, the processor 903 may provide data communication between the wireless terminal and the Ethernet network using the Ethernet PDU session through a base station (e.g., target gNB 255 of FIG. 2) and a UPF entity (e.g., target UPF entity 259 of FIG. 2). The operations of block 957 and block 959 may be implemented as described above with respect to, for example, operations 200d, 200e and / or 200g of FIG. 2, operations 300e, 300f and / or 300h of FIG. 3B, operations 400f, 400h and / or 400k of FIG. 4B, and / or operations 400g, 400i and / or 400m of FIG. 4B.

[0123] The various operations of FIG. 9 may be optional with respect to some embodiments of the inventive concept. For example, operations 953, 957, and / or 959 of FIG. 9 may be optional with respect to exemplary embodiment 9 described below.

[0124] Next, the operation of a user plane function entity (e.g., UPF entity 257 in FIG. 2), also referred to as a UPF node / server in a wireless communication network, will be described with reference to the flowchart of FIG. 10. For example, the UPF entity may be implemented using the structure of FIG. 7, where modules are stored in memory 905, such that the modules provide instructions for processor 903 to perform respective operations when the instructions of the modules are executed by processor 903. Accordingly, the processor 903 of the UPF node may transmit and / or receive communications to / from one or more other network nodes / entities / servers of the wireless communication network through network interface 907.

[0125] In block 1051, processor 903 may establish an Ethernet PDU session for a wireless terminal (e.g., wireless terminal 251 in FIG. 2) to support data communication between the wireless terminal and an Ethernet network through base station 253 and UPF entity 257. In block 1053, processor 903 may provide communication of data between the wireless terminal and the Ethernet network using the Ethernet PDU session through base station 253 and UPF entity 257 through network interface 907. The operation of block 1051 and / or the operation of block 1053 may be implemented as described above with respect to operation 200a in FIG. 2, operation 300b in FIG. 3A, operation 400a in FIG. 4A, and / or operation 400b in FIG. 4A.

[0126] In block 1055, the processor 903 may send an N4 report including an Ethernet context for the wireless terminal to a session management function (SMF) entity (263) of the wireless communication network through the network interface 907, and the Ethernet context includes a media access control (MAC) address for the wireless terminal. The operation of block 1055 may be implemented as described above with respect to, for example, operation 201 of FIG. 2, operation 301 of FIG. 3A, operation 401 of FIG. 4A, and / or operation 403 of FIG. 4A.

[0127] In block 1057, the processor 903 may receive an N4 report confirmation response from the SMF entity through the network interface 907. The operation of block 1057 may be implemented as described above with respect to, for example, operation 202 of FIG. 2, operation 302 of FIG. 3A, operation 402 of FIG. 4A, and / or operation 404 of FIG. 4A.

[0128] In block 1059, the processor 903 may receive an N4 session release request from the SMF entity through the network interface 907, and in response to receiving the session release request, the processor 903 may release the Ethernet PDU session for the wireless terminal in block 1061. The operations of block 1059 and block 1061 may be implemented as described above with respect to, for example, operation 213 of FIG. 2, operation 316 of FIG. 3B, operation 429 of FIG. 4B, and / or operation 431 of FIG. 4B.

[0129] In block 1063, the processor 903 may transmit an end marker for an Ethernet PDU session for a wireless terminal through the network interface 907 in response to a session release request. More specifically, the base station is the first / source base station 253, and the end marker may be transmitted to the first / source base station for retransmission to the second / target base station 255. The operation of block 1063 may be implemented as described above with respect to, for example, operation 200f of FIG. 2, operation 300g of FIG. 3B, operation 400j of FIG. 4B, and / or operation 400L of FIG. 4B.

[0130] Moreover, providing communication in block 1053 may include providing communication of data between the wireless terminal 251 and the Ethernet network using an Ethernet PDU session through the base station 253 and the UPF entity 257 before and after receiving a session release request from the SMF entity in block 1059.

[0131] The various operations of FIG. 10 may be optional with respect to some embodiments of the inventive concept. For example, operations 1053, 1057, 1059, 1063, and / or 1065 of FIG. 10 may be optional with respect to exemplary embodiment 16 described below.

[0132] Referring to FIG. 11, according to one embodiment, a communication system includes a telecommunication network QQ410, such as a 3GPP type cellular network, comprising an access network QQ411, such as a radio access network, and a core network QQ414. The access network QQ411 includes a plurality of base stations QQ412a, QQ412b, QQ412c, such as NB, eNB, gNB, or other types of radio access points, each defining a corresponding coverage area QQ413a, QQ413b, QQ413c. Each base station QQ412a, QQ412b, QQ412c is connectable to the core network QQ414 over a wired or wireless connection QQ415. A first UE QQ491 located in the coverage area QQ413c is configured to wirelessly connect to the corresponding base station QQ412c or be paged by the corresponding base station QQ412c. A second UE QQ492 in the coverage area QQ413a is wirelessly connectable to the corresponding base station QQ412a. Although a plurality of UEs QQ491, QQ492 are shown in this example, the disclosed embodiments are equally applicable to situations where only one UE is in the coverage area or only one UE is connected to the corresponding base station QQ412.

[0133] Telecommunication network QQ410 is itself connected to host computer QQ430, which may be embodied in the hardware and / or software of a stand-alone server, a cloud implementation server, a distributed server, or as processing resources in a server farm. The host computer QQ430 may be under the ownership or control of a service provider, or may be operated by or on behalf of a service provider. The connections QQ421 and QQ422 between the telecommunication network QQ410 and the host computer QQ430 may extend directly from the core network QQ414 to the host computer QQ430, or may proceed via an optional intermediate network QQ420. The intermediate network QQ420 may be one of a public network, a private network, or a hosted network, or a combination of two or more of them, and the intermediate network QQ420 may, if any, be a backbone network or the Internet. In particular, the intermediate network QQ420 may comprise two or more sub-networks (not shown).

[0134] The communication system of FIG. 11 enables connectivity between the connected UEs QQ491, QQ492 and the host computer QQ430. The connectivity can be described as an over-the-top (OTT) connection QQ450. The host computer QQ430 and the connected UEs QQ491, QQ492 are configured to communicate data and / or signaling via the OTT connection QQ450, using the access network QQ411, the core network QQ414, any intermediate network QQ420, and a possible further infrastructure (not shown) as a medium. The OTT connection QQ450 can be transparent in the sense that the participating communication devices through which the OTT connection QQ450 passes are unaware of the routing of the uplink and downlink communications. For example, the base station QQ412 may not be informed or need to be informed of the past routing of an incoming downlink communication with data generated from the host computer QQ430 that is to be forwarded (e.g., handed over) to the connected UE QQ491. Similarly, the base station QQ412 does not need to be aware of the future routing of an outgoing uplink communication originating from the UE QQ491 and destined for the host computer QQ430.

[0135] Next, an exemplary implementation of the UE, base station, and host computer described in the previous paragraph according to one embodiment will be described with reference to FIG. 12. In communication system QQ500, host computer QQ510 includes hardware QQ515 having a communication interface QQ516 configured to set up and maintain a wired or wireless connection with interfaces of different communication devices of communication system QQ500. Host computer QQ510 further includes a processing circuit QQ518 that may have a storage capacity and / or a processing capacity. In particular, processing circuit QQ518 may include one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. Host computer QQ510 further includes software QQ511 stored in or accessible by host computer QQ510 and executable by processing circuit QQ518. Software QQ511 includes a host application QQ512. Host application QQ512 may be operable to provide services to a remote user, such as UE QQ530, that connects via an OTT connection QQ550 that terminates at UE QQ530 and host computer QQ510. When providing services to a remote user, host application QQ512 may provide user data transmitted using OTT connection QQ550.

[0136] The communication system QQ500 further includes a base station QQ520 provided in a telecommunications system, and the base station QQ520 comprises hardware QQ525 that enables the base station QQ520 to communicate with a host computer QQ510 and a UE QQ530. The hardware QQ525 may include a communication interface QQ526 for setting up and maintaining a wired or wireless connection with an interface of different communication devices of the communication system QQ500, and a wireless interface QQ527 for setting up and maintaining at least a wireless connection QQ570 with a UE QQ530 located in a coverage area (not shown in FIG. 12) served by the base station QQ520. The communication interface QQ526 may be configured to facilitate a connection QQ560 to the host computer QQ510. The connection QQ560 may be direct, or the connection QQ560 may pass through a core network (not shown in FIG. 12) of the telecommunications system and / or one or more intermediate networks external to the telecommunications system. In the illustrated embodiment, the hardware QQ525 of the base station QQ520 further includes a processing circuit QQ528, and the processing circuit QQ528 may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The base station QQ520 further has software QQ521 stored internally or accessible via an external connection.

[0137] The communication system QQ500 further includes the UE QQ530 already mentioned. The hardware QQ535 of the UE QQ530 may include a radio interface QQ537 configured to set up and maintain a radio connection QQ570 with a base station serving the coverage area where the UE QQ530 is currently located. The hardware QQ535 of the UE QQ530 further includes a processing circuit QQ538, and the processing circuit QQ538 may comprise one or more programmable processors, application-specific integrated circuits, field-programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The UE QQ530 further comprises software QQ531 stored in or accessible by the UE QQ530 and executable by the processing circuit QQ538. The software QQ531 includes a client application QQ532. The client application QQ532 may be operable to provide services to a human or non-human user via the UE QQ530 under the support of the host computer QQ510. In the host computer QQ510, the running host application QQ512 may communicate with the running client application QQ532 via an OTT connection QQ550 that terminates at the UE QQ530 and the host computer QQ510. When providing services to the user, the client application QQ532 may receive request data from the host application QQ512 and provide user data in response to the request data. The OTT connection QQ550 may transfer both the request data and the user data. The client application QQ532 may interact with the user to generate the user data provided by the client application QQ532.

[0138] Note that the host computer QQ510, base station QQ520, and UE QQ530 shown in FIG. 12 can be the same as or equivalent to one of the host computer QQ430, base stations QQ412a, QQ412b, QQ412c in FIG. 11, and one of the UEs QQ491, QQ492, respectively. That is, the operation inside these entities can be as shown in FIG. 12, and separately, the surrounding network topology can be the same as that in FIG. 11.

[0139] In FIG. 12, the OTT connection QQ550 is abstractly depicted to show communication between the host computer QQ510 and the UE QQ530 via the base station QQ520 without explicit reference to the intermediary devices and the exact routing of messages through these devices. The network infrastructure can determine the routing, and the network infrastructure can be configured to hide the routing from the UE QQ530, from the service provider operating the host computer QQ510, or from both. While the OTT connection QQ550 is active, the network infrastructure can further make a determination to dynamically change the routing (e.g., based on network load distribution considerations or reconfiguration).

[0140] The wireless connection QQ570 between the UE QQ530 and the base station QQ520 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT services provided to the UE QQ530 using the OTT connection QQ550 for which the wireless connection QQ570 forms the last segment. More precisely, the teachings of these embodiments provide redundancy for uplink / downlink communication through the wireless communication network, thereby providing benefits such as improved reliability.

[0141] Measurement procedures may be provided for the purpose of monitoring data rate, latency, and other factors that one or more embodiments improve. There may further be optional network functions for reconfiguring the OTT connection QQ550 between the host computer QQ510 and the UE QQ530 in response to variations in the measurement results. The measurement procedures and / or the network functions for reconfiguring the OTT connection QQ550 may be implemented in the software QQ511 and hardware QQ515 of the host computer QQ510 or in the software QQ531 and hardware QQ535 of the UE QQ530, or both. In an embodiment, a sensor (not shown) may be deployed in or associated with the communication device through which the OTT connection QQ550 passes, and the sensor may participate in the measurement procedure by providing values of the monitored quantities exemplified above, or by providing values of other physical quantities that the software QQ511, QQ531 may calculate or estimate the monitored quantities. The reconfiguration of the OTT connection QQ550 may include message format, retransmission settings, preferred routing, etc., and the reconfiguration need not affect the base station QQ520 and may be unknown or imperceptible to the base station QQ520. Such procedures and functions are known and can be implemented in the art. In some embodiments, the measurement may involve proprietary UE signaling that facilitates measurement of the host computer QQ510 such as throughput, propagation time, latency, etc. The measurement may be implemented in that the software QQ511 and QQ531 cause messages, particularly empty or "dummy" messages, to be transmitted using the OTT connection QQ550 while the software QQ511 and QQ531 monitor propagation time, errors, etc.

[0142] FIG. 13 is a flowchart showing a method implemented in a communication system according to an embodiment. The communication system may include a host computer, a base station, and a UE as described with reference to FIGS. 11 and 12. For simplicity of the present disclosure, only the drawing reference to FIG. 13 is included in this section. In step QQ610, the host computer provides user data. In an optional sub-step QQ611 of step QQ610, the host computer provides user data by executing a host application. In step QQ620, the host computer starts a transmission to carry the user data to the UE. In an optional step QQ630, the base station transmits the user data carried in the transmission started by the host computer to the UE according to the teachings of the embodiments described throughout the present disclosure. In an also optional step QQ640, the UE executes a client application related to the host application executed by the host computer.

[0143] FIG. 14 is a flowchart showing a method implemented in a communication system according to an embodiment. The communication system may include a host computer, a base station, and a UE as described with reference to FIGS. 11 and 12. For simplicity of the present disclosure, only the drawing reference to FIG. 14 is included in this section. In step QQ710 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides user data by executing a host application. In step QQ720, the host computer starts a transmission to carry the user data to the UE. The transmission may pass through the base station according to the teachings of the embodiments described throughout the present disclosure. In an optional step QQ730, the UE receives the user data carried in the transmission.

[0144] FIG. 15 is a flowchart showing a method implemented in a communication system according to an embodiment. The communication system may include a host computer, a base station, and a UE as described with reference to FIGS. 11 and 12. For simplicity of the present disclosure, only the reference to FIG. 15 is included in this section. In optional step QQ810, the UE receives input data provided by the host computer. Additionally or alternatively, in step QQ820, the UE provides user data. In optional sub-step QQ821 of step QQ820, the UE provides user data by executing a client application. In optional sub-step QQ811 of step QQ810, the UE executes a client application that provides user data in response to the received input data provided by the host computer. When providing user data, the executed client application may further consider user input received from the user. Regardless of the particular manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in optional sub-step QQ830. In step QQ840 of the method, the host computer receives the user data transmitted from the UE in accordance with the teachings of the embodiments described throughout the present disclosure.

[0145] FIG. 16 is a flowchart showing a method implemented in a communication system according to one embodiment. The communication system may include a host computer, a base station, and a UE as described with reference to FIGS. 11 and 12. For simplicity of the present disclosure, only the drawing reference to FIG. 16 is included in this section. In an optional step QQ910, according to the teachings of the embodiments described throughout the present disclosure, the base station receives user data from the UE. In an optional step QQ920, the base station starts transmitting the received user data to the host computer. In an optional step QQ930, the host computer receives the user data carried in the transmission started by the base station.

[0146] Any suitable steps, methods, features, functions, or benefits disclosed herein may be implemented through one or more functional units or modules of one or more virtual devices. Each virtual device may comprise several of these functional units. These functional units may be implemented via a processing circuit that may include one or more microprocessors or microcontrollers, as well as other digital hardware that may include a digital signal processor (DSP), dedicated digital logic, etc. The processing circuit may be configured to execute program code stored in a memory that may include one or several types of memory such as read-only memory (ROM), random access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. The program code stored in the memory includes program instructions for executing one or more electrical communication and / or data communication protocols, as well as instructions for performing one or more of the techniques described herein. In some implementations, the processing circuit may be used to cause each functional unit to perform the corresponding function according to one or more embodiments of the present disclosure.

[0147] Additional exemplary embodiments are described below. 1. A method of operating a session management function (SMF) entity of a wireless communication network, the method comprising receiving (851) an Ethernet context for a wireless terminal from a first user plane function (UPF) entity (257), the Ethernet context being provided for an Ethernet protocol data unit (PDU) session for the wireless terminal using the first UPF entity, the Ethernet context including a media access control (MAC) address for the wireless terminal; and transmitting (859) the Ethernet context including the MAC address for the wireless terminal to a second UPF entity (259). 2. The method according to embodiment 1, further comprising selecting (857) a second UPF entity (259), wherein transmitting the Ethernet context includes transmitting, in response to selecting the second UPF entity, the Ethernet context including the MAC address for the wireless terminal to the second UPF entity. 3. The method according to embodiment 2, further comprising receiving (855) a request to switch an Ethernet PDU session for the wireless terminal, wherein selecting the second UPF entity includes selecting the second UPF entity in response to receiving the request to switch the Ethernet PDU session for the wireless terminal. 4. The method according to embodiment 3, wherein the Ethernet context is provided for an Ethernet PDU session for the wireless terminal using the first UPF entity (257) and using a first base station (253), the request to switch the Ethernet PDU session for the wireless terminal includes identification information of a second base station (255) different from the first base station (253), and selecting the second UPF entity (259) includes selecting the second UPF entity based on the identification information of the second base station (255). 5. Receiving a request to switch an Ethernet PDU session includes receiving a request from an Access and Mobility Management Function (AMF) entity. The method further includes, after selecting a second UPF entity, sending (863) a confirmation response of the request to switch to the AMF entity, where the confirmation response includes identification information of the second UPF entity. The method according to any one of Embodiments 3 to 4. 6. Sending an Ethernet context includes sending an Ethernet context to a second UPF entity (259) in a session establishment request. The method according to any one of Embodiments 1 to 5. 7. Further including, in response to selecting a second UPF entity (259), sending (865) a session release request for a wireless terminal to a first UPF entity (257). The method according to any one of Embodiments 2 to 6. 8. The Ethernet context includes a plurality of MAC addresses for a wireless terminal. Sending an Ethernet context includes sending an Ethernet context including a plurality of MAC addresses. The method according to any one of Embodiments 1 to 7. 9. A method of operating a User Plane Function (UPF) entity (259) of a wireless communication network. The method includes receiving (951) a request to establish an Ethernet protocol data unit (PDU) session for a wireless terminal (251) using an Ethernet network, where the request to establish an Ethernet PDU session includes a Media Access Control (MAC) address for the wireless terminal, and updating (955) forwarding for the wireless terminal in the Ethernet network using the MAC address for the wireless terminal in response to receiving the request. 10. Receiving a request includes receiving a request from a Session Management Function (SMF) entity (263) of a wireless communication network. The method according to Embodiment 9. 11. The method according to any one of embodiments 9 to 10, wherein the request includes an Ethernet context for a wireless terminal, and the Ethernet context includes a MAC address for the wireless terminal. 12. The method according to any one of embodiments 9 to 11, wherein updating the forwarding for a wireless terminal comprises flooding an Ethernet network with a frame, the frame including the MAC address of the wireless terminal as the source of the frame. 13. The method according to any one of embodiments 9 to 11, wherein updating the forwarding for a wireless terminal comprises sending an instruction to a controller of the Ethernet network to forward downlink traffic for the wireless terminal through a UPF entity. 14. The method according to any one of embodiments 9 to 13, further comprising establishing an Ethernet PDU session for the wireless terminal to support data communication between the wireless terminal and the Ethernet network through a base station (255) and a UPF entity in response to the request (957), and providing data communication between the wireless terminal and the Ethernet network using the Ethernet PDU session through the base station (255) and the UPF entity (959). 15. The method according to any one of embodiments 11 to 14, wherein the Ethernet context includes a plurality of MAC addresses for the wireless terminal, and updating the forwarding comprises updating the forwarding in the Ethernet network using each of the plurality of MAC addresses. 16. A method of operating a user plane function (UPF) entity (257) of a wireless communication network, the method comprising: establishing (1051) an Ethernet PDU session for a wireless terminal through a base station (253) and the UPF entity to support data communication between the wireless terminal and an Ethernet network; transmitting (1055) an Ethernet context for the wireless terminal to a session management function (SMF) entity of the wireless communication network, the Ethernet context including a media access control (MAC) address for the wireless terminal; and releasing (1061) the Ethernet PDU session for the wireless terminal in response to a session release request after transmitting the Ethernet context for the wireless terminal. 17. The method of embodiment 16, further comprising transmitting (1063) an end marker for the Ethernet PDU session for the wireless terminal in response to a session release request. 18. The method of embodiment 17, wherein the base station is a first base station (253) and the end marker is transmitted to the first base station for retransmission to a second base station (255). 19. The method according to any one of embodiments 16 to 18, further comprising providing (1053) data communication between the wireless terminal and the Ethernet network using the Ethernet PDU session through the base station (253) and the UPF entity (257) before releasing the Ethernet PDU session. 20. The method of embodiment 19, wherein providing the communication includes providing data communication between the wireless terminal and the Ethernet network using the Ethernet PDU session through the base station and the UPF entity before and after receiving a session release request from the SMF entity. 21. A session management function (SMF) entity of a wireless communication network, the SMF entity being adapted to perform the operations according to any one of embodiments 1 to 8. 22. A user plane function (UPF) entity of a wireless communication network, the UPF entity being adapted to perform the operations described in any one of Embodiments 9 to 20. 23. A session management function (SMF) entity of a wireless communication network, the SMF entity comprising a processor (903) and a memory (905) coupled to the processor, the memory comprising instructions that, when executed by the processor, cause the processor to perform the operations described in any one of Embodiments 1 to 8. 24. A user plane function (UPF) entity of a wireless communication network, the UPF entity comprising a processor (903) and a memory (905) coupled to the processor, the memory comprising instructions that, when executed by the processor, cause the processor to perform the operations described in any one of Embodiments 9 to 20.

[0148] Explanations of various abbreviations used in this specification are described below. Abbreviation Explanation AMF Access and Mobility Management Function AS Application Server BS Base Station C-MTC Critical Machine-Type Communication CN Core Network DC Dual Connectivity DNN Data Network Name DPI Deep Packet Inspection EPC Evolved Packet Core gNB NR Node B IP Internet Protocol LTE Long Term Evolution MAC Media Access Control MgNB Master gNB NEF Network Exposure Function NRF Network Resource Function OTA Over-the-Air PCF Policy Control Function PDCP Packet Data Convergence Protocol PDU Protocol Data Unit PSA PDU Session Anchor RAN Radio Access Network SgNB Secondary gNB SMF Session Management Function SSC Session and Service Continuity SW Switching TSN Time Sensitive Networking UDM User Data Management UE User Equipment UPF User Plane Function

[0149] Various references are described above and are identified below. · 3GPP TS23.501 V15.1.0 (2018-03), Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 (Release 15) · 3GPP TS23.502 V15.1.0 (2018-03), Technical Specification Group Services and System Aspects; Procedures for the 5G System; Stage 2 (Release 15) · 3GPP TS37.340 V15.1.0 (2018-03), Technical Specification Group Radio Access Network; Extended Universal Terrestrial Radio Access (E-UTRA) and NR; Multiconnectivity; Stage 2 (Release 15) · International Application No. PCT / IB2017 / 058517, entitled "Methods Providing Dual Connectivity For Redundant User Plane Paths And Related Network Nodes", filed on December 29, 2017 · 3GPP TS23.725 v2.0.0 (2018-12), Technical Specification Group Services and System Aspects; Study on Enhancement of Support for Ultra-Reliable Low-Latency Communication (URLLC) in 5G Core Network (5GC) (Release 16) · Ericsson, "Anchor change for Ethernet PDU Sessions", 3GPP TSG-SA WG2 Meeting #128, S2-186420, Vilnius, Lithuania, July 2 - 6, 2018

[0150] Further provisions and embodiments are described below.

[0151] In the above description of various embodiments of the inventive concept, it should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the inventive concept. Unless otherwise specified, all terms (including technical and scientific terms) used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept pertains. Terms such as those defined in commonly used dictionaries shall be interpreted as having a meaning consistent with the meaning of those terms in the context of the present specification and the related art, and shall not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0152] When an element is said to be "connected to", "coupled to", "responsive to", or a variation thereof, with respect to another element, that element can be directly connected to, coupled to, or responsive to the other element, or intervening elements may be present. In contrast, when an element is said to be "directly connected to", "directly coupled to", "directly responsive to", or a variation thereof, with respect to another element, no intervening elements are present. Like reference numerals refer to like elements throughout. Further, as used herein, "coupled to", "connected to", "responsive to", or variations thereof can include being wirelessly coupled to, wirelessly connected to, or wirelessly responsive to. As used herein, the singular forms "a", "an" and "the" include the plural forms as well, unless the context clearly dictates otherwise. For brevity and / or clarity, well-known functions or constructions may not be described in detail. The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0153] To describe various elements / acts, terms such as first, second, third, etc. may be used herein, but it should be understood that these elements / acts should not be limited by these terms. These terms are only used to distinguish one element / act from another. Thus, a first element / act in some embodiments may be referred to as a second element / act in other embodiments without departing from the teachings of the inventive concept. The same reference numeral or the same reference sign indicates the same or similar elements throughout this specification.

[0154] As used herein, the terms "comprise," "comprising," "comprises," "include," "including," "includes," "have," "has," "having," or variations thereof are open-ended and include one or more of the recited features, integers, elements, steps, components, or functions, but do not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions, or groups thereof. Further, as used herein, the common abbreviation "e.g.", which is derived from the Latin phrase "exempli gratia", may be used to introduce or specifically list one or more general examples of the foregoing items and is not limiting of such items. The common abbreviation "i.e.", which is derived from the Latin phrase "id est", may be used to specifically list a particular item from a more general statement.

[0155] Exemplary embodiments are described herein with reference to block diagrams and / or flowchart illustrations of a computer-implemented method, apparatus (system and / or device), and / or computer program product. It should be understood that blocks of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by computer program instructions executed by one or more computer circuits. These computer program instructions can be provided to the processor circuits of a general purpose computer circuit, a special purpose computer circuit, and / or other programmable data processing circuits for creating machines, and thus the instructions executed via the processor of a computer and / or other programmable data processing apparatus transform and control transistors, values stored in memory locations, and other hardware components within such circuits to implement the functions / acts specified in one or more blocks of the block diagrams and / or flowchart.

[0156] These computer program instructions can also be stored in a tangible computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, and thus, the instructions stored in the computer-readable medium produce an article of manufacture including instructions for implementing the functions / acts specified in one or more blocks of the block diagrams and / or flowchart. Accordingly, embodiments of the inventive concept can be embodied in hardware and / or software (including firmware, resident software, microcode, etc.) running on a processor such as a digital signal processor, which may sometimes be collectively referred to as a "circuit", "module", or a variation thereof.

[0157] Also, in some alternative implementations, note that the functions / acts recited in a block may occur out of the order recited in the flowchart. For example, depending on the functions / acts involved, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in reverse order. Moreover, the functionality of a given block of a flowchart and / or block diagram may be separated into multiple blocks, and / or the functionality of two or more blocks of a flowchart and / or block diagram may be at least partially integrated. Finally, other blocks may be added / inserted between the blocks shown, and / or blocks / acts may be omitted without departing from the scope of the inventive concept. Moreover, although some of the figures include arrows on communication paths to indicate a primary direction of communication, understand that communication may occur in the direction opposite to that shown by the arrows.

[0158] Many variations and modifications can be made to the embodiments without substantially departing from the principles of the inventive concept. All such variations and modifications are intended to be included herein within the scope of the inventive concept. Accordingly, the subject matter disclosed above should be regarded as illustrative and not restrictive, and the examples of embodiments are intended to cover all such modifications, extensions, and other embodiments that fall within the spirit and scope of the inventive concept. Accordingly, to the maximum extent permitted by law, the scope of the inventive concept should be determined by the broadest permissible interpretation of this disclosure, including examples of embodiments and their equivalents, and should not be limited or restricted by the foregoing detailed description.

Claims

1. A method for operating a session management function (SMF) entity of a wireless communication network, the method comprising: Receiving an Ethernet context for a wireless terminal from a first user plane function (UPF) entity, the Ethernet context being provided for an Ethernet protocol data unit (PDU) session for the wireless terminal using the first UPF entity, the Ethernet context including a media access control (MAC) address for the wireless terminal; Receiving, from the first UPF entity, a request from an access and mobility management function (AMF) entity to switch the Ethernet PDU session for the wireless terminal to a second UPF entity; Sending, to the AMF entity, a confirmation response to the request to switch the Ethernet PDU session for the wireless terminal, the confirmation response including an end markerless flag indicating that there will be no end marker for the Ethernet PDU session; Sending the Ethernet context including the MAC address for the wireless terminal to the second UPF entity A method comprising:

2. Further comprising selecting the second UPF entity wherein Sending the Ethernet context comprises, in response to selecting the second UPF entity, sending the Ethernet context including the MAC address for the wireless terminal to the second UPF entity, The method according to claim 1.

3. Selecting the second UPF entity comprises, in response to receiving the request to switch the Ethernet PDU session for the wireless terminal, selecting the second UPF entity, The method according to claim 2.

4. The Ethernet context is provided for the Ethernet PDU session for the wireless terminal using the first UPF entity and using a first base station, and the request to switch the Ethernet PDU session for the wireless terminal includes identification information of a second base station different from the first base station, and selecting the second UPF entity includes selecting the second UPF entity based on the identification information of the second base station, the method according to claim 3.

5. After selecting the second UPF entity, transmitting, to the AMF entity, the confirmation response of the request to switch, the confirmation response including identification information of the second UPF entity The method according to claim 4, further comprising.

6. Transmitting the Ethernet context includes transmitting the Ethernet context to the second UPF entity in a session establishment request, the method according to claim 1.

7. In response to selecting the second UPF entity, transmitting a session release request for the wireless terminal to the first UPF entity The method according to claim 2, further comprising.

8. The Ethernet context includes a plurality of MAC addresses for the wireless terminal, and transmitting the Ethernet context includes transmitting the Ethernet context including the plurality of MAC addresses, the method according to claim 1.

9. A session management function (SMF) entity of a wireless communication network, the SMF entity comprising a processor; a memory coupled to the processor and, when executed by the processor, causing the processor to receive an Ethernet context for a wireless terminal from a first user plane function (UPF) entity, the Ethernet context being provided for an Ethernet protocol data unit (PDU) session for the wireless terminal using the first UPF entity, the Ethernet context including a media access control (MAC) address for the wireless terminal, receiving the Ethernet context; Receiving, from the first UPF entity, a request to switch the Ethernet PDU session for the wireless terminal to a second UPF entity from an access and mobility management function (AMF) entity; Sending, to the AMF entity, a confirmation response to the request to switch the Ethernet PDU session for the wireless terminal, the confirmation response including an end markerless flag indicating that there will be no end marker for the Ethernet PDU session; Sending, to the second UPF entity, the Ethernet context including the MAC address for the wireless terminal; An SMF entity comprising an instruction to cause the above to be performed.

10. When executed by the processor, the memory further causes the processor to Select the second UPF entity And further comprises an instruction to cause the above to be performed, Sending the Ethernet context includes, in response to selecting the second UPF entity, sending the Ethernet context including the MAC address for the wireless terminal to the second UPF entity. The SMF entity according to claim 9.

11. The first UPF entity functions as a first PDU session anchor (PSA) of the Ethernet PDU session for the wireless terminal using the Ethernet context including the MAC address for the wireless terminal; Selecting the second UPF entity includes selecting the second UPF entity that functions as a second PSA of the Ethernet PDU session of the wireless terminal using the Ethernet context including the MAC address for the wireless terminal; Sending the Ethernet context includes sending the Ethernet context including the MAC address for the wireless terminal to the second UPF, and using the Ethernet context without releasing the PDU session, changing from the first PSA of the PDU session to the second PSA of the PDU session. The method according to claim 2.

12. The first UPF entity functions as a first Packet Data Unit (PDU) session anchor (PSA) of the Ethernet PDU session for the wireless terminal, using the Ethernet context including the MAC address for the wireless terminal. Selecting the second UPF entity includes selecting the second UPF entity that functions as a second PSA of the Ethernet PDU session for the wireless terminal, using the Ethernet context including the MAC address for the wireless terminal. Transmitting the Ethernet context includes transmitting the Ethernet context including the MAC address for the wireless terminal to the second UPF and using the Ethernet context to change from the first PSA of the PDU session to the second PSA of the PDU session without releasing the PDU session. The SMF entity according to claim 10.

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