Method, apparatus and computer program for operation in a cell cluster

Abstract

There is provided a method performed at a user equipment, the method comprising: receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster comprising the first node providing the first cell, a second node providing a second cell, and a cluster node; and transmitting a connection establishment request indicating the cluster connection request to the first node or to the cluster node via the first node; or after moving to the first cell, sending a switching request to the first node; or storing the cluster identifier for subsequent use when residing in a cell within the cluster.

Description

Technical Field

[0001] This application relates to methods, apparatus, systems, and computer programs, particularly but not limited to enabling user equipment to connect to a radio node cluster and switch user plane services within the radio node cluster. Background Technology

[0002] A communication system can be viewed as a facility that enables a communication session between two or more entities (such as user terminals, base stations, and / or other nodes) by providing carrier waves between the various entities involved in the communication path. A communication system can be provided, for example, by means of a communication network and one or more compatible communication devices. The communication session can include, for example, data communication used to carry communications such as voice, video, email, SMS, multimedia, and / or content data. Non-limiting examples of the services provided include two-way or multi-way calling, data communication or multimedia services, and access to data network systems such as the Internet.

[0003] In wireless communication systems, at least a portion of a communication session between at least two sites occurs via a wireless link. Examples of wireless systems include Public Land Mobile Networks (PLMNs), satellite communication systems, and various wireless local area networks (WLANs). Some wireless systems can be divided into cells and are therefore often referred to as cellular systems.

[0004] Users can access a communication system using appropriate communication equipment or terminals. A user's communication equipment can be referred to as user equipment (UE) or user device. The communication equipment is equipped with appropriate signal receiving and transmission means for enabling communication, such as access to a communication network or direct communication with other users. The communication equipment can access a carrier provided by a base station (e.g., a cell's base station) and transmit and / or receive communication on that carrier.

[0005] Communication systems and their associated equipment typically operate according to a given standard or specification that defines the operations permitted to be performed by the various entities associated with the system and how those operations are implemented. The communication protocols and / or parameters used for connectivity are also usually defined. An example of a communication system is UTRAN (3G Radio). Other examples include the Long Term Evolution (LTE) of Universal Mobile Telecommunications System (UMTS) radio access technology, so-called 5G or New Radio (NR) networks, and future 6G networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP). Summary of the Invention

[0006] According to one aspect, a user equipment is provided, comprising components for: receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster including a first node providing the first cell, a second node providing a second cell, and a cluster node; and sending a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or sending a handover request to the first node after moving to the first cell; or storing the cluster identifier for subsequent use while residing in a cell within the cluster.

[0007] Receiving may include: receiving a cluster identifier as broadcast information in a first cell; or receiving at least one of the cluster identifier and / or the cluster identifier of the user equipment in signaling dedicated to the user equipment, wherein the cluster identifier is unique for the cluster and the cluster identifier of the user equipment is unique for the user equipment.

[0008] The user equipment may also include components for: determining, based on a received cluster identifier, that the user equipment has entered the coverage area of ​​the cluster; and in response to the determination: sending a connection establishment request to a first node or via the first node to a cluster node indicating a cluster connection request; or sending a handover request to the first node.

[0009] The user equipment may also include components for: receiving, from a first node or from a cluster node, a cluster identifier of the user equipment as part of a connection establishment initiated by the first node or the cluster node for use in a handover toward the cluster.

[0010] The user equipment may also include components for: receiving, from a first node or from a cluster node, a cluster identifier of the user equipment as part of establishing a connection with the first node or the cluster node.

[0011] The user equipment may also include components for: receiving a destination layer 2 address from a first node to provide it in uplink user plane packets sent by the user equipment to the cluster.

[0012] This Layer 2 address may include the media access control address.

[0013] The user equipment may also include components for: sending a Protocol Data Unit (PDU) session request to a session management function via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; and receiving a response from the session management function via the first node, the response indicating that a PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery use within the cluster.

[0014] The protocol data unit session request may also include information indicating the layer 2 address of the user equipment.

[0015] The user equipment may also include components for: determining that the user equipment has entered the coverage area of ​​the second cell; and in response to determining that the user equipment has entered the coverage area of ​​the second cell, performing signaling with the first node and the second node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the user equipment's cluster identifier or the user equipment's Layer 2 address.

[0016] The execution signaling may include executing signaling with the first node, the second node, and the cluster node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling may include the cluster identifier of the user equipment or the layer 2 address of the user equipment.

[0017] The user equipment may also include components for: transmitting one or more uplink data packets including the layer 2 address of the user equipment via the second node; and / or receiving one or more downlink data packets via the second node.

[0018] One or more uplink data packets may also include the destination address of the target user plane function, or may also include an identifier mapped to the destination address of the target user plane function.

[0019] User equipment may also include components for receiving the destination address of a target user plane function via a control plane (e.g., non-access stratum signaling or radio resource control signaling) or via a user plane procedure.

[0020] According to one aspect, a cluster node for a cluster is provided, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the cluster node including components for: receiving from the first node or the second node one or more uplink data packets including a destination address of a target user plane function and information indicating a Layer 2 address of a user equipment; determining that the Layer 2 address of the user equipment is served by one of the first node or the second node that is reachable via a transmission link, wherein the one or more uplink data packets have been received via the transmission link; and storing an association between the Layer 2 address of the user equipment and the transmission link.

[0021] The cluster node may also include components for: receiving one or more downlink data packets destined for a user equipment; determining a transport link based on information indicating the layer 2 address of the user equipment and a stored transport link associated with the layer 2 address of the user equipment, for transmitting downlink data packets destined for the user equipment on the transport link; and transmitting the received one or more downlink data packets on the determined link.

[0022] Cluster nodes may also include components for: sending one or more uplink data packets to a target user plane function based on the destination address.

[0023] According to one aspect, a cluster node for a cluster is provided, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the cluster node including components for: receiving a connection request for a user equipment from a user equipment via the first cell; sending a connection response to the user equipment via the first node based on the connection request of the user equipment, the connection response including a cluster identifier of the user equipment for the user equipment; and generating user equipment-specific context data including the cluster identifier of the user equipment.

[0024] User device-specific context data can be stored in a database accessible to at least the first and second nodes.

[0025] Cluster nodes may also include components for sending user equipment-specific context data to the first node and the second node.

[0026] A connection request may include the user device’s unique Layer 2 address.

[0027] The cluster node may also include components for: receiving, via a first node, a Protocol Data Unit (PDU) session request for the user equipment, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; establishing, based on the PDU session request, a PDU session within the cluster using Layer 2 delivery to provide IP connectivity; and sending, via the first node, a message to the user equipment indicating that the PDU session providing IP connectivity has been established, and the PDU session is used for Layer 2 delivery within the cluster.

[0028] The cluster node may also include components for: receiving a request for user equipment-specific context data from a first node; and, in response to receiving the request for user equipment-specific context data, sending the generated user equipment context data to the first node.

[0029] The cluster node may also include components for: receiving information from a first node or a second node indicating changes in user equipment-specific context data; and updating the user equipment-specific context data stored at the cluster node based on the received information.

[0030] The cluster node may also include components for: receiving information from the second node indicating the Layer 2 address of the user equipment, wherein the information indicating the Layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0031] Cluster nodes may also include components for binding user equipment layer 2 addresses to outgoing ports, signaling paths, or network information of the cluster node, or to a second node.

[0032] According to one aspect, a first node of a cluster is provided, the cluster including the first node providing a first cell, a second node providing a second cell, and a cluster node, the first node including components for: sending a cluster identifier for the cluster to a user equipment; and receiving a connection establishment request from the user equipment indicating a cluster connection request; or receiving a handover request from the user equipment indicating a handover to the cluster.

[0033] Transmission may also include sending the cluster identifier as a broadcast message in the first cell or in signaling dedicated to user equipment.

[0034] The first node may also include components for: establishing a connection with the user equipment based on a connection establishment request; determining the layer 2 address of the user equipment; and sending information indicating the layer 2 address of the user equipment to at least the cluster nodes and the second node.

[0035] The first node may also include components for: sending the user equipment's cluster identifier to the user equipment as part of establishing a connection with the user equipment.

[0036] The first node may also include components for: sending a destination layer 2 address to the user equipment for provision in uplink user plane packets sent by the user equipment to the cluster.

[0037] This Layer 2 address may include the media access control address.

[0038] Determining the Layer 2 address of a user equipment may include receiving the Layer 2 address from the user equipment.

[0039] The first node may also include components for: determining changes in user equipment-specific context data; and sending information indicating changes in user equipment-specific context data to cluster nodes.

[0040] Sending may also include sending information to the second node that indicates changes in specific context data of the user equipment.

[0041] The first node may further include components for: receiving a Protocol Data Unit (PDU) session request from a user equipment, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; sending a PDU session request to a cluster node, the PDU session request including information indicating support for IP with Layer 2 delivery; receiving a response from a cluster node indicating that a PDU session providing IP connectivity has been established, the PDU session having use of Layer 2 delivery within the cluster; and sending a response to the user equipment indicating that a requested PDU session providing IP connectivity using Layer 2 delivery within the cluster has been established.

[0042] According to one aspect, a second node of a cluster is provided, the cluster including a first node providing a first cell, the second node providing a second cell, and a cluster node, the second node including components for: receiving from the cluster node user equipment-specific context data associated with a cluster identifier of a user equipment for the user equipment; receiving a signaling message from the user equipment when the user equipment is within the coverage area of ​​the second cell, wherein the signaling message includes a cluster identifier of the user equipment for the user equipment and a Layer 2 address of the user equipment; determining user equipment-specific context data based on the user equipment-specific context data received from the cluster node and the user equipment-specific context identifier received from the user equipment; and establishing a connection with the user equipment based on the determined user equipment-specific context data.

[0043] The second node may also include components for: determining that the user equipment has been connected to the second node; determining the layer 2 address of the user equipment; sending information indicating the layer 2 address of the user equipment to at least the cluster nodes and the first node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment; and omitting tunnel handover between the first node and the second node due to handover.

[0044] Determining that a user equipment is connected to a second node can be based on signaling received from at least one of the following: the user equipment, the first node, the cluster node, or another network node.

[0045] The second node may also include components for: determining changes in user equipment-specific context data; and sending information indicating changes in user equipment-specific context data to cluster nodes.

[0046] Sending may also include sending information to the first node that indicates changes in specific context data of the user equipment.

[0047] The second node may also include components for: after establishing a connection with the user equipment, sending information indicating a change in the layer 2 address of the user equipment to at least the cluster nodes and the first node.

[0048] The second node may further include components for: receiving from the user equipment one or more uplink data packets including a destination address of a target user plane function; and sending to the cluster node one or more uplink data packets including a destination address of a target user plane function and information indicating the layer 2 address of the user equipment, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0049] According to one aspect, a user equipment is provided, comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to at least: receive a cluster identifier for a cluster from a first node providing a first cell, the cluster including the first node providing the first cell, a second node providing a second cell, and a cluster node; and send a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or send a handover request to the first node after moving to the first cell; or store the cluster identifier for subsequent use while residing in a cell within the cluster.

[0050] At least one processor may also be configured to cause the user equipment to: receive a cluster identifier as broadcast information in the first cell; or receive at least one of the cluster identifier and the user equipment's cluster identifier in signaling dedicated to the user equipment, wherein the cluster identifier is unique for the cluster and the user equipment's cluster identifier is unique for the user equipment.

[0051] At least one processor may also be configured to enable the user equipment to: determine, based on the received cluster identifier, that the user equipment has entered the coverage area of ​​the cluster; and in response to the determination, send a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or send a handover request to the first node.

[0052] At least one processor may also be configured to enable the user equipment to receive, from the first node or from the cluster node, the cluster identifier of the user equipment as part of a connection establishment initiated by the first node or the cluster node for use in a handover toward the cluster.

[0053] At least one processor may also be configured to enable the user equipment to receive, from the first node or from the cluster node, the cluster identifier of the user equipment as part of the connection establishment with the first node or the cluster node.

[0054] At least one processor may also be configured to enable the user equipment to receive a destination layer 2 address from the first node for delivery in uplink user plane packets sent by the user equipment to the cluster.

[0055] This Layer 2 address may include the media access control address.

[0056] At least one processor may also be configured to enable the user equipment to: send a Protocol Data Unit (PDU) session request to the session management function via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; and receive a response from the session management function via the first node, the response indicating that a PDU session providing IIP connectivity has been established, the PDU session having Layer 2 delivery use within the cluster.

[0057] The protocol data unit session request may also include information indicating the layer 2 address of the user equipment.

[0058] At least one processor may also be configured to cause the user equipment to: determine that the user equipment has entered the coverage area of ​​the second cell; and in response to determining that the user equipment has entered the coverage area of ​​the second cell, perform signaling with the first node and the second node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the user equipment's cluster identifier or the user equipment's Layer 2 address.

[0059] At least one processor may also be configured to cause the user equipment to: perform signaling with the first node, the second node, and the cluster node to establish a connection to the second node and terminate a connection with the first node, wherein the signaling may include the user equipment's cluster identifier or the user equipment's layer 2 address.

[0060] At least one processor may also be configured to enable the user equipment to: transmit one or more uplink data packets including the layer 2 address of the user equipment via the second node, and / or receive one or more downlink data packets via the second node.

[0061] One or more uplink data packets may also include the destination address of the target user plane function, or may also include an identifier mapped to the destination address of the target user plane function.

[0062] At least one processor may also be configured to enable the user equipment to receive the destination address of the target user plane function via a control plane (e.g., non-access stratum signaling or radio resource control signaling) or via a user plane procedure.

[0063] According to one aspect, a cluster node for a cluster is provided, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the cluster node including at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the cluster node to at least: receive from the first node or the second node one or more uplink data packets including a destination address of a target user plane function and information indicating a Layer 2 address of a user equipment; determine that the Layer 2 address of the user equipment is served by one of the first node or the second node that is reachable via a transmission link, wherein the one or more uplink data packets have been received via the transmission link; and store the association between the Layer 2 address of the user equipment and the transmission link.

[0064] At least one processor may also be configured to enable a cluster node to: receive one or more downlink data packets destined for a user equipment; determine a transport link based on information indicating the layer 2 address of the user equipment and a stored transport link associated with the layer 2 address of the user equipment, to transmit downlink data packets destined for the user equipment on that transport link; and transmit the received one or more downlink data packets on the determined link.

[0065] At least one processor can also be configured to enable cluster nodes to send one or more uplink data packets to the target user plane function based on the destination address.

[0066] According to one aspect, a cluster node for a cluster is provided, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the cluster node including at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the cluster node to at least: receive a connection request for a user equipment via the first cell; send a connection response to the user equipment via the first node based on the connection request, the connection response including a cluster identifier for the user equipment; and generate user equipment-specific context data including the cluster identifier for the user equipment.

[0067] User device-specific context data can be stored in a database accessible to at least the first and second nodes.

[0068] At least one processor can also be configured to enable cluster nodes to send user equipment-specific context data to the first and second nodes.

[0069] A connection request may include the user device’s unique Layer 2 address.

[0070] At least one processor may also be configured to enable a cluster node to: receive a Protocol Data Unit (PDU) session request for a user equipment via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; establish a PDU session within the cluster that provides IP connectivity using Layer 2 delivery based on the PDU session request; and send a message to the user equipment via the first node indicating that a PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery usage within the cluster.

[0071] At least one processor may also be configured to enable cluster nodes to: receive requests for user equipment-specific context data from a first node; and, in response to receiving a request for user equipment-specific context data, send the generated user equipment context data to the first node.

[0072] At least one processor may also be configured to enable the cluster node to: receive information from a first node or a second node indicating changes in user equipment-specific context data; and update the user equipment-specific context data stored at the cluster node based on the received information.

[0073] At least one processor may also be configured to enable the cluster node to receive information from the second node indicating the Layer 2 address of the user equipment, wherein the information indicating the Layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0074] At least one processor can also be configured to enable cluster nodes to bind the layer 2 address of the user equipment to the outgoing port, signaling path, or network information of the cluster node, or to a second node.

[0075] According to one aspect, a first node of a cluster is provided, the cluster including the first node providing a first cell, a second node providing a second cell, and a cluster node, the first node including at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the first node to at least: send a cluster identifier for the cluster to a user equipment; and receive a connection establishment request from the user equipment indicating a cluster connection request; or receive a handover request from the user equipment indicating a handover to the cluster.

[0076] At least one processor may also be configured to enable the first node to send the cluster identifier as a broadcast message in the first cell or in signaling dedicated to user equipment.

[0077] At least one processor may also be configured to enable the first node to: establish a connection with the user equipment based on a connection establishment request; determine the layer 2 address of the user equipment; and send information indicating the layer 2 address of the user equipment to at least the cluster nodes and the second node.

[0078] At least one processor may also be configured to enable the first node to send the user equipment’s cluster identifier to the user equipment as part of establishing a connection with the user equipment.

[0079] At least one processor may also be configured to enable the first node to send a destination layer 2 address to the user equipment for provision in uplink user plane packets sent by the user equipment to the cluster.

[0080] This Layer 2 address may include the media access control address.

[0081] At least one processor can also be configured to enable the first node to receive the Layer 2 address from the user equipment.

[0082] At least one processor may also be configured to enable the first node to: determine changes in user equipment-specific context data; and send information indicating changes in user equipment-specific context data to cluster nodes.

[0083] At least one processor may also be configured to cause the first node to send information to the second node indicating changes in user equipment-specific context data.

[0084] At least one processor may also be configured to cause the first node to: receive a Protocol Data Unit (PDU) session request from a user equipment, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; send a PDU session request to a cluster node, the PDU session request including information indicating support for IP with Layer 2 delivery; receive a response from a cluster node indicating that a PDU session providing IP connectivity has been established, the PDU session having use of Layer 2 delivery within the cluster; and send a response to the user equipment indicating that a PDU session providing IP connectivity has been established, the PDU session having use of Layer 2 delivery within the cluster.

[0085] According to one aspect, a second node of a cluster is provided, the cluster including a first node providing a first cell, the second node providing a second cell, and a cluster node, the second node including at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the second node to at least: receive from the cluster node user equipment-specific context data associated with a cluster identifier for the user equipment; when the user equipment is located within the coverage area of ​​the second cell, receive a signaling message from the user equipment, wherein the signaling message includes a cluster identifier for the user equipment and a Layer 2 address of the user equipment; determine user equipment-specific context data based on the user equipment-specific context data received from the cluster node and the user equipment-specific context data received from the user equipment; and establish a connection with the user equipment based on the determined user equipment-specific context data.

[0086] At least one processor may also be configured to cause the second node to: determine that the user equipment is connected to the second node; determine the layer 2 address of the user equipment; send information indicating the layer 2 address of the user equipment to at least the cluster nodes and the first node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment; and omit tunnel switching between the first node and the second node due to handover.

[0087] At least one processor may also be configured to enable the second node to determine that the user equipment is connected to the second node based on signaling received from at least one of the following: the user equipment, the first node, the cluster node, or other network nodes.

[0088] At least one processor may also be configured to enable the second node to: determine changes in user equipment-specific context data; and send information indicating changes in user equipment-specific context data to the cluster nodes.

[0089] At least one processor may also be configured to enable the second node to send information to the first node indicating changes in user equipment-specific context data.

[0090] At least one processor may also be configured to enable the second node to send information indicating a change in the layer 2 address of the user equipment to at least the cluster nodes and the first node after establishing a connection with the user equipment.

[0091] At least one processor may also be configured to cause the second node to: receive one or more uplink data packets from the user equipment including a destination address of the target user plane function; and send one or more uplink data packets including a destination address of the target user plane function and information indicating the layer 2 address of the user equipment to the cluster node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0092] According to one aspect, a method is provided to be performed at a user equipment, the method comprising: receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster including a first node providing the first cell, a second node providing a second cell, and a cluster node; and sending a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or sending a handover request to the first node after moving to the first cell; or storing the cluster identifier for subsequent use while residing in a cell within the cluster.

[0093] Receiving may include: receiving a cluster identifier as broadcast information in a first cell; or receiving the cluster identifier and / or the cluster identifier of the user equipment in signaling dedicated to the user equipment, wherein the cluster identifier is unique for the cluster and the cluster identifier of the user equipment is unique for the user equipment.

[0094] The method may further include: determining, based on the received cluster identifier, that the user equipment has entered the coverage area of ​​the cluster; and in response to the determination: sending a connection establishment request indicating a cluster connection request to a first node or via the first node to a cluster node; or sending a handover request to the first node.

[0095] The method may further include: receiving the cluster identifier of the user equipment from a first node or from a cluster node as part of a connection establishment initiated by the first node or the cluster node for use in a handover toward the cluster.

[0096] The method may further include: receiving the cluster identifier of the user equipment from the first node or from the cluster node as part of establishing a connection with the first node or the cluster node.

[0097] The method may further include: receiving a destination layer 2 address from a first node for provision in an uplink user plane packet sent by the user equipment to the cluster.

[0098] This Layer 2 address may include the media access control address.

[0099] The method may further include: sending a Protocol Data Unit (PDU) session request to a session management function via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; and receiving a response from the session management function via the first node, the response indicating that a PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery use within the cluster.

[0100] The protocol data unit session request may also include information indicating the layer 2 address of the user equipment.

[0101] The method may further include: determining that the user equipment has entered the coverage area of ​​the second cell; and in response to determining that the user equipment has entered the coverage area of ​​the second cell, performing signaling with the first node and the second node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the user equipment's cluster identifier or the user equipment's Layer 2 address.

[0102] The execution signaling may include executing signaling with the first node, the second node, and the cluster node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling may include the cluster identifier of the user equipment or the layer 2 address of the user equipment.

[0103] The method may further include: sending one or more uplink data packets including the Layer 2 address of the user equipment via the second node; and / or receiving one or more downlink data packets via the second node.

[0104] One or more uplink data packets may also include the destination address of the target user plane function, or may include an identifier mapped to the destination address of the target user plane function.

[0105] The method may also include receiving the destination address of the target user plane function via a control plane (e.g., non-access stratum signaling or radio resource control signaling) or via a user plane procedure.

[0106] According to one aspect, a method is provided to be performed at a cluster node of a cluster, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the method comprising: receiving from the first node or the second node one or more uplink data packets including a destination address of a target user plane function and information indicating a Layer 2 address of a user equipment; determining that the Layer 2 address of the user equipment is served by one of the first node or the second node that is reachable via a transmission link, wherein the one or more uplink data packets have been received via the transmission link; and storing an association between the Layer 2 address of the user equipment and the transmission link.

[0107] The method may further include: receiving one or more downlink data packets destined for a user equipment; determining a transmission link based on information indicating the layer 2 address of the user equipment and a stored transmission link associated with the layer 2 address of the user equipment, for transmitting downlink data packets destined for the user equipment on the transmission link; and transmitting the received one or more downlink data packets on the determined link.

[0108] The method may also include sending one or more uplink data packets to the target user plane function based on the destination address.

[0109] According to one aspect, a method is provided to be executed at a cluster node of a cluster, the cluster including a first node providing a first cell, a second node providing a second cell, and the cluster node, the method comprising: receiving a connection request for a user equipment from a user equipment via the first cell; sending a connection response to the user equipment via the first node based on the connection request of the user equipment, the connection response including a cluster identifier of the user equipment for the user equipment; and generating user equipment-specific context data including the cluster identifier of the user equipment for the user equipment.

[0110] User equipment-specific context data can be stored in a database accessible to at least the first and second nodes.

[0111] Cluster nodes may also include components for sending user equipment-specific context data to the first and second nodes.

[0112] A connection request may include the user device’s unique Layer 2 address.

[0113] The method may include: receiving a Protocol Data Unit (PDU) session request for a user equipment via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; establishing a PDU session within the cluster that provides IP connectivity using Layer 2 delivery based on the PDU session request; and sending a message to the user equipment via the first node indicating that the PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery usage within the cluster.

[0114] The method may include: receiving a request for user equipment-specific context data from a first node; and in response to receiving the request for user equipment-specific context data, sending the generated user equipment context data to the first node.

[0115] The method may include: receiving information from a first node or a second node indicating changes in user equipment-specific context data; and updating the user equipment-specific context data stored on cluster nodes based on the received information.

[0116] The method may further include: receiving information indicating the Layer 2 address of the user equipment from the second node, wherein the information indicating the Layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0117] The method may also include binding the layer 2 address of the user equipment to the outgoing port, signaling path or network information of the cluster node, or binding it to a second node.

[0118] According to one aspect, a method is provided for execution at a first node of a cluster, the cluster including the first node providing a first cell, a second node providing a second cell, and a cluster node, the method comprising: sending a cluster identifier for the cluster to a user equipment; and receiving from the user equipment a connection establishment request indicating a cluster connection request; or receiving from the user equipment a handover request indicating a handover to the cluster.

[0119] Sending may include sending the cluster identifier as a broadcast message in the first cell or in signaling dedicated to user equipment.

[0120] The method may further include: establishing a connection with the user equipment based on a connection establishment request; determining the layer 2 address of the user equipment; and sending information indicating the layer 2 address of the user equipment to at least the cluster nodes and the second node.

[0121] The method may further include sending the user equipment's cluster identifier to the user equipment as part of establishing a connection with the user equipment.

[0122] The method may further include sending a destination layer 2 address to the user equipment for provision in uplink user plane packets sent by the user equipment to the cluster.

[0123] This Layer 2 address may include the media access control address.

[0124] Determining the Layer 2 address of a user equipment may include receiving the Layer 2 address from the user equipment.

[0125] The method may further include: determining changes in user equipment-specific context data; and sending information indicating changes in user equipment-specific context data to cluster nodes.

[0126] Sending may also include sending information about changes in user equipment-specific context data to a second node.

[0127] The method may further include: receiving a Protocol Data Unit (PDU) session request from a user equipment, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; sending a PDU session request to a cluster node, the PDU session request including information indicating support for IP with Layer 2 delivery; receiving a response from the cluster node indicating that a requested PDU session providing IP connectivity using Layer 2 delivery within the cluster has been established; and sending a response to the user equipment indicating that a PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery within the cluster.

[0128] According to one aspect, a method is provided to be executed at a second node of a cluster, the cluster including a first node providing a first cell, the second node providing a second cell, and a cluster node, the method comprising: receiving from the cluster node user equipment-specific context data associated with a cluster identifier for a user equipment; receiving from the user equipment a signaling message when the user equipment is located within the coverage area of ​​the second cell, wherein the signaling message includes a cluster identifier for the user equipment and a Layer 2 address of the user equipment; determining user equipment-specific context data based on the user equipment-specific context data received from the cluster node and the user equipment-specific context identifier received from the user equipment; and establishing a connection with the user equipment based on the determined user equipment-specific context data.

[0129] The method may further include: determining that the user equipment is connected to the second node; determining the layer 2 address of the user equipment; sending information indicating the layer 2 address of the user equipment to at least the cluster nodes and the first node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment; and omitting tunnel handover between the first node and the second node due to handover.

[0130] Determining that a user equipment is connected to a second node can be based on signaling received from at least one of the following: the user equipment, the first node, the cluster node, or another network node.

[0131] The method may further include: determining changes in user equipment-specific context data; and sending information indicating changes in user equipment-specific context data to cluster nodes.

[0132] Sending may also include sending information to the first node that indicates changes in specific context data of the user equipment.

[0133] The method may further include: after establishing a connection with the user equipment, sending information indicating a change in the layer 2 address of the user equipment to at least the cluster nodes and the first node.

[0134] The method may further include: receiving one or more uplink data packets from a user equipment including a destination address of a target user plane function; and sending one or more uplink data packets including a destination address of a target user plane function and information indicating the layer 2 address of the user equipment to a cluster node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that a second node is serving the user equipment.

[0135] According to one aspect, a computer-readable medium is provided, the computer-readable medium including instructions that, when executed by a user equipment, cause the user equipment to perform at least the following operations: receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster including a first node providing the first cell, a second node providing a second cell, and a cluster node; sending a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or sending a handover request to the first node after moving to the first cell; or storing the cluster identifier for subsequent use while residing in a cell within the cluster.

[0136] Receiving may include: receiving a cluster identifier as broadcast information in a first cell; or receiving a cluster identifier and / or a cluster identifier of a user equipment in signaling dedicated to the user equipment, wherein the cluster identifier is unique for the cluster and the cluster identifier of the user equipment is unique for the user equipment.

[0137] When executed by the user equipment, these instructions can be further executed by the user equipment to: determine that the user equipment has entered the coverage area of ​​the cluster based on the received cluster identifier; and in response to the determination, send a connection establishment request indicating a cluster connection request to the first node or via the first node to the cluster node; or send a handover request to the first node.

[0138] When executed by the user equipment, these instructions can be further executed by the user equipment: receiving the user equipment's cluster identifier from the first node or from the cluster node as part of the connection establishment initiated by the first node or the cluster node for use in switching toward the cluster.

[0139] When executed by the user equipment, these instructions can be further executed by the user equipment: receiving the user equipment's cluster identifier from the first node or from the cluster node as part of establishing a connection with the first node or the cluster node.

[0140] When executed by the user equipment, these instructions can be further executed by the user equipment: receiving the destination layer 2 address from the first node to provide it in the uplink user plane packets sent by the user equipment to the cluster.

[0141] This Layer 2 address may include the media access control address.

[0142] When executed by the user equipment, these instructions can be further executed by the user equipment to: send a Protocol Data Unit (PDU) session request to the session management function via the first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; and receive a response from the session management function via the first node, the response indicating that a PDU session providing Internet Protocol connectivity has been established, the PDU session having Layer 2 delivery use within the cluster.

[0143] The protocol data unit session request may also include information indicating the layer 2 address of the user equipment.

[0144] When executed by the user equipment, these instructions can be further performed by the user equipment to: determine that the user equipment has entered the coverage area of ​​the second cell; and in response to determining that the user equipment has entered the coverage area of ​​the second cell, perform signaling with the first node and the second node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the user equipment's cluster identifier or the user equipment's Layer 2 address.

[0145] The execution signaling may include executing signaling with the first node, the second node, and the cluster node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling may include the cluster identifier of the user equipment or the layer 2 address of the user equipment.

[0146] When executed by the user equipment, these instructions can be further executed by the user equipment to: send one or more uplink data packets including the layer 2 address of the user equipment via the second node; and / or receive one or more downlink data packets via the second node.

[0147] One or more uplink data packets may also include the destination address of the target user plane function, or may include an identifier mapped to the destination address of the target user plane function.

[0148] When executed by the user equipment, these instructions can be further executed by the user equipment: receiving the destination address of the target user plane function via the control plane (e.g., non-access stratum signaling or radio resource control signaling) or via user plane procedures.

[0149] According to one aspect, a computer-readable medium is provided, comprising instructions that, when executed by a cluster node of a cluster (the cluster comprising a first node providing a first cell, a second node providing a second cell, and a cluster node), cause the cluster node to perform at least the following operations: receiving from the first node or the second node one or more uplink data packets including a destination address for a target user plane function and information indicating a Layer 2 address of a user equipment; determining that the Layer 2 address of the user equipment is served by one of the first node or the second node, which is reachable via a transmission link, and that the one or more uplink data packets have been received via the transmission link; and storing an association between the Layer 2 address of the user equipment and the transmission link.

[0150] When executed by a cluster node, these instructions can enable the cluster node to further perform the following actions: receive one or more downlink data packets destined for a user equipment; determine a transport link based on information indicating the layer 2 address of the user equipment and a stored transport link associated with the layer 2 address of the user equipment, so as to transmit downlink data packets destined for the user equipment on that transport link; and transmit the received one or more downlink data packets on the determined link.

[0151] When executed by cluster nodes, these instructions can enable cluster nodes to perform further actions: sending one or more uplink data packets to the target user plane function based on the destination address.

[0152] According to one aspect, a computer-readable medium is provided, the computer-readable medium including instructions that, when executed by a cluster node of a cluster (the cluster including a first node providing a first cell, a second node providing a second cell, and a cluster node), cause the cluster node to perform at least the following operations: receiving a connection request for a user equipment from a user equipment via the first cell; sending a connection response to the user equipment via the first node based on the connection request of the user equipment, the connection response including a cluster identifier of the user equipment for the user equipment; and generating user equipment-specific context data including the cluster identifier of the user equipment for the user equipment.

[0153] User equipment-specific context data can be stored in a database accessible to at least the first and second nodes.

[0154] When executed by cluster nodes, these instructions can enable cluster nodes to perform further actions: sending user equipment-specific context data to the first and second nodes.

[0155] A connection request may include the user device’s unique Layer 2 address.

[0156] When executed by the cluster nodes, these instructions enable the cluster nodes to further perform the following actions: receiving a Protocol Data Unit (PDU) session request for the user equipment via a first node, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; establishing a PDU session within the cluster that provides IP connectivity using Layer 2 delivery based on the PDU session request; and sending a message to the user equipment via the first node indicating that the PDU session providing IP connectivity has been established, the PDU session having Layer 2 delivery usage within the cluster.

[0157] When executed by the cluster nodes, these instructions enable the cluster nodes to perform further actions: receive a request for user equipment-specific context data from the first node; and, in response to receiving the request for user equipment-specific context data, send the generated user equipment context data to the first node.

[0158] When executed by the cluster nodes, these instructions enable the cluster nodes to perform further actions: receive information from the first or second node indicating changes in the user equipment-specific context data; and update the user equipment-specific context data stored at the cluster nodes based on the received information.

[0159] When executed by the cluster node, these instructions can enable the cluster node to perform further actions: receive information from the second node indicating the Layer 2 address of the user equipment, wherein the information indicating the Layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0160] When executed by a cluster node, these instructions can enable the cluster node to perform further actions: binding the layer 2 address of the user equipment to the outgoing port, signaling path, network information of the cluster node, or binding it to a second node.

[0161] According to one aspect, a computer-readable medium is provided, the computer-readable medium including instructions that, when executed by a first node of a cluster (the cluster including a first node providing a first cell, a second node providing a second cell, and a cluster node), cause the first node to perform at least the following operations: send a cluster identifier for the cluster to a user equipment; and receive from the user equipment a connection establishment request indicating a cluster connection request; or receive from the user equipment a handover request indicating a handover to the cluster.

[0162] Sending may include sending the cluster identifier as a broadcast message in the first cell or in signaling dedicated to user equipment.

[0163] When executed by the first node, these instructions enable the first node to perform further actions: establish a connection with the user equipment based on the connection establishment request; determine the layer 2 address of the user equipment; and send information indicating the layer 2 address of the user equipment to at least the cluster nodes and the second node.

[0164] When executed by the first node, these instructions can enable the first node to perform further actions: send the user equipment's cluster identifier to the user equipment as part of establishing a connection with the user equipment.

[0165] When executed by the first node, these instructions can enable the first node to perform further actions: send the destination layer 2 address to the user equipment for provision in the uplink user plane packets sent by the user equipment to the cluster.

[0166] This Layer 2 address may include the media access control address.

[0167] Determining the Layer 2 address of a user equipment may include receiving the Layer 2 address from the user equipment.

[0168] When executed by the first node, these instructions enable the first node to perform further actions: determine changes in user equipment-specific context data; and send information indicating changes in user equipment-specific context data to the cluster nodes.

[0169] When executed by the first node, these instructions can enable the first node to perform further actions: sending information to the second node indicating changes in specific context data of the user equipment.

[0170] When executed by the first node, these instructions can cause the first node to further perform the following actions: receive a Protocol Data Unit (PDU) session request from the user equipment, the PDU session request including information indicating support for Internet Protocol (IP) with Layer 2 delivery; send a PDU session request to the cluster node, the PDU session request including information indicating support for IP with Layer 2 delivery; receive a response from the cluster node indicating that a requested PDU session for providing IP connectivity using Layer 2 delivery within the cluster has been established; and send a response to the user equipment indicating that a PDU session for providing IP connectivity has been established, the PDU session having the use of Layer 2 delivery within the cluster.

[0171] According to one aspect, a computer-readable medium is provided, the computer-readable medium including instructions that, when executed by a second node of a cluster (the cluster including a first node providing a first cell, a second node providing a second cell, and a cluster node), cause the second node to perform at least the following operations: receiving from the cluster node user equipment-specific context data associated with a cluster identifier for the user equipment; receiving from the user equipment a signaling message when the user equipment is within the coverage area of ​​the second cell, wherein the signaling message includes a cluster identifier for the user equipment and a Layer 2 address of the user equipment; determining user equipment-specific context data based on the user equipment-specific context data received from the cluster node and the user equipment-specific cluster identifier received from the user equipment; and establishing a connection with the user equipment based on the determined user equipment-specific context data.

[0172] When executed by the second node, these instructions enable the second node to perform further actions: determine that the user equipment is connected to the second node; determine the layer 2 address of the user equipment; send information indicating the layer 2 address of the user equipment to at least the cluster nodes and the first node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment; and omit tunnel handover between the first node and the second node due to handover.

[0173] Determining that a user equipment is connected to a second node can be based on signaling received from at least one of the following: the user equipment, the first node, the cluster node, or another network node.

[0174] When executed by the second node, these instructions enable the second node to perform further actions: determine changes in user equipment-specific context data; and send information indicating changes in user equipment-specific context data to the cluster nodes.

[0175] Sending may also include sending information to the first node that indicates changes in specific context data of the user equipment.

[0176] When executed by the second node, these instructions enable the second node to perform further actions: after establishing a connection with the user equipment, send information indicating changes in the layer 2 address of the user equipment to at least the cluster nodes and the first node.

[0177] When executed by the second node, these instructions can cause the second node to further perform: receiving one or more uplink data packets from the user equipment including the destination address of the target user plane function; and sending one or more uplink data packets including the destination address of the target user plane function and information indicating the layer 2 address of the user equipment to the cluster node, wherein the information indicating the layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

[0178] According to one aspect, a non-transient computer-readable medium comprising program instructions that, when executed by a device, cause the device to perform at least any of the foregoing aspects is provided.

[0179] In any of the examples above, a cluster node may include one of the following: a radio central unit; user plane functionality; and a combination of central unit and user plane functionality.

[0180] In any of the examples above, the first cell and the second cell can be small cells.

[0181] In any of the examples above, the first node and / or the second node may include a radio unit and a radio distributed unit or a radio access point.

[0182] Many different embodiments have been described above. It should be understood that other embodiments can be provided by combining any two or more of the above embodiments. Attached Figure Description

[0183] Embodiments will now be described by way of example only with reference to the accompanying drawings, in which:

[0184] Figure 1 The following are representations of network systems based on some examples;

[0185] Figure 2 The diagram shows a representation of a control device based on some examples;

[0186] Figure 3 A representation of the apparatus based on some examples is shown;

[0187] Figure 4 The methods are shown based on some examples;

[0188] Figure 5 An example cluster configuration is shown; and

[0189] Figures 6 to 9 The signaling exchange is shown based on some examples. Detailed Implementation

[0190] For ease of reference, a non-exhaustive list of some abbreviations used in this disclosure is provided below: 3GPP Third Generation Partnership Project 5G (Fifth Generation) 5GC 5G Core Network 5G-RAN 5G Radio Access Network 5GS 5G system 6G sixth generation AMF Access and Mobility Management Functions AP access point CU Central Unit CU-CP Central Unit Control Plane CU-UP Central Unit User Plane DC dual connectivity DL downlink DNN Data Network Name DRB Data Radio Bearer DU Distributed Unit ePDG (evolved packet data gateway) HO switch HSS (Host Subscriber Server) IMSI International Mobile Subscriber Identity L2 / 3, Level 2 / 3 LAN (Local Area Network) MAC Media Access Control MC multi-connectivity MP-QUIC Multipath QUIC MP-TCP Multipath TCP N3IWF Non-3GPP Interoperability Function NAS Non-access Layer NEF Network Exposure Function NF Network Functions NGAP Next Generation Applications NG-RAN (Next Generation Radio Access Network) NR New Radio PDCP (Packet Data Convergence Protocol) PDU (Packet Data Unit) PSA PDU Session Anchor QoS (Quality of Service) RLC Radio Link Control RRC Radio Resource Control RU radio unit SMF Session Management Function TA tracking area TAC tracking area code TNGF Trusted Non-3GPP Gateway Function UDM Unified Data Management UE User Equipment UL uplink UP User Plane UPF User Plane Functions

[0191] The following explanation will refer to mobile communication devices capable of communicating via wireless cellular systems and mobile communication systems serving such mobile communication devices. Before explaining the exemplary embodiments in detail, reference will be made to… Figure 1 , Figure 2 and Figure 3 Briefly explain some general principles of wireless communication systems, their access systems, and mobile communication devices to help understand the technologies upon which the described examples are based.

[0192] Figure 1 The diagram illustrates a representation of a 5G system (5GS). 5GS may include a terminal or user equipment (UE), a 5G radio access network (5GRAN) or a next-generation radio access network (NG-RAN), a 5G core network (5GC), one or more application functions (AF), and one or more data networks (DN).

[0193] 5G-RAN may include one or more gNodeBs (GNBs), or one or more gNodeB (GNB) distributed unit functions connected to one or more gNodeB (GNB) centralized unit functions.

[0194] 5GC can include the following entities: Network Slice Selection Function (NSSF); Network Exposure Function (NEF); Network Repository Function (NRF); Policy Control Function (PCF); Unified Data Management (UDM); Application Function (AF); Authentication Server Function (AUSF); Access and Mobility Management Function (AMF); and Session Management Function (SMF). Figure 1 Various interfaces (N1, N2, etc.) that can be implemented between the various components of the system are also shown.

[0195] Figure 2 It shows the control in Figure 1An example of a control device 200 for a 5GRAN or 5GC function is shown above. This control device may include at least one random access memory (RAM) 211a, at least one read-only memory (ROM) 211b, at least one processor 212, 213, and an input / output interface 214. At least one processor 212, 213 may be coupled to RAM 211a and ROM 211b. At least one processor 212, 213 may be configured to execute appropriate software code 215. For example, the software code 215 may allow the execution of one or more steps to perform one or more aspects of this disclosure. The software code 215 may be stored in ROM 211b. Control device 200 may be interconnected with another control device 200 that controls another function of the 5GRAN or 5GC. In some embodiments, each function of the 5GRAN or 5GC includes control device 200. In alternative embodiments, two or more functions of the 5GRAN or 5GC may share a control device.

[0196] Figure 3 An example of terminal 300 is shown, such as in Figure 1 The terminal shown above. Terminal 300 can be provided by any device capable of transmitting and receiving radio signals. Non-limiting examples include user equipment, mobile station (MS) or mobile device (such as a mobile phone or so-called "smartphone"), computer provided with a wireless interface card or other wireless interface facility (such as a USB dongle), personal data assistant (PDA) or tablet computer provided with wireless communication capabilities, machine-type communication (MTC) device, Internet of Things (IoT) type communication device, or any combination of these devices, etc. Terminal 300 can provide, for example, communication for carrying data. Communication can be one or more of voice, email, SMS, multimedia, data, machine data, etc.

[0197] Terminal 300 can receive signals via a suitable receiving device, through an air or radio interface 307, and can transmit signals via a suitable radio signal transmission device. Figure 3 In this diagram, the transceiver device is schematically designated as block 306. The transceiver device 306 may be provided, for example, by means of a radio section and an associated antenna arrangement. The antenna arrangement may be located inside or outside the mobile device.

[0198] Terminal 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b, and other possible components 303 for performing tasks designed to be performed with software and hardware assistance, including controlling access to and communication with access systems and other communication devices. At least one processor 301 is coupled to RAM 302b and ROM 302a. At least one processor 301 may be configured to execute appropriate software code 308. For example, software code 308 may allow the execution of one or more aspects of this disclosure. Software code 308 may be stored in ROM 302a.

[0199] Processors, storage devices, and other related control devices may be provided on a suitable circuit board and / or in a chipset. This feature is indicated by reference numeral 304. The device may optionally have a user interface, such as a keyboard 305, a touchscreen or touchpad, a combination thereof, etc. Depending on the type of device, one or more of a display screen, speakers, and microphones may also optionally be provided.

[0200] Consider some cellular radio technologies, such as 5G or next-generation cellular radio (6G), whose frequency range exceeds 100 GHz and even extends to terahertz frequencies. As a result, cell size and ISD (inter-site distance) may begin to decrease. Cell radii may be only tens of meters or less (maximum approximately 100 meters). Line-of-sight (LOS) may be one of the only feasible ways for senders and receivers to communicate. Furthermore, next-generation cellular radio technologies can be deployed in low-frequency bands, allowing for wide-area coverage while maintaining the advantages of traditional cellular networks. It should be understood that the examples in this disclosure are applicable to other network topologies or configurations and are not necessarily limited to small cells using terahertz frequency bands.

[0201] Another possible future use case is the deployment of dedicated networks based on 5G or 6G radio technologies, where 5G / 6G replaces Wi-Fi or fixed access, or serves as an additional access technology. This could involve integrating cellular access technologies as smoothly as possible into existing local area network (LAN) infrastructure, for example, by reusing L2 switching technologies or simple bridging technologies as much as possible.

[0202] Several possible solutions can be considered to address some of the problems mentioned above. These solutions include: 1. Use low-band dual connectivity (DC) or multiple connectivity (MC) at the PDCP layer. This may require additional signaling between the primary and secondary nodes and could lead to changes in PDCP in cases of mobility. Furthermore, availability of the low-band coverage layer may be required, which generally cannot be assumed, especially in high-frequency deployments. 2. Higher-level technologies that allow multiple connectivity, such as MP-TCP and MP-QUIC. This approach may require path / link measurement, which can lead to excessive signaling and potential ping-pong effects (hopping back and forth between different paths). The performance of these higher-level solutions may not be sufficient to allow seamless handover in voice calls or URLLC services. 3. Pure application-layer solutions, such as applications using different connections on different paths to send / receive data. This may not be suitable for URLLC services due to performance issues. 4.3GPP systems can treat Wi-Fi networks as untrusted networks, and therefore interoperability between Wi-Fi and 3GPP networks can be performed via the ePDG / N3IWF architecture. This may have disadvantages in terms of QoS and mobility support—for example, QoS cannot be guaranteed in the underlying (non-3GPP) network, and seamless mobility cannot be supported with full data integrity. This approach may be limited to basic data connectivity and basic-level service continuity, and may increase deployment overhead.

[0203] Using small cell radio connectivity to provide full mobility for a device (UE) may result in an increase in the number of signaling messages (including air signaling and intra-network signaling, such as path switching signaling) to enable idle-mode mobility, particularly for connectivity mode switching between small cells, where each or more small cells are served by a small base station or access point (AP).

[0204] It should be understood that different configurations are possible, such as an integrated solution where the radio unit (RU) and baseband unit are co-located; or a central unit (CU) that controls several distributed units (DU), which may be co-located with the radio unit or separated via a fronthaul interface. As used herein, "radio access point" refers to a configuration where RU and DU or RU, DU and CU are co-located.

[0205] When a UE moves between small cells in idle or connected modes (a scenario more likely given that small cells are reduced to the tens of meters in size), changes to the network architecture and mobility procedures can be beneficial in avoiding excessive signaling between the UE and the network (radio access network and core network) (e.g., RRC and NAS type signaling) and within the network (e.g., from RAN to AMF, and from AMF to UDM in 5G terminology). Furthermore, network architecture and mobility procedures can also provide ways to integrate with macro networks and support service continuity.

[0206] In short, in small cell clusters or LAN-type environments such as those deployed in factories or campuses, it may be important to emulate the simplicity and signaling efficiency of Wi-Fi networks while supporting the seamless mobility offered by cellular technologies. Currently, Wi-Fi networks can be integrated with 5G systems (or EPS) as untrusted, non-3GPP access points using entities called N3IWF (or ePDG) to connect to the 3GPP core network. This approach has some limitations in terms of mobility and QoS. Furthermore, small cell clusters may be trusted and therefore may not need to be treated as untrusted access, so using ePDG or N3IWF for untrusted access may not be appropriate. Integrating Wi-Fi networks as trusted, non-3GPP access networks into 5GC may also be feasible, but this may require the deployment of TNGF to achieve connectivity with 5GC network functions, which could lead to higher complexity and cost due to the use of IPSec between the UE and TNGF, thus posing a barrier to implementation.

[0207] Some examples provide an architecture that enables lightweight connectivity and user plane (UP) service handover within a cluster of radio nodes. Some examples also allow for mobility with macro networks when needed. Some examples can leverage a lightweight connectivity model (similar to that provided by Wi-Fi) for dense deployment while simultaneously taking advantage of the seamless mobility of cellular networks.

[0208] right Figure 4 For reference, this diagram illustrates the method based on some examples.

[0209] At 400, one method includes receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster including a first node providing the first cell, a second node providing a second cell, and a cluster node.

[0210] At 402a, the method includes: sending a connection establishment request to a first node or via the first node to a cluster node indicating a cluster connection request; or, at 402b, the method includes: sending a handover request to the first node when moving into a first cell; or, at 402c, the method includes: storing a cluster identifier for later use while residing in a cell within the cluster.

[0211] In some examples, the methods in steps 400 and 402a-c can be performed at the user equipment.

[0212] At 404, the method includes: receiving one or more uplink data packets from a first node or a second node, the one or more uplink data packets including a destination address of a target user plane function and information indicating a layer 2 address of a user equipment.

[0213] At 406, the method includes: determining that the layer 2 address of the user equipment is served by one of a first node or a second node that is reachable via a transmission link, wherein one or more uplink data packets have been received via the transmission link.

[0214] At 408, the method includes: storing the association between the layer 2 address of the user equipment and the transport link.

[0215] In some examples, the methods of steps 404-408 can be executed at a cluster node of a cluster, which includes a first node providing a first cell, a second node providing a second cell, and the cluster node.

[0216] At 410, the method includes: receiving a connection request for the user equipment from the user equipment via a first cell.

[0217] At 412, the method includes: sending a connection response to the user equipment via a first node based on a connection request from the user equipment, the connection response including a cluster identifier for the user equipment.

[0218] At 414, the method includes: generating user device-specific context data including a cluster identifier for the user device.

[0219] In some examples, the methods of steps 410-414 can be executed at a cluster node of a cluster, which includes a first node providing a first cell, a second node providing a second cell, and the cluster node.

[0220] At 416, the method includes: sending a cluster identifier for clustering to the user equipment.

[0221] At 418a, the method includes: receiving a connection establishment request from a user equipment indicating a cluster connection request; or, at 418b, the method includes: receiving a handover request from a user equipment indicating a handover to a cluster.

[0222] In some examples, the methods of steps 416, 418a, and 418b can be executed at the first node of the cluster, which includes the first node providing the first cell, the second node providing the second cell, and the cluster node.

[0223] At 420, one method includes receiving from a cluster node user device-specific context data associated with a cluster identifier for the user device.

[0224] At 422, the method includes: when the user equipment is within the coverage area of ​​the second cell, receiving a signaling message from the user equipment, wherein the signaling message includes the cluster identifier of the user equipment and the layer 2 address of the user equipment.

[0225] At 424, the method includes: determining the user equipment specific context data based on user equipment specific context data received from the cluster node and the user equipment cluster identifier of the user equipment received from the user equipment.

[0226] At 426, the method includes: establishing a connection with the user equipment based on determined user equipment-specific context data.

[0227] In some examples, the methods of steps 420-426 can be executed at the second node of the cluster, which includes the first node providing the first cell, the second node providing the second cell, and the cluster node.

[0228] In some examples, cells can be combined into logical radio trunks. Figure 5 An example cluster configuration is shown, consisting of multiple clusters 500a-c and one UPF 502, which may be referred to as the cluster UPF in this document. In some examples, cluster nodes may be combined with a UPF. In some examples, cluster nodes can provide L2 switching within the cluster and L3 routing outside the cluster.

[0229] Each cluster may include one or more cluster nodes and one or more other nodes (e.g., access points) controlled by those cluster nodes. For example, see reference... Figure 5 In cluster 500a, CU 506 can act as a cluster node for DU504a-c. In cluster 500b, cluster UPF 502 can act as a cluster node for gNB 508a-c. In some examples, cluster nodes may include a combination of UPF and CU-UP.

[0230] In some examples, such as that shown for cluster 500a, the cluster may include one or more DU nodes 504a-c that are connected to one or more central CU nodes 506. In this case, explicit RRC or N2 signaling (between the RAN and the core network) may not be required for UE mobility within the cluster (e.g., from DU 504a to DU 504b).

[0231] In some examples, such as that shown for cluster 500b, the cluster may include one or more gNBs 508a-c, which include radio units and baseband portions (e.g., in a classic distributed RAN configuration). In this case, RRC signaling may not be required for mobility within the cluster, but N2 signaling may be required, depending on the capabilities of the UPF (if the UPF supports the ability to detect UE mobility based on checking the source MAC address of its received frames, then N2 signaling is not required).

[0232] In some examples, each cluster may be served by one or more CU-UP functions, as shown by CU-UP 510. In some examples, CU-UP may connect to one or more DUs, as shown by DU 512a-c.

[0233] In some examples, multiple CU-UP functions can terminate PDCP and detect UE mobility based on received UL traffic from the UE. UE mobility detection can occur within the CU-UP, for example, by examining the source MAC address from which data packets originate (e.g., the DU address). To simplify solution deployment (making it a purely radio-based solution), in some examples, the CU-UP can be separated from the UPF, thus avoiding any changes to existing UPF deployments.

[0234] In some examples, (multiple) cluster nodes can control the cluster and may include CU (Central Unit) functionality (e.g., including RRC and PDCP). Access points can provide Radio Unit (RU) and DU functionality (up to the RLC layer). The access point (RU+DU) can store UE context data in the cluster nodes and request UE identifier assignments from the cluster nodes.

[0235] In some examples, CU functionality can be distributed to (multiple) DUs. That is, in some examples, an access point can include CU+DU+RU functionality. The combined CU+DU+RU functionality can also be referred to as gNodeB. This may lead to some disadvantages in terms of mobility and increased signaling, depending on the frequency band used.

[0236] In some examples, a DU (Access Point) or access point can register with the cluster nodes when it is configured in the cluster. In this way, the cluster nodes can know which access points are part of their cluster.

[0237] In some examples, the size of the cluster can vary, for example, based on different conditions, and can change dynamically or not dynamically—that is, the cluster can grow or shrink.

[0238] In some examples, a cluster can be defined by a specific service area, which can be identified by a cluster ID within the TA (Tracking Area) or by a single TAC (Tracking Area Code). The TAC can be defined in a specific way to enable the UE to identify the TA as a cluster. The UE can consider the TAC and / or cluster ID during cell (re)selection. The UE can consider the TAC and / or cluster ID when mobility occurs between cells. Furthermore, the UE can consider the TAC and / or cluster ID in RRC_INACTIVE mode and in the case of registration area updates to determine when to perform RAN notification.

[0239] In some examples, when a cluster is identified by a cluster ID, the access point (DU) can broadcast that cluster ID to allow the UE to be aware of when it moves into or out of the cluster. The cluster ID can be unique for a given cluster. In some implementations, a UE cluster identifier can be assigned to identify the UE and provided to the UE—for example, each UE is assigned a unique UE cluster identifier. When a UE moves into or out of the cluster, cell (re)selection principles and HO (handover) procedures, such as those defined in R18 3GPP TS 23.502, TS 38.331, or 38.300, can be applied.

[0240] Although within the cluster, the UE can provide measurement data to the access point and / or cluster nodes, it does not need to send explicit HO signaling because all access nodes (e.g., DU+RU, access point, or gNodeB) can receive user plane traffic from all UEs camped within the cluster. Signaling can be exchanged between the UE and the cluster nodes to establish radio bearers for subsequent signaling and user plane traffic exchange. The cell (re)selection criteria within the UE can be updated so that, in addition to using TAC, the cluster ID (if available) can also be used to determine which cell to select.

[0241] Therefore, in some examples, the UE can move and send / receive data within the cluster while minimizing control plane and user plane signaling between the UE and the network, and minimizing network signaling overhead due to UE mobility between cells in the cluster.

[0242] Some examples enable L2 mobility within a radio node cluster, as well as support for L3 mobility between clusters and / or L3 mobility between a cluster and a macro network. Some examples allow the UE and network (e.g., a CU-UP or UPF at the edge of a cluster) to simultaneously support L2- and L3-based networking for a given session (e.g., L2 switching within a cluster and L3 routing outside a cluster). In this way, some examples enable lightweight connectivity and simplified home hops (HO) when the UE moves within a cluster, and seamless mobility between a cluster and a macro network.

[0243] As used in this article, L3 mobility can refer to existing handover RRC signaling between the UE and the network, as well as N2 signaling between the RAN and the core network, while preserving the UE's IP address (in some examples, this address can be assigned by a PSA UPF, which can be the same as the cluster UPF or can be a separate entity); L2 mobility can refer to cluster nodes using MAC address learning techniques (such as Ethernet-based networking) to associate the UE's MAC (or L2) address with a specific outgoing port; and L2-L3 mobility can refer to the ability to support interoperability between L2 switching and L3 HO for a given session.

[0244] right Figure 6 For reference, this diagram illustrates signaling exchange based on some examples.

[0245] exist Figure 6 In the example, the cluster includes cluster nodes (e.g., UPF+CU), a first cell provided by a first node, and a second cell provided by a second node. The cluster can be served by one or more cluster UPFs. For a given UE, there can be one cluster UPF assigned to serve the UE. For example, the first and second nodes may include DUs, while the cluster nodes may include CUs. Cluster nodes may include UPFs.

[0246] At 600, when a UE enters a first cell, the UE can receive a Tracking Area Code (TAC) and a cluster indicator and / or a cluster ID from the first node. In response to receiving the TAC and / or cluster ID, the UE can determine that it has entered the coverage area of ​​that cluster. The cluster ID can be received from the first node as broadcast information or in dedicated signaling. The cluster ID may correspond to information different from the Tracking Area Code (TAC), or it may correspond to the Tracking Area Code (TAC) along with an indication that the tracking area corresponds to a cluster.

[0247] At 602, the UE can establish a connection with the first node. For example, the UE can establish a connection in response to receiving a TAC and / or a cluster identifier. Establishment may include indicating a cluster connection request when requesting a connection. As part of the connection establishment (or later in step 606 when a connection response is received), the UE can receive from the first node the destination layer 2 address provided in the uplink user plane packets sent by the user equipment to the cluster.

[0248] In some examples, as part of connection establishment, the UE can send information indicating the Layer 2 address of the user equipment to the first node. The first node can then send the information indicating the Layer 2 address of the user equipment to other nodes in the cluster—such as the cluster node and the second node.

[0249] In some examples, as part of connection establishment, the UE can send a Layer 2 address to other nodes in the cluster.

[0250] In some examples, connection establishment can be initiated by the UE, such as Figure 6 As shown in the diagram. In other examples, connection establishment can be initiated by the UE handover from a cell outside the cluster. In the latter case (UE handover from a cell outside the cluster), steps 604 / 606 may not apply, and the UE may receive the UE cluster identifier for the UE as part of the L3 handover procedure.

[0251] In some examples, when a UE first enters the cluster, it can connect to the cluster, depending on whether the UE enters the cluster in idle mode or connected mode (via L3 handover). This can correspond to an explicit RRC connection request from the UE (if the UE enters the cluster in idle mode) or to handover-related signaling. For example, the UE can perform an RRC procedure with the CU or any unit that provides RRC functionality, which may trigger a UE-specific cluster identifier assignment and / or other procedures that lead the UE to connect to the cluster.

[0252] For example, at 604, after a connection is established, the UE can send a connection request to the cluster node via the first node. This connection request may include the user equipment's unique Layer 2 address.

[0253] In some examples, the UE may follow the initial access procedure defined in 3GPP TS 38.401. However, it should be understood that the examples in this disclosure are not limited to such access procedures, and other procedures for initial UE access are also within the scope of this disclosure.

[0254] As part of the initial UE access, the cluster node ensures that the UE is authenticated once it enters the cluster. Afterward, the UE can be "trusted" and allowed to move between access points within the cluster, for example, using L2 technology. The following will refer to... Figure 7 This will be discussed in more detail.

[0255] At point 606, the UE can receive a connection response from the cluster node via the first node. The connection response may include the UE cluster identifier for the user equipment.

[0256] In some examples, the connection response may also include information indicating support for certain capabilities provided by the cluster node (e.g., emergency service support) and / or UE-specific feature capabilities (e.g., DRB ID and other parameters such as SRB information).

[0257] In some examples, cluster nodes may generate and / or allocate cluster identifiers for user equipment during the initial connection establishment. Otherwise, an access point (e.g., the first node) may request a cluster identifier for that user equipment from the cluster nodes via additional signaling. In some examples, the cluster identifier for that user equipment may be allocated from a pool by the appropriate access point and distributed to all other access points, or it may be centrally stored in the cluster nodes and distributed by the cluster nodes to all other nodes in the cluster.

[0258] In some examples, the cluster identifier for a user equipment (UE) can be an identifier derived from L3 (e.g., IP address) or L2 (e.g., MAC ID). In some examples, cluster nodes can ensure that the identifier is unpredictable to ensure privacy and subscriber confidentiality. The identifier can be updated periodically to avoid being traced back to a specific UE.

[0259] At point 608, after successful UE registration, the cluster node can generate UE-specific context data (e.g., UE identifier, security key, radio bearer, timer, etc.) and send it to other nodes in the cluster (e.g., DU / gNB) at point 610. In some examples, the UE context data may include the user equipment's cluster identifier. The UE context data may also include one or more UE-specific keys. The UE context data can be updated periodically if necessary.

[0260] For example, such as Figure 6 As shown, cluster nodes can send UE-specific context data to the first and second nodes. UE-specific context data may include the user equipment's cluster identifier or otherwise associate it with it.

[0261] In other examples, UE context data can be centrally stored on cluster nodes or in a database, from which access points can request context data. Access to the context data can be provided based on the user equipment's cluster identifier.

[0262] In some examples, when a service node determines that the UE context data has changed, the service node can notify the cluster node of the changes in the UE context data, and optionally notify other nodes.

[0263] In some examples, when a UE leaves the cluster, the cluster node can remove the UE context data from the access point and the central database. In other examples, the removal can be performed after the UE has left the cluster and a certain period of time has passed.

[0264] In some examples, to ensure privacy and confidentiality, cluster nodes and access points can maintain an association for each UE, and cluster nodes can encrypt the UE-specific portion of the identifier using a key received during UE registration. In some examples, addressing only the UE or the UE-associated portion within the access point can be used for packet forwarding. The access point can receive DL packets and forward them to the corresponding data radio bearer.

[0265] At position 612, the UE can establish a PDU session with the network. See below for reference. Figure 9 Describe an example of establishing a PDU session.

[0266] right Figure 8 For reference, this diagram illustrates signaling exchange based on some examples.

[0267] exist Figure 8 In the example, the cluster includes cluster nodes (e.g., UPF+CU), a first cell provided by a first node, and a second cell provided by a second node. The cluster can be served by one or more cluster UPFs. For a given UE, there can be a cluster UPF assigned to serve the UE. For example, the first and second nodes can include access nodes (e.g., gNodeB) that provide combined CU+DU functionality. Cluster nodes can include UPFs.

[0268] At 800, when a UE enters a first cell, the UE can receive a Tracking Area Code (TAC) and a cluster indicator and / or a cluster ID from the first node. In response to receiving the TAC and / or cluster ID, the UE can determine that it has entered the coverage area of ​​that cluster. The cluster ID can be received from the first node as broadcast information or in dedicated signaling. The cluster ID may correspond to information different from the Tracking Area Code (TAC), or it may correspond to the Tracking Area Code (TAC) along with an indication that the tracking area corresponds to a cluster.

[0269] At 802, the UE can establish a connection with the first node. For example, the UE can establish a connection in response to receiving a TAC and a cluster indicator and / or a cluster identifier. Establishment may include indicating a cluster connection request when requesting a connection. As part of the connection establishment (or later in step 806 when a connection response is received), the UE can receive from the first node the destination layer 2 address provided in the uplink user plane packets sent by the user equipment to the cluster.

[0270] In some examples, as part of connection establishment, the UE can send information indicating the Layer 2 address of the user equipment to the first node. The first node can then send the information indicating the Layer 2 address of the user equipment to other nodes in the cluster—such as the cluster node and the second node.

[0271] In some examples, as part of connection establishment, the UE can send a Layer 2 address to other nodes in the cluster.

[0272] In some examples, connection establishment can be initiated by the UE, such as Figure 8 The steps are shown in steps 804 / 806. In other examples, connection establishment may be initiated by the UE handover from a cell outside the cluster. In the latter case (UE handover from a cell outside the cluster), steps 804 / 806 may not be applicable, and the UE may receive a UE cluster identifier for the UE as part of the L3 handover procedure.

[0273] In some examples, when a UE first enters the cluster, it can connect to the cluster, depending on whether the UE enters the cluster in idle mode or connected mode (via L3 handover). This can correspond to an explicit RRC connection request from the UE (e.g., the UE enters the cluster in idle mode) or to handover-related signaling. For example, the UE can perform an RRC procedure with the CU or any unit providing RRC functionality, which may trigger a UE-specific UE cluster identifier assignment and / or other procedures that lead the UE to connect to the cluster.

[0274] For example, at 804, after a connection is established, the UE can send a connection request to the first node. This connection request may include the user equipment's unique Layer 2 address.

[0275] In some examples, the UE may follow the initial access procedure defined in 3GPP TS 38.401. However, it should be understood that the examples in this disclosure are not limited to such access procedures, and other procedures for initial UE access are also within the scope of this disclosure.

[0276] As part of the initial UE access, the first node ensures that the UE is authenticated once it enters the cluster. Afterward, the UE can be "trusted" and allowed to move between access points within the cluster, for example, using L2 technology. The following will refer to... Figure 7 This will be discussed in more detail.

[0277] At point 806, the UE can receive a connection response from the first node. The connection response may include a UE cluster identifier for the user equipment.

[0278] In some examples, the connection response may also include information indicating support for certain capabilities provided by the cluster (e.g., emergency service support) and / or UE-specific feature capabilities (e.g., DRBID and other parameters, such as SRB information).

[0279] In some examples, cluster nodes may generate and / or assign cluster identifiers for user equipment during the initial connection establishment. Otherwise, access points (e.g., the first node) may request cluster identifiers for user equipment from cluster nodes via additional signaling. In some examples, the cluster identifiers for user equipment may be assigned from a pool by the appropriate access point and distributed to all other access points, or they may be centrally stored in the cluster nodes and distributed by the cluster nodes to all other nodes in the cluster.

[0280] In some examples, the cluster identifier of a user equipment (UE) can be an identifier derived from L3 (e.g., IP address) or L2 (e.g., MACID). In some examples, cluster nodes can ensure that the identifier is unpredictable to protect privacy and subscriber confidentiality. The identifier can be updated periodically to avoid being traced to a specific UE.

[0281] At 808, after the UE successfully connects to the cluster, the first node can generate UE-specific context data (e.g., UE identifier, security key, radio bearer, timer, etc.).

[0282] At point 810, the UE can send information to the cluster node indicating the user equipment connection.

[0283] At point 812, a cluster node can send UE-specific context data to other nodes in the cluster (e.g., a second node). In some examples, the UE context data may include the user equipment's cluster identifier. The UE context data may also include one or more UE-specific keys. The UE context data may be updated periodically if necessary. The UE-specific context data may include the user equipment's cluster identifier or otherwise associate it with it.

[0284] In some examples, when a UE leaves the cluster, the cluster node can remove the UE context data from the access point and the central database. In other examples, the removal can be performed after the UE has left the cluster and a certain period of time has passed.

[0285] In some examples, to ensure privacy and confidentiality, cluster nodes and access points can maintain an association for each UE, and cluster nodes can encrypt the UE-specific portion of the identifier using a key received during UE registration. In some examples, addressing only the UE or the UE-associated portion within the access point can be used for packet forwarding.

[0286] In some examples, as part of the initial access of the UE to the cluster, the UE and the cluster node can exchange capability information to support “hybrid” IP / L2 PDU sessions, thereby enabling L2 mobility within the cluster and L3 mobility outside the cluster.

[0287] In some examples, when the UE and the cluster node support hybrid IP / L2 PDU sessions, the first node, the second node, or the UE can advertise the UE's new L2 address to the cluster node—for example, via an L2 mechanism. This allows the cluster node to forward DL packets destined for the UE to this new cell. This may occur, for example, when the UE first enters the cluster or when the UE moves within the cluster. See below for further details. Figure 7 An example describing this behavior.

[0288] At point 814, the UE can establish a PDU session with the network. See below for further details. Figure 9 Describe an example of establishing a PDU session.

[0289] right Figure 9 For reference, this diagram illustrates signaling exchange based on some examples. Figure 9 Signaling exchange can be used, for example, to establish PDU sessions, as mentioned above. Figure 6 Step 612 or Figure 8 The session at step 814.

[0290] At 900, the UE can send a PDU session request to the session management function via the first node. This PDU session request may include information indicating support for IP with L2 transport or IP and Ethernet (hybrid PDU session). The PDU session request may also include information indicating the UE's Layer 2 address.

[0291] At position 902, based on this request, the session management function can establish a PDU session in the core network and notify the cluster nodes. This PDU session can be a PDU session within the cluster that provides IP connectivity using enabled L2 transport / Ethernet.

[0292] At 904, the session management function can send a message to the UE via the first node indicating that a PDU session has been established, for example, a message indicating that a PDU session has been established within the cluster using L2 transport / Ethernet to provide IP connectivity.

[0293] When establishing a Layer 2 Transport / Ethernet IP PDU session, the cluster node and / or UPF can act as an L2 switch inside the cluster (e.g., forwarding Ethernet frames to the UE based on the UE source address (e.g., MAC ID)) or as an L3 router outside the cluster (e.g., forwarding packets based on the destination address (e.g., IP address)).

[0294] right Figure 7 For reference, this diagram illustrates signaling exchanges based on some examples. In this example, it is assumed that the UE and the trunking node support hybrid IP / L2 PDU sessions, thereby enabling L2 mobility within the trunking. Furthermore, it is assumed that the UE has already established a hybrid IP / Ethernet PDU session with the trunking node.

[0295] At 700, the UE can determine that it has moved from a first cell to a second cell—for example, from the coverage area of ​​the first node to the coverage area of ​​the second node. This can be based, for example, on one or more measurements performed by the UE.

[0296] At 702, the UE performs signaling (e.g., low-layer signaling) with the first and second nodes to establish a connection to the second node and disconnect from the first node. Establishing a new connection to the second node and terminating the existing connection with the first node can be triggered by the network during HO signaling, or it can be triggered by the UE without explicit handover signaling.

[0297] As part of the signaling, the UE can provide the UE cluster identifier to the second node. The UE can also provide its Layer 2 address. The second node can retrieve UE-specific context data associated with the UE's UE cluster identifier, or use the UE's Layer 2 address. The UE-specific context data can be stored locally at the second node when it is sent by the cluster node, or it can be retrieved from the cluster node or a central database if it is not available locally. The second node can establish a connection based on the UE-specific context data.

[0298] In some examples, the first cell and the second cell may be controlled or provided by different entities—for example, the first DU may cover the first cell, and the second DU may cover the second cell. However, in other examples, the first cell and the second cell may be covered by the same entity (e.g., the same DU). In this case, the UE may not need to perform the underlying signaling at 702 when moving from the first cell to the second cell.

[0299] In some examples, when a UE connects to a second node, the second node or the UE can advertise the UE's new L2 address (e.g., MAC ID or MAC address) to nodes in the cluster (e.g., at least the cluster node and the first node) – for example, via L2 mechanisms. In some examples, the second node can determine that the UE context data has changed and can notify the cluster node and (optionally) nodes covering other cells of the changes in the UE context data.

[0300] Once the UE has established a signaling connection to the second node, at point 704, the second node can send information indicating the L2 address of the UE to other nodes in the cluster (e.g., the cluster node and the first node). The information indicating the L2 address of the UE may include information indicating that the second node is serving the UE.

[0301] Once the UE has established a signaling connection to the second node, at point 705, the UE can send information indicating the Layer 2 address of the UE to other nodes in the cluster (e.g., the cluster node and the first node). The information indicating the Layer 2 address of the UE may include information indicating that the second node is serving the UE. In some examples, tunnel handover between the first and second nodes due to handover is not performed.

[0302] After establishing a signaling connection, the UE can send uplink data packets associated with the established PDU session or receive downlink data packets associated with the established PDU session via the second node.

[0303] For example, at 706, the UE can send uplink data packets to the second node. The uplink data packets may include the UE's target UPF destination address (e.g., MAC ID or MAC address) and source address (e.g., MAC ID).

[0304] At point 708, the second node can forward uplink data packets to the cluster node. In some examples, HO and Xn signaling are not performed between the first and second nodes. In some examples, the F1 interface between the DU and CU can use Ethernet instead of the GTP-U protocol, which avoids the need to switch GTP-U tunnels between the first and second DUs. In some examples, tunnel switching due to handover is not performed.

[0305] In some examples, after receiving uplink data packets, the cluster node can determine that the Layer 2 address of the user equipment (UE) is served by a second node reachable via a transport link, wherein one or more uplink data packets have been received via the transport link. The cluster node can then store the association between the UE's Layer 2 address and the transport link.

[0306] It should be understood that a similar mechanism can be used when a cluster node receives uplink data packets from a first node—for example, the cluster node can determine that the Layer 2 address of the user equipment is served by a first node reachable via a transport link, and that one or more uplink data packets have been received via the transport link. The cluster node can then store the association between the UE's Layer 2 address and the transport link.

[0307] At point 710, cluster nodes can forward uplink data packets to the target UPF based on the destination address. In other words, cluster nodes can act as L3 routers for uplink data packets to route them to the correct destination.

[0308] At point 712, downlink data packets for the UE can be received at the cluster node. These downlink data packets can be sent, for example, by the target UPF.

[0309] At point 714, the cluster node can determine the transport link for sending downlink data packets. This determination can be based on information indicating the Layer 2 address of the user equipment and the stored transport link associated with the Layer 2 address of the user equipment.

[0310] As previously mentioned, in some examples, cluster nodes can determine the attachment point (e.g., access point, such as DU / gNB) to which each frame is sent by using a MAC learning process. Once the UE is attached to an access point, the access point can advertise the UE's MAC address to the cluster or specifically to the cluster nodes, or the UE can send MAC frames in the uplink direction, allowing the cluster nodes to associate the UE's MAC address with the radio node address or next-hop address to which DL packets are to be sent. In some examples, when the cluster nodes do not know the UE's attachment point or that it is outdated, the cluster nodes can send broadcast messages to all access points within the cluster to learn which access point the UE is currently connected to.

[0311] At point 716, the cluster node sends the downlink data packets on the determined link to the determined next-hop node or other nodes— Figure 7 In the example, this is the second node. That is, a cluster node can act as an L2 switch for downlink data packets, routing downlink data packets to the correct node within the cluster that serves the UE.

[0312] At point 718, the second node sends downlink data packets to the UE.

[0313] In some examples, the UE and / or cluster node may not support hybrid IP / L2 PDU sessions, and therefore L2 mobility within the cluster cannot be enabled. In this case, the UE can establish a regular PDU session with the cluster node to achieve IP connectivity.

[0314] In some examples, the first node can receive information from the core network instructing it to operate within the cluster using Layer 2 transport (e.g., Ethernet transport) without UE support—for example, the first node must rely on signaling with the second node (e.g., via the Xn interface) to perform UE handover.

[0315] In some examples, the UE can determine that it has moved from a first cell to a second cell—for example, from the coverage area of ​​the first node to the coverage area of ​​the second node. This can be based, for example, on one or more measurements performed by the UE. The handover from the first node to the second node can then be performed according to existing handover mechanisms. As part of the handover, the second node can receive the destination address (e.g., MAC address) of the target UPF for the UE's PDU session from the first node.

[0316] In some examples, the second node can send a virtual packet (e.g., a GTP-U packet) to the target UPF. Based on the receipt of this virtual packet, the target UPF can identify the second node.

[0317] In some examples, the UE can send uplink data packets to a second node, and the second node can send these uplink data packets to the target UPF. When sending the uplink data packets to the target UPF, the second node can also send information identifying the UE's source address (e.g., MAC ID).

[0318] Based on the UE's source address and virtual packet, the target UPF can associate the second node with the UE—for example, it can associate the UE's MAC ID with the second node's GTP-U address. In this way, the target UPF can determine that the UE is being served by the second node after a handover has been performed.

[0319] In some examples, the target UPF can send downlink packets destined for the UE to the cluster UPF. The cluster UPF can then forward the downlink packets to the nodes in the cluster—for example, the first node and the second node. The node serving the UE (e.g., the second node) can then receive the downlink packets and forward them to the UE.

[0320] In some examples, the user plane can be centrally anchored to avoid frequent interruptions during service delivery. The UE can support multihoming, enabling frequent relocations without IP anchor changes, while simultaneously supporting stable IP anchors in the central UPF. Even if the UE leaves the cluster, in some examples, the cluster UPF can be maintained to avoid IP address changes. In other examples, the cluster UPF can change. In examples where the central UPF assigns IP addresses to the UE, changes to the cluster UPF may not disrupt session continuity.

[0321] In some examples, the same or similar processes can be used for cluster-to-macro network mobility and cluster-to-cluster mobility. Cluster-to-cluster mobility (i.e., UE mobility from a source cluster to a target cluster) can be achieved by forwarding UE context data and packets between the source cluster node and the target cluster node. The target cluster node can assign a new cluster identifier and security key to the UE after it enters the target cluster.

[0322] In some examples, when a UE leaves the cluster, it may no longer receive the cluster ID in broadcast messages. Therefore, the UE can register in the target cell using conventional methods (e.g., providing measurement reports, establishing RRC connections, or using authentication for the registration process, as described in 3GPP TS 23.502, TS 38.331, and / or TS 38.300). The HO (House of Interest) for context data can be provided via an Xn-like interface between the cluster node and the target base station or via an AMF (Active Frame Function) using the NGAP protocol. After the HO is executed, the cluster node (including the CU) can locally remove the UE context data from all DUs in a given cluster.

[0323] In some examples, the first node and / or the second node may include a radio unit (RU) + a radio distributed unit (DU). In some examples, the first node and / or the second node may include a radio access point, such as a gNodeB (gNB) or a 6G access point.

[0324] Examples have been provided to group clusters, cluster nodes, and multiple access points into a logical radio cluster. A UE entering the coverage area of ​​one of the access points in the cluster for the first time can register with the cluster node and, once authorized, can move freely between the access points in the cluster using L2 technology. The cluster node can determine the UE's L2 address, for example, from the UE in uplink data packets or from the access point when the UE establishes a connection with the access point. Uplink data packets sent by the UE can be routed based on L3 addresses (e.g., IP addresses), while downlink data packets destined for the UE can be routed to the serving access point based on L2 addresses (e.g., MAC IDs). Thus, some examples can achieve lightweight connectivity, simplified handover when the UE moves within the cluster, and seamless mobility between clusters or between a cluster and a macro network.

[0325] In some examples, the apparatus may include components for performing any of the steps described above.

[0326] In some examples, the user equipment may include components for: receiving a cluster identifier for a cluster from a first node providing a first cell, the cluster including the first node providing the first cell, a second node providing a second cell, and a cluster node; and sending a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or sending a handover request to the first node when moving into the first cell; or storing the cluster identifier for later use while residing in a cell within the cluster.

[0327] In some examples, a cluster node (including a cluster of nodes providing a first cell, a second cell, and a cluster of nodes) may include components for: receiving one or more uplink data packets from the first or second node, the one or more uplink data packets including a destination address for a target user plane function and information indicating a Layer 2 address of a user equipment; determining that the Layer 2 address of the user equipment is served by one of the first or second nodes reachable via a transmission link, the one or more uplink data packets having been received via the transmission link; and storing the association between the Layer 2 address of the user equipment and the transmission link.

[0328] In some examples, a cluster node (including a cluster of nodes providing a first node for a first cell, a second node for a second cell, and a cluster node) may include components for: receiving a connection request for a user equipment from a user equipment via the first cell; sending a connection response to the user equipment via the first node based on the connection request, the connection response including a cluster identifier of the user equipment; and generating user equipment-specific context data including the cluster identifier of the user equipment.

[0329] In some examples, the first node (including the first node providing the first cell, the second node providing the second cell, and the cluster node) may include components for: sending a cluster identifier to the user equipment for clustering; and receiving a connection establishment request from the user equipment indicating a cluster connection request; or receiving a handover request from the user equipment indicating a handover to the cluster.

[0330] In some examples, the second node (including a first node providing a first cell, a second node providing a second cell, and a cluster of cluster nodes) may include components for: receiving user equipment-specific context data associated with a UE cluster identifier for the user equipment from the cluster node; receiving a signaling message from the user equipment when the user equipment is within the coverage area of ​​the second cell, wherein the signaling message includes a UE cluster identifier for the user equipment and a Layer 2 address of the user equipment; determining user equipment-specific context data based on the user equipment-specific context data received from the cluster node and a cluster unique identifier of the user equipment received from the user equipment; and establishing a connection with the user equipment based on the determined user equipment-specific context data.

[0331] In some examples, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least any of the steps described above.

[0332] In some examples, a user equipment may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to at least: receive a cluster identifier for a cluster from a first node providing a first cell, the cluster including the first node providing the first cell, a second node providing a second cell, and a cluster node; and send a connection establishment request to the first node or via the first node to the cluster node indicating a cluster connection request; or send a handover request to the first node when moving into the first cell; or store the cluster identifier for later use while residing in a cell within the cluster.

[0333] In some examples, a cluster node (including a cluster of nodes providing a first cell, a second cell, and a cluster of nodes) may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the cluster node to at least: receive one or more uplink data packets from the first or second node, the one or more uplink data packets including a destination address for a target user plane function and information indicating a Layer 2 address of a user equipment; determine that the Layer 2 address of the user equipment is served by one of the first or second nodes that is reachable via a transmission link, wherein the one or more uplink data packets have been received via the transmission link; and store the association between the Layer 2 address of the user equipment and the transmission link.

[0334] In some examples, a cluster node (including a cluster of nodes providing a first cell, a second cell, and a cluster node) may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the cluster node to at least: receive a connection request for a user equipment via the first cell; send a connection response to the user equipment via the first node based on the connection request, the connection response including a cluster identifier of the user equipment; and generate user equipment-specific context data including the cluster identifier of the user equipment.

[0335] In some examples, the first node (of a cluster including a first node providing a first cell, a second node providing a second cell, and a cluster node) may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first node to at least: send a cluster identifier for the cluster to a user equipment; and receive a connection establishment request from the user equipment indicating a cluster connection request; or receive a handover request from the user equipment indicating a handover to the cluster.

[0336] In some examples, the second node (including a first node providing a first cell, a second node providing a second cell, and a cluster of cluster nodes) may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second node to at least: receive user equipment-specific context data associated with a UE cluster identifier for the user equipment from the cluster node; receive a signaling message from the user equipment when the user equipment is within the coverage area of ​​the second cell, wherein the signaling message includes a UE cluster identifier for the user equipment and a Layer 2 address of the user equipment; determine user equipment-specific context data based on the user equipment-specific context data received from the cluster node and the UE cluster identifier for the user equipment received from the user equipment; and establish a connection with the user equipment based on the determined user equipment-specific context data.

[0337] It should be understood that the references above to various network functions (e.g., AMF, SMF, etc.) may include means for performing at least some of the functionalities associated with these network functions. Furthermore, means including a network function may include a virtual network function instance of that network function.

[0338] It should be understood that these devices may include or be coupled to other units or modules, such as radio sections or radio heads for transmission and / or reception. Although these devices have been described as a single entity, different modules and memories may be implemented in one or more physical or logical entities.

[0339] It should be noted that while some embodiments of 5G networks have been described, similar principles can be applied to other networks and communication systems. Therefore, although some embodiments have been described by way of example with reference to certain wireless networks, technologies, and standards, these embodiments can also be applied to any other suitable form of communication system besides the communication systems shown and described herein.

[0340] It should also be noted that although exemplary embodiments have been described above, several variations and modifications can be made to the disclosed solutions without departing from the scope of the invention.

[0341] As used herein, “at least one of the following: ” and “at least one of ” and similar expressions, wherein the list of two or more elements is connected by “and” or “or”, means at least any one element, or at least any two or more elements, or at least all elements.

[0342] Generally, various embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects of this disclosure can be implemented in hardware, while others can be implemented in firmware or software, which can be executed by a controller, microprocessor, or other computing device, but this disclosure is not limited thereto. Although various aspects of this disclosure may be shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, by way of non-limiting example, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0343] As used in this application, the term "circuit system" may refer to one or more of the following: (a) Pure hardware circuit implementation (such as implementations only in analog and / or digital circuit systems) and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of the (multiple) hardware processors having software (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device (such as a mobile phone or server) to perform various functions) and iii) Multiple hardware circuits and / or multiple processors, such as multiple microprocessors or a portion thereof, that require software (e.g., firmware) to operate, but which may be absent when no software is required to operate.

[0344] This definition of "circuit system" applies to all uses of the term in this application, including all uses in any claim. As a further example, as used herein, the term "circuit system" also covers the implementation of only hardware circuitry or a processor (or processors) or a portion thereof and its (or their) accompanying software and / or firmware. For example, and where suitable for a particular claim element, the term "circuit system" also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0345] Embodiments of this disclosure can be implemented via computer software executable by a data processor of a mobile device (such as in a processor entity), or via hardware, or via a combination of hardware and software. Computer software or programs (also referred to as program products), including software routines, applets, and / or macros, can be stored in any device-readable data storage medium, and they include program instructions for performing a specific task. A computer program product may include one or more computer-executable components that are configured to execute embodiments when the program is run. The one or more computer-executable components may be at least one piece of software code or a portion thereof.

[0346] Furthermore, it should be noted that any block in the logical flow shown in the figure can represent a program step, or interconnected logic circuits, blocks, and functions, or a combination of program steps and logic circuits, blocks, and functions. Software can be stored on physical media such as memory chips or storage blocks implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data versions, CDs, etc. The physical media are non-transient media.

[0347] As used in this article, the term “non-transient” refers to the limitations of the medium itself (i.e., tangible, not signal-based), rather than limitations on the persistence of data storage (e.g., RAM and ROM).

[0348] The memory can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The data processor can be of any type suitable for the local technical environment and, by way of non-limiting example, can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, gate-level circuits, and processors based on multi-core processor architectures.

[0349] The embodiments of this disclosure can be implemented in a variety of components, such as integrated circuit modules. The design of integrated circuits is largely a highly automated process. Complex and powerful software tools are available to convert logic-level designs into semiconductor circuit designs for etching and shaping on semiconductor substrates.

[0350] The scope of protection sought by the various embodiments of this disclosure is defined by the independent claims. Embodiments and features described in this specification that do not fall within the scope of the independent claims (if any) should be interpreted as examples that aid in understanding the various embodiments of this disclosure.

[0351] The foregoing description provides a complete and informative description of exemplary embodiments of the present disclosure by way of non-limiting examples. However, various modifications and adjustments will likely be apparent to those skilled in the art in light of the foregoing description (when read in conjunction with the accompanying drawings and appended claims). Nevertheless, all such and similar modifications to the teachings of the present disclosure will still fall within the scope of the invention as defined in the appended claims. In fact, other embodiments exist, including combinations of one or more embodiments with any other embodiments discussed above.

Claims

1. A method performed at a user equipment, the method comprising: Receive a cluster identifier for a cluster from a first node providing a first cell, the cluster including the first node providing the first cell, a second node providing a second cell, and a cluster node; as well as Send a connection establishment request indicating a cluster connection request to the first node or via the first node to the cluster node; or After moving to the first cell, a handover request is sent to the first node; or The cluster identifier is stored for later use when residing in a cell within the cluster.

2. The method of claim 1, wherein receiving comprises: Receive the cluster identifier as broadcast information in the first cell; or The user equipment receives at least one of the cluster identifier and the user equipment's cluster identifier in signaling dedicated to the user equipment, wherein the cluster identifier is unique for the cluster and the user equipment's cluster identifier is unique for the user equipment.

3. The method according to claim 1 or 2, further comprising: Based on the received cluster identifier, it is determined that the user equipment has entered the coverage area of ​​the cluster; as well as In response to the determination: Send the connection establishment request indicating the cluster connection request to the first node or via the first node to the cluster node; or Send the switching request to the first node.

4. The method according to any of the preceding claims, further comprising: The user equipment's cluster identifier is received from the first node or the cluster node as part of the connection establishment initiated by the first node or the cluster node, for use in switching toward the cluster.

5. The method according to any of the preceding claims, further comprising: Receive the cluster identifier of the user equipment from the first node or from the cluster node as part of establishing a connection with the first node or the cluster node.

6. The method according to any of the preceding claims further comprises: The destination layer 2 address is received from the first node to be provided in the uplink user plane packets sent by the user equipment to the cluster.

7. The method of claim 6, wherein the layer 2 address includes a media access control address.

8. The method according to any of the preceding claims, further comprising: The protocol data unit session request is sent to the session management function via the first node. The protocol data unit session request includes information indicating support for Internet protocols with layer 2 transmission. as well as The first node receives a response from the session management function indicating that a Protocol Data Unit (PDU) session providing Internet Protocol (IP) connectivity has been established, and the PDU session has Layer 2 transport usage within the cluster.

9. The method of claim 8, wherein the protocol data unit session request further includes information indicating the layer 2 address of the user equipment.

10. The method according to any of the preceding claims, further comprising: It is determined that the user equipment has entered the coverage area of ​​the second cell; as well as In response to determining that the user equipment has entered the coverage area of ​​the second cell, signaling is performed with the first node and the second node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the cluster identifier of the user equipment or the layer 2 address of the user equipment.

11. The method of claim 10, wherein executing the signaling includes executing signaling with the first node, the second node, and the cluster node to establish a connection to the second node and terminate the connection with the first node, wherein the signaling includes the cluster identifier of the user equipment or the layer 2 address of the user equipment.

12. The method of claim 11, further comprising: Send one or more uplink data packets, including the Layer 2 address of the user equipment, via the second node, and / or Receive one or more downlink data packets via the second node.

13. The method of claim 12, wherein the one or more uplink data packets further include a destination address of a target user plane function, or further include an identifier mapped to the destination address of the target user plane function.

14. The method of claim 13, further comprising: The destination address of the target user plane function is received via the control plane, such as non-access stratum signaling or radio resource control signaling, or via user plane procedures.

15. A method executed at a cluster node of a cluster, the cluster comprising a first node providing a first cell, a second node providing a second cell, and the cluster node, the method comprising: Receive information from the first node or the second node, including the destination address of the target user plane function and the layer 2 address indicating the user equipment; It is determined that the Layer 2 address of the user equipment is served by one of the first node or the second node that can be reached via the transmission link, and the one or more uplink data packets have been received via the transmission link; as well as The association between the Layer 2 address of the user equipment and the transmission link is stored.

16. The method of claim 15, further comprising: Receive one or more downlink data packets destined for the user equipment; Based on information indicating the Layer 2 address of the user equipment and based on a stored transport link associated with the Layer 2 address of the user equipment, the transport link is determined to transmit downlink data packets to the user equipment on the transport link; as well as Transmit the received one or more downlink data packets on the determined link.

17. The method according to claim 15 or 16, further comprising: Based on the destination address, send one or more uplink data packets to the target user plane function.

18. A method executed at a cluster node of a cluster, the cluster comprising a first node providing a first cell, a second node providing a second cell, and the cluster node, the method comprising: Receive a connection request for the user equipment from the user equipment via the first cell; Based on the user equipment connection request, a connection response is sent to the user equipment via the first node, the connection response including the cluster identifier of the user equipment for the user equipment; as well as Generate user device-specific context data, including the cluster identifier of the user device.

19. The method of claim 18, wherein the user equipment-specific context data is stored in a database accessible by at least the first node and the second node.

20. The method of claim 18, further comprising: Send the user equipment-specific context data to the first node and the second node.

21. The method according to any one of claims 18 to 20, wherein the connection request includes a unique Layer 2 address of the user equipment.

22. The method according to any one of claims 18 to 21, further comprising: The protocol data unit session request for the user equipment is received from the user equipment via the first node, the request including information indicating support for Internet protocols with layer 2 transmission; Based on the protocol data unit session request, a protocol data session is established within the cluster using Layer 2 transmission to provide Internet Protocol connectivity; as well as A message is sent to the user equipment via the first node, the message indicating that a Protocol Data Unit (PDU) session providing Internet Protocol (IP) connectivity has been established, the PDU session having Layer 2 transport usage within the cluster.

23. The method according to any one of claims 18 to 22, further comprising: Receive a request for context-specific data for the user equipment from the first node; as well as In response to receiving the request for specific context data for the user equipment, the generated user equipment context data is sent to the first node.

24. The method according to any one of claims 18 to 23, further comprising: Receive information indicating changes in specific context data of the user equipment from the first node or the second node; as well as Based on the received information, update the user equipment-specific context data stored at the cluster node.

25. The method according to any one of claims 18 to 24, further comprising: Receive information from the second node indicating the Layer 2 address of the user equipment, wherein the information indicating the Layer 2 address of the user equipment includes information indicating that the second node is serving the user equipment.

26. The method of claim 25, further comprising: The layer 2 address of the user equipment is bound to a signaling path or network information or the outgoing port of the cluster node, or bound to the second node.

27. A method executed at a first node of a cluster, the cluster comprising a first node providing a first cell, a second node providing a second cell, and cluster nodes, the method comprising: Send a cluster identifier for the cluster to the user equipment; as well as Receive a connection establishment request from the user equipment indicating a cluster connection request; or Receive a handover request from the user equipment instructing it to switch to the cluster.

28. The method of claim 27, wherein the transmission includes transmitting the cluster identifier as broadcast information in the first cell or in signaling dedicated to the user equipment.

29. The method according to claim 27 or 28, further comprising: Based on the connection establishment request, establish a connection with the user equipment; Determine the Layer 2 address of the user equipment; as well as Information indicating the Layer 2 address of the user equipment is sent to at least the cluster node and the second node.

30. The method according to any one of claims 27 to 29, further comprising: Send the user equipment's cluster identifier to the user equipment as part of establishing a connection with the user equipment.

31. The method according to any one of claims 27 to 30, further comprising: Send the destination layer 2 address to the user equipment to provide it in the uplink user plane packets sent by the user equipment to the cluster.

32. The method of claim 31, wherein the layer 2 address includes a media access control address.

33. The method according to any one of claims 29 to 32, wherein determining the layer 2 address of the user equipment includes receiving the layer 2 address from the user equipment.

34. The method according to any one of claims 27 to 33, further comprising: Determine changes in user equipment-specific context data; as well as Send information to the cluster nodes indicating the changes in the user equipment's specific context data.

35. The method of claim 34, wherein the sending further comprises: Send the information to the second node indicating the changes in the user equipment-specific context data.

36. The method according to any one of claims 27 to 35, further comprising: The user equipment receives a Protocol Data Unit (PDU) session request, the PDU session request including information indicating support for an Internet protocol with Layer 2 delivery; Send the Protocol Data Unit Session Request to the cluster node, the Protocol Data Unit Session Request including: the information indicating support for Internet Protocol with Layer 2 transmission; Receive a response from the cluster node indicating that a requested Protocol Data Unit (PDU) session providing Internet Protocol (IP) connectivity has been established, and that the PDU session has Layer 2 transport usage within the cluster; and The response is sent to the user equipment, indicating that a requested Protocol Data Unit (PDU) session providing Internet Protocol (IP) connectivity has been established, and the PDU session has Layer 2 transport usage within the cluster.

37. A method executed at a second node of a cluster, the cluster comprising a first node providing a first cell, a second node providing a second cell, and a cluster node, the method comprising: Receive user equipment-specific context data associated with the cluster identifier of the user equipment from the cluster node; When the user equipment is within the coverage area of ​​the second cell, a signaling message is received from the user equipment, wherein the signaling message includes the cluster identifier of the user equipment and the layer 2 address of the user equipment; The user equipment specific context data is determined based on the user equipment specific context data received from the cluster node and the user equipment cluster identifier received from the user equipment. as well as A connection to the user equipment is established based on the determined user equipment-specific context data.

38. The method of claim 37, further comprising: It is determined that the user equipment has been connected to the second node; Determine the Layer 2 address of the user equipment; At least the cluster node and the first node are sent information indicating the Layer 2 address of the user equipment, wherein the information indicating the Layer 2 address of the user equipment includes: information indicating that the second node is serving the user equipment; as well as The tunnel switching between the first node and the second node caused by the switching is omitted.

39. The method of claim 38, wherein determining that the user equipment is connected to the second node is based on signaling received from at least one of: the user equipment, the first node, the cluster node, or other network node.

40. The method according to any one of claims 37 to 39, further comprising: Determine changes in user equipment-specific context data; as well as Send information to the cluster nodes indicating the changes in the user equipment's specific context data.

41. The method of claim 40, wherein the sending further comprises: Send the information to the first node indicating the changes in the user equipment-specific context data.

42. The method according to any one of claims 37 to 41, further comprising: After establishing the connection to the user equipment, information indicating a change in the layer 2 address of the user equipment is sent to at least the cluster node and the first node.

43. The method according to any one of claims 37 to 42, further comprising: Receive one or more uplink data packets from the user equipment, including the destination address of the target user plane function; as well as Send one or more uplink data packets to the cluster node, the one or more uplink data packets including: the destination address of the target user plane function, and information indicating the layer 2 address of the user equipment, wherein the information indicating the layer 2 address of the user equipment includes: information indicating that the second node is serving the user equipment.

44. An apparatus comprising components for performing the method of any one of claims 1 to 43.

45. An apparatus comprising at least one processor and at least one memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform the method according to any one of claims 1 to 43.

46. ​​A computer-readable medium comprising instructions that, when executed by a device, cause the device to perform the method according to any one of claims 1 to 43.

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