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WO2024094479A1 - Procédé, appareil et programme informatique - Google Patents

Procédé, appareil et programme informatique Download PDF

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Publication number
WO2024094479A1
WO2024094479A1 PCT/EP2023/079579 EP2023079579W WO2024094479A1 WO 2024094479 A1 WO2024094479 A1 WO 2024094479A1 EP 2023079579 W EP2023079579 W EP 2023079579W WO 2024094479 A1 WO2024094479 A1 WO 2024094479A1
Authority
WO
WIPO (PCT)
Prior art keywords
user equipment
configuration
indication
source node
node
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2023/079579
Other languages
English (en)
Inventor
Rathi GANESHAN
Srinivasan Selvaganapathy
Ahmad AWADA
Halit Murat Gürsu
Umur KARABULUT
Krzysztof Kordybach
Panagiotis SPAPIS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nokia Technologies Oy
Original Assignee
Nokia Technologies Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Technologies Oy filed Critical Nokia Technologies Oy
Priority to CN202380077275.2A priority Critical patent/CN120153702A/zh
Publication of WO2024094479A1 publication Critical patent/WO2024094479A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0079—Transmission or use of information for re-establishing the radio link in case of hand-off failure or rejection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/34—Reselection control
    • H04W36/36—Reselection control by user or terminal equipment
    • H04W36/362—Conditional handover

Definitions

  • the present application relates to a method, apparatus, and computer program for a wireless communication system.
  • a communication system may be a facility that enables communication sessions between two or more entities such as user terminals, base stations/access points and/or other nodes by providing carriers between the various entities involved in the communications path.
  • a communication system may be provided, for example, by means of a communication network and one or more compatible communication devices.
  • the communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on.
  • Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.
  • an apparatus comprising: means for communicating with a user equipment, wherein the user equipment is served by a serving cell, the serving cell provided by a source node; means for receiving an indication that the user equipment is moving from the serving cell to a target cell; and means for, based on the received indication: i) retaining configuration information associated with a configuration for the user equipment, and ii) resetting information related to at least one protocol layer associated with the configuration for the user equipment.
  • the configuration for the user equipment is a user equipment context.
  • the apparatus comprises: means for reconnecting with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • the configuration information associated with configuration for the user equipment to be retained is received in a user equipment context setup request message,
  • the configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the means for resetting information related to at least one protocol layer comprises: means for resetting resources associated with the configuration for the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • the means for resetting information related to at least one protocol layer comprises at least one of: means for resetting signalling transport resources associated with the configuration for the user equipment; means for resetting user data transport resources associated with the configuration for the user equipment; means for performing a radio link control re-establishment associated with the configuration for the user equipment; means for performing a medium access control reset associated with the configuration for the user equipment; means for creating at least one tunnel endpoint identifier for at least one data radio bearer associated with the configuration for the user equipment; means for maintaining at least one existing tunnel endpoint identifier associated with the configuration for the user equipment.
  • the means for maintaining at least one existing tunnel endpoint identifier comprises: means for flushing an existing tunnel associated with the tunnel endpoint identifier.
  • the means for flushing comprises means for discarding data comprised within the existing tunnel.
  • the means for creating at least one tunnel endpoint identifier comprises: means for determining resources for a tunnel associated with the at least one tunnel endpoint identifier.
  • the means for creating tunnel endpoint identifiers for at least one data radio bearer associated with the user equipment comprises: means for receiving, from the centralised unit, uplink user-plane transport network layer information with the indication; and means for applying the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is received in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • the indication is received from a second node.
  • the second node is one of: a centralised unit, a master node, a target node, a gNodeB-centralised unit.
  • the apparatus is for the source node
  • the apparatus is comprised in the source node
  • the apparatus is the source node
  • the source node is one of: a gNodeB, a source distributed unit, and a source gNodeB.
  • an apparatus comprising: means for communicating with a user equipment via a source node, wherein the user equipment is served by a serving cell, the serving cell provided by the source node; and means for providing, to the source node, an indication that the user equipment is moving from the serving cell to a target cell, wherein the indication is for the source node to: i) retain configuration information associated with a configuration for the user equipment, and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment.
  • the configuration for the user equipment is a user equipment context.
  • the apparatus comprises: means for receiving signalling, from the source node, to reconnect with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • apparatus comprises: means for providing, to the source node, the configuration for the user equipment to be retained in a user equipment context setup request message,
  • configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • apparatus comprises: means for providing, to the source node, uplink user-plane transport network layer information with the indication, wherein the source node is indicated to apply the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is provided in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • one of: the apparatus is for a second node, the apparatus is comprised in the second node, and the apparatus is the second node.
  • the second node is one of: a centralised unit, a master node, a gNodeB-centralised unit.
  • a method comprising: communicating with a user equipment, wherein the user equipment is served by a serving cell, the serving cell provided by a source node; receiving an indication that the user equipment is moving from the serving cell to a target cell; and based on the received indication: i) retaining configuration information associated with a configuration for the user equipment, and ii) resetting information related to at least one protocol layer associated with the configuration for the user equipment.
  • the method comprises: reconnecting with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • the configuration information associated with configuration for the user equipment to be retained is received in a user equipment context setup request message.
  • the configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the resetting information related to at least one protocol layer comprises: resetting resources associated with the configuration for the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • the resetting information related to at least one protocol layer comprises at least one of: resetting signalling transport resources associated with the configuration for the user equipment; resetting user data transport resources associated with the configuration for the user equipment; performing a radio link control re-establishment associated with the configuration for the user equipment; performing a medium access control reset associated with the configuration for the user equipment; creating at least one tunnel endpoint identifier for at least one data radio bearer associated with the configuration for the user equipment; maintaining at least one existing tunnel endpoint identifier associated with the configuration for the user equipment.
  • the maintaining at least one existing tunnel endpoint identifier comprises: flushing an existing tunnel associated with the tunnel endpoint identifier.
  • the flushing comprises discarding data comprised within the existing tunnel.
  • the creating at least one tunnel endpoint identifier comprises: determining resources for a tunnel associated with the at least one tunnel endpoint identifier.
  • the creating tunnel endpoint identifiers for at least one data radio bearer associated with the user equipment comprises: receiving, from the centralised unit, uplink user-plane transport network layer information with the indication; and applying the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is received in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • the indication is received from a second node.
  • the second node is one of: a centralised unit, a master node, a target node, a gNodeB-centralised unit.
  • the method is performed by the source node.
  • the source node is one of: a gNodeB, a source distributed unit, and a source gNodeB.
  • a method comprising: communicating with a user equipment via a source node, wherein the user equipment is served by a serving cell, the serving cell provided by the source node; and providing, to the source node, an indication that the user equipment is moving from the serving cell to a target cell, wherein the indication is for the source node to: i) retain configuration information associated with a configuration for the user equipment, and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment.
  • the configuration for the user equipment is a user equipment context.
  • the method comprises: receiving signalling, from the source node, to reconnect with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • method comprises: providing, to the source node, the configuration for the user equipment to be retained in a user equipment context setup request message,
  • the configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • method comprises: providing, to the source node, uplink userplane transport network layer information with the indication, wherein the source node is indicated to apply the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is provided in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • method is performed by a second node.
  • the second node is one of: a centralised unit, a master node, a gNodeB-centralised unit.
  • an apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: communicating with a user equipment, wherein the user equipment is served by a serving cell, the serving cell provided by a source node; receiving an indication that the user equipment is moving from the serving cell to a target cell; and based on the received indication: i) retaining configuration information associated with a configuration for the user equipment, and ii) resetting information related to at least one protocol layer associated with the configuration for the user equipment.
  • the apparatus is caused is perform: reconnecting with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • the configuration information associated with configuration for the user equipment to be retained is received in a user equipment context setup request message
  • the configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the resetting information related to at least one protocol layer comprises: resetting resources associated with the configuration for the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • the resetting information related to at least one protocol layer comprises at least one of: resetting signalling transport resources associated with the configuration for the user equipment; resetting user data transport resources associated with the configuration for the user equipment; performing a radio link control re-establishment associated with the configuration for the user equipment; performing a medium access control reset associated with the configuration for the user equipment; creating at least one tunnel endpoint identifier for at least one data radio bearer associated with the configuration for the user equipment; maintaining at least one existing tunnel endpoint identifier associated with the configuration for the user equipment.
  • the maintaining at least one existing tunnel endpoint identifier comprises: flushing an existing tunnel associated with the tunnel endpoint identifier.
  • the flushing comprises discarding data comprised within the existing tunnel.
  • the creating at least one tunnel endpoint identifier comprises: determining resources for a tunnel associated with the at least one tunnel endpoint identifier.
  • the creating tunnel endpoint identifiers for at least one data radio bearer associated with the user equipment comprises: receiving, from the centralised unit, uplink user-plane transport network layer information with the indication; and applying the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is received in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • the indication is received from a second node.
  • the second node is one of: a centralised unit, a master node, a target node, a gNodeB-centralised unit.
  • the apparatus is for the source node
  • the apparatus is comprised in the source node
  • the apparatus is the source node
  • the source node is one of: a source distributed unit, and a source gNodeB.
  • an apparatus comprising: at least one processor, and at least one memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: communicating with a user equipment via a source node, wherein the user equipment is served by a serving cell, the serving cell provided by the source node; and providing, to the source node, an indication that the user equipment is moving from the serving cell to a target cell, wherein the indication is for the source node to: i) retain configuration information associated with a configuration for the user equipment, and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment.
  • the method comprises: receiving signalling, from the source node, to reconnect with the user equipment using the configuration information associated with the user equipment, such that the user equipment is served by the cell of the source node.
  • method comprises: providing, to the source node, the configuration for the user equipment to be retained in a user equipment context setup request message,
  • the configuration information comprises user-plane transport network layer information associated with the user equipment.
  • the indication comprises a further indication to maintain transport layer resources associated with the configuration for the user equipment.
  • method comprises: providing, to the source node, uplink userplane transport network layer information with the indication, wherein the source node is indicated to apply the uplink user-plane transport network layer information after the user equipment has moved from the serving cell to the target cell.
  • the uplink user-plane transport network layer information is comprised in a data radio bearer to be modified list.
  • the indication is provided in one of: an F1 application protocol message, and an Xn application protocol message.
  • the F1 application protocol message is one of: a user equipment context modification request message, a user equipment context release command message, and a user equipment context reset request message.
  • method is performed by a second node.
  • the second node is one of: a centralised unit, a master node, a gNodeB-centralised unit.
  • a computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: communicating with a user equipment, wherein the user equipment is served by a serving cell, the serving cell provided by a source node; receiving an indication that the user equipment is moving from the serving cell to a target cell; and based on the received indication: i) retaining configuration information associated with a configuration for the user equipment, and ii) resetting information related to at least one protocol layer associated with the configuration for the user equipment.
  • a computer program comprising instructions, which when executed by an apparatus, cause the apparatus to perform at least the following: communicating with a user equipment via a source node, wherein the user equipment is served by a serving cell, the serving cell provided by the source node; and providing, to the source node, an indication that the user equipment is moving from the serving cell to a target cell, wherein the indication is for the source node to: i) retain configuration information associated with a configuration for the user equipment, and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment.
  • a computer program comprising instructions stored thereon to perform the methods as described herein:
  • a computer product stored on a medium may cause an apparatus to perform the methods as described herein.
  • a non-transitory computer readable medium comprising program instructions, that, when executed by an apparatus, cause the apparatus to perform the methods as described herein.
  • An electronic device may comprise apparatus as described herein.
  • DL Downlink eNB: eNodeB
  • gNB gNodeB
  • NEF Network Exposure Function
  • NG-RAN Next Generation Radio Access Network
  • NRF Network Repository Function
  • PDCP Packet data convergence protocol
  • PLMN Public Land Mobile Network
  • PSCell Primary Serving Cell
  • SMF Session Management Function
  • UE User Equipment
  • 5GC 5G Core network
  • 5G-AN 5G Radio Access Network 5GS: 5G System
  • Figure 1 shows a schematic representation of a 5G system
  • Figure 2 shows a schematic representation of a control apparatus
  • Figure 3 shows a schematic representation of a terminal
  • Figure 4 shows a schematic representation of a user equipment moving from a source cell to a target cell
  • Figure 5 shows a signalling diagram between a user equipment and network entities for a conditional PSCell change
  • Figure 6 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a first example
  • Figure 7 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a second example
  • Figure 8 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a third example
  • Figure 9 shows a method flow diagram performed by an apparatus
  • Figure 10 shows a method flow diagram performed by a further apparatus
  • Figure 11 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the method of Figures 9 and 10.
  • mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices 102 are provided wireless access via at least one base station (not shown) or similar wireless transmitting and/or receiving node or point.
  • a communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices.
  • the communication device may access a carrier provided by a station or access point, and transmit and/or receive communications on the carrier.
  • FIG. 1 shows a schematic representation of a wireless communication system 100.
  • the wireless communication system 100 may comprise one more devices 102 such as user equipments (UEs), or terminals.
  • the wireless communication system 100 may also comprise a 5G system (5GS), as shown in Figure.
  • the 5GS comprises a 5G radio access network (5G-RAN) 106, a 5G core network (5GC) 104 comprising one or more network functions (NF), one or more application functions (AFs) 108, and one or more data networks (DNs) 110.
  • 5G-RAN 5G radio access network
  • 5GC 5G core network
  • NF network functions
  • AFs application functions
  • DNs data networks
  • the 5G-RAN 106 may comprise one or more gNodeB (gNB) distributed unit (DU) functions connected to one or more gNodeB (gNB) centralized unit (CU) functions.
  • gNB gNodeB
  • DU distributed unit
  • gNB gNodeB
  • CU centralized unit
  • the 5GC 104 may comprise an access management function (AMF) 112, a session management function (SMF) 114, an authentication server function (AUSF) 116, a user data management (UDM) 118, a user plane function (UPF) 120, a network exposure function (NEF) 122 and/or other NFs.
  • AMF access management function
  • SMF session management function
  • AUSF authentication server function
  • UDM user data management
  • UPF user plane function
  • NEF network exposure function
  • mobile communication devices/terminals or user apparatuses, and/or user equipments (UE), and/or machine-type communication devices are provided with wireless access via at least one base station or similar wireless transmitting and/or receiving node or point.
  • the terminal is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other devices.
  • the communication device may access a carrier provided by a base station or access point, and transmit and/or receive communications on the carrier.
  • FIG 2 illustrates an example of a control apparatus 200 for controlling a function of the 5G-RAN or the 5GC as illustrated on Figure 1 .
  • the control apparatus may comprise at least one random access memory (RAM) 211a, at least one read only memory (ROM) 211 b, at least one processor 212, 213 and an input/output interface 214.
  • the at least one processor 212, 213 may be coupled to the RAM 211 a and the ROM 211 b.
  • the at least one processor 212, 213 may be configured to execute an appropriate software code 215.
  • the software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects.
  • the software code 215 may be stored in the ROM 211 b.
  • the control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5G-AN or the 5GC.
  • each function of the 5G-AN or the 5GC comprises a control apparatus 200.
  • two or more functions of the 5G-AN or the 5GC may share a control apparatus.
  • FIG 3 illustrates an example of a terminal 300, such as the terminal illustrated on Figure 1 .
  • the terminal 300 may be provided by any device capable of sending and receiving radio signals.
  • Non-limiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like.
  • the terminal 300 may provide, for example, communication of data for carrying communications.
  • the communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.
  • the terminal 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals.
  • a transceiver apparatus is designated schematically by block 306.
  • the transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement.
  • the antenna arrangement may be arranged internally or externally to the mobile device.
  • the 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 use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices.
  • the at least one processor 301 is coupled to the RAM 302b and the ROM 302a.
  • the at least one processor 301 may be configured to execute an appropriate software code 308.
  • the software code 308 may for example allow to perform one or more of the present aspects.
  • the software code 308 may be stored in the ROM 302a.
  • the processor, storage and other relevant control apparatus may be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304.
  • the device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like.
  • a display, a speaker and a microphone may be provided depending on the type of the device.
  • a handover is a process in telecommunications and mobile communications in which a cellular connection is transferred from one cell to another cell, without disconnecting the session.
  • a UE releases all stored conditional reconfiguration information after successfully executing a conditional primary serving cell (PSCell) change (CPC) procedure.
  • PSCell conditional primary serving cell
  • CPC conditional primary serving cell
  • NR-DC New Radio Dual Connectivity
  • SCG secondary cell group
  • CPC conditional primary serving cell
  • CPC/conditional PSCell addition CPC/conditional PSCell addition
  • Figure 4 shows a schematic representation of a user equipment moving from a source cell to a target cell.
  • double-ended arrows indicate two-way communication between the two relevant entities.
  • a user equipment (UE) 401 which moves from a first location to a second location.
  • the moving of the UE 401 is illustrated with a block arrow.
  • the first location is within the coverage of a first cell 403. While the UE 401 is located within the area of the first cell 403, the UE 401 is served by the first cell 403.
  • the first cell 403 is provided by a first gNB 405.
  • the first gNB 405 comprises a distributed unit (DU) (not shown), which provides the first cell 403.
  • DU distributed unit
  • the UE 401 may change cells. This may be referred to as a handover.
  • the handover may be a conditional handover (CHO), or a condition primary serving cell change (CPC).
  • the serving cell of the UE 401 changes from the first cell 403 to a second cell 407.
  • the second cell 407 is provided by a second gNB 409.
  • the second gNB 409 comprises a distributed unit (DU) (not shown), which provides the second cell 407.
  • DU distributed unit
  • the UE 401 may change to a target cell, whereby the source and target cells are provided by the same gNB (with different DUs).
  • the UE 401 may change to a target cell, whereby the source and target cells are provided by the same gNB, and the same DU.
  • the first gNB 405 and the second gNB 409 are able to communicate with a centralised unit (CU) 411 .
  • the CU 411 may be provided by a further gNB.
  • the CU 411 is used to change the serving cell of the UE 401 from the first cell 403 to the second cell 407.
  • the UE 401 Once the UE 401 has successfully moved to the second cell 407 and is connected to the second gNB 409, the UE 401 with stop communicating with the first gNB 405. At this point, all uplink and downlink traffic will take place with the second gNB 409.
  • Figure 5 shows a signalling diagram between a user equipment and network entities for a conditional PSCell change.
  • the UE is connected to a source gNB-DU, whereby uplink and downlink data is communicated between the UE and the source gNB-DU via a gNB-CU.
  • the UE sends a measurement report to the source gNB-DU.
  • the source gNB-DU sends an uplink resource radio control (RRC) message transfer to the gNB-CU.
  • RRC uplink resource radio control
  • the gNB-CU sends a UE context setup request to a target gNB-DU.
  • the target gNB-DU sends a UE context setup response message to the gNB-CU.
  • the gNB-CU sends a downlink RRC message transfer to the source gNB-DU.
  • the source gNB-Dll sends an RRC reconfiguration message to the
  • the UE sends an RRC reconfiguration complete message to the source gNB-DU.
  • the source gNB-DU sends an uplink RRC message transfer to the gNB-CU.
  • the UE determines that a condition for the PSCell change has been fulfilled. This may be referred to as the execution condition being fulfilled.
  • the UE and the target gNB-DU perform a random access procedure with each other. Once the random access procedure is successfully completed, the target gNB-DU provides an ‘access success’ indication to the gNB-CU.
  • the UE sends an RRC reconfiguration complete message to the target gNB-DU.
  • the target gNB-DU sends an uplink RRC message transfer to the gNB- CU.
  • the gNB-CU sends a UE context modification request to the target gNB-DU.
  • a UE context modification request to the target gNB-DU.
  • downlink and uplink data may be communicated between the UE and the target gNB-DU, via the gNB-CU.
  • the target gNB-DU sends a UE context modification response message to the gNB-CU.
  • the gNB-CU sends a UE context release command to the target gNB- DU.
  • the target gNB-DU sends a UE context release complete message to the gNB-CU.
  • the UE has successfully changed serving cell from a cell of the source gNB-DU to a cell of the target gNB-DU.
  • the CU is informed with an ‘access success’ message.
  • the CU then indicates to modify the UE context (S513).
  • the UE context modification comprises stopping the data radio bearers (DRBs) that transmit data towards the UE and requests for the source DU to send the downlink data delivery status to the CU.
  • DRBs data radio bearers
  • the CU indicates to release the UE context (S515) and release all related signalling and data transport resources reserved for the UE.
  • a UE may be configured with selective activation for a conditional handover (CHO), or for CPC with candidate cell(s) in candidate-gNB-DU. Selective activation allows subsequent cell group changes after changing cell group without reconfiguration and re-initiation of CPC/CPA. Said another way, a network configures a UE once, with multiple handover configurations, to allow the UE to execute handovers from one cell to another without requiring any further handover related configurations.
  • CHO conditional handover
  • CPC conditional handover
  • the UE moves from the source gNB-DU controlling the serving cell to the target gNB-DU.
  • a network instructs the UE to travel between the cells freely and seamlessly. Since a UE context in a source cell may be released after handover when selective activation is not used, this requires extra configuration if the UE goes back to the source cell again in a ‘ping-pong’ scenario.
  • a so-called ‘ping-pong’ scenario is when a UE hands over to a target cell and then back to the original source cell, in a short amount of time.
  • the UE context is not released when selective activation is used, this may lead to problems associated with layers such as, RLC and MAC layers. For example, this may lead to RLC and MAC layers having old protocol data units (PDUs), timeouts, incorrect state variables, incomplete procedures, etc.
  • PDUs protocol data units
  • One or more of the following examples aims to address one or more of the problems identified above.
  • a UE is connected to a serving cell provided by a source node.
  • the connection between the UE and source node allows for uplink/downlink communications between these entities.
  • the UE may then handover to a different serving cell. This may be due to, for example, the UE moving location.
  • the source node then receives an indication that the UE is moving from the serving cell to a target cell.
  • the source node will then, based on the received indication: i) retain configuration information associated with a configuration for the UE; and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment In this way, if the UE is to move/change back to the cell provided by the source node, the UE and the source node can connect more quickly using the retained UE configuration rather than performing a ‘full’ configuration procedure.
  • a source node may be a source DU.
  • the source DU may be provided in a gNB (i.e. source gNB-DU).
  • a target node may be a target DU.
  • the target DU may be provided in a gNB (i.e. target gNB-DU).
  • a second node may be a CU.
  • the CU may be provided in a gNB (i.e. gNB-CU).
  • a ‘new’ indication is provided from the CU to the source DU to maintain the transport layer resources related to the UE.
  • the indication also instructing the source DU to release/re-prepare/reset information related to communication layers/protocol layers, such as for example, MAC and RLC layers. This may comprise resetting MAC and RLC layer buffers, in some examples.
  • the re- preparing/resetting of the communication layers/protocol layers may comprise resetting the configurations to zero. Alternatively, the re-preparing or resetting of the other configurations may comprise resetting the configurations to their default value.
  • the UE configuration received for the UE is retained at the source DU/source node, while the MAC and RLC layers are reset or re-established.
  • a MAC reset is performed.
  • the MAC reset may be performed according to the specification of 3GPP 38.321 , 5.12.
  • an RLC re-establishment is performed.
  • the RLC re-establishment may be performed according to the specification of 3GPP 38.322, 5.1.2.
  • the completion phase is performed.
  • the UE configuration in the source gNB is retained in order to enable UE to ‘come back’ to the last serving cell, when selective activation or successive CPC/CHO is configured for this cell.
  • the preparation phase comprises the configuration at the target node being acquired and provided to the UE.
  • the execution phase comprises the UE completing random access and re-configuration towards the target cell.
  • the completion phase comprises stopping transmission at the source DU and doing a path switch towards the target DU for the user plane.
  • the mechanisms described may be applicable to i) inter gNB inter DU CHO or CPC, whereby the UE hands over to different gNB, and thus a different DU, ii) intra gNB inter DU CHO or CPC, whereby the UE hands over to the same gNB, but a new cell from a different DU, and iii) intra gNB intra DU CHO or CPC, whereby the UE hands over to the same gNB and the same DU, but a different cell of the same DU.
  • UP user-plane
  • TNL transport network layer
  • the source DU receives a UE context/UE configuration associated with a UE, from a CU.
  • the UE context/UE configuration may be received at the source DU in a UE context setup request message, from the CU (similar to the target DU receiving a message in S503).
  • the UE context/UE configuration is used by the source DU to initially connect with the UE.
  • the source DU retains at least part of the information of the UE context/UE configuration, while the also resetting information related to at least one protocol layer of the UE context/UE configuration.
  • the resetting t may include at least one of the following steps: i) RLC re-establishment, ii) ‘new’ tunnel endpoint identifiers (TEID) creation for at least one DRB, iii) maintenance of at least one existing TEID, and iv) MAC reset.
  • TEID tunnel endpoint identifiers
  • MAC reset may not be applicable for intra gNB intra DU scenarios.
  • the reset of the UE contexts/resources at the source DU, during the completion phase, is triggered by the gNB-CU.
  • the trigger may be the message provided by the CU to the source DU, indicating that the UE is moving cell.
  • the reset is triggered by a messaged from the target DU.
  • the trigger is implicit.
  • the trigger will be the source DU not receiving a message during a predetermined time frame.
  • the CU initiates the re-establishment or reset of the UE context in the source DU by making changes to at least one of the F1 AP messages of the CHO/CPC procedure (as shown in Figure 5).
  • the F1AP messages to be changed include: the UE context setup request (S503), the UE context modification request (S513), the UE context modification response (S514), and the UE context release request (S515).
  • Xn application protocol messages are used (in place of the F1AP messages).
  • Figure 6 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a first example.
  • FIG. 6 there is a trigger to reset resources of a UE context, at a source DU (also referred to as source gNB-DU), comprised in a UE context release command.
  • a source DU also referred to as source gNB-DU
  • the following is done in the source DU to receive data from the CU-UP to enable early data forwarding, or to receive DL data once UE moves back to the source DU.
  • the tunnel is a protocol that is used to transfer the data between two network entities.
  • the two network entities may be the source DU and the CU, in some examples.
  • the tunnel may comprise a transport layer address, a tunnel endpoint identifier, and QoS mapping information to setup the protocol between the two network entities.
  • a flushing of the tunnel comprises discarding any data comprised within the reused tunnel.
  • the source DU shall reset related signalling transport resources and user data transport resources. This is described in more detail below.
  • the UE Before S601 , it is assumed that the UE is connected to the source DU, whereby uplink and downlink data may be communicated between the UE and the source DU via a CU.
  • the source DU provides the serving cell for the UE.
  • the UE sends a measurement report message to the source DU/source node (which is also referred to as a source gNB-DU).
  • the source DU/source node which is also referred to as a source gNB-DU.
  • the source DU sends an UL RRC message transfer message to the CU (which is also referred to as a gNB-CU, or a second node) to convey the received measurement report message.
  • the CU which is also referred to as a gNB-CU, or a second node
  • the CU sends a UE context setup request message to a target DU (which is also referred to as a target/candidate gNB-DU) to create a UE context and setup one or more data bearers.
  • the UE context setup request message is sent to each target/candidate DU.
  • the UE context setup request message may comprise ‘HandoverPreparation Information’, for a conditional handover.
  • the UE context setup request message may comprise ‘CG-Configlnfo’ for a conditional PSCell change.
  • the UE context setup request message comprises an indication that selective activation is enabled. The selective activation is configured by the network (by the CU) so that the UE knows that the provided configuration is for selective activation.
  • the target DU responds to the CU with a UE context setup response message.
  • the CU sends a DL RRC message transfer message to the source DU.
  • the DL RRC message transfer message includes a generated RRCReconfigu ration message.
  • the source DU forwards the received RRCReconfigu ration message to the UE.
  • the UE responds by providing, to the source DU, an RRCReconfigurationComplete message.
  • the source DU forwards the RRCReconfigurationComplete message to the CU.
  • the RRCReconfigurationComplete message may be provided in an UL RRC message transfer message.
  • an execution condition to trigger the initiation of a conditional handover or a conditional PSCell change is fulfilled.
  • the UE measures an A3 event whereby the target becomes an offset better than the serving cell, or the UE measures an A4 event whereby the target becomes better than a threshold.
  • a random access procedure is performed between the UE and the target DU.
  • the target DU sends a downlink data delivery status frame to inform the CU.
  • the target DU also sends an ‘ACCESS SUCCESS’ message to the CU, to inform the CU of which cell the UE has successfully accessed.
  • the UE sends, to the target DU, with an RRCReconfigurationComplete message.
  • the target DU sends, to the CU, an UL RRC message transfer message.
  • the UL RRC message transfer comprising the RRCReconfigurationComplete message.
  • DL packets may then be sent to the UE from the target DU. Also, uplink packets may be sent from the UE, which are forwarded to the CU through the target DU.
  • the CU sends a UE context modification request message to the source DU.
  • the UE context modification request message indicates for the source DU to stop data transmissions with the UE.
  • the source DU sends a DL data delivery status frame to the CU, to inform the CU about any unsuccessfully transmitted DL data to the UE.
  • Any DL packets including, for example, PDCP protocol data units (PDUs) that have not been successfully transmitted from the source DU, are sent from the CU to the target DU.
  • the target DU may then transmit those DL packets to the UE.
  • PDUs PDCP protocol data units
  • the CU when an existing UP TNL is not reused at the CU, the CU includes a ‘DRB to Be Modified List’ in the modification request. It may be indicated that the UL UP TNL information included in the UE context modification request message is to be applied after CHO or CPC is complete.
  • the UP TNL refers to uplink UP TNL information which refers to the CU (i.e. , gNB-CU endpoint of the F1 transport bearer that is used by the DU for delivery of UL PDUs to the CU).
  • the source DU will continue using the same UP TNL for delivery of UL data to the CU.
  • S613 may occur before S612. S613 may take place as soon as the CU knows which cell the UE has successfully accessed.
  • the CU when selective activation is enabled, the CU does not initiate a UE context release procedure towards any other signalling connections or other target DUs, if any, to cancel conditional handover or conditional PSCell change for the UE. In some scenarios, the CU may initiate a release procedure for other target cells. However, for selective activation, this should be prevented as the preparations are intended to be preserved and used by the UE afterwards. Therefore, resources in source DU should not be released.
  • the UE context modification request message indicates for the source DU to retain configuration information associated with the user equipment, and to reset information related to at least one protocol layer associated with the configuration of the user equipment.
  • the configuration information may be retained by the source DU, so that the source DU can reconnect with the UE more quickly in the future.
  • the UE configuration to be retained may be received at the source DU in a UE context setup request from the CU.
  • the resetting comprises: when an existing UP tunnel is reused at the source DU, flushing the existing tunnel to clear any buffered data in the tunnel.
  • the CU when new UP TNL is to be created, the CU includes a ‘DRB to Be Modified List’ in the UE context modification request message.
  • DL UP TNL information may also be provided in the UE context modification request message. It may be indicated for the DL UP TNL information to be applied after CHO or CPC is complete.
  • the CU sends “UL UP TNL Information” in a “UL UP TNL information to be setup List” which may be comprised in a “DRB to Be Modified List”, to the source DU.
  • Uplink (UL) UP TNL is the CU endpoint of the F1 transport bearer, and used for delivery of UL protocol data units (PDUs) from the source DU to CU.
  • PDUs protocol data units
  • UL) UP TNL is sent from the CU to the source DU in the UE context modification request.
  • Downlink (DL) UP TNL is the source DU endpoint of the F1 transport bearer, and used for delivery of DL PDUs.
  • DL UP TNL is sent from the source DU to the CU in a UE context modification response (as discussed below).
  • the source DU flushes the existing tunnel to clear any buffered data in the tunnel.
  • the source DU stores the received “DRB to Be Modified List”, and ii) the source DU sends the “DRB Modified List” including new DL UP TNL information in a UE context modification response message (as described in S614 below).
  • the received UL UP TNL information will be applied by the source DU after CHO or CPC is complete.
  • the source DU responds to the CU with a UE context modification response message.
  • a ‘DRB Modified List’ is to include new DL UP TNL information.
  • the DL UP TNL information may be applied after CHO or CPC is complete.
  • the source DU may provide the new “DL UP TNL information” corresponding to the new “UL UP TNL information”, received from the CU.
  • the CU sends a UE context release command message to the source DU.
  • the UE context release command comprises an indication for selective activation.
  • information related to at least one protocol layer e.g. MAC
  • the source DU resets information related to at least one protocol layer associated with the configuration for the UE .
  • the source DU resetting may include at least one of the following: RLC re-establishment, new TEID creation for the DRBs, or maintenance of existing TEIDs, MAC reset.
  • the source DU responds to the CU with a UE context release complete message.
  • one or more of the steps of Figure 6 above may not be performed, or may be performed in a different order.
  • Figure 7 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a second example.
  • a trigger to reset resources of a UE context at a source DU (also referred to as source gNB-DU), comprised in a UE context modification request.
  • the source DU on receiving the UE context modification request, shall release signalling transport resources and user data transport resources, and either i) create new data tunnel resources, or ii) flush an existing tunnel. This is described in more detail below.
  • the UE Before S701 , it is assumed that the UE is connected to the source DU, whereby uplink and downlink data may be communicated between the UE and the source DU via a CU.
  • the source DU provides the serving cell for the UE.
  • the UE sends a measurement report message to the source DU (which is also referred to as a source gNB-DU, or source node).
  • the source DU which is also referred to as a source gNB-DU, or source node.
  • the source DU sends an UL RRC message transfer message to the CU (which is also referred to as a gNB-CU, or second node, or master node) to convey the received measurement report message.
  • the CU which is also referred to as a gNB-CU, or second node, or master node
  • the CU sends a UE context setup request message to a target DU (which is also referred to as a target/candidate gNB-DU, or target node) to create a UE context and setup one or more data bearers.
  • the UE context setup request message is sent to each target/candidate DU.
  • the UE context setup request message may comprise ‘HandoverPreparationlnformation’, for a conditional handover.
  • the UE context setup request message may comprise ‘CG-Configlnfo’ for a conditional PSCell change.
  • the UE context setup request message comprises an indication that selective activation is enabled.
  • the selective activation is configured by the network (by the CU) so that the UE knows that the provided configuration is for selective activation.
  • the target DU responds to the CU with a UE context setup response message.
  • the CU sends a DL RRC message transfer message to the source DU.
  • the DL RRC message transfer message includes a generated RRCReconfiguration message.
  • the source DU forwards the received RRCReconfiguration message to the UE.
  • the UE responds by providing, to the source DU, an RRCReconfigurationComplete message.
  • the source DU forwards the RRCReconfigurationComplete message to the CU.
  • the RRCReconfigurationComplete message may be provided in an UL RRC message transfer message.
  • an execution condition to trigger the initiation of a conditional handover or a conditional PSCell change is fulfilled.
  • the UE measures an A3 event whereby the target becomes an offset better than the serving cell, or the UE measures an A4 event whereby the target becomes better than a threshold.
  • a random access procedure is performed between the UE and the target DU.
  • the target DU sends a downlink data delivery status frame to inform the CU.
  • the target DU also sends an ‘ACCESS SUCCESS’ message to the CU, to inform the CU of which cell the UE has successfully accessed.
  • the UE sends, to the target DU, with an RRCReconfigurationComplete message.
  • the target DU sends, to the CU, an UL RRC message transfer message.
  • the UL RRC message transfer comprising the RRCReconfigurationComplete message.
  • the CU sends a UE context modification request message to the source DU.
  • the UE context modification request message indicates for the source DU to stop data transmissions with the UE.
  • the source DU sends a DL data delivery status frame to the CU, to inform the CU about any unsuccessfully transmitted DL data to the UE.
  • Any DL packets including, for example, PDCP protocol data units (PDUs) that have not been successfully transmitted from the source DU, are sent from the CU to the target DU.
  • the target DU may then transmit those DL packets to the UE.
  • the UE context modification request message indicates for the source DU to retain configuration information associated with the user equipment, and to reset information related to at least one protocol layer associated with the configuration of the user equipment.
  • the configuration information may be retained by the source DU, so that the source DU can reconnect with the UE more quickly in the future.
  • the CU may include a ‘DRB to Be Modified List’ in the UE context modification request. It may be indicated that the UL UP TNL information included in the UE context modification request message is to be applied after CHO or CPC is complete.
  • S713 may occur before S712. S713 may take place as soon as the CU knows which cell the UE has successfully accessed.
  • the UE may continue to store configuration information associated with the UE.
  • the UE may reset or re-establish information related to at least one protocol layer associated with the UE configuration.
  • the source DU resetting may include at least one of the following: RLC reestablishment, new TEID creation for the DRBs, or maintenance of existing TEIDs, MAC reset.
  • DL packets may then be sent to the UE from the target DU. Also, uplink packets may be sent from the UE, which are forwarded to the CU through the target DU.
  • the resetting comprises: when an existing UP tunnel is reused at the source DU, flushing the existing tunnel to clear any buffered data in the tunnel.
  • the source DU responds to the CU with a UE context modification response message.
  • the resetting comprises: storing a received ‘DRB to Be Modified List’ (from the UE context modification request), and sending a ‘DRB Modified List’ which includes DL UP TNL information in a UE context modification response message. This may take place after CHO or CPC is complete.
  • one or more of the steps of Figure 7 above may not be performed, or may be performed in a different order.
  • FIG. 8 shows a signalling diagram between a user equipment and network entities for a serving cell change according to a third example.
  • a trigger to reset resources of a UE context at a source DU (also referred to as source gNB-DU), in a UE context reset request.
  • the UE context reset command is a ‘new’ F1 application protocol (F1AP) message.
  • F1AP application protocol
  • the UE context reset command is ‘new’ in that it is not found in the signalling shown in Figure 5.
  • the source DU shall reset the signalling transport resources and data transport resources, and either i) create new data tunnel resources, or ii) flush an existing tunnel. This will be described in more detail below.
  • the UE Before S801 , it is assumed that the UE is connected to the source DU, whereby uplink and downlink data may be communicated between the UE and the source DU via a CU.
  • the source DU provides the serving cell for the UE.
  • the UE sends a measurement report message to the source DU (which is also referred to as a source gNB-DU, or source node).
  • the source DU which is also referred to as a source gNB-DU, or source node.
  • the source DU sends an UL RRC message transfer message to the CU (which is also referred to as a gNB-CU, or second node, or master node) to convey the received measurement report message.
  • the CU which is also referred to as a gNB-CU, or second node, or master node
  • the CU sends a UE context setup request message to a target DU (which is also referred to as a target/candidate gNB-DU, or target node) to create a UE context and setup one or more data bearers.
  • the UE context setup request message is sent to each target/candidate DU.
  • the UE context setup request message may comprise ‘HandoverPreparationlnformation’, for a conditional handover.
  • the UE context setup request message may comprise ‘CG-Configlnfo’ for a conditional PSCell change.
  • the UE context setup request message comprises an indication that selective activation is enabled.
  • the selective activation is configured by the network (by the CU) so that the UE knows that the provided configuration is for selective activation.
  • the target DU responds to the CU with a UE context setup response message.
  • the CU sends a DL RRC message transfer message to the source DU.
  • the DL RRC message transfer message includes a generated RRCReconfigu ration message.
  • the source DU forwards the received RRCReconfigu ration message to the UE.
  • the UE responds by providing, to the source DU, an RRCReconfigurationComplete message.
  • the source DU forwards the RRCReconfigurationComplete message to the CU.
  • the RRCReconfigurationComplete message may be provided in an UL RRC message transfer message.
  • an execution condition to trigger the initiation of a conditional handover or a conditional PSCell change is fulfilled.
  • the UE measures an A3 event whereby the target becomes an offset better than the serving cell, or the UE measures an A4 event whereby the target becomes better than a threshold.
  • a random access procedure is performed between the UE and the target DU.
  • the target DU sends a downlink data delivery status frame to inform the CU.
  • the target DU also sends an ‘ACCESS SUCCESS’ message to the CU, to inform the CU of which cell the UE has successfully accessed.
  • the UE sends, to the target DU, with an RRCReconfigurationComplete message.
  • the target DU sends, to the CU, an UL RRC message transfer message.
  • the UL RRC message transfer comprising the RRCReconfigurationComplete message.
  • the CU sends a UE context modification request message to the source DU.
  • the UE context modification request message indicates for the source DU to stop data transmissions with the UE.
  • the source DU sends a DL data delivery status frame to the CU, to inform the CU about any unsuccessfully transmitted DL data to the UE.
  • Any DL packets including, for example, PDCP protocol data units (PDUs) that have not been successfully transmitted from the source DU, are sent from the CU to the target DU.
  • the target DU may then transmit those DL packets to the UE.
  • PDUs PDCP protocol data units
  • DL packets may then be sent to the UE from the target DU. Also, uplink packets may be sent from the UE, which are forwarded to the CU through the target DU.
  • the source DU responds to the CU with a UE context modification response message.
  • the CU sends a UE context reset command message to the source DU.
  • the UE context reset command is an F1AP message.
  • the UE context reset command message may indicate for the source DU to retain configuration information associated with the user equipment, and to reset information related to at least one protocol layer associated with the user equipment. The configuration information may be retained by the source DU, so that the source DU can reconnect with the UE more quickly in the future.
  • the CU indicates that a ‘DRB Modified List’ is to include DL UP TNL information. It may be indicated that the DL UP TNL information included in the UE context reset command message is to be applied after CHO or CPC is complete.
  • the source DU retains configuration information associated with the UE.
  • the source DU resets information related to at least one protocol layer associated with the UE configuration.
  • the source DU on receiving the UE context reset command message, shall reset signalling transport resources and data transport resources, and/or either i) create new data tunnel resources, or ii) flush an existing tunnel.
  • the source DU resetting may include at least one of the following: RLC reestablishment, new TEID creation for the DRBs, or maintenance of existing TEIDs, MAC reset.
  • the source DU flushes the existing tunnel to clear any buffered data in the tunnel.
  • the source DU stores the received “DRB to Be Modified List”, and ii) the source DU sends the “DRB Modified List” including new DL UP TNL information in a UE context reset complete message (as described in S816 below).
  • the source DU sends a UE context reset complete message to the CU.
  • the source DU also sends the ‘DRB Modified List’, to the CU, which includes DL UP TNL information associated with the UE, to be applied after CHO or CPC is complete.
  • the ‘DRB Modified List’ may be included in the UE context reset complete message.
  • one or more of the steps of Figure 8 above may not be performed, or may be performed in a different order. Even though the examples of Figures 6 to 8 are shown with conditional handovers and serving cell changes, the mechanisms are equally applicable to nonconditional handovers and serving cell changes.
  • a trigger to reset resources of a UE context, at a source DU, with TNL modification using a UE context release command On receiving a UE context release command, at the source DU, the following is performed: either i) create new data tunnel resources, or ii) flush an existing tunnel. Furthermore, on receiving the UE context release command, the source DU shall reset related signalling transport resources and user data transport resources (while retaining configuration information associated with the UE).
  • the source DU may send a ‘DRB Modified List’, to the CU, which includes DL UP TNL information associated with the UE.
  • the ‘DRB Modified List’ may be included in a UE context release complete message.
  • a UE moves from a source cell to target cell.
  • information related to the UE stored at the DU provided the source cell is typically deleted (or similar). Therefore, if the UE is to move back to the source cell, a further configuration procedure will have to take place in order to connect the UE to the source cell, which takes times.
  • One or more of the examples above show a partial release of the UE context at the source DU after a serving cell change execution. This enables the UE to go back to the same DU without any extra re-configuration.
  • Figure 9 shows an example method flow performed by an apparatus.
  • the apparatus may be for a source node, in some examples.
  • the apparatus may be comprised in the source node, in some examples.
  • the apparatus may be the source node, in some examples.
  • the source node is one of: a gNB, a source distributed unit, and a source gNB.
  • the method comprises communicating with a user equipment, wherein the user equipment is served by a serving cell, the serving cell provided by a source node.
  • the method comprises receiving an indication that the user equipment is moving from the serving cell to a target cell.
  • the method comprises, based on the received indication: i) retaining configuration information associated with a configuration for the user equipment, and ii) resetting information related to at least one protocol layer associated with the configuration for the user equipment.
  • Figure 10 shows an example method flow performed by a further apparatus.
  • the further apparatus may be for a second node, in some examples.
  • the further apparatus may be comprised in the second node, in some examples.
  • the further apparatus may be the second node, in some examples.
  • the second node is one of: a centralised unit, a master node, a gNB-centralised unit
  • the method comprises communicating with a user equipment via a source node, wherein the user equipment is served by a serving cell, the serving cell provided by the source node.
  • the method comprises providing, to the source node, an indication that the user equipment is moving from the serving cell to a target cell, wherein the indication is for the source node to: i) retain configuration information associated with a configuration for the user equipment, and ii) reset information related to at least one protocol layer associated with the configuration for the user equipment.
  • Figure 11 shows a schematic representation of non-volatile memory media 1100a (e.g. blu-ray disk (BD), computer disc (CD) or digital versatile disc (DVD)) and 1100b (e.g. solid state drive (SSD), universal serial bus (USB) memory stick) storing instructions and/or parameters 1102 which when executed by a processor allow the processor to perform one or more of the steps of the methods of Figure 9 and Figure 10.
  • non-volatile memory media 1100a e.g. blu-ray disk (BD), computer disc (CD) or digital versatile disc (DVD)
  • 1100b e.g. solid state drive (SSD), universal serial bus (USB) memory stick
  • instructions and/or parameters 1102 which when executed by a processor allow the processor to perform one or more of the steps of the methods of Figure 9 and Figure 10.
  • some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof.
  • some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto.
  • firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
  • the examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions.
  • the software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.
  • non-transitory is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. RAM vs ROM).
  • the memory may be of any type suitable to the local technical environment and may 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 processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi core processor architecture, as non-limiting examples. Alternatively, or additionally some examples may be implemented using circuitry.
  • the circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device.
  • circuitry may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.
  • hardware-only circuit implementations such as implementations in only analogue and/or digital circuitry
  • combinations of hardware circuits and software such as: (i) a combination of analogue and/or digital hardware circuit(s)
  • circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware.
  • circuitry also covers, for example integrated device.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un appareil comprenant : des moyens pour communiquer avec un équipement utilisateur, l'équipement utilisateur étant desservi par une cellule de desserte, la cellule de desserte étant fournie par un nœud source, et des moyens pour recevoir une indication selon laquelle l'équipement utilisateur se déplace de la cellule de desserte vers une cellule cible. L'appareil comprend également des moyens pour, sur la base de l'indication reçue : i) conserver des informations de configuration associées à une configuration pour l'équipement utilisateur, et ii) réinitialiser des informations relatives à au moins une couche de protocole associée à la configuration pour l'équipement utilisateur.
PCT/EP2023/079579 2022-11-04 2023-10-24 Procédé, appareil et programme informatique Ceased WO2024094479A1 (fr)

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IN202241063028 2022-11-04
IN202241063028 2022-11-04

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WO (1) WO2024094479A1 (fr)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2578018B1 (fr) * 2010-05-28 2020-04-22 Samsung Electronics Co., Ltd Appareil et procédé destinés à supporter la mobilité dans un système de communication sans fil hétérogène

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2578018B1 (fr) * 2010-05-28 2020-04-22 Samsung Electronics Co., Ltd Appareil et procédé destinés à supporter la mobilité dans un système de communication sans fil hétérogène

Non-Patent Citations (4)

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Title
NOKIA ET AL: "[TP to TS 38.423 for Selective Activation] RAN signalling problems for Selective Activation", vol. RAN WG3, no. Incheon, Korea; 20230522 - 20230526, 12 May 2023 (2023-05-12), XP052391225, Retrieved from the Internet <URL:https://ftp.3gpp.org/tsg_ran/WG3_Iu/TSGR3_120/Docs/R3-232692.zip R3-232692 MobEnh-SelAct_TP38423.docx> [retrieved on 20230512] *
NTT DOCOMO INC: "Discussion of selective activation", vol. RAN WG3, no. Online; 20221010 - 20221018, 28 September 2022 (2022-09-28), XP052278304, Retrieved from the Internet <URL:https://ftp.3gpp.org/tsg_ran/WG3_Iu/TSGR3_117bis-e/Docs/R3-225649.zip R3-225649.docx> [retrieved on 20220928] *
SAMSUNG: "Considerations on selective activation of the cell groups", vol. RAN WG3, no. Online; 20221010 - 20221018, 28 September 2022 (2022-09-28), XP052278369, Retrieved from the Internet <URL:https://ftp.3gpp.org/tsg_ran/WG3_Iu/TSGR3_117bis-e/Docs/R3-225713.zip R3-225713_Considerations on selective activation of the cell groups-v1.docx> [retrieved on 20220928] *
SRINIVASAN SELVAGANAPATHY ET AL: "Discussion on configuration management and procedure aspects of selective activation", vol. 3GPP RAN 2, no. Toulouse, FR; 20221114 - 20221118, 4 November 2022 (2022-11-04), XP052216189, Retrieved from the Internet <URL:https://www.3gpp.org/ftp/TSG_RAN/WG2_RL2/TSGR2_120/Docs/R2-2212103.zip R2-2212103-Selective-Activation.docx> [retrieved on 20221104] *

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