Enhanced baseline mobility procedure

Abstract

Various examples of embodiments described herein relate to methods and apparatuses, and computer programs for a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g., for 6G). One such example of an embodiment relates to a method that includes obtaining, at an endpoint terminal, a radio resource control, RRC, configuration; providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiating a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

Description

[0001] ENHANCED BASELINE MOBILITY PROCEDURE

[0002] Technical Field

[0003] Various examples of embodiments described in the subject disclosure relate to a method, apparatus, and computer program for a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g., for 6G).

[0004] Background

[0005] Over time, an increasing extension of communication networks has taken place all over the world. Various organizations, such as the European Telecommunications Standards Institute (ETSI), the 3rdGeneration Partnership Project (3GPP), Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN), the International Telecommunication Union (ITU), 3rdGeneration Partnership Project 2 (3GPP2), Internet Engineering Task Force (IETF), the IEEE (Institute of Electrical and Electronics Engineers), the WiMAX Forum (and the like) are working on standards or specifications for telecommunication networks and access environments.

[0006] By way of example, 3GPP defines 5G Core Network Function’s (NF’s) interfaces and relevant Application Programming Interfaces (APIs) for each NF to communicate between NFs.

[0007] Various examples of embodiments described in the subject disclosure provide certain advantages, for example in the form of one or more improvements that are either explicitly described herein or otherwise apparent to a person skilled in the relevant art(s) from the subject disclosure. Hence, at least some examples of embodiments of the subject disclosure aim to provide (or otherwise contribute to) at least part of these aforementioned advantages and improvements.

[0008] Certain aspects of various examples of embodiments described in the subject disclosure are set forth in the claims and pertain to methods, apparatuses and computer program products in the context of a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G).

[0009] At least some of the aforementioned advantages and improvements may be achieved through the methods, apparatuses and non-transitory storage media as specified in the claims. Further advantages and improvements may be achieved through the methods, apparatuses and non-transitory storage media set forth in respective dependent claims.

[0010] Insofar, according to various examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: obtain a radio resource control, RRC, configuration; provide a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; receive a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiate a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

[0011] According to various examples of embodiments, the apparatus may further be caused to, if the initiated handover is completed, provide a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the apparatus.

[0012] According to various examples of embodiments, the apparatus may further be caused to obtain the first RRC configuration when the apparatus is caused to establish or resume an RRC connection. Further, according to various examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: receive, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, select from among the cells one cell as a target cell for the endpoint terminal to handover; generate a reconfiguration on its (e.g., the apparatus’) own in relation to the target cell; and provide the generated reconfiguration to the endpoint terminal.

[0013] According to various examples of embodiments, the apparatus may further be caused to: start a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the apparatus is caused to provide the generated reconfiguration to the endpoint terminal; and release the endpoint terminal context after expiry of the started release timer.

[0014] Furthermore, according to various examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: receive a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the apparatus, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and provide a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the apparatus.

[0015] According to various examples of embodiments, the apparatus may further be caused to receive, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal. Moreover, according to various examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: determine, whether or not the apparatus, which is associated with a first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the apparatus is not able to serve the endpoint terminal, select a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and request network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0016] According to at least some examples of embodiments, the apparatus may further be caused to receive a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, provide, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

[0017] Moreover, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: receive a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the apparatus and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; provide, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; receive a response indicative of the requested PDU session update and the requested SM context; and based on the received response, provide to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0018] Further, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: provide a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; based on the measurement report, receive a redirection message indicating the apparatus to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and switch to the target cell based on the received redirection message.

[0019] According to at least some examples of embodiments, the apparatus may further be caused to initiate a radio resource control, RRC, connection re-establishment procedure at the target cell.

[0020] According to at least some examples of embodiments, the apparatus may further be caused that to switch to the target cell comprises the apparatus being caused to maintain a connected state, RRC_CONNECTED / CM-CONNECTED.

[0021] Furthermore, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: receive, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, select from among the cells one cell as a target cell for the endpoint terminal to switch to; and provide a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell. According to at least some examples of embodiments, the apparatus caused to provide the redirection message may further comprise the apparatus being caused to at least one of indicate a physical cell ID of the target cell, indicate a target carrier frequency related to the target cell, or indicate physical cell ID and system information of the target cell; and / or the apparatus caused to provide the redirection message may further comprise the apparatus being caused to at least one of, on signalling to indicate the target cell to, reuse RRC release, or a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0022] Moreover, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: participate in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the apparatus; retrieve endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, provide an RRC connection re-establishment to the endpoint terminal.

[0023] According to various examples of embodiments, if the retrieval of the endpoint terminal context fails, the apparatus caused to provide the RRC connection reestablishment may further comprise the apparatus being caused to establish an RRC connection from scratch (e.g., anew, de novo, once again, etc.) and to provide the RRC connection established from scratch (e.g., anew, de novo, once again, etc.) to the endpoint terminal.

[0024] Further, according to various examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: determine, whether or not to perform a handover from a serving cell of the apparatus and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, select, from among at least one neighbour cell of the serving cell, one cell as the second cell; and switch to the second cell.

[0025] According to at least some examples of embodiments, wherein the apparatus caused to perform the determining may be based on the apparatus being caused to obtain measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or wherein the apparatus caused to perform the selecting may comprise the apparatus being caused to increase the serving quality in relation to the serving quality of the serving cell.

[0026] Further, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: establish, resume or reconfigure a radio resource control, RRC, connection; and receive, from a first access network entity or function associated with the apparatus, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0027] Furthermore, according to at least some examples of embodiments, an apparatus may comprise: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to: perform for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; determine a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and indicate, towards the endpoint terminal, the determined preconfigured handover variant.

[0028] Moreover, according to various examples of embodiments, an apparatus may comprise means for obtaining a radio resource control, RRC, configuration; means for providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; means for receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and means for initiating a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

[0029] According to various examples of embodiments, the apparatus may further comprise, if the initiated handover is completed, means for providing a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the apparatus.

[0030] According to various examples of embodiments, the apparatus may further comprise means for obtaining the first RRC configuration when the apparatus is caused to establish or resume an RRC connection.

[0031] Further, according to various examples of embodiments, an apparatus may comprise: means for receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, means for selecting from among the cells one cell as a target cell for the endpoint terminal to handover; means for generating a reconfiguration on its (e.g., the apparatus’) own in relation to the target cell; and means for providing the generated reconfiguration to the endpoint terminal.

[0032] According to various examples of embodiments, the apparatus may further comprise means for starting a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the means for providing provide the generated reconfiguration to the endpoint terminal; and means for releasing the endpoint terminal context after expiry of the started release timer.

[0033] Furthermore, according to various examples of embodiments, an apparatus may comprise: means for receiving a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the apparatus, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and means for providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the apparatus.

[0034] According to various examples of embodiments, the apparatus may further comprise means for receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

[0035] Moreover, according to various examples of embodiments, an apparatus may comprise: means for determining, whether or not the apparatus, which is associated with a first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the apparatus is not able to serve the endpoint terminal, means for selecting a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and means for requesting network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0036] According to at least some examples of embodiments, the apparatus may further comprise means for receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, means for providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal. Moreover, according to at least some examples of embodiments, an apparatus may comprise: means for receiving a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the apparatus and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; means for providing, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; means for receiving a response indicative of the requested PDU session update and the requested SM context; and based on the received response, means for providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0037] Further, according to at least some examples of embodiments, an apparatus may comprise means for providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; based on the measurement report, means for receiving a redirection message indicating the apparatus to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and means for switching to the target cell based on the received redirection message.

[0038] According to at least some examples of embodiments, the apparatus may further comprise means for initiating a radio resource control, RRC, connection re-establishment procedure at the target cell.

[0039] According to at least some examples of embodiments, the apparatus may further comprise, when switching to the target cell, means for maintaining a connected state, RRC_CONNECTED / CM-CONNECTED. Furthermore, according to at least some examples of embodiments, an apparatus may comprise means for receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, means for selecting from among the cells one cell as a target cell for the endpoint terminal to switch to; and means for providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0040] According to at least some examples of embodiments, the apparatus, when providing the redirection message, may further comprise means for indicating at least one of a physical cell ID of the target cell, a target carrier frequency related to the target cell, or physical cell ID and system information of the target cell; and / or the apparatus, when providing the redirection message, may further comprise, on signalling to indicate the target cell, means for reusing RRC release, and / or means for providing a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0041] Moreover, according to at least some examples of embodiments, an apparatus may comprise: means for participating in a radio resource control, RRC, connection reestablishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the apparatus; means for retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising Information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, means for providing an RRC connection re-establishment to the endpoint terminal.

[0042] According to various examples of embodiments, if the retrieval of the endpoint terminal context fails, the apparatus may further comprise means for establishing an RRC connection from scratch (e.g., anew, once again) and means for providing the RRC connection established from scratch (e.g., anew, once again) to the endpoint terminal. Further, according to various examples of embodiments, an apparatus may comprise means for determining, whether or not to perform a handover from a serving cell of the apparatus and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, means for selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell; and means for switching to the second cell.

[0043] According to at least some examples of embodiments, wherein the apparatus may further comprise means for obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or wherein the apparatus caused to perform the selecting may comprise the apparatus being caused to increase the serving quality in relation to the serving quality of the serving cell.

[0044] Further, according to at least some examples of embodiments, an apparatus may comprise means for establishing, resuming or reconfiguring a radio resource control, RRC, connection; and means for receiving, from a first access network entity or function associated with the apparatus, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0045] Furthermore, according to at least some examples of embodiments, an apparatus may comprise: means for performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; means for determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and means for indicating, towards the endpoint terminal, the determined preconfigured handover variant.

[0046] Further, according to at least some examples of embodiments, a method may comprise obtaining, at an endpoint terminal, a radio resource control, RRC, configuration; providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiating a handover to the target cell based on the received reconfiguration; wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

[0047] According to at least some examples of embodiments, the method may further comprise, if the initiated handover is completed, providing a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal.

[0048] According to at least some examples of embodiments, the method may further comprises obtaining the first RRC configuration when the endpoint terminal is caused to establish or resume an RRC connection.

[0049] Furthermore, according to various examples of embodiments, a method may comprise receiving, at a first access network entity or function and from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting from among the cells one cell as a target cell for the endpoint terminal to handover; generating, at the first access network entity or function, a reconfiguration in relation to the target cell; and providing the generated reconfiguration to the endpoint terminal.

[0050] According to various examples of embodiments, the method may further comprise starting, at a first access network entity or function, a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the providing of the generated reconfiguration is performed; and releasing the endpoint terminal context after expiry of the started release timer. Furthermore, according to various examples of embodiments, a method may comprise receiving, at a second access network entity or function, a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the second access network entity or function, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the second access network entity or function.

[0051] According to various examples of embodiments, the method may further comprise receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

[0052] Moreover, according to various examples of embodiments, a method may comprise determining, at a first network entity or function managing endpoint terminal mobility, whether or not the first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the first network entity or function managing endpoint terminal mobility is not able to serve the endpoint terminal, selecting a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and requesting network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0053] According to various examples of embodiments, the method may further comprise receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

[0054] In addition, according to various examples of embodiments, a method may comprise receiving, at a second network entity or function managing endpoint terminal mobility, a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the second network entity or function managing endpoint terminal mobility and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; providing, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; receiving a response indicative of the requested PDU session update and the requested SM context; and based on the received response, providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0055] Moreover, according to various examples of embodiments, a method may comprise providing, at an endpoint terminal, a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; based on the measurement report, receiving a redirection message indicating the endpoint terminal to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and switching to the target cell based on the received redirection message.

[0056] According to at least some examples of embodiments, the method may further comprise initiating a radio resource control, RRC, connection re-establishment procedure at the target cell. According to various examples of embodiments, the switching to the target cell may comprise maintaining a connected state, RRC_CONNECTED / CM-CONNECTED.

[0057] Furthermore, according to various examples of embodiments, a method may comprise receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting from among the cells one cell as a target cell for the endpoint terminal to switch to; and providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0058] According to various examples of embodiments, the providing may further comprise at least one of indicating a physical cell ID of the target cell, indicating a target carrier frequency related to the target cell, or indicating physical cell ID and system information of the target cell; and / or the providing may further comprise at least one of, on signalling to indicate the target cell to, reuse RRC release, or provide a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0059] Further, according to various examples of embodiments, a method may comprise participating, at a second access network entity or function, in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the second access network entity or function; retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, provide an RRC connection re-establishment to the endpoint terminal.

[0060] According to various examples of embodiments, if the retrieval of the endpoint terminal context fails, the providing of the RRC connection re-establishment may further comprise establishing an RRC connection from scratch (e.g., anew, de novo, once again, etc.) and providing the RRC connection established from scratch (e.g., anew, de novo, once again, etc.) to the endpoint terminal.

[0061] Furthermore, according to various examples of embodiments, a method may comprise determining, at an endpoint terminal, whether or not to perform a handover from a serving cell of the endpoint terminal and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell; and switching to the second cell.

[0062] According to various examples of embodiments, the determining may be based on obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or the selecting may comprise increasing a serving quality in relation to the serving quality of the serving cell.

[0063] Furthermore, according to various examples of embodiments, a method may comprise establishing, resuming or reconfiguring, at an endpoint terminal, a radio resource control, RRC, connection; and receiving, from a first access network entity or function associated with the endpoint terminal, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0064] Further, according to various examples of embodiments, a method may comprise performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection, determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and indicating, towards the endpoint terminal, the determined preconfigured handover variant.

[0065] Furthermore, according to various examples of embodiments, there may be provided a computer program product for a computer, including software code portions for performing any of the above-outlined methods (or portions thereof), when said product is run on the computer.

[0066] According to at least some examples of embodiments, the computer program product may include a computer-readable medium on which said software code portions are stored, and / or the computer program product may be directly loadable into the internal memory of the computer and / or transmittable via a network by means of at least one of upload, download or push procedures.

[0067] Any one of the aspects mentioned according to the claims may facilitate a baseline mobility procedure, and more specifically (but not exclusively) an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G); thereby providing at least part of the aforementioned advantages and improvements.

[0068] Further advantages may become apparent to a person skilled in the art in view of the following.

[0069] Brief Description of the Drawings

[0070] Some examples of embodiments of the subject disclosure are described below, by way of illustrative and non-limiting example only, with reference to the accompanying drawings, in which:

[0071] FIG. 1 (including part 1 of 2 and part 2 of 2) shows a high level comparison between an example handover (HO) and an enhanced (e.g., simplified) HO (e.g., for 6G) according to various examples of embodiments of the subject disclosure;

[0072] FIG. 2 (including part 1 of 2 and part 2 of 2) shows an overall procedure of baseline handover w / o NW preparation with Access and Mobility Management Function (AMF) and / or User Plane Function (UPF) relocation according to various examples of embodiments of the subject disclosure; FIG. 3 (including part 1 of 2 and part 2 of 2) shows an overall procedure of baseline handover via NW initiated redirection, with AMF and / or UPF relocation, according to various examples of embodiments of the subject disclosure;

[0073] FIG. 4 shows a fallback procedure when baseline handover via NW initiated redirection fails according to various examples of embodiments of the subject disclosure;

[0074] FIG. 5 (including part 1 of 2 and part 2 of 2) shows an overall procedure of baseline handover via user equipment (UE) initiated redirection, with AMF and / or UPF relocation, according to various examples of embodiments of the subject disclosure;

[0075] FIG. 6 shows a fallback procedure when baseline handover via UE initiated redirection fails according to various examples of embodiments of the subject disclosure;

[0076] FIG. 7 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0077] FIG. 8 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0078] FIG. 9 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0079] FIG. 10 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0080] FIG. 11 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0081] FIG. 12 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0082] FIG. 13 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure; FIG. 14 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0083] FIG. 15 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0084] FIG. 16 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0085] FIG. 17 shows a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure;

[0086] FIG. 18 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0087] FIG. 19 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0088] FIG. 20 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0089] FIG. 21 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0090] FIG. 22 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0091] FIG. 23 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0092] FIG. 24 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure; FIG. 25 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0093] FIG. 26 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure;

[0094] FIG. 27 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure; and

[0095] FIG. 28 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0096] Detailed Description

[0097] In general, two or more end points involved in a communication therebetween may be implemented as a particular type of end point (e.g. a communication station or entity or function, such as a terminal device, user equipment (UE), or other communication network element, a database, a server, host, etc.), or as one or more network elements or functions (e.g. virtualized network functions), such as communication network control elements or functions, for example access network elements like access points (APs), radio base stations (BSs), relay stations, eNBs, gNBs etc., and core network elements or functions, for example control nodes, support nodes, service nodes, gateways, user plane functions, access and mobility functions, etc. These end points may belong to a single communication network system, different communication network systems, or a combination of at least one same communication network system and at least one different communication network system.

[0098] In the following, various examples of embodiments will be described using, as an example of a communication network to which examples of embodiments may be applied, a communication network architecture based on 3GPP standards for a communication network, such as a 5G / NR, without restricting the examples of embodiments to such an architecture. It, however, would be apparent to a person skilled in the art that the examples of embodiments may also be applied to other kinds of communication networks like 4G and / or LTE (and even 6G and higher) where mobile communication principles are integrated, e.g. Wi-Fi, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra- wideband (UWB) technology, mobile ad-hoc networks (MANETs), wired access, etc. Furthermore, without loss of generality, the description of some examples of embodiments is related to a mobile communication network, but the subject disclosure can be extended and applied to any other type of communication network, such as a wired communication network or datacenter networking.

[0099] Any examples of embodiments described in the subject disclosure are to be understood only as non-limiting and illustrative in nature. Although portions of the subject disclosure may refer to the expressions “an”, “one”, or “some” example(s) of embodiment(s) in several specific locations, this does not necessarily mean that each such reference is related to the same example(s) of embodiment(s), or that the described feature only applies to a single example of an embodiment. Individual features from different examples of embodiments may also be combined to provide other examples of embodiments. Furthermore, terms like “comprising” and “including” should be understood as not limiting the described examples of embodiments to consist of only those features that have been mentioned; such examples of embodiments can also contain features, structures, units, modules etc. that have not been specifically mentioned.

[0100] A simplified system architecture of a (tele)communication network including a mobile communication system, where some examples of embodiments, are applicable may include an architecture of one or more communication networks. The one or more communication networks may include wireless access network subsystem(s) and core network(s). Such an architecture may include one or more communication network control elements or functions, access network elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station (BS), an access point (AP), a NodeB (NB), an eNB or a gNB, a distributed ora centralized unit (CU), which controls a respective coverage area or cell(s) and with which one or more communication stations such as communication elements or functions, like user devices (e.g. customer devices), mobile devices, or terminal devices, like a UE, or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a station, an element, a function or an application configured to conduct a communication, such as a UE, an entity or function usable in a machine-to-machine communication architecture, or attached as a separate element to such an element, function or application capable of conducting a communication, or the like, are configured to communicate via one or more channels via one or more communication beams for transmitting several types of data in a plurality of access domains. Furthermore, (core) network elements or network functions ((core) network control elements or network functions, (core) network management elements or network functions), such as gateway network elements / functions, mobility management entities, a mobile switching center, servers, databases and the like may be included.

[0101] Functions and interconnections of the described elements and functions, which also depend on the actual network type, are apparent to those skilled in the art and may be described in corresponding specifications, so that a description thereof is omitted herein. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication endpoint, a communication network control element, such as a server, a gateway, a radio network controller, and other elements of the same or other communication networks besides those described in detail herein below.

[0102] It should be appreciated that according to some examples of embodiments, a so- called “liquid” or flexible network concept may be implemented where the operations and functionalities of a network element, a network function, or of another entity of the network, may be performed in different entities or functions, such as in a node, host or server, in a flexible manner. Thus, a “division of labor” between involved network elements, functions or entities may vary case by case.

[0103] The subject disclosure, in some examples of embodiments, relates to a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g., for 6G).

[0104] In the first release of LTE (Rel-8) and NR (Rel-15), handover procedures were introduced, which is mandatory support for UE and so regarded as the baseline mobility management for UE in the connected mode (RRC_CONNECTED). FIG. 9.2.3.2.1-1 from 3GPP TS 38.300 shows the baseline handover procedures for NR without AMF / UPF relocation, which is the same as for LTE in Rel-8. After the first release of LTE and NR, mobility features were continuously evolved and increased as optional support for UE. For 6G, it is likewise expected that the baseline handover mechanism is introduced as mandatory for UE in the first release of specifications.

[0105] The baseline mobility for NR is designed to avoid data loss while UE is handed over to a target gNB. This can be achieved by enabling (or otherwise facilitating) user plane data forwarding between the source gNB and target gNB. Packet reordering is also supported to ensure the packet delivery in sequence. For this to work, the source and target gNBs need to prepare for UE to perform handover in advance as illustrated in FIG. 9.2.3.2.1-1 from 3GPP TS 38.300. During the handover preparation, the source gNB checks if the target gNB can accept in-coming handover for UE. After the target gNB is determined with acceptance of the target gNB, handover is executed. During handover, AMF and / or UPF can also be relocated, e.g. due to load balancing, network topological coverage of AMF / UPF. AMF / UPF relocation is prepared in advance of handover and executed during handover, as illustrated in FIG. 4.9.1.3.2-1 from 3GPP TS 23.502 and FIG. 4.9.1.3.3-1 from 3GPP TS 23.502.

[0106] Whilst the similar handover scheme could be supported for 6G, it might not be necessary for all UEs to be supported as the baseline. Owing to wide range mobility requirements expected for new use cases for 6G, not all of the use cases require loss less mobility support. Recently, applications have become tolerant to data loss and can recover it by their own. Furthermore, there exists a case that a handover occurs while there is no data transaction between UE and gNB. From the viewpoints thereof, the current NR baseline handover mechanism would serve more than what is required for all potential 6G use cases as minimum.

[0107] Even for the current NR baseline handover (as well as LTE), user plane data forwarding is optional for the network. The network can decide not to perform user plane data forwarding, resulting in lossy handover. Nevertheless, handover preparation is still required, and the source gNB requires the handover permission from the target gNB. For NR and LTE, a conditional handover is defined by which UE itself executes handover when execution condition(s) are met. Although UE can execute handover, the handover preparation is required beforehand for all potential target gNB(s), as illustrated in FIG. 9.2.3.4.2-1 from 3GPP TS 38.300. User plane data forwarding is supported as optional. The conditional handover is aimed at enhancing mobility robustness, and so not intended for simplifying the baseline handover procedure.

[0108] 3GPP has been working on standardizing a solution to switch a cell in lower layers, e.g. Physical layer or MAC layer, in Release 18, which is so called L1 / L2 based inter cell mobility as in RP-223520. The solution is to perform handover via lower layers, rather than RRC and NAS as in the baseline handover. It is aimed at reducing mobility latency, and so not intended for simplification.

[0109] However, with regard to the issues identified and / or potentially foreseeable as outlined above in detail, there is room for improvement. Therefore, various examples of embodiments described in the subject disclosure provide certain advantages, for example in the form of one or more improvements that are either explicitly described herein or those otherwise apparent to a person skilled in the art from the subject disclosure.

[0110] At least some example embodiments may pertain to a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G) as indicated above.

[0111] To address wide range mobility requirements, e.g. for 6G, the baseline mobility supported for all 6G capable UE can be simplified without the preparation phase and data forwarding, as illustrated in FIG. 1 (including part 1 of 2 and part 2 of 2, to be connected at A’-A” and B’-B”). Multiple solution variants can be considered as to how the baseline handover can be simplified without the handover preparation. Details on each solution variant are described in the following according to various examples of embodiments of the subject disclosure.

[0112] For example, according to various examples of embodiments of the subject disclosure, the following three variants are considered, by way of non-limiting and illustrative example, for a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline handover (e.g. for 6G). It is noted that throughout this document, Node B for 6G is denoted as xNB.

[0113] Variant 1 : the NR baseline handover is executed without NW preparation.

[0114] In an example NR (baseline) handover, the target gNB generates a HO command (i.e. RRCReconfiguration) to be delivered to UE. The HO command comprises the UE configuration used at the target gNB. In contrast, Variant 1 enables (or otherwise facilitates) the source xNB to generate the HO command and send it to UE. Unlike the example NR handover, AMF and / or (intermediate) UPF can be relocated, upon the handover between the UE and the target xNB being completed. The overall procedure is illustrated in FIG. 2 (including part 1 of 2 and part 2 of 2, to be connected at A’-A” and B’-B”), in conjunction with the following description.

[0115] 0. UE 210 obtains common / dedicated RRC configurations applicable to all cells / TRPs beforehand, e.g. when UE 210 establishes or resumes an RRC connection.

[0116] 1. Upon fulfilling the condition (e.g. quality of one neighbour cell at least is better than that of the serving cell with a pre-configured threshold, the quality of the serving cell becomes lower than a pre-configured value or in addition, the quality of at least one neighbor cell becomes better than a pre-configured value), UE 210 sends a measurement report to the source xNB 220, which includes measurement results of one or more neighbour cells.

[0117] 2. Based on the measurement results obtained from the UE 210 and / or any other information obtained in the network, the source xNB 220 selects a target cell for UE 210 to handover. The source xNB 220 generates and sends a HO command (i.e. RRCReconfiguration) applied for the target cell. The source xNB 220 starts a release timer of UE context.

[0118] 3. In accordance with the received HO command, UE 210 initiates handover to the target cell indicated in the HO command.

[0119] 4. UE 210 switches to a target cell as indicated in the HO command.

[0120] 5. UE 210 obtains synchronization (i.e., DL radio frame timing) and UL timing alignment (e.g., via random access procedure). 1

[0121] 6. UE 210 sends a HO complete (RRCRecnofigurationComplete) to target xNB 230. The HO Complete message includes an AMF identifier, indicating which AMF (i.e. source AMF 240) is currently selected for the UE 210.

[0122] 7. The target gNB 230 sends a request (e.g., path switch request) for the source AMF 240 to switch the user plane data path towards the target xNB 230.

[0123] 8. When the source AMF 240 cannot serve the UE 210 anymore, e.g., the target xNB is not managed ty the source AMF, source AMF is to perform load balancing to offload UE mobility management to the other AMF, etc., the source AMF 240 selects the target AMF 250.

[0124] 9. The source AMF 240 requests AMF relocation towards the selected target AMF 250.

[0125] 10. The target AMF 250 requests protocol data unit (PDU) session update and Session Management (SM) context towards Session Management Function (SMF) 260.

[0126] 11. If needed, SMF 260 performs (intermediate) UPF selection, e.g., to shorten user plane latency by selecting a UPF close to the target xNB.

[0127] 12. SMF 260 interacts with the selected target (intermediate) UPF 280 to update the session for involving the target (intermediate) UPF 280.

[0128] 13. SMF 260 interacts with the source UPF 270 to update the session for removing the source (intermediate) UPF 270.

[0129] 14. SMF 260 interacts with the UPF (PSA) 290 to update the session for modifying the (intermediate) UPF.

[0130] 15. Upon completion of modifying the session to relocate (intermediate) UPF, SMF 260 responds with a PDU session update to the target AMF 250.

[0131] 16. The target AMF 250 responds with an AMF relocation request from the source AMF 240.

[0132] 17. The source AMF 240 responds to the user plane data path switch request from the target xNB 230 and informs of the target AMF 250 as a new AMF to serve the UE 210.

[0133] 18. Upon the timer expiry, the source xNB 220 releases the stored UE context.

[0134] 19. Mobility registration update is performed, if required, e.g. TA update, temporary UE identity renewal due to AMF relocation.

[0135] Some advantages of Variant 1 over the example NR handover may include the following:

[0136] • the source xNB can execute handover without negotiating neighbour xNBs,

[0137] • latency incurred by the HO preparation phase can be reduced, signaling for handover can be reduced in the network side, and / or peer-to-peer connection between xNBs (like Xn in NR) is not required.

[0138] Variant 2: NW initiated redirection

[0139] Unlike Variant 1 , the source xNB in Variant 2 neither generates a HO command nor sends it / such to the UE. Rather, it may be said that the source xNB merely requests the UE to switch to a target cell. The UE initiates an RRC connection re-establishment at the target cell and obtains a new RRC configuration over the target cell during the RRC connection re-establishment procedure. Upon the RRC connection reestablishment, AMF and / or (intermediate) UPF can be relocated, similar to Variant 1. The overall procedure is illustrated in FIG. 3 (including part 1 of 2 and part 2 of 2, to be connected at A’-A” and B’-B”), in conjunction with the following description.

[0140] 1. Upon fulfilling the condition (e.g. quality of one neighbour cell at least is better than that of the serving cell with a pre-configured threshold, the quality of the serving cell becomes lower than a pre-configured value or in addition, the quality of at least one neighbor cell becomes better than a pre-configured value), UE 310 sends a measurement report to the source xNB 320, which includes measurement results of one or more neighbour cells.

[0141] 2. Based on the measurement results obtained from the UE 310 and / or any other information obtained in the network, the source xNB 320 selects a target cell for UE 310 to handover. The source xNB 320 indicates the UE 310 is to switch to the target cell. On how to indicate “the target cell”, the following options can be implemented: a. indicate Physical cell ID of the target cell. b. indicate the target carrier frequency (in this case, UE 310 performs cell selection over the indicated carrier frequency). c. indicate Physical cell ID and system information of the target cell.

[0142] On the signalling to indicate the target cell, the following options can be implemented: a. reuse RRC release (to be defined for RRC connection release). b. (provide) a new message specific to redirect the UE not including UE RRC configuration (unlike Variant 1). UE 310 switches to a target cell as indicated in the redirection message. Unlike the existing RRC release procedure, the UE 310 does not go to idle / inactive, but keeps the connected state (RRC_CONNECTED / CM-CONNECTED). UE 310 obtains synchronization (i.e., DL radio frame timing) and UL timing alignment (e.g. via random access procedure). UE 310 initiates an RRC connection re-establishment on the target cell. It shall be noted that although the RRC connection re-establishment is a procedure supported for NR / LTE, the procedure is currently not used upon RRC release ora new message to redirect. Hence, according to various examples of embodiments of the subject disclosure, a new condition for UE to initiate the RRC connection re-establishment is defined, such as: a. initiation of RRC connection re-establishment is indicated (e.g., implicitly, explicitly, or otherwise) in the RRC release message; or b. Physical cell ID of the target cell is indicated in the RRC release message; or c. indicate Physical cell ID and system information of the target cell is indicated in the RRC release message; or d. UE switched to a target cell upon receiving a new message specific to redirect the UE; or The target xNB 330 retrieves the UE context, including UE radio capability from the source xNB 320. It shall be noted that the Retrieve UE Context procedure is supported by NR / LTE (over Xn / X2), which is used for RRC connection resume. On the other hand, the specification is currently not intended to use the Retrieve UE Context procedure for RRC connection re-establishment, as disclosed herewith according to various examples of embodiments of the subject disclosure. A new condition for the xNB to initiate the Retrieve UE Context procedure is defined such that xNB receives an RRC connection re-establishment request from the UE. The target xNB 330 acquires the UE radio capability, which is a part of the UE context retrieved from the source xNB 320. The target xNB 330 accepts the connection re-establishment request from the UE 310 and send the RRC connection re-establishment to the UE 310. The message can include the UE RRC configuration applied for the target cell, which is built based on the UE radio capability retrieved from the source xNB 320. The UE 310 sends the re-establishment complete message to the target xNB 330. 10. Optionally, the target xNB 330 can reconfigure the UE RRC configuration, after the connection re-establishment, especially if it is not configured in 8.

[0143] 11. 11 to 22 are the same as 7 to 19 as outlined above with reference to Variant 1 and FIG. 2.

[0144] According to various examples of embodiments of the subject disclosure and with reference to FIG. 4, there may be a case that the target xNB 430 fails to retrieve the UE context from the source xNB 420 (e.g. there is no peer-to-peer connection between the two xNBs 420, 430 or the retrieve UE context procedure is not supported, etc.). For this case, the target xNB 430 establishes an RRC connection from scratch (e.g., anew, de novo, once again, etc.). The UE 410 performs initial registration as illustrated in FIG: 4.

[0145] Some advantages of Variant 2 over the example NR handover may include the folllowing:

[0146] • the source xNB can execute handover without negotiating neighbour xNBs,

[0147] • latency incurred by the HO preparation phase can be reduced, and / or

[0148] • signaling for handover can be reduced in the network side.

[0149] Variant 3: UE initiated redirection

[0150] In contrast to Variant 2, in Variant 3 the UE itself switches to a target cell autonomously, rather than the NW initiated approach. Based on the measurement results of the serving and neighbour cells obtained by itself, the UE decides the target cell. The overall procedure is illustrated in FIG. 5 (including part 1 of 2 and part 2 of 2, to be connected at A’-A” and B’-B”), in conjunction with the following description.

[0151] 1 . The UE 510 decides if handover from the serving cell is performed and to which cell the handover is attempted.

[0152] 2. 2 to 21 are the same as 3 to 22 as outlined above with reference to Variant 2 and FIG. 3.

[0153] With reference to FIG. 6, same as in Variant 2, if the UE context retrieval is failed in Variant s, the target xNB 630 establishes an RRC connection from scratch (e.g., anew, de novo, once again, etc.). The UE 610 performs initial registration as illustrated in FIG.

[0154] 6.

[0155] Some advantages ofVariant 3 overthe example NR handover may include the following:

[0156] • the source xNB does not have to involve with handover execution until the UE context retrieval is requested,

[0157] • latency incurred by the HO preparation phase can be reduced,

[0158] • signaling for handover can be reduced in the network side, and / or

[0159] • UE does not have to wait for NW indication to execute handover.

[0160] With regard to all above-outlined variants, i.e. Variant 1 , Variant 2 and Variant 3, supposing that a mobility capable UE supports all the three variants, the network should be able to configure to UE as to which variant is used for handover. This can be supported such that xNB indicates which variant is used to UE (e.g., explicitly, such as when UE establishes or resumes an RRC connection to the network).

[0161] Further, suppose that the UE supports all three variants (i.e. Variant 1 , Variant 2 and Variant 3), the network may select to use Varian 1 , when the network prepares the common RRC configuration applicable to all radio cells, TRPs in the access network. In contrast, Variants 2 and 3 may be selected when the common RRC configuration is not provided by the network. Variant 3 may experience longer latency to perform handover as it relies on UE autonomous behavior and hinges on UE processing and implementation performance. Variants 1 and 2 are comparable for some use cases, or Variant 1 may be better than Variant 2 for some use cases in terms of the handover latency. If the outlined variants are configurable, the network can select the variant applied for each UE, according to e.g. the required QoS, network deployment scenarios, etc.

[0162] In the following, further examples of embodiments are described in relation to the aforementioned methods and / or apparatuses.

[0163] Referring now to FIG. 7, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure. In particular, according to FIG. 7, in S710, the method comprises obtaining, at an endpoint terminal, a radio resource control, RRC, configuration. The RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of a first access network entity or function or a second access network entity or function associated with a target cell.

[0164] S710 may represent at least part of 0 as shown in FIG. 2.

[0165] Further, in S720, the method comprises providing a measurement report to the first access network entity or function (e.g. Source xNB), the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function.

[0166] S720 may represent at least part of 1 as shown in FIG. 2.

[0167] Additionally, in S730, the method comprises receiving a reconfiguration (e.g. handover command) applied for the target cell, wherein the target cell is one cell of the at least one neighbour cell.

[0168] S730 may represent at least part of 2 as shown in FIG 2.

[0169] Further, in S740, the method comprises initiating a handover to the target cell based on the received reconfiguration.

[0170] S740 may represent at least part of 3 as shown in FIG 2.

[0171] Moreover, according to at least some examples of embodiments, if the initiated handover is completed, the method may further comprise providing a message (e.g. HO complete) to the second access network entity or function (e.g. Target xNB), wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility (e.g. AMF identifier) indicating a first network entity or function managing endpoint terminal mobility (e.g. Source AMF) selected for the endpoint terminal. Such providing may represent at least part of 6 as shown in FIG 2.

[0172] Moreover, according to at least some examples of embodiments, wherein the method may further comprise obtaining the first RRC configuration when the endpoint terminal is caused to establish or resume an RRC connection.

[0173] Furthermore, according to various examples of embodiments, the method may further comprise obtaining the measurement results by measuring the service quality of the at least one neighbour cell and the service quality of the serving cell.

[0174] Referring now to FIG. 8, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0175] In particular, according to FIG. 8, in S810, the method comprises receiving, at a first access network entity or function and from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell which serves the endpoint terminal and at least one neighbour cell of the serving cell.

[0176] S810 may represent at least part of 1 as shown in FIG. 2.

[0177] Further, in S820, the method comprises, based on the measurement report, selecting from among the cells one cell as a target cell for the endpoint terminal to handover.

[0178] S820 may represent at least part of 2 as shown in FIG. 2.

[0179] Further, in S830, the method comprises generating, at the first access network entity or function, a reconfiguration (e.g. handover command) in relation to the target cell.

[0180] S830 may represent at least part of 2 as shown in FIG. 2. Furthermore, in S840, the method comprises providing the generated reconfiguration to the endpoint terminal.

[0181] S840 may represent at least part of 2 as shown in FIG. 2.

[0182] Moreover, according to at least some examples of embodiments, the method may further comprise starting, at a first access network entity or function (e.g. Source xNB) a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the providing of the generated reconfiguration is performed; and releasing the endpoint terminal context after expiry of the started release timer.

[0183] Such starting may represent at least part of 2 as shown in FIG. 2, wherein such releasing may represent at least part of 18 as shown in FIG. 2

[0184] Referring now to FIG. 9, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0185] In particular, according to FIG. 9, in S910, the method comprises receiving, at a second access network entity or function (e.g. Target xNB), a message (e.g. HO complete) from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function (e.g. Source xNB) and wherein the second cell is associated with the second access network entity or function, the message comprising an ID of a network entity or function managing endpoint terminal mobility (e.g. AMF identifier) indicating a first network entity or function managing endpoint terminal mobility (e.g. Source AMF) selected for the endpoint terminal.

[0186] S910 may represent at least part of 6 as shown in FIG. 2.

[0187] Further, in S920, the method comprises providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the second access network entity or function.

[0188] S920 may represent at least part of 7 as shown in FIG. 2. Moreover, according to at least some examples of embodiments, the method may further comprise receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility (e.g. Target AMF) has been selected to serve the endpoint terminal.

[0189] Such receiving may represent at least part of 17 as shown in FIG. 2.

[0190] Referring now to FIG. 10, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0191] In particular, according to FIG. 10, in S1010, the method comprises determining, at a first network entity or function managing endpoint terminal mobility (e.g. Source AMF), whether or not the first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function (e.g. Source xNB) to a second cell associated with a second access network entity or function (e.g. Target xNB).

[0192] S1010 may represent at least part of 8 as shown in FIG. 2 and / or 12 as shown in FIG. 3.

[0193] Further, if determined in S1015 that the first network entity or function managing endpoint terminal mobility is not able to serve the endpoint terminal (NO in S1015), in S1020, the method comprises selecting a second network entity or function managing endpoint terminal mobility (e.g. Target AMF) to serve the endpoint terminal.

[0194] In addition, in S1030, the method comprises requesting network entity or function managing endpoint terminal mobility relocation (e.g. AMF relocation) towards the second network entity or function managing endpoint terminal mobility.

[0195] S1030 may represent at least part of 9 as shown in FIG. 2 and / or 13 as shown in

[0196] FIG. 3. Moreover, according to at least some examples of embodiments, the method may further comprises receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and, based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

[0197] Such receiving may represent at least part of 7 as shown in FIG. 2 and / or 11 as shown in FIG. 3, wherein such providing may represent at least part of 17 as shown in FIG. 2 and / or 21 as shown in FIG. 3

[0198] Referring now to FIG. 11 , there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0199] In particular, according to FIG. 11 , in S1110, the method comprises receiving, at a second network entity or function managing endpoint terminal mobility (e.g. Target AMF), a request for a network entity or function managing endpoint terminal mobility relocation (e.g. AMF relocation), the relocation from a first network entity or function managing endpoint terminal mobility (e.g. Source AMF) to the second network entity or function managing endpoint terminal mobility and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function (e.g. Source xNB) to a second cell associated with a second access network entity or function (e.g. Target xNB).

[0200] S1110 may represent at least part of 9 as shown in FIG. 2 and / or 13 as shown in FIG. 3.

[0201] Further, in S1120, the method comprises providing, towards a network session management entity or function (e.g. SMF), a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal. S1120 may represent at least part of 10 as shown in FIG. 2 and / or 14 as shown in FIG. 3.

[0202] In addition, in S1130, the method comprises receiving a response indicative of the requested PDU session update and the requested SM context.

[0203] S1130 may represent at least part of 15 as shown in FIG. 2 and / or 19 as shown in FIG. 3.

[0204] Further, in S1140, the method comprises, based on the received response, providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0205] S1140 may represent at least part of 16 as shown in FIG. 2 and / or 20 as shown in FIG. 3.

[0206] Referring now to FIG. 12, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0207] In particular, according to FIG. 12, in S1210, the method comprises providing, at an endpoint terminal, a measurement report to a first access network entity or function (e.g. Source xNB), the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell serves the endpoint terminal and is associated with the first access network entity or function.

[0208] S1210 may represent at least part of 1 as shown in FIG. 3.

[0209] Further, in S1220, the method comprises, based on the measurement report, receiving a redirection message indicating the endpoint terminal to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell.

[0210] S1220 may represent at least part of 2 as shown in FIG. 3. In addition, in S1230, the method comprises switching to the target cell based on the received redirection message.

[0211] S1230 may represent at least part of 3 as shown in FIG. 3.

[0212] Moreover, according to at least some examples of embodiments, the method may further comprise initiating a radio resource control, RRC, connection re-establishment procedure at the target cell.

[0213] Such initiating may represent at least part of 5 as shown in FIG. 3.

[0214] Further, according to at least some examples of embodiments, the switching to the target cell may comprise maintaining a connected state, RRC_CONNECTED / CM- CONNECTED.

[0215] Referring now to FIG. 13, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0216] In particular, according to FIG. 13, in S1310, the method comprises receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell which serves the endpoint terminal and at least one neighbour cell of the serving cell.

[0217] S1310 may represent at least part of 1 as shown in FIG. 3.

[0218] Further, in S1320, the method comprises, based on the measurement report, selecting from among the cells one cell as a target cell for the endpoint terminal to switch to.

[0219] S1320 may represent at least part of 2 as shown in FIG. 3. In addition, in S1330, the method comprises providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0220] S1330 may represent at least part of 2 as shown in FIG. 3.

[0221] Further, according to at least some examples of embodiments, the providing may further comprise at least one of indicating a physical cell ID of the target cell, indicating a target carrier frequency related to the target cell, or indicating physical cell ID and system information of the target cell; and / or the providing may further comprise at least one of, on signalling to indicate the target cell to, reuse RRC release, or provide a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0222] Referring now to FIG. 14, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0223] In particular, according to FIG. 14, in S1410, the method comprises participating, at a second access network entity or function (e.g. Target xNB), in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function (e.g. Source xNB) to a second cell associated with the second access network entity or function.

[0224] S1410 may represent at least part of 5 as shown in FIG. 3 and / or at least part of 5 as shown in FIG. 5.

[0225] Further, in S1420, the method comprises retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability.

[0226] S1420 may represent at least part of 6 as shown in FIG. 3 and / or at least part of

[0227] 6 as shown in FIG. 5. In addition, in S1430, the method comprises, based on the retrieved endpoint terminal context, provide an RRC connection re-establishment to the endpoint terminal.

[0228] S1430 may represent at least part of 8 as shown in FIG. 3 and / or at least part of 7 as shown in FIG. 5.

[0229] Further, according to at least some examples of embodiments, if the retrieval of the endpoint terminal context fails, the providing of the RRC connection re-establishment may further comprise establishing an RRC connection from scratch (e.g., anew, de novo, once again, etc.) and providing the RRC connection established from scratch (e.g., anew, de novo, once again, etc.) to the endpoint terminal.

[0230] Such establishing may represent at least part of 7 as shown in FIG. 4 and / or at least part of 6 as shown in FIG. 6.

[0231] Referring now to FIG. 15, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0232] In particular, according to FIG. 15, in S1510, the method comprises determining, at an endpoint terminal, whether or not to perform a handover from a serving cell, which serves the endpoint terminal and which is associated with a first access network entity or function (e.g. Source xNB), to a second cell associated with a second access network entity or function (e.g. Target xNB),

[0233] S1510 may represent at least part of 1 as shown in FIG. 5.

[0234] Further, if it is determined in S1515 to perform the handover (YES in S1515), the method further comprises in S1520, the method comprises selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell.

[0235] In addition, in S1530, the method comprises switching to the second cell.

[0236] S1530 may represent at least part of 2 as shown in FIG. 5. Further, according to at least some examples of embodiments, the determining may be based on obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or the selecting may comprise increasing a serving quality in relation to the serving quality of the serving cell.

[0237] Referring now to FIG. 16, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure.

[0238] In particular, according to FIG. 16, in S1610, the method comprises establishing, resuming or reconfiguring, at an endpoint terminal, a radio resource control, RRC, connection.

[0239] In addition, in S1620, the method comprises receiving, from at first access network entity or function associated with the endpoint terminal, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0240] It shall be noted that these several preconfigured handover variants may comprise the variants Variant 1 , Variant 2 and Variant 3 as outlined above with reference to FIGS. 2 to 15. Moreover, the endpoint terminal may be such UE / endpoint terminal as outlined above with reference to FIGS. 2 to 6, 7, 12 or 15, wherein the endpoint terminal may, first, perform the example method as outlined with reference to FIG. 16 and may then, in case the endpoint terminal may perform a handover process, perform the example method as outlined with reference to FIGS. 2 to 6, 7, 12 or 15. In addition, the first access network entity or function according to FIG. 16 may be such Source xNB / first access network entity or function as outlined above with reference to FIGS. 2 to 6, 8 or 13.

[0241] Referring now to FIG. 17, there is shown a flowchart illustrating an example method according to various examples of embodiments of the subject disclosure. In particular, according to FIG. 17, in S1710, the method comprises performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection.

[0242] In addition, in S1720, the method comprises determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process.

[0243] Further, in S1730, the method comprises indicating, towards the endpoint terminal, the determined preconfigured handover variant.

[0244] It shall be noted that these several preconfigured handover variants may comprise the variants Variant 1 , Variant 2 and Variant 3 as outlined above with reference to FIGS. 2 to 15. In addition, the method may be applied at an apparatus for a first access network entity or function. Execution, by at least one processor of the apparatus, of instructions stored by at least one memory of the apparatus, may cause the apparatus to implement, at least in part, functionality of the first access network entity or function. Such first access network entity or function according to FIG. 17 may be such Source xNB / first access network entity or function as outlined above with reference to FIGS. 2 to 6, 8 or 13, wherein the first access network entity or function may, first, perform the example method as outlined with reference to FIG. 17 and may then, in case the endpoint terminal may perform a handover process, perform the example method as outlined with reference to FIGS. 2 to 6, 8 or 13. Moreover, the endpoint terminal may be such UE / endpoint terminal as outlined above with reference to FIGS. 2 to 6, 7, 12 or 15.

[0245] Referring now to FIG. 18, FIG. 18 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0246] Specifically, FIG. 18 shows a block diagram illustrating an apparatus 1800, which may represent an endpoint terminal (e.g. UE) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to an endpoint terminal, the endpoint terminal may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0247] The apparatus 1800 shown in FIG. 18 may include a processing circuitry, a processing function, a control unit or a processor 1810, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 1810 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 1831 and 1832 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 1810. The I / O units 1831 and 1832 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 1820 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 1810 and / or as a working storage of the processor or processing function 1810. It is to be noted that the memory 1820 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0248] The processor or processing function 1810 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 1810 includes one or more of the following sub-portions. Sub-portion 1811 is an obtaining portion, which is usable as a portion for obtaining a first RRC configuration. The portion 1811 may be configured to perform processing according to S710 of FIG. 7. Further, sub-portion 1812 is a providing portion, which is usable as a portion for providing a measurement report. The portion 1812 may be configured to perform processing according to S720 of FIG. 7. Moreover, sub-portion 1813 is a receiving portion, which is usable as a portion for receiving a reconfiguration. The portion 1813 may be configured to perform processing according to S730 of FIG. 7. Furthermore, sub-portion 1814 is an initiating portion, which is usable as a portion for initiating a handover. The portion 1814 may be configured to perform processing according to S740 of FIG. 7.

[0249] Referring now to FIG. 19, FIG. 19 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0250] Specifically, FIG. 19 shows a block diagram illustrating an apparatus 1900, which may represent a first access network entity or function (e.g. Source xNB) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a first access network entity or function, the first access network entity or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0251] The apparatus 1900 shown in FIG. 19 may include a processing circuitry, a processing function, a control unit or a processor 1910, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 1910 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 1931 and 1932 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 1910. The I / O units 1931 and 1932 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 1920 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 1910 and / or as a working storage of the processor or processing function 1910. It is to be noted that the memory 1920 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0252] The processor or processing function 1910 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 1910 includes one or more of the following sub-portions. Sub-portion 1911 is a receiving portion, which is usable as a portion for receiving a measurement report. The portion 1911 may be configured to perform processing according to S810 of FIG. 8. Further, sub-portion 1912 is a selecting portion, which is usable as a portion for selecting a target cell. The portion 1912 may be configured to perform processing according to S820 of FIG. 8. Moreover, sub-portion 1913 is a generating portion, which is usable as a portion for generating a reconfiguration. The portion 1913 may be configured to perform processing according to S830 of FIG. 8. Furthermore, sub-portion 1914 is a providing portion, which is usable as a portion for providing the generated reconfiguration. The portion 1914 may be configured to perform processing according to S840 of FIG. 8.

[0253] Referring now to FIG. 20, FIG. 20 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0254] Specifically, FIG. 20 shows a block diagram illustrating an apparatus 2000, which may represent a second access network entity or function (e.g. Target xNB) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a second access network entity or function, the second access network entity or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0255] The apparatus 2000 shown in FIG. 20 may include a processing circuitry, a processing function, a control unit or a processor 2010, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2010 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2031 and 2032 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2010. The I / O units 2031 and 2032 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2020 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2010 and / or as a working storage of the processor or processing function 2010. It is to be noted that the memory 2020 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0256] The processor or processing function 2010 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2010 includes one or more of the following sub-portions. Sub-portion 2011 is a receiving portion, which is usable as a portion for receiving a message. The portion 2011 may be configured to perform processing according to S910 of FIG. 9. Further, sub-portion 2012 is a providing portion, which is usable as a portion for providing a request. The portion 2012 may be configured to perform processing according to S920 of FIG. 9.

[0257] Referring now to FIG. 21 , FIG. 21 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0258] Specifically, FIG. 21 shows a block diagram illustrating an apparatus 2100, which may represent a first network entity or function managing endpoint terminal mobility (e.g. Source AMF) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a first network entity or function managing endpoint terminal mobility, the first network entity or function managing endpoint terminal mobility may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0259] The apparatus 2100 shown in FIG. 21 may include a processing circuitry, a processing function, a control unit or a processor 2110, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2110 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2131 and 2132 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2110. The I / O units 2131 and 2132 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2120 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2110 and / or as a working storage of the processor or processing function 2110. It is to be noted that the memory 2120 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0260] The processor or processing function 2110 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2110 includes one or more of the following sub-portions. Sub-portion 2111 is a determining portion, which is usable as a portion for determining whether service can be provided. The portion 2111 may be configured to perform processing according to S1010 of FIG. 10. Further, sub-portion 2112 is a selecting portion, which is usable as a portion for selecting a second network entity or function managing endpoint terminal mobility. The portion 2112 may be configured to perform processing according to S1020 of FIG. 10. Moreover, sub-portion 2113 is a requesting portion, which is usable as a portion for requesting network entity or function managing endpoint terminal mobility relocation. The portion 2113 may be configured to perform processing according to S1030 of FIG. 10.

[0261] Referring now to FIG. 22, FIG. 22 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0262] Specifically, FIG. 22 shows a block diagram illustrating an apparatus 2200, which may represent a second network entity or function managing endpoint terminal mobility (e.g. Target AMF) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a second network entity or function managing endpoint terminal mobility, the second network entity or function managing endpoint terminal mobility may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0263] The apparatus 2200 shown in FIG. 22 may include a processing circuitry, a processing function, a control unit or a processor 2210, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2210 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2231 and 2232 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2210. The I / O units 2231 and 2232 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2220 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2210 and / or as a working storage of the processor or processing function 2210. It is to be noted that the memory 2220 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0264] The processor or processing function 2210 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2210 includes one or more of the following sub-portions. Sub-portion 2211 is a receiving portion, which is usable as a portion for receiving a relocation request. The portion 2211 may be configured to perform processing according to S1110 of FIG. 11. Further, sub-portion 2212 is a providing portion, which is usable as a portion for providing a request. The portion 2212 may be configured to perform processing according to S1120 of FIG. 11. Moreover, sub-portion 2213 is a receiving portion, which is usable as a portion for receiving a response. The portion 2213 may be configured to perform processing according to S1130 of FIG. 11. Furthermore, sub-portion 2214 is a providing portion, which is usable as a portion for providing an indication. The portion

[0265] 2214 may be configured to perform processing according to S1140 of FIG. 11.

[0266] Referring now to FIG. 23, FIG. 23 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0267] Specifically, FIG. 23 shows a block diagram illustrating an apparatus 2300, which may represent an endpoint terminal (e.g. UE) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to an endpoint terminal, the endpoint terminal may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0268] The apparatus 2300 shown in FIG. 23 may include a processing circuitry, a processing function, a control unit or a processor 2310, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2310 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2331 and 2332 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2310. The I / O units 2331 and 2332 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2321 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2310 and / or as a working storage of the processor or processing function 2310. It is to be noted that the memory 2320 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0269] The processor or processing function 2310 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2310 includes one or more of the following sub-portions. Sub-portion 2311 is a providing portion, which is usable as a portion for providing a measurement report. The portion 2311 may be configured to perform processing according to S1210 of FIG. 12. Further, sub-portion 2312 is a receiving portion, which is usable as a portion for receiving a redirection message. The portion 2312 may be configured to perform processing according to S1220 of FIG. 12. Moreover, sub-portion 2313 is a switching portion, which is usable as a portion for switching to a target cell. The portion 2313 may be configured to perform processing according to S1230 of FIG. 12.

[0270] Referring now to FIG. 24, FIG. 24 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0271] Specifically, FIG. 24 shows a block diagram illustrating an apparatus 2400, which may represent a first access network entity or function (e.g. Source xNB) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a first access network entity or function, the first access network entity or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0272] The apparatus 2400 shown in FIG. 24 may include a processing circuitry, a processing function, a control unit or a processor 2410, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified baseline mobility procedure (e.g. for 6G). The processor 2410 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2431 and 2432 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2410. The I / O units 2431 and 2432 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2422 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2410 and / or as a working storage of the processor or processing function 2410. It is to be noted that the memory 2420 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0273] The processor or processing function 2410 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2410 includes one or more of the following sub-portions. Sub-portion 2411 is a receiving portion, which is usable as a portion for receiving a measurement report. The portion 2411 may be configured to perform processing according to S1310 of FIG. 13. Further, sub-portion 2412 is a selecting portion, which is usable as a portion for selecting a target cell. The portion 2412 may be configured to perform processing according to S1320 of FIG. 13. Moreover, sub-portion 2413 is a providing portion, which is usable as a portion for providing a redirection message. The portion 2413 may be configured to perform processing according to S1330 of FIG. 13.

[0274] Referring now to FIG. 25, FIG. 25 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure. Specifically, FIG. 25 shows a block diagram illustrating an apparatus 2500, which may represent a second access network entity or function (e.g. Target xNB) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a second access network entity or function, the second access network entity or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0275] The apparatus 2500 shown in FIG. 25 may include a processing circuitry, a processing function, a control unit or a processor 2510, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2510 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2531 and 2532 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2510. The I / O units 2531 and 2532 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2522 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2510 and / or as a working storage of the processor or processing function 2510. It is to be noted that the memory 2520 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server. The processor or processing function 2510 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2510 includes one or more of the following sub-portions. Sub-portion

[0276] 2511 is a participating portion, which is usable as a portion for participating in an RRC connection re-establishment procedure. The portion 2511 may be configured to perform processing according to S1410 of FIG. 14. Further, sub-portion 2512 is a retrieving portion, which is usable as a portion for retrieving endpoint terminal context. The portion

[0277] 2512 may be configured to perform processing according to S1420 of FIG. 14. Moreover, sub-portion 2513 is a providing portion, which is usable as a portion for providing an RRC connection re-establishment. The portion 2513 may be configured to perform processing according to S1430 of FIG. 14.

[0278] Referring now to FIG. 26, FIG. 26 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0279] Specifically, FIG. 26 shows a block diagram illustrating an apparatus 2600, which may represent an endpoint terminal (e.g. UE) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to an endpoint terminal, the endpoint terminal may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0280] The apparatus 2600 shown in FIG. 26 may include a processing circuitry, a processing function, a control unit or a processor 2610, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2610 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2631 and 2632 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2610. The I / O units 2631 and 2632 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2622 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2610 and / or as a working storage of the processor or processing function 2610. It is to be noted that the memory 2620 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0281] The processor or processing function 2610 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2610 includes one or more of the following sub-portions. Sub-portion 2611 is a determining portion, which is usable as a portion for determining whether or not to perform a handover. The portion 2611 may be configured to perform processing according to S1510 of FIG. 15. Further, sub-portion 2612 is a selecting portion, which is usable as a portion for selecting a second cell. The portion 2612 may be configured to perform processing according to S1520 of FIG. 15. Moreover, sub-portion 2613 is a switching portion, which is usable as a portion for switching to the second cell. The portion 2613 may be configured to perform processing according to S1530 of FIG. 15.

[0282] Referring now to FIG. 27, FIG. 27 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0283] Specifically, FIG. 27 shows a block diagram illustrating an apparatus 2700, which may represent an endpoint terminal (e.g. UE) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to an endpoint terminal, the endpoint terminal may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0284] The apparatus 2700 shown in FIG. 27 may include a processing circuitry, a processing function, a control unit or a processor 2710, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2710 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2731 and 2732 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2710. The I / O units 2731 and 2732 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2722 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2710 and / or as a working storage of the processor or processing function 2710. It is to be noted that the memory 2720 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0285] The processor or processing function 2710 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2710 includes one or more of the following sub-portions. Sub-portion 2711 is an establishing, resuming or reconfiguring portion, which is usable as a portion for establishing, resuming or reconfiguring an RRC connection. The portion 2711 may be configured to perform processing according to S1610 of FIG. 16. Further, sub-portion 2712 is a receiving portion, which is usable as a portion for receiving an indication. The portion 2712 may be configured to perform processing according to S1620 of FIG. 16.

[0286] Referring now to FIG. 28, FIG. 28 shows a block diagram illustrating an example apparatus according to various examples of embodiments of the subject disclosure.

[0287] Specifically, FIG. 28 shows a block diagram illustrating an apparatus 2800, which may represent a first access network entity or function (e.g. Source xNB) as outlined above with reference to FIGS. 1 to 6, according to various examples of embodiments, which may participate in a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). Furthermore, even though reference is made to a first access network entity or function, the first access network entity or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and / or circuitry.

[0288] The apparatus 2800 shown in FIG. 28 may include a processing circuitry, a processing function, a control unit or a processor 2810, such as a CPU or the like, which is suitable to enable (or otherwise facilitate) a baseline mobility procedure, and more specifically (but not exclusively) to an enhanced (e.g., simplified) baseline mobility procedure (e.g. for 6G). The processor 2810 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference signs 2831 and 2832 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 2810. The I / O units 2831 and 2832 may be a combined unit including communication equipment towards several entities / elements, or may include a distributed structure with a plurality of different interfaces for different entities / elements. Reference sign 2822 denotes a memory usable, for example, for storing data and programs / instructions to be executed by the processor or processing function 2810 and / or as a working storage of the processor or processing function 2810. It is to be noted that the memory 2820 may be implemented by using one or more memory portions of the same or different type of memory, but may also represent an external memory, e.g. an external database provided on a cloud server.

[0289] The processor or processing function 2810 is configured to execute processing related to the above described processing. In particular, the processor or processing circuitry or function 2810 includes one or more of the following sub-portions. Sub-portion 2811 is a detecting portion, which is usable as a portion for performing for an endpoint terminal establishing, resuming or reconfiguring an RRC connection. The portion 2811 may be configured to perform processing according to S1710 of FIG. 17. Further, subportion 2812 is a determining portion, which is usable as a portion for determining a preconfigured handover variant. The portion 2812 may be configured to perform processing according to S1720 of FIG. 17. Moreover, sub-portion 2813 is an indicating portion, which is usable as a portion for indicating a determined preconfigured handover variant. The portion 2813 may be configured to perform processing according to S1730 of FIG. 17.

[0290] It shall be noted that the apparatuses 1800 to 2800 as outlined above with reference to FIGS. 18 to 28 may comprise further / additional sub-portions, which may allow the apparatuses 1800 to 2800 to perform such methods / method as outlined above with reference to FIGS. 1 to 6.

[0291] Moreover, according to various examples of embodiments, an apparatus may comprise means for obtaining a radio resource control, RRC, configuration; means for providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; means for receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and means for initiating a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

[0292] According to various examples of embodiments, the apparatus may further comprise, if the initiated handover is completed, means for providing a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the apparatus.

[0293] According to various examples of embodiments, the apparatus may further comprise means for obtaining the first RRC configuration when the apparatus is caused to establish or resume an RRC connection.

[0294] Further, according to various examples of embodiments, an apparatus may comprise: means for receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, means for selecting from among the cells one cell as a target cell for the endpoint terminal to handover; means for generating a reconfiguration on its (e.g., the apparatus’) own in relation to the target cell; and means for providing the generated reconfiguration to the endpoint terminal.

[0295] According to various examples of embodiments, the apparatus may further comprise means for starting a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the means for providing provide the generated reconfiguration to the endpoint terminal; and means for releasing the endpoint terminal context after expiry of the started release timer.

[0296] Furthermore, according to various examples of embodiments, an apparatus may comprise: means for receiving a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the apparatus, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and means for providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the apparatus.

[0297] According to various examples of embodiments, the apparatus may further comprise means for receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

[0298] Moreover, according to various examples of embodiments, an apparatus may comprise: means for determining, whether or not the apparatus, which is associated with a first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the apparatus is not able to serve the endpoint terminal, means for selecting a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and means for requesting network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0299] According to at least some examples of embodiments, the apparatus may further comprise means for receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, means for providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

[0300] Moreover, according to at least some examples of embodiments, an apparatus may comprise: means for receiving a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the apparatus and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; means for providing, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; means for receiving a response indicative of the requested PDU session update and the requested SM context; and based on the received response, means for providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0301] Further, according to at least some examples of embodiments, an apparatus may comprise means for providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; based on the measurement report, means for receiving a redirection message indicating the apparatus to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and means for switching to the target cell based on the received redirection message.

[0302] According to at least some examples of embodiments, the apparatus may further comprise means for initiating a radio resource control, RRC, connection re-establishment procedure at the target cell.

[0303] According to at least some examples of embodiments, the apparatus may further comprise, when switching to the target cell, means for maintaining a connected state, RRC_CONNECTED / CM-CONNECTED.

[0304] Furthermore, according to at least some examples of embodiments, an apparatus may comprise means for receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, means for selecting from among the cells one cell as a target cell for the endpoint terminal to switch to; and means for providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0305] According to at least some examples of embodiments, the apparatus, when providing the redirection message, may further comprise means for indicating at least one of a physical cell ID of the target cell, a target carrier frequency related to the target cell, or physical cell ID and system information of the target cell; and / or the apparatus, when providing the redirection message, may further comprise, on signalling to indicate the target cell, means for reusing RRC release, and / or means for providing a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0306] Moreover, according to at least some examples of embodiments, an apparatus may comprise: means for participating in a radio resource control, RRC, connection reestablishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the apparatus; means for retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, means for providing an RRC connection re-establishment to the endpoint terminal.

[0307] According to various examples of embodiments, if the retrieval of the endpoint terminal context fails, the apparatus may further comprise means for establishing an RRC connection from scratch (e.g., anew, de novo, once again, etc.) and means for providing the RRC connection established from scratch (e.g., anew, de novo, once again, etc.) to the endpoint terminal.

[0308] Further, according to various examples of embodiments, an apparatus may comprise means for determining, whether or not to perform a handover from a serving cell of the apparatus and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, means for selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell; and means for switching to the second cell.

[0309] According to at least some examples of embodiments, wherein the apparatus may further comprise means for obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or wherein the apparatus caused to perform the selecting may comprise the apparatus being caused to increase the serving quality in relation to the serving quality of the serving cell.

[0310] Further, according to at least some examples of embodiments, an apparatus may comprise means for establishing, resuming or reconfiguring a radio resource control, RRC, connection; and means for receiving, from a first access network entity or function associated with the apparatus, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0311] Furthermore, according to at least some examples of embodiments, an apparatus may comprise: means for performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; means for determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and means for indicating, towards the endpoint terminal, the determined preconfigured handover variant.

[0312] As described herein, the subject disclosure describes a baseline mobility procedure, and more specifically (but not exclusively) an enhanced (e.g., simplified) baseline mobility procedure (e.g., for 6G), which may, according to some examples of embodiments, prove advantageous over a proprietary solution for at least the following reasons.

[0313] Examples of embodiments described in the subject disclosure may, for instance, e.g. with regard to New Radio (NR) baseline handover executed without network (NW) preparation according to various examples of embodiments of the subject disclosure, realize that a source access network entity or function (e.g. source xNB, wherein xNB represents a Node B for6G) can execute handover without negotiating neighbour access network entities or functions (e.g. neighbour xNBs). Additionally and / or alternatively, latency incurred by the handover preparation phase can be reduced, signaling for handover can be reduced in the network side, and / or a peer-to-peer connection between xNBs (like Xn in NR) is not required. Moreover, with regard to a NW initiated redirection according to various examples of embodiments of the subject disclosure, it may be realized that a source access network entity or function can execute handover without negotiating neighbour access network entities or functions, that latency incurred by the handover preparation phase can be reduced, and / or that signaling for handover can be reduced in the network side. Furthermore, with regard to an endpoint terminal initiated (e.g. user equipment (UE) initiated) redirection according to various examples of embodiments of the subject disclosure, it may be realized that the source access network entity or function does not have to involve with handover execution until the endpoint terminal context (e.g. UE context) retrieval is requested, that latency incurred by the handover preparation phase can be reduced, that signaling for handover can be reduced in the network side, and / or that endpoint terminal (e.g. UE) does not have to wait for NW indication to execute handover.

[0314] Further advantages may become apparent to a person skilled in the art in view of the subject disclosure.

[0315] It also should be appreciated that:

[0316] - an access technology via which traffic is transferred to and from an entity in the communication network may be any suitable present or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), LTE, LTE-A, 5G, 6G, Bluetooth, Infrared, and the like may be used; additionally, examples of embodiments may also apply wired technologies, e.g. IP based access technologies like cable networks or fixed lines.

[0317] - examples of embodiments suitable to be implemented as software code or portions thereof and being run using a processor or processing function are software code independent and can be specified using any known or future developed programming language, such as a high-level programming language, such as objective-C, C, C++, C#, Java, Python, Javascript, other scripting languages etc., or a low-level programming language, such as a machine language, or an assembler. - implementation of examples of embodiments is hardware independent and may be implemented using any known or future developed hardware technology or any hybrids of these, such as a microprocessor or CPU (Central Processing Unit), MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), and / or TTL (Transistor-Transistor Logic).

[0318] - examples of embodiments may be implemented as individual devices, apparatuses, units, means or functions, or in a distributed fashion, for example, one or more processors or processing functions may be used or shared in the processing, or one or more processing sections or processing portions may be used and shared in the processing, wherein one physical processor or more than one physical processor may be used for implementing one or more processing portions dedicated to specific processing as described,

[0319] - an apparatus may be implemented by a semiconductor chip, a chipset, or a (hardware) module including such chip or chipset;

[0320] - examples of embodiments may also be implemented as any combination of hardware and software, such as ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) or CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components.

[0321] - examples of embodiments may also be implemented as computer program products, including a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to execute a process as described in embodiments, wherein the computer usable medium may be a non- transitory medium.

[0322] The term “circuitry” may refer to one or more or all of the following examples of embodiments:

[0323] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0324] (b) combinations of hardware circuits and software, such as (as applicable):

[0325] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0326] (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 a mobile phone or server, to perform various functions) and 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.”

[0327] This definition of circuitry applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term 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. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0328] The term “non-transitory,” as used herein, is a limitation of the medium itself (e.g., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0329] It shall be understood that although the terms “first,” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the various example of embodiments of the subject disclosure.

[0330] As used herein, “at least one of the following:” and “at least one of” and similar expressions, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements. As used herein, the expression “and / or” includes any and all combinations of the listed terms, including any one of the elements, any two or more of the elements, and all of the elements.

[0331] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included. Analogously, performing a step or functionality “based on A” does not indicate that the step or functionality is performed solely based on “A” as one or more additional conditions may be included.

[0332] Although the subject disclosure has been described herein before with reference to various examples of embodiments thereof, the subject disclosure is not limited thereto and it will be apparent to a person skilled in the art that various modifications can be made to the subject disclosure.

[0333] Some of the various examples of embodiments of the subject disclosure are listed below by way of non-limiting and illustrative example.

[0334] Example Embodiment 1 : An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: obtain a radio resource control, RRC, configuration; provide a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; receive a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiate a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

[0335] Example Embodiment 2: The apparatus according to Example Embodiment 1 , wherein, if the initiated handover is completed, the apparatus is further caused to provide a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the apparatus.

[0336] Example Embodiment 3: The apparatus according to Example Embodiment 1 or 2, wherein the apparatus is further caused to obtain the first RRC configuration when the apparatus is caused to establish or resume an RRC connection. Example Embodiment 4: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, select, from among the cells, one cell as a target cell for the endpoint terminal to handover; generate a reconfiguration in relation to the target cell; and provide the generated reconfiguration to the endpoint terminal.

[0337] Example Embodiment 5: The apparatus according to Example Embodiment 4, wherein the apparatus is further caused to start a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the apparatus is caused to provide the generated reconfiguration to the endpoint terminal; and release the endpoint terminal context after expiry of the started release timer.

[0338] Example Embodiment 6: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the apparatus, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and provide a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the apparatus. Example Embodiment 7: The apparatus according to Example Embodiment 6, wherein the apparatus is further caused to receive, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

[0339] Example Embodiment 8: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine, whether or not the apparatus, which is associated with a first network entity or function managing endpoint terminal mobility, is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the apparatus is not able to serve the endpoint terminal, select a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and request network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0340] Example Embodiment 9: The apparatus according to Example Embodiment 8, wherein the apparatus is further caused to receive a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, provide, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

[0341] Example Embodiment 10: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the apparatus and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; provide, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; receive a response indicative of the requested PDU session update and the requested SM context; and based on the received response, provide, to the first network entity or function managing endpoint terminal mobility, an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0342] Example Embodiment 11 : An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: provide a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the apparatus and is associated with the first access network entity or function; based on the measurement report, receive a redirection message indicating the apparatus to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and switch to the target cell based on the received redirection message.

[0343] Example Embodiment 12: The apparatus according to Example Embodiment 11 , wherein the apparatus is further caused to initiate a radio resource control, RRC, connection re-establishment procedure at the target cell. Example Embodiment 13: The apparatus according to Example Embodiment 11 or 12, wherein the apparatus caused to switch to the target cell comprises the apparatus being caused to maintain a connected state, RRC_CONNECTED / CM-CONNECTED.

[0344] Example Embodiment 14: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, select, from among the cells, one cell as a target cell for the endpoint terminal to switch to; and provide a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0345] Example Embodiment 15: The apparatus according to Example Embodiment 14, wherein the apparatus caused to provide the redirection message

[0346] - further comprises the apparatus being caused to at least one of indicate a physical cell ID of the target cell, indicate a target carrier frequency related to the target cell, or indicate physical cell ID and system information of the target cell;

[0347] - and / or further comprises the apparatus being caused to at least one of, on signalling to indicate the target cell to, reuse RRC release, or provide a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0348] Example Embodiment 16: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: participate in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the apparatus; retrieve endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, provide an RRC connection reestablishment to the endpoint terminal.

[0349] Example Embodiment 17: The apparatus according to Example Embodiment 16, wherein, if the retrieval of the endpoint terminal context fails, the apparatus caused to provide the RRC connection re-establishment further comprises the apparatus being caused to establish an RRC connection anew and to provide the RRC connection established anew to the endpoint terminal.

[0350] Example Embodiment 18: An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine, whether or not to perform a handover from a serving cell, which serves the apparatus and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, select, from among at least one neighbour cell of the serving cell, one cell as the second cell; and switch to the second cell.

[0351] Example Embodiment 19: The apparatus according to Example Embodiment 18, wherein the apparatus caused to perform the determining is based on the apparatus being caused to obtain measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or wherein the apparatus caused to perform the selecting comprises the apparatus being caused to increase the serving quality in relation to the serving quality of the serving cell. Example Embodiment 20: An apparatus comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: establish, resume or reconfigure a radio resource control, RRC, connection; and receive, from a first access network entity or function associated with the apparatus, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0352] Example Embodiment 21 : An apparatus, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: perform for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; determine a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and indicate, towards the endpoint terminal, the determined preconfigured handover variant.

[0353] Example Embodiment 22: A method, comprising obtaining, at an endpoint terminal, a radio resource control, RRC, configuration; providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiating a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell. Example Embodiment 23: The method according to Example Embodiment 22, wherein, if the initiated handover is completed, the method further comprises providing a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal.

[0354] Example Embodiment 24: The method according to Example Embodiment 22 or 23, wherein the method further comprises obtaining the first RRC configuration when the endpoint terminal is caused to establish or resume an RRC connection.

[0355] Example Embodiment 25: A method, comprising receiving, at a first access network entity or function and from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting, from among the cells, one cell as a target cell for the endpoint terminal to handover; generating, at the first access network entity or function, a reconfiguration in relation to the target cell; and providing the generated reconfiguration to the endpoint terminal.

[0356] Example Embodiment 26: The method according to Example Embodiment 25, wherein the method further comprises starting, at a first access network entity or function, a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the providing of the generated reconfiguration is performed; and releasing the endpoint terminal context after expiry of the started release timer.

[0357] Example Embodiment 27: A method, comprising receiving, at a second access network entity or function, a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the second access network entity or function, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the second access network entity or function.

[0358] Example Embodiment 28: The method according to Example Embodiment 27, wherein the method further comprises receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

[0359] Example Embodiment 29: A method, comprising determining, at a first network entity or function managing endpoint terminal mobility, whether or not the first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; if determined that the first network entity or function managing endpoint terminal mobility is not able to serve the endpoint terminal, selecting a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and requesting network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

[0360] Example Embodiment 30: The method according to claim 29, wherein the method further comprises receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal. Example Embodiment 31 : A method, comprising receiving, at a second network entity or function managing endpoint terminal mobility, a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the second network entity or function managing endpoint terminal mobility and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; providing, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; receiving a response indicative of the requested PDU session update and the requested SM context; and based on the received response, providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

[0361] Example Embodiment 32: A method, comprising providing, at an endpoint terminal, a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; based on the measurement report, receiving a redirection message indicating the endpoint terminal to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and switching to the target cell based on the received redirection message.

[0362] Example Embodiment 33: The method according to Example Embodiment 32, wherein the method further comprises initiating a radio resource control, RRC, connection reestablishment procedure at the target cell. Example Embodiment 34: The method according to Example Embodiment 32 or 33, wherein the switching to the target cell comprises maintaining a connected state, RRC_CONNECTED / CM-CONNECTED.

[0363] Example Embodiment 35: A method, comprising receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting, from among the cells, one cell as a target cell for the endpoint terminal to switch to; and providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

[0364] Example Embodiment 36: The method according to Example Embodiment 35, wherein the providing further comprises at least one of indicating a physical cell ID of the target cell, indicating a target carrier frequency related to the target cell, or indicating physical cell ID and system information of the target cell; and / or wherein the providing further comprises at least one of, on signalling to indicate the target cell to, reuse RRC release, or provide a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

[0365] Example Embodiment 37: A method, comprising participating, at a second access network entity or function, in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the second access network entity or function; retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, provide an RRC connection reestablishment to the endpoint terminal.

[0366] Example Embodiment 38: The method according to Example Embodiment 37, wherein, if the retrieval of the endpoint terminal context fails, the providing of the RRC connection re-establishment further comprises establishing an RRC connection anew and providing the RRC connection established from anew to the endpoint terminal.

[0367] Example Embodiment 39: A method, comprising determining, at an endpoint terminal, whether or not to perform a handover from a serving cell of the endpoint terminal and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell; and switching to the second cell.

[0368] Example Embodiment 40: The method according to Example Embodiment 39, wherein the determining is based on obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / or wherein the selecting comprises increasing a serving quality in relation to the serving quality of the serving cell.

[0369] Example Embodiment 41 : A method, comprising establishing, resuming or reconfiguring, at an endpoint terminal, a radio resource control, RRC, connection; and receiving, from a first access network entity or function associated with the endpoint terminal, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

[0370] Example Embodiment 42: A method, comprising performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and indicating, towards the endpoint terminal, the determined preconfigured handover variant.

[0371] Example Embodiment 43: A computer program product for a computer, including software code portions for performing of any of Example Embodiments 22 to 24, 25 to 26, 27 to 28, 29 to 30, 31 , 32 to 34, 35 to 36, 37 to 38, 39 to 40, 41 or 42, when said product is run on the computer.

[0372] Example Embodiment 44: The computer program product according to Example Embodiment 43, wherein the computer program product includes a computer-readable medium on which said software code portions are stored, and / or the computer program product is directly loadable into the internal memory of the computer and / or transmittable via a network by means of at least one of upload, download or push procedures.

[0373] The following meanings for the abbreviations used herein apply:

[0374] 3GPP 3rdGeneration Partnership Project

[0375] 3GGP2 3rdGeneration Partnership Project 2

[0376] 4G Fourth Generation

[0377] 5G Fifth Generation

[0378] 5GC 5G Core Network

[0379] 6G Sixth Generation

[0380] AMF Access and Mobility Management Function

[0381] AP Access Point

[0382] API Application Programming Interface

[0383] BS Base Station

[0384] CDMA Code Division Multiple Access

[0385] CN Core Network

[0386] DRB Data Radio Bearer eNB Evolved Node B EPC Evolved Packet Core

[0387] ETSI European Telecommunications Standards Institute gNB Next Generation Node B

[0388] HO Handover

[0389] IEEE Institute of Electrical and Electronics Engineers

[0390] ITU International Telecommunication Union

[0391] L1 / L2 Layer- 1 / Layer-2

[0392] LTE Long Term Evolution

[0393] LTE-A Long Term Evolution-Advanced

[0394] MAC Medium Access Control

[0395] MANETs Mobile Ad-Hoc Networks

[0396] MIMO Multiple Input Multiple Output

[0397] NAS Non-Access Stratum

[0398] NB Node B

[0399] NF Network Function

[0400] NG-RAN NG Radio Access Network

[0401] NR NR Radio access

[0402] NW Network

[0403] PDU Protocol Data Unit

[0404] PSA PDU Session Anchor

[0405] RAM Random Access Memory

[0406] RAN Radio Access Network

[0407] Rel Release

[0408] ROM Read Only Memory

[0409] RRC Radio Resource Control

[0410] S-TMSI shortened Temporary Mobile Subscriber Identity

[0411] SM Session Management

[0412] SMF Session Management Function

[0413] SRB Signaling Radio Bearer

[0414] TISPAN Telecoms & Internet converged Services & Protocols for Advanced

[0415] Networks

[0416] TRP Transmission and Reception Point

[0417] UE User Equipment

[0418] UL Uplink UPF User Plane Function

[0419] UWB Ultra- Wideband

[0420] WCDMA Wideband Code Division Multiple Access

[0421] WiMAX Worldwide Interoperability for Microwave Access WLAN Wireless Local Area Network

Claims

CLAIMS:

1. A method, comprising obtaining, at an endpoint terminal, a radio resource control, RRC, configuration; providing a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; receiving a reconfiguration applied for a target cell, wherein the target cell is one cell of the at least one neighbour cell; and initiating a handover to the target cell based on the received reconfiguration, wherein the RRC configuration is a common RRC configuration applicable to radio cells and / or transmission and reception points, TRPs, associated with at least one of the first access network entity or function or a second access network entity or function associated with the target cell.

2. The method according to claim 1 , wherein, if the initiated handover is completed, the method further comprises providing a message to the second access network entity or function, wherein the message comprises an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal.

3. The method according to claim 1 or 2, wherein the method further comprises obtaining the first RRC configuration when the endpoint terminal is caused to establish or resume an RRC connection.

4. A method, comprising receiving, at a first access network entity or function and from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting, from among the cells, one cell as a target cell for the endpoint terminal to handover;generating, at the first access network entity or function, a reconfiguration in relation to the target cell; and providing the generated reconfiguration to the endpoint terminal.

5. The method according to claim 4, wherein the method further comprises starting, at a first access network entity or function, a release timer of endpoint terminal context related to the handover of the endpoint terminal, when the providing of the generated reconfiguration is performed; and releasing the endpoint terminal context after expiry of the started release timer.

6. A method, comprising receiving, at a second access network entity or function, a message from an endpoint terminal indicating completion of a handover of the endpoint terminal from a first cell to a second cell, wherein the first cell is associated with a first access network entity or function and wherein the second cell is associated with the second access network entity or function, the message comprising an ID of a network entity or function managing endpoint terminal mobility indicating a first network entity or function managing endpoint terminal mobility selected for the endpoint terminal; and providing a request to the first network entity or function managing endpoint terminal mobility to switch a user plane data path related to the endpoint terminal towards the second access network entity or function.

7. The method according to claim 6, wherein the method further comprises receiving, based on the provided request, information that a second network entity or function managing endpoint terminal mobility has been selected to serve the endpoint terminal.

8. A method, comprising determining, at a first network entity or function managing endpoint terminal mobility, whether or not the first network entity or function managing endpoint terminal mobility is able serve an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function;if determined that the first network entity or function managing endpoint terminal mobility is not able to serve the endpoint terminal, selecting a second network entity or function managing endpoint terminal mobility to serve the endpoint terminal; and requesting network entity or function managing endpoint terminal mobility relocation towards the second network entity or function managing endpoint terminal mobility.

9. The method according to claim 8, wherein the method further comprises receiving a request to switch a user plane data path related to the endpoint terminal towards the second access network entity or function; and based on the received request and the requested network entity or function managing endpoint terminal mobility relocation, providing, to the second access network entity or function, information that the second network entity or function managing endpoint terminal mobility serves the endpoint terminal.

10. A method, comprising receiving, at a second network entity or function managing endpoint terminal mobility, a request for a network entity or function managing endpoint terminal mobility relocation, the relocation from a first network entity or function managing endpoint terminal mobility to the second network entity or function managing endpoint terminal mobility and in relation to an endpoint terminal, which handed over or switched from a first cell associated with a first access network entity or function to a second cell associated with a second access network entity or function; providing, towards a network session management entity or function, a request for a protocol data unit, PDU, session update and session management, SM, context related to the handover or switch of the endpoint terminal; receiving a response indicative of the requested PDU session update and the requested SM context; and based on the received response, providing to the first network entity or function managing endpoint terminal mobility an indication that the requested network entity or function managing endpoint terminal mobility relocation is completed.

11. A method, comprisingproviding, at an endpoint terminal, a measurement report to a first access network entity or function, the measurement report comprising measurement results indicating a service quality of a serving cell and a service quality of at least one neighbour cell of the serving cell, wherein the serving cell is a serving cell of the endpoint terminal and is associated with the first access network entity or function; based on the measurement report, receiving a redirection message indicating the endpoint terminal to switch to a target cell, wherein the target cell is one cell among the at least one neighbour cell; and switching to the target cell based on the received redirection message.

12. The method according to claim 11 , wherein the method further comprises initiating a radio resource control, RRC, connection re-establishment procedure at the target cell.

13. The method according to claim 11 or 12, wherein the switching to the target cell comprises maintaining a connected state, RRC_CONNECTED / CM-CONNECTED.

14. A method, comprising receiving, from an endpoint terminal, a measurement report comprising measurement results indicating a service quality of cells, the cells comprising a serving cell of the endpoint terminal and at least one neighbour cell of the serving cell; based on the measurement report, selecting, from among the cells, one cell as a target cell for the endpoint terminal to switch to; and providing a redirection message to the endpoint terminal, the redirection message indicating the endpoint terminal to switch to the target cell.

15. The method according to claim 14, wherein the providing further comprises at least one of indicating a physical cell ID of the target cell, indicating a target carrier frequency related to the target cell, or indicating physical cell ID and system information of the target cell; and / or wherein the providing further comprises at least one of, on signalling to indicate the target cell to, reuse RRC release, orprovide a message specific to redirect the endpoint terminal under avoiding an endpoint terminal RRC configuration.

16. A method, comprising participating, at a second access network entity or function, in a radio resource control, RRC, connection re-establishment procedure initiated by an endpoint terminal, the endpoint terminal having switched from a first cell associated with a first access network entity or function to a second cell associated with the second access network entity or function; retrieving endpoint terminal context related to the endpoint terminal from the first access network entity or function, the endpoint terminal context comprising information about the endpoint terminal’s radio capability; and based on the retrieved endpoint terminal context, provide an RRC connection reestablishment to the endpoint terminal.

17. The method according to claim 16, wherein, if the retrieval of the endpoint terminal context fails, the providing of the RRC connection re-establishment further comprises establishing an RRC connection anew and providing the RRC connection established from anew to the endpoint terminal.

18. A method, comprising determining, at an endpoint terminal, whether or not to perform a handover from a serving cell of the endpoint terminal and which is associated with a first access network entity or function, to a second cell associated with a second access network entity or function, if it is determined to perform the handover, selecting, from among at least one neighbour cell of the serving cell, one cell as the second cell; and switching to the second cell.

19. The method according to claim 18, wherein the determining is based on obtaining measurement results, the measurement results indicating a service quality of the serving cell and a service quality of the at least one neighbour cell; and / orwherein the selecting comprises increasing a serving quality in relation to the serving quality of the serving cell.

20. A method, comprising establishing, resuming or reconfiguring, at an endpoint terminal, a radio resource control, RRC, connection; and receiving, from a first access network entity or function associated with the endpoint terminal, an indication which preconfigured handover variant from among several preconfigured handover variants to use in a handover process.

21. A method, comprising performing for an endpoint terminal establishing, resuming or reconfiguring a radio resource control, RRC, connection; determining a preconfigured handover variant from among several preconfigured handover variants for the endpoint terminal to use in a handover process; and indicating, towards the endpoint terminal, the determined preconfigured handover variant.

22. A computer program product for a computer, including software code portions for performing of any of claims 1 to 3, 4 to 5, 6 to 7, 8 to 9, 10, 11 to 13, 14 to 15, 16 to 17, 18 to 19, 20, or 21 , when said product is run on the computer.

23. The computer program product according to claim 22, wherein the computer program product includes a computer-readable medium on which said software code portions are stored, and / or the computer program product is directly loadable into the internal memory of the computer and / or transmittable via a network by means of at least one of upload, download or push procedures.

Images