System and method for handover signaling reduction

Abstract

Systems and methods discussed herein relate to handover signaling reduction in the case of handover of one or more user equipments (UEs) from a source serving cell of a source base station to a target serving cell of a target base station based on common configuration information for operating on the target serving cell and dedicated configuration information for each particular UE. In various cases, point-to-multipoint (PTM) transmissions include common configuration information for the UEs, a handover command instructs the UE to independently acquire the common configuration information from a system information block (SIB) of the target serving cell, or a handover command for the UE instructs the UE to reuse the common configuration for the source serving cell. Handover commands may be used to provide dedicated configuration information for each UE. Configuration-related communications sent over the Xn interface and the F1 interface are also discussed.

Description

Technical Field

[0001] The present application generally relates to wireless communication systems, including wireless communication systems implementing non-terrestrial network (NTN) communication mechanisms. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to send data between base stations and wireless communication devices. For example, wireless communication system standards and protocols may include the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the Institute of Electrical and Electronics Engineers (IEEE) 502.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as WLANs). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to communicate between base stations of the RAN (which may also sometimes be referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices referred to as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN may use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (sometimes referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to as 5G RAT, 5G NR RAT, or NR in this document). In some deployments, E-UTRAN may also implement NR RAT. In some deployments, NG-RAN may also implement LTE RAT.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a g-Node B or gNB).

[0006] The RAN provides its communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC) while NG-RAN may utilize the 5G Core Network (5GC).

[0007] The frequency bands of 5G NR can be divided into two or more different frequency ranges. For example, frequency range 1 (FR1) may include frequency bands operating at frequencies below 6 gigahertz (GHz), some of which are available for use by previous standards and can potentially be expanded to cover new spectrum products from 410 megahertz (MHz) to 7125MHz. Frequency range 2 (FR2) may include frequency bands from 24.25GHz to 52.6GHz. It should be noted that in some systems, FR2 may also include frequency bands from 52.6GHz to 71GHz (or higher). The frequency bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage than the frequency bands in FR1 but potentially higher available bandwidth. Technicians will recognize that these frequency ranges provided by way of example may vary over time or region. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces the element.

[0009] Figure 1 An NTN architecture of a wireless communication system according to an embodiment is illustrated.

[0010] Figure 2 A diagram for comparing terrestrial cell characteristics and NTN cell characteristics is illustrated.

[0011] Figure 3 A table illustrating NTN conditional handover conditions according to embodiments of the present invention.

[0012] Figure 4 Various definitions for NTN conditional handover conditions according to embodiments of this document are illustrated.

[0013] Figure 5 A diagram illustrating a handover scenario for an NTN cell according to an embodiment is illustrated.

[0014] Figure 6 A flow chart illustrating a framework for separate processing of public configuration information and private configuration information according to embodiments herein.

[0015] Figure 7 A flow chart for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment is illustrated.

[0016] Figure 8 The PDCP PDU format for PTM transmission according to the embodiments of this document is illustrated.

[0017] Fig. 9 A flow chart for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment is illustrated.

[0018] Fig.10 A flow chart for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment is illustrated.

[0019] Fig.11 A flow chart illustrating UE acquisition of common configuration information according to an implementation scheme.

[0020] Fig.12 A flow chart illustrating UE acquisition of common configuration information according to an implementation scheme.

[0021] Fig.13 A flow chart illustrating a first case of reusing a common configuration for a source serving cell for handover to a target serving cell according to an embodiment.

[0022] Fig.14 A flow chart illustrating a second case of reusing a common configuration for a source serving cell for handover to a target serving cell according to an embodiment.

[0023] Fig.15 A flow chart illustrating a first option for providing dedicated configuration information to a UE.

[0024] Fig.16 A flow chart illustrating a second option for providing dedicated configuration information to a UE.

[0025] Fig.17 A flow chart illustrating a third option for providing dedicated configuration information to a UE.

[0026] Fig.18 The use of a group handover command accompanying performing a handover of a group of UEs is illustrated.

[0027] Fig.19 A method of a UE according to an embodiment of this document is illustrated.

[0028] Fig. 20 A method of a source base station according to an embodiment of the present invention is illustrated.

[0029] Fig.21 A method of a UE according to an embodiment of this document is illustrated.

[0030] Fig. 22A method of a source base station according to an embodiment of the present invention is illustrated.

[0031] Fig.23 A method of a UE according to an embodiment of this document is illustrated.

[0032] Fig.24 A method of a UE according to an embodiment of this document is illustrated.

[0033] Fig.25 A method of a source base station according to an embodiment of the present invention is illustrated.

[0034] Fig.26 A diagram illustrating a first option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment.

[0035] Fig. 27 A diagram illustrating a second option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment.

[0036] Fig.28 A diagram illustrating a third option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment.

[0037] Fig.29 A diagram illustrating a fourth option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment.

[0038] Fig.30 A diagram illustrating a fifth option for communicating a common configuration between a source base station and a target base station according to an embodiment.

[0039] Fig.31 A flow chart is illustrated for group configuration of multiple UEs between a target DU and a CU on an F1 interface according to an embodiment.

[0040] Fig.32 A method of a source base station according to an embodiment of the present invention is illustrated.

[0041] Fig.33 A method of a target base station according to an embodiment of this document is illustrated.

[0042] Fig.34 A method of a source base station according to an embodiment of the present invention is illustrated.

[0043] Fig.35 A method of a source base station according to an embodiment of the present invention is illustrated.

[0044] Fig.36 A method of a target base station according to an embodiment of this document is illustrated.

[0045] Fig.37 A method of a source base station according to an embodiment of the present invention is illustrated.

[0046] Fig.38 A method of a target base station according to an embodiment of this document is illustrated.

[0047] Fig.39 A method of DU according to embodiments herein is illustrated.

[0048] Fig.40 A method of CU according to an embodiment of the present invention is illustrated.

[0049] Fig.41 An example architecture of a wireless communication system according to embodiments disclosed herein is illustrated.

[0050] Fig.42 A system for performing signaling between a wireless device and a RAN device connected to a core network of a CN device according to an embodiment of the present invention is illustrated. DETAILED DESCRIPTION

[0051] Various embodiments are described with respect to UE. However, reference to UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, UE as described herein is used to represent any suitable electronic component.

[0052] A non-terrestrial network (NTN) refers to a network (or a segment of a network) that uses airborne vehicles and / or spaceborne vehicles to perform communications.

[0053] Figure 1 The NTN architecture 100 of a wireless communication system according to an embodiment is illustrated. The NTN architecture 100 includes a core network (CN) 102, a base station 104, an aircraft 106 with a payload 118, and a UE 108. The base station 104 and the payload 118 of the aircraft 106 may be included in the RAN 110.

[0054] In some embodiments, RAN 110 includes NG-RAN, CN 102 includes 5GC, and base station 104 includes gNB or next generation eNB (ng-eNB). In such a case, the CN link 112 connecting CN 102 and base station 104 may include an NG interface.

[0055] In the NTN architecture 100, the payload 118 of the aircraft 106 is a network node of the RAN 110. The payload 118 may be equipped with one or more antennas capable of operating (e.g., broadcasting, facilitating communications, etc.) a cell 120 of the RAN 110 as directed / configured by the base station 104. The base station 104 communicates with the payload 118 of the aircraft 106 via a feeder link 114 (e.g., via a non-terrestrial gateway (not shown)). The UE 108 may be equipped with one or more antennas (e.g., mobile parabolic antennas, omnidirectional phased array antennas, etc.) capable of communicating with the payload 118 via a Uu interface on the cell 120 of the RAN via a service link 116. In this document, a cell (such as the cell 120) provided by a payload of an NTN aircraft may be referred to as an "NTN cell". It should also be noted that the payload of the NTN may sometimes be referred to as an "NTN payload" in this document.

[0056] The NTN architecture 100 illustrates a "bent pipe" or "transparent" satellite-based architecture. In such a system, a payload 118 transparently forwards data between a base station 104 and a UE 108 using a feeder link 114 between the base station 104 and the payload 118 and a service link 116 between the payload 118 and the UE 108. The payload 118 may perform radio frequency (RF) conversion and / or amplification in both the uplink (UL) and downlink (DL) to enable this communication.

[0057] exist Figure 1 In the illustrated embodiment, the base station 104 is illustrated as not having the (explicit) capability of directly communicating with the UE on the ground wirelessly. However, it is contemplated that in an embodiment, such a base station that communicates with the payload 118 using a non-ground gateway may (also) have this functionality (either with the UE 108 or with another (not illustrated) UE).

[0058] The NTN architecture 100 illustrates the aircraft 106 as a satellite onboard. In this case, it is possible that the aircraft 106 is a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geosynchronous earth orbit (GEO) satellite, or a high earth orbit (HEO) satellite. It should also be noted that aircraft other than satellites can be used in the NTN. For example, the aircraft 106 can alternatively be a high altitude platform station (HAPS) (such as, for example, an airship or an airplane).

[0059] In some cases, NTN can be used to address mobile broadband needs and / or public safety needs in areas not served / underserved by ground-based network elements. Some such example cases include maritime applications, aircraft connectivity applications, railway applications, etc.

[0060] It is possible that in some cases, NTN supports / uses, for example, LEO and GEO, with further implicit compatibility for supporting HAPS and air-to-ground (ATG) scenarios. In addition, NTN can focus on frequency division duplex (FDD) mechanisms, with time division duplex (TDD) mechanisms being applied to related scenarios, such as for HAPS, ATG, etc.

[0061] Some NTNs may use Earth-fixed tracking areas for defined areas that do not change corresponding to any movement of the NTN's payload.

[0062] The UE may also have the ability to determine its own location (eg, via a global navigation satellite system (GNSS), such as Global Positioning System (GPS), Galileo GNSS, etc.) and further communicate that location information to a base station (eg, via a payload).

[0063] UEs that may be used in the NTN may include, but are not limited to, handheld devices (eg, power class 3 devices) operating in FR1 and / or very small aperture terminal (VSAT) devices with external antennas in at least FR2.

[0064] It is contemplated that the coverage of a cell (or beam of a cell) broadcast by an NTN aircraft may be relatively larger than the coverage of a cell (or beam of a cell) broadcast by a ground RAN element. In some cases, the coverage of a single NTN cell may span multiple countries, states, etc.

[0065] In some NTN systems, the UE handover (HO) mechanism may operate according to some restrictions. For example, in such systems, it may not be required that the UE is connected to both the NTN cell and the terrestrial cell simultaneously during HO. Furthermore, in such a case, it may not be supported to support the use of a dual active protocol stack (DAPS).

[0066] This article discusses Conditional Handover (CHO). In some cases, due to specific NTN radio characteristics, conditional handover conditions can be introduced for NTN specific conditional handover.

[0067] Figure 2 A diagram 200 for comparing terrestrial cell characteristics and NTN cell characteristics is illustrated. Diagram 200 illustrates a terrestrial cell 202 broadcast by a terrestrial base station 204 and an NTN cell 206 broadcast by a payload 208 of a satellite 210.

[0068] UE 212 operates in terrestrial cell 202. When UE 212 is in cell center 214, the UE may experience a higher relative reference signal received power (RSRP) 218. As UE 212 moves to cell edge 216, the UE may experience a lower relative RSRP 220 than the higher relative RSRP 218 due to its increased distance from terrestrial base station 204.

[0069] UE 222 operates in NTN cell 206. When UE 222 is in cell center 224, the UE may experience higher relative RSRP 228. As UE 222 moves to cell edge 226, the UE may experience lower relative RSRP 230 than higher relative RSRP 228 due to its increased distance from payload 208.

[0070] As can be seen with reference to diagram 200, the variation in RSRP between the cell center and the cell edge is less significant for NTN cells than for cells broadcast by ground-based equipment. Therefore, NTN-specific conditional handover conditions reflecting this difference may be used in certain wireless communication systems using NTN.

[0071] Figure 3 Table 300 of NTN conditional handover conditions according to embodiments of the present invention is illustrated. The first NTN conditional handover condition 302 may be a "condEventA4" condition. The first NTN conditional handover condition 302 may check for "measurement event A4", which may be defined as a situation where the quality (e.g., RSRP) of a neighboring cell of a current serving cell has become better than the quality of the current serving cell.

[0072] The second NTN conditional handover condition 304 may be a "condEventT1" condition. The second NTN conditional handover condition 304 may be a time-based trigger condition, where a conditional handover may be performed only between a first time T1 and a second time T2. The network may configure the time T1 (e.g., as t1-threshold) and the duration corresponding to T2 starting from T1.

[0073] The third NTN conditional handover condition 306 may be a "condEventD1" condition. The third NTN conditional handover condition 306 may be a location-based trigger condition, where a conditional handover may be performed when a distance between the UE and a first reference location is greater than a distance threshold for the first reference location and when a distance between the UE and a second reference location is less than a distance threshold for the second reference location. In this case, the first reference location may be the location of a current serving cell, and the second reference location may be the location of a candidate serving cell for conditional handover.

[0074] In some cases, the “condEventT1” NTN conditional handover condition and the “condEventD1” NTN conditional handover condition may be configured together with a measurement-based NTN conditional handover condition, such as “condEventA4” or another measurement-based trigger condition (e.g., conditional handover using A3, A4, and / or A5 measurement events).

[0075] When using the "condEventT1" NTN conditional handover condition for a candidate cell, it is possible that conditional handover recovery cannot be performed when necessary if timer T2 has not expired.

[0076] When using the "condEventD1" NTN conditional handover condition for a candidate cell, it is possible that conditional handover recovery can be performed without first checking "condEventD1" if necessary.

[0077] It is contemplated that the "condEventD1" NTN conditional handover condition may be configured as a normal measurement event for measurement reporting.

[0078] Figure 4 Various definitions 400 for NTN conditional handover conditions according to embodiments herein are illustrated. The definitions 400 may be used in a wireless communication system defined, for example, in accordance with one or more 3GPP specifications.

[0079] Definitions 400 include a first definition 402 for a “condEventA4” NTN conditional handover condition, a second definition 404 for a “condEventD1” NTN conditional handover condition, and a third definition 406 for a “condEventT1” NTN conditional handover condition.

[0080] There are various scenarios where an NTN cell moves relative to the surface of the Earth (e.g., because the satellite on which the payload is located is not in GEO, such as in LEO). When such an NTN cell moves relative to the surface of the Earth, it is possible that UEs in the geographic area may begin to lose coverage and therefore may need to perform a handover to a new cell (e.g., a new cell broadcast by another payload on another satellite).

[0081] In some cases, a satellite moving relative to the surface of the Earth will begin to be operated by a new base station (e.g., closer to its current location than the base station that previously operated the satellite). Such cases involve establishing a new feeder link between the satellite and the (new) base station. In the case of a feeder link switch, the cell served by the payload on the satellite may change (e.g., become the cell of the new base station). In this case, all UEs currently in that cell / served by the payload may need to perform a handover to the new cell due to the change in cell information (even though there may be no change in their serving link with the payload).

[0082] Given the large size of NTN cells (relative to cells broadcast by, for example, ground-based equipment), it is possible that many devices may be served by a single NTN cell. Furthermore, depending on the constellation assumptions (e.g., propagation delays and / or satellite speeds) and UE density, it is possible that a very large number of UEs may need to perform handovers to / from the NTN cell simultaneously. This may mean a correspondingly large amount of signaling overhead with respect to these handovers. Furthermore, service continuity challenges during handovers and / or cell congestion (e.g., due to group UE handovers) may be issues of concern.

[0083] Figure 5 A diagram 500 showing a handover scenario for an NTN cell 502 according to an embodiment is illustrated. At a first time 504 (time T), a satellite 510 having a payload 512 broadcasting an NTN cell 502 is positioned such that the coverage of the NTN cell 502 is coextensive with a first geographic area 514, as shown. Within the first geographic area 514, there may be a large number of UEs served by the NTN cell 502 (the diagram 500 provides 65,519 such UEs by way of example and not limitation). As shown, there are also a large number of UEs in the second geographic area 516 that are physically located outside the coverage of the NTN cell 502 and are therefore not served by the NTN cell (the diagram 500 provides 65,519 such UEs by way of example and not limitation).

[0084] Because the satellite 510 moves 518 relative to the surface of the earth (e.g., at a speed of 7.56 km / s, as shown in the diagram 500, which speed is given by way of example and not limitation), at the second time 506 (time T+Δt), the satellite 510 is positioned so that the NTN cell 502 covers a portion of the first geographic area 514 and a portion of the second geographic area 516, as shown. At this time, UEs from the first geographic area 514 located in the uncovered area 520 of the first geographic area 514 have been handed over out of the NTN cell 502, while UEs from the second geographic area 516 located in the covered area 522 have been handed over to the NTN cell 502. Due to the large number of UEs in each of the first geographic area 514 and the second geographic area 516, the number of such handovers may have been very large (e.g., as shown, a large number of UEs remain connected via the NTN cell 502 at the second time 506).

[0085] At a third time 508 (time T+ is the time for all UEs to perform all handovers), satellite 510 is positioned such that the coverage of NTN cell 502 is coextensive with second geographic area 516, as shown. In addition, NTN cell 502 can serve UEs present in second geographic area 516.

[0086] Using the example numbering in diagram 500, from the first time 504 to the third time 508, 65,519 UEs located in the first geographic area 514 are handed over out of the NTN cell 502, and 65,519 UEs located in the second time 506 are handed over into the NTN cell 502. This large number of handovers means a large amount of signaling overhead (and the potential for service continuity challenges and / or cell congestion during handovers, as discussed herein). Therefore, systems and methods for handover signaling reduction can be used to alleviate such problems and / or allow handovers of large numbers of UEs within system signaling constraints.

[0087] A first direction for reducing handover signaling involves reducing the portion of the handover signaling corresponding to the target serving cell configuration (where the target serving cell is the cell to which the UE is to perform the handover). It is possible that the portion of the handover configuration and / or the handover execution indication that notifies the configuration for operating with the target serving cell for handover may be common to multiple / many UEs. Therefore, it is possible to split the configuration for operating on the target serving cell into two parts: a common configuration (e.g., which corresponds to common configuration information for operating on the target serving cell, which is the same for multiple UEs) and a dedicated configuration (which corresponds to dedicated configuration information for operating on the target serving cell, which is specific to that particular UE).

[0088] Figure 6Flowchart 600 illustrating a framework for separate processing of public configuration information and dedicated configuration information according to embodiments of the present invention. A network 602 sends 608 public configuration information for operating on a target serving cell to a plurality of UEs in a point-to-multipoint (PTM) transmission (e.g., a broadcast transmission), the plurality of UEs including, but not limited to, a first UE 604 and a second UE 606. The PTM transmission may be sent by a source base station operating a source serving cell currently serving the plurality of UEs. The public configuration information may include a public configuration for the target serving cell, and / or it may include information allowing the UE to derive a public configuration for the target serving cell.

[0089] Each UE in the plurality of UEs optionally sends feedback to the network 602 indicating that a PTM transmission with common configuration information is received at a particular UE. For example, a first UE 604 optionally sends 610 such feedback to the network 602, and a second UE 606 optionally sends 612 such feedback to the network 602.

[0090] The network then sends (e.g., via the source serving cell) a handover command to one or more UEs in the plurality of UEs (e.g., all UEs in the plurality of UEs, or those UEs in the plurality of UEs that provide feedback). These handover commands may be dedicated transmissions, one handover command for each such UE. In addition, each such dedicated transmission may include dedicated configuration information for operating on the target serving cell for that particular UE. For example, the dedicated configuration information may include a dedicated configuration for the UE for the target serving cell, and / or it may include information that allows the UE to derive a dedicated configuration for the UE for the target serving cell. As shown in the figure, in some cases, these handover commands may be conditional handover commands.

[0091] For example, as shown, the network 602 sends 614 a first such dedicated transmission to the first UE 604 (e.g., via the source serving cell), the first such dedicated transmission including dedicated configuration information for the first UE 604 for operating on the target serving cell. In addition, the network 602 sends 616 (e.g., via the source serving cell)

[0092] In response to receiving a PTM transmission having common configuration information for operating with a target serving cell and a dedicated transmission having dedicated configuration information for operating with the target serving cell, the UE is then enabled to perform a handover to the target serving cell according to a public configuration corresponding to the common configuration information and a dedicated configuration corresponding to the dedicated configuration information.

[0093] In some cases, the common configuration may include a cell-specific configuration. The cell-specific configuration may correspond to information found, for example, in a master information block (MIB) and / or one or more system information blocks (SIBs) for a cell. The cell-specific information may represent a common portion of a serving cell configuration for a cell.

[0094] In some cases, a common configuration may include a group-specific configuration. For example, a common configuration may be used to configure UEs within a certain geographic area within an NTN cell (e.g., UEs communicating on beams of an associated NTN payload for that geographic area within the NTN cell). Thus, it should be understood that in some cases, a common configuration for a UE may be for a group of UEs that does not (necessarily) include all UEs of a serving cell. Parameters that may be associated with this type of common configuration may depend on the network specific implementation.

[0095] In some cases, a common configuration may also be understood to include any common portion of a UE-specific configuration (e.g., a portion of a nominally dedicated UE-specific configuration that is the same for multiple / many / all UEs within a cell in any case). Parameters that may be associated with this type of common configuration may depend on the network specific implementation.

[0096] Figure 7 A flowchart 700 is illustrated for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment. Flowchart 700 illustrates a mechanism for using a (full) common configuration for a target serving cell as common configuration information in a PTM transmission. Flowchart 700 illustrates communication between a first UE 702, a second UE 704, a source base station (labeled "S-BS") 706, and a target base station (labeled "T-BS") 708.

[0097] A plurality of UEs including but not limited to a first UE 702 and a second UE 704 are currently served by a source serving cell on a source base station 706 and are to be handed over to a target serving cell. In some cases, it is possible that the target serving cell is a cell of a target base station 708. In this case, the target base station 708 sends 710 a common configuration for the target serving cell to the source base station 706 so that the source base station 706 is aware of the common configuration for the target serving cell.

[0098] In other cases, it is possible that the target serving cell is a cell of the source base station operating the source serving cell, in which case the source base station already knows the common configuration for the target serving cell.

[0099] The source base station 706 then transmits 712 a common configuration for the target serving cell in a PTM transmission to multiple UEs (including the first UE 702 and the second UE 704, as shown). Note that the use of PTM transmissions reduces signaling relative to the case where a separate transmission with the common configuration is sent for each of the multiple UEs instead.

[0100] The PTM transmission may be sent in a message using a group radio network temporary identifier (G-RNTI) that is known to each of a plurality of UEs, thereby indicating that the PTM transmission is directed to the plurality of UEs. In this case, it is understood that the plurality of UEs to which the PTM transmission is directed is a group of UEs corresponding to the G-RNTI. The G-RNTI used for the PTM transmission may be pre-configured to the UE (e.g., by prior dedicated signaling to the UE) and / or may be derived in a known manner based on the cell radio network temporary identifier (C-RNTI) of the UE.

[0101] Once the UEs receive the PTM transmission, they may provide feedback to the source base station 706. For example, the first UE 702 sends 714 a first feedback message to the source base station 706, and the second UE 704 sends 716 a second feedback message to the source base station 706. In some cases, the feedback message may include a UE-specific layer 3 (L3) RRCReconfigurationComplete message (e.g., as shown in flowchart 700). The L3 RRCReconfigurationComplete message may be used, for example, in situations where conditional handover is used. In some cases, the feedback message may include a layer 2 (L2) radio link control (RLC) acknowledgement (ACK) feedback. In some cases, the feedback message may include a layer 1 (L1) hybrid automatic repeat request acknowledgement (HARQ-ACK) signaling. In some embodiments, the feedback message may include a medium access control control element (MAC CE).

[0102] The PTM transmission may include the common configuration in an RRCReconfiguration message, which may use an existing signaling radio bearer (SRB). In other cases, the common configuration may instead be included in a radio resource control (RRC) message on a newly established SRB.

[0103] In some cases, PTM transmissions with public configuration may be transmitted in a secure manner. This may not be necessary in the case where the public configuration contains / corresponds to cell-level public configuration, since such information is already broadcast by the system (e.g., in the MIB / SIB) and is therefore assumed to be already available on an unsecured basis in any case. However, in the case where the public configuration information contains / corresponds to a public configuration that, for example, is a group-specific configuration or reflects a public part of a UE-specific configuration, the use of security protection may be beneficial.

[0104] In some cases, a group encryption key and a group integrity protection key are configured and generated for multiple UEs. The PTM transmission is then encrypted at the source base station 706 for use with the group encryption key and the group integrity protection key, and multiple UEs (including, for example, the first UE 702 and the second UE 704) then use the group encryption key and the group integrity protection key to decrypt the PTM transmission. Based on the name, it will be understood that the group encryption key is used to decrypt the PTM transmission at the UE, while the group integrity protection key is used to verify the integrity of the received PTM transmission.

[0105] In some cases, a dedicated integrity protection key is configured and generated for each of the multiple UEs. A message authentication code (MAC-I) for the integrity of each of the multiple UEs corresponding to the data of the PTM transmission is then generated at the source base station 706 and sent in the PTM transmission with a common configuration. Upon receiving the PTM transmission, each UE can verify the integrity of the PTM transmission by applying its dedicated integrity protection key with the PTM transmission and checking for a match for the corresponding MAC-I of the UE included in the PTM transmission.

[0106] Figure 8 A packet data convergence protocol (PDCP) protocol data unit (PDU) format 800 for PTM transmission according to an embodiment of the present invention is illustrated. The PDCP PDU format 800 includes a PDCP header 802 and an RRC common configuration 804 (which may be an example of common configuration information as discussed herein). In addition, the PDCP PDU format 800 includes a first MAC-I 806 for a first UE of a plurality of UEs to receive PTM transmission, a second MAC-I 808 for a second UE of a plurality of UEs to receive PTM transmission, a third MAC-I 810 for a third UE of a plurality of UEs to receive PTM transmission, and a fourth MAC-I 812 for a fourth UE of a plurality of UEs to receive PTM transmission.

[0107] In some cases, the common configuration information sent in the PTM transmission may include differential configuration information. The differential configuration information may include a portion of the common configuration for the target serving cell that is different from the common configuration for the source serving cell. The differential configuration information may not include a portion of the common configuration for the target serving cell that is the same as the common configuration for the source serving cell. In this way, the amount of information transmitted in the PTM transmission may be reduced (compared to, for example, the case where the entire common configuration for the target serving cell is sent in the PTM transmission).

[0108] Then, the UEs that have received the differential configuration information may use the differential configuration information to update their common configuration for the source serving cell to generate or derive the common configuration for the target serving cell.

[0109] Fig. 9 A flowchart 900 is illustrated for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment. Flowchart 900 illustrates a first option for generating differential configuration information and using it as common configuration information in a PTM transmission. Flowchart 900 illustrates communications between a first UE 902, a second UE 904, a source base station (labeled "S-BS") 906, and a target base station (labeled "T-BS") 908.

[0110] In some cases, it is possible that the target serving cell is a cell of the target base station 908. In this case, the source base station 906 sends 910 a common configuration for the source serving cell to the target base station 908, so that the target base station 908 knows the common configuration of the source serving cell. Then, the target base station 908 generates 912 differential configuration information for the target serving cell relative to the common configuration of the source serving cell. Then, the target base station 908 sends 914 the differential configuration information to the source base station 906.

[0111] In other cases, it is possible that the target serving cell is a cell of a source base station operating the source serving cell, in which case the source base station already knows the public configuration for the target serving cell. In this case, the source base station can generate differential configuration information for the target serving cell relative to the public configuration for the source serving cell.

[0112] Then, the source base station 906 sends 916 a PTM transmission including the differential configuration information to a plurality of UEs (e.g., including the first UE 902 and the source base station 906, as shown). These UEs can then update their common configuration for the source serving cell using the differential configuration information to generate or derive a common configuration for the target serving cell.

[0113] It is contemplated that the behavior discussed with respect to the PTM transmission of flowchart 700 (which includes the (full) public configuration for the target serving cell as the public configuration information, rather than the differential configuration information as the public configuration information) can be similarly used in the case of the PTM transmission of flowchart 900. For example, the PTM transmission of flowchart 900 can similarly utilize the G-RNTI, UE feedback message, RRC message transmission, ciphering and / or integrity protection mechanism, as described with respect to the PTM transmission of flowchart 700.

[0114] Fig.10 A flowchart 1000 is illustrated for providing common configuration information for operating on a target serving cell in a broadcast or PTM manner according to an embodiment. Flowchart 1000 illustrates a second option for generating differential configuration information and using it as common configuration information in a PTM transmission. Flowchart 1000 illustrates communications between a first UE 1002, a second UE 1004, a source base station (labeled "S-BS") 1006, and a target base station (labeled "T-BS") 1008.

[0115] In some cases, it is possible that the target serving cell is a cell of the target base station 1008. In this case, the source base station 1006 sends 1010 a request for a common configuration for the source serving cell to the target base station 1008. In response, the target base station 1008 sends 1012 a common configuration for the target serving cell to the source base station 1006, so that the source base station 1006 knows the target serving cell common configuration.

[0116] In other cases, it may be that the target serving cell is the cell of the source base station operating the source serving cell, in which case the source base station already knows the common configuration for the target serving cell and therefore does not use this signalling.

[0117] Then, using the common configuration for each of the source serving cell and the target serving cell, the source base station 1006 generates 1014 differential configuration information for the target serving cell relative to the common configuration for the source serving cell.

[0118] Then, the source base station 1006 sends 1016 a PTM transmission including differential configuration information to multiple UEs (e.g., including the first UE 1002 and the second UE 1004, as shown). These UEs can then use the differential configuration information to update their common configuration for the source serving cell to generate or derive a common configuration for the target serving cell.

[0119] It is contemplated that the behaviors discussed with respect to the PTM transmission of flowchart 700 (which includes the (full) public configuration for the target serving cell as the public configuration information, rather than the differential configuration information as the public configuration information) can be similarly used in the case of the PTM transmission of flowchart 1000. For example, the PTM transmission of flowchart 1000 can similarly utilize the G-RNTI, UE feedback message, RRC message transmission, ciphering and / or integrity protection mechanism, as described with respect to the PTM transmission of flowchart 700.

[0120] In some cases, the UE may obtain public configuration information for the target serving cell without using a PTM transmission from a base station with a public configuration, as described in some embodiments herein. It is possible that, for example, the public configuration for the target serving cell as a cell-specific configuration may correspond to information broadcast by the target serving cell, such as information found in a MIB and / or one or more SIBs broadcast by the serving cell. In this case, the UE may obtain the public configuration for the target serving cell from the MIB and / or one or more SIBs.

[0121] Fig.11 A flowchart 1100 is illustrated for UE acquisition of common configuration information according to an embodiment. Flowchart 1100 illustrates a first option for implementing handover based on UE acquisition of common configuration for a target serving cell from broadcast signaling (e.g., one or more SIBs) of the target serving cell. Flowchart 1100 illustrates communications between a UE 1102, a source base station (labeled "S-BS") 1104, and a target base station (labeled "T-BS") 1106.

[0122] The source base station may first send a request to the UE for the UE to obtain one or more SIBs of the target serving cell, the one or more SIBs having common configuration information that can be used by the UE on the target serving cell. As shown in flowchart 1100, source base station 1104 sends 1108 to UE 1102 a request for UE 1102 to obtain SIB1 of the target serving cell.

[0123] Flowchart 1100 corresponds to a case where SIB1 includes (by itself) sufficient public configuration information for the UE to determine the public configuration for operation on the target serving cell. This use of SIB1 is given by way of example and not limitation. It is contemplated that in other non-illustrated embodiments, multiple SIBs may be acquired in order to provide appropriate public configuration information to the UE. It is also contemplated that in some cases, in order to provide appropriate public configuration information, SIBs other than SIB1 may be provided to the UE (for example, the case where the target serving cell is an NTN cell, in which case, in some wireless communication systems, acquisition of SIB19 may be appropriate).

[0124] The request from the source base station to the UE may identify one or more SIBs to be acquired by the UE. For example, in flowchart 1100, the illustrated request identifies SIB1 of the target serving cell to the UE 1102.

[0125] The request from the source base station to the UE may be carried in the SIB of the source serving cell. Alternatively, the request may be carried in the paging between the source base station 1104 and the UE. Alternatively, the request may be carried in an RRC message between the source base station 1104 and the UE. Alternatively, the request may be carried in one of the L2 message and the L1 message between the source base station 1104 and the UE.

[0126] In response to the described request, the UE may acquire the appropriate SIB for the target serving cell (eg, prior to performing initial access on the target serving cell). In flow diagram 1100, UE 1102 acquires 1110 SIB1 for the target serving cell according to a previously received request.

[0127] Once the SIB with the common configuration information has been received, the UE sends an acknowledgement (ACK) to the source base station. For example, in flowchart 1100, once UE 1102 receives SIB1, it sends an ACK illustrated by 1112 to the source base station 1104. Such an ACK may be sent in any of L3 signaling, L2 signaling, or L1 signaling.

[0128] Once the ACK is received at the source base station, the source base station may send a handover command to the UE 1102 to perform the handover to the target serving cell. For example, in flow chart 1100, once the illustrated ACK is received at the source base station 1104, the source base station 1104 sends 1114 a handover command to the UE 1102. The handover command may include dedicated configuration information for operating the UE on the target serving cell.

[0129] It is contemplated that in some cases (such as shown in flowchart 1100 ), the handover command may be a conditional handover command.

[0130] In response to the handover command, the UE may perform a handover from the source serving cell to the target serving cell. The handover may be based on the common configuration information (received in the SIB) and the dedicated configuration information (received in the handover command), with the result that the UE operates on the target serving cell according to the common configuration corresponding to the common configuration information and the dedicated configuration corresponding to the dedicated configuration information.

[0131] Note that during the period between the request and the handover, the UE may maintain communications with the source base station 1104. For example, in flowchart 1100, UE 1102 continues to perform communications 1116 with the source base station 1104. However, as shown at 1118, the gaps in communications 1116 with the source serving cell may be used while UE 1102 acquires the SIBs of the target serving cell (to allow acquisition of the SIBs).

[0132] It should also be noted that although flowchart 1100 illustrates the case where the source serving cell is operated by source base station 1104 and the target serving cell is operated by a (separate) target base station 1106, this is given by way of example and not limitation. It is possible that the target serving cell is also a cell operated by the source base station operating the source serving cell, in which case the UE will perform acquisition of the SIB from the target serving cell broadcasted from the (same) base station.

[0133] Fig.12 1200 illustrates a flow chart of UE acquisition of common configuration information according to an embodiment. Flow chart 1200 illustrates a second option for implementing handover based on UE acquisition of common configuration for a target serving cell from broadcast signaling (one or more SIBs) of the target serving cell. Flow chart 1200 illustrates communications between a UE 1202, a source base station (labeled "S-BS") 1204, and a target base station (labeled "T-BS") 1206.

[0134] The source base station sends 1208 a handover command to the UE 1202 to perform the handover to the target serving cell. The handover command may include a request for the UE to obtain one or more SIBs of the target serving cell, the one or more SIBs having common configuration information that can be used by the UE on the target serving cell. As an example, the handover request illustrated in the flow chart includes a request for the UE 1202 to obtain SIB1 of the target serving cell.

[0135] Flowchart 1200 corresponds to the case where SIB1 includes (by itself) sufficient public configuration information for the UE to determine the public configuration for operation on the target serving cell. This use of SIB1 is given by way of example and not limitation. It is contemplated that in other non-illustrated embodiments, multiple SIBs may be acquired in order to provide appropriate public configuration information to the UE. It is also contemplated that in some cases, in order to provide appropriate public configuration, SIBs other than SIB1 may be provided to the UE (for example, the case where the target serving cell is an NTN cell, in which case, in some wireless communication systems, acquisition of SIB19 may be appropriate).

[0136] The request portion of the handover command from the source base station to the UE may identify one or more SIBs to be acquired by the UE. For example, in flowchart 1200, the illustrated request portion of the handover command identifies to the UE 1202 the SIB1 of the target serving cell.

[0137] The handover command may also include dedicated configuration information for operating the UE on the target serving cell.

[0138] It is contemplated that in some cases (such as shown in flowchart 1100 ), the handover command may be a conditional handover command.

[0139] In response to the handover command, the UE performs (e.g., performs 1210) a handover from the source serving cell to the target serving cell. As part of the handover, the UE may obtain the SIB indicated in the request portion of the handover command. For example, in flowchart 1200, UE 1202 obtains 1212 the SIB1 of the target serving cell according to the request in the illustrated handover command.

[0140] The handover is performed based on the common configuration information (received in the SIB) and the dedicated configuration information (received in the handover command), with the result that the UE operates on the target serving cell according to the common configuration corresponding to the common configuration information and the dedicated configuration corresponding to the dedicated configuration information.

[0141] Once the handover is completed, the UE sends 1214 a handover completion message to the target base station indicating that the handover to the target base station is complete. For example, in flowchart 1200, once UE 1202 completes the handover to target base station 1206, it sends 1214 a handover completion message to target base station 1206 as illustrated.

[0142] It should also be noted that although flowchart 1200 illustrates the case where the source serving cell is operated by source base station 1204 and the target serving cell is operated by a (separate) target base station 1206, this is given by way of example and not limitation. It is possible that the target serving cell is also a cell operated by the source base station operating the source serving cell, in which case the UE will perform acquisition of the SIB from the target serving cell broadcasted from the (same) base station.

[0143] In some cases where UE acquisition of SIBs of a target serving cell is used before handover (e.g., as in flowchart 1100 and / or flowchart 1200), it is possible that not all UEs capable of operating within the wireless communication system have the capability to acquire one or more SIBs before handover in the manner that has been described with respect to flowchart 1100 and flowchart 1200. It is contemplated that in some such systems, the UE may be able to send a UE capability message to the source base station indicating that the UE is capable of acquiring SIBs of the target serving cell before handover (e.g., before and / or as a prerequisite for the source base station to send a request to the UE to perform such acquisition). Such capability message may indicate / distinguish whether the UE has such capability in one or more specific cases applicable to the source serving cell and the target serving cell, such as in an inter-frequency case, in an intra-frequency case, in a FR1 / FR2 distinction case, in a TDD / FDD distinction case, in a band level case, etc.

[0144] In some cases, it is possible that the public configuration for the target serving cell is the same (or similar) as the current public configuration for the source serving cell of the UE currently being used by the UE. For example, it is possible that the public configuration for the source serving cell is consistent / compatible with similar information found in one or more SIBs of the target serving cell, and / or the public configurations for the source serving cell and the target serving cell are the same at least when they are related to the initial access of the UE. In this case, the network can indicate to the UE that the public configuration for the source serving cell is also reused for the target serving cell (e.g., via an indication that there is no change between the public configuration for the source serving cell and the public configuration for the target serving cell).

[0145] Fig.13 Flowchart 1300 illustrates a first case of reusing a common configuration for a source serving cell to handover to a target serving cell according to an embodiment. Flowchart 1300 illustrates communications between a first UE 1302, a second UE 1304, and a network 1306.

[0146] As shown, the network 1306 may send 1308 a handover command to the first UE 1302 that includes an indication that the common configuration for the source serving cell is to be reused for the target serving cell (eg, an indication that the common configuration between the source serving cell and the target serving cell is unchanged).

[0147] The handover command may also include dedicated configuration information for operating the UE on the target serving cell.

[0148] The first UE 1302 can then perform handover based on the public configuration of the source service cell for the first UE 1302 and (reuse of) the dedicated configuration information (received in the handover command to the first UE 1302), with the result that the first UE 1302 operates on the target service cell according to the reused public configuration and the dedicated configuration corresponding to the dedicated configuration information it received.

[0149] Furthermore, as shown, similar actions may be performed between the network 1306 and the second UE 1304. In this case, the network 1306 sends 1310 a handover command to the second UE 1304, instructing the second UE 1304 to reuse the common configuration of the source serving cell for the second UE 1304 (which may be different from the common configuration of the source serving cell for the first UE 1302) and the dedicated configuration information provided in the handover command to the second UE 1304 (which may be different from the dedicated information provided to the first UE 1302), with the result that the second UE 1304 operates on the target serving cell according to the reused common configuration and the dedicated configuration corresponding to the dedicated configuration information it received.

[0150] In the event that the common configuration for the target serving cell is similar but not identical to the current common configuration for the UE's source serving cell currently being used by the UE, the network may indicate that the common configuration is to be reused, along with one or more updated parameters for the common configuration.

[0151] Fig.14 Flowchart 1400 illustrates a second case of reusing a common configuration for a source serving cell to handover to a target serving cell according to an embodiment. Flowchart 1400 illustrates communications between a first UE 1402, a second UE 1404, and a network 1306.

[0152] Similar to About Fig.13 1300, the network 1406 sends 1408 a handover command to a first UE 1402 having a dedicated configuration for operating the UE on a target serving cell, and an indication to reuse a common configuration of a source serving cell for the UE. In addition, the handover command also includes an indication of one or more updated parameters for the common configuration to be reused. The UE may then continue to reuse the common configuration for the source serving cell in order to hand over to the target serving cell in conjunction with any updated parameters.

[0153] It can be seen that in the case where the network 1406 sends 1410 a handover command to the second UE 1404, similar indications may be made in the handover command between the network 1406 and the second UE 1404. The updated parameters for the second UE 1404 may be different from the updated parameters for the first UE 1402 and / or use different values ​​than the updated parameters for the first UE.

[0154] The updated parameters for the common configuration may include, for example, an updated physical cell identity (PCI) and the like.

[0155] The mechanisms for delivering application specific configuration information are now discussed. Fig.15 1500 is a flowchart illustrating a first option for providing dedicated configuration information to a UE. The network 1504 sends 1506 a handover command to the UE 1502, which includes a dedicated configuration for the target serving cell to the UE, which can be used by the UE to perform a handover to the target serving cell. The handover command can be sent to the UE on a dedicated transmission. Once the UE 1502 applies the dedicated configuration, it sends 1508 an RRCReconfigurationComplete message to the network 1504.

[0156] In some cases, a type of dedicated configuration information other than a dedicated configuration may be sent as described by the handover command shown in flowchart 1500. For example, it is contemplated that an index of the dedicated configuration may be sent to the UE, thereby enabling the UE to identify the dedicated configuration to use based on the index. In this case, in various embodiments, the handover command may be any of an L1 indication, an L2 indication, or an L3 indication.

[0157] It is contemplated that, in some embodiments, Fig.15 The handover command may be a conditional handover command for conditional handover.

[0158] Fig.16 A flowchart 1600 of a second option for providing dedicated configuration information to a UE is illustrated. A network may send a set of candidate dedicated configurations (e.g., for a corresponding set of target serving cells) in a broadcast and / or PTM manner so that multiple UEs served by the network may receive the candidate dedicated configurations. For example, in flowchart 1600, network 1606 sends 1608 a PTM transmission including a set of candidate dedicated configurations, the set of candidate dedicated configurations including a first dedicated configuration ("Config#1") and a second dedicated configuration ("Config#2"), the set of candidate dedicated configurations being received at each of first UE 1602 and second UE 1604. As shown, the PTM transmission may include an RRCReconfiguration message with the information.

[0159] In some embodiments, the set of candidate dedicated configurations may be included in, for example, a PTM transmission that is also used to deliver common configuration information to multiple UEs, as discussed herein. In other embodiments, a new / different PTM / broadcast transmission is used instead.

[0160] The network may then use the index in a dedicated handover command for the UE to indicate a candidate dedicated configuration to be used by the UE (e.g., instead of including the substantive data of the dedicated configuration in the handover command). For example, in flow chart 1600, the network 1606 sends 1610 to the first UE 1602 a first handover command having an index indicating to the first UE 1602 that it will use a first dedicated configuration, and further sends 1612 to the second UE 1604 a second handover command having an index indicating to the second UE 1604 that it will use a second dedicated configuration.

[0161] In this case of flowchart 1600 using an index according to a handover command, in various embodiments, the handover command may be any of an L1 indication, an L2 indication, or an L3 indication.

[0162] It is contemplated that, in some embodiments, Fig.16 The handover command may be a conditional handover command for conditional handover.

[0163] Fig.17 A flowchart 1700 of a third option for providing dedicated configuration information to a UE is illustrated. The network may send a set of candidate dedicated configurations (e.g., for a corresponding set of target serving cells) in a broadcast and / or PTM manner so that multiple UEs served by the network can receive these dedicated configurations. The transmission may also include one or more conditions for each of the dedicated configurations, which the UE may use to determine whether to perform handover based on the associated configuration. For example, in flowchart 1700, the network 1706 sends 1708 a PTM transmission including a set of candidate dedicated configurations, the set of candidate dedicated configurations including a first dedicated configuration ("Config#1") and a first one or more conditions associated with the first dedicated configuration ("Cond#1") and a second dedicated configuration ("Config#2") and a second one or more conditions associated with the second dedicated configuration ("Cond#2"), and the PTM transmission is received at each of the first UE 1702 and the second UE 1704. As shown, the PTM transmission may include an RRCReconfiguration message with the information.

[0164] Examples of conditions used may be, for example, a "condEventA4" NTN handover condition, a "condEventD1" NTN handover condition, and / or a "condEventT1" NTN handover condition, as discussed herein.

[0165] In some embodiments, the set of candidate dedicated configurations and any associated conditions may be included in, for example, a PTM transmission that is also used to deliver common configuration information to multiple UEs, as discussed herein. In other embodiments, a new / different PTM / broadcast transmission is used instead.

[0166] Each UE may then identify its dedicated configuration that should be used for handover based on the associated conditions. For example, the first UE 1702 may identify 1710 that the first one or more conditions for the first dedicated configuration are satisfied, and thus determine to perform handover based on the first dedicated configuration. Similarly, the second UE 1704 may identify 1712 that the second one or more conditions for the second dedicated configuration are satisfied, and thus determine to perform handover based on the second dedicated configuration.

[0167] It is also contemplated that in some cases the handover command may be a group handover command directed to multiple UEs in a broadcast or PTM manner. Fig.18 The use of a group handover command accompanying the execution of a handover of a group of UEs is illustrated. The network may send a set of candidate dedicated configurations (e.g., for a corresponding set of target serving cells) in a broadcast and / or PTM manner so that multiple UEs served by the network may receive these candidate dedicated configurations. For example, in flowchart 1800, network 1806 sends 1808 a PTM transmission including a set of candidate dedicated configurations, the set of candidate dedicated configurations including a first dedicated configuration ("Config#1") and a second dedicated configuration ("Config#2"), the set of candidate dedicated configurations being received at each of first UE 1802 and second UE 1804. As shown, the PTM transmission may include an RRCReconfiguration message with this information.

[0168] In some embodiments, the set of candidate dedicated configurations may be included in, for example, a PTM transmission that is also used to deliver common configuration information to multiple UEs, as discussed herein. In other embodiments, a new / different PTM / broadcast transmission is used instead.

[0169] Then, the network can then use the group handover command sent in a broadcast or PTM manner to cause multiple UEs to perform handover respectively. The dedicated configuration information in the group handover command may include a value for each UE in the UE, which indicates a candidate dedicated configuration to be used by the UE for its HO in multiple candidate dedicated configurations. For example, in flowchart 1800, the network 1806 sends 1810 a group handover command in a broadcast or PTM manner so that it is received by each of the first UE 1802 and the second UE 1804. The group handover command includes dedicated configuration information for each of (at least) the first UE 1802 and the second UE 1804. The dedicated configuration information for the first UE 1802 arrives as the value of the first bit in the group handover command. As shown in the figure, the value indicates the use of the first dedicated configuration. The dedicated configuration information for the second UE 1804 arrives as the value of the second bit in the group handover command. As shown in the figure, the value indicates the use of the second dedicated configuration.

[0170] Then, the UE selects a dedicated configuration for performing the handover from the candidate dedicated configurations based on the value in the dedicated configuration information corresponding to the UE received from the group handover command. For example, in flowchart 1800, the first UE 1802 selects 1812 a first dedicated configuration for handover based on the value of its corresponding bit in the group handover command. In addition, the second UE 1804 selects 1814 a second dedicated configuration for handover based on the value of its corresponding bit in the group handover command.

[0171] The use of a single bit to convey a value indicating a specific candidate dedicated configuration for use with a specific UE (as shown in flowchart 1800) is given by way of example and not limitation. It is contemplated that in some cases (e.g., when there are more than two candidate dedicated configurations), multiple bits may be used to represent a value for indicating a specific candidate dedicated configuration for a specific UE in a group handover command.

[0172] The presentation order of the dedicated configuration information for the corresponding UE in the group handover command may be preconfigured or predefined. It is also contemplated that the group handover command may be sent in any of L1 signaling, L2 signaling or L3 signaling between the network and the plurality of UEs.

[0173] Fig.19 A method 1900 of a UE according to embodiments herein is illustrated. The method 1900 includes receiving 1902 a PTM transmission including common configuration information for operating on a target serving cell from a source base station operating a source serving cell serving the UE.

[0174] The method 1900 also includes receiving 1904 from the source base station dedicated configuration information for operating the UE on the target serving cell.

[0175] The method 1900 also includes performing 1906 a handover to a target serving cell based on the common configuration information and the dedicated configuration information.

[0176] In some implementations of method 1900, the target serving cell is a cell of a target base station.

[0177] In some embodiments, method 1900 further comprises sending feedback signaling to the source base station in response to receiving the common configuration information. In some such embodiments, the feedback signaling comprises an L3RRCReconfigurationComplete message. In some such embodiments, the feedback signaling comprises an L2 RLC ACK feedback. In some such embodiments, the feedback signaling comprises an L1 HARQ-ACK signaling. In some such embodiments, the feedback signaling comprises a MAC CE.

[0178] In some embodiments of method 1900, the PTM transmission includes an RRCReconfiguration message with common configuration information received over an existing SRB.

[0179] In some embodiments of method 1900, the PTM transmission includes an RRC message with common configuration information received over a newly established SRB.

[0180] In some embodiments of method 1900, the PTM transmission uses a G-RNTI of a UE corresponding to a UE group including the UE.

[0181] In some embodiments, method 1900 also includes decrypting the PTM transmission using the group encryption key and the group integrity protection key.

[0182] In some embodiments, method 1900 also includes verifying the integrity of the PTM transmission by using a dedicated integrity protection key with the PTM transmission to match a MAC-I for the UE included in the PTM transmission.

[0183] In some implementations of method 1900, the common configuration information includes differential configuration information relative to a common configuration for the source serving cell.

[0184] In some embodiments of method 1900, the dedicated configuration information includes a dedicated configuration for the UE.

[0185] In some embodiments of method 1900, the PTM transmission further includes a plurality of candidate dedicated configurations, and wherein the dedicated configuration information includes an index corresponding to one of the candidate dedicated configurations for the UE.

[0186] In some embodiments of method 1900, the dedicated configuration information is sent in a dedicated handover command. In some of these embodiments, the dedicated handover command comprises a conditional handover command.

[0187] In some embodiments of method 1900, the PTM transmission further includes a plurality of candidate dedicated configurations, the dedicated configuration information is sent in a group handover command, and the dedicated configuration information includes a value in the group handover command indicating a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0188] Fig. 20 A method 2000 of a source base station according to embodiments herein is illustrated. The method 2000 includes sending 2002 a PTM transmission to a plurality of UEs operating on a source serving cell of the source base station, the PTM transmission including common configuration information for operating on a target serving cell.

[0189] The method 2000 also includes sending 2004 to a first UE of the plurality of UEs first dedicated configuration information for operating the first UE on a target serving cell.

[0190] The method 2000 also includes sending 2006 to a second UE of the plurality of UEs second dedicated configuration information for operating the second UE on the target serving cell.

[0191] In some embodiments of method 2000, the target serving cell is a cell of a target base station, and method 2000 further includes receiving a public configuration for the target serving cell from the target base station, wherein the public configuration for the target serving cell includes public configuration information for operating on the target serving cell.

[0192] In some embodiments, the method 2000 further comprises receiving feedback signaling from the first UE in response to sending the common configuration information. In some such embodiments, the feedback signaling comprises a dedicated L3RRCReconfigurationComplete message. In some such embodiments, the feedback signaling comprises L2 RLC ACK feedback. In some such embodiments, the feedback signaling comprises L1 HARQ-ACK signaling. In some such embodiments, the feedback signaling comprises MAC CE.

[0193] In some embodiments of method 2000, the PTM transmission includes an RRCReconfiguration message with common configuration information sent over an existing SRB.

[0194] In some embodiments, method 2000 also includes establishing a new SRB for communicating with the plurality of UEs, wherein the PTM transmission includes an RRC message with common configuration information sent on the new SRB.

[0195] In some embodiments of method 2000, the PTM transmission uses a G-RNTI corresponding to a UE group including a plurality of UEs.

[0196] In some embodiments, method 2000 also includes encrypting the PTM transmission for use with a group encryption key at the plurality of UEs and a group integrity protection key at the plurality of UEs.

[0197] In some embodiments of method 2000, the PTM transmission also includes a MAC-I for a corresponding UE among the plurality of UEs for use with a dedicated integrity protection key at the corresponding UE among the plurality of UEs.

[0198] In some embodiments of method 2000, the common configuration information includes differential configuration information relative to a common configuration for the source serving cell. In some such embodiments, method 2000 also includes sending a common configuration for operation on the source serving cell to a target base station for the target serving cell, and receiving the differential configuration information from the target base station. In some such embodiments, method 2000 includes sending a request for a common configuration for the target serving cell to a target base station for the target serving cell, receiving a common configuration for the target serving cell from the target base station, and determining the differential configuration information based on the common configuration for the target serving cell.

[0199] In some embodiments of method 2000, the first dedicated configuration information includes a dedicated configuration for the first UE.

[0200] In some embodiments of method 2000, the PTM transmission also includes a plurality of candidate dedicated configurations, and the first dedicated configuration information includes an index corresponding to one of the plurality of candidate dedicated configurations for the UE.

[0201] In some implementations of method 2000, the first dedicated configuration information is sent in a first dedicated handover command, and the second dedicated configuration information is sent in a second dedicated handover command. In some such implementations, the first dedicated handover command comprises a conditional handover command.

[0202] In some embodiments of method 2000, the PTM transmission also includes multiple candidate dedicated configurations, and first dedicated configuration information and second dedicated configuration information are sent in a group handover command, the first dedicated configuration information includes a first value in the group handover command, the first value indicating one of the multiple candidate dedicated configurations for the first UE, and the second dedicated configuration information includes a second value in the group handover command, the second value indicating one of the multiple candidate dedicated configurations for the second UE.

[0203] Fig.21A method 2100 of a UE according to embodiments herein is illustrated. The method 2100 includes receiving 2102 a request from a source base station operating a source serving cell serving the UE for the UE to acquire one or more SIBs of a target serving cell having common configuration information for operating on the target serving cell.

[0204] The method 2100 also includes acquiring 2104 one or more SIBs of the target serving cell having common configuration information for operating on the target serving cell.

[0205] The method 2100 also includes sending 2106 to the source base station a confirmation that the UE has acquired one or more SIBs.

[0206] The method 2100 also includes receiving 2108 from the source base station a handover command including dedicated configuration information for operating the UE on the target serving cell.

[0207] The method 2100 also includes performing 2110 a handover to the target serving cell based on common configuration information and dedicated configuration information from one or more SIBs of the target serving cell in response to the handover command.

[0208] In some embodiments of method 2100, the request identifies one or more SIBs of the target serving cell.

[0209] In some embodiments of method 2100, the handover command includes a conditional handover command.

[0210] In some implementations of method 2100, the request is carried in a SIB of the source serving cell.

[0211] In some implementations of method 2100, the request is carried in an RRC message.

[0212] In some implementations of method 2100, the request is carried in one of an L1 message and an L2 message.

[0213] In some embodiments, method 2100 also includes sending a UE capability message to the source base station indicating that the UE is capable of acquiring one or more SIBs prior to handover.

[0214] In some embodiments of method 2100, the dedicated configuration information includes a dedicated configuration for the UE.

[0215] In some embodiments, method 2100 further includes receiving a plurality of candidate dedicated configurations from a source base station in a PTM transmission, and the dedicated configuration information includes an index corresponding to a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0216] In some embodiments of method 2100, the handover command includes a dedicated handover command.

[0217] In some embodiments, method 2100 also includes receiving multiple candidate dedicated configurations from the source base station in a PTM transmission, wherein the handover command includes a group handover command, and the dedicated configuration information includes a value in the group handover command indicating one of the multiple candidate dedicated configurations for the UE.

[0218] Fig. 22 A method 2200 of a source base station according to embodiments herein is illustrated. The method 2200 includes sending 2202 to a UE operating on a source serving cell of the source base station a request for the UE to acquire one or more SIBs of a target serving cell having common configuration information for operating on the target serving cell.

[0219] The method 2200 also includes receiving 2204 from the UE a confirmation that the UE has acquired one or more SIBs of the target serving cell.

[0220] The method 2200 also includes sending 2206 to the UE a handover command including dedicated configuration information for operating the UE on the target serving cell.

[0221] In some implementations of method 2200, the target serving cell is a cell of a target base station.

[0222] In some embodiments of method 2200, the request identifies one or more SIBs of the target serving cell.

[0223] In some embodiments of method 2200, the handover command includes a conditional handover command.

[0224] In some implementations of method 2200, the request is carried in a SIB of the source serving cell.

[0225] In some implementations of method 2200, the request is carried in an RRC message.

[0226] In some implementations of method 2200, the request is carried in one of an L1 message and an L2 message.

[0227] In some embodiments, method 2200 also includes receiving a UE capability message from the UE indicating that the UE is capable of acquiring one or more SIBs prior to handover.

[0228] In some embodiments of method 2200, the dedicated configuration information includes a dedicated configuration for the UE.

[0229] In some embodiments, the method 2200 further comprises sending a plurality of candidate dedicated configurations to the UE in a PTM transmission, and the dedicated configuration information comprises an index corresponding to a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0230] In some embodiments of method 2200, the handover command includes a dedicated handover command.

[0231] In some embodiments, method 2200 also includes sending multiple candidate dedicated configurations to the UE in a PTM transmission, wherein the handover command includes a group handover command, and the dedicated configuration information includes a value in the group handover command indicating one of the multiple candidate dedicated configurations for the UE.

[0232] Fig.23 A method 2300 of a UE according to an embodiment of the present invention is illustrated. The method 2300 includes receiving 2302 a handover command from a source base station operating a source serving cell serving the UE, the handover command including dedicated configuration information for operating the UE on a target serving cell and instructions for obtaining one or more SIBs of the target serving cell having public configuration information for operating on the target serving cell.

[0233] The method 2300 also includes performing 2304 a handover to a target serving cell in response to the handover command, wherein the handover includes acquiring one or more SIBs of the target serving cell having common configuration information, and wherein the handover is performed based on the common configuration information and the dedicated configuration information.

[0234] The method 2300 also includes, after completing the handover to the target serving cell, sending 2306 an indication on the target serving cell that the handover to the target serving cell is complete.

[0235] In some embodiments of method 2300, the handover command identifies one or more SIBs of the target serving cell.

[0236] In some embodiments of method 2300, the handover command includes a conditional handover command.

[0237] In some embodiments of method 2300, the dedicated configuration information includes a dedicated configuration for the UE.

[0238] In some embodiments, the method 2300 further includes receiving a plurality of candidate dedicated configurations from the source base station in a PTM transmission, and wherein the dedicated configuration information includes an index corresponding to a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0239] In some embodiments of method 2300, the handover command includes a dedicated handover command.

[0240] In some embodiments, method 2300 also includes receiving multiple candidate dedicated configurations from the source base station in a PTM transmission, wherein the handover command includes a group handover command, and the dedicated configuration information includes a value in the group handover command indicating one of the multiple candidate dedicated configurations for the UE.

[0241] Fig.24 A method 2400 of a UE according to an embodiment of the present invention is illustrated. The method 2400 includes receiving 2402 a handover command from a source base station that operates a source serving cell serving the UE according to a common configuration for the source serving cell, the handover command including dedicated configuration information for operating the UE on a target serving cell and an indication that the common configuration for the source serving cell is to be reused for the target serving cell.

[0242] The method 2400 also includes performing 2404 a handover to the target serving cell based on the common configuration for the source serving cell and dedicated configuration information for operating the UE on the target serving cell in response to the handover command.

[0243] In some embodiments of method 2400, the handover command also includes updated parameters for the common configuration of the source serving cell.

[0244] In some embodiments of method 2400, the handover command includes a conditional handover command.

[0245] In some embodiments of method 2400, the dedicated configuration information includes a dedicated configuration for the UE.

[0246] In some embodiments, method 2400 further includes receiving a plurality of candidate dedicated configurations from a source base station in a PTM transmission, and wherein the dedicated configuration information includes an index corresponding to a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0247] In some embodiments of method 2400, the handover command includes a dedicated handover command.

[0248] In some embodiments, method 2400 also includes receiving multiple candidate dedicated configurations from the source base station in a PTM transmission, wherein the handover command includes a group handover command, and the dedicated configuration information includes a value in the group handover command indicating one of the multiple candidate dedicated configurations for the UE.

[0249] Fig.25 A method 2500 of a source base station according to embodiments herein is illustrated. The method 2500 includes determining 2502 that a first common configuration for a source serving cell of the source base station is the same as a second common configuration for a target serving cell.

[0250] Method 2500 also includes sending 2504 a handover command to a UE operating on a source serving cell according to the first common configuration, the handover command including dedicated configuration information for operating the UE on a target serving cell and an indication that the first common configuration for the source serving cell is to be reused for the target serving cell.

[0251] In some embodiments of method 2500, the handover command also includes updated parameters of the first common configuration for the source serving cell.

[0252] In some embodiments of method 2500, the handover command includes a conditional handover command.

[0253] In some embodiments of method 2500, the dedicated configuration information includes a dedicated configuration for the UE.

[0254] In some embodiments, method 2500 further comprises sending a plurality of candidate dedicated configurations to the UE in a PTM transmission, and wherein the dedicated configuration information comprises an index corresponding to a candidate dedicated configuration for the UE in the plurality of candidate dedicated configurations.

[0255] In some embodiments of method 2500, the handover command includes a dedicated handover command.

[0256] In some embodiments, method 2500 also includes sending multiple candidate dedicated configurations to the UE in a PTM transmission, wherein the handover command includes a group handover command, and the dedicated configuration information includes a value in the group handover command indicating one of the multiple candidate dedicated configurations for the UE.

[0257] It is possible that the target base station operating the target service cell can deliver the public configuration for the target service cell to the source base station. This enables the source base station to provide its UE with public configuration information for operating on the target service cell (for example, where the public configuration information may include the public configuration for the target service cell and / or the difference configuration information for the target service cell that the source base station has determined by comparing the public configuration for the target service cell with the public configuration for the source service cell, etc.). Therefore, the system and method for transmitting the public configuration between base stations on the Xn interface between base stations can be used to facilitate such communication between the source base station and the target base station.

[0258] Fig.26A diagram 2600 of a first option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment is illustrated. A source base station (labeled "S-BS" in diagram 2600) 2602 may be operating a source serving cell and a target base station (labeled "T-BS" in diagram 2600) 2604 may be operating a target serving cell, as discussed in embodiments herein. The source base station 2602 sends 2606 a common configuration request to the target base station 2604. As shown, the common configuration request may optionally include a target cell list for the target serving cell for which the source base station 2602 is requesting common configuration.

[0259] In response to the common configuration request, the target base station 2604 sends 2608 a common configuration response. As shown, the common configuration response includes one or more common configurations for one or more serving cells operated by the target base station 2604, which may include a common configuration for the target serving cell from the perspective of the source base station 2602. If a target cell list is provided in the common configuration request, the target base station 2604 may use the target cell list to determine which of its serving cells to include a common configuration for in the common configuration response.

[0260] Fig. 27 A diagram 2700 of a second option for communicating a common configuration between a source base station and a target base station over an Xn interface according to an embodiment is illustrated. A source base station (labeled "S-BS" in diagram 2700) 2702 may be operating a source serving cell and a target base station (labeled "T-BS" in diagram 2700) 2704 may be operating a target serving cell, as discussed in embodiments herein. The target base station 2704 sends 2706 a common configuration update message that includes one or more common configurations for one or more serving cells operated by the target base station 2704 (from the perspective of the source base station 2702, where the one or more serving cells may be target serving cells).

[0261] The common configuration update message may be sent by the target base station 2704 without receiving any previous message from the source base station 2702 for triggering this action.

[0262] Fig.28A diagram 2800 of a third option for communicating a common configuration between a source base station and a target base station on an Xn interface according to an embodiment is illustrated. A source base station (labeled "S-BS" in diagram 2800) 2802 may be operating a source serving cell and a target base station (labeled "T-BS" in diagram 2800) 2804 may be operating a target serving cell, as discussed in the embodiments herein. The source base station 2802 sends 2806 an Xn start message (e.g., the illustrated Xn setup request message) to the target base station 2804. The Xn start message may include a request for one or more common configurations for one or more target serving cells. Diagram 2800 illustrates that in some embodiments, the request may take the form of an indication ("common configuration") in a request for serving cell information ("served cell information NR") from the target base station 2804.

[0263] In response to the Xn Start message, the target base station 2804 sends 2808 an Xn Reply message (e.g., the illustrated Xn Setup Response message). The Xn Reply message includes one or more common configurations for one or more serving cells operated by the target base station 2804, which may include a common configuration for the target serving cell from the perspective of the source base station 2802. Diagram 2800 illustrates that in some embodiments, in response to a previous request for serving cell information (“served cell information NR”), the response may take the form of responsive data (“common configuration”) in a larger overall data set.

[0264] Examples of pairs of Xn start messages and corresponding Xn reply messages that may be used in the discussion corresponding to FIG2800 include Xn setup request messages and Xn setup response messages, NG-RAN node configuration update messages and NG-RAN node configuration update ACK, cell activation request messages and cell activation response messages, and resource status request messages and resource status response messages, etc.

[0265] Fig.29 A diagram 2900 of a fourth option for communicating a common configuration between a source base station and a target base station on an Xn interface according to an embodiment is illustrated. A source base station (labeled "S-BS" in diagram 2900) 2902 may be operating a source serving cell and a target base station (labeled "T-BS" in diagram 2900) 2904 may be operating a target serving cell, as discussed in the embodiments herein. The source base station 2902 sends 2906 a handover request (e.g., the illustrated HO REQ message) to the target base station 2904. The handover request indicates a target serving cell ("CELL-2") operated by the target base station and a UE ("UE-1") that is the object of the handover request.

[0266] In response to the handover request, the target base station 2904 sends 2908 a handover response (e.g., the illustrated HO RESP message). The handover response indicates a common configuration for the target serving cell ("common configuration for CELL-2") and a dedicated configuration for the UE to operate on the target serving cell ("UE-1 dedicated configuration").

[0267] In the case where there is no change between the public configuration for the target serving cell and the public configuration for the current serving cell of the UE, the source base station 2902 may include an indication of the public configuration for the target serving cell in the handover response, rather than including the public configuration for the target serving cell in the handover response. Therefore, it can be understood that such an implementation according to the handover request may use a handover response that generally has public configuration information but not necessarily has a specific public configuration itself.

[0268] Fig.30 A diagram 3000 of a fifth option for communicating a common configuration between a source base station and a target base station according to an embodiment is illustrated. A source base station (labeled "S-BS" in diagram 3000) 3002 may be operating a source serving cell and a target base station (labeled "T-BS" in diagram 3000) 3004 may be operating a target serving cell, as discussed in the embodiments of this document. The source base station 3002 sends 3006 a handover request (e.g., the illustrated HO REQ message) to the target base station 3004. The handover request indicates a target serving cell ("CELL-2") operated by the target base station and a plurality of UEs ("UE-1", "UE-2") that are the objects of the handover request.

[0269] In response to the handover request, the target source base station 3002 sends 3008 a handover response (e.g., the illustrated handover RESP message). The handover response indicates a common configuration for the target serving cell ("common configuration of CELL-2") and a dedicated configuration for each of the UEs for operating on the target serving cell ("UE-1 dedicated configuration", "UE-2 dedicated configuration").

[0270] In the case where there is no change between the public configuration for the target serving cell and the public configuration for the current serving cell of the UE, the source base station 2902 may include an indication of the public configuration for the target serving cell in the handover response, rather than including the public configuration for the target serving cell in the handover response. Therefore, it can be understood that such an implementation according to the handover request may use a handover response that generally has public configuration information but not necessarily has a specific public configuration itself.

[0271] In implementations where base station functionality is divided between a centralized unit (CU) and a distributed unit (DU), such as in the case of Integrated Access and Backhaul (IAB), it is possible to communicate about the configuration of a group of UEs using the F1 interface between the CU and the DU.

[0272] Fig.31 A flowchart 3100 for group configuration of multiple UEs between a target DU 3102 and a CU 3104 on an F1 interface according to an implementation scheme is illustrated. The DU sends a message 3106 to the CU 3104, which includes a public configuration for operating on a target serving cell and one or more dedicated configurations for corresponding one or more UEs for operating on the target serving cell. As shown in the figure, in some implementation schemes, the message may be a UE context establishment request, wherein "CELL-1's public configuration" represents a public configuration for operating on a target serving cell, "UE-1 dedicated configuration" represents a dedicated configuration for a first UE, "UE-2 dedicated configuration" represents a dedicated configuration for a second UE, and "UE-3 dedicated configuration" represents a dedicated configuration for a third UE. In other implementation schemes, another message (different from the UE context establishment request) may be used.

[0273] In response, the CU 3104 sends 3108 to the target DU 3102 a message indicating that the common configuration and one or more dedicated configurations are successfully received. As shown, in some embodiments (e.g., corresponding to the receipt of a UE context establishment request), the message may be a UE context establishment response message indicating that a context for each of the UEs is successfully established at the CU based on the common configuration and one or more dedicated configurations. In other embodiments, another message (different from the UE context establishment request) may be used.

[0274] In some alternative cases, it is possible that the CU initiates the process by sending a message to the target DU including a common configuration for operating on the target service cell and one or more dedicated configurations for corresponding one or more UEs operating on the target service cell, and in response, the target DU then sends a message indicating that the common configuration and the one or more dedicated configurations are successfully received.

[0275] Fig.32 A method 3200 of a source base station according to embodiments herein is illustrated. The method 3200 includes sending 3202 a request to a target base station for one or more common configurations corresponding to one or more target serving cells operated by the target base station.

[0276] The method 3200 also includes receiving 3204 from the target base station one or more common configurations corresponding to one or more target serving cells.

[0277] In some embodiments of method 3200, a request is made to identify one or more target serving cells.

[0278] Fig.33 A method 3300 of a target base station according to embodiments herein is illustrated. The method 3300 includes receiving 3302 a request from a source base station for one or more common configurations corresponding to one or more target serving cells operated by the target base station.

[0279] The method 3300 also includes sending 3304 to the source base station one or more common configurations corresponding to the one or more target serving cells.

[0280] In some embodiments of method 3300, a request is made to identify one or more target serving cells.

[0281] Fig.34 A method 3400 of a source base station according to embodiments herein is illustrated. The method 3400 includes sending 3402 to the source base station one or more common configurations corresponding to one or more target serving cells operated by a target base station.

[0282] Fig.35 A method 3500 of a source base station according to embodiments herein is illustrated. The method 3500 includes sending 3502 a request in an Xn Start message to a target base station for one or more common configurations corresponding to one or more target serving cells operated by the target base station.

[0283] The method 3500 also includes receiving 3504 one or more common configurations corresponding to one or more target serving cells from the target base station in an Xn reply message corresponding to the Xn start message.

[0284] In some embodiments of method 3500, the Xn Initiation message includes an Xn Setup Request message, and wherein the Xn Reply message includes an Xn Setup Response message.

[0285] In some embodiments of method 3500, the Xn start message includes a NG-RAN node configuration update message, and wherein the Xn reply message includes a NG-RAN node configuration update ACK message.

[0286] In some embodiments of method 3500, the Xn start message includes a cell activation request message, and wherein the Xn reply message includes a cell activation response message.

[0287] In some embodiments of method 3500, the Xn initiation message includes a resource status request message, and wherein the Xn reply message includes a resource status response message.

[0288] Fig.36 A method 3600 of a target base station according to embodiments herein is illustrated. The method 3600 includes receiving 3602 a request in an Xn Start message from a source base station for one or more common configurations corresponding to one or more target serving cells operated by the target base station.

[0289] The method 3600 also includes sending 3604 one or more common configurations corresponding to one or more target serving cells to the source base station in an Xn reply message corresponding to the Xn start message.

[0290] In some embodiments of 3600, the Xn Initiation message includes an Xn Setup Request message, and wherein the Xn Reply message includes an Xn Setup Response message.

[0291] In some embodiments of 3600, the Xn start message includes a NG-RAN node configuration update message, and wherein the Xn reply message includes a NG-RAN node configuration update ACK message.

[0292] In some embodiments of 3600, the Xn start message includes a cell activation request message, and wherein the Xn reply message includes a cell activation response message.

[0293] In some embodiments of 3600, the Xn initiation message includes a resource status request message, and wherein the Xn reply message includes a resource status response message.

[0294] Fig.37 A method 3700 of a source base station according to an embodiment of the present invention is illustrated. The method 3700 includes sending 3702 a handover request to a target base station, the handover request indicating a target serving cell operated by the target base station and a first UE as a first object of the handover request.

[0295] The method 3700 also includes receiving 3704 a handover response from the target base station, the handover response indicating common configuration information for the target serving cell and a first dedicated configuration for the first UE for operating on the target serving cell.

[0296] In some embodiments of method 3700, the common configuration information includes a common configuration for the target serving cell.

[0297] In some implementations of method 3700, the common configuration information includes an indication that no change is necessary between the first common configuration for the source serving cell and the second common configuration for the target serving cell.

[0298] In some embodiments of method 3700, the handover request further indicates a second UE that is a second object of the handover request, and wherein the handover response further indicates a second dedicated configuration for the second UE for operating on the target serving cell.

[0299] Fig.38 A method 3800 of a target base station according to an embodiment of this document is illustrated. The method 3800 includes receiving 3802 a handover request from a source base station, the handover request indicating a target serving cell operated by the target base station and a first UE as a first object of the handover request.

[0300] The method 3800 also includes sending 3804 a handover response to the source base station, the handover response indicating common configuration information for the target serving cell and a first dedicated configuration for the first UE for operating on the target serving cell.

[0301] In some implementations of method 3800, the common configuration information includes a common configuration for the target serving cell.

[0302] In some implementations of method 3800, the common configuration information includes an indication that no change is necessary between the first common configuration for the source serving cell and the second common configuration for the target serving cell.

[0303] In some embodiments of method 3800, the handover request further indicates a second UE that is a second object of the handover request, and wherein the handover response further indicates a second dedicated configuration for the second UE for operating on the target serving cell.

[0304] Fig.39 A method 3900 of a DU according to an embodiment of the present invention is illustrated. The method 3900 includes sending 3902 a first message to a CU, the first message including a common configuration for operating on a target serving cell and one or more dedicated configurations for corresponding one or more UEs for operating on the target serving cell.

[0305] The method 3900 also includes receiving 3904 a second message from the CU, the second message indicating that the common configuration and the one or more private configurations are successfully received.

[0306] In some embodiments of method 3900, the first message includes a UE context establishment request and the second message includes a UE context establishment response indicating that a context for each of the one or more UEs is successfully established at the CU based on a common configuration and one or more dedicated configurations.

[0307] Fig.40A method 4000 of a CU according to an embodiment of the present invention is illustrated. The method 4000 includes receiving 4002 a first message from a DU, the first message including a common configuration for operating on a target serving cell and one or more dedicated configurations for corresponding one or more UEs for operating on the target serving cell.

[0308] The method 4000 also includes sending 4004 a second message to the DU, the second message indicating that the common configuration and the one or more private configurations are successfully received.

[0309] In some embodiments of method 4000, the first message includes a UE context establishment request, and the second message includes a UE context establishment response indicating that a context for each of the one or more UEs is successfully established at the CU based on a common configuration and one or more dedicated configurations.

[0310] Fig.41 An example architecture of a wireless communication system 4100 according to an embodiment disclosed herein is illustrated. The description provided below is for an example wireless communication system 4100 operating in conjunction with LTE system standards and / or 5G or NR system standards provided in 3GPP technical specifications and other 3GPP documents.

[0311] like Fig.41 As shown, wireless communication system 4100 includes UE 4102 and UE 4104 (although any number of UEs may be used). In this example, UE 4102 and UE 4104 are illustrated as smartphones (e.g., handheld touch screen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0312] UE 4102 and UE 4104 may be configured to be communicatively coupled to RAN 4106. In an embodiment, RAN 4106 may be NG-RAN, E-UTRAN, etc. UE 4102 and UE 4104 utilize connections (or channels) (shown as connection 4108 and connection 4110, respectively) with RAN 4106, where each connection (or channel) includes a physical communication interface. RAN 4106 may include one or more base stations (such as base station 4112 and base station 4114) and / or other entities (e.g., a payload on satellite 4136, which may operate a cell as indicated by one of base station 4112 and / or base station 4114) that enable connection 4108 and connection 4110. One or more non-terrestrial gateways 4134 may be configured to communicate with RAN 4106 in a manner related to the terrestrial network. Figure 1 The NTN architecture 100 describes a manner in which the payload 4138 on the satellite 4136 is integrated into the RAN 4106.

[0313] In this example, connection 4108 and connection 4110 are air interfaces that implement such communication coupling and may conform to the RAT used by RAN 4106, such as, for example, LTE and / or NR. It is contemplated that in some embodiments, connection 4108 and connection 4110 may include service links between their respective UE 4102, UE 4104 and payload 4138 of satellite 4136.

[0314] In some embodiments, UE 4102 and UE 4104 can also directly exchange communication data via side link interface 4116.

[0315] UE 4104 is shown as being configured to access an access point (shown as AP 4118) via connection 4120. By way of example, connection 4120 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, wherein AP 4118 may include In this example, AP 4118 can connect to another network (e.g., the Internet) without going through CN 4124.

[0316] In an embodiment, UE 4102 and UE 4104 may be configured to communicate with each other, base station 4112, base station 4114, and / or payload 4138 of satellite 4136 using orthogonal frequency division multiplexing (OFDM) communication signals over a multi-carrier communication channel in accordance with various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communications) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0317] In some embodiments, all or part of base station 4112 and / or base station 4114 may be implemented as one or more software entities running on a server computer as part of a virtual network.

[0318] In addition, or in other embodiments, base station 4112 or base station 4114 may be configured to communicate with each other via interface 4122. In embodiments where wireless communication system 4100 is an LTE system (e.g., when CN 4124 is an EPC), interface 4122 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. It is contemplated that an inter-satellite link (ISL) may carry the X2 interface between two satellite base stations.

[0319] In an embodiment where the wireless communication system 4100 is an NR system (e.g., when the CN 4124 is a 5GC), the interface 4122 may be an Xn interface. The Xn interface is defined between two or more base stations connected to the 5GC (e.g., the CN 4124). For example, the Xn interface may be between two or more gNBs connected to the 5GC, between a gNB and an eNB connected to the 5GC, or between two eNBs connected to the 5GC.

[0320] In an embodiment where the wireless communication system 4100 is an LTE system (e.g., when the CN 4124 is an EPC), the interface 4122 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC.

[0321] RAN 4106 is shown as being communicatively coupled to CN 4124. CN 4124 may include one or more network elements 4126 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 4102 and users of UE 4104) connected to CN 4124 via RAN 4106. The components of CN 4124 may be implemented in one physical device or separate physical devices including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). For example, the components of CN 4124 may be implemented in one or more processors and / or one or more associated memories.

[0322] In an embodiment, CN 4124 may be an EPC, and RAN 4106 may be connected to CN 4124 via an S1 interface 4128. In an embodiment, S1 interface 4128 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 4112, base station 4114, and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 4112 and / or base station 4114 and a mobility management entity (MME).

[0323] In an embodiment, CN 4124 may be a 5GC, and RAN 4106 may be connected to CN 4124 via an NG interface 4128. In an embodiment, NG interface 4128 may be divided into two parts: an NG user plane (NG-U) interface, which carries service data between base station 4112 and / or base station 4114 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 4112 and / or base station 4114 and an access and mobility management function (AMF).

[0324] Generally speaking, the application server 4130 may be an element that provides applications that use Internet Protocol (IP) bearer resources with the CN 4124 (e.g., packet-switched data services). The application server 4130 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 4102 and UE 4104 via the CN 4124. The application server 4130 may communicate with the CN 4124 via an IP communication interface 4132.

[0325] Fig.42 A system 4200 for performing signaling 4234 between a wireless device 4202 and a RAN device 4218 of a core network connected to a CN device 4236 according to an embodiment of the present invention is illustrated. The system 4200 can be part of a wireless communication system as described herein. The wireless device 4202 can be, for example, a UE of a wireless communication system. The RAN device 4218 can be, for example, a base station (e.g., an eNB or gNB) of a wireless communication system that is a ground base station. In the case where the RAN device 4218 is a ground base station, the RAN device 4218 can communicate with a payload of a satellite that directly provides radio access connectivity to the UE in the manner described herein. The CN device 4236 can be one or more devices that make up the CN, as described herein.

[0326] The wireless device 4202 may include one or more processors 4204. The processor 4204 may execute instructions to cause various operations of the wireless device 4202 to be performed, as described herein. The processor 4204 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0327] The wireless device 4202 may include a memory 4206. The memory 4206 may be a non-transitory computer-readable storage medium storing instructions 4208 (which may include, for example, instructions executed by the processor 4204). The instructions 4208 may also be referred to as program code or a computer program. The memory 4206 may also store data used by the processor 4204 and results calculated by the processor.

[0328] The wireless device 4202 may include one or more transceivers 4210 that may include RF transmitter and / or receiver circuitry that uses an antenna 4212 of the wireless device 4202 to facilitate signaling (e.g., signaling 4234) transmitted and / or received by the wireless device 4202 with other devices (e.g., RAN devices 4218) according to a corresponding RAT. In some embodiments, the antenna 4212 may include a mobile parabolic antenna, an omnidirectional phased array antenna, or some other antenna suitable for communicating with a satellite payload (e.g., as described above in conjunction with Figure 1 108 described by UE 108).

[0329] In the NTN case, network equipment signaling 4234 may occur on the service link between the wireless device 4202 and the payload on the satellite and the feeder link between the payload on the satellite and the RAN equipment 4218 (e.g., as described with respect to Figure 1 described).

[0330] The wireless device 4202 may include one or more antennas 4212 (e.g., one, two, four, or more). For embodiments with multiple antennas 4212, the wireless device 4202 may exploit the spatial diversity of such multiple antennas 4212 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). The MIMO transmission by the wireless device 4202 may be implemented based on precoding (or digital beamforming) applied at the wireless device 4202, which multiplexes the data streams between the antennas 4212 based on known or assumed channel characteristics, so that each data stream is received with appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain embodiments may use a single-user MIMO (SU-MIMO) approach (where data streams are all directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0331] In certain embodiments with multiple antennas, the wireless device 4202 may implement analog beamforming techniques whereby the phases of signals transmitted by antennas 4212 are relatively adjusted to enable directional (joint) transmissions from antennas 4212 (this is sometimes referred to as beam steering).

[0332] The wireless device 4202 may include one or more interfaces 4214. The interface 4214 may be used to provide input to the wireless device 4202 or provide output from the wireless device. For example, a wireless device 4202 that is a UE may include an interface 4214, such as a microphone, a speaker, a touch screen, buttons, etc., to allow a user of the UE to input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuits (e.g., in addition to the transceiver 4210 / antenna 4212 described above), which allow the UE to communicate with other devices and may communicate according to known protocols (e.g., etc.) to perform the operation.

[0333] The wireless device 4202 may include a handover configuration module 4216. The handover configuration module 4216 may be implemented via hardware, software, or a combination thereof. For example, the handover configuration module 4216 may be implemented as a processor, circuit, and / or instructions 4208 stored in the memory 4206 and executed by the processor 4204. In some examples, the handover configuration module 4216 may be integrated within the processor 4204 and / or the transceiver 4210. For example, the handover configuration module 4216 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuit systems) within the processor 4204 or the transceiver 4210.

[0334] The handover configuration module 4216 may be used in various aspects of the present disclosure, for example, Figures 1 to 25 The handover configuration module 4216 is configured to receive public configuration information and / or dedicated configuration information, for example, from a base station (eg, the RAN device 4218 as a base station).

[0335] The RAN device 4218 may include one or more processors 4220. The processor 4220 may execute instructions to perform various operations of the RAN device 4218, as described herein. The processor 4204 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0336] The RAN device 4218 may include a memory 4222. The memory 4222 may be a non-transitory computer-readable storage medium storing instructions 4224 (which may include, for example, instructions executed by the processor 4220). The instructions 4224 may also be referred to as program code or a computer program. The memory 4222 may also store data used by the processor 4220 and results calculated by the processor.

[0337] The RAN device 4218 may include one or more transceivers 4226 that may include RF transmitter and / or receiver circuit systems that use antennas 4228 of the RAN device 4218 to facilitate signaling (e.g., signaling 4234) sent and / or received by the RAN device 4218 with other devices (e.g., wireless device 4202) in accordance with a corresponding RAT.

[0338] The RAN device 4218 may include one or more antennas 4228 (e.g., one, two, four, or more). In an embodiment with multiple antennas 4228, the RAN device 4218 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc. as described above.

[0339] In the NTN case, the transceiver 4226 and antenna 4228 may alternatively reside on the payload of a satellite associated with the base station.

[0340] The RAN device 4218 may include one or more interfaces 4230. The interface 4230 may be used to provide input to or output from the RAN device 4218. For example, the RAN device 4218 as a base station may include an interface 4230 composed of a transmitter, a receiver, and other circuit systems (e.g., in addition to the transceiver 4226 / antenna 4228 already described), which enables the base station to communicate with other equipment in the CN and / or enables the base station to communicate with external networks, computers, databases, etc., for the purpose of operating, managing, and maintaining the base station or other equipment operably connected to the base station.

[0341] The RAN device 4218 may include a handover configuration module 4232. The handover configuration module 4232 may be implemented via hardware, software, or a combination thereof. For example, the handover configuration module 4232 may be implemented as a processor, a circuit, and / or an instruction 4224 stored in the memory 4222 and executed by the processor 4220. In some examples, the handover configuration module 4232 may be integrated within the processor 4220 and / or the transceiver 4226. For example, the handover configuration module 4232 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuit systems) within the processor 4220 or the transceiver 4226.

[0342] The handover configuration module 4232 may be used in various aspects of the present disclosure, for example, Figures 1 to 40The handover configuration module 4232 is configured to, for example, send public configuration information and / or dedicated configuration information to a UE (e.g., the wireless device 4202 as a UE), receive public configuration information from a target base station (e.g., another instance of the RAN device 4218 as a target base station) on an Xn interface, and / or send public configuration information to a source base station (e.g., another instance of the RAN device 4218 as a target of the source base station) on an Xn interface. In addition, in the case where the RAN wireless device 4202 includes a DU and / or a CU, the handover configuration module 4232 can operate to process the transmission of handover configuration related information between the CU and the DU on the F1 interface.

[0343] RAN device 4218 can communicate with CN device 4236 via interface 4248, which can be similar to Fig.41 Interface 4128 (for example, it can be S1 and / or NG interface, either of which can be divided into a user plane part and a control plane part).

[0344] The CN device 4236 may include one or more processors 4238. The processor 4238 may execute instructions to perform various operations of the CN device 4236 as described herein. The processor 4238 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0345] CN device 4236 may include memory 4240. Memory 4240 may be a non-transitory computer-readable storage medium storing instructions 4242 (which may include, for example, instructions executed by processor 4238). Instructions 4242 may also be referred to as program code or a computer program. Memory 4240 may also store data used by processor 4238 and results calculated by the processor.

[0346] The CN device 4236 may include one or more interfaces 4244. The interface 4244 may be used to provide input to or output from the CN device 4236. For example, the CN device 4236 may include an interface 4230 composed of a transmitter, a receiver, and other circuits, which enables the CN device 4236 to communicate with other equipment in the CN, and / or enables the CN device 4236 to communicate with an external network, computer, database, etc., for the purpose of operating, managing, and maintaining the CN device 4236 or other equipment operably connected to the CN device.

[0347] The CN device 4236 may include a handover configuration module 4246. The handover configuration module 4246 may be implemented via hardware, software, or a combination thereof. For example, the handover configuration module 4246 may be implemented as a processor, circuit, and / or instructions 4242 stored in the memory 4240 and executed by the processor 4238. In some examples, the handover configuration module 4246 may be integrated within the processor 4238. For example, the handover configuration module 4246 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 4238.

[0348] The handover configuration module 4246 may be used in various aspects of the present disclosure, for example, Figures 1 to 40 The handover configuration module 4246 is configured, for example, to configure the RAN device 4218 to use the handover configuration module 4232 of the RAN device 4218 in the manner described.

[0349] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of any of the methods 1900, 2100, 2300, and / or 2400. The apparatus may be, for example, an apparatus of a UE (such as wireless device 4202 as a UE, as described herein).

[0350] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of any of method 1900, method 2100, method 2300, and / or method 2400. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 4206 of wireless device 4202 as a UE, as described herein).

[0351] Embodiments contemplated herein include an apparatus comprising logical components, modules, or circuits for performing one or more elements of any of the methods 1900, 2100, 2300, and / or 2400. The apparatus may be, for example, an apparatus of a UE (such as the wireless device 4202 as a UE, as described herein).

[0352] Embodiments contemplated herein include an apparatus comprising: one or more processors; and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of any of the methods 1900, 2100, 2300, and / or 2400. The apparatus may be, for example, an apparatus of a UE (such as wireless device 4202 as a UE, as described herein).

[0353] Embodiments contemplated herein include a signal as described in or associated with one or more elements of any of method 1900 , method 2100 , method 2300 , and / or method 2400 .

[0354] Embodiments contemplated herein include a computer program or computer program product including instructions, wherein execution of the program by a processor causes the processor to perform one or more elements of any of the methods 1900, 2100, 2300, and / or 2400. The processor may be a processor of a UE (such as the processor 4204 of the wireless device 4202 as a UE, as described herein). These instructions may be located, for example, in a processor of the UE and / or on a memory (such as the memory 4206 of the wireless device 4202 as a UE, as described herein).

[0355] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of any of method 2000, method 2200, method 2500, method 3200, method 3300, method 3400, method 3500, method 3600, method 3700, method 3800, and / or method 3900. The apparatus may be, for example, an apparatus that is a base station (such as RAN device 4218 that is a base station, as described herein).

[0356] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of any of methods 2000, 2200, 2500, 3200, 3300, 3400, 3500, 3600, 3700, 3800, and / or 3900. The non-transitory computer-readable medium may be, for example, a memory of a base station (such as memory 4222 of RAN device 4218 as a base station, as described herein).

[0357] Embodiments contemplated herein include an apparatus comprising logical components, modules, or circuits to perform one or more elements of any of method 2000, method 2200, method 2500, method 3200, method 3300, method 3400, method 3500, method 3600, method 3700, method 3800, and / or method 3900. The apparatus may be, for example, an apparatus that is a base station (such as RAN device 4218 as a base station, as described herein).

[0358] Embodiments contemplated herein include an apparatus comprising: one or more processors; and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of any of methods 2000, 2200, 2500, 3200, 3300, 3400, 3500, 3600, 3700, 3800, and / or 3900. The apparatus may be, for example, an apparatus of a base station (such as RAN device 4218 as a base station, as described herein).

[0359] Embodiments contemplated herein include signals as described in or related to one or more elements of any of method 2000, method 2200, method 2500, method 3200, method 3300, method 3400, method 3500, method 3600, method 3700, method 3800, and / or method 3900.

[0360] Embodiments contemplated herein include a computer program or computer program product including instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of any of methods 2000, 2200, 2500, 3200, 3300, 3400, 3500, 3600, 3700, 3800, and / or 3900. The processor may be a processor of a base station (such as processor 4220 of RAN device 4218 as a base station, as described herein). These instructions may be located, for example, in a processor and / or on a memory of a base station (such as memory 4222 of RAN device 4218 as a base station, as described herein).

[0361] For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein. For another example, circuits associated with a UE, a base station, a network element, etc. as described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein.

[0362] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of various embodiments.

[0363] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine executable instructions to be executed by a computer system. A computer system may include one or more general or special purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic components for performing operations; or may include a combination of hardware, software, and / or firmware.

[0364] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of another embodiment may be used in one embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated herein.

[0365] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0366] Although the foregoing has been described in considerable detail for the sake of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways to implement both the processes and the apparatus described herein. Therefore, the embodiments of the present invention should be regarded as illustrative rather than restrictive, and the specification is not limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method of a user equipment (UE), the method comprising: receiving, from a source base station operating a source serving cell serving the UE, a point-to-multipoint (PTM) transmission including common configuration information for operating on a target serving cell; receiving dedicated configuration information for operating the UE on the target serving cell from the source base station; as well as A handover to the target serving cell is performed based on the common configuration information and the dedicated configuration information. The method according to claim 1 , wherein the target serving cell is a cell of a target base station. 3 . The method according to claim 1 , further comprising sending feedback signaling to the source base station in response to receiving the public configuration information.

4. The method of claim 3, wherein the feedback signaling comprises a dedicated Layer 3 (L3) RRCReconfigurationComplete message.

5. The method of claim 3, wherein the feedback signaling comprises Layer 2 (L2) Radio Link Control (RLC) Acknowledgement (ACK) feedback.

6. The method of claim 3, wherein the feedback signaling comprises Layer 1 (L1) Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) signaling.

7. The method of claim 3, wherein the feedback signaling comprises a Medium Access Control Control Element (MACCE).

8. The method of claim 1, wherein the PTM transmission comprises an RRCReconfiguration message with the common configuration information received on an existing signaling radio bearer (SRB).

9. The method of claim 1, wherein the PTM transmission comprises a radio resource control (RRC) message with the common configuration information received on a newly established signaling radio bearer (SRB). 10 . The method of claim 1 , wherein the PTM transmission uses a Group Radio Network Temporary Identifier (G-RNTI) of the UE corresponding to a UE group including the UE.

11. The method of claim 1 , further comprising decrypting the PTM transmission using a group encryption key and a group integrity protection key.

12. The method of claim 1, further comprising verifying the integrity of the PTM transmission by using a dedicated integrity protection key with the PTM transmission to match a message authentication code (MAC-I) for integrity of the UE included in the PTM transmission.

13. The method of claim 1, wherein the common configuration information comprises differential configuration information relative to a common configuration for the source serving cell. The method according to claim 1 , wherein the dedicated configuration information comprises a dedicated configuration for the UE.

15. The method of claim 1, wherein the PTM transmission further comprises a plurality of candidate dedicated configurations, and wherein the dedicated configuration information comprises an index corresponding to one of the candidate dedicated configurations for the UE.

16. The method of claim 1, wherein the dedicated configuration information is sent in a dedicated handover command. The method of claim 16 , wherein the dedicated handover command comprises a conditional handover command.

18. The method of claim 1, wherein: The PTM transmission also includes a plurality of candidate dedicated configurations; The dedicated configuration information is sent in a group handover command; and The dedicated configuration information includes a value in the group handover command indicating a candidate dedicated configuration for the UE among the multiple candidate dedicated configurations.

19. A method of a source base station, the method comprising: sending a point-to-multipoint (PTM) transmission to a plurality of user equipments (UEs) operating on a source serving cell of the source base station, the PTM transmission including common configuration information for operating on a target serving cell; Sending, to a first UE among the multiple UEs, first dedicated configuration information for operating the first UE on the target serving cell; as well as Second dedicated configuration information for operating a second UE on the target serving cell is sent to a second UE among the multiple UEs.

20. The method according to claim 19, wherein the target service cell is a cell of a target base station, and the method further comprises receiving a public configuration for the target service cell from the target base station, wherein the public configuration for the target service cell comprises the public configuration information for operating on the target service cell.

21. The method of claim 19, further comprising receiving feedback signaling from the first UE in response to sending the common configuration information.

22. The method of claim 21, wherein the feedback signaling comprises a dedicated Layer 3 (L3) RRCReconfigurationComplete message.

23. The method of claim 21, wherein the feedback signaling comprises Layer 2 (L2) Radio Link Control (RLC) Acknowledgement (ACK) feedback.

24. The method of claim 21, wherein the feedback signaling comprises Layer 1 (L1) Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) signaling.

25. The method of claim 21, wherein the feedback signaling comprises a Medium Access Control Control Element (MACCE).

26. The method of claim 19, wherein the PTM transmission comprises an RRCReconfiguration message with the common configuration information sent on an existing signaling radio bearer (SRB).

27. The method of claim 19, further comprising establishing a new signaling radio bearer (SRB) for communicating with the plurality of UEs, wherein the PTM transmission comprises a radio resource control (RRC) message with the common configuration information sent on the new SRB.

28. The method of claim 19, wherein the PTM transmission uses a Group Radio Network Temporary Identifier (G-RNTI) corresponding to a UE group including the plurality of UEs.

29. The method of claim 19, further comprising encrypting the PTM transmission for use with a group encryption key at the plurality of UEs and a group integrity protection key at the plurality of UEs.

30. The method of claim 19, wherein the PTM transmission further comprises a message authentication code (MAC-I) for integrity of a corresponding UE among the plurality of UEs for use with a dedicated integrity protection key at the corresponding UE among the plurality of UEs.

31. The method of claim 19, wherein the common configuration information comprises differential configuration information relative to a common configuration for the source serving cell.

32. The method of claim 31 , further comprising: sending a common configuration for operating on the source serving cell to a target base station of the target serving cell; as well as The difference configuration information is received from the target base station.

33. The method of claim 31 , further comprising: sending a request for a common configuration for the target serving cell to a target base station of the target serving cell; receiving the common configuration for the target serving cell from the target base station; as well as The differential configuration information is determined based on the common configuration for the target serving cell.

34. The method of claim 19, wherein the first dedicated configuration information comprises a dedicated configuration for the first UE.

35. The method of claim 19, wherein the PTM transmission further comprises a plurality of candidate dedicated configurations, and wherein the first dedicated configuration information comprises an index corresponding to one of the plurality of candidate dedicated configurations for the UE.

36. The method of claim 19, wherein the first dedicated configuration information is sent in a first dedicated handover command and the second dedicated configuration information is sent in a second dedicated handover command.

37. The method of claim 36, wherein the first dedicated handover command comprises a conditional handover command.

38. The method of claim 19, wherein: The PTM transmission also includes a plurality of candidate dedicated configurations; The first dedicated configuration information and the second dedicated configuration information are sent in a group handover command; The first dedicated configuration information includes a first value in the group handover command indicating a candidate dedicated configuration for the first UE among the plurality of candidate dedicated configurations; and The second dedicated configuration information includes a second value in the group handover command indicating a candidate dedicated configuration for the second UE among the multiple candidate dedicated configurations.

39. An apparatus comprising means for performing the method according to any one of claims 1 to 38.

40. A computer-readable medium comprising instructions, which, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 38.

41. An apparatus comprising logic components, modules or circuits for performing the method of any one of claims 1 to 38.

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