Conditional procedures for adding and modifying secondary nodes (SNs), initiated by secondary nodes (SNs).

Abstract

This invention provides a method for supporting the addition and modification of conditional new radio (NR) secondary nodes (SNs) by using a conditional handover (CHO) procedure in wireless communications. [Solution] A method implemented by a user device (UE) includes receiving configuration information from a master node (MN) that identifies a set of candidate cells for conditional addition or modification of an SN for the UE based on execution criteria; detecting that the execution criteria are met for one of the candidate cells; and taking action to add or modify the candidate cell as an SN based on the detection.

Description

Technical Field

[0001] Cross - reference to Related Applications

[0001] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 931,651, filed on November 6, 2019, which is assigned to the assignee of this application and is hereby incorporated by reference in its entirety for all applicable purposes as if fully set forth herein, and claims the priority of U.S. Application No. 17 / 089,565, filed on November 4, 2020.

[0002]

[0002] Aspects of the present disclosure relate to wireless communication, and more particularly, to procedures for supporting conditional new radio (NR) secondary node (SN) addition and change by reusing a conditional handover (CHO) procedure.

Background Art

[0003]

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ a multiple access technology that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple access technologies include Long Term Evolution (LTE (registered trademark)) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC - FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD - SCDMA) systems.

[0004]

[0004] In some examples, a wireless multiple access communication system may include several base stations (BS), each simultaneously supporting communication for multiple communication devices, which may be known as user equipment (UE). In an LTE or LTE-A network, one or more sets of BS may define an e-node B (eNB). In other examples (for example, in a next-generation or 5G network), a wireless multiple access communication system may include several distributed units (DUs) (for example, edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit / receive points (TRPs), etc.) communicating with several central units (CUs) (for example, a central node (CN), an access node controller (ANC), etc.), where one or more sets of distributed units communicating with the central units may define access nodes (for example, new radio base stations (NR BSs), new radio node B (NR NBs), network nodes, 5G NBs, g-node B (gNBs), etc.). A BS or DU may communicate with a set of UEs over a downlink channel (for example, for transmission from the BS to the UE) and over an uplink channel (for example, for transmission from the UE to the BS or DU).

[0005]

[0005] These multiple access technologies are employed in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at urban, national, regional, and even global levels. An example of a new telecommunications standard is New Radio (NR), also known as 5G radio access. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, utilizing new spectrum, and better integrating with other open standards by using OFDMA with cyclic prefixes (CP) on downlink (DL) and uplink (UL), as well as supporting beamforming, multiple input multiple output (MIMO) antenna technology, and carrier aggregation (CA).

[0006]

[0006] However, as the demand for mobile broadband access continues to increase, further improvements to NR technology are needed. Preferably, these improvements should be applicable to other multiple access technologies and to the telecommunications standards that employ these technologies. [Overview of the project]

[0007]

[0007] The systems, methods, and devices of the present disclosure each have several embodiments, and no single embodiment alone may constitute the desired attributes of the present disclosure. Some features are briefly described below without limiting the scope of the present disclosure as expressed by the following claims. After considering this description, and especially after reading the section entitled “Modes for Carrying Out the Invention,” it will be understood how the features of the present disclosure provide benefits including improved communication between access points and stations in a wireless network.

[0008]

[0008] Some embodiments relate to methods for wireless communication by a secondary node (SN). These methods generally include identifying a set of one or more candidate cells for a conditional addition or change as an SN for a user device (UE) based on execution criteria, and signaling information about the set of candidate cells to a master node (MN).

[0009]

[0009] Some embodiments relate to a method for wireless communication by an MN. The method generally includes receiving signaling from an SN that identifies a set of candidate cells for conditional addition or modification as an SN for a UE based on execution criteria, and signaling the UE configuration information relating to the set of candidate cells.

[0010]

[0010] Some embodiments relate to a method for wireless communication by a UE. The method generally includes receiving configuration information and execution criteria from an MN that identify a set of candidate cells for conditional addition or modification as an SN for the UE, wherein the execution criteria are obtained from the MN in a transparent container, detecting that the execution criteria are met for one of the candidate cells, and taking action to add or modify the candidate cell as an SN based on the detection.

[0011]

[0011] Some embodiments relate to an apparatus for wireless communication by an SN, comprising a memory and at least one processor coupled to the memory, wherein the at least one processor is configured to identify one or more sets of candidate cells for conditional addition or modification of an SN for a UE based on execution criteria and to signal information about the set of candidate cells to an MN.

[0012]

[0012] Some embodiments relate to an apparatus for wireless communication by an MN, comprising a memory and at least one processor coupled to the memory, wherein the at least one processor is configured to receive signaling from an SN that identifies a set of candidate cells for conditional addition or modification of an SN for a UE based on execution criteria, and to signal configuration information relating to the set of candidate cells to the UE.

[0013]

[0013] Some embodiments relate to an apparatus for wireless communication by a UE, comprising a memory and at least one processor coupled to the memory, wherein the at least one processor is configured to receive from an MN configuration information and execution criteria for conditionally adding or changing an SN for a UE, to detect that the execution criteria are met for one of the candidate cells, and to take action to add or change the candidate cell as an SN based on the detection.

[0014]

[0014] The embodiments are generally substantially described herein with reference to the accompanying drawings and include methods, apparatus, systems, computer-readable media, and processing systems as shown by the accompanying drawings.

[0015]

[0015] To achieve the above and related objectives, one or more embodiments shall have features that are fully described below and, in particular, pointed out in the claims. The following description and accompanying drawings shall describe in detail some exemplary features of one or more embodiments. However, these features shall represent only a few of the various ways in which the principles of various embodiments may be employed, and this description shall include all such embodiments and their equivalents.

[0016]

[0016] A more specific description than that briefly summarized above can be obtained by referring to the embodiments shown in part in the accompanying drawings, so that the features described above can be understood in detail. However, it should be noted that the accompanying drawings show only some typical embodiments of the disclosure and should not be considered to limit the scope of the disclosure, as that description may apply to other equally valid embodiments. [Brief explanation of the drawing]

[0017] [Figure 1]

[0017] A block diagram conceptually illustrating an exemplary telecommunications system according to some aspects of the present disclosure. [Figure 2]

[0018] A block diagram illustrating an exemplary architecture of a distributed radio access network (RAN) according to several aspects of this disclosure. [Figure 3]

[0019] A block diagram conceptually illustrating the design of exemplary base station (BS) and user equipment (UE) according to several aspects of this disclosure. [Figure 4]

[0020] A diagram illustrating an example call flow diagram for determining the HO configuration for a RAN handover (HO) procedure, according to several aspects of this disclosure. [Figure 5] A diagram illustrating an example call flow diagram for determining the HO configuration for a RAN handover (HO) procedure, according to several aspects of this disclosure. [Figure 6]

[0021] A diagram illustrating exemplary operations for wireless communication by a master node (MN) according to some aspects of the present disclosure. [Figure 7]

[0022] A diagram illustrating exemplary operations for wireless communication by a UE according to some aspects of the present disclosure. [Figure 8]

[0023] A diagram illustrating exemplary operations for wireless communication by a secondary node (SN) according to some aspects of the present disclosure. [Figure 9]

[0024] A first call flow diagram illustrating exemplary communication between a UE, a MN, and a SN according to various aspects of the present disclosure. [Figure 10]

[0025] A second call flow diagram illustrating exemplary communication between a UE, a MN, and a SN according to various aspects of the present disclosure. [Figure 11]

[0026] A diagram showing a communication device that may include various components configured to perform operations for the techniques disclosed herein according to an aspect of the present disclosure. [Figure 12]

[0027] A diagram showing a communication device that may include various components configured to perform operations for the techniques disclosed herein according to an aspect of the present disclosure. [Figure 13]

[0028] A diagram showing a communication device that may include various components configured to perform operations for the techniques disclosed herein according to an aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]

[0029] For ease of understanding, the same reference numbers are used, where possible, to designate the same elements common to each figure. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without particular recitation.

[0019]

[0030] Aspects of this disclosure provide apparatus, methods, processing systems, and computer-readable media for supporting conditional (e.g., New Radio (NR)) secondary node (SN) additions and modifications by reusing a conditional handover (CHO) procedure.

[0020]

[0031] Some aspects of this disclosure may be applied to New Radio (NR) (New Radio Access Technology or 5G Technology). NR supports a variety of wireless communication services, including Extended Mobile Broadband (eMBB) targeting high bandwidth (e.g., over 80 MHz), millimeter wave (mmW) targeting high carrier frequency (e.g., 60 GHz), Massive MTC (mMTC) targeting non-backward compatible MTC techniques, and / or mission-critical targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTI) to meet their respective quality of service (QoS) requirements. Furthermore, these services may coexist in the same subframe.

[0021]

[0032] The following descriptions are illustrative and not intended to limit the scope, applicability, or examples described in the claims. Modifications may be made to the function and configuration of the elements described without departing from the scope of this disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the methods described may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Also, features described in some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be carried out using any number of embodiments described herein. Furthermore, the scope of this disclosure shall cover any such apparatus or method carried out using other structures, functions, or structures and functions in addition to or in addition to the various embodiments of this disclosure described herein. It should be understood that any embodiment of this disclosure disclosed herein may be carried out by one or more elements of the claims. The word “exemplary” is used herein to mean “acting as an example, case, or illustration.” Any embodiment described herein as "exemplary" should not necessarily be construed as being more preferable or advantageous than any other embodiment.

[0022]

[0033] The techniques described herein can be used for a variety of wireless communication networks, including Long-Term Evolution (LTE), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and other networks. The terms “network” and “system” are often used interchangeably. CDMA networks may implement radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. UTRA includes broadband CDMA (WCDMA®) and other variations of CDMA. CDMA2000 covers the IS-2000, IS-95, and IS-856 standards. TDMA networks may implement radio technologies such as the Global System for Mobile Communications (GSM®). OFDMA networks can implement wireless technologies such as NR (e.g., 5G RA), Advanced UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, and Flash-OFDMA. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). NR is a new wireless communication technology under development in collaboration with the 5G Technology Forum (5GTF). 3GPP® LTE and LTE Advanced (LTE-A) are UMTS releases that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are documented in documents from an organization called the "Third Generation Partnership Project" (3GPP). CDMA2000 and UMB are documented in documents from an organization called the "Third Generation Partnership Project II" (3GPP2). The techniques described herein may be used for the wireless networks and wireless technologies described above, as well as for other wireless networks and wireless technologies.For clarity, embodiments may be described using terms generally related to 3G and / or 4G wireless technologies, but embodiments of this disclosure may also be applicable to other generation-based communication systems, such as 5G and beyond, including NR technologies.

[0023] Example Wireless Communication System

[0034] Figure 1 shows an exemplary wireless network 100 in which embodiments of the present disclosure may be implemented. For example, the wireless communication network 100 may be a new radio (NR) system (e.g., a 5G NR network). For example, as shown in Figure 1, a user device (UE) 120a may include a handover manager 142, which may be configured to receive configuration information identifying a set of candidate cells for a conditional addition or modification of a secondary node (SN) for the UE based on execution criteria. The handover manager 142 may also be configured to detect whether the execution criteria are met for one of the candidate cells. If the execution criteria are met for one of the candidate cells, the handover manager 142 may also be configured to perform a conditional addition or modification of the candidate cell as an SN based on the detection.

[0024]

[0035] Similarly, a base station (BS) 110a may have a handover manager 144 that can be configured for handover operations. For example, if BS110a acts as an SN, the handover manager 144 may be configured to identify a set of candidate cells for conditional addition or modification of the SN for a UE based on execution criteria. The handover manager 144 may also be configured to signal configuration information about the set of candidate cells to the master node (MN). In another example, if BS110a acts as an MN, the handover manager 144 may be configured to receive signaling from the SN that identifies a set of candidate cells for conditional addition or modification of the SN for a UE based on execution criteria. The handover manager 144 may also be configured to signal configuration information about the set of candidate cells to the UE.

[0025]

[0036] As shown in Figure 1, the wireless network 100 may include several BS110s and other network entities. A BS may be a station that communicates with a UE. Each BS110 may provide communication coverage to a specific geographic area. In 3GPP, the term “cell” may refer to the coverage area of ​​Node B and / or the Node B subsystem that serves this coverage area, depending on the context in which the term is used. In NR systems, the terms “cell” and eNB, Node B, 5G NB, AP, NR BS, NR BS, or TRP may be interchangeable. In some examples, a cell may not necessarily be fixed, and the geographic area of ​​a cell may move according to the location of the mobile base station. In some examples, base stations may interconnect with each other and / or with one or more other base stations or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as direct physical connections and virtual networks, using any suitable transport network.

[0026]

[0037] Generally, any number of wireless networks can be deployed within a given geographical area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RATs are sometimes called radio technologies or air interfaces. Frequencies are sometimes called carriers or frequency channels. Each frequency may support a single RAT within a given geographical area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0027]

[0038] A BS can provide communication coverage to macrocells, picocells, femtocells, and / or other types of cells. A macrocell may cover a relatively large geographical area (e.g., a radius of several kilometers) and may enable unrestricted access by UEs (Users) subscribed to the service. A picocell may cover a relatively small geographical area and may enable unrestricted access by UEs subscribed to the service. A femtocell may cover a relatively small geographical area (e.g., a home) and may enable limited access by UEs associated with a femtocell (e.g., UEs in a limited subscriber group (CSG), UEs for users in a home, etc.). A BS for a macrocell is sometimes called a macroBS. A BS for a picocell is sometimes called a picoBS. A BS for a femtocell is sometimes called a femtoBS or homeBS. In the example shown in Figure 1, BS110a, 110b, and 110c could be macroBSs for macrocells 102a, 102b, and 102c, respectively. BS110x may be a pico BS for picocell 102x. BS110y and 110z may be femto BS for femtocells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0028]

[0039] The wireless network 100 may also include relay stations. A relay station is a station that receives transmissions of data and / or other information from an upstream station (e.g., a BS or UE) and sends transmissions of that data and / or other information to a downstream station (e.g., a UE or BS). A relay station may also be a UE that relays transmissions to other UEs. In the example shown in Figure 1, relay station 110r may communicate with BS110a and UE120r to facilitate communication between BS110a and UE120r. Relay stations are sometimes called relay BS, relay, etc.

[0029]

[0040] The wireless network 100 may be a heterogeneous network including different types of BS, such as macro BS, pico BS, femto BS, and relays. These different types of BS may have different transmission power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmission power level (e.g., 20 watts), while pico BS, femto BS, and relays may have a lower transmission power level (e.g., 1 watt).

[0030]

[0041] The wireless network 100 may support synchronous or asynchronous operation. In synchronous operation, BSs may have similar frame timings, and transmissions from different BSs may be approximately time-coordinated. In asynchronous operation, BSs may have different frame timings, and transmissions from different BSs may not be time-coordinated. The techniques described herein may be used for both synchronous and asynchronous operation.

[0031]

[0042] The network controller 130 can be coupled to a set of BSs and coordinate and control these BSs. The network controller 130 can communicate with the BSs 110 via backhaul. The BSs 110 can also communicate with each other directly or indirectly, for example, via wireless backhaul or wireline backhaul.

[0032]

[0043] UE120 (e.g., 120x, 120y, etc.) may be distributed across the entire wireless network 100, and each UE may be stationary or mobile. UEs may also be referred to as mobile stations, terminals, access terminals, subscriber units, stations, customer premises equipment (CPE), cellular phones, smartphones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, laptop computers, cordless phones, wireless local loop (WLL) stations, tablets, cameras, gaming devices, netbooks, smartbooks, ultrabooks, medical devices or medical equipment, biosensors / biometric devices, smartwatches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets, etc.), entertainment devices (e.g., music devices, video devices, satellite radios, etc.), vehicle components or vehicle sensors, smart meters / smart sensors, industrial manufacturing equipment, global positioning system devices, or any other suitable device configured to communicate via wireless or wired media. Some UEs may be considered advanced or machine-type communication (MTC) devices or advanced MTC (eMTC) devices. MTC UEs and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, and location tags that can communicate with BS, other devices (e.g., remote devices), or any other entities. Wireless nodes may provide connectivity to or for a network (e.g., a wide area network such as the Internet or a cellular network) via wired or wireless communication links. Some UEs may be considered Internet of Things (IoT) devices.

[0033]

[0044] In Figure 1, solid lines with double arrows indicate desired transmissions between a UE and a serving BS, which is a BS designated to service that UE, on the downlink and / or uplink. Dashed lines with double arrows indicate interference transmissions between the UE and the BS.

[0034]

[0045] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into several (K) orthogonal subcarriers, commonly called tones or bins. Each subcarrier can be modulated with data. Generally, the modulation symbol is transmitted in the frequency domain in OFDM and in the time domain in SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz, and the minimum resource allocation (called a "resource block") can be 12 subcarriers (or 180 kHz). Therefore, the nominal Fast Fourier Transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048 for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth can also be divided into subbands. For example, a subband may cover 1.8 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there may be 1, 2, 4, 8, or 16 subbands, respectively.

[0035]

[0046] While the embodiments of the examples described herein may relate to LTE technology, the embodiments of this disclosure may also be applicable to other wireless communication systems, such as NR.

[0036]

[0047] NR may include support for half-duplex operation using Time Division Duplex (TDD) with OFDM with CP on the uplink (UL) and downlink (DL). A single component carrier bandwidth of 100 MHz may be supported. An NR resource block may span 12 subcarriers with a subcarrier bandwidth of 75 kHz over a duration of 0.1 ms. Each radio frame may consist of 50 subframes, each 10 ms long. Thus, each subframe may have a length of 0.2 ms. Each subframe may indicate the link direction for data transmission (i.e., DL or UL), and the link direction for each subframe may be dynamically switched. Each subframe may contain DL / UL data and DL / UL control data.

[0037]

[0048] Beamforming may be supported, and the beam direction may be dynamically configured. Multiple-input multiple-output (MIMO) transmission with precoding may also be supported. MIMO configurations in DL may support up to eight transmitting antennas with multilayer DL transmission of up to eight streams and up to two streams per UE. Multilayer transmission with up to two streams per UE may be supported. Aggregation of multiple cells may be supported with up to eight serving cells. Alternatively, NR may support different air interfaces other than OFDM-based. NR networks may include entities such as CUs and / or DUs.

[0038]

[0049] In some examples, access to an air interface may be scheduled, where a scheduling entity (e.g., a BS) allocates resources for communication between some or all devices and equipment within its service area or cell. Within this disclosure, as further described below, a scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more dependent entities. That is, for scheduled communication, the dependent entities utilize the resources allocated by the scheduling entity. A BS is not the only entity that can function as a scheduling entity; that is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more dependent entities (e.g., one or more other UEs). In this example, the UE functions as the scheduling entity, and the other UEs utilize the resources scheduled by the UE for wireless communication. UEs may function as scheduling entities in peer-to-peer (P2P) networks and / or mesh networks. In the mesh network example, UEs may, in addition to communicating with scheduling entities, optionally communicate directly with each other.

[0039]

[0050] Therefore, in a wireless communication network having cellular, P2P, and mesh configurations, with scheduled access to time-frequency resources, a scheduling entity and one or more dependent entities can communicate using the scheduled resources.

[0040]

[0051] As described above, a radio access network (RAN) may include a central unit (CU) and a distributed unit (DU). An NR BS (e.g., gNB, 5G node B, node B, transmit / receive point (TRP), access point (AP)) may correspond to one or more BSs. An NR cell may be configured as an access cell (ACell) or a data-only cell (DCell). For example, a RAN (e.g., a central unit or a distributed unit) can constitute a cell. A DCell may be used for carrier aggregation (CA) or dual connectivity, but not for initial access, cell selection / re-selection, or handover. In some cases, a DCell may not transmit a synchronization signal, and in some cases, a DCell may transmit synchronization signaling (SS). An NR BS may transmit a DL signal to the UE indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, based on the indicated cell type, the UE may determine which NR BS to consider for cell selection, access, handover, and / or measurement.

[0041]

[0052] Figure 2 shows an exemplary architecture of a distributed RAN 200 that may be implemented in the wireless communication network 100 shown in Figure 1. As shown in Figure 2, the distributed RAN includes a core network (CN) 202 and access nodes 208 (for example, BS110a in Figure 1).

[0042]

[0053] CN202 may host core network functions. CN202 may be centrally deployed. CN202 functions may be offloaded (for example, to Advanced Wireless Services (AWS)) to handle peak capacity. CN202 may include Access and Mobility Management (AMF) 204 and User Plane (UPF) 206. AMF204 and UPF206 may perform one or more of the core network functions.

[0043]

[0054] AN208 may communicate with CN202 (for example, via a backhaul interface). AN208 may communicate with AMF204 via the N2 (for example, NG-C) interface. AN208 may communicate with UPF206 via the N3 (for example, NG-U) interface. AN208 may include a central unit control plane (CU-CP) 210, one or more central unit user planes (CU-UP) 212, one or more DUs 214-218, and one or more antenna / remote radio units (AU / RRU) 220-224. CUs and DUs are sometimes referred to as gNB-CUs and gNB-DUs, respectively. One or more components of AN208 may be implemented in gNB226. AN208 may communicate with one or more neighboring gNBs / BSs.

[0044]

[0055] CU-CP210 can be connected to one or more of DU214-218. CU-CP210 and DU214-218 can be connected via the F1-C interface. As shown in Figure 2, CU-CP210 can be connected to multiple DUs, but a DU can be connected to only one CU-CP. Figure 2 shows only one CU-UP212, but AN208 can contain multiple CU-UPs. CU-CP210 selects the appropriate (one or more) CU-UP for the requested service (for example, for UE120a). One or more CU-UP212 can be connected to CU-CP210. For example, one or more DU-UP212 and CU-CP210 can be connected via the E1 interface. One or more CU-CP212 can be connected to one or more of DU214-218. One or more CU-UP212s and DU214-218s can be connected via the F1-U interface. As shown in Figure 2, a CU-CP210 can be connected to multiple CU-UPs, but a CU-UP can be connected to only one CU-CP.

[0045]

[0056] DUs, such as DU214, 216, and / or 218, may host one or more TRPs (transmit / receive points, which may include edge nodes (EN), edge units (EU), radio heads (RH), smart radio heads (SRH), etc.). DUs may be located at the edge of a network with radio frequency (RF) capabilities. DUs may be connected to multiple CU-UPs (e.g., under the control of the same CU-CP) connected to the same CU-CP (e.g., for RAN sharing, radio as a service (RaaS), and service-specific deployments). DUs may be configured to service traffic to UEs individually (e.g., dynamic selection) or together (e.g., joint transmit). Each DU214-216 may be connected to one of the AU / RRU220-224.

[0046]

[0057] CU-CP210 may be connected to multiple DUs that are connected to the same CU-UP212 (for example, under the control of the same CU-UP212). Connectivity between CU-UP212 and DUs may be established by CU-CP210. For example, connectivity between CU-UP212 and DUs may be established using bearer context management functionality. Data forwarding between (one or more) CU-UP212s may be via the Xn-U interface.

[0047]

[0058] The distributed RAN200 can support fronthauling solutions across different deployment types. For example, the RAN200 architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and / or jitter). The distributed RAN200 may share features and / or components with LTE. For example, the AN208 may support dual connectivity with NR and share a common fronthaul for LTE and NR. The distributed RAN200 may enable collaboration between DU214-218, for example, via CU-CP212. Inter-DU interfaces may not be used.

[0048]

[0059] Figure 3 shows a block diagram of the design of BS110, which may be one of the BSs in Figure 1, and UE120, which may be one of the UEs in Figure 1. In a limited association scenario, BS110 may be macro BS110c in Figure 1, and UE120 may be UE120y. BS110 may also be any other type of BS shown in Figures 1 and 2, and UE120 may be any other type of UE shown in Figure 1. BS110 may be equipped with antennas 334a-334t, and the processors 320, 330, 338, and / or controller / processor 340 of BS110 may be used to implement the various techniques and methods described herein. For example, as shown in Figure 3, the controller / processor 340 of BS110 may include a handover manager 144 which may be configured for handover operation. For example, if BS110 acts as SN, the handover manager 144 may be configured to identify a set of candidate cells for conditional addition or modification of SN for UE based on execution criteria. The handover manager 144 may also be configured to signal configuration information about the set of candidate cells to the MN. In another example, if BS110a acts as MN, the handover manager 144 may be configured to receive signaling from SN that identifies a set of candidate cells for conditional addition or modification of SN for UE based on execution criteria. The handover manager 144 may also be configured to signal configuration information about the set of candidate cells to the UE.

[0049]

[0060] Similarly, the UE 120 includes a processor 380, which includes a handover manager 142, which may be configured to receive configuration information identifying a set of candidate cells for conditional addition or modification of secondary nodes (SNs) for the UE based on execution criteria. The handover manager 142 may also be configured to detect whether the execution criteria are met for one of the candidate cells. If the execution criteria are met for one of the candidate cells, the handover manager 142 may also be configured to perform a conditional addition or modification of the candidate cell as an SN based on the detection.

[0050]

[0061] In BS110, the transmit processor 320 may receive data from the data source 312 and control information from the controller / processor 340. The control information may be for the Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), etc. The data may be for the Physical Downlink Shared Channel (PDSCH), etc. The processor 320 may process the data and control information (e.g., encoding and symbol mapping) to obtain data symbols and control symbols, respectively. The processor 320 may also generate reference symbols for, for example, primary synchronous signaling (PSS), secondary synchronous signaling (SSS), and cell-specific reference signals (CRS). The transmit (TX) MIMO processor 330 may, where applicable, perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols and provide the output symbol stream to the modulators (MODs) 332a-332t. Each modulator 332 may process its respective output symbol stream (for example, for OFDM) to obtain an output sample stream. Each modulator 332 may further process the output sample stream (for example, convert to analog, amplify, filter, and upconvert) to obtain a downlink signal. The DL signals from modulators 332a to 332t may be transmitted via antennas 334a to 334t, respectively.

[0051]

[0062] In UE120, antennas 352a to 352r can receive downlink signals from BS110 and provide the received signals to demodulators 354a to 354r, respectively. Each demodulator 354 can adjust its respective received signals (e.g., filter, amplify, downconvert, and digitize) to acquire input samples. Each demodulator 354 can further process the input samples (e.g., for OFDM, etc.) to acquire received symbols. A MIMO detector 356 can acquire received symbols from all demodulators 354a to 354r, perform MIMO detection on the received symbols where applicable, and provide the detected symbols. A receiving processor 358 can process the detected symbols (e.g., demodulate, deinterleave, and decode), provide the decoded data for UE120 to the data sink 360, and provide the decoded control information to the controller / processor 380.

[0052]

[0063] On the UL, in UE120, the transmitting processor 364 may receive and process data from data source 362 (for example, for a physical uplink shared channel (PUSCH)) and control information from controller / processor 380 (for example, for a physical uplink control channel (PUCCH)). The transmitting processor 364 may also generate reference symbols for reference signals. Symbols from the transmitting processor 364 may be precoded by TX MIMO processor 366 where applicable, further processed by demodulators 354a-354r (for example, for SC-FDM, etc.), and transmitted to BS110. In BS110, the UL signal from UE120 is received by antenna 334, processed by modulator 332, detected by MIMO detector 336 where applicable, and further processed by receiving processor 338 to obtain the decoded data and control information sent by UE120. The receiving processor 338 may provide the decoded data to the data sink 339 and the decoded control information to the controller / processor 340.

[0053]

[0064] Controllers / processors 340 and 380 can direct operations in BS110 and UE120, respectively. Memories 342 and 382 can store data and program code for BS110 and UE120, respectively. Scheduler 344 can schedule UEs for data transmission on DL and / or UL. Processors 340 and / or other processors and modules in BS110 can perform or direct the execution of various processes for the techniques described herein, for example, the execution of the functional blocks shown in Figures 6 and 7. Processors 380 and / or other processors and modules in UE120 can also perform or direct the execution of the functional blocks shown in Figure 8, for example.

[0054] Example Handover Scenarios

[0065] Several techniques and devices described herein provide low-latency or zero-latency handover from a source base station (BS) to a target BS (e.g., in a network such as a 4G / LTE or 5G / NR network). For example, several techniques and devices described herein provide a handover configuration using a first protocol stack of the user equipment (UE) and a second protocol stack of the UE, where the first protocol stack is used for communication with the first BS and the second protocol stack is used for communication with the second BS. The use of two protocol stacks may allow the handover configuration with respect to the target BS to be implemented while communication with the source BS is in progress. Thus, the latency associated with handing over the UE from the source BS to the target BS is reduced. Furthermore, several techniques and devices described herein provide buffering and backhauling of UE traffic between the source BS and the target BS so that the flow of traffic to the UE is not interrupted (or the interruption is reduced or minimized), thereby further reducing the latency associated with handing over the UE. In this way, during UE handover, the service level at the UE can be met, which enables the satisfaction of performance requirements for several types of traffic (e.g., gaming traffic, multimedia traffic, high-reliability traffic, low-latency traffic, etc.).

[0055]

[0066] Furthermore, some techniques and devices described herein may provide Common Packet Data Convergence Protocol (PDCP) functionality for make-before-break (MBB) handover procedures, which may streamline security key management, encryption / decryption, integrity protection, integrity verification, data unit sorting / deduplication, link selection logic, etc. Some techniques and devices described herein provide control plane (e.g., BS, network controller, control entity, etc.) messaging and processing to support MBB handover. Some techniques and devices described herein provide MBB handover using Carrier Aggregation (CA) Multiple Input Multiple Output (MIMO) techniques, where a reduced MIMO configuration is signaled to ensure that at least one antenna is available for use for MBB handover. Also, some techniques and devices described herein provide role-switch-based MBB handover techniques, where the UE's master cell group is switched from source base station to target base station while connections with source and target base stations are active. In this way, low-latency or zero-latency handover (and the benefits of low-latency or zero-latency handover described above) are achieved.

[0056]

[0067] Figure 4 is a call flow diagram showing Example 400 for determining a handover configuration for a handover procedure in a radio access network (RAN) according to various aspects of the present disclosure. As shown in Figure 4, UE120 is handed over from source BS110-1 to target BS110-2. UE120 may be implemented by any UE in Figure 1 (e.g., UE120a), and source BS110-1 and target BS110-2 may be implemented by any BS110 in Figure 1 (e.g., BS110a), or by TRPs hosted by DU214-248 in Figure 2 (e.g., AN208), DU214-248 in Figure 4, or DU214-218 in Figure 4. The handover described in relation to Figure 4 may be intra-frequency or inter-frequency, and / or intra-CU or inter-CU.

[0057]

[0068] As shown in Figure 4, in 405, UE120 may establish a wireless communication connection with source BS110-1 (hereinafter referred to as source connection). In 410, UE120 may demonstrate its capabilities to one or more other network entities, such as source BS110-1, target BS110-2, or other network entities such as AMF (e.g., AMF204 in Figure 2), UPF (e.g., UPF206 in Figure 2), or any other CN function. For example, in 410, UE120 may demonstrate that it has simultaneous transmit and receive capabilities, as well as / or dual connectivity capabilities.

[0058]

[0069] In 415, UE120 may provide a measurement report to source BS110-1. The measurement report may be generated by UE120 and may indicate to source BS110-1 that a handover from source BS110-1 to target BS110-2 should be performed. For example, UE120 may perform cell quality measurements (e.g., L3 cell quality measurements) to assess the quality of the radio link between UE120 and one or more of source BS110-1 and target BS110-2. Thus, the measurement report may include the results of the cell quality measurements. In some examples, if the quality of the radio link between UE120 and source BS110-1 is sufficient to enable successful UL communication of the measurement report, successful reception of the measurement report at source BS110-1 may indicate to source BS110-1 that a handover from source BS110-1 to target BS110-2 should be performed.

[0059]

[0070] (Assuming successful reception of the measurement report in 415) In 420, source BS110-1 may determine a configuration for the handover procedure, at least in part, based on the capabilities shown in step 2. For example, source BS110-1 may provide a handover request to target BS110-2 and receive a handover acknowledgment (ACK) from target BS110-2. In some embodiments, source BS110-1 may communicate with target BS110-2 to determine a handover configuration for UE120.

[0060]

[0071] In 425, source BS110-1 may provide UE120 with a configuration for a handover procedure. For example, the handover configuration may include a configuration for a handover procedure that utilizes or does not utilize the indicated capabilities of UE120. In some embodiments, the handover configuration may indicate that a make-before-break (MBB) handover procedure and / or a DC-based MBB handover procedure will be performed. Thus, the configuration may indicate to UE120 whether to maintain the wireless link connection to source BS110-1 while the wireless link connection to target BS110-2 is established and / or thereafter.

[0061]

[0072] In step 430, UE120 requests to connect to target BS110-2 (for example, using the configuration received from source BS110-1). For example, UE120 may perform a random access procedure to establish a connection with target BS110-2 (hereinafter referred to as the target connection).

[0062]

[0073] In response, target BS110-2 may respond with an acknowledgment at 435. UE120 and target BS110-2 may then establish a target connection at 440. As is evident in Example 400 shown in Figure 4, UE120 may maintain both a source connection with source BS110-1 and a target BS110-2 concurrently during the handover process. In such a case, since UE120 maintains active connections with both source BS110-1 and target BS110-2 for a certain period of time, UE120 may experience reduced latency and / or minimum data interruption time (e.g., 0ms handover) compared to the previous technique.

[0063]

[0074] In 445, target BS110-2 may instruct UE120 to release the source connection between UE120 and source BS110-1 in order to complete the handover. For example, if UE120 and / or target BS110-2 determine that the target connection is sufficiently strong (for example, the communication parameters measured by UE120 and / or target BS110-2 meet a first threshold indicating a strong connection), target BS110-2 may send an instruction to complete the handover.

[0064]

[0075] In some embodiments, the release of a source connection may not be based on an instruction from target BS110-2. Instead, UE120 may release the source connection without an instruction from target BS110-2, at least partially based on the establishment of a target connection (for example, UE120 determines that the communication parameters measured by UE120 meet a first threshold indicating a strong target connection). In some embodiments, UE120 may release the source connection based on an instruction from source BS110-1. In such examples, that instruction may be at least partially based on source BS110-1 receiving instructions from target BS110-2 or from UE120 to establish a target connection.

[0065]

[0076] At 450, UE120 may release the source connection to source BS110-1. At 455, additional communication between the UE and target BS110-2 may be performed using the target connection.

[0066]

[0077] Therefore, as shown by Example 400 in Figure 4, a UE may provide capabilities to a BS or network entity, and the BS may configure an MBB handover procedure for the UE to enable the UE to use its capabilities during the handover procedure. Thus, the UE may achieve improved performance during the handover procedure and experience minimal mobility interruption time (e.g., via a 0ms handover) compared to a handover procedure that does not consider or utilize the capabilities of the UE.

[0067]

[0078] As described above, Figure 4 is provided as an example. Other examples may differ from those described with respect to Figure 4.

[0068]

[0079] Figure 5 is a call flow diagram illustrating Example 500 for determining a handover configuration for a RAN handover procedure according to various aspects of the present disclosure. More specifically, Figure 5 shows an exemplary in-CU handover procedure using an extended MBB handover, where both source BS110-1 and target BS110-2 are related to the same CU502.

[0069]

[0080] Prior to the start of the call flow, UE120 may exchange user data (e.g., UL user data from UE120 on PUSCH and / or DL ​​user data received by UE on PDSCH) with CU502 via source BS110-1. In 505, UE120 may send a measurement report to source BS110-1.

[0070]

[0081] The generation and transmission of the measurement report in Figure 5 may include the features of the measurement report described in Figure 4. In some embodiments, the UE120 may generate and transmit the measurement report based at least in part on an event trigger (e.g., a signal measurement that meets a threshold) related to determining that a handover procedure should be initiated. For example, the execution criteria for conditional SN addition may be accompanied by an inter-RAT measurement event configured to indicate whether (i) the measured signal quality value of at least one inter-RAT neighbor is greater than a first threshold (e.g., the signal is sufficiently strong), or (ii) the measured signal quality value of a PCell is less than a first threshold and the measured signal quality value of at least one inter-RAT neighbor (e.g., another BS or PCell in the current BS) is greater than a second threshold.

[0071]

[0082] In some examples, UE120 may include simultaneous transmit and receive capabilities (e.g., MBB capability) that allow UE120 to transmit and receive data and / or information concurrently during handover. In such cases, UE120 may establish and maintain multiple connections with multiple different BSs (e.g., with source BS110-1 and target BS110-2).

[0072]

[0083] In 510, source BS110-1 may send a UL radio resource control (RRC) transfer to CU502. In some embodiments, the UL RRC transfer may include a measurement report. In additional embodiments, the UL RRC transfer may cause CU502 to determine the handover configuration that should be used for the handover procedure for UE120. For example, CU502 may select from possible handover procedures that can be performed by UE120, at least in part on the indicated capabilities of UE120. In some embodiments, CU502 may select an extended MBB handover procedure for UE120, at least in part on the indication of UE120's simultaneous transmit and receive capabilities.

[0073]

[0084] In 515, CU502 may send a UE context setup request to target BS110-2. In some examples, CU502 may send a UE context setup request to target BS110-2 in part to indicate that UE120 will be handed over to target BS110-2 during the handover procedure.

[0074]

[0085] In 520, target BS110-2 may respond to a UE context setup request by sending a UE context setup response. Target BS110-2 may send a UE context setup response to acknowledge the request and / or to indicate its ability to support the handover procedure and to service UE120 after the handover procedure.

[0075]

[0086] In 525, CU502 may send a DL RRC transfer to source BS110-1. In some embodiments, the DL RRC transfer may include an RRC reconfiguration message indicating the configuration for a handover procedure in which UE120 should be handed over from source BS110-1 to target BS110-2.

[0076]

[0087] In 530, source BS110-1 sends RRC reconfiguration to UE120. In some embodiments, the RRC reconfiguration may include information identifying target BS110-2, information identifying the handover configuration, and / or any other suitable information. In some examples, the RRC reconfiguration may include information indicating that UE120 should perform an extended MBB handover procedure with target BS110-2 using UE120's simultaneous transmit and receive capabilities. In such cases, UE120 may determine that it is possible to maintain a connection with source BS110-1 while establishing a connection with target BS110-2.

[0077]

[0088] In 535, UE120 may perform a random access procedure with target BS110-2 (for example, to initiate and / or establish a connection with target BS110-2). In some embodiments, UE120 may continue to exchange user data (e.g., uplink user data and / or downlink user data) with CU502 via source BS110-1 during and after the random access procedure.

[0078]

[0089] In 540, UE120 may send a reconfiguration complete message to target BS110-2. In some embodiments, UE120 may use a dual protocol stack, which includes a source protocol stack for communicating with source BS110-1 and a target protocol stack for communicating with target BS110-2. Each of these protocol stacks may include a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Media Access Control (MAC) layer, and / or a Physical (PHY) layer. In some embodiments, the source protocol stack and the target protocol stack may share one or more layers, such as a common PDCP layer or entity. In some embodiments, UE120 may use the target protocol stack for UL data transmission.

[0079]

[0090] In 545, target BS110-2 may send a UL RRC transfer to CU502. In some examples, the UL RRC transfer may indicate that RRC reconstruction is complete. Thus, in some embodiments, CU502 may determine a handover completion configuration at least in part based on having received an instruction that RRC reconstruction is complete. For example, when making a completion determination, CU502 may utilize and / or configure one or more thresholds for one or more measurement parameters to perform a handover completion procedure (e.g., to release source BS110-1). Furthermore, in some embodiments, after RRC reconstruction is complete, UE120 may perform uplink user / control plane replication with source BS110-1 and CU502. For example, control plane data may be replicated and shared between BS110-1 and CU502. Furthermore, in some embodiments, after CU502 determines that RRC reconstruction is complete, CU502 may continue to send DL user data to UE120 via target BS110-2 and also send DL user / control plane copies to UE120 via source BS110-1. Thus, UE120 can achieve improved reliability when receiving data on the downlink.

[0080]

[0091] In 550, CU502 may send a UE context correction request to source BS110-1. The UE context correction request may include a transmission stop indicator to indicate that source BS110-1 should be released from servicing UE120 (for example, releasing the radio link between source BS110-1 and UE120). In some examples, source BS110-1 may provide CU502 with a DL data delivery status indicating the status of the DL user / control plane replica that source BS110-1 is communicating with UE120.

[0081]

[0092] In 555, source BS110-1 may send a UE context correction response to CU502. For example, the UE context correction response may include an affirmation that source BS110-1 should be released during the handover procedure and / or should no longer service UE120.

[0082]

[0093] In 560, CU502 may send a DL RRC transfer to target BS110-2. The DL RRC transfer may include an RRC reconfiguration message indicating that a handover procedure from source BS110-1 to target BS110-2 should be performed.

[0083]

[0094] In step 565, target BS110-2 may send an RRC reconfiguration to UE120. In some examples, the RRC reconfiguration message may indicate that UE120 should release the connection with source BS110-1. Thus, UE120 may release the connection with source BS110-1, at least in part, based on having received the RRC reconfiguration message. Furthermore, UE120 may then begin exchanging uplink and downlink user data with CU502 via target BS110-2.

[0084]

[0095] In step 570, UE120 may send an RRC reconstruction complete message to target BS110-2. The RRC reconstruction complete message may indicate that UE120 has released its connection to source BS110-1.

[0085]

[0096] In 575, target BS110-2 may transmit a UL RRC transfer to CU502. In some embodiments, the UL RRC transfer may be performed in response to the receipt of an RRC reconstruction complete message, which may indicate that the RRC reconstruction complete message was received from UE120.

[0086]

[0097] In 580, CU502 may then send a UE context release command to source BS110-1 (for example, to prevent source BS110-1 from continuing to attempt to service UE120).

[0087]

[0098] In 585, source BS110-1 may send a UE context release complete message to CU502. The UE context release complete message may be an acknowledgment that source BS110-1 is no longer communicating with UE120 and / or is no longer servicing UE120.

[0088]

[0099] As described above, Figure 5 is provided as an example. Other examples may differ from those described with respect to Figure 5.

[0089] Exemplary optimization for Extended Handover (HO) procedures using a Conditional Handover (CHO) form

[0100] Aspects of this disclosure relate to wireless communications, and more particularly to enhanced handover (HO) procedures configured to improve make-before-break (MBB) and conditional handover (CHO) procedures. In some cases, the optimization may support MBB and / or CHO procedures with N2 signaling. In some cases, the optimization may include taking action to prioritize handover procedures to target base stations (BS) that may be able to utilize Xn connectivity.

[0090]

[0101] N2 signaling generally refers to signaling via the physical N2 interface between NG-RAN g-node B (gNB) and the Access and Mobility Management Function (AMF) in a 5G core (5GC) network, as well as the logical N1 interface between user equipment (UE) and the AMF. N2 generally acts as the control plane interface between the access network (NG-RAN or non-3GPP wireless local area network (WLAN)) and the 5GC network. N2 generally relates to connectivity management, UE context and protocol data unit (PDU) session management, and UE mobility management. Xn signaling generally refers to signaling using Xn interfaces that exist between base stations (e.g., between gNBs). Xn generally refers to network interfaces between NG-RAN nodes.

[0091]

[0102] The techniques presented herein may help provide optimizations for supporting MBB and CHO for NG RAN handover. In some cases of extended handover procedures, the source BS and target BS are connected via Xn, which provides a relatively low-latency communication interface. In such cases, data forwarding can be communicated between these nodes over Xn. Thus, aspects of the present disclosure may enable an N2-based HO procedure to prioritize such nodes to take advantage of the lower latency associated with Xn signaling.

[0092]

[0103] Generally, the CHO configuration is sent to the UE before the actual HO event. The source BS may prepare one or more candidate target cells for the CHO. For each candidate target cell, the network (e.g., source BS and / or CN) configures the UE with information to enable the UE to connect to the target cell during the HO, and conditions to trigger the HO for the target cell. When the HO conditions are met, the UE initiates a Random Access Procedure (RACH) with the target cell. In such cases, the UE does not need to send a measurement report or wait for RRC reconfiguration to perform the HO.

[0093]

[0104] As described above, in the CHO procedure defined for N2-based candidate cell preparation, the source BS may prepare and / or select candidate cells based solely on metrics. If some of the cells belong to different AMFs, there may be benefits in optimizing the source BS and UE CHO execution logic to prioritize cells that use the same AMF. In some cases, data forwarding on N2 may benefit from optimizations regarding when data forwarding should be enabled for the MBB and / or CHO handover procedure.

[0094] Conditional procedures for adding and modifying secondary nodes (SNs), initiated by secondary nodes (SNs).

[0105] Aspects of this disclosure provide techniques that can help optimize / improve extended handover (HO) procedures, such as make-before-break (MBB) and conditional handover (CHO).

[0095]

[0106] As described herein, CHO is an HO procedure in which the user equipment (UE) selects a target cell for HO from among candidate target cells based on CHO execution criteria. As described herein, the CHO procedure may be implemented for secondary node (SN) addition or modification procedures, which can reduce delays associated with SN addition or modification in dual connectivity scenarios.

[0096]

[0107] In the case of conditional primary-secondary cell (PSCell) changes, various scenarios for SN changes can include master node (MN)-initiated SN changes and SN-initiated SN changes. As the name suggests, in MN-initiated SN changes, the MN generally determines the execution criteria, in addition to which PSCells can be configured as candidate PSCells, and performs the SN addition procedure using the candidate SN. Alternatively, in SN-initiated SN changes, the SN generally determines which PSCells can be configured as candidate PSCells and performs the SN addition procedure using the candidate SN. In some cases, SN-initiated SN changes may involve the SN determining the execution criteria.

[0097]

[0108] Figures 6, 7, and 8 are flowcharts illustrating exemplary behavior for an SN-initiated SN change procedure, which can be performed by a BS acting as an SN (e.g., any type of BS shown in Figure 1, Figure 2, or Figure 3), a BS acting as an MN (e.g., any type of BS shown in Figure 1, Figure 2, or Figure 3), and an UE (e.g., any type of UE shown in Figure 1 or Figure 3), respectively.

[0098]

[0109] Figure 6 shows exemplary operation 600 that may be performed by a secondary node (SN) according to several embodiments of this disclosure. Operation 600 may be performed, for example, by a BS that services the SN and / or acts as the SN (e.g., BS110 shown in Figures 1, 2, or 3). Operation 600 may complement operation 700 performed by an MN and / or operation 800 performed by a UE, which are described below with respect to Figures 7 and 8. Operation 600 may be implemented as a software component that runs on and operates on one or more processors (e.g., controller / processor 340 in Figure 3). Furthermore, the transmission and reception of signals by the SN in operation 600 may be enabled, for example, by one or more antennas (e.g., antenna 334 in Figure 3). In some embodiments, the transmission and / or reception of signals by the SN may be implemented via a bus interface of one or more processors (e.g., controller / processor 340) that acquire and / or output signals.

[0099]

[0110] Operation 600 begins in block 602 with SN identifying one or more candidate cell sets for conditional addition or modification of SN for UE based on execution criteria. In block 604, SN signals MN information about the candidate cell set.

[0100]

[0111] Figure 7 shows exemplary operation 700 that may be performed by a master node (MN) according to several embodiments of the present disclosure. Operation 700 may be performed, for example, by a BS that services and / or acts as an MN (e.g., BS110 shown in Figures 1, 2, or 3, or one or more of its processors shown in Figure 3). Operation 700 may complement operation 600 performed by an SN and / or operation 800 performed by a UE, which are described with respect to Figures 6 and 8. Operation 700 may be implemented as a software component that runs and operates on one or more processors (e.g., controller / processor 340 in Figure 3). Furthermore, the transmission and reception of signals by the MN in operation 700 may be enabled, for example, by one or more antennas (e.g., antenna 334 in Figure 3). In some embodiments, the transmission and / or reception of signals by the MN may be implemented via a bus interface of one or more processors (e.g., controller / processor 340) that acquire and / or output signals.

[0101]

[0112] Operation 700 may begin in block 702 by receiving a signal from SN that identifies a set of candidate cells for conditional addition or modification of SN for UE based on execution criteria. In block 604, MN signals configuration information regarding the set of candidate cells to UE.

[0102]

[0113] Figure 8 shows exemplary operation 800 that may be performed by a UE in some aspects of the present disclosure. Operation 800 may be performed by a UE participating in a procedure with the MN and SN, such as UE120 (or one or more of its processors shown in Figure 3) as shown in Figures 1 and 3. Operation 800 may complement operation 600 performed by the SN and / or operation 700 performed by the MN, which are described with respect to Figures 6 and 7. Operation 800 may be implemented as a software component that runs on and operates on one or more processors (e.g., controller / processor 380 in Figure 3). Furthermore, the transmission and reception of signals by the UE in operation 800 may be enabled by, for example, one or more antennas (e.g., antenna 352 in Figure 3). In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller / processor 380) that acquire and / or output signals.

[0103]

[0114] Operation 800 begins in block 802 when the UE receives configuration information from the MN that identifies a set of candidate cells for conditional addition or modification of an SN for the UE based on execution criteria. In block 804, the UE detects that the execution criteria are met for one of the candidate cells. In block 806, the UE takes action to add or modify the candidate cell as an SN based on the detection.

[0104]

[0115] As described above, UE120 can be configured with conditional PSCell execution criteria for SN add and modify procedures. The measurement events used to trigger PSCell add and / or PSCell modify may differ based on the type of dual connectivity architecture. Furthermore, measurement events may be configured independently by MN110a and SN. Therefore, the conditional PSCell add / modify RRC message must support configuring separate execution criteria configurations for each PSCell of multiple PSCells in order to enable UE120 to perform PSCell add and / or PSCell modify.

[0105]

[0116] For conditional PSCell additions and / or modifications, various options exist to support SN-initiated SN modifications. In some embodiments, for an SN-triggered SN modification, the SN may identify a set of one or more PSCells that could constitute a candidate cell, and the MN may determine the execution criteria for the candidate cell. In some embodiments, for an SN-triggered SN modification, the SN may do both identify a set of one or more PSCells that could constitute a candidate cell and determine the execution criteria for the candidate cell.

[0106]

[0117] Figure 9 shows a diagram of a first call flow 900 illustrating exemplary communication between a UE, an MN, and an SN according to various aspects of the present disclosure. As shown in the first option shown in Figure 9, the SN may identify one or more sets of PSCells that can be configured as candidate cells, and the MN determines the execution criteria for the candidate cells. Upon determining a triggering event, the UE 120 may decide to fall back to communication with the SN 110a (e.g., BS 110a in Figure 1). For example, a triggering event may include the detection by the UE 120 of an HO failure (e.g., T304 expiration) or a radio link failure (RLF) on the SN connection while the UE 120 is still connected to the SN 110a (e.g., the source cell is active). In this example, the UE 120 may declare an RLF on the SN connection and operate using the existing SN 110a connection, but refrain from triggering a radio resource control (RRC) re-establishment.

[0107]

[0118] Before and during a triggering event, UE120 may monitor neighboring cells. In the example in Figure 9, neighboring cells may include a first candidate secondary node (CSN1) and a second candidate secondary node (CSN2) (for example, BS110c and BS110d, respectively). In response to a triggering event, UE120 may send a measurement report identifying CSN1 and CSN2 to MN110b, which was configured for measurement in step 1. MN110b may then forward the measurement report to SN110a. The measurement report may be generated by UE120 and may indicate to MN110b and SN110a that UE120 is requesting a CHO to a new or additional SN.

[0108]

[0119] Based on the received measurement report, the SN may decide which of the candidate cells should be configured as the new PSCell for UE120 (for example, CSN1 and CSN2 in this example). After identifying the set of candidate cells for the SN list, the SN110a may, in step 2, initiate a conditional SN change by sending an additional candidate SN list containing both CSN1 and CSN2 to the MN110b in an XN message.

[0109]

[0120] As shown in the figure, MN110b may perform an SN addition procedure using a candidate SN. In step 3, MN110b may send a first conditional SN addition message (e.g., an SN addition request to CSN1) to initiate a first conditional SN addition procedure using CSN1. In step 4, MN110b may receive an SN addition acknowledgment sent by CSN1.

[0110]

[0121] In step 5, MN110b may send a second conditional SN addition message (e.g., an SN addition request to CSN2) to initiate a second conditional SN addition procedure using CSN2. In step 6, MN110b may receive an SN addition acknowledgment sent by CSN2.

[0111]

[0122] MN110b may also determine implementation criteria for each candidate SN, where the implementation criteria provide the criteria by which the implementation of a particular addition or modification (e.g., HO) of CSN1 110b or CSN2 110c should be carried out.

[0112]

[0123] In some embodiments, UE120, MN110b, and SN110a may support the use of A3 / A5 event execution criteria for conditional NR PSCell additional execution conditions.

[0113]

[0124] In step 7, MN100b may send execution conditions (e.g., execution criteria) and a list of candidate SNs to UE120 in an RRC configuration message to UE120 (e.g., an "RRC reconfiguration message" for an NR). In some examples, an RRC configuration message may configure UE120 for multiple candidate SNs in a single message. For example, an RRC configuration message may include configuration information for both CSN1 and CSN1. In some examples, an RRC configuration message may include one or more of the following: (i) source cell RRC configuration changes (if any), (ii) conditional SN addition or modification execution criteria for each candidate cell in the set (configured by MN110b), and / or (iii) RRC reconfiguration for each CSN.

[0114]

[0125] After receiving an RRC configuration message, the UE120 may monitor the conditions for modifying the PSCell based on the configuration received from the MN.

[0115]

[0126] For example, UE120 may determine whether the quality of a neighbor cell is greater than the threshold of the execution criteria that MN110b sent to UE120. If UE120 determines that the quality is greater than the threshold, the execution criteria are met. In the case of CHO, instead of UE120 sending the measurement report to MN110b (which may be forwarded to SN110a), UE may determine that the execution criteria for a candidate PSCell (e.g., B1 event criteria or A3 / A5 event criteria) are met, and UE120 may perform the handover to the candidate PSCell.

[0116]

[0127] As shown in the diagram, if SN110a decides to change the candidate SN list, SN110a may initiate another conditional SN change in step 8 by sending a new candidate SN addition list to MN110b in the Xn message. Since the UE120 channel conditions are constantly changing, UE120 may send subsequent measurement reports after some time. A new measurement report (for example, a measurement report sent at time t2) may differ from the measurement report sent in step 1 (i.e., a measurement report sent at time t1). Thus, a new measurement report may indicate to the SN that some candidate cells may no longer be suitable for the candidate SN list.

[0117]

[0128] In some examples, as shown in Figure 9, SN110a may decide to release CSN2 and include only CSN1 in the SN addition list. Thus, in step 9, MN110b may send the candidate addition / release list to UE120. Furthermore, MN110b may perform the SN release procedure with CSN2 in steps 10 and 11.

[0118]

[0129] Figure 10 shows a second call flow diagram 1000 illustrating exemplary communication between a UE, an MN, and an SN according to various aspects of the present disclosure. As shown in the first option shown by Figure 9, the SN may both identify a set of one or more PSCells that may constitute a candidate cell and determine the execution criteria for the candidate cell.

[0119]

[0130] Similar to Figure 9, a triggering event (e.g., HO fault or RLF) may, in step 1, cause the UE120 to send a measurement report identifying CSN1 and CSN2 to the MN110b configured for measurement, which the MN110b may forward to the SN110a. The SN110a may select candidate cells (again CSN1 and CSN2) based on the measurement report for a candidate SN list. Again, in step 2, the SN110a may send the candidate SN list to the MN110b in an Xn message, and the MN110b may perform the SN addition procedure (in steps 3-6).

[0120]

[0131] Unlike the example shown in Figure 9, SN110a in Figure 10 may also determine execution criteria for candidate cells and signal information regarding the execution criteria to MN110b. MN110b may include the execution criteria in the RRC reconfiguration message sent to UE120 in step 7. Various options may exist for sending the execution criteria from SN110a to MN110b.

[0121]

[0132] In some examples, the RRC message may contain the execution criteria configuration for each candidate cell in the transparent container. In some examples, the RRC message may contain the RRC reconfiguration for each candidate cell in the set in the transparent container.

[0122]

[0133] In some cases, according to the first option, MN110b may be able to modify the execution criteria in the Xn message from SN110a to MN110b. Thus, the RRC message sent by MN110b to UE120 may signal information about candidate cells and the modified execution criteria (similar to the option shown in Figure 9).

[0123]

[0134] In some examples, according to the second option, as shown in step 2 of Figure 10, SN110a may include conditional SN modification execution criteria in the transparent container from SN to MN, and thus MN110b may modify it. In this case, MN110b may simply forward the container to the UE (without modification) in the SN-defined execution criteria and candidate SN reconstruction in the RRC reconstruction message sent by MN110b to UE120.

[0124]

[0135] In some examples where the UE is configured with conditional SN change configurations from both MN110b and SN110a, the UE120 can monitor both configurations independently. Thus, the UE120 can trigger an SN change when either the MN-defined execution criteria or the SN-defined execution criteria are met (for example, based on the first condition to occur).

[0125]

[0136] In some embodiments, after performing an SN change to a new SN (e.g., CSN1 or CSN2), UE120 may stop monitoring the execution conditions (e.g., criteria) configured by the old SN110a. In such cases, UE120 may notify MN110b of the SN change (e.g., via an RRC reconfiguration complete message). In response, MN110b may clean up the old SN-selected candidate SN configuration. For example, MN110b may remove old candidate cells if they are no longer suitable as candidate SNs.

[0126]

[0137] Figure 11 shows a communication device 1100 which may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operation shown in Figure 6. The communication device 1100 includes a processing system 1102 coupled to a transceiver 1108. The transceiver 1108 is configured to transmit and receive signals for the communication device 1100, such as various signals described herein, via an antenna 1110. The processing system 1102 may be configured to perform processing functions for the communication device 1100, including processing signals received and / or to be transmitted by the communication device 1100.

[0127]

[0138] The processing system 1102 includes a processor 1104 coupled to a computer-readable medium / memory 1112 via a bus 1106. In some embodiments, the computer-readable medium / memory 1112 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1104, cause the processor 1104 to perform the operations shown in Figure 6 or other operations to implement the various techniques described herein. In some embodiments, the computer-readable medium / memory 1112 stores a code 1114 for identification (e.g., for identifying a set of one or more candidate cells for a conditional addition or modification of an SN for a UE based on execution criteria) and a code 1116 for signaling (e.g., for signaling information about a set of candidate cells to an MN). In some embodiments, the processor 1104 has circuitry configured to implement the code stored in the computer-readable medium / memory 1112. The processor 1104 includes a circuit 1124 for identification (for example, for identifying a set of one or more candidate cells for a conditional addition or modification of an SN for a UE based on execution criteria) and a circuit 1126 for signaling (for example, for signaling information about a set of candidate cells to an MN).

[0128]

[0139] Figure 12 shows a communication device 1200 which may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operation shown in Figure 7. The communication device 1200 includes a processing system 1202 coupled to a transceiver 1208. The transceiver 1208 is configured to transmit and receive signals for the communication device 1200, such as various signals described herein, via an antenna 1210. The processing system 1202 may be configured to perform processing functions for the communication device 1200, including processing signals received and / or to be transmitted by the communication device 1200.

[0129]

[0140] The processing system 1202 includes a processor 1204 coupled to a computer-readable medium / memory 1212 via a bus 1206. In some embodiments, the computer-readable medium / memory 1212 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1204, cause the processor 1204 to perform the operations shown in Figure 7 or other operations to implement the various techniques described herein. In some embodiments, the computer-readable medium / memory 1212 stores code 1214 for receiving (e.g., for receiving signaling from an SN that identifies a set of candidate cells for conditional addition or modification of an SN for a UE based on execution criteria) and code 1216 for signaling (e.g., for signaling configuration information about the set of candidate cells to the UE). In some embodiments, the processor 1204 has circuitry configured to implement the code stored in the computer-readable medium / memory 1212. The processor 1204 includes a circuit 1224 for receiving (for example, receiving signaling from SN that identifies a set of candidate cells for conditional addition or modification of SN for UE based on execution criteria) and a circuit 1226 for signaling (for example, signaling configuration information about the set of candidate cells to the UE).

[0130]

[0141] Figure 13 shows a communication device 1300 which may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operation shown in Figure 8. The communication device 1300 includes a processing system 1302 coupled to a transceiver 1308. The transceiver 1308 is configured to transmit and receive signals for the communication device 1300, such as various signals described herein, via an antenna 1310. The processing system 1302 may be configured to perform processing functions for the communication device 1300, including processing signals received and / or to be transmitted by the communication device 1300.

[0131]

[0142] The processing system 1302 includes a processor 1304 coupled to a computer-readable medium / memory 1312 via a bus 1306. In some embodiments, the computer-readable medium / memory 1312 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1304, cause the processor 1304 to perform the operations shown in Figure 8 or other operations to perform the various techniques described herein. In some embodiments, the computer-readable medium / memory 1312 stores code 1314 for receiving (e.g., for receiving configuration information from an MN that identifies a set of candidate cells for the conditional addition or modification of an SN for a UE based on execution criteria), code 1316 for detecting (e.g., for detecting that the execution criteria are met for one of the candidate cells), and code 1318 for taking action (e.g., for taking action to add or modify a candidate cell as an SN based on the detection). In some embodiments, the processor 1304 has circuitry configured to implement the code stored in the computer-readable medium / memory 1312. The processor 1304 includes a circuit 1324 for receiving (for example, receiving configuration information from an MN that identifies a set of candidate cells for conditional addition or modification of an SN for a UE based on execution criteria), a circuit 1326 for detecting (for example, detecting that an execution criterion is met for one of the candidate cells), and a circuit 1328 for taking action (for example, taking action to add or modify a candidate cell as an SN based on the detection).

[0132] Example Aspects

[0143] Embodiment 1. A method for wireless communication by a user device (UE), comprising: receiving configuration information and execution criteria from a master node (MN) that identify a set of candidate cells for conditionally adding or changing a secondary node (SN) for the UE; detecting that the execution criteria are met for one of the candidate cells; and taking action to add or change the candidate cell as an SN based on the detection.

[0133]

[0144] Embodiment 2. The method according to Embodiment 1, wherein configuration information is received by the UE in a radio resource control (RRC) message.

[0134]

[0145] Embodiment 3. The method according to Embodiment 2, wherein the RRC message includes at least one of the following information for conditional addition or modification of an SN: namely, source cell RRC configuration change, conditional SN addition or modification execution criteria configuration for each candidate cell in the set, or RRC reconfiguration for each candidate cell in the set.

[0135]

[0146] Embodiment 4. The method according to Embodiment 3, wherein the RRC message includes an execution criteria configuration for each candidate cell in the transparent container.

[0136]

[0147] Embodiment 5. The method of any one of embodiments 1 to 4, further comprising sending a radio resource control (RRC) message to an MN indicating when a conditional SN addition or modification execution criterion is met for one of the selected candidate cells in the set, provided that the configuration of the selected cell is valid.

[0137]

[0148] Embodiment 6. The method according to any one of Embodiments 1 to 5, wherein the configuration information indicates a first configuration information determined by MN and a second configuration information determined by SN, and the UE independently monitors the execution criteria for the first configuration and the execution criteria for the second configuration, and when either the execution criteria for the first configuration or the execution criteria for the second configuration is met, it performs an SN change on the candidate cell.

[0138]

[0149] Embodiment 7. The method of Embodiment 6, wherein the UE stops monitoring the execution criteria determined by the old SN after performing an SN change on a candidate cell.

[0139]

[0150] Embodiment 8. The method of Embodiment 6 or 7, further comprising sending a notification to the MN indicating that an SN change has been performed on a candidate cell.

[0140]

[0151] Embodiment 9. The method according to Embodiment 8, wherein the notification is sent via a radio resource control (RRC) reconfiguration completion message.

[0141]

[0152] Embodiment 10.2 A method for wireless communication by a secondary node (SN), comprising: identifying one or more candidate cell sets for conditional addition or modification of an SN for a user device (UE) based on execution criteria; and signaling information about the candidate cell set to a master node (MN).

[0142]

[0153] Embodiment 11. The method of Embodiment 10, wherein information regarding a set of candidate cells is signaled to the MN via a message without execution criteria, the MN determines the execution criteria for the candidate cells, and signals the candidate cells and the execution criteria to the UE.

[0143]

[0154] Embodiment 12. The method according to Embodiment 10 or 11, further comprising determining execution criteria for a candidate cell and signaling information regarding the execution criteria to the MN.

[0144]

[0155] Embodiment 13. The method of Embodiment 12, wherein the MN is enabled to modify the execution criteria for a candidate cell and to signal information about the candidate cell and the modified execution criteria to the UE.

[0145]

[0156] Embodiment 14. The method of Embodiment 12 or 13, wherein the SN signals to the MN information regarding performance criteria that should be forwarded to the UE without modification.

[0146]

[0157] Embodiment 15. The method according to Embodiment 14, wherein SN signals information regarding execution standards within a transparent container, and MN forwards the transparent container to UE.

[0147]

[0158] Embodiment 16. The method according to any one of embodiments 10 to 15, further comprising deciding to change one or more sets of candidate cells and signaling information regarding the change to the MN.

[0148]

[0159] Embodiment 17. A method for wireless communication by a master node (MN), comprising: receiving a signaling from a secondary node (SN) that identifies a set of candidate cells for conditional addition or modification of the SN for a user device (UE) based on execution criteria; and signaling configuration information relating to the set of candidate cells to the UE.

[0149]

[0160] Embodiment 18. The method of Embodiment 17, wherein the MN receives information from the SN regarding a set of candidate cells via a message without execution criteria, the MN determines the execution criteria for the candidate cells, and signals the candidate cells and the execution criteria to the UE.

[0150]

[0161] Embodiment 19. The method according to Embodiment 17 or 18, further comprising receiving information from SN regarding execution criteria for candidate cells.

[0151]

[0162] Embodiment 20. The method of Embodiment 19, further comprising modifying the execution criteria for a candidate cell and signaling information about the candidate cell and the modified execution criteria to the UE.

[0152]

[0163] Embodiment 21. The method of Embodiment 20, wherein SN signals MN to perform criteria information which should be forwarded to UE without modification, and MN forwards the perform criteria information to SN without modification.

[0153]

[0164] Embodiment 22. The method according to Embodiment 21, wherein SN signals information regarding execution standards within a transparent container, and MN forwards the transparent container to UE.

[0154]

[0165] Embodiment 23. The method according to any one of embodiments 17 to 22, further comprising performing an SN addition procedure using candidate cells.

[0155]

[0166] Embodiment 24. The method according to any one of embodiments 17 to 23, wherein configuration information is signaled to the UE in a radio resource control (RRC) message.

[0156]

[0167] Embodiment 25. The method according to any one of embodiments 17 to 24, further comprising receiving a radio resource control (RRC) message from the UE indicating when a conditional SN addition or modification execution criterion is met for one of the selected candidate cells in the set, provided that the configuration of the selected cell is valid.

[0157]

[0168] Embodiment 26. The method according to any one of embodiments 17 to 25, wherein configuration information is signaled to the UE in a radio resource control (RRC) message that includes separate execution criteria for conditional SN addition and SN modification.

[0158]

[0169] Embodiment 27. The method of any one embodiment 17 to 26, further comprising receiving notification from the UE regarding a change in SN via a Radio Resource Control (RRC) reconfiguration completion message, and updating the candidate SN configuration to remove cells that are no longer suitable candidate cells for conditional addition or modification as SNs.

[0159]

[0170] Embodiment 28. A device for wireless communication by a user device (UE), comprising a memory and at least one processor coupled to the memory, wherein the at least one processor is configured to receive configuration information from a master node (MN) that identifies a set of candidate cells for conditional addition or modification of secondary nodes (SNs) for the UE based on execution criteria, to detect that the execution criteria are met for one of the candidate cells, and to take action to add or modify the candidate cell as an SN based on the detection.

[0160]

[0171] Embodiment 29.2 A device for wireless communication by a secondary node (SN), comprising a memory and at least one processor coupled to the memory, wherein the at least one processor is configured to identify one or more sets of candidate cells for conditional addition or modification of an SN for a user device (UE) based on execution criteria, and to signal information about the set of candidate cells to a master node (MN).

[0161]

[0172] Embodiment 30. A device for wireless communication by a master node (MN), comprising memory and at least one processor coupled to the memory, wherein the at least one processor is configured to receive signaling from a secondary node (SN) that identifies a set of candidate cells for conditional addition or modification of an SN for a user device (UE) based on execution criteria, and to signal configuration information relating to the set of candidate cells to the UE.

[0162] Additional Considerations

[0173] The methods disclosed herein comprise one or more steps or actions for achieving the described method. The steps and / or actions of the methods may be interchangeable with one another without departing from the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of any particular steps and / or actions may be modified without departing from the claims.

[0163]

[0174] As used herein, the phrase “at least one of” the list of items refers to any combination of those items that contains a single member. For example, “at least one of a, b, or c” shall include a, b, c, ab, ac, bc, and abc, as well as any combination having multiple identical elements (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other order of a, b, and c).

[0164]

[0175] As used herein, the term “deciding” encompasses a wide variety of actions. For example, “deciding” may include calculating, calculating, processing, deriving, investigating, looking up (e.g., looking up in a table, database, or other data structure), and confirming. It may also include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and resolving, selecting, choosing, and establishing.

[0165]

[0176] The above description is provided so that a person skilled in the art may carry out the various embodiments described herein. Various modifications to these embodiments will be readily apparent to a person skilled in the art, and the general principles defined herein may apply to other embodiments. Accordingly, the claims should not be limited to the embodiments shown herein, but should be given the entire scope consistent with the wording of the claims, where, unless otherwise explicitly stated, a singular reference to an element means "one or more" and not "one unique." Unless otherwise explicitly stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various embodiments described throughout this disclosure, known to a person skilled in the art, or to be known thereafter, are expressly incorporated herein by reference and are included in the claims. Furthermore, nothing disclosed herein, whether such disclosure is expressly represented in the claims or not, is not made public. No claim element should be construed under Section 112, paragraph 6 of the United States Patent Act unless it is explicitly stated using the phrase “means for” or, in the case of a method claim, “steps for.”

[0166]

[0177] The various operations of the methods described above may be carried out by any suitable means capable of performing the corresponding functions. These means may include, but are not limited to, a variety of (one or more) hardware and / or software components and / or modules, including circuits, application-specific integrated circuits (ASICs), or processors. Generally, where there are operations shown in the figures, those operations may have corresponding means-plus-function components of similar numbering.

[0167]

[0178] The various exemplary logic blocks, modules, and circuits described in connection with this disclosure may be implemented or carried out using general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working with a DSP core, or any other such configuration.

[0168]

[0179] When implemented in hardware, an exemplary hardware configuration may include a processing system within the wireless node. The processing system may be implemented using a bus architecture. The bus may include any number of interconnecting buses and bridges, depending on the specific application of the processing system and the overall design constraints. The bus may link various circuits, including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, in particular, to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of user terminal 120 (see Figure 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, but these circuits are well known in the art and are therefore not described further. The processor may be implemented using one or more general-purpose and / or dedicated processors. An example includes a microprocessor, a microcontroller, a DSP processor, and other circuits capable of running software. Those skilled in the art will understand how the described functions of the processing system can be best implemented, depending on the specific application and the overall design constraints imposed on the system as a whole.

[0169]

[0180] When implemented in software, functionality may be stored on or transmitted via computer-readable media as one or more instructions or code. Software should be broadly interpreted as meaning instructions, data, or any combination thereof, regardless of the name, such as software, firmware, middleware, microcode, or hardware description language. Computer-readable media includes both computer storage media and communication media, including any medium that enables the transfer of computer programs from one location to another. A processor may be responsible for managing buses and general operations, including the execution of software modules stored on machine-readable storage media. Computer-readable storage media may be coupled to a processor so that the processor can read information from and write information to the storage media. Alternatively, the storage media may be integrated with the processor. As an example, machine-readable media may include computer-readable storage media storing instructions on which it is located, separate from transmission lines, data-modulated carriers, and / or wireless nodes, all of which can be accessed by the processor via a bus interface. Alternatively, or as an addition, machine-readable media, or any part thereof, may be integrated into the processor, such as caches and / or general-purpose register files. Examples of machine-readable storage media may include, as an example, RAM (Random Access Memory), flash memory, ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electronically Erasable Programmable Read-Only Memory), registers, magnetic disks, optical disks, hard drives, or other suitable storage media, or any combination thereof. Machine-readable media may be implemented in computer program products.

[0170]

[0181] A software module may consist of a single instruction or a number of instructions, and may be distributed across several different code segments, between different programs, and across multiple storage media. A computer-readable medium may contain several software modules. A software module contains instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a send module and a receive module. Each software module may reside in a single storage device or be distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. While a software module is executing, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general-purpose register file for execution by the processor. When the functions of a software module are referred to below, it will be understood that such functions are implemented by the processor when executing instructions from that software module.

[0171]

[0182] Furthermore, any connection is appropriately referred to as a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laserdisc (disc), optical disc (disc), digital versatile disc (disc) (DVD), floppy disk (disk), and Blu-ray (disc), where disk typically reproduces data magnetically and disc optically reproduces data by laser. Thus, in some embodiments, a computer-readable medium may include non-temporary computer-readable medium (e.g., tangible medium). Furthermore, in other embodiments, the computer-readable medium may include a temporary computer-readable medium (e.g., a signal). The above combinations should also be included within the scope of computer-readable mediums.

[0172]

[0183] Accordingly, some embodiments may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium storing (and / or encoding) instructions thereon that are executable by one or more processors for performing the operations described herein.

[0173]

[0184] Furthermore, it should be understood that modules and / or other suitable means for carrying out the methods and techniques described herein may be downloaded and / or otherwise obtained by user terminals and / or base stations where applicable. For example, such devices may be coupled to a server to enable the transfer of means for carrying out the methods described herein. Alternatively, the various methods described herein may be provided by storage means so that user terminals and / or base stations can obtain the various methods by coupling or providing storage means (e.g., physical storage media such as RAM, ROM, compact disks (CDs), or floppy disks) to a device. Moreover, any other suitable techniques for providing the methods and techniques described herein to a device may be utilized. It should be understood that the claims are not limited to the exact configurations and components shown above. Various modifications, changes, and variations may be made to the configuration, operation, and details of the methods and apparatus described above without departing from the claims.

Claims

1. A method for wireless communication using user equipment (UE), Receiving configuration information and execution criteria from the master node (MN) for the conditional addition or modification of secondary nodes (SN) for the UE, The process involves detecting that the execution criteria are met for one of the candidate cells, A method comprising taking action to add or modify the candidate cell as an SN based on the detection.

2. The method according to claim 1, wherein the configuration information is received by the UE in a radio resource control (RRC) message.

3. The RRC message contains the following information for the conditional addition or modification of SN, namely: Source cell RRC configuration change, Conditional SN addition or modification execution criteria configuration for each candidate cell in the set, or The method according to claim 2, comprising at least one of RRC reconstruction for each candidate cell in the set.

4. The method according to claim 3, wherein the RRC message includes the execution criteria configuration for each candidate cell in the transparent container.

5. The method according to claim 1, further comprising sending a radio resource control (RRC) message to the MN indicating when the conditional SN addition or modification execution criterion is met for one of the selected candidate cells in the set, provided that the configuration of the selected cell is valid.

6. The aforementioned configuration information includes a first configuration information determined by the MN and a second configuration information determined by the SN. The UE independently monitors the execution criteria according to the first configuration and the execution criteria according to the second configuration. The method according to claim 1, wherein an SN change is performed on a candidate cell when either the execution criterion according to the first configuration or the execution criterion according to the second configuration is met.

7. The method according to claim 6, wherein the UE stops monitoring the execution criteria determined by the old SN after performing the SN change on the candidate cell.

8. The method according to claim 6, further comprising sending a notification to the MN indicating that the SN change for a candidate cell has been performed.

9. The method according to claim 8, wherein the notification is sent via a radio resource control (RRC) reconfiguration completion message.

10. A method for wireless communication using a secondary node (SN), Identifying one or more candidate cell sets for conditional addition or modification of SN for user equipment (UE) based on execution criteria, A method comprising signaling information about the set of candidate cells to a master node (MN).

11. The information relating to the set of candidate cells is signaled to the MN via a message without execution criteria. The method according to claim 10, wherein the MN determines the execution criteria for the candidate cell and signals the candidate cell and the execution criteria to the UE.

12. Determining the execution criteria for the aforementioned candidate cells, The method according to claim 10, further comprising signaling information relating to the aforementioned execution criteria to the MN.

13. The method according to claim 12, wherein the MN is enabled to modify the execution criteria for the candidate cell and to signal the UE with information relating to the candidate cell and the modified execution criteria.

14. The method according to claim 12, wherein the SN signals the MN to the information relating to the execution criteria which should be forwarded to the UE without modification.

15. The SN signals the information relating to the execution criteria within the transparent container, The method according to claim 14, wherein the MN forwards the transparent container to the UE.

16. Deciding to change the aforementioned set of candidate cells for one period, The method according to claim 10, further comprising signaling information regarding the aforementioned change to the MN.

17. A method for wireless communication by a master node (MN), Receiving signaling from a secondary node (SN) that identifies a set of candidate cells for conditional addition or modification of the SN for a user device (UE) based on execution criteria, A method comprising signaling configuration information relating to the set of candidate cells to the UE.

18. The MN receives the information regarding the set of candidate cells from the SN via a message without execution criteria. The method according to claim 17, wherein the MN determines the execution criteria for the candidate cell and signals the candidate cell and the execution criteria to the UE.

19. The method according to claim 17, further comprising receiving information from the SN regarding execution criteria for the candidate cell.

20. Modify the execution criteria for the candidate cell, The method of claim 19, further comprising signaling the UE with information relating to the candidate cell and the modified execution criteria.

21. The SN signals the MN to the MN the information relating to the execution criteria which should be forwarded to the UE without modification. The method according to claim 19, wherein the MN forwards the information relating to the execution criteria to the SN without modification.

22. The SN signals the information relating to the execution criteria within the transparent container, The method according to claim 21, wherein the MN forwards the transparent container to the UE.

23. The method according to claim 17, further comprising performing an SN addition procedure using the candidate cells.

24. The method according to claim 17, wherein the configuration information is signaled to the UE in a radio resource control (RRC) message.

25. The method according to claim 17, further comprising receiving a radio resource control (RRC) message from the UE indicating when the conditional SN addition or modification execution criterion is met for one of the selected candidate cells in the set, provided that the configuration of the selected cell is valid.

26. The method according to claim 17, wherein the configuration information is signaled to the UE in a radio resource control (RRC) message that includes separate execution criteria for conditional SN addition and SN modification.

27. Receiving notification from the UE regarding a change in SN via a Radio Resource Control (RRC) reconfiguration completion message, The method of claim 17, further comprising updating the candidate SN configuration to remove cells that are no longer suitable candidate cells for conditional addition or modification as SNs.

28. A device for wireless communication using user equipment (UE), Memory and The system comprises at least one processor coupled to the memory, and the at least one processor is Receiving configuration information and execution criteria from the master node (MN) for the conditional addition or modification of secondary nodes (SN) for the UE, The process involves detecting that the execution criteria are met for one of the candidate cells, A device configured to take action to add or modify the candidate cell as an SN based on the detection.

29. A device for wireless communication using a secondary node (SN), Memory and The system comprises at least one processor coupled to the memory, and the at least one processor is Identifying one or more candidate cell sets for conditional addition or modification of SN for user equipment (UE) based on execution criteria, A device configured to signal information about the set of candidate cells to a master node (MN).

30. A device for wireless communication using a master node (MN), Memory and The system comprises at least one processor coupled to the memory, and the at least one processor is Receiving signaling from a secondary node (SN) that identifies a set of candidate cells for conditional addition or modification of the SN for a user device (UE) based on execution criteria, A device configured to signal configuration information relating to the set of candidate cells to the UE.

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