PATENT DOCUMENT

Publication Number: US-12022335-B2
Application Number: US-201917276059-A
Country: US
Kind Code: B2

Title: UE capability indication for multi-connectivity handover

Abstract:
Techniques to configure a UE for a multi-connectivity handover with a source base station (SBS) and a target base station (TBS) include encoding UE capability information for transmission to the SBS, the UE capability information indicating tire UE supports multi-connectivity handover. A measurement report is encoded for transmission to the SBS, the measurement report triggered based on a measurement event configured by the SBS. RRC signaling is received from the SBS and includes a handover command for a multi-connectivity handover from the SBS to the TBS. The handover command is in response to the measurement report and the UE capability information. First UL data and second UL data are encoded for transmission during the multi-connectivity handover. The first UL data is encoded for transmission to the SBS and the second UL data is encoded for transmission to the TBS during the multi-connectivity handover.

Claims:
What is claimed is: 
     
       1. An apparatus of a user equipment (UE), the apparatus comprising:
 processing circuitry, wherein to configure the UE for multi-connectivity handover with a source base station (SBS) and a target base station (TBS), the processing circuitry is to: 
 encode UE capability information for transmission to the SBS, the UE capability information indicating the UE supports multi-connectivity handover, wherein the UE capability information further indicates that the UE supports multi-connectivity handover with an intra-frequency configuration of the SBS and the TBS, where the SBS and the TBS are in a same carrier; 
 encode a measurement report for transmission to the SBS, the measurement report triggered based on a measurement event configured by the SBS; 
 decode radio resource control (RRC) signaling from the SBS, the RRC signaling including a handover command for a multi-connectivity handover from the SBS to the TBS, the handover command in response to the measurement report and the UE capability information; and 
 encode first uplink (UL) data and second UL data for transmission during the multi-connectivity handover, wherein the first UL data is encoded for transmission to the SBS and the second UL data is encoded for transmission to the TBS during the multi-connectivity handover; and 
 memory coupled to the processing circuitry and configured to store the handover command. 
 
     
     
       2. The apparatus of  claim 1 , wherein the UE capability information indicates that the UE supports multi-connectivity handover with time-division multiplexing (TDM). 
     
     
       3. The apparatus of  claim 2 , wherein the handover command indicates a TDM pattern for transmitting the first UL data to the SBS and the second UL data to the TBS during the multi-connectivity handover. 
     
     
       4. The apparatus of  claim 1 , wherein the UE capability information indicates that the UE supports multi-connectivity handover for a carrier aggregation (CA) band combination. 
     
     
       5. The apparatus of  claim 4 , wherein the first UL data and the second UL data are encoded for transmission within the CA band combination during the multi-connectivity handover. 
     
     
       6. The apparatus of  claim 1 , wherein:
 the UE capability information indicates that the UE supports multi-connectivity handover for a dual connectivity (DC) carrier aggregation (CA) band combination; and 
 the first UL data and the second UL data are encoded for transmission within the DC CA band combination during the multi-connectivity handover. 
 
     
     
       7. The apparatus of  claim 1 , wherein the UE capability information further indicates that the UE supports multi-connectivity handover with time-division multiplexing (TDM) of uplink transmissions to both the SBS and the TBS. 
     
     
       8. The apparatus of  claim 1 , further comprising transceiver circuitry coupled to the processing circuitry; and, one or more antennas coupled to the transceiver circuitry. 
     
     
       9. A computer-readable storage medium that stores instructions for execution by one or more processors of a source base station (SBS), the instructions to configure the SBS for a multi-connectivity handover with a user equipment (UE) and a target base station (TBS), and to cause the SBS to:
 decode UE capability information from the UE, the UE capability information indicating the UE supports multi-connectivity handover, wherein the UE capability information further indicates that the UE supports multi-connectivity handover with an inter-frequency configuration of the SBS and the TBS, where the SBS and the TBS are in different carriers; 
 decode a measurement report from the UE, the measurement report triggered based on a measurement event configured by the SBS; 
 encode radio resource control (RRC) signaling for transmission to the UE, the RRC signaling including a handover command for a multi-connectivity handover from the SBS to the TBS, the handover command in response to the measurement report and the UE capability information; 
 decode uplink (UE) data received from the UE, wherein transmission of the UL data is based on the handover command and takes place during the multi-connectivity handover. 
 
     
     
       10. The computer-readable storage medium of  claim 9 , wherein the UE capability information indicates the UE supports multi-connectivity handover with time-division multiplexing (TDM) of uplink transmissions to both the SBS and the TBS, and wherein executing the instructions further cause the SBS to:
 encode the RRC signaling to further include a TDM pattern; and 
 decode the UL data from the UE, wherein the UL data is time-division multiplexed with communications between the UE and the TBS during the multi-connectivity handover based on the TDM pattern. 
 
     
     
       11. The computer-readable storage medium of  claim 9 , wherein the UE capability information indicates that the UE supports multi-connectivity handover for a dual connectivity (DC) carrier aggregation (CA) band combination. 
     
     
       12. The computer-readable storage medium of  claim 11 , wherein the first UL data and the second UL data are encoded for transmission within the DC CA band combination during the multi-connectivity handover. 
     
     
       13. A computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the instructions to configure the UE for a multi-connectivity handover with a source base station (SBS) and a target base station (TBS), and to cause the UE to:
 encode UE capability information for transmission to the SBS, the UE capability information indicating the UE supports multi-connectivity handover, wherein the UE capability information further indicates that the UE supports multi-connectivity handover with an inter-frequency configuration of the SBS and the TBS, where the SBS and the TBS are in different carriers; 
 encode a measurement report for transmission to the SBS, the measurement report triggered based on a measurement event configured by the SBS; 
 decode radio resource control (RRC) signaling from the SBS, the RRC signaling including a handover command for a multi-connectivity handover from the SBS to the TBS, the handover command in response to the measurement report and the UE capability information; and 
 encode first uplink (UL) data and second UL data for transmission during the multi-connectivity handover, wherein the first UL data is encoded for transmission to the SBS and the second UL data is encoded for transmission to the TBS during the multi-connectivity handover; and 
 store the handover command in the computer-readable storage medium. 
 
     
     
       14. The computer-readable storage medium of  claim 13 , wherein the UE capability information indicates that the UE supports multi-connectivity handover with time-division multiplexing (TDM). 
     
     
       15. The computer-readable storage medium of  claim 14 , wherein the handover command indicates a TDM pattern for transmitting the first UL data to the SBS and the second UL data to the TBS during the multi-connectivity handover. 
     
     
       16. The computer-readable storage medium of  claim 13 , wherein the UE capability information indicates that the UE supports multi-connectivity handover for a carrier aggregation (CA) band combination. 
     
     
       17. The computer-readable storage medium of  claim 16 , wherein the first UL data and the second UL data are encoded for transmission within the CA band combination during the multi-connectivity handover. 
     
     
       18. The computer-readable storage medium of  claim 13 , wherein the UE capability information indicates that the UE supports multi-connectivity handover for a dual connectivity (DC) carrier aggregation (CA) band combination. 
     
     
       19. The computer-readable storage medium of  claim 18 , wherein the first UL data and the second UL data are encoded for transmission within the DC CA band combination during the multi-connectivity handover. 
     
     
       20. The computer-readable storage medium of  claim 13 , wherein the UE capability information indicates that the UE supports multi-connectivity handover with time-division multiplexing (TDM) of uplink transmissions to both the SBS and the TBS.

Description:
PRIORITY CLAIM 
     This application is a U.S. National Stage filing of International Application No. PCT/US2019/053222, filed Sep. 26, 2019, titled “UE CAPABILITY INDICATION FOR MULTI-CONNECTIVITY HANDOVER,” which claims the benefit of priority to the U.S. Provisional Application No. 62/737,506, filed Sep. 27, 2018, titled “USER EQUIPMENT CAPABILITY FOR MULTI-CONNECTIVITY HANDOVER.” All of the aforementioned applications are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     Aspects pertain to wireless communications. Some aspects relate to wireless networks including 3GPP (Third Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (LTE Advanced) networks, and fifth-generation (5G) networks including 5G new radio (MR) (or 5G-NR) networks and 5G-LTE networks. Other aspects are directed to systems and methods for user equipment (UE) capability indication for multi-connectivity handover. 
     BACKGROUND 
     Mobile communications have evolved significantly from early voice systems to today&#39;s highly sophisticated integrated communication platform. With the increase in different types of devices communicating with various network devices, usage of 3GPP LTE systems has increased. The penetration of mobile devices (user equipment or UEs) in modern society has continued to drive demand for a wide variety of networked devices in a number of disparate environments. Fifth-generation (5G) wireless systems are forthcoming and are expected to enable even greater speed, connectivity, and usability. Next generation 5G networks (or NR networks) are expected to increase throughput, coverage, and robustness and reduce latency and operational and capital expenditures. 5G-NR networks will continue to evolve based on 3GPP LTE-Advanced with additional potential new radio access technologies (RATs) to enrich people&#39;s lives with seamless wireless connectivity solutions delivering fast, rich content and services. As current cellular network frequency is saturated, higher frequencies, such as millimeter wave (mmWave) frequency, can be beneficial due to their high bandwidth. 
     Potential LTE operation in the unlicensed spectrum includes (and is not limited to) the LTE operation in the unlicensed spectrum via dual connectivity (DC), or DC-based LAA, and the standalone LTE system in the unlicensed spectrum, according to which LTE-based technology solely operates in unlicensed spectrum without requiring an “anchor” in the licensed spectrum, called MulteFire. MulteFire combines the performance benefits of LTE technology with the simplicity of Wi-Fi-like deployments. 
     Further enhanced operation of LTE systems in the licensed as well as unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operations can include techniques for UE capability indication for multi-connectivity handover. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document. 
         FIG.  1 A  illustrates an architecture of a network, in accordance with some aspects. 
         FIG.  1 B  and  FIG.  1 C  illustrate a non-roaming 5G system architecture in accordance with some aspects. 
         FIG.  2    illustrates a swimlane diagram of a multi-connectivity handover with UE capability indication, in accordance with some aspects. 
         FIG.  3    illustrates a block diagram of a communication device such as an evolved Node-B (eNB), a new generation Node-B (gNB), an access point (AP), a wireless station (STA), a mobile station (MS), or a user equipment (UE), in accordance with some aspects. 
     
    
    
     DETAILED DESCRIPTION 
     The following description and the drawings sufficiently illustrate aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes. Portions and features of some aspects may be included in or substituted for, those of other aspects. Aspects set forth in the claims encompass all available equivalents of those claims. 
       FIG.  1 A  illustrates an architecture of a network in accordance with some aspects. The network  140 A is shown to include user equipment (UE)  101  and UE  102 . The UEs  101  and  102  are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs  101  and  102  can be collectively referred to herein as UE  101 , and UE  101  can be used to perform one or more of the techniques disclosed herein. 
     Any of the radio links described herein (e.g., as used in the network  140 A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard. 
     LTE and LTE-Advanced are standards for wireless communications of high-speed data for UE such as mobile telephones. In LTE-Advanced and various wireless systems, carrier aggregation is a technology according to which multiple carrier signals operating on different frequencies may be used to carry communications for a single UE, thus increasing the bandwidth available to a single device. In some aspects, carrier aggregation may be used where one or more component carriers operate on unlicensed frequencies. 
     Aspects described herein can be used in the context of any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and further frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHZ and further frequencies). 
     Aspects described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources. 
     In some aspects, any of the UEs  101  and  102  can comprise an Internet-of-Things (IoT) UE or a Cellular IoT (CIoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. In some aspects, any of the LTEs  101  and  102  can include a narrowband (NB) IoT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or MT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network includes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network. 
     In some aspects, any of the UEs  101  and  102  can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs. 
     The UEs  101  and  102  may be configured to connect, e.g., communicatively couple, with a radio access network (RAN)  110 . The RAN  110  may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs  101  and  102  utilize connections  103  and  104 , respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections  103  and  104  are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth-generation (5G) protocol, a New Radio (NR) protocol, and the like. 
     In an aspect, the UEs  101  and  102  may further directly exchange communication data via a ProSe interface  105 . The ProSe interface  105  may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH). 
     The UE  102  is shown to be configured to access an access point (AP)  106  via connection  107 . The connection  107  can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP  106  can comprise a wireless fidelity (WiFi®) router. In this example, the AP  106  is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below). 
     The RAN  110  can include one or more access nodes that enable the connections  103  and  104 . These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes  111  and  112  can be transmission/reception points (TRPs). In instances when the communication nodes  111  and  112  are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The RAN  110  may include one or more RAN nodes for providing macrocells, e.g., macro RAN node  111 , and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node  112 . 
     Any of the RAN nodes  111  and  112  can terminate the air interface protocol and can be the first point of contact for the UEs  101  and  102 . In some aspects, any of the RAN nodes  111  and  112  can fulfill various logical functions for the RAN  110  including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes  111  and/or  112  can be a new generation Node-B (gNB), an evolved node-B (eNB), or another type of RAN node. 
     The RAN  110  is shown to be communicatively coupled to a core network (CN)  120  via an S1 interface  113 . In aspects, the CN  120  may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to  FIGS.  1 B- 1 I ). In this aspect, the S1 interface  113  is split into two parts: the S1-U interface  114 , which carries traffic data between the RAN nodes  111  and  112  and the serving gateway (S-GW)  122 , and the S1-mobility management entity (MMF) interface  115 , which is a signaling interface between the RAN nodes  111  and  112  and MMEs  121 . 
     In this aspect, the CN  120  comprises the MMEs  121 , the S-GW  122 , the Packet Data Network (PDN) Gateway (P-GW)  123 , and a home subscriber server (HSS)  124 . The MMEs  121  may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs  121  may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS  124  may comprise a database for network users, including subscription-related information to support the network entities&#39; handling of communication sessions. The CN  120  may comprise one or several HSSs  124 , depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS  124  can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. 
     The S-GW  122  may terminate the S1 interface  113  towards the RAN  110 , and routes data packets between the RAN  110  and the CN  120 . In addition, the S-GW  122  may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW  122  may include a lawful intercept, charging, and some policy enforcement. 
     The P-GW  123  may terminate an SGi interface toward a PDN. The P-GW  123  may route data packets between the EPC network  120  and external networks such as a network including the application server  184  (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface  125 . The P-GW  123  can also communicate data to other external networks  131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server  184  may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW  123  is shown to be communicatively coupled to an application server  184  via an IP interface  125 . The application server  184  can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VOIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs  101  and  102  via the CN  120 . 
     The P-GW  123  may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF)  126  is the policy and charging control element of the CN  120 . In a non-roaming scenario, in some aspects, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE&#39;s Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE&#39;s IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF  126  may be communicatively coupled to the application server  184  via the P-GW  123 . 
     In some aspects, the communication network  140 A can be an IoT network. One of the current enablers of IoT is the narrowband-IoT (NB-IoT). 
     An NG system architecture can include the RAN  110  and a 5G network core (SGC)  120 . The NG-RAN  110  can include a plurality of nodes, such as gNBs and NG-eNBs. The core network  120  (e.g., a 5G core network or SGC) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some aspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces. 
     In some aspects, the NG system architecture can use reference points between various nodes as provided by 3GPP Technical Specification (TS) 23.501 (e.g., V15.4.0, 2018-12). In some aspects, each of the gNBs and the NG-eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some aspects, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture. 
       FIG.  1 B  illustrates a non-roaming 5G system architecture in accordance with some aspects. Referring to  FIG.  1 B , there is illustrated a 5G system architecture  140 B in a reference point representation. More specifically, UE  102  can be in communication with RAN  110  as well as one or more other 5G core (SGC) network entities. The 5G system architecture  140 B includes a plurality of network functions (NFs), such as access and mobility management function (AMF)  132 , session management function (SMF)  136 , policy control function (PCF)  148 , application function (AF)  150 , user plane function (UPF)  134 , network slice selection function (NSSF)  142 , authentication server function (AUSF)  144 , and unified data management (UDM)/home subscriber server (HSS)  146 . The UPB  134  can provide a connection to a data network (DN)  152 , which can include, for example, operator services, Internet access, or third-party services. The AMF  132  can be used to manage access control and mobility and can also include network slice selection functionality. The SMF  136  can be configured to set up and manage various sessions according to network policy. The UPF  134  can be deployed in one or more configurations according to the desired service type. The PCF  148  can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system). 
     In some aspects, the 5G system architecture  1409  includes an IP multimedia subsystem (IMS)  168 B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS  168 B includes a CSCF, which can act as a proxy CSCF (P-CSCF)  162 BE, a serving CSCF (S-CSCF)  164 B, an emergency CSCF (E-CSCF) (not illustrated in  FIG.  1 B , or interrogating CSCF (I-CSCF)  166 B. The P-CSCF  162 B can be configured to be the first contact point for the UE  102  within the IM subsystem (IMS)  168 B. The S-CSCF  164 B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain aspects of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF  166 B can be configured to function as the contact point within an operator&#39;s network for all LMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator&#39;s service area. In some aspects, the I-CSCF  166 B can be connected to another IP multimedia network  170 E, e.g. an IMS operated by a different network operator. 
     In some aspects, the UDM/HSS  146  can be coupled to an application server  160 E, which can include a telephony application server (TAS) or another application server (AS). The AS  160 B can be coupled to the IMS  168 B via the S-CSCF  164 B or the I-CSCF  166 B. 
     A reference point representation shows that interaction can exist between corresponding NF services. For example,  FIG.  1 B  illustrates the following reference points: N1 (between the UE  102  and the AMF  132 ), N2 (between the RAN  110  and the AMF  132 ), N3 (between the RAN  110  and the UPF  134 ), N4 (between the SMF  136  and the UPF  134 ), N5 (between the PCF  148  and the AF  150 , not shown), N6 (between the UPF  134  and the DN  152 ), N7 (between the SMF  136  and the PCF  148 , not shown), N8 (between the UDM  146  and the AMF  132 , not shown), N9 (between two UPFs  134 , not shown), N10 (between the UDM  146  and the SMF  136 , not shown), N11 (between the AMF  132  and the SMF  136 , not shown), N12 (between the AUSF  144  and the AMF  132 , not shown), N13 (between the AUSF  144  and the UDM  146 , not shown), N14 (between two AMFs  132 , not shown), N15 (between the PCF  148  and the AMF  132  in case of a non-roaming scenario, or between the PCF  148  and a visited network and AMF  132  in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF  132  and NSSF  142 , not shown). Other reference point representations not shown in  FIG.  1 E  can also be used. 
       FIG.  1 C  illustrates a 5G system architecture  140 C and a service-based representation. In addition to the network entities illustrated in  FIG.  1 B , system architecture  140 C can also include a network exposure function (NEF)  154  and a network repository function (NRF)  156 . In some aspects, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces. 
     In some aspects, as illustrated in  FIG.  1 C , service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture  140 C can include the following service-based interfaces: Namf  158 H (a service-based interface exhibited by the AMF  132 ), Nsmf  158 I (a service-based interface exhibited by the SMF  136 ), Nnef  158 B (a service-based interface exhibited by the NEF  154 ), Npcf  158 D (a service-based interface exhibited by the PCF  148 ), a Nudm  158 E (a service-based interface exhibited by the UDM  146 ), Naf  158 F (a service-based interface exhibited by the AF  150 ), Nnrf  158 C (a service-based interface exhibited by the NRF  156 ), Nnssf  158 A (a service-based interface exhibited by the NSSF  142 ), Nausf  158 G (a service-based interface exhibited by the AUSF  144 ). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in  FIG.  1 C  can also be used. 
     In some aspects, if the UE does not support multiple RF chains, which allows the UE to perform simultaneous Tx/Rx to/from both a serving cell and a target cell, TDM can be considered (e.g., in connection with multi-connectivity during a handover as illustrated in  FIG.  2   ). 
     Multi-connectivity handover is one of the potential solutions to achieve 0 ms interruption time goal both in LTE and NR. One may extend make-before-break introduced in LTE, they will have a similar option as to how to resolve some of the main issues. In multi-connectivity, the UE will go through the following 3 phases: a single connected phase with serving cell (also referred to as a serving base station or SBS) (this is before the handover starts); a multi-connected phase with both the serving cell and the target cell (also referred to as a target base station or TBS) (this is during handover); and a single connected phase with the target cell (this is after the serving cell is released). 
     In some aspects, the following communication scenarios may be used in connection with techniques disclosed herein:
         Scenario 1: Both the serving cell and the target cell are in the same carrier (intra-frequency case).   Scenario 2: The serving cell and the target cell are within the UE support carrier aggregation (CA) band combination.   Scenario 3: The serving cell and the target cell are within the UE support dual connectivity (DC) CA band combination.   Scenario 4: The serving cell and the target cell are in different carriers (inter-frequency case) and communication does not fall into scenario 2 and 3.       

     In some aspects, the following UE configurations can be considered in connection with a multi-connectivity handover. 
     Configuration 1: Intra-frequency multi-connectivity non-TDM is not supported. 
     Configuration 2: Intra-frequency multi-connectivity with TDM can be considered. 
     For Configuration 2 and 3, the LTE may be able to perform simultaneous Tx/Rx in those cases. 
     Configuration 3: The UE may perform simultaneous Tx/Rx if the UE supports the CA band combination and DC CA band combination of the serving and the target cells. Since the serving cell and the target cell may not be within the UE capable CA band combination and DC CA band combination, the UE may not be able to perform simultaneous Tx/Rx for multi-connectivity. In some aspects, configuration 4 may not be supported for multi-connectivity handover if TDM is not enabled. 
     Configuration 4: Inter-frequency (but not fall into UE supported DC/CA band combination) multi-connectivity non-TDM is not supported. 
     Configuration 5: Inter-frequency (but not fall into UE supported DC/CA band combination) multi-connectivity with TDM can be considered. 
     In some aspects associated with TDM multi-connectivity handover, a UE is configured with a TDM pattern which can indicate a pattern for multiplexing time and/or frequency resources for performing communication with a serving cell and a target cell in a TDM manner. For example, the TDM pattern can be used to indicate when the UE can transmit uplink data to (or received downlink data from) the serving cell while being in a handover procedure with the target cell. TDM multi-connectivity handover is further illustrated in  FIG.  2   . 
       FIG.  2    illustrates a swimlane diagram  200  of a multi-connectivity handover (HO) with UE capability indication, in accordance with some aspects. Referring to  FIG.  2   , at operation  207 , the UE communicates UE capability information to the serving cell  204 . 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover. 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover with TDM. 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover for carrier aggregation (CA) band combination. 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover for dual connectivity (DC) CA band combination. 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover for CA and DC CA band combination. 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover with TDM for an intra-frequency configuration (e.g., the source and target cells use the same center frequency). 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports a multi-connectivity handover with TDM for an inter-frequency configuration (e.g., the source and target cells use different center frequencies). 
     In some aspects, the UE capability information provides a capability indication on whether the UE supports all support band combinations of multi-connectivity handover. 
     At operation  208 , a measurement report (for target cell  206 ) is communicated from UE  202  to a serving cell  204  when a measurement event is triggered. The measurement event can be configured prior to operation  208 , by the serving cell  204 . The serving cell  204  can make a handover decision for a multi-connectivity handover to the target cell  206  based on the received measurement report at operation  208  as well as the UE capability information received at operation  207 . 
     At operation  210 , the serving cell  204  communicates a handover request to the target cell  206 . The handover request can include an indication of a multi-connectivity enable (e.g., a TDM enable indicator) and, optionally, a TDM pattern provided by the serving cell  204  (when a TDM-based multi-connectivity handover is supported by the UE and the serving cell). The multi-connectivity enable indicates to the target cell  206  that the serving cell  204  supports a multi-connectivity handover. 
     Option 1: In some aspects, the source (e.g., serving cell  204 ) proposes a TDM pattern (implicitly by including pattern or explicitly over the Xn interface). In this step, the serving cell may also send a suggested TDM pattern to the target cell. If the target cell accepts the TDM pattern, it may include the TDM pattern in the HO command. 
     Option 2: In some aspects, the target cell may suggest a new pattern (e.g., via step  3  at operation  212 ), which the serving cell can either accept or reject. The serving cell  204  may send the TDM pattern to the target cell after receiving an acceptance (e.g., an HO ACK potential information with the support of multi-connectivity HO and TDM) from the target cell. After the TDM pattern is accepted by both the serving cell and the target cell, the target cell may generate the TDM pattern and include it in the HO command. Since option 2 may introduce additional delay, option 1 may be preferred. 
     Option 3: In some aspects, a class-1 Xn Application Protocol (XnAP) procedure may be used by the serving cell and the target cell for further negotiation of a TDM pattern. 
     Option 4: In some aspects, an HO command can be created, which has a two-part generation—one part of the command is generated by the serving cell (e.g., the TDM pattern) and a remaining part of the HO command is generated by the target cell. 
     At operation  212 , the target cell  206  communicates a handover acknowledgment to the serving cell  204 . The handover acknowledgment can include a handover command for a multi-connectivity handover. Optionally, the handover acknowledgment can include a TDM enable indicator (e.g., to indicate that the target cell supports TDM-based multi-connectivity handover) and a TDM pattern (e.g., a pattern proposed by the target cell). 
     In aspects when the target cell  206  supports TDM-based multi-connectivity, the target cell responds (at operation  212 ) with a multi-connectivity HO command (containing required HO parameters such as random access channel (RACH) procedure parameters) to the serving cell  204  as well as an Xn message to indicate the multi-connectivity handover support, if the serving cell cannot read the HO command. 
     If the target cell does not support TDM-based multi-connectivity, the target cell may reject the HO request for TDM-based multi-connectivity HO and proceed with a regular HO. In this case, the HO command will still be generated with an indication of no TDM-based multi-connectivity support (similarly, an Xn message may be used if the serving cell cannot read the HO command communicated at operation  212 ) 
     Option 1: In some aspects, the target cell can only accept or reject the TDM pattern provided by the serving cell at operation  210 . If rejected, a regular HO will be performed. If the target cell accepts the proposed TDM pattern, the TDM pattern may be included in the HO command and may be sent to the UE (at operation  212 ). 
     Option 2: In some aspects, the target cell may provide a suggested (new) TDM pattern to the serving cell via an Xn interference. In this case, the serving cell may either accept or reject and proceed with a regular HO. This option may introduce additional delay and, therefore, option 1 may be preferred. 
     Option 3: In some aspects, the target cell makes the final decision on the TDM pattern. For example, the target cell  206  may accept the TDM pattern suggested by the serving cell  204  or create a new TDM pattern. The latter case may have a problem with serving cell but it may just not send data if not compatible. 
     At operation  214 , the serving cell  204  communicates a handover command for a multi-connectivity handover, which command may also include the TDM pattern if TDM-based handover is supported by the UE, the serving cell, and the target cell. More specifically, the serving cell may read the response from the target cell for the case of HO with simultaneous support (i.e., multi-connectivity with the target and serving cells) with TDM, or a regular HO, or reject an HO. Then the serving cell forwards the HO command to the UE at operation  214  (the HO command may include simultaneous support with TDM option enabled to indicate the TDM-based multi-connectivity is enabled for the UE using the indicated TDM pattern). 
     After the handover command is communicated at operation  214 , at operation  216 , the serving cell tool can store data forwarding of UE uplink or downlink data to the target cell  206 . 
     At operation  218 , UE  202  initiates the handover while maintaining connectivity with the serving cell. If a TDM pattern was communicated with the HO command, then the UE also applies the received TDM pattern to subsequent communications with the serving cell. For example, data communications  220  and  222  between the UE  202  and the serving cell  204  are performed based on the TDM pattern received with the handover command at operation  214 . Furthermore,  FIG.  2    illustrates additional data communications  228 ,  230 ,  240 , and  242  between the UE  202  and the serving cell  204 , which communications can be time-division multiplexed with communications between the UE and the target cell based on the TDM pattern. 
     At operation  224 , UE  202  performs a RACH procedure with the target cell  206 . In case of an HO with TDM-based multi-connectivity, the UE maintains the serving cell connection. If the UE receives the TDM pattern at operation  214 , the UE may apply it immediately to the serving cell and perform the RACH procedure to target. Otherwise, the UE performs RACH to access the target cell using the RACH information in the HO command provided by the target cell and communicated to the UE at operation  214 . Alternatively, once the RACH procedure is successful, the target cell  206  may send the TDM pattern to the UE once it is finalized with the serving cell. However, this option may not be preferred due to RRC delay. 
     At operation  226 , the target cell  206  indicates a response message to indicate successful completion of the RACH procedure. At operation  232 , the UE  22  indicates an RRC Connection Reconfiguration Complete message to the target cell  206  to indicate HO completion. 
     At operation  234 , the target cell  206  sends an HO success indication to the serving cell  204 . After the handover success indication, data communications  236  and  238  can be performed between the UE and the target cell, which communications are down division multiplexed with data communications  240  and  242  between the UE and the serving cell, based on the TDM pattern. 
     At operation  244 , serving cell  204  communicates a release message to the target cell  206 . At operation  246 , the target cell  206  communicates a serving cell release message to the UE  202 . At operation  248 , the UE releases the serving cell (and removes the TDM pattern if such pattern was received with the HO command). At operation  250 , the UE communicates a release complete message indicates that the serving cell has been released (and the TDM pattern is removed if a TDM pattern was used during the handover). 
       FIG.  3    illustrates a block diagram of a communication device such as an evolved Node-B (eNB), a next generation Node-B (gNB), an access point (AP), a wireless station (STA), a mobile station (MS), or a user equipment (UE), in accordance with some aspects and to perform one or more of the techniques disclosed herein. In alternative aspects, the communication device  300  may operate as a standalone device or may be connected (e.g., networked) to other communication devices. 
     Circuitry (e.g., processing circuitry) is a collection of circuits implemented in tangible entities of the device  300  that include hardware (e.g., simple circuits, gates, logic, etc.). Circuitry membership may be flexible over time. Circuitries include members that may, alone or in combination, perform specified operations when operating. In an example, the hardware of the circuitry may be immutably designed to carry out a specific operation (e.g., hardwired). In an example, the hardware of the circuitry may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) including a machine-readable medium physically modified (e.g., magnetically, electrically, moveable placement of invariant massed particles, etc.) to encode instructions of the specific operation. 
     In connecting the physical components, the underlying electrical properties of a hardware constituent are changed, for example, from an insulator to a conductor or vice versa. The instructions enable embedded hardware (e.g., the execution units or a loading mechanism) to create members of the circuitry in hardware via the variable connections to carry out portions of the specific operation when in operation. Accordingly, in an example, the machine-readable medium elements are part of the circuitry or are communicatively coupled to the other components of the circuitry when the device is operating. In an example, any of the physical components may be used in more than one member of more than one circuitry. For example, under operation, execution units may be used in a first circuit of a first circuitry at one point in time and reused by a second circuit in the first circuitry, or by a third circuit in a second circuitry at a different time. Additional examples of these components with respect to the device  300  follow. 
     In some aspects, the device  300  may operate as a standalone device or may be connected (e.g., networked) to other devices. In a networked deployment, the communication device  300  may operate in the capacity of a server communication device, a client communication device, or both in server-client network environments. In an example, the communication device  300  may act as a peer communication device in peer-to-peer (P2P) (or other distributed) network environment. The communication device  300  may be a UE, eNB, PC, a tablet PC, a STB, a PDA, a mobile telephone, a smartphone, a web appliance, a network router, switch or bridge, or any communication device capable of executing instructions (sequential or otherwise) that specify actions to be taken by that communication device. Further, while only a single communication device is illustrated, the term “communication device” shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), and other computer cluster configurations. 
     Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device-readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. 
     Accordingly, the term “module” is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using the software, the general-purpose hardware processor may be configured as respective different modules at different times. The software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time. 
     Communication device (e.g., UE)  300  may include a hardware processor  302  (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory  304 , a static memory  306 , and mass storage  307  (e.g., hard drive, tape drive, flash storage, or other block or storage devices), some or all of which may communicate with each other via an interlink (e.g., bus)  308 . 
     The communication device  300  may further include a display device  310 , an alphanumeric input device  312  (e.g., a keyboard), and a user interface (UI) navigation device  314  (e.g., a mouse). In an example, the display device  310 , input device  312  and UI navigation device  314  may be a touchscreen display. The communication device  300  may additionally include a signal generation device  318  (e.g., a speaker), a network interface device  320 , and one or more sensors  321 , such as a global positioning system (GPS) sensor, compass, accelerometer, or another sensor. The communication device  300  may include an output controller  328 , such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.). 
     The storage device  307  may include a communication device-readable medium  322 , on which is stored one or more sets of data structures or instructions  324  (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. In some aspects, registers of the processor  302 , the main memory  304 , the static memory  306 , and/or the mass storage  307  may be, or include (completely or at least partially), the device-readable medium  322 , on which is stored the one or more sets of data structures or instructions  324 , embodying or utilized by any one or more of the techniques or functions described herein. In an example, one or any combination of the hardware processor  302 , the main memory  304 , the static memory  306 , or the mass storage  316  may constitute the device-readable medium  322 . 
     As used herein, the term “device-readable medium” is interchangeable with “computer-readable medium” or “machine-readable medium”. While the communication device-readable medium  322  is illustrated as a single medium, the term “communication device-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions  324 . The term “communication device-readable medium” is inclusive of the terms “machine-readable medium” or “computer-readable medium”, and may include any medium that is capable of storing, encoding, or carrying instructions (e.g., instructions  324 ) for execution by the communication device  300  and that cause the communication device  300  to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting communication device-readable medium examples may include solid-state memories and optical and magnetic media. Specific examples of communication device-readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, communication device-readable media may include non-transitory communication device-readable media. In some examples, communication device-readable media may include communication device-readable media that is not a transitory propagating signal. 
     The instructions  324  may further be transmitted or received over a communications network  326  using a transmission medium via the network interface device  320  utilizing any one of a number of transfer protocols. In an example, the network interface device  320  may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network  326 . In an example, the network interface device  320  may include a plurality of antennas to wirelessly communicate using at least one of single-input-multiple-output (SIMO), MIMO, or multiple-input-single-output (MISO) techniques. In some examples, the network interface device  320  may wirelessly communicate using Multiple User MIMO techniques. 
     The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the communication device  300 , and includes digital or analog communications signals or another intangible medium to facilitate communication of such software. In this regard, a transmission medium in the context of this disclosure is a device-readable medium. 
     Although an aspect has been described with reference to specific exemplary aspects, it will be evident that various modifications and changes may be made to these aspects without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various aspects is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

Metadata:
Filing Date: 20190926
Publication Date: 20240625
Grant Date: 20240625
Priority Date: 20180927
Inventors: YIU, Candy
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W36/0069", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W36/00692", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0072", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0061", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0058", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/00692", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W8/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W36/0072", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W36/0072", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0061", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0058", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W36/0069", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 69950788