Method for handling radio resource control cell group configuration

Abstract

This disclosure relates to a method for processing Radio Resource Control (RRC) cell group configuration. This document describes techniques and apparatus for processing RRC cell group configuration. In one implementation, a base station (120) receives a first RRC message (e.g., 325, 425, 1325) requesting a connection process between a user equipment (110) and the base station, such as a RRC recovery request or a RRC establishment request. In response to receiving the first RRC message, the base station (120) generates a second RRC message (e.g., 330, 430, 1330) including cell group configuration information elements excluding synchronization reconfiguration information elements. The base station (120) then sends the second RRC message to the user equipment (110) (e.g., 335, 435, 1345). Afterward, the base station (120) receives a third RRC message (e.g., 340, 440, 1350) from the user equipment (110) indicating the completion of the connection process.

Description

[0001] Case Analysis

[0002] This application is a divisional application of Chinese invention patent application 201980004750.7, filed on October 3, 2019. Background Technology

[0003] Radio Resource Control (RRC) connection restoration procedures are typically designed for User Equipment (UEs) in an RRC inactive state. A UE in an RRC inactive state initiates an RRC connection restoration procedure to transition to an RRC connected state or for periodic Radio Access Network (RAN)-based Notification Area (RNA) updates. Cell group configurations are typically configured by the base station and provided to UEs in an RRC connected state. Cell group configurations include Radio Link Control (RLC) bearer configurations, Media Access Control (MAC) configurations (e.g., MACCellGroupConfig), Physical Layer configurations (e.g., PhysicalCellGroupConfig), Special Cell Configurations (e.g., SpCellConfig), or Secondary Cell Configurations (e.g., SCellConfig) for the UE to communicate with one or more cells of the base station. Synchronization Reconfiguration Information Elements (IEs) (e.g., ReconfigurationWithSync) are configured by the base station in the cell group configuration. The synchronous reconfiguration IE includes serving cell configuration (e.g., ServingCellConfigCommon), a new UE identifier (e.g., Radio Network Temporary Identifier (RNTI) value), and timer value configuration (e.g., timer T304). The synchronous reconfiguration IE may or may not include dedicated random access channel (RACH) configuration (e.g., RACH-ConfigDedicated).

[0004] However, during some RRC establishment, recovery, and reconstruction processes, synchronization between the UE and the base station may be lost or interrupted, leading to process failure. This behavior is inefficient and may cause communication delays between the UE and the base station. Summary of the Invention

[0005] This document describes techniques and apparatus for processing Radio Resource Control (RRC) cell group configuration. These techniques include identifying a base station that excludes a synchronization reconfiguration IE (e.g., ReconfigurationWithSync) in the cell group configuration information element (IE) (e.g., CellGroupConfig) of an RRC message when an RRC message responds to an RRC request message from a User Equipment (UE). Alternatively, these techniques include the UE ignoring the synchronization reconfiguration IE in the cell group configuration IE, determining the synchronization reconfiguration IE as a reconfiguration failure, or initiating a random access procedure to establish a new RRC connection with the base station during an RRC connection recovery or RRC connection establishment process. These techniques prevent the synchronization reconfiguration IE from triggering a UE reset of the Media Access Control (MAC) entity and causing uplink synchronization failure.

[0006] In this implementation, the base station receives a first radio resource control message, such as a radio resource control recovery request or a radio resource establishment request, requesting a connection process between the user equipment and the base station. In response to receiving the first radio resource control message, the base station generates a second radio resource control message including cell group configuration information elements excluding synchronization reconfiguration information elements. The base station then sends the second radio resource control message to the user equipment. Afterward, the base station receives a third radio resource control message from the user equipment indicating that the connection process is complete.

[0007] In one implementation, the user equipment (UE) sends a first radio resource control (RFC) message to the base station to request a connection procedure between the UE and the base station. Subsequently, the UE receives a second RRF message from the base station, wherein the second RRF message includes cell group configuration information elements excluding synchronization reconfiguration information elements. Then, based at least in part on the second RRF message, the UE performs the connection procedure with the base station by sending a third RRF message to the base station indicating the completion of the connection procedure.

[0008] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features and advantages will be apparent from the specification, drawings, and claims. This summary is provided to illustrate the subject matter further depicted in the detailed description and drawings. Therefore, this summary should not be construed as describing essential features nor should it be used to limit the scope of the claimed subject matter. Attached Figure Description

[0009] The following describes in detail one or more aspects of handling Radio Resource Control (RRC) cell group configuration. The same reference numerals are used in different instances in the specification and accompanying drawings to indicate similar elements:

[0010] Figure 1An example operating environment is shown that can handle various aspects of RRC cell group configuration.

[0011] Figure 2 Example equipment diagrams of user equipment and base stations that can be used to implement various aspects of processing RRC cell group configuration are shown.

[0012] Figure 3 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0013] Figure 4 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0014] Figure 5 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0015] Figure 6 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0016] Figure 7 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0017] Figure 8 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0018] Figure 9 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0019] Figure 10 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0020] Figure 11 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0021] Figure 12 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0022] Figure 13 An example signaling and control transaction diagram is shown for an implementation based on one or more processing RRC cell group configurations.

[0023] Figure 14A method for handling RRC cell group configuration by a base station is described.

[0024] Figure 15 An example method for handling RRC cell group configuration by a base station is described.

[0025] Figure 16 An example method for handling RRC cell group configuration by the UE is described.

[0026] Figure 17 An example method for handling RRC cell group configuration by the UE is described.

[0027] Figure 18 An example method for handling RRC cell group configuration by the UE is described.

[0028] Figure 19 An example method for handling RRC cell group configuration by the UE is described.

[0029] Figure 20 An example method for handling RRC cell group configuration by the UE is described. Detailed Implementation

[0030] Overview

[0031] In conventional wireless communication systems, base stations automatically include a synchronization reconfiguration information element (IE) (e.g., ReconfigurationWithSync) in the Radio Resource Control (RRC) messages sent to the User Equipment (UE). However, the synchronization reconfiguration IE triggers the UE to reset its Media Access Control (MAC) entity, which causes the UE to treat any ongoing random access procedure's time alignment timer as expired. The UE then uses the expired time alignment timer to determine that the uplink is not synchronized. Therefore, this inefficient process introduces latency because the uplink can still actually be synchronized when the RRC connection is restored or re-established, for example, when the UE is moved from an RRC inactive or RRC idle state to an RRC connected state.

[0032] This document describes techniques and apparatus for processing Radio Resource Control (RRC) cell group configurations that prevent the UE from resetting its MAC entity and unintentionally determining the uplink as unsynchronized. In an implementation, a base station receives a first RRC message, such as a RRC recovery request or a RRC establishment request, requesting a connection process between the user equipment (UE) and the base station. In response to receiving the first RRC message, the base station generates second RRC information including cell group configuration information elements excluding synchronization reconfiguration information elements. The base station then sends the second RRC message to the UE. Subsequently, the base station receives a third RRC message from the UE indicating that the connection process is complete. By determining, based on the received (first) RRC message, that synchronization reconfiguration information elements have been excluded from the cell group configuration information elements, the base station avoids sending a synchronization reconfiguration element (IE) to the UE and prevents the UE from resetting the corresponding MAC entity. This, in turn, prevents the UE from detecting erroneous indications of uplink synchronization failure and removes the source of delay during the connection process.

[0033] In one implementation, the User Equipment (UE) sends a first Radio Resource Control (RRC) message to the base station to request a connection procedure between the UE and the base station. Subsequently, the UE receives a second RRC message from the base station, which includes a cell group configuration information element excluding the synchronization reconfiguration information element. The UE then performs the connection procedure with the base station, at least in part, based on the second RRC message, by sending a third RRC message to the base station indicating the completion of the connection procedure. In some implementations, the UE performs the connection procedure based on the second RRC message excluding the synchronization reconfiguration information element without resetting the corresponding MAC entity. This avoids (erroneous) uplink synchronization failure indications caused by resetting the time alignment timer (and by resetting the MAC entity) and improves the connection procedure by reducing and / or eliminating latency.

[0034] Example Environment

[0035] Figure 1 An example wireless network environment 100 is shown, comprising a user equipment 110 (UE 110) communicating with a base station 120 (serving base station 120) acting as a serving cell via one or more wireless communication links 130 (e.g., wireless links 131, 133 and 135).

[0036] Although shown as a smartphone, user equipment 110 can be implemented as any suitable computing or electronic device, such as mobile communication devices, computing devices, client devices, modems, cellular phones, mobile phones, entertainment devices, gaming devices, mobile game consoles, personal media devices, navigation devices, media devices, laptops, desktop computers, tablets, smart appliances, vehicle-based communication systems, charging devices, advanced driver assistance systems (ADAS), point-of-sale (POS) transaction systems, health monitoring devices, drones, cameras, wearable smart devices, mobile internet devices (MID), Internet of Things (IoT) devices, fifth-generation new radio user equipment, etc.

[0037] Macrocells, microcells, small cells, picocells, or any combination thereof can be used to implement base station 120 (e.g., Evolved Universal Terrestrial Radio Access Network Node B, E-UTRAN Node B, Evolved Node B, eNodeB, eNB, Next Generation eNB, ng-eNB, Next Generation Node B, gNode B, gNB, etc.), base station transceiver systems, wireless local access network (WLAN) routers, satellites, terrestrial television broadcasting towers, access points, peering devices, another smartphone acting as a base station, etc. In some cases, base station 120 is a Next Generation Node B base station (gNB). A gNB may include a gNB base station central unit (gNB-CU) and one or more gNB base station distributed units (gNB-DU). In some cases, the gNB-CU is a logical node that hosts the radio resource control (RRC) and packet data convergence protocol (PDCP) protocols of the gNB or hosts the RRC and PDCP protocols of the en-gNB that control the operation of one or more gNB-DUs. In some cases, the gNB-CU is a logical unit without physical units (e.g., baseband processing unit, radio frequency (RF) chain, antenna). In a typical implementation, a gNB-DU connects to only one gNB-CU. In some cases, the terms "gNB Distributed Unit" and "gNB-DU" refer to the logical node that hosts the radio link control (RLC), media access control (MAC), and physical (PHY) layers of the gNB or en-gNB. The gNB-CU at least partially controls the operation of the gNB-DU.

[0038] Base station 120 communicates with UE 110 (e.g., UE 111, UE 112) via radio link 130 (e.g., radio link 131, radio link 133, radio link 135). Radio link 130 can be implemented using any suitable type of radio link. Radio link 130 may include a downlink for communicating data and control information from base station 120 to UE 110, an uplink for communicating other data and control information from UE 110 to base station 120, or both. Radio link 130 may include one or more radio links or bearers implemented using any suitable communication protocol or standard, such as 3GPP LTE, 5G, etc.

[0039] In all aspects, UE 110 communicates with base station 124 via radio link 131. In this respect, base station 124 is a next-generation Node B base station 124 (gNB 124). Figure 1 In this configuration, gNB 124 includes a gNB base station central unit 121 (gNB-CU121) and a gNB base station distributed unit 122 (gNB-DU122). gNB-CU 121 is connected to gNB-DU122 via an F1 interface 117. The use of "F1 interface" (F1) refers to the logical interface connecting the gNB-CU and gNB-DU. The F1 interface specification facilitates the interconnection of gNB-CUs and gNB-DUs supplied by different manufacturers. The F1 interface, along with the NG and Xn interfaces, are logical interfaces described by technical specifications and related specifications for new radios. The F1 Application Protocol (F1AP) supports the functionality of the F1 interface.

[0040] like Figure 1 As shown, UE 110 can communicate with gNB-DU 122 via radio link 133. Radio link 133 can be implemented using the same communication protocol or standard as radio link 130, or a different communication protocol or standard.

[0041] like Figure 1 As shown, UE 110 can communicate with gNB-CU 121 via radio link 133 to gNB-DU 122 and F1 interface 117. The F1AP interface provides gNB-CU 121 with a "container" forwarded by gNB-DU 122 for sending RRC messages to the UE. gNB-DU does not open the container to read or inspect the messages within. In other words, gNB-CU 121 configures the UE context separately for both gNB-DU 122 and UE 110, and then they communicate with each other based on the UE context.

[0042] In all respects, UE 110 can communicate with another base station 125 (neighboring base station 125) via radio link 135. Radio link 135 can be implemented using the same communication protocol or communication standard as radio link 135, or a different communication protocol or communication standard. Neighboring base station 125 can be a gNB base station (gNB 125).

[0043] gNB 124 (e.g., gNB-CU 121, gNB-DU 122), gNB 125, and any other base stations (not shown for clarity) together form Radio Access Network 140 (RAN 140, Evolved Universal Terrestrial Radio Access Network 140, E-UTRAN140, 5G NR RAN 140). RAN 140 is connected to the fifth-generation core network 150 (5GC 150) via links (e.g., link 102, link 104) to form a radio operator network.

[0044] Base stations 121 and 125 are connected to 5GC 150 via NG2 interface for control plane signaling and NG3 interface for user plane data communication, respectively, on links 102 and 104. In addition to their connection to the core network, base stations 120 can communicate with each other. For example, at 116, gNB 124 (e.g., base station 121) and gNB 125 (e.g., neighboring base station 125) can communicate using the Xn Application Protocol (XnAP) to exchange user plane and control plane data. 5GC 150 includes Access and Mobility Management Function 152 (AMF 152), which provides control plane functions such as registration and authentication, authorization, mobility management, etc., for multiple UE devices 110 in the 5G NR network. AMF 152 communicates with base station 120 in RAN 140. AMF 152 also communicates with multiple UE devices 110 via base station 120.

[0045] Example device

[0046] Figure 2 Example device diagram 200 shows UE 110 and base station 120. UE 110 and base station 120 may include Figure 2Additional functions and interfaces are omitted for clarity. UE 110 includes an antenna 202, a radio frequency front-end 204 (RF front-end 204), a radio transceiver such as an LTE transceiver 206, and / or a 5G NR transceiver 208 for communicating with one or more base stations 120 in a 5G RAN 140. The RF front-end 204 of UE 110 can couple or connect the LTE transceiver 206 and the 5G NR transceiver 208 to the antenna 202 to facilitate various types of wireless communication. The antenna 202 of UE 110 may include an array of multiple antennas configured to be similar or different from each other. The antenna 202 and the RF front-end 204 can be tuned to and / or tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and can be implemented as any suitable type of radio transceiver (e.g., LTE transceiver 206 and / or 5G NR transceiver 208). Additionally, antenna 202, RF front-end 204, LTE transceiver 206, and / or 5G NR transceiver 208 can be configured to support beamforming for transmission and reception of communications with base station 120. By way of example, and not limitation, antenna 202 and RF front-end 204 can be implemented for operation in sub-gigahertz bands, sub-6 GHz bands, and / or above 6 GHz bands as defined by the 3GPP LTE and 5G NR communication standards.

[0047] UE 110 also includes a processor 210 and a computer-readable storage medium 212 (CRM 212). The processor 210 may be a single-core or multi-core processor made of various materials such as silicon, polysilicon, high-k dielectrics, copper, etc. The computer-readable storage medium described herein excludes propagated signals. CRM 212 may include any suitable memory or storage device such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory that can be used to store device data 214 of UE 110. Device data 214 includes user data, multimedia data, beamforming codebook, applications, and / or operating system of UE 110, which can be executed by the processor 210 to enable user plane communications, control plane signaling, and user interaction with UE 110.

[0048] Figure 2The illustrated device diagram for base station 120 includes a single network node (e.g., gNode B). The functionality of base station 120 can be distributed across multiple network nodes or devices and can be distributed in any manner suitable for performing the functions described herein. Base station 120 includes an antenna 252, a radio frequency front-end 254 (RF front-end 254), and one or more radio transceivers such as one or more LTE transceivers 256 and / or one or more 5G NR transceivers 258 for communicating with UE 110. The RF front-end 254 of base station 120 can couple or connect the LTE transceivers 256 and 5G NR transceivers 258 to the antenna 252 to facilitate various types of wireless communication. The antenna 252 of base station 120 may include an array of multiple antennas configured to be similar or different from each other. The antenna 252 and RF front-end 254 can be tuned to and / or tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and are implemented by radio frequency transceivers such as the LTE transceivers 256 and / or 5G NR transceivers 258. In addition, antenna 252, RF front end 254, LTE transceiver 256 and / or 5G NR transceiver 258 can be configured to support beamforming, such as Massive-MIMO, for transmitting and receiving communications with UE 110.

[0049] Base station 120 also includes processor 260 and computer-readable storage medium 262 (CRM 262). Processor 260 may be a single-core or multi-core processor made of various materials such as silicon, polysilicon, high-k dielectric, copper, etc. CRM 262 may include any suitable memory or storage device, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory that can be used to store device data 264 of base station 120. Device data 264 includes network scheduling data, radio resource management data, beamforming codebook, applications and / or operating system of base station 120, which can be executed by processor 260 to enable communication with UE 110.

[0050] CRM 262 also includes a base station manager 266. Alternatively or additionally, the base station manager 266 may be implemented, in whole or in part, as hardware logic or circuitry integrated or separate from other components of the base station 120. In at least some aspects, the base station manager 266 configures the LTE transceiver 256 and the 5G NR transceiver 258 for communication with the UE 110 and with the core network. The base station 120 includes an inter-base station interface 268, such as Xn, X2, and / or F1 interfaces, which the base station manager 266 configures to exchange user plane and control plane data between another base station 120 and to manage communication between the base station 120 and the UE 110. The F1 interface is a logical interface connecting the gNB-CU and gNB-DU. The base station 120 includes a core network interface 270 configured by the base station manager 266 to exchange user plane and control plane data with core network functions and entities.

[0051] Figures 3 to 13 This diagram illustrates various example signaling and control transactions used to process RRC cell group configurations during the RRC connection recovery or RRC connection establishment process. Figure 3 and Figure 4 In response to an RRC request message from a User Equipment (UE), the base station determines to exclude the Synchronization Reconfiguration IE in the Cell Group Configuration Information Element (IE) of the RRC message. If the UE receives the Synchronization Reconfiguration IE in the Cell Group Configuration IE, Figure 5 and Figure 6 This describes how the UE can ignore the synchronization reconfiguration IE in the cell group configuration IE when appropriate. If the UE receives the synchronization reconfiguration IE in the cell group configuration IE... Figure 7 and Figure 8 This demonstrates how the UE correctly determines the basis for reconfiguration failure when synchronous reconfiguration of the IE fails. Figure 9 and Figure 10 During this process, the UE initiates a random access procedure to establish a new RRC connection with the base station. Figures 11 to 13 The diagram illustrates a distributed base station architecture in which different components of the disaggregated base station determine whether to exclude the synchronous reconfiguration IE in the RRC message to the UE.

[0052] Figure 3 Figure 300 illustrates example signaling and control transactions according to one or more implementations of processing RRC cell group configuration. In one implementation, Figure 300 depicts example transactions associated with the RRC connection recovery process that can be used to restore a previous RRC connection when the UE is in an RRC inactive state. Figure 4 Example RRC procedures for establishing, restoring, or re-establishing an RRC connection are described for UEs in RRC idle state, RRC inactive state, or RRC connected state, respectively.

[0053] Signaling and Control Transaction Diagram 300 illustrates various aspects of a base station handling Radio Resource Control (RRC) cell group configurations for an RRC connection restoration procedure. As shown at 305, UE 110 initiates an RRC connection restoration procedure to restore the previous RRC connection state with base station 120 (e.g., gNB). In some implementations, the UE initiates the RRC connection restoration procedure when operating in an RRC inactive state. As part of initiating the RRC connection restoration procedure and / or in response to it, UE 110 sends a random access preamble to base station 120 at 310. At 315, base station 120 responds with a Random Access Response (RAR) including a timing advance command. Then, at 320, UE 110 applies the timing advance command in response to the RAR to synchronize the uplink and starts a time alignment timer (e.g., TimeAlignmentTimer). Then, at 325, the UE sends an RRC request message (e.g., RRCResumeRequest or RRCResumeRequest1) to base station 120.

[0054] At 330, base station 120 determines to exclude the synchronization reconfiguration IE (e.g., ReconfigWithSync) in the cell group configuration information element (IE) (e.g., CellGroupConfig) of the RRC recovery message for UE 110. Typically, this synchronization reconfiguration information element (IE) causes UE 110 to reset the Media Access Control (MAC) entity, which leads UE 110 to believe that the time alignment timer has expired. Since UE 110 also uses the state of the time alignment timer to determine whether the uplink is synchronized with base station 120, the expired timer state prevents UE 110 from sending the RRC recovery complete message (e.g., RRCResumeComplete). In conventional systems operating according to current 3GPP communication standards, base stations are required to include the synchronization reconfiguration IE in the RRC recovery message.

[0055] Unlike conventional systems that require base station 120 to include a synchronous reconfiguration IE in the RRC recovery message, base station 120 using the aforementioned technique determines that a synchronous reconfiguration IE is not included in the cell group configuration IE. Specifically, base station 120 generates a cell group configuration IE without a synchronous reconfiguration IE and includes the cell group configuration IE in the RRC recovery message. At 335, base station 120, in response to the RRC recovery request message, sends an RRC recovery message with the cell group configuration IE to UE 110. Because the synchronous reconfiguration IE is not included in the RRC recovery message, UE 110 is not triggered to reset the MAC entity, the time alignment timer remains unexpired, and the uplink remains synchronized. In other words, the UE maintains the state of the MAC entity instead of resetting it. At 340, UE 110 then, in response to RRC recovery message 314, sends an RRC recovery complete message to base station 120 to indicate that the RRC connection recovery process is complete.

[0056] Figure 4 An example signaling and control transaction diagram 400 is illustrated according to one or more implementations of processing RRC cell group configuration. As shown, at 405, UE 110 initiates an RRC procedure to establish, restore, or rebuild an RRC connection. Initiating an RRC procedure may include initiating an RRC connection establishment procedure, an RRC connection restoration procedure, or an RRC connection rebuild procedure. In implementations, UE 110 initiates an RRC connection establishment procedure when operating in an RRC idle state, an RRC connection restoration procedure when operating in an RRC inactive state, and / or an RRC connection rebuild procedure when operating in an RRC connected state.

[0057] As part of the initiation and / or in response to the initiation, UE 110 sends a random access preamble to base station 120 at 410. At 415, in response to receiving the random access preamble, base station 120 sends a random access response including a timing advance command to UE 110. In response to receiving the random access response, UE 110 applies the timing advance command to synchronize the uplink and starts a time alignment timer at 420.

[0058] At 425, UE 110 then sends an RRC request message (e.g., an RRC recovery request message, an RRC establishment request message, or an RRC reconstruction request message) to base station 120. When base station 120 receives one of the RRC recovery request message, RRC establishment request message, or RRC reconstruction request message, base station 120 determines at 430 to exclude the synchronization reconfiguration IE in the cell group configuration IE for UE 110. At 435, base station 120 generates an RRC establishment message with a cell group configuration IE (without a synchronization reconfiguration IE) and sends the RRC establishment message to UE 110. At 440, in response to receiving the RRC establishment message, UE 110 sends an RRC establishment complete message to base station 120 to complete one of the RRC connection establishment process, RRC connection recovery process, or RRC connection reconstruction process.

[0059] Using these techniques prevents the UE from sending a synchronization reconfiguration IE to the UE, thus avoiding resetting the MAC entity, treating the time alignment timer as expired, and determining that the uplink is out of sync. In other words, the UE maintains the state of the MAC entity instead of resetting it, and avoids resetting the time alignment timer. This avoids uplink synchronization failures that would be problematic in a conventional system.

[0060] However, in some instances, the base station can still send the synchronization reconfiguration IE in the RRC message to the UE. In this case, the UE implements the function of avoiding uplink synchronization failure. For illustration, a scenario where the UE ignores the synchronization reconfiguration IE in the cell group configuration IE will be considered. Figure 5 and Figure 6 . Figure 5 The signaling and control transaction diagram 500 is shown, which in some cases depicts an example transaction corresponding to an RRC connection recovery procedure used to restore a previous RRC connection for a UE operating in an RRC inactive state. Figure 6 The signaling and control transaction diagram 600 illustrates example transactions used in establishing, restoring, or re-establishing an RRC connection when a UE is operating in one of the following states: RRC idle state, RRC inactive state, or RRC connected state.

[0061] Figure 5Figure 500 illustrates a UE configured to handle an RRC cell group during an RRC connection restoration procedure. As shown at 505, when operating in an RRC inactive state, UE 110 initiates an RRC connection restoration procedure to restore the previous RRC connection state with base station 120 (e.g., gNB). As part of initiating and / or in response to the RRC connection restoration procedure, UE 110 sends a random access preamble to base station 120 at 510. At 515, base station 120 responds with a random access response (RAR) including a timing advance command. Subsequently, at 520, UE 110 applies the timing advance command in response to the RAR to synchronize the uplink and starts a time alignment timer (e.g., TimeAlignmentTimer). Then, at 525, UE 110 sends an RRC recovery request message (e.g., RRCResumeRequest or RRCResumeRequest1) to base station 120.

[0062] At 530, base station 120 sends an RRC recovery message including the cell group configuration IE for the primary cell group (MCG), where the cell group configuration includes a synchronization reconfiguration IE. In this case, at 535, UE 110 ignores the synchronization reconfiguration IE in the cell group configuration IE. UE 110 can apply the configuration in the cell group configuration IE while ignoring the synchronization reconfiguration IE. Subsequently, at 540, UE 110 sends an RRC recovery complete message to the base station. In this way, uplink synchronization failure is avoided because UE 110 is not triggered to reset its MAC entity by the synchronization reconfiguration IE.

[0063] Figure 6 Figure 600 illustrates a UE configured for handling RRC cell groups during the RRC procedure. As shown at 605, UE 110 initiates one of the following RRC connection establishment, RRC connection recovery, or RRC connection re-establishment procedures. At 610, UE 110 sends a random access preamble to base station 120, and base station 120 responds at 615 with a random access response including a timing advance command. Correspondingly, UE 110 applies the timing advance command at 620 to synchronize the uplink and start a time alignment timer.

[0064] Next, at 625, UE 110 sends a request message (e.g., RRCSetupRequest, RRCResumeRequest, RRCResumeRequest1, or RRCReestablishmentRequest) to base station 120 to establish, restore, or rebuild an RRC connection. At 630, in response to receiving the request message, base station 120 sends an RRC establishment message including the cell group configuration IE. If the cell group configuration IE includes a synchronization reconfiguration IE, UE 110 ignores the synchronization reconfiguration IE at 635 and applies the configuration in the cell group configuration IE. Then, at 640, UE 110 sends an RRC establishment completion message (RRCSetupComplete) to base station 120 based on the RRC establishment message to complete one of the RRC connection establishment, RRC connection restoration, or RRC connection rebuilding processes.

[0065] As for Figures 3 to 4 As a replacement for the aforementioned technology, the UE can perform different functions in response to receiving a synchronized reconfiguration IE from the base station. For example, Figure 7 and Figure 8 An example signaling and control transaction diagram is shown corresponding to the UE that correctly forms the basis for the reconfiguration failure when determining the synchronous reconfiguration IE. Figure 7 This includes signaling and control transaction diagram 700, which describes an example implementation in which a UE requests to restore a previous RRC connection when operating in an RRC inactive state. Figure 8 Figure 800 includes signaling and control transactions in which the UE requests to establish, restore, or rebuild an RRC connection when operating in RRC idle state, RRC inactive state, or RRC connected state, respectively.

[0066] Figure 7Figure 700 illustrates an example transaction between a UE and a base station using RRC cell group configuration for an RRC connection recovery procedure. At 705, UE 110 initiates an RRC connection recovery procedure. As part of the initiation and / or in response to the initiation, UE 110 sends a random access preamble to base station 120 at 710. At 715, in response to receiving the random access preamble, base station 120 sends a random access response with a timing advance command to UE 110. At 720, UE 110 applies the timing advance command to synchronize the uplink and starts a time alignment timer in response to the random access response. At 725, UE 110 sends an RRC request message (e.g., RRCResumeRequest or RRCResumeRequest1) to base station 120, and at 730, the base station returns an RRC recovery message including a cell group configuration IE for the cell group (e.g., primary cell group (MCG), secondary cell group (SCG)) and a synchronization reconfiguration IE.

[0067] At 735, instead of interpreting the Synchronous Reconfiguration IE as triggering a MAC entity reset and treating the time alignment timer as expired, as is done in conventional techniques, UE 110 determines that the Synchronous Reconfiguration IE in the RRC Recovery message indicates reconfiguration failure. In response, as shown at 740, UE 110 initiates an RRC connection reconstruction procedure to recover from the reconfiguration failure, instead of sending an RRC recovery complete message. In this implementation, UE 110 initiates the RRC connection reconstruction procedure at 745 by sending a random access preamble to base station 120. At 750, base station 120 sends a random access response 720 with a timing advance command to UE 110. Then, UE 110 sends an RRC reconstruction request message to base station 120 at 755. In response, at 760, base station 120 sends an RRC reconstruction message to UE 110, and UE 110 sends an RRC reconstruction complete message to base station 120 at 765 to indicate that the RRC connection reconstruction procedure is complete.

[0068] Figure 8 Figure 800 illustrates an example transaction between a UE and a base station corresponding to an RRC procedure using an RRC cell group configuration. Similar to the discussion above, UE 110 initiates one of the following RRC connection establishment, RRC connection restoration, or RRC connection reconstruction procedures at 805. In response to initiation and / or as part of initiation, UE 110 sends a random access preamble to base station 120 at 810. In response to receiving the random access preamble, base station 120 sends a random access response, including a timing advance command, to UE 110 at 815.

[0069] At 820, UE 110 responds to the random access response by applying a timing advance command to synchronize the uplink and starting a time alignment timer. Subsequently, at 825, UE 110 sends an RRC request message (e.g., RRCResumeRequest, RRCResumeRequest1, RRCSetupRequest, or RRCReestablishmentRequest) to base station 120 to request the restoration, establishment, or reconstruction of the RRC connection.

[0070] At 830, the base station returns an RRC establishment message including the cell group configuration IE for the cell group and the synchronization reconfiguration IE. Sometimes, base station 120 returns an RRC establishment message, such as when base station 120 does not have the RRC configuration used during the previous RRC connection state of UE 110.

[0071] At 835, UE 110 determines that the Synchronization Reconfiguration IE in the Cell Group Configuration IE has failed. Based on this failure determination, at 840, UE 110 initiates an RRC connection re-establishment procedure. As part of initiating the RRC connection re-establishment procedure and / or in response to it, UE 110 sends a Random Access Preamble to the base station at 845. At 850, base station 120 sends a Random Access Response (RAR) to UE 110. In response to receiving the RAR, UE sends an RRC Re-establishment Request to base station 120 at 855, instead of sending an RRC Establishment Complete Message in response to the RRC Establishment Message, to recover from the reconfiguration failure. Then, at 860, base station 120 sends an RRC Re-establishment Message, and in response, UE 110 sends an RRC Re-establishment Complete Message at 865 to indicate that the RRC connection re-establishment procedure is complete.

[0072] Not like Figure 7 and Figure 8 The reconfiguration failed as stated above. Figure 9 and Figure 10 Example signaling and control transaction diagrams are shown in which a UE initiates a random access procedure to establish a new RRC connection with a base station in response to receiving a synchronous reconfiguration IE from the base station. Figure 9 Figure 900 illustrates the signaling and control transactions depicting a UE requesting to restore a previous RRC connection when operating in an RRC inactive state. Figure 10 Figure 1000 illustrates the signaling and control transactions depicting a UE requesting to establish, restore, or re-establish an RRC connection with a base station when operating in an RRC idle state, an RRC inactive state, or an RRC connected state.

[0073] Figure 9Figure 900 illustrates the Radio Resource Control cell group configuration handled by UE 110 for the RRC connection restoration procedure. As described above, at 905, UE 110 initiates the RRC connection restoration procedure. In response to initiation and / or as part of initiation, UE 110 sends a random access preamble to base station 120 at 910. In response to receiving the random access preamble, base station 120 sends a random access response to UE 110 at 915, wherein the random access response includes a timing advance command and indicates one or more uplink (communication) resources provided by uplink grant.

[0074] At 920, and after receiving the random access response, UE 110 applies a timing advance command to synchronize the uplink and start a time alignment timer. Then, at 925, UE 110 sends an RRC request message (e.g., RRCResumeRequest or RRCResumeRequest1) to base station 120. In response, base station 120 returns an RRC recovery message at 930, which includes the cell group configuration IE for the cell group and the synchronization reconfiguration IE.

[0075] At 935, in response to the synchronous reconfiguration of the IE in the cell group configuration, UE 110 initiates a new random access procedure. In response to initiating and / or as part of this initiation, UE 110 sends a random access preamble to base station 120 at 940.

[0076] At 945, UE 110 receives a random access response from base station 120, wherein, in this implementation, base station 120 sends the random access response based on the received random access preamble sent at 940. At 950, UE 110 applies a time advance command to synchronize the uplink and starts a new time alignment timer. Then, at 955, UE 110 sends an RRC recovery complete message to base station 120, wherein the UE sends the RRC recovery complete message using one or more uplink resources indicated by the uplink grant sent / received in the random access response depicted at 945.

[0077] In one example, the UE performs a new random access procedure based on the random access configuration in the Synchronous Reconfiguration IE or RRC Recovery message. Alternatively, the UE performs a new random access procedure based on the random access configuration in one or more system information blocks broadcast by base station 120.

[0078] Figure 10Figure 1000 depicts UE 110 configuring the radio resource control cell group for the RRC procedure. Similar to the discussion above, at 1005, UE 110 initiates one of the following RRC connection establishment, RRC connection recovery, or RRC connection reconstruction procedures. In response to the initiation and / or as part of the initiation, the UE sends a random access preamble to base station 120 at 1010.

[0079] In response to receiving the random access preamble, base station 120 sends a random access response to UE 110 at 1015, wherein the random access response includes a timing advance command. At 1020, UE 110 applies the timing advance command in response to the random access response to synchronize the uplink and start a time alignment timer. Then, UE 110 sends an RRC request message (e.g., RRCResumeRequest, RRCResumeRequest1, RRCSetupRequest, or RRCReestablishmentRequest) to base station 120 at 1025 to request the establishment of an RRC connection. Then, the base station returns an RRC establishment message at 1030, wherein the RRC establishment message includes a cell group configuration IE for the cell group and a synchronization reconfiguration IE.

[0080] At 1035, UE 110 initiates a new random access procedure in response to the synchronous reconfiguration IE in the cell group configuration IE. In response to the initiation and / or as part of the initiation, the UE sends a random access preamble to base station 120 at 1040.

[0081] At 1045, base station 120 responds to the random access preamble by sending a random access response. In some implementations, the random access response sent at 1045 includes a timing advance command and / or an indication of one or more uplink (communication) resources provided by an uplink grant. Then, at 1050, UE 110 applies the timing advance command 1020 to synchronize the uplink and start a new time alignment timer. Furthermore, at 1055, UE 110 sends an RRC establishment complete message to base station 120 on the uplink resources configured by the uplink grant sent at 1045.

[0082] In one example, UE 110 performs a new random access procedure based on the random access configuration in the Synchronous Reconfiguration IE or RRC Recovery message. Alternatively, UE 110 performs a new random access procedure based on the random access configuration in one or more system information blocks broadcast by base station 120.

[0083] Figures 11 to 13An example signaling and control transaction diagram is shown in which the different components of the distributed base station determine whether to exclude the synchronous reconfiguration IE in the RRC message to the UE. During the RRC connection restoration process, Figure 11 The gNB-CU determines whether to exclude the synchronized reconfiguration IE from the RRC messages to the UE during the RRC connection restoration process. Alternatively, in Figure 12 In China, gNB-DU made this determination. However, Figure 13 The gNB-DU shows the process of making this determination during the establishment, restoration, or reconstruction of an RRC connection for a UE in RRC idle, RRC inactive, or RRC connected states, respectively.

[0084] Figure 11 The signaling and control transaction diagram 1100 illustrates an example transaction depicting the RRC recovery process in a distributed base station architecture. (See diagram 1100.) Figure 11 As shown, a distributed base station (e.g., gNB) architecture consists of a gNB-CU (gNB-CU 121) connected to one or more gNB-DUs (gNB-DU 122) using an F1 interface. Here, UE 110 connects to gNB-CU 121 using one or more gNB-DUs' gNB-DU 122.

[0085] At 1105, UE 110 initiates an RRC connection recovery procedure. In response to the initiation and / or as part of the initiation, UE 110 sends a random access preamble to gNB-DU 122 at 1110. gNB-DU 122 then responds at 1115 with a random access response, where the random access includes a timing advance command. At 1120, UE 110 applies the timing advance command to synchronize the uplink and starts a time alignment timer. Then, at 1125, UE 110 sends an RRC request message (e.g., RRCResumeRequestor RRCResumeRequest1) to gNB-DU 122.

[0086] In some implementations, gNB-CU 121 receives an RRC request message from UE 110 via gNB-DU 122. For example, at 1130, gNB-DU 122 communicates the RRC request message to gNB-CU 121 using an F1AP Initial UL RRC Message Transmission message that includes the UE identifier assigned by gNB-DU 122 (e.g., gNB-DU UE F1APID). To avoid triggering a MAC entity reset in UE 110 and causing uplink synchronization failure, gNB-CU 121 determines at 1135 to exclude the synchronization reconfiguration IE in the RRC recovery message or RRC establishment message. Then, gNB-CU 121 generates a UE context establishment request message with explicit indication to gNB-DU 122 to generate a cell group configuration IE without a synchronization reconfiguration IE. At 1140, gNB-CU 121 sends an F1AP UE context establishment request with explicit indication to gNB-DU 122.

[0087] In some implementations, gNB-CU 121 includes an indication in the UE context establishment request message and sets the indication to one of two values. The first value instructs gNB-DU 122 to generate a cell group configuration IE without a synchronized reconfiguration IE. The second value instructs gNB-DU 122 to generate a synchronized reconfiguration IE within the cell group configuration IE.

[0088] In some implementations, and in response to an indication set to the first value, gNB-DU 122 generates a cell group configuration IE without a synchronized reconfiguration IE at 1145 and sends a UE context establishment response message including the cell group configuration IE to gNB-CU 121. Based on a UE context establishment request message including the indication, gNB-DU 122 sometimes generates a cell group configuration IE without a synchronized reconfiguration IE. Alternatively or additionally, based on a UE context establishment request message excluding the indication, some implementations of gNB-DU 122 generate a cell group configuration IE with a synchronized reconfiguration IE.

[0089] In some implementations, the instruction gNB-DU 122 generates a synchronized reconfiguration IE in the cell group configuration IE. Based on a UE context establishment request message that excludes the instruction, gNB-DU 122 sometimes generates a cell group configuration IE without a synchronized reconfiguration IE.

[0090] In response to receiving a UE Context Establishment Request message sent at 1145, gNB-CU 121 sends an RRC recovery message to gNB-DU 122 at 1150 using F1AP DL RRC message transmission. Subsequently, at 1155, gNB-DU 122 forwards the RRC recovery message to UE 110. Therefore, in response to the RRC Request message sent by UE 110 at 1125, gNB-CU 121 uses gNB-DU 122 to send an RRC recovery message including the Cell Group Configuration IE to UE 110.

[0091] At 1160, UE 110 sends an RRC recovery complete message to gNB-DU122. Then, at 1165, gNB-DU122 uses F1AP UL RRC message transmission to send the RRC recovery complete message to gNB-CU 121, where the RRC recovery complete message indicates the completion of the RRC connection recovery process. Therefore, the transaction described in Figure 1100 prevents UE 110 from triggering a reset of the corresponding MAC entity, thereby avoiding synchronization failure in the uplink.

[0092] Figure 12 Diagram 1200 illustrates the signaling and control transactions for the RRC recovery process in a distributed base station architecture. At 1205, UE 110 initiates an RRC connection recovery process to transition from an RRC inactive state to an RRC connected state. In response to the initiation and / or as part of the initiation, UE 110 sends a random access preamble to gNB-DU 122 at 1210. At 1215, gNB-DU 122 responds with a random access response including a timing advance command. UE 110 applies the timing advance command at 1220 to synchronize the uplink. In some implementations, UE 110 also starts a time alignment timer at 1220. Subsequently, UE 110 sends an RRC request message (e.g., RRCResumeRequest or RRCResumeRequest1) to gNB-DU 122 at 1225.

[0093] At 1230, and in response to receiving the RRC request message, gNB-DU 122 communicates the RRC recovery request message to gNB-CU 121 using the F1AP Initial UL RRC Message Transmission. In other words, gNB-CU 121 receives the RRC request message from UE 110 in the Initial UL RRC Message Transmission message from gNB-DU 122. In this implementation, the Initial UL RRC Message Transmission message includes the UE identifier assigned by gNB-DU 122 (e.g., gNB-DU UE F1AP ID).

[0094] At 1235, gNB-CU 121 uses an F1AP message to communicate a UE context establishment request message to gNB-DU 122, wherein the UE context establishment request message includes the UE identifier from the initial UL RRC message transmission message received at 1230. Then, at 1240, gNB-DU 122 determines whether the UE context establishment request message 1214 includes the UE identifier.

[0095] In response to determining that the UE context establishment request message includes the UE identifier, gNB-DU 122 generates a cell group configuration IE without a synchronized reconfiguration IE. Alternatively or additionally, in response to determining that the UE context establishment request message excludes the UE identifier, gNB-DU 122 generates a cell group configuration IE with a synchronized reconfiguration IE. At 1245, gNB-DU 122 communicates the cell group configuration IE from the UE context establishment response message to gNB-CU121. This scenario can be applied to mobility situations when UE 110 moves from one gNB-DU to another.

[0096] In response to receiving a UE context establishment response message with a cell group configuration IE that excludes the synchronization reconfiguration IE, gNB-CU121 encodes an RRC recovery message based on the exchange with gNB-DU122 and sends the RRC recovery message to UE110. For illustration, gNB-CU121 communicates an F1AP message (e.g., an F1AP DL RRC message transmission) to gNB-DU122 at 1250. Subsequently, gNB-DU122 sends an RRC recovery message including the cell group configuration IE to UE110 at 1255. Alternatively or additionally, in response to receiving a UE context establishment response message with a cell group configuration IE that includes the synchronization reconfiguration IE, gNB-DU122 sends an RRC reconfiguration message to UE110 (not shown).

[0097] In response to receiving the RRC recovery message sent at 1255, UE 110 sends an RRC recovery complete message to gNB-DU122 at 1260. Subsequently, gNB-DU sends the RRC recovery message to gNB-CU 121 at 1265 using F1AP UL RRC message transmission. Using these techniques, UE 110 is not triggered to reset its MAC entity, and synchronization failure is avoided. Therefore, the transaction described in Figure 1200 prevents UE 110 from triggering a reset of the corresponding MAC entity, thereby avoiding synchronization failure in the uplink.

[0098] Figure 13A signaling and control transaction diagram 1300 is shown, depicting an example transaction used for establishing, restoring, or re-establishing an RRC connection in a distributed base station architecture. At 1305, UE 110 initiates one of the following RRC connection establishment, RRC connection restoration, or RRC connection re-establishment procedures. In response to the initiation and / or as part of the initiation, UE 110 sends a random access preamble to gNB-DU122 at 1310. In response to receiving the random access preamble, gNB-DU 122 sends a random access response at 1315, wherein the random access response includes a timing advance command. Subsequently, at 1320, UE 110 applies the timing advance command to synchronize the uplink. Alternatively or additionally, UE 110 starts a time alignment timer at 1320.

[0099] To establish an RRC connection, UE 110 sends an RRC request message (e.g., RRCSetupRequest, RRCResumeRequest, RRCResumeRequest1, or RRCReestablishmentRequest) to gNB-DU122 at 1325. For example, UE 110 generates an RRC request message (RRRCResumeRequest or RRCResumeRequest1), an RRC connection establishment request message (RRCSetupRequest), or an RRC connection reconstruction request message (RRCReestablishmentRequests) and sends these messages to gNB-DU122. At 1330, in response to receiving the RRC request message, gNB-DU122 generates a cell group configuration IE without a synchronized reconfiguration IE. At 1335, gNB-DU122 sends the cell group configuration IE from the initial UL RRC message transmission message to gNB-CU121. In this implementation, the initial UL RRC message transmission message includes a UE identifier (e.g., gNB-DU UE F1AP ID) assigned by gNB-DU 122.

[0100] At 1340, and in response to receiving the UL RRC message transmission, gNB-CU 121 encodes the DL RRC message transmission using F1AP and sends it to gNB-DU122. Subsequently, gNB-DU122 sends an RRC setup message to UE 110 at 1345. UE 110 replies at 1350 by sending an RRC setup complete message (RRCSetupComplete). Then, gNB-DU 122 communicates the RRC setup complete message to gNB-CU 121 at 1355 using an F1AP UL RRC message transmission. Therefore, the transaction, as described in Figure 1300, prevents UE 110 from triggering a reset of the corresponding MAC entity, thereby avoiding synchronization failure in the uplink.

[0101] In the implementation, if gNB-CU 121 receives the RRC recovery request message and decides to restore UE 110, gNB-CU 121 initiates a UE context establishment procedure to gNB-DU 122 and as follows: Figure 11 or Figure 12 The process described herein can be applied to gNB-CU 121 and gNB-DU 122. For example, gNB-DU 122 generates a cell group configuration IE (e.g., CellGroupConfig) without a synchronized reconfiguration IE and sends the cell group configuration IE in the UE context establishment response message to gNB-CU 121.

[0102] Example process

[0103] Figure 14 , 15 Examples 1400, 1500, 1600, 1700, 1800, 1900, and 2000, respectively, are described in 16, 17, 18, 19, and 2000 for processing RRC cell group configuration. Methods 1400, 1500, 1600, 1700, and 1800 illustrate a set of operations (or actions) performed in accordance with, but not limited to, the order or combination of operations shown herein. Furthermore, any one or more of the operations may be repeated, combined, reorganized, skipped, or linked to provide a wide variety of additional and / or alternative methods.

[0104] Figures 14 to 16 The different processes executed by the base station to handle RRC cell group configuration are illustrated. Figure 14 In this process, the base station determines whether to exclude synchronous reconfiguration IE in the cell group configuration IE based on whether the cell group needs to be configured. Figure 15 In this process, the base station determines whether to exclude the synchronization reconfiguration IE in the cell group configuration IE based on the type of RRC message received from the UE. Figure 16In this process, the base station determines whether the synchronous reconfiguration IE is used for the primary cell group or the secondary cell group. Figure 17 and Figure 18 The procedure for handling RRC cell group configuration is shown and executed by the UE. Figure 18 It shows the relationship with Figure 17 Method 1700 is an alternative to UE 110 for handling synchronous reconfiguration of IE. Figure 19 This example illustrates how a base station determines, based on a connection procedure request received from the UE, that a synchronous reconfiguration IE has been excluded from the cell group configuration IE. Figure 20 An example of a UE requesting a connection from a base station is shown.

[0105] In the section discussed below, you may refer to Figure 1 Example wireless network environment 100 Figure 2 Example device diagram 200, and Figure 1 The entities detailed herein are referenced for illustrative purposes only. The techniques described herein are not limited to those performed by one or more entities operating on a single device. Figures 14 to 16 In the method described, the base station can be a next-generation base station NodeB (gNB) base station configured as a distributed base station or a non-distributed base station.

[0106] Example method 1400 describes a method for use by, for example Figure 1 The method for base station 120 to handle RRC cell group configuration.

[0107] At position 1405, the base station receives an RRC request message from the UE. In one example, the base station (e.g., base station 120) as follows: Figure 3 The method described at point 325 receives an RRC recovery request from the UE (e.g., UE 110) as an RRC request message. Alternatively or additionally, the base station (e.g., base station 120) as... Figure 4 The base station receives an RRC request message from UE 110 as described at point 425. For example, when the UE is in an RRC inactive state, the base station receives an RRC recovery request (as an RRC request message). As another example, when the UE 110 is in an RRC idle state, the base station receives an RRC establishment request as an RRC request message. As another example, when the UE is in an RRC inactive state, the base station receives an RRC recovery request as an RRC request message. In some implementations, when the UE 110 is in an RRC connected state, the base station receives an RRC reconstruction request as an RRC request message.

[0108] At 1410, the base station determines whether a cell group (e.g., a primary or secondary cell group) needs configuration. If cell group configuration is not required, the base station determines to exclude the Synchronization Reconfiguration Information Element (IE) for the cell group from the RRC Response message in response to the RRC Request message. For example, similar to... Figure 3 As described at 330, when a base station generates a cell group configuration IE for a primary cell group included in an RRC response message, base station 120 determines to exclude a synchronization reconfiguration IE from the cell group configuration IE and / or determines not to generate a synchronization reconfiguration IE. Alternatively or additionally, in an implementation, when base station 120 generates a cell group configuration IE for a secondary cell group (SCG) included in an RRC response message, base station 120 determines (not shown) to include a synchronization reconfiguration IE in the cell group configuration IE. In another instance, if the RRC message (e.g., RRCReconfiguration) is not an RRC response message, base station 120 determines (not shown) to include a synchronization reconfiguration IE in the cell group configuration IE of the RRC message. As another example, if the RRC message (e.g., RRCReconfiguration) is an RRC response message, such as in Figure 3 As described in 330, base station 120 determines (not shown) to exclude the synchronization reconfiguration IE in the cell group configuration IE in the RRC message.

[0109] Table 1 below shows an example in which a base station can determine whether to include or exclude a Synchronous Reconfiguration IE based on RRC messages and cell group configurations intended for use with the MCG or SCG.

[0110]

[0111] Table 1: Base station determines whether to include or exclude synchronization reconfiguration in RRC messages

[0112] The conventional approach requires the base station to include the synchronization reconfiguration IE in the cell group configuration, which may lead to synchronization failure. As mentioned above, if the synchronization reconfiguration IE is included in the cell group configuration IE, it will trigger UE 110 to reset its MAC entity and subsequently determine that synchronization has failed.

[0113] At 1415, if the cell group does not require configuration (“No”), base station 120 generates a cell group configuration IE without a synchronized reconfiguration IE. Based on the determination at 1410, base station 120 generates a cell group configuration for the cell group (e.g., primary cell group or secondary cell group), but does not generate or include a synchronized reconfiguration IE.

[0114] Alternatively, at 1420. If base station 120 determines that the cell group needs configuration (“Yes”), base station 120 generates a cell group configuration IE with a synchronous reconfiguration IE for the cell group. As described in Table 1 above, the synchronous reconfiguration IE may be specific to the cell group, such as a primary cell group or a secondary cell group.

[0115] At 1425, the base station sends an RRC response message including the cell group configuration IE to the UE. In one example, base station 120 sends an RRC recovery message 314 including the cell group configuration IE to UE 110, and the cell group configuration IE does not include a synchronization reconfiguration IE. In another example, base station 120 will send an RRC establishment message including the cell group configuration IE (e.g., in...). Figure 4 (at position 435) is sent to UE 110, and the cell group configuration IE does not include synchronous reconfiguration IE.

[0116] At 1430, the base station receives an RRC completion message from the UE in response to the RRC response message. For example, base station 120 may receive an RRC recovery completion message from UE 110 indicating the completion of the RRC connection recovery process, or an RRC establishment completion message from UE 110 indicating the completion of the RRC connection establishment process, such as in Figure 3 340 locations and / or Figure 4 As described at point 440 in the document.

[0117] In one example, if the RRC response message is an RRC recovery message, base station 120 determines to include a synchronization reconfiguration IE for the secondary cell group (SCG) in the RRC response message. If the RRC response message is not an RRC recovery message, base station 120 determines to exclude the synchronization reconfiguration IE for the SCG from the cell group configuration of the RRC response message. In an implementation, the synchronization reconfiguration IE for the secondary cell group instructs UE 110 to perform at least one action, some examples of which are described below.

[0118] For example, in some implementations, the action performed by UE 110 in response to the Synchronization Reconfiguration IE includes: stopping a timer (e.g., timer T310) for a specific cell (SpCell) configured in the Synchronization Reconfiguration IE (e.g., the primary cell (PCell) or secondary cell (SCell) of base station 120) in response to the operation of a timer. Alternatively or additionally, the action includes starting a timer (e.g., timer T304) for the SpCell, while the timer value is set to a value defined in the Synchronization Reconfiguration IE. In some implementations, the action includes: considering the SpCell as one of the following based on the Synchronization Reconfiguration IE including the Frequency Information Downlink IE (frequencyInfoDL): having a Synchronization Signal Block (SSB) frequency indicated by the Frequency Information Downlink IE with a physical cell identifier indicated by the Physical Cell Identifier IE, or the SSB frequency of a source SpCell having a Physical Cell Identifier IE.

[0119] Alternatively or additionally, the actions include one or more of the following: initiating DL synchronization with the SpCell and obtaining the SpCell's Management Information Base (MIB); resetting the MAC entity of the cell group (e.g., primary or secondary cell group) configured with the Synchronization Reconfiguration IE; treating the SCell of the cell group configured with the Synchronization Reconfiguration IE as inactive; applying the value of the new UE identifier as the cell RNTI (C-RNTI) for the cell group configured with the Synchronization Reconfiguration IE; configuring a lower layer according to the SpCell configuration IE (e.g., spCellConfigCommon) in the Synchronization Reconfiguration IE or according to any other field included in the Synchronization Reconfiguration IE; and performing a random access procedure on the SpCell according to the random access configuration in the Synchronization Reconfiguration IE or the RRC reconfiguration message including the Synchronization Reconfiguration IE.

[0120] In some implementations, if the cell group configuration IE is configured for the primary cell group, base station 120 applies at least one of the cell group configuration IEs for the primary cell group to communicate with UE 110. If the cell group configuration IE is configured for the secondary cell group, another base station may apply at least one of the cell group configuration IEs for the secondary cell group to communicate with UE 110.

[0121] Figure 15 An example method 1500 for handling RRC cell group configuration by a base station is described. In method 1500, the base station can be a next-generation base station, such as a NodeB (gNB) base station. Although base station 120 is... Figure 14 Method 1400 depends on whether the cell group needs to be reconfigured, but in Figure 15In Method 1500, the base station relies on the criteria associated with the RRC message to determine whether to include or exclude the Synchronous Reconfiguration IE in the RRC message to UE 110.

[0122] At point 1505, the base station initiates the generation of an RRC response message. For example, the base station (e.g., base station 120) initiates the generation of an RRC response message in response to an RRC message received from the UE (e.g., UE 110), such as in... Figure 3 At 325 or in Figure 4 As stated at point 425.

[0123] At 1510, the base station determines whether the RRC response message is in response to an RRC request message, such as base station 120 determining whether the RRC response message corresponds to an RRC request message from a UE (e.g., UE 110). In response to determining that the RRC response message corresponds to a response to an RRC request message (e.g., RRC establishment request, RRC recovery request, RRC reconstruction request), then at 1515 (e.g., "Yes"), base station 120 determines to exclude the synchronization reconfiguration IE from the cell group configuration IE in the RRC response message. Some implementations direct the cell group configuration IE to the primary or secondary cell group.

[0124] In response to determining that the RRC response message does not correspond to a response to an RRC request message, then at 1520 (e.g., "No"), base station 120 determines whether the RRC message received from the UE (e.g., UE 110) corresponds to an RRC reconfiguration message (e.g., RRCReconfiguration). In response to determining that the RRC message received from the UE does not correspond to an RRC reconfiguration message ("No"), the method proceeds to 1515. In other words, base station 120 determines to exclude the synchronization reconfiguration IE from the RRC response message, such as by excluding the synchronization reconfiguration IE in the cell group configuration IE directed to the primary cell group or the secondary cell group.

[0125] Conversely, in response to determining that the RRC message from the UE corresponds to an RRC reconfiguration message, at 1525 (e.g., "Yes"), base station 120 generates a synchronization reconfiguration IE and inserts the synchronization reconfiguration IE into the RRC response message. In this implementation, base station 120 configures the synchronization reconfiguration IE for RRC reconfiguration rather than necessarily for establishing an RRC connection.

[0126] At 1530, the base station sends an RRC response message to the UE. For example, the base station (e.g., base station 120) sends an RRC response message to the UE (e.g., UE 110) associated with the received RRC message. In some implementations, such as in implementations where the RRC message received (from the UE) corresponds to an RRC reconfiguration message, the sent RRC response message includes a synchronization reconfiguration IE. Alternatively or additionally, if the RRC message received (from the UE) is not an RRC reconfiguration message, or if the RRC response message is in response to an RRC request message, the RRC response message excludes a synchronization reconfiguration IE. In either case, base station 120 applies at least one of the cell group configuration IEs to communicate with UE 110.

[0127] Figure 16 An example method 1600 for handling RRC cell group configuration by a UE is described. In some aspects of method 1600, the UE communicates with a base station such as a next-generation base station NodeB (gNB). Although base station 120 is in Figure 15 Method 1500 relies on standards associated with RRC messages to determine whether to include or exclude the Synchronous Reconfiguration IE in the RRC message to UE110, but in Figure 16 Method 1600 base station 120 depends on whether the synchronous reconfiguration IE is for the primary cell group or the secondary cell group.

[0128] At position 1605, the UE sends an RRC request message to the base station. For example, as in... Figure 5 525 locations and / or at Figure 6 As described at 625, the UE (e.g., UE110) sends RRC request messages such as RRC establishment request messages, RRC recovery request messages, and RRC reconstruction request messages to the base station (e.g., base station 120).

[0129] At 1610, the UE receives an RRC response message from the base station, where the RRC response message includes a synchronization reconfiguration IE in the cell group configuration IE. In some cases, UE 110 receives an RRC recovery message as an RRC response message, such as by... Figure 5 As shown in the example of base station 120 at location 530. As another example, UE 110 receives an RRC establishment message as an RRC response message, such as in... Figure 6 As described at point 630, the RRC response message includes a cell group configuration IE with a synchronized reconfiguration IE. In this implementation, the cell group configuration IE is directed to the primary cell group or for the secondary cell group.

[0130] At 1615, the UE determines whether the synchronous reconfiguration IE corresponds to the primary cell group (MCG) or the secondary cell group (SCG).

[0131] In response to the determination that the synchronization reconfiguration IE corresponds to the MCG, at 1620, the UE ignores the synchronization reconfiguration. For example, the UE (e.g., UE 110) ignores the synchronization reconfiguration IE included in the RRC response message instead of performing an action based on the synchronization reconfiguration IE (e.g., an action that might cause uplink synchronization failure). To illustrate that UE 110 ignores the synchronization reconfiguration IE, such as in Figure 5 535 locations and / or Figure 6 As stated at point 635.

[0132] Alternatively, at 1625, if the cell group is configured with an IE for the secondary cell group, UE 110 applies a synchronous reconfiguration of the IE. In this case, UE 110 performs a random access procedure on the primary and secondary cells based on the synchronously reconfigured IE.

[0133] At 1630, the UE applies at least one configuration in the cell group configuration. In one or more examples, the UE (e.g., UE 110) applies one or more configurations in the cell group configuration IE other than the synchronization reconfiguration IE. This allows UE 110 to perform at least one action for the primary or secondary cell group, in addition to the action associated with the synchronization reconfiguration IE.

[0134] At position 1635, the UE sends an RRC completion message to the base station in response to the RRC response message. For example, if the UE (e.g., UE110) is in Figure 5 The RRC recovery completion message is described at point 540, or as in Figure 6 As described at point 640, an RRC establishment completion message is sent to a base station (e.g., base station 120) to indicate the completion of the RRC connection recovery process or the RRC connection establishment process.

[0135] Figure 17 An example method 1700 for handling RRC cell group configuration by a UE is described. In some aspects of method 1700, the UE communicates with a base station such as a next-generation base station NodeB (gNB) base station. Although methods 1400, 1500, and 1600 involve processing performed by base station 120, method 1700 is implemented by UE 110.

[0136] At position 1705, the UE sends an RRC request message (e.g., 710, 810) to base station 120. For example, if the UE (e.g., UE110) is in... Figure 7 725 or Figure 8At point 825, the UE sends an RRC Reestablishment Request, RRC Resume Request1, RRC Setup Request, or RRC Reestablishment Request. At point 1710, the UE receives an RRC response message from the base station. For example, the UE (e.g., UE 110) receives the RRC response message from the base station (e.g., base station 120) via radio link 130, as described in... Figure 7 730 places or Figure 8 As described at 830. In an implementation, the RRC response message includes a cell group configuration IE, which includes a synchronization reconfiguration IE for cell groups such as the primary cell group (MCG) or the secondary cell group (SCG).

[0137] At 1715, the UE determines that the synchronized reconfiguration of the IE is an invalid configuration for the cell group, such as in... Figure 7 735 locations and / or Figure 8 As described at 835. In one implementation, the UE (e.g., UE 110) determines that the Synchronous Reconfiguration IE is invalid based on an RRC request message sent at 1705 (e.g., the reconfiguration is an invalid response to an RRC request message requesting the restoration or establishment of an RRC connection). Alternatively or additionally, the UE (e.g., UE 110) determines that the Synchronous Reconfiguration IE is invalid based on an RRC response message received at 1710. In some implementations, UE 110 determines that the Synchronous Reconfiguration IE is invalid based on identifying the cell group and configuring the IE for the MCG. In other implementations (not shown), UE 110 determines that the Synchronous Reconfiguration IE is valid for the cell group based on identifying the cell group and configuring the IE for the SCG. If UE 110 receives the Synchronous Reconfiguration IE in an RRC message that is not an RRC response message, such as an RRC reconfiguration message, UE 110 determines that the Synchronous Reconfiguration IE is valid.

[0138] At 1720, in response to determining that the synchronization reconfiguration IE is invalid, the UE (e.g., UE 110) declares a reconfiguration failure for the cell group. In the implementation, at 1725, the UE (e.g., UE 110) performs an RRC connection re-establishment procedure with the base station (e.g., base station 120) in response to the reconfiguration failure. This prevents UE 110 from performing actions that could lead to uplink synchronization failure in response to synchronization reconfiguration. An example of the RRC connection re-establishment procedure is provided in... Figure 7 At positions 740 to 765 and / or at Figure 8 It is described as stated in sections 840 to 865.

[0139] As described above, UE 110 can apply at least one of the cell group configurations for the cell group, in addition to the configuration associated with the synchronization reconfiguration IE. Alternatively, UE 110 does not apply the cell group configuration.

[0140] Figure 18 An example method 1800 for handling RRC cell group configuration by a UE is described. In method 1800, the UE communicates with a base station such as a next-generation base station NodeB (gNB) base station. Compared to method 1700, method 1800 includes alternative functions performed by UE 110 for handling RRC cell group configuration. For example, while method 1700 involves UE 110 determining an invalid reconfiguration, method 1800 involves UE 110 initiating a random access procedure.

[0141] At position 1805, the UE sends an RRC request message to the base station, such as in... Figure 9 At 925 locations and / or in Figure 10 As described at 1025. For example, the UE (e.g., UE 110) sends an RRC request message to the base station (e.g., base station 120), where the RRC request message corresponds to RRCReestablishmentRequest, RRCResumeRequest1, RRCSetupRequest, or RRCReestablishmentRequest.

[0142] At 1810, the UE receives an RRC response message from the base station, which includes a cell group configuration IE, comprising a synchronization reconfiguration IE for cell groups such as the primary cell group (MCG) or secondary cell group (SCG). For example, similar to... Figure 9 930 locations and / or Figure 10 As described at 1030, the UE (e.g., UE 110) uses Figure 1 The wireless link 130 receives an RRC response message from the base station (e.g., base station 120).

[0143] At point 1815, the UE performs a random access procedure in response to the synchronization reconfiguration IE for the cell group by sending a random access preamble to the base station. For example, the UE (e.g., UE 110) initiates a random access procedure similar to... Figure 9 935 locations and / or Figure 10 As described at 1035, and the random access preamble is sent to the base station (e.g., base station 120), similar to in Figure 9 940 locations and / or Figure 10 As stated at point 1040.

[0144] At 1820, the UE receives a random access response message from the base station in response to the random access preamble. For example, the UE (e.g., UE 110) is similar to... Figure 9 Receive random access response from base station (e.g., base station 120) as described at 945, or as... Figure 10 The random access response described at point 1045.

[0145] At 1825, if the cell group is configured with IE for MCG, the UE sends an RRC completion message on the uplink resources configured with uplink grant in the random access response message and on the uplink resources configured with uplink grant in the downlink control information received on the physical downlink control channel (PDCCH). For example, if the UE (e.g., UE110) is in Figure 9 As described at 955, the RRC recovery completion message will be sent or similar to that in Figure 10 As described at 1055, an RRC establishment completion message is sent to the base station (e.g., base station 120) to indicate that the RRC connection recovery process or the RRC connection establishment process has been completed, respectively.

[0146] Figure 19 An example method 1900 for handling RRC cell group configuration by a base station is described. In some aspects of method 1900, the base station may be a next-generation base station NodeB (gNB) base station.

[0147] At point 1905, the base station receives a first radio resource control message requesting a connection between the user equipment and the base station. For example, similar to... Figure 3 As described at 325, the base station (e.g., base station 120) receives an RCResumeRequest message or an RCResumeRequest1 message from the UE (e.g., UE 110) to request a connection restoration procedure. As another example, similar to... Figure 4 As described at 425, a base station (e.g., base station 120) receives an RRCSetupRequest message from a UE (e.g., UE 110) to request a connection establishment procedure, receives an RRCResumeRequest message to request a connection recovery procedure, or receives an RRCReestablishmentRequest to request a connection reconstruction procedure. In some implementations, the base station operates as part of a distributed base station architecture in which different components of the distributed base stations determine whether to exclude the synchronous reconfiguration IE in the RRC message to the UE. For example, similar to in Figure 13As described at 1325, a base station (e.g., base station 122) operating in a distributed base station architecture receives a first radio resource control message from a UE (e.g., UE 110), such as an RRCResumeRequest or RRCResumeRequest1 message for requesting a connection restoration procedure, an RRCSetupRequest message for requesting a connection establishment procedure, an RRCResumeRequest message for requesting a connection restoration procedure, or an RRCReestablishmentRequest message for requesting a connection re-establishment procedure.

[0148] At point 1910, the base station generates a second radio resource control message that includes cell group configuration information elements excluding synchronization reconfiguration information elements. For example, similar to... Figure 3 330 locations and / or Figure 4 As described at 430, a base station (e.g., base station 120) generates an RRC recovery message, wherein this generation is based on a determination that excludes the synchronization reconfiguration IE from the cell group configuration IE included in the RRC recovery message. As another example, a base station (e.g., base station 122) operating in a distributed base station architecture generates a similar message. Figure 13 The RRC establishment message as described at 1345, wherein the RRC establishment message includes Figure 13 The cell group configuration IE generated at position 1330 excludes synchronous reconfiguration of IE.

[0149] At 1915, the base station sends a second radio resource control message to the user equipment. For example, similar to... Figure 3 335 places or Figure 4 As described at 435, the base station (e.g., base station 120) sends an RRC recovery message and / or an RRC establishment message to the UE (e.g., UE 110). As another example, as in... Figure 13 As described at 1345, after communicating with another base station (e.g., base station 121) included in a distributed base station architecture, a base station (e.g., base station 122) sends an RRC establishment message to the UE (e.g., UE 110). For example, base station 122 uses UL RRC message transmission to communicate the cell group configuration IE, which excludes synchronous reconfiguration IE, to base station 121. Then, as in Figure 13 As described at 1335, 1340 and 1345, base station 122 receives a DL RRC message transmission response from base station 121 and sends an RRC establishment message to the UE.

[0150] At 1920, the base station received a third radio resource control message from the user equipment indicating that the connection process was complete. For example, as in... Figure 3As described at 340, the base station (e.g., base station 120) receives an RRCResumeComplete message from the UE (e.g., UE 110). As another example, as in... Figure 4 As described at 440, base station 120 receives an RRCSetupComplete message from UE 110. As yet another example, as in... Figure 13 As described at 1350, a base station (e.g., base station 122) operating in a distributed base station architecture receives an RRCSetupComplete message from UE 110.

[0151] Figure 20 An example method 2000 for handling RRC cell group configuration by a UE is described. In method 2000, the UE communicates with a base station such as a next-generation base station NodeB (gNB) base station.

[0152] In 2005, the UE sends a first radio resource control message to the base station to request a connection between the user equipment and the base station. For example, similar to... Figure 3 As described at 325, the UE (e.g., UE 110) sends an RCResumeRequest message or an RCResumeRequest1 message to the base station (e.g., base station 120) to request a connection restoration procedure. As another example, similar to... Figure 4 As described at 425, the UE (e.g., UE 110) sends an RRCSetupRequest message to request a connection establishment procedure, an RRCResumeRequest message to request a connection restoration procedure, or an RRCReestablishmentRequest message to request a connection reconstruction procedure. (See also...) Figure 13 As described at 1325, in some embodiments, UE 110 communicates a first radio resource control message to a base station (e.g., base station 122) operating in a distributed base station architecture.

[0153] At 2010, the UE receives a second radio resource control message from the base station, wherein the second radio resource control message includes a cell group configuration IE that excludes the synchronization reconfiguration IE. As an example, refer to... Figure 3 335 places or Figure 4 As described at 435, the UE (e.g., UE 110) receives an RRC recovery message and / or an RRC establishment message from a base station (e.g., base station 120). As another example, as in... Figure 13 As described at 1345, the UE (e.g., UE 110) receives an RRC establishment message from a base station (e.g., base station 122) operating in a distributed base station architecture.

[0154] In 2015, the UE performs a connection procedure with the base station, at least in part, by sending a third radio resource control message to the base station indicating the completion of the connection procedure, based on a second radio resource control message. In an implementation, the UE (e.g., UE 110) as in... Figure 3 As described at point 340, send the RRRCResumeComplete message, or as in Figure 4 The RRCSetupComplete message is sent as described at position 440. As another example, such as in... Figure 13 As described at 1350, the UE (e.g., UE110) sends the RRCSetupComplete message to the base station (e.g., base station 122) operating in the distributed base station architecture.

[0155] describe Figure 14 , 15 The order of method blocks 16, 17, 18, 19, and 20 is not intended to be construed as a limitation, and any number of said method blocks may be combined in any order to implement a method or an alternative method.

[0156] Typically, any component, module, method, and operation described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example methods can be described within the general context of executable instructions stored on computer-readable storage memory local to and / or remote from the computer processing system, and implementations may include software applications, programs, functions, etc. Alternatively or additionally, any function described herein may be performed at least in part by one or more hardware logic components, such as, but not limited to, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0157] Although techniques and apparatus for processing radio resource control cell group configurations have been described in language specific to features and / or methods, it should be understood that the subject matter of the appended claims is not necessarily limited to the specific features or methods described. Rather, specific features and methods are disclosed as exemplary embodiments for processing radio resource control cell group configurations.

[0158] The following describes several examples.

[0159] Example 1: A method for a base station to process radio resource control cell group configuration, the method comprising the base station: receiving from a user equipment a first radio resource control message requesting a connection process between the user equipment and the base station; generating a second radio resource control message including cell group configuration information elements excluding synchronization reconfiguration information elements; sending the second radio resource control message to the user equipment; and receiving from the user equipment a third radio resource control message indicating that the connection process is complete.

[0160] Example 2: The method as described in Example 1, wherein: the first radio resource control message includes a radio resource control recovery request message, the second radio resource control message includes a radio resource control recovery message, the third radio resource control message includes a radio resource control recovery completion message, and the connection process includes a connection recovery process.

[0161] Example 3: The method as described in Example 1, wherein: the first radio resource control message includes a radio resource control establishment request message, the second radio resource control message includes a radio resource control establishment message, the third radio resource control message includes a radio resource control establishment completion message, and the connection process includes a connection establishment process.

[0162] Example 4: The method as described in any of Examples 1 to 3, wherein generating the second radio resource control message further comprises: in response to receiving the first radio resource control message, the base station determining to exclude the synchronization reconfiguration information element from the cell group configuration information element.

[0163] Example 5: The method as described in Example 1, wherein the base station includes a base station distributed unit that communicates with a base station central unit, and generating the second radio resource control message includes: sending a cell group configuration information element excluding the synchronization reconfiguration information element to the base station central unit using an initial uplink radio resource control transmission message; receiving a downlink radio resource control transmission message from the base station central unit; and generating the second radio resource control message as a radio resource control establishment message based on the reception, wherein the radio resource control establishment message is configured with the cell group configuration information element excluding the synchronization reconfiguration information element.

[0164] Example 6: The method as described in Example 5, wherein the first radio resource control message includes a radio resource control recovery request.

[0165] Example 7: The method as described in Example 5, wherein the first radio resource control message includes a radio resource control establishment request.

[0166] Example 8: The method as described in any of Examples 5 to 7, wherein the third radio resource control message includes a radio resource control establishment complete message, the initial uplink radio resource control transmission message includes a first uplink radio resource control transmission message, and the method further includes: communicating the radio resource control establishment complete message to the base station central unit using a second uplink radio resource control transmission message.

[0167] Example 9: The base station device includes: a wireless transceiver; and a processor and memory system coupled to the wireless transceiver and configured to instruct the base station device to perform any one of methods 1 to 8.

[0168] Example 10: A method for a user equipment to process radio resource control cell group configuration, the method comprising: the user equipment sending a first radio resource control message to a base station to request a connection procedure between the user equipment and the base station; receiving a second radio resource control message from the base station, the second radio resource control message including cell group configuration information elements excluding synchronization reconfiguration information elements; and performing the connection procedure with the base station by sending a third radio resource control message indicating completion of the connection procedure, at least in part based on the second radio resource control message.

[0169] Example 11: The method as described in Example 10, wherein: the first radio resource control message includes a radio resource control recovery request message, the second radio resource control message includes a radio resource control recovery message, the third radio resource control message includes a radio resource control recovery completion message, and the connection process includes a connection recovery process.

[0170] Example 12: The method as described in Example 10, wherein: the first radio resource control message includes a radio resource control establishment request message, the second radio resource control message includes a radio resource control establishment message, the third radio resource control message includes a radio resource control establishment completion message, and the connection process includes a connection establishment process.

[0171] Example 13: The method as described in Examples 10 to 12, wherein performing the connection process with the base station based at least in part on the second radio resource control message further comprises: determining, in response to receiving the second radio resource control message, that a time alignment timer associated with the connection process has not expired; determining, based on the determination that the time alignment timer has not expired, that the uplink connection with the base station is synchronized; and determining, based on the determination that the uplink connection is synchronized, to send the third radio resource control message.

[0172] Example 14: The method as described in any of Examples 10 to 13 further includes: maintaining the state of the media access control entity in response to receiving the second radio resource control message.

[0173] Example 15: The user equipment includes: a wireless transceiver; and a processor and memory system coupled to the wireless transceiver and configured to instruct the user equipment to perform any one of methods 10 to 14.

Claims

1. A method for handling radio resource control cell group configuration by a distributed unit of a base station, the method comprising the distributed unit performing the following operations: receiving, from a user equipment, a first radio resource control message requesting a connection procedure between the user equipment and the base station; sending, to a central unit, the first radio resource control message and a cell group configuration information element that excludes a synchronization reconfiguration field; receiving, from the central unit, a second radio resource control message in response to the first radio resource control message; sending, to the user equipment, the second radio resource control message; and receiving, from the user equipment, a third radio resource control message indicating completion of the connection procedure.

2. The method of claim 1, wherein: the second radio resource control message is a radio resource control setup message or a radio resource control resume message. the first radio resource control message is sent from the distributed unit to the central unit in an initial uplink radio resource control message transfer message.

3. The method of claim 1, wherein, sending the second radio resource control message comprises:

4. The method of claim 1, wherein, receiving, from the central unit, a downlink radio resource control message transfer message that includes the second radio resource control message.

5. The method of claim 1, further comprising the distributed unit performing the following operations: in response to receiving the third radio resource control message from the user equipment, sending the third radio resource control message to the central unit using an uplink radio resource control message transfer message. the first radio resource control message includes a radio resource control resume request.

6. The method of claim 1, wherein, the first radio resource control message includes a radio resource control setup request.

7. The method of claim 1, wherein, the cell group configuration information element that excludes the synchronization reconfiguration field is sent from the distributed unit to the central unit in a UE context setup response message.

8. The method of claim 1, wherein, 9. A base station distributed unit device comprising: a wireless transceiver; and a processor and memory system coupled to the wireless transceiver and configured to direct the base station distributed unit device to perform the following operations: receiving, from a user equipment, a first radio resource control message requesting a connection procedure between the user equipment and the base station; sending, to a central unit, the first radio resource control message and a cell group configuration information element that excludes a synchronization reconfiguration field; receiving, from the central unit, a second radio resource control message in response to the first radio resource control message; sending, to the user equipment, the second radio resource control message; and receiving, from the user equipment, a third radio resource control message indicating completion of the connection procedure.

10. The base station distributed unit device of claim 9, wherein: the second radio resource control message is a radio resource control setup message or a radio resource control resume message. the first radio resource control message is sent from the base station distributed unit to the central unit in an initial uplink radio resource control message transfer message. ​ 11. The base station distributed unit device of claim 9, wherein, ​ 12. The base station distributed unit device of claim 9, wherein, The processor and memory system are further configured to instruct the base station distributed unit device to perform the following operations: receive, from the central unit, a downlink, DL, radio resource control message transmission message comprising the second radio resource control message.

13. The base station distributed unit device of claim 9, the processor and memory system further configured to instruct the base station distributed unit device to perform the following operations: in response to the receipt of the third radio resource control message from the user equipment, send the third radio resource control message to the central unit using an uplink radio resource control message transmission message.

14. The base station distributed unit device of claim 9, wherein, The first radio resource control message comprises a radio resource control resume request.

15. The base station distributed unit device of claim 9, wherein, The first radio resource control message comprises a radio resource control setup request.

16. The base station distributed unit device of claim 9, wherein, The cell group configuration information element is sent from the base station distributed unit to the central unit in a UE context setup response message.

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