Disconnection Recovery in Wireless Communication

Abstract

A technical method and system for preventing or reducing failures in a central unit of a base station are disclosed. In one implementation, a method of wireless communication includes: a first network element receiving, from a user equipment, a signaling connection setup completion message indicating establishment of a connection of a signaling message between the user equipment and a network device associated with the first network element; the first network element determining whether a network slice corresponding to the signaling connection setup completion message is supported by a second network element; and when it is determined that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element, the first network element transmitting the signaling message and information regarding the network slice to a third network element.

Description

Technical Field

[0001] This patent document generally relates to wireless communication.

Background Art

[0002] Mobile communication technology is leading the world towards an increasingly connected and networked society. Due to the rapid growth and technological progress of mobile communication, the demand for capacity and connectivity is increasing. To meet the needs of various communication scenarios, other aspects such as energy consumption, device cost, spectral efficiency, and latency are also important. Various technologies have been discussed, including new methods for providing higher-quality services, longer battery life, and improved performance.

Summary of the Invention

Problems to be Solved by the Invention

[0003] This patent document particularly describes a technique for preventing or reducing failures in the central unit of a base station.

Means for Solving the Problems

[0004] In one aspect, a method of data communication is disclosed. The method includes steps in which a first network element receives a signaling connection setup completion message from a user equipment indicating the establishment of a signaling message connection between the user equipment and a network device associated with the first network element; the first network element determines whether a network slice corresponding to the signaling connection setup completion message is supported by a second network element; and when it is determined that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element, the first network element transmits information regarding the signaling message and the network slice to a third network element.

[0005] In another aspect, a method of data communication is disclosed. The method includes steps of: a second network element receiving, from a first network element, a signaling container and a transfer message for transferring a signaling message, where the signaling container includes at least one of a signaling connection setup request message for requesting a connection of the signaling message or a signaling connection setup completion message indicating establishment of the connection of the signaling message; the second network element determining whether a network slice corresponding to the signaling message is supported by the second network element; and when it is determined that the network slice corresponding to the signaling message is not supported by the second network element, the second network element transmitting the signaling message and information about the network slice to a third network element.

[0006] In another aspect, a method of data communication is disclosed. The method includes steps of: a first network element transmitting to a second network element a request message and information about the number of user equipment devices served by a network device associated with the first network element; the first network element receiving a response message from the second network element; and based on the information about the number of user equipment devices served by the network device, allocating the user equipment devices among different control planes of the second network element associated with the network device.

[0007] In another exemplary aspect, a wireless communication device comprising a processor configured to execute the method described above is disclosed.

[0008] In another exemplary aspect, a computer storage medium storing code for implementing the above-described method is disclosed.

[0009] These and other aspects are described in this document.

Brief Description of the Drawings

[0010]

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Best Mode for Carrying Out the Invention

[0011] The section headings are used only to facilitate understanding in this document and do not limit the scope of the embodiments to the sections in which they are described. Further, although the embodiments are described with reference to examples of 5G, the disclosed technology can be applied to wireless systems using protocols other than 5G or 3GPP (registered trademark) protocols.

[0012] FIG. 1 shows an example of a wireless communication system (e.g., Long Term Evolution (LTE), 5G or NR cellular network) comprising a BS 120 and one or more user equipments (UEs) 111, 112, 113. In some embodiments, the uplink transmissions (131, 132, 133) can include uplink control information (UCI), upper layer signaling (e.g., UE assistance information or UE capabilities), or uplink information. In some embodiments, the downlink transmissions (141, 142, 143) can include DCI or upper layer signaling or downlink information. The UE can be, for example, a smartphone, a tablet, a mobile computer, a machine-to-machine (M2M) device, a terminal, a mobile device, an Internet of Things (IoT) device, etc.

[0013] FIG. 2 is a block diagram representation of a part of an apparatus based on some embodiments of the disclosed technology. An apparatus 205, such as a network device or a base station or a wireless device (or UE), can include processor electronics 210, such as a microprocessor, that implements one or more of the technologies disclosed in this document. The apparatus 205 can include transceiver electronics 215 to transmit and / or receive wireless signals through one or more communication interfaces, such as an antenna 220. The apparatus 205 can include other communication interfaces for sending and receiving data. The apparatus 205 can include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some implementations, the processor electronics 210 can include at least a part of the transceiver electronics 215. In some embodiments, at least a part of the disclosed technology, module, or function is implemented using the apparatus 205.

[0014] In a wireless communication network, a next-generation radio access network (NG-RAN) architecture may be split for each split gNodeB (gNB) by the presence of a single logical gNB-central unit (CU)-control plane (CP) connected to a plurality of logical gNB-distributed units (DUs) and a logical gNB-CU-user plane (UP). Additionally, a failure in the gNB-CU (e.g., gNB-CU-CP) can cause an interruption of multi-user plane (UP) traffic and disconnection of multiple UEs. The disclosed technology can be implemented in some embodiments to address these problems.

[0015] FIG. 3 shows an exemplary architecture for the separation of the gNB-central unit (CU)-control plane (CP) and the gNB-CU-user plane (UP).

[0016] In some implementation manners, a base station (e.g., gNB) may include a control plane of a central unit (e.g., gNB-CU-CP), a plurality of user planes of a control unit (e.g., gNB-CU-UP), and a plurality of distributed units (e.g., gNB-DU). In some implementation manners, gNB-CU-CP is connected to gNB-DU via an interface (e.g., F1-C interface). In some implementation manners, gNB-CU-UP is connected to gNB-DU via another interface (e.g., F1-U interface). In some implementation manners, gNB-CU-UP is connected to gNB-CU-CP via an E1 interface. In some implementation manners, one gNB-DU is connected to only one gNB-CU-CP. In some implementation manners, one gNB-CU-UP is connected to only one gNB-CU-CP.

[0017] In some implementation manners, for the purpose of resilience, gNB-DU and / or gNB-CU-UP may be connected to a plurality of gNB-CU-CP.

[0018] In an implementation manner where gNB-DU and / or gNB-CU-UP is connected to a plurality of gNB-CU-CP, one gNB-DU or gNB-CU-UP can connect a plurality of gNB-CU-UP simultaneously.

[0019] In one embodiment of the disclosed technology, by differentiating the central unit (CU) function across services, the failure of gNB-CU-CP can be prevented or mitigated. In some implementations, different gNB-CUs may be assigned to different network slices to support different services. In this case, two scenarios can be considered. In one scenario where the gNB-CU does not support the selected slice, the gNB-DU can send a radio resource control (RRC) message with slice information to a backup gNB-CU. In another scenario where the gNB-CU detects a failure and cannot support the selected slice, the gNB-CU can re-route the RRC message with slice information to the backup gNB-CU.

[0020] In another embodiment of the disclosed technology, by evenly allocating users (or user equipment devices (UEs)) among different gNB-CU-CPs, the failure of gNB-CU(-CP) can be prevented or mitigated. Additionally, the number of users in different gNB-CU-CPs may be transmitted from gNB-DU / gNB-CU-UP to gNB-CU-CP through F1AP / E1AP messages. In this case, even if a particular gNB-CU-CP detects a failure, it may not affect the user plane (UP) traffic and the connections of UEs located in other gNB-CU-CPs.

[0021] Embodiment 1: Dedicated CUs for network slicing to support different services.

[0022] In some embodiments of the disclosed technology, after interpreting an RRC message with slice information, the gNB - distributed unit (DU) transmits the RRC message to a backup gNB - central unit (CU).

[0023] Figure 4 shows an example of the F1 Application Protocol (F1AP) procedure for a dedicated Central Unit (CU) for network slicing, based on some embodiments of the disclosed technology.

[0024] In operation 1, the UE transmits an RRC setup request message to the gNB-DU. In operation 2, the gNB-DU transmits an initial uplink (UL) RRC message to the gNB-CU. In operation 3, the gNB-CU transmits a downlink (DL) RRC message transfer message to the gNB-DU. In operation 4, the gNB-DU transmits an RRC setup message to the UE. In operation 5, the UE transmits an RRC setup complete message to the gNB-DU. Operations 1 to 5 may be common initial access procedures on F1.

[0025] In some implementations of the disclosed technology, after performing operation 5, the gNB-DU interprets the RRC setup complete message and detects that a certain slice (e.g., a network slice) is not supported by the gNB-CU.

[0026] In operation 6, the gNB-DU transmits a UE context release request message with the cause value "S-NSSAI (Slice) not supported by the CU" to the gNB-CU. Here, the cause value can indicate the release cause value.

[0027] In operation 7, the gNB-DU transmits an initial UL RRC message with an RRC container to the backup gNB-CU. The RRC container may include at least one of the RRC setup request message or the RRC setup complete message.

[0028] In operation 8, the gNB-CU triggers a UE context release procedure to release the UE context.

[0029] In operation 9, the backup gNB-CU triggers the UE context setup procedure with the gNB-DU.

[0030] In the case of a dedicated CU for network slicing, even if one of the gNB-CUs does not support the slice, the gNB-DU can reselect a new appropriate gNB-CU to support the same type of service.

[0031] Embodiment 2: Dedicated CU for network slicing by rerouting procedure.

[0032] In some embodiments of the disclosed technology, after detecting a failure, the gNB-CU directly transmits an RRC message with slice information to the backup gNB-CU.

[0033] FIG. 5 shows another example of the F1AP procedure for a dedicated CU for network slicing by a rerouting procedure according to some embodiments of the disclosed technology.

[0034] In operation 1, the UE transmits an RRC setup request message to the gNB-DU. In operation 2, the gNB-DU transmits an initial uplink (UL) RRC message to the gNB-CU. In operation 3, the gNB-CU transmits a downlink (DL) RRC message transfer message to the gNB-DU. In operation 4, the gNB-DU transmits an RRC setup message to the UE. In operation 5, the UE transmits an RRC setup complete message to the gNB-DU. Operations 1 to 5 may be common initial access procedures on F1.

[0035] In operation 6, the gNB-DU transmits an uplink (UL) RRC message transfer message to the gNB-CU in an RRC container. The RRC container may include at least one of the RRC setup request message or the RRC setup complete message, and the slice information is included in the RRC message.

[0036] In operation 7, the gNB-CU has detected a failure but cannot support the slice, and can transfer the RRC message with slice information to the backup gNB-CU by performing a rerouting RRC request procedure (e.g., XnAP signaling). In some implementation manners, the rerouting RRC request procedure may be a class 1 procedure or a class 2 procedure. In addition to XnAP signaling, a user plane method such as a data transfer procedure can be used to process the rerouting RRC procedure.

[0037] In operation 8, the backup gNB-CU triggers a UE context setup procedure with the gNB-DU.

[0038] In the case of a dedicated CU for network slicing, even if one of the gNB-CUs detects a failure, the gNB-DU can reselect a new appropriate gNB-CU to support the same type of service as the old gNB-CU.

[0039] Embodiment 3: Equal allocation of users between different gNB-CU-CPs.

[0040] In some embodiments of the disclosed technology, the gNB-CU-CP transmits the number of users to the gNB-DU / gNB-CU-UP.

[0041] FIG. 6 shows an example of an F1AP procedure for equal allocation of users according to some embodiments of the disclosed technology.

[0042] In operation 1, the gNB-CU transmits an F1 application protocol (F1AP) request message to the gNB-DU together with the number of users to be served. In some implementation manners, the F1AP request message may be one of a gNB-CU configuration update message, or a UE context setup request message, or a backhaul adaptation protocol (BAP) mapping configuration message.

[0043] In operation 2, the gNB-DU returns a corresponding F1AP response message that includes one of the gNB-CU configuration update confirmation message, or the UE context setup response message, or the BAP mapping configuration confirmation message.

[0044] Figure 7 shows another example of an F1AP procedure for user equal allocation based on some embodiments of the disclosed technology.

[0045] In operation 1, the gNB-CU-CP transmits an E1AP request message to the gNB-CU-UP together with the number of users to be served. Further, the E1AP request message can be one of the gNB-CU-CP configuration update message, or the bearer context setup request message.

[0046] In operation 2, the gNB-CU-UP returns a corresponding E1 Application Protocol (E1AP) response message that includes one of the gNB-CU-CP configuration update confirmation message or the bearer context setup response message.

[0047] In the case of user allocation, even if one of the multiple gNB-CU-CPs detects a failure, not all UP traffic and UE connections will be affected. For example, in a scenario where there are a total of 100 users served by the gNB-DU, 40 users are allocated to gNB-CU-CP 1, and 60 users are allocated to gNB-CU-CP 2. If gNB-CU-CP 1 detects a failure, the UP traffic and connections of the remaining 60 users can be maintained.

[0048] In the case of a dedicated CU for network slicing, if the gNB-CU does not support the selected slice, the gNB-DU triggers the UE context release request procedure with the cause value "S-NSSAI (Slice) not supported by the CU". In addition, the gNB-DU transmits an RRC container with slice information to the backup gNB-CU.

[0049] In the case of a dedicated CU for network slicing, if the gNB-CU detects a failure and cannot support the slice, the gNB-CU triggers a rerouting RRC request procedure to the backup gNB-CU.

[0050] In this way, the disclosed technology can be implemented in some embodiments to prevent failures of the gNB-CU-CP and evenly allocate users in the gNB-DU among different gNB-CU-CPs. In this case, even if one of the multiple gNB-CU-CPs detects a failure, not all of the UP traffic and UE connections will be affected. In addition, the gNB-CU-CP transmits the number of served users to the gNB-DU / gNB-CU-UP through F1AP / E1AP signaling.

[0051] FIG. 8 shows an example of a process for wireless communication according to some exemplary embodiments of the disclosed technology.

[0052] In some implementations, a process 800 for wireless communication may include step 810 where a first network element receives a signaling connection setup complete message indicating the establishment of a signaling message connection between a user equipment device and a network device associated with the user equipment device and the first network element, step 820 where the first network element determines whether a network slice corresponding to the signaling connection setup complete message is supported by a second network element, and step 830 where, if it is determined that the network slice corresponding to the signaling connection setup complete message is not supported by the second network element, the first network element transmits the signaling message and information regarding the network slice to a third network element.

[0053] Figure 9 shows another example of a process for wireless communication based on some exemplary embodiments of the disclosed technology.

[0054] In some implementations, process 900 for wireless communication may include step 910 where a second network element receives from a first network element a signaling container and a transfer message for transferring a signaling message, the signaling container including at least one of a signaling connection setup request message requesting a connection for the signaling message or a signaling connection setup complete message indicating establishment of a connection for the signaling message; step 920 where the second network element determines whether a network slice corresponding to the signaling message is supported by the second network element; and step 930 where, if it is determined that the network slice corresponding to the signaling message is not supported by the second network element, the second network element transmits the signaling message and information regarding the network slice to a third network element.

[0055] Figure 10 shows another example of a process for wireless communication based on some exemplary embodiments of the disclosed technology.

[0056] In some implementations, process 1000 for wireless communication may include step 1010 where a first network element transmits to a second network element a request message and information regarding the number of user equipment devices served by a network device associated with the first network element; step 1020 where the first network element receives a response message from the second network element; and step 1030 where, based on the information regarding the number of user equipment devices served by the network device, user equipment devices are assigned between different control planes of the second network element associated with the network device.

[0057] It will be appreciated that this document discloses techniques that may be embodied in various embodiments for determining downlink control information in a wireless network. The disclosure and other embodiments, modules, and functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware (including the structures disclosed in this document and their structural equivalents), or in combinations of one or more of them. The present disclosure and other embodiments can be implemented as one or more computer program products, i.e., as one or more modules of computer program instructions encoded on a computer-readable medium for execution by, or to control the operation of, a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter acting on a machine-readable propagated signal, or a combination of one or more of them. The term "data processing apparatus" includes, by way of example, all apparatus, devices, and machines for processing data, including programmable processors, computers, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program, e.g., code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., an electrical, optical, or electromagnetic signal generated by a machine, generated to encode information for transmission to an appropriate receiver device.

[0058] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, such as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. The program can be stored as part of a file that holds other programs or data (such as one or more scripts stored in a markup language document), a single file dedicated to the program, or multiple related files (such as files that hold one or more modules, subprograms, or portions of code). A computer program can be deployed to execute on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

[0059] The processes and logical flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logical flows can also be performed by special-purpose logic circuits, such as FPGAs (field programmable gate arrays) or ASICs (application specific integrated circuits), and the apparatus can be implemented as special-purpose logic circuits, such as FPGAs (field programmable gate arrays) or ASICs (application specific integrated circuits).

[0060] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. In general, a processor receives instructions and data from a read only memory or a random access memory or both. Essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. In general, a computer also includes one or more mass storage devices for storing data, such as, magnetic disks, magneto-optical disks, optical disks, or is operatively coupled to receive data from, transfer data to, or both, such devices. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include, by way of example, semiconductor memory devices, such as, EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuits.

[0061] Some embodiments may preferably implement one or more of the following solutions, which are listed in clause form. The following clauses are supported and further explained throughout the above embodiments and the present document. As used in the following clauses and the claims, a wireless device may be any other wireless terminal including a user equipment, a mobile station, or a fixed node such as a base station. A network device includes a base station including a next generation node B (gNB), an enhanced node B (eNB), or any other device functioning as a base station.

[0062] Clause 1: A method for wireless communication, comprising: a first network element receiving, from a user equipment device, a signaling connection setup completion message indicating establishment of a connection of a signaling message between the user equipment device and a network device associated with the first network element; the first network element determining whether a network slice corresponding to the signaling connection setup completion message is supported by a second network element; and when it is determined that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element, the first network element transmitting the signaling message and information about the network slice to a third network element.

[0063] Clause 2: The method according to clause 1, further comprising: the first network element transmitting a user equipment context release request message and a release cause value to the second network element, wherein the release cause value indicates that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element.

[0064] Clause 3: The method according to clause 1, further comprising: the first network element transmitting an initial signaling message and a signaling container to the third network element, wherein the signaling container includes at least one of a connection setup request message or the signaling connection setup completion message.

[0065] Clause 4: The method according to clause 1, wherein the second network element triggers a user equipment context release procedure to release an established user equipment context.

[0066] Clause 5: The method according to clause 1, wherein the third network element triggers a user equipment context setup procedure to establish a user equipment context.

[0067] Clause 6: A method of wireless communication, comprising: a step in which a second network element receives, from a first network element, a signaling container and a transfer message for transferring a signaling message, wherein the signaling container includes at least one of a signaling connection setup request message for requesting a connection of the signaling message or a signaling connection setup completion message indicating establishment of a connection of the signaling message; a step in which the second network element determines whether a network slice corresponding to the signaling message is supported by the second network element; and a step in which, when it is determined that the network slice corresponding to the signaling message is not supported by the second network element, the second network element transmits the signaling message and information regarding the network slice to a third network element.

[0068] Clause 7: The method according to clause 6, wherein transmission of the signaling message is a re-routing radio resource control (RRC) request procedure.

[0069] Clause 8: The method according to clause 6, wherein the third network element triggers a user equipment context setup procedure to establish a user equipment context.

[0070] Clause 9: The method according to any one of clauses 1 to 8, wherein the first network element includes a distributed unit (DU), the second network element includes a central unit (CU), and the third network element includes a backup central unit (CU).

[0071] Clause 10: The signaling includes radio resource control (RRC) signaling, the connection setup completion message is an RRC setup completion message, the connection setup request message is an RRC setup request message, and the signaling container is an RRC container, the method according to any one of Clauses 1 to 8.

[0072] Clause 11: A method for wireless communication, comprising the steps of: a first network element transmitting to a second network element a request message and information regarding the number of user equipment devices served by a network device associated with the first network element; the first network element receiving a response message from the second network element; and allocating the user equipment devices among different control planes of the second network element associated with the network device based on the information regarding the number of user equipment devices served by the network device.

[0073] Clause 12: The method according to Clause 11, wherein the first network element is a central unit (CU) of a base station and the second network element is a distributed unit (DU) of the base station.

[0074] Clause 13: The method according to Clause 12, wherein the request message includes at least one of a next-generation node B (gNB)-CU configuration update message, a user equipment (UE) context setup request message, or a backhaul adaptation protocol (BAP) mapping configuration message.

[0075] Clause 14: The method according to Clause 12, wherein the response message includes a gNB-CU configuration update confirmation message, a UE context setup response message, or a BAP mapping configuration confirmation message.

[0076] Clause 15: The method according to clause 11, wherein the first network element is a control plane (CP) of a central unit (CU) of a base station, and the second network element is a user plane (UP) of the central unit (CU) of the base station.

[0077] Clause 16: The method according to clause 15, wherein the request message includes at least one of a gNB-CU-CP configuration update message or a bearer context setup request message.

[0078] Clause 17: The method according to clause 15, wherein the response message includes a gNB-CU-CP configuration update confirmation message or a bearer context setup response message.

[0079] Clause 18: An apparatus for wireless communication, comprising a processor configured to execute the method according to any one of clauses 1 to 17.

[0080] Clause 19: A non-transitory computer-readable medium storing code, which when executed by a processor, causes the processor to implement the method according to any one of clauses 1 to 17.

[0081] Some of the embodiments described herein are described in the general context of a method or process that, in one embodiment, may be implemented by a computer program product embodied in a computer-readable medium that includes computer-executable instructions, such as program code, executed by a computer in a networked environment. The computer-readable medium may include removable and non-removable storage devices including, but not limited to, read only memory (ROM), random access memory (RAM), compact disc (CD), digital versatile disc (DVD), etc. Thus, the computer-readable medium may include non-transitory storage media. In general, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing the steps of the methods disclosed herein. A particular sequence of such executable instructions or associated data structures represents an example of corresponding acts for implementing the functions described in such steps or processes.

[0082] Some of the disclosed embodiments can be implemented as devices or modules that use hardware circuits, software, or combinations thereof. For example, a hardware circuit implementation can include, for example, individual analog and / or digital components integrated as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules can be implemented as application-specific integrated circuits (ASICs) and / or as field-programmable gate array (FPGA) devices. Some implementations can additionally or alternatively include a digital signal processor (DSP) that is a dedicated microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionality of the present application. Similarly, the various components or sub-components within each module can be implemented in software, hardware, or firmware. Connectivity between modules and / or components within a module can be provided using any one of the connection methods and media known in the art, including but not limited to communication over the Internet, wired, or wireless networks using appropriate protocols.

[0083] Although this document contains many details, these should not be construed as limiting the scope of the claimed invention or what may be claimed, but rather as descriptions of features particular to specific embodiments. Specific features described in the context of separate embodiments in this document may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately, or in any suitable sub-combination, in multiple embodiments. Further, even if features are described above as acting in a particular combination and were initially claimed as such, one or more features from the claimed combination may be deleted in some implementations, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown, or sequentially, or that all of the illustrated operations be performed, in order to achieve desirable results.

[0084] Only some implementations and examples are described, and based on what is described and illustrated in this disclosure, other implementations, enhancements, and variations can also be made.

Claims

Claim 1 A method of wireless communication, comprising: a first network element receiving a signaling connection setup completion message from a user equipment device indicating establishment of a connection of a signaling message between the user equipment device and a network device associated with the first network element; the first network element determining whether a network slice corresponding to the signaling connection setup completion message is supported by a second network element; if the first network element determines that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element, the first network element transmitting the signaling message and information about the network slice to a third network element; A method comprising the steps of. Claim 2 The method according to claim 1, further comprising: the first network element transmitting a user equipment context release request message and a release cause value to the second network element, wherein the release cause value indicates that the network slice corresponding to the signaling connection setup completion message is not supported by the second network element. Claim 3 The method according to claim 1, further comprising: the first network element transmitting an initial signaling message and a signaling container to the third network element, wherein the signaling container includes at least one of a connection setup request message or the signaling connection setup completion message. Claim 4 The method according to claim 1, wherein the second network element triggers a user equipment context release procedure to release an established user equipment context. Claim 5 The method according to claim 1, wherein the third network element triggers a user equipment context setup procedure to establish a user equipment context. Claim 6 A method of wireless communication, comprising: The step in which a second network element receives, from a first network element, a signaling container and a transfer message for transferring a signaling message, wherein the signaling container includes at least one of a signaling connection setup request message for requesting a connection of the signaling message or a signaling connection setup completion message indicating establishment of a connection of the signaling message. The step in which the second network element determines whether a network slice corresponding to the signaling message is supported by the second network element. The step in which, when it is determined that the network slice corresponding to the signaling message is not supported by the second network element, the second network element transmits the signaling message and information about the network slice to a third network element. A method comprising the above.

7. The method according to claim 6, wherein the transmission of the signaling message is a re-routing radio resource control (RRC) request procedure.

8. The method according to claim 6, wherein the third network element triggers a user equipment context setup procedure to establish a user equipment context.

9. The method according to any one of claims 1 to 8, wherein the first network element includes a distributed unit (DU), the second network element includes a central unit (CU), and the third network element includes a backup central unit (CU).

10. The method according to any one of claims 1 to 8, wherein the signaling includes radio resource control (RRC) signaling, the connection setup completion message is an RRC setup completion message, the connection setup request message is an RRC setup request message, and the signaling container is an RRC container.

11. A method of wireless communication, comprising: The step in which a first network element transmits to a second network element a request message and information about the number of user equipment devices served by a network device associated with the first network element. The step of the first network element receiving a response message from the second network element; Based on the information regarding the number of user equipment devices for which the service is provided by the network device, allocating the user equipment devices among different control planes of the second network element associated with the network device; A method comprising the above.

12. The method according to claim 11, wherein the first network element is a central unit (CU) of a base station, and the second network element is a distributed unit (DU) of the base station.

13. The method according to claim 12, wherein the request message includes at least one of a next-generation node B (gNB)-CU configuration update message, a user equipment (UE) context setup request message, or a backhaul adaptation protocol (BAP) mapping configuration message.

14. The method according to claim 12, wherein the response message includes a gNB-CU configuration update confirmation message, a UE context setup response message, or a BAP mapping configuration confirmation message.

15. The method according to claim 11, wherein the first network element is a control plane (CP) of a central unit (CU) of a base station, and the second network element is a user plane (UP) of the central unit (CU) of the base station.

16. The method according to claim 15, wherein the request message includes at least one of a gNB-CU-CP configuration update message or a bearer context setup request message.

17. The method according to claim 15, wherein the response message includes a gNB-CU-CP configuration update confirmation message or a bearer context setup response message.

18. An apparatus for wireless communication, comprising a processor configured to execute the method according to any one of claims 1 to 17.

19. A non-transitory computer-readable medium storing code, which when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 17.

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