Wireless communication methods for supporting NG-RAN node resilience

Abstract

In wireless communication, devices may establish a connection for communication to reduce interruptions caused by base station failures. Resiliency or redundancy may be improved by selection of a backup base station central unit (CU) when a first base station CU fails. Configuration information used for this selection and connection configuration may be stored and communicated via different nodes in various embodiments. In one embodiment, a wireless communication method includes transmitting, by a first network element, a request message for obtaining configuration information, and receiving, from a second network element, a response message to the request message including the configuration information.

Description

[Technical Field]

[0001] Technical Field

[0001] This specification is generally directed to wireless communications. More specifically, in a communication system for mobile devices, there may be improved signaling or architectures for reducing interruptions caused by base station failures. [Background technology]

[0002] background Wireless communication technologies are moving the world toward an increasingly connected and networked society. Wireless communication relies on efficient network resource management and allocation between user mobile stations and radio access network nodes (including, but not limited to, radio base stations). New generation networks are expected to provide high-speed, low-latency, and ultra-reliable communication capabilities and meet requirements from different industries and users. User mobile stations or user equipment (UE) are becoming more complex, and the amount of data communicated is constantly increasing. Communication improvements should be made to improve communication and meet the reliability requirements of vertical industries as well as support new generation network services. Summary of the Invention [Means for solving the problem]

[0003] overview This specification relates to methods, systems, and devices for wireless communication having improved signaling or architecture to reduce interruptions caused by base station failures. Resiliency or redundancy can be improved by selection of a backup base station central unit (CU) when a primary base station CU fails. Configuration information used for this selection and connection configuration can be stored and communicated via different nodes in various embodiments.

[0004] In one embodiment, a wireless communication method includes transmitting, by a first network element, a request message for obtaining configuration information and receiving, from a second network element, a response message to the request message including the configuration information. The first network element includes a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element includes a common storage node. The transmitting is by the backup base station CU CP or the backup base station CU to the common storage node, and the common storage node stores the configuration information. The common storage node provides the configuration information to the backup base station CU CP or the backup base station CU in a response message after receiving the request message. The configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The first network element includes the backup base station central unit (CU) control plane (CP) or the backup base station CU, and the second network element includes the first base station CU CP or the first base station CU. The sending is by the backup base station CU CP or the backup base station CU to the first base station CU CP or the first base station CU, and includes configuration information. The configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The backup base station CU CP or the backup base station CU triggers reception of a handover request for the user equipment (UE) so that the UE can switch from the first base station CU CP or the first base station CU. The receiving is by data transfer. The receiving is by XnAP signaling.

[0005] In another embodiment, a wireless communication method includes receiving configuration information related to a first network element and configuring a connection from a second network element to the first network element based on the configuration information. The first network element includes a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element includes a common storage node. The receiving includes receiving the configuration information from the common storage node, where the common storage node stores the configuration information. The configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The first network element includes the backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element includes the first base station CU CP or a first base station CU. The connection is with a user equipment (UE) device initially with the first base station CU CP or the first base station CU, and then with the backup base station CU CP or the backup base station CU. The configuring includes moving the connection to the backup base station CU CP or the backup base station CU. The configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. Receiving is by data forwarding. Receiving is by XnAP signaling.

[0006] In another embodiment, a wireless communication method includes triggering a backup procedure and transmitting configuration information for switching as part of the backup procedure. The triggering is for a connection by a first base station central unit (CU) to a backup base station CU. The method includes detecting a failure and selecting a backup base station CU for switching from the first base station CU. The configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information.

[0007] In another embodiment, a system includes a backup base station central unit (CU) for providing a backup wireless connection and a storage node configured to store configuration information for the wireless connection. The system includes a base station distribution unit (DU), a first base station CU, and a user equipment (UE) configured to hand over a wireless connection with the first base station CU via the base station DU for a wireless connection with the backup base station CU based on the configuration information. The storage node provides the configuration information to the backup base station CU as part of a response message after receiving a request message. The configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The wireless connection with the first base station CU is replaced with a connection with the backup base station CU when a failure is detected in the first base station CU. An availability indicator identifies when the configuration information was stored in the storage node.

[0008] In one embodiment, a wireless communications device comprises a processor and a memory, the processor configured to read code from the memory and implement any of the embodiments described above.

[0009] In one embodiment, a computer program product includes computer readable program medium code stored thereon, the code, when executed by a processor, causing the processor to implement any of the embodiments described above.

[0010] In some embodiments, there is a wireless communication device comprising a processor and a memory, the processor configured to read code from the memory and perform any method described in any of the embodiments. In some embodiments, a computer program product comprises a computer readable program medium code stored thereon, the code, when executed by a processor, causing the processor to perform any method described in any of the embodiments. These and other aspects and their implementations are described in more detail in the drawings, this specification, and the claims. The present invention provides, for example, the following items. (Item 1) 1. A wireless communication method, comprising: sending, by a first network element, a request message to obtain configuration information; receiving a response message to the request message from a second network element, the response message including the configuration information; A method comprising: (Item 2) Item 10. The method of claim 1, wherein the first network element comprises a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element comprises a common storage node. (Item 3) 3. The method according to item 2, wherein the transmitting is by the backup base station CU CP or the backup base station CU to the common storage node, and the common storage node stores the configuration information. (Item 4) Item 4. The method according to item 3, wherein the common storage node provides the configuration information to the backup base station CU CP or the backup base station CU in the response message after receiving the request message. (Item 5) Item 5. The method of item 4, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 6) The method according to item 1, wherein the first network element comprises a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element comprises a first base station CU CP or a first base station CU. (Item 7) 7. The method according to item 6, wherein the transmitting is by the backup base station CU CP or the backup base station CU to the first base station CU CP or the first base station CU, and includes the configuration information. (Item 8) Item 8. The method of item 7, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 9) Item 8. The method according to item 7, wherein the backup base station CU CP or the backup base station CU triggers the reception of a handover request for a user equipment (UE) so that the UE can switch from the first base station CU CP or the first base station CU. (Item 10) 7. The method according to claim 6, wherein the receiving is by data transfer. (Item 11) Item 7. The method according to item 6, wherein the receiving is via XnAP signaling. (Item 12) 1. A wireless communication method, comprising: receiving configuration information regarding a first network element; configuring a connection from a second network element to the first network element based on the configuration information; A method comprising: (Item 13) Item 13. The method of item 12, wherein the first network element comprises a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element comprises a common storage node. (Item 14) Item 14. The method of item 13, wherein the receiving includes receiving configuration information from the common storage node, the common storage node storing the configuration information. (Item 15) Item 15. The method of item 14, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 16) Item 13. The method of item 12, wherein the first network element comprises a backup base station central unit (CU) control plane (CP) or a backup base station CU, and the second network element comprises a first base station CU CP or a first base station CU. (Item 17) Item 17. The method according to item 16, wherein the connection is with a user equipment (UE) device that is initially with the first base station CU CP or the first base station CU, and then with the backup base station CU CP or the backup base station CU. (Item 18) 18. The method according to claim 17, wherein the configuring includes moving the connection to the backup base station CU CP or the backup base station CU. (Item 19) Item 19. The method of item 18, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 20) Item 17. The method of item 16, wherein the receiving is by data transfer. (Item 21) Item 17. The method according to item 16, wherein the receiving is via XnAP signaling. (Item 22) 1. A wireless communication method, comprising: Triggering a backup procedure; As part of the backup procedure, sending configuration information for reselection is required. A method comprising: (Item 23) 23. The method according to item 22, wherein the triggering is for a connection by a first base station central unit (CU) to a backup base station CU. (Item 24) Detecting the fault; selecting a backup base station CU for the switching from the first base station CU; 24. The method of claim 23, further comprising: (Item 25) 23. The method of claim 22, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 26) 26. A wireless communication device comprising a processor and a memory, the processor configured to read code from the memory and to perform the method described in any one of items 1 to 25. (Item 27) 26. A computer program product comprising a computer-readable program medium code stored thereon, said code, when executed by a processor, causing said processor to perform a method according to any one of items 1 to 25. (Item 28) a backup base station central unit (CU) for providing backup wireless connectivity; a storage node configured to store configuration information for the wireless connection; A system comprising: (Item 29) a base station distributed unit (DU); a first base station CU; and a user equipment (UE) configured to hand over the wireless connection with the first base station CU via the base station DU for a wireless connection with the backup base station CU based on the configuration information; Item 29. The system of item 28, further comprising: (Item 30) 30. The system of claim 29, wherein the storage node provides the configuration information to the backup base station CU as part of a response message after receiving a request message. (Item 31) 30. The system of claim 29, wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. (Item 32) 30. The system of claim 29, wherein the wireless connection with the first base station CU is replaced with a connection with the backup base station CU when a failure is detected in the first base station CU. (Item 33) 30. The system of claim 29, wherein an availability indicator identifies when the configuration information was stored on the storage node. [Brief explanation of the drawings]

[0011] [Figure 1] 1 illustrates an example of an exemplary base station.

[0012] [Figure 2] 1 illustrates an example of a random access (RA) messaging environment.

[0013] [Figure 3] 1 shows the network architecture of a base station central unit (CU) and a base station distributed unit (DU).

[0014] [Figure 4] 1 shows a network architecture with several base station central units (CUs) and base station distributed units (DUs).

[0015] [Figure 5] 1 illustrates one embodiment of intra-DU mobility for user equipment (UE).

[0016] [Figure 6] 1 illustrates one embodiment of intra-CU and inter-DU mobility of user equipment (UE).

[0017] [Figure 7] 1 illustrates one embodiment of inter-CU mobility for user equipment (UE).

[0018] [Figure 8a] 1 illustrates an embodiment of a network architecture having storage nodes.

[0019] [Figure 8b] 1 illustrates another embodiment of a network architecture having storage nodes.

[0020] [Figure 9] 1 illustrates one embodiment of a context acquisition procedure using a common storage node.

[0021] [Figure 10] 10 illustrates another embodiment of a context acquisition procedure using a common storage node.

[0022] [Figure 11] 1 illustrates an embodiment of a context acquisition procedure using data transfer.

[0023] [Figure 12] 1 illustrates an embodiment of a context acquisition procedure using Xn signaling.

[0024] [Figure 13] 1 illustrates one embodiment of a context backup procedure. DETAILED DESCRIPTION OF THE INVENTION

[0025] Detailed Description The present disclosure will now be described in detail hereinafter with reference to the accompanying drawings, which form a part hereof and which show, by way of illustration, specific embodiments. It should be noted, however, that the present disclosure may be embodied in a variety of different forms, and therefore, the subject matter as directed or claimed should not be construed as limited to any of the embodiments set forth below.

[0026] Throughout this specification and claims, terms may have subtly different meanings suggested or implied in context beyond their explicitly stated meaning. Similarly, the phrases "in one embodiment" or "in some embodiments" used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" used herein do not necessarily refer to different embodiments. The phrases "in one implementation" or "in some implementations" used herein do not necessarily refer to the same implementation, and the phrases "in another implementation" or "in other implementations" used herein do not necessarily refer to different implementations. For example, the claimed subject matter is intended to include, in whole or in part, example embodiments or combinations of implementations.

[0027] In general, terms may be understood, at least in part, from their usage in context. For example, terms such as "and," "or," and "and / or," as used herein, may include a variety of meanings that may depend, at least in part, on the context in which such terms are used. Typically, "or," when used to relate a list such as A, B, or C, is intended to mean A, B, and C, which in this case is used in an inclusive sense, as well as A, B, or C, which in this case is used in an exclusive sense. Furthermore, as used herein, the terms "one or more" or "at least one" may be used in a singular sense to describe any feature, structure, or characteristic, or may be used in a plural sense to describe a combination of features, structures, or characteristics, depending, at least in part, on the context. Similarly, terms such as "a," "an," and "the" may also be understood to convey singular or plural usage, depending, at least in part, on the context. Furthermore, the terms "based on" or "determined by" may be understood as not necessarily intended to convey an exclusive set of factors, but instead may allow for the existence of additional factors not necessarily explicitly described, again depending, at least in part, on the context.

[0028] Radio Resource Control ("RRC") is a protocol layer between a UE and a base station at the IP level (network layer). Various Radio Resource Control (RRC) states may exist, such as the RRC_CONNECTED state, the RRC_INACTIVE state, and the RRC_IDLE state. RRC messages are carried via the Packet Data Convergence Protocol ("PDCP"). As described, a UE can transmit data via a Random Access Channel ("RACH") protocol or a Configuration Grant ("CG") scheme. CG may be used to reduce waste of periodically allocated resources by allowing multiple devices to share the periodic resources. A base station or node may allocate CG resources to eliminate packet transmission delays and increase utilization of allocated periodic radio resources. The CG scheme is only one example of a protocol scheme for communication; other examples are possible, including but not limited to RACH. Wireless communication described herein may be via radio access.

[0029] A user equipment ("UE") device may move between nodes or cells, where a changeover, switchover, handover, or modification / add operation may be performed to improve network reliability for the UE as it moves. The movement may be from a source cell to a target cell based on several potential target cells, called candidates. A cell-to-cell movement may include several target cells that are potential candidate cells. A handover may include a conditional handover ("CHO") or a conditional PSCell addition / modification ("CPAC").

[0030] As described below with respect to Figures 1-8, a network provider may include several network nodes (i.e., base stations) for providing network access to user equipment (UE) devices. The network nodes are referred to as base stations in some embodiments. Figures 5-7 illustrate cell mobility, in which a UE device moves between cells. Control signaling may be used to facilitate this mobility. Figures 3-8 illustrate a central unit (CU) separated from distributed units (DUs). Figure 3 shows a network architecture of a base station CU and a base station DU.

[0031] The Next Generation Application Protocol (NGAP) provides control plane (CP) signaling between the Next Generation Random Access Node (NG-RAN) or base station and the Access Mobility Management Function (AMF). Services provided by NGAP can be divided into UE-associated and non-UE-associated. In the fifth generation (5G) core, establishing a bearer can also be called a protocol data unit (PDU) session. A bearer can be an information transmission path (with defined capacity, delay, and bit error rate) or a tunnel used to connect a user equipment (UE) to a packet data network (PDN) such as the Internet. Bearer capabilities include the transmission functions that a UE requests from the network. A bearer service can be a type of telecommunications service that provides the ability to transmit signals between access points.

[0032] As described below, Figure 4 illustrates the separation of the control plane (CP) and the user plane (UP). In one embodiment, the resilience or redundancy of a base station CU control plane CP (such as a gNB-CU-CP) is to find another base station CU CP for backup. The backup base station CU-CP can be selected from a set of base stations CU-CP. The selection of the backup can be to avoid a failure or in the case of a failure. To avoid interruption of user plane UP traffic and disconnection of the UE, the base station CU-CP should indicate to the base station DU or base station CU-UP that it is unavailable.

[0033] The selection or reselection may include configuration information. Exemplary configuration information includes user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. The embodiments described below include different scenarios for obtaining the configuration information.

[0034] FIG. 1 illustrates an exemplary base station 102. A base station may also be referred to as a radio network node and may be a network node (such as a master node (“MN”), secondary node (“SN”), and source / target node) illustrated in FIGS. 3A-7B. The base station 102 may be further identified as a Node B (NB, e.g., eNB, gNB, xNB, etc.) in a mobile communication context. An exemplary base station may include wireless Tx / Rx circuitry 113 for receiving and transmitting to and from a user equipment (UE) 104. The base station may include network interface circuitry 116, e.g., optical or wired interconnection, Ethernet, and / or other data transmission medium / protocol, for coupling the base station to a core network 110.

[0035] The base station may also include system circuitry 122. The system circuitry 122 may include one or more processors 124 and / or memory 126. The memory 126 may include operations 128 and control parameters 130. The operations 128 may include instructions for execution by one or more of the processors 124 to support the functionality of the base station. For example, the operations may process random access transmission requests from multiple UEs. The control parameters 130 may include parameters or support the execution of the operations 128. For example, the control parameters may include network protocol settings, random access messaging formatting rules, bandwidth parameters, radio frequency mapping assignments, and / or other parameters.

[0036] 2 illustrates an exemplary random access messaging environment 200. In the random access messaging environment, a UE 104 may communicate with a base station 102 via a random access channel 252. In this example, the UE 104 supports one or more subscriber identity modules (SIMs), such as SIM1 202. An electrical and physical interface 206 connects SIM1 202 to the rest of the user equipment hardware, for example, via a system bus 210.

[0037] The mobile device 200 includes a communications interface 212, system logic 214, and a user interface 218. The system logic 214 may include any combination of hardware, software, firmware, or other logic. The system logic 214 may be implemented using, for example, one or more systems on a chip (SoC), application-specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuits. The system logic 214 is part of the implementation of any desired functionality in the UE 104. In this regard, the system logic 214 may include, by way of example, logic to facilitate music and video decoding and playback, e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback, application execution, acceptance of user input, storage and retrieval of application data, establishment, maintenance, and termination of data connections for cellular phone calls or Internet connections, for example, establishment, maintenance, and termination of wireless network connections, Bluetooth connections, or other connections, and display of related information on the user interface 218. The user interface 218 and input 228 may include a graphical user interface, a touch-sensitive display, haptic feedback or other tactile output, voice or facial recognition input, buttons, switches, speakers, and other user interface elements. Further examples of input 228 include microphones, video and still image cameras, temperature sensors, vibration sensors, rotational and orientation sensors, headset and microphone input / output jacks, universal serial bus (USB) connectors, memory card slots, radiation sensors (such as IR sensors), and other types of input.

[0038] The system logic 214 may include one or more processors 216 and memory 220. The memory 220 stores, for example, control instructions 222 that the processor 216 executes to perform desired functions of the UE 104. Control parameters 224 provide and specify configuration and operational options for the control instructions 222. The memory 220 may also store BT, WiFi, 3G, 4G, 5G, or other data 226 that the UE 104 transmits or receives via the communication interface 212. In various implementations, system power may be provided by a power storage device, such as a battery 282.

[0039] In the communications interface 212, radio frequency (RF) transmit (Tx) and receive (Rx) circuitry 230 handles the transmission and reception of signals via one or more antennas 232. The communications interface 212 may include one or more transceivers, which may be wireless transceivers that include modulation / demodulation circuitry, digital-to-analog converters (DACs), shaping tables, analog-to-digital converters (ADCs), filters, waveform shapers, filters, preamplifiers, power amplifiers, and / or other logic for transmitting and receiving via one or more antennas or (for some devices) via a physical (e.g., wired) medium.

[0040] Transmitted and received signals may conform to any of a wide variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, 256-QAM), frequency channels, bit rates, and encodings. As one specific example, communication interface 212 may include a transceiver supporting transmission and reception in 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High-Speed ​​Packet Access (HSPA)+, and 4G / Long Term Evolution (LTE) standards. However, the techniques described below are applicable to other wireless communication technologies, whether they originate from the 3rd Generation Partnership Project (3GPP), GSM Association, 3GPP2, IEEE, or other partnerships or standards bodies.

[0041] Multiple RAN nodes (eNBs, gNBs, etc.) of the same or different radio access technologies ("RATs") can be deployed in a particular geographic region on the same or different frequency carriers, and these RAN nodes can interoperate via dual connectivity operations to provide joint communication services to the same (one or more) target UEs. A multi-RAT dual connectivity ("MR-DC") architecture may have a non-co-located master node ("MN") and secondary node (SN). The access mobility management function ("AMF") and session management function ("SMF") may be control plane entities, and the user plane function ("UPF") is the user plane entity in New Radio ("NR") or 5GC. The signaling connection between the AMF / SMF and the master node ("MN") may be a next-generation control plane ("NG-C") / MN interface. The signaling connection between the MN and SN may be an Xn-control plane ("Xn-C") interface. The signaling connection between the MN and the UE is the Uu-Control Plane ("Uu-C") RRC interface. All these connections manage the configuration and operation of the MR-DC. The user plane connection between the User Plane Function ("UPF") and the MN may be an instance of the NG-U(MN) interface.

[0042] Figure 3 shows a network architecture of base station central units (CUs) and base station distributed units (DUs). Figure 3 illustrates a base station (labeled gNB) communicating with an overall network (labeled "5GC"). The base stations can communicate with each other via a control plane interface ("Xn-C"). One base station is shown as having one CU connected to two DUs via an F1 interface. This is only one example of a base station arrangement. In some embodiments, there may be one or any number of DUs connected to a single CU.

[0043] A base station can be divided into two physical entities named a central unit ("CU") and a distributed unit ("DU"). In general, the CU may provide support for the upper layers of the protocol stack, such as SDAP, PDCP, and RRC, while the DU may provide support for the lower layers of the protocol stack, such as RLC, MAC, and the physical layer. The CU may include operations for user data transfer, mobility control, radio access network sharing, session management, etc., except for functions exclusively allocated to the DU. The DU(s) are logical node(s) having a subset of base station functions and may be controlled by the CU.

[0044] A CU may be a logical node that hosts the RRC, SDAP, and PDCP protocols of a base station, or the RRC and PDCP protocols of a base station that controls the operation of one or more DUs. A DU may be a logical node that hosts the RLC, MAC, and PHY layers of a base station, and its operation may be at least partially controlled by a CU. A single DU may support one or more cells. However, each cell is supported by only a single DU. Each base station may support multiple cells. As described in the embodiments herein, cell mobility between cells may be from different CUs or DUs, or may be internal to a CU and / or DU.

[0045] The inter-cell mobility described herein can occur in many different examples. Intra-DU mobility can occur, where a UE changes cells within a single DU. In another mobility embodiment, intra-CU and inter-DU mobility can occur, where a UE changes cells between different DUs but within a single CU. In another mobility embodiment, inter-CU mobility can occur, where a UE changes cells between different CUs.

[0046] FIG. 4 illustrates a network architecture with several base station central units (CUs) and base station distributed units (DUs). In one embodiment, an architecture for separating the base station CU-CP and the base station CU-UP is shown in FIG. 4. This may be used in the event of a failure of the base station CU. In some embodiments, the base station may include a base station CU-CP, several base stations CU-UP, and several base stations DU. The base station CU-CP may be connected to the base station DU via an F1-C interface. In some embodiments, the base station CU-UP may be connected to the base station DU via an F1-U interface. In some embodiments, the base station CU-UP may be connected to the base station CU-CP via an E1 interface. In some embodiments, one base station DU may be connected to only one base station CU-CP. In some embodiments, one base station CU-UP is connected to only one base station CU-CP. For resilience, the base station DU and / or the base station CU-UP may be connected to multiple base stations CU-CP. In some embodiments, the backup, which may be referred to as the new base station CU-CP, may be located away from the original / initial / first base station CU-CP.

[0047] FIG. 5 illustrates one embodiment of intra-DU mobility for user equipment (UE). A base station may include a CU and at least one DU. In this embodiment, a single DU with multiple cells is shown. Both cell 1 and cell 2 are from a single DU. In this example, UE 502 can move from cell 1 to cell 2, as illustrated in FIG. 4 with the UE's trajectory from cell 1 to cell 2. Mobility from cell 402 can occur when UE 402 is in a position between two cells and proceeds to a third position within cell 2. This is intra-DU mobility because the UE is moving between cells within a single DU.

[0048] FIG. 6 illustrates one embodiment of intra-CU and inter-DU mobility for user equipment (UE). In this embodiment, a base station may include a CU and two DUs (DU_1 and DU_2). While each DU may have multiple cells, in this example, each DU is shown serving a single cell, with DU_1 serving cell 1 and DU_2 serving cell 2. In this example, a UE 602 may move from cell 1 to cell 2, and FIG. 6 illustrates the UE's trajectory from cell 1 to cell 2, which also results in a transition from DU_1 to DU_2. Mobility from a cell may occur when the UE 502 is located between two cells and proceeds to a third location within cell 2. This is intra-CU mobility because the UE is moving between cells within a single CU. However, this is also inter-DU mobility because the UE is moving between different DUs.

[0049] FIG. 7 illustrates one embodiment of inter-CU mobility for a user equipment (UE). In this embodiment, a base station may include multiple CUs (CU_1 and CU_2). Each CU may include multiple DUs, but in this example, each CU is shown as having one corresponding DU (CU_1 has DU_1, and CU_2 has DU_2). Each DU is shown with multiple cells. In this example, the UE trajectory of UE 702 goes from Cell_2 to Cell_3, through inter-CU location 704 (between CU_1 and CU_2), Cell_5, and Cell_6. As the UE moves, mobility may change cells and transition between several cells as shown. Because UE 702 switches cells from CU_1 to CU_2 (at inter-CU location 704), this transition is referred to as inter-CU mobility.

[0050] FIG. 8a illustrates one embodiment of a network architecture having a storage node. FIG. 8b illustrates another embodiment of a network architecture having a storage node. FIG. 8a illustrates a common storage node coupled with a backup base station CU. In other embodiments, it may also be coupled with a base station CU and / or a UE. FIG. 8b illustrates a common storage node as part of either the backup base station CU and / or the base station CU. In some embodiments, the common storage nodes may be connected such that they are common to the UE. Although not shown, the UE may communicate with the base station CU and / or the backup base station CU via one or more base station DUs, which are not shown for simplicity.

[0051] The embodiment shown in Figures 8a-8b illustrates a common storage node. The common storage node may store configuration information, which may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. Information (such as configuration information) is stored in this storage node and can be retrieved by various nodes in the network, such as a backup base station CU-CP. The backup base station CU-CP may trigger an F1AP UE context setup procedure and an E1AP bearer context setup procedure, as shown in Figures 9-10.

[0052] FIG. 9 illustrates one embodiment of a context acquisition procedure using a common storage node. FIG. 9 illustrates an exemplary process using the common storage node discussed with respect to FIGS. 8a-8b. In block 902, the base station CU-CP detects a failure and selects a backup base station CU-CP from the set of candidate base stations CU-CP. In block 904, the base station CU-CP sends a bearer context modification request message to the base station CU-UP with a base station CU-CP unavailability indicator. In block 906, the base station CU-CP sends a UE context modification request message to the base station DU with a base station CU unavailability indicator. In block 908, the base station CU-CP sends a handover request message to the backup base station CU-CP to indicate a change of base station CU-CP. In block 910, the base station CU-UP responds with a bearer context modification response message. In block 912, the base station DU responds with a UE context modification response message. In block 914, the backup base station CU-CP responds with a handover request acknowledgement message.

[0053] The backup base station CU-CP sends a UE context acquisition request message to the common storage node in block 916. This message may include a base station CU-CP identification (ID). The base station CU-CP ID may include at least one of a base station CU-CP UE E1AP ID or a base station DU UE F1AP ID. In block 918, the common storage node sends a UE context acquisition response message along with configuration information. As described above, the configuration information may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. In some embodiments, the IAB routing information may include at least one of an IAB TNL address, a BAP routing ID, a BAP path ID, a BAP address, or a backhaul RLC channel ID. As discussed with respect to FIGS. 8a-8b, the common storage node may be a node in the network that stores the configuration information. The backup base station CU-CP triggers a bearer context setup procedure with the base station CU-UP in block 920. In block 922, the backup base station CU-CP triggers a UE context setup procedure with the base station DU.

[0054] FIG. 10 illustrates another embodiment of the context acquisition procedure using a common storage node. In this embodiment, the UE context acquisition procedure using the common storage node of FIGS. 8a and 8b is performed, but this may be a process for when a disaster-detected failure occurs and the base station CU-CP is unable to transmit information. In this embodiment, the backup base station CU-CP receives configuration information directly from the common node, rather than from the base station CU-CP. In other words, reselection is triggered differently in FIG. 10 than in FIG. 9. In block 1002, the base station CU-CP detects a disaster failure. Examples of disaster failures include natural disasters such as earthquakes, tsunamis, and hurricanes. In the disaster example, if the backup base station CU-CP is selected, the base station CU-CP cannot transmit messages to the base stations DU and CU-UP. In this embodiment, the base stations CU-UP and DU can detect the failure of the base station CU-CP by monitoring a decrease in throughput and data traffic on E1 and F1, respectively.

[0055] In block 1004, the backup base station CU-CP sends a UE context get request message with the base station CU-CP identification (ID). The base station CU-CP ID includes at least one of the base station CU-CP UE E1AP ID or the base station DU UE F1AP ID. In block 1006, the common storage node sends a UE context get response message with the configuration information. As described above, the configuration information may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. In some embodiments, the IAB routing information may include at least one of an IAB TNL address, a BAP routing ID, a BAP path ID, a BAP address, or a backhaul RLC channel ID. As discussed with respect to FIGS. 8a-8b, the common storage node may be a node in the network that stores the configuration information. The backup base station CU-CP triggers a bearer context setup procedure with the base station CU-UP in block 1008. In block 1010, the backup base station CU-CP triggers a UE context setup procedure with the base station DU.

[0056] 11 illustrates an embodiment of a context acquisition procedure using data transfer. In this embodiment, there is no common storage node in the NG-RAN for storing configuration information. In this embodiment, the backup base station CU-CP acquires the configuration information from the base station CU-CP via the Xn interface by data transfer. After receiving the configuration information, the backup base station CU-CP may trigger an F1AP UE context setup procedure and an E1AP bearer context setup procedure.

[0057] In block 1102, the base station CU-CP detects the failure and selects a backup base station CU-CP from the set of candidate base stations CU-CP. In block 1104, the base station CU-CP sends a bearer context modification request message to the base station CU-UP with a base station CU-CP unavailable indicator. In block 1106, the base station CU-CP sends a UE context modification request message to the base station DU with a base station CU unavailable indicator. In block 1108, the base station CU-CP sends a handover request message to the backup base station CU-CP to instruct the change of base station CU-CP. In block 1110, the base station CU-UP responds with a bearer context modification response message. In block 1112, the base station DU responds with a UE context modification response message. In block 1114, the backup base station CU-CP responds with a handover request acknowledgement message.

[0058] The configuration information may be communicated using data transfer in block 1116. The backup base station CU-CP receives the configuration information by initiating data transfer from the base station CU-CP to the backup base station CU-CP. As described above, the configuration information may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. In some embodiments, the IAB routing information may include at least one of an IAB TNL address, a BAP routing ID, a BAP path ID, a BAP address, or a backhaul RLC channel ID. The data transfer may be performed using a UP tunnel between the base stations. The backup base station CU-CP triggers a bearer context setup procedure with the base station CU-UP in block 1118. In block 1120, the backup base station CU-CP triggers a UE context setup procedure with the base station DU.

[0059] 12 illustrates an embodiment of a context acquisition procedure using Xn signaling. In this embodiment, there is no common storage node in the NG-RAN for storing configuration information. In this embodiment, the backup base station CU-CP acquires the configuration information from the base station CU-CP via XnAP signaling. After receiving the configuration information, the backup base station CU-CP may trigger an F1AP UE context setup procedure and an E1AP bearer context setup procedure.

[0060] In block 1202, the base station CU-CP detects a failure and selects a backup base station CU-CP from the set of candidate base stations CU-CP. In block 1204, the base station CU-CP sends a bearer context modification request message to the base station CU-UP with a base station CU-CP unavailable indicator. In block 1206, the base station CU-CP sends a UE context modification request message to the base station DU with a base station CU unavailable indicator. In block 1208, the base station CU-CP sends a backup base station CU-CP handover request message to indicate a change of base station CU-CP. In block 1210, the base station CU-UP responds with a bearer context modification response message. In block 1214, the base station DU responds with a UE context modification response message. In block 1216, the backup base station CU-CP responds with a handover request acknowledgement message.

[0061] The configuration information may be communicated in block 1216 using a UE context acquisition request, which is responded to with a UE context acquisition response in block 1218. The backup base station CU-CP sends a UE context acquisition request message to the base station CU-CP in block 1216 to obtain the configuration information. As described above, the configuration information may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. In some embodiments, the IAB routing information may include at least one of an IAB TNL address, a BAP routing ID, a BAP path ID, a BAP address, or a backhaul RLC channel ID. The backup base station CU-CP obtains the configuration information in the UE context acquisition response from the base station CU-CP to the backup base station CU-CP in block 1218. The backup base station CU-CP triggers a bearer context setup procedure with the base station CU-UP in block 1220. In block 1222, the backup base station CU-CP triggers a UE context setup procedure with the base station DU.

[0062] Figure 13 shows an embodiment of the context backup procedure. The base station CU-CP may store configuration information in the backup base station CU-UP in advance. If the base station CU-CP detects a failure, the backup base station CU-UP can directly trigger the F1AP UE context setup procedure and the E1AP bearer context setup procedure. In other words, it may send the configuration information before detecting a failure, rather than in response to the failure.

[0063] In block 1302, the base station CU-CP triggers a UE context backup procedure with the backup base station CU-CP and sends configuration information to the backup base station CU-CP via Xn signaling. As described above, the configuration information may include user equipment (UE) context, bearer context, transport network layer (TNL) association, or integrated access backhaul (IAB) routing information. The configuration information may be used by the base station CU-CP to trigger a bearer context setup procedure or a UE context setup procedure. In some embodiments, the IAB routing information may include at least one of an IAB TNL address, a BAP routing ID, a BAP path ID, a BAP address, or a backhaul RLC channel ID.

[0064] The UE context backup procedure may be a class 1 procedure or a class 2 procedure. For a class 1 procedure, the base station CU-CP sends a UE context backup request message to the backup base station CU-CP along with at least one of the UE context, bearer context, TNL association, or IAB routing information. The backup base station CU-CP may send a UE context backup response message. In another embodiment for a class 2 procedure, the base station CU-CP sends a UE context backup indication message to the backup base station CU-CP along with at least one of the UE context, bearer context, TNL association, or IAB routing information. In addition to XnAP signaling, the UE context backup procedure may be processed in a user plane (UP) procedure, such as a data transfer procedure.

[0065] In block 1304, the base station CU-CP detects a disaster failure and selects a backup base station CU-CP from the set of candidate base stations CU-CP. Examples of disaster failures may include natural disasters such as earthquakes, tsunamis, and hurricanes. In the disaster example, if the backup base station CU-CP is selected, the base station CU-CP cannot send messages to the base stations DU and CU-UP. In this embodiment, the base stations CU-UP and DU can detect the failure of the base station CU-CP by monitoring a decrease in throughput and data traffic on E1 and F1, respectively. The backup base station CU-CP triggers a bearer context setup procedure with the base station CU-UP in block 1306. In block 1308, the backup base station CU-CP triggers a UE context setup procedure with the base station DU.

[0066] The above-described systems and processes may be encoded in a computer-readable medium, such as a signal-bearing medium or memory, or may be programmed into a device, such as one or more integrated circuits or one or more processors, or may be processed by a controller or computer. The data may be analyzed in a computer system and used to generate a spectrum. If the method is performed by software, the software may reside in a non-volatile or volatile memory in communication with or interfaced to a storage device, synchronizer, communication interface, or transmitter. The circuit or electronic device is designed to transmit the data to another location. The memory may contain an ordered list of executable instructions for implementing logical functions. The described logical functions or any system elements may be implemented via optical circuitry, digital circuitry, source code, analog circuitry, analog sources such as analog electrical signals, audio signals, video signals, or any combination thereof. The software may be embodied in any computer-readable or signal-bearing medium for use by or in connection with an instruction-executable system, apparatus, or device. Such a system may include a computer-based system, a system including a processor, or another system that may selectively fetch instructions from an instruction-executable system, apparatus, or device that may also execute the instructions.

[0067] "Computer-readable medium," "machine-readable medium," "propagating signal" medium, and / or "signal-bearing medium" may include any device that contains, stores, communicates, propagates, or carries software for use by or in connection with an instruction-executable system, apparatus, or device. Machine-readable media may optionally be, but are not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. A non-exhaustive list of examples of machine-readable media includes an electrical connection "electronic" having one or more wires, a portable magnetic or optical disk, a volatile memory such as random access memory "RAM," a read-only memory "ROM," an erasable programmable read-only memory (EPROM or flash memory), or an optical fiber. Machine-readable media may also include tangible media on which software is printed, when the software is stored electronically as an image or in another format (e.g., via optical scanning) and can then be compiled and / or interpreted or otherwise processed. The processed media may then be stored in computer and / or machine memory.

[0068] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of various embodiments. These illustrations are not intended to serve as a complete description of all elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments will be apparent to those skilled in the art upon reviewing the present disclosure. Other embodiments may be utilized and derived from the present disclosure, and thus structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Furthermore, the illustrations are merely representational and may not be drawn to scale. Certain parts within the illustrations may be exaggerated, while other parts may be minimized. Accordingly, the present disclosure and the drawings should be considered illustrative and not limiting.

[0069] One or more embodiments of the present disclosure may be individually and / or collectively referred to herein by the term "invention," merely for convenience and without any intention to intentionally limit the scope of the present application to any particular invention or inventive concept. Furthermore, although specific embodiments have been illustrated and described herein, it should be understood that any subsequent device designed to achieve the same or similar purpose may be substituted for the specific embodiment shown. The present disclosure is intended to cover any and all subsequent adaptations or modifications of the various embodiments. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reviewing the description.

[0070] The phrase "coupled with" is defined to mean directly connected or indirectly connected through one or more intermediate components. Such intermediate components may include both hardware-based and software-based components. Changes in the arrangement and type of components may be made without departing from the spirit or scope of the claims set forth herein. Additional, different, or fewer components may be provided.

[0071] The subject matter disclosed above should be considered illustrative rather than limiting, and the appended claims are intended to cover all such modifications, extensions, and other embodiments that fall within the true spirit and scope of the present invention. Accordingly, to the maximum extent permitted by law, the scope of the present invention should be determined by the broadest permissible interpretation of the following claims and their equivalents, and not be limited or constrained by the foregoing detailed description. While various embodiments of the present invention have been described, it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the present invention. Accordingly, the present invention should not be limited except in light of the appended claims and their equivalents.

Claims

1. 1. A method of wireless communication, comprising: A backup base station CU CP of a current base station central unit (CU) control plane (CP), or a backup base station CU of the current base station CU, or a backup base station CU CP of the current base station CU, sends a request message to a common storage node to obtain configuration information, such that the request message is triggered by a handover request from the current base station CU CP or the current base station CU, or is directly triggered by detecting a failure of the current base station CU CP or the current base station CU; The backup base station CU CP or the backup base station CU receives a response message to the request message from the common storage node, and the response message includes the configuration information stored in the common storage node; A method comprising:

2. The method of claim 1 , wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information.

3. The method of claim 2 , wherein the common storage node comprises the current base station CU CP or the current base station CU.

4. The method of claim 3 , wherein the backup base station CU CP or the backup base station CU receives the handover request for a UE, and the UE switches from the current base station CU CP or the current base station CU.

5. The method of claim 3 , wherein the receiving is by data transfer or XnAP signaling.

6. 1. A method of wireless communication, comprising: A backup base station CUCP of a current base station central unit (CU) control plane (CP), or a backup base station CU of the current base station CU, or a backup base station CU CP of the current base station CU receives configuration information about the backup base station CUCP or the backup base station CU from a common storage node; configuring a connection from the common storage node to the backup base station CU CP or the backup base station CU based on the configuration information stored in the common storage node and triggered by a handover request from the current base station CU CP or the current base station CU, or triggered directly by detection of a failure of the current base station CU CP or the current base station CU; A method comprising:

7. The method of claim 6 , wherein the configuration information includes a user equipment (UE) context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information.

8. The method of claim 7 , wherein the common storage node comprises the current base station CU CP or the current base station CU.

9. The method according to claim 8, wherein the connection is from a UE device, and the UE device is initially to the current base station CU CP or the current base station CU, and is switched to the backup base station CU CP or the backup base station CU.

10. The method of claim 9, wherein the configuring includes moving the connection to the backup base station CU CP or the backup base station CU.

11. The method of claim 8 , wherein the receiving is by data transfer or XnAP signaling.

12. The method comprising: Triggering a backup procedure; transmitting backup base station reselection information as part of the backup procedure; The method of claim 3 further comprising:

13. The method according to claim 12, wherein the triggering of the backup procedure is for the current base station CU to connect to the backup base station CU CP or the backup base station CU.

14. The method comprising: The current base station CU CP or the current base station CU detects the failure; The current base station CU CP or the current base station CU selects the backup base station CU CP or the backup base station CU for switching from the current base station CU CP or the current base station CU; 14. The method of claim 13, further comprising:

15. A system, comprising: a backup base station central unit (CU) for providing a backup radio connection to the current base station CU; a common storage node configured to store configuration information for the backup wireless connection; Equipped with The backup base station CU is configured to send a request message to a common storage node to obtain the configuration information, as triggered by a handover request from the current base station CU or as triggered directly by detection of a failure of the current base station CU.

16. The system according to claim 1, a base station distribution unit (DU); the current base station CU; a user equipment (UE) configured to hand over the wireless connection with the current base station CU via the base station DU for a wireless connection with the backup base station CU based on the configuration information; The system of claim 15 further comprising:

17. The system of claim 16, wherein the common storage node provides the configuration information to the backup base station CU as part of a response message after receiving the request message.

18. 17. The system of claim 16, wherein the configuration information includes a UE context, a bearer context, a transport network layer (TNL) association, or integrated access backhaul (IAB) routing information.

19. The system of claim 16, wherein the wireless connection with the current base station CU is replaced with a connection with the backup base station CU when the failure is detected in the current base station CU.

20. The system of claim 16 , wherein an availability indicator identifies when the configuration information was stored on the common storage node.

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