Transmission of segmented radio resource control messages

Abstract

A method in a user equipment configured to communicate with a first base station via a radio link for managing transmission of a segmented radio resource control (RRC) message comprising N segments includes transmitting (212) a first M segments of the segmented RRC message to the first base station, M being an integer greater than zero and less than N; detecting (220), by processing hardware of the user equipment and prior to transmitting a (M+l)th segment of the segmented RRC message, a failure of the radio link; and transmitting (264), after detecting the failure of the radio link, at least a last N-M+l segments of the segmented RRC message to the first base station or a second base station.

Description

Technical Field

[0001] This disclosure relates to the transmission of radio resource control messages, and more specifically, to a wireless communication system for transmitting radio resource control messages divided into multiple segments. Background Technology

[0002] The background description provided herein is intended to generally present the context of this disclosure. The work of the currently designated inventor, with respect to the scope described in this background section and in aspects that may not be worthy of being considered prior art at the time of application, is neither expressly nor implicitly acknowledged as prior art to this disclosure.

[0003] In some wireless communication networks, user equipment (often referred to by the acronym "UE") can segment certain radio resource control (RRC) messages into multiple segments and transmit these segments sequentially to a base station in the radio access network (RAN). According to a proposal in the 3rd Generation Partnership Project (3GPP) specification for fifth-generation (5G) radio access ("NR") networks, for example, a user equipment can segment an RRC protocol data unit (PDU) (and therefore the message itself) containing a UECapabilityInformation message into multiple segments and transmit these segments sequentially to a base station via a radio link. The UE capability delivery process is described in more detail in 3GPP TS 38.331v15.5.1.

[0004] However, segmenting RRC messages can be problematic. In some cases, such as when a radio link fails before the user equipment (UE) has transmitted all segments of a particular RRC message, the segmentation can be problematic. Furthermore, the UE may not know whether the intended receiver (base station) successfully received all segments transmitted by the UE before the failure. For example, if the UE detects a radio link failure after transmitting the first two segments of a four-segment RRC message, the UE may not know whether the base station successfully received the second segment. Therefore, if the UE and base station re-establish the RRC connection, the UE may simply continue transmitting the next (third) segment in the sequence, while the base station may never receive the second segment. As a more specific example, if the segmented message is a UECapabilityInformation message, the UE and base station may fail to complete the UE capability transmission process, in which case the base station may not be aware of certain capabilities of the UE. Summary of the Invention

[0005] The techniques of the present disclosure increase the probability that a user equipment will successfully transmit all segments of a segmented RRC message (e.g., UECapabilityInformation message) to one or more base stations of a RAN even in the case of a radio link failure, and without unnecessarily retransmitting segments. The techniques relate to a scenario where a user equipment detects a failure of a radio link after transmitting the first M segments (0 < M ≤ N) of an RRC message including N segments to the RAN. Thereafter, the user equipment transmits at least the last N - M + 1 segments of the segmented RRC message to the RAN. In some of these embodiments, the user equipment transmits all N segments to the RAN after detecting the failure (e.g., after completing an RRC connection establishment or re - establishment procedure), including all M segments that the user equipment had previously transmitted (before detecting the failure). Thus, the RAN can successfully receive all segments of the segmented RRC message even if the RAN fails to receive one or more segments that the user equipment had transmitted around the time of the radio link failure.

[0006] In other embodiments, the user equipment transmits only a subset of the N segments (but still at least the last N - M + 1 segments) of the segmented RRC message to the RAN after detecting the failure. In some of these embodiments, to inform the user equipment which segments to transmit or re - transmit, the RAN sends an RRC message to the user equipment that indicates (explicitly or implicitly) the last (the L - th) segment successfully received by the RAN. For example, L can be 1 less than M (i.e., if only one transmitted segment is lost). Then, the user equipment can transmit, in response to the RRC message / indication, only those segments that the RAN did not successfully receive (i.e., the last N - L segments). Again, thus, the RAN can also successfully receive all segments of the segmented RRC message even if the RAN fails to receive one or more segments that the user equipment had transmitted around the time of the radio link failure. Further, these later embodiments can improve network efficiency by only requiring the user equipment to transmit (or re - transmit) those segments that the RAN did not successfully receive.

[0007] An example embodiment of these techniques is a method for managing the transmission of a segmented RRC message including N segments in a user equipment configured to communicate with a first base station via a radio link. The method includes transmitting the first M segments of the segmented RRC message (M is an integer greater than zero and less than N) to the first base station, detecting a failure of the radio link by processing hardware of the user equipment and before transmitting the (M + 1)-th segment of the segmented RRC message, and after detecting the failure of the radio link, transmitting at least the last N - M + 1 segments of the segmented RRC message to the first base station or a second base station.

[0008] Another example implementation of these technologies is a method for managing the transmission of segmented RRC messages comprising N segments in a base station configured to communicate with a user equipment via a radio link. The method includes receiving the first L segments of the segmented RRC message (L is an integer greater than zero and less than N) from the user equipment or another base station, and generating an RRC message indicating that the base station has received the first L segments via processing hardware after a radio link failure. The method also includes transmitting the RRC message to the user equipment to cause the user equipment to transmit at least the last NL segments of the segmented RRC message to the base station. Attached Figure Description

[0009] Figure 1 This is a block diagram of an example wireless communication network in which user equipment and base stations of this disclosure can transmit segmented RRC messages;

[0010] Figure 2 -9 describes the relationship with Figure 1 A diagram showing the various message transmissions related to the transmission of segmented RRC messages in a wireless communication network;

[0011] Figure 10 This is a flowchart of an example method for managing the transmission of segmented RRC messages comprising N segments, viewed from the user equipment's perspective; and

[0012] Figure 11 This is a flowchart of an example method for managing the transmission of segmented RRC messages comprising N segments, viewed from the perspective of the base station. Detailed Implementation

[0013] Generally, the technology disclosed herein allows a user equipment (UE) to successfully transmit all segments of a segmented RRC message to one or more base stations of the RAN even in the event of a radio link failure, without unnecessarily retransmitting segments. In this disclosure, depending on the implementation and / or scenario, any reference to different actions performed by the “RAN” (e.g., receiving, transmitting, etc.) may indicate that the action is performed entirely by a single base station of the RAN, or by different base stations of the RAN. For example, if a handover occurs during a series of communications between the user equipment and the RAN, these communications may involve two different base stations. Also in this disclosure, and depending on the implementation and / or scenario, a “failure” of the radio link may specifically refer to a radio link failure (RLF) (e.g., as defined in the 5G standard), or more generally, to the inability of the user equipment and the RAN to communicate via the radio link for any reason.

[0014] These technologies are discussed below with illustrative reference to 5G radio access (“NR”) networks and 5G core networks (5GC). However, the technologies disclosed herein can be applied to other radio access and / or core network technologies.

[0015] First refer to Figure 1 UE 102 can operate in example wireless communication network 100. Wireless communication network 100 includes base stations 104-1 and 104-2 associated with corresponding cells 106-1 and 106-2. When used herein, "RAN 104" refers to a radio access network that includes at least base stations 104-1 and 104-2. Although Figure 1 Each of base stations 104-1 and 104-2 is depicted as serving only one cell; however, it should be understood that base stations 104-1 and / or 104-2 may also provide coverage. Figure 1 One or more additional cells not shown. Typically, the wireless communication network 100 may include any number of base stations, and each base station may cover one, two, three, or any other suitable number of cells.

[0016] For example, base stations 104-1 and 104-2 can each operate as 5G Node Bs (gNBs), and are referred to in themselves as... Figure 2 Example message transmission diagram -9 (discussed below). For example... Figure 1 As shown, both base station 104-1 and base station 104-2 are connected to 5GC 110, which in turn is connected to the Internet 112. In various alternative implementations and / or scenarios, the wireless communication network 100 may not include base station 104-2 and / or cell 106-2, or base station 104-2 may be a Next Generation Evolved Node B (ng-eNB) and cell 106-2 may be an Evolved Universal Terrestrial Radio Access (EUTRA) cell, etc.

[0017] UE 102 may support the NR air interface and exchange messages with base station 104-1 when operating in cell 106-1 or with base station 104-2 when operating in cell 106-2. In other embodiments, UE 102 may also support the EUTRA air interface and exchange messages with base station 104-1 via 5G NR when operating in cell 106-1, and with base station 104-2 via EUTRA when operating in cell 106-2. As described below, UE 102 may be any suitable device capable of wireless communication.

[0018] UE 102 is equipped with processing hardware 120, which may include one or more general-purpose processors (e.g., CPUs) and non-transitory computer-readable storage of instructions executable by the one or more general-purpose processors. Additionally or alternatively, for example, processing hardware 120 may include dedicated processing units, such as wireless communication chipsets. Processing hardware 120 includes an RRC controller 122. The RRC controller 122 is responsible for inbound message transmission, outbound message transmission, and internal processes at the corresponding layer of the wireless communication protocol stack 130, which will be discussed further below. Although in Figure 1 Not shown, but processing hardware 120 may also include controllers for each of several other layers, such as a mobility management (MM) controller and / or a packet data convergence protocol (PDCP) controller. For example, the PDCP controller of UE 102 may generate a PDU that packages / contains an RRC PDU (containing RRC messages) generated by RRC controller 122.

[0019] The RRC controller 122 can be implemented using any suitable combination of hardware, software, and / or firmware. In one example implementation, the RRC controller 122 is a set of instructions defining a corresponding component of the operating system of the UE 102, and one or more CPUs of the processing hardware 120 execute these instructions to perform the corresponding RRC function. In another implementation, the RRC controller 122 is implemented as part of a wireless communication chipset using firmware.

[0020] exist Figure 1 The protocol stack 130, shown in a simplified manner, includes, among other possible layers, a physical layer 132 (often abbreviated as PHY layer), a media access control layer 134 (often abbreviated as MAC layer), a radio link control (RLC) layer 136, a PDCP layer 138, and an RRC layer 140, as parts of the access stratum 142. The non-access stratum (NAS) 150 of the protocol stack 130 includes, among other possible layers, one or more MM layers 152 for handling registration, attachment, or tracking area update processes. Figure 1 As further shown, protocol stack 130 also supports higher-level protocols 154 for various services and applications. For example, higher-level protocols 154 may include Internet Protocol (IP), Transmission Control Protocol, and User Datagram Protocol (UDP).

[0021] RRC layer 140 packages and interprets RRC PDUs. An RRC PDU can contain any of the various types of RRC messages associated with different RRC procedures (e.g., connection establishment or reconstruction procedures, UE capability transmission procedures, measurement reporting procedures, etc.). Layers 132, 134, 136, 138, 140, 141, 152, and 154 can be used as follows: Figure 1 The layers are arranged as shown. However, it will be understood that in some implementations and / or situations, one or more of the depicted layers may be arranged in a manner that is not strictly in accordance with... Figure 1 Perform the operation according to the sorting method shown.

[0022] On the UE 102 side, the RRC layer 140 (i.e., the RRC controller 122) can divide one or more types of RRC messages into multiple segments and transmit these segments sequentially. In some embodiments, the RRC controller 122 achieves this by including a specific RRC message in an RRC PDU and then segmenting the RRC PDU such that each RRC PDU segment includes the corresponding RRC message segment. In this disclosure, references to the transmission or reception of RRC message segments may indicate (in some embodiments) that the RRC message segments are transmitted or received separately within segments of the RRC PDU. As an example, if the UE 102 receives a UECapabilityEnquiry message from the base station 104-1, the RRC controller 122 can respond by generating a UECapabilityInformation message, packaging the UECapabilityInformation message into an RRC PDU, dividing the RRC PDU into multiple segments, and then having the UE 102 sequentially transmit the RRC PDU segments to the base station 104-1.

[0023] Base station 104-1 is equipped with processing hardware 160, which may include one or more general-purpose processors (e.g., CPUs) and non-transitory computer-readable storage of one or more instructions executable by the general-purpose processor. Additionally or alternatively, for example, processing hardware 160 may include dedicated processing units, such as wireless communication chipsets. Similar to the processing hardware 120 of UE 102, processing hardware 160 includes an RRC controller 162. While the RRC controller 122 of UE 102 implements the functionality of RRC layer 140 on the user equipment 102 side, the RRC controller 162 of base station 104-1 implements the functionality of RRC layer 140 on the base station 104-1 side. As an example only, RRC controller 122 can generate measurement report messages and cause UE 102 to transmit measurement report messages to base station 104-1, while RRC controller 162 can interpret the measurement report messages upon receiving them at base station 104-1. Figure 1Not shown, but the processing hardware 160 may also include controllers for each of the multiple other layers, such as MM and / or PDCP controllers.

[0024] The RRC controller 162 can be implemented using any suitable combination of hardware, software, and / or firmware. In one example implementation, the RRC controller 162 is a set of instructions defining a corresponding component of the operating system of base station 104-1, and one or more CPUs of processing hardware 160 execute these instructions to perform the corresponding RRC function. In another implementation, the RRC controller 162 is implemented as part of a wireless communication chipset using firmware. In some implementations, base station 104-2 includes processing hardware similar to the processing hardware 160 of base station 104-1. In other implementations, base station 104-2 may be co-located with and share some of the processing hardware 160 of base station 104-1.

[0025] On the base station 104-1 side, the RRC layer 140 (i.e., the RRC controller 162) can process one or more types of RRC messages received as multiple consecutive segments. As an example, if base station 104-1 receives a segment sequence of UECapabilityInformation messages from UE 102 (e.g., within an RRC PDU segment sequence), then the RRC controller 162 can successfully interpret the segmented messages (i.e., determine the capabilities of UE 102 as indicated in the entire UECapabilityInformation message).

[0026] For simplicity, Figure 1 The various components of UE 102 and base stations 104-1 and 104-2 are not depicted. In addition to the layer-specific controllers described above, UE 102 and base stations 104-1 and 104-2 also include corresponding transceivers, which include various hardware, firmware, and software components configured to transmit and receive radio signals via the NR air interface. Processing hardware 120 and processing hardware 160 (and similar processing hardware in base station 104-2) can send commands and exchange information with the corresponding transceivers as needed to perform various connection establishment procedures, perform various RRC or MM procedures, or communicate with other network elements, etc.

[0027] Now refer to Figure 2 -9 Discusses example message sequences and methods that UE 102, base station 104-1, and / or base station 104-2 may implement and perform individually or in conjunction with other components of network 100 (e.g., 5GC 110). UE 102 and / or base stations 104-1, 104-2 may implement at least some of the actions described below in software, firmware, hardware, or any suitable combination of software, firmware, and hardware. Although referenced below... Figure 1 The components and 5G systems described in the discussion Figure 2 -9, but usually any suitable component or wireless communication network can be used.

[0028] First refer to Figure 2 Message transmission diagram 200 depicts a scenario that can be implemented according to one embodiment and scenario. Figure 1 The example messages exchanged between UE102 and RAN 104, along with associated operations, are shown in Message Transmission Diagram 200. All operations shown for UE102 in the diagram can be performed (or triggered, for example, by) the RRC controller 122 of UE102. Similarly, operations shown for RAN 104 can be performed (or triggered) by the RRC controller 162 of base station 104-1 or a similar RRC controller of base station 104-2.

[0029] At the beginning of message transmission diagram 200, UE 102 and RAN 104 have established an RRC connection. (As follows...) Figure 2 As shown, RAN104 determines that 202 initiates a specific RRC procedure (“RRC Procedure A”), and then transmits an RRC message (“RRC Message A”) to UE102 via 204. For example, RRC Procedure A may be a UE capability transmission procedure defined in 3GPP TS 38.331v15.5.1, and RRC Message A may be a UECapabilityEnquiry message.

[0030] In response to receiving and processing RRC message A, UE 102 generates 210 segments of an RRC PDU containing an RRC response message (“RRC Response Message A”), where N is an integer greater than 1 (e.g., 2, 4, 10, 16, etc.). For example, if RRC procedure A is a UE capability transmission procedure, then RRC response message A could be a UECapabilityInformation message specifying various capabilities of UE 102 (e.g., radio access technologies supported by UE 102, etc.). As an example, generating 210 N segments could include generating RRC response message A, including RRC response message A in the RRC PDU, and then dividing the RRC PDU into N segments.

[0031] UE 102 then sequentially transmits the first M of the N segments (212-1 to 212-M) to RAN 104, where M is an integer greater than zero and less than N. In other embodiments, UE 102 does not generate all N segments 210 before transmitting the first segment 212-1. For example, UE 102 may alternatively generate segment 210 exactly before transmitting each segment 212, such that the generation of 210 and the transmission of 212 are interleaved.

[0032] like Figure 2 As shown (using the symbol "X"), the radio link between UE 102 and RAN 104 fails before RAN 104 receives the Mth segment. In this disclosure, references to devices, components, etc., failing to receive messages or segments can indicate that the device, component, etc., failed to receive any part of a segment or message, or only received a portion of a segment or message.

[0033] For example, a radio link may suffer a large and sudden drop in signal quality. At some point shortly after a radio link failure, UE 102 detects the failure (e.g., during or shortly after the transmission of the Mth segment). For example, UE 102 may periodically measure one or more radio link quality metrics (e.g., signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), block, bit, or packet error rate, and / or other suitable metrics) and determine from these measurements that the radio link quality has degraded beyond a certain threshold. However, UE 102 may not know whether RAN 104 successfully received the Mth segment, and may not know whether RAN 104 successfully received one or more additional segments before the Mth segment. For example, the difference between the time of the radio link failure and the time UE 102 detects the failure may be large enough that UE 102 transmits several additional segments that RAN 104 cannot receive due to the failure.

[0034] Therefore, UE 102 knows how many segments it has transmitted to RAN 104, but does not know how many segments RAN 104 has successfully received. Figure 2 One option reflected in (and Figure 3-7) is to have UE 102 restart the transmission of the entire RRC PDU (i.e., all N segments). Another option is for RAN 104 to provide feedback to UE 102, informing UE 102 which segments RAN 104 has successfully received. The latter option, allowing UE 102 to avoid transmitting segments already received by RAN 104, is reflected in… Figure 8 And in Figure 9 (discussed below).

[0035] In response to the fault, UE 102 and RAN 104 perform the 230 RRC connection re-establishment procedure. After UE 102 and RAN 104 re-establish the RRC connection, RAN 104 determines that the same RRC procedure A is initiated 260, and therefore transmits another RRC message A (e.g., another UECapabilityEnquiry message) to UE 102 262.

[0036] In response to receiving and processing RRC message A, UE 102 sequentially transmits all N segments (264-1 to 264-N) of RRC response message A to RAN 104. That is, UE 102 sequentially retransmits the first M segments (264-1 to 264-M), and then sequentially transmits the remaining segments M+1 to N (264-(M+1) to 264-N), thereby increasing the likelihood that RAN 104 will successfully receive all segments. After RAN 104 receives all segments, it can assemble all segments into a complete RRC PDU.

[0037] In an alternative scenario, if RAN 104 is unsure whether 260 will initiate RRC procedure A and instead transmits another RRC message A, or if UE 102 fails to successfully receive the RRC message A, then UE 102 may not transmit any segment, and RRC procedure A may fail or be further delayed.

[0038] In some implementation methods and / or scenarios, Figure 2 All operations of RAN 104 shown are performed by base station 104-1. However, in other implementations and / or scenarios, UE 102 connects to a new base station in response to a radio link failure. In such implementations / scenarios, this occurs before the RRC connection re-establishment process. Figure 2 All operations of RAN 104 shown are performed by base station 104-1, and occur after the RRC connection re-establishment process. Figure 2 All operations of RAN 104 shown (as well as at least some operations of the RRC connection reconstruction process itself) are performed by base station 104-2.

[0039] One of these subsequent implementation methods / scenarios is in Figure 3A and 3B The message transmission diagram is shown in Message Transmission Diagram 300. In Message Transmission Diagram 300, all operations shown for UE 102 can be performed by (or triggered by) the RRC controller 122 of UE 102, for example, in the case of message transmission. Similarly, operations shown for base station 104-1 may be performed by (or triggered by) the RRC controller 162, except for communication between base stations 104-1 and 104-2, and operations shown for base station 104-2 may be performed by (or triggered by) the RRC controller of base station 104-2, which is similar to the RRC controller 162.

[0040] At the beginning of message transmission diagram 300, UE 102 and base station 104-1 have established an RRC connection. (As follows...) Figure 3AAs shown, base station 104-1 determines that 302 initiates RRC procedure A (e.g., UE capability transmission procedure), and then transmits RRC message A (e.g., UECapabilityEnquiry message) 304 to UE 102. In response, UE 102 generates 310 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and sequentially transmits the first M segments of the N segments (312-1 to 312-M) to base station 104-1. The operations of generating 310 and transmitting 312 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2 (As discussed in the generation 210 and transmission 212 operations). In the depicted scenario, a radio link failure causes base station 104-1 to fail to successfully receive at least the Mth segment. That is, base station 104-1 only receives the first L segments, where L is an integer greater than zero and less than M. UE 102 detects a 320 fault (e.g., as referenced above). Figure 2 (As discussed), and in response, UE 102 initiates an RRC connection re-establishment procedure with the new base station (i.e., base station 104-2). Then, UE 102 transmits an RRCReestablishmentRequest message 334 to base station 104-2.

[0041] If base station 104-2 does not have the context information of UE 102 (e.g., the "UE context" defined by the 5G specification) when receiving the RRCReestablishmentRequest message from UE 102, then base station 104-2 transmits a 336 RETRIEVE UE CONTEXT REQUEST message to base station 104-1, and base station 104-1 responds by transmitting a 338 UE 102 context information to base station 104-2 in a RETRIEVE UE CONTEXT RESPONSE message. In some implementations, base station 104-1 does not include the segments of the successfully received RRC PDU (i.e., the first L segments) in the RETRIEVE UE CONTEXT RESPONSE message or any other message transmitted by base station 104-1 to base station 104-2.

[0042] In other scenarios, when base station 104-2 already possesses the context information of UE 102 when receiving the RRCReestablishmentRequest from UE 102, base station 104-2 does not transmit the 336 RETRIEVE UECONTEXT REQUEST message to base station 104-1, and base station 104-1 does not transmit the 338 RETRIEVE UE CONTEXT RESPONSE message. The following discussion... Figure 5A and 5B This reflects a scenario where base station 104-2 cannot obtain context information from UE 102.

[0043] Now for reference Figure 3B Base station 104-2 transmits a 340RRCReestablishment message to UE 102, and UE 102 responds by transmitting a 342RRCReestablishmentComplete message to base station 104-2. Subsequently, base station 104-2 determines that 360 initiates an RRC procedure A (e.g., a UE Capability Transfer procedure) and transmits another 362RRC message A (e.g., another UECapabilityEnquiry message) to UE 102. In response to RRC message A, UE 102 sequentially transmits all N segments (364-1 to 364-N) of the RRC response message A (e.g., a UECapabilityInformation message) to base station 104-2. Therefore, despite radio link failure, and despite base station 104-1 not forwarding successfully received segments (e.g., the first L segments) to base station 104-2, base station 104-2 can still receive all segments and assemble a complete RRC PDU containing the RRC response message A.

[0044] Figure 4A and 4BExample message transmission diagram 400 is depicted corresponding to different implementations and / or scenarios. In particular, and as further discussed below, message transmission diagram 400 may reflect a scenario where RAN 104 cannot respond to an RRCReestablishmentRequest message from UE 102 with an RRCReestablishment message. For example, message transmission diagram 400 may reflect an implementation of the same wireless communication network 100 as message transmission diagrams 200 and / or 300, but in a different scenario (e.g., where RAN 104 cannot obtain context information from UE 102 and therefore cannot re-establish the connection with UE 102). In message transmission diagram 400, all operations shown for UE 102 can be performed (or triggered, for example, by its RRC controller 122 in the case of message transmission). Similarly, operations shown for RAN 104 can be performed (or triggered) by its RRC controller 162 of base station 104-1 or a similar RRC controller of base station 104-2.

[0045] At the beginning of message transmission diagram 400, UE 102 and RAN 104 have established an RRC connection. (As follows...) Figure 4A As can be seen, RAN 104 determines that 402 initiates RRC procedure A (e.g., UE capability transfer procedure), and then transmits 404RRC message A (e.g., UECapabilityEnquiry message) to UE 102. In response, UE 102 generates 410 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and transmits the first M segments of the N segments sequentially (412-1 to 412-M) to RAN 104. The generation of 410 and the transmission of 412 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2 The generation 210 and transmission 212 operations are discussed. In the depicted scenario, a radio link failure causes RAN 104 to fail to receive the Mth segment (i.e., L = M-1). UE 102 detects a 420 fault (e.g., as referenced above). Figure 2 (As discussed), and in response, determines that 432 initiates an RRC connection re-establishment procedure with RAN 104. Then, UE 102 transmits a 434RRCReestablishmentRequest message to RAN 104.

[0046] As mentioned above, in Figure 4A and 4BIn this scenario, RAN 104 cannot respond to the RRCReestablishmentRequest message from UE 102 with an RRCReestablishment message. For example, due to some other reason, RAN 104 may not be able to obtain the context information of UE 102, or may not be able to transmit the RRCReestablishment message. Therefore, RAN 104 instead transmits a 446RRCSetup message to UE 102, and UE 102 responds by transmitting a 448RRCSetupComplete message to RAN 104. Subsequently, RAN 104 transmits a 450SecurityModeCommand message to UE 102 (e.g., to enable integrity protection, encryption, and / or other security schemes for communication between RAN 104 and UE 102), and UE 102 responds by transmitting a 452SecurityModeComplete message to RAN 104.

[0047] Now for reference Figure 4B RAN 104 then determines that 460 initiates RRC procedure A (e.g., UE Capability Transmission procedure) and transmits another RRC message A (e.g., another UECapabilityEnquiry message) to UE 102. In response to RRC message A, UE 102 sequentially transmits all N segments (464-1 to 464-N) of the RRC response message A (e.g., UECapabilityInformation message) to RAN 104. Therefore, despite the radio link failure, RAN 104 can still receive all segments and assemble a complete RRC PDU containing the RRC response message A.

[0048] In some implementation methods and / or scenarios, Figure 4A and 4B All operations of RAN 104 shown are performed by base station 104-1. However, in other implementations and / or scenarios, UE 102 connects to a new base station in response to a radio link failure. In such implementations / scenarios, events occurring before the radio link failure... Figure 4A and 4B All operations of RAN104 shown are performed by base station 104-1, and occur after a radio link failure. Figure 4A and 4B All operations of RAN104 shown are performed by base station 104-2. However, as will be... Figure 5A and 5B As seen in the discussion, other post-fault operations of RAN 104 can be performed by base station 104-1. Figure 4A and4B (Not shown in the image).

[0049] One implementation / scenario of UE 102 connecting to a new base station in response to a radio link failure is as follows: Figure 5A and 5B The message transmission diagram 500 illustrates this. In the message transmission diagram 500, all operations shown for UE 102 can be performed by (or triggered by) the RRC controller 122 of UE 102, for example, in the case of message transmission. Similarly, except for communication between base stations 104-1 and 104-2, operations shown for base station 104-1 can be performed by (or triggered by) the RRC controller 162, and operations shown for base station 104-2 can be performed by (or triggered by) the RRC controller of base station 104-2, which is similar to the RRC controller 162.

[0050] At the beginning of message transmission diagram 500, UE 102 and base station 104-1 have established an RRC connection. (As follows...) Figure 5A As can be seen, base station 104-1 determines that 502 initiates RRC procedure A (e.g., UE capability transmission procedure), and then transmits 504 RRC message A (e.g., UECapabilityEnquiry message) to UE 102. In response, UE 102 generates 510 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and sequentially transmits the first M segments of the N segments (512-1 to 512-M) to base station 104-1. The operations of generating 510 and transmitting 512 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2 The generation 210 and transmission 212 operations are discussed. In the depicted scenario, a radio link failure causes base station 104-1 to fail to successfully receive the Mth segment (i.e., L = M-1). UE 102 detects a 520 fault (e.g., as referenced above). Figure 2 (As discussed), and in response, determines that UE 102 initiates an RRC connection re-establishment procedure with the new base station (i.e., base station 104-2). Then, UE 102 transmits an RRCReestablishmentRequest message 534 to base station 104-2.

[0051] If base station 104-2 does not have the context information of UE 102 (e.g., the "UE context" defined by the 5G specification) when receiving the RRCReestablishmentRequest message from UE 102, then base station 104-2 transmits a 536RETRIEVE UE CONTEXT REQUEST message to base station 104-1. However, in Figure 5A and 5BIn the example scenario, base station 104-1 cannot obtain the context information of UE 102, and therefore transmits a 544 RETRIEVE UE CONTEXT FAILURE message to base station 104-2. In some implementations, base station 104-1 does not include the successfully received RRC PDU segments (i.e., the first L segments) in the RETRIEVE UE CONTEXT FAILURE message or any other message transmitted by base station 104-1 to base station 104-2.

[0052] Now for reference Figure 5B In response to the RETRIEVE UE CONTEXT FAILURE message, base station 104-2 transmits a 546RRCSetup message to UE 102, and UE 102 responds by transmitting a 548RRCSetupComplete message to base station 104-2. Subsequently, base station 104-2 transmits a 550SecurityModeCommand message to UE 102 (e.g., to enable integrity protection, encryption, and / or other security schemes for communication between base station 104-2 and UE 102), and UE 102 responds by transmitting a 552SecurityModeComplete message to base station 104-2. In an alternative implementation, if base station 104-2 does not have the context information of UE 102 when it receives the RRCReestablishmentRequest message from UE 102, then base station 104-2 instead transmits the 546RRCSetup message to UE 102 earlier (e.g., before and / or instead of transmitting the 536RETRIEVE UECONTEXT REQUEST message to base station 104-1).

[0053] Next, base station 104-2 determines that 560 initiates RRC procedure A (e.g., UE Capability Transmission procedure) and transmits another RRC message A (e.g., another UECapabilityEnquiry message) to UE 102. In response to RRC message A, UE 102 sequentially transmits all N segments (564-1 to 564-N) of the RRC response message A (e.g., UECapabilityInformation message) to base station 104-2. Therefore, despite the radio link failure and despite not receiving any segments from base station 104-1, base station 104-2 can still receive all segments and assemble a complete RRC PDU containing the RRC response message A.

[0054] Figure 6A and 6B Example message transmission diagram 600 is depicted corresponding to yet another implementation and / or scenario. In particular, and as further discussed below, message transmission diagram 600 may reflect an implementation and / or scenario where, after a radio link failure, UE 102 determines to initiate an RRC connection establishment process instead of an RRC connection reconstruction process. For example, message transmission diagram 600 may reflect an implementation of the same wireless communication network 100 as message transmission diagrams 200, 300, 400, and / or 500, but in a different scenario (e.g., where certain conditions cause UE 102 to decide to establish a new RRC connection). In message transmission diagram 600, all operations shown for UE 102 can be performed (or triggered, for example, by its RRC controller 122 in the case of message transmission). Similarly, the operations shown for RAN 104 can be performed (or triggered) by (or by) the RRC controller 162 of base station 104-1 or a similar RRC controller of base station 104-2.

[0055] At the beginning of message transmission diagram 600, UE 102 and RAN 104 have established an RRC connection. (As follows...) Figure 6A As shown, RAN104 determines that 602 initiates RRC procedure A (e.g., UE capability transfer procedure), and then transmits 604 RRC message A (e.g., UECapabilityEnquiry message) to UE 102. In response, UE 102 generates 610 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and transmits the first M segments of the N segments sequentially (612-1 to 612-M) to RAN 104. The operations of generating 610 and transmitting 612 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2 The generation 210 and transmission 212 operations are discussed. In the depicted scenario, a radio link failure causes RAN 104 to fail to successfully receive the Mth segment (i.e., L = M-1). UE 102 detects a 620 fault (e.g., as referenced above). Figure 2 (as discussed), and in response, it is determined that 632 initiates an RRC connection establishment procedure with RAN 104.

[0056] Subsequently, UE 102 transmits a 645 RRCSetupRequest message to RAN 104. In response, RAN 104 transmits a 646 RRCSetup message to UE 102, and UE 102 responds to the RRCSetup message by transmitting a 648 RRCSetupComplete message to RAN 104. Then, RAN 104 transmits a 650 SecurityModeCommand message to UE 102 (e.g., to enable integrity protection, encryption, and / or other security schemes for communication between RAN 104 and UE 102), and UE 102 responds by transmitting a 652 SecurityModeComplete message to RAN 104.

[0057] Now for reference Figure 6B RAN 104 then determines that 660 initiates RRC procedure A (e.g., UE Capability Transmission procedure) and transmits another RRC message A (e.g., another UECapabilityEnquiry message) to UE 102 at 662. In response to RRC message A, UE 102 sequentially transmits all N segments (664-1 to 664-N) of the RRC response message A (e.g., UECapabilityInformation message) to RAN 104. Therefore, despite the radio link failure, RAN 104 can still receive all segments and assemble a complete RRC PDU containing the RRC response message A.

[0058] In some implementation methods and / or scenarios, Figure 6A and 6B All operations of RAN 104 shown are performed by base station 104-1. However, in other implementations and / or scenarios, UE 102 connects to a new base station in response to a radio link failure. In such implementations / scenarios, events occurring before the radio link failure... Figure 6A and 6B All operations of RAN104 shown are performed by base station 104-1, and occur after a radio link failure. Figure 6A and 6B All operations of RAN104 shown are performed by base station 104-2. However, as will be... Figure 7A and 7B As seen in the discussion, other post-fault operations of RAN 104 can be performed by base station 104-1. Figure 6A and 6B (Not shown in the image).

[0059] One implementation / scenario of UE 102 connecting to a new base station in response to a radio link failure is as follows: Figure 7A and7B The message transmission diagram is shown in Message Transmission Diagram 700. In Message Transmission Diagram 700, all operations shown for UE 102 can be performed by (or triggered by) the RRC controller 122 of UE 102, for example, in the case of message transmission. Similarly, operations shown for base station 104-1 can be performed by (or triggered by) the RRC controller 162, and operations shown for base station 104-2 can be performed by (or triggered by) the RRC controller of base station 104-2, which is similar to the RRC controller 162.

[0060] At the beginning of message transmission diagram 700, UE 102 and base station 104-1 have established an RRC connection. (As follows...) Figure 7A As shown, base station 104-1 determines that 702 initiates RRC procedure A (e.g., UE capability transmission procedure), and then transmits 704 RRC message A (e.g., UECapabilityEnquiry message) to UE 102. In response, UE 102 generates 710 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and transmits the first M segments of the N segments sequentially (712-1 to 712-M) to base station 104-1. The operations of generating 710 and transmitting 712 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2 The generation 210 and transmission 212 operations are discussed. In the depicted scenario, a radio link failure causes base station 104-1 to fail to successfully receive the Mth segment (i.e., L = M-1). UE 102 detects a 720 fault (e.g., as referenced above). Figure 2 (As discussed), and in response, determines that 732 initiates an RRC connection establishment procedure with the new base station (i.e., base station 104-2). Then, UE 102 transmits a 745 RRCSetupRequest message to base station 104-2, and base station 104-2 responds by transmitting a 746 RRCSetup message to UE 102.

[0061] UE 102 responds to the RRCSetup message by transmitting a 748 RRCSetupComplete message to base station 104-2, after which base station 104-2 transmits a 750 SecurityModeCommand message to UE 102 (e.g., to enable integrity protection, encryption, and / or other security schemes for communication between base station 104-2 and UE 102). Now refer to Figure 7B UE 102 responds to the SecurityModeCommand message by transmitting a 752SecurityModeComplete message to base station 104-2.

[0062] Next, base station 104-2 determines that 760 initiates RRC procedure A (e.g., UE Capability Transmission procedure) and transmits another RRC message A (e.g., another UECapabilityEnquiry message) to UE 102. In response to RRC message A, UE 102 sequentially transmits all N segments (764-1 to 764-N) of the RRC response message A (e.g., UECapabilityInformation message) to base station 104-2. Therefore, despite the radio link failure and despite not receiving any segments from base station 104-1, base station 104-2 can still receive all segments and assemble a complete RRC PDU containing the RRC response message A.

[0063] Figure 8 And Figure 9 reflects and Figure 2 Figure 7 shows different implementation methods. Specifically, Figure 8 Figure 9 illustrates an implementation where UE 102 does not retransmit each of the first M segments of RRC message A to RAN 104, thereby reducing the amount of message transmission required without causing segment loss (as will become clear from the following discussion).

[0064] First refer to Figure 8 Message transmission diagram 800 depicts a scenario that can be implemented according to one embodiment. Figure 1 The example messages and associated operations exchanged between UE102 and RAN 104 are shown in Message Transmission Figure 800. All operations shown for UE102 in the Message Transmission Figure 800 can be performed (or triggered, for example, by) the RRC controller 122 of UE102. Similarly, the operations shown for RAN 104 can be performed (or triggered) by the RRC controller 162 of base station 104-1 or a similar RRC controller of base station 104-2.

[0065] At the beginning of message transmission diagram 800, UE 102 and RAN 104 have established an RRC connection. (As follows...) Figure 8 As shown, RAN104 determines that 802 initiates RRC procedure A (e.g., UE capability transfer procedure), and then transmits 804 RRC message A (e.g., UECapabilityEnquiry message) to UE 102. In response, UE 102 generates 810 all N segments of an RRC PDU containing N corresponding segments of RRC response message A, and transmits the first M segments of the N segments sequentially (812-1 to 812-M) to RAN 104. The generation of 810 and the transmission of 812 can occur during two different time periods or in an interleaved manner (e.g., as described above for...). Figure 2The operations of generation 210 and transmission 212 are discussed). In the depicted scenario, a radio link failure causes RAN 104 to fail to successfully receive at least the Mth segment. That is, RAN 104 only successfully receives the first L segments, where 0 < L < M ≤ N. UE 102 detects 820 the failure (e.g., as discussed above with reference to Figure 2 discussed), but does not know how many segments RAN 104 successfully received before the failure (i.e., does not know the value of L).

[0066] In response to the failure, UE 102 and RAN 104 perform 830 an RRC connection reestablishment procedure. After UE 102 and RAN 104 reestablish the RRC connection, RAN 104 determines 860 to initiate the same RRC procedure A and thus transmits 862 another RRC message A (e.g., another UE Capability Enquiry message) to UE 102. However, in this RRC message A, RAN 104 includes a request for the (L + 1)th segment of the RRC PDU (i.e., the (L + 1)th segment of the RRC response message A). This request can take any suitable form capable of conveying to UE 102 that RAN 104 still needs the (L + 1)th to the Nth segments. For example, the request can include a field with a value equal to L + 1 (indicating the next segment that RAN 104 needs in the segment sequence), a field with a value equal to L (indicating the last segment that RAN 104 successfully received), a field with a value equal to N - L (indicating the number of segments at the end of the RRC PDU that RAN 104 still needs), etc.

[0067] In response to receiving and processing this RRC message A, including the request for the Lth segment, UE 102 sequentially transmits (864-(L + 1) to 864-N) the (L + 1)th to the Nth segments of the RRC response message A to RAN 104. Thus, despite the radio link failure and despite UE 102 not retransmitting at least some of the first M segments, RAN 104 can still successfully receive all N segments and assemble all N segments into a complete RRC PDU.

[0068] In some embodiments and / or scenarios, Figure 8 all operations of RAN 104 shown in Figure 8 are performed by base station 104-1. However, in other embodiments and / or scenarios, UE 102 connects to a new base station in response to a radio link failure. In such embodiments / scenarios, before the RRC connection reestablishment procedure Figure 8All operations of the RAN 104 shown (and at least some operations of the RRC connection re - establishment process itself) are performed by the base station 104 - 2.

[0069] One of these later embodiments / scenarios is shown in Figure 9A and 9B the message transfer diagram 900. In the message transfer diagram 900, all operations shown for the UE 102 can be performed (or triggered, e.g., in the case of message transfer) by the RRC controller 122 of the UE 102. Similarly, except possibly for the communication between the base stations 104 - 1 and 104 - 2, the operations shown for the base station 104 - 1 can be performed (or triggered) by the RRC controller 162, and the operations shown for the base station 104 - 2 can be performed (or triggered) by the RRC controller of the base station 104 - 2 similar to the RRC controller 162.

[0070] At the start of the message transfer diagram 900, the UE 102 and the base station 104 - 1 have established an RRC connection. As Figure 9A shown, the base station 104 - 1 determines 902 to initiate an RRC process A (e.g., a UE capability transfer process), and then transmits 904 an RRC message A (e.g., a UECapabilityEnquiry message) to the UE 102. In response, the UE 102 generates 910 all N segments of an RRC PDU containing N corresponding segments of an RRC response message A, and sequentially transmits (912 - 1 to 912 - M) the first M segments of the N segments to the base station 104 - 1. The generation 910 and transmission 912 operations can occur during two different time periods or in an interleaved manner (e.g., as discussed above for the generation 210 and transmission 212 operations for Figure 2 . In the depicted scenario, a radio link failure causes the base station 104 - 1 to fail to successfully receive at least the Mth segment. That is, the base station 104 - 1 only successfully receives the first L segments, where 0 < L < M ≤ N. The UE 102 detects 920 the failure (e.g., as discussed above in reference to Figure 2 ), but does not know how many segments the base station 104 - 1 successfully received before the failure (i.e., does not know the value of L). In response to detecting the failure, the UE 102 determines 932 to initiate an RRC connection re - establishment process with a new base station (i.e., the base station 104 - 2). Then, the UE 102 transmits 934 an RRCReestablishmentRequest message to the base station 104 - 2.

[0071] If base station 104-2 does not have the context information of UE 102 (e.g., the "UE context" defined by the 5G specification) when receiving the RRCReestablishmentRequest message from UE 102, then base station 104-2 transmits a 936 RETRIEVE UE CONTEXT REQUEST message to base station 104-1, and base station 104-1 responds by transmitting the context information of UE 102 (938 UE 102) to base station 104-2 in a RETRIEVE UE CONTEXT RESPONSE message. Base station 104-1 includes the segments of the successfully received RRC PDU (i.e., the first L segments) in the RETRIEVE UE CONTEXT RESPONSE message. In some implementations, base station 104-1 includes not only the segments themselves but also an indication of the segment numbers received in the RETRIEVE UECONTEXT RESPONSE message. For example, base station 104-1 may include in the message a field containing number L (the number of the segment that base station 104-1 successfully received), number L+1 (the number of the next segment that base station 104-2 will need), or another suitable indicator of how many segments base station 104-1 successfully received.

[0072] Now for reference Figure 9B Base station 104-2 transmits a 940RRCReestablishment message to UE 102, and UE 102 responds by transmitting a 942RRCReestablishmentComplete message to base station 104-2. Subsequently, base station 104-2 determines that 960 RRC procedure A (e.g., UE capability transfer procedure) has been initiated, and transmits another 962 RRC message A (e.g., another UECapabilityEnquiry message) to UE 102. However, in this RRC message A, base station 104-2 includes a request for the (L+1)th segment of the RRC PDU (i.e., the (L+1)th segment of the RRC response message A). As described above... Figure 8 As indicated, the request can take any suitable form that can convey to UE 102 that base station 104-2 still requires segments (L+1) to N.

[0073] In response to receiving and processing the RRC message A, including the request for the (L+1)th segment, UE 102 sequentially transmits segments (L+1) to Nth of the RRC response message A (964-(L+1) to 964-N) to base station 104-2. Therefore, despite the radio link failure and although UE 102 does not retransmit at least some of the first M segments, base station 104-2 can still successfully receive all N segments and assemble all N segments into a complete RRC PDU.

[0074] As pointed out throughout the above discussion, in Figure 2 In any of the implementations and scenarios described in -9, RRC message A can be a UECapabilityEnquiry message and RRC response message A can be a UECapabilityInformation message. Furthermore, in some implementations, the RRC PDU can be a UL-DCCH-MESSAGE that includes a UECapabilityInformation message. Alternatively, the RRC PDU can be the UECapabilityInformation message itself.

[0075] In other implementations, RRC procedure A can be a UE information procedure (e.g., as defined in the 5G specification), in which case RRC message A can be a UEInformationRequest message and RRC response message A can be a UEInformationResponse message. In one such implementation, the RRC PDU can be a UL-DCCH-MESSAGE that includes a UEInformationResponse message. Alternatively, the RRC PDU can be the UEInformationResponse message itself.

[0076] Furthermore, in some implementations, RRC message A may include information (e.g., fields or information elements) indicating that UE 102 is permitted to transmit RRC response message A (e.g., UE capability) in a segment. If UE 102 receives RRC message A without this information element, then UE 102 cannot segment RRC response message A (e.g., such that transmissions 212-1, 312-1, 412-1, 512-1, 612-1, 712-1, 812-1, or 912-1 must contain the entire RRC response message A).

[0077] Additionally, in some implementations, RRC message A may include a transaction identifier, and RRC response message A may include the same transaction identifier. Each RRC message A may include a different transaction identifier, and each RRC response message A may include the same transaction identifier as the corresponding RRC message A. Furthermore, each segment of RRC response message A may include the same transaction identifier. In one implementation, each segment of RRC response message A (or each segment of an RRC PDU including RRC response message A) may include a segment number indicating the order of the segments in the sequence. In this implementation, UE 102 may be allowed to transmit segments of RRC response message A (or segments of an RRC PDU including RRC response message A) out of order. In another implementation, the last segment of RRC response message A may include an indication that it is the last segment.

[0078] Furthermore, in some implementations, UE 102 includes each segment of RRC response message A (or each segment of the RRC PDU that includes RRC response message A) in a new RRC message. In one implementation, the new RRC message may include segment numbers indicating the order of the segments in the sequence. In this implementation, UE 102 may be allowed to transmit segments of RRC response message A (or segments of the RRC PDU that includes RRC response message A) out of order. In another implementation, the new RRC message includes the last segment of RRC response message A (or the last segment of the RRC PDU that includes RRC response message A) and also includes an indication that the new RRC message includes the last segment of RRC response message A. In other implementations, instead of using a new RRC message, UE 102 includes each segment number of RRC response message A (or each segment number of the RRC PDU that includes RRC response message A) in RRC response message A by using a key extended field / information element of RRC response message A.

[0079] Similarly, combine the above. Figure 2In any of the implementation methods and scenarios discussed in section -9, RAN 104 can utilize the transaction identifier to determine which RRC response messages (e.g., RRC response message A) transmitted by UE 102 correspond to which RRC message (e.g., RRC message A) transmitted by RAN 104. In some implementations, for example, RAN 104 (e.g., base station 104-1) sets the transaction identifier to a first value and includes the transaction identifier in the first RRC message A (e.g., in transmissions 204, 304, 404, 504, 604, 704, 804, or 904). In response, UE 102 sets the transaction identifier to the first value and includes the transaction identifier somewhere in RRC response message A (e.g., in transmissions 212, 312, 412, 512, 612, 712, 812, or 912). By examining this transaction identifier, RAN 104 (e.g., base station 104-1) can determine that RRC response message A belongs to the same transaction as the first RRC message A.

[0080] Alternatively, UE 102 may include transaction indicators in each segment of RRC response message A, such that RAN 104 (e.g., base station 104-1) can determine that each segment of RRC response message A belongs to the same transaction as the first RRC message A. In still other embodiments, UE 102 may not include transaction indicators associated with RRC message A in any segment of RRC response message A. For example, UE 102 may include different transaction indicators / values ​​in RRC response message A or its segments, or may not include any transaction indicators. In these embodiments, RAN 104 may not know that RRC response message A (or its segments) and RRC message A belong to the same transaction until and unless RAN 104 assembles all segments into a complete RRC PDU and subsequently obtains RRC response message A from the RRC PDU. In some of the embodiments described above, RAN 104 may not assemble segments of RRC response message A that include different transaction indicators.

[0081] Furthermore, in any of the scenarios discussed above involving a complete RRC connection re-establishment process, RAN 104 (e.g., base station 104-2) may transmit an RRCReconfiguration message to UE 102 before transmitting the second RRC message A to UE 102 (e.g., in transmission 362 or 962) and after transmitting an RRCReestablishment message to UE 102 (e.g., in transmission 340 or 940). UE 102 can then respond by transmitting an RRCReconfigurationComplete message to RAN 104 (e.g., base station 104-2), as in transmission 342 or 942. RAN 104 (e.g., base station 104-2) may then transmit the second RRC message A to UE 102 after receiving the RRCReconfigurationComplete message (e.g., in transmission 362 or 962).

[0082] Now for reference Figure 10 An example method 1000 for managing the transmission of segmented RRC messages can be implemented in a user equipment (e.g., through processing hardware 120 of UE 102) configured to communicate with a first base station (e.g., base station 104-1) via a radio link. In method 1000, the segmented RRC message comprises N segments (e.g., within N corresponding segments of an RRC PDU), where N is an integer greater than 1. For example, the segmented RRC message may be a message indicating the capabilities of the user equipment (e.g., a UECapabilityInformation message).

[0083] At block 1002 of method 1000, the user equipment transmits the first M segments of the segmented RRC message to the first base station, where M is an integer greater than zero and less than N. As a more specific example, this transmission may include... Figure 2 Transmission from 212-1 to 212-M Figure 3A Transmission from 312-1 to 312-M Figure 4A Transmission from 412-1 to 412-M Figure 5A Transmission from 512-1 to 512-M Figure 6A Transmission from 612-1 to 612-M Figure 7A Transmission from 712-1 to 712-M Figure 8 Transmission from 812-1 to 812-M or Figure 9A The transmission from 912-1 to 912-M.

[0084] At box 1004, before the (M+1)th segment of the segmented RRC message is transmitted, the user equipment detects a radio link failure. As a more specific example, this detection may include... Figure 2 Detection 220, Figure 3A Detection 320, Figure 4A Detection 420 Figure 5A Detection 520 Figure 6A The detection of 620, Figure 7A Detection 720, Figure 8 The detection of 820 or Figure 9A The detection rate is 920. The user equipment (UE) can detect the fault almost immediately after it occurs, or after some delay. Therefore, the first base station may not be able to receive only the Mth segment transmitted by the UE, or it may be unable to receive multiple segments transmitted by the UE. In either case, the UE may not know how many segments the first base station failed to receive.

[0085] At box 1006, after a radio link failure is detected, the user equipment transmits at least the last N-M+1 segments of the segmented RRC message to the first base station or the second base station (e.g., base station 104-1 or base station 104-2). As a more specific example, this transmission may include... Figure 2 Transmission from 264-1 to 264-N Figure 3B Transmission from 364-1 to 364-N Figure 4B Transmission from 464-1 to 464-N Figure 5B Transmission from 564-1 to 564-N Figure 6B Transmission from 664-1 to 664-N Figure 7B Transmission from 764-1 to 764-N Figure 8 Transmission from 864-(L+1) to 864-N or Figure 9B The transmission is from 964-(L+1) to 964-N.

[0086] In some implementations and / or scenarios, method 1000 includes Figure 10 One or more additional boxes are not shown in the diagram. For example, method 1000 may include an additional box occurring before box 1006, wherein the user equipment receives an RRC message from a first base station or a second base station indicating that the first base station has received the first L segments of a segmented RRC message, where L is an integer greater than zero and less than M. In this implementation / scenario, box 1006 may include transmitting only the last NL segments of the segmented RRC message and may occur in response to receiving an RRC message from the first or second base station. As a more specific example, the RRC message received by the user equipment from the first or second base station may be in... Figure 8 Transmission 862 or Figure 9B The RRC message A transmitted in transmission 962.

[0087] As another example, method 1000 may include an additional box prior to box 1002 in which the user equipment receives an RRC message from the first base station via a radio link, and box 1002 may occur in response to the user equipment receiving the RRC message. As a more specific example, the RRC message received by the user equipment from the first base station may be... Figure 2 Transmission 204 Figure 3A Transmission 304, Figure 4A 404 error message Figure 5A Transmission 504, Figure 6A Transmission 604 Figure 7A Transmission 704, Figure 8 Transmission 804 or Figure 9A The RRC message A transmitted in transmission 904.

[0088] As another example, method 1000 may include an additional box, wherein the user equipment, in response to detecting a radio link failure at box 1004, initiates an RRC connection reconstruction procedure (with the first or second base station) or an RRC connection establishment procedure. In such an implementation, box 1006 may occur after the user equipment and the first or second base station have established or reconstructed an RRC connection. As a more specific example, the user equipment may via... Figure 3A Transmission 334 or Figure 9A The transmission 934 initiates the RRC connection establishment or reconstruction process.

[0089] Now for reference Figure 11 An example method 1100 for managing the transmission of segmented RRC messages can be implemented in a base station (e.g., through processing hardware 160 of base station 104-1 or similar processing hardware of base station 104-2) configured to communicate with a user equipment (e.g., UE 102) via a radio link. In method 1100, the segmented RRC message comprises N segments (e.g., within N corresponding segments of an RRCPDU), where N is an integer greater than 1. For example, the segmented RRC message may be a message indicating the capabilities of the user equipment (e.g., a UECapabilityInformation message).

[0090] At block 1102 of method 1100, the base station receives the first L segments of a segmented RRC message from a user equipment or another base station, where L is an integer greater than zero and less than N. As a more specific example, in an implementation and / or scenario where the base station receives the first L segments from the user equipment, the base station may... Figure 8 In transmissions 812-1 to 812-L or transmissions 912-1 to 912-L in Figure 9, L segments are received (where L can be understood to be less than M). As another example, in an implementation and / or scenario where the base station changes to receive the first L segments from another base station, the base station can... Figure 9AThe transmission 938 receives L segments.

[0091] At box 1104, following a radio link failure, the base station generates an RRC message indicating that it has received the first L segments. For example, the RRC message could specify number L (the last segment successfully received) or number L+1 (the next segment required by the base station), etc. Box 1104 can occur, for example, after the user equipment and the base station have established or re-established an RRC connection.

[0092] At box 1106, the base station transmits an RRC message to the user equipment so that the user equipment transmits at least the last NL segments of the segmented RRC message to the base station. As a more specific example, the transmission performed by the base station could be... Figure 8 Transmission 862 or Figure 9B The transmission 962, and the transmission triggered (by the user equipment) may include Figure 8 Transmission from 864-(L+1) to 864-N or Figure 9B The transmission is from 964-(L+1) to 964-N.

[0093] In some implementations and / or scenarios, method 1100 includes Figure 11 One or more additional boxes are not shown in the diagram. For example, method 1100 may include an additional box occurring before box 1102, wherein the base station transmits an RRC request message requesting segmentation of an RRC message to the user equipment. As a more specific example, this transmission may be Figure 8 Transmission 804 or Figure 9A The transmission is 904.

[0094] As an example and not a limitation, the public assumptions in this document are at least as follows:

[0095] Aspect 1 - A method for managing the transmission of segmented radio resource control (RRC) messages comprising N segments in a user equipment configured to communicate with a first base station via a radio link, the method comprising: transmitting the first M segments of the segmented RRC message to the first base station, where M is an integer greater than zero and less than N; detecting a fault in the radio link by processing hardware of the user equipment before transmitting the (M+1)th segment of the segmented RRC message; and after detecting the fault in the radio link, transmitting at least the last N-M+1 segments of the segmented RRC message to the first base station or a second base station.

[0096] Aspect 2 - According to the method of Aspect 1, wherein transmitting at least the last N-M+1 segments of a segmented RRC message includes transmitting the N segments.

[0097] Aspect 3 - According to the method of Aspect 1, wherein at least the last N-M+1 segments of the segmented RRC message are transmitted, which includes only a subset of the N segments.

[0098] Aspect 4 - The method according to aspect 1 further includes: before transmitting at least the last N-M+1 segments, receiving from a first base station or a second base station an RRC message indicating that the first base station has received the first L segments of the segmented RRC message, where L is an integer greater than zero and less than M, wherein transmitting at least the last N-M+1 segments includes transmitting only the last NL segments of the segmented RRC message, and occurs in response to receiving the RRC message.

[0099] Aspect 5 - The method according to any one of Aspects 1 to 4 further includes: receiving an RRC message from a first base station via a radio link, wherein the first M segments of transmission occur in response to receiving the RRC message.

[0100] Aspect 6 - According to the method of Aspect 5, wherein: the RRC message is a message requesting user equipment capability information; and the segmented RRC message is a message indicating the capabilities of the user equipment.

[0101] Aspect 7 - The method according to aspect 5 or 6 further includes: receiving an additional RRC message from a first base station or a second base station after a radio link failure is detected, wherein the transmission of at least the last N-M+1 segments occurs in response to the receipt of the additional RRC message.

[0102] Aspect 8 - The method according to any one of Aspects 1 to 7, wherein the segmented RRC message is included in the segmented RRC Protocol Data Unit (PDU).

[0103] Aspect 9 - The method according to any one of Aspects 1 to 8 further includes: in response to detecting a failure of the radio link, initiating an RRC connection reconstruction process or an RRC connection establishment process with the first base station or the second base station, wherein the transmission of at least the last N-M+1 segments occurs after the user equipment and the first base station or the second base station have established or reconstructed the RRC connection.

[0104] Aspect 10 - The method according to any one of Aspects 1 to 9, wherein transmitting the first M segments includes, for each of the first M segments, transmitting a message including the segment and a segment number indicating the order of the segment in the segmented RRC message; and transmitting at least the last N-M+1 segments includes, for each of at least the (M+1)th to (N-1)th segments of the segmented RRC message, transmitting a message including the segment and a segment number indicating the order of the segment in the segmented RRC message.

[0105] Aspect 11 - The method according to any one of Aspects 1 to 10, wherein transmitting at least the last N-M+1 segments includes transmitting a message including the Nth segment of a segmented RRC message and an indication that the message includes the last segment of the segmented RRC message.

[0106] Aspect 12 - A user equipment including processing hardware configured to perform a method according to any one of aspects 1 to 11.

[0107] Aspect 13 - A method for managing the transmission of segmented radio resource control (RRC) messages comprising N segments in a base station configured to communicate with a user equipment via a radio link, the method comprising: receiving the first L segments of the segmented RRC message from the user equipment or another base station, where L is an integer greater than zero and less than N; generating, via processing hardware of the base station, an indication that the base station has received the first L segments of the RRC message after a failure of the radio link; and transmitting the RRC message to the user equipment to cause the user equipment to transmit at least the last NL segments of the segmented RRC message to the base station.

[0108] Aspect 14 - According to the method of aspect 13, wherein causing the user equipment to transmit at least the last NL segments includes causing the user equipment to transmit only the last NL segments.

[0109] Aspect 15 - The method according to aspect 13 or 14 further includes: transmitting an RRC request message requesting segmentation RRC messages to the user equipment before receiving the first L segments.

[0110] Aspect 16 - According to the method of aspect 15, wherein the instruction that the base station has received the first L segments of RRC messages is an additional RRC request message.

[0111] Aspect 17 - According to the method of Aspect 16, wherein: both the RRC request message and the supplementary RRC request message request user equipment capability information; and the segmented RRC message is a message indicating the capabilities of the user equipment.

[0112] Aspect 18 - The method according to any one of Aspects 13 to 17, wherein the segmented RRC message is included in the segmented RRC Protocol Data Unit (PDU).

[0113] Aspect 19 - The method according to any one of Aspects 13 to 18, wherein the generation of an RRC message indicating that the base station has received the first L segments occurs after the user equipment and the base station have established or rebuilt an RRC connection.

[0114] Aspect 20 - The method according to any one of aspects 13 to 19, wherein receiving the first L segments includes receiving the first L segments from the user equipment in a sequential manner.

[0115] Aspect 21 - The method according to any one of Aspects 13 to 19, wherein receiving the first L segments includes receiving the first L segments from another base station in a single message providing information about the user equipment.

[0116] Aspect 22 - A method according to any one of Aspects 13 to 21, wherein receiving the first L segments includes, for each of the first L segments, receiving a message including the segment and a segment number indicating the order of the segment in the segmented RRC message.

[0117] Aspect 23 - The method according to any one of aspects 13 to 22 further includes: receiving at least the last NL segments from the user equipment, wherein receiving the last NL segments from the user equipment includes receiving a message including the Nth segment of the segmented RRC message and an indication that the message includes the last segment of the segmented RRC message.

[0118] Aspect 24 - A base station including processing hardware configured to perform the method according to any one of aspects 13 to 23.

[0119] The following additional considerations apply to the foregoing discussion.

[0120] User equipment (e.g., UE 102) in which the technologies of this disclosure can be implemented can be any suitable device capable of wireless communication, such as a smartphone, tablet computer, laptop computer, mobile game console, point-of-sale (POS) terminal, health monitoring device, drone, camera, streaming dongle or other personal media device, wearable device (such as a smartwatch), wireless hotspot, femtocell, or broadband router. Furthermore, in some cases, the user equipment can be embedded in electronic systems, such as a vehicle head unit or advanced driver assistance system (ADAS). Additionally, the user equipment can operate as an Internet of Things (IoT) device or a mobile internet device (MID). Depending on the type, the user equipment may include one or more general-purpose processors, computer-readable storage, a user interface, one or more network interfaces, one or more sensors, etc.

[0121] In this disclosure, certain implementations are described as including logic or multiple components or modules. A module can be a software module (e.g., code stored on a non-transitory machine-readable medium) or a hardware module. A hardware module is a tangible unit capable of performing certain operations and can be configured or arranged in a certain way. A hardware module may include permanently configured dedicated circuitry or logic (e.g., as a dedicated processor, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC)) to perform certain operations. A hardware module may also include programmable logic or circuitry (e.g., contained within a general-purpose processor or other programmable processor) temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations.

[0122] When implemented in software, these technologies can be provided as part of an operating system, a library used by multiple applications, a specific software application, etc. The software can be executed by one or more general-purpose processors or one or more dedicated processors.

[0123] Upon reading this disclosure, those skilled in the art will understand that alternative structures and functional designs for managing the transmission of segmented RRC messages can be derived using the principles disclosed herein. Therefore, while specific embodiments and applications have been described and illustrated, it should be understood that the disclosed embodiments are not limited to the precise configurations and components disclosed herein. Various modifications, alterations, and variations that will be apparent to those skilled in the art may be made to the arrangement, operation, and details of the methods and apparatus disclosed herein without departing from the spirit and scope defined by the appended claims.

Claims

1. A method for managing the transmission of segmented Radio Resource Control (RRC) messages comprising N segments in a user equipment configured to communicate with a first base station via a radio link, wherein, The segmented RRC message includes RRC messages that have been segmented by the RRC layer of the user equipment, and the method includes: The first M segments of the segmented RRC message are transmitted to the first base station, where M is an integer greater than zero and less than N; Before transmitting the (M+1)th segment of the segmented RRC message, a radio link fault is detected; and After detecting a failure in the radio link, N segments of the segmented RRC message are transmitted to the first base station or the second base station.

2. The method according to claim 1, further comprising: Receive RRC messages from the first base station via the radio link. The transmission of the first M segments occurs in response to receiving the RRC message.

3. The method according to claim 2, wherein: The RRC message is a message requesting user equipment capability information; and The segmented RRC message is a message indicating the capabilities of the user equipment.

4. The method according to claim 2 or 3, further comprising: After detecting a failure in the radio link, an additional RRC message is received from either the first base station or the second base station. The transmission of N segments occurs in response to receiving the additional RRC message.

5. The method according to claim 2 or 3, further comprising: In response to the detection of a radio link failure, an RRC connection reconstruction process or an RRC connection establishment process is initiated with the first base station or the second base station. The transmission of N segments occurs after the user equipment establishes or re-establishes an RRC connection with the first base station or the second base station.

6. A user equipment, including processing hardware, and configured to perform the method according to any one of claims 1 to 5.

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