Separate bearer communication

Abstract

The present disclosure relates to techniques for performing wireless communications using separate bearers. A user equipment device may perform a recovery operation on a lost uplink packet. The recovery operation may be in response to an instruction from a network or may be initiated autonomously by the device.

Description

Technical Field

[0001] The present application relates to wireless communications, including avoiding delays and / or desynchronization of split bearer transmissions.

[0002] Related technical description

[0003] The use of wireless communication systems is growing rapidly. In addition, wireless communication technology has evolved from voice communications only to also include the transmission of data such as the Internet and multimedia content.

[0004] Mobile electronic devices may take the form of smartphones or tablets that are commonly carried by users. Wearable devices (also referred to as accessory devices) are a newer form of mobile electronic devices, an example being smart watches. In addition, low-cost, low-complexity wireless devices intended for static or dynamic deployment are also increasing rapidly as part of the development of the "Internet of Things". In other words, the complexity, capabilities, traffic patterns and other characteristics of the required devices are increasingly wide-ranging. In general, it is desirable to recognize and provide improved support for a wide range of required wireless communication characteristics. One feature may be the use of separate bearers. Improvements in this area are desired. Summary of the invention

[0005] Embodiments of systems, apparatus, and methods are presented herein for, inter alia, performing a radio resource control connection procedure for fast-moving wireless devices in a wireless communication system.

[0006] As described above, there are an increasing number of use cases for wireless network communications with different types of user equipment devices (UE) having widely varying capabilities and usage expectations. One direction of expansion of possible use cases supported by wireless communication techniques may include increasing the use of communication techniques that use multiple paths. The transmission of a packet may fail, and the failure may result in desynchronization between multiple paths. Therefore, the techniques described herein include techniques for a UE (e.g., communicating with a network) to quickly recover and retransmit failed packets (e.g., without desynchronization).

[0007] For example, the UE may communicate with the network via a separate bearer. One path or branch of the separate bearer may be designated as a primary path / branch, and one or more other paths / branches may be secondary paths / branches. The UE may use a packet data convergence protocol (PDCP) entity associated with the separate bearer to transmit packets to the network. The transmission may use one of the paths / branches. The network may transmit to the UE a confirmation of received packets and / or a negative confirmation of unreceived packets. The network may also transmit instructions to use different paths / branches and / or perform recovery operations. Alternatively, the UE may autonomously (or automatically) determine to perform a recovery operation, for example, without explicit instructions from the network. The UE may perform a recovery operation and may retransmit any packets that were not successfully received by the network.

[0008] The techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to mobile phones or smartphones (e.g., iPhones TM , based on Android TM phones), tablets (e.g., iPad TM 、Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smart watches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, vehicles, automobiles, unmanned aerial vehicles (e.g., drones) and unmanned flight controllers, other cellular network infrastructure equipment, servers, and any of a variety of other computing devices.

[0009] This disclosure is intended to provide a brief overview of some of the topics described in this document. Therefore, it should be understood that the above features are only examples and should not be construed as narrowing the scope or essence of the topics described herein in any way. Other features, aspects, and advantages of the topics described herein will become apparent through the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A better understanding of the present subject matter may be obtained when the following detailed description of the embodiments is considered in conjunction with the accompanying drawings.

[0011] Figure 1 An exemplary wireless communication system including an accessory device according to some embodiments is shown;

[0012] Figure 2 An exemplary wireless communication system is shown in which two wireless devices can perform direct device-to-device communication according to some embodiments;

[0013] Figure 3 is a block diagram illustrating an example wireless device according to some embodiments;

[0014] Figure 4 is a block diagram illustrating an exemplary base station according to some embodiments;

[0015] Figure 5is a communication flow diagram illustrating an exemplary method of communicating using split bearers according to some embodiments;

[0016] Figures 6 to 8 illustrates aspects of dual connectivity communications according to some embodiments;

[0017] Fig. 9 illustrates aspects of receiving according to some embodiments;

[0018] Fig.10 and Fig.11 illustrates aspects of a split-bearing configuration according to some embodiments;

[0019] Fig.12 illustrates aspects of delays in split bearer operations according to some embodiments;

[0020] Figures 13 to 17 illustrates aspects of a network-initiated recovery operation according to some embodiments; and

[0021] Figures 18 to 24 Various aspects of UE-initiated recovery operations according to some embodiments are shown.

[0022] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and detailed description thereof are not intended to limit this document to the specific forms disclosed, but on the contrary, their purpose is to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0023] Acronyms and abbreviations

[0024] The following acronyms and abbreviations are used in this disclosure:

[0025] 3GPP: Third Generation Partnership Project

[0026] 3GPP2: Third Generation Partnership Project 2

[0027] GSM: Global System for Mobile Communications

[0028] UMTS: Universal Mobile Telecommunications System

[0029] LTE: Long Term Evolution

[0030] RRC: Radio Resource Control

[0031] MAC: Media Access Control

[0032] CE: Control Element

[0033] Tx: Transmit (or transmit)

[0034] Rx: Receive (or receive)

[0035] RS: Reference signal

[0036] CSI: Channel State Information

[0037] PDCP: Packet Data Convergence Protocol

[0038] RLC: Radio Link Control

[0039] the term

[0040] The following are definitions of terms used in this disclosure:

[0041] Memory medium - any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROM, floppy disk or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard disk drive or optical storage device; registers or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or a combination thereof. In addition, the memory medium may be located in the first computer system executing the program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., in the form of a computer program) that may be executed by one or more processors.

[0042] Carrier Media—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic, or digital signals.

[0043] Programmable hardware element - includes various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGA (field programmable gate array), PLD (programmable logic device), FPOA (field programmable object array), and CPLD (complex PLD). Programmable function blocks can vary from fine-grained (combinational logic unit or lookup table) to coarse-grained (arithmetic logic unit or processor core). Programmable hardware elements may also be referred to as "configurable logic units".

[0044] Computer System—Any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0045] User Equipment (UE) (or "UE device") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile phones or smart phones (e.g., iPhone TM , based on Android TM phones), tablets (e.g., iPad TM 、Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smart watches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, vehicles, cars, unmanned aerial vehicles (e.g., drones) and unmanned flight controllers, etc. In general, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunication device (or combination of these devices) that is easily transportable by a user and capable of wireless communication.

[0046] Wireless Device—Any of various types of computer systems or devices that perform wireless communications. A wireless device may be portable (or mobile), or may be stationary or fixed at a certain location. A UE is an example of a wireless device.

[0047] Communication device - any of various types of computer systems or devices that perform communication, where the communication may be wired or wireless. A communication device may be portable (or mobile), or may be stationary or fixed at a location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0048] Base Station—The term “base station” has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless communication system.

[0049] Link budget limited—includes the full range of its ordinary meaning and includes at least the characteristics of a wireless device (e.g., UE) that exhibits limited communication capabilities or limited power relative to a device that is not link budget limited or relative to a device for which a radio access technology (RAT) standard has been developed. A link budget limited wireless device may experience relatively limited receive capabilities and / or transmit capabilities, which may be due to one or more factors, such as device design, device size, battery size, antenna size or design, transmit power, receive power, current transmission medium conditions, and / or other factors. Such devices may be referred to herein as "link budget limited" (or "link budget constrained") devices. A device may be inherently link budget limited due to the size of the device, battery power, and / or transmit / receive power. For example, a smart watch that communicates with a base station via LTE or LTE-A may be inherently link budget limited due to its reduced transmit / receive power and / or antenna reduction. Wearable devices such as smart watches are generally link budget limited devices. Alternatively, a device may not be inherently link budget limited, e.g., may have sufficient size, battery power, and / or transmit / receive power for normal communication over LTE or LTE-A, but may be temporarily link budget limited due to current communication conditions, e.g., a smartphone at a cell edge, etc. It is noted that the term "link budget limited" includes or encompasses power limitations, and thus a link-limited device may be considered a link budget limited device.

[0050] Processing element (or processor) – refers to various elements or combinations of elements that are capable of performing functions in a device, such as a user equipment device or a cellular network device. Processing elements may include, for example, processors and associated memory, portions or circuits of individual processor cores, entire processor cores, separate processors, processor arrays, circuits such as ASICs (application specific integrated circuits), programmable hardware elements such as field programmable gate arrays (FPGAs), and any of the above combinations.

[0051] Automatic—refers to an action or operation being performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the action or operation being directly specified or performed by a user input. Thus, the term "automatically" is in contrast to an operation being manually performed or specified by a user, where the user provides input to directly perform the operation. An automatic process may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing in information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. The form may be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As indicated above, a user may invoke automatic filling out of a form, but not participate in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0052] Configured to - Various components may be described as being "configured to" perform one or more tasks. In such environments, "configured to" is a broad statement that generally means "having a structure" that performs one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad statement that generally means "having a structure" that performs one or more tasks during operation. Thus, the component can be configured to perform a task even when the component is not currently turned on. Typically, the circuitry that forms the structure corresponding to "configured to" may include hardware circuitry.

[0053] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to". The description of a component being configured to perform one or more tasks is expressly intended to not invoke the interpretation of the sixth paragraph of Section 112 of Title 35 of the United States Code on that component.

[0054] Figure 1-Figure 2 —Wireless communication system

[0055] Figure 1 An example of a wireless cellular communication system is illustrated. It should be noted that Figure 1This represents one possibility among many, and the features of the present disclosure may be implemented by any of a variety of systems as desired.For example, the embodiments described herein may be implemented in any type of wireless device.

[0056] As shown, the exemplary wireless communication system includes a cellular base station 102 that communicates over a transmission medium with one or more wireless devices 106A, 106B, etc., and an accessory device 107. Wireless devices 106A, 106B, and 107 may be user devices, which may be referred to herein as "user equipment" (UE) or UE devices.

[0057] The base station 102 may be a base transceiver station (BTS) or a cell site and may include hardware and / or software that implements wireless communications with the UE device 106A, the UE device 106B, and the UE device 107. If the base station 102 is implemented in the context of LTE, it may be referred to as an "eNodeB" or "eNB". If the base station 102 is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB". The base station 102 may also be equipped to communicate with the network 100 (e.g., a core network of a cellular service provider, a telecommunications network such as a public switched telephone network (PSTN), and / or the Internet, as well as a variety of possible networks). Thus, the base station 102 may facilitate communications between the UE device 106 and the UE device 107 and / or communications between the UE device 106 / 107 and the network 100. Also as used herein, with respect to the UE, the base station may sometimes be considered to represent the network in the case of considering the uplink (UL) and downlink (DL) communications of the UE. Therefore, a UE communicating with one or more base stations in a network may also be understood as a UE communicating with the network.

[0058] In other embodiments, base station 102 may be configured to provide communications via one or more other wireless technologies, such as an access point supporting one or more WLAN protocols, such as 802.11a, b, g, n, ac, ad and / or ax, or LTE in an unlicensed band (LAA).

[0059] The communication area (or coverage area) of the base station 102 may be referred to as a “cell.” The base station 102 and the UE 106 / 107 may be configured to communicate over a transmission medium using any of various radio access technologies (RATs) or wireless communication technologies, such as GSM, UMTS (WCDMA, TDS-CDMA), LTE, Advanced LTE (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, etc.

[0060] Thus, base station 102 and other similar base stations (not shown) operating according to one or more cellular communication technologies can be provided as a cell network that can provide continuous or near-continuous overlapping service to UE devices 106A-N and UE device 107 and similar devices within a geographic area via one or more cellular communication technologies.

[0061] Note that, at least in some cases, UE device 106 / 107 may be able to communicate using any of a variety of wireless communication technologies. For example, UE device 106 / 107 may be configured to communicate using one or more of GSM, UMTS, CDMA2000, LTE, LTE-A, NR, WLAN, Bluetooth, one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication technologies (including more than two wireless communication technologies) are also possible. Similarly, in some cases, UE device 106 / UE device 107 may be configured to communicate using only a single wireless communication technology.

[0062] UE 106A and UE 106B may include handheld devices such as smart phones or tablets, and / or may include any of various types of devices with cellular communication capabilities. For example, one or more of UE 106A and UE 106B may be wireless devices intended for static or dynamic deployment, such as home appliances, measurement devices, control devices, etc. UE 106B may be configured to communicate with UE device 107, which may be referred to as accessory device 107. Accessory device 107 may be any of various types of wireless devices, which may generally be wearable devices with a small form factor and limited battery, output power and / or communication capabilities relative to UE 106. As a common example, UE 106B may be a smart phone carried by a user, and accessory device 107 may be a smart watch worn by the same user. UE 106B and accessory device 107 may communicate using any of various short-range communication protocols, such as Bluetooth or Wi-Fi. In some cases, UE 106B and accessory device 107 can utilize proximity services (ProSe) technology, for example, in a manner supported by a cellular base station to perform direct peer-to-peer communications. For example, such ProSe communications can be performed as part of a relay link to support a radio resource control connection between accessory device 107 and BS 102, such as according to various embodiments described herein.

[0063] UE 106B may also be configured to communicate with UE 106A. For example, UE 106A and UE 106B may be able to perform direct device-to-device (D2D) communications. D2D communications may be supported by cellular base station 102 (e.g., BS 102 may facilitate discovery, as well as various possible forms of assistance), or may be performed in a manner that is not supported by BS 102. For example, it may be possible that UE 106A and UE 106B are able to arrange and perform D2D communications (e.g., including discovery communications) even when BS 102 and other cellular base stations have no coverage.

[0064] BS 102 may control one or more transmit and receive points (TRPs) and may use the TRPs to communicate with UEs. The TRPs may be collocated with the BS and / or at a separate physical location.

[0065] Figure 2 An exemplary BS 102 is shown communicating with a UE device 106, which in turn communicates with an accessory device 107. The UE device 106 and the accessory device 107 may be any of a mobile phone, a tablet or any other type of handheld device, a smart watch or other wearable device, a media player, a computer, a laptop, an unmanned aerial vehicle (UAV), an unmanned flight controller, a vehicle, or virtually any type of wireless device. In some embodiments, the accessory device may be a wireless device designed to have low cost and / or low power consumption, and may benefit from a relay link with the UE device 106 (and / or another companion device) to support communications with the BS 102. For example, in Figure 2 In the exemplary scenario of , a device that utilizes a relay link with another wireless device to communicate with a cellular base station may also be referred to herein as a remote wireless device, a remote device, or a remote UE apparatus, and a wireless device that provides such a relay link may also be referred to herein as a relay wireless device, a relay device, or a relay UE device. According to some embodiments, such BS 102, UE 106, and accessory device 107 may be configured to perform radio resource control procedures for the remote wireless device according to the various techniques described herein.

[0066] Both UE 106 and accessory device 107 may include a device or integrated circuit called a cellular modem for facilitating cellular communication. The cellular modem may include one or more processors (processing elements) configured to execute program instructions stored in a memory and / or various hardware components described herein. UE 106 and / or accessory device 107 may each execute any of the method implementation schemes described herein by executing such stored instructions. Alternatively or in addition thereto, UE 106 and / or accessory device 107 may include a programmable hardware element configured to (e.g., individually or in combination) execute any of the method implementation schemes described herein or any part of any of the method implementation schemes described herein, such as an FPGA (field programmable gate array), an integrated circuit and / or any of various other possible hardware components. The cellular modem described herein may be used in a UE device as defined herein, a wireless device as defined herein, or a communication device as defined herein. The cellular modem described herein may also be used in a base station or other similar network side device.

[0067] UE 106 and / or accessory device 107 may include one or more antennas for communicating according to one or more RAT standards using one or more wireless communication protocols. In some embodiments, one or both of UE 106 or accessory device 107 may be configured to communicate using a single shared radio component. The shared radio may be coupled to a single antenna, or may be coupled to multiple antennas (e.g., for MIMO) for performing wireless communications. Typically, the radio component may include any combination of a baseband processor, analog radio frequency (RF) signal processing circuits (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuits (e.g., for digital modulation and other digital processing). Similarly, the radio component may use the aforementioned hardware to implement one or more receive chains and transmit chains.

[0068] Alternatively, UE 106 and / or accessory device 107 may include two or more radio components. For example, in some embodiments, UE 106 and / or accessory device 107 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, UE 106 and / or accessory device 107 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, UE 106 and / or accessory device 107 may include a shared radio component for communicating using either LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and a shared radio component for communicating using Wi-Fi and BLUETOOTH. TM Each of the two devices communicates with a separate radio component. Other configurations are also possible.

[0069] Figure 3 —Block diagram of UE equipment

[0070] Figure 3 One possible block diagram of a UE device, such as UE device 106 or 107, is shown. As shown, the UE device 106 / 107 may include a system on a chip (SOC) 300, which may include parts for various purposes. For example, as shown, the SOC 300 may include a processor 302, which may execute program instructions for the UE device 106 / 107, and a display circuit 304, which may perform graphics processing and provide display signals to a display 360. The SOC 300 may also include a motion sensing circuit 370, which may detect the motion of the UE 106, for example, using any of a gyroscope, an accelerometer, and / or various other motion sensing components. Processor 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, flash memory 310) and / or other circuits or devices, such as display circuit 304, radio 330, I / F 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of processor 302.

[0071] As shown, the SOC 300 may be coupled to various other circuits of the UE 106 / 107. For example, the UE 106 / 107 may include various types of memory (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 360, and wireless communication circuits 330 (e.g., for LTE, LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

[0072] The UE device 106 / 107 may include at least one antenna and may include multiple antennas 335a and 335b for performing wireless communications with a base station and / or other devices in some embodiments. For example, the UE device 106 / 107 may use antennas 335a and 335b to perform wireless communications. As described above, the UE device 106 / 107 may be configured to use multiple wireless communication standards or radio access technologies (RATs) for wireless communications in some embodiments.

[0073] Wireless communication circuitry 330 may include Wi-Fi logic 332, cellular modem 334, and Bluetooth logic 336. Wi-Fi logic 332 is used to enable UE device 106 / 107 to perform Wi-Fi communications on an 802.11 network. Bluetooth logic 336 is used to enable UE device 106 / 107 to perform Bluetooth communications. Cellular modem 334 may be a lower power cellular modem capable of performing cellular communications according to one or more cellular communication technologies.

[0074] As described herein, UE 106 / 107 may include hardware components and software components for implementing embodiments of the present disclosure. For example, by executing program instructions stored on a storage medium (e.g., a non-transitory computer-readable memory medium), the processor 302 of the UE device 106 / 107 may be configured to implement part or all of the methods described herein. In other embodiments, the processor 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). In addition, the processor 302 may be coupled to a processor such as a processor 106 / 107. Figure 3The other components shown and / or may interoperate with the other components to perform radio resource control processes for remote wireless devices according to various embodiments disclosed herein. The processor 302 may also implement various other applications and / or end-user applications running on the UE 106. Alternatively or in addition, one or more components of the wireless communication circuit 330 (e.g., cellular modem 334) of the UE device 106 / 107 may be configured as a processor that executes program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), is configured as an FPGA (field programmable gate array) and / or uses a dedicated hardware component that may include an ASIC (application-specific integrated circuit) to implement part or all of the methods described herein.

[0075] Figure 4 —Block diagram of a base station

[0076] Figure 4 An exemplary block diagram of a base station 102 according to some embodiments is shown. Note that Figure 4 The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device, which may be configured to receive addresses from the processor 404 and convert these addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0077] The base station 102 may include at least one network port 470. Figure 1 and Figure 2 As described in , the network port 470 can be configured to couple to a telephone network and provide multiple devices, such as the UE devices 106 / 107, with access to the telephone network.

[0078] The network port 470 (or an additional network port) may also be configured or alternatively configured to be coupled to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices such as UE devices 106 / 107. For example, the core network may include, for example, a mobility management entity (MME) for providing mobility management services, a serving gateway (SGW) and / or a packet data network gateway (PGW) for providing external data connections such as to the Internet, and the like. In some cases, the network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., between other UE devices served by the cellular service provider).

[0079] The base station 102 may include at least one antenna 434 and possibly multiple antennas. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE device 106 / 107 via the radio component 430. The antenna 434 communicates with the radio component 430 via a communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio component 430 may be configured to communicate via various wireless communication standards, including but not limited to LTE, LTE-A, NR, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0080] Base station 102 may be configured to communicate wirelessly using multiple wireless communication standards. In some cases, base station 102 may include multiple radios that enable base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, base station 102 may include an LTE radio for performing communications according to LTE and a Wi-Fi radio for performing communications according to Wi-Fi. In such cases, base station 102 may be capable of operating as both an LTE base station and a Wi-Fi access point. As another possibility, base station 102 may include a multimode radio component capable of performing communications according to any of multiple wireless communication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0081] As further described later herein, BS 102 may include hardware and software components for implementing or supporting a specific implementation of the features described herein. According to some embodiments, the processor 404 of the base station 102 may be configured to implement a portion or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit) or a combination thereof. Alternatively (or in addition thereto), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, 470, the processor 404 of the BS 102 may be configured to implement or support implementation of any of the various other features of the radio resource control process for remote wireless devices according to the various embodiments described herein, and / or the features described herein.

[0082] Figure 5 -Communication Flowchart

[0083] Communications between the network and the UE may use one or more paths (e.g., branches). For example, a separate bearer may be established between the UE and the network so that communications may be separated between multiple paths. For example, different paths may be associated with different cells and / or different radio access technologies.

[0084] A transmission (e.g., an uplink transmission from a UE to a network) may fail on a first path. The network may configure the UE to use a second path. However, due to any of various possibilities regarding the reordering window, reordering timer, reconfiguration, and relative timing of retransmissions of failed transmissions, the delay between the initial transmission of the packet and the successful retransmission may be sufficient to cause desynchronization of the paths and / or otherwise interfere with efficient communication between the UE and the network.

[0085] Figure 5 is a communication flow diagram illustrating an exemplary method for performing communications using multiple paths according to some embodiments. Figure 5 The method can alleviate some delay and / or desynchronization challenges. In various embodiments, some of the elements of the method shown may be performed simultaneously in an order different from the order shown, may be replaced by other method elements, or may be omitted. Additional method elements may also be performed as needed.

[0086] Figure 5 Various aspects of the method may be implemented by a UE such as UE 106 or 107, a cellular network and / or one or more BSs 102, for example, as shown in the figure and described with reference to the figure, or more generally in combination with any of the computer systems, circuits, elements, components or devices shown in the figure, etc. For example, one or more processors (or processing elements) (in various possibilities, for example, processors 302, 404, baseband processors, processors associated with communication circuits such as 330, 430 or 432, processors associated with various core network elements, etc.) may cause the UE, network element and / or BS to perform some or all of the elements of the method shown. Note that although the method is described in a manner involving the use of communication techniques and / or features associated with LTE, NR and / or 3GPP specification documents, Figure 5 At least some elements of the method, but this description is not intended to limit the present disclosure and can be used in any suitable wireless communication system as needed Figure 5 Aspects of the method. As shown, the method can be operated as follows.

[0087] According to some embodiments, the UE and the network may establish communication (502). The UE and the network may communicate using one or more radio access technologies (RATs), including, for example, NR. The UE and the network may communicate using one or more BSs 102. The BS 102 may provide one or more cells and / or cell groups, and the communication between the UE and the network may use one or more cells and / or cell groups.

[0088] The UE and the network may exchange application and / or control data in the uplink and / or downlink directions. Communication and measurement may occur on any frequency or frequency combination, including, for example, licensed and / or unlicensed spectrum. Communication and measurement may continue (e.g., periodically, randomly, as needed, etc.) for any amount of time. For example, communication and measurement may occur on any number of subframes, time slots, and / or symbols. These measurements may include any radio link measurement results, such as signal-to-noise ratio (SNR), signal-to-interference noise ratio (SINR), reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indication (RSSI), block error rate (BLER), bit error rate (BER), channel impulse response (CIR), channel error response (CER), etc. The UE and / or network may keep a history of the measured values. The UE / network may compare the measured value or the metric calculated based on the measured value with one or more thresholds. In such comparisons, the UE / network may use various parameters, for example, for hysteresis. The measurement results, thresholds, and / or parameters may be configured by the network (e.g., by the network) and / or by the UE. The UE and / or the network may report measurement values ​​(eg, directly and / or as a channel quality indication (CQI), channel state information (CSI), etc.), comparison results, etc., to each other at any time.

[0089] Communications may use acknowledged mode (AM) and / or unacknowledged mode (UM). For example, in AM, transmissions may use a hybrid automatic repeat request (HARQ) system to acknowledge (ACK) and / or to deny (NACK). In UM, transmissions may not be acknowledged (e.g., acknowledged and / or denied). For example, the network may configure the UE to use AM.

[0090] According to some embodiments, the network may transmit control information to the UE to configure one or more bearers (504). For example, the UE may be configured to communicate with the network using separate bearers and / or other communication methods using multiple logical paths. For example, separate bearers may use a combination of a primary cell group (MCG) and a secondary cell group (SCG). In some cases, separate bearers may use non-cellular RATs. For example, one path may use a cellular RAT (e.g., LTE, NR, etc.) and another path may use a non-cellular RAT, such as WLAN.

[0091] In some embodiments, the network may configure the bearer in the AM.

[0092] In some embodiments, additional and / or different bearers may be configured.

[0093] The control information configuring the bearer may identify the primary path. Other paths may be identified (e.g., explicitly or implicitly) as secondary, tertiary, etc. For example, a path using an SCG may be configured as a primary path, while a path using an MCG may be a secondary path, or vice versa.

[0094] The control information may indicate a data separation threshold. Uplink transmissions with data volumes less than the threshold may use a single path (eg, primary path), while transmissions with data volumes greater than or equal to the threshold may use two paths (eg, scheduled by the network).

[0095] The control information may specify, among various possibilities, conditions (e.g., one condition or a set of conditions) for performing a recovery operation, e.g., a Packet Data Convergence Protocol (PDCP) data recovery procedure. Existing technical specifications may specify the use of PDCP data recovery in three situations, e.g., switching without changing security, changing the bearer type, and reconfiguration after reconstruction. As further described herein, according to some embodiments, additional situations may be allowed. For example, the control information may indicate that the network may use a flag associated with (e.g., future) bearer reconfiguration to explicitly trigger a recovery operation. Alternatively, the control information may indicate conditions under which the UE may autonomously (or automatically) perform a recovery operation. For example, the control information may indicate that the UE may perform a recovery operation in response to an implicit indication from the network, based on measurements and / or based on a transmission failure threshold, as well as other possibilities.

[0096] In addition, the control information may specify various aspects of the recovery operation for the UE to perform. In some embodiments, various aspects of the recovery operation for the UE to perform may depend on the conditions that trigger the recovery operation. For example, the control information may indicate when / whether the UE should: reestablish a radio link control (RLC) entity, perform recovery without reestablishing an RLC entity, and / or suspend an RLC entity.

[0097] In some implementations, the control information may be transmitted via Radio Resource Control (RRC), among other possibilities.

[0098] According to some embodiments, the UE may transmit a plurality of packets to the network (506). The plurality of packets may include uplink data.

[0099] Packets may be transmitted on a bearer (e.g., a separate bearer configured according to control information). For example, packets may be transmitted on a primary path or a secondary path based on a data separation threshold and / or scheduling performed by the network (e.g., based on a path for which an uplink grant is provided by the network). Packets may be provided to the PDCP layer from an upper layer (e.g., of the UE). The PDCP layer may maintain sequence number (SN) information for the packets. The PDCP layer of the UE may route the packets to one or more RLC entities, e.g., corresponding to one or more paths over which the packets are to be transmitted. The RLC entity may provide the packets to a medium access control (MAC) layer entity (e.g., based on the RAT used by the path) for further processing and transmission.

[0100] According to some embodiments, these packets may be protocol data units (PDUs).According to some embodiments, the RLC layer may assemble the PDUs from service data units (SDUs) that may be provided by higher layers (eg, PDCP).

[0101] The packets may be transmitted on any combination of time / frequency resources, such as resource blocks (RBs) or resource elements (REs).According to some embodiments, the packets may be transmitted using an AM RLC entity.

[0102] The network may receive some or all of these packets, for example, using MAC, RLC, and PDCP entities corresponding to the UE's entities. For example, the RLC entity (or entities) may track which packets are received (e.g., based on the SN). For example, before providing the packets to upper layers, the network's PDCP entity may perform functions including duplicate detection and / or reordering packets (e.g., based on the SN).

[0103] The packet may be or include a data packet. In some embodiments, the packet may include control information in addition to or in lieu of data.

[0104] According to some embodiments, the network may detect that at least one packet of the plurality of packets is lost (508). For example, based on the SN of the received packets, the network (e.g., at the RLC layer and / or the PDCP layer) may determine that the SN is not received (e.g., based on receiving packets 1, 2, and 4, the network may detect that the packet with SN=3 is lost). The network may maintain one or more timers (e.g., Treordering) associated with any gaps in the received SN values ​​(e.g., SN=3). Thus, when the corresponding timer expires, the packet may be considered lost.

[0105] The network may also maintain a reordering window, which may be associated with one or more paths. The reordering window may represent a range of SN values ​​expected to be received on the corresponding path, for example.

[0106] According to some embodiments, the network may transmit an acknowledgment to the UE based on the received packets (510). For example, in response to receiving a packet or a group of packets, the network (e.g., an RLC entity) may generate a positive acknowledgment (ACK) for the received packets and transmit the ACK to the UE. Similarly, the network may send a negative acknowledgment (NACK) for any unsuccessfully received packets. In some embodiments, the network may not send a NACK and may implicitly indicate that the packet was not received based on the lack of a positive acknowledgment.

[0107] Based on the sent or unsent acknowledgements, the UE can determine which packets of the plurality of packets were received by the network.

[0108] According to some embodiments, the network may reconfigure the bearer (512). For example, the network may reconfigure the bearer to change which path is the primary path. For example, the primary path may be switched from the MCG to the SCG, or vice versa.

[0109] Reconfiguration may be performed for a variety of reasons. For example, reconfiguration may be based on measurements performed by the network and / or measurements reported by the UE. Similarly, reconfiguration may be based on network conditions, such as traffic load on one or more cells or groups of cells, etc. In addition, reconfiguration may be based on the number of lost packets (e.g., in the uplink and / or downlink direction) reaching a threshold. Any combination of these or other reasons may be used.

[0110] The network may transmit the reconfiguration as a message to the UE, for example as an RRC reconfiguration message.

[0111] The reconfiguration message may include or be associated with one or more indications to the UE in response to the network not correctly receiving one or more packets. For example, the message may be associated with an indication to perform a recovery operation. In addition, the message may be associated with an indication to reestablish one or more RLC entities. In addition, the message may be associated with an indication to suspend one or more RLC entities. In addition, the message may be associated with an indication to refresh one or more RLC entities.

[0112] These indications may be provided in any combination of messages. For example, any of these indications may be provided in an RRC reconfiguration message, or any of these indications may be provided in one or more separate messages. If such an indication is included in an RRC reconfiguration message, it may be in the form of a flag in the configuration of the relevant layer. For example, an indication to perform PDCP recovery may be in the form of a flag configured by the PDCP. Similarly, an indication to reestablish, suspend or refresh an RLC entity may be in the form of a flag configured by the RLC.

[0113] It should be understood that although 512 is shown as occurring after 508 and 510, this ordering is exemplary. In some embodiments, 512 may occur before 508 and / or 510, or may occur simultaneously. Thus, reconfiguration may be based in whole or in part on determining packet loss, or reconfiguration may be based entirely on other factors (e.g., radio measurements, network conditions, etc.).

[0114] According to some embodiments, the UE may determine to perform a recovery operation, and the UE may perform the recovery operation (514).

[0115] The determination to perform the recovery operation may be in response to an explicit indication from the network, or may be determined autonomously (or automatically) based on conditions. Such conditions that are autonomously determined (e.g., or implicitly indicated) may be described in the standard and / or configured in the control information (e.g., as described above with respect to 504).

[0116] The recovery operation may include PDCP data recovery. The PDCP recovery may include reestablishing any RLC entities associated with the bearers of the PDCP entity. The PDCP data recovery operation may include providing a PDCP status report to the network. The status report may identify (e.g., by the SN) packets that have or have not been transmitted to the network and / or acknowledged by the network.

[0117] In some embodiments, the recovery operation may include reestablishing, refreshing, suspending one or more entities, such as RLC and / or PDCP entities of the UE. For example, to reestablish the RLC entity, the UE may terminate (or temporarily suspend) the RLC entity associated with the old path and create or activate the RLC entity associated with the new path, such as shown in 512.

[0118] To refresh the RLC entity, the UE may treat one or more packets that were not positively acknowledged (and / or negatively acknowledged) as acknowledged in the RLC entity. The PDCP entity may then re-provision these packets to the RLC entity (e.g., with a new SN) for transmission to the network, e.g., as if they were new packets.

[0119] To suspend an RLC entity, the UE may temporarily suspend RLC operations (eg, for a specific bearer) and await instructions from the network on how / whether to resume those RLC operations (eg, in an existing RLC entity or in a different / new RLC entity).

[0120] In some embodiments, the UE may also provide relevant information to the network. For example, the UE may transmit an indication of a recovery operation being performed (or to be performed or having been performed). In addition, the UE may transmit an indication of the status of any relevant entity (e.g., PDCP and / or RLC entity). For example, the UE may indicate that an RLC entity has been reestablished and may provide information about the reestablished entity. Similarly, if the RLC entity is refreshed, the UE may indicate the SN of any packet being considered for confirmation. In addition, the UE may indicate a suspension of an RLC entity.

[0121] Such indication may be provided in any of a variety of ways. For example, one or more RRC messages may be used to convey the indication using one or more flags. Alternatively or additionally, other forms of uplink control information may be used.

[0122] According to some embodiments, the UE may retransmit one or more packets (516). For example, the UE may retransmit any packets lost by the network as determined by the UE based on received ACKs and / or NACKs (as described above with respect to 510). For example, the UE may perform retransmissions of all packets previously submitted to the AM RLC entity whose successful delivery has not been confirmed by lower layers. The packets may be transmitted in ascending order (e.g., ascending order of SN and / or associated COUNT values) starting with the first packet (e.g., PDCP PDU) whose delivery was not confirmed.

[0123] It should be understood that for clarity, 516 is shown separately from 514. However, according to some embodiments, retransmission can be performed as part of the recovery operation. For example, retransmission of the packet can be performed before, after, during, or simultaneously with other aspects of the recovery operation.

[0124] According to some embodiments, the network may update the entity to correspond to the reconfiguration (518). For example, the network may, for example, reestablish, suspend, release, refresh and / or reconfigure the RLC entity based on an explicit indication from the UE and / or based on an action of determining the UE based on other information (e.g., control information provided to the UE and / or measurement reports, SNs, or other information received from the UE) to match the corresponding RLC entity of the UE. The network may treat any packet that the UE indicates it is treating as being acknowledged as acknowledged. Thus, the network's RLC and / or PDCP buffers may be consistent with those of the UE. In addition, the network may update any timers and / or reordering windows associated with received packets, reconfigured RLC and / or PDCP entities, etc.

[0125] Figures 6 to 8 -Dual connection operation

[0126] A network communicating with a UE may use various types of dual connectivity (DC) operations. For example, multi-RAT dual connectivity (MR-DC) may describe a configuration in which a UE communicates with a network via multiple RATs (e.g., simultaneously) (e.g., using multiplexing).

[0127] Figure 6 A UE in communication with an MCG and an SCG according to some embodiments is shown. In some embodiments, the MCG may be a large cell and the SCG may be a small cell. In other embodiments, the MCG and the SCG may be the same size, or the SCG may be a large cell and the MCG may be a small cell.

[0128] According to the DC operation in the control plane, the UE can maintain two connections, for example, in the MCG and SCG. In the MCG, the primary cell (PCell) can be always activated. In the SCG, the primary cell (PSCell) of the SCG can be always activated.

[0129] According to DC operation in the user plane, the UE can support three bearer types: 1) MCG bearer, 2) SCG bearer and 3) split bearer. Figure 7 The UE-side radio protocol architecture for these three types of bearers according to some embodiments is shown. As shown, each bearer can have its own PDCP entity. The PDCP entity of the separated bearers can be associated with the RLC entity of each cell group (for example, shown as different RATs, but it should be understood that the RATs of these cell groups can be the same, these RATs can be reversed so that the MCG can be NR, and / or different RATs can be used, etc.). At the MAC layer, each path / cell group can be associated with an independent MAC entity.

[0130] For split bearers, uplink operation may be controlled in part by a data split threshold (e.g., DataSplitThreshold). According to some embodiments, the threshold may be configured by RRC. For data amounts less than DataSplitThreshold, UL transmissions may be performed via the main branch (e.g., RRC configured). For data amounts greater than or equal to DataSplitThreshold, UL transmissions may occur via one or both branches, for example, depending on scheduling performed by the network.

[0131] Figure 8An uplink transmission using a split bearer according to some embodiments is shown. Data (e.g., any number of RBs) may be provided from upper layers of the device to a PDCP entity for the split bearer. Based on a data split threshold and / or scheduling information from the network, the PDCP entity may split the data into a first portion for RLC and MAC transmission via the MCG and a second portion for RLC and MAC transmission via the SCG.

[0132] Fig. 9 - Receive Operation

[0133] Fig. 9 Receive operations according to some embodiments are shown. In some embodiments, the PDCP layer (e.g., in the case of uplink transmission, such as at a receiving device at the network) may perform reordering and duplicate detection based on data transmitted from two links (e.g., two paths of a separate bearer). The reordering may apply to all received packets within a PDCP reordering window, e.g., regardless of which path(s) the packets were received on. The reordering window may be a range of SN values.

[0134] The PDCP reordering window (also called the push window) may be moved (e.g., rotated clockwise as shown) based on either of two conditions:

[0135] - Case 1: New packets (e.g., data) are received in sequence from a lower layer. For example, the reordering window may be advanced by the number of packets (e.g., SN) successfully received in sequence. For example, in response to receiving packets with SNs 3-5, the lower edge of the reordering window may be advanced to SN 6.

[0136] - Case 2: Based on expiration of a timer (e.g., Treordering). For example, a timer (e.g., Treordering) may be started based on reception gap detection. In other words, if there is a gap in the SN values ​​of successfully received packets, the timer may be started. The timer may control the delay of the reordering window movement. Upon expiration of the timer, the lower edge of the reordering window may be moved to the next gap in the SN values ​​of successfully received packets. For example, if SN 3 is lost when SN 4 is received, and SN 3 is not received while the timer is running, the lower edge of the reordering window may be advanced to the SN value of the next higher packet that has not yet been received, e.g., SN 5.

[0137] In addition to the above Figure 5In addition to the cases discussed in the method, PDCP recovery can also be used in the following cases: 1) handover (e.g., handover between cells or within a cell) without changing security (e.g., UE can retransmit unacknowledged packets without reestablishing RLC); 2) change of bearer type, such as initiated by the network; and 3) first RRC reconfiguration after UE connection reestablishment (e.g., triggered by radio link failure (RLF)). Among the various possibilities, PDCP recovery may include reestablishing the associated RLC entity and retransmitting unacknowledged PDCP PDUs from the PDCP layer.

[0138] Fig.10 and Fig.11 -Separate load configuration

[0139] Fig.10 and Fig.11 ( Fig.11 yes Fig.10 Continuation of ) shows a split-bearing configuration according to some embodiments. Specifically, Fig.10 and Fig.11 An information element (IE) that may be used to configure functionality related to a split bearer is shown. Note that a data radio bearer (DRB) may be an example of a bearer as described herein.

[0140] The split bearer configuration may be performed by RRC. More than one RLC entity may be associated to a PDCP entity associated with a bearer. The primary path (re)configuration may be performed via normal RRCReconfiguration. The bearer type configuration may be determined by the network (e.g., based on network configuration). The following may be an example of processing associated with (e.g., during) RRC reconfiguration.

[0141] In the first case, a split DRB can be configured with a primary path change. When the amount of available data is less than DataSplitThreshold, the UE can transmit new packets to the new primary path. The UE can continue the ongoing transmission via the previous primary path.

[0142] In the second case, the bearer type may be changed. The change may not include a security change and PDCP may not be reestablished. For example, a detached DRB may be changed (e.g., reconfigured) to an MCG or SCG DRB. The network may trigger a PDCP recovery procedure and the UE's PDCP entity may retransmit unacknowledged packets with the same PDCP SN.

[0143] In the third case, transmission of the separated DRB may be suspended during SCG / MCG fast failure recovery. The UE may suspend transmission via the problematic path / CG and may continue transmission on the normal path / CG. After receiving the associated RRC configuration for recovery purposes, the UE may resume transmission on the previously problematic path.

[0144] Fig.12 - Delays and desynchronization in separate bearer operations

[0145] Fig.12 Example scenarios that may result in delays and / or desynchronization according to some embodiments are shown. Depending on the current PDCP receive operation, the receive window may be moved based on the expiration of the T reordering timer. The configuration of T reordering may be designed to account for potential RLC / MAC retransmission delays between the two branches. The configuration of T reordering may be based on a specific (e.g., assumed) degree of synchronization of transmissions between the two links.

[0146] Desynchronization between the two links may disrupt the PDCP reception operation in the following scenarios. For example, if the network starts T reordering due to a lack of a packet (e.g., PDCP PDU#5), the network may not receive the PDU when T reordering expires. Therefore, the PDCP receive window may move forward. Therefore, the expired PDCP PDU#5 may arrive too late (e.g., after the timer expires), but it may still be in the current PDCP reception / reordering window. Therefore, the network PDCP may treat the PDU as a new packet and may start the t reordering timer for the lost PDU. The network may update the PDCP window and may transmit the packet to the upper layer accordingly.

[0147] Desynchronization may occur in association with an RRC procedure. For example, desynchronization may occur in the following situations: Fig.12As shown. The main path of the separated DRB can be switched from SCG to MCG. Before the switch, the packet (SN#3) transmitted via the SCG may not be successfully received by the network (NW). New data transmission via the new main path (e.g., MCG) may occur. The transmission of the PDCP PDU (e.g., SN#3) in progress on the main path (e.g., SCG) can continue on the current path (SCG). The SCG path may experience poor uplink radio conditions and RLC failure may be detected after a long time. Therefore, the SCG failure process can be triggered. In response to the SCG failure indication, the network can provide RRCReconfiguration to release the SCG and reconfigure the separated DRB as an MCG DRB. In association with the reconfiguration bearer, the network can trigger PDCP recovery (e.g., the network can mark PDCP recovery = true). Therefore, the UE can perform a PDCP recovery process. The UE (e.g., via the PDCP entity) can retransmit the PDCP PDU that was not successfully transmitted in the SCG (e.g., SN#3). However, the following problems may occur. Desynchronization may occur due to the amount of new data transmitted on the MCG and the amount of time before PDCP PDU retransmission. For example, the network may treat an expired PDCP PDU (SN#3) as a new packet and may trigger window movement accordingly. For example, a PDCP PDU may arrive too late for the correct reordering window (e.g., after a timer expires) and may be treated as a new PDU (thus moving a later reordering window and potentially affecting the processing of other packets). For example, packets received after SN#3 may be discarded (e.g., before the reordering timer expires while the network is expecting packet SN#4, e.g., SN-REORD=4). Therefore, the next packet to be received and not discarded may be SN#14000.

[0148] Figures 13 to 17 -Network initiated recovery operations

[0149] Fig.13 Network-initiated recovery operations are shown according to some embodiments. Fig.13 The beginning and Fig.12 Similarly, for example, packets 1-4 are transmitted on separate bearer SCGs. Packet SN#3 may not be received by the network. The network may start a timer (Treorder), for example, while expecting packet SN#3. Fig.12 As shown, the network may reconfigure the split bearer to use the MCG as the primary path. The network may transmit a positive acknowledgment for packets 1, 2, and 4 and / or a negative acknowledgment for packet 3. Thus, the UE may determine that packet 3 was not received. The acknowledgment may be transmitted before, at the same time, or after the reconfiguration indication. However, unlike Fig.12Instead, the network may explicitly instruct the UE to perform a recovery operation in the RRC reconfiguration message or in another message. Among various options, the network may instruct the recovery operation as follows:

[0150] Option 1: PDCP Recovery Flag in PDCP-Config = True. In this case, the UE may not be explicitly instructed to re-establish the RLC entity, but may determine (e.g., based on an implicit understanding that the RLC may be re-established as part of the recovery operation) to do so. In some embodiments, the UE may determine various configuration options for the re-established RLC entity.

[0151] Option 2: PDCP Recovery Flag in PDCP-Config = True; and Reestablish RLC Flag in RLC-Config = True. According to some embodiments, in this case, the network may explicitly indicate to reestablish RLC, and may further (eg, optionally) specify any RLC configuration options.

[0152] Other options for the indication may also be used. For example, other types of control information (eg, MAC CE, DCI) or separate messages may be used as needed.

[0153] In response to the indication to reconfigure and / or perform resumption, the UE may perform any of the following operations.

[0154] The UE may reestablish the associated RLC entity. For example, the RLC entity associated with the SCG may be reestablished in association with the MCG.

[0155] The UE may perform a PDCP data recovery procedure and may retransmit the unacknowledged PDCP PDU via another link. Thus, SN#3 may be retransmitted on the MCG, for example, without waiting for the SCG to fail.

[0156] The UE and the network may continue to exchange uplink and / or downlink data using the reconfigured bearer, thereby avoiding desynchronization of the split bearer.

[0157] Figures 14 to 17 Potential specification changes associated with network-initiated recovery operations according to some embodiments are shown. Note that the changes shown are examples and alternative or additional changes may be used.

[0158] like Fig.14As shown, an option to trigger a PDCP recovery operation (e.g., recoverPDCP) may be added to a control message (e.g., RRCreconfiguration message) and / or an information element (IE) to add or modify a bearer (e.g., a data radio bearer (DRB)). Thus, the control message may allow the network to use the recovery configuration (e.g., triggering PDCP recovery) in a flexible manner.

[0159] like Fig.15 As shown, an option to trigger RLC reestablishment (eg, reestablishRLC) may be added to control messages and / or IEs regarding RLC and / or bearer configuration.

[0160] like Figure 16 to Figure 17 As shown in ( Fig.17 yes Fig.16 Continuation), an option to trigger a PDCP recovery operation (e.g., PDCPrecover or recoverPDCP) may be added to control messages and / or IEs regarding PDCP configuration.

[0161] Figures 14 to 17 The changes shown in may allow the network to provide PDCP recovery and / or RLC re-establishment configuration. In addition, a note may be added to the specification document to indicate the permission. For example, the network may use Figure 16 to Figure 17 IE to explicitly indicate the enhanced primary path switching. According to some embodiments, in response to such indication, the UE may: perform a primary branch change, reestablish the RLC entity of the previous primary branch, and / or trigger a PDCP recovery procedure.

[0162] Figures 18 to 24 -UE initiated recovery operation

[0163] In some embodiments, the UE may autonomously perform a recovery operation, for example, without explicit instructions from the network. For example, when one or more of the following conditions are met (e.g., in addition to determining that the packet has not been positively acknowledged by the network), the UE may perform a recovery operation (e.g., PDCP recovery). In addition, the UE may optionally indicate the recovery operation to the network. Exemplary conditions for performing a recovery operation include:

[0164] Condition 1: The UE may perform a recovery operation upon receiving an indication of a primary path switch, for example, if the UE also determines that no packets have been received by the network.

[0165] Condition 2: If the radio quality of one branch is worse than a threshold, for example, if the UE also determines that the network has not received a packet, the UE may perform a recovery operation.

[0166] Condition 3: If the RLC transmission failure count and / or rate reaches a threshold, the UE may perform recovery operations. Such thresholds may be lower than the thresholds used to trigger link failures.

[0167] The conditions for resuming operation may be explicitly configured by the network and / or defined in the standard.

[0168] A (e.g., optional) UE report of autonomous recovery operation may be performed via L3 (e.g., RRC) and / or L2 (e.g., PDCP, MAC) messaging. Such a report may indicate a reestablished RLC entity, a suspension of an RLC entity, and / or a refreshed RLC SN. For example, an RRC message may be used when the UE receives a primary path switching configuration (e.g., condition 1). The UE may indicate the recovery information to the network via a reconfiguration complete message. In other words, an RRC reconfiguration message may be sent, and an indication of the recovery operation may be piggybacked in the RRC message. The L2 message may carry the indication in one or more PDCP, MAC, and / or RLC packets.

[0169] When the network receives the indication, the network may reconstruct the corresponding RLC entity and / or mark the refreshed RLC SN as the received packet. More generally, in response to the indication of the UE's recovery operation, the network may adjust / update its RLC (and / or other) entity to match the UE's RLC entity.

[0170] According to some embodiments, the triggering conditions and network understanding (without indication from the UE) may be as described in the following table.

[0171]

[0172] Figures 18 to 21 is a communication flow diagram illustrating an example of a UE autonomously performing recovery operations according to some embodiments.

[0173] Fig.18 A recovery operation in response to switching the configuration of a primary path for a split bearer according to some embodiments is shown. The network may send a first RRC configuration (or reconfiguration) message (1802) indicating that the UE may autonomously perform recovery in response to the primary path change (e.g., if no packets have yet been confirmed). The network may signal a path switch for the split bearer (e.g., from an SCG to an MCG) (1804). In response to the path change and the determination of an unconfirmed uplink transmission, the UE may autonomously perform a recovery operation, reestablish an RLC entity (e.g., from an SCG to an MCG), and retransmit the transmission (e.g., using a new primary path). The UE may also send a message indicating the recovery operation, for example in an RRC reconfiguration complete message (1806).

[0174] Fig.19 A recovery operation in response to a measurement event according to some embodiments is shown. The network may send a first RRC configuration (or reconfiguration) message (1902) indicating that the UE may autonomously perform recovery (e.g., if no packets have been confirmed) in response to one or more measurements below a threshold. The network may also configure the measurement and / or threshold, for example, regarding the type and / or timing of the measurement, the hysteresis, the value of the threshold, etc. The UE may perform the measurement according to the configuration. In response to reaching a measurement threshold (e.g., the radio condition of the primary path (e.g., SCG) meets the threshold condition, for example, is bad enough for autonomous recovery operation) and the pending uplink transmission is not confirmed, the UE may autonomously perform recovery operation, reestablish and / or suspend the RLC entity, and retransmit the transmission (e.g., using a different path). The UE may also send a measurement report (1904). Based on the measurement report, the network may determine that the PDCP recovery condition is met. Therefore, the network may update the PDCP and / or RLC entity to correspond to the changes made by the UE. In some embodiments, the UE may also send a message indicating the recovery operation and / or describing further details about the recovery operation.

[0175] Fig. 20 A recovery operation in response to satisfying a recovery condition and indicating RLC reconstruction according to some embodiments is shown. The network may send a first RRC configuration (or reconfiguration) message (2002) indicating that the UE may autonomously perform recovery in response to satisfying a (e.g., specified) recovery condition (e.g., if no packets have been confirmed). The configuration message may also indicate that if the condition is satisfied, the UE may reconstruct the RLC entity. Subsequently, the UE may determine, for example, based on configuration and / or other information that the condition is satisfied. In response to the condition being satisfied and pending uplink transmissions not being confirmed, the UE may autonomously perform recovery operations, reconstruct and / or suspend the RLC entity, and retransmit the transmission (e.g., using a different path). The UE may also send a message indicating the recovery operation (2004). The UE may also indicate details of the recovery operation, for example, that the RLC entity is reconstructed and / or released. Thus, the network may update the PDCP and / or RLC entity to correspond to the changes made by the UE.

[0176] Fig.21A recovery operation in response to satisfying a recovery condition and not indicating RLC reconstruction according to some embodiments is shown. The network may send a first RRC configuration (or reconfiguration) message (2102) indicating that the UE may autonomously perform recovery in response to satisfying a (e.g., specified) recovery condition (e.g., if no packets have been confirmed). The configuration message may also indicate that if the condition is satisfied, the UE may not rebuild the RLC entity. Alternatively, the configuration message may also indicate that if the condition is satisfied, the UE may refresh any unconfirmed packets from the RLC entity. Subsequently, the UE may determine, for example, based on configuration and / or other information that the condition is satisfied. In response to the condition being satisfied and the pending uplink transmission being unconfirmed, the UE may autonomously perform recovery operations, refresh the RLC entity, and retransmit the transmission (e.g., using a different path). Refreshing the RLC entity may include processing or marking any unconfirmed packets as if they were confirmed. Therefore, the RLC entity may stop any further attempts to retransmit the refreshed packets. The UE may also send a message indicating the refreshed packets (2104). The network may update its RLC entity to correspond to the changes made by the UE. For example, the network may treat the refreshed packets (e.g., SN values) as if they were received. In other words, the network may update any timers (e.g., Treordering) and / or reordering / push windows as if the refreshed packets were received. The UE may also retransmit the refreshed packets, for example, using a new SN value.

[0177] Figure 22 to Figure 24 is a communication flow diagram illustrating an example of a UE autonomously performing a recovery operation, including illustrations of possible RLC operations. Various options for RLC operations associated with the recovery operation are described below. According to some embodiments, the network may configure which options may be performed by the UE and / or may configure the conditions for selecting any particular option.

[0178] According to the first option, the associated RLC can be reestablished using PDCP recovery. For example, the UE can reset the RLC variables when performing RLC reestablishment. In other words, SN#0 can also be provided for the next transmitted packet.

[0179] Fig. 22This first option according to some embodiments is shown. The network may send RRC configuration (or reconfiguration) information (2202) to the UE. The information may indicate a condition (or a set of conditions) for the recovery operation. The information may also indicate that if the recovery condition is met, the RLC should (or can) be rebuilt. The UE may (e.g., later) determine that the condition is met, and in response, may perform a recovery operation and rebuild the RLC entity. For example, the UE may rebuild an RLC entity previously associated with the SCG as an RLC entity associated with the MCG. The UE may provide a recovery indication (2204) to the network. In response, the network may rebuild the corresponding RLC entity. The network may determine how to rebuild the RLC entity based on the control information and / or based on information provided together with the recovery indication.

[0180] According to the second option, the UE may suspend the associated RLC with PDCP resumption, e.g., without retransmission. In other words, during the suspension of the associated RLC entity, the UE may not perform any transmit (Tx) and / or receive (Rx) operations. For example, for an AM RLC entity, the UE may suspend the entire AM RLC entity and may stop both Rx and Tx of the RLC AM entity. The UE may notify the network of the suspension. The UE may wait for an explicit RLC configuration from the network to delete and / or resume the RLC entity. When any RLC configuration information is received, the UE may resume retransmission according to the new configuration.

[0181] Fig.23 This second option according to some embodiments is shown. The network may send RRC configuration (or reconfiguration) information (2302) to the UE. The information may indicate a condition (or a set of conditions) for resuming the operation. The information may also indicate that if the recovery condition is met, the RLC should (or may) be suspended. The UE may (e.g., later) determine that the condition is met, and in response, a recovery operation may be performed and the RLC entity may be suspended, for example, an SCG RLC entity in the case where the SCG is the primary path. For example, the UE may temporarily stop retransmission operations for the suspended RLC entity. The UE may provide a recovery indication (2304) to the network. In response, the network may determine that the UE has suspended the RLC entity. The network may indicate to the UE to cancel the suspension (e.g., release and / or reestablish) of the RLC entity (2306). The indication may be an RRC reconfiguration message. In some embodiments, the network may also indicate whether the RLC should be released in a previous configuration or reestablished in a different configuration (e.g., associated with a different path). In some embodiments, the UE may autonomously determine whether the RLC should be released in a previous configuration or reestablished in a different configuration, for example based on a previous configuration, standard information, and / or an evaluation of specified conditions. The UE and the network may release or suspend the RLC entity accordingly.

[0182] According to the third option, no associated RLC reestablishment may be performed together with PDCP recovery. For example, the UE may not reestablish the RLC associated with PDCP recovery and may treat unacknowledged RLC PDUs as if they were acknowledged (ACK). The UE may rely on PDCP retransmission. The UE may inform the network of the refreshed (self-ACK) RLC PDU SN information. Based on the received information, the network may set the corresponding RLC PDU to receive state and may move the RLC receive window accordingly.

[0183] Fig.24 This third option according to some embodiments is shown. The network may send RRC configuration (or reconfiguration) information to the UE (2402). The information may indicate a condition (or a set of conditions) for the recovery operation. The information may also indicate that if the recovery condition is met, the RLC should (or may) be refreshed. The UE may (e.g., later) determine that the condition is met, and in response, the recovery operation may be performed and the RLC entity may be refreshed, for example, the SCG RLC entity in the case where the SCG is the primary path. For example, the UE may treat any unconfirmed packets of the refreshed RLC entity as if they were confirmed (e.g., SN 3, 5, and 6 in the figure). The UE may provide an indication to the network (2404), for example, specifying a refreshed SN value. In response, the network may determine that the UE has refreshed the RLC entity. The network may treat the indicated SNs as if they have been confirmed, and may reset any timers and / or receive windows accordingly. In other words, the network may adjust the RLC buffer so that SN 3, 5, and 6 are considered received and confirmed. The UE (e.g., the PDCP layer of the UE) may initiate a retransmission of the packet (2406). The UE (eg, RLC layer) may retransmit the packet, for example, with a new SN value of 7-9 (2408). The RLC layer may treat the packet as a new packet.

[0184] In some embodiments, additional conditions may be associated with different options. For example, a first condition may be indicated for the recovery operation. In addition, different secondary conditions may be indicated for each option of the RLC operation. For example, if the first condition is met, the UE may determine which of the various secondary conditions is met. Based on the determination of the secondary conditions, the UE may select and execute the corresponding option of the RLC operation.

[0185] Additional information and implementation options

[0186] Although the above embodiments are primarily described with respect to separate bearers, it should be understood that other types of bearers and / or paths are also contemplated according to some embodiments. Figure 5The method may be applied to situations where a (eg, non-split) bearer is reconfigured to use a different or changed path.

[0187] In a first group of embodiments, a user equipment device (UE) may include: a radio component; and a processor, the processor being operably connected to the radio component and configured to enable the UE to: establish communication with a cellular network via a separate bearer; transmit a plurality of packets to the network via the separate bearer, wherein transmitting the plurality of packets via the separate bearer includes using a packet data convergence protocol (PDCP) entity associated with the separate bearer; receive an indication from the cellular network to restore the PDCP entity associated with the separate bearer; and in response to the indication to restore the PDCP entity associated with the separate bearer: perform a PDCP recovery process; and retransmit at least one of the plurality of packets.

[0188] In some embodiments, the plurality of packets are transmitted via a first group of cells, wherein the at least one packet of the plurality of packets is retransmitted using a second group of cells.

[0189] In some embodiments, transmitting the multiple packets includes tracking the multiple packets using a radio link control (RLC) entity associated with the first cell group, wherein in response to the indication of restoring the PDCP entity associated with the separated bearer, the processor is further configured to cause the UE to re-establish the RLC entity associated with the second cell group.

[0190] In some embodiments, reestablishing the RLC entity in association with the second cell group includes refreshing a sequence number of the RLC entity.

[0191] In some embodiments, the indication to resume the PDCP entity associated with the split bearer comprises a radio resource control (RRC) reconfiguration message.

[0192] In some embodiments, the indication to resume the PDCP entity associated with the split bearer comprises a flag in a PDCP configuration of the RRC reconfiguration message.

[0193] In some embodiments, the indication to resume the PDCP entity associated with the split bearer comprises a flag in a radio link control (RLC) configuration of the RRC reconfiguration message.

[0194] In a second set of embodiments, an apparatus may include a processor configured to enable a user equipment device (UE): establish communication with a cellular network; receive control information configuring a separate bearer from the cellular network; transmit multiple packets to the cellular network via the separate bearer; determine that conditions for performing a packet data convergence protocol (PDCP) recovery are met; in response to the determination that the conditions for performing the PDCP recovery are met: perform the PDCP recovery; and retransmit a first packet of the multiple packets.

[0195] In some embodiments, the condition comprises an indication from the cellular network for switching the split bearer from the first primary branch to the second primary branch.

[0196] In some embodiments, the condition comprises a determination that a radio quality associated with a primary leg of the split bearer is less than a threshold.

[0197] In some embodiments, the condition includes a determination that a transmission failure threshold has been reached.

[0198] In some embodiments, in response to the determination that the condition for performing the PDCP resumption is met, the processor is further configured to cause the UE to transmit an indication of the PDCP resumption to the network.

[0199] In some embodiments, in response to the determination that the conditions for performing the PDCP recovery are met, the processor is also configured to cause the UE to reestablish a radio link control (RLC) entity, wherein the indication of the PDCP recovery includes an indication of the reestablished RLC entity.

[0200] In some embodiments, in response to the determination that the conditions for performing the PDCP recovery are met, the processor is also configured to cause the UE to refresh a radio link control (RLC) entity, wherein the indication of the PDCP recovery includes an indication of a sequence number of the first packet among the multiple packets.

[0201] In a third group of embodiments, a method may include: at a base station of a cellular network: establishing communication with a user equipment device (UE); transmitting configuration information of a separate bearer to the UE, wherein the configuration information identifies a first main branch of the separate bearer; receiving a first packet from the UE via the first main branch; determining based on the first packet that a second packet is not received; in response to the determination that the second packet is not received, transmitting an indication to the UE to reconfigure the separate bearer, wherein the indication to reconfigure the separate bearer identifies the second main branch of the separate bearer, wherein the indication to reconfigure the separate bearer includes an indication to restore the second packet; and receiving the second packet from the UE via the second main branch.

[0202] In some embodiments, the method may also include: starting a reordering timer in response to the determination that the second packet has not been received; maintaining the reordering timer while reconfiguring the separate bearer; and stopping the reordering timer in response to receiving the second packet via the second main branch.

[0203] In some embodiments, the indication to resume the second packet comprises a Packet Data Convergence Protocol (PDCP) resume flag.

[0204] In some embodiments, the indication to resume the second packet includes a radio link control (RLC) re-establishment flag.

[0205] In some embodiments, the configuration information of the separate bearer indicates that data recovery is enabled.

[0206] In some embodiments, the method may further include reestablishing a radio link control (RLC) entity in response to the determination that the second packet was not received.

[0207] In various implementations, various combinations of the above adjustments may be performed together. For example, the network may send control information to the UE so that the UE processes the downlink RS according to the above implementation and transmits the uplink RS according to the above implementation.

[0208] Yet another example embodiment may include a method, comprising: performing, by a wireless device: any or all of the foregoing examples.

[0209] Another exemplary embodiment may include a wireless device comprising: an antenna; a radio component coupled to the antenna; and a processing element operably coupled to the radio component, wherein the device is configured to implement any or all portions of the foregoing examples.

[0210] Another example embodiment may include an apparatus comprising: a processing element configured to cause a wireless device to implement any or all of the foregoing examples.

[0211] Another exemplary set of embodiments may include a non-transitory computer-accessible storage medium including program instructions that, when executed at a device, cause the device to implement any or all portions of any of the foregoing examples.

[0212] Another exemplary set of embodiments may include a computer program comprising instructions for performing any or all portions of any of the foregoing examples.

[0213] Another exemplary set of embodiments may include an apparatus including means for performing any or all of the elements of any of the preceding examples.

[0214] Any of the methods for operating a UE described herein may become the basis for a corresponding method for operating a base station by interpreting each message / signal X received by a user equipment (UE) in DL as a message / signal X transmitted by a base station, and interpreting each message / signal Y transmitted by the UE in UL as a message / signal Y received by the base station. In addition, the methods described with respect to the base station may be interpreted as methods for the UE in a similar manner.

[0215] In addition to the exemplary embodiments described above, more embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0216] In some embodiments, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and / or data, wherein if executed by a computer system, the program instructions cause the computer system to perform a method, such as any one of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets.

[0217] In some embodiments, a device (e.g., UE 106 or 107) may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions may be executed to implement any of the various method implementations described herein (or any combination of the method implementations described herein, or any subset of any method implementations described herein or any combination of such subsets). The device may be implemented in any of various forms.

[0218] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0219] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for wireless communication, comprising: At a cellular network base station: Establishing communication with a user equipment UE; Transmitting configuration information of the split bearer to the UE, wherein the configuration information identifies a first primary branch of the split bearer; receiving a first uplink packet from the UE via the first main branch; determining, based on the first uplink packet, that a second uplink packet is not received; In response to the determination that the second uplink packet is not received, transmitting to the UE an indication to reconfigure the split bearer, wherein the indication to reconfigure the split bearer identifies a second primary branch of the split bearer, wherein the indication to reconfigure the split bearer includes an indication to resume the second uplink packet; as well as The second uplink packet is received from the UE via the second primary branch.

2. The method according to claim 1, further comprising: starting a reordering timer in response to the determination that the second uplink packet was not received; maintaining the reordering timer while reconfiguring the split bearer; as well as The reordering timer is stopped in response to receiving the second uplink packet via the second primary branch.

3. The method of claim 1, wherein the indication to resume the second uplink packet comprises a Packet Data Convergence Protocol (PDCP) resume flag.

4. The method of claim 1, wherein the indication to resume the second uplink packet comprises a radio link control (RLC) re-establishment flag. The method according to claim 1 , wherein the configuration information of the split bearer indicates enabling of data recovery.

6. The method according to claim 1, further comprising: A radio link control (RLC) entity is reestablished in response to the determination that the second uplink packet was not received.

7. A method for wireless communication, comprising: establishing communications with a base station of a cellular network; receiving configuration information of a split bearer from the base station, wherein the configuration information identifies a first main branch of the split bearer; transmitting a first uplink packet to the base station via the first main branch; transmitting a second uplink packet to the base station; receiving, from the base station, an indication to reconfigure the split bearer, wherein the indication to reconfigure the split bearer identifies a second primary branch of the split bearer, wherein the indication to reconfigure the split bearer comprises an indication to resume the second uplink packet, wherein the indication is responsive to determining, based on the first uplink packet, that the second uplink packet is not received; and In response to the indication of resuming the second uplink packet, the second uplink packet is retransmitted to the base station via the second main branch.

8. The method of claim 7, wherein the indication to resume the second uplink packet comprises a Packet Data Convergence Protocol (PDCP) resume flag.

9. The method of claim 7, wherein the indication to resume the second uplink packet comprises a radio link control (RLC) re-establishment flag.

10. The method of claim 7, wherein the configuration information of the split bearer indicates enabling of data recovery.

11. The method according to claim 7, further comprising: After receiving the indication to resume the second uplink packet, a radio link control (RLC) entity is reestablished.

12. A baseband processor configured to perform operations comprising: establishing communications with a base station of a cellular network; receiving configuration information of a split bearer from the base station, wherein the configuration information identifies a first main branch of the split bearer; transmitting a first uplink packet to the base station via the first main branch; transmitting a second uplink packet to the base station; receiving, from the base station, an indication to reconfigure the split bearer, wherein the indication to reconfigure the split bearer identifies a second primary branch of the split bearer, wherein the indication to reconfigure the split bearer comprises an indication to resume the second uplink packet, wherein the indication is responsive to determining, based on the first uplink packet, that the second uplink packet is not received; and In response to the indication of resuming the second uplink packet, the second uplink packet is retransmitted to the base station via the second main branch.

13. The baseband processor of claim 12, wherein the indication to resume the second uplink packet comprises a Packet Data Convergence Protocol (PDCP) resume flag.

14. The baseband processor of claim 12, wherein the indication to resume the second uplink packet comprises a radio link control (RLC) re-establishment flag.

15. The baseband processor of claim 12, wherein the configuration information of the separate bearer indicates enabling data recovery.

16. The baseband processor according to claim 12, further comprising: After receiving the indication to resume the second uplink packet, a radio link control (RLC) entity is reestablished.

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