Patent Publication Number: US-11395162-B2

Title: Path selection scheme for master cell group failure reporting

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Pursuant to 35 U.S.C. § 119 (a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2019-0122492, filed on Oct. 2, 2019, the contents of which are all hereby incorporated by reference herein in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to path selection scheme for a master cell group (MCG) failure reporting. 
     BACKGROUND 
     3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement. 
     Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future. 
     The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible. 
     Carrier aggregation is a technique used in wireless communication to increase the data rate per user, whereby multiple frequency blocks (called component carriers) are assigned to the same user. The maximum possible data rate per user is increased the more frequency blocks are assigned to a user. The sum data rate of a cell is increased as well because of a better resource utilization. 
     Dual connectivity (DC) was introduced in 3GPP to allow a user equipment (UE) to simultaneously transmit and receive data on multiple component carriers from two cell groups one providing E-UTRA access (4G) and the other one providing NR access (5G). One scheduler is located in the master node and the other in the secondary node. The master node and secondary node are connected via a network interface and at least the master node is connected to the core network. 
     SUMMARY 
     In an aspect, a method performed by a wireless device configured to operate in a wireless communication system is provided. The method includes determining a path for master cell group (MCG) failure information to inform a failure on a primary cell (PCell) of a MCG from among the at least one secondary cell (SCell) of the MCG and a secondary cell group (SCG), and transmitting the MCG failure information via the determined path. 
     In another aspect, an apparatus for implementing the above method is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an example of a communication system to which implementations of the present disclosure is applied. 
         FIG. 2  shows an example of wireless devices to which implementations of the present disclosure is applied. 
         FIG. 3  shows an example of a wireless device to which implementations of the present disclosure is applied. 
         FIG. 4  shows another example of wireless devices to which implementations of the present disclosure is applied. 
         FIG. 5  shows an example of UE to which implementations of the present disclosure is applied. 
         FIGS. 6 and 7  show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied. 
         FIG. 8  shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied. 
         FIG. 9  shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied. 
         FIG. 10  shows an example of EN-DC overall architecture to which implementations of the present disclosure is applied. 
         FIG. 11  shows an example of a control plane architecture for EN-DC to which implementations of the present disclosure is applied. 
         FIG. 12  shows an example of a control plane architecture for MR-DC to which implementations of the present disclosure is applied. 
         FIG. 13  shows an example of a method performed by a wireless device configured to operate in a wireless communication system to which implementations of the present disclosure is applied. 
     
    
    
     DETAILED DESCRIPTION 
     The following techniques, apparatuses, and systems may be applied to a variety of wireless multiple access systems. Examples of the multiple access systems include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (SC-FDMA) system, and a multicarrier frequency division multiple access (MC-FDMA) system. CDMA may be embodied through radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be embodied through radio technology such as global system for mobile communications (GSM), general packet radio service (GPRS), or enhanced data rates for GSM evolution (EDGE). OFDMA may be embodied through radio technology such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or evolved UTRA (E-UTRA). UTRA is a part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA in DL and SC-FDMA in UL. LTE-advanced (LTE-A) is an evolved version of 3GPP LTE. 
     For convenience of description, implementations of the present disclosure are mainly described in regards to a 3GPP based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP based wireless communication system, aspects of the present disclosure that are not limited to 3GPP based wireless communication system are applicable to other mobile communication systems. 
     For terms and technologies which are not specifically described among the terms of and technologies employed in the present disclosure, the wireless communication standard documents published before the present disclosure may be referenced. 
     In the present disclosure, “A or B” may mean “only A”, “only B”, or “both A and B”. In other words, “A or B” in the present disclosure may be interpreted as “A and/or B”. For example, “A, B or C” in the present disclosure may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. 
     In the present disclosure, slash (/) or comma (,) may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”. 
     In the present disclosure, “at least one of A and B” may mean “only A”, “only B” or “both A and B”. In addition, the expression “at least one of A or B” or “at least one of A and/or B” in the present disclosure may be interpreted as same as “at least one of A and B”. 
     In addition, in the present disclosure, “at least one of A, B and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. In addition, “at least one of A, B or C” or “at least one of A, B and/or C” may mean “at least one of A, B and C”. 
     Also, parentheses used in the present disclosure may mean “for example”. In detail, when it is shown as “control information (PDCCH)”, “PDCCH” may be proposed as an example of “control information”. In other words, “control information” in the present disclosure is not limited to “PDCCH”, and “PDDCH” may be proposed as an example of “control information”. In addition, even when shown as “control information (i.e., PDCCH)”, “PDCCH” may be proposed as an example of “control information”. 
     Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously. 
     Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and/or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and/or connection (e.g., 5G) between devices. 
     Hereinafter, the present disclosure will be described in more detail with reference to drawings. The same reference numerals in the following drawings and/or descriptions may refer to the same and/or corresponding hardware blocks, software blocks, and/or functional blocks unless otherwise indicated. 
       FIG. 1  shows an example of a communication system to which implementations of the present disclosure is applied. 
     The 5G usage scenarios shown in  FIG. 1  are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in  FIG. 1 . 
     Three main requirement categories for 5G include (1) a category of enhanced mobile broadband (eMBB), (2) a category of massive machine type communication (mMTC), and (3) a category of ultra-reliable and low latency communications (URLLC). 
     Partial use cases may require a plurality of categories for optimization and other use cases may focus only upon one key performance indicator (KPI). 5G supports such various use cases using a flexible and reliable method. 
     eMBB far surpasses basic mobile Internet access and covers abundant bidirectional work and media and entertainment applications in cloud and augmented reality. Data is one of 5G core motive forces and, in a 5G era, a dedicated voice service may not be provided for the first time. In 5G, it is expected that voice will be simply processed as an application program using data connection provided by a communication system. Main causes for increased traffic volume are due to an increase in the size of content and an increase in the number of applications requiring high data transmission rate. A streaming service (of audio and video), conversational video, and mobile Internet access will be more widely used as more devices are connected to the Internet. These many application programs require connectivity of an always turned-on state in order to push real-time information and alarm for users. Cloud storage and applications are rapidly increasing in a mobile communication platform and may be applied to both work and entertainment. The cloud storage is a special use case which accelerates growth of uplink data transmission rate. 5G is also used for remote work of cloud. When a tactile interface is used, 5G demands much lower end-to-end latency to maintain user good experience. Entertainment, for example, cloud gaming and video streaming, is another core element which increases demand for mobile broadband capability. Entertainment is essential for a smartphone and a tablet in any place including high mobility environments such as a train, a vehicle, and an airplane. Other use cases are augmented reality for entertainment and information search. In this case, the augmented reality requires very low latency and instantaneous data volume. 
     In addition, one of the most expected 5G use cases relates a function capable of smoothly connecting embedded sensors in all fields, i.e., mMTC. It is expected that the number of potential Internet-of-things (IoT) devices will reach 204 hundred million up to the year of 2020. An industrial IoT is one of categories of performing a main role enabling a smart city, asset tracking, smart utility, agriculture, and security infrastructure through 5G. 
     URLLC includes a new service that will change industry through remote control of main infrastructure and an ultra-reliable/available low-latency link such as a self-driving vehicle. A level of reliability and latency is essential to control a smart grid, automatize industry, achieve robotics, and control and adjust a drone. 
     5G is a means of providing streaming evaluated as a few hundred megabits per second to gigabits per second and may complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS). Such fast speed is needed to deliver TV in resolution of 4K or more (6K, 8K, and more), as well as virtual reality and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include almost immersive sports games. A specific application program may require a special network configuration. For example, for VR games, gaming companies need to incorporate a core server into an edge network server of a network operator in order to minimize latency. 
     Automotive is expected to be a new important motivated force in 5G together with many use cases for mobile communication for vehicles. For example, entertainment for passengers requires high simultaneous capacity and mobile broadband with high mobility. This is because future users continue to expect connection of high quality regardless of their locations and speeds. Another use case of an automotive field is an AR dashboard. The AR dashboard causes a driver to identify an object in the dark in addition to an object seen from a front window and displays a distance from the object and a movement of the object by overlapping information talking to the driver. In the future, a wireless module enables communication between vehicles, information exchange between a vehicle and supporting infrastructure, and information exchange between a vehicle and other connected devices (e.g., devices accompanied by a pedestrian). A safety system guides alternative courses of a behavior so that a driver may drive more safely drive, thereby lowering the danger of an accident. The next stage will be a remotely controlled or self-driven vehicle. This requires very high reliability and very fast communication between different self-driven vehicles and between a vehicle and infrastructure. In the future, a self-driven vehicle will perform all driving activities and a driver will focus only upon abnormal traffic that the vehicle cannot identify. Technical requirements of a self-driven vehicle demand ultra-low latency and ultra-high reliability so that traffic safety is increased to a level that cannot be achieved by human being. 
     A smart city and a smart home/building mentioned as a smart society will be embedded in a high-density wireless sensor network. A distributed network of an intelligent sensor will identify conditions for costs and energy-efficient maintenance of a city or a home. Similar configurations may be performed for respective households. All of temperature sensors, window and heating controllers, burglar alarms, and home appliances are wirelessly connected. Many of these sensors are typically low in data transmission rate, power, and cost. However, real-time HD video may be demanded by a specific type of device to perform monitoring. 
     Consumption and distribution of energy including heat or gas is distributed at a higher level so that automated control of the distribution sensor network is demanded. The smart grid collects information and connects the sensors to each other using digital information and communication technology so as to act according to the collected information. Since this information may include behaviors of a supply company and a consumer, the smart grid may improve distribution of fuels such as electricity by a method having efficiency, reliability, economic feasibility, production sustainability, and automation. The smart grid may also be regarded as another sensor network having low latency. 
     Mission critical application (e.g., e-health) is one of 5G use scenarios. A health part contains many application programs capable of enjoying benefit of mobile communication. A communication system may support remote treatment that provides clinical treatment in a faraway place. Remote treatment may aid in reducing a barrier against distance and improve access to medical services that cannot be continuously available in a faraway rural area. Remote treatment is also used to perform important treatment and save lives in an emergency situation. The wireless sensor network based on mobile communication may provide remote monitoring and sensors for parameters such as heart rate and blood pressure. 
     Wireless and mobile communication gradually becomes important in the field of an industrial application. Wiring is high in installation and maintenance cost. Therefore, a possibility of replacing a cable with reconstructible wireless links is an attractive opportunity in many industrial fields. However, in order to achieve this replacement, it is necessary for wireless connection to be established with latency, reliability, and capacity similar to those of the cable and management of wireless connection needs to be simplified. Low latency and a very low error probability are new requirements when connection to 5G is needed. 
     Logistics and freight tracking are important use cases for mobile communication that enables inventory and package tracking anywhere using a location-based information system. The use cases of logistics and freight typically demand low data rate but require location information with a wide range and reliability. 
     Referring to  FIG. 1 , the communication system  1  includes wireless devices  100   a  to  100   f , base stations (BSs)  200 , and a network  300 . Although  FIG. 1  illustrates a 5G network as an example of the network of the communication system  1 , the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system. 
     The BSs  200  and the network  300  may be implemented as wireless devices and a specific wireless device may operate as a BS/network node with respect to other wireless devices. 
     The wireless devices  100   a  to  100   f  represent devices performing communication using radio access technology (RAT) (e.g., 5G new RAT (NR)) or LTE) and may be referred to as communication/radio/5G devices. The wireless devices  100   a  to  100   f  may include, without being limited to, a robot  100   a , vehicles  100   b - 1  and  100   b - 2 , an extended reality (XR) device  100   c , a hand-held device  100   d , a home appliance  100   e , an IoT device  100   f , and an artificial intelligence (AI) device/server  400 . For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. The vehicles may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an AR/VR/Mixed Reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter. 
     In the present disclosure, the wireless devices  100   a  to  100   f  may be called user equipments (UEs). A UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, a connected car, an UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a weather/environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field. 
     The UAV may be, for example, an aircraft aviated by a wireless control signal without a human being onboard. 
     The VR device may include, for example, a device for implementing an object or a background of the virtual world. The AR device may include, for example, a device implemented by connecting an object or a background of the virtual world to an object or a background of the real world. The MR device may include, for example, a device implemented by merging an object or a background of the virtual world into an object or a background of the real world. The hologram device may include, for example, a device for implementing a stereoscopic image of 360 degrees by recording and reproducing stereoscopic information, using an interference phenomenon of light generated when two laser lights called holography meet. 
     The public safety device may include, for example, an image relay device or an image device that is wearable on the body of a user. 
     The MTC device and the IoT device may be, for example, devices that do not require direct human intervention or manipulation. For example, the MTC device and the IoT device may include smartmeters, vending machines, thermometers, smartbulbs, door locks, or various sensors. 
     Here, the radio communication technologies implemented in the wireless devices in the present disclosure may include narrowband internet-of-things (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of low power wide area network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and/or LTE Cat NB2, and may not be limited to the above-mentioned names. Additionally and/or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in at least one of the various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and may not be limited to the above-mentioned names. Additionally and/or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and/or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names. For example, ZigBee technology may generate personal area networks (PANs) associated with small/low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names. 
     The medical device may be, for example, a device used for the purpose of diagnosing, treating, relieving, curing, or preventing disease. For example, the medical device may be a device used for the purpose of diagnosing, treating, relieving, or correcting injury or impairment. For example, the medical device may be a device used for the purpose of inspecting, replacing, or modifying a structure or a function. For example, the medical device may be a device used for the purpose of adjusting pregnancy. For example, the medical device may include a device for treatment, a device for operation, a device for (in vitro) diagnosis, a hearing aid, or a device for procedure. 
     The security device may be, for example, a device installed to prevent a danger that may arise and to maintain safety. For example, the security device may be a camera, a closed-circuit TV (CCTV), a recorder, or a black box. 
     The FinTech device may be, for example, a device capable of providing a financial service such as mobile payment. For example, the FinTech device may include a payment device or a point of sales (POS) system. 
     The weather/environment device may include, for example, a device for monitoring or predicting a weather/environment. 
     The wireless devices  100   a  to  100   f  may be connected to the network  300  via the BSs  200 . An AI technology may be applied to the wireless devices  100   a  to  100   f  and the wireless devices  100   a  to  100   f  may be connected to the AI server  400  via the network  300 . The network  300  may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a beyond-5G network. Although the wireless devices  100   a  to  100   f  may communicate with each other through the BSs  200 /network  300 , the wireless devices  100   a  to  100   f  may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs  200 /network  300 . For example, the vehicles  100   b - 1  and  100   b - 2  may perform direct communication (e.g., vehicle-to-vehicle (V2V)/vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices  100   a  to  100   f.    
     Wireless communication/connections  150   a ,  150   b  and  150   c  may be established between the wireless devices  100   a  to  100   f  and/or between wireless device  100   a  to  100   f  and BS  200  and/or between BSs  200 . Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication  150   a , sidelink communication (or device-to-device (D2D) communication)  150   b , inter-base station communication  150   c  (e.g., relay, integrated access and backhaul (IAB)), etc. The wireless devices  100   a  to  100   f  and the BSs  200 /the wireless devices  100   a  to  100   f  may transmit/receive radio signals to/from each other through the wireless communication/connections  150   a ,  150   b  and  150   c . For example, the wireless communication/connections  150   a ,  150   b  and  150   c  may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/de-mapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure. 
       FIG. 2  shows an example of wireless devices to which implementations of the present disclosure is applied. 
     Referring to  FIG. 2 , a first wireless device  100  and a second wireless device  200  may transmit/receive radio signals to/from an external device through a variety of RATs (e.g., LTE and NR). In  FIG. 2 , {the first wireless device  100  and the second wireless device  200 } may correspond to at least one of {the wireless device  100   a  to  100   f  and the BS  200 }, {the wireless device  100   a  to  100   f  and the wireless device  100   a  to  100   f } and/or {the BS  200  and the BS  200 } of  FIG. 1 . 
     The first wireless device  100  may include one or more processors  102  and one or more memories  104  and additionally further include one or more transceivers  106  and/or one or more antennas  108 . The processor(s)  102  may control the memory(s)  104  and/or the transceiver(s)  106  and may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor(s)  102  may process information within the memory(s)  104  to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s)  106 . The processor(s)  102  may receive radio signals including second information/signals through the transceiver(s)  106  and then store information obtained by processing the second information/signals in the memory(s)  104 . The memory(s)  104  may be connected to the processor(s)  102  and may store a variety of information related to operations of the processor(s)  102 . For example, the memory(s)  104  may store software code including commands for performing a part or the entirety of processes controlled by the processor(s)  102  or for performing the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. Herein, the processor(s)  102  and the memory(s)  104  may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s)  106  may be connected to the processor(s)  102  and transmit and/or receive radio signals through one or more antennas  108 . Each of the transceiver(s)  106  may include a transmitter and/or a receiver. The transceiver(s)  106  may be interchangeably used with radio frequency (RF) unit(s). In the present disclosure, the first wireless device  100  may represent a communication modem/circuit/chip. 
     The second wireless device  200  may include one or more processors  202  and one or more memories  204  and additionally further include one or more transceivers  206  and/or one or more antennas  208 . The processor(s)  202  may control the memory(s)  204  and/or the transceiver(s)  206  and may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. For example, the processor(s)  202  may process information within the memory(s)  204  to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s)  206 . The processor(s)  202  may receive radio signals including fourth information/signals through the transceiver(s)  106  and then store information obtained by processing the fourth information/signals in the memory(s)  204 . The memory(s)  204  may be connected to the processor(s)  202  and may store a variety of information related to operations of the processor(s)  202 . For example, the memory(s)  204  may store software code including commands for performing a part or the entirety of processes controlled by the processor(s)  202  or for performing the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts described in the present disclosure. Herein, the processor(s)  202  and the memory(s)  204  may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s)  206  may be connected to the processor(s)  202  and transmit and/or receive radio signals through one or more antennas  208 . Each of the transceiver(s)  206  may include a transmitter and/or a receiver. The transceiver(s)  206  may be interchangeably used with RF unit(s). In the present disclosure, the second wireless device  200  may represent a communication modem/circuit/chip. 
     Hereinafter, hardware elements of the wireless devices  100  and  200  will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors  102  and  202 . For example, the one or more processors  102  and  202  may implement one or more layers (e.g., functional layers such as physical (PHY) layer, media access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, radio resource control (RRC) layer, and service data adaptation protocol (SDAP) layer). The one or more processors  102  and  202  may generate one or more protocol data units (PDUs) and/or one or more service data unit (SDUs) according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The one or more processors  102  and  202  may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The one or more processors  102  and  202  may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers  106  and  206 . The one or more processors  102  and  202  may receive the signals (e.g., baseband signals) from the one or more transceivers  106  and  206  and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. 
     The one or more processors  102  and  202  may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors  102  and  202  may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in the one or more processors  102  and  202 . descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure may be implemented using firmware or software and the firmware or software may be configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure may be included in the one or more processors  102  and  202  or stored in the one or more memories  104  and  204  so as to be driven by the one or more processors  102  and  202 . The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure may be implemented using firmware or software in the form of code, commands, and/or a set of commands. 
     The one or more memories  104  and  204  may be connected to the one or more processors  102  and  202  and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories  104  and  204  may be configured by read-only memories (ROMs), random access memories (RAMs), electrically erasable programmable read-only memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or more memories  104  and  204  may be located at the interior and/or exterior of the one or more processors  102  and  202 . The one or more memories  104  and  204  may be connected to the one or more processors  102  and  202  through various technologies such as wired or wireless connection. 
     The one or more transceivers  106  and  206  may transmit user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, to one or more other devices. The one or more transceivers  106  and  206  may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, from one or more other devices. For example, the one or more transceivers  106  and  206  may be connected to the one or more processors  102  and  202  and transmit and receive radio signals. For example, the one or more processors  102  and  202  may perform control so that the one or more transceivers  106  and  206  may transmit user data, control information, or radio signals to one or more other devices. The one or more processors  102  and  202  may perform control so that the one or more transceivers  106  and  206  may receive user data, control information, or radio signals from one or more other devices. 
     The one or more transceivers  106  and  206  may be connected to the one or more antennas  108  and  208  and the one or more transceivers  106  and  206  may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure, through the one or more antennas  108  and  208 . In the present disclosure, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). 
     The one or more transceivers  106  and  206  may convert received radio signals/channels, etc., from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc., using the one or more processors  102  and  202 . The one or more transceivers  106  and  206  may convert the user data, control information, radio signals/channels, etc., processed using the one or more processors  102  and  202  from the base band signals into the RF band signals. To this end, the one or more transceivers  106  and  206  may include (analog) oscillators and/or filters. For example, the transceivers  106  and  206  can up-convert OFDM baseband signals to a carrier frequency by their (analog) oscillators and/or filters under the control of the processors  102  and  202  and transmit the up-converted OFDM signals at the carrier frequency. The transceivers  106  and  206  may receive OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and/or filters under the control of the transceivers  102  and  202 . 
     In the implementations of the present disclosure, a UE may operate as a transmitting device in uplink (UL) and as a receiving device in downlink (DL). In the implementations of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device  100  acts as the UE, and the second wireless device  200  acts as the BS. For example, the processor(s)  102  connected to, mounted on or launched in the first wireless device  100  may be configured to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s)  106  to perform the UE behavior according to an implementation of the present disclosure. The processor(s)  202  connected to, mounted on or launched in the second wireless device  200  may be configured to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s)  206  to perform the BS behavior according to an implementation of the present disclosure. 
     In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB. 
       FIG. 3  shows an example of a wireless device to which implementations of the present disclosure is applied. 
     The wireless device may be implemented in various forms according to a use-case/service (refer to  FIG. 1 ). 
     Referring to  FIG. 3 , wireless devices  100  and  200  may correspond to the wireless devices  100  and  200  of  FIG. 2  and may be configured by various elements, components, units/portions, and/or modules. For example, each of the wireless devices  100  and  200  may include a communication unit  110 , a control unit  120 , a memory unit  130 , and additional components  140 . The communication unit  110  may include a communication circuit  112  and transceiver(s)  114 . For example, the communication circuit  112  may include the one or more processors  102  and  202  of  FIG. 2  and/or the one or more memories  104  and  204  of  FIG. 2 . For example, the transceiver(s)  114  may include the one or more transceivers  106  and  206  of  FIG. 2  and/or the one or more antennas  108  and  208  of  FIG. 2 . The control unit  120  is electrically connected to the communication unit  110 , the memory  130 , and the additional components  140  and controls overall operation of each of the wireless devices  100  and  200 . For example, the control unit  120  may control an electric/mechanical operation of each of the wireless devices  100  and  200  based on programs/code/commands/information stored in the memory unit  130 . The control unit  120  may transmit the information stored in the memory unit  130  to the exterior (e.g., other communication devices) via the communication unit  110  through a wireless/wired interface or store, in the memory unit  130 , information received through the wireless/wired interface from the exterior (e.g., other communication devices) via the communication unit  110 . 
     The additional components  140  may be variously configured according to types of the wireless devices  100  and  200 . For example, the additional components  140  may include at least one of a power unit/battery, input/output (I/O) unit (e.g., audio I/O port, video I/O port), a driving unit, and a computing unit. The wireless devices  100  and  200  may be implemented in the form of, without being limited to, the robot ( 100   a  of  FIG. 1 ), the vehicles ( 100   b - 1  and  100   b - 2  of  FIG. 1 ), the XR device ( 100   c  of  FIG. 1 ), the hand-held device ( 100   d  of  FIG. 1 ), the home appliance ( 100   e  of  FIG. 1 ), the IoT device ( 100   f  of  FIG. 1 ), a digital broadcast terminal, a hologram device, a public safety device, an MTC device, a medicine device, a FinTech device (or a finance device), a security device, a climate/environment device, the AI server/device ( 400  of  FIG. 1 ), the BSs ( 200  of  FIG. 1 ), a network node, etc. The wireless devices  100  and  200  may be used in a mobile or fixed place according to a use-example/service. 
     In  FIG. 3 , the entirety of the various elements, components, units/portions, and/or modules in the wireless devices  100  and  200  may be connected to each other through a wired interface or at least a part thereof may be wirelessly connected through the communication unit  110 . For example, in each of the wireless devices  100  and  200 , the control unit  120  and the communication unit  110  may be connected by wire and the control unit  120  and first units (e.g.,  130  and  140 ) may be wirelessly connected through the communication unit  110 . Each element, component, unit/portion, and/or module within the wireless devices  100  and  200  may further include one or more elements. For example, the control unit  120  may be configured by a set of one or more processors. As an example, the control unit  120  may be configured by a set of a communication control processor, an application processor (AP), an electronic control unit (ECU), a graphical processing unit, and a memory control processor. As another example, the memory  130  may be configured by a RAM, a DRAM, a ROM, a flash memory, a volatile memory, a non-volatile memory, and/or a combination thereof. 
       FIG. 4  shows another example of wireless devices to which implementations of the present disclosure is applied. 
     Referring to  FIG. 4 , wireless devices  100  and  200  may correspond to the wireless devices  100  and  200  of  FIG. 2  and may be configured by various elements, components, units/portions, and/or modules. 
     The first wireless device  100  may include at least one transceiver, such as a transceiver  106 , and at least one processing chip, such as a processing chip  101 . The processing chip  101  may include at least one processor, such a processor  102 , and at least one memory, such as a memory  104 . The memory  104  may be operably connectable to the processor  102 . The memory  104  may store various types of information and/or instructions. The memory  104  may store a software code  105  which implements instructions that, when executed by the processor  102 , perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the software code  105  may implement instructions that, when executed by the processor  102 , perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the software code  105  may control the processor  102  to perform one or more protocols. For example, the software code  105  may control the processor  102  may perform one or more layers of the radio interface protocol. 
     The second wireless device  200  may include at least one transceiver, such as a transceiver  206 , and at least one processing chip, such as a processing chip  201 . The processing chip  201  may include at least one processor, such a processor  202 , and at least one memory, such as a memory  204 . The memory  204  may be operably connectable to the processor  202 . The memory  204  may store various types of information and/or instructions. The memory  204  may store a software code  205  which implements instructions that, when executed by the processor  202 , perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the software code  205  may implement instructions that, when executed by the processor  202 , perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. For example, the software code  205  may control the processor  202  to perform one or more protocols. For example, the software code  205  may control the processor  202  may perform one or more layers of the radio interface protocol. 
       FIG. 5  shows an example of UE to which implementations of the present disclosure is applied. 
     Referring to  FIG. 5 , a UE  100  may correspond to the first wireless device  100  of  FIG. 2  and/or the first wireless device  100  of  FIG. 4 . 
     A UE  100  includes a processor  102 , a memory  104 , a transceiver  106 , one or more antennas  108 , a power management module  110 , a battery  1112 , a display  114 , a keypad  116 , a subscriber identification module (SIM) card  118 , a speaker  120 , and a microphone  122 . 
     The processor  102  may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The processor  102  may be configured to control one or more other components of the UE  100  to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor  102 . The processor  102  may include ASIC, other chipset, logic circuit and/or data processing device. The processor  102  may be an application processor. The processor  102  may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), a modem (modulator and demodulator). An example of the processor  102  may be found in SNAPDRAGON™ series of processors made by Qualcomm®, EXYNOS™ series of processors made by Samsung®, A series of processors made by Apple®, HELIO™ series of processors made by MediaTek®, ATOM™ series of processors made by Intel® or a corresponding next generation processor. 
     The memory  104  is operatively coupled with the processor  102  and stores a variety of information to operate the processor  102 . The memory  104  may include ROM, RAM, flash memory, memory card, storage medium and/or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in the present disclosure. The modules can be stored in the memory  104  and executed by the processor  102 . The memory  104  can be implemented within the processor  102  or external to the processor  102  in which case those can be communicatively coupled to the processor  102  via various means as is known in the art. 
     The transceiver  106  is operatively coupled with the processor  102 , and transmits and/or receives a radio signal. The transceiver  106  includes a transmitter and a receiver. The transceiver  106  may include baseband circuitry to process radio frequency signals. The transceiver  106  controls the one or more antennas  108  to transmit and/or receive a radio signal. 
     The power management module  110  manages power for the processor  102  and/or the transceiver  106 . The battery  112  supplies power to the power management module  110 . 
     The display  114  outputs results processed by the processor  102 . The keypad  116  receives inputs to be used by the processor  102 . The keypad  16  may be shown on the display  114 . 
     The SIM card  118  is an integrated circuit that is intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards. 
     The speaker  120  outputs sound-related results processed by the processor  102 . The microphone  122  receives sound-related inputs to be used by the processor  102 . 
       FIGS. 6 and 7  show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied. 
     In particular,  FIG. 6  illustrates an example of a radio interface user plane protocol stack between a UE and a BS and  FIG. 7  illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to a path through which control messages used to manage call by a UE and a network are transported. The user plane refers to a path through which data generated in an application layer, for example, voice data or Internet packet data are transported. Referring to  FIG. 6 , the user plane protocol stack may be divided into Layer 1 (i.e., a PHY layer) and Layer 2. Referring to  FIG. 7 , the control plane protocol stack may be divided into Layer 1 (i.e., a PHY layer), Layer 2, Layer 3 (e.g., an RRC layer), and anon-access stratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as an access stratum (AS). 
     In the 3GPP LTE system, the Layer 2 is split into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 is split into the following sublayers: MAC, RLC, PDCP and SDAP. The PHY layer offers to the MAC sublayer transport channels, the MAC sublayer offers to the RLC sublayer logical channels, the RLC sublayer offers to the PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAP sublayer radio bearers. The SDAP sublayer offers to 5G core network quality of service (QoS) flows. 
     In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing/de-multiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in case of carrier aggregation (CA)); priority handling between UEs by means of dynamic scheduling; priority handling between logical channels of one UE by means of logical channel prioritization; padding. A single MAC entity may support multiple numerologies, transmission timings and cells. Mapping restrictions in logical channel prioritization control which numerology(ies), cell(s), and transmission timing(s) a logical channel can use. 
     Different kinds of data transfer services are offered by MAC. To accommodate different kinds of data transfer services, multiple types of logical channels are defined, i.e., each supporting transfer of a particular type of information. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used for the transfer of control plane information only, and traffic channels are used for the transfer of user plane information only. Broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, paging control channel (PCCH) is a downlink logical channel that transfers paging information, system information change notifications and indications of ongoing public warning service (PWS) broadcasts, common control channel (CCCH) is a logical channel for transmitting control information between UEs and network and used for UEs having no RRC connection with the network, and dedicated control channel (DCCH) is a point-to-point bi-directional logical channel that transmits dedicated control information between a UE and the network and used by UEs having an RRC connection. Dedicated traffic channel (DTCH) is a point-to-point logical channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink. In downlink, the following connections between logical channels and transport channels exist: BCCH can be mapped to broadcast channel (BCH); BCCH can be mapped to downlink shared channel (DL-SCH); PCCH can be mapped to paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH. In uplink, the following connections between logical channels and transport channels exist: CCCH can be mapped to uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH. 
     The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM). The RLC configuration is per logical channel with no dependency on numerologies and/or transmission durations. In the 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include: transfer of upper layer PDUs; sequence numbering independent of the one in PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only). 
     In the 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression using robust header compression (ROHC); transfer of user data; reordering and duplicate detection; in-order delivery; PDCP PDU routing (in case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDUs and duplicate discard indication to lower layers. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering and integrity protection; transfer of control plane data; reordering and duplicate detection; in-order delivery; duplication of PDCP PDUs and duplicate discard indication to lower layers. 
     In the 3GPP NR system, the main services and functions of SDAP include: mapping between a QoS flow and a data radio bearer; marking QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each individual PDU session. 
     In the 3GPP NR system, the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by 5GC or NG-RAN; establishment, maintenance and release of an RRC connection between the UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility); QoS management functions; UE measurement reporting and control of the reporting; detection of and recovery from radio link failure; NAS message transfer to/from NAS from/to UE. 
       FIG. 8  shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied. 
     The frame structure shown in  FIG. 8  is purely exemplary and the number of subframes, the number of slots, and/or the number of symbols in a frame may be variously changed. In the 3GPP based wireless communication system, OFDM numerologies (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be differently configured between a plurality of cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for the cell, an (absolute time) duration of a time resource (e.g., a subframe, a slot, or a TTI) including the same number of symbols may be different among the aggregated cells. Herein, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols). 
     Referring to  FIG. 8 , downlink and uplink transmissions are organized into frames. Each frame has T f =10 ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5 ms duration. Each half-frame consists of 5 subframes, where the duration T sf  per subframe is 1 ms. Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols. The numerology is based on exponentially scalable subcarrier spacing Δf=2 u *15 kHz. 
     Table 1 shows the number of OFDM symbols per slot N slot   symb , the number of slots per frame N frame,u   slot , and the number of slots per subframe N subframe,u   slot  for the normal CP, according to the subcarrier spacing Δf=2 u *15 kHz. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 u 
                 N slot   symb   
                 N frame, u   slot   
                 N subframe, u   slot   
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 0 
                 14 
                 10 
                 1 
               
               
                   
                 1 
                 14 
                 20 
                 2 
               
               
                   
                 2 
                 14 
                 40 
                 4 
               
               
                   
                 3 
                 14 
                 80 
                 8 
               
               
                   
                 4 
                 14 
                 160 
                 16 
               
               
                   
                   
               
            
           
         
       
     
     Table 2 shows the number of OFDM symbols per slot N slot   symb , the number of slots per frame N frame,u   slot , and the number of slots per subframe N subframe,u   slot  for the extended CP, according to the subcarrier spacing Δf=2 u *15 kHz. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 u 
                 N slot   symb   
                 N frame, u   slot   
                 N subframe, u   slot   
               
               
                   
                   
               
             
            
               
                   
                 2 
                 12 
                 40 
                 4 
               
               
                   
                   
               
            
           
         
       
     
     A slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain. For each numerology (e.g., subcarrier spacing) and carrier, a resource grid of N size,u   grid,x *N RB   sc  subcarriers and N subframe,u   symb  OFDM symbols is defined, starting at common resource block (CRB) N start,u   grid  indicated by higher-layer signaling (e.g., RRC signaling), where N size,u   grid,x  is the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink. N RB   sc  is the number of subcarriers per RB. In the 3GPP based wireless communication system, N RB   sc  is 12 generally. There is one resource grid for a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL). The carrier bandwidth N size,u   grid  for subcarrier spacing configuration u is given by the higher-layer parameter (e.g., RRC parameter). Each element in the resource grid for the antenna port p and the subcarrier spacing configuration u is referred to as a resource element (RE) and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an index kin the frequency domain and an index l representing a symbol location relative to a reference point in the time domain. In the 3GPP based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. 
     In the 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with ‘point A’ which serves as a common reference point for resource block grids. In the 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and numbered from 0 to N size   BWP,i −1, where i is the number of the bandwidth part. The relation between the physical resource block n PRB  in the bandwidth part i and the common resource block n CRB  is as follows: n PRB =n CRB +N size   BWP,i , where N size   BWP,i  is the common resource block where bandwidth part starts relative to CRB 0. The BWP includes a plurality of consecutive RBs. A carrier may include a maximum of N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE&#39;s operating bandwidth within the cell&#39;s operating bandwidth. 
     The NR frequency band may be defined as two types of frequency range, i.e., FR1 and FR2. The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 3 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean “sub 6 GHz range”, FR2 may mean “above 6 GHz range,” and may be referred to as millimeter wave (mmW). 
     
       
         
           
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 Frequency Range 
                 Corresponding frequency 
                 Subcarrier 
               
               
                 designation 
                 range 
                 Spacing 
               
               
                   
               
             
            
               
                 FR1 
                  450 MHz-6000 MHz 
                  15, 30, 60 kHz 
               
               
                 FR2 
                 24250 MHz-52600 MHz 
                 60, 120, 240 kHz 
               
               
                   
               
            
           
         
       
     
     As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving). 
     
       
         
           
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Frequency Range 
                 Corresponding frequency 
                 Subcarrier 
               
               
                 designation 
                 range 
                 Spacing 
               
               
                   
               
             
            
               
                 FR1 
                  410 MHz-7125 MHz 
                  15, 30, 60 kHz 
               
               
                 FR2 
                 24250 MHz-52600 MHz 
                 60, 120, 240 kHz 
               
               
                   
               
            
           
         
       
     
     In the present disclosure, the term “cell” may refer to a geographic area to which one or more nodes provide a communication system, or refer to radio resources. A “cell” as a geographic area may be understood as coverage within which a node can provide service using a carrier and a “cell” as radio resources (e.g., time-frequency resources) is associated with bandwidth which is a frequency range configured by the carrier. The “cell” associated with the radio resources is defined by a combination of downlink resources and uplink resources, for example, a combination of a DL component carrier (CC) and a UL CC. The cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources. Since DL coverage, which is a range within which the node is capable of transmitting a valid signal, and UL coverage, which is a range within which the node is capable of receiving the valid signal from the UE, depends upon a carrier carrying the signal, the coverage of the node may be associated with coverage of the “cell” of radio resources used by the node. Accordingly, the term “cell” may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times. 
     In CA, two or more CCs are aggregated. A UE may simultaneously receive or transmit on one or multiple CCs depending on its capabilities. CA is supported for both contiguous and non-contiguous CCs. When CA is configured, the UE only has one RRC connection with the network. At RRC connection establishment/re-establishment/handover, one serving cell provides the NAS mobility information, and at RRC connection re-establishment/handover, one serving cell provides the security input. This cell is referred to as the primary cell (PCell). The PCell is a cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on UE capabilities, secondary cells (SCells) can be configured to form together with the PCell a set of serving cells. An SCell is a cell providing additional radio resources on top of special cell (SpCell). The configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of the master cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). An SpCell supports PUCCH transmission and contention-based random access, and is always activated. The MCG is a group of serving cells associated with a master node, comprised of the SpCell (PCell) and optionally one or more SCells. The SCG is the subset of serving cells associated with a secondary node, comprised of the PSCell and zero or more SCells, for a UE configured with DC. For a UE in RRC_CONNECTED not configured with CA/DC, there is only one serving cell comprised of the PCell. For a UE in RRC_CONNECTED configured with CA/DC, the term “serving cells” is used to denote the set of cells comprised of the SpCell(s) and all SCells. In DC, two MAC entities are configured in a UE: one for the MCG and one for the SCG. 
       FIG. 9  shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied. 
     Referring to  FIG. 9 , “RB” denotes a radio bearer, and “H” denotes a header. Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data. The MAC PDU is transmitted/received using radio resources through the PHY layer to/from an external device. The MAC PDU arrives to the PHY layer in the form of a transport block. 
     In the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to their physical channels physical uplink shared channel (PUSCH) and physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to physical downlink shared channel (PDSCH), physical broadcast channel (PBCH) and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to physical uplink control channel (PUCCH), and downlink control information (DCI) is mapped to physical downlink control channel (PDCCH). A MAC PDU related to UL-SCH is transmitted by a UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCH is transmitted by a BS via a PDSCH based on a DL assignment. 
     Multi-radio dual connectivity (MR-DC) is described. Section 4 of 3GPP TS 37.340 V15.6.0 (2019-06) can be referred. 
     In MR-DC, the following definitions may be used.
         en-gNB: node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DC.   Master cell group (MCG): in MR-DC, a group of serving cells associated with the master node, comprising of the SpCell (PCell) and optionally one or more SCells.   Master node (MN): in MR-DC, the radio access node that provides the control plane connection to the core network. It may be a master eNB (in EN-DC), a master ng-eNB (in NGEN-DC) or a master gNB (in NR-DC and NE-DC).   MCG bearer: in MR-DC, a radio bearer with an RLC bearer (or two RLC bearers, in case of CA packet duplication) only in the MCG.   MN terminated bearer: in MR-DC, a radio bearer for which PDCP is located in the MN.   MCG SRB: in MR-DC, a direct SRB between the MN and the UE.   Multi-radio dual connectivity (MR-DC): Dual connectivity between E-UTRA and NR nodes, or between two NR nodes.   Ng-eNB: node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC.   PCell: SpCell of a master cell group.   PSCell: SpCell of a secondary cell group.   RLC bearer: RLC and MAC logical channel configuration of a radio bearer in one cell group.   Secondary cell group (SCG): in MR-DC, a group of serving cells associated with the Secondary Node, comprising of the SpCell (PSCell) and optionally one or more SCells.   Secondary node (SN): in MR-DC, the radio access node, with no control plane connection to the core network, providing additional resources to the UE. It may be an en-gNB (in EN-DC), a Secondary ng-eNB (in NE-DC) or a Secondary gNB (in NR-DC and NGEN-DC).   SCG bearer: in MR-DC, a radio bearer with an RLC bearer (or two RLC bearers, in case of CA packet duplication) only in the SCG.   SN terminated bearer: in MR-DC, a radio bearer for which PDCP is located in the SN.   SpCell: primary cell of a master or secondary cell group.   Split bearer: in MR-DC, a radio bearer with RLC bearers both in MCG and SCG.   Split SRB: in MR-DC, a SRB between the MN and the UE with RLC bearers both in MCG and SCG.       

     MR-DC is a generalization of the intra-E-UTRA DC, where a multiple Rx/Tx UE may be configured to utilize resources provided by two different nodes connected via non-ideal backhaul, one providing NR access and the other one providing either E-UTRA or NR access. One node acts as the MN and the other as the SN. The MN and SN are connected via a network interface and at least the MN is connected to the core network. 
     MR-DC is designed based on the assumption of non-ideal backhaul between the different nodes but can also be used in case of ideal backhaul. 
       FIG. 10  shows an example of EN-DC overall architecture to which implementations of the present disclosure is applied. 
     E-UTRAN supports MR-DC via E-UTRA-NR dual connectivity (EN-DC), in which a UE is connected to one eNB that acts as a MN and one en-gNB that acts as a SN. The eNB is connected to the EPC via the S1 interface and to the en-gNB via the X2 interface. The en-gNB might also be connected to the EPC via the S1-U interface and other en-gNBs via the X2-U interface. 
     NG-RAN supports NG-RAN E-UTRA-NR dual connectivity (NGEN-DC), in which a UE is connected to one ng-eNB that acts as a MN and one gNB that acts as a SN. The ng-eNB is connected to the 5GC and the gNB is connected to the ng-eNB via the Xn interface. 
     NG-RAN supports NR-E-UTRA dual connectivity (NE-DC), in which a UE is connected to one gNB that acts as a MN and one ng-eNB that acts as a SN. The gNB is connected to 5GC and the ng-eNB is connected to the gNB via the Xn interface. 
     NG-RAN supports NR-NR dual connectivity (NR-DC), in which a UE is connected to one gNB that acts as a MN and another gNB that acts as a SN. The master gNB is connected to the 5GC via the NG interface and to the secondary gNB via the Xn interface. The secondary gNB might also be connected to the 5GC via the NG-U interface. In addition, NR-DC can also be used when a UE is connected to two gNB-DUs, one serving the MCG and the other serving the SCG, connected to the same gNB-CU, acting both as a MN and as a SN. 
       FIG. 11  shows an example of a control plane architecture for EN-DC to which implementations of the present disclosure is applied.  FIG. 12  shows an example of a control plane architecture for MR-DC to which implementations of the present disclosure is applied. 
     In MR-DC, the UE has a single RRC state, based on the MN RRC and a single C-plane connection towards the core network. Referring to  FIGS. 11 and 12 , each radio node has its own RRC entity (E-UTRA version if the node is an eNB or NR version if the node is a gNB) which can generate RRC PDUs to be sent to the UE. 
     RRC PDUs generated by the SN can be transported via the MN to the UE. The MN always sends the initial SN RRC configuration via MCG SRB (SRB1), but subsequent reconfigurations may be transported via MN or SN. When transporting RRC PDU from the SN, the MN does not modify the UE configuration provided by the SN. 
     In E-UTRA connected to EPC, at initial connection establishment SRB1 uses E-UTRA PDCP. If the UE supports EN-DC, regardless whether EN-DC is configured or not, after initial connection establishment, MCG SRBs (SRB1 and SRB2) can be configured by the network to use either E-UTRA PDCP or NR PDCP (either SRB1 and SRB2 are both configured with E-UTRA PDCP, or they are both configured with NR PDCP). Change from E-UTRA PDCP to NR PDCP (or vice-versa) is supported via a handover procedure (reconfiguration with mobility) or, for the initial change of SRB1 from E-UTRA PDCP to NR PDCP, with a reconfiguration without mobility before the initial security activation. 
     If the SN is a gNB (i.e., for EN-DC, NGEN-DC and NR-DC), the UE can be configured to establish a SRB with the SN (SRB3) to enable RRC PDUs for the SN to be sent directly between the UE and the SN. RRC PDUs for the SN can only be transported directly to the UE for SN RRC reconfiguration not requiring any coordination with the MN. Measurement reporting for mobility within the SN can be done directly from the UE to the SN if SRB3 is configured. 
     Split SRB is supported for all MR-DC options, allowing duplication of RRC PDUs generated by the MN, via the direct path and via the SN. Split SRB uses NR PDCP. 
     In EN-DC, the SCG configuration is kept in the UE during suspension. The UE releases the SCG configuration (but not the radio bearer configuration) during resumption initiation. 
     In MR-DC with 5GC, the UE stores the PDCP/SDAP configuration when moving to RRC Inactive but it releases the SCG configuration. 
     In MR-DC, from a UE perspective, three bearer types exist: MCG bearer, SCG bearer and split bearer. 
     For EN-DC, the network can configure either E-UTRA PDCP or NR PDCP for MN terminated MCG bearers while NR PDCP is always used for all other bearers. 
     In MR-DC with 5GC, NR PDCP is always used for all bearer types. In NGEN-DC, E-UTRA RLC/MAC is used in the MN while NR RLC/MAC is used in the SN. In NE-DC, NR RLC/MAC is used in the MN while E-UTRA RLC/MAC is used in the SN. In NR-DC, NR RLC/MAC is used in both MN and SN. 
     From a network perspective, each bearer (MCG, SCG and split bearer) can be terminated either in MN or in SN. 
     Even if only SCG bearers are configured for a UE, for SRB1 and SRB2 the logical channels are always configured at least in the MCG, i.e., this is still an MR-DC configuration and a PCell always exists. 
     If only MCG bearers are configured for a UE, i.e., there is no SCG, this is still considered an MR-DC configuration, as long as at least one of the bearers is terminated in the SN. 
     In MR-DC, there is an interface between the MN and the SN for control plane signaling and coordination. For each MR-DC UE, there is also one control plane connection between the MN and a corresponding core network entity. The MN and the SN involved in MR-DC for a certain UE control their radio resources and are primarily responsible for allocating radio resources of their cells. 
     In MR-DC with EPC (EN-DC), the involved core network entity is the mobility management entity (MME). S1-MME is terminated in MN and the MN and the SN are interconnected via X2-C. 
     In MR-DC with 5GC (NGEN-DC, NE-DC and NR-DC), the involved core network entity is the access and mobility management function (AMF). NG-C is terminated in the MN and the MN and the SN are interconnected via Xn-C. 
     There are different U-plane connectivity options of the MN and SN involved in MR-DC for a certain UE. The U-plane connectivity depends on the bearer option configured:
         For MN terminated bearers, the user plane connection to the CN entity is terminated in the MN;   For SN terminated bearers, the user plane connection to the CN entity is terminated in the SN;   The transport of user plane data over the Uu either involves MCG or SCG radio resources or both:
           For MCG bearers, only MCG radio resources are involved;   For SCG bearers, only SCG radio resources are involved;   For split bearers, both MCG and SCG radio resources are involved.   
           For split bearers, MN terminated SCG bearers and SN terminated MCG bearers, PDCP data is transferred between the MN and the SN via the MN-SN user plane interface.       

     For MR-DC with EPC (EN-DC), X2-U interface is the user plane interface between MN and SN, and S1-U is the user plane interface between the MN, the SN or both and the serving gateway (S-GW). 
     For MR-DC with 5GC (NGEN-DC, NE-DC and inter-gNB NR-DC), Xn-U interface is the user plane interface between MN and SN, and NG-U is the user plane interface between the MN, the SN or both and the user plane function (UPF). 
     Packet duplication is described. Section 16.1.3 of 3GPP TS 38.300 V15.6.0 (2019-06) can be referred. 
     When duplication is configured for a radio bearer by RRC, a secondary RLC entity is added to the radio bearer to handle the duplicated PDCP PDUs, where the logical channel corresponding to the primary RLC entity is referred to as the primary logical channel, and the logical channel corresponding to the secondary RLC entity, the secondary logical channel. The two RLC entities have the same RLC mode. Duplication at PDCP therefore consists in submitting the same PDCP PDUs twice: once to the primary RLC entity and a second time to the secondary RLC entity. With two independent transmission paths, packet duplication therefore increases reliability and reduces latency and is especially beneficial for URLLC services. 
     PDCP control PDUs are not duplicated and always submitted to the primary RLC entity. 
     When configuring duplication for a DRB, RRC also sets the initial state (either activated or deactivated). After the configuration, the state can then be dynamically controlled by means of a MAC control element (CE) and in DC, the UE applies the MAC CE commands regardless of their origin (MCG or SCG). When duplication is configured for an SRB the state is always active and cannot be dynamically controlled. 
     When activating duplication for a DRB, NG-RAN should ensure that at least one serving cell is activated for each logical channel of the DRB; and when the deactivation of SCells leaves no serving cells activated for a logical channel of the DRB, NG-RAN should ensure that duplication is also deactivated. 
     When duplication is activated, the original PDCP PDU and the corresponding duplicate shall not be transmitted on the same carrier. The primary and secondary logical channels can either belong to the same MAC entity (referred to as CA duplication) or to different ones (referred to as DC duplication). In CA duplication, logical channel mapping restrictions are used in MAC to ensure that the primary and secondary logical channels are not sent on the same carrier. When CA duplication is configured for an SRB, one of the logical channels associated to the SRB is mapped to SpCell. 
     When duplication is deactivated for a DRB, the secondary RLC entity is not re-established, the HARQ buffers are not flushed, and the transmitting PDCP entity should indicate to the secondary RLC entity to discard all duplicated PDCP PDUs. In addition, in case of CA duplication, the logical channel mapping restrictions of the primary and secondary logical channels are lifted for as long as duplication remains deactivated. 
     When an RLC entity acknowledges the transmission of a PDCP PDU, the PDCP entity shall indicate to the other RLC entity to discard it. In addition, in case of CA duplication, when an RLC entity restricted to only SCell(s) reaches the maximum number of retransmissions for a PDCP PDU, the UE informs the gNB but does not trigger radio link failure (RLF). 
     SCG failure information is described. Section 5.3.7 of 3GPP TS 38.331 V15.6.0 (2019-06) can be referred. 
     The purpose of this procedure is to inform E-UTRAN or NR MN about an SCG failure the UE has experienced, i.e., SCG radio link failure, failure of SCG reconfiguration with sync, SCG configuration failure for RRC message on SRB3 and SCG integrity check failure. 
     A UE initiates the procedure to report SCG failures when SCG transmission is not suspended and when one of the following conditions is met: 
     1&gt; upon detecting radio link failure for the SCG; 
     1&gt; upon reconfiguration with sync failure of the SCG; 
     1&gt; upon SCG configuration failure; 
     1&gt; upon integrity check failure indication from SCG lower layers concerning SRB3. 
     Upon initiating the procedure, the UE shall: 
     1&gt; suspend SCG transmission for all SRBs and DRBs; 
     1&gt; reset SCG MAC; 
     1&gt; stop T 304 , if running; 
     1&gt; if the UE is in (NG)EN-DC: 
     2&gt; initiate transmission of the SCGFailureInformationNR message. 
     1&gt; else: 
     2&gt; initiate transmission of the SCGFailureInformation message. 
     Like SCG failure information procedure, it has been discussed that a UE may report MCG failure information upon detecting MCG failure. Upon the MCG failure information procedure is initiated, the MCG failure information may be transmitted, and MCG transmission should be suspended. If SCG failure (e.g., radio link failure on SCG) is also detected while the MCG failure information procedure is being performed, then the UE may perform an RRC re-establishment procedure. 
     When a UE is configured with DC and CA has been activated on MCG, there are two available paths for reporting the MCG failure information. The first available path for reporting the MCG failure information is via SN (i.e., using DC), and the second available path for reporting the MCG failure information is via MCG SCell (i.e., using CA). Hence, it is necessary how a UE determines the path for MCG failure information reporting. 
     The following drawings are created to explain specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals/messages/fields shown in the drawings are provided by way of example, and thus the technical features of the present disclosure are not limited to the specific names used in the following drawings. 
       FIG. 13  shows an example of a method performed by a wireless device configured to operate in a wireless communication system to which implementations of the present disclosure is applied. 
     In step S 1300 , the wireless device establishes a connection with both MCG, including PCell and at least one SCell, and SCG. Therefore, the wireless device is configured with DC and CA has been activated on the MCG. 
     In some implementations, the wireless device establishes a connection with network (e.g., gNB). The wireless device may perform initial access towards the cell. The wireless device and the cell may perform random access channel (RACH) procedure. The wireless device may establish or resume a connection with the gNB and enters RRC_CONNECTED. The wireless device may perform AS security activation upon receiving Security Mode Command from the gNB. The wireless device may configure radio bearers and radio configuration upon receiving RRC reconfiguration message or resumes radio bearers and radio configuration upon receiving RRC resume message. 
     In step S 1310 , the wireless device detects a failure on the PCell of the MCG. 
     In some implementations, the wireless device shall: 
     1&gt; upon receiving N 310  consecutive “out-of-sync” indications for the PCell from lower layers while neither T 300 , T 301 , T 304 , T 311  nor T 319  are running: 
     2&gt; start timer T 310  for the corresponding PCell. 
     In some implementations, the wireless device shall: 
     1&gt; upon T 310  expiry in PCell; or 
     1&gt; upon random access problem indication from MCG MAC while neither T 300 , T 301 , T 304 , T 311  nor T 319  are running; or 
     1&gt; upon indication from MCG RLC that the maximum number of retransmissions has been reached: 
     2&gt; if the indication is from MCG RLC and CA duplication is configured and activated, and for the corresponding logical channel allowedServingCells only includes SCell(s): 
     3&gt; initiate the failure information procedure as specified in 5.7.5 to report RLC failure. 
     2&gt; else: 
     3&gt; consider radio link failure to be detected for the MCG., i.e. RLF; 
     In step S 1320 , the wireless device determines a path for MCG failure information to inform the failure on the PCell of the MCG from among the at least one SCell of the MCG and the SCG. 
     In some implementations, the wireless device may receive information on the path (e.g., path indication) for the MCG failure information from a network (e.g., from MCG). Or, the wireless device may be configured with a prioritized path to report the MCG failure information. The prioritized path may be pre-configured in the wireless device and/or may be received from the network. 
     In some implementations, the information on the path (e.g., path indication) and/or the prioritized path may inform 1) reporting the MCG failure information via SN/SCG, and/or 2) reporting the MCG failure information via SCell of the MCG. 
     In step S 1330 , the wireless device transmits the MCG failure information via the determined path. 
     In some implementations, upon detecting the MCG failure (i.e., failure on the PCell of the MCG), if the information on the path (e.g., path indication) is received/configured, the wireless device may report the MCG failure information via the path informed by the path indication. If the information on the path (e.g., path indication) informs reporting of the MCG failure information via SN/SCG, the wireless device may report the MCG failure information via the SN/SCG. Alternatively, if the information on the path (e.g., path indication) informs reporting of the MCG failure information via the SCell of the MCG, the wireless device may report the MCG failure information via the SCell of the MCG. 
     In some implementations, upon detecting the MCG failure (i.e., failure on the PCell of the MCG), if the information on the path (e.g., path indication) is not received/configured, the wireless device may report the MCG failure information via the prioritized path which may be pre-configured in the wireless device and/or may be received from the network. 
     For example, the prioritized path may be configured as the SCG before detecting SCG failure, and the prioritized path may be configured as the SCell of the MCG after detecting SCG failure. In this case, upon detecting the MCG failure first, a wireless device may report the MCG failure information via the SCG. Once both MCG and SCG failures are detected, the wireless device may report the MCG failure information via the SCell of the MCG. 
     For example, the prioritized path may be configured as both the SCG and the SCell of the MCG. Or, the information on the path (e.g., path indication) may inform reporting of the MCG failure information via both the SCG and the SCell of the MCG. In this case, upon detecting the MCG failure, a wireless device may report the MCG failure information via both the SCG and the SCell of the MCG, with duplication of the MCG failure information. The duplication may include at least one of PDCP PDU duplication, CA duplication and/or RLC duplication. 
     In some implementations, the wireless device may be in communication with at least one of a mobile device, a network, and/or autonomous vehicles other than the wireless device. 
     According to the present disclosure, the MCG failure information can be transmitted instead of performing a connection re-establishment procedure. Moreover, transmission reliability for MCG failure information can be increased with duplicated message transmissions. 
     Furthermore, the method in perspective of the wireless device described above in  FIG. 13  may be performed by first wireless device  100  shown in  FIG. 2 , the wireless device  100  shown in  FIG. 3 , the first wireless device  100  shown in  FIG. 4  and/or the UE  100  shown in  FIG. 5 . 
     More specifically, the wireless device comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations. The operations comprises establishing a connection with both MCG, including PCell and at least one SCell, and SCG, detecting a failure on the PCell of the MCG, determining a path for MCG failure information to inform the failure on the PCell of the MCG from among the at least one S Cell of the MCG and the SCG, and transmitting the MCG failure information via the determined path. 
     In some implementations, information on the path for the MCG failure information may be received from a network. 
     In some implementations, the path for the MCG failure information may be a prioritized path configured by a network or pre-configured in the wireless device. 
     In some implementations, the path for the MCG failure information may be via the at least one SCell of the MCG. 
     In some implementations, the path for the MCG failure information may be via the SCG. 
     In some implementations, the path for the MCG failure information is via the SCG before detecting SCG failure, and the path for the MCG failure information may be via the at least one SCell of the MCG after detecting the SCG failure. 
     In some implementations, the path for the MCG failure information may be both via the at least one SCell of the MCG and via the SCG, and the MCG failure information may be transmitted both via the at least one SCell of the MCG and via the SCG, with duplication. The duplication may include at least one of PDCP PDU duplication, CA duplication and/or RLC duplication. 
     Furthermore, the method in perspective of the wireless device described above in  FIG. 13  may be performed by control of the processor  102  included in the first wireless device  100  shown in  FIG. 2 , by control of the communication unit  110  and/or the control unit  120  included in the wireless device  100  shown in  FIG. 3 , by control of the processor  102  included in the first wireless device  100  shown in  FIG. 4  and/or by control of the processor  102  included in the UE  100  shown in  FIG. 5 . 
     More specifically, an apparatus for configured to operate in a wireless communication system (e.g., wireless device) comprises at least processor, and at least one computer memory operably connectable to the at least one processor. The at least one processor is configured to perform operations comprising establishing a connection with both MCG, including PCell and at least one SCell, and SCG, detecting a failure on the PCell of the MCG, determining a path for MCG failure information to inform the failure on the PCell of the MCG from among the at least one SCell of the MCG and the SCG, and transmitting the MCG failure information via the determined path. 
     In some implementations, information on the path for the MCG failure information may be received from a network. 
     In some implementations, the path for the MCG failure information may be a prioritized path configured by a network or pre-configured in the wireless device. 
     In some implementations, the path for the MCG failure information may be via the at least one SCell of the MCG. 
     In some implementations, the path for the MCG failure information may be via the SCG. 
     In some implementations, the path for the MCG failure information is via the SCG before detecting SCG failure, and the path for the MCG failure information may be via the at least one SCell of the MCG after detecting the SCG failure. 
     In some implementations, the path for the MCG failure information may be both via the at least one SCell of the MCG and via the SCG, and the MCG failure information may be transmitted both via the at least one SCell of the MCG and via the SCG, with duplication. The duplication may include at least one of PDCP PDU duplication, CA duplication and/or RLC duplication. 
     Furthermore, the method in perspective of the wireless device described above in  FIG. 13  may be performed by a software code  105  stored in the memory  104  included in the first wireless device  100  shown in  FIG. 4 . 
     More specifically, at least one computer readable medium (CRM) stores instructions that, based on being executed by at least one processor, perform operations comprising establishing a connection with both MCG, including PCell and at least one SCell, and SCG, detecting a failure on the PCell of the MCG, determining a path for MCG failure information to inform the failure on the PCell of the MCG from among the at least one SCell of the MCG and the SCG, and transmitting the MCG failure information via the determined path. 
     In some implementations, information on the path for the MCG failure information may be received from a network. 
     In some implementations, the path for the MCG failure information may be a prioritized path configured by a network or pre-configured in the wireless device. 
     In some implementations, the path for the MCG failure information may be via the at least one SCell of the MCG. 
     In some implementations, the path for the MCG failure information may be via the SCG. 
     In some implementations, the path for the MCG failure information is via the SCG before detecting SCG failure, and the path for the MCG failure information may be via the at least one SCell of the MCG after detecting the SCG failure. 
     In some implementations, the path for the MCG failure information may be both via the at least one SCell of the MCG and via the SCG, and the MCG failure information may be transmitted both via the at least one SCell of the MCG and via the SCG, with duplication. The duplication may include at least one of PDCP PDU duplication, CA duplication and/or RLC duplication. 
     An example of an operation of the wireless device according to an embodiment of the present disclosure may be as follows. This example corresponds to reselection of the path for reporting MCG failure information. 
     (1) A wireless device establishes a connection with network (e.g. gNB). The wireless device may perform initial access towards the cell. The wireless device and the cell may perform RACH procedure. The wireless device may establish or resume a connection with the gNB and enters RRC_CONNECTED. The wireless device may perform AS security activation upon receiving Security Mode Command from the gNB. The wireless device may configure radio bearers and radio configuration upon receiving RRC reconfiguration message or resumes radio bearers and radio configuration upon receiving RRC resume message. 
     (2) The wireless device receives a configuration of path reselection to report MCG failure information. 
     (3) Upon detecting the MCG failure, the wireless device reports the MCG failure information via the SCG. 
     (4) If SCG failure is also detected, the wireless device reselects the path for failure reporting based on the configuration of path reselection. Then, the wireless device reports the MCG failure information and/or SCG failure information via the SCell of the MCG. 
     Another example of an operation of the wireless device according to an embodiment of the present disclosure may be as follows. This example corresponds to duplication of the MCG failure information. 
     (1) A wireless device establishes a connection with network (e.g. gNB). The wireless device may perform initial access towards the cell. The wireless device and the cell may perform RACH procedure. The wireless device may establish or resume a connection with the gNB and enters RRC_CONNECTED. The wireless device may perform AS security activation upon receiving Security Mode Command from the gNB. The wireless device may configure radio bearers and radio configuration upon receiving RRC reconfiguration or resumes radio bearers and radio configuration upon receiving RRC resume. 
     (2) The wireless device receives a configuration of duplication to report MCG failure information. The duplication may include at least one of the followings:
         Duplication for PDCP PDU   CA duplication   RLC duplication       

     (3) Upon detecting the MCG failure, the wireless device duplicates the PDU containing the MCG failure information based on the configuration of duplication. 
     (4) The wireless device reports the duplicated PDU containing the MCG failure information both via SCG and the SCell of the MCG simultaneously. 
     At least one of embodiments/examples/scenarios described above may be combined with one another. 
     The present disclosure can have various advantageous effects. 
     For example, the present disclosure is beneficial in a latency perspective that UE does not need to perform the re-establishment procedure while MCG and SCG failures occur. 
     For example, transmission reliability for MCG failure information can be increased with duplicated message transmission according to the present disclosure. 
     Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure. 
     Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.