Method and apparatus for random access procedure based on discontinuous transmission pattern

Abstract

A method and apparatus for a random access procedure based on a discontinuous transmission pattern is provided. A wireless device receives a configuration including information related to a discontinuous transmission pattern for a certain beam. The wireless device transmits a random access preamble related to the certain beam. The wireless device monitors a response window for a random access response message, wherein the response window is started during a next DL ON period.

Description

METHOD AND APPARATUS FOR RANDOM ACCESS PROCEDURE BASED ON DISCONTINUOUS TRANSMISSION PATTERN

[0001] The present disclosure relates to a method and apparatus for a random access procedure based on a discontinuous transmission pattern.

[0002] 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.

[0003] 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.

[0004] 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.

[0005] In NR-NTN (non-terrestrial network) system, satellite payload has power limitation, which affects the number of beams that can be activated simultaneously. In detail, due to the large size of satellite coverage and large number of satellite beams, approximately 10% of the cells deployed in the satellite can be activated simultaneously.

[0006] In 3GPP Rel-19 NR-NTN, beam hopping operation based on Rel-18 NES DTX (discontinuous transmission) operation is studied and considered for downlink coverage enhancement. However, due to the limited power of satellite payload, DTX operation in NTN system assumes that the satellite beam is completely off and any DL data may not be transmitted during the DTX off period. As the satellite payload has less power limitation on UL reception, UE might transmit UL data without limitation, such as DRX operation. In that case, NTN cell might operate with DTX operation but not with DRX operation.

[0007] However, if the NTN cell operates with cell and / or beam DTX operation but not operates with cell and / or beam DRX operation, the NTN cell cannot transmit feedback in response to the UL data from the UE during the satellite beam off period. In case, the UE cannot ensure whether the NTN cell successfully receives UL data from the UE, which might result in that the UE determines failure of UL transmission.

[0008] For example, when a UE performs a random access (RA) procedure during the beam DTX operation, successful probability of RA procedure may be determined by the state of beam DTX pattern. If the UE transmits random access response (RAR) preamble to the NTN cell during beam DTX off period or NTN cell receives preamble during beam DTX off period, NTN cell should wait beam DTX off period to be end and can transmit RAR after the start of the beam DTX on period.

[0009] In this case, UE might receive RAR after RAR window expiry and may declare RA failure. Even though NTN cell successfully receive preamble from a UE, UE might have to retransmit preamble if the RA procedure is considered as failure. In addition, even if the UE successfully receive RAR and transmits Msg3 in response to the received RAR, the UE may not receive Msg4 during the Contention Resolution Timer and consider the Contention Resolution not successful due to the beam DTX off period. Overall, the successful rate of RA procedure is declined, which affects service quality of the NTN cell operating with DTX.

[0010] Therefore, in order to ensure the transmission of the successful RA procedure, a mechanism to select the offset of RAR window and the offset of Contention Resolution Timer based on beam DTX pattern, in order to avoid unnecessary service interruption due to RA failure, for example, preamble retransmission or reselection to other cells.

[0011] Therefore, studies for a random access procedure based on a discontinuous transmission pattern are required.

[0012] In an aspect, a method is provided. The method comprises: receiving, by a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; transmitting, by the wireless device, a random access preamble related to the certain beam; and monitoring, by the wireless device, a response window for a random access response message, wherein the response window is started during a next DL ON period.

[0013] In another aspect, an apparatus for implementing the above method is provided.

[0014] The present disclosure can have various advantageous effects.

[0015] According to some embodiments of the present disclosure, the wireless device could efficiently perform a random access procedure based on a discontinuous transmission pattern.

[0016] According to some embodiments of the present disclosure, when the cell is operating with the DTX operation and not with the DRX operation, the UE selects the RAR window offset based on the selected SSB which ensures the successful competition of the RA procedure.

[0017] Therefore, when the selected SSB beam is in the beam DTX off period, the UE can start the RAR window at the time when UE can receive RAR, for example, when the selected SSB beam's DTX pattern transitions from the beam DTX off period to beam DTX on period.

[0018] For example, by considering the DTX pattern, the wireless device and the RAN node could perform a random access procedure efficiently.

[0019] According to some embodiments of the present disclosure, the wireless communication system could provide an efficient solution for a random access procedure based on the discontinuous transmission pattern.

[0020] 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.

[0021] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0022] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0023] FIG. 3 shows an example of a wireless device to which implementations of the present disclosure is applied.

[0024] FIG. 4 shows another example of wireless devices to which implementations of the present disclosure is applied.

[0025] FIG. 5 shows an example of UE to which implementations of the present disclosure is applied.

[0026] 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.

[0027] FIG. 8 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0028] FIG. 9 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0029] FIG. 10 shows an example of contention-based random access (CBRA) with 4-step RA type.

[0030] FIG. 11 shows an example of CBRA with 2-step RA type.

[0031] FIG. 12 shows an example of contention-free random access (CFRA) with 4-step RA type.

[0032] FIG. 13 shows an example of CFRA with 2-step RA type.

[0033] FIG. 14 shows an example of CFRA without network response with 4-step RA type.

[0034] FIG. 15 shows an example of Fallback for CBRA with 2-step RA type.

[0035] FIG. 16 shows an example of a method for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure.

[0036] FIG. 17 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0037] FIG. 18 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0038] FIG. 19 shows an example of operations for selecting offset of RAR window and offset of Contention Resolution Timer based on the selected SSB.

[0039] FIG. 20 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0040] FIG. 21 shows an example of a method for a RA resource selection based on DTX pattern.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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".

[0045] 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".

[0046] 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".

[0047] 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".

[0048] 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 "PDCCH" 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".

[0049] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0050] 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.

[0051] 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.

[0052] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0053] 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.

[0054] 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).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 5G is a means of providing streaming evaluated as a few hundred megabits per second to gigabits per second and may complement fibre-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.

[0060] 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 behaviour 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.

[0061] 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.

[0062] 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 behaviours 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.

[0063] 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.

[0064] 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 constructible 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.

[0065] 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.

[0066] Referring to FIG. 1, the communication system 1 includes wireless devices 100a to 100f, 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.

[0067] 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.

[0068] The wireless devices 100a to 100f 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 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an IoT device 100f, 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 smart pad, a wearable device (e.g., a smartwatch or a smart glasses), 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 smart meter.

[0069] In the present disclosure, the wireless devices 100a to 100f may be called user equipment's (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.

[0070] The UAV may be, for example, an aircraft availed by a wireless control signal without a human being onboard.

[0071] 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.

[0072] 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.

[0073] 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 smart meters, vending machines, thermometers, smart bulbs, door locks, or various sensors.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] The weather / environment device may include, for example, a device for monitoring or predicting a weather / environment.

[0078] The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f 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 100a to 100f may communicate with each other through the BSs 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 200 / network 300. For example, the vehicles 100b-1 and 100b-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 100a to 100f.

[0079] Wireless communication / connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and / or between wireless device 100a to 100f 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 150a, sidelink communication (or device-to-device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc. The wireless devices 100a to 100f and the BSs 200 / the wireless devices 100a to 100f may transmit / receive radio signals to / from each other through the wireless communication / connections 150a, 150b and 150c. For example, the wireless communication / connections 150a, 150b and 150c 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.

[0080] 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 (mMTC). 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.

[0081] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0082] 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 100a to 100f and the BS 200}, {the wireless device 100a to 100f and the wireless device 100a to 100f} and / or {the BS 200 and the BS 200} of FIG. 1.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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 (analogy) 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 (analogy) oscillators and / or filters under the control of the transceivers 102 and 202.

[0091] 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 behaviour according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behaviour 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 behaviour according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behaviour according to an implementation of the present disclosure.

[0092] In the present disclosure, a BS is also referred to as a node B (NB), an eNodeB B (eNB), or a gNB.

[0093] FIG. 3 shows an example of a wireless device to which implementations of the present disclosure is applied.

[0094] The wireless device may be implemented in various forms according to a use-case / service (refer to FIG. 1).

[0095] 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.

[0096] 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 (100a of FIG. 1), the vehicles (100b-1 and 100b-2 of FIG. 1), the XR device (100c of FIG. 1), the hand-held device (100d of FIG. 1), the home appliance (100e of FIG. 1), the IoT device (100f 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.

[0097] 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.

[0098] FIG. 4 shows another example of wireless devices to which implementations of the present disclosure is applied.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] FIG. 5 shows an example of UE to which implementations of the present disclosure is applied.

[0103] 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.

[0104] 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.

[0105] 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 SNAPDRAGONTMseries of processors made by Qualcomm®, EXYNOSTMseries of processors made by Samsung®, A series of processors made by Apple®, HELIOTMseries of processors made by MediaTek®, ATOMTMseries of processors made by Intel®or a corresponding next generation processor.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 a non-access stratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as an access stratum (AS).

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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).

[0118] 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.

[0119] 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.

[0120] 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.

[0121] FIG. 8 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0122] 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).

[0123] Referring to FIG. 8, downlink and uplink transmissions are organized into frames. Each frame has Tf= 10ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5ms duration. Each half-frame consists of 5 subframes, where the duration Tsfper subframe is 1ms. 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 △f = 2u*15 kHz.

[0124] Table 1 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the normal CP, according to the subcarrier spacing △f = 2u*15 kHz.

[0125] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0126] Table 2 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the extended CP, according to the subcarrier spacing △f = 2u*15 kHz.

[0127] uNslotsymbNframe,uslotNsubframe,uslot212404

[0128] 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 ofNsize,ugrid,x*NRBscsubcarriers andNsubframe,usymbOFDM symbols is defined, starting at common resource block (CRB)Nstart,ugridindicated by higher-layer signaling (e.g., RRC signaling), whereNsize,ugrid,xis the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink.NRBscis the number of subcarriers per RB. In the 3GPP based wireless communication system,NRBscis 12 generally. There is one resource grid for a given antenna portp, subcarrier spacing configurationu, and transmission direction (DL or UL). The carrier bandwidthNsize,ugridfor subcarrier spacing configurationuis given by the higher-layer parameter (e.g., RRC parameter). Each element in the resource grid for the antenna portpand the subcarrier spacing configurationuis 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 indexkin the frequency domain and an indexlrepresenting 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.

[0129] 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 configurationu. The center of subcarrier 0 of CRB 0 for subcarrier spacing configurationucoincides 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 toNsizeBWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRBin the bandwidth part i and the common resource block nCRBis as follows: nPRB= nCRB+NsizeBWP,i, whereNsizeBWP,iis 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's operating bandwidth within the cell's operating bandwidth.

[0130] 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).

[0131] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0132] 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 410MHz to 7125MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6GHz (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).

[0133] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0134] 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.

[0135] 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.

[0136] FIG. 9 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0137] 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.

[0138] In the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to their physical channels PUSCH and PRACH, respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to PDSCH, PBCH and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to PUCCH, and downlink control information (DCI) is mapped to 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.

[0139] Hereinafter, technical features related to a random access procedure are described. Sections of 3GPP TS 38.300 v 18.4.0 may be referred.

[0140] FIG. 10 shows an example of contention-based random access (CBRA) with 4-step RA type.

[0141] FIG. 11 shows an example of CBRA with 2-step RA type.

[0142] FIG. 12 shows an example of contention-free random access (CFRA) with 4-step RA type.

[0143] FIG. 13 shows an example of CFRA with 2-step RA type.

[0144] FIG. 14 shows an example of CFRA without network response with 4-step RA type.

[0145] FIG. 15 shows an example of Fallback for CBRA with 2-step RA type.

[0146] The random access procedure is triggered by a number of events:

[0147] - Initial access from RRC_IDLE;

[0148] - RRC Connection Re-establishment procedure;

[0149] - DL or UL data arrival, during RRC_CONNECTED or during RRC_INACTIVE while SDT procedure is ongoing, when UL synchronisation status is "non-synchronised";

[0150] - UL data arrival, during RRC_CONNECTED or during RRC_INACTIVE while SDT procedure is ongoing, when there are no PUCCH resources for SR available;

[0151] - Handover, except for when RACH-less HO is configured;

[0152] - SR failure;

[0153] - Explicit request by RRC upon synchronous reconfiguration;

[0154] - RRC Connection Resume procedure from RRC_INACTIVE;

[0155] - To establish time alignment for a primary or a secondary TAG;

[0156] - Request for Other SI;

[0157] - Beam failure recovery;

[0158] - Consistent UL LBT failure on SpCell;

[0159] - SDT in RRC_INACTIVE;

[0160] - Positioning purpose during RRC_CONNECTED requiring random access procedure, e.g., when timing advance is needed for UE positioning;

[0161] - Early UL synchronization with an LTM candidate cell;

[0162] - RACH-based LTM cell switch.

[0163] Two types of random access procedure are supported: 4-step RA type with MSG1 and 2-step RA type with MSGA. Both types of RA procedure support contention-based random access (CBRA) and contention-free random access (CFRA) as shown on FIG. 10 to FIG. 14 below.

[0164] The UE selects the type of random access at initiation of the random access procedure based on network configuration:

[0165] - when CFRA resources are not configured, an RSRP threshold is used by the UE to select between 2-step RA type and 4-step RA type;

[0166] - when CFRA resources for 4-step RA type are configured, UE performs random access with 4-step RA type;

[0167] - when CFRA resources for 2-step RA type are configured, UE performs random access with 2-step RA type.

[0168] The network does not configure CFRA resources for 4-step and 2-step RA types at the same time for a Bandwidth Part (BWP). CFRA with 2-step RA type is only supported for handover.

[0169] The MSG1 of the 4-step RA type consists of a preamble on PRACH. After MSG1 transmission, the UE monitors for a response from the network within a configured window. For CFRA, dedicated preamble for MSG1 transmission is assigned by the network and upon receiving random access response from the network, the UE ends the random access procedure as shown in FIG. 12. For CBRA, upon reception of the random access response, the UE sends MSG3 using the UL grant scheduled in the response and monitors contention resolution as shown in FIG. 10.

[0170] If contention resolution is not successful after MSG3 (re)transmission(s), the UE goes back to MSG1 transmission. The MSGA of the 2-step RA type includes a preamble on PRACH and a payload on PUSCH. After MSGA transmission, the UE monitors for a response from the network within a configured window. For CFRA, dedicated preamble and PUSCH resource are configured for MSGA transmission and upon receiving the network response, the UE ends the random access procedure as shown in FIG. 10. For CBRA, if contention resolution is successful upon receiving the network response, the UE ends the random access procedure as shown in FIG. 11; while if fallback indication is received in MSGB, the UE performs MSG3 transmission using the UL grant scheduled in the fallback indication and monitors contention resolution as shown in FIG. 15. If contention resolution is not successful after MSG3 (re)transmission(s), the UE goes back to MSGA transmission.

[0171] If the random access procedure with 2-step RA type is not completed after a number of MSGA transmissions, the UE can be configured to switch to CBRA with 4-step RA type.

[0172] For the random access procedure towards an LTM candidate cell for early UL TA acquisition, CFRA triggered by a PDCCH order is used. The UE sends MSG1 towards the cell without monitoring for a response from it as shown in FIG. 14. To support UE power ramping, the UE may perform MSG1 retransmission as indicated by the network.

[0173] For random access in a cell configured with SUL, the network can explicitly signal which carrier to use (UL or SUL). Otherwise, the UE selects the SUL carrier if and only if the measured quality of the DL is lower than a broadcast threshold. UE performs carrier selection before selecting between 2-step and 4-step RA type. The RSRP threshold for selecting between 2-step and 4-step RA type can be configured separately for UL and SUL. Once started, all uplink transmissions of the random access procedure remain on the selected carrier.

[0174] The network can associate a set of RACH resources with feature(s) applicable to a Random Access procedure: Network Slicing, (e)RedCap, SDT, and NR coverage enhancement. A set of RACH resources associated with a feature is only valid for random access procedures applicable to at least that feature; and a set of RACH resources associated with several features is only valid for random access procedures having at least all of these features. The UE selects the set(s) of applicable RACH resources, after uplink carrier (i.e. NUL or SUL) and BWP selection and before selecting the RA type.

[0175] When CA is configured, random access procedure with 2-step RA type is only performed on PCell while contention resolution can be cross-scheduled by the PCell.

[0176] When CA is configured, for random access procedure with 4-step RA type, the first three steps of CBRA always occur on the PCell while contention resolution (step 4) can be cross-scheduled by the PCell. The three steps of a CFRA started on the PCell remain on the PCell. CFRA on SCell can only be initiated by the gNB to establish timing advance for a secondary TAG: the procedure is initiated by the gNB with a PDCCH order (step 0) that is sent on an activated SCell of the secondary TAG, preamble transmission (step 1) takes place on the SCell, and Random Access Response (step 2) takes place on PCell.

[0177] When two TAG IDs are configured for the serving cell, the TAG for which the TA command is applied is indicated in Random Access Response message or in MSGB. To establish timing advance for the other PTAG, CFRA is initiated by the gNB with a PDCCH order.

[0178] Hereinafter, technical features related to a random access procedure are described. Sections of 3GPP TS 38.321 v 18.2.0 may be referred.

[0179] The Random Access procedure described in this clause is initiated by a PDCCH order, by the MAC entity itself, or by RRC for the events. There is only one Random Access procedure ongoing at any point in time in a MAC entity. The Random Access procedure on an SCell or an LTM candidate cell shall only be initiated by a PDCCH order withra-PreambleIndexdifferent from 0b000000.

[0180] If a new Random Access procedure is triggered while another is already ongoing in the MAC entity, it is up to UE implementation whether to continue with the ongoing procedure or start with the new procedure (e.g. for SI request).

[0181] - If there was an ongoing Random Access procedure that is triggered by a PDCCH order while the UE receives another PDCCH order indicating the same Random Access Preamble, PRACH mask index and uplink carrier, the Random Access procedure is considered as the same Random Access procedure as the ongoing one and not initialized again.

[0182] When a Random Access procedure is initiated, UE selects a set of Random Access resources and initialises the following parameters for the Random Access procedure according to the values configured by RRC for the selected set of Random Access resources:

[0183] -prach-ConfigurationIndex: the available set of PRACH occasions for the transmission of the Random Access Preamble for Msg1. These are also applicable to the MSGA PRACH if the PRACH occasions are shared between 2-step and 4-step RA types;

[0184] -prach-ConfigurationPeriodScaling-IAB: the scaling factor and applicable to IAB-MTs, extending the periodicity of the PRACH occasions baseline configuration indicated byprach-ConfigurationIndex;

[0185] -prach-ConfigurationFrameOffset-IAB: the frame offset and applicable to IAB-MTs, altering the ROs frame defined in the baseline configuration indicated byprach-ConfigurationIndex;

[0186] -prach-ConfigurationSOffset-IAB: the subframe / slot offset and applicable to IAB-MTs, altering the ROs subframe or slot defined in the baseline configuration indicated byprach-ConfigurationIndex;

[0187] -msgA-PRACH-ConfigurationIndex: the available set of PRACH occasions for the transmission of the Random Access Preamble for MSGA in 2-step RA type;

[0188] -preambleReceivedTargetPower: initial Random Access Preamble power for 4-step RA type;

[0189] -msgA-PreambleReceivedTargetPower: initial Random Access Preamble power for 2-step RA type;

[0190] -rsrp-ThresholdSSB: an RSRP threshold for the selection of the SSB for 4-step RA type. If the Random Access procedure is initiated for beam failure recovery,rsrp-ThresholdSSBused for the selection of the SSB withincandidateBeamRSListrefers torsrp-ThresholdSSBinBeamFailureRecoveryConfigIE;

[0191] -rsrp-ThresholdCSI-RS: an RSRP threshold for the selection of CSI-RS for 4-step RA type. If the Random Access procedure is initiated for beam failure recovery,rsrp-ThresholdCSI-RSis equal torsrp-ThresholdSSBinBeamFailureRecoveryConfigIE;

[0192] -msgA-RSRP-ThresholdSSB: an RSRP threshold for the selection of the SSB for 2-step RA type;

[0193] -rsrp-ThresholdSSB-SUL: an RSRP threshold for the selection between the NUL carrier and the SUL carrier;

[0194] -msgA-RSRP-Threshold: an RSRP threshold for selection between 2-step RA type and 4-step RA type when both 2-step and 4-step RA type Random Access Resources are configured in the UL BWP;

[0195] Selection of the set of Random Access resources based on feature prioritization

[0196] The MAC entity shall:

[0197] 1> among the available sets of Random Access resources for this Random Access procedure, identify those configured with a feature which has the highest priority assigned infeaturePrioritiesamong all the features applicable to this Random Access procedure.

[0198] 1> if a single set of Random Access resources is identified:

[0199] 2> select this set of Random Access resources.

[0200] 1> else if more than one set of Random Access resources is identified:

[0201] 2> if all the identified sets of Random Access resources are configured with Msg1 repetition indication and the samefeatureCombination:

[0202] 3> select the set of Random Access resources that associated with highest Msg1 repetition number among the identified sets of Random Access resources.

[0203] 2> else:

[0204] 3> repeat the procedure taking as an input the identified sets of Random Access resources and the feature applicable to the current Random Access procedure with the highest priority assigned infeaturePrioritiesamong all the features applicable to this Random Access procedure, except the features considered already.

[0205] 1> else (i.e. no set of Random Access resources is identified):

[0206] 2> repeat the procedure taking as an input the previous identified available sets of Random Access resources and the feature applicable to the current Random Access procedure with the highest priority assigned infeaturePrioritiesamong all the features applicable to this Random Access procedure, except the features considered already.

[0207] Random Access Preamble transmission

[0208] The MAC entity shall, for each Random Access Preamble:

[0209] 1> ifPREAMBLE_TRANSMISSION_COUNTERis greater than one; and

[0210] 1> if the notification of suspending power ramping counter has not been received from lower layers; and

[0211] 1> if LBT failure indication was not received from lower layers for the last Random Access Preamble transmission; and

[0212] 1> if SSB or CSI-RS selected is not changed from the selection in the last Random Access Preamble transmission; and

[0213] 1> if the Random Access procedure is not initiated by the PDCCH order for an LTM candidate cell:

[0214] 2> incrementPREAMBLE_POWER_RAMPING_COUNTERby 1.

[0215] 1> if the Random Access procedure is initiated by the PDCCH order for an LTM candidate cell as preamble re-transmission; and

[0216] 1> if the PDCCH order indicates the same LTM candidate cell and the same SSB as the last Random Access Preamble transmission:

[0217] 2> incrementPREAMBLE_POWER_RAMPING_COUNTERby 1.

[0218] 1> select the value ofDELTA_PREAMBLE;

[0219] 1> setPREAMBLE_RECEIVED_TARGET_POWERtopreambleReceivedTargetPower+DELTA_PREAMBLE+ (PREAMBLE_POWER_RAMPING_COUNTER- 1) ×PREAMBLE_POWER_RAMPING_STEP+POWER_OFFSET_2STEP_RA;

[0220] 1> except for contention-free Random Access Preamble for beam failure recovery request and contention-free Random Access Preamble triggered by a PDCCH order for an LTM candidate cell, compute the RA-RNTI associated with the PRACH occasion in which the Random Access Preamble is transmitted;

[0221] 1> instruct the physical layer to transmit the Random Access Preamble using the selected PRACH occasion, corresponding RA-RNTI (if available),PREAMBLE_INDEX, andPREAMBLE_RECEIVED_TARGET_POWER.

[0222] 1> if the Random Access Procedure is triggered by a PDCCH order for an LTM candidate cell:

[0223] 2> consider this Random Access procedure completed.

[0224] 1> if LBT failure indication is received from lower layers for this Random Access Preamble transmission:

[0225] 2> iflbt-FailureRecoveryConfigis configured:

[0226] 3> perform the Random Access Resource selection procedure.

[0227] 2> else:

[0228] 3> incrementPREAMBLE_TRANSMISSION_COUNTERby 1;

[0229] 3> ifPREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+ 1:

[0230] 4> if the Random Access Preamble is transmitted on the SpCell:

[0231] 5> indicate a Random Access problem to upper layers;

[0232] 5> if this Random Access procedure was triggered for SI request:

[0233] 6> consider the Random Access procedure unsuccessfully completed.

[0234] 4> else if the Random Access Preamble is transmitted on an SCell:

[0235] 5> consider the Random Access procedure unsuccessfully completed.

[0236] 3> if the Random Access procedure is not completed:

[0237] 4> perform the Random Access Resource selection procedure.

[0238] MSGA transmission

[0239] The MAC entity shall, for each MSGA:

[0240] 1> ifPREAMBLE_TRANSMISSION_COUNTERis greater than one; and

[0241] 1> if the notification of suspending power ramping counter has not been received from lower layers; and

[0242] 1> if LBT failure indication was not received from lower layers for the last MSGA Random Access Preamble transmission; and

[0243] 1> if SSB selected is not changed from the selection in the last Random Access Preamble transmission:

[0244] 2> incrementPREAMBLE_POWER_RAMPING_COUNTERby 1.

[0245] 1> select the value ofDELTA_PREAMBLEaccording to clause 7.3;

[0246] 1> setPREAMBLE_RECEIVED_TARGET_POWERtomsgA-PreambleReceivedTargetPower+DELTA_PREAMBLE+ (PREAMBLE_POWER_RAMPING_COUNTER- 1) ×PREAMBLE_POWER_RAMPING_STEP;

[0247] 1> if this is the first MSGA transmission within this Random Access procedure:

[0248] 2> if the transmission is not being made for the CCCH logical channel:

[0249] 3> indicate to the Multiplexing and assembly entity to include a C-RNTI MAC CE in the subsequent uplink transmission.

[0250] 2> if the Random Access procedure was initiated for SpCell beam failure recovery andspCell-BFR-CBRAwith valuetrueis configured:

[0251] 3> if there is at least one Serving Cell of this MAC entity configured with two BFD-RS sets:

[0252] 4> indicate to the Multiplexing and assembly entity to include an Enhanced BFR MAC CE or a Truncated Enhanced BFR MAC CE in the subsequent uplink transmission.

[0253] 3> else:

[0254] 4> indicate to the Multiplexing and assembly entity to include a BFR MAC CE or a Truncated BFR MAC CE in the subsequent uplink transmission.

[0255] 2> else if the Random Access procedure was initiated for beam failure recovery of both BFD-RS sets of SpCell:

[0256] 3> indicate to the Multiplexing and assembly entity to include an Enhanced BFR MAC CE or a Truncated Enhanced BFR MAC CE in the subsequent uplink transmission.

[0257] 2> obtain the MAC PDU to transmit from the Multiplexing and assembly entity according to the HARQ information determined for the MSGA payload and store it in the MSGA buffer.

[0258] 1> compute the MSGB-RNTI associated with the PRACH occasion in which the Random Access Preamble is transmitted;

[0259] 1> instruct the physical layer to transmit the MSGA using the selected PRACH occasion and the associated PUSCH resource of MSGA (if the selected preamble and PRACH occasion is mapped to a valid PUSCH occasion), using the corresponding RA-RNTI, MSGB-RNTI,PREAMBLE_INDEX,PREAMBLE_RECEIVED_TARGET_POWER,msgA-PreambleReceivedTargetPower, and the amount of power ramping applied to the latest MSGA preamble transmission (i.e. (PREAMBLE_POWER_RAMPING_COUNTER- 1) ×PREAMBLE_POWER_RAMPING_STEP);

[0260] 1> if LBT failure indication is received from lower layers for the transmission of this MSGA Random Access Preamble:

[0261] 2> instruct the physical layer to cancel the transmission of the MSGA payload on the associated PUSCH resource;

[0262] 2> iflbt-FailureRecoveryConfigis configured:

[0263] 3> perform the Random Access Resource selection procedure for 2-step RA type (see clause 5.1.2a).

[0264] 2> else:

[0265] 3> incrementPREAMBLE_TRANSMISSION_COUNTERby 1;

[0266] 3> ifPREAMBLE_TRANSMISSION_COUNTER =preambleTransMax+ 1:

[0267] 4> indicate a Random Access problem to upper layers;

[0268] 4> if this Random Access procedure was triggered for SI request:

[0269] 5> consider this Random Access procedure unsuccessfully completed.

[0270] 3> if the Random Access procedure is not completed:

[0271] 4> ifmsgA-TransMaxis applied andPREAMBLE_TRANSMISSION_COUNTER=msgA-TransMax+ 1:

[0272] 5> set theRA_TYPEto4-stepRA;

[0273] 5> perform initialization of variables specific to Random Access type;

[0274] 5> if the Msg3 buffer is empty:

[0275] 6> obtain the MAC PDU to transmit from the MSGA buffer and store it in the Msg3 buffer;

[0276] 5> flush HARQ buffer used for the transmission of MAC PDU in the MSGA buffer;

[0277] 5> discard explicitly signalled contention-free 2-step RA type Random Access Resources, if any;

[0278] 5> perform the Random Access Resource selection procedure.

[0279] 4> else:

[0280] 5> perform the Random Access Resource selection procedure for 2-step RA type.

[0281] Random Access Response reception

[0282] Once the Random Access Preamble is transmitted and regardless of the possible occurrence of a measurement gap, the MAC entity shall:

[0283] 1> if the contention-free Random Access Preamble for beam failure recovery request was transmitted by the MAC entity:

[0284] 2> if the contention-free Random Access Preamble for beam failure recovery request was transmitted on a non-terrestrial network:

[0285] 3> start thera-ResponseWindowconfigured inBeamFailureRecoveryConfigat the PDCCH occasion.

[0286] 2> else:

[0287] 3> start thera-ResponseWindowconfigured inBeamFailureRecoveryConfigat the first PDCCH occasion from the end of the Random Access Preamble transmission.

[0288] 2> monitor for a PDCCH transmission on the search space indicated byrecoverySearchSpaceIdof the SpCell identified by the C-RNTI whilera-ResponseWindowis running.

[0289] 1> else:

[0290] 2> if the Random Access Preamble was transmitted on a non-terrestrial network:

[0291] 3> if the Random Access Preamble is transmitted with repetitions:

[0292] 4> start thera-ResponseWindowconfigured inRACH-ConfigCommonat the PDCCH occasion from the end of all repetitions of the Random Access Preamble transmission.

[0293] 3> else:

[0294] 4> start thera-ResponseWindowconfigured inRACH-ConfigCommonat the PDCCH occasion.

[0295] 2> else if the Random Access Preamble is transmitted with repetitions:

[0296] 3> start thera-ResponseWindowconfigured inRACH-ConfigCommonat the first PDCCH occasion from the end of all repetitions of the Random Access Preamble transmission.

[0297] 2> else:

[0298] 3> start thera-ResponseWindowconfigured inRACH-ConfigCommonat the first PDCCH occasion from the end of the Random Access Preamble transmission.

[0299] 2> monitor the PDCCH of the SpCell for Random Access Response(s) identified by the RA-RNTI while thera-ResponseWindowis running.

[0300] 1> if notification of a reception of a PDCCH transmission on the search space indicated byrecoverySearchSpaceIdis received from lower layers on the Serving Cell where the preamble was transmitted; and

[0301] 1> if PDCCH transmission is addressed to the C-RNTI; and

[0302] 1> if the contention-free Random Access Preamble for beam failure recovery request was transmitted by the MAC entity:

[0303] 2> consider the Random Access procedure successfully completed.

[0304] 1> else if a valid downlink assignment has been received on the PDCCH for the RA-RNTI and the received TB is successfully decoded:

[0305] 2> if the Random Access Response contains a MAC subPDU with Backoff Indicator:

[0306] 3> set thePREAMBLE_BACKOFFto value of the BI field of the MAC subPDU, multiplied withSCALING_FACTOR_BI.

[0307] 2> else:

[0308] 3> set thePREAMBLE_BACKOFFto 0 ms.

[0309] 2> if the Random Access Response contains a MAC subPDU with Random Access Preamble identifier corresponding to the transmittedPREAMBLE_INDEX:

[0310] 3> consider this Random Access Response reception successful.

[0311] 2> if the Random Access Response reception is considered successful:

[0312] 3> if the Random Access Response includes a MAC subPDU with RAPID only:

[0313] 4> consider this Random Access procedure successfully completed;

[0314] 4> indicate the reception of an acknowledgement for SI request to upper layers.

[0315] 3> else:

[0316] 4> apply the following actions for the Serving Cell where the Random Access Preamble was transmitted:

[0317] 5> process the received Timing Advance Command;

[0318] 5> indicate thepreambleReceivedTargetPowerand the amount of power ramping applied to the latest Random Access Preamble transmission to lower layers (i.e. (PREAMBLE_POWER_RAMPING_COUNTER- 1) ×PREAMBLE_POWER_RAMPING_STEP);

[0319] 5> if the Random Access procedure for an SCell is performed on uplink carrier wherepusch-Configis not configured:

[0320] 6> ignore the received UL grant.

[0321] 5> else:

[0322] 6> process the received UL grant value and indicate it to the lower layers.

[0323] 4> if the Random Access Preamble was not selected by the MAC entity among the contention-based Random Access Preamble(s):

[0324] 5> consider the Random Access procedure successfully completed.

[0325] 4> else:

[0326] 5> set theTEMPORARY_C-RNTIto the value received in the Random Access Response;

[0327] 5> if this is the first successfully received Random Access Response within this Random Access procedure:

[0328] 6> if the transmission is not being made for the CCCH logical channel:

[0329] 7> indicate to the Multiplexing and assembly entity to include a C-RNTI MAC CE in the subsequent uplink transmission.

[0330] 6> if the Random Access procedure was initiated for SpCell beam failure recovery andspCell-BFR-CBRAwith valuetrueis configured:

[0331] 7> if there is at least one Serving Cell of this MAC entity configured with two BFD-RS sets:

[0332] 8> indicate to the Multiplexing and assembly entity to include an Enhanced BFR MAC CE or a Truncated Enhanced BFR MAC CE in the subsequent uplink transmission.

[0333] 7> else:

[0334] 8> indicate to the Multiplexing and assembly entity to include a BFR MAC CE or a Truncated BFR MAC CE in the subsequent uplink transmission.

[0335] 6> else if the Random Access procedure was initiated for beam failure recovery of both BFD-RS sets of SpCell:

[0336] 7> indicate to the Multiplexing and assembly entity to include an Enhanced BFR MAC CE or a Truncated Enhanced BFR MAC CE in the subsequent uplink transmission.

[0337] 6> obtain the MAC PDU to transmit from the Multiplexing and assembly entity and store it in the Msg3 buffer.

[0338] - If within a Random Access procedure, an uplink grant provided in the Random Access Response for the same group of contention-based Random Access Preambles has a different size than the first uplink grant allocated during that Random Access procedure, the UE behavior is not defined.

[0339] 1> ifra-ResponseWindowconfigured inBeamFailureRecoveryConfigexpires and if a PDCCH transmission on the search space indicated byrecoverySearchSpaceIdaddressed to the C-RNTI has not been received on the Serving Cell where the preamble was transmitted; or

[0340] 1> ifra-ResponseWindowconfigured inRACH-ConfigCommonexpires, and if the Random Access Response containing Random Access Preamble identifiers that matches the transmittedPREAMBLE_INDEXhas not been received:

[0341] 2> consider the Random Access Response reception not successful;

[0342] 2> incrementPREAMBLE_TRANSMISSION_COUNTERby 1;

[0343] 2> ifPREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+ 1:

[0344] 3> if the Random Access Preamble is transmitted on the SpCell:

[0345] 4> indicate a Random Access problem to upper layers;

[0346] 4> if this Random Access procedure was triggered for SI request:

[0347] 5> consider the Random Access procedure unsuccessfully completed.

[0348] 3> else if the Random Access Preamble is transmitted on an SCell:

[0349] 4> consider the Random Access procedure unsuccessfully completed.

[0350] 2> if the Random Access procedure is not completed:

[0351] 3> if the Random Access Preamble is transmitted with repetitions and neither contention-free Random Access Resources nor Random Access resources for SI request have been provided for this Random Access procedure:

[0352] 4> ifPREAMBLE_TRANSMISSION_COUNTER= [preambleTransMax-Msg1-Repetition] + 1; or

[0353] 4> ifPREAMBLE_TRANSMISSION_COUNTER= 2 × [preambleTransMax-Msg1-Repetition] + 1:

[0354] 5> if set of Random Access resources configured with the sameprach-ConfigurationIndexand associated with a higher Msg1 repetition number with the same feature or feature combination as the current set of Random Access resources is available:

[0355] 6> select the set of Random Access resources associated with the next higher Msg1 repetition number with the same feature or feature combination for this Random Access procedure;

[0356] 6> initializestartPreambleForThisPartition,numberOfPreamblesPerSSB-ForThisPartition,ssb-SharedRO-MaskIndexandnumberOfRA-PreamblesGroupAparameters for the Random Access procedure according to the values configured by RRC for the selected set of Random Access resources.

[0357] 3> select a random backoff time according to a uniform distribution between 0 and thePREAMBLE_BACKOFF;

[0358] 3> if the criteria to select contention-free Random Access Resources is met during the backoff time:

[0359] 4> perform the Random Access Resource selection procedure.

[0360] 3> else if the Random Access procedure for an SCell is performed on uplink carrier wherepusch-Configis not configured:

[0361] 4> delay the subsequent Random Access transmission until the Random Access Procedure is triggered by a PDCCH order with the samera-PreambleIndex,ra-ssb-OccasionMaskIndex, and UL / SUL indicator.

[0362] 3> else:

[0363] 4> perform the Random Access Resource selection procedure after the backoff time.

[0364] The MAC entity may stopra-ResponseWindow(and hence monitoring for Random Access Response(s)) after successful reception of a Random Access Response containing Random Access Preamble identifiers that matches the transmittedPREAMBLE_INDEX.

[0365] HARQ operation is not applicable to the Random Access Response reception.

[0366] Contention Resolution

[0367] Once Msg3 is transmitted the MAC entity shall:

[0368] 1> if the Msg3 transmission (i.e. initial transmission or HARQ retransmission) is scheduled with PUSCH repetition Type A:

[0369] 2> if Msg3 is transmitted on a non-terrestrial network:

[0370] 3> start or restart thera-ContentionResolutionTimerin the first symbol after the end of all repetitions of the Msg3 transmission plus the UE-gNB RTT.

[0371] 2> else:

[0372] 3> start or restart thera-ContentionResolutionTimerin the first symbol after the end of all repetitions of the Msg3 transmission.

[0373] 1> else if Msg3 transmission (i.e. initial transmission or HARQ retransmission) is transmitted on a non-terrestrial network:

[0374] 2> start or restart thera-ContentionResolutionTimerin the first symbol after the end of the Msg3 transmission plus the UE-gNB RTT.

[0375] 1> else:

[0376] 2> start or restart thera-ContentionResolutionTimerin the first symbol after the end of the Msg3 transmission.

[0377] 1> monitor the PDCCH while thera-ContentionResolutionTimeris running regardless of the possible occurrence of a measurement gap;

[0378] 1> if notification of a reception of a PDCCH transmission of the SpCell is received from lower layers:

[0379] 2> if the C-RNTI MAC CE was included in Msg3:

[0380] 3> if the Random Access procedure was initiated for SpCell beam failure recovery or for beam failure recovery of both BFD-RS sets of SpCell and the PDCCH transmission is addressed to the C-RNTI; or

[0381] 3> if the Random Access procedure was initiated by a PDCCH order and the PDCCH transmission is addressed to the C-RNTI; or

[0382] 3> if the Random Access procedure was initiated for SDT beam failure recovery and the PDCCH transmission is addressed to the C-RNTI; or

[0383] 3> if the Random Access procedure was initiated by the MAC sublayer itself or by the RRC sublayer and the PDCCH transmission is addressed to the C-RNTI and contains a UL grant for a new transmission:

[0384] 4> consider this Contention Resolution successful;

[0385] 4> stopra-ContentionResolutionTimer;

[0386] 4> discard theTEMPORARY_C-RNTI;

[0387] 4> consider this Random Access procedure successfully completed.

[0388] 2> else if the CCCH SDU was included in Msg3 and the PDCCH transmission is addressed to itsTEMPORARY_C-RNTI:

[0389] 3> if the MAC PDU is successfully decoded:

[0390] 4> stopra-ContentionResolutionTimer;

[0391] 4> if the MAC PDU contains a UE Contention Resolution Identity MAC CE; and

[0392] 4> if the UE Contention Resolution Identity in the MAC CE matches the CCCH SDU transmitted in Msg3:

[0393] 5> consider this Contention Resolution successful and finish the disassembly and demultiplexing of the MAC PDU;

[0394] 5> if this Random Access procedure was initiated for SI request:

[0395] 6> indicate the reception of an acknowledgement for SI request to upper layers.

[0396] 5> else:

[0397] 6> set the C-RNTI to the value of theTEMPORARY_C-RNTI;

[0398] 5> discard theTEMPORARY_C-RNTI;

[0399] 5> consider this Random Access procedure successfully completed.

[0400] 4> else:

[0401] 5> discard theTEMPORARY_C-RNTI;

[0402] 5> consider this Contention Resolution not successful and discard the successfully decoded MAC PDU.

[0403] 3> else, for eRedCap UE, if lower layer detects that PDSCH transmission scheduled by PDCCH has a larger bandwidth than UE can receive or process per slot:

[0404] 4> stopra-ContentionResolutionTimer;

[0405] 4> discard theTEMPORARY_C-RNTI;

[0406] 4> consider this Contention Resolution not successful.

[0407] 1> ifra-ContentionResolutionTimerexpires:

[0408] 2> if Msg3 transmission was transmitted on a non-terrestrial network:

[0409] 3> if no PDCCH addressed to TC-RNTI indicating uplink grant for a Msg3 retransmission is received after the start of thera-ContentionResolutionTimer:

[0410] 4> discard theTEMPORARY_C-RNTI;

[0411] 4> consider the Contention Resolution not successful.

[0412] 2> else:

[0413] 3> discard theTEMPORARY_C-RNTI;

[0414] 3> consider the Contention Resolution not successful.

[0415] 1> if the Contention Resolution is considered not successful:

[0416] 2> flush the HARQ buffer used for transmission of the MAC PDU in the Msg3 buffer;

[0417] 2> incrementPREAMBLE_TRANSMISSION_COUNTERby 1;

[0418] 2> ifPREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+ 1:

[0419] 3> indicate a Random Access problem to upper layers.

[0420] 3> if this Random Access procedure was triggered for SI request:

[0421] 4> consider the Random Access procedure unsuccessfully completed.

[0422] 2> if the Random Access procedure is not completed:

[0423] 3> if theRA_TYPEis set to4-stepRA:

[0424] 4> if the Random Access Preamble is transmitted with repetitions and contention-free Random Access Resources have not been provided for this Random Access procedure:

[0425] 5> ifPREAMBLE_TRANSMISSION_COUNTER= [preambleTransMax-Msg1-Repetition] + 1; or

[0426] 5> ifPREAMBLE_TRANSMISSION_COUNTER= 2 × [preambleTransMax-Msg1-Repetition] + 1:

[0427] 6> if set of Random Access resources configured with the sameprach-ConfigurationIndexand associated with a higher Msg1 repetition number with the same feature or feature combination as the current set of Random Access resources is available:

[0428] 7> select the set of Random Access resources associated with the next higher Msg1 repetition number with the same feature or feature combination for this Random Access procedure;

[0429] 7> initializestartPreambleForThisPartition,numberOfPreamblesPerSSB-ForThisPartition,ssb-SharedRO-MaskIndexandnumberOfRA-PreamblesGroupAparameters for the Random Access procedure according to the values configured by RRC for the selected set of Random Access resources.

[0430] 4> select a random backoff time according to a uniform distribution between 0 and thePREAMBLE_BACKOFF;

[0431] 4> if the criteria to select contention-free Random Access Resources is met during the backoff time:

[0432] 5> perform the Random Access Resource selection procedure;

[0433] 4> else:

[0434] 5> perform the Random Access Resource selection procedure after the backoff time.

[0435] 3> else (i.e. theRA_TYPEis set to2-stepRA):

[0436] 4> ifmsgA-TransMaxis applied andPREAMBLE_TRANSMISSION_COUNTER=msgA-TransMax+ 1:

[0437] 5> set theRA_TYPEto4-stepRA;

[0438] 5> perform initialization of variables specific to Random Access type;

[0439] 5> flush HARQ buffer used for the transmission of MAC PDU in the MSGA buffer;

[0440] 5> discard explicitly signalled contention-free 2-step RA type Random Access Resources, if any;

[0441] 5> perform the Random Access Resource selection.

[0442] 4> else:

[0443] 5> select a random backoff time according to a uniform distribution between 0 and thePREAMBLE_BACKOFF;

[0444] 5> if the criteria to select contention-free Random Access Resources is met during the backoff time:

[0445] 6> perform the Random Access Resource selection procedure for 2-step RA type.

[0446] 5> else:

[0447] 6> perform the Random Access Resource selection for 2-step RA type procedure after the backoff time.

[0448] Completion of the Random Access procedure

[0449] Upon completion of the Random Access procedure, the MAC entity shall:

[0450] 1> discard any explicitly signalled contention-free Random Access Resources for 2-step RA type and 4-step RA type except the 4-step RA type contention-free Random Access Resources for beam failure recovery request, if any;

[0451] 1> flush the HARQ buffer used for transmission of the MAC PDU in the Msg3 buffer and the MSGA buffer.

[0452] Upon successful completion of the Random Access procedure initiated for DAPS handover, the target MAC entity shall:

[0453] 1> indicate the successful completion of the Random Access procedure to the upper layers.

[0454] Meanwhile, in NR-NTN (non-terrestrial network) system, satellite payload has power limitation, which affects the number of beams that can be activated simultaneously. In detail, due to the large size of satellite coverage and large number of satellite beams, approximately 10% of the cells deployed in the satellite can be activated simultaneously.

[0455] In 3GPP Rel-19 NR-NTN, beam hopping operation based on Rel-18 NES DTX (discontinuous transmission) operation is studied and considered for downlink coverage enhancement. However, due to the limited power of satellite payload, DTX operation in NTN system assumes that the satellite beam is completely off and any DL data may not be transmitted during the DTX off period. As the satellite payload has less power limitation on UL reception, UE might transmit UL data without limitation, such as DRX operation. In that case, NTN cell might operate with DTX operation but not with DRX operation.

[0456] However, if the NTN cell operates with cell and / or beam DTX operation but not operates with cell and / or beam DRX operation, the NTN cell cannot transmit feedback in response to the UL data from the UE during the satellite beam off period. In case, the UE cannot ensure whether the NTN cell successfully receives UL data from the UE, which might result in that the UE determines failure of UL transmission.

[0457] For example, when a UE performs a random access (RA) procedure during the beam DTX operation, successful probability of RA procedure may be determined by the state of beam DTX pattern. If the UE transmits random access response (RAR) preamble to the NTN cell during beam DTX off period or NTN cell receives preamble during beam DTX off period, NTN cell should wait beam DTX off period to be end and can transmit RAR after the start of the beam DTX on period.

[0458] In this case, UE might receive RAR after RAR window expiry and may declare RA failure. Even though NTN cell successfully receive preamble from a UE, UE might have to retransmit preamble if the RA procedure is considered as failure. In addition, even if the UE successfully receive RAR and transmits Msg3 in response to the received RAR, the UE may not receive Msg4 during the Contention Resolution Timer and consider the Contention Resolution not successful due to the beam DTX off period. Overall, the successful rate of RA procedure is declined, which affects service quality of the NTN cell operating with DTX.

[0459] Therefore, in order to ensure the transmission of the successful RA procedure, a mechanism to select the offset of RAR window and the offset of Contention Resolution Timer based on beam DTX pattern, in order to avoid unnecessary service interruption due to RA failure, for example, preamble retransmission or reselection to other cells.

[0460] Therefore, studies for a random access procedure based on a discontinuous transmission pattern are required.

[0461] Hereinafter, a method for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described with reference to the following drawings.

[0462] 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. Herein, a wireless device may be referred to as a user equipment (UE).

[0463] FIG. 16 shows an example of a method for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure.

[0464] In particular, FIG. 16 shows an example of a method performed by a wireless device in a wireless communication system.

[0465] In step S1601, the wireless device may receive a configuration including information related to a discontinuous transmission pattern for a certain beam.

[0466] For example, the information related to the discontinuous transmission pattern may include information related to at least one DL ON period and at least one DL OFF period for the certain beam.

[0467] For example, the configuration may include (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.

[0468] For example, a first DL OFF period for the first beam may be not overlapped with a second DL OFF period for the second beam. For example, the discontinuous transmission pattern may be configured per beam.

[0469] For example, there is no DL transmission for the certain beam from a network during the at least one DL OFF period. For example, DL transmission for the certain beam from the network may be allowed during the at least one DL ON period.

[0470] In step S1602, the wireless device may transmit a random access preamble related to the certain beam.

[0471] For example, the wireless device may transmit a random access preamble to a base station. For example, the base station may be a non-terrestrial networks (NTN) node. For example, the base station may include a NTN satellite.

[0472] For example, the random access preamble related to the certain beam may be transmitted during (i) a current DL ON period or (ii) a DL OFF period.

[0473] For example, the wireless device may select a Synchronization Signal Block (SSB). For example, the wireless device may select the random access preamble associated with the selected SSB.

[0474] For example, the base station may be an NTN node. For example, the base station may include a NTN satellite.

[0475] In step S1603, the wireless device may monitor a response window for a random access response message.

[0476] For example, the response window may be started during a next DL ON period.

[0477] For other example, the response window may be started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.

[0478] For example, the wireless device may determine the response window among a first response window and a second response window. The first response window may be started at a first PDCCH occasion from end of transmission of the the random access preamble, and the second response window may be started after a DL OFF period.

[0479] For example, the wireless device may determine the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.

[0480] For example, the wireless device may determine the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.

[0481] For other example, the wireless device may determine the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.

[0482] According to some embodiments of the present disclosure, the wireless device may be in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.

[0483] Hereinafter, technical features for an RA resource selection based on DTX pattern are described.

[0484] After transmitting a random access preamble to network, UE determines whether to monitor the first RA response window or the second RA response window based on the first RA response window being overlapped with the DL OFF period. There is no DL transmission during the OFF period.

[0485] The first response window is started at the first PDCCH occasion from the end of the Random Access Preamble transmission. The first response window is started at the first PDCCH occasion from the end of the Random Access Preamble transmission plus the round trip time between UE and gNB.

[0486] The second response window is started after the DL OFF period overlapped with the first response window.

[0487] UE may consider the first RAR window is overlapped with the DL OFF period, if the Random Access Preamble transmission completes during the DL OFF period.

[0488] UE may consider the first RAR window is overlapped with the DL OFF period, if the first PDCCH monitoring occasion from the Random Access Preamble transmission plus the round trip time between UE and gNB occurs during the DL OFF period.

[0489] UE may consider the first RAR window is overlapped with the DL OFF period, if the Random Access Preamble is transmitted during the DL OFF period.

[0490] UE may consider the first RAR window is overlapped with the DL OFF period, if the first RAR window is started during the DL OFF period.

[0491] UE may consider the first RAR window is overlapped with the DL OFF period, if the DL OFF period starts during the first RAR window.

[0492] If the first RAR window is overlapped with the DL OFF period, the UE does not start RAR window at the first PDCCH monitoring occasion from the end of the Random Access Preamble transmission.

[0493] If the first RAR window is overlapped with the DL OFF period, the UE starts the second RAR window.

[0494] UE starts the second RAR window at the first PDCCH occasion from the end of the OFF period. For example, as shown in figure below, it is expected that the first RAR window is overlapped with the OFF period.

[0495] FIG. 17 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0496] UE determines when to start the second RAR window using an offset. For instance, the offset may indicate the distance between the start of the second RAR window and the start of the first RAR window. The offset may indicate the distance between the start of the second RAR window and the end of the first RAR window. The offset may indicate the distance between the start of the second RAR window and the end of the DL OFF period. The offset may indicate the distance between the start of the second RAR window and the RACH occasion.

[0497] The DL OFF period can be different per SSB. UE selects a SSB to use for Random Access procedure. After transmitting a random access preamble to network, UE determines whether to monitor the first RA response window or the second RA response window based on the first RA response window being overlapped with the DL OFF period associated with the selected SSB.

[0498] After transmitting a random access preamble to network, UE determines when to start RAR window based on whether the potential RAR window is overlapped with the DL OFF period.

[0499] If it is expected that the potential RAR window is not overlapped with a DL OFF period, UE starts RAR window at the first PDCCH occasion from the end of the Random Access Preamble transmission.

[0500] If it is expected that the potential RAR window is overlapped with a DL OFF period, UE starts RAR window at the first PDCCH occasion from the end of the DL OFF period plus the round trip time between the UE and gNB.

[0501] If it is expected that the potential RAR window is overlapped with a DL OFF period, UE starts RAR window at the first PDCCH occasion from the end of the DL OFF period.

[0502] If it is expected that the potential RAR window is overlapped with a DL OFF period, UE starts RAR window at the first PDCCH occasion from the start of the DL ON period.

[0503] If it is expected that the potential RAR window is overlapped with a DL OFF period, UE starts RAR window at the first PDCCH occasion after an offset from the end of the DL OFF period.

[0504] In the present disclosure, when the RA procedure is initiated, if the UE detect that the NTN cell is operating with beam DTX pattern, the UE selects RAR window offset based on selected RO of selected SSB beam which ensures the successful reception of RAR during RAR window even though the NTN cell delays the RAR transmission due to the beam DTX off period.

[0505] A UE receives a RRC message including a RA configuration and / or cell / beam DTX operation configuration. Each SSB beam is configured with RACH resources at least including a set of RA preamble and RACH occasions (RO). Each SSB beam is associated with a different beam DTX pattern. The RRC message can be transmitted by a dedicated message or a system information, or a broadcasting message. The RACH configuration may consist of one or more of followings, but not limited to:

[0506] - RACH occasion configuration: the available set of RACH occasions for the transmission of the RA preamble;

[0507] - RSRP threshold for SSB: as RSRP threshold for the selection of the SSB;

[0508] - RAR window: the time window to monitor RAR;

[0509] - RAR window offset: the offset for the start of the RAR window per SSB beam;

[0510] - Contention Resolution Timer: the maximum waiting time to resolve Contention Resolution;

[0511] - Contention Resolution Timer offset: the offset for the start of the Contention Resolution timer per SSB beam;

[0512] The beam DTX pattern may consist of followings, but not limited to:

[0513] - SSB index: an associated SSB index to a beam DTX pattern;

[0514] - DTX on period: duration that the satellite beam is completely on and NTN cell transmits PDCCHs, PDSCHs, PBCH;

[0515] - Cycle: specifies the periodic repetition of the beam on duration followed by a period of beam off duration;

[0516] FIG. 18 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0517] The RAR window offset is configured to ensure the reception of delayed RAR due to the DTX off period. As SSB have different DTX patterns, for example, different configuration of DTX on / off period, network configures RAR window offset per SSB. Even if the selected RO is in the DTX on period, the RO position also affects whether the NTN cell can transmit the RAR associated to selected RO in the same DTX on period. The RAR window offset may configured as followings, but not limited to:

[0518] The Case 1-2 are the cases that the network can configure the RAR window offset as the legacy NTN cell, for example, only considering the UE-gNB RTT.

[0519] Case 1: The selected RO is in the beam DTX on period, and if NTN cell can transmit RAR during the current beam DTX on period, the network configures the RAR window offset as legacy NTN cell, for example, RAR window starts at the time calculated based on the UE-gNB RTT.

[0520] Case 2: The selected RO is in the beam DTX off period, and if NTN cell can transmit RAR associated with the selected RO as the beam DTX off period ends at the time NTN cell receive RA preamble or NTN cell is ready to transmit RAR, the network configures RAR window offset as legacy, for example, RAR window starts at the time calculated based on the UE-gNB RTT.

[0521] The Case 3~6 are the cases that the NTN cell should wait the next beam DTX on period to transmit RAR.

[0522] Case 3: The selected RO is in the beam DTX on period, and if the beam DTX on period ends before the NTN cell transmits the RAR associated with the selected RO, the network configures the RAR window offset to start the RAR window at the start of the next DTX on period plus the propagation delay between UE and gNB.

[0523] Case 4: The selected RO is in the DTX off period, and if NTN cell should wait the next DTX on period to transmit RAR associated with the selected RO, network configures the RAR window offset to start RAR window at the start of the next DTX on period plus the propagation delay between UE and gNB.

[0524] Case 5: The RAR associated with the selected RO should wait next DTX on period, for example, the selected RO is in the beam DTX off period, or the NTN cell cannot transmit RAR associated with the selected RO in the same beam DTX on period of the selected RO. Then network can configure the RAR window offset to start RAR window at the start of the next DTX on period.

[0525] Case 6: The RO is overlapped with the beam DTX on period and the DTX off period. The NTN cell should wait the next DTX on period to transmit RAR associated with the selected RO, network configures the RAR window offset to start RAR window at the start of the next DTX on period.

[0526] If the contention resolution timer is running in the beam DTX off period, when the NTN cell cannot transmit Msg4 in response to the Msg3 received from the UE, UE can consider this Contention Resolution not successful. The network may configure the Contention Resolution Timer offset in the same way as the RAR window offset to receive Msg4 during the running time of Contention Resolution Timer.

[0527] When UE initiates RA procedure, UE selects a SSB to transmit a RA preamble based on SS-RSRP. A UE selects a RA preamble randomly with equal probability from the RA Preambles associated with the selected SSB. After UE transmits the RA preamble in selected RO, UE starts the RAR window at the time after the RAR window offset associated with the selected SSB and the selected RO. And then, UE monitors RAR during RAR window. If UE successfully receives RAR during RAR window and the RAR contains RA Preamble identifier corresponding to the transmitted RA preamble, the UE considers RAR reception successful and applies the timing advance command in the RAR, then transmits the Msg3 using the uplink grant and temporary C-RNTI indicated in the RAR. The UE starts a Contention Resolution Timer with the Contention Resolution Timer offset after the end of the Msg3 transmission. If the UE receives the Msg4 containing UE Contention Resolution Identity which matches the information transmitted in Msg3, the RA procedure is successfully completed.

[0528] FIG. 19 shows an example of operations for selecting offset of RAR window and offset of Contention Resolution Timer based on the selected SSB.

[0529] In step S1901, the UE transmits a selected RA preamble at the RO associated with the selected SSB.

[0530] In step S1902, the UE starts the RAR window after the RAR time offset from the end time point of the RAR preamble transmission.

[0531] For example, in step S1901-1, if the UE selects the SSB0, UE transmits selected RA preamble at the RO associated with the SSB0 during beam DTX on period of SSB0.

[0532] In step S1902-1, the UE starts the RAR window after the RAR time offset1 from the end time point of the RAR preamble transmission.

[0533] For example, in step S1901-2, if the UE selects the SSB1, UE transmits selected RA preamble at the RO associated with the SSB1 during beam DTX off period of SSB1.

[0534] In step S1902-2, the UE starts the RAR window after the RAR time offset2 from the end time point of the RAR preamble transmission.

[0535] In step S1903, if the UE successfully receives the RAR during the RAR window, UE transmits Msg3 using the uplink grant and temporary C-RNTI indicated in the RAR.

[0536] Otherwise, the UE considers the RAR reception unsuccessful and determines a backoff time and performs RA resource selection again after the backoff time and retransmits the reselected RA preamble.

[0537] In step S1904, the UE starts a Contention Resolution Timer with the Contention Resolution Timer offset after the end of the Msg3 transmission.

[0538] In step S1905, if the UE successfully receives the Msg4 containing UE Contention Resolution Identity which matches the information transmitted in Msg3, during the Contention Resolution Timer, UE considers this RA procedure successfully completed.

[0539] Otherwise, the UE considers this Contention Resolution not successful and determines a backoff time and performs RA resource selection again after the backoff time and retransmits the reselected RA preamble.

[0540] FIG. 20 shows an example of a scenario for a RA resource selection based on DTX pattern.

[0541] In FIG. 20, UE1 may use SSB0-beam 1 and UE2 may use SSB1-beam 2.

[0542] Beam DTX period for SSB0 may be different from beam DTX period for SSB1.

[0543] For example, UE1 may transmit a RA preamble and receive an RAR message, during the beam DTX period for SSB0,

[0544] For example, UE2 may transmit a RA preamble, during the beam DTX period for SSB0. In this case, UE2 may receive an RAR message during the beam DTX period for SSB1.

[0545] FIG. 21 shows an example of a method for a RA resource selection based on DTX pattern.

[0546] In particular, FIG. 21 shows an example of a method performed by a wireless device in a wireless communication system.

[0547] In step S2101, the wireless device may receive a configuration on DL OFF period, wherein there is no DL transmission during the DL OFF period.

[0548] In step S2102, the wireless device may receive a RACH configuration.

[0549] In step S2103, the wireless device may initiate a Random Access procedure.

[0550] In step S2104, the wireless device may select an SSB.

[0551] In step S2105, the wireless device may select a Random Access resource associated with the selected SSB according to the RACH configuration.

[0552] In step S2106, the wireless device may transmit a Random Access preamble using the selected random access resource.

[0553] In step S2107, the wireless device may (i) monitor the second response window based on the first response window being overlapped with the OFF period, or (ii) monitor the first response window based on the first response window not being overlapped with the OFF period.

[0554] For example, the first response window may be started at the first PDCCH occasion from the end of the Random Access Preamble transmission.

[0555] For example, , the second response window may be started after the OFF period overlapped with the first response window.

[0556] For example, the DL OFF period can be different per beam. For example, the wireless device may monitor the second response window based on the first response window being overlapped with the OFF period associated with the selected SSB.

[0557] Some of the detailed steps shown in the examples of FIGS. 16, 17, 18, 19, 20, and 21 may not be essential steps and may be omitted. In addition to the steps shown in FIGS. 16, 17, 18, 19, 20, and 21, other steps may be added, and the order of the steps may vary. Some of the above steps may have their own technical meaning.

[0558] Hereinafter, an apparatus for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described. Herein, the apparatus may be a wireless device (100 or 200) in FIGS. 2, 3, 5, and 10.

[0559] For example, a wireless device may perform methods described above. The detailed description overlapping with the above-described contents could be simplified or omitted.

[0560] Referring to FIG. 5, a wireless device 100 may include a processor 102, a memory 104, and a transceiver 106.

[0561] According to some embodiments of the present disclosure, the processor 102 may be configured to be coupled operably with the memory 104 and the transceiver 106. For example, referring to FIG. 10, a wireless device 100 may include a main receiver 106 and a low-power receiver 208.

[0562] For example, the wireless device may include at least one transceiver, at least one processor, and at least one 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.

[0563] The operations comprise: receiving a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; transmitting a random access preamble related to the certain beam; and monitoring a response window for a random access response message, wherein the response window is started during a next DL ON period.

[0564] For example, the random access preamble related to the certain beam is transmitted during (i) a current DL ON period or (ii) a DL OFF period.

[0565] For example, the operations further comprise: determining the response window among a first response window and a second response window, wherein the first response window is started at a first PDCCH occasion from end of transmission of the the random access preamble, and wherein the second response window is started after a DL OFF period.

[0566] For example, the operations further comprise: determining the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.

[0567] For example, the operations further comprise: determining the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.

[0568] For example, the operations further comprise: determining the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.

[0569] For example, the response window is started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.

[0570] For example, the base station is a non-terrestrial networks (NTN) node.

[0571] For example, the base station includes a NTN satellite.

[0572] For example, the operations further comprise: selecting a Synchronization Signal Block (SSB); and selecting the random access preamble associated with the selected SSB.

[0573] For example, there is no DL transmission for the certain beam from a network during the at least one DL OFF period.

[0574] For example, the configuration includes (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.

[0575] For example, a first DL OFF period for the first beam is not overlapped with a second DL OFF period for the second beam.

[0576] For example, the processor may be adapted to be in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.

[0577] Hereinafter, a processor for a wireless device for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described.

[0578] The processor may be adapted to control the wireless device to perform operations.

[0579] The operations comprise: receiving a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; transmitting a random access preamble related to the certain beam; and monitoring a response window for a random access response message, wherein the response window is started during a next DL ON period.

[0580] For example, the random access preamble related to the certain beam is transmitted during (i) a current DL ON period or (ii) a DL OFF period.

[0581] For example, the operations further comprise: determining the response window among a first response window and a second response window, wherein the first response window is started at a first PDCCH occasion from end of transmission of the the random access preamble, and wherein the second response window is started after a DL OFF period.

[0582] For example, the operations further comprise: determining the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.

[0583] For example, the operations further comprise: determining the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.

[0584] For example, the operations further comprise: determining the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.

[0585] For example, the response window is started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.

[0586] For example, the base station is a non-terrestrial networks (NTN) node.

[0587] For example, the base station includes a NTN satellite.

[0588] For example, the operations further comprise: selecting a Synchronization Signal Block (SSB); and selecting the random access preamble associated with the selected SSB.

[0589] For example, there is no DL transmission for the certain beam from a network during the at least one DL OFF period.

[0590] For example, the configuration includes (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.

[0591] For example, a first DL OFF period for the first beam is not overlapped with a second DL OFF period for the second beam.

[0592] For example, the processor may be adapted to control the wireless device to be in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.

[0593] Hereinafter, a non-transitory computer-readable medium has stored thereon a plurality of instructions for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described.

[0594] According to some embodiment of the present disclosure, the technical features of the present disclosure could be embodied directly in hardware, in a software executed by a processor, or in a combination of the two. For example, a method performed by a wireless device in a wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, a software may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other storage medium.

[0595] Some example of storage medium is coupled to the processor such that the processor can read information from the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. For another example, the processor and the storage medium may reside as discrete components.

[0596] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0597] For example, non-transitory computer-readable media may include random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, magnetic or optical data storage media, or any other medium that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the above.

[0598] In addition, the method described herein may be realized at least in part by a computer-readable communication medium that carries or communicates code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer.

[0599] According to some embodiment of the present disclosure, a non-transitory computer-readable medium has stored thereon a plurality of instructions. The stored a plurality of instructions may be executed by a processor of a wireless device. The stored a plurality of instructions may cause the wireless device to perform operations.

[0600] The operations comprise: receiving a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; transmitting a random access preamble related to the certain beam; and monitoring a response window for a random access response message, wherein the response window is started during a next DL ON period.

[0601] For example, the random access preamble related to the certain beam is transmitted during (i) a current DL ON period or (ii) a DL OFF period.

[0602] For example, the operations further comprise: determining the response window among a first response window and a second response window, wherein the first response window is started at a first PDCCH occasion from end of transmission of the the random access preamble, and wherein the second response window is started after a DL OFF period.

[0603] For example, the operations further comprise: determining the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.

[0604] For example, the operations further comprise: determining the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.

[0605] For example, the operations further comprise: determining the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.

[0606] For example, the response window is started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.

[0607] For example, the base station is a non-terrestrial networks (NTN) node.

[0608] For example, the base station includes a NTN satellite.

[0609] For example, the operations further comprise: selecting a Synchronization Signal Block (SSB); and selecting the random access preamble associated with the selected SSB.

[0610] For example, there is no DL transmission for the certain beam from a network during the at least one DL OFF period.

[0611] For example, the configuration includes (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.

[0612] For example, a first DL OFF period for the first beam is not overlapped with a second DL OFF period for the second beam.

[0613] For example, the stored a plurality of instructions may cause the wireless device to be in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.

[0614] Hereinafter, a method performed by a base station (BS) for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described.

[0615] The method comprises: transmitting, by a base station to a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; and receiving, by the base station from the wireless device, a random access preamble related to the certain beam, wherein the wireless device monitors a response window for a random access response message, and wherein the response window is started during a next DL ON period.

[0616] Hereinafter, a base station (BS) for a random access procedure based on a discontinuous transmission pattern, according to some embodiments of the present disclosure, will be described.

[0617] The BS may include a transceiver, a memory, and a processor operatively coupled to the transceiver and the memory.

[0618] The processor may be adapted to control the transceiver to perform operations. The operations comprise: transmitting, to a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam, wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; and receiving, from the wireless device, a random access preamble related to the certain beam, wherein the wireless device monitors a response window for a random access response message, and wherein the response window is started during a next DL ON period.

[0619] The present disclosure can have various advantageous effects.

[0620] According to some embodiments of the present disclosure, the wireless device could efficiently perform a random access procedure based on a discontinuous transmission pattern.

[0621] According to some embodiments of the present disclosure, when the cell is operating with the DTX operation and not with the DRX operation, the UE selects the RAR window offset based on the selected SSB which ensures the successful competition of the RA procedure.

[0622] Therefore, when the selected SSB beam is in the beam DTX off period, the UE can start the RAR window at the time when UE can receive RAR, for example, when the selected SSB beam's DTX pattern transitions from the beam DTX off period to beam DTX on period.

[0623] For example, by considering the DTX pattern, the wireless device and the RAN node could perform a random access procedure efficiently.

[0624] According to some embodiments of the present disclosure, the wireless communication system could provide an efficient solution for a random access procedure based on the discontinuous transmission pattern.

[0625] 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.

[0626] 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.

Claims

1.A method, comprising:receiving, by a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam;transmitting, by the wireless device, a random access preamble related to the certain beam; andmonitoring, by the wireless device, a response window for a random access response message,wherein the response window is started during a next DL ON period.2.The method of claim 1,wherein the random access preamble related to the certain beam is transmitted during (i) a current DL ON period or (ii) a DL OFF period.3.The method of claim 1, wherein the method further comprising:determining, by the wireless device, the response window among a first response window and a second response window,wherein the first response window is started at a first PDCCH occasion from end of transmission of the the random access preamble, andwherein the second response window is started after a DL OFF period.4.The method of claim 3, wherein the method further comprising:determining, by the wireless device, the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.5.The method of claim 3, wherein the method further comprising:determining, by the wireless device, the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.6.The method of claim 3, wherein the method further comprising:determining, by the wireless device, the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.7.The method of claim 1,wherein the response window is started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.8.The method of claim 7,wherein the base station is a non-terrestrial networks (NTN) node.9.The method of claim 7,wherein the base station includes a NTN satellite.10.The method of claim 1, wherein the method further comprising:selecting, by the wireless device, a Synchronization Signal Block (SSB); andselecting, by the wireless device, the random access preamble associated with the selected SSB.11.The method of claim 1,wherein there is no DL transmission for the certain beam from a network during the at least one DL OFF period.12.The method of claim 1,wherein the configuration includes (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.13.The method of claim 12,wherein a first DL OFF period for the first beam is not overlapped with a second DL OFF period for the second beam.14.The method of claim 1,wherein the wireless device is in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.15.A wireless device, comprising:at least one transceiver;at least one processor; andat least one 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 comprising:receiving a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam;transmitting a random access preamble related to the certain beam; andmonitoring a response window for a random access response message,wherein the response window is started during a next DL ON period.16.The wireless device of claim 15,wherein the random access preamble related to the certain beam is transmitted during (i) a current DL ON period or (ii) a DL OFF period.17.The wireless device of claim 15, wherein the operations further comprising:determining the response window among a first response window and a second response window,wherein the first response window is started at a first PDCCH occasion from end of transmission of the the random access preamble, andwherein the second response window is started after a DL OFF period.18.The wireless device of claim 17, wherein the operations further comprising:determining the first response window as the response window, based on that the first response window is not overlapped with the DL OFF period.19.The wireless device of claim 17, wherein the operations further comprising:determining the second response window as the response window, based on that the first response window is overlapped with the DL OFF period.20.The wireless device of claim 17, wherein the operations further comprising:determining the second response window as the response window, based on that (i) a random access timer starts after transmission of the random access preamble and (ii) a DL OFF period starts before the random access timer expires.21.The wireless device of claim 15,wherein the response window is started at start of the next DL ON period period plus a propagation delay between the wireless device and a base station.22.The wireless device of claim 21,wherein the base station is a non-terrestrial networks (NTN) node.23.The wireless device of claim 21,wherein the base station includes a NTN satellite.24.The wireless device of claim 15, wherein the operations further comprising:selecting a Synchronization Signal Block (SSB); andselecting the random access preamble associated with the selected SSB.25.The wireless device of claim 15,wherein there is no DL transmission for the certain beam from a network during the at least one DL OFF period.26.The wireless device of claim 15,wherein the configuration includes (i) information related to a first discontinuous transmission pattern for a first beam and (ii) information related to a second discontinuous transmission pattern for a second beam.27.The wireless device of claim 26,wherein a first DL OFF period for the first beam is not overlapped with a second DL OFF period for the second beam.28.The wireless device of claim 15,wherein the wireless device is in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.29.A processor for a wireless device in a wireless communication system, wherein the processor is adapted to control the wireless device to perform operations comprising:receiving a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam;transmitting a random access preamble related to the certain beam; andmonitoring a response window for a random access response message,wherein the response window is started during a next DL ON period.30.A non-transitory computer-readable medium having stored thereon a plurality of instructions, which, when executed by a processor of a wireless device, cause the wireless device to perform operations, the operations comprising,receiving a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam;transmitting a random access preamble related to the certain beam; andmonitoring a response window for a random access response message,wherein the response window is started during a next DL ON period.31.A method, the method comprising,transmitting, by a base station to a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; andreceiving, by the base station from the wireless device, a random access preamble related to the certain beam,wherein the wireless device monitors a response window for a random access response message, andwherein the response window is started during a next DL ON period.32.A base station, comprising:a transceiver;a memory; andat least one processor operatively coupled to the transceiver and the memory, and adapted to perform operations, the operations comprising:transmitting, to a wireless device, a configuration including information related to a discontinuous transmission pattern for a certain beam,wherein the information related to the discontinuous transmission pattern includes information related to at least one DL ON period and at least one DL OFF period for the certain beam; andreceiving, from the wireless device, a random access preamble related to the certain beam,wherein the wireless device monitors a response window for a random access response message, andwherein the response window is started during a next DL ON period.

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