Method and apparatus for measurement offloading based on low-power receiver

Abstract

A method and apparatus for cell re-selection based on a low-power receiver are provided. The method comprises: receiving, by a wireless device, information informing that a LP-WUS is transmitted on a first frequency; determining, by the wireless device, a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; and performing, by the wireless device, a cell re-selection procedure based on the determined priority of the first frequency.

Description

METHOD AND APPARATUS FOR MEASUREMENT OFFLOADING BASED ON LOW-POWER RECEIVER

[0001] The present disclosure relates to a method and apparatus for cell re-selection based on a low-power receiver.

[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] If UE does not support the inter-frequency LP-WUS operation, for example, it can receive LP-WUS only from the intra-frequency, the use of LP-WUS is limited to cases where the UE is camping on a frequency supported by LP-receiver. If such UE camps on a frequency not supported by its LP-receiver, it cannot use LP-WUS even though the LP-WUS is being transmitted on that frequency. To facilitate the power saving using LP-WUS, the UE should be allowed to prioritize the frequency where LP-WUS is transmitted so that it can have more opportunity to use LP-WUS.

[0006] The network may not operate LP-WUS on all frequency layers, hence the network should inform UE of the cells / frequencies where the LP-WUS is transmitted. However, the frequencies supported by the LP-receiver may vary depending on the UE implementation. If UE prioritizes and camps on a frequency which was indicated as a LP-WUS frequency but is not supported by LP-receiver, it may lead to unnecessary overload on that frequency. Although a frequency is indicated as a LP-WUS frequency by network, if the UE's LP-receiver does not support the frequency, the UE should not prioritize the frequency.

[0007] Therefore, studies for cell re-selection based on a low-power receiver are required.

[0008] In an aspect, a method is provided. The method comprises: receiving, by a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency; determining, by the wireless device, a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; and performing, by the wireless device, a cell re-selection procedure based on the determined priority of the first frequency.

[0009] In another aspect, an apparatus for implementing the above method is provided.

[0010] The present disclosure can have various advantageous effects.

[0011] According to some embodiments of the present disclosure, the wireless device could efficiently perform a cell re-selection procedure based on a low-power receiver.

[0012] For example, the wireless device could efficiently handle frequency priority for a low power receiver.

[0013] For example, even though the LP-WUS specific priority is assigned for frequencies by the network, the potential overload problem on the LP-WUS frequency can be proactively prevented by allowing UE to apply the LP-WUS specific priority only to the frequencies that its LP-receiver supports.

[0014] For example, even though a frequency is indicated as a LP-WUS frequency by the network, the potential overload problem on the LP-WUS frequency can be proactively prevented by allowing UE to prioritize only the frequencies that its LP-receiver supports.

[0015] For example, LP-WUS can be received efficiently by adjusting the frequency priority based on the capability of the LP-receiver of the wireless device.

[0016] According to some embodiments of the present disclosure, the wireless communication system could provide an efficient solution for handling frequency priority for a low-power receiver.

[0017] 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.

[0018] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0019] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0020] FIG. 3 shows an example of a wireless device to which implementations of the present disclosure is applied.

[0021] FIG. 4 shows another example of wireless devices to which implementations of the present disclosure is applied.

[0022] FIG. 5 shows an example of UE to which implementations of the present disclosure is applied.

[0023] 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.

[0024] FIG. 8 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0025] FIG. 9 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0026] FIG. 10 shows an example of UE to which implementations of the present disclosure is applied.

[0027] FIG. 11 shows an example of time-frequency structure of SSB.

[0028] FIG. 12 shows an example of Measurement Model.

[0029] FIG. 13 shows an example of RRC_IDLE and RRC_INACTIVE Cell Selection and Reselection.

[0030] FIG. 14 shows an example of a method for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure.

[0031] FIG. 15 shows an example of a method for frequency priority handling for low power receiver.

[0032] FIG. 16 shows an example of a method for frequency priority handling for low power receiver.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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".

[0037] 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".

[0038] 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".

[0039] 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".

[0040] 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".

[0041] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0042] 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.

[0043] 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.

[0044] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0045] 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.

[0046] 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).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The UAV may be, for example, an aircraft availed by a wireless control signal without a human being onboard.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] The weather / environment device may include, for example, a device for monitoring or predicting a weather / environment.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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).

[0082] 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.

[0083] 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.

[0084] In the present disclosure, a BS is also referred to as a node B (NB), an eNodeB B (eNB), or a gNB.

[0085] FIG. 3 shows an example of a wireless device to which implementations of the present disclosure is applied.

[0086] The wireless device may be implemented in various forms according to a use-case / service (refer to FIG. 1).

[0087] 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.

[0088] 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.

[0089] 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.

[0090] FIG. 4 shows another example of wireless devices to which implementations of the present disclosure is applied.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] FIG. 5 shows an example of UE to which implementations of the present disclosure is applied.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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).

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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).

[0110] 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.

[0111] 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.

[0112] 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.

[0113] FIG. 8 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0114] 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).

[0115] 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.

[0116] 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.

[0117] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0118] 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.

[0119] uNslotsymbNframe,uslotNsubframe,uslot212404

[0120] 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.

[0121] 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.

[0122] 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).

[0123] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0124] 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).

[0125] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0126] 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.

[0127] 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.

[0128] FIG. 9 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0129] 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.

[0130] 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.

[0131] FIG. 10 shows an example of UE to which implementations of the present disclosure is applied.

[0132] Referring to FIG. 5, a UE 100 may correspond to the first wireless device 100 of FIG. 2, the first wireless device 100 of FIG. 4, and / or the UE 100 of FIG. 5.

[0133] A UE 100 includes a processor 102, a memory 104, a transceiver 106, first 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, a microphone 122, and a low-power (LP) transceiver 1106, second one or more antennas 1108 for the LP Transceiver 1106.

[0134] For example, a processor 102, a memory 104, a transceiver 106, first 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 / or a microphone 122 may be same as the features included in the UE 100 of FIG. 5.

[0135] The LP transceiver 1106 is operatively coupled with the processor 102, and transmits and / or receives a radio signal. For example, the LP transceiver 1106 includes a receiver. For example, the LP transceiver 1106 may optionally include a transmitter. The LP transceiver 1106 may include baseband circuitry to process radio frequency signals. The LP transceiver 1106 controls the second one or more antennas 1108 to transmit and / or receive a radio signal.

[0136] For example, the LP transceiver 1106 may be called a LP wake-up receiver (LP WUR).

[0137] For example, the LP transceiver 1106 may be used for monitoring an LP wake-up signal (LP WUS) in the LP wake-up radio.

[0138] For example, the UE 100 may deactivate the transceiver 106 (that is, the main transceiver which is not the LP transceiver 1106), while monitoring LP-WUS by the LP transceiver 1106.

[0139] Hereinafter, technical features related to Low-power wake-up signal and receiver for NR (LP-WUS_WUR) are described.

[0140] 5G systems are designed and developed targeting for both mobile telephony and vertical use cases. Besides latency, reliability, and availability, UE energy efficiency is also critical to 5G. Currently, 5G devices may have to be recharged per week or day, depending on individual's usage time. In general, 5G devices consume tens of milliwatts in RRC idle / inactive state and hundreds of milliwatts in RRC connected state. Designs to prolong battery life is a necessity for improving energy efficiency as well as for better user experience.

[0141] Energy efficiency is even more critical for UEs without a continuous energy source, e.g., UEs using small rechargeable and single coin cell batteries. Among vertical use cases, sensors and actuators are deployed extensively for monitoring, measuring, charging, etc. Generally, their batteries are not rechargeable and expected to last at least few years as described in TR38.875. Wearables include smart watches, rings, eHealth related devices, and medical monitoring devices. With typical battery capacity, it is challenging to sustain up to 1-2 weeks as required.

[0142] The power consumption depends on the configured length of wake-up periods, e.g., paging cycle. To meet the battery life requirements above, long eDRX cycle may be used, resulting in high latency, which is not suitable for such services with requirements of both long battery life and low latency. For example, in fire detection and extinguishment use case, fire shutters shall be closed and fire sprinklers shall be turned on by the actuators within 1 to 2 seconds from the time the fire is detected by sensors, long eDRX cycle cannot meet the delay requirements. eDRX is apparently not suitable for latency-critical use cases.

[0143] The Rel-18 study item for "Study on low-power wake up signal and receiver for NR" includes investigations to the followings.

[0144] - The low-power wake-up signal and receiver, including power saving benefit, coverage, system overhead impact, network energy impact and other related aspects.

[0145] - The receiver architecture for low-power wake-up receiver and provide analysis for power consumption, noise figure and etc.

[0146] - L1 design and procedure changes needed to support the low-power wake-up signal and evaluations for the link performances.

[0147] - Higher layer protocol changes needed to support the low-power wake-up signals

[0148] - Related RAN4 impacts

[0149] In RRC IDLE / INACTIVE modes, it's observed that significant UE power saving gain (up to more than 90%) is obtained by using LP-WUS / WUR to trigger UE MR paging monitoring compared with existing I-DRX operation (with and without PEI), if sufficient relaxation to MR RRM measurement is applied. Further, compared with existing eDRX operation, significant paging latency reduction and moderate UE power saving gain is observed, if LP-WUS monitoring and the corresponding paging monitoring after MR wake-up is performed not restricted within existing PTW of eDRX.

[0150] In RRC CONNECTED mode, it's observed that moderate UE power saving gain (up to more than 10%) is obtained with marginal impact to capacity by using LP-WUS / WUR to trigger UE MR PDCCH monitoring compared with existing UE power saving techniques, across different types of XR traffic and system load scenarios. It's also observed that significant UE power saving gain (up to more than 60%) and moderate UPT improvement (up to more than 10%) is obtained for FTP and IM traffic, when the UE MR enters deep sleep state during LR LP-WUS monitoring. Furthermore, Rel-18 study verified the feasibility on serving cell RRM measurement offloading from UE MR to LP-WUR by reasonable evaluation methodology. RAN4 also identified some issues which could be further discussed in WI phase.

[0151] The objectives of the work item are the following:

[0152] - To specify an LP-WUS design commonly applicable to both IDLE / INACTIVE and CONNECTED modes (RAN1, RAN4)

[0153] - Specify OOK (OOK-1 and / or OOK-4) based LP-WUS with overlaid OFDM sequence(s) over OOK symbol

[0154] - The LP-WUS design shall ensure that for IDLE / INACTIVE operation, the same information is delivered irrespective of LP-WUR type. The OFDM sequence can carry information.

[0155] - At least duty-cycled monitoring of LP-WUS is supported

[0156] - For IDLE / INACTIVE modes

[0157] - Specify procedure and configuration of LP-WUS indicating paging monitoring triggered by LP-WUS, including at least configuration, sub-grouping and entry / exit condition for LP-WUS monitoring (RAN2, RAN1, RAN3, RAN4)

[0158] - Specify LP-SS with periodicity with Yms for LP-WUR, for synchronization and / or RRM for serving cell. (RAN1, RAN4)

[0159] - LP-SS is based on OOK-1 and / or OOK-4 waveform with or without overlaid OFDM sequences. Further down selection between with and without overlaid OFDM sequences is to be done within WI.

[0160] - For LP-WUR that can receive existing PSS / SSS, existing PSS / SSS can be used for synchronization and RRM instead of LP-SS.

[0161] - Y will be decided within WI. 320ms is the start point.

[0162] - Specify further RRM relaxation of UE MR for both serving and neighbor cell measurements, and UE serving cell RRM measurement offloaded from MR to LP-WUR, including the necessary conditions (RAN4, RAN2)

[0163] - For CONNECTED mode, specify procedures to allow UE MR PDCCH monitoring triggered by LP-WUS including activation and deactivation procedure of LP-WUS monitoring (RAN2, RAN1)

[0164] - Check in RAN#105 for potential TU adjustment in RAN2

[0165] - In CONNECTED mode, UE MR ultra-deep sleep is not considered, and UE RRM / RLM / BFD / CSI measurements are performed by MR

[0166] - The target coverage of LP-WUS and LP-SS shall be the coverage of PUSCH for message3.

[0167] - The optimization of LP-WUS signal design for idle / inactive mode is prioritized over the optimization for connected mode.

[0168] - Specify the necessary RAN4 core requirement(s) to support the feature (RAN4).

[0169] - Specify UE low-power wake-up receiver requirements, at least REFSENS, ACS and ASCS requirements with consideration of possible new methodology to assess the low-power wake-up receiver performance

[0170] - Define guard RBs for ACS and ASCS cases

[0171] - Study testability of above requirements

[0172] - Consider impacts of different architecture and impairments, and set requirements that enable all types of reasonable implementation

[0173] - Study and if necessary specify or support by declaration, the corresponding BS requirements, e.g., dynamic range for LP-WUS / LP-SS.

[0174] - Current NR BS requirements is baseline

[0175] - Specify necessary RRM requirements

[0176] 1. Specify the UE demodulation performance and test cases for LP-WUS / WUR (RAN4).

[0177] - Study testability of above requirements

[0178] 2. Specify RRM measurement performance requirement if identified, and corresponding test cases for the LP-WUS / WUR (RAN4).

[0179] Hereinafter, technical features related to LP-WUS design and L1 procedure are described. Sections of 3GPP TR 38.869 V18.0.0 may be referred.

[0180] When evaluating and / or comparing link performance of MC-ASK, MC-FSK, and CP-OFDMA waveforms of LP-WUS at least

[0181] - raw information bit-size

[0182] - Alt 1: - average EPRE within the [time] / frequency resources used for LP-WUS (including any guard bands), - time / frequency resources used for LP-WUS (including any guard bands)

[0183] - Alt 2: - average EPRE within the [time] / frequency resources used for LP-WUS (including any guard bands),

[0184] - SNR is calculated as average EPRE divided by power of noise [and interference].

[0185] - whether and how power pooling across and within MR OFDMA symbols is used.

[0186] - time / frequency resources (including any guard bands) for the scheme

[0187] - false alarm probability / rate and misdetection probability / rate

[0188] - receiver architecture type and its relative power consumption

[0189] - When comparing waveforms of LP-WUS, consider the impact to gNB for each of the waveform generation schemes. Consider whether there is impact to PAPR and a need for additional hardware for WUS.

[0190] Waveform

[0191] - Study generation and link performance of multi-carrier (MC)-ASK (including OOK) waveform

[0192] - study techniques to generate waveform by modulating sub-carriers of CP-OFDM symbol, consider up to M bits transmitted per OFDM symbol, where M is FFS.

[0193] - Study generation and link performance of multi-carrier (MC)-FSK waveforms

[0194] - study techniques to generate waveform by modulating sub-carriers of CP-OFDM symbol symbol, consider up to M bits transmitted per OFDM symbol, where M is FFS.

[0195] - Study link performance of OFDMA-based signals / channels considering at least the existing signal / channel structure (e.g. CSI-RS, SSS)

[0196] - Other signal / channel structures are not precluded

[0197] For MC-ASK or MC-FSK waveform generation, SCS of a CP-OFDM symbol used for LP-WUS generation can be the same as SCS used for other NR transmissions in CP-OFDM symbol overlapping in time with, study whether SCS can be different, also study

[0198] - FDM / TDM multiplexing with other NR transmissions

[0199] - link performance

[0200] - impact to legacy UEs

[0201] - impact on gNB

[0202] For waveform generation the following observations are made

[0203] - Flat spectrum in frequency domain provides robustness against frequency selective fading compared to concentrated energy in frequency domain.

[0204] - for OOK-4, sequence before DFT / LS with variation in phase via such as ZC, M-sequence or QAM sequence can achieve more flattened spectrum.

[0205] - Sequences(s) used in LP-WUS symbol generation with different pulse shape or spectral shape may have different performance.

[0206] - Knowledge of sequence(s) used in LP-WUS waveform generation may improve performance for at least a receiver with I / Q branches

[0207] Further discuss the following potential observations for waveform generation:

[0208] - When DFT is employed in OOK-4 (M>=2), -1 / 1 alternation in time or frequency shift in frequency domain may be needed to match CP-OFDM generation.

[0209] - Pre-storing of the generated frequency domain samples at gNB may reduce complexity of waveform generation at gNB with memory requirement depending on number of possible combination. This may be up to gNB implementation.

[0210] - Quantization of generated waveform in frequency domain to existing constellation (e.g. 64QAM) has low impact on performance and reduces complexity. This may be up to gNB implementation.

[0211] - Repetition of a sequence(s) used in LP-WUS generation in frequency can be used to improve diversity for MC-OOK and robustness against frequency offsets for MC-FSK.

[0212] L1 procedures - RRM measurements

[0213] Study potential measurement metric used for RRM measurements performed by LP-WUR.

[0214] - examples of measurement metric are signal quality, signal power, detection rate of LP-WUS / synch signal

[0215] - companies to report assumption of signal used for measurements

[0216] For at least RRM serving cell measurement performed by LP-WUR based on reference signal(s), RAN1 identified at least the following metrics for further study and evaluation (including feasibility, complexity, power consumption, etc)

[0217] - LP-RSSI or Energy detection: linear average of total received power over a RSSI resource.

[0218] - LP-RSRP: linear average of received power of resource of reference signal(s) or signal(s) parts.

[0219] - LP-SINR = LP-RSRP / (power of interference and noise)

[0220] - LP-RSRQ= [N x] LP-RSRP / LP-RSSI, where N is the factor of resource size difference for evaluation LP-RSRP and LP-RSSI.

[0221] - Accounting AGC accuracy, ADC of at least 4 bits is required.

[0222] RRC IDLE / INACTIVE mode

[0223] For a UE support LP-WUR in IDLE / INACTIVE mode,

[0224] - Study how to reduce UE power consumption due to existing RRM measurement requirements at least for mobility support,

[0225] - study feasibility of RRM measurements performed by LP-WUR, at least for serving / camping cell, based on signals detected by LP-WUR

[0226] - For Idle / Inactive mode, study offloading of RRM measurements of serving cell to LP-WUR under certain conditions, if any, and relaxation of serving / neighboring cell RRM measurements in MR considering

[0227] - Periodic reference signal(s) is / are used for LR measurements.

[0228] - MR performs measurements

[0229] - Alt2: with relaxed periodicity if RRM measurement in MR is relaxed.

[0230] - Can apply for both neighboring and serving cell

[0231] - Alt3: only when reference signal(s) based measurements by LP-WUR satisfy certain condition(s), e.g. are below threshold.

[0232] - Above MR measurement under certain conditions can apply for both neighboring and serving cell

[0233] - Potentially with relaxation methods for MR neighboring cell measurement

[0234] - Other alternatives are not precluded

[0235] The followings are observed,

[0236] - At least for LP-WUR that cannot receive existing PSS / SSS, periodic LP-SS signal is beneficial for the following functionality.

[0237] - RRM measurements by LP-WUR, if supported

[0238] - at least coarse time synchronization of LP-WUR.

[0239] - at least coarse frequency synchronization of LP-WUR.

[0240] - Additional periodic LP-SS system overhead depends on LP-SS periodicity, system BW, # of beams, and resource required to fulfil the target functionality, etc. Periodic signal if used for coarse synchronization may reduce overhead of signal preceding LP-WUS, if any. LP-SS can be designed to be common among UE groups (cell-specific) and such further reduce system overhead.

[0241] - For LP-WUR that can receive existing PSS / SSS potentially assisted by PBCH DMRS / TRS for synchronization, existing PSS / SSS potentially assisted by PBCH DMRS / TRS may be used for above functionality.

[0242] - Periodic LP-SS coverage should be equal to or better than that of LP-WUS.

[0243] - For fine time and frequency synchronization, a signal (e.g. preamble) preceding or part of LP-WUS may be used.

[0244] RRC CONNECTED mode

[0245] Synchronization of LP-WUR

[0246] Study synchronisation signal used by LP-WUR, if needed, based on

[0247] - Option 1: aperiodic signal transmitted as part of LP-WUS

[0248] - Whether the signal can additionally be transmitted separately from LP-WUS

[0249] - Option 2: periodic signal transmitted separately from LP-WUS

[0250] - Option 3: Option1 + Option2

[0251] LP-WUSmonitoring

[0252] Study further pros and cons of the following monitoring behaviours of LP-WUR

[0253] - Option1: Duty cycle, corresponds to LP-WUR switches between ON / OFF states

[0254] - Option2: Continuous monitoring, corresponds to LP-WUR is ON all the time

[0255] Activation / Deactivation procedures of LP-WUS

[0256] - Study RRC connected mode LP-WUS activation / deactivation procedures.

[0257] - For Idle / Inactive mode, following options for activation and deactivation of LP-WUS monitoring by LP-WUR for a UE can be considered for study

[0258] - Alt 1a: - gNB transmits legacy paging indication and LP-WUS, - UE activation and / or deactivation of LP-WUS WUS monitoring is up to UE implementation. - This behavior may apply based on channel condition, e.g. when coverage is sufficient / insufficient.

[0259] - Alt 1b: - gNB transmits legacy paging indication and LP-WUS, - UE activation and / or deactivation of LP-WUS monitoring is based on preconfigured criteria, - This behavior may apply based on channel condition, e.g. when coverage is sufficient / insufficient.

[0260] - Alt 2: - activation and / or deactivation of LP-WUS monitoring in a cell is based on signalling.

[0261] - Paging misdetection performance shall not be impacted.

[0262] - In RRC CONNECTED mode, LP-WUS monitoring can be activated / deactivated by at least one or more of - by gNB RRC signaling, with or without UE assistance. - by gNB L1 / L2 LP-WUS activation / deactivation signaling, with or without UE assistance. - based on pre-configured condition(s), such as timer. - LP-WUS monitoring by UE is known to gNB, study whether it could be transparent to gNB. - other options are not precluded.

[0263] Coverage

[0264] - Study techniques / mechanisms to enhance coverage performance of LP-WUS

[0265] - Study potential gains available as well as drawback(s) of the technique(s) / mechanisms(s), e.g. system overhead, increased complexity network energy consumption etc쪋

[0266] - Study potential issues and corresponding solutions for the case when LP-WUS coverage is insufficient

[0267] - At least study fallback mechanisms where the Main Radio switches to legacy operation in case the channel condition of LP-WUS is not sufficient, e.g. below threshold.

[0268] RRC_IDLE / INACTIVE mode procedures

[0269] In RRC_IDLE and RRC_INACTIVE states, UEs shall perform RRC_IDLE / INACTIVE mode procedures defined in TS 38.304 and TS 38.331, which specify how UEs shall monitor paging, keep system information up to date, receive ETWS / CMAS information, and perform RRM measurements and corresponding cell selection / re-selection to ensure that UE is camping on the best cell. These procedures may need to be modified to accommodate operation using LP-WUS / WUR.

[0270] Though the network may use different signals to page UE for the case that UE monitors LP-WUS and the case that UE doesn't monitor LP-WUS, the network doesn't need to be aware of whether the UE is monitoring LP-WUS or not in RRC_IDLE / RRC_INACTIVE. Otherwise, it requires the UE to switch on MR or wake up MR to inform the network whether the UE is monitoring LP-WUS or not, which leads to further signalling overhead, Uu resource consumption and also UE power consumption accordingly.

[0271] With LP-WUS / WUR, the Main Receiver (MR) of a UE could enter ultra-deep sleep state, which denotes a state when the MR may sleep or turn off. Such ultra-deep sleep state could be entered when predefined condition (e.g. quality of LP-SS and / or SSB is better than the threshold) is fulfilled. An operation like the one for Mobile Initiated Communication Only (MICO), where both monitoring of the downlink and RRM measurements are stopped until there is a subsequent uplink transmission, is however not feasible for LP-WUS / WUR. Thhe point with LP-WUS / WUR is to reduce UE power consumption while maintaining some downlink monitoring functionality, and this is not possible if either the UE stops monitoring in downlink or if the UE does not detect that it has moved into a new cell / area and therefore apply the incorrect configuration for downlink monitoring. According to TS 38.300, the functionality to be supported over Uu interface in RRC_IDLE and RRC_INACTIVE includes PLMN selection, SI reception, cell re-selection mobility, and paging, etc. Therefore, it is feasible to introduce LP-WUS / WUR as a power saving feature for RRC_IDLE and RRC_INACTIVE, while ultra-deep sleep state as a power saving state for RRC_IDLE and RRC_INACTIVE.

[0272] LP-WUSmonitoring and wake up procedure

[0273] Paging reception in RRC_IDLE and RRC_INACTIVE is supported both with discontinuous reception (DRX), and from Rel-17 and Rel-18, respectively, with extended DRX (eDRX). LP-WUS / WUR could also be supported with or without duty-cycled operation, i.e., as 'continuous' or as 'duty-cycled'. Since the LP-WUS / WUR feature is introduced to lower the UE energy consumption, it is for these two options feasible to introduce support for the LP-WUR option which can introduce the greatest UE energy consumption reduction compared to baseline as discussed above in section 6. If the gain is similar, the magnitude of implementation complexity, specification impact, and latency impact should be the determining factors for which LP-WUR option to support.

[0274] Currently, paging monitoring in RRC_IDLE / INACTIVE mode is based on the configured I-DRX, as well as PEI is also designed as 'duty-cycled' associated with legacy PO. The specification impact for 'continuous' and 'duty-cycled' depends on the detailed design. While, a potential benefit of 'continuous' is shorter downlink latency. That is, since the UE monitors the downlink continuously the downlink latency could potentially be shorter.

[0275] Due to the transition time to start up the main receiver however, LP-WUR operation may always have worse latency performance than legacy, i.e., comparing to legacy continuous monitoring or DRX. 'Continuous' could still provide shorter downlink latency compared to 'duty-cycled', comparing at the same UE energy consumption reduction gain. This however depends on the UE procedure triggered by LP-WUS and the LP-WUS payload content and size.

[0276] On one hand, after waking up by LP-WUS, the legacy paging monitoring procedure could be triggered for the main receiver. That is, if the UE detects LP-WUS it would start up its main receiver to monitor legacy paging, i.e., the PDCCH scheduling of the paging message on PDSCH, and at first after finding its own PagingRecord in the paging message the UE could determine that it is being paged (similar to Rel-15 WUS for NB-IoT / LTE-M or Rel-17 PEI). In this case, the downlink latency will be determined by the periodicity of the legacy paging occasions (POs).

[0277] - In some case, 'continuous' mode may not have latency benefit compared to 'duty-cycled'. That is, even if LP-WUS is immediately received using 'continuous' mode the UE might anyway need to wait for the subsequent PO (i.e., maybe a same PO as if 'duty-cycled' is used).

[0278] - In some other case, the beneficial part comes from the margin that LP-WUS could be received earlier in case 'continuous' than 'duty-cycled', which would wake up the main receiver earlier and an earlier PO will be monitored by main receiver after waking up by LP-WUS.

[0279] - On the other hand, after waken up by LP-WUS, the main receiver could also monitor legacy PEI defined in Rel-17, if it is configured by network and it is supported by UE. Especially for the case that LP-WUS doesn't have full coverage compared to legacy signalling, e.g. SSB, main receiver needs to wake up to perform legacy operation out of LP-WUS coverage. In this case, network could still configure PEI for the use of fallback mechanism to save UE power consumption for paging monitoring. It means, the network would configure and transmit both LP-WUS and PEI for the UE, especially when the network is not aware of UE's entry / exit of LP-WUS monitoring. From UE perspective, LP-WUS may be used together with PEI if both LP-WUS and PEI are configured, to achieve more power saving gain.

[0280] After waking up from LP-WUS, in case UE needs to monitor PO, the time offset between LP-WUS and the PO should be long enough to include the transition time to start up the main receiver to be ready for PDCCH monitoring, which depends on the design of LP-WUR and the detailed procedure after waking up. After waking up from LP-WUS, some PO(s) needs to be monitored. Whether there is association between LP-WUS and PO, and how to define the association if yes, depends on the detailed procedure. For reference, in legacy, Rel-17 PEI supports mapping of up to 8 POs (configured the parameter po-NumPerPEI), and Rel-15 WUS and Rel-16 GWUS for NB-IoT / LTE-M supports mapping of up to 4 POs, but only when the UE is configured with eDRX.

[0281] Furthermore, after waking up from LP-WUS, either all UEs could be triggered to wake up to monitor paging in associated PO(s), or just a subset of the UEs sharing the PO, so called LP-WUS UE subgrouping. The latter can be used to reduce the negative impact from false paging, i.e., unnecessary energy consumption in the UE caused by paging intended for another UE. In the latter case, LP-WUS UE subgrouping information corresponding to 2 bits or more, would be indicated by LP-WUS. How to indicate the subgrouping information, e.g. included in the LP-WUS payload or from the use of multiple LP-WUS signals corresponding to different subgroups, etc., depends on the design of LP-WUS. For reference, both Rel-17 PEI and Rel-16 GWUS for NB-IoT / LTE-M support up 8 subgroups per PO (configured by the parameters subgroupsNumPerPO and GWUS-NumGroups, respectively). The number of subgroups depends on the decision on payload of LP-WUS

[0282] Both these features rely on I-DRX and UEs already being distributed over the different POs in the cell, and the UE subgrouping therefore refers to further subgrouping of the UEs already divided into the same PO. This would be the same for 'duty-cycled' operation. For 'continuous' operation, UE should monitor the downlink continuously. false paging could apply to all UEs in the cell since all UEs are monitoring the downlink continuously. False paging would therefore be much more severe for 'continuous' and a larger number of LP-WUS / WUR UE subgroups would be required to achieve the same false paging rate.

[0283] In Rel-17 PEI, two subgrouping methods were introduced, which includes: CN assigned and UE_ID based subgrouping. For CN assigned subgrouping, UE's subgroup is assigned by CN taking into account the UE's characters, such as mobility pattern, paging probabilities, etc. While for UE_ID based subgrouping, UE's subgroup is formed based on UE_ID and the subgroup number in RAN. UE supporting CN assigned subgrouping in RRC_IDLE or RRC_INACTIVE state can be assigned a subgroup ID by AMF through NAS signalling. The UE belonging to the assigned subgroup ID monitors its associated PEI which indicates the paged subgroup(s). Paging with UE_ID based subgrouping is used in the cell which supports UE_ID based subgrouping. It is up to network configuration to determine which subgrouping should be used.

[0284] Similar as PEI, the subgrouping methods for LP-WUS could include the CN assigned, and UE_ID based subgrouping. Details, e.g. which one / both should be supported, how to support / provide the configuration, etc., could be further determined during WI phase.

[0285] LP-WUScoverage and trigger condition

[0286] According to evaluation in section 8.2, LP-WUS link performance is considerably worse than legacy physical channels (e.g., PDCCH or PUSCH), and there could be partial LP-WUS coverage in the cell. Another possible scenario is LP-WUS could also have same coverage as legacy cell, while the details depend on the signalling and LP-WUR design. For the partial coverage case, UE may need to keep track of whether it moves in and out of LP-WUS coverage in the cell, this to be able to fall back to monitoring paging using the main receiver when the coverage of LP-WUS is not sufficient (see network awareness in 7.3.1.1 above). The UE could determine this based on the measured RSRP, e.g., compared to an RSRP threshold in system information.

[0287] For the partial coverage case, UE's MR could stay in ultra-deep sleep power state only when UE is in the coverage of LP-WUS. When UE moves out of the coverage of LP-WUS, the network cannot wake up UE's MR via LP-WUS. Hence, UE should start up its MR when it moves out of the coverage of LP-WUS to avoid missing the paging message. In this way, one of the exit conditions for using LP-WUS or ultra-deep sleep power state should be that the UE is out of LP-WUS coverage. A quality threshold of target Reference Signal can be pre-configured to UE to define the exit condition for using LP-WUS. With this threshold, UE can stop using LP-WUS and exit the ultra-deep sleep power state when the quality of target Reference Signal is lower than the threshold.

[0288] During ultra-deep sleep or when using LP-WUS, UE's MR may not perform measurement as per legacy procedures and requirements. Thus, in order to be applicable for all cases, the pre-configured exit condition should be based on the measurement of target Reference Signal by LR and / or MR.

[0289] Similarly, the measurements and trigger conditions would need to be defined for using LP-WUS. One way is to define a quality threshold for the target Reference Signal measurement to determine the coverage. One entry condition for using LP-WUS could be configured to UE based on this quality threshold. From network perspective, the threshold could be set based on the coverage of LP-WUS. With this threshold, LP-WUS could be used, and UE's MR could enter ultra-deep-sleep power state when the quality of target Reference Signal is better than the threshold.

[0290] Before the entry condition is fulfilled, UE should perform legacy measurement on serving cell based on legacy SSB, e.g. for cell (re)selection purpose. Hence, it is straightforward to use the legacy SSB as the target Reference Signal for pre-configured entry condition. That is, when the quality of the serving cell's SSB measured by MR is better than a pre-configured threshold, UE considers the entry condition is fulfilled, then, LP-WUS could be used and MR could enter ultra-deep-sleep power state for power saving. Alternatively, LP-SS could be introduced for LR measurement, the pre-condition could be also defined based on the measurement on LP-SS via LR. In this way, the target Reference Signal could be the LP-SS sent by the serving cell, i.e. when the quality of the LP-SS measured by LR is better than a pre-configured threshold, UE considers the entry condition for using LP-WUS is fulfilled. The solution requires the UE to perform measurement on LP-SS via LR before using LP-WUS. In this way, the UE needs to turn on its LR before entering ultra-deep-sleep power state, which may lead to extra power consumption, but it is not an issue as the power consumption of LR is very low.

[0291] From the network perspective, if a unique UE identifier (e.g., 48-bit 5G-S-TMSI or 24 / 40-bit I-RNTI) is not carried in the LP-WUS payload, a gNB may need to transmit both LP-WUS and the associated legacy PDCCH and PDSCH for the paging message. In this case, the gNB would in principle not need to consider whether the UE is within LP-WUS coverage in the cell or not, but in case it is not there would be some unnecessary control signalling overhead from the transmission of LP-WUS. If instead a unique UE identifier is carried in the LP-WUS payload, the gNB could either transmit LP-WUS or legacy paging depending on if the UE is within LP-WUS coverage or not. However, without any signalling from the UE upon LP-WUS coverage change, or from being in the cell or not, this would have to be done blindly and would be left to the gNB implementation (similar to paging the UE in two different cells, i.e., up to trial and error). With partial coverage, the most severe error case would be if the UE from inaccurate measurements incorrectly concludes that it is in LP-WUS coverage when it is not, and therefore becomes unreachable in the downlink (the UE only monitors using LP-WUR but is outside LP-WUS coverage).

[0292] Configuration

[0293] Regarding the LP-WUS configuration, both UE and gNB must have a common understanding of when LP-WUS should be applied to avoid that UEs become unreachable in the downlink. Both UE and gNB could apply LP-WUS if LP-WUS has been configured in the cell in SI. This would further determine the conditions for entering and leaving LP-WUS monitoring operation as being tied to the monitoring of paging in a cell: A UE enables LP-WUS monitoring if it is configured with LP-WUS and camp on a cell in RRC_IDLE or RRC_INACTIVE state in which LP-WUS is configured, for example when re-selecting a cell in which LP-WUS is configured or being released from RRC_CONNECTED in a cell in which LP-WUS is configured.

[0294] System information update andPWS

[0295] Reception of system information (SI) broadcast and ETWS / CMAS are RRC_IDLE mode procedures which must be supported for UE with LP-WUS / WUR. When the UE initiates the acquisition of SI, for example when SI has become outdated or upon cell change, the UE anyway needs to start up the main receiver for the reception of the SI message(s). However, this is not the case for a gNB notification of SI update and it must be possible to notify also UEs with LP-WUR about an upcoming SI change in the cell. For reference, in Rel-16 GWUS for NB-IoT / LTE-M this is done by a subgroup common to all UEs (configured by the parameter commonSequence), whereas for Rel-17 PEI the gNB must transmit PEI to all subgroups separately and upon the reception of PEI UEs continue to, as in legacy operation, monitor for the systemInfoModification and systemInfoModification-eDRX in the Short Messages transmitted on PDCCH using P-RNTI. When UE is using LP-WUS, UE could wake up by LP-WUS firstly and then receive the notification of SI change based on the systemInfoModification and systemInfoModification-eDRX in the Short Messages transmitted on PDCCH using P-RNTI as legacy.

[0296] ETWS / CMAS is regulatory requirement for UEs supporting ETWS / CMAS. Therefore, even for UE in ultra-deep sleep, the ETWS / CMAS messages should be ensured to be reachable if the UE is capable of ETWS / CMAS. As in legacy, the gNB would upon ETWS / CMAS information need to wake up UE by LP-WUS from ultra-deep sleep. Similar to the notification of SI change, when UE is using LP-WUS, UE could wake up by LP-WUS and receive the notification of ETWS / CMAS notification based on etwsAndCmasIndication in the Short Messages.

[0297] Mobility andRRM

[0298] To ensure a UE in RRC_IDLE or RRC_INACTIVE is camping on the best cell it needs to perform mobility measurements. RRM measurement for mobility includes serving cell measurements and neighbour cell measurements, which can be intra-frequency or inter-frequency (including inter-RAT) measurements. In general, the neighbour cell measurements however only need to be performed by the UE if the serving cell is not strong enough, i.e., when the intra-frequency cell re-selection criterion (Srxlev > SIntraSearchP and Squal > SIntraSearchQ) or the inter-frequency cell re-selection criterion (Srxlev > SnonIntraSearchP and Squal > SnonIntraSearchQ) is not fulfilled. For the majority of UEs, and in a well deployed network without coverage holes, it is therefore the serving cell measurements that need to be performed the most frequently, and therefore they will also have the biggest impact on UE energy consumption.

[0299] For a UE operating with LP-WUR, infrequently starting up the main receiver (MR) for neighbour cell measurements is not expected to have any significant impact on UE energy consumption. However, using the MR for serving cell measurements has a significant impact on UE energy consumption and reduce the LP-WUS / WUR gain according to the observations from the study evaluation results. Serving cell measurements must be performed every or every second I-DRX cycle in FR1 (and somewhat more relaxed in FR2). Starting the main receiver for RRM measurements every I-DRX cycle removes a large part of the UE energy consumption reductions from LP-WUS / WUR.

[0300] In order to achieve the UE power saving gain by LP-WUS / WUR, the RRM measurement on serving cell and neighbouring cell via MR is relaxed or may be stopped when UE is using LP-WUS or MR is in ultra-deep sleep. In Rel-16 / 17 PowSav and RedCap WI, RRM measurement relaxation on neighbouring cell was introduced. But here, further relaxation or even no measurement by MR could be considered while serving cell measurements are offloaded to LR. The relaxation on RRM measurement may impact the performance of mobility performance in RRC_IDLE or RRC_INACTIVE. In order to avoid or minimize such impact, the RRM measurement on LP-WUR could be considered. Thus, the above RRM measurement relaxation on serving cell and neighbouring cell should be premised on the feasibility or support of RRM measurement on LR.

[0301] RRC_CONNECTED mode procedures

[0302] For legacy UE in RRC_CONNECTED state, it should keep MR monitoring PDCCH in C-DRX active time, if C-DRX is configured, also when there is nothing scheduled for the UE. As a result, the power consumption caused by unnecessary PDCCH monitoring is unavoidable. The gain for legacy UE power saving features in RRC_CONNECTED, such as Short C-DRX, Long C-DRX, Rel-16 PDCCH-based WUS, or Rel-17 PDCCH monitor adaptation, comes from reducing the PDCCH monitoring time.

[0303] Both Rel-16 DCP and Rel-17 PDCCH monitor adaptation are both PDCCH based signalling. For a UE equipped with LR, the MR can be in a sleep state while the LR remains active to monitor Low-Power Wake-Up Signal (LP-WUS), and when LP-WUS is received by LR, it will trigger the MR to wake up to monitor PDCCH. As LR would adopt a minimalistic design, the power consumption of LR is expected to be significantly lower than legacy PDCCH based signaling using the main receiver (MR) in some cases. In this way, LP-WUS in RRC_CONNECTED can potentially further reduce the UE energy consumption by being able the monitor the downlink with a LR such that the MR used for PDCCH monitoring can be kept in a sleep state. The LP-WUS / WUR solution should target power saving gain compared to the existing Rel-15 / 16 / 17 UE power saving mechanisms, e.g., according to the evaluation results above, {6%~15%} additional UE power saving gain with no capacity loss in both low load and high load cases for DL only XR traffic compared to the existing Rel-15 / 16 / 17 power saving solutions.

[0304] Compared with UE in RRC_IDLE / INACTIVE state, UE in RRC_CONNECTED state is more sensitive to the latency. Therefore, the RAN2 study on LP-WUS procedures in RRC_ CONNECTED should target to reduce power consumption while guarantee the latency performance.

[0305] The MR sleep states considered for LP-WUS / WUR evaluation in RRC_CONNECTED are the same as for baseline: deep sleep state with a 20 ms transition time, light sleep state with a 6 ms transition time, or micro sleep without any transition time, as described TR 38.840. Ultra-deep sleep state is not considered for LP-WUS / WUR in RRC_CONNECTED state as a 400 ms transition time is too long to allow the MR to be ready for PDCCH monitoring from the ultra-deep sleep state considering the traffic requirements for NR. Therefore, the power saving gain for LP-WUS / WUR would be determined by the time duration in which the MR can be kept in a sleep state, and significantly lower power consumed by LP-WUS / LP-WUR compared to the PDCCH monitoring by MR. Regarding latency, the transition time for the MR to start up upon LP-WUS detection by LP-WUR would in principle not be worse comparing to the existing power saving mechanism since the MR could be in micro, light, or deep sleep state as legacy, but is not allowed to be in ultra-deep sleep state when LR is monitoring LP-WUS, as described above.

[0306] When using LP-WUS, other conditions could also trigger MR to wake up for PDCCH monitor, e.g. UL transmission by MR, which would be similar to using baseline solutions, e.g. C-DRX, with the same MR sleep state.

[0307] LP-WUSmonitoring

[0308] Similar as in RRC_IDLE / INACTIVE, there are two mechanisms to monitor LP-WUS for LP-WUS in RRC_CONNECTED, i.e. 'continuous' and 'duty-cycled' mode. For 'continuous' mode, LP-WUS is monitored continuously in time, while for 'duty-cycled' mode, LP-WUS is monitored based on a defined duty cycle, which is similar as DRX mechanism. 'Continuous' mode could be expected to have lower latency than 'duty-cycled' mode, but both solutions will have the same lower latency bound from the MR transition time as described above, and in the same way as for legacy C-DRX the duty cycle length for 'duty-cycled' mode would be defined or configured based on the downlink latency requirement. Therefore, any performance comparison of these two LP-WUS monitoring mechanisms, or any down selection between them, should be considered based on the downlink latency requirement. The corresponding pros / cons for these two mechanisms are summarized in the below table.

[0309] Configuration

[0310] A UE is expected to be configured with LP-WUS / WUR in RRC_CONNECTED mode, e.g. upon RRC connection establishment, i.e., either during RRC Connection Setup or RRC Connection Resumption. Therefore, UE specific LP-WUS / WUR configuration is possible in RRC_CONNECTED mode.

[0311] The time gap between the LP-WUS monitoring occasion and the PDCCH monitoring occasion for MR must be designed or configured long enough to cover the transition time of the MR to be ready for PDCCH monitoring. Another alternative is similar to Rel-15 WUS for NB-IoT / LTE-M, different transition time gaps, if introduced, could be defined as UE capability. Then, gNB could, based on this capability, know which time gap to configure for the UE (which if, several sleep states are supported, lets the UE to determine the MR sleep state to apply).

[0312] For partial LP-SS / LP-WUS coverage in the cell, LP-WUS should only be configured / used for a UE within LP-SS / LP-WUS coverage:

[0313] - In one solution, the coverage determination is similar as in RRC_IDLE / INACTIVE, which is based on the measurement of LR and / or MR, and the corresponding threshold determined / configured by network. Furthermore, when UE moves out of LP-WUS coverage, LP-WUS cannot be used at the UE, as it is unreachable by the gNB for LP-WUS. It should be either released or de-activated by the network. Otherwise, some conditions would have to be introduced to ensure the UE could autonomously fall back to legacy operation without LP-WUS.

[0314] - In another solution, monitoring LP-WUS can be explicitly activated and de-activated by the network, e.g., entry / exit condition(s) of using LP-WUS may not be needed.

[0315] Meanwhile, for full LP-SS / LP-WUS coverage in the cell, no special configuration would be required. That is, LP-WUS could be configured / activated for a UE in the cell, and not used when it is released / de-activated in the cell.

[0316] According to above analysis, LP-WUS in RRC_CONNECTED with partial LP-WUS coverage is expected to have more standardization impacts than the scenario with full LP-WUS coverage.

[0317] LP-WUScoexistence withDCP

[0318] On one hand, LP-WUS could be configured together with Rel-16 DCP for a specific UE. However, the UE may only use one of them at any time, e.g. depend on the network configuration or link quality, etc. It should be noted that this operation is more useful for the partial LP-SS / LP-WUS coverage. For example, for partial LP-SS / LP-WUS coverage, when the UE is in LP-SS / LP-WUS coverage, UE could monitor LP-WUS autonomously or UE could monitor LP-WUS if the gNB activate the LP-WUS monitoring. When UE moves out of LP-SS / LP-WUS coverage, the measurement quality of LP-SS via LR is not good enough, UE could consider to use Rel-16 DCP as in legacy in this case.

[0319] On the other hand, the LP-WUS could be used in conjunction with Rel-16 DCP. That is, the UE firstly monitor LP-WUS and, in case the MR is waked up by the LP-WUS, then, the UE will continue to monitor DCP.

[0320] Hereinafter, technical features related to SSB, measurement are described. Sections of 3GPP TR 38.300 v 17.6.0 may be referred.

[0321] FIG. 11 shows an example of time-frequency structure of SSB.

[0322] The Synchronization Signal and PBCH block (SSB) consists of primary and secondary synchronization signals (PSS, SSS), each occupying 1 symbol and 127 subcarriers, and PBCH spanning across 3 OFDM symbols and 240 subcarriers, but on one symbol leaving an unused part in the middle for SSS as shown in FIG. 10. The possible time locations of SSBs within a half-frame are determined by sub-carrier spacing and the periodicity of the half-frames where SSBs are transmitted is configured by the network. During a half-frame, different SSBs may be transmitted in different spatial directions (i.e. using different beams, spanning the coverage area of a cell).

[0323] Within the frequency span of a carrier, multiple SSBs can be transmitted. The PCIs of SSBs transmitted in different frequency locations do not have to be unique, i.e. different SSBs in the frequency domain can have different PCIs. However, when an SSB is associated with an RMSI, the SSB is referred to as a Cell-Defining SSB (CD-SSB). A PCell is always associated to a CD-SSB located on the synchronization raster.

[0324] Polar coding is used for PBCH.

[0325] The UE may assume a band-specific sub-carrier spacing for the SSB unless a network has configured the UE to assume a different sub-carrier spacing.

[0326] PBCH symbols carry its own frequency-multiplexed DMRS.

[0327] QPSK modulation is used for PBCH.

[0328] Measurements

[0329] In RRC_CONNECTED, the UE measures multiple beams (at least one) of a cell and the measurements results (power values) are averaged to derive the cell quality. In doing so, the UE is configured to consider a subset of the detected beams. Filtering takes place at two different levels: at the physical layer to derive beam quality and then at RRC level to derive cell quality from multiple beams. Cell quality from beam measurements is derived in the same way for the serving cell(s) and for the non-serving cell(s). Measurement reports may contain the measurement results of theXbest beams if the UE is configured to do so by the gNB.

[0330] The corresponding high-level measurement model is described in FIG. 12.

[0331] FIG. 12 shows an example of Measurement Model.

[0332] For example, K beams correspond to the measurements on SSB or CSI-RS resources configured for L3 mobility by gNB and detected by UE at L1.

[0333] -A: measurements (beam specific samples) internal to the physical layer.

[0334] -Layer 1 filtering: internal layer 1 filtering of the inputs measured at point A. Exact filtering is implementation dependent. How the measurements are actually executed in the physical layer by an implementation (inputs A and Layer 1 filtering) is not constrained by the standard.

[0335] -A1: measurements (i.e. beam specific measurements) reported by layer 1 to layer 3 after layer 1 filtering.

[0336] - Beam Consolidation / Selection: beam specific measurements are consolidated to derive cell quality. The behaviour of the Beam consolidation / selection is standardised and the configuration of this module is provided by RRC signalling. Reporting period at B equals one measurement period at A1.

[0337] - B: a measurement (i.e. cell quality) derived from beam-specific measurements reported to layer 3 after beam consolidation / selection.

[0338] -Layer 3 filtering for cell quality: filtering performed on the measurements provided at point B. The behaviour of the Layer 3 filters is standardised and the configuration of the layer 3 filters is provided by RRC signalling. Filtering reporting period at C equals one measurement period at B.

[0339] -C: a measurement after processing in the layer 3 filter. The reporting rate is identical to the reporting rate at point B. This measurement is used as input for one or more evaluation of reporting criteria.

[0340] -Evaluation of reporting criteria: checks whether actual measurement reporting is necessary at point D. The evaluation can be based on more than one flow of measurements at reference point C e.g. to compare between different measurements. This is illustrated by input C and C1. The UE shall evaluate the reporting criteria at least every time a new measurement result is reported at point C, C1. The reporting criteria are standardised and the configuration is provided by RRC signalling (UE measurements).

[0341] -D: measurement report information (message) sent on the radio interface.

[0342] -L3 Beam filtering: filtering performed on the measurements (i.e. beam specific measurements) provided at point A1. The behaviour of the beam filters is standardised and the configuration of the beam filters is provided by RRC signalling. Filtering reporting period at E equals one measurement period at A1.

[0343] -E: a measurement (i.e. beam-specific measurement) after processing in the beam filter. The reporting rate is identical to the reporting rate at point A1. This measurement is used as input for selecting the X measurements to be reported.

[0344] -Beam Selection for beam reporting: selects the X measurements from the measurements provided at point E. The behaviour of the beam selection is standardised and the configuration of this module is provided by RRC signalling.

[0345] -F: beam measurement information included in measurement report (sent) on the radio interface.

[0346] Layer 1 filtering introduces a certain level of measurement averaging. How and when the UE exactly performs the required measurements is implementation specific to the point that the output at B fulfils the performance requirements set. Layer 3 filtering for cell quality and related parameters used are specified and do not introduce any delay in the sample availability between B and C. Measurement at point C, C1is the input used in the event evaluation. L3 Beam filtering and related parameters used are specified and do not introduce any delay in the sample availability between E and F.

[0347] Layer 1 filtering introduces a certain level of measurement averaging. How and when the UE exactly performs the required measurements is implementation specific to the point that the output at B fulfils the performance requirements set. Layer 3 filtering for cell quality and related parameters used are specified and do not introduce any delay in the sample availability between B and C. Measurement at point C, C1is the input used in the event evaluation. L3 Beam filtering and related parameters used are specified and do not introduce any delay in the sample availability between E and F.

[0348] Measurement reports are characterized by the following:

[0349] - Measurement reports include the measurement identity of the associated measurement configuration that triggered the reporting;

[0350] - Cell and beam measurement quantities to be included in measurement reports are configured by the network;

[0351] - The number of non-serving cells to be reported can be limited through configuration by the network;

[0352] - Cells belonging to an exclude-list configured by the network are not used in event evaluation and reporting, and conversely when an allow-list is configured by the network, only the cells belonging to the allow-list are used in event evaluation and reporting;

[0353] - Beam measurements to be included in measurement reports are configured by the network (beam identifier only, measurement result and beam identifier, or no beam reporting).

[0354] Intra-frequency neighbour (cell) measurements and inter-frequency neighbour (cell) measurements are defined as follows:

[0355] - SSB based intra-frequency measurement: a measurement is defined as an SSB based intra-frequency measurement provided the center frequency of the SSB of the serving cell and the center frequency of the SSB of the neighbour cell are the same, and the subcarrier spacing of the two SSBs is also the same.

[0356] - SSB based inter-frequency measurement: a measurement is defined as an SSB based inter-frequency measurement provided the center frequency of the SSB of the serving cell and the center frequency of the SSB of the neighbour cell are different, or the subcarrier spacing of the two SSBs is different.

[0357] - CSI-RS based intra-frequency measurement: a measurement is defined as a CSI-RS based intra-frequency measurement provided that:

[0358] - The subcarrier spacing of CSI-RS resources on the neighbour cell configured for measurement is the same as the SCS of CSI-RS resources on the serving cell indicated for measurement; and

[0359] - For 60kHz subcarrier spacing, the CP type of CSI-RS resources on the neighbour cell configured for measurement is the same as the CP type of CSI-RS resources on the serving cell indicated for measurement; and

[0360] - The centre frequency of CSI-RS resources on the neighbour cell configured for measurement is the same as the centre frequency of CSI-RS resource on the serving cell indicated for measurement.

[0361] - CSI-RS based inter-frequency measurement: a measurement is defined as a CSI-RS based inter-frequency measurement if it is not a CSI-RS based intra-frequency measurement.

[0362] Whether a measurement is non-gap-assisted or gap-assisted depends on the capability of the UE, the active BWP of the UE and the current operating frequency:

[0363] - For SSB based inter-frequency measurement, if the measurement gap requirement information is reported by the UE, a measurement gap configuration may be provided according to the information. Otherwise, a measurement gap configuration is always provided in the following cases:

[0364] - If the UE only supports per-UE measurement gaps;

[0365] - If the UE supports per-FR measurement gaps and any of the serving cells are in the same frequency range of the measurement object.

[0366] - For SSB based intra-frequency measurement, if the measurement gap requirement information is reported by the UE, a measurement gap configuration may be provided according to the information. Otherwise, a measurement gap configuration is always provided in the following case:

[0367] - Other than the initial BWP, if any of the UE or RedCap UE configured BWPs do not contain the frequency domain resources of the SSB associated to the initial DL BWP, and for RedCap UE, are not configured with NCD-SSB for serving cell measurement.

[0368] In non-gap-assisted scenarios, the UE shall be able to carry out such measurements without measurement gaps. In gap-assisted scenarios, the UE cannot be assumed to be able to carry out such measurements without measurement gaps.

[0369] Network may request the UE to measure NR and / or E-UTRA carriers in RRC_IDLE or RRC_INACTIVE via system information or via dedicated measurement configuration inRRCRelease. If the UE was configured to perform measurements of NR and / or E-UTRA carriers while in RRC_IDLE or in RRC_INACTIVE, it may provide an indication of the availability of corresponding measurement results to the gNB in theRRCSetupCompletemessage. The network may request the UE to report those measurements after security activation. The request for the measurements can be sent by the network immediately after transmitting the Security Mode Command (i.e. before the reception of the Security Mode Complete from the UE).

[0370] If the UE was configured to perform measurements of NR and / or E-UTRA carriers while in RRC_INACTIVE, the gNB can request the UE to provide corresponding measurement results in theRRCResumemessage and then the UE can include the available measurement results in theRRCResumeCompletemessage. Alternatively, the UE may provide an indication of the availability of the measurement results to the gNB in theRRCResumeCompletemessage and the gNB can then request the UE to provide these measurement results.

[0371] Hereinafter, technical features related to Cell selection and reselection are described. Sections of 3GPP TR 38.304 v 17.6.0 may be referred.

[0372] UE shall perform measurements for cell selection and reselection purposes.

[0373] When evaluating Srxlev and Squal of non-serving cells for reselection evaluation purposes, the UE shall use parameters provided by the serving cell and for the final check on cell selection criterion, the UE shall use parameters provided by the target cell for cell reselection.

[0374] The NAS can control the RAT(s) in which the cell selection should be performed, for instance by indicating RAT(s) associated with the selected PLMN, and by maintaining a list of forbidden registration area(s) and a list of equivalent PLMNs. The UE shall select a suitable cell based on RRC_IDLE or RRC_INACTIVE state measurements and cell selection criteria.

[0375] In order to expedite the cell selection process, stored information for several RATs, if available, may be used by the UE.

[0376] When camped on a cell, the UE shall regularly search for a better cell according to the cell reselection criteria. If a better cell is found, that cell is selected. The change of cell may imply a change of RAT.

[0377] The NAS is informed if the cell selection and reselection result in changes in the received system information relevant for NAS.

[0378] For normal service, the UE shall camp on a suitable cell, monitor control channel(s) of that cell so that the UE can:

[0379] - receive system information from the PLMN or SNPN; and

[0380] - receive registration area information from the PLMN or SNPN, e.g., tracking area information; and

[0381] - receive other AS and NAS Information; and

[0382] - if registered:

[0383] - receive paging and notification messages from the PLMN or SNPN; and

[0384] - initiate transfer to Connected mode.

[0385] For cell selection in multi-beam operations, measurement quantity of a cell is up to UE implementation.

[0386] For cell reselection in multi-beam operations, including inter-RAT reselection from E-UTRA to NR, the measurement quantity of this cell is derived amongst the beams corresponding to the same cell based on SS / PBCH block as follows:

[0387] - ifnrofSS-BlocksToAverage(maxRS-IndexCellQualin E-UTRA) is not configured inSIB2 / SIB4(SIB24in E-UTRA); or

[0388] - ifabsThreshSS-BlocksConsolidation(threshRS-Indexin E-UTRA)is not configured inSIB2 / SIB4(SIB24in E-UTRA); or

[0389] - if the highest beam measurement quantity value is below or equal toabsThreshSS-BlocksConsolidation(threshRS-Indexin E-UTRA):

[0390] - derive a cell measurement quantity as the highest beam measurement quantity value.

[0391] - else:

[0392] - derive a cell measurement quantity as the linear average of the power values of up tonrofSS-BlocksToAverage(maxRS-IndexCellQualin E-UTRA) of highest beam measurement quantity values aboveabsThreshSS-BlocksConsolidation(threshRS-Indexin E-UTRA).

[0393] For example, if both suitable cell(s) and suitable L2 U2N Relay UE(s) are available, it is up to L2 U2N Remote UE's implementation to select either a suitable cell or a suitable L2 U2N Relay UE.

[0394] States and state transitions in RRC_IDLE state and RRC_INACTIVE state

[0395] FIG. 13 shows an example of RRC_IDLE and RRC_INACTIVE Cell Selection and Reselection.

[0396] In particular, FIG. 13 shows the states and state transitions and procedures in RRC_IDLE and RRC_INACTIVE. Whenever a new PLMN selection or new SNPN selection is performed, it causes an exit to number 1.

[0397] Cell Selection process

[0398] Cell selection is performed by one of the following two procedures:

[0399] a) Initial cell selection (no prior knowledge of which RF channels are NR frequencies):

[0400] 1. The UE shall scan all RF channels in the NR bands according to its capabilities to find a suitable cell.

[0401] 2. On each frequency, the UE need only search for the strongest cell, except for operation with shared spectrum channel access where the UE may search for the next strongest cell(s).

[0402] 3. Once a suitable cell is found, this cell shall be selected.

[0403] b) Cell selection by leveraging stored information:

[0404] 1. This procedure requires stored information of frequencies and optionally also information on cell parameters from previously received measurement control information elements or from previously detected cells.

[0405] 2. Once the UE has found a suitable cell, the UE shall select it.

[0406] 3. If no suitable cell is found, the initial cell selection procedure in a) shall be started.

[0407] For example, priorities between different frequencies or RATs provided to the UE by system information or dedicated signalling are not used in the cell selection process.

[0408] CellReselectionevaluation process,Reselectionpriorities handling

[0409] Absolute priorities of different NR frequencies or inter-RAT frequencies may be provided to the UE in the system information, in theRRCReleasemessage, or by inheriting from another RAT at inter-RAT cell (re)selection. In the case of system information, an NR frequency or inter-RAT frequency may be listed without providing a priority (i.e. the fieldcellReselectionPriorityis absent for that frequency). If any fields withcellReselectionPriorityornsag-CellReselectionPriorityare provided in dedicated signalling, the UE shall ignore any fields withcellReselectionPriorityandnsag-CellReselectionPriorityprovided in system information.

[0410] When UE is in camped normally state, if it supports slice-based cell reselection and has received the network slice(s) and NSAG information from NAS to be used for cell reselection, UE shall derive reselection priorities.

[0411] For example, UE derives reselection priorities also in caseSIB16is not broadcast in the camped cell.

[0412] If UE is incamped on any cellstate, UE shall only apply the priorities provided by system information from current cell, and the UE preserves priorities provided by dedicated signalling anddeprioritisationReqreceived inRRCReleaseunless specified otherwise. When the UE in camped normally state, has only dedicated priorities other than for the current frequency, the UE shall consider the current frequency to be the lowest priority frequency (i.e. lower than any of the network configured values). When the HSDN capable UE is in High-mobility state, the UE shall always consider the HSDN cells to be the highest priority (i.e., higher than any other network configured priorities). When the HSDN capable UE is not in High-mobility state, the UE shall always consider HSDN cells to be the lowest priority (i.e., lower than any other network configured priorities). If the UE is configured to perform both NR sidelink communication and V2X sidelink communication, the UE may consider the frequency providing both NR sidelink communication configuration and V2X sidelink communication configuration to be the highest priority. If the UE is configured to perform NR sidelink communication and not perform V2X communication, the UE may consider the frequency providing NR sidelink communication configuration to be the highest priority. If the UE is configured to perform V2X sidelink communication and not perform NR sidelink communication, the UE may consider the frequency providing V2X sidelink communication configuration to be the highest priority.

[0413] For example, the frequency only providing the anchor frequency configuration should not be prioritized for V2X service during cell reselection, as specified in TS 38.331[3].

[0414] For example, when UE is configured to perform NR sidelink communication or V2X sidelink communication performs cell reselection, it may consider the frequencies providing the intra-carrier and inter-carrier configuration have equal priority in cell reselection.

[0415] For example, the prioritization among the frequencies which UE considers to be the highest priority frequency is left to UE implementation unless otherwise stated.

[0416] For example, the UE is configured to perform V2X sidelink communication or NR sidelink communication, if it has the capability and is authorized for the corresponding sidelink operation.

[0417] For example, when UE is configured to perform both NR sidelink communication and V2X sidelink communication, but cannot find a frequency which can provide both NR sidelink communication configuration and V2X sidelink communication configuration, UE may consider the frequency providing either NR sidelink communication configuration or V2X sidelink communication configuration to be the highest priority.

[0418] The UE shall only perform cell reselection evaluation for NR frequencies and inter-RAT frequencies that are given in system information and for which the UE has a priority provided.

[0419] If the MBS broadcast capable UE is receiving or interested to receive an MBS broadcast service(s) and can only receive this MBS broadcast service(s) by camping on a frequency on which it is provided, the UE may consider that frequency to be the highest priority during the MBS broadcast session as specified in TS 38.300 [2] as long as the two following conditions are fulfilled:

[0420] 1) SIB1 scheduling information of the cell reselected by the UE due to frequency prioritization for MBS contains SIB20;

[0421] 2) Either:

[0422] - One or more MBS FSAI(s) of that frequency is indicated in SIB21 of the serving cell and the same MBS FSAI(s) is also indicated for this MBS broadcast service in MBS User Service Description (USD) as specified in TS 26.346

[0020] , or

[0423] - SIB21 is not provided in the serving cell and that frequency is included in the USD of this service, or

[0424] - SIB21 is provided in the serving cell but does not provide the frequency mapping for the concerned service, and that frequency is included in the USD of this service.

[0425] For example, it is up to UE implementation which frequency to select, when the USD provides multiple frequencies for the service the UE is interested in.

[0426] If the MBS broadcast capable UE is receiving or interested to receive an MBS broadcast service, the UE may consider cell reselection candidate frequencies at which it cannot receive the MBS broadcast service to be of the lowest priority during the MBS broadcast session, as long as SIB1 scheduling information of the cell contains SIB20 on the MBS frequency which the UE monitors and as long as the condition 2) above is fulfilled for the serving cell.

[0427] For example, example scenarios in which such down-prioritisation may be needed include the cases where camping is not possible for the UE on the MBS broadcast frequency (e.g. the MBS broadcast frequency belongs to a PLMN different from UE's registered PLMN) while the UE can receive the MBS broadcast service when camped on another frequency than the MBS broadcast frequency or current frequency.

[0428] For example, the frequency prioritization for MBS broadcast, NR sidelink communication, or V2X sidelink communication may override the re-selection priorities for slice-based cell reselection.

[0429] In case UE receivesRRCReleasewithdeprioritisationReq, UE shall consider current frequency and stored frequencies due to the previously receivedRRCReleasewithdeprioritisationReqor all the frequencies of NR to be the lowest priority frequency (i.e. lower than any of the network configured values) while T325 is running irrespective of camped RAT. The UE shall delete the stored deprioritisation request(s) when a PLMN selection or SNPN selection is performed on request by NAS.

[0430] For example, UE should search for a higher priority layer for cell reselection as soon as possible after the change of priority.

[0431] For example, the UE does not consider MBS broadcast, NR sidelink communication or V2X sidelink communication functionality to replace cell reselection priorities caused by HSDN ordeprioritisationReqfunctionality.

[0432] The UE shall delete priorities provided by dedicated signalling when:

[0433] - the UE enters a different RRC state; or

[0434] - the optional validity time of dedicated priorities (T320) expires; or

[0435] - the UE receives anRRCReleasemessage with the fieldcellReselectionPrioritiesabsent; or

[0436] - a PLMN selection or SNPN selection is performed on request by NAS.

[0437] For example, equal priorities between RATs are not supported.

[0438] The UE shall not consider any exclude-listed cells as candidate for cell reselection.

[0439] The UE shall consider only the allow-listed cells, if configured, as candidates for cell reselection.

[0440] The UE in RRC_IDLE state shall inherit the priorities provided by dedicated signalling and the remaining validity time (i.e. T320 in NR and E-UTRA), if configured, at inter-RAT cell (re)selection.

[0441] For example, the network may assign dedicated cell reselection priorities for frequencies not configured by system information.

[0442] Measurement rules for cell re-selection

[0443] Following rules are used by the UE to limit needed measurements:

[0444] - If the serving cell fulfils Srxlev> SIntraSearchPand Squal > SIntraSearchQ:

[0445] - IfdistanceThreshandreferenceLocationare broadcasted in SIB19, and if UE supports location-based measurement initiation and has obtained its location information:

[0446] - If the distance between UE and the serving cell reference locationreferenceLocationis shorter thandistanceThresh, the UE may not perform intra-frequency measurements;

[0447] - Else, the UE shall perform intra-frequency measurements;

[0448] - Else, the UE may not perform intra-frequency measurements;

[0449] - Else, the UE shall perform intra-frequency measurements.

[0450] - The UE shall apply the following rules for NR inter-frequencies and inter-RAT frequencies which are indicated in system information and for which the UE has priority provided:

[0451] - For a NR inter-frequency or inter-RAT frequency with a reselection priority higher than the reselection priority of the current NR frequency, the UE shall perform measurements of higher priority NR inter-frequency or inter-RAT frequencies.

[0452] - For a NR inter-frequency with an equal or lower reselection priority than the reselection priority of the current NR frequency and for inter-RAT frequency with lower reselection priority than the reselection priority of the current NR frequency:

[0453] - If the serving cell fulfils Srxlev > SnonIntraSearchPand Squal > SnonIntraSearchQ:

[0454] - IfdistanceThreshandreferenceLocationare broadcasted in SIB19, and if UE supports location-based measurement initiation and has obtained its UE location information:

[0455] - If the distance between UE and the serving cell reference locationreferenceLocationis shorter thandistanceThresh, the UE may choose not to perform measurements of NR inter-frequency cells of equal or lower priority, or inter-RAT frequency cells of lower priority;

[0456] - Else, the UE shall perform measurements of NR inter-frequency cells of equal or lower priority, or inter-RAT frequency cells of lower priority;

[0457] - Else, the UE may choose not to perform measurements of NR inter-frequency cells of equal or lower priority, or inter-RAT frequency cells of lower priority;

[0458] - Else,the UE shall perform measurements of NR inter-frequency cells of equal or lower priority, or inter-RAT frequency cells of lower priority.

[0459] - If the UE supports relaxed measurement andrelaxedMeasurementis present inSIB2, the UE may further relax the needed measurements.

[0460] If thet-Serviceof the serving cell is present in SIB19, and if UE supports time-based measurement initiation, the UE shall perform intra-frequency, inter-frequency or inter-RAT measurements before the t-Service, regardless of the distance between UE and the serving cell reference location or whether the serving cell fulfils Srxlev > SIntraSearchPand Squal > SIntraSearchQ, or Srxlev > SnonIntraSearchPand Squal > SnonIntraSearchQ, The exact time to start measurement beforet-Serviceis up to UE implementation. UE shall perform measurements of higher priority NR inter-frequency or inter-RAT frequencies regardless of the remaining service time of the serving cell (i.e. time remaining untilt-Service).

[0461] For example, when evaluating the distance between UE and the serving cell reference location, it's up to UE implementation to obtain UE location information.

[0462] NRInter-frequency and inter-RAT CellReselectioncriteria

[0463] IfthreshServingLowQis broadcast in system information and more than 1 second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:

[0464] - A cell of a higher priority NR or EUTRAN RAT / frequency fulfils Squal > ThreshX,HighQduring a time interval TreselectionRAT

[0465] Otherwise, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:

[0466] - A cell of a higher priority RAT / frequency fulfils Srxlev > ThreshX, HighPduring a time interval TreselectionRAT; and

[0467] - More than 1 second has elapsed since the UE camped on the current serving cell.

[0468] Cell reselection to a cell on an equal priority NR frequency shall be based on ranking for intra-frequency cell reselection.

[0469] IfthreshServingLowQis broadcast in system information and more than 1 second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:

[0470] - The serving cell fulfils Squal < ThreshServing,LowQand a cell of a lower priority NR or E-UTRAN RAT / frequency fulfils Squal > ThreshX,LowQduring a time interval TreselectionRAT.

[0471] Otherwise, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:

[0472] - The serving cell fulfils Srxlev < ThreshServing,LowPand a cell of a lower priority RAT / frequency fulfils Srxlev > ThreshX,LowPduring a time interval TreselectionRAT; and

[0473] - More than 1 second has elapsed since the UE camped on the current serving cell.

[0474] Cell reselection to a higher priority RAT / frequency shall take precedence over a lower priority RAT / frequency if multiple cells of different priorities fulfil the cell reselection criteria.

[0475] If more than one cell meets the above criteria, the UE shall reselect a cell as follows:

[0476] - If the highest-priority frequency is an NR frequency, the highest ranked cell among the cells on the highest priority frequency(ies) meeting the criteria;

[0477] - If the highest-priority frequency is from another RAT, the strongest cell among the cells on the highest priority frequency(ies) meeting the criteria of that RAT.

[0478] Meanwhile, if UE does not support the inter-frequency LP-WUS operation, for example, it can receive LP-WUS only from the intra-frequency, the use of LP-WUS is limited to cases where the UE is camping on a frequency supported by LP-receiver. If such UE camps on a frequency not supported by its LP-receiver, it cannot use LP-WUS even though the LP-WUS is being transmitted on that frequency. To facilitate the power saving using LP-WUS, the UE should be allowed to prioritize the frequency where LP-WUS is transmitted so that it can have more opportunity to use LP-WUS.

[0479] The network may not operate LP-WUS on all frequency layers, hence the network should inform UE of the cells / frequencies where the LP-WUS is transmitted. However, the frequencies supported by the LP-receiver may vary depending on the UE implementation. If UE prioritizes and camps on a frequency which was indicated as a LP-WUS frequency but is not supported by LP-receiver, it may lead to unnecessary overload on that frequency. Although a frequency is indicated as a LP-WUS frequency by network, if the UE's LP-receiver does not support the frequency, the UE should not prioritize the frequency.

[0480] Therefore, studies for cell re-selection based on a low-power receiver are required.

[0481] Hereinafter, a method for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure, will be described with reference to the following drawings.

[0482] 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).

[0483] FIG. 14 shows an example of a method for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure.

[0484] In particular, FIG. 14 shows an example of a method performed by a wireless device in a wireless communication system.

[0485] In step S1401, the wireless device may receive information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency.

[0486] For example, the wireless device may pause Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring. For example, the PDCCH monitoring may be performed by at least one main receiver which does not monitor the LP-WUS. For example, the LP-WUS monitoring is performed by the low power-receiver.

[0487] For example, the wireless device may resume the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring. For example, when the wireless device receives the LP-UWS based on the low-power receiver, the wireless device may perform the PDCCH monitoring.

[0488] In step S1402, the wireless device may determine a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not.

[0489] For example, the wireless device may perform reselection priorities handling based on whether the first frequency is supported by a low power-receiver of the wireless device or not.

[0490] For example, absolute priorities of different NR frequencies or inter-RAT frequencies may be provided to the wireless device in the system information, in theRRCReleasemessage, or by inheriting from another RAT at inter-RAT cell (re)selection.

[0491] According to some embodiments of the present disclosure, the wireless device may receive information related to a first priority and a second priority for the first frequency. For example, the wireless device may receive information related to a first frequency priority list and information related to a second frequency priority list. For example, the information related to the first priority for the first frequency may be included in the first frequency priority list. For example, the information related to the second priority for the first frequency may be included in the second frequency priority list.

[0492] For example, information related to a first frequency priority list and information related to a second frequency priority list may be included in a system information message (for example, SIB) and / or a radio resource control (RRC) release message.

[0493] For example, information related to a first frequency priority list may be a common frequency priority list for all wireless devices. For example, information related to a second frequency priority list may be a dedicated frequency priority list only for wireless devices which support the LP-WUS (for example, wireless devices which have a low power-receiver).

[0494] For example, the wireless device may select either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.

[0495] For example, based on that the first frequency is not supported by the low power-receiver of the wireless device, the wireless device may consider the priority of the first frequency as the first priority.

[0496] For example, based on that the first frequency is supported by the low power-receiver of the wireless device, the wireless device may consider the priority of the first frequency as the second priority.

[0497] For example, the wireless device may information related to a first priority and a second priority for a second frequency. For example, the LP-WUS may not be transmitted on the second frequency. For example, the information related to the first priority for the second frequency may be included in the first frequency priority list. For example, the information related to the second priority for the second frequency may be included in the second frequency priority list.

[0498] For example, the wireless device may consider a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS. For example, the wireless device may consider a priority of the second frequency as the first priority, based on that the wireless device does not support the LP-WUS.

[0499] According to some embodiments of the present disclosure, the wireless device may receive information related to a frequency priority list. For example, the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies. For example, information related to a frequency priority list may be included in a system information message (for example, SIB) and / or a radio resource control (RRC) release message.

[0500] For example, the wireless device may determine the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device. For example, the wireless device may determine the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.

[0501] In step S1403, the wireless device may perform a cell re-selection procedure based on the determined priority of the first frequency.

[0502] For example, the wireless device may perform measurements for cell reselection. When evaluating Srxlev and Squal of non-serving cells for reselection evaluation purposes, the wireless device shall use parameters provided by the serving cell and for the final check on cell selection criterion, the UE shall use parameters provided by the target cell for cell reselection.

[0503] When camped on a cell, the wireless device shall regularly search for a better cell according to the cell reselection criteria. If a better cell is found, that cell is selected.

[0504] For example, the wireless device may perform the cell reselection based on NR Inter-frequency and inter-RAT Cell Reselection criteria, considering the determined priorities of the frequencies.

[0505] 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.

[0506] Hereinafter, technical features related to frequency priority handling for low power receiver are described.

[0507] Embodiment #1

[0508] UE determines whether to apply the first frequency priority or the second frequency priority to a frequency based on whether the frequency is supported by its LP-receiver.

[0509] UE applies the first frequency priority to a frequency based on the frequency not being supported by its LP-receiver. UE applies the second frequency priority to a frequency based on the frequency being supported by its LP-receiver.

[0510] The first frequency priority is not related to the LP-WUS. UEs which are not capable of LP-WUS applies the first frequency priority to all frequencies. The first frequency priority is not related to the LP-receiver. UEs which has no LP-receiver applies the first frequency priority to all frequencies.

[0511] The second frequency priority is related to the LP-WUS. UEs which are capable of LP-WUS applies the second frequency priority to frequences that its LP-receiver supports. UEs which are capable of LP-WUS applies the first frequency priority to frequences that its LP-receiver does not support. The first frequency priority is related to the LP-receiver. UEs with LP-receiver applies the second frequency priority to frequences that its LP-receiver supports. UEs with LP-receiver applies the first frequency priority to frequences that its LP-receiver does not support.

[0512] The network assign two frequency priorities, for example, the first frequency priority and the second frequency priority to a single frequency. The network informs UEs of the two frequency priorities per frequency, e.g. via system information.

[0513] UE determines whether to apply the first frequency priority or the second frequency priority to a frequency based on whether the frequency is LP-WUS frequency and whether the frequency is supported by its LP-receiver.

[0514] UE capable of LP-WUS applies the first frequency priority to a frequency based on the frequency not being supported by its LP-receiver and the frequency being LP-WUS frequency. UE capable of LP-WUS applies the second frequency priority to a frequency based on the frequency being supported by its LP-receiver and the frequency being LP-WUS frequency. UE capable of LP-WUS applies the second frequency priority to a frequency based on the frequency not being LP-WUS frequency.

[0515] LP-WUS capable UE applies the second frequency priority to a LP-WUS frequency, if its LP-receiver supports the LP-WUS frequency, for example, the LP-receiver can receive LP-WUS on the LP-WUS frequency.

[0516] LP-WUS capable UE applies the first frequency priority to a LP-WUS frequency, if its LP-receiver does not support the LP-WUS frequency, for example, the LP-receiver cannot receive LP-WUS on the LP-WUS frequency.

[0517] LP-WUS capable UE applies the second frequency priority to a non-LP-WUS frequency.

[0518] The network informs UEs of which frequency is LP-WUS frequency. The network informs UEs of which cells are the LP-WUS cell, for example, cells transmitting LP-WUS. The network informs UEs of frequency and cell ID of the LP-WUS cells. UE considers the frequency of LP-WUS cells as LP-WUS frequency. The LP-WUS frequency is a frequency where a cell transmitting LP-WUS is deployed. The network informs UEs of which frequency is non-LP-WUS frequency. The non-LP-WUS frequency is a frequency where no cell transmitting LP-WUS is deployed.

[0519] Table 5 shows an example of frequency priority based on a LP-receiver.

[0520] FrequencyLP-WUSFirst frequency prioritySecond frequency priorityAO05BO37CNo LP-WUS42DNo LP-WUS61

[0521] The LP-WUS is being transmitted on the frequency A and B (=LP-WUS frequency), while it is not transmitted on the frequency C and D (non-LP-WUS frequency). The network assigned a relatively high second frequency priority (5 and 7, respectively) but assigned a relatively low first frequency priority (0 and 3) to the LP-WUS frequencies.

[0522] UE#1 supports LP-WUS and its LP-receiver support frequency A but does not support frequency B.

[0523] UE#2 supports LP-WUS and its LP-receiver support frequency B but does not support frequency A.

[0524] UE#3 does not support LP-WUS.

[0525] UE#1 applies the second frequency priority, for example, 5, for frequency A, because its LP-receiver supports that frequency.

[0526] UE#1 applies the first frequency priority, for example, 3, for frequency B, because its LP-receiver does not support that frequency.

[0527] UE#1 applies the second frequency priority, for example, 2 and 1, for frequency C and D, because it supports LP-WUS and these frequencies are non-LP-WUS frequency.

[0528] UE#2 applies the first frequency priority, for example, 0, for frequency A, because its LP-receiver does not support that frequency.

[0529] UE#2 applies the second frequency priority, for example, 7, for frequency B, because its LP-receiver supports that frequency.

[0530] UE#2 applies the second frequency priority, for example, 2 and 1, for frequency C and D, because it supports LP-WUS and these frequencies are non-LP-WUS frequency.

[0531] UE#3 applies the first frequency priority, for example, 0, 3, 4, and 6, respectively) for frequency A, B, C, and D, because it does not support LP-WUS.

[0532] UE#1, #2, and #3 perform cell re-selection applying the frequency priority.

[0533] Embodiment #2

[0534] UE determines whether to consider a LP-WUS frequency to be the highest priority based on whether its LP-receiver supports the LP-WUS frequency.

[0535] UE considers a LP-WUS frequency to be the highest priority based on the LP-WUS frequency being supported by its LP-receiver. UE does not consider a LP-WUS frequency to be the highest priority based on the LP-WUS frequency not being supported by its LP-receiver. UE applies the frequency priority configured by network to a LP-WUS frequency based on the LP-WUS frequency not being supported by its LP-receiver. UE applies the frequency priority configured by network to the non-LP-WUS frequency.

[0536] If UE's LP-receiver supports a LP-WUS frequency, for example, if the LP-receiver can receive LP-WUS transmitted on the LP-WUS frequency, the UE considers the LP-WUS frequency to be the highest priority.

[0537] If UE's LP-receiver does not support a LP-WUS frequency, for example, if the LP-receiver cannot receive LP-WUS transmitted on the LP-WUS frequency, the UE does not consider the LP-WUS frequency to be the highest priority.

[0538] If UE's LP-receiver does not support a LP-WUS frequency, the UE considers the frequency priority of the LP-WUS frequency is the value configured for the LP-WUS frequency by the network.

[0539] Table 6 shows an example of frequency priority based on a LP-receiver.

[0540] FrequencyLP-WUSFrequency priorityConfigured by NWUE#1 considersUE#2 considersUE#3 considersAO33BO22CX (No LP-WUS)55

[0541] The LP-WUS is being transmitted on the frequency A and B (=LP-WUS frequency), but is not transmitted on the frequency C (non-LP-WUS frequency). The network assign the frequency priority '3', '2', and '5' to frequency A, B, and C, respectively.

[0542] UE#1 is capable of LP-WUS and its LP-receiver supports frequency A but does not support frequency B.

[0543] UE#2 is capable of LP-WUS and its LP-receiver supports frequency B but does not support frequency A.

[0544] UE#3 is not capable of LP-WUS.

[0545] UE#1 considers the frequency A to be the highest priority, since its LP-receiver supports frequency A.

[0546] UE#1 considers the priority of frequency B is '2', since its LP-receiver does not support frequency B.

[0547] UE#1 considers the priority of frequency C is '5', since it is non-LP-WUS frequency.

[0548] UE#2 considers the priority of frequency A is '3', since its LP-receiver does not support frequency A.

[0549] UE#2 considers the frequency B to be the highest priority, since its LP-receiver supports frequency B.

[0550] UE#2 considers the priority of frequency C is '5', since it is non-LP-WUS frequency.

[0551] UE#3 considers the priority of frequency A, B, and C are '3', '2', and '5', respectively, since it is not capable of LP-WUS.

[0552] FIG. 15 shows an example of a method for frequency priority handling for low power receiver.

[0553] In particular, FIG. 15 shows an example of a method performed by a wireless device in a wireless communication system.

[0554] In step S1501, the wireless device may receive two frequency priorities for a frequency.

[0555] For example, the first frequency priority is not related to LP-receiver and the second frequency priority is related to LP-receiver.

[0556] In step S1502, the wireless device may select the first frequency priority for the frequency based on the frequency not being supported by LP-receiver, and the wireless device may select the second frequency priority for the frequency based on the frequency being supported by LP-receiver.

[0557] In step S1503, the wireless device may perform cell re-selection applying the selected frequency priority.

[0558] FIG. 16 shows an example of a method for frequency priority handling for low power receiver.

[0559] In particular, FIG. 16 shows an example of a method performed by a wireless device in a wireless communication system.

[0560] In step S1601, the wireless device may receive information informing that LP-WUS is transmitted on a frequency.

[0561] In step S1602, the wireless device may consider the frequency to be the highest priority based on the frequency being supported by LP-receiver.

[0562] In step S1603, the wireless device may perform cell re-selection applying the frequency priority.

[0563] Some of the detailed steps shown in the examples of FIGS. 14, 15, and 16 may not be essential steps and may be omitted. In addition to the steps shown in FIGS. 14, 15, and 16, other steps may be added, and the order of the steps may vary. Some of the above steps may have their own technical meaning.

[0564] Hereinafter, an apparatus for cell re-selection based on a low-power receiver, 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.

[0565] For example, a wireless device may perform methods described above. The detailed description overlapping with the above-described contents could be simplified or omitted.

[0566] Referring to FIG. 5, a wireless device 100 may include a processor 102, a memory 104, and a transceiver 106.

[0567] 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 206.

[0568] 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.

[0569] The operations comprise: receiving information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency; determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; and performing a cell re-selection procedure based on the determined priority of the first frequency.

[0570] For example, the operations further comprise: receiving information related to a first priority and a second priority for the first frequency.

[0571] For example, the operations further comprise: selecting either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.

[0572] For example, the operations further comprise: based on that the first frequency is not supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the first priority.

[0573] For example, the operations further comprise: based on that the first frequency is supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the second priority.

[0574] For example, the operations further comprise: receiving information related to a first frequency priority list and information related to a second frequency priority list, wherein the information related to the first priority for the first frequency is included in the first frequency priority list, and wherein the information related to the second priority for the first frequency is included in the second frequency priority list.

[0575] For example, the operations further comprise: receiving information related to a first priority and a second priority for a second frequency, wherein the LP-WUS is not transmitted on the second frequency.

[0576] For example, the operations further comprise: considering a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS.

[0577] For example, the operations further comprise: determining the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device.

[0578] For example, the operations further comprise: determining the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.

[0579] For example, the operations further comprise: receiving information related to a frequency priority list, wherein the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies.

[0580] For example, the operations further comprise: pausing Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring. For example, the PDCCH monitoring is performed by at least one main receiver which does not monitor the LP-WUS, and the LP-WUS monitoring is performed by the low power-receiver.

[0581] For example, the operations further comprise: resuming the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring.

[0582] 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.

[0583] Hereinafter, a processor for a wireless device for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure, will be described.

[0584] The processor may be adapted to control the wireless device to perform operations.

[0585] The operations comprise: receiving information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency; determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; and performing a cell re-selection procedure based on the determined priority of the first frequency.

[0586] For example, the operations further comprise: receiving information related to a first priority and a second priority for the first frequency.

[0587] For example, the operations further comprise: selecting either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.

[0588] For example, the operations further comprise: based on that the first frequency is not supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the first priority.

[0589] For example, the operations further comprise: based on that the first frequency is supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the second priority.

[0590] For example, the operations further comprise: receiving information related to a first frequency priority list and information related to a second frequency priority list, wherein the information related to the first priority for the first frequency is included in the first frequency priority list, and wherein the information related to the second priority for the first frequency is included in the second frequency priority list.

[0591] For example, the operations further comprise: receiving information related to a first priority and a second priority for a second frequency, wherein the LP-WUS is not transmitted on the second frequency.

[0592] For example, the operations further comprise: considering a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS.

[0593] For example, the operations further comprise: determining the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device.

[0594] For example, the operations further comprise: determining the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.

[0595] For example, the operations further comprise: receiving information related to a frequency priority list, wherein the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies.

[0596] For example, the operations further comprise: pausing Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring. For example, the PDCCH monitoring is performed by at least one main receiver which does not monitor the LP-WUS, and the LP-WUS monitoring is performed by the low power-receiver.

[0597] For example, the operations further comprise: resuming the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring.

[0598] 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.

[0599] Hereinafter, a non-transitory computer-readable medium has stored thereon a plurality of instructions for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure, will be described.

[0600] 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.

[0601] 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.

[0602] The computer-readable medium may include a tangible and non-transitory computer-readable storage medium.

[0603] 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.

[0604] 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.

[0605] 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.

[0606] The operations comprise: receiving information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency; determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; and performing a cell re-selection procedure based on the determined priority of the first frequency.

[0607] For example, the operations further comprise: receiving information related to a first priority and a second priority for the first frequency.

[0608] For example, the operations further comprise: selecting either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.

[0609] For example, the operations further comprise: based on that the first frequency is not supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the first priority.

[0610] For example, the operations further comprise: based on that the first frequency is supported by the low power-receiver of the wireless device, considering the priority of the first frequency as the second priority.

[0611] For example, the operations further comprise: receiving information related to a first frequency priority list and information related to a second frequency priority list, wherein the information related to the first priority for the first frequency is included in the first frequency priority list, and wherein the information related to the second priority for the first frequency is included in the second frequency priority list.

[0612] For example, the operations further comprise: receiving information related to a first priority and a second priority for a second frequency, wherein the LP-WUS is not transmitted on the second frequency.

[0613] For example, the operations further comprise: considering a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS.

[0614] For example, the operations further comprise: determining the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device.

[0615] For example, the operations further comprise: determining the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.

[0616] For example, the operations further comprise: receiving information related to a frequency priority list, wherein the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies.

[0617] For example, the operations further comprise: pausing Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring. For example, the PDCCH monitoring is performed by at least one main receiver which does not monitor the LP-WUS, and the LP-WUS monitoring is performed by the low power-receiver.

[0618] For example, the operations further comprise: resuming the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring.

[0619] 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.

[0620] Hereinafter, a method performed by a base station (BS) for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure, will be described.

[0621] The method comprises: transmitting, by a base station to a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency. The wireless device determines a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not. The wireless device performs a cell re-selection procedure based on the determined priority of the first frequency.

[0622] Hereinafter, a base station (BS) for cell re-selection based on a low-power receiver, according to some embodiments of the present disclosure, will be described.

[0623] The BS may include a transceiver, a memory, and a processor operatively coupled to the transceiver and the memory.

[0624] The processor may be adapted to control the transceiver to transmit, to a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency. The wireless device determines a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not. The wireless device performs a cell re-selection procedure based on the determined priority of the first frequency.

[0625] The present disclosure can have various advantageous effects.

[0626] According to some embodiments of the present disclosure, the wireless device could efficiently perform a cell re-selection procedure based on a low-power receiver.

[0627] For example, the wireless device could efficiently handle frequency priority for a low power receiver.

[0628] For example, even though the LP-WUS specific priority is assigned for frequencies by the network, the potential overload problem on the LP-WUS frequency can be proactively prevented by allowing UE to apply the LP-WUS specific priority only to the frequencies that its LP-receiver supports.

[0629] For example, even though a frequency is indicated as a LP-WUS frequency by the network, the potential overload problem on the LP-WUS frequency can be proactively prevented by allowing UE to prioritize only the frequencies that its LP-receiver supports.

[0630] For example, LP-WUS can be received efficiently by adjusting the frequency priority based on the capability of the LP-receiver of the wireless device.

[0631] According to some embodiments of the present disclosure, the wireless communication system could provide an efficient solution for handling frequency priority for a low-power receiver.

[0632] 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.

[0633] 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

A method, comprising:receiving, by a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency;determining, by the wireless device, a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andperforming, by the wireless device, a cell re-selection procedure based on the determined priority of the first frequency.The method of claim 1, wherein the method further comprising:receiving, by the wireless device, information related to a first priority and a second priority for the first frequency.The method of claim 2, wherein the method further comprising:selecting, by the wireless device, either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.The method of claim 2, wherein the method further comprising:based on that the first frequency is not supported by the low power-receiver of the wireless device:- considering, by the wireless device, the priority of the first frequency as the first priority.The method of claim 2, wherein the method further comprising:based on that the first frequency is supported by the low power-receiver of the wireless device:- considering, by the wireless device, the priority of the first frequency as the second priority.The method of claim 2, wherein the method further comprising:receiving, by the wireless device, information related to a first frequency priority list and information related to a second frequency priority list,wherein the information related to the first priority for the first frequency is included in the first frequency priority list, andwherein the information related to the second priority for the first frequency is included in the second frequency priority list.The method of claim 1, wherein the method further comprising:receiving, by the wireless device, information related to a first priority and a second priority for a second frequency,wherein the LP-WUS is not transmitted on the second frequency.The method of claim 7, wherein the method further comprising:considering, by the wireless device, a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS.The method of claim 1, wherein the method further comprising:determining, by the wireless device, the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device.The method of claim 1, wherein the method further comprising:determining, by the wireless device, the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.The method of claim 10, wherein the method further comprising:receiving, by the wireless device, information related to a frequency priority list,wherein the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies.The method of claim 1, wherein the method further comprising:pausing, by the wireless device, Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring.The method of claim 12,wherein the PDCCH monitoring is performed by at least one main receiver which does not monitor the LP-WUS, andwherein the LP-WUS monitoring is performed by the low power-receiver.The method of claim 12, wherein the method further comprising:resuming, by the wireless device, the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring.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.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 information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency;determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andperforming a cell re-selection procedure based on the determined priority of the first frequency.The wireless device of claim 16, wherein the operations further comprising:receiving information related to a first priority and a second priority for the first frequency.The wireless device of claim 17, wherein the operations further comprising:selecting either the first priority or the second priority for the first frequency, based on whether the first frequency is supported by the low power-receiver or not.The wireless device of claim 17, wherein the operations further comprising:based on that the first frequency is not supported by the low power-receiver of the wireless device:- considering the priority of the first frequency as the first priority.The wireless device of claim 17, wherein the operations further comprising:based on that the first frequency is supported by the low power-receiver of the wireless device:- considering the priority of the first frequency as the second priority.The wireless device of claim 17, wherein the operations further comprising:receiving information related to a first frequency priority list and information related to a second frequency priority list,wherein the information related to the first priority for the first frequency is included in the first frequency priority list, andwherein the information related to the second priority for the first frequency is included in the second frequency priority list.The wireless device of claim 16, wherein the operations further comprising:receiving information related to a first priority and a second priority for a second frequency,wherein the LP-WUS is not transmitted on the second frequency.The wireless device of claim 22, wherein the operations further comprising:considering a priority of the second frequency as the second priority, based on that the wireless device supports the LP-WUS.The wireless device of claim 16, wherein the operations further comprising:determining the priority of the first frequency to be a highest priority, based on that the first frequency is supported by the low power-receiver of the wireless device.The wireless device of claim 16, wherein the operations further comprising:determining the priority of the first frequency to be a default priority, based on that the first frequency is not supported by the low power-receiver of the wireless device.The wireless device of claim 25, wherein the operations further comprising:receiving information related to a frequency priority list,wherein the frequency priority list includes one or more default frequency priorities for one or more carrier frequencies.The wireless device of claim 16, wherein the operations further comprising:pausing Physical Downlink Control Channel (PDCCH) monitoring, while the wireless device performs LP-WUS monitoring.The wireless device of claim 27,wherein the PDCCH monitoring is performed by at least one main receiver which does not monitor the LP-WUS, andwherein the LP-WUS monitoring is performed by the low power-receiver.The wireless device of claim 27, wherein the operations further comprising:resuming the PDCCH monitoring, upon receiving the LP-WUS from the LP-WUS monitoring.The wireless device of claim 16,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.A processor for a wireless device, wherein the processor is adapted to control the wireless device to perform operations comprising:receiving information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency;determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andperforming a cell re-selection procedure based on the determined priority of the first frequency.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 information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency;determining a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andperforming a cell re-selection procedure based on the determined priority of the first frequency.A method, the method comprising,transmitting, by a base station to a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency,wherein the wireless device determines a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andwherein the wireless device performs a cell re-selection procedure based on the determined priority of the first frequency.A base station, comprising:a transceiver;a memory; andat least one processor operatively coupled to the transceiver and the memory, and adapted to:transmit, to a wireless device, information informing that a low power-wake up signal (LP-WUS) is transmitted on a first frequency,wherein the wireless device determines a priority of the first frequency based on whether the first frequency is supported by a low power-receiver of the wireless device or not; andwherein the wireless device performs a cell re-selection procedure based on the determined priority of the first frequency.

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