WO2020166952A1

WO2020166952A1 - Method and apparatus for measurement report in wireless communication system

Info

Publication number: WO2020166952A1
Application number: PCT/KR2020/001942
Authority: WO
Inventors: Jongwoo HONG; Sunghoon Jung; Taehun Kim; Sangwon Kim
Original assignee: Lg Electronics Inc.
Priority date: 2019-02-14
Filing date: 2020-02-12
Publication date: 2020-08-20

Abstract

The present disclosure relates to method and apparatus for measurement report wireless communications. According to an embodiment of the present disclosure, a method performed by a wireless device in a wireless communication system comprises: generating a measurement report comprising measurement results on one or more cells; constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and transmitting the RRC message during an RRC connection procedure.

Description

METHOD AND APPARATUS FOR MEASUREMENT REPORT IN WIRELESS COMMUNICATION SYSTEM

The present disclosure relates to method and apparatus for measurement report wireless communications.

3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible.

In a wireless communication system, a UE may detect and measure one or more cells, and report the measurement results to a network. For example, the UE may receive a measurement configuration from a network, and may perform a measurement on the one or more cells based on the measurement configuration. There might be various situations in which the UE is required to transmit a measurement report to a network. For example, the UE may transmit the measurement report to the network so that the network can configure multi-cell communication (e.g., CA/DC) for the UE.

An aspect of the present disclosure is to provide method and apparatus for measurement report in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for transmitting a measurement report during an RRC connection procedure in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for transmitting a measurement report to obtain a configuration for multi-cell communication in a wireless communication system.

Another aspect of the present disclosure is to provide method and apparatus for fast CA/DC setup in a wireless communication system.

According to an embodiment of the present disclosure, a method performed by a wireless device in a wireless communication system comprises: generating a measurement report comprising measurement results on one or more cells; constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and transmitting the RRC message during an RRC connection procedure.

According to an embodiment of the present disclosure, a wireless device in a wireless communication system comprises: a transceiver; a memory; and at least one processor operatively coupled to the transceiver and the memory, and configured to: generate a measurement report comprising measurement results on one or more cells, construct a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available, and control the transceiver to transmit the RRC message during an RRC connection procedure.

According to an embodiment of the present disclosure, a processor for a wireless device in a wireless communication system is configured to control the wireless device to perform operations comprising: generating a measurement report comprising measurement results on one or more cells; constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and transmitting the RRC message during an RRC connection procedure.

According to an embodiment of the present disclosure, a computer-readable medium having recorded thereon a program for performing each step of a method on a computer is provided. The method comprises: generating a measurement report comprising measurement results on one or more cells; constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and transmitting the RRC message during an RRC connection procedure.

The present disclosure can have various advantageous effects.

For example, a wireless device may transmit a part of a measurement report and information informing that the other part of the measurement report is available to a network during an RRC connection procedure so that a fast CA/DC configuration for the wireless device can be realized.

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.

FIG. 1 shows examples of 5G usage scenarios to which the technical features of the present disclosure can be applied.

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 3 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 4 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 7 illustrates a frame structure in a 3GPP based wireless communication system.

FIG. 8 illustrates a data flow example in the 3GPP NR system.

FIG. 9 shows an example of a dual connectivity (DC) architecture to which technical features of the present disclosure can be applied.

FIG. 10 shows an example of 4-step random access procedure to which technical features of the present disclosure can be applied.

FIG. 11 shows an example of 2-step random access procedure to which technical features of the present disclosure can be applied.

FIG. 12 shows an example of possible RRC states in a wireless communication system to which technical features of the present disclosure can be applied.

FIG. 13 shows an example of RRC connection establishment procedure in a case RRC connection establishment is successful to which technical features of the present disclosure can be applied.

FIG. 14 shows an example of a RRC connection resume procedure in a case RRC connection resume is successful to which technical features of the present disclosure can be applied.

FIG. 15 shows an example of reporting additional measurement for fast cell setup for multi-cell communication to which technical features of the present disclosure can be applied.

FIG. 16 shows an example of RRC connection establishment procedure to transport additional measurement results to which technical features of the present disclosure can be applied.

FIG. 17 shows an example of a method for fast DC/CA cell setup according to an embodiment of the present disclosure.

FIG. 18 shows an example of a method for transmitting a measurement report for a configuration of multi-cell communication according to an embodiment of the present disclosure.

FIG. 19 shows a UE to implement an embodiment of the present disclosure.

FIG. 20 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 21 shows an example of an AI device to which the technical features of the present disclosure can be applied.

FIG. 22 shows an example of an AI system to which the technical features of the present disclosure can be applied.

The technical features described below may be used by a communication standard by the 3rd generation partnership project (3GPP) standardization organization, a communication standard by the institute of electrical and electronics engineers (IEEE), etc. For example, the communication standards by the 3GPP standardization organization include long-term evolution (LTE) and/or evolution of LTE systems. The evolution of LTE systems includes LTE-advanced (LTE-A), LTE-A Pro, and/or 5G new radio (NR). The communication standard by the IEEE standardization organization includes a wireless local area network (WLAN) system such as IEEE 802.11a/b/g/n/ac/ax. The above system uses various multiple access technologies such as orthogonal frequency division multiple access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA) for downlink (DL) and/or uplink (UL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA may be used for DL and/or UL.

In the present disclosure, “A or B” may mean “only A”, “only B”, or “both A and B”. In other words, “A or B” in the present disclosure may be interpreted as “A and/or B”. For example, “A, B or C” in the present disclosure may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”.

In the present disclosure, slash (/) or comma (,) may mean “and/or". For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”.

In the present disclosure, “at least one of A and B” may mean “only A”, “only B” or “both A and B”. In addition, the expression “at least one of A or B” or “at least one of A and/or B” in the present disclosure may be interpreted as same as “at least one of A and B”.

In addition, in the present disclosure, “at least one of A, B and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. In addition, “at least one of A, B or C” or “at least one of A, B and/or C” may mean “at least one of A, B and C”.

Also, parentheses used in the present disclosure may mean “for example”. In detail, when it is shown as “control information (PDCCH)”, "PDCCH" may be proposed as an example of “control information”. In other words, “control information” in the present disclosure is not limited to “PDCCH”, and "PDDCH" may be proposed as an example of “control information”. In addition, even when shown as “control information (i.e., PDCCH)”, “PDCCH” may be proposed as an example of “control information”.

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

The terms used throughout the disclosure can be defined as the followings:

"Multi-cell communication" refers to a scheme in which a wireless device (e.g., UE) performs a communication with a plurality of cells. The plurality of cells may be located in the same RAN node, or may be located in different RAN nodes. Examples of the multi-cell communication may comprise a carrier aggregation (CA) and/or a dual-connectivity (DC), which will be further described below. Therefore, configuration for the multi-cell communication may comprise at least one of a CA configuration, or a DC configuration.

"Blind configuration of a cell" refers to a scheme for providing cell configuration for the cell without performing a cell detection and measurement by the UE. Instead, the cell detection and the measurement may be performed by the UE after the blind configuration signalling. Example benefits of the blind configuration may comprise reducing signalling overhead and delay.

Throughout the disclosure, the terms 'radio access network (RAN) node', 'base station', 'eNB', 'gNB' and 'cell' may be used interchangeably. Further, a UE may be a kind of a wireless device, and throughout the disclosure, the terms 'UE' and 'wireless device' may be used interchangeably.

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.

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.

Referring to FIG. 1, the three main requirements areas of 5G include (1) enhanced mobile broadband (eMBB) domain, (2) massive machine type communication (mMTC) area, and (3) ultra-reliable and low latency communications (URLLC) area. Some use cases may require multiple areas for optimization and, other use cases may only focus on only one key performance indicator (KPI). 5G is to support these various use cases in a flexible and reliable way.

eMBB focuses on across-the-board enhancements to the data rate, latency, user density, capacity and coverage of mobile broadband access. The eMBB aims ~10 Gbps of throughput. eMBB far surpasses basic mobile Internet access and covers rich interactive work and media and entertainment applications in cloud and/or augmented reality. Data is one of the key drivers of 5G and may not be able to see dedicated voice services for the first time in the 5G era. In 5G, the voice is expected to be processed as an application simply using the data connection provided by the communication system. The main reason for the increased volume of traffic is an increase in the size of the content and an increase in the number of applications requiring high data rates. Streaming services (audio and video), interactive video and mobile Internet connectivity will become more common as more devices connect to the Internet. Many of these applications require always-on connectivity to push real-time information and notifications to the user. Cloud storage and applications are growing rapidly in mobile communication platforms, which can be applied to both work and entertainment. Cloud storage is a special use case that drives growth of uplink data rate. 5G is also used for remote tasks on the cloud and requires much lower end-to-end delay to maintain a good user experience when the tactile interface is used. In entertainment, for example, cloud games and video streaming are another key factor that increases the demand for mobile broadband capabilities. Entertainment is essential in smartphones and tablets anywhere, including high mobility environments such as trains, cars and airplanes. Another use case is augmented reality and information retrieval for entertainment. Here, augmented reality requires very low latency and instantaneous data amount.

mMTC is designed to enable communication between devices that are low-cost, massive in number and battery-driven, intended to support applications such as smart metering, logistics, and field and body sensors. mMTC aims ~10 years on battery and/or ~1 million devices/km2. mMTC allows seamless integration of embedded sensors in all areas and is one of the most widely used 5G applications. Potentially by 2020, internet-of-things (IoT) devices are expected to reach 20.4 billion. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture and security infrastructures.

URLLC will make it possible for devices and machines to communicate with ultra-reliability, very low latency and high availability, making it ideal for vehicular communication, industrial control, factory automation, remote surgery, smart grids and public safety applications.　URLLC aims ~1ms of latency. URLLC includes new services that will change the industry through links with ultra-reliability / low latency, such as remote control of key infrastructure and self-driving vehicles. The level of reliability and latency is essential for smart grid control, industrial automation, robotics, drones control and coordination.

Next, a plurality of use cases included in the triangle of FIG. 1 will be described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) as a means of delivering streams rated from hundreds of megabits per second to gigabits per second. This high speed can be required to deliver TVs with resolutions of 4K or more (6K, 8K and above) as well as virtual reality (VR) and augmented reality (AR). VR and AR applications include mostly immersive sporting events. Certain applications may require special network settings. For example, in the case of a VR game, a game company may need to integrate a core server with an edge network server of a network operator to minimize delay.

Automotive is expected to become an important new driver for 5G, with many use cases for mobile communications to vehicles. For example, entertainment for passengers demands high capacity and high mobile broadband at the same time. This is because future users will continue to expect high-quality connections regardless of their location and speed. Another use case in the automotive sector is an augmented reality dashboard. The driver can identify an object in the dark on top of what is being viewed through the front window through the augmented reality dashboard. The augmented reality dashboard displays information that will inform the driver about the object's distance and movement. In the future, the wireless module enables communication between vehicles, information exchange between the vehicle and the supporting infrastructure, and information exchange between the vehicle and other connected devices (e.g. devices accompanied by a pedestrian). The safety system allows the driver to guide the alternative course of action so that he can drive more safely, thereby reducing the risk of accidents. The next step will be a remotely controlled vehicle or self-driving vehicle. This requires a very reliable and very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, a self-driving vehicle will perform all driving activities, and the driver will focus only on traffic that the vehicle itself cannot identify. The technical requirements of self-driving vehicles require ultra-low latency and high-speed reliability to increase traffic safety to a level not achievable by humans.

Smart cities and smart homes, which are referred to as smart societies, will be embedded in high density wireless sensor networks. The distributed network of intelligent sensors will identify conditions for cost and energy-efficient maintenance of a city or house. A similar setting can be performed for each home. Temperature sensors, windows and heating controllers, burglar alarms and appliances are all wirelessly connected. Many of these sensors typically require low data rate, low power and low cost. However, for example, real-time high-definition (HD) video may be required for certain types of devices for monitoring.

The consumption and distribution of energy, including heat or gas, is highly dispersed, requiring automated control of distributed sensor networks. The smart grid interconnects these sensors using digital information and communication technologies to collect and act on information. This information can include supplier and consumer behavior, allowing the smart grid to improve the distribution of fuel, such as electricity, in terms of efficiency, reliability, economy, production sustainability, and automated methods. The smart grid can be viewed as another sensor network with low latency.

The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine to provide clinical care in remote locations. This can help to reduce barriers to distance and improve access to health services that are not continuously available in distant rural areas. It is also used to save lives in critical care and emergency situations. Mobile communication based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring costs are high for installation and maintenance. Thus, the possibility of replacing a cable with a wireless link that can be reconfigured is an attractive opportunity in many industries. However, achieving this requires that wireless connections operate with similar delay, reliability, and capacity as cables and that their management is simplified. Low latency and very low error probabilities are new requirements that need to be connected to 5G.

Logistics and freight tracking are important use cases of mobile communications that enable tracking of inventory and packages anywhere using location based information systems. Use cases of logistics and freight tracking typically require low data rates, but require a large range and reliable location information.

NR supports multiple numerology (or, subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, wide area in traditional cellular bands may be supported. When the SCS is 30 kHz/60 kHz, dense-urban, lower latency and wider carrier bandwidth may be supported. When the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

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 1 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).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	450MHz - 6000MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

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 2 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).

Frequency Range designation	Corresponding frequency range	Subcarrier Spacing
FR1	410MHz - 7125MHz	15, 30, 60kHz
FR2	24250MHz - 52600MHz	60, 120, 240kHz

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.Referring to FIG. 2, the wireless communication system may include a first device 210 and a second device 220.

The first device 210 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an AR device, a VR device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

The second device 220 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, a 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 fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

For example, the UE may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate personal computer (PC), a tablet PC, an ultrabook, a wearable device (e.g. a smartwatch, a smart glass, a head mounted display (HMD)) . For example, the HMD may be a display device worn on the head. For example, the HMD may be used to implement AR, VR and/or MR.

For example, the drone may be a flying object that is flying by a radio control signal without a person boarding it. For example, the VR device may include a device that implements an object or background in the virtual world. For example, the AR device may include a device that implements connection of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the MR device may include a device that implements fusion of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the hologram device may include a device that implements a 360-degree stereoscopic image by recording and playing stereoscopic information by utilizing a phenomenon of interference of light generated by the two laser lights meeting with each other, called holography. For example, the public safety device may include a video relay device or a video device that can be worn by the user's body. For example, the MTC device and the IoT device may be a device that do not require direct human intervention or manipulation. For example, the MTC device and the IoT device may include a smart meter, a vending machine, a thermometer, a smart bulb, a door lock and/or various sensors. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, handling, or preventing a disease. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, or correcting an injury or disorder. For example, the medical device may be a device used for the purpose of inspecting, replacing or modifying a structure or function. For example, the medical device may be a device used for the purpose of controlling pregnancy. For example, the medical device may include a treatment device, a surgical device, an (in vitro) diagnostic device, a hearing aid and/or a procedural device, etc. For example, a security device may be a device installed to prevent the risk that may occur and to maintain safety. For example, the security device may include a camera, a closed-circuit TV (CCTV), a recorder, or a black box. For example, the fin-tech device may be a device capable of providing financial services such as mobile payment. For example, the fin-tech device may include a payment device or a point of sales (POS). For example, the climate/environmental device may include a device for monitoring or predicting the climate/environment.

The first device 210 may include at least one or more processors, such as a processor 211, at least one memory, such as a memory 212, and at least one transceiver, such as a transceiver 213. The processor 211 may perform the functions, procedures, and/or methods of the first device described throughout the disclosure. The processor 211 may perform one or more protocols. For example, the processor 211 may perform one or more layers of the air interface protocol. The memory 212 is connected to the processor 211 and may store various types of information and/or instructions. The transceiver 213 is connected to the processor 211 and may be controlled by the processor 211 to transmit and receive wireless signals.

The second device 220 may include at least one or more processors, such as a processor 221, at least one memory, such as a memory 222, and at least one transceiver, such as a transceiver 223. The processor 221 may perform the functions, procedures, and/or methods of the second device 220 described throughout the disclosure. The processor 221 may perform one or more protocols. For example, the processor 221 may perform one or more layers of the air interface protocol. The memory 222 is connected to the processor 221 and may store various types of information and/or instructions. The transceiver 223 is connected to the processor 221 and may be controlled by the processor 221 to transmit and receive wireless signals.

The

memory

212, 222 may be connected internally or externally to the

processor

211, 212, or may be connected to other processors via a variety of technologies such as wired or wireless connections.

The first device 210 and/or the second device 220 may have more than one antenna. For example, antenna 214 and/or antenna 224 may be configured to transmit and receive wireless signals.

Specifically, FIG. 3 shows a system architecture based on an evolved-UMTS terrestrial radio access network (E-UTRAN). The aforementioned LTE is a part of an evolved-UTMS (e-UMTS) using the E-UTRAN.

Referring to FIG. 3, the wireless communication system includes one or more user equipment (UE) 310, an E-UTRAN and an evolved packet core (EPC). The UE 310 refers to a communication equipment carried by a user. The UE 310 may be fixed or mobile. The UE 310 may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, etc.

The E-UTRAN consists of one or more evolved NodeB (eNB) 320. The eNB 320 provides the E-UTRA user plane and control plane protocol terminations towards the UE 10. The eNB 320 is generally a fixed station that communicates with the UE 310. The eNB 320 hosts the functions, such as inter-cell radio resource management (RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provision, dynamic resource allocation (scheduler), etc. The eNB 320 may be referred to as another terminology, such as a base station (BS), a base transceiver system (BTS), an access point (AP), etc.

A downlink (DL) denotes communication from the eNB 320 to the UE 310. An uplink (UL) denotes communication from the UE 310 to the eNB 320. A sidelink (SL) denotes communication between the UEs 310. In the DL, a transmitter may be a part of the eNB 320, and a receiver may be a part of the UE 310. In the UL, the transmitter may be a part of the UE 310, and the receiver may be a part of the eNB 320. In the SL, the transmitter and receiver may be a part of the UE 310.

The EPC includes a mobility management entity (MME), a serving gateway (S-GW) and a packet data network (PDN) gateway (P-GW). The MME hosts the functions, such as non-access stratum (NAS) security, idle state mobility handling, evolved packet system (EPS) bearer control, etc. The S-GW hosts the functions, such as mobility anchoring, etc. The S-GW is a gateway having an E-UTRAN as an endpoint. For convenience, MME/S-GW 330 will be referred to herein simply as a “gateway,” but it is understood that this entity includes both the MME and S-GW. The P-GW hosts the functions, such as UE Internet protocol (IP) address allocation, packet filtering, etc. The P-GW is a gateway having a PDN as an endpoint. The P-GW is connected to an external network.

The UE 310 is connected to the eNB 320 by means of the Uu interface. The UEs 310 are interconnected with each other by means of the PC5 interface. The eNBs 320 are interconnected with each other by means of the X2 interface. The eNBs 320 are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs / S-GWs and eNBs.

Specifically, FIG. 4 shows a system architecture based on a 5G NR. The entity used in the 5G NR (hereinafter, simply referred to as "NR") may absorb some or all of the functions of the entities introduced in FIG. 3 (e.g. eNB, MME, S-GW). The entity used in the NR may be identified by the name “NG” for distinction from the LTE/LTE-A.

Referring to FIG. 4, the wireless communication system includes one or more UE 410, a next-generation RAN (NG-RAN) and a 5th generation core network (5GC). The NG-RAN consists of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the eNB 320 shown in FIG. 3. The NG-RAN node consists of at least one gNB 421 and/or at least one ng-eNB 422. The gNB 421 provides NR user plane and control plane protocol terminations towards the UE 410. The ng-eNB 422 provides E-UTRA user plane and control plane protocol terminations towards the UE 410.

The 5GC includes an access and mobility management function (AMF), a user plane function (UPF) and a session management function (SMF). The AMF hosts the functions, such as NAS security, idle state mobility handling, etc. The AMF is an entity including the functions of the conventional MME. The UPF hosts the functions, such as mobility anchoring, protocol data unit (PDU) handling. The UPF an entity including the functions of the conventional S-GW. The SMF hosts the functions, such as UE IP address allocation, PDU session control.

The gNBs 421 and ng-eNBs 422 are interconnected with each other by means of the Xn interface. The gNBs 421 and ng-eNBs 422 are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF by means of the NG-C interface and to the UPF by means of the NG-U interface.

A protocol structure between network entities described above is described. On the system of FIG. 3 and/or FIG. 4, layers of a radio interface protocol between the UE and the network (e.g. NG-RAN and/or E-UTRAN) may be classified into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied. FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

The user/control plane protocol stacks shown in FIG. 5 and FIG. 6 are used in NR. However, user/control plane protocol stacks shown in FIG. 5 and FIG. 6 may be used in LTE/LTE-A without loss of generality, by replacing gNB/AMF with eNB/MME.

Referring to FIG. 5 and FIG. 6, a physical (PHY) layer belonging to L1. The PHY layer offers information transfer services to media access control (MAC) sublayer and higher layers. The PHY layer offers to the MAC sublayer transport channels. Data between the MAC sublayer and the PHY layer is transferred via the transport channels. Between different PHY layers, i.e., between a PHY layer of a transmission side and a PHY layer of a reception side, data is transferred via the physical channels.

The MAC sublayer belongs to L2. The main services and functions of the MAC sublayer include mapping between logical channels and transport channels, multiplexing/de-multiplexing of MAC service data units (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), priority handling between UEs by means of dynamic scheduling, priority handling between logical channels of one UE by means of logical channel prioritization (LCP), etc. The MAC sublayer offers to the radio link control (RLC) sublayer logical channels.

The RLC sublayer belong to L2. The RLC sublayer supports three transmission modes, i.e. transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM), in order to guarantee various quality of services (QoS) required by radio bearers. The main services and functions of the RLC sublayer depend on the transmission mode. For example, the RLC sublayer provides transfer of upper layer PDUs for all three modes, but provides error correction through ARQ for AM only. In LTE/LTE-A, the RLC sublayer provides concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer) and re-segmentation of RLC data PDUs (only for AM data transfer). In NR, the RLC sublayer provides segmentation (only for AM and UM) and re-segmentation (only for AM) of RLC SDUs and reassembly of SDU (only for AM and UM). That is, the NR does not support concatenation of RLC SDUs. The RLC sublayer offers to the packet data convergence protocol (PDCP) sublayer RLC channels.

The PDCP sublayer belong to L2. The main services and functions of the PDCP sublayer for the user plane include header compression and decompression, transfer of user data, duplicate detection, PDCP PDU routing, retransmission of PDCP SDUs, ciphering and deciphering, etc. The main services and functions of the PDCP sublayer for the control plane include ciphering and integrity protection, transfer of control plane data, etc.

The service data adaptation protocol (SDAP) sublayer belong to L2. The SDAP sublayer is only defined in the user plane. The SDAP sublayer is only defined for NR. The main services and functions of SDAP include, mapping between a QoS flow and a data radio bearer (DRB), and marking QoS flow ID (QFI) in both DL and UL packets. The SDAP sublayer offers to 5GC QoS flows.

A radio resource control (RRC) layer belongs to L3. The RRC layer is only defined in the control plane. The RRC layer controls radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS. The main services and functions of the RRC layer include broadcast of system information related to AS and NAS, paging, establishment, maintenance and release of an RRC connection between the UE and the network, security functions including key management, establishment, configuration, maintenance and release of radio bearers, mobility functions, QoS management functions, UE measurement reporting and control of the reporting, NAS message transfer to/from NAS from/to UE.

In other words, the RRC layer controls logical channels, transport channels, and physical channels in relation to the configuration, reconfiguration, and release of radio bearers. A radio bearer refers to a logical path provided by L1 (PHY layer) and L2 (MAC/RLC/PDCP/SDAP sublayer) for data transmission between a UE and a network. Setting the radio bearer means defining the characteristics of the radio protocol layer and the channel for providing a specific service, and setting each specific parameter and operation method. Radio bearer may be divided into signaling RB (SRB) and data RB (DRB). The SRB is used as a path for transmitting RRC messages in the control plane, and the DRB is used as a path for transmitting user data in the user plane.

An RRC state indicates whether an RRC layer of the UE is logically connected to an RRC layer of the E-UTRAN. In LTE/LTE-A, when the RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected state (RRC_CONNECTED). Otherwise, the UE is in the RRC idle state (RRC_IDLE). In NR, the RRC inactive state (RRC_INACTIVE) is additionally introduced. RRC_INACTIVE may be used for various purposes. For example, the massive machine type communications (MMTC) UEs can be efficiently managed in RRC_INACTIVE. When a specific condition is satisfied, transition is made from one of the above three states to the other.

A predetermined operation may be performed according to the RRC state. In RRC_IDLE, public land mobile network (PLMN) selection, broadcast of system information (SI), cell re-selection mobility, core network (CN) paging and discontinuous reception (DRX) configured by NAS may be performed. The UE shall have been allocated an identifier (ID) which uniquely identifies the UE in a tracking area. No RRC context stored in the BS.

In RRC_CONNECTED, the UE has an RRC connection with the network (i.e. E-UTRAN/NG-RAN). Network-CN connection (both C/U-planes) is also established for UE. The UE AS context is stored in the network and the UE. The RAN knows the cell which the UE belongs to. The network can transmit and/or receive data to/from UE. Network controlled mobility including measurement is also performed.

Most of operations performed in RRC_IDLE may be performed in RRC_INACTIVE. But, instead of CN paging in RRC_IDLE, RAN paging is performed in RRC_INACTIVE. In other words, in RRC_IDLE, paging for mobile terminated (MT) data is initiated by core network and paging area is managed by core network. In RRC_INACTIVE, paging is initiated by NG-RAN, and RAN-based notification area (RNA) is managed by NG-RAN. Further, instead of DRX for CN paging configured by NAS in RRC_IDLE, DRX for RAN paging is configured by NG-RAN in RRC_INACTIVE. Meanwhile, in RRC_INACTIVE, 5GC-NG-RAN connection (both C/U-planes) is established for UE, and the UE AS context is stored in NG-RAN and the UE. NG-RAN knows the RNA which the UE belongs to.

NAS layer is located at the top of the RRC layer. The NAS control protocol performs the functions, such as authentication, mobility management, security control.

The physical channels may be modulated according to OFDM processing and utilizes time and frequency as radio resources. The physical channels consist of a plurality of orthogonal frequency division multiplexing (OFDM) symbols in time domain and a plurality of subcarriers in frequency domain. One subframe consists of a plurality of OFDM symbols in the time domain. A resource block is a resource allocation unit, and consists of a plurality of OFDM symbols and a plurality of subcarriers. In addition, each subframe may use specific subcarriers of specific OFDM symbols (e.g. first OFDM symbol) of the corresponding subframe for a physical downlink control channel (PDCCH), i.e. L1/L2 control channel. A transmission time interval (TTI) is a basic unit of time used by a scheduler for resource allocation. The TTI may be defined in units of one or a plurality of slots, or may be defined in units of mini-slots.

The transport channels are classified according to how and with what characteristics data are transferred over the radio interface. DL transport channels include a broadcast channel (BCH) used for transmitting system information, a downlink shared channel (DL-SCH) used for transmitting user traffic or control signals, and a paging channel (PCH) used for paging a UE. UL transport channels include an uplink shared channel (UL-SCH) for transmitting user traffic or control signals and a random access channel (RACH) normally used for initial access to a cell.

Different kinds of data transfer services are offered by MAC sublayer. 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. The control channels include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH) and a dedicated control channel (DCCH). The BCCH is a DL channel for broadcasting system control information. The PCCH is DL channel that transfers paging information, system information change notifications. The CCCH is a channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network. The DCCH is a point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. This channel is used by UEs having an RRC connection.

Traffic channels are used for the transfer of user plane information only. The traffic channels include a dedicated traffic channel (DTCH). The DTCH is a point-to-point channel, dedicated to one UE, for the transfer of user information. The DTCH can exist in both UL and DL.

Regarding mapping between the logical channels and transport channels, in DL, BCCH can be mapped to BCH, BCCH can be mapped to DL-SCH, PCCH can be mapped to PCH, CCCH can be mapped to DL-SCH, DCCH can be mapped to DL-SCH, and DTCH can be mapped to DL-SCH. In UL, CCCH can be mapped to UL-SCH, DCCH can be mapped to UL- SCH, and DTCH can be mapped to UL-SCH.

The frame structure illustrated in FIG. 7 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, an OFDM numerology (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be differently configured between a plurality of cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for the cell, an (absolute time) duration of a time resource (e.g. a subframe, a slot, or a TTI) including the same number of symbols may be different among the aggregated cells. Herein, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).

Referring to FIG. 7, downlink and uplink transmissions are organized into frames. Each frame has Tf = 10 ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5 ms duration. Each half-frame consists of 5 subframes, where the duration Tsf per subframe is 1 ms. Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols. The numerology is based on exponentially scalable subcarrier spacing △f = 2u*15 kHz. The following table shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per for the normal CP, according to the subcarrier spacing △f = 2u*15 kHz.

U	Nslotsymb	Nframe,uslot	Nsubframe,uslot
0	14	10	1
1	14	20	2
2	14	40	4
3	14	80	8
4	14	160	16

The following table shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per for the extended CP, according to the subcarrier spacing △f = 2u*15 kHz.

u	Nslotsymb	Nframe,uslot	Nsubframe,uslot
2	12	40	4

A slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain. For each numerology (e.g. subcarrier spacing) and carrier, a resource grid of Nsize,ugrid,x*NRBsc subcarriers and Nsubframe,usymb OFDM symbols is defined, starting at common resource block (CRB) Nstart,ugrid indicated by higher-layer signaling (e.g. radio resource control (RRC) signaling), where Nsize,ugrid,x is the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink. NRBsc is the number of subcarriers per RB. In the 3GPP based wireless communication system, NRBsc is 12 generally. There is one resource grid for a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL). The carrier bandwidth Nsize,ugrid for subcarrier spacing configuration u is given by the higher-layer parameter (e.g. RRC parameter). Each element in the resource grid for the antenna port p and the subcarrier spacing configuration u is referred to as a resource element (RE) and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing a symbol location relative to a reference point in the time domain. In the 3GPP based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. In the 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with 'point A' which serves as a common reference point for resource block grids. In the 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and numbered from 0 to NsizeBWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRB in the bandwidth part i and the common resource block nCRB is as follows: nPRB = nCRB + NsizeBWP,i, where NsizeBWP,i is the common resource block where bandwidth part starts relative to CRB 0. The BWP includes a plurality of consecutive RBs. A carrier may include a maximum of N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.

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" of 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 (BW) 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 downlink (DL) component carrier (CC) and a uplink (UL) CC. The cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources. Since DL coverage, which is a range within which the node is capable of transmitting a valid signal, and UL coverage, which is a range within which the node is capable of receiving the valid signal from the UE, depends upon a carrier carrying the signal, the coverage of the node may be associated with coverage of the "cell" of radio resources used by the node. Accordingly, the term "cell" may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times.

In carrier aggregation (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 radio resource control (RRC) connection with the network. At RRC connection establishment/re-establishment/handover, one serving cell provides the non-access stratum (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. The configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells. For dual connectivity operation, the term Special Cell (SpCell) refers to the PCell of the master cell group (MCG) or the 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, comprising of the SpCell (PCell) and optionally one or more SCells. The SCG is the subset of serving cells associated with a secondary node, comprising of the PSCell and zero or more SCells, for a UE configured with dual connectivity (DC). For a UE in RRC_CONNECTED not configured with CA/DC there is only one serving cell comprising 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 comprising of the SpCell(s) and all SCells. In DC, two MAC entities are configured in a UE: one for the MCG and one for the SCG.

FIG. 8 illustrates a data flow example in the 3GPP NR system.

In FIG. 8, “RB” denotes a radio bearer, and “H” denotes a header. Radio bearers are categorized into two groups: data radio bearers (DRB) for user plane data and signalling radio bearers (SRB) for control plane data. The MAC PDU is transmitted/received using radio resources through the PHY layer to/from an external device. The MAC PDU arrives to the PHY layer in the form of a transport block.

In the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to their physical channels 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.

Data unit(s) (e.g. PDCP SDU, PDCP PDU, RLC SDU, RLC PDU, RLC SDU, MAC SDU, MAC CE, MAC PDU) in the present disclosure is(are) transmitted/received on a physical channel (e.g. PDSCH, PUSCH) based on resource allocation (e.g. UL grant, DL assignment). In the present disclosure, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. The resource allocation includes time domain resource allocation and frequency domain resource allocation. In the present disclosure, an uplink grant is either received by the UE dynamically on PDCCH, in a Random Access Response, or configured to the UE semi-persistently by RRC. In the present disclosure, downlink assignment is either received by the UE dynamically on the PDCCH, or configured to the UE semi-persistently by RRC signalling from the BS.

FIG. 9 shows an example of a dual connectivity (DC) architecture to which technical features of the present disclosure can be applied. In FIG. 9 and throughout the disclosure, 'radio access network (RAN) node' refers to a network entity to which a wireless device can access through a radio channel. Examples of the RAN node may comprise gNB, eNB, base station, and/or cell.

Referring to FIG. 9, MN 911, SN 921, and a UE 930 communicating with both the MN 911 and the SN 921 are illustrated. As illustrated in FIG. 9, DC refers to a scheme in which a UE (e.g., UE 930) utilizes radio resources provided by at least two RAN nodes comprising a MN (e.g., MN 911) and one or more SNs (e.g., SN 921). In other words, DC refers to a scheme in which a UE is connected to both the MN and the one or more SNs, and communicates with both the MN and the one or more SNs. Since the MN and the SN may be in different sites, a backhaul between the MN and the SN may be construed as non-ideal backhaul (e.g., relatively large delay between nodes).

MN (e.g., MN 911) refers to a main RAN node providing services to a UE in DC situation. SN (e.g., SN 921) refers to an additional RAN node providing services to the UE with the MN in the DC situation. If one RAN node provides services to a UE, the RAN node may be a MN. SN can exist if MN exists.

For example, the MN may be associated with macro cell whose coverage is relatively larger than that of a small cell. However, the MN does not have to be associated with macro cell - that is, the MN may be associated with a small cell. Throughout the disclosure, a RAN node that is associated with a macro cell may be referred to as 'macro cell node'. MN may comprise macro cell node.

For example, the SN may be associated with small cell (e.g., micro cell, pico cell, femto cell) whose coverage is relatively smaller than that of a macro cell. However, the SN does not have to be associated with small cell - that is, the SN may be associated with a macro cell. Throughout the disclosure, a RAN node that is associated with a small cell may be referred to as 'small cell node'. SN may comprise small cell node.

The MN may be associated with a master cell group (MCG). MCG may refer to a group of serving cells associated with the MN, and may comprise a primary cell (PCell) and optionally one or more secondary cells (SCells). User plane data and/or control plane data may be transported from a core network to the MN through a MCG bearer. MCG bearer refers to a bearer whose radio protocols are located in the MN to use MN resources. As shown in FIG. 9, the radio protocols of the MCG bearer may comprise PDCP, RLC, MAC and/or PHY.

The SN may be associated with a secondary cell group (SCG). SCG may refer to a group of serving cells associated with the SN, and may comprise a primary secondary cell (PSCell) and optionally one or more SCells. User plane data may be transported from a core network to the SN through a SCG bearer. SCG bearer refers to a bearer whose radio protocols are located in the SN to use SN resources. As shown in FIG. 9, the radio protocols of the SCG bearer may comprise PDCP, RLC, MAC and PHY.

User plane data and/or control plane data may be transported from a core network to the MN and split up/duplicated in the MN, and at least part of the split/duplicated data may be forwarded to the SN through a split bearer. Split bearer refers to a bearer whose radio protocols are located in both the MN and the SN to use both MN resources and SN resources. As shown in FIG. 9, the radio protocols of the split bearer located in the MN may comprise PDCP, RLC, MAC and PHY. The radio protocols of the split bearer located in the SN may comprise RLC, MAC and PHY.

According to various embodiments, PDCP anchor/PDCP anchor point/PDCP anchor node refers to a RAN node comprising a PDCP entity which splits up and/or duplicates data and forwards at least part of the split/duplicated data over X2/Xn interface to another RAN node. In the example of FIG. 9, PDCP anchor node may be MN.

According to various embodiments, the MN for the UE may be changed. This may be referred to as handover, or a MN handover.

According to various embodiments, a SN may newly start providing radio resources to the UE, establishing a connection with the UE, and/or communicating with the UE (i.e., SN for the UE may be newly added). This may be referred to as a SN addition.

According to various embodiments, a SN for the UE may be changed while the MN for the UE is maintained. This may be referred to as a SN change.

According to various embodiments, DC may comprise E-UTRAN NR - DC (EN-DC), and/or multi-radio access technology (RAT) - DC (MR-DC). EN-DC refers to a DC situation in which a UE utilizes radio resources provided by E-UTRAN node and NR RAN node. MR-DC refers to a DC situation in which a UE utilizes radio resources provided by RAN nodes with different RATs.

Referring to FIG. 10, in step S1001, The UE may transmit a random access preamble on RACH in uplink, to a RAN node. The UE may transmit a RACH message 1 (RACH MSG1, or simply MSG1) comprising the random access preamble. There are two possible groups defined and one is optional. If both groups are configured the size of message 3 and the pathloss are used to determine which group a preamble is selected from. The group to which a preamble belongs provides an indication of the size of the message 3 and the radio conditions at the UE. The preamble group information along with the necessary thresholds are broadcast on system information.

In step S1003, The UE may receive a random access response generated by MAC on downlink-shared channel (DL-SCH), from the RAN node. The UE may receive a RACH message 2 (RACH MSG2, or simply MSG2) comprising the random access response. The random access response may be Semi-synchronous (within a flexible window of which the size is one or more transit time interval (TTI)) with the MSG1. The random access response message comprises at least one of a random access preamble identifier, timing alignment information for a primary timing advance group (pTAG), initial uplink (UL) grant and assignment of temporary C-RNTI.

In step S1005, the UE may transmit a device identification message to the RAN node. The UE may transmit a RACH message 3 (RACH MSG3, or simply MSG3) comprising the device identification message. The device identification message may be a first scheduled UL transmission on UL-SCH. For initial access, the device identification message may comprise at least a NAS UE identifier. If the UE is in the RRC_CONNECTED state and has a C-RNTI, the device identification message may include the C-RNTI.

In step S1007, the UE may receive a contention resolution message from the RAN node. The UE may receive a RACH message 4 (RACH MSG4, or simply MSG4) comprising the contention resolution message. The contention resolution message may be addressed to the temporary C-RNTI on PDCCH for initial access and after radio link failure, or addressed to the C-RNTI on PDCCH for UE in RRC_CONNECTED state. The temporary C-RNTI is promoted to C-RNTI for a UE which detects RA success and does not already have a C-RNTI. A UE which detects RA success and already has a C-RNTI resumes using the C-RNTI.

Referring to FIG. 11, in step S1101, a UE may transmit a random access preamble together with a device identification message to a RAN node. The UE may transmit a MSG1 comprising the random access preamble and the device identification message to the RAN node.

In step S1103, the UE may receive a random access response together with a contention resolution message from the RAN node. The UE may receive a MSG2 comprising the random access response and the contention resolution message from the RAN node.

Referring to FIG. 12, there may be 3 possible RRC states in a wireless communication system (i.e., RRC_IDLE, RRC_CONNECTED and/or RRC_IDLE).

In RRC_IDLE (or, idle mode/state), RRC context for communication between a UE and a network may not be established in RAN, and the UE may not belong to a specific cell. Also, in RRC_IDLE, there is no core network connection for the UE. Since the device remains in sleep mode in most of the time to reduce battery consumption, data transfer between the UE and the network may not occur. UEs in RRC_IDLE may periodically wake-up to receive paging messages from the network. Mobility may be handled by the UE through cell reselection. Since uplink synchronization is not maintained, the UE may not perform uplink transmission other than transmissions for random access (e.g., random access preamble transmission) to move to RRC_CONNECTED.

In RRC_CONNECTED (or, connected state/mode), RRC context for communication between a UE and a network may be established in RAN. Also, in RRC_CONNECTED, core network connection is established for the UE. Since the UE belongs to a specific cell, cell - radio network temporary identifier (C-RNTI) for signallings between the UE and the network may be configured for the UE. Data transfer between the UE and the network may occur. Mobility may be handled by the network - that is, the UE may provide measurement report to the network, and the network may transmit mobility commands to the UE to perform a mobility. Uplink time alignment may need to be established based on a random access and maintained for data transmission.

In RRC_INACTIVE (or, inactive state/mode), RRC context for communication between a UE and a network may be kept in RAN. Data transfer between the UE and the network may not occur. Since core network connection may also be kept for the UE, the UE may fast transit to a connected state for data transfer. In the transition, core network signalling may not be needed. The RRC context may be already established in the network and idle-to-active transitions can be handled in the RAN. The UE may be allowed to sleep in a similar way as in RRC_IDLE, and mobility may be handled through cell reselection without involvement of the network. The RRC_INCATIVE may be construed as a mix of the idle state and the connected state.

As illustrated in FIG. 12, the UE may transit to RRC_CONNECTED from RRC_IDLE by performing initial attach procedure or RRC connection establishment procedure. The UE may transit to RRC_IDLE from RRC_CONNECTED when detach, RRC connection release and/or connection failure (e.g., radio link failure (RLF)) has occurred. The UE may transit to RRC_INACTIVE from RRC_INACTIVE when RRC connection is suspended, and transit to RRC_CONNECTED from RRC_INACTIVE when RRC connection is resume. The UE may transit to RRC_IDLE from RRC_INACTIVE when connection failure such as RLF has occurred.

FIG. 13 shows an example of RRC connection establishment procedure in a case RRC connection establishment is successful to which technical features of the present disclosure can be applied. The RRC connection establishment procedure may be performed when UE is in RRC_IDLE.

Referring to FIG. 13, in step S1301, a UE may transmit a RRCSetupRequest (or, RRCConenctionSetupRequest) message to a network. The UE may transmit the RRCSetupRequest message for requesting an establishment of a RRC connection between the UE and the network.

In step S1303, the UE may receive a RRCSetup (or, RRCConnectionSteup) message from the network. The RRCSetup message may be received in response to the RRCSetupRequest message, if a RRC connection establishment is successful.

In step S1305, the UE may transmit a RRCSetupComplete (or, RRCConnectionSetupComplete) message to the network. On receiving the RRCSetup message, the UE may enter RRC_CONNECTED, and may transmit the RRCSetupComplete message to the network as a response for the RRCSetup message.

According to various embodiments, the RRC connection establishment procedure can be performed together with random access procedure.

For example, the RRCSetupRequest message may be transmitted together with RACH MSG3 (i.e., device identification message). That is, UE may transmit MSG3 comprising the RRCSetupRequest message and the device identification message to the network.

For example, the RRCSetup message may be received together with RACH MSG4 (i.e., contention resolution message). That is, the UE may receive MSG4 comprising the RRCSetup message and the contention resolution message from the network.

For example, the RRCSetupComplete message may be transmitted via RACH MSG5 (or, simply MSG5). That is, the UE may transmit MSG5 comprising the RRCSetupComplete message to the network.

FIG. 14 shows an example of a RRC connection resume procedure in a case RRC connection resume is successful to which technical features of the present disclosure can be applied. The RRC connection resume procedure may be performed when UE is in RRC_INACTIVE.

Referring to FIG. 14, in step S1401, a UE may transmit a RRCResumeRequest (or, RRCConnectionResumeRequest) message to a network. The UE may transmit the RRCResumeRequest message for requesting a resume of a RRC connection between the UE and the network.

In step S1403, the UE may receive a RRCResume (or, RRCConnectionResume) message from the network. The RRCResume message may be received in response to the RRCResumeRequest message, if a RRC connection resume is successful.

In step S1405, the UE may transmit a RRCResumeComplete message to the network. On receiving the RRCResume message, the UE may enter RRC_CONNECTED, and may transmit the RRCResumeComplete (or, RRCConenctionResumeComplete) message to the network as a response for the RRCSetup message.

According to various embodiments, the RRC connection resume procedure can be performed together with random access procedure.

For example, the RRCResumeRequest message may be transmitted together with RACH MSG3 (i.e., device identification message). That is, UE may transmit MSG3 comprising the RRCResumeRequest message and the device identification message to the network.

For example, the RRCResume message may be received together with RACH MSG4 (i.e., contention resolution message). That is, the UE may receive MSG4 comprising the RRCResume message and the contention resolution message from the network.

For example, the RRCResumeComplete message may be transmitted via RACH MSG5 (or, simply MSG5). That is, the UE may transmit MSG5 comprising the RRCResumeComplete message to the network.

In a wireless communication system, fast cell setup for MR-DC may need to be supported. With regard to the fast cell setup, SCG lower layer configuration may need to be kept when the UE initiates resume procedure (i.e. until the UE receives resume message including SCG configuration from the network) and blind SCG configuration in the resume message may need to be supported.

However, even if UE keeps SCG lower layer configuration when the UE initiates resume procedure and network sends resume message with SCG configuration blindly configured, the SCG configuration can be failed because the network doesn't know which cell(s) is valid in the UE when providing the SCG configuration. Some or all of cells in SCG configuration kept (stored) in the UE can be invalid (e.g. due to UE mobility) in the moment while all cells in the SCG configuration are valid when the UE transits from RRC connected mode to RRC inactive. If some or all of the cells in the SCG configuration are invalid, (re)configuration may be failed. Therefore, the latency for cell setup may increase.

For fast cell setup to perform multi-cell communication, additional measurement may be required. Some steps related to the additional measurement are described as the followings:

1. Starting/initiating the additional measurement

If available RRC connection establishment/resume cause is included in the additional measurement configuration, UE may initiate the additional measurement when the UE is going to establish/resume RRC connection due to an establishment/resume cause which is indicated in the additional measurement configuration received.

Desirably, the UE may initiate the additional measurement when MAC layer starts RACH procedure (e.g. upon sending MSG1). The UE may also initiate the additional measurement when RRC layer starts RRC connection establishment procedure (e.g. upon sending RRC connection setup request).

For example, if the additional measurement configuration indicates only 'mo-Data' and establishmentCause received from higher layers is set to 'mo-Signallling', then the UE may not initiate the additional measurement.

For another example, if the additional measurement configuration indicates only 'mt-Data' and establishmentCause received from higher layers is set to 'mt-Data', then the UE may initiate the additional measurement.

2. Performing the additional measurement

Though some threshold(s) has been configured for the UE to restrict the neighbor cell measurement when serving cell quality is good (i.e. serving cell quality is better than the threshold), the UE may perform the additional measurement regardless of the serving cell quality.

If a measurement object is included in the additional measurement configuration, the UE may perform the additional measurement only for the frequency of cell indicated by the measurement object.

3. Reporting additional measurement results

If report event is included in the additional measurement configuration, the UE may report the additional measurement results only when the report event is satisfied for some measured cell.

If report event is included in the additional measurement configuration, the UE may report the additional measurement results only for cell for which the report event is satisfied.

Examples of the report event may comprise a condition that a serving cell quality is worse than threshold 1 (i.e., serving cell threshold) and a neighbor cell quality is better than threshold 2 (i.e., neighbor cell threshold). Such condition may be referred to as event A5.

4. Stopping the additional measurement

UE may stop performing the additional measurement if the UE acquires available measurement results to report, or after reporting the measurement results to serving cell.

Referring to FIG. 15, in step S1501, UE in RRC_IDLE state may change serving cell by performing cell re-selection procedure.

In step S1503, UE may send system information (SI) requests to acquire additional measurement configuration.

In step S1505, UE may receive the additional measurement configuration. The additional measurement configuration may comprise at least one of:

A. Measurement object: carrier frequency #1, #2 and #4;

B. Report event: neighbor cell quality is better than threshold; or

C. Establishment/resume cause: mo-Data and mt-Access.

In step S1507, upon receiving the paging message including UE identity of a UE and additional measurement indication, the UE may initiate the additional measurement based on the additional measurement configuration. For example, the UE may measure frequency #1, #2 and #4 regardless of serving cell quality. The UE may find two cells (e.g., cell S and cell W) for which the report event is satisfied.

In step S1509, UE may initiate RRC connection establishment procedure with establishmentCause 'mt-Access'. The UE may transmit an RRC connection request message to a serving cell.

In step 1511, UE may construct an RRC connection setup complete message comprising the additional measurement results of cell S and cell W, and send the RRC connection setup complete message to the serving cell.

During RRC connection establishment procedure, UE may indicate, to the network, whether the UE has valid measurement results of the additional measurement via, for example, MSG3 (i.e., RRC connection setup request or RRC connection resume request message).

During RRC connection establishment procedure, if UE receives the additional reporting indication from network and the UE has valid measurement results of the additional measurement, the UE may report the additional measurement results to the network. The additional reporting indication can be included in MSG4 (i.e., RRC connection setup/resume message). The additional measurement results can be included in the MSG5 (i.e., RRC connection setup/resume complete message).

Desirably, the additional reporting indication can be included in MAC CE in MSG2. In this case, the additional measurement results can be reported to network via MSG 3.

Referring to FIG. 16, in step S1601, UE may transmit a random access preamble (i.e., MSG1). Upon transmitting the MSG1, UE may initiate the additional measurement.

In step S1603, the UE may receive a random access response (i.e., MSG2).

In step S1605, if UE has valid measurement results of the additional measurement, UE may set the valid measurement indication to TRUE. If not, the UE may set the valid measurement indication to FALSE. The UE may transmit RRC connection request message (i.e., MSG3) comprising the valid measurement indication.

In step S1607, the UE may receive RRC connection setup message (i.e., MSG4). The RRC connection setup message may or may not include additional reporting indication.

In step S1609, if RRC connection setup message includes the additional reporting indication, the UE may transmit an RRC connection setup complete message (i.e., MSG5) comprising the additional measurement results. Otherwise, the RRC connection setup complete message may not include the additional measurement results.

In the early measurement reporting procedure for multi-cell communication, the network may configure measurement configuration (i.e. frequency, cells) while a UE performs measurement in RRC_IDLE (or RRC_INACTIVE). Then a UE may report an indication (i.e. idleMeasAvailable) via MSG5 during RRC connection establishment/resume procedure when available cells are found. Then the may UE report whole measurement results (via e.g., UE information response message) after receiving UE information request message.

Referring to FIG. 17, in step S1701, a UE may receive, from a network, system information block (SIB) comprising cell-specific idle measurement configuration to perform measurement in RRC_IDLE (or RRC_INACTIVE). For another example, the UE may receive, from the network, RRC connection release message comprising UE-specific idle measurement configuration to perform measurement in RRC_IDLE (or RRC_INACTIVE).

The UE in RRC_IDLE (or RRC_INACTIVE) may perform a measurement on one or more cells based on the received configuration to obtain measurement results on the one or more cells, and check whether the measurement results satisfy a specific criteria (i.e., RSRP, RSRQ). The UE may generate a measurement report comprising the measurement results on the one or more cells. For example, the measurement report may comprise at least one of a list of measured/detected cells or a cell quality of the one or more cells (e.g., channel quality, channel state, signal quality, signal strength, RSRP, RSRQ of the one or more cells), as the measurement results.

In step S1703, the UE may transmit RRCSetupRequest message to the network.

In step S1705, the UE may receive RRCSetup message from the network.

In step S1707, the UE may transmit RRCSetupComplete message to the network. While the UE transmits the RRC setup complete message, the UE may include simple and essential information (e.g., a list of measured/detected cells) for MR-DC and/or CA setup in the RRC setup complete message instead of including the (whole) measurement results in the RRC setup complete message.

For example, if a size of a received resource grant for MSG5 is enough to convey the whole essential information, the UE may transmit the whole essential information via the MSG 5 based on the received resource grant.

For another example, if a size of the received resource grant for MSG5 is not enough to convey the whole essential information, the UE may transmit a part of the essential information according to size of the received resource grant, via the MSG 5 based on the received resource grant. The UE may insert to the MSG 5 an explicit indication which means that the other part of the essential information is still remaining.

In step S1709, the UE may receive a resource grant from a network.

In step S1711, the UE may report the essential information based on the received resource grant.

Steps S1709 and S1711 may be performed if a size of the received resource grant for MSG5 is not enough to convey the whole essential information and therefore the UE has transmitted a part of the essential information according to size of the received resource grant. Steps S1709 and S1711 may be omitted if a size of a received resource grant for MSG5 is enough to convey the whole essential information and therefore the UE has transmitted the whole essential information via the MSG 5 based on the received resource grant

Upon receiving the RRC setup complete message comprising the indication, the network may determine whether to configure DC/CA immediately or request full measurement report to configure DC/CA.

If the received essential information is enough to configure DC (or CA), in step S1713, the network may configure DC (or CA) immediately to the UE after security activation. Further, in this case, in step S1715, the UE may perform multi-cell communication and UL transmissions to the network based on the DC/CA configuration.

On the other hand, if the received essential information is not enough to configure to DC (or CA), the network may request the UE to send stored measurement results to the network.

FIG. 18 shows an example of a method for transmitting a measurement report for a configuration of multi-cell communication according to an embodiment of the present disclosure. Steps illustrated in FIG. 18 may be performed by a wireless device and/or a UE.

Referring to FIG. 18, in step S1801, the wireless device may generate a measurement report comprising measurement results on one or more cells. The wireless device may perform a measurement on the one or more cells to obtain the measurement results in an idle mode or an inactive mode.

In step S1803, the wireless device may construct an RRC message comprising a part of the measurement report (i.e., part of contents of the measurement report) and information informing that the other part of the measurement report is available. For example, the information may inform that the remaining part of the measurement report available to be reported exists in the wireless device. For example, the information may inform that the other part or the remaining part of the measurement report available to be reported is stored in the wireless device. For example, the information may inform that the other part of the measurement report available to be reported remains in the wireless device.

In step S1805, the wireless device may transmit the RRC message during an RRC connection procedure. The RRC connection procedure may comprise at least one of a RRC connection establishment procedure, or RRC connection resume procedure.

According to various embodiments, the wireless device may transmit, to a network, an RRC setup request message. The wireless device may receive, from the network, an RRC setup message. The wireless device may transmit an RRC setup complete message comprising the part of the measurement report and the information informing that the other part of the measurement report is available.

According to various embodiments, the wireless device may transmit, to a network, an RRC resume request message. The wireless device may receive, from the network, an RRC resume message. The wireless device may transmit an RRC resume complete message comprising the part of the measurement report and the information informing that the other part of the measurement report is available.

According to various embodiments, the wireless device may transmit the RRC message during the RRC connection procedure based on a resource grant. Whether the RRC message comprises the part of the measurement report or all contents of the measurement report is determined based on a size of the resource grant. For example, if the size of the resource grant is enough to convey all contents of the measurement report as well as an RRC setup/resume complete message, the RRC message may comprise all contents of the measurement report. On the other hand, if the size of the resource grant is not enough to convey all contents of the measurement report, the RRC message may comprise the part of the measurement report and the information informing that the other part of the measurement report is available. The wireless device may report the other part of the measurement report to a network when the network sends report request to the wireless device and/or allocates additional resource grant used for the reporting.

According to various embodiments, the wireless device may receive, from a network, an additional resource grant after transmitting the RRC message. The wireless device may transmit to the network, the other part of the measurement report based on the additional resource grant.

According to various embodiments, the wireless device may receive a configuration for multi-cell communication after transmitting the RRC message. The wireless device may communicate with a plurality of cells based on the configuration for multi-cell communication.

According to various embodiments, the multi-cell communication may comprise CA, and the plurality of cells may comprise a PCell and an SCell for the CA.

According to various embodiments, the multi-cell communication may comprise DC, and the plurality of cells may comprise a PCell and a PSCell for the DC.

According to various embodiments, the measurement results on the one or more cells may comprise a list of the one or more cells and a cell quality of the one or more cells.

According to various embodiments, the part of the measurement report may comprise the list of the one or mare cells and excludes the cell quality of the one or more cells.

According to various embodiments, the one or more cells may comprise a plurality of cells. The part of the measurement report may comprise a list of a part of the plurality of cells and a cell quality of the part of the plurality of cells.

FIG. 19 shows a UE to implement an embodiment of the present disclosure. The present disclosure described above for UE side may be applied to this embodiment.

A UE includes a processor 1910, a power management module 1911, a battery 1912, a display 1913, a keypad 1914, a subscriber identification module (SIM) card 1915, a memory 1920, a transceiver 1930, one or more antennas 1931, a speaker 1940, and a microphone 1941.

The processor 1910 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of the radio interface protocol may be implemented in the processor 1910. The processor 1910 may include application-specific integrated circuit (ASIC), other chipset, logic circuit and/or data processing device. The processor 1910 may be an application processor (AP). The processor 1910 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 1910 may be found in SNAPDRAGONTM series of processors made by Qualcomm®, EXYNOSTM series of processors made by Samsung®, A series of processors made by Apple®, HELIOTM series of processors made by MediaTek®, ATOMTM series of processors made by Intel® or a corresponding next generation processor.

The processor 1910 may be configured to, or configured to control the transceiver 1930 to implement steps performed by the UE and/or the wireless device throughout the disclosure.

The power management module 1911 manages power for the processor 1910 and/or the transceiver 1930. The battery 1912 supplies power to the power management module 1911. The display 1913 outputs results processed by the processor 1910. The keypad 1914 receives inputs to be used by the processor 1910. The keypad 1914 may be shown on the display 1913. The SIM card 1915 is an　integrated circuit　that is intended to　securely store the　international mobile subscriber identity　(IMSI) number and its related　key, which are used to identify and authenticate subscribers on　mobile telephony　devices (such as　mobile phones　and　computers). It is also possible to store contact information on many SIM cards.

The memory 1920 is operatively coupled with the processor 1910 and stores a variety of information to operate the processor 1910. The memory 1920 may include read-only memory (ROM), random access memory (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, and so on) that perform the functions described herein. The modules can be stored in the memory 1920 and executed by the processor 1910. The memory 1920 can be implemented within the processor 1910 or external to the processor 1910 in which case those can be communicatively coupled to the processor 1910 via various means as is known in the art.

The transceiver 1930 is operatively coupled with the processor 1910, and transmits and/or receives a radio signal. The transceiver 1930 includes a transmitter and a receiver. The transceiver 1930 may include baseband circuitry to process radio frequency signals. The transceiver 1930 controls the one or more antennas 1931 to transmit and/or receive a radio signal.

The speaker 1940 outputs sound-related results processed by the processor 1910. The microphone 1941 receives sound-related inputs to be used by the processor 1910.

FIG. 18 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

Referring to FIG. 18, the wireless communication system may include a first device 1810 (i.e., first device 210) and a second device 1820 (i.e., second device 220).

The first device 1810 may include at least one transceiver, such as a transceiver 1811, and at least one processing chip, such as a processing chip 1812. The processing chip 1812 may include at least one processor, such a processor 1813, and at least one memory, such as a memory 1814. The memory may be operably connectable to the processor 1813. The memory 1814 may store various types of information and/or instructions. The memory 1814 may store a software code 1815 which implements instructions that, when executed by the processor 1813, perform operations of the first device 910 described throughout the disclosure. For example, the software code 1815 may implement instructions that, when executed by the processor 1813, perform the functions, procedures, and/or methods of the first device 1810 described throughout the disclosure. For example, the software code 1815 may control the processor 1813 to perform one or more protocols. For example, the software code 1815 may control the processor 1813 to perform one or more layers of the radio interface protocol.

The second device 1820 may include at least one transceiver, such as a transceiver 1821, and at least one processing chip, such as a processing chip 1822. The processing chip 1822 may include at least one processor, such a processor 1823, and at least one memory, such as a memory 1824. The memory may be operably connectable to the processor 1823. The memory 1824 may store various types of information and/or instructions. The memory 1824 may store a software code 1825 which implements instructions that, when executed by the processor 1823, perform operations of the second device 1820 described throughout the disclosure. For example, the software code 1825 may implement instructions that, when executed by the processor 1823, perform the functions, procedures, and/or methods of the second device 1820 described throughout the disclosure. For example, the software code 1825 may control the processor 1823 to perform one or more protocols. For example, the software code 1825 may control the processor 1823 to perform one or more layers of the radio interface protocol.

Referring to FIG. 20, the wireless communication system may include a first device 2010 (i.e., first device 210) and a second device 2020 (i.e., second device 220).

The first device 2010 may include at least one transceiver, such as a transceiver 2011, and at least one processing chip, such as a processing chip 2012. The processing chip 2012 may include at least one processor, such a processor 2013, and at least one memory, such as a memory 2014. The memory may be operably connectable to the processor 2013. The memory 2014 may store various types of information and/or instructions. The memory 2014 may store a software code 2015 which implements instructions that, when executed by the processor 2013, perform operations of the first device 910 described throughout the disclosure. For example, the software code 2015 may implement instructions that, when executed by the processor 2013, perform the functions, procedures, and/or methods of the first device 2010 described throughout the disclosure. For example, the software code 2015 may control the processor 2013 to perform one or more protocols. For example, the software code 2015 may control the processor 2013 to perform one or more layers of the radio interface protocol.

The second device 2020 may include at least one transceiver, such as a transceiver 2021, and at least one processing chip, such as a processing chip 2022. The processing chip 2022 may include at least one processor, such a processor 2023, and at least one memory, such as a memory 2024. The memory may be operably connectable to the processor 2023. The memory 2024 may store various types of information and/or instructions. The memory 2024 may store a software code 2025 which implements instructions that, when executed by the processor 2023, perform operations of the second device 2020 described throughout the disclosure. For example, the software code 2025 may implement instructions that, when executed by the processor 2023, perform the functions, procedures, and/or methods of the second device 2020 described throughout the disclosure. For example, the software code 2025 may control the processor 2023 to perform one or more protocols. For example, the software code 2025 may control the processor 2023 to perform one or more layers of the radio interface protocol.

The present disclosure may be applied to various future technologies, such as AI, robots, autonomous-driving/self-driving vehicles, and/or extended reality (XR).

<AI>

AI refers to artificial intelligence and/or the field of studying methodology for making it. Machine learning is a field of studying methodologies that define and solve various problems dealt with in AI. Machine learning may be defined as an algorithm that enhances the performance of a task through a steady experience with any task.

An artificial neural network (ANN) is a model used in machine learning. It can mean a whole model of problem-solving ability, consisting of artificial neurons (nodes) that form a network of synapses. An ANN can be defined by a connection pattern between neurons in different layers, a learning process for updating model parameters, and/or an activation function for generating an output value. An ANN may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may contain one or more neurons, and an ANN may include a synapse that links neurons to neurons. In an ANN, each neuron can output a summation of the activation function for input signals, weights, and deflections input through the synapse. Model parameters are parameters determined through learning, including deflection of neurons and/or weights of synaptic connections. The hyper-parameter means a parameter to be set in the machine learning algorithm before learning, and includes a learning rate, a repetition number, a mini batch size, an initialization function, etc. The objective of the ANN learning can be seen as determining the model parameters that minimize the loss function. The loss function can be used as an index to determine optimal model parameters in learning process of ANN.

Machine learning can be divided into supervised learning, unsupervised learning, and reinforcement learning, depending on the learning method. Supervised learning is a method of learning ANN with labels given to learning data. Labels are the answers (or result values) that ANN must infer when learning data is input to ANN. Unsupervised learning can mean a method of learning ANN without labels given to learning data. Reinforcement learning can mean a learning method in which an agent defined in an environment learns to select a behavior and/or sequence of actions that maximizes cumulative compensation in each state.

Machine learning, which is implemented as a deep neural network (DNN) that includes multiple hidden layers among ANN, is also called deep learning. Deep learning is part of machine learning. In the following, machine learning is used to mean deep learning.

The AI device 2100 may be implemented as a stationary device or a mobile device, such as a TV, a projector, a mobile phone, a smartphone, a desktop computer, a notebook, a digital broadcasting terminal, a PDA, a PMP, a navigation device, a tablet PC, a wearable device, a set-top box (STB), a digital multimedia broadcasting (DMB) receiver, a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, etc.

Referring to FIG. 21, the AI device 2100 may include a communication part 2110, an input part 2120, a learning processor 2130, a sensing part 2140, an output part 2150, a memory 2160, and a processor 2170.

The communication part 2110 can transmit and/or receive data to and/or from external devices such as the AI devices and the AI server using wire and/or wireless communication technology. For example, the communication part 2110 can transmit and/or receive sensor information, a user input, a learning model, and a control signal with external devices. The communication technology used by the communication part 2110 may include a global system for mobile communication (GSM), a code division multiple access (CDMA), an LTE/LTE-A, a 5G, a WLAN, a Wi-Fi, BluetoothTM, radio frequency identification (RFID), infrared data association (IrDA), ZigBee, and/or near field communication (NFC).

The input part 2120 can acquire various kinds of data. The input part 2120 may include a camera for inputting a video signal, a microphone for receiving an audio signal, and a user input part for receiving information from a user. A camera and/or a microphone may be treated as a sensor, and a signal obtained from a camera and/or a microphone may be referred to as sensing data and/or sensor information. The input part 2120 can acquire input data to be used when acquiring an output using learning data and a learning model for model learning. The input part 2120 may obtain raw input data, in which case the processor 2170 or the learning processor 2130 may extract input features by preprocessing the input data.

The learning processor 2130 may learn a model composed of an ANN using learning data. The learned ANN can be referred to as a learning model. The learning model can be used to infer result values for new input data rather than learning data, and the inferred values can be used as a basis for determining which actions to perform. The learning processor 2130 may perform AI processing together with the learning processor of the AI server. The learning processor 2130 may include a memory integrated and/or implemented in the AI device 2100. Alternatively, the learning processor 2130 may be implemented using the memory 2160, an external memory directly coupled to the AI device 2100, and/or a memory maintained in an external device.

The sensing part 2140 may acquire at least one of internal information of the AI device 2100, environment information of the AI device 2100, and/or the user information using various sensors. The sensors included in the sensing part 2140 may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, a light detection and ranging (LIDAR), and/or a radar.

The output part 2150 may generate an output related to visual, auditory, tactile, etc. The output part 2150 may include a display unit for outputting visual information, a speaker for outputting auditory information, and/or a haptic module for outputting tactile information.

The memory 2160 may store data that supports various functions of the AI device 2100. For example, the memory 2160 may store input data acquired by the input part 2120, learning data, a learning model, a learning history, etc.

The processor 2170 may determine at least one executable operation of the AI device 2100 based on information determined and/or generated using a data analysis algorithm and/or a machine learning algorithm. The processor 2170 may then control the components of the AI device 2100 to perform the determined operation. The processor 2170 may request, retrieve, receive, and/or utilize data in the learning processor 2130 and/or the memory 2160, and may control the components of the AI device 2100 to execute the predicted operation and/or the operation determined to be desirable among the at least one executable operation. The processor 2170 may generate a control signal for controlling the external device, and may transmit the generated control signal to the external device, when the external device needs to be linked to perform the determined operation. The processor 2170 may obtain the intention information for the user input and determine the user's requirements based on the obtained intention information. The processor 2170 may use at least one of a speech-to-text (STT) engine for converting speech input into a text string and/or a natural language processing (NLP) engine for acquiring intention information of a natural language, to obtain the intention information corresponding to the user input. At least one of the STT engine and/or the NLP engine may be configured as an ANN, at least a part of which is learned according to a machine learning algorithm. At least one of the STT engine and/or the NLP engine may be learned by the learning processor 2130 and/or learned by the learning processor of the AI server, and/or learned by their distributed processing. The processor 2170 may collect history information including the operation contents of the AI device 2100 and/or the user's feedback on the operation, etc. The processor 2170 may store the collected history information in the memory 2160 and/or the learning processor 2130, and/or transmit to an external device such as the AI server. The collected history information can be used to update the learning model. The processor 2170 may control at least some of the components of AI device 2100 to drive an application program stored in memory 2160. Furthermore, the processor 2170 may operate two or more of the components included in the AI device 2100 in combination with each other for driving the application program.

Referring to FIG. 22, in the AI system, at least one of an AI server 2220, a robot 2210a, an autonomous vehicle 2210b, an XR device 2210c, a smartphone 2210d and/or a home appliance 2210e is connected to a cloud network 2200. The robot 2210a, the autonomous vehicle 2210b, the XR device 2210c, the smartphone 2210d, and/or the home appliance 2210e to which the AI technology is applied may be referred to as AI devices 2210a to 2210e.

The cloud network 2200 may refer to a network that forms part of a cloud computing infrastructure and/or resides in a cloud computing infrastructure. The cloud network 2200 may be configured using a 3G network, a 4G or LTE network, and/or a 5G network. That is, each of the devices 2210a to 2210e and 2220 consisting the AI system may be connected to each other through the cloud network 2200. In particular, each of the devices 2210a to 2210e and 2220 may communicate with each other through a base station, but may directly communicate with each other without using a base station.

The AI server 2220 may include a server for performing AI processing and a server for performing operations on big data. The AI server 2220 is connected to at least one or more of AI devices constituting the AI system, i.e. the robot 2210a, the autonomous vehicle 2210b, the XR device 2210c, the smartphone 2210d and/or the home appliance 2210e through the cloud network 2200, and may assist at least some AI processing of the connected AI devices 2210a to 2210e. The AI server 2220 can learn the ANN according to the machine learning algorithm on behalf of the AI devices 2210a to 2210e, and can directly store the learning models and/or transmit them to the AI devices 2210a to 2210e. The AI server 2220 may receive the input data from the AI devices 2210a to 2210e, infer the result value with respect to the received input data using the learning model, generate a response and/or a control command based on the inferred result value, and transmit the generated data to the AI devices 2210a to 2210e. Alternatively, the AI devices 2210a to 2210e may directly infer a result value for the input data using a learning model, and generate a response and/or a control command based on the inferred result value.

Various embodiments of the AI devices 2210a to 2210e to which the technical features of the present disclosure can be applied will be described. The AI devices 2210a to 2210e shown in FIG. 22 can be seen as specific embodiments of the AI device 2100 shown in FIG. 21.

The present disclosure can have various advantageous effects.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description 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 performed by a wireless device in a wireless communication system, the method comprising:

generating a measurement report comprising measurement results on one or more cells;

constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and

transmitting the RRC message during an RRC connection procedure.
The method of claim 1, wherein the RRC connection procedure comprises at least one of a RRC connection establishment procedure, or RRC connection resume procedure.
The method of claim 1, further comprising:

transmitting, to a network, an RRC setup request message; and

receiving, from the network, an RRC setup message,

wherein the transmitting of the RRC message comprises transmitting an RRC setup complete message comprising the part of the measurement report and the information informing that the other part of the measurement report is available.
The method of claim 1, further comprising:

transmitting, to a network, an RRC resume request message; and

receiving, from the network, an RRC resume message,

wherein the transmitting of the RRC message comprises transmitting an RRC resume complete message comprising the part of the measurement report and the information informing that the other part of the measurement report is available.
The method of claim 1, wherein the transmitting of the RRC message comprises transmitting the RRC message during the RRC connection procedure based on a resource grant, and

wherein whether the RRC message comprises the part of the measurement report or all contents of the measurement report is determined based on a size of the resource grant.
The method of claim 5, further comprising:

receiving, from a network, an additional resource grant after transmitting the RRC message; and

transmitting, to the network, the other part of the measurement report based on the additional resource grant.
The method of claim 1, further comprising:

receiving a configuration for multi-cell communication after transmitting the RRC message; and

communicating with a plurality of cells based on the configuration for multi-cell communication.
The method of claim 7, wherein the multi-cell communication comprises carrier aggregation (CA), and

wherein the plurality of cells comprises a primary cell (PCell) and a secondary cell (SCell) for the CA.
The method of claim 7, wherein the multi-cell communication comprises dual-connectivity (DC), and

wherein the plurality of cells comprise a primary cell (PCell) and a primary secondary cell (PSCell) for the DC.
The method of claim 1, wherein the measurement results on the one or more cells comprise a list of the one or more cells and a cell quality of the one or more cells.
The method of claim 10, wherein the part of the measurement report comprises the list of the one or mare cells and excludes the cell quality of the one or more cells.
The method of claim 10, wherein the one or more cells comprise a plurality of cells, and

wherein the part of the measurement report comprises a list of a part of the plurality of cells and a cell quality of the part of the plurality of cells.
The method of claim 1, wherein the wireless device is in communication with at least one of a user equipment, a network, or autonomous vehicles other than the wireless device.
A wireless device in a wireless communication system comprising:

a transceiver;

a memory; and

at least one processor operatively coupled to the transceiver and the memory, and configured to:

generate a measurement report comprising measurement results on one or more cells,

construct a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available, and

control the transceiver to transmit the RRC message during an RRC connection procedure.
A processor for a wireless device in a wireless communication system, wherein the processor is configured to control the wireless device to perform operations comprising:

generating a measurement report comprising measurement results on one or more cells;

constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and

transmitting the RRC message during an RRC connection procedure.
A computer-readable medium having recorded thereon a program for performing each step of a method on a computer, the method comprising:

generating a measurement report comprising measurement results on one or more cells;

constructing a radio resource control (RRC) message comprising a part of the measurement report and information informing that the other part of the measurement report is available; and

transmitting the RRC message during an RRC connection procedure.