Access control method and apparatus for use in mobile communications

Abstract

The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system and Internet of Things (IoT) technology. The disclosure can be applied to intelligent services based on the 5G communication technology and the IoT-related technology. The disclosure provides a method performed by a terminal in a communication system. The method includes receiving a paging message from a base station when the terminal is in a radio resource control (RRC) inactive state, identifying whether to enter an RRC idle state or perform an RRC connection resume procedure based on the paging message, entering the RRC idle state in case that the terminal is identified to enter the RRC idle state based on the paging message, and in case that the terminal is identified to perform the RRC connection resume procedure based on the paging message, transmitting an RRC resume request message to the base station, receiving an RRC release message from the base station as a response to the RRC resume request message, and entering the RRC idle state based on the RRC release message.

Description

[0001] This application is a divisional application of the application filed on July 13, 2017, with application number 201780043793.7, entitled "Access Control Method and Apparatus Used in Mobile Communications". Technical Field

[0002] This disclosure relates to mobile communication systems, and more particularly to a method for determining whether to prohibit access in a mobile communication system.

[0003] Furthermore, this disclosure relates to a method for configuring discontinuous reception (DRX) in a mobile communication system.

[0004] Furthermore, this disclosure relates to a method for sending paging signals to a terminal in a mobile communication system.

[0005] Furthermore, this disclosure relates to methods for transmitting and receiving data for ultra-reliable and low-latency communication (URLLC) services in mobile communication systems.

[0006] Furthermore, this disclosure relates to a method for reducing data interruption time and handling faults related to reduced data interruption time during handover processes in a mobile communication system.

[0007] Furthermore, this disclosure relates to a method and apparatus for a terminal to autonomously switch to a large paging area preference mode and update the paging area in a mobile communication system.

[0008] Furthermore, this disclosure relates to a paging message-based mode switching method and apparatus for use in terminals of mobile communication systems. Background Technology

[0009] To meet the growing demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems." The implementation of 5G communication systems in higher frequency (millimeter wave) bands (e.g., the 60GHz band) is being considered to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed in 5G communication systems. Furthermore, in 5G communication systems, development is underway to improve system networks based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), while filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) have been developed as advanced access technologies.

[0010] The Internet, as a human-centric network in which humans generate and consume information, is now evolving into the Internet of Things (IoT), in which distributed entities (such as objects) exchange and process information without human intervention. The Internet of Everything (IoE), a combination of IoT technology connected to cloud servers and big data processing technology, has emerged. As technological elements, IoT implementation requires technologies such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology. Recently, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected objects. Through the integration and combination of existing information technology (IT) with various industrial applications, IoT can be applied to multiple fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0011] Consistent with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communication (MTC), and machine-to-machine (M2M) communication can be implemented using beamforming, MIMO, and array antennas. The application of cloud radio access networks (RAN), as a big data processing technology, can also be seen as an example of the convergence between 5G and IoT technologies. Summary of the Invention

[0012] Technical issues

[0013] At the same time, LTE systems can determine whether to enforce application-specific access denial and control for each application. However, the complexity of application-specific access denial mechanisms increases the need for consistent access control mechanisms.

[0014] Meanwhile, using the two DRX cycles (long and short) specified in the LTE standard may not allow for dynamic adjustment of the DRX cycle based on Data Radio Bearer (DRB) characteristics, service modes, and buffer states. Therefore, a method for effectively adjusting the length of the DRX cycle is needed.

[0015] In LTE, a new operating mode called Light Connected mode has been proposed to define a mode in which the base station (eNB) and the terminal (UE) maintain the state of UE information (e.g., context information) even when the connection between them is lost, in addition to idle mode and connected mode. In an LTE system, if the tracking area of ​​a UE in Light Connected mode changes, the UE can switch to connected mode and send a tracking area update message to the core network. This means that the UE must switch to connected mode even when there is no data to send.

[0016] For next-generation mobile communication systems, Ultra Reliable Low Latency Communication (URLLC) services (with a packet error rate of 10⁻⁵) can be considered. Examples of URLLC services include autonomous vehicle services, eHealth services, and drone services. In LTE systems, negative acknowledgments (NACKs) corresponding to packet transmissions trigger retransmissions, which can lead to transmission delays. Therefore, detailed operations for effectively retransmitting URLLC service packets need to be specified.

[0017] In an LTE system, when a UE switches from one eNB to another, the UE cannot communicate data with the network during the time period between receiving the handover command message from the source eNB and sending the handover completion message to the target eNB. This period of inability to transmit data is called the data interruption time. Typically, the data interruption time lasts at least tens of milliseconds, leading to data loss. Therefore, a method is needed to minimize the data interruption time.

[0018] In networks supporting light connectivity mode, a UE in idle mode can report its location while on the move within a paging area configured by the network. In this scenario, significant signaling is required between the UE and the eNB to allow the UE to switch to a large paging area preference mode to conserve battery power.

[0019] Furthermore, when a UE remains in lightly connected mode for an extended period, the network must store and maintain the UE context and S1-U bearer information. This means the network cannot continuously manage UEs in lightly connected mode, but instead controls their transition to RRC idle mode. This operation of transitioning the UE's operating mode from lightly connected mode to RRC idle mode can result in significant signaling overhead.

[0020] Technical solution

[0021] To address the aforementioned shortcomings, the primary objective is to provide a method and apparatus that employs a consistent access control mechanism.

[0022] Furthermore, this disclosure aims to provide a method and apparatus for dynamically changing the DRX cycle based on DRB characteristics, business mode, and buffer state.

[0023] Furthermore, this disclosure aims to provide a method and apparatus for paging a UE within a cell in a heterogeneous network environment that includes eNBs with different cell sizes.

[0024] Furthermore, this disclosure aims to provide a method and apparatus for sending / receiving data for URLLC services.

[0025] Furthermore, this disclosure aims to provide a method and apparatus for reducing data interruption time during UE handover and for handling fault data interruption time reduction.

[0026] Furthermore, this disclosure aims to provide a method and apparatus for switching the operating mode of a UE, for autonomously switching to a large paging area preference mode to reduce signaling overhead.

[0027] Furthermore, this disclosure aims to provide a method and apparatus for operation mode switching based on paging messages to reduce signaling overhead.

[0028] According to one aspect of this disclosure, a method performed by a terminal in a communication system includes: receiving a paging message from a base station when the terminal is in a Radio Resource Control (RRC) inactive state; identifying, based on the paging message, whether to enter an RRC idle state or perform an RRC connection recovery process; entering an RRC idle state if the terminal is identified to be entering an RRC idle state based on information included in the paging message, wherein the information is used to identify that the terminal will enter an RRC idle state; and, if the terminal is identified to be performing an RRC connection recovery process based on the paging message: sending an RRC recovery request message to the base station, receiving an RRC release message from the base station as a response to the RRC recovery request message, and entering an RRC idle state based on the RRC release message.

[0029] According to another aspect of this disclosure, a method performed by a base station in a communication system includes: identifying a paging message; sending a paging message to a terminal in a Radio Resource Control (RRC) inactive state, wherein the paging message is used to identify whether the terminal has entered an RRC idle state or is performing an RRC connection recovery procedure; receiving an RRC recovery request message from the terminal if an RRC connection recovery procedure is initiated based on the paging message; and sending an RRC release message to the terminal as a response to the RRC recovery request message, wherein the terminal's state is converted to an RRC idle state based on the RRC release message, and wherein the terminal's state is converted to an RRC idle state if information included in the paging message is used to identify that the terminal will enter an RRC idle state.

[0030] According to another aspect of this disclosure, a terminal in a communication system includes a transceiver and a controller, the controller being coupled to the transceiver and configured to: when the terminal is in a Radio Resource Control (RRC) inactive state, receive a paging message from a base station via the transceiver; identify, based on the paging message, whether to enter an RRC idle state or perform an RRC connection recovery process; enter an RRC idle state if the terminal is identified to be entering an RRC idle state based on information included in the paging message, wherein the information is used to identify that the terminal will enter an RRC idle state; and if the terminal is identified to be performing an RRC connection recovery process based on the paging message: send an RRC recovery request message to the base station; receive an RRC release message from the base station as a response to the RRC recovery request message; and enter an RRC idle state based on the RRC release message.

[0031] According to another aspect of this disclosure, a base station in a communication system includes a transceiver and a controller, the controller being coupled to the transceiver and configured to: identify paging messages; send paging messages via the transceiver to a terminal in a Radio Resource Control (RRC) inactive state, wherein the paging message is used to identify whether the terminal has entered an RRC idle state or is performing an RRC connection recovery process; in the case of initiating an RRC connection recovery process based on the paging message; receive an RRC recovery request message from the terminal; and send an RRC release message to the terminal as a response to the RRC recovery request message, wherein the terminal's state is converted to an RRC idle state based on the RRC release message; and wherein the terminal's state is converted to an RRC idle state when information included in the paging message is used to identify that the terminal will enter an RRC idle state.

[0032] According to another aspect of this disclosure, a method for a user equipment (UE) in a mobile communication system includes: sending UE capability information including a random access-free handover indicator to a first base station, receiving a handover command message from the first base station, and if the handover command message includes uplink resource information, sending a handover completion message to a second base station based on the uplink resource information.

[0033] According to another aspect of this disclosure, a method for a first base station in a mobile communication system includes: receiving UE capability information including a random access-free handover indicator from a user equipment (UE), sending a handover request message to a second base station, receiving a handover request confirmation (ACK) message, and if the handover request ACK message includes uplink resource information, sending a handover command message including uplink resource information to the UE, wherein the uplink resource information is used to send a handover completion message from the UE to the second base station.

[0034] According to another aspect of this disclosure, a method for a second base station in a mobile communication system includes: receiving a handover request message from a first base station, sending a handover request acknowledgment (ACK) message, and if the handover request ACK message includes uplink resource information, receiving a handover completion message from a user equipment (UE) based on the uplink resource information.

[0035] According to another aspect of this disclosure, a user equipment (UE) in a mobile communication system includes: a transceiver configured to transmit or receive signals; and a controller configured to transmit UE capability information including a random access handover indicator to a first base station, receive a handover command message from the first base station, and, if the handover command message includes uplink resource information, transmit a handover completion message to a second base station based on the uplink resource information.

[0036] According to another aspect of this disclosure, a first base station in a mobile communication system includes: a transceiver configured to transmit or receive signals; and a controller configured to receive user equipment (UE) capability information including a random access handover indicator from a UE, send a handover request message to a second base station, receive a handover request acknowledgment (ACK) message from the second base station, and, if the handover request ACK message includes uplink resource information, send a handover command message including the uplink resource information to the UE, wherein the uplink resource information is used to send a handover completion message from the UE to the second base station.

[0037] According to another aspect of this disclosure, a second base station in a mobile communication system includes: a transceiver configured to transmit or receive signals; and a controller configured to receive a handover request message from a first base station, transmit a handover request acknowledgment (ACK) message, and, if the handover request ACK message includes uplink resource information, receive a handover completion message from a user equipment (UE) based on the uplink resource information.

[0038] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used in this patent document: the terms “comprising” and “including” and their derivatives mean to include rather than to limit; the term “or” is inclusive, meaning and / or; the phrases “associated with” and “related to” and their derivatives may mean including, including in, interconnected with, containing, contained within, connected to or connected to, coupled to or coupled to, communicable to, cooperating with, interleaved, juxtaposed, proximate, bound to or bound to, having, possessing the properties of, etc.; the term “controller” means any device, system or part thereof that controls at least one operation, such device may be implemented by hardware, firmware or software or some combination of at least two of them. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote.

[0039] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data and media in which data can be stored and subsequently overwritten, such as rewritable optical discs or erasable memory devices.

[0040] Definitions of certain words and phrases are provided throughout this patent document, and those skilled in the art will understand that, in many cases (if not most), these definitions apply to the prior and future use of these defined words and phrases.

[0041] Beneficial technical effects

[0042] As described above, the access control method of this disclosure is advantageous in reducing the complexity of UE operation by applying a single access control procedure.

[0043] Furthermore, the access control method disclosed herein has the advantage that the eNB can effectively configure the UE's DRX operation by dynamically changing the DRX period.

[0044] Furthermore, the access control method disclosed herein is advantageous in addressing network overload by conducting paging operations in multiple areas of a specified cell within a heterogeneous environment comprising eNBs with different cell sizes.

[0045] Furthermore, the access control method disclosed herein is advantageous in increasing the probability of successful reception and reducing latency during data transmission.

[0046] Furthermore, the access control method disclosed herein is advantageous in preventing data transmission interruptions and improving data communication efficiency by employing a data interruption time reduction mechanism and specifying UE operations for data interruption time reduction failures.

[0047] Furthermore, the access control method disclosed herein is advantageous in terms of saving battery power and reducing signaling overhead by autonomously switching the operating mode of a UE disconnected from a network that supports light connectivity to a large paging area preference mode.

[0048] Furthermore, the access control method disclosed herein is advantageous in reducing signaling overhead between the UE and the network by switching a UE in light connection mode to idle mode based on a paging message from the eNB. Attached Figure Description

[0049] To gain a more complete understanding of this disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals denote like parts:

[0050] Figure 1A The architecture of an LTE system applying this disclosure is shown;

[0051] Figure 1B This illustrates a method for determining access prohibition in an LTE system;

[0052] Figure 1C This illustrates the ACDC process in an LTE system;

[0053] Figure 1D The structure of the ACDC configuration information used for requesting information is shown in the LTE system;

[0054] Figure 1E The method for determining access prohibition disclosed herein is illustrated;

[0055] Figure 1F The structure of the access prohibition configuration information according to this disclosure is shown;

[0056] Figure 1G A method for determining access prohibition according to this disclosure is shown;

[0057] Figure 1H The operation of the UE according to this disclosure is illustrated;

[0058] Figure 1I A method for determining access prohibition of a UE according to this disclosure is shown;

[0059] Figure 1J The configuration of the UE disclosed herein is shown;

[0060] Figure 1K The configuration of the eNB of this disclosure is shown;

[0061] Figure 2A The LTE architecture is shown;

[0062] Figure 2B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0063] Figure 2C The DRX operation is shown;

[0064] Figure 2D This illustrates the concept of DRX operation in a connection mode according to this disclosure;

[0065] Figure 2E The signal flow during the DRX process of a UE according to this disclosure is shown;

[0066] Figure 2FA The DRX operation of a UE according to this disclosure is illustrated;

[0067] Figure 2FB The DRX operation of an eNB according to this disclosure is illustrated;

[0068] Figure 2G The MAC CE format according to this disclosure is shown;

[0069] Figure 2H The optimal beam pair according to this disclosure is shown;

[0070] Figure 2I The DRX operation in the beam measurement result reporting process according to this disclosure is illustrated;

[0071] Figure 2J The process for reporting beam measurement results according to this disclosure is illustrated;

[0072] Figure 2KA The UE operation during the beam measurement result reporting process according to this disclosure is illustrated;

[0073] Figure 2KB The operation of the eNB in ​​the beam measurement result reporting process according to this disclosure is illustrated;

[0074] Figure 2L The configuration of the UE according to this disclosure is shown;

[0075] Figure 2M The configuration of an eNB according to this disclosure is shown;

[0076] Figure 3A The LTE system architecture is shown;

[0077] Figure 3B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0078] Figure 3C This illustrates the network environment in which this disclosure is applied;

[0079] Figure 3D The paging process proposed between the terminal and the network according to this disclosure is illustrated;

[0080] Figure 3E The paging area update process of a terminal according to this disclosure is shown;

[0081] Figure 3F The configuration of the terminal according to this disclosure is shown;

[0082] Figure 4A The LTE system architecture is shown;

[0083] Figure 4B The protocol stack of the interface between the terminal and the eNB in ​​an LTE system is shown.

[0084] Figure 4C The signal flow between the terminal and the base station in the signal transmission method proposed in this disclosure is shown;

[0085] Figure 4DA The transmission scheme proposed in this disclosure is shown;

[0086] Figure 4DB Another transmission scheme proposed in this disclosure is shown;

[0087] Figure 4DC Another transmission scheme proposed in this disclosure is shown;

[0088] Figure 4EA Terminal operation according to this disclosure is shown;

[0089] Figure 4EB Base station operation according to this disclosure is shown:

[0090] Figure 4F The configuration of a terminal according to an embodiment of the present disclosure is shown;

[0091] Figure 4G The configuration of a base station according to an embodiment of the present disclosure is shown;

[0092] Figure 5A The LTE system architecture is shown;

[0093] Figure 5B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0094] Figure 5C This illustrates the handover process in a traditional LTE system;

[0095] Figure 5D The RACH-less handover method proposed in this disclosure is illustrated.

[0096] Figure 5E Another RACH-free handover method proposed in this disclosure is shown;

[0097] Figure 5F A RACH-free handover procedure is shown for reducing data transmission pause time by configuring a UE-initiated timer (Timer 1), especially when the UE cannot be allocated uplink resources for transmission to the target eNB for any reason;

[0098] Figure 5G Another RACH-free handover procedure is shown for reducing data transmission pause time by configuring a UE-initiated timer, especially when the UE cannot be allocated uplink resources for transmission to the target eNB for any reason;

[0099] Figure 5H A RACH-free handover procedure is shown for reducing data transmission pause time by configuring a network-initiated timer (Timer 2), especially when the UE cannot be allocated uplink resources for transmission to the target eNB for any reason;

[0100] Figure 5I Another RACH-free handover procedure is shown for reducing data transmission pause time by configuring a network-initiated timer (Timer 2), especially when the UE cannot be allocated uplink resources for transmission to the target eNB for any reason;

[0101] Figure 5J The operation of the UE according to this disclosure is illustrated;

[0102] Figure 5K Another UE operation according to this disclosure is shown;

[0103] Figure 5L Another UE operation according to this disclosure is shown;

[0104] Figure 5M The configuration of a UE according to an embodiment of the present disclosure is shown;

[0105] Figure 5N The configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of the present disclosure is shown;

[0106] Figure 6A The LTE system architecture is shown;

[0107] Figure 6B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0108] Figure 6C This illustrates the concept of light connections;

[0109] Figure 6DA and 6DBThe signal flow between the UE context and S1 bearer reused UE, anchor eNB, new eNB and MME in the light connection process is shown according to this disclosure;

[0110] Figure 6E The PA update process of a UE in a network supporting light connectivity technology according to this disclosure is illustrated;

[0111] Figure 6F Different types of PAs according to this disclosure are shown;

[0112] Figure 6G The signal flow between the UE and eNB is shown during PA reconfiguration according to this disclosure;

[0113] Figure 6H Another process for PA reconfiguration for a UE according to this disclosure is shown;

[0114] Figure 6I The autonomous PA reconfiguration process of the UE according to this disclosure is illustrated;

[0115] Figure 6J The configuration of a UE according to an embodiment of the present disclosure is shown;

[0116] Figure 6K The configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of the present disclosure is shown;

[0117] Figure 7A The LTE system architecture is shown;

[0118] Figure 7B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0119] Figure 7C This illustrates the concept of light connections;

[0120] Figure 7DA and 7DB The signal flow between the UE context and S1 bearer reused UE, anchor eNB, new eNB and MME in the light connection process is shown according to this disclosure;

[0121] Figure 7E A method for switching a UE in light connection mode to RRC idle mode for an eNB, according to this disclosure, is shown.

[0122] Figure 7F This disclosure illustrates a method for switching a UE in light connection mode to RRC idle mode when the UE moves to the PA of another eNB;

[0123] Figure 7GAnother procedure for switching a UE in light connection mode to RRC idle mode according to this disclosure is shown;

[0124] Figure 7H A method is shown for an eNB to switch a UE in lightly connected mode to RRC idle mode using a paging message that includes an RRC idle mode switching indicator;

[0125] Figure 7I This disclosure illustrates a method by which an eNB, when a UE moves to the PA of another eNB, uses a paging message including an RRC idle mode transition indicator to transition the UE from lightly connected mode to RRC idle mode.

[0126] Figure 7J Another procedure for switching a UE in light connection mode to RRC idle mode according to this disclosure is shown;

[0127] Figure 7K The UE operation according to this disclosure when a paging message is received is illustrated;

[0128] Figure 7L The configuration of a UE according to an embodiment of this disclosure is shown; and

[0129] Figure 7M The configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of this disclosure is shown. Detailed Implementation

[0130] The following discussion Figures 1A to 7M The various embodiments used to describe the principles of this disclosure in this patent document are by way of example only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or device.

[0131] Although the description is primarily directed toward Long Term Evolution (LTE) and Evolved Packet Core (EPC) for Radio Access Networks (RAN) and Core Networks (CN) standardized by the 3rd Generation Partnership Project (3GPP), those skilled in the art will understand that this disclosure can be applied, with minor modifications, to other communication / computing systems with similar technical backgrounds and channel formats without departing from the spirit and scope of this disclosure.

[0132] Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of this disclosure. This is intended to omit unnecessary descriptions to make the subject matter of this disclosure clear.

[0133] For the same reason, some elements have been exaggerated, omitted, or simplified in the accompanying drawings, and in practice, elements may have different dimensions and / or shapes than those shown in the drawings. The same reference numerals are used throughout the drawings to refer to the same or similar parts.

[0134] It will be understood that those skilled in the art can change or modify the embodiments without departing from the technical concept of this disclosure. Therefore, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0135] In the embodiments described above in this disclosure, steps and message transmissions may be selectively performed or omitted. In each embodiment of this disclosure, operations need not be performed in the described order, but may be performed in a different order. Each step and message may be performed independently.

[0136] Some or all of the tables exemplified in the above description are provided to aid in understanding this disclosure. Therefore, the detailed description of the tables expresses a portion of the methods and apparatus presented in this disclosure. That is, the contents of the tables in the specification are preferably semantically rather than grammatically approximated. Although various embodiments of this disclosure have been described using specific terminology, the specification and drawings should be considered illustrative rather than restrictive in order to aid in understanding this disclosure. It will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the broader spirit and scope of this disclosure.

[0137] The advantages and features of this disclosure, as well as methods of implementing them, can be more readily understood by referring to the following detailed description of exemplary embodiments and the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concepts of this disclosure to those skilled in the art, and this disclosure will be defined only by the appended claims. Throughout the specification, the same reference numerals refer to the same elements.

[0138] It will be understood that each box in a flowchart and / or block diagram, and combinations of boxes in a flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that instructions executed via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / actions specified in the flowchart and / or block diagram. These computer program instructions can also be stored in a non-transitory computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to function in a particular manner, such that instructions stored in the non-transitory computer-readable storage medium produce an article of manufacture of an embedded instruction means that implements the functions / actions specified in the flowchart and / or block diagram. Computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that instructions executing on the computer or other programmable apparatus provide steps for implementing the functions / actions specified in the flowchart and / or block diagram.

[0139] Furthermore, the block diagrams may illustrate portions of a module, segment, or code that include at least one or more executable instructions for performing specific logical functions. Additionally, it should be noted that the functions of blocks can be executed in different orders in several modifications. For example, two consecutive blocks may be executed substantially simultaneously, or they may be executed in reverse order depending on their functions.

[0140] According to various embodiments of this disclosure, the term "module" means, but is not limited to, software or hardware components, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs) that perform certain tasks. Modules can advantageously be configured to reside on addressable memory media and to execute on one or more processors. Thus, by way of example, modules can include components such as software components, object-oriented software components, class components, and task components; procedures, functions, properties, processes, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and modules can be combined into fewer components and modules, or further divided into additional components and modules. Additionally, components and modules can be implemented such that they execute one or more CPUs within a device or secure multimedia card.

[0141] First Embodiment

[0142] Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of this disclosure. Exemplary embodiments of this disclosure are described in detail with reference to the accompanying drawings.

[0143] Figure 1A An LTE system applying this disclosure is shown.

[0144] refer to Figure 1A The radio access network (RAN) of the LTE system includes: evolved Node Bs (eNBs) 1a-05, 1a-10, 1a-15, and 1a-20; a Mobility Management Entity (MME) 1a-25; and a Service Gateway (S-GW) 1a-30. User Equipment (UE) 1a-35 connects to external networks via eNBs 1a-05, 1a-10, 1a-15, and 1a-20, and S-GW 1a-30.

[0145] eNBs 1a-05, 1a-10, 1a-15 and 1a-20 are equivalent to traditional Node Bs in the Universal Mobile Telecommunications System (UMTS).

[0146] UE 1a-35 connects to one of the eNBs via a radio channel, and this eNB has more control functions than a traditional Node B. In LTE systems that serve all user services, including real-time services such as Voice over IP (VoIP), via a shared channel, it is necessary to schedule the UE based on scheduling information such as buffer state, power margin state, and channel state collected from the UE. The eNB serving the UE is responsible for this function.

[0147] Typically, one eNB carries multiple cells. For example, LTE systems use Orthogonal Frequency Division Multiplexing (OFDM) as the radio access technology to ensure data rates up to 100 Mbps in a 20 MHz bandwidth. LTE systems also employ Adaptive Modulation and Coding (AMC) to determine the modulation scheme and channel coding rate appropriate for the UE's channel conditions.

[0148] The S-GW 1a-30, as the entity that processes the data bearers, establishes and releases data bearers under the control of the MME 1a-25.

[0149] The MME 1a-25 is responsible for various control functions and maintains connections with multiple eNBs.

[0150] This disclosure presents an access control method for determining whether to prohibit access in a mobile communication system.

[0151] If network congestion occurs, the network may limit the number of initial access attempts. This is called access barring. The network broadcasts pre-defined access barring configuration information (hereinafter referred to as barring configuration information) so that each UE can determine that its access is barred. Based on the barring configuration information, the UE wanting to access the network determines whether to attempt access. This disclosure proposes a UE-specific (application-specific) access barring determination method.

[0152] Figure 1BThe method for determining access prohibition in an LTE system is illustrated.

[0153] The protocols residing in an LTE UE can be divided into Layer 1 and Layer 2. For example, Layer 1 can be labeled Access Layer (AS), and Layer 2 can be labeled Non-Access Stratum (NAS).

[0154] The AS (Access Controller) can handle all access-related functions. Regardless of the access method, the NAS (Access Denial) can handle other functions (such as service requests). Access denial can be determined at the UE's AS.

[0155] As described above, in steps 1b-35, if network congestion occurs, the network can restrict initial access by broadcasting access prohibition configuration information to help each UE make an access attempt decision. For example, the configuration information can be broadcast in system information and includes at least one of prohibition configuration information, access class prohibition (ACB) configuration information, ACB skip indicator, application-specific congestion control (ACDC) configuration information for data communication, and service-specific access class (SSAC) configuration information.

[0156] To meet the requirements newly added to the LTE standard, a new access prohibition mechanism has been proposed for performing the multi-access prohibition check process.

[0157] In steps 1b-10, the UE NAS can generate a service request to the UE AS. If a service request is received, the UE AS determines whether to block network access.

[0158] Specifically, if the reason for establishing the service request is set to "delay-tolerant access" or indicates a value of "delay-tolerant access", then the UE AS performs an Extended Access Denial (EAB) check in steps 1b-20.

[0159] The EAB mechanism applies only to Machine Class Communication (MTC). If the EAB check passes, the UE AS performs an application-specific congestion control (ACDC) check for data communication in steps 1b-22.

[0160] The application requesting the service is assigned an ACDC category, and the value of the ACDC category is included in the service request transmitted to the UE AS.

[0161] The network can provide prohibition configuration information according to ACDC categories. That is, prohibition configuration information can include information about the category of the application that is the target of access control.

[0162] Therefore, the UE can perform access checks on application groups categorized according to ACDC categories. In other words, the UE can perform access checks based on the category of the application requesting the service. If no ACDC category prohibition configuration information is provided to the network, the UE AS can skip the ACDC access check process.

[0163] If the ACDC check passes, the UE AS performs an Access Class Denial (ACB) in steps 1b-30. The ACB can represent the access check procedure performed by the UE AS using denial configuration information provided based on Mobile Originating (MO) data or MO signaling. The denial configuration information for the ACB can be sent to the UE in the ACB configuration information or SIB.

[0164] However, in the case of MMTEL voice / video / SMS, the UE AS can skip the ACB procedure in steps 1b-25. In this case, the network can send an ACB skip indicator to skip the ACB check procedure. Therefore, the UE AS can skip the ACB check procedure in steps 1b-25 based on the ACB skip indicator.

[0165] If access is permitted through the multiple access check procedure, the UE AS may attempt to access the network. That is, in steps 1b-40, the UE AS performs a random access procedure by sending a Radio Resource Control (RRC) Connection Request message.

[0166] Access checks may exist that are not performed by the UE AS. If an MMTEL voice / video access denial information (SSAC) is received from the network in step 1b-45, the UE AS transmits the access denial information to the UE's IMS layer in step 1b-50. Here, the SSAC denial information can be sent to the UE in the SSAC configuration information or SIB. If the denial configuration information is received, the IMS layer performs the access denial check procedure when the service is triggered. SSAC is designed to allow the UE AS to perform functions regardless of the type of application or service. Therefore, in order to control access denial for specific services such as MMTEL voice / video, it is necessary to transmit the denial configuration information to the layer that manages the corresponding service, whereby the corresponding layer performs the access check procedure.

[0167] Such a complex process is unnecessary in next-generation mobile communication systems. This is because a consistent access check process can be implemented, encompassing all requirements introduced from the initial design phase in LTE.

[0168] Figure 1C The ACDC process in an LTE system is illustrated.

[0169] In LTE systems, ACDC (Application-Specific Access Denial) is proposed for the purpose of determining application-specific (service-specific) access denials. Each application is assigned at least one ACDC category value. For example, ACDC categories 1 to 16 can exist.

[0170] Network 1c-20 can use NAS messages to provide application-specific ACDC category information to UE 1c-05. Specifically, in step 1c-25, ACDC category information can be transmitted to UE NAS 1c-10. The ACDC category information can be included in the ACDC configuration information.

[0171] In step 1c-50, the network can send ACDC disallow configuration information to UE 1c-05. Specifically, network 1c-20 can use SIB2 to send ACDC category-specific disallow configuration information.

[0172] The prohibition configuration information may include at least one of the ac-BarringFactor (ac-prohibition factor) information element (IE) and the ac-Barringtime (ac-prohibition time) IE. Here, the ac-BarringFactor α is selected in the range of 0 ≤ α < 1.

[0173] UE 1c-05(AS) selects a random value (rand) within the range of 0 ≤ rand < 1. This random value is less than ac-BarringFactor, which indicates access is denied; and equal to or greater than ac-BarringFactor, which indicates access is permitted. If access is denied, UE AS 1c-15 delays access for a predetermined time period calculated using equation (1).

[0174] “Tbarring”=(0.7 + 0.6 rand) ac- Barringtime (1)

[0175] If a service request is triggered, in step 1c-30, the UE (NAS) infers the ACDC category value corresponding to the application requesting the service. In step 1c-35, the UE NAS can send the service request, including the ACDC category value, to the UE AS 1c-15.

[0176] Upon receiving a service request, the UE (AS) may perform a denial check. In step 1c-40, the UE 1c-05 determines whether to deny access based on the denial configuration information included in SIB2 and the ACDC category value of the application for the service request.

[0177] If SIB2 does not include the prohibition configuration information corresponding to the ACDC category, it is assumed that the application corresponding to the ACDC category has passed the ACDC process and is allowed to access the network. If access to the network is allowed through the access prohibition check process, the UE (AS) sends an RRC connection request message for the random access network in step 1c-45.

[0178] Figure 1D The structure of the ACDC configuration information used in the LTE system is shown.

[0179] ACDC configuration information may include PLMN-specific prohibition information sets (ACDC-BarringPerPLMN 1, ACDC-BarringPerPLMN 2, ...) 1d-35 and 1d-40. If all PLMNs have the same prohibition information set, the network may broadcast a common prohibition information set (ACDC-BarringForCommon-r13) 1d-05.

[0180] A PLMN-specific or public set of prohibited configuration information may include prohibited configuration information 1d-20, 1d-25, and 1d-30 for each category. As mentioned above, prohibited configuration information 1d-45 includes ac-BarringFactorIE and ac-BarringtimeIE.

[0181] Therefore, the UE can determine whether to allow network access based on the prohibition configuration information and the category of the application that has requested the corresponding service. If no prohibition configuration information corresponding to a specific ACDC category is provided, it is assumed that applications with the corresponding ACDC category are allowed to access the network.

[0182] Figure 1E The method for determining access prohibition according to this disclosure is shown.

[0183] The distinguishing feature of this disclosure is the use of a single, consistent prohibition mechanism instead of multiple prohibition mechanisms. The proposed prohibition mechanism 1e-20 is based on service-specific (application-specific) ACDC implementation.

[0184] However, this disclosure can also be implemented by classifying UE type, call type, or fragment type rather than application type, and by blocking access from the UE based on factors other than application. This will be described in detail later.

[0185] In steps 1e-25, the network broadcasts a prohibition configuration information in the system information. As described above, the prohibition configuration information may include category-specific information. The prohibition configuration information may include category-specific ac-BarringFactor IE and ac-Barringtime IE, as well as an indicator indicating the category to which access is prohibited.

[0186] If a service request is triggered, UE NAS 1e-05 can send a service request 1e-10 to UE AS 1e-15. Here, the UE includes application category information in the service request. Each legacy service or application is assigned at least one category value.

[0187] Therefore, in steps 1e-20, the UE AS determines whether to prohibit access based on the prohibition configuration information and category value. According to this disclosure, the UE can determine whether to prohibit access to an application that has triggered a service request.

[0188] If access is permitted, the UE AS sends an RRC connection request message to the network in step 1e-30.

[0189] Figure 1F The structure of the access prohibition configuration information according to this disclosure is shown.

[0190] According to this disclosure, PLMN-specific barring information sets (ACDC-BarringPerPLMN 1, ACDC-BarringPerPLMN 2, ...) 1f-15 and 1f-20 may be included. If all PLMNs have the same barring information set, the network may broadcast a common barring information set (ACDC-BarringForCommon) 1f-05.

[0191] A PLMN-specific set of prohibited configuration information or a common set of prohibited configuration information (ACDC-BarringForCommon) may include prohibited configuration information 1f-50, 1f-55, and 1f-60 for each category.

[0192] As described above, this disclosure can be implemented by classifying UE type, call type, or fragment type rather than application type.

[0193] For example, conventional ACDC does not provide any prohibition configuration information for MO signaling, MO data, and emergency signaling. This disclosure features a network that also provides MO signaling, MO data, and emergency prohibition configuration information 1f-25, 1f-30, and 1f-40. Special-purpose prohibition configuration information 1f-35 can also be provided. Categories of MO signaling, MO data, and emergency situations can be defined; when a service request corresponding to MO signaling is triggered, the UE NAS can provide dedicated MO signaling category information to the UE AS.

[0194] If, as described above, an MO signaling establishment reason value is sent to the UE AS in the service request, then a prohibition check can be performed using dedicated MO signaling prohibition configuration information.

[0195] As described above, in this disclosure, specific factors rather than applications can be categorized, allowing the UE to determine whether to prohibit access based on the corresponding category information.

[0196] In legacy systems, there is no configuration information for categories with new prohibition mechanisms. It's assumed that applications belonging to that category are prohibited from access. Therefore, even though the same prohibition configuration information applies to multiple categories, the system information should include configuration information for each category. This can lead to signaling overhead.

[0197] The feature of this disclosure is that if the same prohibition configuration information is applied to multiple categories, common prohibition configuration information 1f-30 is provided for multiple categories to reduce signaling overhead. In this disclosure, prohibition configuration information typically applied to multiple categories is referred to as common prohibition configuration or default prohibition configuration information. Therefore, the network can include common prohibition configuration information in the system information.

[0198] For example, if Category 1 and Category 2 have the same prohibited configuration information, the network will not include all prohibited configuration information for both Category 1 and Category 2 in the system information. Instead, the network will only include common prohibited configuration information in the system information. This is useful for applying common prohibited configuration information to specific services.

[0199] The characteristic of UE operation is that access prohibition is determined based on public prohibition configuration information, which is different from traditional technology. In traditional technology, if there is no prohibition configuration information corresponding to the category of interest, access is assumed to be allowed.

[0200] Therefore, the UE can inspect service (application) requests for a specific category, and if prohibited configuration information corresponding to that category exists, it can determine whether to prohibit access based on the prohibited configuration information; if prohibited configuration information does not exist, the UE can determine whether to prohibit access based on common prohibited configuration information. In other words, when no prohibited configuration information is defined for a specific category, access can be prohibited based on common prohibited configuration information. The aforementioned MO signaling, MO data, and emergency prohibited configuration information can be common prohibited configuration information.

[0201] Access denial is determined by generating random values ​​as described above, checking the ac-BarringFactor value included in the public denial configuration information, and determining whether the random value generated according to the method (described later) is less than the ac-BarringFactor value.

[0202] Access prohibition determination can also be based on a 1-bit indicator (described later) or a specific ac-BarringFactor included in the public prohibition configuration information in all service requests.

[0203] When using public prohibition configuration information, an access prohibition check process is performed for each category. Therefore, a method is needed to indicate which categories should skip the access prohibition check process if necessary. This disclosure proposes a method for indicating categories that should skip the access prohibition check process using a 1-bit indicator or a specific ac-BarringFactor.

[0204] In this case, a 1-bit indicator can be included in the prohibition configuration information for the category that skips the access prohibition check process, instead of ac-BarringFactor IE and ac-Barringtime IE. The UE AS skips the access prohibition check process for the category whose prohibition configuration information includes this 1-bit indicator and assumes access is allowed. (Reference) Figure 1G Describe in detail the methods for configuring specific ac-BarringFactor values.

[0205] The network may also include separate prohibition configuration information in system information used for special purposes or emergency services.

[0206] Therefore, it may be necessary to define separate categories for emergency services and special purposes so that the UE NAS can provide the UE AS with category information for emergency calls or special purposes when a request for an emergency call or special service is triggered.

[0207] Separate barring configuration information can be provided in the form of an ac-BarringFactor IE and an ac-BarringTime IE. The barring configuration information may also include a 1-bit indicator indicating whether to skip the access barring check process. The barring configuration information may also include a specific barring factor for skipping the access barring check process for special purposes or emergency services. This is because the priority of such services is generally higher than that of other services.

[0208] Figure 1G An access barring determination method according to the present disclosure is shown.

[0209] As described above, a specific ac-BarringFactor1g-10 of a category that skips the access barring check process can be considered.

[0210] Since the range of the traditional ac-BarringFactorα is 0 ≤ α < 1, as shown by reference numerals 1g-05 or 1g-30 and 1g-15, it is impossible to use the ac-BarringFactor adjustment method to skip the access barring check process to obtain access permission without restriction. This is because if the random value generated by the UE AS is within the range of 0 ≤ α < ac-BarringFactor, as shown by reference numeral 1g-20, access is assumed to be allowed.

[0211] Refer to Figure 1G part (a) of. As Figure 1G shown, if the random value generated by the UE is within the range of 1g-20, that is, equal to or greater than 0 and less than ac-BarringFactor, access is allowed.

[0212] If the random value is within the range of 1g-25, that is, ac-BarringFactor ≤ α < 1, as shown by reference numeral 1g-25, access is assumed to be prohibited. Refer to Figure 1G part (b) of, if the random value generated by the UE is equal to or greater than ac-BarringFactor and less than 1, as shown by reference numeral 1g-25, access can be prohibited.

[0213] If the ac-BarringFactor 1g-35 is 1, as Figure 1GAs shown in section (b), the random value generated by the UE is less than ac-BarringFactor, which means that access is allowed without any restrictions (this is equivalent to skipping the access prohibition check process). In this disclosure, unnecessary ac-BarringTime can be reduced by skipping the category-specific access prohibition check process by setting ac-BarringFactor, which is included in the corresponding prohibition configuration information, to 1. That is, if the prohibition factor is set to 1, the prohibition time value (ac-BarringTime) may not be included in the prohibition configuration information.

[0214] Figure 1H The UE operation according to this disclosure is shown.

[0215] refer to Figure 1H In step 1h-05, the UE can receive the prohibition configuration information broadcast by the eNB.

[0216] Next, in steps 1h-10, the UE can trigger a service request for a specific service. Here, the service request can be triggered by the UE NAS.

[0217] In steps 1h-15, the UE can retrieve the category value corresponding to the service. Here, the category value corresponding to the service can be determined by the UE NAS.

[0218] Next, in steps 1h-20, the UE can determine whether to deny access based on the denial configuration information. The access denial determination can be made by the UE AS, and the UE NAS can send a service request to the UE AS. The service request may include a category value.

[0219] The following describes in detail the method for determining access prohibition for a UE based on prohibition configuration information.

[0220] Figure 1I A method for determining access prohibition of a UE according to this disclosure is shown.

[0221] In step 1i-05, the UE determines whether the triggered service is a special purpose or an emergency service.

[0222] If so, then in steps 1i-30, the UE performs an access denial check procedure for the service. As mentioned above, access can be denied based on individual denial configuration information, or a 1-bit indicator can be used to skip the access denial process determination.

[0223] Otherwise, if the triggered service is a normal service, then in steps 1i-10, the UE determines whether it has received prohibition configuration information for the category corresponding to the service from the eNB.

[0224] If a prohibition configuration message corresponding to the service category has been received from the eNB, the UE checks the access prohibition indication in the corresponding prohibition configuration message. In steps 1i-25, the UE can attempt to access the service based on the access prohibition indication.

[0225] Otherwise, if the UE has not yet received a prohibition configuration information for the category corresponding to the service from the eNB, in step 1i-20, the UE checks the access prohibition indication in the public access prohibition configuration information. If the public access prohibition configuration information is not included, the UE skips the access prohibition check process. That is, the UE assumes access is allowed. Next, in step 1i-25, the UE can attempt to access the service based on the access prohibition indication.

[0226] In this disclosure, steps 1i-05 and 1i-30 may be omitted. As stated above, special purpose or emergency services can be classified into a special category.

[0227] In this disclosure, the step of determining whether access prohibition configuration information corresponding to the service category has been received from the eNB can be performed after steps 1i-15 of retrieving the service category value. Then, the UE checks the corresponding configuration information for the case where access prohibition configuration information corresponding to the service category has been received from the eNB, and the common access prohibition configuration information for the case where access prohibition configuration information corresponding to the service category has not been received from the eNB, to obtain an access prohibition indication.

[0228] Figure 1J The configuration of the UE disclosed herein is shown.

[0229] refer to Figure 1J The UE includes a radio frequency (RF) processing unit (RF processor) 1j-10, a baseband processing unit (baseband processor) 1j-20, a memory (storage unit) 1j-30, and a controller 1j-40. In this disclosure, the controller 1j-40 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to a transceiver.

[0230] RF processing unit 1j-10 has signal band conversion and amplification functions for transmitting signals through a radio channel. That is, RF processing unit 1j-10 converts the baseband signal from baseband processing unit 1j-20 into an RF band signal to be transmitted via the antenna, and converts the RF band signal received by the antenna back into a baseband signal. For example, RF processing unit 1j-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC). Although the figure depicts one antenna, the UE may be provided with multiple antennas. RF processing unit 1j-10 may also include multiple RF chains. RF processing unit 1j-10 can perform beamforming. For beamforming, RF processing unit 1j-10 can adjust the phase and magnitude of signals transmitted / received through multiple antennas or antenna elements. RF processing unit 1j-10 can perform MIMO signal processing and receive signals through multiple layers during MIMO operation.

[0231] The baseband processing unit 1j-20 has the function of converting between baseband signals and bitstreams according to the system's physical layer standard. For example, in data transmission mode, the baseband processing unit 1j-20 performs encoding and modulation on the transmitted bitstream to generate complex symbols. In data reception mode, the baseband processing unit 1j-20 also performs demodulation and decoding on the baseband signal from the RF processing unit 1j-10 to recover the original bitstream. When using OFDM, in data transmission mode, the baseband processing unit 1j-20 performs encoding and modulation on the transmitted bitstream to generate complex symbols, maps the complex symbols to subcarriers, performs an inverse fast Fourier transform (IFFT) on the mapped symbols, and inserts a cyclic prefix (CP) into the symbols after the IFFT to generate OFDM symbols. In the data reception mode, the baseband processing unit 1j-20 separates the baseband signal from the RF processing unit 1j-10 into OFDM symbols, performs a Fast Fourier Transform (FFT) on the OFDM symbols to recover the signal mapped to the subcarrier, and performs demodulation and decoding on the signal to recover the original bit stream.

[0232] Baseband processing unit 1j-20 and RF processing unit 1j-10 participate in signal transmission and reception. Therefore, baseband processing unit 1j-20 and RF processing unit 1j-10 can be referred to as a transmitting unit, receiving unit, transceiver, or communication unit. At least one of baseband processing unit 1j-20 and RF processing unit 1j-10 may include multiple communication modules for supporting different radio access technologies. At least one of baseband processing unit 1j-20 and RF processing unit 1j-10 may also include multiple communication modules for processing signals in different frequency bands. For example, radio access technologies may include wireless local area network (WLAN) technologies such as IEEE 802.11 and cellular technologies such as LTE. Different frequency bands may include ultra-high frequency (SHF) bands such as the 2.5 GHz band and the 5 GHz band, and millimeter wave (mmW) bands such as the 60 GHz band.

[0233] The memory 1j-30 can store basic programs, application programs, and setting information for the operation of the UE. Specifically, the memory 1j-30 can store information about the auxiliary access node for performing radio communication using auxiliary radio access technology. The memory 1j-30 can provide the stored information in response to a request from the controller 1j-40.

[0234] Controller 1j-40 controls the overall operation of the UE. For example, controller 1j-40 transmits / receives signals via baseband processing unit 1j-20 and RF processing unit 1j-10. Controller 1j-40 writes data to and reads data from memory 1j-30. For this purpose, controller 1j-40 may include at least one processor (multi-connection processor 1j-42). For example, controller 1j-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher-level applications.

[0235] In detail, according to this disclosure, the controller 1j-40 can receive prohibition configuration information broadcast by the eNB. The controller 1j-40 can retrieve the category value corresponding to the triggered service. The controller 1j-40 can also determine whether to prohibit access based on the prohibition configuration information.

[0236] In detail, controller 1j-40 can determine whether it has received access prohibition configuration information corresponding to the service category. When it receives access prohibition configuration information corresponding to the category, controller 1j-40 can also check the access prohibition indication in the access prohibition configuration information corresponding to the category. When it does not receive access prohibition configuration information corresponding to the category, controller 1j-40 can also check the access prohibition indication in the common access prohibition configuration information.

[0237] Figure 1KThe configuration of the eNB of this disclosure is shown.

[0238] like Figure 1K As shown, the eNB includes an RF processing unit (RF processor) 1k-10, a baseband processing unit (baseband processor) 1k-20, a backhaul communication unit 1k-30, a memory 1k-40, and a controller 1k-50. In this disclosure, the controller 1k-50 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to a transceiver.

[0239] The RF processing unit 1k-10 has signal band conversion and amplification functions for transmitting signals through a radio channel. Specifically, the RF processing unit 1k-10 up-converts the baseband signal from the baseband processing unit 1k-20 into an RF band signal transmitted via the antenna, and down-converts the RF band signal received by the antenna back into a baseband signal. For example, the RF processing unit 1k-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although the accompanying drawings depict one antenna, the eNB may be provided with multiple antennas. The RF processing unit 1k-10 may also include multiple RF chains. The RF processing unit 1k-10 can perform beamforming. For beamforming, the RF processing unit 1k-10 can adjust the phase and magnitude of signals transmitted / received through multiple antennas or antenna elements. The RF processing unit 1k-10 can perform MIMO signal processing during MIMO operation and receive signals with multiple layers.

[0240] The baseband processing unit 1k-20 has the function of converting between baseband signals and bitstreams according to the physical layer standards of major radio access technologies. For example, in data transmission mode, the baseband processing unit 1k-20 performs encoding and modulation on the transmitted bitstream to generate complex symbols. In data reception mode, the baseband processing unit 1k-20 also performs demodulation and decoding on the baseband signal from the RF processing unit 1k-10 to recover the original bitstream. When using OFDM, in data transmission mode, the baseband processing unit 1k-20 performs encoding and modulation on the transmitted bitstream to generate complex symbols, maps the complex symbols to subcarriers, performs IFFT on the mapped symbols, and inserts a cyclic prefix (CP) into the IFFT-processed symbols to generate OFDM symbols. In data reception mode, the baseband processing unit 1k-20 separates the baseband signal from the RF processing unit 1k-10 into OFDM symbols, performs Fast Fourier Transform (FFT) on the OFDM symbols to recover the signal mapped to the subcarriers, and performs demodulation and decoding on the signal to recover the original bitstream. The signal transmission and reception involve a baseband processing unit 1k-20 and an RF processing unit 1k-10. Therefore, the baseband processing unit 1k-20 and the RF processing unit 1k-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit.

[0241] The backhaul communication unit 1k-30 provides an interface for intra-node communication. That is, the backhaul communication unit 1k-30 converts bit streams sent from the primary eNB to another node (e.g., secondary eNB and core network) into physical signals, and converts physical signals received from another node into bit streams.

[0242] Memory 1k-40 can store basic programs, applications, and settings information for eNB operation. Specifically, memory 1k-40 can store information about bearers assigned to connected UEs and measurement results reported by the connected UEs. Memory 1k-40 can also store information for enabling or disabling multiple connections for UEs. Memory 1k-40 provides stored data in response to requests from controller 1k-50.

[0243] The controller 1k-50 controls the overall operation of the master eNB. For example, the controller 1k-50 transmits / receives signals using the baseband processing unit 1k-20 and the RF processing unit 1k-10. The controller 1k-50 writes data to and reads data from the memory 1k-40. For this purpose, the controller 1k-50 may include at least one processor (multi-connection processor 1k-52).

[0244] In detail, the controller 1k-50 according to this disclosure can broadcast prohibition configuration information. Here, the controller 1k-50 can determine category prohibition configuration information for each service category and send the prohibition configuration information for each service category to the UE. The controller 1k-50 can also determine common prohibition configuration information for multiple categories and send the common prohibition configuration information to the UE. Here, the common prohibition configuration information can be applied to all categories for which no prohibition configuration information has been specified.

[0245] The controller 1k-50 can also categorize special-purpose or emergency services into a single category and determine prohibition configuration information for skipping the access prohibition check process for the corresponding service. Here, the prohibition configuration information may include a 1-bit indicator or a predetermined prohibition factor for indicating that the access prohibition check process should be skipped.

[0246] Second Embodiment

[0247] This embodiment proposes a DRX operation that can dynamically change the DRX period and inactive timer.

[0248] Figure 2A The architecture of an LTE system applying this disclosure is shown. References have been made. Figure 1A The LTE system architecture has been described in detail, so it will be omitted here.

[0249] Figure 2B This is a diagram illustrating the protocol stack of the interface between the UE and eNB in ​​an LTE system using the present disclosure.

[0250] refer to Figure 2B In an LTE system, the protocol stack of the interface between the UE and the eNB includes multiple protocol layers stacked from bottom to top: the physical (PHY) layer, represented by reference numerals 2b-20 and 2b-25; the media access control (MAC) layer, represented by reference numerals 2b-15 and 2b-30; the radio link control (RLC) layer, represented by reference numerals 2b-10 and 2b-35; and the packet data convergence control (PDCP) layer, represented by reference numerals 2b-05 and 2b-40.

[0251] The PDCP layer, denoted by reference numerals 2b-05 and 2b-40, is responsible for compressing / decompressing IP headers. The main functions of the PDCP layer are as follows:

[0252] Header compression and decompression (ROHC only);

[0253] Transmit user data;

[0254] Upper-layer PDUs are delivered sequentially during PDCP reconstruction for RLC AM;

[0255] Used to separate bearers in DC (RLC AM only);

[0256] PDCP PDU routing for transmission and PDCP PDU reordering for reception;

[0257] Repeated detection of low-level SDUs during PDCP reconstruction for RLC AM;

[0258] For bearers in a separate DC, PDCP SDUs are retransmitted during handover; for RLC AM, PDCP PDUs are retransmitted during PDCP data recovery.

[0259] Encryption and decryption;

[0260] In the uplink, timer-based SDUs are discarded.

[0261] The RLC layer, denoted by reference numerals 2b-10 and 2b-35, is responsible for segmenting the PDCP PDU into segments of appropriate size for Automatic Repeat Request (ARQ) operations. The main functions of the RLC layer are as follows:

[0262] Transmit the upper-layer PDU;

[0263] Error correction via ARQ (only for AM data transmission);

[0264] Cascading, segmentation, and reassembly of RLC SDUs (for UM and AM data transfers only);

[0265] Re-segment RLC data PDUs (only for AM data transmission);

[0266] Reorder RLC data PDUs (only for UM and AM data transfers);

[0267] Duplicate detection (only for UM and AM data transfers);

[0268] Protocol error detection (AM data transmission only);

[0269] RLC SDU discard (only for UM and AM data transmissions);

[0270] RLC reconstruction.

[0271] The MAC layer, denoted by reference numerals 2b-15 and 2b-30, allows the establishment of connections between multiple RLC entities for a UE and is responsible for multiplexing RLC PDUs from the RLC layer into MAC PDUs and demultiplexing MAC PDUs into RLC PDUs.

[0272] Mapping between logical channels and transmission channels;

[0273] Multiplexing MAC SDUs belonging to one or different logical channels into transport blocks (TBs) delivered to / from the physical layer on the transport channel, or demultiplexing transport blocks (TBs) delivered to / from the physical layer on the transport channel into MAC SDUs belonging to one or different logical channels;

[0274] Dispatch information report;

[0275] Error correction is performed using HARQ;

[0276] Priority processing between logical channels of a UE;

[0277] Priority processing is performed among UEs using dynamic scheduling;

[0278] MBMS service identification;

[0279] Transmission format selection;

[0280] filling.

[0281] The PHY layer, denoted by reference numerals 2b-20 and 2b-25, is responsible for channel coding and modulation of higher-layer data to generate OFDM symbols and transmit them via radio channels, as well as demodulating and channel decoding of OFDM symbols received via radio channels. The decoded data is then delivered to higher layers.

[0282] Figure 2C The DRX operation is shown.

[0283] DRX is a technique for monitoring the Physical Downlink Control Channel (PDCCH) to schedule information only during a predetermined time period to minimize UE power consumption. DRX is applicable to both idle and connected modes, but with slight differences. This disclosure relates to operation in connected mode. However, this disclosure is not limited thereto, but can be applied to operation in idle mode.

[0284] If the UE is constantly awake to monitor the PDCCH for scheduling information, this can lead to high power consumption. Basic DRX operation has a DRX period 2c-00, and the UE only monitors the PDCCH during the on-duration period 2c-05 within the DRX period 2c-00.

[0285] In connected mode, at least one of a long DRX period and a short DRX period can be configured. During normal operation, the long DRX period is applied, and the eNB can trigger a short DRX period using a MAC control element (CE) if needed. After a predetermined period, the UE can change the short DRX period for the long DRX period. Initial scheduling information for a UE is transmitted on a predetermined PDCCH. The UE periodically monitors the PDCCH to minimize power consumption.

[0286] If scheduling information for a new packet is received on the PDCCH during the communication duration segment 2c-05, the UE starts a DRX inactivity timer, as shown in reference numeral 2c-15. While the DRX inactivity timer is running, the UE remains active. That is, the UE continues to monitor the PDCCH. As shown in reference numeral 2c-20, the UE also starts a HARQ round-trip time (RTT) timer. The HARQ RTT timer is used to prevent unnecessary PDCCH monitoring during the HARQ RTT, so the UE does not need to monitor the PDCCH while the HARQ RTT timer is running. However, when both the DRX inactivity timer and the HARQ RTT timer are running, the UE monitors the PDCCH until the DRX inactivity timer expires.

[0287] If the HARQ RTT timer expires, the DRX retransmission timer is started as shown in reference numeral 2c-25. While DRX retransmission is in progress, the UE must monitor the PDCCH. Typically, as shown in reference numeral 2c-30, scheduling information for HARQ retransmission is received while the DRX retransmission timer is running. If scheduling information is received, the UE immediately stops the DRX retransmission timer and restarts the HARQ RTT timer. This process is repeated until packets are successfully received as shown in reference numeral 2c-35.

[0288] Configuration information related to DRX operation in connected mode is sent to the UE in the RRC Connection Reconfiguration message. Each of the on-time duration timer, DRX inactivity timer, and DRX retransmission timer corresponds to multiple subframes. The timer expires if a predetermined number of PDCCH subframes are reached after the timer starts. In Frequency Division Duplex (FDD), all downlink subframes are PDCCH subframes; in Time Division Duplex (TDD), downlink and special subframes are PDCCH subframes. In TDD, downlink, uplink, and special subframes exist in the same frequency band. Downlink and special subframes are considered PDCCH subframes.

[0289] The eNB can be configured with two DRX states: longDrx and shortDRX. Taking into account power preference indication information reported by the UE, UE mobility log information, and the characteristics of the configured DRB, the eNB can use one of the two DRX states. The transition between the two states is triggered by the expiration of a timer or by the transmission of a predetermined MAC CE from the eNB to the UE.

[0290] However, it is difficult to dynamically adjust the length of the DRX cycle based on DRB characteristics, service mode, and buffer status using only the two DRX cycles specified in LTE.

[0291] This disclosure proposes a DRX operation that can dynamically adjust the length of the DRX period or the DRX inactivity timer based on DRB characteristics, service mode, and buffer state. Here, DRB characteristics, service mode, and buffer state can be referred to as data communication information. That is, in this disclosure, the eNB can dynamically adjust the DRX period or timer value based on the data communication information.

[0292] Specifically, the eNB configures a default DRX period or a default DRX inactivity timer for the UE and uses MAC CE to dynamically adjust the length of the DRX period. This disclosure also proposes a method to stop DRX operation upon receiving a beam measurement report (particularly a new optimal beam report) and maintain the activity time.

[0293] Figure 2D The concept of DRX operation in the connection mode according to this disclosure is illustrated.

[0294] In this disclosure, the eNB can configure DRX functionality for the UE using a default DRX period and a default drx-InactivityTimer. In this disclosure, the DRX period and DRX-related timer values ​​initially configured by the eNB for the UE can be referred to as the initial DRX period and initial DRX-related timers, and the eNB can configure at least one initial DRX period and at least one initial DRX-related timer for the UE. Examples of DRX-related timers here include the aforementioned drx-InactivityTimer and drx-retransmissionTimer.

[0295] If DRX functionality is configured for the UE, the UE initiates DRX operation at a predetermined time. DRX operation begins using the default DRX period 2d-10. The UE monitors the control channel during the onDuration period 2d-05 of each period. The control channel may include downlink or uplink scheduling information for the UE. The onDuration period is also configured by the eNB.

[0296] Simultaneously, as shown in reference numeral 2d-15, the eNB can check DRB characteristics, service mode, buffer status, and frame structure. If a shorter DRX period is required, the eNB can use a predefined MAC CE 2d-20 to adjust the DRX period as shown in reference numerals 2d-30 and 2d-40, and the drx-InactivityTimer value as shown in reference numerals 2d-25 and 2d-35. The MAC CE includes the new DRX period or drx-InactivityTimer value. Here, the MAC CE carrying the DRX period or drx-InactivityTimer value can be referred to as DRX reconfiguration information, and the information changed by the MAC CE can be referred to as DRX parameters. Although the description focuses on the case of changing the DRX period or DRX-related timer values ​​by means of the MAC CE, this disclosure is not limited thereto. For example, the eNB can use the MAC CE to change other DRX-related information (DRX parameters) included in the DRX configuration information, as well as the DRX period and DRX-related timer values.

[0297] New parameter values ​​can be provided in various ways. Although this embodiment focuses on changing the value of drx-InactivityTimer for ease of explanation, this disclosure is not limited to this embodiment. That is, this disclosure can be applied to changing the value of any of all DRX-related timers.

[0298] - Option 1: MAC CE can include information about the default DRX period and the multiple of the default drx-InactivityTimer value (or the index corresponding to the multiple), such as 1 / 4, 1 / 2, 2, 4, 6, and 8 times the default DRX period and the default drx-InactivityTimer value.

[0299] - Option 2, MAC CE can include the DRX period to be applied and the absolute value (or the index corresponding to the absolute value) of the default drx-InactivityTimer value.

[0300] In option 1, the eNB sends information about the default DRX period and a multiple of the default drx-InactivityTimer, or an index corresponding to the multiple, to the UE in the MAC CE. The UE can then obtain the DRX period and timer value based on the default DRX period and the default drx-InactivityTimer value, along with the information contained in the MAC CE. The information about the multiple of the default DRX period value and the information about the multiple of the default drx-InactivityTimer value can be configured separately and differently. Alternatively, the information about the multiple of the default DRX period value and the information about the multiple of the default drx-InactivityTimer value can be configured identically.

[0301] In addition, the eNB can change one of the default DRX period and the default drx-InactivityTimer value by sending information about a multiple of the default DRX period and the default drx-InactivityTimer value to the UE in the MAC CE.

[0302] For example, if MAC CE includes a value of 1 / 4, the UE applies the DRX period corresponding to 1 / 4 of the default DRX period. If configured to apply the information about the multiplier equally to the default DRX period and the default drx-InactivityTimer value, the UE can apply the inactivity timer value of 1 / 4 of the default drx-InactivityTimer.

[0303] If information about the multiple of the default DRX period value and information about the multiple of the default drx-InactivityTimer value are configured separately, the UE can maintain the default drx-InactivityTimer value.

[0304] When using option 2, the eNB can include at least one of the DRX period and drx-InactivityTimer value in the MAC CE. The UE can operate using the DRX period and drx-InactivityTimer value included in the MAC CE.

[0305] In this disclosure, the eNB can configure two or more DRX-related timer values ​​for the UE and use MAC CE to change the DRX-related timer values.

[0306] Typically, applying a short DRX period involves reducing the arrival interval (difference in packet arrival times) in a service mode. In next-generation mobile communication systems, the frame structure can even be altered depending on the objective. For example, if a shorter latency is required, the Transmission Time Interval (TTI) may be reduced. This implies a reduction in the Reduction Time Limit (RRT). Here, even with a shorter drx-inactivityTimer, UE power consumption can be reduced without compromising performance.

[0307] New parameter values ​​can be applied immediately after receiving a MAC CE or at a predetermined time. A new MAC CE can be defined to trigger a DRX operation.

[0308] The predetermined time point can be configured by the eNB or pre-configured at the UE. This time point can be indicated by the number of subframes that have arrived since the MACCE was received.

[0309] The value applied by the new application is valid for the specified time period or until the specified event occurs. If the specified time period expires or the specified event occurs, the parameter is initialized to the default value or updated to a new value.

[0310] The pre-defined time period can be configured by the eNB and sent to the UE. The pre-defined time period can be provided as a timer or a multiple of the default DRX period. The pre-defined time period can also be fixed to a pre-defined value. The applied value can be initialized to a default value or updated to a new value.

[0311] As shown in reference numeral (2d-55), if any of the DRB characteristics, service mode, buffer state, and frame structure changes, and a MAC CE (2d-50) including the new value is received, then the UE applies the new value, as shown in reference numerals 2d-35 and 2d-40. If a MAC CE indicating initialization to the default value is received, the UE applies the default value.

[0312] Figure 2E The signal flow during the DRX process of a UE according to this disclosure is shown.

[0313] In step 2e-15, UE 2e-05 can receive DRX configuration information from eNB 2e-10.

[0314] If the DRX period and drx-InactivityTimer value to be applied are not the default DRX period and default drx-InactivityTimer value, then the DRX configuration information includes at least one timer value (or a multiple of the default DRX value instead of the timer value) and the start time point for applying the non-default values.

[0315] If DRX configuration information is received, UE 2e-05 will either immediately initiate DRX operation based on the configuration information or initiate DRX operation at a predetermined time. Alternatively, in 2e-20, eNB 2e-10 can send a MAC CE to UE 2e-05 (which is newly defined to trigger DRX operation). In this case, the UE can perform DRX operation immediately upon receiving the new MAC CE or perform DRX operation at a predetermined time.

[0316] Next, in step 2e-25, the eNB 2e-10 can calculate the optimal DRX period or drx-InactivityTimer value based on various information such as DRB characteristics, service mode, buffer status and frame structure.

[0317] In step 2e-30, UE 2e-05 can collect information about DRX features, service modes, and buffer status, and in step 2e-35 send the information to eNB 2e-10 to help eNB generate optimal DRX configuration information.

[0318] If it is determined that the DRX period or DRX-related time will be reset to a new value instead of the current default value, then in step 2e-40, eNB 2e-10 will send a MAC CE including the new value to UE 2e-05.

[0319] As described above, the eNB 2e-10 can send a MAC CE to the UE 2e-05 including information about a multiple of at least one of the DRX period and DRX-related timer values. As described above, the multiples of the DRX period value and the multiples of the DRX-related timer values ​​can be configured independently. The eNB 2e-10 can send a MAC CE to the UE 2e-05 including at least one of the DRX period value and DRX-related timer values.

[0320] If a MAC CE is received, the UE 2e-05 applies the newly configured values ​​immediately or at a predetermined time. Information regarding the predetermined time can be configured based on DRX configuration information or pre-configured by the UE 2e-05.

[0321] In step 2e-45, UE 2e-05 applies the newly configured value to DRX operation during a predetermined time period or until a predetermined event occurs. Here, the newly configured value, based on information included in the MAC CE, may be referred to as a temporary DRX period value and a temporary DRX-related timer value.

[0322] In step 2e-50, eNB 2e-10 may send a MAC CE to UE 2e-05 to apply a default value or a newly configured value. If a MAC CE is received from eNB 2e-10, then in step 2e-55, UE 2e-05 updates the DRX cycle or initializes the DRX cycle to the default value.

[0323] Figure 2FA The DRX operation of the UE according to this disclosure is shown.

[0324] In step 2f-05, the UE receives DRX configuration information from the eNB. As described above, if the DRX period and drx-InactivityTimer value to be applied are not the default DRX period and default drx-InactivityTimer value, the DRX configuration information includes at least one timer value (or a multiple of the default DRX value instead of the timer value) and the start time point for applying the non-default value.

[0325] In step 2f-10, after receiving the DRX configuration information, the UE initiates DRX operation at a predetermined time. The eNB can send a MAC CE to trigger the DRX operation, and the UE can execute the DRX operation immediately upon receiving the MAC CE or at a predetermined time.

[0326] In step 2f-15, the UE receives a DRX MAC CE (or DRX configuration information). The MAC CE may include configuration information for updating DRX parameters. The MAC CE may include a multiple of at least one of the DRX period and DRX-related timer values, or a new DRX period and drx-InactivityTimer value.

[0327] If new DRX configuration information is received, then in step 2f-20, the UE stops the currently running onDurationTimer and drx-InactivityTimer.

[0328] The UE applies the new parameter values ​​immediately upon receiving the MAC CE or at a predetermined time point (steps 2f-25). Here, the predetermined time point can be configured based on the DRX configuration information or pre-configured by the UE, and has been described in detail above, so it is omitted here.

[0329] In steps 2f-30, the UE initializes the parameters to default values ​​or updates them to new values ​​after a predetermined time period or when a predetermined event occurs. Specifically, the UE can initialize the DRX period and DRX-related timers to default values ​​when the predetermined time period expires. The eNB can send a MAC CE, and the UE can update the DRX period and DRX-related timers or initialize them to default values ​​based on the information included in the MAC CE.

[0330] Figure 2FB The DRX operation of an eNB according to this disclosure is shown.

[0331] In steps 2f-35, the eNB sends DRX configuration information to the UE. As described above, if the DRX period and drx-InactivityTimer value to be applied are not the default DRX period and default drx-InactivityTimer value, the DRX configuration information includes at least one timer value (or a multiple of the default DRX value instead of the timer value) and the start time point for applying the non-default value.

[0332] In steps 2f-40, the eNB calculates the optimal DRX parameters (DRX period and drx-InactivityTimer) based on various information such as DRB characteristics, service mode, buffer state and frame structure.

[0333] In steps 2f-45, the eNB may send a DRX MAC CE (or DRX configuration information) to the UE. The MAC CE may include configuration information for updating DRX parameters. The MAC CE may include a multiple of at least one of the DRX period and DRX-related timer values, or a new DRX period and drx-InactivityTimer value.

[0334] The UE applies the new parameter values ​​immediately upon receiving the MAC CE or at a predetermined time. If a predetermined time period has elapsed or an event occurs, the UE applies the default values ​​or the new values. Here, the eNB can update the DRX parameters or initialize them to their default values ​​by sending a MAC CE to the UE.

[0335] It is possible to consider the eNB sending DRX configuration information including two or more timer values ​​for updating DRX-related timers, and instructing the UE to select and use one of the timer values ​​by sending a MAC CE.

[0336] Figure 2G The MAC CE format according to this disclosure is shown. This disclosure proposes a new MAC CE format for providing new values.

[0337] -Option A- 1-byte structure

[0338] The first method is to use, for example Figure 2G The upper part shows the 1-byte (8-bit) MAC CE format. This 8-bit MAC CE format carries the DRX period and the relative value of drx-InactivityTimer.

[0339] Specifically, the first bit of this 8-bit array, 2g-05, indicates whether the MAC CE carries the relevant DRX cycle value. For example, this bit can be set to 0 to indicate that it does not contain the relevant DRX cycle value, or 1 to indicate that it does contain the relevant DRX cycle value.

[0340] The second bit of the 8-bit 2g-10 indicates whether the MAC CE carries the associated drx-InactivityTimer value. For example, this bit can be set to 0 to indicate that the associated drx-InactivityTimer value is not included, or 1 to indicate that the associated drx-InactivityTimer value is included.

[0341] In this way, the eNB can configure the DRX period and drx-InactivityTimer value separately. Three bits of the remaining bits are used to indicate the relevant DRX period value. For example, if the new value is one of the multiples of the default value (i.e., 1 / 8, 1 / 6, 1 / 4, 1 / 2, 2, 4, 6, and 8), the index of each multiple can be indicated using 3 bits. That is, the multiples can be mapped to the individual indices as follows.

[0342]

[0343] The remaining 3 bits, 2g-20, are used to indicate the relevant drx-InactivityTimer value. For example, if the new value is one of the multiples of the default value (i.e., 1 / 8, 1 / 6, 1 / 4, 1 / 2, 2, 4, 6, and 8), the index of each multiple can be represented by 3 bits.

[0344] This indicates that the initialization should be to the default values ​​if both bits specified for determining whether the MAC CE carries the relevant DRX period and drx-InactivityTimer value are set to 0.

[0345] Within this 1-byte structure, the bit positions specified for the corresponding purpose can be changed. The reason for using the two most significant bits, 2g-05 and 2g-10, to indicate the inclusion / exclusion of the relevant DRX period and drx-InactivityTimer value in the MAC CE format is to prioritize determining whether to perform decoding on the bits following these two bits.

[0346] Three bits, 2g-15 or 2g-20, can indicate an absolute value rather than a relative value. Here, at least the absolute value differs from the default value. The absolute value can be derived from a multiple of the default value.

[0347] In this disclosure, multiple value information or absolute values ​​can be used to update parameters other than the DRX period and drx-InactivityTimer. In this case, the number of bits in the MAC CE used for other parameters can be increased, the number of bits in the relevant multiple value information indication field can be reduced to 2 bits to carry multiple value information for other DRX parameters, or one of the DRX period and drx-InactivityTimer indication fields can be used for other DRX parameters.

[0348] -Option B- 2-byte structure

[0349] The second method is to use, for example Figure 2G The lower part shows the 2-byte (16-bit) MAC CE format. The 16-bit MAC CE format carries the DRX period and the relative value of drx-InactivityTimer.

[0350] Specifically, the first bit 2g-25 of the first byte indicates whether the MAC CE carries the value of the relevant DRX cycle. For example, this bit is set to: 0 to indicate that no relevant DRX cycle value is included; or 1 to indicate that a relevant DRX cycle value is included.

[0351] In addition, the first bit 2g-35 of the second byte indicates whether the MAC CE carries the relevant drx-InactivityTimer value. For example, this bit can be set to 0 to indicate that the relevant drx-InactivityTimer value is not included, or 1 to indicate that the relevant drx-InactivityTimer value is included.

[0352] In this way, the eNB can configure the DRX period and drx-InactivityTimer value separately. The remaining 7 bits of the first byte, 2g-40, are used to carry the relevant DRX period value. Here, an index indicating the multiplier (multiplier information) can be carried in these 7 bits. The 7 bits can carry an absolute value instead of a relative value.

[0353] In addition, the remaining 7 bits of the second byte, 2g-45, are used to carry the associated drx-InactivityTimer value. Here, an index indicating the multiplier value (multiplier information) can be carried in these 7 bits. These 7 bits can carry an absolute value rather than a relative value.

[0354] As mentioned above, if the first bit of the first byte and the first bit of the second byte, which are specified for determining whether the MAC CE carries the relevant DRX period and drx-InactivityTimer value, are both set to 0, this can indicate that the initialization is to the default value.

[0355] The position of the corresponding destination bit in this 2-byte structure can be changed. The reason for using the most significant bits 2g-25 and 2g-35 of the first and second bytes to indicate whether the relevant DRX period and drx-InactivityTimer value in the MAC CE format are included or not is to prioritize determining whether to perform decoding on the bits following these two bits.

[0356] In this disclosure, multiple values ​​or absolute values ​​can be used to update parameters other than the DRX period and drx-InactivityTimer. In this case, the number of bits in the MAC CE used for other parameters can be increased, the number of bits in the relevant multiple value information indication field can be reduced to 2 bits to carry multiple value information for other DRX parameters, or one of the DRX period and drx-InactivityTimer indication fields can be used for other DRX parameters.

[0357] Figure 2H The optimal beam pair according to this disclosure is shown.

[0358] In next-generation mobile communication systems, beamforming antennas optimized for very narrow frequency bandwidths can be used. UE 2h-05 and eNB 2h-10 can utilize beamforming. Multiple beams can be formed at different angles to transmit / receive signals in corresponding directions. The eNB and UE ignore all beams except those formed for transmitting and receiving signals to and from them. Although beamforming can be used to transmit / receive data in other directions, little performance improvement can be expected due to the very low beamforming antenna gain. Conversely, beamforming in other directions may interfere with other UEs and / or eNBs.

[0359] In this disclosure, one of the eNB and UE must form a beam in a direction toward the other for data transmission / reception, and these beams are referred to as the optimal beam pair.

[0360] refer to Figure 2H The goal is to achieve maximum beam antenna gain using the first beam (2h-15) formed by UE B towards the eNB and the ninth beam (2h-20) formed by UE B towards the eNB. In this case, the two beams can be shown to be in the optimal beam pair state, as indicated by reference numeral 2h-25.

[0361] Meanwhile, the optimal beam pair may change as the UE moves. To maximize data communication efficiency, the optimal beam pair needs to be maintained regardless of the UE's movement. The optimal beam pair is determined on its own beam or the other party's beam through beam measurement performed by the UE or eNB.

[0362] In other words, the UE sends beam measurement information about the beam with the maximum signal strength gain to the eNB, and the eNB sends beam configuration information (BCC) to the UE to inform the UE of the optimal beam pair for data communication. If the optimal beam pair changes as the UE moves, the eNB can notify the UE of the changed optimal beam pair. The reconfiguration process for the optimal beam pair should be completed as soon as possible to prevent performance degradation.

[0363] However, if the UE is in DRX mode, the optimal beam pair reconfiguration process can be delayed.

[0364] Figure 2I The DRX operation in the beam measurement result reporting process according to this disclosure is illustrated.

[0365] The UE performs beam measurement during the pass duration segment 2i-02 within a DRX cycle 2i-05 to save power.

[0366] As shown in reference numeral 2i-10, the UE can identify that the current beam pair is not the optimal beam pair for data communication.

[0367] If the UE realizes that the current beam pair is not the optimal beam pair for data communication, it must report this to the eNB. Since the optimal beam pair reconfiguration should be completed as quickly as possible, as shown in reference numeral 2i-15, the UE immediately reports the new beam measurement results (optimal beam) to the eNB while ignoring the DRX cycle. In other words, the UE can stop DRX operation and report the beam measurement results to the active eNB.

[0368] Assuming the eNB reconfigures the optimal beam pair upon receiving a report, the UE waits for the optimal beam pair to be reconfigured. If the eNB provides the UE with beam reconfiguration information consistent with the DRX period, this could result in a delay as long as the maximum DRX period. This disclosure allows the UE to report beam measurement results to the eNB regardless of the DRX period. The beam measurement results may include information indicating that the optimal beam has been changed or modified optimal beam information (BBI). If the UE is scheduled to receive beam configuration information from the eNB, then, as shown in reference numerals 2i-25, the UE stops or suspends DRX operation for a predetermined time period or until a predetermined event occurs (e.g., receiving beam configuration information from the eNB). During the DRX operation suspension period, the UE remains in an active-time state (2i-20).

[0369] While maintaining the active time state, the UE can perform beam measurements regardless of the DRX cycle. The predetermined time period can be configured by the eNB or predetermined. This time period is determined by taking into account the eNB's processing time and RTT, making it a value longer than the RTT.

[0370] If the predetermined time period expires or if a predetermined event occurs, the UE will immediately or at the predetermined time point, as shown in reference numerals 2i-30. Here, the predetermined event may be an event that receives beam configuration information, and the UE may determine the optimal beam based on the beam configuration information and resume DRX operation immediately or at the predetermined time point.

[0371] Figure 2J The process for reporting beam measurement results according to this disclosure is illustrated.

[0372] In step 2j-15, UE 2j-05 and eNB 2j-10 check beam-based functional supportability.

[0373] In detail, UE 2j-05 reports its beam-based functional capabilities to eNB 2j-10 in a pre-defined RRC message. For example, the UE can send UE Capability information from the RRC message to eNB 2j-10.

[0374] In addition, the eNB 2j-10 can broadcast its beam-based functionality support information in system information to UEs within its service area.

[0375] In step 2j-20, eNB 2j-10 sends at least one of beam-based measurement configuration information and DRX configuration information to UE 2j-05 in an RRC message.

[0376] In steps 2j-25, upon receiving an RRC message, the UE applies configuration information to perform beam measurement and DRX operations.

[0377] As described above, in steps 2j-30, DRX operation can be initiated after receiving a predetermined MAC CE. However, this disclosure is not limited to this, but may include initiating DRX operation at UE 2j-05 after a predetermined time period (a predetermined number of frames) following the receipt of the DRX configuration.

[0378] UE 2j-05 performs measurements on multiple beams from eNB 2j-10. Based on the beam measurement results, it can be determined that the current beam pair is not the optimal beam pair.

[0379] Therefore, in step 2j-35, UE 2j-05 can identify changes in the optimal beam pair based on the beam measurement results. In step 2j-40, the UE can adjust the current beam pair to maintain the optimal beam pair and report the optimal beam information (optimal beam indication) to eNB 2j-10.

[0380] Then, in step 2j-45, UE 2j-05 suspends DRX operation and remains in the active time state. UE 2j-05 reports the optimal beam information to eNB 2j-10 and stops the currently running DRX operation.

[0381] Next, in step 2j-50, UE 2j-05 can receive new beam configuration information (or beam change command) from eNB 2j-10. If the predetermined time period in step 2j-50 expires or new beam configuration information is received from eNB 2j-10, then in step 2j-55, UE 2j-05 can apply the new optimal beam pair.

[0382] Then, in step 2j-60, UE 2j-05 resumes DRX operation.

[0383] Figure 2KA The UE operation during the beam measurement result reporting process according to this disclosure is illustrated.

[0384] The UE can send an RRC message containing UE capability information to the eNB to notify the eNB of its beam-based functional capabilities. The UE can obtain the eNB's beam-based functional supportability from system information broadcast by the eNB. In this way, the UE and eNB can check the beam-based functions they can support.

[0385] In step 2k-05, the UE can receive at least one of beam measurement configuration information and DRX configuration information from the eNB. The UE can obtain the configuration information from the RRC message sent by the eNB.

[0386] In steps 2k-10, the UE receives configuration information and begins beam measurement and DRX operation immediately or at a predetermined time. Information regarding the start time of beam measurement and DRX operation can be included in the configuration information. The UE may begin beam measurement and DRX operation after receiving the MAC CE.

[0387] Next, in steps 2k-15, the UE periodically performs beam measurements to check for changes in the optimal beam pair.

[0388] In steps 2k-20, the UE can report the change in the optimal beam pair to the eNB, suspend the currently running DRX operation, and maintain the activity duration. Here, the UE can send the optimal beam information to the eNB. The UE can also send information to the eNB indicating that the optimal beam pair has changed.

[0389] In steps 2k-25, the UE maintains activity for a predetermined time period or until a predetermined event occurs, and then immediately or at a predetermined time point restarts DRX operation.

[0390] As described above, a pre-defined event could be receiving new beam configuration information from the eNB. The UE can then receive information about the new optimal beam pair from the eNB and resume DRX operation.

[0391] Information about the predetermined time period for resuming DRX operation can be included in the DRX configuration information, and the UE can resume DRX operation after the predetermined time period expires.

[0392] Figure 2KB The eNB operation in the beam measurement result reporting process according to this disclosure is illustrated.

[0393] The eNB can obtain UE capability information from RRC messages sent by the UE to check the UE's beam-based functional capabilities. The eNB can also broadcast its beam-based functional support in system information.

[0394] In steps 2k-35, the eNB may send at least one of beam measurement configuration information and DRX configuration information. The eNB may send the configuration information in an RRC message.

[0395] Then, in steps 2k-40, the eNB can send a MAC CE to trigger the UE's DRX operation. However, if the information about the DRX start time is included in the DRX configuration information or is predetermined, the step of sending the MAC CE can be omitted.

[0396] If the optimal beam pair changes, then in steps 2k-45, the eNB can receive information about the optimal beam. The eNB can also receive information indicating that the optimal beam pair has changed.

[0397] Then, in step 2k-50, the eNB can send new beam configuration information to the UE indicating the new optimal beam pair.

[0398] Figure 2L The configuration of the UE according to this disclosure is shown.

[0399] refer to Figure 2LThe UE includes an RF processing unit (RF processor) 21-10, a baseband processing unit (baseband processor) 21-20, a memory 21-30, and a controller 21-40. In this invention, the controller 21-40 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to a transceiver.

[0400] RF processing unit 21-10 can perform operations related to... Figure 1J It has the same function as the RF processing unit 1j-10, so its detailed description is omitted here.

[0401] Baseband processing units 21-20 can perform operations related to... Figure 1J It has the same function as the baseband processing unit 1j-20, so its detailed description is omitted here.

[0402] As described above, the baseband processing unit 21-20 and the RF processing unit 21-10 participate in signal transmission and reception. Therefore, the baseband processing unit 21-20 and the RF processing unit 21-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit. (See also...) Figure 1J Its detailed description has been provided, and therefore omitted here. Memory 21-30 can be functionally related to the reference. Figure 1J The memory 1j-30 described is the same, so its detailed description is omitted here.

[0403] Controllers 21-40 control the overall operation of the UE. For example, controllers 21-40 transmit / receive signals via baseband processing unit 21-20 and RF processing unit 21-10. Controllers 21-40 write data to and read data from memory 21-30. For this purpose, controllers 21-40 may include at least one processor (multi-connection processor 21-42), and the controller may be coupled to a transceiver. For example, controllers 21-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher-level applications.

[0404] Specifically, controller 21-40 can control the UE to send an RRC message including UE capability information to the eNB to notify the eNB of its beam-based functional capabilities. Controller 21-40 can also control the UE to obtain information about the eNB's beam-based functional support from system information broadcast by the eNB. In this way, the UE and eNB can check the beam-based functionalities they support. Controller 21-40 can also control the UE to receive DRX configuration information.

[0405] Controller 21-40 can control the UE to start DRX operation immediately upon receiving DRX configuration information or at a predetermined time after receiving DRX configuration information. Controller 21-40 can also control the UE to perform DRX operation immediately upon receiving MAC CE or at a predetermined time after receiving MAC CE.

[0406] Controllers 21-40 can also control the UE to receive DRX MAC CE (or DRX reconfiguration information). The DRX MAC CE may include configuration information for changing DRX parameters. The MAC CE may include a multiple of at least one of the DRX period and DRX-related timer values, or a new DRX period and drx-InactivityTimer value.

[0407] If new DRX reconfiguration information is received, controllers 21-40 can stop the currently running onDurationTimer and drx-InactivityTimer.

[0408] Controller 21-40 applies new parameter values ​​immediately upon receiving a MAC CE or at a predetermined time. Subsequently, when the predetermined time period expires or a predetermined event occurs, controller 21-40 applies default values ​​or newly selected values. Specifically, the UE can apply a default DRX time period and default DRX-related timer values ​​when the predetermined time period expires. Furthermore, the UE can send a MAC CE, and the UE can update the DRX period and DRX-related timers or initialize them to default values ​​based on the information included in the MAC CE.

[0409] According to an alternative embodiment, controllers 21-40 can control the UE to receive at least one of beam measurement configuration information and DRX configuration information from the eNB.

[0410] Controller 21-40 controls the UE to start beam measurement and DRX operation immediately upon receiving configuration information or at a predetermined time after receiving the configuration information. Controller 21-40 may periodically perform beam measurement to check for changes in the optimal beam pair.

[0411] Controller 21-40 can control the UE to report changes in the optimal beam pair to the eNB, suspend the currently running DRX operation, and maintain the activity duration. Here, controller 21-40 can control the UE to send information about the optimal beam to the eNB. Controller 21-40 can also control the UE to send information to the eNB indicating that the optimal beam pair has changed.

[0412] Controllers 21-40 maintain activity for a predetermined time period or until a predetermined event occurs, and then immediately or at the predetermined time point resume DRX operation. As described above, the predetermined event could be receiving new beam configuration information from the eNB. Controllers 21-40 can control the UE to receive information from the eNB about the new optimal beam pair and resume DRX operation.

[0413] Information about the predetermined time period for resuming DRX operation can be included in the DRX configuration information, and controllers 21-40 can control the UE to resume DRX operation after the predetermined time period expires.

[0414] Figure 2M The configuration of an eNB according to this disclosure is shown.

[0415] like Figure 2M As shown, the eNB includes an RF processing unit (RF processor) 2m-10, a baseband processing unit (baseband processor) 2m-20, a backhaul communication unit 2m-30, a memory 2m-40, and a controller 2m-50. In this disclosure, the controller 2m-50 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to a transceiver.

[0416] The RF processing unit 2m-10 can perform operations with... Figure 1K It has the same function as the RF processing unit 1k-10, so its detailed description is omitted here.

[0417] The baseband processing unit 2m-20 can perform operations with... Figure 1K It has the same function as the baseband processing unit 1k-20, so its detailed description is omitted here.

[0418] The baseband processing unit 2m-20 and the RF processing unit 2m-10 are involved in signal transmission and reception. Therefore, the baseband processing unit 2m-20 and the RF processing unit 2m-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit.

[0419] The 2m-30 backhaul communication unit can perform communication with... Figure 1K It has the same function as the 1k-30 backhaul communication unit, so its detailed description is omitted here.

[0420] The 2m-40 memory can execute with Figure 1K It has the same function as the 1k-40 memory. Therefore, its detailed description is omitted here.

[0421] The controller 2m-50 controls the overall operation of the master eNB. For example, the controller 2m-50 transmits / receives signals via a baseband processing unit 2m-20 and an RF processing unit 2m-10. The controller 2m-50 writes data to and reads data from the memory 2m-40. For this purpose, the controller 2m-50 may include at least one processor (multi-connection processor 2m-52), and the controller may be coupled to a transceiver.

[0422] In detail, the controller 2m-50 controls the eNB to send DRX configuration information to the UE. The controller 2m-50 can calculate the optimal DRX parameter (DRX period and drx-InactivityTimer) values ​​based on various information such as DRB characteristics, service mode, buffer state and frame structure.

[0423] The controller 2m-50 can control the eNB to send a DRX MAC CE (or DRX configuration information) to the UE. The MAC CE may include configuration information for updating DRX parameters. The MAC CE may include a multiple of at least one of the DRX period and DRX-related timer values, or a new DRX period and drx-InactivityTimer value.

[0424] The controller 2m-50 can control the eNB to send the MAC CE to the UE to change the DRX configuration information or initialize the DRX parameters to the default DRX parameter values.

[0425] It is possible to consider having the controller 2m-50 control the eNB to send DRX configuration information including two or more timer values ​​for updating DRX-related timers, and instruct the UE to select and use one of the timer values ​​by sending a MAC CE.

[0426] According to another embodiment of this disclosure, the controller 2m-50 can check the beam-based functional capabilities of the UE based on UE capability information included in the RRC message sent by the UE. The controller 2m-50 can use its broadcast system information to notify the UE of its beam-based functional supportability.

[0427] The controller 2m-50 can control the eNB to send at least one of beam measurement configuration information and DRX configuration information. The controller 2m-50 can also control the eNB to send a MAC CE to trigger DRX operation of the UE. However, if information regarding the DRX start time is included in the DRX configuration information or is predetermined, the MAC CE may not be sent.

[0428] If the optimal beam pair is changed, the controller 2m-50 can control the eNB to receive information about the optimal beam. The controller 2m-50 can also control the eNB to receive information indicating that the optimal beam pair has been changed.

[0429] The controller 2m-50 can control the eNB to send new beam configuration information to the UE, indicating the new optimal beam pair.

[0430] Third Embodiment

[0431] Figure 3A The architecture of the LTE system is shown. (Already referenced...) Figure 1A The LTE system architecture has been described in detail, so it is omitted here.

[0432] Figure 3B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0433] refer to Figure 3B In the LTE system, the protocol stack of the interface between the UE and the eNB includes the PDCP layer represented by reference numerals 3b-05 and 3b-40, the RLC layer represented by reference numerals 3b-10 and 3b-35, the MAC layer represented by reference numerals 3b-15 and 3b-30, and the PHY layer represented by reference numerals 3b-20 and 3b-25.

[0434] The PDCP layer, denoted by reference numerals 3b-05 and 3b-40, is responsible for compressing / decompressing the IP header, and the RLC layer, denoted by reference numerals 3b-10 and 3b-35, is responsible for segmenting the PDCP PDU into segments of appropriate size.

[0435] The MAC layer, denoted by reference numerals 3b-15 and 3b-30, allows the establishment of connections between multiple RLC entities for a UE and is responsible for multiplexing RLC PDUs from the RLC layer into MAC PDUs and demultiplexing MAC PDUs into RLC PDUs.

[0436] The PHY layer, denoted by reference numerals 3b-20 and 3b-25, is responsible for channel coding and modulation of higher-layer data to generate and transmit OFDM symbols via radio channels, and for demodulating and channel decoding of OFDM symbols received via radio. The decoded data is then passed to higher layers. The PHY layer, denoted by reference numerals 3b-20 and 3b-25, performs additional error correction using Hybrid Automatic Repeat Request (HARQ) by sending a 1-bit message indicating a positive or negative acknowledgment of a data packet, where the acknowledgment is sent from the receiver to the transmitter. This 1-bit message is called an Acknowledgment / Negative Acknowledgment (ACK / NACK). Downlink HARQ ACK / NACK corresponding to uplink transmissions can be sent on the Physical Hybrid ARQ Indicator Channel (PHICH), and uplink HARQ ACK / NACK corresponding to downlink transmissions can be sent on the Physical Uplink Control Channel (PUCCH) or the Physical Uplink Shared Channel (PUSCH).

[0437] HARQ schemes are generally divided into two types: asynchronous HARQ and synchronous HARQ. Asynchronous HARQ is characterized by a non-fixed retransmission timing, while synchronous HARQ is characterized by a fixed retransmission time (e.g., 8ms). For a single UE, multiple transmissions can be performed simultaneously in both the downlink and uplink, and each transmission is identified by a corresponding HARQ procedure identifier.

[0438] Because retransmission timing is not fixed in asynchronous HARQ, the eNB sends the HARQ procedure identifier (ID) and information about whether the current transmission is a new transmission or a retransmission to the UE via the Physical Downlink Control Channel (PDCCH). Specifically, the HARQ procedure ID is included in the HARQ procedure ID field of the PDCCH, and the New Data Indicator (NDI) bit of the PDCCH indicates whether the current transmission is a new transmission or a retransmission. For a retransmission, the NDI bit is toggled; for a new transmission from a previous transmission, the NDI bit is not toggled. Therefore, the UE checks the details of the corresponding transmission based on the resource allocation information included in the PDCCH sent by the eNB to receive downlink data via the Physical Downlink Shared Channel (PDSCH) and send uplink data via the Physical Uplink Shared Channel (PUSCH).

[0439] Although now shown in the accompanying drawings, the Radio Resource Control (RRC) layer sits above the PDCP layer in the UE and eNB, and it can exchange connection and measurement-related RRC control messages.

[0440] Figure 3C The network environment in which this disclosure is applied is shown.

[0441] exist Figure 3C In this system, the cell is managed by a central unit (CU) 3c-01, and one CU controls one or more distributed units (DUs) 3c-11, 3c-13, 3c-15, 3c-17, 3c-21, 3c-23, 3c-25, 3c-27, 3c-29, 3c-31, 3c-33, and 3c-35. The cell can have a very large coverage area 3c-61, meaning that when data destined for a terminal arrives, the paging area is too large to effectively send paging messages to wake up terminals in idle mode.

[0442] In this disclosure, the cell is divided into multiple paging areas 3c-51, 3c-53 and 3c-55, enabling the network to broadcast paging messages within the paging area where the target terminal is located.

[0443] For example, if a terminal is located near a transmit / receive antenna (or transmit / receive port; TRP) 3c-11 or receives different TRP identifiers (TRP IDs) from multiple TRPs, it reports this to the network that broadcasts the paging message in the corresponding paging area (i.e., paging area 1: 3c-51).

[0444] Figure 3D The proposed paging process between the terminal and the network according to this disclosure is illustrated.

[0445] exist Figure 3D In the exemplary case, it is assumed that terminal 3d-01 is in idle mode and is close to TRP 1 3d-03. Therefore, in step 3d-11, terminal 3d-01 receives the TRP ID or beam identifier (BI) sent by TRP 1 3d-03.

[0446] In step 3d-13, terminal 3d-01 can receive a system information block broadcast by 5G NB 1 (or CU) 3d-07. The system information block is equivalent to the System Information Block in LTE and is used to broadcast cell-specific information to terminals within the cell. The system information block includes a paging area identifier (corresponding to the tracking area code in LTE) and a set of TRP IDs (or BIs) for forming the paging area.

[0447] Terminal 3D-01 can identify the paging area based on system information blocks (e.g., Figure 3C The paging areas are 3c-51, 3c-53, and 3c-55. Figure 3CIn an exemplary scenario, the 5G NB can broadcast information about the TRPs belonging to the corresponding paging areas 3c-51, 3c-53, and 3c-55; if the terminal is located in paging area 1 (3c-51), the 5G NB can notify that paging area 1 (3c-51) is formed using TRPs 3c-11, 3c-13, 3c-15, and 3c-17.

[0448] Upon receiving the system information block, if its location has not yet been registered with the network for receiving paging messages, then in step 3d-15, terminal 3d-01 sends a paging area update message to register its location with the network. In this exemplary case, such as Figure 3C As shown, for ease of explanation, it is assumed that the terminal is located near TRP 3c-17.

[0449] Paging area update messages can be sent to 5G NB 3d-07 and MME 3d-09 (equivalent to MME in LTE). Therefore, the terminal may need to register its location with the 5G NB and MME, which broadcast paging messages to notify the terminal of the arrival of packets destined for it. If a packet destined for the terminal arrives, in step 3d-21, MME 3d-09 can send a paging message to 5G NB 1 (3d-07), in step 3d-23, 5G NB 1 (3d-07) can send the paging message to TRP 1 (3d-03) belonging to the corresponding paging area, and then in step 3d-25, TRP 1 (3d-03) broadcasts the paging message.

[0450] exist Figure 3D In an exemplary scenario, in step 3d-29, terminal 3d-01 moves from one paging area to another. In the following description, as... Figure 3C As shown, for ease of explanation, it is assumed that the terminal moves closer to TRP 3c-23.

[0451] In steps 3d-31, terminal 3d-01 receives a TRP ID from TRP 2 (3d-05) belonging to the new paging area. Based on the TRP ID received in step 3d-31, terminal 3d-01 knows that it has moved to a location close to TRP 2 (3d-05) belonging to the new paging area. Next, in step 3d-35, terminal 3d-01 sends a paging area update message to register its current location with the network.

[0452] In this scenario, since terminal 3d-01 has changed its paging area within the cell, it registers its location with 5G NB 1 (3d-07) in step 3d-31 without sending any signal to MME 3d-09. In other words, terminal 3d-01 can send paging update messages to 5G NB 1 (3d-07).

[0453] When terminal 3d-01 moves within the same cell as this, MME 3d-09 can send the paging message to the same 5G NB, namely 5G NB 1 (3d-07), in step 3d-41. However, since the UE has moved to a new paging area, in step 3d-43, 5G NB 1 (3d-07) sends the paging message to TRP 2 (3d-05), which belongs to the new paging area, and in step 3d-45, TRP 2 (3d-05) broadcasts the paging message.

[0454] However, in LTE, if a UE in lightly connected mode moves from one paging area to another, it switches to connected mode to send paging update messages. This can be interpreted as the UE in lightly connected mode being inactive, meaning the UE is connected to the eNB before the eNB has removed the UE (e.g., UE context). However, this can lead to the problem of the UE unnecessarily switching to connected mode even when there is no data to send or receive.

[0455] Therefore, even when a paging area update message needs to be sent, a UE in light connection mode can switch back to inactive mode instead of connected mode.

[0456] Information indicating a change in the paging area can be included, but is not limited to, in a paging area update message or a recovery request message, and the name of the message sent from the UE to the eNB can be changed.

[0457] exist Figure 3D In an exemplary case, in step 3d-49, terminal 3d-01 moves to another 5G NB, namely 5G NB 2 (3d-08) which has another paging area.

[0458] After moving to 5G NB 2 (3d-08), in step 3d-53, terminal 2d-01 can receive a system information block from 5G NB 2 (3d-08). As described above, the system information block may include a set of TRP IDs (or BIs) and paging area identifiers of the TRP forming the paging area.

[0459] Terminal 3d-01 can perform a paging area update determination based on the paging area identifier and 5G NB / cell identifier included in the system information block to receive paging messages for new cells. In step 3d-55, terminal 3d-01 can send paging area update messages to 5G NB2 (3d-08) and MME 3d-09 to register its location therein.

[0460] Subsequently, if a packet destined for terminal 3d-01 arrives at the network, a paging message can be broadcast in the correct paging area.

[0461] Figure 3E The paging area update process of a terminal according to this disclosure is illustrated.

[0462] In step 3e-03, the terminal can receive cell-specific information and system information blocks from the TRP of the 5G NB. The cell-specific information may include at least one of the cell identifier and TRP ID (or BI).

[0463] The system information block is equivalent to the LTE system information block (System Information Block) and is used to broadcast cell-specific information to terminals within the cell. The system information block includes a set of TRP IDs (or BIs) for forming the paging area and a paging area identifier (corresponding to the tracking area code in LTE).

[0464] If the above information is received, in step 3e-05 the terminal determines whether it has initially registered its location with the network or whether the paging area has been changed.

[0465] If the paging area has been changed, in step 3e-07 the terminal can determine whether the paging area change is within a 5G NB / cell or between 5G NB / cells. In other words, the terminal determines whether the paging area has changed within a cell or changed to another cell.

[0466] If it is determined that the terminal has initially registered its location or the paging area change is a 5G inter-NB / cell paging area change, then in step 3e-09, the terminal contacts the serving 5G ND and MME (e.g., Figure 3D The MME 3d-09 sends a paging area update message.

[0467] Otherwise, if it is determined that the paging area change is a paging area change of the NB / cell within 5G, then in step 3e-11, the terminal will send the paging area update message only to the 5G NB.

[0468] Figure 3F The configuration of the terminal according to this disclosure is shown.

[0469] refer to Figure 3F The terminal includes an RF processing unit (RF processor) 3f-10, a baseband processing unit (baseband processor) 3f-20, a memory 3f-30, and a controller 3f-40. In this invention, the controller 3f-40 can be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller can be coupled to a transceiver.

[0470] RF processing unit 3f-10 can perform operations with Figure 1J It has the same function as the RF processing unit 1j-10, so its detailed description is omitted here.

[0471] The baseband processing unit 3f-20 can perform operations with... Figure 1J It has the same function as the baseband processing unit 1j-20, so its detailed description is omitted here.

[0472] As described above, the baseband processing unit 3f-20 and the RF processing unit 3f-10 participate in signal transmission and reception. Therefore, the baseband processing unit 3f-20 and the RF processing unit 3f-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit. (Already referenced) Figure 1J Its detailed description is described, and therefore omitted here. The memory 3f-30 can be functionally related to the reference... Figure 1J The memory 1j-30 described is the same, so its detailed description is omitted here.

[0473] Controller 3f-40 controls the overall operation of the UE. For example, controller 3f-40 transmits / receives signals through baseband processing unit 3f-20 and RF processing unit 3f-10. Controller 3f-40 writes data to and reads data from memory 3f-30. For this purpose, controller 3f-40 may include at least one processor. For example, controller 3f-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher-level applications. According to embodiments of this disclosure, controller 3f-40 includes a multi-connection processor 3f-42 for operation in a multi-connection mode. For example, controller 3f-40 may control the terminal to perform... Figure 3E The process of operation.

[0474] According to embodiments of this disclosure, the controller 3f-40 performs paging update determination based on the system information block, cell identifier, and TRP ID received from the 5G NB, and sends the paging area update message to the 5G NB and MME, or as referred to Figure 3E The description only sends to the 5G NB.

[0475] Fourth embodiment

[0476] Figure 4A The architecture of an LTE system applying this disclosure is shown. References have been made. Figure 1A The LTE system architecture has been described in detail, so it is omitted here.

[0477] Figure 4B This illustrates the protocol stack of the interface between the terminal and the eNB in ​​an LTE system. (Already referenced...) Figure 2B and Figure 3BA detailed description of the protocol stack has been provided, so it will be omitted here.

[0478] Figure 4C The signal flow between the terminal and the base station in the signal transmission method proposed in this disclosure is shown.

[0479] Although Figure 4C This method relates to uplink data transmission from the terminal (i.e., data transmission from the terminal to the base station), but it can also be applied to downlink data transmission.

[0480] In the transmission method of this disclosure, in step 4c-11, terminal 4c-01 may send its capability information to base station 4c-03. The capability information may include UECapability carried in an RRC message. The capability information may include information indicating whether the terminal supports the method proposed in this disclosure. This disclosure proposes redundant data transmission on multiple resources to provide URLLC services, which will be described later. Therefore, the capability information may include information indicating whether the terminal supports redundant data transmission on multiple resources. The capability information may also include information indicating whether the terminal supports URLLC services.

[0481] In step 4c-13, base station 4c-03 may send configuration information to terminal 4c-01. Base station 4c-03 may send configuration information to allow the use of the transmission method proposed in this disclosure, and the configuration information may include URLLC authorization configuration information. The configuration information may be sent to terminal 4c-01 in an RRC message.

[0482] The message sent from base station 4c-03 to terminal 4c-01 may include at least one of a resource allocation period (grant period), physical resource location and transmission scheme (modulation and coding scheme (MCS)), and information about the carrier used in the transmission. The grant period is information indicating the initial transmission resources for semi-persistent resource allocation, which will be described later, and if this information is included, the base station does not need to send a resource allocation message for each transmission (e.g., the data transmission in step 4c-23).

[0483] If a configuration message is received, in step 4c-15, terminal 4c-01 can notify the base station to use the corresponding transmission method for uplink transmission of the terminal (or downlink transmission of the base station). The configuration message can be a MAC layer message or an RRC layer message used in LTE. This message can be referred to as a URLLC preference message, and if this message is received, the base station can allocate resources according to the method proposed in this disclosure.

[0484] Upon receiving a configuration message or notification message, base station 4c-03 can begin resource allocation according to the method proposed in this disclosure. The corresponding transmission method is characterized in that terminal 4c-01 transmits data in steps 4c-19 and 4c-23 based on the resource allocation message (URLLC resource grant) sent by eNB 4c-03 in steps 4c-17 and 4c-21; a detailed description is provided with reference to Figure 4D.

[0485] The resource allocation message may include at least one of the following: physical resource location and transmission scheme (modulation and coding scheme (MCS)), information about the carriers used for transmission (e.g., in bitmap form), and transmission mode. For example, if the terminal uses four of the ten component carriers configured by the base station for data transmission, the message may include information about the frequencies of the four carriers (in bitmap format). The physical resource location and transmission scheme (MCS) information may be sent per carrier frequency or as common information for the four carrier frequencies. If multiple transmission modes are configured as described later, the resource allocation message may include mode information.

[0486] However, base stations can include resource allocation information as part of their RRC configuration information. A base station can send partial resource allocation information (physical resource location, transmission method, information about the carrier to be transmitted, and transmission mode) via an RRC message, and the remaining portion via a resource allocation message transmitted on the PDCCH. For example, a base station can send transmission mode information to a terminal via an RRC message, and use a resource allocation message on the PDCCH to notify the terminal of the resource location for data transmission. A base station can send the aforementioned information via either a resource allocation message on the PDCCH or an RRC message. For example, if resource allocation information is carried in the RRC message, the terminal can transmit data according to a predetermined transmission mode and physical resource location. If the base station uses a resource allocation message to send resource allocation information, the terminal can use dynamically allocated resources based on the resource allocation information to transmit data.

[0487] Corresponding to the notification message, in step 4c-25, base station 4c-03 may send a message indicating to stop using the configured transmission method.

[0488] Figure 4DA , 4DB The 4DC illustrates a transmission method according to this disclosure.

[0489] Although the attached diagram is for uplink transmission of the UE, the same method can be applied to downlink transmission.

[0490] exist Figure 4DA to 4DCIn the diagram, the horizontal axis represents time, and the vertical axis represents frequency. The accompanying figure illustrates the concept of allocating resources to a terminal in the time domain for data transmission. Reference numeral 4d-01 denotes the resources allocated by the base station and is equivalent to the PDCCH in LTE. The base station allocates resource 4d-01 to the terminal, and resource 4d-01 may include at least one of the following: physical resource location and modulation scheme (MCS) for data transmission, carrier for data transmission (e.g., in the form of a bitmap), and transmission mode.

[0491] Based on the above information, the terminal transmits data to the base station using the modes indicated by reference numerals 4d-11, 4d-13, 4d-15, and 4d-17. Reference numerals 4d-11, 4d-13, 4d-15, and 4d-17 represent data transmitted via PUSCH in LTE, i.e., redundant versions (RVs) of the same data encoded at the physical layer using different channel coding schemes. The receiver (the base station in the figure) cumulatively combines the RVs to increase the probability of successfully receiving data.

[0492] The receiver (base station in the diagram) receives the PUSCH and then checks whether data has been continuously received through the predetermined channel. Reference numeral 4d-03 indicates the channel corresponding to the Physical Hybrid ARQ Indicator Channel (PHICH) in LTE.

[0493] The accompanying figure depicts a scenario in which data is transmitted via four component carriers (CCs), as indicated by reference numerals 4d-21, 4d-23, 4d-25, and 4d-27.

[0494] Figure 4DA The transmission method proposed in this disclosure is shown.

[0495] Figure 4DA Parts (4d-A) and (4d-B) illustrate a scenario in which the terminal continuously transmits data but jumps between CCs in the resources allocated by the base station.

[0496] In other words, the terminal is allocated resources through PDCCH 4d-01 and continuously transmits data according to a predetermined pattern or a pattern configured by the base station, but hopping between CCs.

[0497] Figure 4DA Part (4d-A) illustrates the case of consecutive transmissions of the same RV, and Figure 4DA The (4d-B) portion illustrates the case of continuous transmission of different RVs. As shown, the frequency resource location is fixed on each CC, which helps reduce resource allocation overhead.

[0498] As mentioned above, the base station can use the resource allocation information or RRC message transmitted on the PDCCH to notify the terminal, such as Figure 4DAThe base station can use the transmission mode (or resource mode) shown in part (4d-A) or (4d-B) to transmit data in that transmission mode. The base station can also use resource allocation information or RRC messages transmitted on the PDCCH to send a bitmap and RV mapping scheme indicating the transmission location on each CC to the terminal.

[0499] For example, the base station can notify the UE in the RRC message such as Figure 4DA The transmission mode and RV mapping scheme shown in part (4d-A) or (4d-B), and the data transmission start position notified to the UE terminal in the resource allocation information transmitted on the PDCCH.

[0500] Throughout including Figure 4B and Figure 4C The present disclosure of the embodiments can be applied to the above-described method for sending resource allocation information to a terminal.

[0501] Subsequently, the receiver (the base station in this embodiment) can send an acknowledgment signal 4d-03 corresponding to the data. The base station can send the acknowledgment in each transmission, including the initial transmission or the transmission corresponding to the last transmission in continuous data transmission.

[0502] Figure 4DB The transmission method proposed in this disclosure is shown.

[0503] Figure 4DB Parts (4d-C) and (4d-D) illustrate a scenario in which a terminal simultaneously transmits the same data on multiple CCs within resources allocated by the base station.

[0504] Figure 4DB Part (4d-C) of Figure 4 illustrates the case of transmitting the same RV data simultaneously on multiple CCs, and part (4d-B) of Figure 4 illustrates the case of transmitting different RVs simultaneously on multiple CCs. As shown, the frequency resource location is fixed on each CC, which helps to reduce resource allocation overhead.

[0505] Afterwards, the receiver (the base station in this embodiment) can send an acknowledgment 4d-03 corresponding to the data.

[0506] Figure 4DC The transmission method proposed in this disclosure is shown.

[0507] Figure 4DC Parts (4d-E) and (4d-F) illustrate a scenario in which a terminal simultaneously transmits the same data on multiple CCs within resources allocated by the base station.

[0508] Figure 4DC The example illustrates a scenario where one RV transmits data simultaneously on multiple CCs, and another RV transmits data simultaneously on multiple CCs. Figure 4DC Part (4d-F) illustrates the case of transmitting different RVs simultaneously on multiple CCs in a continuous manner. As shown, the frequency resource location is fixed on each CC, which helps reduce resource allocation overhead.

[0509] Subsequently, the receiver (the base station in this embodiment) can send an acknowledgment 4d-03 corresponding to the data. The base station can send the acknowledgment in each transmission, including the initial transmission or the transmission corresponding to the last transmission in continuous data transmission.

[0510] Figure 4EA This is a flowchart illustrating terminal operation according to this disclosure.

[0511] In step 4e-03, the terminal may send capability information to the base station. The capability information may include UECapability carried in the RRC message. The capability information may include information indicating whether it supports the methods proposed in this disclosure. As mentioned above, the capability information may include information indicating whether the terminal supports redundant data transmission on multiple resources. The capability information may also include information about whether the terminal supports URLLC services. That is, in step 4e-03, the terminal sends information to the base station indicating whether it supports the transmission methods proposed in this disclosure.

[0512] Based on the above information, the base station can configure the transmission method (or transmission scheme or transmission mode) proposed in this disclosure for the terminal.

[0513] In step 4e-05, the terminal receives a configuration message from the base station. The configuration message may include at least one of the following: resource allocation time period, physical resource location, transmission scheme (MCS), and information about the carrier used for transmission (e.g., in the form of a bitmap). The configuration information may be sent to the terminal in an RRC message.

[0514] In step 4e-07, the terminal can either immediately apply the proposed transmission method upon receiving the configuration message, or send a pre-defined message to the base station to notify it that it wants to use the corresponding transmission method for uplink transmission timing. This message can be equivalent to a MAC layer or RRC layer message in LTE. If the transmission method is applied upon receiving the configuration message, the terminal can transmit data based on the resource allocation information included in the configuration message. In this case, step 4e-07 can be omitted.

[0515] To notify interested base stations to use the proposed transmission method, the terminal can send a URLLC preference message to the base station.

[0516] If a configuration message or notification message is received, the base station can use the resource allocation message (corresponding to the message transmitted on the PDCCH in LTE) to configure the proposed transmission method for the terminal.

[0517] In other words, the base station sends a resource allocation message to the terminal, which includes a predetermined indicator indicating one of the transmission methods 1 and 2 disclosed herein.

[0518] The terminal can receive a resource allocation message and, in step 4e-09, determine whether to use transmission method 1 or transmission method 2 based on the information included in the resource allocation message.

[0519] If the base station has been instructed to use transmission method 1, then in step 4e-11 the terminal sends data once based on the resource information specified in the resource allocation message.

[0520] If the base station has been instructed to use transmission method 2, the terminal can transmit data using a predetermined method or the method indicated in the information received in step 4e-05, based on the information included in the resource allocation message. The terminal can also transmit data based on the resource allocation information included in the configuration information received in step 4e-05 and the information included in the resource allocation information.

[0521] For example, the terminal can redundantly (repeatedly or duplicatedly) send data on multiple resources based on the transmission mode indicated in the information received in step 4e-05 and the data transmission timing information included in the resource allocation message.

[0522] In step 4e-13, the terminal can, according to Figure 4DA to Figure 4DC One of the transmission methods illustrated is used to send data. That is, the terminal can redundantly send data on multiple resources used for URLLC services. In other words, the terminal can send the same data across multiple resources. This can be done using... Figure 4DA to Figure 4DC One of the transmission modes described herein is used to perform redundant data transmission across multiple resources. Mode information can be carried in resource allocation messages or RRC configuration information transmitted on the PDCCH.

[0523] For application Figure 4DA to 4DC In one of the illustrated modes, the receiver may use one or more buffers to receive data. For example, the receiver may receive data in such a way that it buffers data received on multiple component carriers in a signal buffer or a carrier-dedicated buffer (for low implementation complexity), combines the buffered data, and if the data is successfully received, it can acknowledge successful reception to the transmitter (the base station in this embodiment).

[0524] In step 4e-15, the terminal may determine whether to stop using the configured uplink transmission method. If it determines to stop using the configured uplink transmission method, in step 4e-17 the terminal sends a message to the base station indicating termination of the configured transmission method.

[0525] Figure 4EB This is a flowchart illustrating the operation of a base station according to this disclosure.

[0526] In steps 4e-51, the base station can receive capability information from the terminal. The capability information may include the UECapability carried in the RRC message, and the terminal may include information indicating whether it supports the transmission method proposed in this disclosure. The transmission method proposed in this disclosure can be redundant data transmission across multiple resources.

[0527] The base station can instruct the terminal to activate the proposed transmission method based on capability information.

[0528] In steps 4e-53, the base station sends a configuration message to the terminal. The configuration message may include at least one of the following: resource allocation time period, physical resource location and transmission scheme (MCS), and information about the carrier used for transmission (e.g., in the form of a bitmap). The configuration information may be sent to the terminal in an RRC message.

[0529] In steps 4e-55, the base station may receive a pre-defined message from the terminal regarding uplink transmission timing, in order to check whether the terminal wants to use the configured transmission method. The terminal may begin transmission immediately upon receiving the configuration message, and in this case, step 4e-55 may be omitted.

[0530] In steps 4e-57, the base station may send a resource allocation message to the terminal. The base station may use the resource allocation message to instruct the terminal to use the proposed transmission method.

[0531] In steps 4e-59, the base station can receive data from the resources allocated to the terminal.

[0532] Here, the base station can receive data transmitted using one of the methods exemplified in 4DA to 4DC. That is, the base station can receive data transmitted using a redundant data transmission method on multiple resources. The terminal performs redundant data transmission on multiple resources in one of the transmission modes depicted in 4DA to 4DC. Mode information can be carried in resource allocation messages or RRC configuration information transmitted via PDCCH.

[0533] Figure 4F The configuration of a terminal according to an embodiment of the present disclosure is shown.

[0534] refer to Figure 4FThe terminal includes an RF processing unit (RF processor) 4f-10, a baseband processing unit (baseband processor) 4f-20, a memory 4f-30, and a controller 4f-40. In this invention, the controller 4f-40 can be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller can be coupled to a transceiver.

[0535] The RF processing unit 4f-10 can perform operations with... Figure 1J It has the same function as the RF processing unit 1j-10. Therefore, its detailed description is omitted here.

[0536] The baseband processing unit 4f-20 can perform operations with... Figure 1J It has the same function as the baseband processing unit 1j-20. Therefore, its detailed description is omitted here.

[0537] As described above, the baseband processing unit 4f-20 and the RF processing unit 4f-10 participate in signal transmission and reception. Therefore, the baseband processing unit 4f-20 and the RF processing unit 4f-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit. (Already referenced) Figure 1J Its detailed description is described, and therefore omitted here. The memory 4f-30 is functionally compatible with the reference... Figure 1J The memory 1j-30 described is identical, therefore its detailed description is omitted here. The controller 4f-40 controls the overall operation of the UE. For example, the controller 4f-40 transmits / receives signals by means of the baseband processing unit 4f-20 and the RF processing unit 4f-10. The controller 4f-40 writes data to and reads data from the memory 4f-30. For this purpose, the controller 4f-40 may include at least one processor. For example, the controller 4f-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling higher-level applications. According to embodiments of this disclosure, the controller 4f-40 includes a multi-connection processor 4f-42 for operation in a multi-connection mode. For example, the controller 4f-40 may control the terminal to perform... Figure 4EA The operation during the process.

[0538] According to embodiments of this disclosure, the controller 4f-40 controls the terminal to transmit data using the proposed transmission method based on configuration information received from the base station.

[0539] Figure 4G The configuration of a base station according to an embodiment of the present disclosure is shown.

[0540] like Figure 4GAs shown, the base station includes an RF processing unit (RF processor) 4g-10, a baseband processing unit (baseband processor) 4g-20, a backhaul communication unit 4g-30, a memory 4g-40, and a controller 4g-50. In this disclosure, the controller 4g-50 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to a transceiver.

[0541] The RF processing unit 4g-10 can perform operations with... Figure 1K It has the same function as the RF processing unit 1k-10, so its detailed description is omitted here.

[0542] The baseband processing unit 4G-20 can perform operations with... Figure 1K It has the same function as the baseband processing unit 1k-20, so its detailed description is omitted here.

[0543] The baseband processing unit 4G-20 and the RF processing unit 4G-10 are involved in signal transmission and reception. Therefore, the baseband processing unit 4G-20 and the RF processing unit 4G-10 can be referred to as a transmitting unit, a receiving unit, a transceiver, or a communication unit.

[0544] The 4G-30 backhaul communication unit can perform operations with... Figure 1K The 4G-40 memory has the same function as the 1K-30 backhaul communication unit, therefore its detailed description is omitted here. Figure 1K It has the same function as the 1k-40 memory, so its detailed description is omitted here.

[0545] The controller 4g-50 controls the overall operation of the base station. For example, the controller 4g-50 transmits / receives signals by means of a baseband processing unit 4g-20 and an RF processing unit 4g-10. The controller 4g-50 writes data to and reads data from the memory 4g-40. For this purpose, the controller 4g-50 may include at least one processor (multi-connection processor 4g-52), and the controller may be coupled to a transceiver.

[0546] According to embodiments of this disclosure, the controller 4G-50 determines whether the terminal supports the proposed transmission method; if so, it configures transmission for the terminal. That is, the base station can allocate resources to the terminal to use the proposed transmission method and instruct the terminal to use the proposed transmission method using a resource allocation message. This has already been described in detail above and is therefore omitted here. The baseband processing unit 4G-20 manages one or more buffers for receiving data and confirms whether the data has been successfully received.

[0547] Fifth embodiment

[0548] Figure 5A The architecture of the LTE system is shown.

[0549] Already referenced Figure 1A The LTE system architecture has been described in detail, so it is omitted here.

[0550] Figure 5B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0551] Reference image already provided Figure 2B and Figure 3B A detailed description of the protocol stack has been provided, so it will be omitted here.

[0552] Figure 5C The handover process in a traditional LTE system is illustrated.

[0553] In step 5c-05, the UE 5c-01 in connected mode periodically or when a predetermined event occurs sends a measurement report to the source eNB 5c-02.

[0554] The source eNB 5c-02 determines whether to trigger a handover of UE 5c-01 to a neighboring eNB. Typically, handover decisions are made for UEs in connected mode to switch control from one eNB to another.

[0555] If the source eNB has already made a handover decision for UE 5c-01, then in step 5c-10 it sends a handover (HO) request message to another eNB (i.e., the target eNB 5c-03) to serve UE 5c-01.

[0556] If the target eNB 5c-03 accepts the handover request, then in step 5c-15 it sends a HO request acknowledgment (Ack) to the source eNB 5c-02.

[0557] If an HO request Ack is received, then in step 5c-20, the source eNB 5c-02 sends an HO command to UE 5c-01. The HO command can be carried in an RRC connection reconfiguration message sent from the source eNB 5c-02 to UE 5c-01. If an RRC connection reconfiguration message is received, UE 5c-01 stops data communication with the source eNB 5c-02 and starts timer T304 in step 5c-25. Timer T304 is used to restore UE 5c-01 to its previous settings and transition to RRC idle state if UE 5c-01 fails to switch to the target eNB 5c-03 within a predetermined duration.

[0558] In step 5c-30, the source eNB 5c-02 sends the sequence number (SN) status information of the uplink / downlink data to the target eNB 5c-03, and if downlink data exists, the downlink data is forwarded to the target eNB 5c-03 in step 5c-35.

[0559] Subsequently, in step 5c-40, UE 5c-01 attempts random access to the target eNB 5c-03. This random access attempt is made to notify the target eNB 5c-03 of its handover and to achieve uplink synchronization. For the random access attempt, UE 5c-01 sends a preamble to the target eNB 5c-03 corresponding to a preamble ID provided by the source eNB 5c-02 or randomly selected.

[0560] After a predetermined number of subframes following the transmission of the preamble, UE 5c-01 monitors the Random Access Response (RAR). The monitoring period is called the RAR window. In step 5c-45, if a RAR is received within the predetermined time period, then in step 5c-55, UE 5c-01 forwards the HO completion message to the target eNB 5c-03 in the RRC Connection Reconfiguration Complete message. If the RAR is successfully received, then in step 5c-50, UE 5c-01 stops the T304 timer.

[0561] In steps 5c-60, the target eNB 5c-03 may send a path handover request message to the MME / S-GW 5c-04 to switch the bearer established towards the source eNB 5c-02 to the bearer established towards the target eNB 5c-03, and in step 5c-65, it receives the path handover request ACK from the MME / S-GW 5c-04. Upon receiving the path handover request ACK, in step 5c-70, the target eNB 5c-03 sends a UE context release message to the source eNB 5c-02. The UE attempts to receive data from the target eNB 5c-03 at the time point of the RAR window, and after receiving the RAR, it initiates transmission to the target eNB 5c-03 after sending an RRCConnectionReconfigurationComplete message.

[0562] exist Figure 5CDuring LTE handover, the UE cannot send / receive data during the time interval between receiving the HO command message (RRCConnectionReconfiguration) and sending the HO completion message (RRCConnectionReconfigurationComplete) (i.e., the handover to the target eNB is complete). This data transmission pause causes delays in data transmission / reception. This disclosure proposes a method for minimizing the data transmission pause time and fine-tuning to achieve the desired result.

[0563] The method for minimizing data transmission pause time disclosed herein is called RACH-free handover. This RACH-free handover method is characterized by allowing the UE to immediately send an RRCConnectionReconfigurationComplete message on uplink resources pre-allocated by the target eNB, thus performing the handover from the source eNB to the target eNB without a traditional random access procedure. For this reason, the RACH-free handover method of this disclosure can also be called random access-free handover. Various embodiments of the RACH-free handover method may exist. RACH-free handover can be implemented using any embodiment of the various embodiments of this disclosure. Embodiments of this disclosure are described below.

[0564] Figure 5D The RACH-free handover method proposed in this disclosure is illustrated.

[0565] exist Figure 5D In step 5d-05, the source eNB 5d-02 can send a UECapabilityEnquiry message to the UE 5d-01 to request UE capability information.

[0566] In steps 5d-10, UE 5d-01 can send a UECapabilityInformation message to the source eNB 5d-02 to report its RACH-free handover capability per frequency band or per combination of frequency bands. If the source eNB 5d-02 supports RACH-free handover per frequency band or per combination of frequency bands, then RACH-free handover can be performed.

[0567] In step 5d-15, UE 5d-01, in connected mode, sends cell measurement information (measurement report) to source eNB 5d-02. This measurement information is sent periodically or upon the occurrence of predetermined events. Source eNB 5d-02 makes a handover decision based on the measurement information. If a handover decision is made, in step 5d-20, source eNB 5d-02 sends a handover request message to target eNB 5d-03.

[0568] The source eNB 5d-02 can also determine whether to perform a RACH-free handover for UE 5d-01. In this case, in step 5d-20, the source eNB 5d-02 requests a RACH-free handover from the target eNB 5d-03. To request a RACH-free handover, the source eNB 5d-02 can include a RACH-free handover indicator (indicator 1) in the handover request message.

[0569] If the target eNB 5d-03 accepts the handover request, then in step 5d-25 it sends a HO request Ack message to the source eNB 5d-02. The HO request Ack message includes target eNB configuration information for the handover process. If the target eNB 5d-03 supports RACH-free handover, the configuration information may include at least one of an indicator indicating the supportability of RACH-free handover (Indication 2) and information about uplink resources used to send an RRC message (RRCConnectionReconfigurationComplete) from UE 5d-01 to the target eNB 5d-03. Here, the indicator indicating that the target eNB 5d-03 supports RACH-free handover (Indication 2) may be referred to as a RACH-free handover indicator or RACH-free handover activation information.

[0570] The configuration information may also include timing advance or timing adjustment information. If timing advance or timing adjustment information is not included, UE 5d-01 can apply the same timing advance or timing advance information as the source eNB 5d-02. Meanwhile, the HO request Ack message sent from the target eNB 5d-03 to the source eNB 5d-02 may not include information about uplink transmission resources. That is, the HO request Ack message may optionally include information about uplink transmission resources.

[0571] If the HO request Ack message includes uplink transmission resource information, it could mean that UE 5d-01 has obtained uplink transmission resources through the RRC message.

[0572] If the HO request Ack message does not include uplink transmission resource information (if UE 5d-01 has not received uplink transmission resource information), then UE 5d-01 can monitor the PDCCH of the target eNB 5d-03 to obtain control information including uplink resource information. This will be described in detail later.

[0573] In step 5d-30, the source eNB 5d-02 sends an RRCConnectionReconfiguration message including the HO command to UE 5d-01. The RRCConnectionReconfiguration message may include a no-RACH handover indicator (Indicator 2) and information about uplink transport resources used to send an RRC message (RRCConnectionReconfigurationComplete) from UE 5d-01 to the target eNB 5d-03. If a handover command is received, UE 5d-01 stops data communication with the source eNB 5d-02 and starts a T304 timer in step 5d-35. The T304 timer value may be included in the RRCConnectionReconfiguration message sent by the source eNB 5d-02. The T304 timer may be a timer used to determine whether the handover failed.

[0574] If the handover to the target eNB 5d-03 is not completed before the T304 timer expires, the UE 5d-01 will revert to its previous settings and transition to the RRC idle state.

[0575] As will be described later, in addition to the T304 timer value (first timer) used to determine whether the handover was successful, the target eNB 5d-03 may include a separate timer value (second timer) in the HO request Ack message. The second timer can be used by the UE to receive uplink resource information via PDCCH when the HO request Ack message sent by the target eNB does not include uplink resource information.

[0576] The source eNB 5d-02 can include a second timer value in the HO command message so that the UE 5d-01 can start the second timer, and if no control information is received via PDCCH before the second timer expires, a random access procedure is performed. This will be described in detail later.

[0577] In step 5d-40, the source eNB 5d-02 sends the sequence number (SN) status information of the uplink / downlink data to the target eNB 5d-03, and if there is downlink data to be sent, the downlink data is forwarded to the target eNB 5d-03 in step 5d-45.

[0578] If a no-RACH handover indicator is received in step 5d-30, UE 5d-01 performs a no-RACH handover operation. That is, UE 5d-01 uses the uplink resources indicated in the RRCConnectionReconfiguration message received in step 5d-30 and sends the RRCConnectionReconfigurationComplete message to the target eNB 5d-03 in step 5d-50, instead of performing a random access procedure. Figure 5C Steps 5c-40 and 5c-45. If the RRCConnectionReconfiguration message received in step 5d-30 does not include a no-RACH handover indicator, then UE 5d-01 performs the following steps as referenced. Figure 5C The described switching operation.

[0579] If the handover is successfully completed, in step 5d-55, UE 5d-01 stops the T304 timer. In step 5d-60, the target eNB 5d-03 sends a path handover request to MME / S-GW 5d-4, receives the path handover request Ack from MME / S-GW 5d-4 in step 5d-65, and sends a UE context release message to the source eNB in ​​step 5d-70.

[0580] Figure 5E Another RACH-free switching method proposed in this disclosure is shown.

[0581] exist Figure 5E In step 5e-05, the source eNB 5e-02 can send a UECapabilityEnquiry message to the UE 5e-01 to request UE capability information.

[0582] UE 5e-01 can send a UECapabilityInformation message to the source eNB 5e-02 in steps 5d-10 to report its RACH-free handover capability per frequency band or per combination of frequency bands. If the source eNB 5e-02 supports RACH-free handover per frequency band or per combination of frequency bands, then RACH-free handover can be performed.

[0583] In step 5e-15, UE 5e-01, in connected mode, sends cell measurement information (measurement report) to source eNB 5e-02. This measurement information is sent periodically or upon the occurrence of predetermined events. Source eNB 5e-02 makes a handover decision based on the measurement information. If a handover decision is made, in step 5e-20, source eNB 5e-02 sends a handover request message to target eNB 5e-03.

[0584] The source eNB 5e-02 can also determine whether to perform a RACH-free handover for UE 5e-01. In this case, in step 5e-20, the source eNB 5e-02 requests a RACH-free handover from the target eNB 5e-03. To request a RACH-free handover, the source eNB 5e-02 can include a RACH-free handover indicator (indicator 1) in the handover request message.

[0585] If the target eNB 5e-03 accepts the handover request, then in step 5e-25 it sends a HO request Ack message to the source eNB 5e-02. The HO request Ack message includes target eNB configuration information for the handover process. If the target eNB 5e-03 supports RACH-free handover, the configuration information may include RACH-free handover (Indicator 2). Here, the indicator (Indicator 2) indicating that the target eNB 5d-03 supports RACH-free handover can be referred to as the RACH-free handover indicator.

[0586] As mentioned above, the HO request Ack message may not include any uplink resource information.

[0587] In step 5e-30, the source eNB 5e-02 sends an RRCConnectionReconfiguration message including the HO command to UE 5e-01. The RRCConnectionReconfiguration message may include a no-RACH handover indicator (Indicator 2). If the RRCConnectionReconfiguration message is received, in step 5e-35, UE 5e-01 stops data communication with the source eNB 5e-02 and starts the T304 timer. The T304 timer value may be included in the RRCConnectionReconfiguration message sent by the source eNB 5e-02.

[0588] The T304 timer is used to restore the previous settings of UE 5e-01 and to transition to the RRC idle state if the handover is not completed until the T304 timer expires.

[0589] In step 5e-40, the source eNB 5e-02 sends the sequence number (SN) status information of the uplink / downlink data to the target eNB 5e-03, and if there is downlink data to be sent, the downlink data is forwarded to the target eNB 5e-03 in step 5e-45.

[0590] If a no-RACH handover indicator is received in step 5e-30, UE 5e-01 performs a no-RACH handover operation. That is, UE 5e-01 can perform a synchronization procedure with the target eNB 5e-03 instead of a random access procedure (i.e., steps 5c-40 and 5c-45), and then monitor the PDCCH for uplink resource allocation information in step 5e-55.

[0591] Here, UE 5e-01 has received the handover command from source eNB 5e-02. Source eNB 5e-02 camps on target cell 5e-03 to achieve synchronization and monitor the PDCCH of target eNB 5e-03 (step 5e-50).

[0592] In step 5e-55, the target eNB 5e-03 allocates uplink resources to the UE via PDCCH so that UE 5e-01 can complete the handover process. If UE 5e-01 is allocated uplink resources, then in step 5e-60 it sends an RRCConnectionReconfigurationComplete message using the allocated resources.

[0593] As described above, in addition to the first timer value (T304) used to determine whether the handover was successfully completed, the target eNB5e-03 can also include a second timer value in the handover request Ack message. If no control information is received via PDCCH before the second timer expires, the UE 5e-01 can trigger a random access procedure. This will be described in detail later.

[0594] If the RRCConnectionReconfiguration message received in step 5e-30 does not include a no-RACH handover indicator, then UE 5e-01 performs the following as referenced. Figure 5C The handover operation is described. If the handover process is successfully completed, in step 5e-65, UE 5e-01 stops the T304 timer. In step 5e-70, the target eNB may send a path handover request message to MME / S-GW 5e-04 to switch the bearer established toward the source eNB 5e-02 to the bearer established toward the target eNB 5e-03. In step 5e-75, the target eNB receives the path handover request ACK from MME / S-GW 5e-04, and in step 5e-80, sends a UE context release message to the source eNB 5e-02.

[0595] Meanwhile, during a RACH-free handover, if uplink resources toward the target eNB5e-03 cannot be allocated to UE 5e-01 for any reason, UE 5e-01 must wait until the T304 timer expires. The T304 timer may run for a long time because its minimum value is 100ms; therefore, the extended transmission pause time may cause data transmission interruptions. This disclosure proposes a method for configuring a UE-initiated timer (Timer 1) or a network-initiated timer (Timer 2) to reduce data transmission pause time. As described above, the T304 timer can be referred to as the first timer, and the UE-initiated or network-initiated timer (Timer 2) used to reduce data transmission pause time can be referred to as the second timer.

[0596] Figure 5F A RACH-free handover process is illustrated by configuring a UE-initiated timer (Timer 1) to reduce data transmission pause time, especially when uplink resources for transmission to the target eNB cannot be allocated to the UE for any reason.

[0597] Figure 5F The switching process is similar to Figure 5E The switching process. Figure 5F Steps 5f-05 to 5f-45 are the same as steps 5e-05 to 5e-45 in Figure 5e, so their detailed description is omitted here.

[0598] If an RRCConnectionReconfiguration message including a no-RACH handover indicator (indicator 2) is received in step 5f-30, then in step 5f-50, UE 5f-01 can achieve synchronization with the target eNB 5f-03.

[0599] If synchronization has been achieved, then in step 5f-55, UE 5f-01 starts Timer 1. Timer 1 runs on UE 5f-01 and can be set to a value less than T304.

[0600] As will be described later, UE 5f-01 can receive a second timer value less than timer T304 from target eNB 5f-03 and start a timer set to the second timer value. For example, target eNB 5f-03 can send the timer value using a handover request Ack message.

[0601] Therefore, in addition to the traditional T304 timer value, UE 5f-01 can also receive a second timer value (e.g., 50ms) from the target eNB 5f-03 and start the second timer. UE 5f-01 can use this timer value for its own timer or use the T304 timer.

[0602] In addition, the T304 timer value can be included in the MobilityControlInfo of the RRCConnectionReconfiguration message (i.e., the handover command message) sent from the source eNB 5f-02 to the UE 5f-01. For example, the T304 timer can be set to 100ms for normal handover or 50ms for handover without RACH.

[0603] In step 5f-60, if uplink resource allocation information is not received from target eNB 5f-03 for any reason before timer 1 expires, then in step 5f-65, UE 5f-01 triggers a random access procedure (fallback to the random access procedure) by sending a random access preamble. In step 5f-70, if a random access response is received in response to the random access preamble, then in step 5f-75, UE 5f-01 stops timer T304. Then, in steps 5f-80, 5f-85, and 5f-90, UE 5f-01 performs an RRC connection reconstruction procedure with target eNB 5f-03.

[0604] Figure 5G This paper illustrates another RACH-free handover procedure by configuring a UE-initiated timer to reduce data transmission pause time, especially when uplink resources for transmission to the target eNB cannot be allocated to the UE for any reason.

[0605] Figure 5G The switching process is similar to Figure 5E The switching process. Figure 5G Steps 5g-05 to 5g-45 and Figure 5E Steps 5e-05 to 5e-45 are the same, so their detailed description is omitted here.

[0606] If an RRCConnectionReconfiguration message including a no-RACH handover indicator (indicator 2) is received in step 5g-30, then in step 5g-50, UE 5g-01 can achieve synchronization with the target eNB 5g-03.

[0607] If synchronization has been achieved, then in step 5g-55, UE 5g-01 starts Timer 1. Timer 1 runs on UE 5g-01 and can be set to a value less than T304.

[0608] As described above, UE 5g-01 can receive the second timer value from the target eNB 5f-03 and start the timer set to the second timer value. This has already been described in detail above, so it will be omitted here.

[0609] In step 5g-60, if UE 5g-01 fails to receive uplink resource allocation information from target eNB 5g-03 for any reason before timer 1 expires, it triggers a random access procedure (fallback to random access procedure). If target eNB 5g-03 is not allocated uplink resources, target eNB 5g-03 may not be the optimal eNB.

[0610] Therefore, in step 5g-65, UE 5g-01 performs a cell reselection procedure to search for the optimal eNB. Then, in steps 5g-70 and 5g-75, UE 5g-01 performs a random access procedure with the newly discovered eNB 5g-04.

[0611] If a random access response is successfully received from the new target eNB 5g-04, then in step 5g-80, UE 5g-01 stops the T304 timer. If the random access procedure has been successfully completed, then UE 5g-01 and the new target eNB 5g-04 perform an RRC connection re-establishment procedure. That is, if a random access response is successfully received in step 5g-75, then in step 5g-85, UE 5g-01 sends an RRCConnectionReestablishmentRequest message to the new target eNB 5g-04.

[0612] If an RCCConnectionReestablishmentRequest message is received, in step 5g-90, the new target eNB 5g-04 sends a Radio Link Failure (RLF) indicator to the source eNB 5g-02, and in step 5g-95, the source eNB 5g-02 sends a handover cancellation message to the old target eNB 5g-03.

[0613] Then, in step 5g-100, the source eNB 5g-02 sends a handover request message to the new target eNB 5g-04, and in step 5g-105, the new target eNB 5g-04 sends a handover request Ack message to the source eNB 5g-02.

[0614] Subsequently, in step 5g-110, the source eNB 5g-02 sends the sequence number (SN) status information to the new target eNB 5g-04, and if downlink data to be sent exists, the data is forwarded to the new target eNB 5g-04 in step 5g-115. If the SN status information and data are received in steps 5g-110 and 5g-115, the new target eNB 5g-04 sends an RCCConnectionReestablishment message to UE 5g-01 in step 5g-120, and in step 5g-125, UE 5g-01 sends an RRCConnectionReestablishmentComplete message, thereby completing the RRC connection reconstruction.

[0615] Figure 5F and 5G The process involves using a UE-initiated timer (Timer 1) to reduce data transmission pause times. However, by having the target eNB notice the uplink resource allocation for the UE to be handed over, the target eNB can determine a more suitable timer value. Therefore, this disclosure proposes a network-initiated timer (Timer 2) configuration method, in which the target eNB determines the timer value.

[0616] Figure 5H A RACH-free handover procedure is illustrated for reducing data transmission pause time by configuring a network-initiated timer (Timer 2), especially when uplink resources for transmission to the target eNB cannot be allocated to the UE for any reason.

[0617] Figure 5H The switching process is similar to Figure 5E The switching process.

[0618] During this handover process, in step 5h-25, the target eNB 5h-03 can send a HO request Ack message to the source eNB 5h-02, including a second timer value (timer 2). Here, the second timer value can be less than the timer value of T304, i.e., 100ms, because the minimum value of T304 is 100ms.

[0619] In step 5h-30, UE 5h-01 can obtain the no-RACH handover indicator (indicator 2) and timer 2 from the RRCConnectionReconfiguration message sent by the source eNB 5h-02. Then, in step 5h-50, UE 5h-01 can achieve synchronization with the target eNB 5h-03. Figure 5H Switching related steps and Figure 5E The switching-related steps are the same. That is, Figure 5H Steps 5h-05 to 5h-45 and Figure 5E The steps 5e-05 to 5e-45 are the same.

[0620] If synchronization has been achieved, then in step 5h-55, UE 5h-01 starts timer 2. Timer 2 is set to the value recommended by the target eNB 5h-03, and the value of timer 2 can be less than the T304 timer value.

[0621] In steps 5h-60, if the UE fails to receive uplink resource allocation information from the target eNB 5h-03 for any reason before timer 2 expires, then in step 5h-65, the UE triggers a random access procedure (fallback to the random access procedure) by sending a random access preamble. If, in step 5h-70, the UE successfully receives a random access response from the target eNB 5h-03 in response to the random access preamble, then in step 5h-75, UE 5h-01 stops timer T304. Then, in steps 5h-80, 5h-85, and 5h-90, UE 5h-01 performs an RRC connection reconstruction procedure with the target eNB 5h-03.

[0622] During this process, the source eNB 5h-02 can reuse timer T304 instead of timer 2. That is, the source eNB 5h-02 can set timer T304 to the value of timer 2 received from the target eNB 5h-03 in step 5h-25.

[0623] Figure 5I Another RACH-free handover procedure is shown for reducing data transmission pause time by configuring a network-initiated timer (Timer 2), especially when uplink resources for transmission to the target eNB cannot be allocated to the UE for any reason.

[0624] Figure 5I The switching process is similar to Figure 5E The switching process.

[0625] During this handover process, the target eNB 5i-03 can send a HO request Ack message, including a second timer value (timer 2), to the source eNB 5i-02 in step 5i-25. Here, the second timer value can be less than the T304 timer value, i.e., 100ms, because the minimum value of T304 is 100ms.

[0626] In step 5i-30, UE 5i-01 can obtain the no-RACH handover indicator (indicator 2) and timer 2 from the RRCConnectionReconfiguration message sent by the source eNB 5i-02. Then, in step 5i-50, UE 5i-01 can achieve synchronization with the target eNB 5i-03. The handover-related steps in Figure 5i are illustrated below. Figure 5E The switching-related steps in Figure 5i are the same. That is, steps 5i-05 to 5i-45 in Figure 5i are the same as those in Figure 5i. Figure 5E The steps 5e-05 to 5e-45 are the same.

[0627] If synchronization has been achieved, then in step 5i-55, UE 5i-01 starts timer 2. Timer 2 is set to the value recommended by the target eNB 5i-03, and the value of timer 2 can be less than the T304 timer value.

[0628] In steps 5i-60, if UE 5i-01 fails to receive uplink resource allocation information from target eNB 5i-03 for any reason before timer 2 expires, it triggers a random access procedure (fallback to random access procedure). If target eNB 5i-03 is not allocated uplink resources, target eNB 5i-03 may not be the optimal eNB.

[0629] Therefore, in steps 5i-65, UE 5i-01 performs a cell reselection procedure to search for the optimal eNB. Then, in steps 5i-70 and 5i-75, UE 5i-01 performs a random access procedure with the newly discovered eNB 5i-04. If a random access response is successfully received from the new target eNB 5i-04, UE 5i-01 stops the T304 timer in step 5i-80. If the random access procedure has been successfully completed, UE 5i-01 performs an RRC connection re-establishment procedure with the new target eNB 5i-04. That is, if a random access response is successfully received in step 5i-75, UE 5i-01 sends an RRCConnectionReestablishmentRequest message to the new target eNB 5i-04 in step 5i-85.

[0630] If an RCCConnectionReestablishmentRequest message is received, in step 5i-90 the new target eNB 5i-04 sends a Radio Link Failure (RLF) indicator to the source eNB 5i-02, and in step 5i-95 the source eNB 5i-02 sends a handover cancellation message to the old target eNB 5i-03.

[0631] Then, in step 5i-100, the source eNB 5i-02 sends a handover request message to the new target eNB 5i-04, and in step 5i-105, the new target eNB 5i-04 sends a handover request Ack message to the source eNB 5i-02.

[0632] Subsequently, in step 5i-110, the source eNB 5i-02 sends the sequence number (SN) status information to the new target eNB 5i-04, and if downlink data to be sent exists, the data is forwarded to the new target eNB 5i-04 in step 5i-115. If the SN status information and data are received in steps 5i-110 and 5i-115, the new target eNB 5i-04 sends an RCCConnectionReestablishment message to UE 5i-01 in step 5i-120, and UE 5i-01 sends an RRCConnectionReestablishmentComplete message in step 5i-125, thereby completing the RRC connection reconstruction.

[0633] During this process, the source eNB 5i-02 can reuse timer T304 instead of timer 2. That is, the source eNB 5i-02 can set timer T304 to the value of timer 2 received from the target eNB 5i-03 in step 5i-25. In the proposed RACH-free handover process of this disclosure, when the UE fails to receive uplink resource allocation information from the target eNB, the UE can store the fault information and report it to the network for later use. Even if the UE fails to receive uplink resource allocation information from the target eNB and then attempts a random access procedure to connect to a new target eNB, it can still store the relevant information and report it to the network for later use.

[0634] Figure 5J The UE operation according to this disclosure is shown.

[0635] exist Figure 5J In step 5j-01, the UE can receive a UECapabilityEnquiry message from the source eNB. In response to the UECapabilityEnquiry message, the UE can send UE capability information (UECapability) to the source eNB.

[0636] UE capability information may include RACH-free handover capability per frequency band or per combination of frequency bands.

[0637] The UE can periodically or when a predetermined event occurs to send cell measurement information to the source eNB, and the source eNB can make a handover decision based on the measurement information.

[0638] If a positive handover decision has been made, in step 5j-02, the UE can receive a handover command message (RRCConnectionReconfiguration) from the source eNB. After receiving the handover command message in step 5j-02, the UE can start the T304 timer.

[0639] In step 5j-10, the UE determines whether the handover command message includes a no-RACH handover indicator. If it is determined that the handover command message does not include a no-RACH handover indicator, then in step 5j-15, the UE performs a conventional LTE handover procedure. That is, the UE triggers a random access procedure to the target eNB. If a random access response (RAR) is successfully received from the target eNB, then in step 5j-20, the UE stops the T304 timer.

[0640] If the handover command message includes a no-RACH handover indicator, then in step 5j-25, the UE establishes a connection to the target eNB by sending a handover completion message (RRCConnectionReconfigurationComplete) using the uplink resources indicated in the message. If the connection to the target eNB is successfully configured, then in step 5j-30, the UE stops the T304 timer.

[0641] Here, uplink resource allocation information can be included in the handover command message. Therefore, the UE can use the resources indicated by the uplink resource allocation information in the handover command message to send a handover completion message to the target eNB.

[0642] If the handover command message does not include uplink resource allocation information, the UE can monitor the target eNB's PDCCH to obtain control information and thus acquire uplink transmission resource information. The UE can then send a handover completion message to the target eNB based on the uplink transmission resource information.

[0643] The handover command message may include a second timer value but not uplink transmission resource information, and in this case, the UE may start a timer set to the second timer value to perform a random access procedure when the timer expires.

[0644] Figure 5K Another UE operation according to this disclosure is shown.

[0645] exist Figure 5K In step 5k-01, the UE can receive a UECapabilityEnquiry message from the source eNB. In response to the UECapabilityEnquiry message, the UE can send UE capability information (UECapability) to the source eNB.

[0646] UE capability information may include RACH-free handover capability per frequency band or per combination of frequency bands.

[0647] The UE can periodically or when a predetermined event occurs to send cell measurement information to the source eNB, and the source eNB can make a handover decision based on the measurement information.

[0648] If a positive handover decision has been made, in step 5k-02, the UE can receive a handover command message (RRCConnectionReconfiguration) from the source eNB. After receiving the handover command message in step 5k-02, the UE can start the T304 timer. The T304 timer value can be referred to as the first timer value.

[0649] In step 5k-10, the UE determines whether the handover command message includes a no-RACH handover indicator. If it is determined that the handover command message does not include a no-RACH handover indicator, then in step 5k-15, the UE performs the following steps as referenced. Figure 5C The traditional LTE handover process is described.

[0650] Otherwise, if the handover command message includes a no-RACH handover indicator, then in steps 5k-20, the UE can synchronize with the target eNB and monitor the target eNB's PDCCH. In this case, the UE starts timer X, which is set to the second timer value.

[0651] The second timer value can be referenced as follows. Figure 5F The description is configured by the UE, or as per the reference. Figure 5H The description is configured by the target eNB. If the second timer value is configured by the target eNB, it can be sent to the UE via a handover command message.

[0652] In step 5k-25, the UE can determine whether timer X has expired. If it is determined that timer X has expired, then in step 5k-30, the UE performs the following steps as referenced. Figure 5C This describes the traditional LTE handover process. Specifically, the UE triggers a random access procedure to the target eNB. If a RAR is successfully received from the target eNB, the UE stops the T304 timer in step 5k-35.

[0653] If it is determined in step 5k-25 that timer X has not yet expired, then in step 5k-40, the UE determines whether it has received an uplink grant from the target eNB. If it is determined in step 5k-40 that an uplink grant has been received, then in step 5k-45, the UE stops timer X and timer T304.

[0654] Then, in steps 5k-50, the UE uses the uplink transport resources indicated by the uplink grant to send an RRCConnectionReconfigurationComplete message to the target eNB to establish a connection. After sending the RRCConnectionReconfigurationComplete message, the T304 timer can expire.

[0655] Figure 5L Another UE operation according to this disclosure is shown.

[0656] exist Figure 5L In this process, the UE can receive a UECapabilityEnquiry message from the source eNB. In response to the UECapabilityEnquiry message, in step 5l-01, the UE can send UE capability information (UECapability) to the source eNB.

[0657] UE capability information may include RACH-free handover capability per frequency band or per combination of frequency bands.

[0658] The UE can periodically or when a predetermined event occurs to send cell measurement information to the source eNB, and the source eNB can make a handover decision based on the measurement information.

[0659] If a positive handover decision has been made, in step 5l-02, the UE can receive a handover command message (RRCConnectionReconfiguration) from the source eNB. In step 5l-02, upon receiving the handover command message, the UE can start the T304 timer. The T304 timer value can be referred to as the first timer value.

[0660] In steps 51-10, the UE determines whether the handover command message includes a no-RACH handover indicator. If it is determined that the handover command message does not include a no-RACH handover indicator, then in steps 51-15, the UE performs the following steps as referenced. Figure 5C The traditional LTE handover process is described.

[0661] Otherwise, if the handover command message includes a no-RACH handover indicator, then in steps 51-20, the UE can synchronize with the target eNB and monitor the target eNB's PDCCH. In this case, the UE starts timer X, which is set to the second timer value.

[0662] The second timer value can be referenced as follows. Figure 5F The description is configured by the UE, or as per the reference. Figure 5H The description is configured by the target eNB. If the second timer value is configured by the target eNB, it can be sent to the UE via a handover command message.

[0663] In steps 51-25, the UE can determine whether timer X has expired. If timer X has expired, in steps 51-30, the UE performs a cell reselection procedure. In steps 51-35, the UE performs a random access procedure with the eNB using the optimal signal strength selected through the cell reselection procedure. If a random access response (RAR) is successfully received from the target eNB, in steps 51-40, the UE stops timer T304.

[0664] If it is determined in step 5l-25 that timer X has not yet expired, then in step 5l-45, the UE determines whether it has received an uplink grant from the target eNB. If it is determined in step 5l-45 that an uplink grant has been received, then in step 5l-50, the UE stops timer X and timer T304.

[0665] Then, in steps 51-55, the UE uses the uplink transport resources indicated by the uplink grant to send an RRCConnectionReconfigurationComplete message to the target eNB to establish a connection. After sending the RRCConnectionReconfigurationComplete message, the T304 timer may expire.

[0666] Figure 5M The configuration of a UE according to an embodiment of the present disclosure is shown.

[0667] refer to Figure 5M The UE includes a transceiver 5m-05, a controller 5m-10, a multiplexer / demultiplexer 5m-15, a control message processor 5m-30, higher-layer processors 5m-20 and 5m-25, an EPS bearer manager 5m-35, and a NAS layer entity 5m-40. In this disclosure, the controller 5m-10 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to the transceiver.

[0668] The transceiver 5m-05 receives data and predetermined control signals through the downlink channel of the serving cell and transmits data and predetermined control signals through the uplink channel. When configured with multiple serving cells, the transceiver 5m-05 can transmit and receive data and control signals through multiple serving cells.

[0669] The multiplexer / demultiplexer 5m-15 can multiplex data generated by the higher-level processors 5m-20 and 5m-25 and the control message processor 5m-30, or demultiplex data received by the transceiver 5m-05, and deliver the demultiplexed data to the corresponding higher-level processors 5m-20 and 5m-25 or the control message processor 5m-30.

[0670] The Control Message Processor 5m-30 is an RRC layer entity that processes control messages received from the eNB and operates accordingly. For example, if an RRC connection establishment message is received, the Control Message Processor 5m-30 configures the Signaling Radio Bearer (SRB) and the Temporary Dedicated Radio Bearer (DRB).

[0671] The higher-level processors are DRB entities established on a service-by-service basis. Higher-level processors 5m-20 and 5m-25 process user service data, such as File Transfer Protocol (FTP) and Voice over Internet Protocol (VoIP) data, and send the processing output to multiplexer / demultiplexer 5m-15, or process data from multiplexer / demultiplexer 5m-15 and deliver the processing output to the higher-level service application. Services can be mapped individually to EPS bearers and higher-level entities.

[0672] The controller 5m-10 checks the scheduling commands received by the transceiver 5m-05, such as uplink grants, and controls the transceiver 5m-05 and the multiplexer / demultiplexer 5m-15 to perform uplink transmissions at appropriate timings with appropriate transmission resources.

[0673] In detail, controller 5m-10 can control the signaling between functional blocks to complete the operation according to the process described in the flowchart above. More specifically, controller 5m-10 can control transceiver 5m-05 to receive UE Capability Enquiry messages from the source eNB and send UE Capability information to the source eNB.

[0674] UE capability information may include band-specific or band-combination-specific no-RACH handover indicators.

[0675] The controller 5m-10 can control the transceiver 5m-05 to receive handover command messages (RRCConnectionReconfiguration) from the source eNB. If a handover command message is received, the controller 5m-10 starts the T304 timer.

[0676] The controller 5m-10 also determines whether the switching command message includes a no-RACH switching indicator.

[0677] If the handover command message includes a no-RACH handover indicator, controller 5m-10 controls transceiver 5m-05 to send a handover completion message (RRCConnectionReconfigurationComplete) using the uplink resources indicated in the handover command message. If the connection to the target eNB is successfully configured, controller 5m-10 stops the T304 timer.

[0678] Here, uplink resource allocation information can be included in the handover command message. Therefore, the controller 5m-05 can control the transceiver 5m-05 to send a handover completion message to the target eNB using the resources indicated by the uplink resource allocation information in the handover command message.

[0679] If the handover command message does not include uplink resource allocation information, controller 5m-10 can control the UE to monitor the target eNB's PDCCH to obtain control information and acquire uplink transmission resource information. Controller 5m-10 can then control transceiver 5m-05 to send a handover completion message to the target eNB based on the uplink transmission resource information.

[0680] The handover command message may include a second timer value instead of uplink transmission resource information, and in this case, the controller 5m-10 may start a timer set to the second timer value to perform a random access procedure when the timer expires.

[0681] The controller 5m-10 can also control other operations of the UE as described in this disclosure.

[0682] Figure 5N The configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of the present disclosure is shown. The eNB includes a transceiver 5n-05, a controller 5n-10, a multiplexer / demultiplexer 5n-20, a control message processor 5n-35, higher-layer processors 5n-25 and 5n-30, a scheduler 5n-15, EPS bearer entities 5n-40 and 5n-45, and a NAS layer entity 5n-50.

[0683] Transceiver 5n-05 transmits data and predetermined control signals through the downlink channel of the serving cell and receives data and predetermined control signals through the uplink channel. When multiple serving cells are configured, transceiver 5n-05 can transmit and receive data and control signals through multiple serving cells.

[0684] The multiplexer / demultiplexer 5n-20 can multiplex data generated by higher-level processors 5n-25 and 5n-30 and control message processor 5n-35, or demultiplex data received by transceiver 5n-05, and deliver the demultiplexed data to the corresponding higher-level processors 5n-25 and 5n-30 or control message processor 5n-35. The control message processor 5n-35 processes control messages received from the UE to perform actions based on the processing results and generates control messages to be sent to the UE via the lower layer.

[0685] A higher-level processor can be established based on the EPS bearer; higher-level processors 5n-25 and 5n-30 process data from the corresponding EPS bearer entities 5n-40 and 5n-45 to generate RLC PDUs to the multiplexer / demultiplexer 5n-20 or process the RLC PDUs from the multiplexer / demultiplexer 5n-20 into PDCP SDUs to the corresponding EPS bearer entities 5n-40 and 5n-45.

[0686] Based on the UE's buffer state and channel conditions, the scheduler allocates transmission resources to the UE for uplink transmission at appropriate timings and assists the transceiver 5n-05 in processing signals received from the UE and signals to be transmitted to the UE.

[0687] EPS bearer entities are established based on EPS bearers; EPS bearer entities 5n-40 and 5n-45 will process the data delivered by the corresponding higher-level processors 5n-25 and 5n-30 into a format to be sent to the next network node.

[0688] The higher-layer processors 5n-25 and 5n-30, as well as the EPS bearer entities 5n-40 and 5n-45, are interconnected via the S1-UE bearer. The higher-layer processors corresponding to the common DRB are connected to the EPS bearer entities established by the common DRB via the common S1-U bearer.

[0689] NAS layer entity 5n-50 processes the IP packets contained in the NAS message and transmits the processed output to the S-GW.

[0690] Controller 5n-10 can control the signaling between function blocks to complete the operations in the above process. Specifically, as the controller of the first eNB (source eNB), controller 5n-10 can control transceiver 5n-05 to send a UE Capability Enquiry message to the UE and receive UE Capability information from the UE.

[0691] UE capability information may include band-specific or band-combination-specific no-RACH handover indicators.

[0692] The controller 5n-10 can control the transceiver 5n-05 to send a handover request message to the target eNB and receive a handover request Ack message from the target eNB. The handover request Ack message may include at least one of the following: a no-RACH handover capability indicator (or a no-RACH handover configuration indicator or a no-RACH handover indicator), uplink resource allocation information, and a timer value.

[0693] The controller 5n-10 can also control the transceiver 5n-05 to send a handover command message (RRCConnectionReconfiguration) to the UE. The handover command message may include information contained in the handover request Ack message.

[0694] If the handover command message includes a no-RACH handover indicator, the UE can use uplink resources to send a handover completion message to the target eNB without performing a random access procedure.

[0695] The UE can use the uplink resource information included in the handover command message. If the handover command message does not include uplink resource information, the UE can monitor the target eNB's PDCCH to obtain control information to acquire uplink transmission resource information. The UE can use the uplink resources indicated by the uplink transmission resource information to send a handover completion message.

[0696] As the controller of the second eNB (target eNB), controller 5n-10 can control transceiver 5n-05 to receive handover request messages from the source eNB and send handover request Ack messages to the source eNB. The handover request Ack message may include at least one of the following: a no-RACH handover capability indicator (or a no-RACH handover configuration indicator or a no-RACH handover indicator), uplink resource allocation information, and a timer value.

[0697] The controller 5n-10 can also control the transceiver 5n-05 to receive the handover completion message based on the uplink resource information.

[0698] The controller 5n-10 can control the transceiver 5n-05 to receive the handover completion message based on the uplink resource information included in the handover command message.

[0699] If the switching command message does not include uplink resource information, the controller 5n-10 can control the transceiver 5n-05 to send control information including uplink resource information via the PDCCH.

[0700] The controller 5n-10 may include a timer value in the handover request Ack message; and if the UE fails to receive control information via PDCCH before the timer set to this timer value expires, it triggers a random access procedure. Here, the timer value may be less than the timer value configured to determine handover failure (T304).

[0701] Sixth Embodiment

[0702] This disclosure proposes a method and apparatus for a regular terminal or a terminal operating in extended coverage mode (hereinafter, interchangeably referred to as NB-IoT UE, low-complexity (BL) UE with reduced bandwidth, UE in coverage enhancement (CE), and enhanced machine-type communication (eMTC) UE) to autonomously switch to a large paging area preference mode and update the paging area to reduce battery power consumption.

[0703] Figure 6A The architecture of the LTE system is shown.

[0704] Already referenced Figure 1A The LTE system architecture has been described in detail, so it is omitted here.

[0705] Figure 6B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0706] Already referenced Figure 2B and Figure 3B A detailed description of the protocol stack has been provided, so it will be omitted here.

[0707] Figure 6C The concept of a light connection is illustrated.

[0708] In addition to the traditional idle and connected modes, a light-connection technology and a new definition of UE operating modes have been introduced to reduce the signaling overhead caused by traditional handover and paging operations. The newly defined modes can be called light-connection mode, inactive mode, etc. (hereinafter referred to as light-connection mode).

[0709] The UE 6c-03 in light connection mode is characterized by maintaining an S1 connection between MME 6c-01 and eNBs 6c-02 and 6c-04, and one of MME 6c-01 and eNBs 6c-02 and 6c-04 can trigger paging.

[0710] MME 6c-01 assumes that the UE in light connection mode is operating in connected mode; therefore, if any data needs to be sent to the UE, MME 6c-01 sends the data to the eNB without triggering a paging procedure. If data is received, the eNB sends a paging message to all eNBs within the paging area (PA) 6c-05, causing these eNBs to broadcast the paging message.

[0711] This disclosure proposes UE and network operations that can reduce UE battery consumption and signaling overhead, taking into account the aforementioned characteristics of lightweight connectivity.

[0712] Figure 6DA and 6DBThe signal flow between the UE context and the S1 bearer reused in the light connection process, the anchor eNB, the new eNB, and the MME, is shown according to this disclosure.

[0713] exist Figure 6DA and 6DB In this scenario, it is assumed that the UE in RRC connection mode is already communicating with the anchor eNB. If data communication stops, the anchor eNB starts a predetermined timer, and if data communication is not resumed before the timer expires in step 6d-05, the UE's RRC connection is determined to be released.

[0714] In steps 6d-10, the eNB stores the UE context and sends a control message (RRC connection release message) to the UE indicating the release of the RRC connection.

[0715] Control messages can include a recovery ID and paging area information. That is, the eNB assigns a recovery ID to the UE and configures the PA (Packet Area) for UEs in light-connection mode to report mobility.

[0716] A PA can include one or more cells. The eNB can send a list of cell IDs that make up the eNB's PA to the UE, and the UE can determine whether the PA has been updated by comparing the cell IDs broadcast by the eNB with the cell IDs contained in the cell ID list.

[0717] The eNB can also send PA identifiers to configure a PA for the UE. The network or eNB can configure a PA with at least one cell and assign a PA identifier to each PA. Therefore, if a PA identifier is received, the UE can check the cell list from the PA identifier and perform a paging area update determination based on the cell ID and PA ID received from the eNB while on the move. This will be described in detail later.

[0718] Cell lists or PA identifiers can be sent to the UE via RRC signaling or broadcast in the SIB.

[0719] The UE can determine the necessity of retaining its UE context based on the recovery ID allocation. The eNB can also send a control message including a context retention indicator to instruct the UE to retain its UE context. This control message may include a context retention period or a list of cells to be used during the UE's RRC connection reconfiguration process within the valid period.

[0720] Even after releasing the RRC connection for the UE, in steps 6d-15, the anchor eNB maintains the UE context and S1 bearer.

[0721] S1 bearers include S1 control plane bearers for exchanging control signals between the eNB and MME, and S1 user plane bearers for exchanging user data between the eNB and S-GW. Maintaining S1 bearers allows the S1 bearer configuration process to be skipped when a UE attempts to establish an RRC connection in the same cell or eNB. If the validity period expires, the eNB can delete the UE context and release the S1 bearers.

[0722] If an RRC connection release message is received, the UE switches to light connection mode in steps 6d-25.

[0723] In steps 6d-20, the eNB sends a control message to the MME requesting a temporary suspension of the connection. If this temporary connection suspension request message is received, in steps 6d-35, the MME instructs the S-GW to continue transmitting downlink data for the UE and triggers a paging procedure, and the S-GW operates based on this instruction. Alternatively, the S-GW can forward the downlink data to the anchor eNB, and the anchor eNB can generate a paging message and send it to the neighboring eNB. If downlink data is received, the anchor eNB buffers the data in a buffer and triggers a paging procedure. The anchor eNB is the eNB that maintains the UE context and maintains the S1-U bearer.

[0724] If an RRC connection release message including a context retention indicator and a recovery ID is received in step 6d-10, the UE releases the RRC connection and starts a timer corresponding to the valid time period. In step 6-25, the UE writes the list of valid cells to memory and maintains the UE context in memory.

[0725] The UE context can be related to the UE's RRC connection, such as signaling radio bearer (SRB) configuration information, data radio bearer (DRB) configuration information, and security key information.

[0726] Subsequently, in steps 6d-30, it may be necessary to establish an RRC connection for any reason. UEs that were neither assigned a recovery ID nor instructed to retain context during the previous RRC connection release process can initiate a conventional RRC connection establishment procedure.

[0727] However, a UE that was assigned a recovery ID during a previous RRC connection release can use the maintained UE context to attempt the RRC connection recovery process.

[0728] In detail, in steps 6d-40, the UE may send message 1, which includes a preamble, to trigger the random access procedure.

[0729] If the available resource allocation is determined based on the preamble included in message 1, then in steps 6d-45, the eNB sends message 2 to allocate uplink resources to the UE. Message 2 may be a Random Access Response (RAR) message.

[0730] Upon receiving the RAR message, in steps 6d-50, the UE sends a recovery request message to the new eNB, including a recovery ID selected based on uplink resource information. The recovery request message can be a modified RRCConnectionRequest message or a newly defined message (e.g., RRCConnectionResumeRequest).

[0731] If a UE that has switched from connected mode to lightly connected mode is camped on the cell of the new eNB, the new eNB can receive the UE's recovery ID and identify the UE's previous serving eNB based on the recovery ID.

[0732] If the new eNB successfully receives the recovery ID, then in steps 6d-55, it performs the procedure for retrieving the UE context from the source eNB (context retrieval procedure). The new eNB can retrieve the UE context from the source eNB via the S1 or X2 interface. If the new eNB successfully receives the recovery ID but fails to recognize the UE, it must send an RRCConnectionSetup message to the UE to perform the traditional RRC connection establishment procedure.

[0733] In steps 6d-60, the new eNB checks the MAC-I based on the UE context retrieved from the source eNB. The MAC-I is a message authentication code calculated by the UE using control messages with the security information (i.e., security key and security counter) of the retrieved UE context.

[0734] The eNB uses the message's MAC-I and the security key and security counter included in the UE context to check message integrity. In steps 6d-65, the new eNB generates RRC configuration information to be applied to the UE and sends an RRC Connection Resume message including the configuration information to the UE.

[0735] An RRC connection restoration message can be a modified RRC connection request message that includes information indicating "RRC context reuse" (REUSE INDICATOR). The RRC connection restoration message may include RRC connection configuration information for the UE, such as an RRC connection establishment message.

[0736] Unlike a UE that has already received a normal RRC connection establishment (RRCConnectionSetup) message and configures the RRC connection based on the configuration information included in the RRC connection establishment message, a UE that has already received an RRC connection recovery message configures the RRC connection by taking into account both the saved configuration information and the configuration information included in the RRC connection recovery message (incremental configuration).

[0737] For example, if an RRC connection restoration message is received, the UE stores the configuration information contained in the RRC connection restoration message and checks the configuration information used for incremental information to update the configuration information or the UE context. For example, if the RRC connection restoration message includes SRB configuration information, the UE configures the SRB based on the SRB configuration information; if the RRC connection restoration message does not include SRB configuration information, the UE configures the SRB based on the SRB configuration information included in the UE context.

[0738] In steps 6d-70, the UE configures the RRC connection based on the updated UE context and configuration information, and sends an RRC connection restoration complete message to the new eNB.

[0739] In steps 6d-75, the new eNB sends a control message to the MME requesting the release of the temporary connection suspension and the reconfiguration of the S1 bearer to the new eNB. If this control message is received, the MME instructs the S-GW to reconfigure the S1 bearer with the new eNB and process the UE's data normally.

[0740] If the RRC connection reconfiguration process has been completed, then in steps 6d-80, the UE restarts data communication through the corresponding cell. During this process, if the UE in light connection mode moves but only slightly and thus re-camps on the source eNB's cell, the source eNB can retrieve the UE context based on the recovery ID included in message 3 and configure the connection based on the UE context as described above.

[0741] If data communication is stopped, the eNB starts a predetermined timer, and if data transmission is not resumed before the timer expires in steps 6d-85, it determines to release the UE's RRC connection.

[0742] In this scenario, the eNB can store the UE context and send a control message (RRC connection release message) instructing the UE to release the RRC connection in steps 6d-90. The eNB assigns a recovery ID to the UE and configures the PA (Active Platform) for reporting mobility for the UE in light-connected mode. That is, the eNB can include the recovery ID and PA information in the RRC connection release message. The PA configuration method is similar to that described above, so its detailed description is omitted here. If the RRC connection release message is received in step 6d-95, the UE transitions to light-connected mode.

[0743] As described above, the UE can switch to light connection mode (or inactive mode) when it receives an RRC connection release message, and update the PA if it moves out of the paging area in light connection mode.

[0744] Figure 6E The PA update process for a UE in a network supporting light connectivity technology according to this disclosure is illustrated. Figure 6E The PA update process in this disclosure is described. In step 6e-05, UE e-01 connected to anchor eNB 6e-02 receives an RRC connection release message from anchor eNB 6e-02.

[0745] The RRC connection release message may include a recovery ID and PA information. UE 6e-01 is assigned a recovery ID and its PA is configured based on the RRC connection release message.

[0746] A PA can include one or more cells. The anchor eNB 6e-02 can send a list of cell IDs that constitute the eNB's PA to the UE 6e-01 or reserve a PA identifier in the network for configuring the PA for the UE 6e-01.

[0747] UE 6e-01 can check a list of cell IDs included in the paging area ID or a cell list, and determine whether the PA has been updated while on the move by comparing the cell ID broadcast by the eNB with the cell IDs included in the list.

[0748] If UE 6e-01 does not send / receive data within the predetermined time period, the anchor eNB 6e-02 will configure the UE to operate in light connection mode. That is, the anchor eNB 6e-02 can send an RRC connection release message to UE 6e-01, including recovery ID and PA information, causing UE 6e-01 to enter light connection mode.

[0749] If an RRC connection release message is received, UE 6e-01 switches to light connection mode. In step 6e-07, anchor eNB 6e-02 maintains the UE context. Anchor eNB 6e-02 can also maintain the S1 bearer with the core network.

[0750] Simultaneously, in step 6e-06, UE 6e-01 can move to the vicinity of another eNB within another PA. In this embodiment, the anchor eNB can be interchangeably referred to as the first eNB, and the other eNB can be interchangeably referred to as the second eNB.

[0751] In step 6e-08, the eNB broadcasts its own PA's cell-specific identifier or PA identifier using a predefined System Information Block (SIB). As described above, PA information can be provided by the eNB broadcasting the cell ID of the cell constituting the PA or a PAID predefined for use with the network.

[0752] If system information is received, UE 6e-01 can determine whether its camped eNB belongs to the same PA as the eNB that sent the RRC Connection Release message (RRCConnectionRelease). If the eNBs do not match, in step 6e-09, UE 6e-01 sends an RRC Connection Resume Request message (RRCConnectionResumeRequest) to its new camped eNB 6e-03 to update the PA.

[0753] RRC connection recovery request messages may include a newly defined establishment reason for requesting a PA update. One of the reserved bits in traditional RRC connection request messages can also indicate a PA update request. RRC connection recovery request messages may include at least one of the recovery ID, MAC-I, and establishment reason.

[0754] If an RCCConnectionResumeRequest message is received, in step 6e-10, the second eNB 6e-03 can identify the anchor eNB 6e-02 of the previously serving UE 6e-01 based on the recovery ID.

[0755] In step 6e-11, the second eNB 6e-03 can send a UE context retrieval request message to the anchor eNB 6e-02 to request the UE context. In step 6e-12, the second eNB 6e-03 can receive a UE context retrieval response message from the anchor eNB and obtain the UE context information from the UE context retrieval response message.

[0756] The second eNB 6e-03 can use the retrieved UE context information to perform security checks. If unnecessary, the UE context retrieval procedures in steps 6e-11 and 6e-12 can be omitted.

[0757] In step 6e-13, the second eNB 6e-03 sends an RRCConnectionRelease message to the UE 6e-01. The RRCConnectionRelease message may include a new recovery ID and PA information. As described above, the PA may include one or more cells. As described above, the anchor eNB 6e-02 may send the UE 6e-01 a list of cell IDs constituting the eNB's PA or a PA identifier reserved for configuring the PA for the UE 6e-01 in the network.

[0758] UE 6e-01 can obtain PA information by comparing the cell ID and PA information broadcast by the eNB and determine whether the PA has been updated while moving.

[0759] After sending the RRCConnectionRelease message, in step 6e-14, the second eNB 6e-03 sends a UE PA update message to the anchor eNB 6e-02 to update the PA for UE 6e-01. This is intended to allow the anchor eNB 6e-02 to appropriately generate a paging message to page UE 6e-01 when downlink data for UE 6e-01 subsequently arrives.

[0760] Figure 6F Various types of PAs according to this disclosure are shown.

[0761] The eNB configures the PA for the UE by sending an RRCConnectionRelease message to switch the UE's operating mode from RRC connected mode to light connected mode, such as... Figure 6E As described in step 6e-05.

[0762] If a small PA (PA1) is configured for the UE as a Type 1 PA, as shown in reference numeral 6f-05, the UE may frequently report its location because the UE must update the PA whenever it changes, resulting in signaling overhead. Frequent signaling can also quickly deplete the battery. However, this facilitates the eNB or MME paged the UE to send downlink data to it.

[0763] Conversely, if a large PA (PA2) as a type 2 PA is configured for the UE, as shown in reference numerals 6f-10, location registration for PA updates is performed relatively less frequently, resulting in reduced battery consumption. However, considering the eNB and MME, this complicates the paging process for downlink data transmission to the UE in lightly connected mode and may lead to paging signaling overhead. This disclosure proposes a paging method that can save battery power and reduce paging signaling overhead in such a way that a UE in lightly connected mode disconnected from the eNB reports its mobility in a small paging area and remains in the small paging area after a predetermined period of time. That is, the UE changes the PA type after the predetermined period of time.

[0764] Although the description pertains to an exemplary case of changing a PA from a small PA to a large PA in a two-step manner, PA changes can be performed in three or more steps. That is, in this disclosure, multiple PA types can be defined and the PA types can be changed in steps over time.

[0765] In this disclosure, it is assumed that a Type 1 PA (PA1) is a small PA (small PA), and a Type 2 PA (PA2) is a large PA (large PA). A Type 1 PA may include one or more cells. A Type 2 PA may include two or more cells. A Type 1 or Type 2 PA may consist of one cell or a group of cells. A Type 1 or Type 2 PA may be identified by a list of cell identifiers or a PA identifier pre-defined for use in the network.

[0766] Figure 6G The signal flow between the UE and eNB is shown during the PA reconfiguration process according to this disclosure.

[0767] exist Figure 6G If data communication between UE 6g-01 and anchor eNB 6g-02 in RRC connection mode stops, eNB 6g-02 starts a predetermined timer, and if communication is not restored before the timer expires, the RRC connection with UE 6g-01 is released.

[0768] If it is determined that the RRC connection with UE 6g-01 will be released, then in step 6g-05, the anchor eNB 6g-02 sends a control message (RRCConnectionRelease) to UE 6g-01. The eNB 6g-02 can use this control message to assign a recovery ID to UE 6g-01 and configure a Type 1 PA for mobility reporting in light-connection mode. For this purpose, the control message includes a recovery ID and a PA1 indicator. A Type 1 PA can include at least one cell, and the number of cells constituting a Type 1 PA is determined by the anchor eNB 6g-02. The anchor eNB 6g-02 can determine the number of cells forming a Type 1 PA. The PA configuration method has already been described above and is therefore omitted here.

[0769] The UE understands the necessity of retaining the UE context based on the fact that a recovery ID has been assigned. Alternatively, the anchor eNB 6g-02 can use a control message (RRCConnectionRelease) to send a context retention indicator to instruct the UE 6g-01 to maintain the UE context.

[0770] If an RRC connection release message including a context retention indicator or recovery ID is received in step 6g-05, UE 6g-01 releases the RRC connection and can start a timer corresponding to the valid time period. UE 6g-01 can store a list of valid cells in its memory and maintain the current UE context in its memory.

[0771] When the connection with UE 6g-01 is released, the anchor eNB 6g-02 starts a UE-specific timer (hereinafter, Timer A). Timer A is used for PA type change and can be referred to as the PA change timer.

[0772] Timer A defines a mobility reporting period in a Type 1 PA for UE 6g-01 after connection release, and anchor eNB 6g-02 can send a paging message to UE 6g-01 when Timer A expires to configure a Type 2 PA to UE 6g-01.

[0773] Therefore, eNB 6g-02 sends an RRC connection release message to UE 6g-01, and then starts timer A in step 6g-15. UEs in light connection mode (6g-10) can perform mobility reporting in type 1 PA until timer A expires.

[0774] If timer A expires in step 6g-20, then anchor eNB 6g-02 sends a paging message to new eNB 6g-03 in step 6g-25, which has already updated the PA for the mobile UE 6g-01. In this disclosure, anchor eNB 6g-02 may be interchangeably referred to as the first eNB, and new eNB 6g-03 may be interchangeably referred to as the second eNB.

[0775] In step 6g-30, the new eNB 6g-03 sends a paging message to UE 6g-01. If UE 6g-01 moves but only slightly and is therefore within the PA of anchor eNB 6g-02, then anchor eNB 6g-02 can directly send a paging message to UE 6g-01.

[0776] If a paging message is received, in step 6g-35, UE 6g-01 sends an RRC connection recovery message to the new eNB 6g-03, which includes the recovery ID assigned during the RRC connection release process and the maintained UE context.

[0777] If a UE in connected mode has moved and camped on a new eNB (second eNB) 6g-03 after being disconnected from the source eNB 6g-02, the new eNB 6g-03 can receive an RRC connection restoration request message and, based on the restoration ID included in the RRC connection restoration request message, identify the anchor eNB 6g-02 as the previous serving eNB of UE 6g-01.

[0778] If the new eNB 6g-03 successfully receives and recognizes the recovery ID, it can retrieve the UE context from the source eNB 6g-02 in steps 6g-40 and 6g-45 (context retrieval procedure). The new eNB 6g-03 can receive the UE context from the source eNB 6g-02 via the S1 or X2 interface. If the new eNB 6g-03 receives the recovery ID but does not recognize the terminal, it can send an RRCConnectionSetup message to trigger the traditional RRC connection establishment procedure with UE 6g-01.

[0779] The new eNB 6g-03 checks the MAC-I based on the retrieved UE context. The MAC-I is a message authentication code calculated using the security information (i.e., security key and security counter) of the retrieved UE context.

[0780] The new eNB 6g-03 uses the message's MAC-I, along with the security key and security counter included in the UE context, to check message integrity. The new eNB 6g-03 can generate RRC configuration information to be applied to UE 6g-01, and in step 6g-50 sends an RRC Connection Resume message including the configuration information to UE 6g-01.

[0781] In step 6g-55, UE 6g-01 configures the RRC connection based on the updated UE context and configuration information, and sends an RRC connection restoration complete message to the new eNB 6g-03.

[0782] In step 6g-60, the new eNB 6g-03 configures the UE 6g-01 with Type 2 PA mode, assigns a new recovery ID, and releases the connection. That is, the new eNB 6g-03 can send a connection release message including the new recovery ID and Type 2 PA information to the UE 6g-01 in step 6g-60. Figure 6G During the process, the RRC connection restoration request message sent in step 6g-35 may include a newly defined establishment reason or have a reserved bit specified for PA update, and in this case, steps 6g-50 and 6g-55 can be omitted.

[0783] Figure 6H Another process for PA reconfiguration for a UE according to this disclosure is shown.

[0784] exist Figure 6H If data communication between UE 6h-01 and anchor eNB 6h-02 in RRC connection mode stops, anchor eNB 6h-02 starts a predetermined timer, and if communication is not restored before the timer expires, the RRC connection with UE 6h-01 is released.

[0785] If it is determined that the RRC connection with UE 6h-01 will be released, then in step 6h-05, the anchor eNB 6h-02 sends a control message (RRCConnectionRelease) to UE 6h-01. The eNB 6h-02 assigns a recovery ID to UE 6h-01 and uses the control message to configure Timer B for UE 6h-01 and Type 1 and Type 2 PAs in light-connection mode for mobility reporting. For this purpose, the control message includes the recovery ID, a Type 1 PA (PA1) indicator, and a Type 2 PA (PA2) indicator. A PA can include at least one cell, and the number of cells used to form a PA is determined by the eNB. That is, the number of cells used to form Type 1 PAs and Type 2 PAs can be changed according to the eNB's configuration. The PA configuration method has already been described above and is therefore omitted here.

[0786] The UE understands the necessity of retaining the UE context based on the fact that a recovery ID has been assigned. Alternatively, the anchor eNB 6h-02 can use a control message (RRCConnectionRelease) to send a context retention indicator to instruct the UE 6h-01 to maintain the UE context.

[0787] If an RRC connection release message including a context retention indicator or recovery ID is received in step 6h-05, UE 6h-01 releases the RRC connection and can start a timer corresponding to the valid time period. UE 6h-01 can store a list of valid cells in its memory and maintain the current UE context in its memory.

[0788] The RRC connection release message may include the timer value of timer B.

[0789] Similar to Timer A, Timer B is used to change the PA type and can be called the PA change timer.

[0790] Timer B defines the mobility reporting time period in a Type 2 PA for UE 6h-01, and anchor eNB 6h-02 and UE 6h-01 start the same Timer B in steps 6h-10 and 6h-15.

[0791] If timer B expires, UE 6h-01 performs a mobility report for a type 2 PA mode characterized by a large PA, and anchor eNB 6h-02 assumes that UE 6h-01 will change the PA to a type 2 PA.

[0792] A Type 1 PA can include one or more cells. A Type 2 PA can include two or more cells. A Type 1 or Type 2 PA can be equivalent to a single cell or a group of one or more cells. A Type 1 or Type 2 PA can be configured as a list of cell IDs or as PA IDs pre-assigned to the network. Figure 6F The PAs of exemplary types 1 and 2 are depicted.

[0793] Specifically, in step 6h-05, the anchor eNB 6h-02 sends an RRCConnectionRelease message to UE 6h-01, and in step 6h-15, timer B is started. Furthermore, in step 6h-10, UE 6h-01 starts timer B with the timer value included in the RRCConnectionRelease message. The start time of timer B can be included in the RRCConnectionRelease message sent to UE 6h-01.

[0794] UE 6h-01 performs mobility reporting in Type 1 PA mode until timer B expires. If timer B expires in step 6h-20, the UE changes from Type 1 PA mode to Type 2 PA mode. From then on, UE 6h-01 performs mobility reporting in Type 2 PA mode.

[0795] If the UE performs mobility reporting in a Type 2 PA mode characterized by a large PA, this means saving battery power. Timer B of anchor eNB 6h-02 expires when Timer B of UE 6h-01 expires. If Timer B of anchor eNB 6h-02 expires in step 6h-25, anchor eNB 6h-25 assumes the UE is in Type 2 PA mode without explicit signaling.

[0796] Meanwhile, if UE 6h-01 moves to another PA in step 6h-30, such as Figure 6E As shown in step 6e-06, the UE then performs the following steps as referenced. Figure 6E The PA update process is described.

[0797] Here, we assume that UE 6h-01 moves to another eNB (the second eNB or the new eNB) 6h-03 in another PA.

[0798] The new eNB 6h-03 can broadcast its PA information in the system information (step 6h-35), and the UE 6h-01 can determine whether the eNB it is camped on is the same as the eNB that has sent the RRC connection release message.

[0799] If the eNB does not match, then in step 6h-40, UE 6h-01 can send an RRC connection restoration request message to the second eNB 6h-03.

[0800] When UE 6h-01 performs a paging update procedure that requires the allocation of a PA, it needs to allocate a large PA, namely a type 2 PA.

[0801] Therefore, UE 6h-01 may need to notify the new eNB 6h-03 that UE 6h-1 is performing mobility reporting in Type 2 PA mode. For this purpose, the establishment reason can be defined in the RRC connection restoration request message sent in step 6h-40, or one of the reserved bits of the RRC connection restoration request message can be used as a Type 2 PA mode indicator (Indicator 1). The RRC connection restoration request message generated by UE 6h-01 may include the newly defined establishment reason or the Type 2 PA mode indicator (Indicator 1). In this disclosure, this indicator may be referred to as the PA type indicator.

[0802] With two PA types defined as described above, the UE can use a 1-bit indicator to notify the eNB of the PA type.

[0803] However, this disclosure is not limited thereto, but may include various modifications. For example, if two or more PA types are defined, the UE may use a multi-bit indicator instead of a 1-bit indicator.

[0804] If an RRC connection restoration request message is received, in step 6h-45 the new eNB 6h-03 can identify the anchor eNB 6h-02 of the previously serving UE 6h-01 based on the restoration ID.

[0805] Then, in step 6h-50, the second eNB 6h-03 sends a Retrieve UE Context Request message to the anchor eNB 6h-02 to request the UE context. In step 6h-55, the anchor eNB 6h-02 sends a Retrieve UE Context Response message, which includes the UE context, to the second eNB 6h-03.

[0806] In order to notify the new eNB 6h-03 that UE 6h-01 is performing mobility reporting in a Type 2 PA mode characterized by a large PA, the PA type indicator can be included in the UE context retrieval response message sent by the old eNB 6h-02 in step 6h-55, instead of including the PA type indicator in the RRC connection restoration request message sent by UE 6h-01 in step 6h-40.

[0807] In step 6h-60, the new eNB 6h-03 uses an RRC connection release message to configure a new PA mode to the UE 6h-01, such as a type 2 PA mode characterized by a large PA. Finally, in step 6h-65, the new eNB 6h-03 uses a UE PA update message to report the updated PA mode to the anchor eNB 6h-02.

[0808] Figure 6I The autonomous PA reconfiguration process of the UE according to this disclosure is illustrated.

[0809] exist Figure 6I If data communication between a UE in RRC connection mode and an eNB stops, the eNB starts a predetermined timer. If communication is not restored before the timer expires, the eNB sends an RRC connection release message to the UE to release the RRC connection with the UE. The eNB releases the RRC connection with the UE, stores the UE context, and sends the RRC connection release message according to predetermined rules. The RRC connection release message includes a recovery ID for the UE to use when switching to light connection mode, timer B, and PA (PA1) information for type 1 and PA (PA2) for type 2.

[0810] In step 6i-01, the UE receives an RRC connection release message. As described above, the RRC connection release message may include a recovery ID, timer B, and at least one of type 1 PA and type 2 PA information.

[0811] If an RRC connection release message is received, the UE can switch to light connection mode in step 6i-02.

[0812] Next, in step 6i-05, the UE starts timer B, which is included in the RRC connection release message. The RRC connection release message may also include information about the start time of timer B.

[0813] Timer B defines the mobility reporting period for Type 1 PA mode, and the eNB also starts Timer B simultaneously. If Timer B expires, the UE performs mobility reporting in Type 2 PA mode, characterized by a large PA, and the eNB assumes the UE is in Type 2 PA mode.

[0814] In steps 6i-10, the UE in light connection mode starts timer B and determines whether there is data to be sent.

[0815] If there is data to be sent, in step 6i-04, the UE performs the RRC connection recovery procedure as described with reference to FIG6D, so as to return the procedure to step 6i-01 to send data in RRC connection mode.

[0816] If there is no data to send, then in step 6i-15, the UE determines whether timer B has expired while performing the cell reselection process.

[0817] If timer B has not yet expired, then in step 6i-20, the UE determines whether the suitable cell found during the cell reselection process belongs to a Type 1 PA. That is, the UE can determine whether it is outside a Type 1 PA. If the cell belongs to a Type 1 PA (or if the UE is within a Type 1 PA), the UE returns to step 6i-10 to determine whether there is data to be transmitted.

[0818] If the cell does not belong to type 1 PA, then in steps 6i-25, the UE performs the following as referenced. Figure 6E The PA update process receives a new type of PA and, in steps 6i-25, updates the old type 1 PA with the new type 1 PA.

[0819] If timer B has expired, the UE can switch from Type 1 PA mode to Type 2 PA mode. Then, the UE can perform mobility reporting in Type 2 PA mode.

[0820] If timer B has expired, then in step 6i-30, the UE determines whether the suitable cell found during the cell reselection process belongs to a Type 2 PA. That is, the UE determines whether it is outside the configured PA.

[0821] If the cell belongs to a Type 2 PA (i.e., if the UE is within the configured PA), the UE returns to steps 6i-10 to determine if there is data to be sent.

[0822] If the cell does not belong to a Type 2 PA (i.e., if the UE is outside the configured PA), the UE performs as described in the reference. Figure 6E The PA update process is described. In this case, it may be necessary to notify the new eNB that the UE is performing mobility reporting in Type 2 PA mode characterized by a large PA. For this purpose, it is possible to... Figure 6H The reason for establishing the connection is defined in the RRC connection restoration request message sent in step 6h-40, or a reserved bit of the RRC connection restoration request message is used as a type 2 PA mode indicator (indicator 1).

[0823] This indicator can be called the PA type indicator, and it has already been described in detail above, so it will be omitted here.

[0824] Or, you can Figure 6HStep 6h-55, the UE context retrieval response message sent from the old eNB to the new eNB, includes a mobility report in type 2 PA mode and an indicator indicating the expiration of the UE's timer B, instead of in... Figure 6H Step 6h-40, the RRC connection restoration request message sent from the UE to the new eNB, includes a PA type indicator. This indicator may also be referred to as the PA type indicator.

[0825] In step 6i-35, the UE uses the indicator to perform a PA update process to receive a new type 2 PA, and in step 6i-35 updates the old type 2 PA with the new type 2 PA.

[0826] Figure 6J The configuration of a UE according to an embodiment of the present disclosure is shown.

[0827] refer to Figure 6J The UE includes a transceiver 6j-05, a controller 6j-10, a multiplexer / demultiplexer 6j-15, a control message processor 6j-30, higher-layer processors 6j-20 and 6j-25, an EPS bearer manager 6j-35, and a NAS layer entity 6j-40. In this disclosure, the controller 6j-10 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to the transceiver.

[0828] The 6J-05 transceiver is functionally similar to... Figure 5M The transceiver 5M-05 is identical to the 6J-15, therefore its detailed description is omitted here. The multiplexer / demultiplexer 6J-15 is functionally similar to... Figure 5M The multiplexer / demultiplexer 5m-15 is the same, so its detailed description is omitted here.

[0829] The control message processor 6J-30 is functionally similar to... Figure 5M The control message processor 5M-30 is the same as the high-level processors 6J-20 and 6J-25, therefore its detailed description is omitted here. Figure 5M The high-level processors 5m-20 and 5m-25 are the same, so their detailed description is omitted here.

[0830] The controller 6j-10 checks the scheduling commands received by the transceiver 5m-05, such as uplink grants, and controls the transceiver 6j-05 and the multiplexer / demultiplexer 6j-15 to perform uplink transmissions at the appropriate time with the appropriate transmission resources.

[0831] Controller 6j-10 can control the signaling between function blocks to complete operations according to the process described with reference to the flowchart above. Specifically, controller 6j-10 can control the reception of RRC connection release messages. As mentioned above, the RRC connection release message may include a recovery ID, timer B, and at least one of type 1 PA and type 2 PA information. Controller 6j-10 can control the transition to light-connection mode.

[0832] The controller 6j-10 can also start a timer indicated in the RRC connection release message. The RRC connection release message may also include information about the start time of the timer.

[0833] A timer defines a predetermined time period for mobility reporting in Type 1 PA mode, and the eNB also starts the same timer. If the timer expires, the controller 6j-10 can control the UE to perform mobility reporting in Type 2 PA mode, characterized by a large PA, and the eNB assumes that the UE is operating in Type 2 PA mode.

[0834] The controller 6j-10 starts a timer and executes the cell reselection process, while monitoring the timer's expiration.

[0835] If the timer expires, the controller 6j-10 can control the UE to switch from a Type 2 PA mode characterized by a small PA to a Type 2 PA mode characterized by a large PA. Afterwards, the UE can perform mobility reporting in Type 2 PA mode.

[0836] If the UE moves outside the configured PA, controller 6j-10 controls the UE to perform a PA update procedure. In this case, it may be necessary to notify the new eNB that the UE is performing mobility reporting in type 2 PA mode. For this purpose, the establishment reason can be defined in the RRC connection restoration request message (see...). Figure 6H Step 6h-40) or use one of the reserved bits of the RRC connection recovery request message as a type 2 PA mode indicator (indicator 1).

[0837] This indicator may be called a PA type indicator, and its detailed description is omitted here.

[0838] Alternatively, a mobility report in type 2 PA mode and an indicator indicating the expiration of the UE's timer B can be included in the UE retrieval context response message sent from the old eNB to the new eNB (see [link to relevant documentation]). Figure 6H (6h-55), instead of in the RRC connection restoration request message sent from the UE to the new eNB (see 6h-55). Figure 6H (6h-55)(Instruction 2) includes a PA type indicator. This indicator may also be referred to as a PA type indicator.

[0839] The controller 6j-10 uses this indicator to control the PA update process to receive the new type 2 PA and update the old type 2 PA with the new type 2 PA.

[0840] Figure 6K This disclosure illustrates a configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of the present disclosure. The eNB includes a transceiver 6k-05, a controller 6k-10, a multiplexer / demultiplexer 6k-20, a control message processor 6k-35, higher-layer processors 6k-25 and 6k-30, a scheduler 6k-15, EPS bearer entities 6k-40 and 6k-45, and a NAS layer entity 6k-50. In this disclosure, the controller 6k-10 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to the transceiver. The EPS bearer entity may reside in the S-GW, and the NAS layer entity may reside in the MME.

[0841] The transceiver 6k-05, multiplexer / demultiplexer 6k-20, higher-layer processors 6k-25 and 6k-30, scheduler 6k-15, EPS bearer entities 6k-40 and 6k-45, and NAS layer entity 6k-50 are functionally identical to the reference. Figure 5N The components described are the same, so their detailed descriptions are omitted here.

[0842] Controller 6k-10 can control the signaling between function blocks to complete the operations described above. Specifically, controller 6k-10 of the first eNB (source eNB or anchor eNB) can control the eNB to send an RRC connection release message including recovery ID, timer value, and PA configuration information. Controller 6k-10 can control the sending of PA configuration information or at least one PA type configuration information according to the PA update scheme of this disclosure.

[0843] According to embodiments of this disclosure, upon receiving a UE context retrieval request message from another eNB, the controller 6k-10 can control the transmission of a UE context retrieval response message that includes a PA type indicator for use by the UE in mobility reporting.

[0844] The controller 6k-10 of the second eNB (the new eNB on which the UE resides) can receive an RRC connection restoration request message from the UE, including a newly defined establishment reason or PA type indicator. Therefore, the controller 6k-10 can configure the PA type for the UE according to the PA type indicator during the PA update process.

[0845] Seventh Embodiment

[0846] This disclosure discloses an operation mode switching method and apparatus for using paging messages in a network supporting lightweight connectivity technology to switch between ordinary terminals or terminals operating in extended coverage mode (hereinafter, interchangeably referred to as NB-IoT UE, Bandwidth Reduction Low Complexity (BL) UE, Coverage Enhancement UE (CE) and Enhanced Machine Type Communication (eMTC) UE).

[0847] Figure 7A The architecture of the LTE system is shown.

[0848] Already referenced Figure 1A The architecture of the LTE system has been described in detail, so it is omitted here.

[0849] Figure 7B The protocol stack of the interface between the UE and eNB in ​​an LTE system is shown.

[0850] Already referenced Figure 2B and Figure 3B A detailed description of the protocol stack has been provided, so it will be omitted here.

[0851] Figure 7C The concept of a light connection is illustrated.

[0852] Already referenced Figure 6C The concept of light connections has been described in detail, so it will be omitted here.

[0853] Figure 7DA and 7DB The signal flow between the UE, anchor eNB, new eNB, and MME for UE context and S1 bearer reuse during the light connection process is shown according to this disclosure.

[0854] Figure 7DA and Figure 7DB The light connection process and Figure 6DA and Figure 6DB The process for light connections is the same, so its detailed description is omitted here.

[0855] If an RRC connection release message is received from the eNB, the UE transitions from RRC connected mode to lightly connected mode, and a mobility report is performed in the PA configured for UEs in lightly connected mode. For UEs in lightly connected mode, the network must maintain the UE context and the S1-U bearer. However, the network may find it difficult to continuously maintain the UE context and the S1-U bearer for all UEs. Therefore, it is necessary to transition UEs in lightly connected mode to RRC idle mode and release the S1-U bearers of these UEs.

[0856] Figure 7E A method for switching a UE in light connection mode to RRC idle mode for an eNB, according to this disclosure, is shown.

[0857] exist Figure 7E In this scenario, UE 7e-01, in RRC connection mode, is communicating with eNB 7e-02. If data communication stops, eNB 7e-02 starts a predetermined timer, and if data communication is not restored before the timer expires, it determines to release the RRC connection of UE 7e-01.

[0858] The eNB 7e-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7e-01 to release the RRC connection. The eNB 7e-02 assigns a recovery ID to the UE 7e-01 and uses the RRC connection release message to configure the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0859] If an RRC connection release message is received, UE 7e-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used for maintaining the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7e-02 maintains the UE context and the UE's S1 bearer.

[0860] If an RRC connection release message is received in step 7e-05, UE 7e-01 transitions to light connection mode in step 7e-10. Anchor eNB 7e-02 can transition the UE in light connection mode to RRC idle mode. The transition from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason. Anchor eNB 7e-02 is the eNB that maintains the UE context and the S1-U bearer of UE 7e-01.

[0861] In step 7e-15, anchor eNB 7e-02 determines whether to switch UE 7e-01 from light connection mode to RRC idle mode. If it is determined that UE 7e-01 should be switched to RRC idle mode, then in step 7e-20, anchor eNB 7e-02 sends a paging message to UE 7e-01. Upon receiving the paging message, UE 7e-01 switches to RRC connected mode.

[0862] In step 7e-25, UE 7e-01, which is in RRC connection mode, sends an RRC connection restoration request message to anchor eNB 7e-02.

[0863] If an RRC connection request message is received, then in step 7e-30, the anchor eNB 7e-02 identifies an RRC connection recovery message for the recovery ID.

[0864] The anchor eNB 7e-02 can identify UE 7e-01 that is considered to be transitioning to RRC idle mode based on the recovery ID.

[0865] Therefore, in step 7e-35, anchor eNB 7e-02 sends an RRC connection release message to UE 7e-01 to switch UE 7e-01 to RRC idle mode. Upon receiving the RRC connection release message, in step 7e-40, UE 7e-01 switches to RRC idle mode.

[0866] Figure 7F A method according to this disclosure is shown for an eNB to switch a UE in light connection mode to RRC idle mode when the UE moves to the PA of another eNB.

[0867] exist Figure 7F In this scenario, UE 7f-01, in RRC connection mode, is communicating with eNB 7f-02. If data communication stops, eNB 7f-02 starts a predetermined timer, and if data communication is not resumed before the timer expires, the RRC connection of UE 7f-01 is released.

[0868] The eNB 7f-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7f-01 to release the RRC connection. Using the RRC connection release message, the eNB 7f-02 assigns a recovery ID to the UE 7f-01 and configures the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0869] If an RRC connection release message is received, UE 7f-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used for maintaining the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7f-02 maintains the UE context and the UE's S1 bearer.

[0870] If an RRC connection release message is received in step 7f-05, then in step 7f-10, UE 7f-01 transitions to light connection mode. Anchor eNB 7f-02 can transition the UE in light connection mode to RRC idle mode. The transition from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason. Anchor eNB 7f-02 is the eNB that maintains the UE context and maintains the S1-U bearer of UE 7f-01.

[0871] In step 7f-15, anchor eNB 7f-02 determines to switch UE 7f-01, which is in light connection mode, to RRC idle mode. If it is determined that UE 7f-01 will switch to RRC idle mode, then in step 7f-20, anchor eNB 7f-02 sends a paging message to the new eNB, and in step 7f-25, it sends a paging message to UE 7f-01. Upon receiving the paging message, UE 7f-01 switches to RRC connected mode.

[0872] The anchor eNB 7f-02 can have information about the PA of UE 7f-01 because UE 7f-01 reports the PA whenever it is updated when UE 7f-01 moves.

[0873] If a paging message is received, then in step 7f-30, UE 7f-01 sends an RRC connection restoration request message to the new eNB 7f-03.

[0874] If an RRC connection recovery request message is received, the new eNB 7f-03 in step 7f-35 can identify the RRC connection recovery message for the recovery ID.

[0875] Next, in steps 7f-40 and 7f-45, the second eNB 7f-03 performs the UE context retrieval procedure using the anchor eNB 7f-02. During this procedure, the anchor eNB 7f-02 may notify the new eNB 7f-03 that UE 7f-01 should switch to RRC idle mode. In step 7f-50, the new eNB 7f-03 sends an RRC connection release message to UE 7f-01, and upon receiving the RRC connection release message, in step 7f-55, UE 7f-01 switches to RRC idle mode.

[0876] Figure 7G Another procedure for switching a UE in light connection mode to RRC idle mode, according to this disclosure, is shown.

[0877] refer to Figure 7GIn the case where the UE moves to the PA of another eNB, the MME determines the UE's operating mode transition from light connection mode to RRC idle mode, and as in LTE, the MME, rather than the anchor eNB, triggers the paging of the UE.

[0878] exist Figure 7G In this process, UE 7g-01, in RRC connection mode, communicates with anchor eNB 7g-02. If data communication stops, anchor eNB 7g-02 starts a predetermined timer, and if data communication is not restored before the timer expires, it determines to release the RRC connection of UE 7g-01.

[0879] The eNB 7g-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7g-01 to release the RRC connection. The eNB 7g-02 uses the RRC connection release message to assign a recovery ID to the UE 7g-01 and configure the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0880] If an RRC connection release message is received, UE 7g-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used for maintaining the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7g-02 maintains the UE context and the UE's S1 bearer.

[0881] If an RRC connection release message is received in step 7g-05, then in step 7g-10, UE 7g-01 switches to light connection mode. MME 7g-04 can switch the UE in light connection mode to RRC idle mode. The switch from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason.

[0882] In step 7g-15, MME 7g-04 determines to switch UE 7g-01, which is in light connection mode, to RRC idle mode. If it is determined that UE 7g-01 should switch to RRC idle mode, then in steps 7g-20 and 7g-25, MME 7g-04 sends paging messages to anchor eNB 7g-02 and new eNB 7g-03, and then in steps 7g-30 and 7g-35, anchor eNB 7g-02 and new eNB 7g-03 broadcast the paging message. Upon receiving the paging message, UE 7g-01 switches to RRC connected mode.

[0883] MME 7g-04 can have information about the PA of UE 7f-01 because UE 7g-01 reports the PA whenever it is updated when UE 7g-01 moves.

[0884] If a paging message is received, in step 7g-40, UE 7g-01 sends an RRC connection restoration request message to the new eNB 7g-03.

[0885] If an RRC connection recovery request message is received, the new eNB 7g-03 in step 7g-45 can identify the RRC connection recovery message for the recovery ID.

[0886] Next, in steps 7g-50 and 7g-55, the second eNB 7g-03 performs the UE context retrieval process using the anchor eNB 7g-02.

[0887] The paging message generated by MME 7g-04 may include information instructing UE 7g-01 to switch to RRC idle mode. This information may be included in the paging message as an indicator. This indicator may be newly defined in the paging record, or 1 bit of the paging message may be used as the indicator. This indicator may be called the UE mode transition indicator. If paging of a UE in lightly connected mode is triggered by MME 7g-04, UE 7g-01 can be pre-configured to switch to RRC idle mode.

[0888] If the new eNB 7g-03 receives a paging message from MME 7g-04 that includes a UE mode transition indicator, it assumes that UE 7g-01 is operating in RRC idle mode.

[0889] Figure 7E , Figure 7F and Figure 7GThe UE mode transition process used to switch a UE from lightly connected mode to RRC idle mode can incur signaling overhead. To reduce this overhead, it may be necessary to define a new indicator in the paging message. The indicator indicating the transition from lightly connected mode to RRC idle mode can be newly defined in the paging recoding of the paging message, or 1 bit of the paging message can be designated as the indicator. This indicator can be called the UE mode transition indicator. This indicator can be the same as or different from the indicator sent from the MME to the eNB.

[0890] Figure 7H This demonstrates a method by which an eNB uses a paging message that includes an RRC idle mode transition indicator to switch a UE in lightly connected mode to RRC idle mode.

[0891] exist Figure 7H In this process, UE 7h-01, in RRC connection mode, communicates with anchor eNB 7h-02. If data communication stops, eNB 7h-02 starts a predetermined timer, and if data communication is not restored before the timer expires, it determines to release the RRC connection of UE 7h-01.

[0892] The eNB 7h-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7h-01 to release the RRC connection. Using the RRC connection release message, the eNB 7h-02 assigns a recovery ID to the UE 7h-01 and configures the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0893] If an RRC connection release message is received, UE 7h-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used for maintaining the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7h-02 maintains the UE context and the UE's S1 bearer.

[0894] If an RRC connection release message is received in step 7h-05, then in step 7h-10, UE 7h-01 transitions to light connection mode. Anchor eNB 7h-02 can transition the UE in light connection mode to RRC idle mode. The transition from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason. Anchor eNB 7h-02 is the eNB that maintains the UE context and the S1-U bearer of UE 7h-01.

[0895] In step 7h-15, anchor eNB 7h-02 can determine to switch UE 7h-01, which is in light connection mode, to RRC idle mode.

[0896] If it is determined that UE 7h-01 will be switched to RRC idle mode, then anchor eNB 7h-02 can send a paging message to UE 7h-01 including an indicator indicating the mode switch to RRC idle mode. Therefore, in step 7h-20, anchor eNB 7h-02 sends a paging message including a mode switch indicator to UE 7h-02.

[0897] Upon receiving a paging message, in step 7h-25, UE 7h-01 checks the mode switching indicator in the paging message and directly switches to RRC idle mode.

[0898] The mode transition indicator included in the paging message is information that instructs the UE to directly switch to RRC idle mode. This indicator can be newly defined in the paging record of the paging message, or 1 bit of the paging message can be used as the indicator. This indicator can be called the UE mode transition indicator.

[0899] After switching to RRC idle mode, in step 7h-30, UE 7h-01 sends an RRC connection restoration request message to anchor eNB 7h-02 to notify anchor eNB 7h-02 that UE has successfully switched to RRC idle mode.

[0900] If an RRC connection restoration request message is received, the anchor eNB 7h-02 checks the restoration ID in the RRC connection restoration request message to confirm that UE 7h-01 has successfully switched to RRC idle mode. In step 7h-35, the anchor eNB 7h-02 may start a predetermined timer after sending a paging message, and if no RRC connection restoration request message is received before the timer expires, it is determined that the paging message was lost.

[0901] Figure 7I This disclosure illustrates a method by which an eNB, when a UE moves to the PA of another eNB, uses a paging message including an RRC idle mode transition indicator to transition the UE from lightly connected mode to RRC idle mode.

[0902] exist Figure 7I In this process, UE 7i-01, in RRC connection mode, communicates with eNB 7i-02. If data communication stops, eNB 7i-02 starts a predetermined timer, and if data communication is not restored before the timer expires, the RRC connection of UE 7i-01 is released.

[0903] The eNB 7i-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7i-01 to release the RRC connection. The eNB 7i-02 uses the RRC connection release message to assign a recovery ID to the UE 7i-01 and configure the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0904] If an RRC connection release message is received, UE 7i-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used to maintain the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7f-02 maintains the UE context and the UE's S1 bearer.

[0905] If an RRC connection release message is received in step 7i-05, UE 7i-01 transitions to light connection mode in step 7i-10. Anchor eNB 7i-02 can transition the UE in light connection mode to RRC idle mode. The transition from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason. Anchor eNB 7i-02 is the eNB that maintains the UE context and the S1-U bearer of UE 7i-01.

[0906] In step 7i-15, anchor eNB 7f-02 can determine whether to switch UE 7i-01, which is in light connection mode, to RRC idle mode. If it is determined that UE 7i-01 will be switched to RRC idle mode, anchor eNB 7i-02 can send a paging message including an indicator indicating the mode switch to RRC idle mode. In step 7i-20, anchor eNB 7i-02 sends the paging message including the mode switch indicator to new eNB 7i-03, and the new eNB broadcasts the paging message to UE 7i-01 in step 7i-25.

[0907] Upon receiving a paging message, UE 7i-01 checks the mode switching indicator in the paging message and immediately switches to RRC idle mode in step 7i-30.

[0908] The mode transition indicator included in the paging message is information that instructs the UE to directly transition to RRC idle mode. This indicator can be newly defined in the paging record of the paging message, or 1 bit of the paging message can be used as the indicator. This indicator can be called the UE mode transition indicator.

[0909] After switching to RRC idle mode, in step 7i-40, UE 7i-01 sends an RRC connection restoration request message to anchor eNB 7i-02 to notify the new eNB 7i-03 that the UE has successfully switched to RRC idle mode.

[0910] If an RRC connection restoration request message is received, in step 7i-35, the new eNB 7i-03 can check the restoration ID in the RRC connection restoration message and confirm that UE 7h-01 has successfully switched to RRC idle mode. The new eNB 7h-03 can start a predetermined timer after broadcasting the paging message, and if no RRC connection restoration request message is received before the timer expires, it is determined in step 7i-40 that the paging message was lost. Figure 7J This is a signal flow diagram illustrating another process for switching a UE in light connection mode to RRC idle mode according to this disclosure.

[0911] refer to Figure 7J In the case where the UE moves to the PA of another eNB, the MME determines that the UE's operating mode has changed from lightly connected mode to RRC idle mode, and as in LTE, the MME, rather than the anchor eNB, triggers paging of the UE; the paging message generated by the MME includes an indicator indicating that the UE in lightly connected mode has changed to RRC idle mode.

[0912] exist Figure 7J In this process, UE 7j-01, in RRC connection mode, communicates with anchor eNB 7j-02. If data communication stops, anchor eNB 7j-02 starts a predetermined timer, and if data communication is not restored before the timer expires, it determines to release the RRC connection of UE 7j-01.

[0913] The eNB 7j-02 can maintain the UE context and send an RRC connection release message to instruct the UE 7j-01 to release the RRC connection. The eNB 7j-02 uses the RRC connection release message to assign a recovery ID to the UE 7j-01 and configure the PA for mobility reporting in light-connection mode. That is, the RRC connection release message can include the recovery ID and PA information. The PA configuration method has already been described above, so its detailed description is omitted here.

[0914] If an RRC connection release message is received, UE 7j-01 switches to light connection mode (or inactive mode) and recognizes that it must maintain the UE context based on the fact that a recovery ID has been assigned or an explicit context retention indicator included in the RRC connection release message. The RRC connection release message may include a list of cells used for maintaining the UE context during RRC connection reconfiguration during the eNB's context retention period or the UE's context validity period. After releasing the RRC connection, eNB 7g-02 maintains the UE context and the UE's S1 bearer.

[0915] If an RRC connection release message is received in step 7j-05, then in step 7j-10, UE 7j-01 switches to light connection mode. MME 7j-04 can switch the UE in light connection mode to RRC idle mode. The switch from light connection mode to RRC idle mode can be determined by an expiration timer or triggered by a predetermined reason.

[0916] In step 7j-15, MME 7j-04 determines to switch UE 7j-01, which is in light connection mode, to RRC idle mode. If it is determined that UE 7j-01 will switch to RRC idle mode, MME 7j-04 sends a paging message, including a mode transition indicator indicating the switch to RRC idle mode, to anchor eNB 7j-02 and new eNB 7j-03 in steps 7j-20 and 7j-25. Next, anchor eNB 7j-02 and new eNB 7j-03 broadcast the paging message in steps 7j-30 and 7j-35.

[0917] MME 7j-04 can have information about the PA of UE 7j-01 because UE 7j-01 reports the PA whenever it is updated when UE 7j-01 moves.

[0918] If a paging message is received, UE 7j-01 checks the mode transition indicator in the paging message and immediately switches to RRC idle mode in step 7j-40.

[0919] The mode transition indicator included in the paging message is information that instructs the UE to directly transition to RRC idle mode. This indicator can be newly defined in the paging record of the paging message, or 1 bit of the paging message can be used as the indicator.

[0920] After switching to RRC idle mode, UE 7j-01 sends an RRC connection restoration request message to the new eNB 7j-03 in step 7j-45 to notify UE 7j-01 that it has successfully switched to RRC idle mode. The new eNB 7j-03 can start a predetermined timer after broadcasting the paging message, and if it does not receive the RRC connection restoration request message before the timer expires, it determines that the paging message was lost in step 7j-50. Figure 7K This is a flowchart illustrating the UE operation when a paging message is received, according to this disclosure. Figure 7K In step 7k-01, the UE in RRC connection mode communicates with the eNB via data.

[0921] If data communication is interrupted and not resumed before a predetermined time period has elapsed, the UE may receive an RRC connection release message in step 7k-02. The RRC connection release message may include at least one of recovery ID and PA information.

[0922] Next, in step 7k-03, the UE transitions to light connectivity mode. The UE stores the recovery ID and UE context, and if PA mode is configured, it transitions to light connectivity mode. When the UE moves along the configured PA area, it can report mobility to the network.

[0923] Then, in step 7k-04, the UE can receive paging messages.

[0924] If a paging message is received, then in steps 7k-10, the UE determines whether the paging message includes a mode transition indicator that indicates a transition to RRC idle mode.

[0925] The mode transition indicator included in the paging message is information that instructs the UE to directly switch to RRC idle mode. This indicator can be newly defined in the paging record of the paging message, or 1 bit of the paging message can be used as the indicator. In this disclosure, this indicator may be referred to as the UE mode transition indicator.

[0926] If it is determined that the paging message does not include a mode transition indicator, the UE triggers the RRC connection recovery procedure in step 7k-15 to return the procedure to step 7k-01.

[0927] If the eNB or MME has already sent a paging message including a mode transition indicator indicating a transition to idle mode, the UE can switch to idle mode upon receiving an RRC connection release message. If the MME triggers a paging of the UE, the MME can send a paging message including a UE mode transition indicator to the eNB. If the MME triggers a paging of the UE, it generates a paging message including a UE mode transition indicator.

[0928] If the paging message is determined to include a mode transition indicator, then in step 7k-20, the UE immediately transitions to RRC idle mode. After transitioning to RRC idle mode, in step 7k-25, the UE sends an RRC connection restoration request message to notify the eNB that the UE has successfully transitioned to RRC idle mode.

[0929] Figure 7L The configuration of a UE according to an embodiment of the present disclosure is shown.

[0930] refer to Figure 7L The UE includes a transceiver 7l-05, a controller 7l-10, a multiplexer / demultiplexer 7l-15, a control message processor 7l-30, higher-layer processors 7l-20 and 7l-25, an EPS bearer manager 7l-35, and a NAS layer entity 7l-40. In this disclosure, the controller 7l-10 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to the transceiver.

[0931] The transceiver 7l-05, multiplexer / demultiplexer 7l-15, control message processor 7l-30, and higher-level processors 7l-20 and 7l-25 are functionally similar to... Figure 5M Those components are the same. Therefore, their detailed description is omitted here.

[0932] The controller 7l-10 checks the scheduling command (e.g., uplink grant) received by the transceiver 7l-05 and controls the transceiver 7l-05 and the multiplexer / demultiplexer 7l-15 to perform uplink transmissions at appropriate timings using appropriate transmission resources.

[0933] Controller 7l-10 can control the signaling between functional blocks to complete operations according to the process described in the flowchart above. Specifically, controller 7l-10 can control the UE in RRC connection mode to communicate with the eNB.

[0934] When data communication is interrupted, controller 7l-10 can start a timer, and if data communication is not restored before the timer expires, controller 7l-10 controls the UE to receive an RRC connection release message. Controller 7l-10 can control the UE to switch to light connection mode. Controller 7l-10 can control the UE to receive paging messages.

[0935] If a paging message is received, the controller 7l-10 can check the aging message for a mode transition indicator that indicates a transition to RRC idle mode.

[0936] The mode transition indicator included in the paging message is information that instructs the UE to directly transition to RRC idle mode. This indicator can be newly defined in the paging record of the paging message, or 1 bit of the paging message can be used as the indicator. In this disclosure, this indicator may be referred to as the UE mode transition indicator.

[0937] If it is determined that the paging message does not include a mode transition indicator, the controller 7l-10 triggers an RRC connection recovery procedure to switch the UE back to RRC connection mode.

[0938] If the eNB or MME has already sent a paging message that includes a mode transition indicator indicating a transition to idle mode, the UE can switch to idle mode upon receiving an RRC connection release message.

[0939] If the paging message is determined to include a mode transition indicator, controller 7l-10 controls the UE to immediately transition to RRC idle mode. After transitioning the UE to RRC idle mode, controller 7l-10 controls the UE to send an RRC connection restoration request message to notify the eNB that the UE has successfully transitioned to RRC idle mode.

[0940] Figure 7M This illustration shows a configuration of an eNB including an MME portion and an S-GW portion according to an embodiment of the present disclosure. The eNB includes a transceiver 7m-05, a controller 7m-10, a multiplexer / demultiplexer 7m-20, a control message processor 7m-35, higher-layer processors 7m-25 and 7m-30, a scheduler 7m-15, EPS bearer entities 7m-40 and 7m-45, and a NAS layer entity 7m-50. In this disclosure, the controller 7m-10 may be interchangeably referred to as a circuit, an application-specific integrated circuit, and at least one processor, and the controller may be coupled to the transceiver. The EPS bearer entity may reside in the S-GW, and the NAS layer entity may reside in the MME.

[0941] The transceiver 7m-05, multiplexer / demultiplexer 7m-20, higher layer processors 7m-25 and 7m-30, scheduler 7m-15, EPS bearer entities 7m-40 and 7m-45, and NAS layer entity 7m-50 are functionally identical to the reference. Figure 5N The components described are the same, so their detailed descriptions are omitted here.

[0942] The controller 7m-10 can control the signaling between function blocks to complete the operations described above. Specifically, the controller 7m-10 can determine whether to switch the UE to idle mode, and if a mode switch is determined, it sends a paging message to switch the UE to RRC connected mode and then sends an RRC connection release message to switch the UE to RRC idle mode.

[0943] The controller 7m-10 can include a UE mode switching indicator in the paging message to switch the UE to idle mode.

[0944] If a paging message is received from the eNB, the controller 7-10 can determine whether to switch the UE to idle mode based on the mode switching indicator included in the paging message or according to predetermined rules. To switch the UE to idle mode, the controller 7-10 can control the eNB to send a paging message to switch the UE to RRC connected mode, and then send an RRC connection release message to switch the UE to RRC idle mode; alternatively, it can control the eNB to send a paging message including a UE mode switching indicator.

[0945] As described above, the access control method of this disclosure is advantageous in reducing the complexity of UE operation by applying a single access control procedure.

[0946] Furthermore, the access control method disclosed herein has the advantage that the eNB can effectively configure the UE's DRX operation by dynamically changing the DRX period.

[0947] Furthermore, the access control method disclosed herein is advantageous in addressing network overload by conducting paging operations in multiple areas of a specified cell within a heterogeneous environment comprising eNBs with different cell sizes.

[0948] Furthermore, the access control method disclosed herein is advantageous in increasing the probability of successful reception and reducing latency during data transmission.

[0949] Furthermore, the access control method disclosed herein is advantageous in preventing data transmission interruptions and improving data communication efficiency by employing a data interruption time reduction mechanism and specifying UE operations for faults that reduce data interruption time.

[0950] Furthermore, the access control method disclosed herein is advantageous in terms of saving battery power and reducing signaling overhead by autonomously switching the operating mode of a UE disconnected from a network that supports light connectivity to a large paging area preference mode.

[0951] Furthermore, the access control method disclosed herein is advantageous in reducing signaling overhead between the UE and the network by switching a UE in light connection mode to idle mode based on a paging message from the eNB.

[0952] The methods specified in the claims and specification can be implemented by hardware, software, or a combination thereof.

[0953] In the case of software implementation, at least one program (software module) may be stored in a computer-readable storage medium. The at least one program stored in the computer-readable storage medium may be configured to be executed by at least one processor embedded in an electronic device. The at least one program includes instructions executable by the electronic device to perform the methods disclosed in the claims and specification of this disclosure.

[0954] Such programs (software modules or software programs) can be stored in non-volatile memory, such as random access memory (RAM) and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, compact disc-ROM (CD-ROM), digital versatile disc (DVD) or other types of optical storage devices, and magnetic tape. Programs can also be stored in memory devices implemented using some or all of the above media. Memory may include multiple memories.

[0955] The program can be stored in an attachable storage device accessible through a communication network, which is a combination of the Internet, intranet, local area network (LAN), wireless LAN (WLAN), and storage area network (SAN). The storage device can be attached to a device performing the method according to embodiments of this disclosure via an external port. A separate storage device installed on the communication network can also be attached to a device performing the method according to embodiments of this disclosure.

[0956] It should be understood that those skilled in the art can change or modify the embodiments without departing from the technical concept of this disclosure. Therefore, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the scope of the disclosure in any way. Consequently, the scope of this disclosure should be determined by the appended claims and their legal equivalents, rather than the description, and various changes and modifications within the definition and scope of the claims are included in the claims.

[0957] In the above embodiments of this disclosure, operations may be selectively performed or omitted. In each embodiment of this disclosure, operations need not be performed in the described order, but may be performed in a different order.

[0958] Some or all of the disclosures described below are provided to aid in understanding this disclosure. Therefore, the detailed description of the disclosures is an integral part of expressing the methods and apparatus presented in this disclosure. That is, it is preferably semantically, rather than grammatically, similar to the content of the specification.

[0959] Although various embodiments of this disclosure have been described using specific terminology, the specification and drawings are intended to be illustrative rather than restrictive in order to aid in the understanding of this disclosure. It will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the broader spirit and scope of this disclosure.

[0960] Although this disclosure has been described using exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. This disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a communication system, the method comprising: When the terminal is in an inactive state of Radio Resource Control (RRC), it receives a paging message from the base station; Based on the paging message, it can be determined whether the system has entered an RRC idle state or is performing an RRC connection recovery process; The terminal enters the RRC idle state when the information included in the paging message indicates that the terminal will enter the RRC idle state. as well as In the case where the terminal based on paging message identification will perform the RRC connection restoration process: Send an RRC recovery request message to the base station. Receive an RRC release message from the base station as a response to the RRC recovery request message, and Entering the RRC idle state based on the RRC release message.

2. The method as described in claim 1, wherein, Receiving paging messages also includes: Receive an RRC release message containing information related to the RRC inactivity status; and Entering the RRC inactive state based on an RRC release message containing information related to the RRC inactive state.

3. The method as described in claim 2, wherein, Information related to the RRC inactivity state includes the paging area and information used to identify the context of the terminal in the RRC inactivity state.

4. The method of claim 3, wherein, Store the terminal context in the RRC inactive state.

5. A method performed by a base station in a communication system, the method comprising: Identify paging messages; Send a paging message to a terminal that is in the Radio Resource Control (RRC) inactive state, wherein the paging message is used to identify whether the terminal has entered the RRC idle state or is performing the RRC connection recovery process; When an RRC connection recovery process is initiated based on a paging message, an RRC recovery request message is received from the terminal. as well as Send an RRC release message to the terminal as a response to the RRC recovery request message. The terminal's state is converted to RRC idle state based on the RRC release message, and The information included in the paging message is used to identify when the terminal will enter the RRC idle state, and the terminal's state is changed to the RRC idle state.

6. The method of claim 5, wherein, Sending paging messages also includes: Send an RRC release message containing information related to the RRC inactivity status. The terminal's state is converted to RRC inactive state based on the RRC release message containing information related to the RRC inactive state.

7. The method of claim 6, wherein, Information related to the RRC inactivity state includes the paging area and information used to identify the context of the terminal in the RRC inactivity state.

8. The method of claim 7, wherein, Store the terminal context in the RRC inactive state.

9. A terminal in a communication system, the terminal comprising: transceiver; and The controller, coupled to the transceiver, is configured to: When the terminal is in an inactive state under Radio Resource Control (RRC), it receives paging messages from the base station via a transceiver. The paging message is used to identify whether the system has entered an RRC idle state or is performing an RRC connection recovery process. The terminal enters the RRC idle state based on information included in the paging message that indicates it will enter the RRC idle state. This information is used to identify that the terminal will enter the RRC idle state. In the case where the terminal based on paging message identification will perform the RRC connection restoration process: Send an RRC recovery request message to the base station. Receive an RRC release message from the base station as a response to the RRC recovery request message, and Entering the RRC idle state based on the RRC release message.

10. The terminal as claimed in claim 9, wherein, The controller is configured as follows: Receive an RRC release message containing information related to the RRC inactivity status, and Entering the RRC inactive state based on an RRC release message containing information related to the RRC inactive state.

11. The terminal as claimed in claim 10, wherein, Information related to the RRC inactivity state includes the paging area and information used to identify the context of the terminal in the RRC inactivity state.

12. The terminal as claimed in claim 11, wherein, Store the terminal context in the RRC inactive state.

13. A base station in a communication system, the base station comprising: transceiver; and The controller, coupled to the transceiver, is configured to: Identify paging messages, A paging message is sent via transceiver to a terminal in an inactive Radio Resource Control (RRC) state. The paging message is used to identify whether the terminal has entered an RRC idle state or is performing an RRC connection restoration procedure. In the case of initiating an RRC connection restoration process based on a paging message, the terminal receives an RRC restoration request message, and Send an RRC release message to the terminal as a response to the RRC recovery request message. The terminal's state is converted to RRC idle state based on the RRC release message, and The information included in the paging message is used to identify when the terminal will enter the RRC idle state, and the terminal's state is changed to the RRC idle state.

14. The base station of claim 13, wherein the controller is configured to send an RRC release message containing information related to the RRC inactivity state, and The terminal's state is converted to RRC inactive state based on the RRC release message containing information related to the RRC inactive state.

15. The base station as described in claim 14, wherein, Information related to the RRC inactivity state includes the paging area and context information used to identify the terminal in the RRC inactivity state, as well as The context of the terminal is stored in the RRC inactive state.

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