Patent Description:
To meet increasing demand with respect wireless data traffic after the commercialization of <NUM>th generation (<NUM>) communication systems, efforts have been made to develop <NUM>th generation (<NUM>) or pre-<NUM> communication systems. For this reason, <NUM> or pre-<NUM> communication systems are called 'beyond <NUM> network' communication systems or 'post long term evolution (post-LTE)' systems. The <NUM> communication system defined in the <NUM>rd Generation Partnership Project (3GPP) is called a New Radio (NR) system. To achieve high data rates, implementation of <NUM> communication systems in an ultra-high frequency or millimeter-wave (mmWave) band (e.g., a <NUM>-gigahertz (GHz) band) is being considered. To reduce path loss of radio waves and increase a transmission distance of radio waves in the ultra-high frequency band for <NUM> communication systems, various technologies such as beamforming, massive multiple-input and multiple-output (massive MIMO), full-dimension MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being studied and applied to the NR system. To improve system networks for <NUM> communication systems, various technologies such as evolved small cells, advanced small cells, cloud radio access networks (Cloud-RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, coordinated multi-points (CoMP), and interference cancellation have been developed. In addition, for <NUM> communication systems, advanced coding modulation (ACM) technologies such as hybrid frequency-shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC), and advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), have been developed.

The Internet has evolved from a human-based connection network, where humans create and consume information, to the Internet of things (IoT), where distributed elements such as objects exchange information with each other to process the information. Internet of everything (IoE) technology has emerged, in which the loT technology is combined with, for example, technology for processing big data through connection with a cloud server. To implement the loT, various technological elements such as sensing technology, wired/wireless communication and network infrastructures, service interface technology, and security technology are required, such that, in recent years, technologies related to sensor networks for connecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. In the loT environment, intelligent Internet technology (IT) services may be provided to collect and analyze data obtained from connected objects to create new value in human life. As existing information technology (IT) and various industries converge and combine with each other, the loT may be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart home appliances, and advanced medical services.

Various attempts are being made to apply <NUM> communication systems to the loT network. For example, <NUM> communication such as sensor networks, M2M communication, MTC, and the like is being implemented by using techniques including beamforming, MIMO, array antennas, and the like. Application of cloud radio access network (Cloud-RAN) as the above-described big data processing technology may be an example of convergence of <NUM> communication technology and loT technology.

As various services can be provided due to the aforementioned technical features and development of mobile communication systems, there is a demand for a method for effectively providing the services.

<CIT> discloses a method for updating a configuration of user equipment (UE) by an access and mobility management function (AMF) in a wireless communication system.

<NPL>, discloses specifies the non-access stratum (NAS) procedures in the <NUM> system (5GS).

Embodiments of the disclosure provide a device and method for effectively providing a service in a mobile communication system.

Embodiments of the disclosure provide a method and device for processing a non-access stratum (NAS) message in a wireless communication system.

Embodiments of the disclosure provide a method and device for effectively providing a service in a mobile communication system.

The invention is set out in the appended set of claims, wherein the figures and respective description relate to advantageous embodiments thereof.

Hereinafter, exemplary embodiments of the disclosure will be described in detail with reference to accompanying drawings. In the accompanying drawings, it will be understood that like reference numerals denote like elements. Also, detailed descriptions of well-known functions and configurations in the art are omitted when it is deemed that they may unnecessarily obscure the essence of the disclosure.

In the following descriptions of embodiments in the specification, descriptions of techniques that are well known in the art and are not directly related to the disclosure are omitted. This is to clearly convey the gist of the disclosure by omitting unnecessary descriptions.

For the same reason, some elements in the drawings are exaggerated, omitted, or schematically illustrated. Also, the size of each element does not entirely reflect the actual size. In the drawings, the same or corresponding elements are denoted by the same reference numerals.

The advantages and features of the disclosure and methods of achieving them will become apparent with reference to embodiments of the disclosure described in detail below with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to embodiments set forth herein; rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure only defined by the claims to one of ordinary skill in the art. Throughout the specification, like reference numerals denote like elements.

Hereinafter, terms identifying an access node, terms indicating network entities, terms indicating messages, terms indicating an interface between network entities, and terms indicating various pieces of identification information, as used in the following description, are exemplified for convenience of descriptions. Accordingly, the disclosure is not limited to the terms to be described below, and other terms indicating objects having equal technical meanings may be used.

In this regard, it will be understood that each block of flowchart illustrations, and combinations of blocks in the flowchart illustrations, may be implemented by computer program instructions. The computer program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which are executed via the processor of the computer or other programmable data processing apparatus, generate means for performing functions specified in the flowchart block(s). The computer program instructions may also be stored in a computer-executable or computer-readable memory that may direct the computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-executable or computer-readable memory produce an article of manufacture including instruction means that perform the functions specified in the flowchart block(s). The computer program instructions may also be loaded onto the 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 the instructions that are executed on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart block(s).

In addition, each block of the flowchart illustrations may represent a module, segment, or portion of code, which includes one or more executable instructions for performing specified logical function(s).

The term "unit", as used in the present embodiment refers to a software or hardware component, such as field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), which performs certain tasks. However, the term "unit" does not mean to be limited to software or hardware. A "unit" may be configured to be in an addressable storage medium or configured to operate one or more processors. Thus, a "unit" may include, by way of example, components, such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided in the components and "units" may be combined into fewer components and "units" or may be further separated into additional components and "units". Further, the components and "units" may be implemented to operate one or more central processing units (CPUs) in a device or a secure multimedia card. Also, in embodiments, a "unit" may include one or more processors.

Hereinafter, for convenience of descriptions, the disclosure uses terms and names defined in the standards for the <NUM>th (<NUM>) and the long term evolution (LTE) system. However, the disclosure is not limited to these terms and names, and may be equally applied to wireless communication systems conforming to other standards.

That is, when particularly describing embodiments of the disclosure, the communication standards defined by the <NUM>rd Generation Partnership Project (3GPP) are mainly applied but the essential concept of the disclosure may be modified without departing from the scope of the disclosure and may be applied to other communication system based on similar technical backgrounds, and the application may be made based on determination by one of ordinary skill in the art.

Also, hereinafter, terms identifying an access node, terms indicating network entities, terms indicating messages, terms indicating an interface between network entities, and terms indicating various pieces of identification information, as used in the following description, are exemplified for convenience of description. Accordingly, the disclosure is not limited to the terms, and other terms indicating objects having equal technical meanings may be used.

In the <NUM> or New Radio (NR) system, an access and mobility management function (AMF) that is a management entity for managing mobility of a UE and a session management function (SMF) that is an entity for managing a session are separate. Accordingly, unlike to an operating scheme of the <NUM>th generation (<NUM>) LTE system in which a mobility management entity (MME) manages both mobility and session, an entity for managing mobility and an entity for managing session are separate such that a communication method and a communication management method between a UE and a network entity are changed.

In the <NUM> or NR system, with respect to non 3GPP access, mobility management is performed by the AMF and session management is performed by the SMF via Non-3GPP Inter Working Function (N3IWF). Also, in the <NUM> or NR system, not only mobility management but also security-related information that is an important factor in the mobility management are managed by the AMF. In the <NUM> network, the MME performs both mobility management and session management. In the <NUM> or NR system, entities for not only the <NUM> communication method but also for communication between <NUM> and <NUM> exist, and in the non-standalone architecture using some <NUM> communication entities for <NUM> communication may perform <NUM> communication.

Accordingly, the disclosure provides a method of processing non-access stratum (NAS) messages when communication is performed using a NAS protocol in <NUM> communication, and more particularly, provides a method of enhancing communication performance by improving efficiency of a protocol.

According to embodiments of the disclosure, communication performance in NAS message exchange and signaling exchange in a <NUM> communication environment is improved, such that communication may be efficiently performed.

<FIG> illustrates an example of a communication procedure, UEs for communication, and a network environment for performing secured communication by using some of <NUM> or <NUM> entities in <NUM> and <NUM> networks according to an embodiment of the disclosure.

According to an embodiment of the disclosure, the <NUM> network system may include network entities such as a user plane function (UPF) <NUM>, a SMF <NUM>, an AMF <NUM>, a <NUM> radio access network (RAN) <NUM>, a user data management (UDM) <NUM>, a policy control function (PCF) <NUM>, and the like. To authenticate the entities, an authentication server function (AUSF) <NUM> and authentication, authorization and accounting (AAA) <NUM> may also exist in the <NUM> network system.

Also, according to some embodiments of the disclosure, the <NUM> network system may include Non-3GPP Interworking Function (N3IWF) for a case in which a UE communicates via non 3GPP access. When communicating via non 3GPP access, session management may be controlled via the UE, the non 3GPP access, the N3IWF, and the SMF, and mobility management may be controlled via the UE, the non 3GPP access, the N3IWF, and the AMF.

Also, for an embodiment of the disclosure, it is assumed that <NUM> system and <NUM> LTE system coexist. In LTE, an MME for managing mobility management and session management exists to control communication of a UE. In <NUM>, an entity for managing mobility management and session management is divided into an AMF and an SMF. For <NUM> communication, standalone deployment architecture in which only <NUM> communication entities perform communication, and non-standalone deployment architecture in which <NUM> and <NUM> entities are used for <NUM> communication are being considered.

When a UE communicates with a network, certain deployment may be available, in which communication is controlled by using eNode B (eNB) and a <NUM> entity of a core network is used. In this case, for NAS that is layer <NUM>, the UE and an AMF perform mobility management and the UE and an SMF perform session management, whereas AS that is layer <NUM> is transmitted via the UE and the eNB, such that there is a demand for a method of generating and managing security context. Accordingly, the disclosure provides descriptions about security context generation, management, and protocol exchange which are applicable to the afore-described deployments.

It is assumed that a communication network system on which the disclosure is based is <NUM> and <NUM> LTE networks, but embodiments of the disclosure are not limited thereto, and may be applied to other systems to the extent that one of ordinary skill in the art can understand.

<FIG> illustrates a NAS message information processing and communicating procedure in a <NUM> network environment according to an embodiment of the disclosure.

In operation <NUM>, a UE <NUM> transmits a registration request message to an AMF <NUM>.

In operation <NUM>, the AMF <NUM> transmits a registration Accept message to the UE <NUM>.

In operation <NUM>, the UE <NUM> is in an idle state, and a session management (SM) message transmitted from an SMF <NUM> to the UE <NUM> via the AMF <NUM> is pending.

In operation <NUM>, the AMF <NUM> performs paging with respect to the UE <NUM>.

In operation <NUM>, the UE <NUM> transmits a service request message to the AMF <NUM>. At this time, when the UE <NUM> transitions from the idle state to a connected state in response to the service accept message, a legacy method involves transmitting a <NUM>-global unique temporary identifier (<NUM>-GUTI) through a UE configuration update command message so as to avoid a risk of exposure of a <NUM>-GUTI of the UE <NUM> due to the idle state, but a method that is different from the legacy method involves transmitting a new update indication to notify a network that a UE can use a method of additionally transmitting a <NUM>-GUTI to be newly used, through the service accept message. Obviously, the update indication may be optionally included in the Service request message as shown in Table <NUM>.

Afterward, in operation <NUM>, the AMF <NUM> transmits the service accept message to the UE <NUM>. According to an embodiment of the disclosure, the AMF <NUM> may transmit a <NUM>-GUTI to be newly used by the UE <NUM>. Obviously, the <NUM>-GUTI may be optionally included in the Service accept message as shown in Table <NUM>.

Afterward, according to an embodiment of the disclosure, a process of transmitting a UE configuration update command message from the AMF <NUM> to the UE <NUM> in operation <NUM> may be omitted. A procedure of updating, through a UE configuration update command, information such as a <NUM>-GUTI which may have a risk of exposure due to the UE <NUM> being in the idle state is omitted, but instead, a <NUM>-GUTI to be used by the UE <NUM> is transmitted through the service accept message in operation <NUM> such that a delay that may occur due to failure of the UE configuration update command procedure may be decreased. Afterward, an SM message may be transmitted from the SMF <NUM> to the UE <NUM>.

In operation <NUM>, the UE <NUM> transmits a registration request message to the AMF <NUM>.

In operation <NUM>, the UE <NUM> is in an idle state, and an SM message transmitted from the SMF <NUM> to the UE <NUM> via the AMF <NUM> is pending.

In operation <NUM>, the AMF <NUM> performs paging with respect to the UE <NUM>.

In operation <NUM>, the UE <NUM> transmits a service request message to the AMF <NUM>.

Afterward, in operation <NUM>, the AMF <NUM> transmits a service accept message to the UE <NUM>. In this regard, according to an embodiment of the disclosure, the AMF <NUM> transmits a delay indication to notify that a UE configuration update command message of operation <NUM> for allocating a new <NUM>-GUTI to the UE <NUM> is to be delayed and transmitted after the SM message is transmitted.

The embodiment shown in <FIG> is provided to solve a delay problem that may occur due to multiple retry attempts to transmit a UE configuration update command when transmission of the UE configuration update command fails in a procedure in which the AMF <NUM> transmits the service Accept message to the UE <NUM> and the AMF <NUM> transmits the UE configuration update command to the UE <NUM>.

That is, in a case where the AMF <NUM> transmits the UE configuration update command, and backoff timer T3555 starts running, if transmission of the UE configuration update command fails, transmission of the UE configuration update command is retried <NUM> more times and thus a total of <NUM> times is tried such that a delay occurs. To prevent occurrence of the delay, the embodiment of <FIG> may be useful.

In other words, due to T <NUM> timer, even when the SM message being transmitted from the SMF <NUM> to the UE <NUM> is retransmitted in response to expiry of backoff timer T3591 running at the SMF <NUM>, because T3555 timer for the AMF <NUM> is running, and the SM message is pending when the UE configuration update command is transmitted from the AMF <NUM> to the UE <NUM>, the AMF <NUM> may transmit the delay indication to the UE <NUM> so as to transmit the UE configuration update command message after the SM message is transmitted, as in operation <NUM>. Obviously, the delay indication may be optionally included in the service accept message as shown in Table <NUM>.

The service accept message thereof is as below. However, the disclosure is not limited thereto.

The SM message is transmitted from the SMF <NUM> to the UE <NUM> in operations <NUM> and <NUM>.

Afterward, according to an embodiment of the disclosure, in operation <NUM>, a procedure of transmitting the UE configuration update command message from the AMF <NUM> to the UE <NUM> may be performed.

In operation <NUM>, the AMF <NUM> transmits a service accept message to the UE <NUM>.

Afterward, according to an embodiment of the disclosure, a procedure of transmitting a UE configuration update command message from the AMF <NUM> to the UE <NUM> in operation <NUM> may be omitted.

In this regard, in a legacy method by which, when the UE <NUM> transitions from the idle state to a connected state in response to the service accept message, a <NUM>-GUTI is transmitted through a UE configuration update command message so as to avoid a risk of exposure of a <NUM>-GUTI of the UE <NUM> due to the idle state, if transmission of the UE configuration update command fails, a backoff timer is set and transmission of the UE configuration update command message is retried <NUM> times, such that transmission of the SM message is delayed. Therefore, to avoid a delay in transmission of the SM message due to repetition of retransmission of the UE configuration update command message, operation <NUM> may be omitted.

Also, according to another embodiment of the disclosure, only when transmission of the UE configuration update command fails, i.e., only when a UE configuration update complete message that is a response to the UE configuration update command is not received while T3555 timer is running, the SM message may be first transmitted and then the UE configuration update command may be re-transmitted. To do so, according to an embodiment of the disclosure, a separate preset timer runs such that retransmission of the UE configuration update command may be controlled.

Also, according to another embodiment of the disclosure, the AMF <NUM> may first transmit the pending SM message, and then may reset timer T3555 and attempt retrying to transmit the UE configuration update command. Because this case corresponds to revision to a legacy procedure and operation, an indication by which the AMF <NUM> indicates the afore-described capability to the UE <NUM> may be added.

Afterward, in operations <NUM> and <NUM>, the SM message may be transmitted from the SMF <NUM> to the UE <NUM>.

<FIG> illustrates a structure of a UE according to an embodiment of the disclosure.

Referring to <FIG>, the UE may include a processor <NUM>, a transceiver <NUM>, and a memory <NUM>. The processor <NUM>, the transceiver <NUM>, and the memory <NUM> of the UE may operate according to the communication method of the UE. However, elements of the UE are not limited to an example described above. For example, the UE may include more elements than the afore-described elements or may include fewer elements than the afore-described elements. Furthermore, the processor <NUM>, the transceiver <NUM>, and the memory <NUM> may be implemented as one chip.

The processor <NUM> may control a series of processes to allow the UE to operate according to the aforementioned embodiment. In an embodiment, the processor <NUM> may perform a NAS message information processing and communicating procedure. For example, the processor <NUM> may transmit a registration request message and may receive a registration Accept message in response to the registration request message, and may transmit a service request message including an indication indicating that it is available to receive a <NUM>-global unique temporary identifier (<NUM>-GUTI) via a service accept message and may receive a service accept message including a <NUM>-GUTI. Although only some operations in the embodiments described above with reference to the operation are described as an example, the disclosure is not limited thereto, and the processor <NUM> may control an entire procedure for the UE to operate according to all or some of the embodiments described above.

The transceiver <NUM> may transmit or receive a signal to or from a base station or a network entity. In this regard, the signal being transmitted or received to or from the base station or the network entity may include control information and data. To do so, the transceiver <NUM> may include a radio frequency (RF) transmitter configured to up-convert and amplify a frequency of a signal to be transmitted, and a RF receiver configured to low-noise amplify a received signal and down-convert a frequency thereof. However, the configuration of the transceiver <NUM> is merely an example, and elements of the transceiver <NUM> are not limited to the RF transmitter and the RF receiver. Also, the transceiver <NUM> may receive a signal by using a radio channel and output the signal to the processor <NUM>, and may transmit a signal output from the processor <NUM>, by using a radio channel.

The memory <NUM> may store programs and data required for the UE to operate. Also, the memory <NUM> may store control information or data included in a signal obtained by the UE. The memory <NUM> may include any or a combination of storage media such as read-only memory (ROM), random access memory (RAM), a hard disk, a compact disc (CD)-ROM, and a digital versatile disc (DVD). Also, the memory <NUM> may correspond to a plurality of memories. In an embodiment of the disclosure, the memory <NUM> may store a program for supporting beam-based cooperative communication.

<FIG> illustrates a structure of a network entity according to an embodiment of the disclosure.

Referring to <FIG>, the network entity may include a processor <NUM>, a transceiver <NUM>, and a memory <NUM>. According to the afore-described communication method by the network entity, the processor <NUM>, the transceiver <NUM>, and the memory <NUM> of the network entity may operate. However, elements of the network entity are not limited to an example described above. For example, the network entity may include more elements than the afore-described elements or may include fewer elements than the afore-described elements. Furthermore, the processor <NUM>, the transceiver <NUM>, and the memory <NUM> may be implemented as one chip.

The processor <NUM> may control a series of processes to allow the network entity to operate according to the aforementioned embodiment. According to an embodiment of the disclosure, the processor <NUM> may receive a registration request message and may transmit a registration Accept message in response to the registration request message, and may receive a service request message including an indication indicating that it is available to receive a <NUM>-GUTI via a service accept message and may transmit a service accept message including a <NUM>-GUTI. Although only some embodiments described above with reference to the operation are described as an example, the disclosure is not limited thereto, and the processor <NUM> may control an entire procedure for an UE to operate according to all or some of the embodiments described above.

The transceiver <NUM> may transmit or receive a signal to or from the UE. In this regard, the signal being transmitted or received to or from the UE may include control information and data. To do so, the transceiver <NUM> may include a RF transmitter configured to up-convert and amplify a frequency of a signal to be transmitted, and a RF receiver configured to low-noise amplify a received signal and down-convert a frequency thereof. However, the configuration of the transceiver <NUM> is merely an example, and elements of the transceiver <NUM> are not limited to the RF transmitter and the RF receiver. Also, the transceiver <NUM> may receive a signal by using a radio channel and output the signal to the processor <NUM>, and may transmit a signal output from the processor <NUM>, by using a radio channel.

The memory <NUM> may store programs and data required for the network entity to operate. Also, the memory <NUM> may store control information or data included in a signal obtained by the network entity. The memory <NUM> may include any or a combination of storage media such as ROM, RAM, a hard disk, a CD-ROM, and a DVD. Also, the memory <NUM> may correspond to a plurality of memories. In an embodiment, the memory <NUM> may store a program for supporting beam-based cooperative communication.

Also, the configuration of <FIG> may be a configuration of an AMF, and descriptions of each operation of <FIG> may correspond to descriptions of each element of the AMF.

The methods according to the embodiments of the disclosure as described herein or in the following claims may be implemented as hardware, software, or a combination of hardware and software.

When implemented as software, a computer-readable storage medium storing one or more programs (e.g., software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions directing the electronic device to execute the methods according to the embodiments of the disclosure as described herein or in the following claims.

The programs (e.g., software modules or software) may be stored in non-volatile memory including RAM or flash memory, ROM, electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a CD-ROM, a DVD, another optical storage device, or a magnetic cassette. Alternatively, the programs may be stored in memory including a combination of some or all of the above-mentioned storage media. Also, a plurality of such memories may be included.

In addition, the programs may be stored in an attachable storage device accessible through any or a combination of communication networks such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN). The storage device may be connected, through an external port, to an apparatus according to the embodiments of the disclosure. Another storage device on the communication network may also be connected to the apparatus performing the embodiments of the disclosure.

In the afore-described embodiments of the disclosure, elements included in the disclosure are expressed in a singular or plural form according to the embodiments of the disclosure. However, the singular or plural form is appropriately selected for convenience of description and the disclosure is not limited thereto. As such, an element expressed in a plural form may also be configured as a single element, and an element expressed in a singular form may also be configured as plural elements.

Claim 1:
A method, performed by a user equipment, UE (<NUM>), of processing a non-access stratum, NAS, message, the method comprising:
receiving a paging request message from an access and mobility management function, AMF (<NUM>), wherein the UE (<NUM>) is in an idle state, and a session management message transmitted from a session management function, SMF (<NUM>), to the UE (<NUM>) via the AMF (<NUM>) is pending;
transmitting a service request message to the AMF (<NUM>);
receiving a service accept message from the AMF (<NUM>);
receiving the session management message from the SMF (<NUM>); and
after receiving the session management message, receiving a UE configuration update command message from the AMF (<NUM>).