WO2017171348A2 - Method for performing operation relating to location registration in slice structure in wireless communication system, and device therefor - Google Patents

Abstract

An embodiment of the present invention relates to a method for performing, by a first mobility management (MM) function, an operation relating to location registration of a user equipment (UE) in a wireless communication system, the method comprising the steps of: receiving an attach request from a UE, by a first MM function; determining a first periodic location registration timer value by the first MM function; transmitting a response to the attach request, which includes the first periodic location registration timer value, to the UE by the first MM function; receiving information including a second periodic location registration timer by the first MM function; comparing the first periodic location registration timer value and a value of the second periodic location registration timer by the first MM function; and determining, as a third periodic location registration timer, a timer having the smaller value determined as a result of the comparison, by the first MM function.

Description

Method for performing operation related to location registration in slice structure in wireless communication system and apparatus therefor

The following description relates to a wireless communication system, and more particularly, to a method and apparatus for performing an operation related to location registration in a slice structure.

Wireless communication systems are widely deployed to provide various kinds of communication services such as voice and data. In general, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access (MCD) systems and multi-carrier frequency division multiple access (MC-FDMA) systems.

Device-to-Device (D2D) communication establishes a direct link between user equipments (UEs), and directly communicates voice and data between terminals without passing through an evolved NodeB (eNB). Say the way. The D2D communication may include a scheme such as UE-to-UE communication, Peer-to-Peer communication, and the like. In addition, the D2D communication scheme may be applied to machine-to-machine (M2M) communication, machine type communication (MTC), and the like.

D2D communication has been considered as a way to solve the burden on the base station due to the rapidly increasing data traffic. For example, according to the D2D communication, unlike the conventional wireless communication system, since the data is exchanged between devices without passing through a base station, the network can be overloaded. In addition, by introducing the D2D communication, it is possible to expect the effect of reducing the procedure of the base station, the power consumption of the devices participating in the D2D, increase the data transmission speed, increase the capacity of the network, load balancing, cell coverage expansion.

Currently, a discussion on vehicle to everything (V2X) communication is being conducted as a form linked to D2D communication. V2X is a concept including V2V between vehicle terminals, V2P between a vehicle and other types of terminals, and V2I communication between a vehicle and a roadside unit (RSU).

In the present invention, a technical task is to efficiently perform location registration, for example, location registration, under a network slicing structure.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

According to an embodiment of the present invention, in a method in which a first mobility management (MM) function performs an operation related to location registration of a user equipment (UE) in a wireless communication system, the first MM function is determined from the UE. Receiving a attach request; Determining, by the first MM function, a first periodic location registration timer value; The first MM function sending a response to the attach request to the UE, wherein the response includes the first periodic location registration timer value; Receiving, by the first MM function, information including a second periodic location registration timer; Comparing, by the first MM function, the first periodic location registration timer value with the second periodic location registration timer value; And determining, by the first MM function, a timer having a small value as a result of the comparison as a third periodic location registration timer.

An embodiment of the present invention provides a first MM function apparatus for performing an operation related to location registration of a user equipment (UE) in a wireless communication system, the apparatus comprising: a transceiver; And a processor, wherein the processor is further configured to receive an attach request from a UE via the transceiver, the first MM function determines a first periodic location registration timer value, and sets the first periodic location registration timer value. And transmitting a response to the attach request to the UE, receiving information including a second periodic location registration timer, and comparing the first periodic location registration timer value with the second periodic location registration timer value. The first MM function apparatus determines a timer having a small value as a third periodic position registration timer as a result of the comparison.

The information including the second periodic location registration timer may be a location registration service subscription request.

The location registration service subscription request is transmitted from the second MM function of the selected slice by the UE performing a session setup request, and the first MM function transmits the third periodic location registration timer to the second MM function. Can be.

The second MM function may be configured to transmit the location registration subscription request to an MM function that transmits and receives a NAS message with the UE.

The first MM function may transmit a session setup request to the second MM function.

The first MM function may also determine a third location registration range when determining the third periodic location registration timer.

The third location registration range may be an area in which the first location registration range determined by the first MM function and the second location registration range determined by the second MM function are common.

According to the present invention, it is possible to efficiently provide mobility management when network slicing is used. Specifically, according to the present invention, due to the different timer for each slice, it is possible to eliminate the inefficiency of the UE to perform location registration repeatedly.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings appended hereto are for the purpose of providing an understanding of the present invention and for illustrating various embodiments of the present invention and for describing the principles of the present invention together with the description of the specification.

1 is a diagram illustrating a schematic structure of an EPS (Evolved Packet System) including an Evolved Packet Core (EPC).

2 is an exemplary view showing the architecture of a general E-UTRAN and EPC.

3 is an exemplary view showing the structure of a radio interface protocol in a control plane.

4 is an exemplary view showing the structure of a radio interface protocol in a user plane.

5 is a flowchart illustrating a random access procedure.

6 is a diagram illustrating a connection process in a radio resource control (RRC) layer.

7 illustrates the concept of network slicing.

8 illustrates a possible scenario when the UE is served from one or more network slices.

9 illustrates an architecture reference model usable in a 5G system.

10 to 11 illustrate a method of performing a terminal location registration related operation according to each embodiment of the present invention.

12 is a diagram illustrating a configuration of a node device according to an embodiment of the present invention.

The following embodiments combine the components and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, some components and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present invention.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

Embodiments of the present invention may be supported by standard documents disclosed in relation to at least one of the Institute of Electrical and Electronics Engineers (IEEE) 802 series system, 3GPP system, 3GPP LTE and LTE-A system, and 3GPP2 system. That is, steps or parts which are not described to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the above documents. In addition, all terms disclosed in the present document can be described by the above standard document.

The following techniques can be used in various wireless communication systems. For clarity, the following description focuses on 3GPP LTE and 3GPP LTE-A systems, but the technical spirit of the present invention is not limited thereto.

Terms used in this document are defined as follows.

UMTS (Universal Mobile Telecommunications System): A third generation mobile communication technology based on Global System for Mobile Communication (GSM) developed by 3GPP.

Evolved Packet System (EPS): A network system composed of an Evolved Packet Core (EPC), which is a packet switched (PS) core network based on Internet Protocol (IP), and an access network such as LTE / UTRAN. UMTS is an evolutionary network.

NodeB: base station of GERAN / UTRAN. It is installed outdoors and its coverage is macro cell size.

eNodeB: base station of E-UTRAN. It is installed outdoors and its coverage is macro cell size.

UE (User Equipment): a user device. The UE may be referred to in terms of terminal, mobile equipment (ME), mobile station (MS), and the like. In addition, the UE may be a portable device such as a laptop, a mobile phone, a personal digital assistant (PDA), a smart phone, a multimedia device, or the like, or may be a non-portable device such as a personal computer (PC) or a vehicle-mounted device. In the context of MTC, the term UE or UE may refer to an MTC device.

Home NodeB (HNB): A base station of a UMTS network, which is installed indoors and has a coverage of a micro cell.

HeNB (Home eNodeB): A base station of an EPS network, which is installed indoors and its coverage is micro cell size.

Mobility Management Entity (MME): A network node of an EPS network that performs mobility management (MM) and session management (SM) functions.

Packet Data Network-Gateway (PDN-GW) / PGW: A network node of an EPS network that performs UE IP address assignment, packet screening and filtering, charging data collection, and the like.

Serving Gateway (SGW): A network node of an EPS network that performs mobility anchor, packet routing, idle mode packet buffering, and triggers the MME to page the UE.

Non-Access Stratum (NAS): Upper stratum of the control plane between the UE and the MME. A functional layer for exchanging signaling and traffic messages between a UE and a core network in an LTE / UMTS protocol stack, which supports session mobility and establishes and maintains an IP connection between the UE and the PDN GW. Supporting is the main function.

Packet Data Network (PDN): A network in which a server supporting a specific service (eg, a Multimedia Messaging Service (MMS) server, a Wireless Application Protocol (WAP) server, etc.) is located.

PDN connection: A logical connection between the UE and the PDN, represented by one IP address (one IPv4 address and / or one IPv6 prefix).

RAN (Radio Access Network): a unit including a NodeB, an eNodeB and a Radio Network Controller (RNC) controlling them in a 3GPP network. It exists between UEs and provides a connection to the core network.

Home Location Register (HLR) / Home Subscriber Server (HSS): A database containing subscriber information in the 3GPP network. The HSS may perform functions such as configuration storage, identity management, and user state storage.

Public Land Mobile Network (PLMN): A network composed for the purpose of providing mobile communication services to individuals. It may be configured separately for each operator.

Proximity Service (or ProSe Service or Proximity based Service): A service that enables discovery and direct communication between physically close devices or communication through a base station or through a third party device. In this case, user plane data is exchanged through a direct data path without passing through a 3GPP core network (eg, EPC).

Evolved Packet Core (EPC)

1 is a diagram illustrating a schematic structure of an EPS (Evolved Packet System) including an Evolved Packet Core (EPC).

EPC is a key element of System Architecture Evolution (SAE) to improve the performance of 3GPP technologies. SAE is a research project to determine network structure supporting mobility between various kinds of networks. SAE aims to provide an optimized packet-based system, for example, supporting various radio access technologies on an IP basis and providing enhanced data transfer capabilities.

Specifically, the EPC is a core network of an IP mobile communication system for a 3GPP LTE system and may support packet-based real-time and non-real-time services. In a conventional mobile communication system (i.e., a second generation or third generation mobile communication system), the core network is divided into two distinct sub-domains of circuit-switched (CS) for voice and packet-switched (PS) for data. The function has been implemented. However, in the 3GPP LTE system, an evolution of the third generation mobile communication system, the sub-domains of CS and PS have been unified into one IP domain. That is, in the 3GPP LTE system, the connection between the terminal and the terminal having the IP capability (capability), IP-based base station (for example, eNodeB (evolved Node B)), EPC, application domain (for example, IMS ( IP Multimedia Subsystem)). That is, EPC is an essential structure for implementing end-to-end IP service.

The EPC may include various components, and in FIG. 1, some of them correspond to a serving gateway (SGW), a packet data network gateway (PDN GW), a mobility management entity (MME), and a serving general packet (SGRS) Radio Service (Supporting Node) and Enhanced Packet Data Gateway (ePDG) are shown.

The SGW (or S-GW) acts as a boundary point between the radio access network (RAN) and the core network, and is an element that functions to maintain a data path between the eNodeB and the PDN GW. In addition, when the UE moves over the area served by the eNodeB, the SGW serves as a local mobility anchor point. That is, packets may be routed through the SGW for mobility in the E-UTRAN (Universal Mobile Telecommunications System (Evolved-UMTS) Terrestrial Radio Access Network defined in 3GPP Release-8 or later). SGW also provides mobility with other 3GPP networks (RANs defined before 3GPP Release-8, such as UTRAN or GERAN (Global System for Mobile Communication (GSM) / Enhanced Data Rates for Global Evolution (EDGE) Radio Access Network). It can also function as an anchor point.

The PDN GW (or P-GW) corresponds to the termination point of the data interface towards the packet data network. The PDN GW may support policy enforcement features, packet filtering, charging support, and the like. In addition, mobility management between 3GPP networks and non-3GPP networks (for example, untrusted networks such as Interworking Wireless Local Area Networks (I-WLANs), code-division multiple access (CDMA) networks, or trusted networks such as WiMax) Can serve as an anchor point for.

Although the example of the network structure of FIG. 1 shows that the SGW and the PDN GW are configured as separate gateways, two gateways may be implemented according to a single gateway configuration option.

The MME is an element that performs signaling and control functions to support access to the network connection of the UE, allocation of network resources, tracking, paging, roaming and handover, and the like. The MME controls control plane functions related to subscriber and session management. The MME manages a number of eNodeBs and performs signaling for the selection of a conventional gateway for handover to other 2G / 3G networks. The MME also performs functions such as security procedures, terminal-to-network session handling, and idle terminal location management.

SGSN handles all packet data, such as user's mobility management and authentication to other 3GPP networks (eg GPRS networks).

The ePDG acts as a secure node for untrusted non-3GPP networks (eg, I-WLAN, WiFi hotspots, etc.).

As described with reference to FIG. 1, a terminal having IP capability is an IP service network provided by an operator (ie, an operator) via various elements in the EPC, based on 3GPP access as well as non-3GPP access. (Eg, IMS).

1 illustrates various reference points (eg, S1-U, S1-MME, etc.). In the 3GPP system, a conceptual link defining two functions existing in different functional entities of E-UTRAN and EPC is defined as a reference point. Table 1 below summarizes the reference points shown in FIG. 1. In addition to the examples of Table 1, there may be various reference points according to the network structure.

Reference point	Explanation
S1-MME	Reference point for the control plane protocol between E-UTRAN and MME
S1-U	Reference point between E-UTRAN and Serving GW for the per bearer user plane tunneling and inter eNodeB path switching during handover
S3	Reference point between the MME and SGSN providing user and bearer information exchange for mobility between 3GPP access networks in idle and / or active state. This reference point can be used in PLMN-to-PLMN-to-for example (for PLMN-to-PLMN handovers) (It enables user and bearer information exchange for inter 3GPP access network mobility in idle and / or active state This reference point can be used intra-PLMN or inter-PLMN (eg in the case of Inter-PLMN HO).)
S4	(Reference point between SGW and SGSN that provides related control and mobility support between the GPRS core and SGW's 3GPP anchor functionality.It also provides user plane tunneling if no direct tunnel is established.) and the 3GPP Anchor function of Serving GW.In addition, if Direct Tunnel is not established, it provides the user plane tunnelling.)
S5	Reference point providing user plane tunneling and tunnel management between the SGW and the PDN GW. It provides user plane tunneling and tunnel management between Serving GW and PDN GW. for Serving GW relocation due to UE mobility and if the Serving GW needs to connect to a non-collocated PDN GW for the required PDN connectivity.)
S11	Reference point between MME and SGW
SGi	Reference point between the PDN GW and the PDN. The PDN may be an operator external public or private PDN or, for example, an in-operator PDN for the provision of IMS services. It is the reference point between the PDN GW and the packet data network.Packet data network may be an operator external public or private packet data network or an intra operator packet data network, eg for provision of IMS services.This reference point corresponds to Gi for 3GPP accesses.)

Among the reference points shown in FIG. 1, S2a and S2b correspond to non-3GPP interfaces. S2a is a reference point that provides the user plane with associated control and mobility support between trusted non-3GPP access and PDN GW. S2b is a reference point that provides the user plane with relevant control and mobility support between the ePDG and PDN GW.

2 is an exemplary view showing the architecture of a general E-UTRAN and EPC.

As shown, an eNodeB can route to a gateway, schedule and send paging messages, schedule and send broadcaster channels (BCHs), and resources in uplink and downlink while an RRC (Radio Resource Control) connection is active. Can perform functions for dynamic allocation to the UE, configuration and provision for measurement of the eNodeB, radio bearer control, radio admission control, and connection mobility control. Within the EPC, paging can occur, LTE_IDLE state management, user plane can perform encryption, SAE bearer control, NAS signaling encryption and integrity protection.

3 is an exemplary diagram illustrating a structure of a radio interface protocol in a control plane between a terminal and a base station, and FIG. 4 is an exemplary diagram illustrating a structure of a radio interface protocol in a user plane between a terminal and a base station. .

The air interface protocol is based on the 3GPP radio access network standard. The air interface protocol is composed of a physical layer, a data link layer, and a network layer horizontally, and a user plane and control for data information transmission vertically. It is divided into a control plane for signal transmission.

The protocol layers are based on the lower three layers of the Open System Interconnection (OSI) reference model, which is widely known in communication systems, and includes L1 (first layer), L2 (second layer), and L3 (third layer). ) Can be separated.

Hereinafter, each layer of the radio protocol of the control plane shown in FIG. 3 and the radio protocol in the user plane shown in FIG. 4 will be described.

The physical layer, which is the first layer, provides an information transfer service using a physical channel. The physical layer is connected to a medium access control layer on the upper side through a transport channel, and data between the medium access control layer and the physical layer is transmitted through the transport channel. In addition, data is transferred between different physical layers, that is, between physical layers of a transmitting side and a receiving side through a physical channel.

The physical channel is composed of several subframes on the time axis and several sub-carriers on the frequency axis. Here, one subframe includes a plurality of symbols and a plurality of subcarriers on the time axis. One subframe consists of a plurality of resource blocks, and one resource block consists of a plurality of symbols and a plurality of subcarriers. The transmission time interval (TTI), which is a unit time for transmitting data, is 1 ms corresponding to one subframe.

According to 3GPP LTE, the physical channels existing in the physical layer of the transmitting side and the receiving side are physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH) and physical downlink control channel (PDCCH), which are control channels, It may be divided into a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid-ARQ Indicator Channel (PHICH), and a Physical Uplink Control Channel (PUCCH).

There are several layers in the second layer.

First, the medium access control (MAC) layer of the second layer serves to map various logical channels to various transport channels, and also logical channel multiplexing to map several logical channels to one transport channel. (Multiplexing). The MAC layer is connected to the upper layer RLC layer by a logical channel, and the logical channel includes a control channel for transmitting information of a control plane according to the type of information to be transmitted. It is divided into a traffic channel that transmits user plane information.

The Radio Link Control (RLC) layer of the second layer adjusts the data size so that the lower layer is suitable for transmitting data to the radio section by segmenting and concatenating data received from the upper layer. It plays a role.

The Packet Data Convergence Protocol (PDCP) layer of the second layer is an IP containing relatively large and unnecessary control information for efficient transmission in a wireless bandwidth where bandwidth is small when transmitting an IP packet such as IPv4 or IPv6. Performs Header Compression which reduces the packet header size. In addition, in the LTE system, the PDCP layer also performs a security function, which is composed of encryption (Ciphering) to prevent third-party data interception and integrity protection (Integrity protection) to prevent third-party data manipulation.

The radio resource control layer (hereinafter RRC) layer located at the top of the third layer is defined only in the control plane, and the configuration and resetting of radio bearers (abbreviated as RBs) are performed. It is responsible for the control of logical channels, transport channels and physical channels in relation to configuration and release. In this case, RB means a service provided by the second layer for data transmission between the terminal and the E-UTRAN.

If there is an RRC connection (RRC connection) between the RRC of the terminal and the RRC layer of the wireless network, the terminal is in the RRC connected mode (Connected Mode), otherwise it is in the RRC idle mode (Idle Mode).

Hereinafter, the RRC state and the RRC connection method of the UE will be described. The RRC state refers to whether or not the RRC of the UE is in a logical connection with the RRC of the E-UTRAN. If the RRC state is connected, the RRC_CONNECTED state is called, and the RRC_IDLE state is not connected. Since the UE in the RRC_CONNECTED state has an RRC connection, the E-UTRAN can grasp the existence of the UE in units of cells, and thus can effectively control the UE. On the other hand, the UE in the RRC_IDLE state cannot identify the existence of the UE by the E-UTRAN, and the core network manages the unit in a larger tracking area (TA) unit than the cell. That is, the terminal in the RRC_IDLE state is only detected whether the terminal exists in a larger area than the cell, and the terminal must transition to the RRC_CONNECTED state in order to receive a normal mobile communication service such as voice or data. Each TA is identified by a tracking area identity (TAI). The terminal may configure a TAI through a tracking area code (TAC), which is information broadcast in a cell.

When the user first turns on the power of the terminal, the terminal first searches for an appropriate cell, then establishes an RRC connection in the cell, and registers the terminal's information in the core network. Thereafter, the terminal stays in the RRC_IDLE state. The terminal staying in the RRC_IDLE state (re) selects a cell as needed and looks at system information or paging information. This is called camping on the cell. When it is necessary to establish an RRC connection, the UE staying in the RRC_IDLE state makes an RRC connection with the RRC of the E-UTRAN through an RRC connection procedure and transitions to the RRC_CONNECTED state. There are several cases in which a UE in RRC_IDLE state needs to establish an RRC connection. For example, a user's call attempt, a data transmission attempt, etc. are required or a paging message is received from E-UTRAN. Reply message transmission, and the like.

A non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.

The following describes the NAS layer shown in FIG. 3 in detail.

ESM (evolved Session Management) belonging to the NAS layer performs functions such as default bearer management and dedicated bearer management, and is responsible for controlling the terminal to use the PS service from the network. The default bearer resource is characterized in that it is allocated from the network when it is connected to the network when it first accesses a specific Packet Data Network (PDN). At this time, the network allocates an IP address usable by the terminal so that the terminal can use the data service, and also allocates QoS of the default bearer. LTE supports two types of bearer having a guaranteed bit rate (GBR) QoS characteristic that guarantees a specific bandwidth for data transmission and reception, and a non-GBR bearer having a best effort QoS characteristic without guaranteeing bandwidth. In case of Default bearer, Non-GBR bearer is assigned. In the case of a dedicated bearer, a bearer having a QoS characteristic of GBR or non-GBR may be allocated.

The bearer allocated to the terminal in the network is called an evolved packet service (EPS) bearer, and when the EPS bearer is allocated, the network allocates one ID. This is called EPS Bearer ID. One EPS bearer has a QoS characteristic of a maximum bit rate (MBR) or / and a guaranteed bit rate (GBR).

5 is a flowchart illustrating a random access procedure in 3GPP LTE.

The random access procedure is used for the UE to get UL synchronization with the base station or to be allocated UL radio resources.

The UE receives a root index and a physical random access channel (PRACH) configuration index from the eNodeB. Each cell has 64 candidate random access preambles defined by a Zadoff-Chu (ZC) sequence, and the root index is a logical index for the UE to generate 64 candidate random access preambles.

Transmission of the random access preamble is limited to a specific time and frequency resource for each cell. The PRACH configuration index indicates a specific subframe and a preamble format capable of transmitting the random access preamble.

The UE sends the randomly selected random access preamble to the eNodeB. The UE selects one of the 64 candidate random access preambles. Then, the corresponding subframe is selected by the PRACH configuration index. The UE transmits the selected random access preamble in the selected subframe.

Upon receiving the random access preamble, the eNodeB sends a random access response (RAR) to the UE. The random access response is detected in two steps. First, the UE detects a PDCCH masked with random access-RNTI (RA-RNTI). The UE receives a random access response in a medium access control (MAC) protocol data unit (PDU) on the PDSCH indicated by the detected PDCCH.

6 shows a connection process in a radio resource control (RRC) layer.

As shown in FIG. 6, the RRC state is shown depending on whether the RRC is connected. The RRC state refers to whether or not an entity of the RRC layer of the UE is in a logical connection with an entity of the RRC layer of the eNodeB. When the RRC state is connected, the RRC state is referred to as an RRC connected state. The non-state is called the RRC idle state.

Since the UE in the connected state has an RRC connection, the E-UTRAN may determine the existence of the corresponding UE in units of cells, and thus may effectively control the UE. On the other hand, the UE in the idle state (idle state) can not be identified by the eNodeB, the core network (core network) is managed by the tracking area (Tracking Area) unit that is larger than the cell unit. The tracking area is a collection unit of cells. That is, the idle state (UE) is determined only in the presence of the UE in a large area, and in order to receive a normal mobile communication service such as voice or data, the UE must transition to the connected state (connected state).

When a user first powers up a UE, the UE first searches for an appropriate cell and then stays in an idle state in that cell. When the UE staying in the idle state needs to establish an RRC connection, the UE establishes an RRC connection with the RRC layer of the eNodeB through an RRC connection procedure and transitions to an RRC connected state. .

There are several cases in which the UE in the idle state needs to establish an RRC connection. For example, a user's call attempt or uplink data transmission is required, or a paging message is received from EUTRAN. In this case, the response message may be transmitted.

In order to establish an RRC connection with the eNodeB, the UE in an idle state must proceed with an RRC connection procedure as described above. The RRC connection process is largely a process in which a UE sends an RRC connection request message to an eNodeB, an eNodeB sends an RRC connection setup message to the UE, and a UE completes RRC connection setup to the eNodeB. (RRC connection setup complete) message is sent. This process will be described in more detail with reference to FIG. 6 as follows.

1) When a UE in idle mode attempts to establish an RRC connection due to a call attempt, a data transmission attempt, or a response to an eNodeB's paging, the UE first sends an RRC connection request message. Send to eNodeB.

2) When the RRC connection request message is received from the UE, the eNB accepts the RRC connection request of the UE when the radio resources are sufficient, and transmits an RRC connection setup message, which is a response message, to the UE. .

3) When the UE receives the RRC connection setup message, it transmits an RRC connection setup complete message to the eNodeB. When the UE successfully transmits an RRC connection establishment message, the UE establishes an RRC connection with the eNodeB and transitions to the RRC connected mode.

Meanwhile, in EPS, the UE performs a tracking area update (TAU) to manage the reachability and location of the UE in the idle mode. For more details on TAU, refer to Section 4.3.5 (Mobility management functions), Section 5.3.3 (Tracking Area Update procedures) of 3GPP TS 23.401, and Section 5.5.3 (Tracking area updating procedure (S1 mode only)) of TS 24.301. For reference, the contents of the present specification are included. The UE periodically performs a TAU (periodic TAU or P-TAU) even if the MME does not depart from the range of tracking the location of the UE. At this time, P-TAU is performed based on a periodic location registration timer.

Table 2 below shows the periodic tracking area update timer (see T3412 and TS 24.301). Typically, the timer value is included in the ATTACH ACCEPT, TRACKING AREA UPDATE ACCEPT message in the network and provided to the UE.

TIMER NUM.	TIMER VALUE	STATE	CAUSE OF START	NORMAL STOP	ON EXPIRY
T3412	Default 54 min.NOTE 2NOTE 5	EMM-REGISTERED	In EMM-REGISTERED, when EMM-CONNECTED mode is left.	When entering state EMM-DEREGISTERED or when entering EMM-CONNECTED mode.	Initiation of the periodic TAU procedure if the UE is not attached for emergency bearer services or T3423 started under the conditions as specified in subclause 5.3.5.Implicit detach from network if the UE is attached for emergency bearer services.
NOTE 2: The default value of this timer is used if the network does not indicate a value in the TRACKING AREA UPDATE ACCEPT message and the UE does not have a stored value for this timer.

The network may provide the UE with an longer periodic tracking area update timer to reduce network load from P-TAU signaling. For further details, see TS 23.401 Section 4.3.17.3.

Table 3 below is the TAU Accept message format described in TS 24.301. The markings 9.x, 9.x.x.x, etc. in the table are indexes in the TS 24.301 document.

IEI	Information Element	Type / Reference	Presence	Format	Length
	Protocol discriminator	Protocol discriminator 9.2	M	V	1/2
	Security header type	Security header type 9.3.1	M	V	1/2
	Tracking area update accept message identity	Message type 9.8	M	V	One
	EPS update result	EPS update result 9.9.3.13	M	V	1/2
	Spare half octet	Spare half octet 9.9.2.9	M	V	1/2
5A	T3412 value	GPRS timer 9.9.3.16	O	TV	2
50	GUTI	EPS mobile identity 9.9.3.12	O	TLV	13
54	TAI list	Tracking area identity list 9.9.3.33	O	TLV	8-98
57	EPS bearer context status	EPS bearer context status 9.9.2.1	O	TLV	4
13	Location area identification	Location area identification 9.9.2.2	O	TV	6
23	MS identity	Mobile identity 9.9.2.3	O	TLV	7-10
53	EMM cause	EMM cause 9.9.3.9	O	TV	2
17	T3402 value	GPRS timer 9.9.3.16	O	TV	2
59	T3423 value	GPRS timer 9.9.3.16	O	TV	2
4A	Equivalent PLMNs	PLMN list 9.9.2.8	O	TLV	5-47
34	Emergency number list	Emergency number list 9.9.3.37	O	TLV	5-50
64	EPS network feature support	EPS network feature support 9.9.3.12A	O	TLV	3
F-	Additional update result	Additional update result 9.9.3.0A	O	TV	One
5E	T3412 extended value	GPRS timer 3 9.9.3.16B	O	TLV	3
6A	T3324 value	GPRS timer 2 9.9.3.16A	O	TLV	3
6E	Extended DRX parameters	Extended DRX parameters 9.9.3.46	O	TLV	3

The MME shall include the T3412 value IE in the normal and combined TAU procedures. In addition, the MME may include the T3412 value IE in the periodic TAU procedure. The network may include a T3412 extended value IE to provide a longer periodic tracking area update timer to the UE. The P-TAU timer T3412 and the longer P-TAU timer T3412 extended value may be set to values of various sizes such as GPRS Timer and GPRS Timer 3 disclosed in TS 24.008 and may be provided to the UE.

The introduction of network slicing is being discussed in next-generation communication systems (eg, 5G systems), in contrast to the traditional LTE / LTE-A system where network functions were performed by an integrated core network. 7 illustrates the concept of network slicing. Referring to FIG. 7, network slicing may include three layers, a service instance layer, a network slice instance layer, and a resource layer. The service instance layer represents the service to be supported (end user service or business service). Each of these services may be represented by a service instance. In general, since the service may be provided by a network operator or a third party, the service instance may represent an operator service or a third party provided service. Network slice instances provide the network characteristics required for service instances. Network slice instances can be shared among multiple service instances provided by network operators. (Other details regarding network slicing may be referred to by TR 23.799.) The UE may be provided with service from one or more network slices as illustrated in FIG. The UE may be provided with services from multiple slices, and may send and receive traffic through several slices at the same time, but may also exchange traffic through only one slice at a time. In the latter case, for example, when Service # 1 is provided with Slice # 1 and Service # 2 is provided with Slice # 2, the UE generates mobile originated (MO) traffic for Service # 1. Can be sent through. Another example is when there is no traffic transmitted and received by the UE (in a mobile communication system such as EPS, the UE may be in the IDLE state in this case) and mobile terminated (MT) traffic for Service # 2 occurs. This can be delivered via Slice # 2.

The UE may be served from one or more network slices, which may be in one of three scenarios as illustrated in FIG. 8.

Referring to FIG. 8, group A targets logical separation / isolation between CN instances where the UE obtains service from different network slices and different CN instances. This group features independent subscription management / mobility management for each network slice dealing with the UE, with the potential side effect of additional signaling in the network and radio. In contrast, isolation in the CN portion of the network is easiest to achieve. Group B assumes that some network functions are common among the network slices, while others are in separate network slices. Group C assumes that control plane processing is common between slices while the user plane is processed with other network slices.

In the conventional EPC, MME has been divided into Core Access and Mobility Management Function (AMF) and Session Management Function (SMF) in 5G CN (Core Network). The NAS interaction and mobility management (MM) with the UE are performed by the AMF, and the session management (SM) is performed by the SMF. In addition, the SMF manages a user plane function (UPF), which has a user-plane function, that is, a gateway for routing user traffic. The SMF is responsible for the control-plane portion of the S-GW and the P-GW in the conventional EPC. The user-plane part can be considered to be in charge of the UPF. There may be one or more UPFs between the RAN and the DN for the routing of user traffic. As a concept corresponding to the PDN connection in the conventional EPS, PDU (Protocol Data Unit) session is defined in 5G system. The PDU session refers to an association between the UE and the DN providing the PDU connectivity service of the Ethernet type or the unstructured type as well as the IP type. In addition, UDM (Unified Data Management) performs a function corresponding to the HSS of the EPC, PCF (Policy Control Function) performs a function corresponding to the PCRF of the EPC. Of course, the functions can be provided in an expanded form to satisfy the requirements of the 5G system. For details on the 5G system architecture, each function and each interface, TS 23.501 is applicable.

Previously, when the UE receives services from a plurality of network slices, it is described that it is possible to receive services by three example scenarios such as Group A, Group B, and Group C. Substituting the architecture resulting from the study of the next generation system (i.e., 5G system) shown in FIG. 9 into Group A, Group B, and Group C is as follows. In particular, AMF, SMF, and UPF play the most important role in terms of receiving a UE. Here is how these functions are included in a slice.

In Group A, all control-plane and user-plane functions are included in each slice. AMF, SMF, and UPF are all included in each slice.

For Group B, three example types of scenarios are possible:

First, AMFs in charge of mobility management are commonly located instead of being included for each slice. That is, there is one AMF in common regardless of how many slices a UE is served by. On the other hand, SMF responsible for session management and UPF, which is a gateway, are included in each slice. Second, SMFs in charge of session management are commonly located instead of being included in each slice. That is, there is one SMF in common regardless of how many slices a UE is served by. On the other hand, SMF responsible for mobility management and UPF, which is a gateway, are included in each slice. Third, among the functions of the AMF, the access management function that the UE performs authentication upon initial registration is commonly used regardless of the slice, and the functions, such as reachability and location tracking, are included in the slice. In addition, SMF and UPF are also included in the slice.

In Group C, all control-plane functions are commonly located. Therefore, AMF and SMF are not included in each slice, and there is a common one regardless of how many slices a UE is served. UPF, on the other hand, is included in each slice.

In the network slice structure as described above, when the UE is provided with various services from a plurality of slices at the same time, it is possible to perform mobility management (MM) in two or more slices. For example, in Group A and Group B illustrated in FIG. 8, each slice may have a control plane (CP) function, if such CP function is a function of the MM or MM (ie reachability, location tracking, etc.). If the P-TAU can be controlled by a plurality of MM functions. If the CP function is shared by the slices as in Group C, a plurality of CP instances may be running for each slice. In this case, the P-TAU may be controlled by the MM function belonging to each CP instance.

As mentioned above, the MM function (MME in the case of EPS) does not use a constant value as a P-TAU timer value provided to the UE, but various values based on network conditions, operator policy, local configuration, subscriber information, etc. It may be set to provide to the UE. This may also be the case in a network system structure sliced to provide various services. That is, a periodic location registration timer may be set in consideration of a service provided by each slice and / or reflecting a situation of each slice (eg, signaling load of a slice). At the same time, if a UE receiving services from multiple slices needs to perform periodic location registration with multiple CP functions in the network, in this case, a different location registration timer causes the UE to perform periodic location registration. do. Even if there is one representative function in the network with the UE and the MM function or periodic location registration, if the periodic location registration timer of different values is operated for each slice, the CP function may inform the UE of the periodic location registration timer. It is unclear whether to provide. Therefore, the following describes a method for efficiently providing an MM under a network slicing structure according to an embodiment of the present invention. In the following description, the MM function may be a part of the MM function or a periodic location registration function. And, a slice may mean the same as a network slice and a network slice instance.

Example 1

10 illustrates an operation related to location registration of each node according to an embodiment of the present invention. Referring to FIG. 10, in step S1001, the UE (UE-1 in the figure) transmits an attach request to perform an attach to the network. In this case, the UE may request an operation of setting up a session with an attach request. Or, after the attach is completed, the session setup operation may be requested to the network. Receiving the attach request from the UE, MM function # 1, if the attach request includes a session setup request, it may be delivered to the network function in charge of session setup or may process it. Here, the session may be a PDU session or a PDN connection. In FIG. 10, the UE transmits an attach request message to the network. Alternatively, the UE may transmit a general MM Request message to the network.

In step S1002, slice # 1 is selected for the UE. Selection of the slice includes information (APN, service descriptor, application related information, UE capability information, etc.) included in the message (attach request message and / or session setup request message) received from the UE described in step S1001, RAT / RAN One or more of the type / information, subscriber information, and network configuration information may be used.

In step S1003, MM function # 1, which is an MM function belonging to slice # 1 (or operating for slice # 1), determines a first periodic location registration (update) timer (ie, P_timer # 1) value. The first periodic location registration timer is used to determine the characteristics of the service provided by the slice, the situation of the user plane function of the slice (e.g. load / congestion of the gateway of the slice), the situation of the control plane function of the slice (e.g. signaling signaling of the slice). / Congestion), subscriber information, and network settings. Alternatively, there may be a default value for each slice.

The MM function # 1 may also determine the location registration range (ie, A # 1) for the UE while determining the first periodic location registration timer value. This may be determined based on one or more of characteristics of a service provided by the slice, a service area of a user plane function of the slice, subscriber information, and network configuration. The location registration range indicates an area / range in which the UE should perform location registration with the network if it is out of the range.

In step S1004, the MM function # 1 transmits a response / allow message for the attach request to the UE. The response / allow message for the attach request may include the first periodic location registration timer value and / or location registration range. Upon receiving this, the UE stores the received first location registration timer value (ie, sets its location registration timer P_timer to the received timer value P_timer # 1). Then start P_timer # 1. MM function # 1 also manages a periodic location registration timer value for the UE and starts it. The UE also stores the received location registration range.

Thereafter, P_timer, the location registration timer of the UE, expires (step S1005), and the UE performs location registration with the network. That is, in step S1006, the UE transmits a location update request, and in step S1007, the MM function # 1 transmits a location update acceptance message in response. In step S1008, the UE sends a session setup request message to the network for setting up an additional session. These messages are delivered to MM function # 1 in the exchange of NAS messages with the UE. That is, the second MM function and the like may be configured to transmit the location registration subscription request to the MM function for transmitting and receiving NAS messages with the UE.

In step S1009, slice # 2 is selected for the UE. At this time, the selection criteria are as described above in step S1002.

The MM function # 1 delivers the session setup request received from the UE to the MM function # 2 which belongs to slice # 2 or operates for slice # 2, thereby completing the session setup. That is, the MM function # 1 transmits a session setup request message to the MM function # 2 (step S1010).

In step S1011, the MM function # 2 determines a second periodic location registration timer (ie, P_timer # 2) value and a location registration range (ie, A # 2) for the UE. For details, refer to step S1003.

In step S1012, the MM function # 2 transmits a location registration service subscription request including the determined P_timer # 2 value and A # 2 to the MM function # 1, which is an MM function that exchanges a NAS message with the UE. That is, the second MM function may be configured to transmit the location registration subscription request to an MM function that transmits and receives a NAS message with the UE. The purpose of the location registration service subscription request is to inform the MM function # 2 that it wants to check reachability with a period of P_timer # 2 for the UE, or vice versa, if the MM function # 2 does not reach reachability with a period of P_timer # 2 for the UE. It may be a request. In addition, the purpose of the location registration service subscription request may be to request that the UE notifies when it leaves the A # 2 area. In step S1013, the MM function # 1 transmits a response to the location registration service subscription request to the MM function # 2.

Thereafter, the MM function # 1 compares the first periodic position registration timer value set by the self and the second periodic position registration timer value received from the MM function # 2 to check / recognize the smallest value (step S1014). . As a result of the comparison, a small value (the smallest value when the timer to be compared is received from several MM functions) is determined as a new P_timer value (third periodic location registration timer) for the UE. In FIG. 10, it is assumed that P_timer # 2 is smaller than P_timer # 1.

In step S1015, the MM function # 1 compares the position registration range set by itself with the position registration range received from the MM function # 2 to check / recognize overlapping ranges (common areas). This range is then determined as a new location registration range for the UE. In FIG. 10, A # 1 includes TAI # 1, TAI # 2, TAI # 3, TAI # 4, and TAI # 5, and A # 2 represents TAI # 2, TAI # 3, TAI # 4, and TAI # 6. It is assumed to be included. Accordingly, the newly determined location registration range A # 3 includes TAI # 2, TAI # 3, and TAI # 4.

If the newly determined P_timer value (third periodic location registration timer value) is different from the P_timer value previously provided to the UE or the newly determined location registration range is different from the previously registered location registration range to the UE, the MM function # 1 transmits a message indicating that the information on location registration has been changed to the UE (step S1016). In FIG. 10, since both the P_timer value and the location registration range are changed, a message (location update information message) including a new P_timer value P_timer # 2 value and a new location registration range A # 3 is transmitted to the UE. In step S1017, the UE having received the location update information message stores the received location registration timer value and location registration range. And start the periodic location registration timer according to the new location registration timer value. The response message is then sent to the MM function #. MM function # 1 also manages a periodic location registration timer value for the UE and starts it.

In steps S1018 to S1019, the MM function # 1 informs the MM function # 2 of the P_timer value and location registration range provided to the UE (via a Notify message). It also informs the UE that it is reachable. This is for re-starting the P_timer value for the UE managed by the MM function of another slice. If the MM function # 2 requests the MM function # 1 to notify the UE only when the UE does not reachability in the period of P_timer # 2, this notification may not be transmitted.

As described above, instead of starting the common P_timer value for all slices serving the UE, the MM function # 1 may start and manage the P_timer value for each slice. In this case, the UE can not only reach reachability of the UE to the slice corresponding to the P_timer period of each slice, or vice versa, but only when not reachable. This applies throughout the present invention.

 Steps S1020 to S1024 describe the case where the timer of the UE expires. Specifically, when the UE's own location registration timer P_timer expires (step S1020), the UE performs location registration with the network (steps S1021 to S1022). The UE restarts P_timer, which is a location registration timer. The MM function # 1 also restarts P_timer, which is a location registration timer for the UE.

In steps S1023 to S1024, the MM function # 1 notifies the MM function # 2 that the UE is reachable (via a Notify message). This may be an explicit or implicit notification that the UE has performed location registration. The MM function # 2 re-starts P_timer, which is a location registration timer for the UE. If, in S1022, the MM function # 1 allocates the location registration range to a new location registration range other than A # 3, unlike this shown in FIG. 10, this information is provided to the MM function # 2.

Steps S1025 to S1029 are explanations for the case where the UE is out of the location registration range as the UE moves. As the UE moves out of the location registration range A # 3 (step S1025). In this case, the UE performs location registration with the network (steps S1026 to S1027). The MM function # 1 responds by allocating a new location registration range A # 4 to the UE. The UE re-starts P_timer, which is a location registration timer. The MM function # 1 also restarts P_timer, which is a location registration timer for the UE.

In steps S1028 to S1029, the MM function # 1 informs the MM function # 2 of a new location registration range of the UE (via a Notify message). The MM function # 2 re-starts P_timer, which is a location registration timer for the UE.

Thereafter, the MM function # 1 may notify the MM function # 2 of the reachability of the UE based on a periodic location registration timer requested by the MM function # 2, which is the MM function of another slice, or notify the UE if the UE has become unreachable.

Example 2

Unlike Embodiment 1, the second embodiment is an example in which a node / entity performing a function of the MM controller exists separately from the MM function. In the following description, the MM controller may be referred to as an MM coordinator, an MM anchor point, a mobility controller, a mobility coordinator, a mobility anchor point, or a central MM function. The MM controller may control the MM function for all slices belonging to a specific slice serving the UE but serving the UE, and control the MM function for all slices serving the UE without belonging to the specific slice. In addition, the MM function may be controlled for all slices serving the UE belonging to the slice including the MM function. Hereinafter, it is assumed that there is one network node controlling the MM function of the UE from the perspective of the UE. That is, the UE performs location registration or periodic location registration for only one MM function. Here, the unit of location registration is a unit of cell, a location registration area of RAN, a tracking area unit, a TA collection unit, a location registration area unit, a location registration area collection unit, a CN location registration area unit CN location registration area Vowel units may vary. This also applies to the unit of location registration of the first embodiment.

Referring to FIG. 11, in step S1101, a UE (UE-1 in the figure) attaches to a network. In this case, the UE may request an operation of setting up a session with an attach request. Or, after the attach is completed, the session setup operation may be requested to the network. Receiving the attach request from the UE, the MM controller may forward the session setup request to the network function in charge of the session setup if the session setup request is included in the UE. In the above, the session may be interpreted as a PDU session or a PDN connection. In this case, the UE transmits the Attach Request message to the network. Alternatively, the UE may transmit the general MM Request message to the network.

In step S1102, slice # 1 is selected for the UE. The selection criteria may include information (eg, APN, service descriptor, application related information, UE capability information, etc.) included in the message received from the UE described in step S1101 (that is, an attach request message and / or a session setup request message), RAT / One or more of RAN type / information, subscriber information, and configuration information of a network may be used. In step S1103, MM function # 1, which is an MM function belonging to slice # 1 or operating for slice # 1, determines a periodic location registration timer (ie, P_timer # 1) value. This includes the characteristics of the services provided by the slice, the context of the slice's user plane function (eg, load / congestion of the gateway of the slice), the context of slice's control plane function (eg, signaling load / congestion of the slice), subscriber information, network You can decide based on one or more of the settings. There may be a default value for each slice.

In step S1104, the MM function # 1 transmits a location registration service subscription request including the determined P_timer # 1 value to the MM controller. The purpose of the location registration service subscription request is to inform the MM function # 1 that it wants to check reachability with a period of P_timer # 1 for the UE, or vice versa, when the MM function # 1 does not reach reachability with a period of P_timer # 1 for the UE. It may be a request.

In step S1105, the MM controller transmits a response to the location registration service subscription request to the MM function # 1. At this time or later, the MM controller may transmit information indicating that the UE is reachable to the MM function # 1.

In step S1106, the MM controller sends a response / allow message for the attach request to the UE. At this time, the periodic location registration timer value is included. Upon receiving this, the UE stores the received location registration timer value (ie, sets its location registration timer P_timer to the received timer value P_timer # 1). And start it. The MM controller also manages the periodic location registration timer value for the UE and starts it.

In step S1107, the UE's own location registration timer P_timer expires. In steps S1108 to S1109, the UE performs location registration with the network.

In steps S1110 to S1111, the MM controller notifies (via a Notify message) that the UE is reachable to the MM function # 1. This may be an explicit or implicit notification that the UE has performed location registration. The MM function # 1 restarts P_timer, which is a location registration timer for the UE.

If in step S1114 the MM function # 1 is requested to inform the UE when the reachability is not reachable in the period of P_timer # 1, steps S1110 to 11 may be omitted. In this case, when the UE does not perform the location registration even though P_timer # 1 has expired, the MM controller notifies the MM function # 1 that the UE is no longer reachable. This may be an explicit or implicit notification that the UE has not performed location registration. The same applies to MM functions belonging to different slices. That is, it is applied throughout the present invention.

In step S1112, the UE sends a request message to set up an additional session to the network. These messages may be received by the MM controller, or may be received by session management (SM) related network functions. In the latter case, it may be a function that performs an SM control function for all slices in the same form as an SM controller, or may be an SM function belonging to a slice in which a session is formed by the session setup request. In this case, as slice # 2 described in step S1113 is selected, the session setup request message may be delivered to the corresponding SM function.

In step S1113, slice # 2 is selected for the UE. The selection criteria refer to step S1102.

In step S1114, MM function # 2, which is an MM function belonging to slice # 2 or operating for slice # 2, determines a periodic location registration timer (ie, P_timer # 2) value. See step S1103 for details.

In steps S1115 to S1116, the MM function # 2 transmits a message including P_timer # 2 to the MM controller. This is the same operation performed by the MM function # 1 and the MM controller in steps S1104 to S1105.

In step S1117, the MM controller checks / recognizes the smallest value by comparing the periodic location registration timer value (ie, P_timer value) received from all slices serving the UE. This value is then determined as a new P_timer value for the UE.

In step S1118, if the newly determined P_timer value is smaller than the P_timer value previously provided to the UE, the MM controller sends a message informing the UE of the new P_timer value. In FIG. 11, it is assumed that P_timer # 2 is smaller than P_timer # 1. Accordingly, a message including a P_timer # 2 value, which is a new P_timer value, is transmitted to the UE.

In step S1119, the UE, which has received this, stores the received location registration timer value (ie, sets its location registration timer P_timer to the received timer value P_timer # 2). And start it. The MM controller also manages the periodic location registration timer value for the UE and starts it.

In steps S1120 to S1121, the MM controller starts the newly adjusted P_timer value, and thus slices other slices (that is, slices other than the slice providing the P_timer value on which the new P_timer value is based). ) (Via Notify message) that the UE is reachable. This is to re-start the P_timer value for the UE managed by the MM function of each slice. If the MM function # 1 requests the UE to notify the UE when it is not reachable with a period of P_timer # 1, this notification is not transmitted.

As described above, instead of starting the common P_timer value for all slices serving the UE, the MM controller may start and manage the P_timer value for each slice. In this case, the UE can not only reach reachability of the UE to the slice corresponding to the P_timer period of each slice, or vice versa, but only when not reachable. This applies throughout the present invention.

In step S1122, the UE's own location registration timer P_timer expires. In steps S1123 to S1124, the UE performs location registration with the network. In steps S1125 to S1126, the MM controller informs MM function # 2 that the UE is reachable (via a Notify message). This may be an explicit or implicit notification that the UE has performed location registration. The MM function # 2 re-starts P_timer, which is a location registration timer for the UE.

Thereafter, the MM controller may notify the MM function # 1 of the reachability of the UE based on the periodic location registration timer requested by the MM function # 1.

That is, the MM controller may notify each MM function of the reachability of the UE based on the periodic location registration timer requested by the MM function of each slice, or notify the UE when the UE has become unreachable.

In the above description, it is assumed that the MM function is in / belongs to the CN (Core Network), but otherwise i) if the RAN function has an MM function and the MM controller is also in the RAN, ii) there is an MM function in the RAN slice and the MM controller Is in the CN, iii) the MM function in the CN slice and the MM controller can be extended even in the RAN.

In addition, the MM controller described the function of adjusting the periodic position registration timer value differently for each slice, but this is also applicable when the position registration range (for example, TAI list in EPS) is set differently for each slice. . In this case, a smaller location registration range can be provided to the UE. Accordingly, the MM controller may simultaneously adjust the periodic location registration timer value and the location registration range.

In the above description of the embodiments, the RAN (or AN: Access network) is illustrated as being common regardless of the slice, but the RAN may be different for each slice. The same RAT or RAN is also sliced so that an appropriate RAN slice may be selected, or a different RAN may be selected because the RAT is different. In addition, when the UE exchanges a message with the network, it may be in the form of a NAS message or an AS message.

12 is a diagram showing the configuration of a preferred embodiment of a terminal device and a network node device according to an example of the present invention.

The terminal device 100 according to the present invention with reference to FIG. 12 may include a transceiver 110, a processor 120, and a memory 130. The transceiver 110 may be configured to transmit various signals, data and information to an external device, and to receive various signals, data and information to an external device. The terminal device 100 may be connected to an external device by wire and / or wirelessly. The processor 120 may control the overall operation of the terminal device 100, and may be configured to perform a function of the terminal device 100 to process and process information to be transmitted and received with an external device. The memory 130 may store the processed information for a predetermined time and may be replaced with a component such as a buffer (not shown). In addition, the processor 120 may be configured to perform a terminal operation proposed in the present invention.

Referring to FIG. 12, the network node device 200 according to the present invention may include a transceiver 210, a processor 220, and a memory 230. The transceiver 210 may be configured to transmit various signals, data and information to an external device, and to receive various signals, data and information to an external device. The network node device 200 may be connected to an external device by wire and / or wirelessly. The processor 220 may control the overall operation of the network node device 200, and may be configured to perform a function of calculating and processing information to be transmitted / received with an external device. The memory 230 may store the processed information for a predetermined time and may be replaced with a component such as a buffer (not shown). In addition, the processor 220 may be configured to perform the network node operation proposed in the present invention. In detail, the processor 220 receives an attach request from the UE through the transmission and reception apparatus, the first MM function determines a first periodic location registration timer value, and includes the first periodic location registration timer value. Transmit a response to the attach request to the UE, receive information including a second periodic location registration timer, compare the first periodic location registration timer value with the second periodic location registration timer value, As a result of the comparison, a timer having a small value may be determined as a third periodic location registration timer.

In addition, the specific configuration of the terminal device 100 and the network device 200 as described above, may be implemented so that the above-described matters described in various embodiments of the present invention can be applied independently or two or more embodiments are applied at the same time, overlapping The description is omitted for clarity.

Embodiments of the present invention described above may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

For implementation in hardware, a method according to embodiments of the present invention may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), and Programmable Logic Devices (PLDs). It may be implemented by field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of an apparatus, procedure, or function for performing the above-described functions or operations. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable any person skilled in the art to make and practice the invention. Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Various embodiments of the present invention as described above have been described with reference to the 3GPP system, but may be applied to various mobile communication systems in the same manner.

Claims (14)

1. A method of performing a function related to location registration of a user equipment (UE) by a first mobility management (MM) function in a wireless communication system,

   The first MM function receiving an attach request from the UE;

   Determining, by the first MM function, a first periodic location registration timer value;

   The first MM function sending a response to the attach request to the UE, wherein the response includes the first periodic location registration timer value;

   Receiving, by the first MM function, information including a second periodic location registration timer;

   Comparing, by the first MM function, the first periodic location registration timer value with the second periodic location registration timer value; And

   Determining, by the first MM function, a timer having a small value as a result of the comparison as a third periodic location registration timer;

   A method of performing an operation related to terminal location registration of a first MM function comprising a.
2. The method of claim 1,

   The information including the second periodic location registration timer is a location registration service subscription request, the method of performing a terminal location registration related operation of the first MM function.
3. The method of claim 2,

   The location registration service subscription request is transmitted from the second MM function of the selected slice by the UE performing a session setup request.

   And the first MM function transmits the third periodic location registration timer to the second MM function.
4. The method of claim 3,

   And the second MM function is configured to transmit the location registration subscription request to an MM function that transmits and receives a NAS message with the UE.
5. The method of claim 1,

   The first MM function transmits a session setup request to the second MM function, terminal location registration related operation of the first MM function.
6. The method of claim 1,

   And the first MM function determines a third location registration range when determining a third periodic location registration timer.
7. The method of claim 6,

   The third location registration range is an area in which the first location registration range determined by the first MM function and the second location registration range determined by the second MM function are common, and the terminal location registration related operation of the first MM function is performed. Way.
8. A first MM function device for performing an operation related to location registration of a user equipment (UE) in a wireless communication system,

   A transceiver; And

   Includes a processor,

   The processor is further configured to receive an attach request from a UE through the transceiver device, wherein the first MM function determines a first periodic location registration timer value and includes the first periodic location registration timer value. Send a response to the request to the UE,

   Receiving information including a second periodic location registration timer, comparing the first periodic location registration timer value with the second periodic location registration timer value, and comparing the timer having a smaller value as a result of the third periodic location registration timer. Determined by, the first MM function device.
9. The method of claim 8,

   And the information including the second periodic location registration timer is a location registration service subscription request.
10. The method of claim 9,

    The location registration service subscription request is transmitted from the second MM function device of the selected slice by the UE performing a session setup request.

    The first MM function device sends the third periodic location registration timer to the second MM function.
11. The method of claim 10,

    The second MM function device is configured to send the location registration subscription request to the MM function for transmitting and receiving NAS messages with the UE, the first MM function device.
12. The method of claim 8,

    And the first MM function device forwards a session setup request to the second MM function device.
13. The method of claim 8,

    Wherein the first MM function device also determines a third location registration range when determining a third periodic location registration timer.
14. The method of claim 13,

    And the third position registration range is an area in which a first position registration range determined by the first MM function device and a second position registration range determined by the second MM function device are common.

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