KR20180033391A

KR20180033391A - Mobility control methods and appartus for Light Connected UE

Info

Publication number: KR20180033391A
Application number: KR1020160122504A
Authority: KR
Inventors: 홍성표; 최우진
Original assignee: 주식회사 케이티
Priority date: 2016-09-23
Filing date: 2016-09-23
Publication date: 2018-04-03

Abstract

The present invention relates to a mobility control method and an apparatus for lightly connected user equipment (UE). More specifically, the present invention provides a method and an apparatus, wherein a method for processing a paging update of the UE comprises a step of providing a signaling to effectively perform a paging update of the UE formed by light connection.

Description

[0001] The present invention relates to a mobility control method and apparatus for a light-

The present invention relates to a mobility control method and apparatus for a lightly connected terminal.

The present invention provides a method and apparatus for processing a paging update of a terminal, the method comprising: providing signaling for efficiently performing a paging update of a terminal configured with a light connection.

FIG. 1 is a diagram for explaining a conventional LTE message processing procedure.
2 is a diagram for explaining a UE initiated connection resume procedure according to the related art.
3 is a diagram for explaining an example of a paging area notification method.
4 is a diagram for explaining another example of the paging area notification method.
5 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
6 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Herein, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In this specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, the MTC terminal may refer to a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. Alternatively, the MTC terminal may support enhanced coverage over the existing LTE coverage or a UE category / type defined in the existing 3GPP Release-12 or lower that supports low power consumption, or a newly defined Release-13 low cost low complexity UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, the base station or the cell in this specification is interpreted as a comprehensive meaning indicating a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-advanced, a standard is constructed by configuring uplink and downlink based on a single carrier or carrier pair. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of PDSCH, and uplink data channel A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

In LTE State transition Signaling

In the conventional LTE technology, the terminal and the network state consist of two states: an idle state and a connected state. The state is consistent between the terminal and the network. The state (RRC state and ECM state) in the radio network (E-UTRAN) and the core network are matched. That is, when the UE transits to the RRC-IDLE state, the UE enters the ECM-IDLE state. When the UE transitions to the RRC-CONNECTED state, the UE enters the ECM-CONNECTED state. In order for an idle terminal to transmit data, a complicated signaling process as shown in FIG. 1 has to be performed. In particular, when a terminal transmits a small amount of data, it becomes a large overhead.

If the terminal periodically transmits a small amount of data, the overhead will be continuously generated. In order to reduce the overhead due to the state transition, the terminal may be kept in a connected state. However, in this case, even if there is no data transmission, the battery is consumed for measurement and reporting and the signaling overhead is increased .

NB- IoT Suspend / Resume for terminal Procedure

In 3GPP Rel-13, standardization for supporting narrow band IoT terminals was performed. The narrow band IoT terminal can be operated in a stationary state. That is, in a fixed position or within a certain range. Rel-13 NB-IoT standardization supports Suspend / Resume procedure in terminal and base station. In the RRC connection release, the base station can request the terminal to maintain the AS context in the RRC_IDLE state. When the UE receives the RRC connection release message including the RRC suspend information and transitions to the RRC IDLE state (or before the BS sends the message to the UE), the BS transmits an S1 message to the core network The ECM enters the IDLE state.

The RRC connection resume procedure is used for RRC connected state transitions in the RRC IDLE used for resuming the RRC connection previously stored in the UE and the base station. When the MS initiates the RRC connection resume procedure and transitions to the RRC Connected state (after the BS sends an RRC connection resume message to the MS), the BS transmits the RRC connection resume message to the core network through the interface between the BS and the core network S1) message to enter the ECM CONNECTED state. 2 shows a UE initiated connection resume procedure according to the prior art.

Light Connected

3GPP is conducting a study on lightweight connections to reduce signaling. The main functions for a lightly connected UE are as follows.

- The S1 connection is maintained in an anchor eNB and is in an active state.

- RAN initiation paging is supported.

- The paging procedure is controlled by the anchor base station.

- The RAN-based paging area may be configured to be terminal specific.

- The terminal AS context is maintained in the terminal and the anchor base station.

- In the MME, the ECM state is the ECM-CONNECTED state.

As described above, the conventional mobile communication technology has a problem of signaling overhead due to state transition, and has been defined for the RRC state (hereinafter referred to as a light connection state for convenience of description) for reducing the signaling overhead. In order for the network to be able to perform data communication with a terminal having a light connection, it is necessary to notify the network of the location / area of the terminal when the terminal having a light connection is out of the paging area (for example, Paging update). When a terminal with a light connection leaves the paging area, the terminal can perform a paging update through a new cell selected. However, no concrete method was provided. In particular, the new base station has to perform proper configuration considering the characteristic of the terminal performing the paging update, but it is difficult for the new base station to collect the characteristic information of the terminal configured with the light connection.

In the conventional mobile communication technology, there has been a signaling overhead problem due to state transition, and a light connection state for reducing the signaling overhead has been defined. When a terminal with a light connection leaves the paging area, the terminal can perform a paging update through a new cell selected. However, no concrete method was provided. In particular, the new base station must perform proper configuration considering the characteristics of the terminal performing the paging update. However, it is difficult for the new base station to collect the characteristic information of the terminal configured with a light connection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a signaling method and related procedure for efficiently performing paging update of a terminal having a light connection. It is another object of the present invention to provide a method for controlling a terminal by effectively processing mobility information of a light connection terminal.

The present invention can be applied not only to a Rel-13 NB-IoT terminal but also to a general mobile communication terminal. The present invention can be applied not only to an LTE mobile communication terminal but also to a next generation mobile communication (5G mobile communication / New RAT) terminal.

For convenience of explanation, the base station may represent an eNodeB of an LTE / E-UTRAN or a base station (CU, DU, or CU and DU) in a 5G wireless network in which a CU (Central Unit) An entity implemented as a single logical entity).

Hereinafter, a signaling method and apparatus for a lightly connected terminal according to the present invention will be described. The methods described below may be used individually or in any combination.

The selly selection can be triggered as the terminal configured in the lightly connected state moves.

If a lightly connected state terminal moves out of a cell associated with an anchor base station that has made a light connection state, the anchor base station can not know the position of the lightly connected state terminal. In order for the network to track the location of the lightly connected state terminal, the anchor base station may configure the lightly connected state of the terminal by specifying the paging area (for convenience of explanation, The paging area configured in the anchor base station is referred to as the paging area in the anchor base station in the present invention. As an example, the paging area configuration may include information (cell list) of one or more cells for the paging area ID. For example, the cell information may include at least one of cell identification information, physical cell identification information, and global cell identification information. As another example, the paging area configuration information may include at least one of anchor base station identification information and terminal identification information in an anchor base station.

For example, the above-described paging area configuration information may be indicated through a UE-specific RRC reconfiguration message. As another example, the above-described paging area configuration information may be indicated through a UE-specific RRC release message. As another example, the above-described paging area configuration information may be indicated through system information. In another example, a terminal with a light connection may perform cell reselection based mobility. When a terminal with a light connection performs cell selection, the same mechanism as the cell selection in RRC_IDLE (to reduce power consumption) may be used. For example, since the paging notification operation of the terminal having a light connection can also occur in the RRC_IDLE state, the paging area configuration information can be transmitted in the idle mode mobility control information (idleModeMobilityControlInfo). In another example, a terminal with a light connection may perform a selly selection in the RRC_IDLE state, but may be in the ECM-CONNECTED state. Therefore, mobility control information of a new connection state (light connection state) different from the idle mode mobility control information (idleModeMobilityControlInfo) can be defined and transmitted.

According to cell re-selection criteria, if the terminal finds a better suitable cell, the terminal re-selects (or reselects and camps on) it. If the terminal is out of the configured paging area (for example, if the reselected cell is not included in at least one paging area information configured in the terminal), the lightly connected terminal must inform the network. For example, a paging area update can be performed. In another example, if the UE does not leave the configured paging area, the UE continues the sellection selection measurement and the selly selection evaluation. When the condition for cell selection is satisfied, the terminal performs cell selection.

Paging area notification method

Hereinafter, a paging area notification method when the mobile station moves out of the paging area configured by the anchor base station will be described. The methods described below can be used individually or in any combination.

1) How to Maintain an Anchor Base Station

3 shows an example of a paging area notification method. This will be described below.

The lightly connected terminal detects that the terminal has entered a location area not included in the list of registration area information / paging area information / notification area information registered in the network (anchor base station). Alternatively, the light connection establishing terminal may include a list of registration area information / paging area information / notification area information (indicated as paging area information below for the sake of convenience of explanation) that the network (anchor base station) instructed Which is not included in the positional area.

For example, the AS (or terminal) of the terminal transmits the received system information to the NAS. The NAS (or terminal) of the terminal detects that the terminal has entered a location area not included in the list of paging area information specified by the anchor base station. The NAS (or terminal) of the terminal instructs the AS of the terminal to resume the RRC connection for network registration / domain registration / paging update (hereinafter referred to as paging update for convenience of explanation). In another example, the AS (or terminal) of the terminal detects that the terminal has entered a location area not included in the list of paging area information indicated by the anchor base station. The AS of the UE initiates RRC connection resumption for paging update.

1. A light connection terminal uses an RRC resume request message (for convenience of explanation, an RRC connection resume request procedure will be described as an example for conveying a paging update, this is merely for convenience of explanation, and other procedures Can be used.)

2. New base station (For convenience of explanation, it is indicated as a new base station, but this is only for the convenience of explanation. It means that a terminal composed of light connection by an anchor base station is a cell which is out of paging area configured by an anchor base station or a base station of a corresponding cell (E.g., may be replaced with a serving cell / serving base station) may perform procedures to extract / interrogate / fetch / retrieve / get the terminal AS context. The new base station receives the terminal AS context from the anchor base station.

3. The new base station transmits an RRC connection resume message to the UE. (For the sake of convenience of description, the RRC connection resumption request procedure will be described as an example of step 1. This is for convenience of explanation only, and other procedures may be separately described.)

4. The terminal transmits an RRC connection resumption complete message to the new base station. (For the sake of convenience, the RRC connection resumption request procedure will be described as an example of step 1/3, which is for the sake of convenience only, and other procedures which will be described separately may be used.)

The RRC connection resume complete message may include paging update information. The paging update information will be described separately.

5. The new base station can send paging update information to the anchor base station. If an anchor base station wishes to configure a new paging area to be terminal specific, an anchor base station can configure (another) paging area while keeping an anchor base station in consideration of a mobile path and a traffic state of the mobile station. For example, an anchor base station can construct a paging area in a terminal through a new base station through an inter-node RRC message. In another example, an anchor base station can configure a terminal to a light connection state through a new base station through an inter-node RRC message.

If there is no inter-base-station interface (X2 interface) between the new base station and the anchor base station, the paging area update information can be transmitted to the anchor base station through the MME. And / or receive an acknowledgment from the anchor base station via the MME. The new BS receiving the paging area update response message from the anchor BS can transmit the RRC message to the MS. For example, the anchor base station may include paging area configuration information that is specific to the UE in a response message to paging area update. The above-described configuration information may include information (cell list) of one or more cells for the paging area ID. For example, the cell information may be cell identification information or global cell identification information. The paging area configuration information may include anchor base station identification information and terminal identification information in an anchor base station. As another example, the new base station may include the information received through the anchor base station in the RRC message to configure the terminal in a light connection state. In this case, the existing anchor base station can be maintained as it is. In another example, the new base station can keep the terminal connected. In another example, a new base station may configure the terminal into an idle state. For example, an RRC connection release message can be transmitted to the mobile station. As another example of this, it is possible to transmit information including an instruction to disconnect the S1 to the anchor base station.

In another example, the light connection terminal may include information for indicating a paging update on the RRC connection resume request message (sent on the CCCH via SRB0). If the new base station confirms that this is a request for paging update by receiving an RRC connection resume request message, the new base station can send a paging update to the anchor base station. The paging update message that the new base station transmits to the anchor base station may include the anchor base station identification information and the terminal identification information included in the RRC connection resume request message received by the new base station. The paging update message that the new base station transmits to the anchor base station may include the cell information of the cell in which the new base station has received the RRC connection resumption request message. The cell information may include at least one of cell identification information, physical cell identification information, global cell identification information, Tracking Area Code, Paging Area Code, and cell system information.

In another example, the light connection terminal may be on the random access procedure Msg3 (or a third message, or a third transmission or transmission according to the scheduling grant included in the RAR, hereinafter referred to as Msg3 for convenience of description) And Msg3 are used to indicate paging update (or connection state transition of light connection terminal, MO data transmission of light connection terminal or MO signal transmission of light connection terminal). For example, a different LCID may be defined or used, a MAC CE may be defined, or an arbitrary information element may be included on the MAC CE. For example, the base station can distinguish the RAR based on the transmission of the UE according to the scheduling grant included in the RAR. If the new base station confirms the indication for paging update via the random access procedure (Msg3), the new base station can send the paging update to the anchor base station. The paging update message transmitted by the new base station to the anchor base station may include the anchor base station identification information and the terminal identification information included in the Msg3 received by the new base station. The paging update message that the new base station transmits to the anchor base station may include the cell information of the cell in which the new base station has received the RRC connection resumption request message. The cell information may include at least one of cell identification information, physical cell identification information, global cell identification information, Tracking Area Code, Paging Area Code, and cell system information.

In another example, the light connection terminal may include information indicating that the request is a request for paging update in an RRC connection resume request message. If the new base station receives and confirms that the request is a request for paging update in the RRC connection resumption request, the new base station requests the terminal context to the anchor base station by using the terminal contact for signaling bearer configuration of the light connection establishment terminal Only the request can be received and received.

This method has the merit of not causing S1 signaling when updating the paging area because it does not perform the path switch procedure for changing the S1 connection by maintaining the anchor base station that has the light connection. There is an advantage that simple paging update can be performed when the light connection terminal only performs the paging update without MO signaling to be transmitted to the originating data (MO DATA) or the core network entity (for example, MME).

However, when MO signaling to be transmitted to the originating data (MO DATA) or the core network entity (for example, MME) occurs during the paging update or before and after performing the paging update, (Or a data bearer or a GTP tunnel) between the anchor base stations or perform signaling for indicating the transmission channel.

For example, when the new base station is different from the anchor base station according to the movement of the terminal, the paging update information may include the anchor base station identification information and the anchor base station identification information so that the new base station, which has received the RRC message including the paging update information, And may include identification information. As another example, the paging update information may indicate information for indicating a paging update. As another example, the paging update information may include terminal identification information, current / serving cell identification information, PLMN identification information, previous cell identification information, last visited cell identification information, visited cell identification information (visitedCellId), visited cell identification information list in the paging area, history information / report, Tracking Area Code, and Paging Area Code.

2) How to transfer / change anchor base station

4 shows another example of the paging area notification method. An anchor base station may be relocated / changed if the terminal performs paging update out of the paging area. The newly constructed anchor base station can configure (another) paging area in consideration of the mobile path and the traffic state of the mobile station. This will be described below.

The light connection establishment terminal detects that the network (anchor base station) has entered a location area that is not included in the list of paging area information instructed (or instructed to configure).

2. The new base station can perform procedures to extract / interrogate / fetch / retrieve / get the terminal AS context. The new base station receives the terminal AS context from the anchor base station.

5. The new base station performs the core network control entity (MME) and path switch procedure for path change. Thus, the (S1) GTP tunnel of the previous anchor base station can be switched to the (S1) GTP tunnel end point of the new base station. Accordingly, the MME can update the terminal location information in the HSS.

6. The core network control entity (MME) performs core network data entity (SGW) and bearer modification procedure.

7. The new base station releases the terminal context of the previous anchor base station.

In another example, the light connection terminal may include information for indicating a paging update on the RRC connection resume request message (sent on the CCCH via SRB0). If the new base station receives the RRC connection resume request message, it can confirm that this is a request for paging update. In another example, the light connection terminal may be on the random access procedure Msg3 (or a third message, or a third transmission or transmission according to the scheduling grant included in the RAR, hereinafter referred to as Msg3 for convenience of description) And Msg3 are used to indicate paging update (or connection state transition of light connection terminal, MO data transmission of light connection terminal or MO signal transmission of light connection terminal). For example, a different LCID may be defined or used, a MAC CE may be defined, or an arbitrary information element may be included on the MAC CE. For example, the base station can distinguish the RAR based on the transmission of the UE according to the scheduling grant included in the RAR.

As another example, when the new base station transmits the connection resumption message to the terminal in step 3, the new base station may include information for indicating the terminal-specific paging area configuration information and / or the light connection state on the connection resume message. Thus, the new base station configures the terminal in a light connection state and becomes a new anchor base station in the terminal. The paging area configuration information may include information (cell list) of one or more cells for the paging area ID. For example, the cell information may be cell identification information or global cell identification information. The paging area configuration information may include new anchor base station identification information and new anchor base station identification information.

As another example, the new base station may instruct the terminal to transition to a light connection state via the RRC connection release message after step 7. Thus, the new base station configures the terminal in a light connection state and becomes a new anchor base station in the terminal. The RRC disconnect message may include terminal specific paging area configuration information and / or information to indicate a light connection state. The paging area configuration information may include information (cell list) of one or more cells for the paging area ID. For example, the cell information may be cell identification information or global cell identification information. The paging area configuration information may include new anchor base station identification information and new anchor base station identification information.

In another example, the new base station may instruct the terminal to transition to a light connection state via the RRC connection reconfiguration message after step 7. Thus, the new base station configures the terminal in a light connection state and becomes a new anchor base station in the terminal. The RRC connection reconfiguration message may include terminal specific paging area configuration information and / or information for indicating a light connection state. The paging area configuration information may include information (cell list) of one or more cells for the paging area ID. For example, the cell information may be cell identification information or global cell identification information. The paging area configuration information may include new anchor base station identification information and new anchor base station identification information.

As another example, separate paging area update information may not be transmitted to the new base station. For example, in step 4, the RRC connection resumption complete message does not include the paging update information. The new base station can be maintained as a light connection terminal transitions to the connected state. The new base station has already been switched from the terminal, the base station, and the core network through the signaling with the anchor base station and the core network entity. Therefore, it may not be necessary to define separate paging area update information.

As another example, after transition to the RRC connection state, the paging area update information can be transmitted to the base station through a separate RRC message such as a terminal information message. For example, in step 4, the RRC connection resumption complete message does not include the paging update information. The new base station can be maintained as a light connection terminal transitions to the connected state. The new base station has already been switched from the terminal, the base station, and the core network through the signaling with the anchor base station and the core network entity. However, a new base station may attempt to configure a mobile station based on a mobile path and a traffic state of the mobile station. For this, the new base station can receive the related information from the terminal. Or may request and receive related information from the terminal.

Mobility information control method

Hereinafter, a mobility information control method of a light connection terminal will be described. The methods described below can be used individually or in any combination.

In the prior art, mobility information (e.g., mobility history information) provided only the RRC connection state and the terminal mobility history information of the RRC idle state. For example, if the UE supports mobility history information, the UE changes its cell to another (E-UTRAN or inter-RAT) cell configured as a serving cell of the PCC or RRC idle state in the RRC connected state ), Or when the terminal enters the out-of-service, the mobility history report variable contains one entry after removing the oldest entry if necessary.

If the global cell identifier of the previous PCell / serving cell is available, the global cell identifier is set in the visitedCellId field of the entry.

Otherwise it contains the physical cell identifier and the carrier frequency in the visited cell identifier (visitedCellId) field of the entry.

Set the time spent in the previous PCell / serving cell to the timespent field.

Therefore, if a light connection state is added to the terminal, the mobility history information of the corresponding cell is not added.

1) Terminal mobility history information is not available in light connection terminal state

In the case of a light connection terminal which can be considered as a new RRC state, it can be prevented from adding it to the terminal mobility history report variable. In the case of a terminal configured in a light connection state, information from the RRC connection state to the previous cell when the cell is changed from the RRC connection state before the terminal is configured in the light connection state is included. A light connection may be a temporary condition for a small amount of data transmission or the like. Or may transition to a released state if data transmission is not expected and may transition to a connected state for data transmission. Therefore, if a cell change occurs after transition to a light connection state, it may not be added to the terminal mobility history report variable.

For example, if the UE transitions to a light connection state, the time spent in the cell may be included in the timespent field. And then set the time spent in the previous PCell / serving cell to the timespent field when the light connection terminal transitions to the RRC connected state or the RRC idle state and the cell is changed to the next cell.

2) Added terminal mobility history information in light connection terminal state

For a lightweight connection terminal that can be considered a new RRC state, it can also be added to the mobility history report variable according to the movement of the terminal. Even when the terminal transits to the light connection state, the mobility history information for the corresponding terminal can be added.

If a light connection state is added, if the terminal supports the mobility history information, it can be operated as follows.

When a UE is changed to another (E-UTRAN or inter-RAT) cell consisting of a serving cell in the RRC connected state or a serving cell in the RRC idle state or a lightly connected state, The mobility history report variable contains one entry, if necessary, after removing the oldest entry.

Set the time spent in the previous PCell / serving cell to the timespent field.

Each time the terminal transits to the light connection state, the time spent in the previous cell can be set to the timespent field.

3) Connection of light connection terminal Restart procedure Include mobility information on procedure

In the process of updating the paging area beyond the paging area configured by the anchor base station or when the light connection terminal performs the RRC connection resumption according to the MO signaling / MO data / RAN based paging or when the light connection terminal is light In the process of transition from the connected state to the RRC connected state, the mobile station can transmit the mobility information to the new base station.

For example, in a process of updating a paging area or in a state where a cell change / base station is changed (for example, in a state where a corresponding cell is changed through system information), a light connection terminal transmits a RRC connection resume request Message, the RRC connection resumption request message may include information indicating that the mobile station history information is available to the terminal.

For example, in a case where the light connection terminal performs a paging area update or when the cell connection / base station is changed (for example, in a state where the corresponding cell is changed through the system information) Message and transmits an RRC connection resumption complete message after receiving an RRC connection resumption message from the new base station, the RRC connection resumption complete message may include information indicating that the mobile station history information is available to the terminal.

For example, in a case where the light connection terminal performs a paging area update or when the cell connection / base station is changed (for example, in a state where the corresponding cell is changed through the system information) And transmits the RRC connection resumption completion message after receiving the RRC connection resumption message from the new base station, it can send the mobility history information (e.g., mobilityhistoryreport) to the terminal in the RRC connection resumption complete message.

A non-access stratum (NAS) state and a light connection state transition method of a terminal

For example, a NAS state and a light connection state transition method of a terminal for a light connection state terminal can use the following methods individually or in combination.

1) When NAS recognizes a light connection status (terminal NAS: ECM-CONNECTED, terminal AS: RRC-IDLE)

For example, when a light connection is established to the terminal through RRC signaling, the terminal's RRC may indicate (inform) the NAS to it. In this case, the NAS of the terminal can consider the terminal as ECM-CONNECTED but in the RRC-IDLE state (or the NAS of the terminal is lightly connected). The NAS of the terminal maintains the NAS context.

When the terminal is triggered by the NAS signaling or MO data, the NAS / higher layer may instruct the RRC to transition to the connected state via the maintained / stored AS context.

In the Suspend / Resume procedure for the conventional NB-IoT terminal, the RRC Connection Resume Request is initiated by an instruction of the upper layer. In resuming the RRC connection at the instruction of the upper layer, the resume cause (resumeCause-r13) included in the RRC Connection Resume Request message has one of the following setup causes (EstablishmentCause-NB-r13).

ExceptionData, spare4, spare3, spare2, spare1} {mt-Access, mo-Signaling, mo-Data, mo-ExceptionData}

If it is intended to transit a lightly connected terminal to a connected state, the corresponding base station must recognize the cause to extract the terminal AS context from the anchor base station. For example, the upper layer and / or the RRC Connection Resume Request message may include a spare value of a setting cause (EstablishmentCause-NB-r13) for indicating a resume cause (resumeCause-r13) Or the like.

As another example for distinguishing and instructing the upper layer and / or the RRC Connection Resume Request message, the upper layer and / or the RRC Connection Resume Request message may specify the indication information for distinguishing the upper layer and / or the RRC Connection Resume Request message by defining a different field from the resume cause (resumeCause-r13). In this case, it is assumed that the cause of the resumption is mt-Access, mo-Signaling, mo-Data, mo-ExceptionData and that the resumption request message is triggered to transition the light connection terminal into the connection state. It is instructed to extract the context. As another example for distinguishing and instructing the upper layer and / or the RRC Connection Resume Request message, the upper layer and / or the RRC Connection Resume Request message includes a setting cause on the existing resume cause (resumeCause-r13) It is possible to designate and direct a field indicating that it is for instructing to extract the terminal AS context from the anchor base station.

2) When NAS recognizes the light connection status (terminal NAS: ECM-IDLE, terminal AS: RRC-IDLE)

As another example, when a light connection is established to the terminal through RRC signaling, the terminal's RRC may indicate (notify) it to the NAS. For example, the RRC can pass information to the NAS indicating a light connection status. In this case, the NAS of the terminal can consider the terminal as an ECM-IDLE and an RRC-IDLE state. It can be seen that the terminal is lightly connected (or the NAS of the terminal is lightly connected).

The NAS of the terminal may perform one or more of the following operations.

- The terminal maintains the NAS context.

- The terminal stores the NAS context.

- The terminal releases the NAS context but stores it. When NAS signaling or MO data is triggered in the terminal, it is reused / resumed / recovered / maintained / invoked.

- The terminal suspends the NAS context. When NAS signaling or MO data is triggered in the terminal, it is reused / resumed / recovered / maintained / invoked.

When the MS signaling or MO data is triggered, the MS / layer transmits it to the RRC. The RRC may be allowed to transition to a connected state via a maintained / stored AS context.

3) If NAS does not recognize the light connection status (terminal NAS: ECM-CONNECTED, terminal AS: RRC-IDLE)

As another example, when a light connection is established to the terminal through RRC signaling, the terminal's RRC may not indicate (notify) it to the NAS. In this case, the NAS of the terminal considers the terminal to be in the ECM-CONNECTED state. The AS (or RRC) of the terminal can be considered as the RRC-IDLE state. It can be seen that the terminal (or AS or RRC of the terminal) is in a light connection state. When the NAS signaling or MO data is triggered, the NAS / higher layer forwards it to the corresponding SRB or DRB. Once the data is transferred to the SRB / DRB, the RRC may transition to the connected state via the maintained / stored AS context.

Hereinafter, when the light connection terminal is out of the paging area configured in the terminal, the terminal can perform the paging area notification. The UE may initiate an RRC connection resumption procedure for paging area notification. Hereinafter, an RRC connection resuming procedure for a light connection state terminal to transmit MO data / MO signaling / RAN-based paging response / paging area notification / RRC connection state transition will be described.

In the case where a terminal composed / lighted and / or a light connection has received uplink data / signaling (for MO data or MO signaling) or a lighted connection, The UE moves from the cell to the RRC connection state (or resumes the RRC connection or initiates / triggers the transition to the RRC connection state, hereinafter referred to as the RRC connection resumption in the light connection state for convenience of explanation) Or RRC connection state transition).

- How to use RRC Connection request message

The MS may transmit an RRC Connection Request message to the BS through a common control channel (e.g., CCCH).

If a transition from a lightly connected state to a connected state is triggered by an upper layer, and the upper layer has provided an S-TMSI, a value received from the upper layer may be set with a UE identity.

If a transition from a lightly connected state to a connected state is triggered in the AS, the value received from the base station with the terminal identifier can be set. This will be described later.

If a transition from a lightly connected state to a connected state is triggered by an upper layer,

An establishment cause value corresponding to the information received from the upper layer can be set.

For example, the terminal may add information indicating a transition from a light connection state to a connection state.

An establishment cause value corresponding to the information received from the upper layer can be set

If a transition from a lightly connected state to a connected state is triggered in the AS, a value indicating the transition from lightly connected state to connected state can be set to the set cause value.

In another example, the UE may add information indicating a transition from a light connection state to a connection state to an RRC Connection setup complete message.

- How to use RRC Connection re-establishment Request message

The MS may transmit an RRC Connection Reset Request message to the BS through a common control channel (e.g., CCCH).

The UE sets the C-RNTI used in the cell indicating the light connection state to the c-RNTI.

The terminal sets the physical cell identifier in the cell indicating the light connection state to phyCellId.

The terminal may set a reestablishmentCause to a value indicating a transition from a light connection state to a connection state.

As another example, if a transition from a lightly connected state to a connected state is triggered in the AS, the terminal identifier may be set to a value received from the base station and stored. This will be described later.

- How to use RRC Connection resume Request message

The MS may transmit an RRC Connection Resumption Request message to the BS through a common control channel (e.g., CCCH).

A value received from the base station and stored as a terminal identifier can be set. This will be described later.

It is possible to set the restart cause / setting cause value corresponding to the information received from the upper layer.

The resume cause / setting cause value corresponding to the information received from the upper layer can be set

In another example, the UE may add information indicating a transition from a light connection state to a connection state to an RRC Connection resume complete message.

- How to use the new RRC Connection Request message using the common control channel

The MS can transmit a new RRC Connection Request message to the BS through a common control channel (e.g., CCCH).

In another example, the UE may add information indicating a transition from a light connection state to a connection state to a new RRC Connection setup complete message.

Hereinafter, the light connection status terminal identification information will be described.

The selly selection can be triggered by the movement of the lightly connected state terminal. Therefore, even if the terminal is lightly connected, the terminal must be able to identify the terminal. Also, when the terminal moves, it may require the base station identification information and / or the cell identification information in which the terminal is configured in a light connection state in order to inquire / fetch / interrogate the terminal context for the terminal. The following information can be used individually or in combination as the light connection state terminal identification information in order to effectively perform state transition and data transmission for the corresponding terminal.

- Save the terminal identification information of the core network as terminal identification information

The terminal identification information of the core network consists of the core network entity code and the identification information temporarily assigned by the core network entity. Therefore, it is possible to uniquely identify the UE within the core network entity.

- Cell identification information, wireless network temporary identification information is stored as terminal identification information

If the cell in the network can be uniquely identified through the cell identification information, it can be uniquely identified by combining the cell identification information and the wireless network provisional identification information temporarily allocated by the base station accommodating the cell.

- store base station identification information, wireless network temporary identification information as terminal identification information

If the base station in the network can be uniquely identified through the base station identification information, the terminal can be uniquely identified by combining the base station identification information and the wireless network provisional identification information temporarily allocated by the base station.

- CU identification information, wireless network temporary identification information is stored as terminal identification information

If the CU in the network can be uniquely identified through the CU identification information, the terminal can be uniquely identified by combining the CU identification information and the wireless network provisional identification information temporarily assigned by the corresponding CU.

Hereinafter, another example of a signaling method of a light connection terminal according to the present invention will be described. - How to perform RRC connection establishment procedure by inquiring necessary information from higher layer

For a light connection terminal to perform paging area notification (for RRC connection state transition for paging area notification), or for light connection terminal to transmit RRC connection state transition for MO signaling, The serving BS can request the terminal AS context to the anchor BS for the RRC connection state transition. If the serving base station is not responded for any reason (e.g., expiration of the timer to limit the maximum response time in response to the AS context request). In this case, the serving BS transmits a RRC connection resumption request (for convenience of description, the RRC connection resume request in the following description). Category.) You can not proceed with the procedure.

For example, the base station may transmit an RRC connection reject message to the UE. The BS does not obtain the AS context for the corresponding terminal, so that even if the light connection terminal attempts to perform the paging area notification, the paging area notification can not be performed. Therefore, by transmitting an RRC connection refusal message to the RRC connection resume request, the UE can transition from the light connection state to the idle state. To this end, the RRC connection rejection message may include information for instructing the light connection terminal to transition to the idle state.

If the RRC connection rejection is received in response to the RRC connection resume request,

If the information for instructing the light connection terminal to transition to the idle state is included,

The terminal may perform one or more of the following operations.

- The terminal discards the stored terminal AS context and the terminal identifier / resume identifier.

- The UE transitions to the RRC IDLE state (eg, it can perform one or more of the operations that leave the RRC CONNECTED state, eg including RLC entity, MAC configuration and associated PDCP entity for all configured radio bearers). Releases all radio resources, instructs upper layer to release RRC connection.)

- The UE transitions to the ECM-IDLE state.

In another example, the base station may forward an RRC message to instruct the RRC light connection terminal to transition to the idle state.

The BS may transmit a message for releasing the S1 connection between the MME and the anchor BS to the MME or the anchor BS. The MME or the anchor base station, which has received the message for releasing the S1 connection between the MME and the anchor base station, can perform a procedure for releasing the corresponding S1 connection.

In another example, the base station may send an RRC connection setup message to the terminal. The BS does not obtain the AS context for the corresponding terminal, so that even if the light connection terminal attempts to perform the paging area notification, the paging area notification can not be performed. This may require a change to the corresponding S1 connection. The base station may transmit an RRC connection setup message to the RRC connection resumption request so that the corresponding terminal may discard the stored terminal AS context and store the light connection state in the connection state.

If the RRC connection setup is received in response to the RRC connection resume request,

The terminal discards the stored terminal AS context and the terminal identifier / resume identifier.

The terminal requests and receives information necessary for the upper layer.

If the upper layer has provided the S-TMSI, the terminal sets the s-TMSI to a value received from the upper layer.

If the upper layer has provided a "Registered MME", the terminal shall set the gummei-Type to the value received from the upper layer.

The MS transmits an RRC connection setup complete message to the BS.

The serving base station may perform the terminal context setup procedure with the MME. The MME can perform a procedure for releasing the S1 connection with the anchor base station.

- How to store necessary information in higher layer

The terminal knows the indicated information from the upper layer in the connected state. When the terminal in the idle state establishes the RRC connection according to the instruction from the upper layer, the RRC connection establishment procedure is started using the information indicated from the upper layer. When an anchor base station constructs a terminal with a light connection state, the terminal stores the terminal AS context. When the terminal is configured in a light connection state, the terminal may store information instructed by the upper layer in addition to the terminal AS context. The information stored when the terminal is configured in a light connection state may be at least one of MMEC, S-TMSI, Registered MME, gummei-Type, mmegi, and mobilityState.

- How to perform the RRC connection resume procedure through upper layer

The terminal notifies the upper layer (instructs it).

The upper layer of the UE instructs the RRC to complete the RRC connection setup.

The MS transmits an RRC connection setup complete message to the BS.

- When IMSI-enabled paging is received, it is forwarded to the upper layer

Paging using IMSI is an unusual procedure used for error recovery in a network. If the S-TMSI is not available due to network failure, the network may initiate paging for the EPS service using the IMSI.

The anchor base station can transmit paging using the IMSI to the UE.

Upon receiving the paging using the IMSI, the terminal (RRC) can instruct it to the upper layer.

For example, when a terminal transited / configured as a light connection requests an RRC connection establishment / light connection start / resume / reset to transition from a light connection state to an RRC connection state, the terminal can receive a paging message. The terminal (RRC) can direct the paging message to the upper layer.

The UE can transition to the RRC IDLE state.

The upper layer can locally disable the EPS bearer context and detach from the EPS. After the local detachment, the terminal can perform the attach procedure.

- state transition due to paging failure

If a downlink data is received for a terminal that is transited / configured as a light connection, a paging message may be sent to transition from a light connection state to an RRC connection state. At this time, if for some reason (for example, terminal power-off), the paging may fail.

For example, if the paging fails (according to a predetermined number of times / standard), the base station may instruct the corresponding terminal to release the connection state to the core network.

To this end, the terminal may send a terminal context disable / terminal context release message to the control plane core network entity (e.g., MME).

The anchor base station may discard the stored terminal context.

The anchor base station can release the S1 connection.

An anchor base station can discard buffered user data.

As described above, the present invention has an effect of efficiently performing signaling for a terminal having a light connection. Also, the new base station has an effect of effectively controlling the mobility information so as to perform the proper configuration considering the characteristics of the terminal performing the paging update.

5 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

5, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The controller 1010 controls the overall operation of the base station according to the signaling method and related procedures for efficiently performing the paging update of the terminal having the light connection required to perform the above-described present invention.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

6 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

6, a user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

The receiving unit 1110 receives downlink control information, data, and messages from the base station through the corresponding channel.

The controller 1120 controls the overall operation of the terminal according to the signaling method and related procedures for efficiently performing the paging update of the terminal having the light connection necessary for carrying out the present invention described above.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and some of the standard documents is added to or contained in the scope of the present invention, as falling within the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims

A method for processing a paging update of a terminal,
And providing signaling for efficiently performing a paging update of a terminal configured with a light connection.