KR20170125292A

KR20170125292A - Methods for changing connection status and Apparatuses thereof

Info

Publication number: KR20170125292A
Application number: KR1020170044062A
Authority: KR
Inventors: 홍성표; 최우진
Original assignee: 주식회사 케이티
Priority date: 2016-05-03
Filing date: 2017-04-05
Publication date: 2017-11-14
Also published as: KR102016106B1

Abstract

The present invention relates to a method and a device of a control plane signaling for reducing a signaling according to a terminal state change. More specifically, the present invention relates to a method for efficiently changing a terminal connection state in a wireless network without mobility of a terminal and a transition change in a core network. According to an embodiment of the present invention, the method for changing the terminal connection state comprises the following steps of: the terminal transmitting terminal capability information instructing support of a light connection to a base station; receiving a radio resource control (RRC) message including instruction information instructing a state change from the base station to a light connection state; and performing an operation of changing the terminal connection state from an RRC connection state into the light connection state based on the instruction information.

Description

[0001] The present invention relates to a method for changing connection status,

The present invention relates to a control plane signaling method and apparatus for reducing signaling due to terminal state change, and more particularly, to a method for efficiently changing a terminal connection state in a wireless network without changing mobility or state transition of the terminal in the core network.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. In a mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the current 3GPP series, a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data outside a voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method.

In addition, due to the increase of terminals using machine type communication (hereinafter referred to as "MTC" communication), data transmission / reception through a mobile communication system is rapidly increasing. Meanwhile, in the case of MTC communication, it is necessary to periodically transmit and receive a small amount of data, and a low-power low-cost terminal can be used.

Therefore, there is a demand for a technology for transmitting and receiving data by a plurality of terminals while reducing power consumption.

In particular, in the case of a terminal that transmits a small amount of data periodically or aperiodically, it is necessary to change the RRC connection state in order to transmit a small amount of data. However, in order to change the RRC connection state by the conventional method, the data transmission / reception procedure of the terminal, the base station, the base station, and the core network has been complicated.

Such a transmission / reception procedure causes a relatively high data load compared to a small amount of data to be transmitted by the terminal. That is, there is a problem that unnecessary data overload occurs in the RRC connection state change procedure for transmitting a small amount of data.

This problem is likely to result in an increase in data load throughout the communication system as the number of terminals for transmitting a small amount of data periodically increases.

Therefore, it is necessary to study a method and a procedure for changing the terminal connection state, which can transmit and receive a small amount of data without seriously increasing the data load of the entire communication system according to the change of the wireless communication environment.

In the above-described background, a connection state of a terminal is added to a RRC connection and a RRC idle, and a light connection state is additionally provided to reduce the load on the entire communication system, And a method and an apparatus for configuring the system to be implemented.

In addition, one embodiment of the present invention proposes a specific procedure for a terminal to perform a connection state transition including a state of a light connection connection.

According to an embodiment of the present invention, there is provided a method for changing a connection state of a terminal, the method comprising: transmitting, to a base station, terminal capability information indicating that the terminal supports a light connection; Receiving an RRC message including instruction information for instructing a state change to a connection state and performing an operation of changing a connection state of the terminal from the RRC connection state to the right connection state based on the instruction information .

According to another aspect of the present invention, there is provided a method of changing a connection state of a terminal in a base station, the method comprising: receiving terminal capability information indicating that the terminal supports a light connection state from a terminal; Transmitting a RRC message including instruction information for instructing a state change of the RRC connection state, and changing a connection state between the RRC connection state and the terminal to a light connection state, The SRB and the DRB of the UE are in a suspended state.

In an exemplary embodiment of the present invention, a terminal that changes a connection state includes a transmitter that transmits terminal capability information indicating that a light connection is supported to a base station, and a transmission unit that transmits an instruction to change a state from the base station to a light connection state And a control unit for performing an operation of changing the connection state of the terminal from the RRC connection state to the light connection state based on the reception unit and the instruction information for receiving the RRC message including the information.

According to another aspect of the present invention, there is provided a base station for changing a connection state of a terminal, the base station including a receiving unit for receiving terminal capability information indicating that the terminal supports a light connection state, A transmitter for transmitting an RRC message including instruction information for instructing a change and a controller for changing a connection state between the RRC connection state and the terminal to a light connection state, State, but all SRBs and DRBs of the UE are in a suspended state.

The embodiments described above provide a reduced signaling procedure for a terminal performing frequent connection state changes, thereby reducing the data load of the entire communication system.

In addition, the present embodiments provide data load reduction through quick connection state change of the terminal and reduction of core network signaling.

1 is a diagram illustrating a specific procedure for changing a connection state of a conventional terminal.
2 is a flowchart illustrating a terminal operation according to an exemplary embodiment.
3 is a flowchart illustrating a terminal operation according to another embodiment.
4 is a flowchart illustrating an operation of a base station according to an embodiment.
5 is a flowchart illustrating an operation of a base station according to another embodiment.
6 is a diagram illustrating a terminal configuration according to another embodiment of the present invention.
7 is a diagram illustrating a configuration of a base station 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 numerals whenever 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, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B 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 a transmission / reception point of a signal transmitted from a transmission / reception point, and the 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 a PDSCH, 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.

The connection state transition procedure of the terminal

In the conventional mobile communication technology, a terminal and a network state are classified into a terminal idle state and a connected state. The terminal and the network state coincide. For example, the states in the radio network (E-UTRAN) and the core network (for example, the RRC state and the ECM state) coincide. 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. The terminal in the idle state has to perform a complicated signaling process as shown in FIG. 1 in order to transmit data according to the terminal state. In particular, when a terminal transmits a small amount of data, it becomes a large overhead.

1 is a diagram illustrating a specific procedure for changing a connection state of a conventional terminal.

Referring to FIG. 1, the MS 100 transmits a random access preamble to the BS 110 in order to transmit data by transiting from the RRC idle state to the RRC connected state (S100). Thereafter, the terminal 100 receives a random access response from the base station 110 (S101), and requests the base station 110 to reset the RRC connection (S102).

The base station 110 sets up an RRC connection setup in the terminal 100 (S103), and the terminal 100 reports completion (S104).

When the RRC connection setup is completed, the base station 110 transmits an initial terminal message to the MME 120 to request a service (S105). The MME 120 requests the base station 110 to perform initial context setup (S107). Between step S105 and step S107, the base station 110 may transmit the RRC connection reconfiguration message to the terminal 100 to set the measurement configuration (S106). When the measurement configuration is completed, the UE 100 transmits an RRC connection reconfiguration message to the BS 110 (S108).

The base station 110 transmits a security mode command of the terminal 100 (S109), and receives a response thereto (S110).

Thereafter, the BS 110 transmits an RRC connection reconfiguration message to the UE 100 for setting up the RB (S111), and receives a response to the RRC connection reconfiguration message (S112). The base station 110 transmits a response to the initial context setup to the MME 120 in step S113 and the MME 120 transmits the bearer modification request to the gateway 130 in step S114.

The terminal 100 transmits a UDP / IP packet to the base station 110 in step S115 and the base station 110 transmits the packet to the gateway 130 in step S116. The gateway 130 transmits a response to the bearer modification to the MME 120 (S117), and transmits a UDP / IP packet response to the base station 110 (S118). The base station 110 transmits the packet to the terminal 100 (S119).

Through this procedure, the AT 100 transmits the packet to the core network.

Thereafter, the terminal 100 transmits a measurement report to the base station 120 periodically or at the time of occurrence of an event according to the measurement configuration (S120). The base station 120 determines whether to release the terminal 100 based on the measurement report or deactivation timer (S121). When the RRC connection release of the terminal 100 is determined, the base station 110 requests the MME 120 to release the terminal context (S122). The MME 120 instructs the base station 110 to release the terminal context (S123), and the base station 110 instructs the terminal 100 to release the RRC connection accordingly (S124).

After releasing the RRC connection of the terminal 100, the base station 110 transmits a response to the MME 120 (S125).

Through this procedure, the RRC connection terminal can be transited to the RRC idle state.

As described above, in the prior art, a plurality of signaling procedures are required between the UE, the BS, the BS, and the core network in order for the UE to transition from the RRC idle state to the RRC connected state or from the RRC connected state to the RRC idle state. In this procedure, when the UE periodically transmits a small amount of data, the overhead continuously occurs. Meanwhile, in order to reduce the overhead due to the state transition, the UE can be maintained in a connected state. In this case, even when there is no data transmission, it is necessary to periodically measure the network status according to the measurement configuration, Consumption may be caused. In addition, when the RRC connection state is maintained, the handover signaling overhead due to the movement of the UE increases.

NB- IoT Connection state transition for the terminal Procedure

A narrow band IoT terminal may be operated in a fixed state and may be installed in a specific location or located within a certain range. Due to this characteristic, the NB-IoT terminal and the base station support the Suspend / Resume procedure. In the RRC connection release message, the base station can request the terminal to maintain an 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 the RRC Connected transition in the RRC IDLE used to resume the RRC connection previously stored in the terminal 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 sends an S1 message requesting state transition of the MS to the core network to transmit the ECM CONNECTED state &Lt; / RTI >

However, even in this case, the RRC connection state and the ECM connection state are made the same, and thus unnecessary overhead is generated between the base station and the core network. That is, as described above, in the conventional mobile communication technology, there is a signaling overhead problem due to state transition, and in the case of the Suspend / Resume procedure for the terminal in the fixed location which can reduce the overhead, the NB-IoT terminal can be applied . Accordingly, when the UE moves out of a cell (or a base station) providing the previously stored AS Context, the UE has to perform the service request procedure as shown in FIG. 1 to transmit the uplink data. In addition, since the transition between the Suspend state and the Resume state is the same as the transition between the IDLE state and the CONNECTED state, the core network signaling (S1 signaling) is continuously generated.

In order to solve this problem, we propose a concrete procedure for transiting only the wireless network connection state without core network signaling.

In the prior art, since a terminal and a base station have undergone a wireless network connection state transition based on signaling and user data generated in an upper layer (for example, Non Access Stratum, IP, GTP, etc.) of an AS (Access Stratum) In order to transit only the wireless network connection without signaling, detailed operation procedure is necessary.

Also, if only the wireless network connection state is transited without core network signaling, incoming data for the terminal can not be received properly. As a method to solve this problem, it is possible to consider a method of self-triggering paging in a wireless network, but no concrete method has been proposed. In particular, paging according to the prior art is triggered through the core network. Therefore, there is a problem that the method of triggering paging in the wireless network can not sufficiently provide the paging function triggered through the core network.

The present embodiment, which has been devised to solve the above-described problems, provides a method and apparatus for efficiently transmitting and receiving data by performing a radio network state transition without accompanying core network signaling in order to reduce core network signaling overhead The purpose.

The embodiments described below can be applied to terminals using all mobile communication technologies. For example, the present embodiments can be applied not only to mobile communication terminals to which LTE technology is applied but also to next generation mobile communication (for example, 5G mobile communication) terminals. For convenience of description, the base station may represent an eNode-B of an LTE / E-UTRAN, a base station (CU, DU, or CU) in a 5G wireless network in which a CU (Central Unit) And DU is an entity implemented as a single logical entity).

Core network Signaling How to Perform a Wireless Network State Transition Not Accompanying

In order to reduce the signaling due to the state transition of the MS, the BS maintains a connection between the BS and the core network for the MS (for example, S1 connection in LTE or interface connection between the BS and the core network in 5G) (E.g., cell reselection, paging, radio resource release / suspend / suspend, and / or at least one operation of some radio resource maintenance / standby) in the RRC idle state so that terminal power similar to the idle state is consumed. As shown in FIG.

For convenience of description, a state in which a control plane or user plane connection is maintained on a base station and a core network interface to a terminal is referred to as a light connection state, in which a part or all of operations of the RRC idle state are performed. The light connection state includes a new RRC state, a sub-state of the RRC connection, a terminal mobility providing connection state, a wireless network paging state, a connection standby state, an RRC idle state for maintaining the S1 connection, an RRC idle state for maintaining the core network connection, Standby state, light connection state, and the like, and the name is not limited.

Also, when the base station instructs to switch the RRC Connected terminal to the light connection state in the light connection state, it may not send the terminal context release request message to the core network. That is, signaling is not performed to release the connection on the interface between the core network and the base station. Or (S1) connection on the interface between the core network and the base station is maintained. For reference, in the prior art, when releasing the RRC connection state to the terminal, the base station sends a terminal context release request message to request the MME to release the logical S1 connection associated with the terminal.

As described above, the newly connected connection state of the terminal is described as a write connection state. As described above, in the write connection state, the connection between the base station and the core network for the terminal is maintained and the terminal is in the RRC idle state But the present invention is not limited to the exemplary names corresponding to the exemplary names indicating the states performing some operations.

Hereinafter, a method of transitioning the state of the light connection state of the terminal according to the present embodiment will be described in detail.

2 is a flowchart illustrating a terminal operation according to an exemplary embodiment.

Referring to FIG. 2, the terminal performs a step of transmitting terminal capability information indicating that the terminal supports a light connection to the base station (S210). For example, the terminal may transmit information on whether the terminal supports the light connection state to the base station. That is, the terminal can transmit to the base station that it supports the RRC connection, the RRC idle, and the light connection state.

For example, the terminal capability information may be transmitted to the base station or the core network through the AS capability or the NAS capability. As another example, the terminal capability information may be included in terminal wireless connection capability or terminal core network capability.

The terminal can transmit the terminal capability information to the base station through RRC signaling.

The light connection state refers to a state in which the connection state between the base station and the core network for the UE is maintained while all signaling radio bearers (SRBs) and data radio bearers (DRBs) of the UE are suspended. That is, the light connection state may indicate a state in which the RRC and the ECM state do not coincide with each other.

The terminal performs a step of receiving an RRC message including indication information indicating a state change from the base station to the light connection state (S220). For example, the RRC message may be an RRC connection reconfiguration message or an RRC connection release message. Alternatively, the indication information may be included in a newly defined RRC message.

The terminal performs a step of changing the connection state of the terminal from the RRC connection state to the light connection state based on the instruction information (S230). For example, when the UE receives the instruction information indicating the state change from the base station to the light connection state, it stops all SRBs and DRBs for the base station. However, unlike the RRC idle state, the terminal can store the terminal context. In this case, the base station also stores the terminal context for that terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception.

In addition, the terminal in the light connection state can perform the cell reselection operation instead of the handover when moving. That is, since the RRC connection of the UE is similar to the released state of the BS, the UE can perform a process of reselecting the cell when the UE moves.

3 is a flowchart illustrating a terminal operation according to another embodiment.

Referring to FIG. 3, the terminal may change from the state transitioned to the light connection state to the RRC connected state through steps S210 through S230 described above.

To this end, the MS may transmit an RRC connection resumption request message to the BS (S340). For example, when the transition to the RRC connection state is triggered, the terminal in the right connection state can perform the transition from the light connection state to the RRC connection state by transmitting an RRC connection resumption request message to the base station.

In one example, the change of state to the RRC connected state may be triggered by the operation of either a paging message reception, an origination data trigger, and an outgoing signaling trigger. Specifically, when the paging message for the terminal in the light connection state is received, the terminal can perform the transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state. Or if the outgoing signaling to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state.

Meanwhile, the RRC connection resumption request message may include the cause information that causes the state change trigger to the RRC connection state. The cause information of the cause of the trigger may include information on whether it is due to the above-described paging, origination data trigger, or origination signaling trigger.

4 is a flowchart illustrating an operation of a base station according to an embodiment.

Referring to FIG. 4, the base station can perform step S410 of receiving terminal capability information indicating that the terminal supports a light connection state from the terminal. The base station can receive the terminal capability information from the terminal and confirm that the terminal supports the RRC connection, the RRC id, and the right connection state.

For example, the terminal capability information may be transmitted to the base station or the core network through the AS capability or the NAS capability. As another example, the terminal capability information may be included in terminal wireless connection capability or terminal core network capability. The base station can receive the terminal capability information through RRC signaling.

As described above, the write connection state may mean a state in which the connection state between the base station and the core network for the UE is maintained, but all SRBs and DRBs of the UE are suspended.

The base station may perform a step of transmitting an RRC message including indication information indicating a state change to a light connection state to the terminal (S420). The base station may transmit an RRC message to transition the terminal to the light connection state. For example, the RRC message may be an RRC connection reconfiguration message or an RRC connection release message. Alternatively, the indication information may be included in a newly defined RRC message.

The base station may perform a step of changing the connection state from the RRC connection state to the light connection state at step S430. When a terminal transitions to a light connection state, the base station stops all SRBs and DRBs for the terminal. However, unlike the RRC idle state, the base station can store the terminal context of the corresponding terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception.

The base station can also control the transition to the RRC connected state with respect to the terminal in the light connection state. This will be described below with reference to FIG.

5 is a flowchart illustrating an operation of a base station according to another embodiment.

Referring to FIG. 5, the base station can transition the terminal to the light connection state through steps S410 to S430. Thereafter, the terminal can be transited to the RRC connection state again.

For example, the base station may receive an RRC connection resume request message requesting a change of state from a write connection state to an RRC connection state from a terminal at step S540. For example, if a transition to the RRC connection state for a terminal in the right connection state is triggered, the base station can perform an RRC connection state transition operation of the corresponding terminal by receiving the RRC connection resumption request message.

As an example, the change of state to the RRC connection state may be triggered by either operation of either a paging message reception of the terminal, an origination data trigger, and an outgoing signaling trigger. Specifically, when a paging message for a terminal in the right connection state is transmitted, the terminal can perform a transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state. Or if the outgoing signaling to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state.

Each of the steps of FIGS. 2 to 5 described above may be changed in order, or some steps may be omitted or added.

Hereinafter, various embodiments of the individual step operation of the embodiments described with reference to Figs. 2 to 5 will be described.

Light of terminal connection Communicate Support Example

In order to provide a suitable configuration to the UE, the BS must correctly recognize the capability (hereinafter, referred to as a UE or a UE for convenience of description, but it may mean a 5G UE as well as an LTE UE). RRC signaling carries AS capabilities and NAS signaling carries NAS capabilities. The core network control plane entity (for example, MME, hereinafter denoted as MME, core network control plane entity) stores UE capabilities (or terminal capability configured with UE Radio Access Capability and UE Core Network Capability).

For example, the UE Core Network Capability can be indicated by the UE through NAS signaling (attach procedure, etc.). As another example, the UE Radio Access Capability may be transmitted from the UE to the Node B using the UE capability transfer procedure and transmitted through the S1 interface. As another example of this, the UE Radio Access Capability can be indicated to the MME through the NAS signaling (attach procedure, etc.) by the UE and transmitted to the base station via the S1 interface.

If available, the MME transmits UE Radio Access Capability to the base station whenever the UE enters RRC Connected. For example, the MME may transmit the UE radio capability to the base station through the S1 Initial context setup request message.

The base station may request UE capability information if necessary. For example, after the handover is completed, the base station may obtain the UE capability information from the UE using the UE capability transfer procedure, and then transmit the UE capability information to the MME.

As an example, information for instructing to support a light connection may be defined in the UE capability information (e.g., UE radio capability information). As another example, the information for indicating that the WLAN connection is supported may be defined by modifying / extending the UE capability information for NB-IoT suspend / resume (or AS context caching).

The base station may receive information to indicate that the terminal supports the light connection using the methods described above.

light connection Configuration Example

The base station can indicate the light connection state to the terminal by individually or in combination of the following methods.

1) Define a new release cause in the RRC Connection Release message

When the base station recognizes that the terminal supports the write connection, the base station may send an RRC disconnect message to the terminal indicating the release connection as a releasecause.

The terminal that has received the RRC connection release message indicating the cause of releasing the light connection can perform the operation for the light connection state.

The terminal operation for the light connection state indicates performing one or more of the following operations.

- Store terminal context

- Save light connection status terminal identification information

- Perform some or all of the operations of the RRC IDLE terminal (eg, cell reselection, paging, radio resource release / suspension / suspend)

1-1) An embodiment in which the upper layer does not indicate the write connection state

Upon receiving the RRC connection release message indicating the cause of the release of the write connection, the UE transmits a write connection state to the upper layer in order to hide the state transition in the upper layer (NAS: Non Access Stratum and / or user plane radio bearer upper layer) May not be indicated. In this case, the upper layer can not distinguish the light connection state.

For example, when originated data (MO data) to be transmitted in the light connection state is generated, it is considered to be in the RRC Connected state and transmitted to the PDCP buffer mapped to the corresponding bearer. If the suspend PDCP entity is suspended due to the radio resource suspend operation according to the change of the light connection state, data transmission can not be performed. Therefore, if the terminal receiving the RRC disconnect message indicating the cause of the release of the light connection does not indicate the light connection state to the upper layer, it must maintain the PDCP in the light connection state (or keep the PDCP the same as the connection state do). When data is received in the PDCP buffer, it must be able to initiate a transition to the RRC connection state. For example, if the terminal receives a PDCP SDU in the PDCP entity in the light connection state, it can request the RRC to transition from the light connection state to the connection state.

As another example, when an originating signaling (MO signaling, NAS signaling, for example) to be transmitted in the light connection state occurs, the UL information transfer RRC message can be transmitted to the base station in consideration of the RRC Connected state. Since the terminal RRC entity knows that it is in the right connection state, it can initiate a transition to the RRC connection state when origination signaling (e.g., MO signaling or NAS signaling) to be transmitted occurs.

1-2) An example of directing the light connection state to the upper layer and switching only the RRC connection state

The terminal receiving the RRC connection release message indicating the cause of the release of the light connection can indicate the write connection state to the upper layer. In this case, the upper layer can distinguish the light connection state.

For example, when the MO data is transmitted in the light connection state, the upper layer (e.g., NAS) of the terminal may not trigger the service request procedure. When the MO data is transmitted in the light connection state, the upper layer (e.g., NAS) of the UE transmits the RRC connection state (for example, RRC) from the light connection state to the lower layer Lt; / RTI > Upon receiving a transition instruction from the upper layer to the RRC connection state from the light connection state, the RRC can start the transition from the light connection state to the RRC connection state.

As another example, when an originating signaling (for example, MO signaling or NAS signaling) to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the terminal may not trigger the service request procedure. When origination signaling to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the terminal can instruct the lower layer (e.g., RRC) to transition from the light connection state to the RRC connection state. Upon receiving a transition instruction from the upper layer to the RRC connection state from the light connection state, the RRC can start the transition from the light connection state to the RRC connection state. That is, upon receiving a transition instruction from the upper layer to the connection state in the write connection state on the RRC, the RRC can start the transition from the write connection state to the connection state.

When a transition from a light connection state to a connection state is received from an upper layer and a transition to the RRC connection state is started, the terminal transmits the corresponding NAS signaling information (e.g., a transition instruction to the light connection state) There is no need to pass it through the core network.

1-3) An example in which the upper layer indicates the write connection state and the upper layer procedure is performed

For example, when the MO data to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the MS may trigger the service request procedure.

As another example, when an MO data to be transmitted in a light connection state occurs, a higher layer (e.g., NAS) of the terminal may trigger a NAS procedure (e.g., an attach procedure or a TAU procedure).

As another example, when the MO data to be transmitted in the light connection state occurs, the upper layer (for example, NAS) of the terminal may trigger a new NAS procedure for transition from the light connection state to the RRC connection state .

When starting the NAS procedure (one of the service procedure, the attach procedure, the TAU procedure and the new NAS procedure) from the upper layer, the RRC of the terminal can recognize that it is in the write connection state, Can be performed. For example, the above-described NAS procedure can be performed between the terminal and the core network entity. As another example, the above-described NAS procedure is not performed between the UE and the core network entity, and only the transition to the RRC connection state occurs, and then the RRC may respond to the NAS. For example, only the transition to the RRC connection state is performed and the terminal does not need to transmit the corresponding NAS signaling information (for example, a transition instruction to the light connection state) to the core network through the base station.

2) How to define and direct information for indicating a write connection to RRC Connection Reconfiguration message

When the base station recognizes that the terminal supports the write connection, the base station can define information for indicating the write connection to the RRC connection reconfiguration message and instruct the terminal to the information.

The terminal receiving the RRC connection reconfiguration message indicating the light connection can perform the operation for the light connection state.

- Store terminal context

- Save light connection status terminal identification information

- Perform some or all of the operations of the RRC IDLE terminal (eg, one or more of cell reselection, paging, and suspend radio resources)

Meanwhile, the base station may include additional configuration information for instructing the terminal to perform additional detailed operations in the light connection state.

If the UE receives the RRC Connection Reconfiguration message indicating the light connection state and suspends the radio resource according to the indication information, the UE can not transmit the RRC Connection Reconfiguration Complete message to the BS. For example, if the SRB for delivering an RRC message is suspended, it can not deliver the RRC signaling. Or if the MAC is reset, or if the radio configuration information of the cell is suspended, an RRC connection reconfiguration acknowledgment message can not be delivered to the base station.

2-1) Reconfiguring the RRC connection pointing to the light connection Reconfirmation of messages Embodiments that do not send messages

For example, the UE receiving the RRC connection reconfiguration message including the information for indicating the light connection may not transmit the RRC connection reconfiguration acknowledgment message to the base station.

2-2) Light Connection Upon receiving the RRC connection reconfiguration message instructing to send a reconfirmation confirmation message and transition to the light connection,

For example, the MS having received the RRC connection reconfiguration message including the information for indicating the right connection may first reply to the RRC connection reconfirmation confirmation message to the base station and then apply the right connection.

2-3) Example of transition to a light connection through a new RRC connection configuration message different from the RRC connection reconfiguration message

As an example, information for indicating a light connection may be received via a downlink RRC message that is distinct from the RRC connection reconfiguration message. This downlink RRC message may be defined as a message that does not require a success or acknowledgment message. The terminal can receive the downlink message and enter the light connection state.

The terminal does not need to forward acknowledgment or failure messages for this downlink RRC message to the base station.

2-4) An embodiment supporting some communication functions when receiving an RRC connection reconfiguration message indicating a light connection and applying the corresponding operation

For example, when a terminal that has received an RRC connection reconfiguration message including information for indicating a light connection transitions to a light connection state, a function for performing an operation for instructing an RRC connection reconfiguration confirmation message to the base station , L2 entity, and MAC maintenance) can be maintained for a predetermined time or until a predetermined criterion is satisfied.

2-5) Receive a RRC connection reconfiguration message indicating a light connection and place a timer when applying the corresponding action to indicate that the corresponding timer By connection Convert Example

As an example, a terminal receiving an RRC connection reconfiguration message including information for indicating a light connection may operate a timer for transition to a light connection. When the terminal receives an RRC connection reconfiguration message containing information for indicating a write connection, the terminal starts the corresponding timer. When the timer expires, it transitions to the light connection state. The UE may transmit an RRC connection reconfiguration acknowledgment message to the Node B until the timer expires.

light connection Status terminal identification information

As described above, the terminal in the light connection state does not perform the handover operation since it is not in the RRC connection state. Therefore, the light connection state terminal can perform the cell re-selection operation according to the movement of the terminal.

For this, even if the light connection state terminal moves, it must be able to identify the corresponding terminal in the network. In addition, when the terminal moves, the base station identification information and / or the cell identification information constituting the terminal in a light connection state may be required to process / 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.

One) Core network Store terminal identification information 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.

2) 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.

3) Store base station identification information and 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.

4) 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.

light connection State terminal Uplink Data or Signaling Transfer method

The terminal in the light connection state can perform the transition to the RRC connection state and transmit / receive data. To this end, the terminal in the light connection state performs a transition operation to the RRC connection state when the transition to the RRC connection state is triggered.

For example, when there is uplink data or signaling in the terminal in the light connection state (for MO data or MO signaling) or when the terminal in the light connection state receives the paging, the terminal switches from the cell to the RRC connection state (Or start transiting to RRC connection or transition to RRC connection state, hereinafter referred to as transition from the light connection state to the RRC connection state or transition to the RRC connection state).

Hereinafter, a specific procedure for transiting the terminal to the RRC connected state will be described by dividing an embodiment.

1) Using the RRC Connection request message Example

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

If the transition from the light connection state to the RRC connection state is triggered by the upper layer, and the upper layer has provided the S-TMSI, the value received from the upper layer by the UE identity (ue-Identity) can be set.

If a transition from the light connection state to the RRC connection 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 the light connection state to the RRC connection state is triggered by the upper layer, an establishment cause value corresponding to the information received from the upper layer may be set. The set cause value may mean information about a trigger cause in which a transition to the RRC connection state occurs. For example, the terminal can add information indicating a transition from the light connection state to the RRC connection state. As another example, the terminal may add information indicating a transition from the write connection state to the RRC connection state to the RRC Connection setup complete message.

If a transition from the light connection state to the RRC connection state is triggered in the AS, a value indicating the transition from the light connection state to the RRC connection state can be set as the setting cause value.

2) Using the RRC Connection re-establishment Request message Example

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

The terminal 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 UE sets the MAC-I to the calculated MAC-I 16 least significant bits.

The terminal may set a reestablishmentCause to a value indicating a transition from the right connection state to the RRC connection state.

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

3) Using the RRC Connection resume Request message Example

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.

If a transition from the light connection state to the RRC connection state is triggered by the upper layer, an establishment cause value corresponding to the information received from the upper layer may be set. The set cause value may include information about the cause of the transition to the RRC connection state being triggered. For example, the set cause value may include information indicating either a paging message reception, an origination data trigger, or an outgoing signaling trigger. For example, the terminal can add information indicating a transition from the light connection state to the RRC connection state. As another example, the UE may add information indicating a transition from the write connection state to the RRC connection state to the RRC Connection resume complete message.

If a transition from the light connection state to the RRC connection state is triggered in the AS, a value indicating the transition from the light connection state to the connection state can be set as the setting cause value.

The UE sets the MAC-I to the calculated MAC-I 16 least significant bits.

4) Embodiment using a new RRC Connection Request message using a common control channel

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

If a transition from the light connection state to the RRC connection state is triggered by the upper layer, an establishment cause value corresponding to the information received from the upper layer may be set. For example, the terminal can add information indicating a transition from the light connection state to the RRC connection state. As another example, the UE may add information indicating a transition from the write connection state to the RRC connection state to the RRC Connection resume complete message.

If a transition from the light connection state to the RRC connection state is triggered in the AS, a value indicating the light connection transition can be set to the setting cause value.

The UE sets the MAC-I to the calculated MAC-I 16 least significant bits.

As described above, the embodiments of the present invention allow less processing effort for terminals that perform frequent connection setups and allow more capacity to be used for network nodes. In addition, there is an effect that battery consumption of the terminal can be reduced.

Hereinafter, a configuration of a terminal and a base station capable of performing a part or all of the embodiments described with reference to FIG. 1 to FIG. 5 will be described with reference to the drawings.

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

6, the terminal 600 that changes the connection state includes a transmitter 620 that transmits terminal capability information indicating support of a light connection to a base station, And a controller 610 that performs an operation of changing the connection state of the terminal from the RRC connection state to the light connection state based on the instruction information and the reception unit 630 that receives the RRC message including the instruction information indicating the instruction have.

For example, the transmitting unit 620 may transmit information to the base station as to whether the corresponding terminal supports the light connection state. That is, the transmitter 620 can inform the base station that it supports the RRC connection, the RRC id, and the light connection state.

For example, the terminal capability information may be transmitted to the base station or the core network through the AS capability or the NAS capability. As another example, the terminal capability information may be included in terminal wireless connection capability or terminal core network capability. The transmitter 620 can transmit the terminal capability information to the base station through RRC signaling.

In addition, the transmitter 620 may transmit an RRC connection resumption request message to the base station requesting the terminal to change the connection state from the light connection state to the RRC connection state. The RRC connection resume request message may include the cause information that causes the state change trigger to the RRC connection state. The change of state to the RRC connection state can be triggered by the operation of either a paging message reception, an origination data trigger, and an outgoing signaling trigger.

The receiving unit 630 can receive the instruction information indicating the state transition from the base station to the light connection state through the RRC message. For example, the RRC message may be an RRC connection reconfiguration message or an RRC connection release message. Alternatively, the indication information may be included in a newly defined RRC message.

The control unit 610 stops all SRBs and DRBs for the base station upon receiving the instruction information for instructing the state change from the base station to the light connection state. However, unlike the RRC idle state, the controller 610 may store the terminal context. In this case, the base station also stores the terminal context for that terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception.

In addition, when the terminal in the light connection state moves, the control unit 610 can perform the cell reselection operation instead of the handover.

In addition, the receiver 630 receives downlink control information, data, and messages from the base station through the corresponding channel. Further, the controller 610 controls the overall operation of the terminal 600 related to the mutual transition operation between the light connection state and the RRC connected state. The transmitter 620 transmits uplink control information, data, and a message to the base station through the corresponding channel.

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

7, the BS 700 for changing the connection state of the MS includes a receiving unit 730 for receiving the MS capability information indicating that the MS supports the light connection state from the MS, A transmission unit 720 for transmitting an RRC message including instruction information for instructing a state change to a state, and a control unit 710 for changing the connection state from the RRC connection state to the light connection state, Refers to a state in which a connection state between a base station and a core network for a UE is maintained while all SRBs and DRBs of the UE are suspended.

The control unit 710 can confirm that the corresponding terminal supports the RRC connection, the RRC id, and the right connection state by receiving the terminal capability information from the terminal.

For example, the terminal capability information may be transmitted to the base station or the core network through the AS capability or the NAS capability. As another example, the terminal capability information may be included in terminal wireless connection capability or terminal core network capability. The receiving unit 730 can receive the terminal capability information through RRC signaling.

Transmitter 720 may transmit an RRC message to transition the terminal to the light connection state. For example, the RRC message may be an RRC connection reconfiguration message or an RRC connection release message. Alternatively, the indication information may be included in a newly defined RRC message.

The control unit 710 suspends all SRBs and DRBs for the terminal when the terminal transitions to the light connection state. However, unlike the RRC idle state, the controller 710 can store the terminal context of the corresponding terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception. Also, the control unit 710 can also control the transition to the RRC connection state for the terminals in the light connection state

Meanwhile, the receiving unit 730 may receive an RRC connection resume request message requesting a state change from the light connection state to the RRC connected state from the terminal. For example, when the transition to the RRC connection state for the terminal in the right connection state is triggered, the controller 710 can perform the RRC connection state transition operation of the corresponding terminal by receiving the RRC connection resume request message. As an example, the change of state to the RRC connection state may be triggered by either operation of either a paging message reception of the terminal, an origination data trigger, and an outgoing signaling trigger. Specifically, when a paging message for a terminal in the right connection state is transmitted, the terminal can perform a transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state. Or if the outgoing signaling to be transmitted from the terminal in the light connection state to the base station is triggered, the terminal can perform the transition operation to the RRC connected state. Meanwhile, the RRC connection resumption request message may include the cause information that causes the state change trigger to the RRC connection state. The cause information of the cause of the trigger may include information on whether it is due to the above-described paging, origination data trigger, or origination signaling trigger.

In addition, the control unit 710 controls the overall operation of the base station 700 to control the transition operation to the light connection state of the terminal and the transition to the RRC connection state from the light connection state necessary for performing the above-described embodiments .

The transmission unit 720 and the reception unit 730 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

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 a terminal to change a connection state,
Transmitting terminal capability information indicating that the terminal supports a light connection to a base station;
Receiving a Radio Resource Control (RRC) message including indication information for instructing a state change from the base station to a light connection state; And
And changing the connection state of the terminal from the RRC connection state to the light connection state based on the instruction information.

The method according to claim 1,
The light-
Wherein a state of connection between the base station and the core network for the MS is maintained while all Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs) of the MS are suspended.

The method according to claim 1,
The RRC message includes:
RRC connection reconfiguration message or an RRC connection release message.

The method according to claim 1,
The step of changing a connection state of the terminal may include:
(SRB) and a DRB (Data Radio Bearer) of the UE, and stores the UE context.

The method according to claim 1,
Further comprising the step of transmitting an RRC connection resumption request message to the base station requesting the terminal to change the connection status from the right connection state to the RRC connection state.

6. The method of claim 5,
The RRC connection resumption request message includes:
And a cause change cause information of a state change trigger to an RRC connection state.

6. The method of claim 5,
The state change to the RRC connection state may include:
Wherein the triggering is triggered by an operation of either a paging message reception, an origination data trigger, and an outgoing signaling trigger.

A method for a base station to change a connection state of a terminal,
Receiving from the terminal terminal capability information indicating that the terminal supports a light connection state;
Transmitting a Radio Resource Control (RRC) message including indication information for instructing a state change to a light connection state to the terminal; And
And changing the connection state from the RRC connection state to the light connection state,
The light-
Wherein a connection state between the base station and the core network for the MS is maintained, and all Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs) of the MS are suspended.

9. The method of claim 8,
Wherein the changing to the light connection state comprises:
Storing the terminal context of the terminal, and stopping all SRBs and DRBs with the terminal.

9. The method of claim 8,
The RRC message includes:
RRC connection reconfiguration message or an RRC connection release message.

9. The method of claim 8,
Further comprising receiving an RRC connection resumption request message from the terminal requesting a state change from a write connection state to the RRC connection state.

12. The method of claim 11,
The RRC connection resumption request message includes:
And cause information that causes a state change trigger to the RRC connection state.

In a terminal that changes a connection state,
A transmitter for transmitting terminal capability information indicating that the terminal supports light connection to a base station;
A receiving unit for receiving an RRC (Radio Resource Control) message including instruction information for instructing a state change from the base station to a light connection state; And
And changing a connection state of the terminal from the RRC connection state to the light connection state based on the instruction information.

14. The method of claim 13,
The light-
Wherein a state of connection between the base station and the core network for the MS is maintained, and all signaling radio bearers (SRBs) and data bearers (DRBs) of the MS are suspended.

14. The method of claim 13,
The RRC message includes:
An RRC connection reconfiguration message or an RRC connection release message.

14. The method of claim 13,
Wherein,
(SRB) and a DRB (Data Radio Bearer) of the UE, and stores the terminal context.

14. The method of claim 13,
The transmitter may further comprise:
Further comprising: an RRC connection resumption request message requesting a change of a connection state of the MS from a light connection state to the RRC connection state to the BS.

18. The method of claim 17,
The RRC connection resumption request message includes:
Wherein the trigger information includes cause information that causes a state change to an RRC connection state.

18. The method of claim 17,
The state change to the RRC connection state may include:
Wherein the triggering is triggered by an operation of either a paging message reception, an origination data trigger, and an outgoing signaling trigger.

A base station for changing a connection state of a terminal,
A receiving unit for receiving, from a terminal, terminal capability information indicating that the terminal supports a light connection state;
A transmitter for transmitting an RRC (Radio Resource Control) message including instruction information for instructing a state change to a light connection state to the terminal; And
And a control unit for changing a connection state from the RRC connection state to the light connection state,
The light-
Wherein a connection state between the base station and the core network for the MS is maintained, and all Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs) of the MS are suspended.

21. The method of claim 20,
Wherein,
Storing the terminal context of the terminal, and stopping all SRBs and DRBs with the terminal.

21. The method of claim 20,
The RRC message includes:
RRC connection reconfiguration message or an RRC connection release message.

21. The method of claim 20,
The receiver may further comprise:
Further comprising an RRC connection resumption request message requesting a change of state from the terminal to the RRC connection state in the light connection state.

24. The method of claim 23,
The RRC connection resumption request message includes:
And a cause information for causing a state change trigger to the RRC connection state.