WO2014148746A1

WO2014148746A1 - Method and apparatus for transmitting small amount of data

Info

Publication number: WO2014148746A1
Application number: PCT/KR2014/001665
Authority: WO
Inventors: 홍성표
Original assignee: 주식회사 케이티
Priority date: 2013-03-21
Filing date: 2014-02-28
Publication date: 2014-09-25

Abstract

The present invention relates to a method and an apparatus for transmitting a small amount of data between a terminal and a base station in a short lived connection type or a connectionless type. A method for transmitting a small amount of data by a terminal comprises the steps of transmitting a RRC connection request message, which includes small-amount data indication information, to a base station; receiving a RRC connection setup message, which includes radio bearer configuration information for small-amount data transmission, from the base station; configuring a data radio bearer for small-amount data transmission based on the radio bearer configuration information; transmitting a RRC connection setup complete message, which includes setup complete information for small-amount data transmission, to the base station; and transmitting a small amount of data to the base station via the data radio bearer.

Description

Method and apparatus for small data transfer

The present invention relates to a method and apparatus for transmitting a small amount of data in a short lived connection or a connectionless method between a terminal and a base station.

As communication systems have evolved, consumers, such as businesses and individuals, have used a wide variety of wireless terminals.

Currently, mobile communication systems such as Long Term Evolution (LTE) and LTE-Advanced of the 3GPP series require high-speed large-capacity communication systems capable of transmitting and receiving various data such as video and wireless data, beyond voice-oriented services.

In addition, as various types of communication such as, for example, Machine Type Communication (MTC) communication have been developed, the necessity of frequently transmitting and receiving a small amount of data periodically or aperiodically is emerging.

Accordingly, there is an increasing demand for a method and apparatus for efficiently communicating while reducing signaling load of a terminal and a base station in accordance with a frequently transmitted and received form of a small amount of data.

In accordance with the above-described demands, the present invention proposes a method and apparatus for transmitting a small amount of data in a short connection method or a connection-free method.

In addition, the present invention proposes a specific method and apparatus for the terminal to transmit a small amount of data according to a short connection scheme to reduce the signaling load of the terminal and the base station.

In order to solve the above-mentioned problems, the present invention provides a method for transmitting small amount of data by a terminal, the method comprising: transmitting an RRC connection request message including a small amount of data indication information to a base station and transmitting a small amount of data from the base station; Receiving an RRC connection setup message including radio bearer configuration information for configuring and configuring a data radio bearer for transmitting a small amount of data based on the radio bearer configuration information and the base station A method includes transmitting an RRC connection setup complete message including setup completion information for a small amount of data transmission, and transmitting a small amount of data to a base station through a data radio bearer.

The present invention also provides a method for controlling a small amount of data transmission by a base station, the method comprising: receiving an RRC connection request message including a small amount of data indication information from a terminal and configuring a radio bearer for small amount of data transmission; A RRC connection setup complete message including generating information and transmitting an RRC connection setup message including radio bearer configuration information and setup completion information for a small amount of data transmission. And receiving the small amount of data via a data radio bearer configured based on the radio bearer configuration information.

The present invention also provides a transmitter for transmitting an RRC connection request message including a small amount of data indication information to a base station and an RRC connection setup including radio bearer configuration information for transmitting a small amount of data from the base station. A receiver configured to receive a message and a controller configured to configure a data radio bearer for transmitting a small amount of data based on the radio bearer configuration information, wherein the transmitter comprises an RRC including setup completion information for transmitting a small amount of data to the base station; Provided is a terminal apparatus for transmitting a connection setup complete message and transmitting a small amount of data to a base station through a data radio bearer.

The present invention also provides a receiver for receiving an RRC connection request message including a small amount of data indication information from a terminal, a control unit for generating radio bearer configuration information for small amount of data transmission, and an RRC including radio bearer configuration information. A transmitter for transmitting a connection setup (RRC connection setup) message, wherein the receiver receives an RRC connection setup complete message including setup completion information for a small amount of data transmission, and based on radio bearer configuration information; It provides a base station apparatus for further receiving a small amount of data through the configured data radio bearer.

When applying the present invention, there is an effect that the terminal provides a method and apparatus for transmitting a small amount of data in a short connection or no connection method.

In addition, when applying the present invention, there is an effect that can reduce the signaling load of the terminal and the base station in transmitting a small amount of data.

1 is a diagram illustrating a service request procedure for data transmission between a terminal and a base station in an existing wireless communication network.

2 is a diagram schematically illustrating a structure of an MTC communication network to which the present invention may be applied.

3 is a diagram illustrating a small amount of data transmission procedure according to an embodiment of the present invention.

4 is a diagram illustrating an information field of an RRC connection request message that may include a small amount of data indication information according to another embodiment of the present invention.

FIG. 5 is a diagram illustrating an information element of an RRC connection request message that may include small amount of data indication information according to another embodiment of the present invention.

6 is a diagram illustrating an example of an information element of an RRC connection setup message that may include radio bearer configuration information according to another embodiment of the present invention.

7 is a diagram illustrating an information element of data radio bearer dedicated radio resource configuration information that may be included in radio bearer configuration information according to another embodiment of the present invention.

8 is a diagram illustrating an information element of an RRC connection setup complete message transmitted to a base station according to another embodiment of the present invention.

9 is a flowchart illustrating the operation of a terminal according to another embodiment of the present invention.

10 is a flowchart illustrating the operation of a base station according to another embodiment of the present invention.

11 is a diagram illustrating a small amount of data transmission procedure including small amount of data transmission timer information according to another embodiment of the present invention.

12 is a diagram illustrating a small amount of data transmission procedure according to another embodiment of the present invention.

13 is a diagram illustrating a small amount of data transmission procedure according to another embodiment of the present invention.

14 is a diagram illustrating a small amount of data transmission procedure according to another embodiment of the present invention.

15 is a diagram illustrating a small amount of data transmission procedure according to another embodiment of the present invention.

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

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

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system includes a user equipment (UE) and a base station (Base Station, BS, or base station). In the present specification, a user terminal is a comprehensive concept of a terminal in wireless communication. In addition to user equipment (UE) in WCDMA, LTE, and HSPA, as well as MS (Mobile Station), UT (User Terminal), SS in GSM, It should be interpreted as a concept that includes a subscriber station, a wireless device, and the like.

A base station or cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, a sector, a site, and a BTS. It may be called other terms such as a base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and the like.

In other words, in the present specification, a base station or a cell is a generic meaning representing a partial area or function covered by a base station controller (BSC) in CDMA, a Node-B in WCDMA, a base station or sector (site) in LTE, and the like. It should be interpreted as, and it is meant to cover all the various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU communication range.

In the present specification, the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to. The user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to. Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques 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-TDMA, OFDM-CDMA Can be used. One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

In addition, in systems such as LTE and LTE-Advanced, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers. Uplink and downlink transmit control information through control channels such as Physical Downlink Control CHannel (PDCCH), Physical Control Format Indicator CHannel (PCFICH), Physical Hybrid ARQ Indicator CHannel (PHICH), and Physical Uplink Control CHannel (PUCCH). A data channel is configured such as PDSCH (Physical Downlink Shared CHannel), PUSCH (Physical Uplink Shared CHannel) and the like to transmit data.

In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

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

The multiple transmit / receive point is at least one having a base station or a macro cell (hereinafter referred to as a “base station”) and a high transmission power or a low transmission power in the macro cell region, which is wired controlled by an optical cable or an optical fiber to the base station. May be RRH.

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

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

The base station performs downlink transmission to the terminals. The base station includes downlink control information such as a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission, and scheduling required for reception of the PDSCH and an uplink data channel (eg, For example, a physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission on a physical uplink shared channel (PUSCH) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

In the Long Term Evolution (LTE) mobile communication network, data transmission to a terminal in an IDLE state is provided through a service request procedure of a Non Access Stratum (NAS) layer.

In the process of performing the service request procedure, the terminal performs a process of performing a random access procedure to the base station.

In the process of performing the random access procedure, the UE and the base station exchange at least seven RRC signaling messages through an RRC connection establishment, security activation, and RRC connection reconfiguration procedure. If the aforementioned at least seven times of signaling are for one small amount of data packet transmission, such signaling may be considered inefficient.

In particular, a small amount of data (for example, keep-alive, heartbeat data, etc.) periodically generated by the mobile application within the terminal may repeatedly generate an inefficient signaling by repeating the transition between the IDLE state and the CONNECTED state. have.

In addition, periodic small amount of data transmission by a large-scale machine type communication (MTC) terminal may cause signaling load on the terminal and the base station.

Referring to FIG. 1, the terminal 101 in the conventional IDLE state performs a plurality of procedures to transmit data to the base station 102.

In more detail, for example, the terminal 101 transmits an RRC connection request message to the base station 102 (S110). In this process, the terminal 101 requests an RRC connection for data transmission.

Thereafter, the base station 102 transmits an RRC connection setup message including information necessary for the terminal 101 to establish an RRC connection with the base station 102 (S120).

The terminal 101 receives an RRC connection setup message, establishes an RRC connection with the base station 102, and transmits an RRC connection setup complete message (S130).

The base station 102 transmits a security mode command message for security activation to the terminal 101 (S140).

The terminal 101 activates security based on the received security mode command message and transmits a security mode complete message (S150).

After completing the security activation, the base station 102 transmits an RRC connection reconfiguration message (S160) in order to perform the RRC connection reconfiguration procedure.

After performing the RRC connection reconfiguration, the terminal 101 transmits an RRC connection reconfiguration complete message (S170).

After a plurality of signaling transmission and reception steps as described above, the terminal 101 can transmit data to the base station 102.

Accordingly, there is a problem in that a plurality of signaling procedures as described above should be performed in the case of a terminal that frequently transmits a small amount of data. This problem may cause signaling loads of the base station and the terminal, and there is also a problem of rapidly consuming the power of the terminal.

In particular, as described above, in the case of a machine type communication (MTC) terminal requiring frequent transmission of a small amount of data, the problem may be further increased.

Machine type communication (MTC) is a form of data communication that refers to machine or machine communication in which one or more entities do not necessarily require human interaction.

MTC, which does not require human interaction, refers to all communication methods in which communication is performed without human intervention in the communication process. Meanwhile, the MTC may be applied to various business areas, and the communication quality required by these business areas may vary. In particular, devices do not always require to be connected to a communication network, and information transmitted and received may also be transmitted and received with a predetermined pattern, and data may be transmitted and received without a pattern. In addition, a small amount of data may be frequently transmitted periodically or aperiodically according to the transmission and reception pattern.

The MTC may intermittently communicate or transmit and receive data at lower priority within the network, depending on the business area to which it applies. On the other hand, the MTC terminal does not always maintain a communication connection state, but has a time control attribute. Therefore, a time other than the time for transmitting and receiving data can maintain the IDLE state, and if a small amount of data is frequently transmitted and received, there is a problem in that the above-described procedure for transmitting and receiving data is frequently performed.

Referring to FIG. 2, the MTC terminal 210 may perform communication between an MTC server and a device through a wireless network of a mobile communication service provider. An example of such an MTC terminal is an electricity meter or vending machine equipped with a mobile communication module.

The MTC IWF (Interworking function, or MTC-IWF, 220) controls functions such as relaying or converting signaling, authorization of an MTC server, and authorization of a control message to perform a terminal triggering function at the request of the MTC server 215. Can be performed.

The MTC server (MTC Server) 215 may communicate with the MTC terminal through a wireless network of the mobile communication operator to control the MTC terminal and collect data of the MTC terminal.

The MTC terminal 210 uses a mobile communication network for communication with the MTC server 215, for example, an LTE network may be used. As described above, the MTC terminal 210 may periodically transition from the IDLE mode to the connected mode to communicate with the MTC server 215. Therefore, in case of the MTC terminal 210 which frequently transmits a small amount of data, there may be a problem in that the above-described multiple access procedure steps need to be performed.

As a solution to solve this problem, a method of transmitting a small amount of data in a short lived connection or a connectionless method may be proposed.

The short data transmission method of the short connection method or the connectionless method described above is a method for delivering a small amount of data through a user plane without excessive signaling procedures caused by the idle-connected state transition.

According to this method, the network provides the terminal with information about the PDN connection or the end-point of its bearer, and forwards this information to the base station in addition to the small amount of data to be sent on the uplink. The base station uses the added information to generate a GPRS Tunneling Protocol User Plane (GTP-U) Packet Data Unit (PDU) and delivers the small amount of data to the S-GW over the S1-U interface.

The S-GW may deliver the received uplink packet through the existing S-GW operation.

When transmitting a small amount of data through a short lived connection or a connectionless method without a transition of the IDLE state and the CONNECTED state between the terminal and the base station as described above, RRC signaling is required.

However, in the current RRC layer of the LTE network, the terminal in the IDLE state has to transition from the IDLE state to the CONNECTED state through the RRC connection establishment procedure in order to transmit user plane data.

Therefore, the current LTE network cannot transmit a small amount of data using the short lived connection or the connectionless method without a transition from the IDLE state to the CONNECTED state.

In other words, the existing LTE mobile communication network has a problem that can cause excessive signaling between the terminal and the base station to transmit a small amount of data. To solve this problem, a short lived connection or a connectionless method of transmitting a small amount of data has a problem that cannot be processed through RRC signaling of an existing LTE mobile communication network.

In order to solve the above problems, the present invention provides an RRC signaling method and apparatus between a terminal and a base station required for transmitting a small amount of data in a short lived connection or connectionless method in an LTE mobile communication network.

In order to transmit a small amount of data in the short connection method or the connectionless method of the present invention, the terminal identifies identification information (eg, SGW information, Tunnel Endpoint ID) of an end point of the PDN connection or its bearer through the network. Can be provided. Then, if the base station detects user inactivity for a predetermined time, the base station sends an RRC Connection Release message to the terminal and the terminal transitions to the IDLE state.

The terminal may be configured to transmit a small amount of data in the above short connection or no connection method in the IDLE state.

In addition, the terminal may receive timer information related to a small amount of data transmission time through a short connection method or a connectionless method. The contents related to the timer information of the terminal will be described in more detail with reference to FIG. 11.

Hereinafter, the small data transmission method of the present invention will be described in detail according to each embodiment.

The RRC signaling procedure of the short connection method or the connectionless method may be implemented according to various embodiments as follows.

First embodiment: A method for establishing a short or no connection radio bearer (RB) for small data transmission in IDLE mode.

In a method for transmitting a small amount of data, a terminal according to an embodiment of the present invention includes transmitting an RRC connection request message including a small amount of data indication information to a base station and wirelessly transmitting the small amount of data from the base station. Receiving an RRC connection setup message including data radio bearer configuration information and configuring a data radio bearer for small amount of data transmission based on the radio bearer configuration information. And transmitting an RRC connection setup complete message including setup completion information for transmitting a small amount of data to the base station, and transmitting a small amount of data to the base station through a data radio bearer.

In addition, the base station according to an embodiment of the present invention in the method for controlling a small amount of data transmission of the terminal, receiving an RRC connection request (RRC connection request) message including a small amount of data indication information from the terminal and a small amount of data transmission Generating an RRC connection setup message for generating radio bearer configuration information for the RRC connection and including an RRC connection setup message including radio bearer configuration information, and RRC connection setup completion including setup completion information for a small amount of data transmission; and receiving a small amount of data through the data radio bearer configured based on the radio bearer configuration information.

Referring to FIG. 3, the terminal 301 according to the first embodiment of the present invention transmits a small amount of data by a short connection without a transition from an IDLE state to a CONNECTED state or transmits a small amount of data to the base station 302 according to a method without a connection. Can be.

Specifically, when the terminal 301 configured to transmit a small amount of data in a short connection or no connection method is in an IDLE state, data satisfying a certain small amount of data criteria in an upper layer (for example, a NAS or an application layer). Upon determining the transmission, the terminal may initiate a procedure for transmitting a small amount of data.

The terminal 301 determines the small amount of data transmission and transmits the small amount of data indication information to the base station 302 by including the small data indicator in the RRC connection request message (S310).

The base station 302 receives the RRC connection request message including the small amount of data indication information from the terminal 301 to determine the small amount of data transmission, and generates radio bearer configuration information for the small amount of data transmission (S320). Thereafter, an RRC connection setup message including the generated radio bearer configuration information is transmitted to the terminal 301 (S330).

The terminal 301 configures a radio bearer for small amount of data transmission based on the radio bearer configuration information included in the RRC connection setup message (S340).

The terminal 301 transmits an RRC connection setup complete message to the base station 301 (S350).

Thereafter, the terminal 301 may transmit a small amount of data to the base station 302 through a short connection or no connection method (S360).

Hereinafter, each step described above with reference to FIGS. 4 to 8 will be described in more detail.

The terminal may transmit an RRC Connection Request message to the base station for transmitting a small amount of data.

The RRC connection request message according to an embodiment of the present invention may be transmitted to the base station by including a small amount of data indication information (Small data indicator) in the setting cause field.

The small amount of data indication information may indicate information indicating that the small amount of data is to be transmitted in a short connection or no connection. Or, it may indicate that the small amount of data of the above-mentioned specific criterion exists to request the transmission.

Alternatively, the RRC connection request message according to an embodiment of the present invention may further include at least one or more information of establishment cause information including UE identifier information and small amount of data indication information. can do.

For example, with reference to FIG. 4, the RRC connection request message transmitted by the UE may include fields 401 to 410.

The small amount of data indication information for the small amount of data transmission described above may be included in the setting cause field 401 as one of the setting cause values. Alternatively, it may be included in a separate small amount of data indication field 415 or may be included as an information element in at least one field of the terminal identification field 410.

The terminal identifier information may include identification information (eg, S-TMSI, random value) of the terminal and may be included in the terminal identification field 410 and transmitted. Alternatively, when the RRC connection is set up for a small amount of data transmission through a short connection or no connection, the terminal identification information may include information about an end point of the PDN connection or its bearer. The setting cause information may include information that the setting cause is a request for small amount of data transmission, and may be included in the setting cause field 401 and transmitted.

FIG. 5 is a diagram illustrating an example of an RRC connection request message and indicates information elements of each field described with reference to FIG. 4.

For example, the aforementioned terminal identifier information may be included in the ue-Identity information element of the RRCConnectionRequest field and transmitted. In addition, the setting cause information may be included in the establishmentCause information element. Or it may be included in the EstablishmentCause field.

The small data indicator may be added as one information element to each field shown in FIG. 5 and transmitted, or may be transmitted as included as a value (Establishment = small data) in the establishmentCause information element. Alternatively, a small amount of data indication field may be added as a new field.

The terminal may transmit a separate RRC message that can be newly defined as a base station for small data transmission.

In order for the terminal to transmit the RRC connection request message, the MAC layer in the terminal performs a random access procedure. If the terminal reselects the cell during the random access procedure, the RRC layer in the terminal may inform the upper layer that the aforementioned small amount of data transmission procedure has failed.

When the base station receives the RRC connection request message for the small amount of data transmission including the small amount of data indication information from the terminal, the base station generates the radio bearer configuration information for the small amount of data transmission or sets the radio bearer configuration information preset for small amount of data Can be called

The above-described preset radio bearer configuration information may be configured when the base station and the terminal are initially configured to transmit a small amount of data in a short connection or no connection in a network registration process (eg, an attach procedure) (eg, a PDN connectivity procedure). , attach procedure) The applied radio bearer configuration information may be used, or may be used as radio bearer configuration information for transmitting a small amount of data in a short connection method or a connectionless method set by a local configuration. A radio bearer for transmitting a small amount of data in a short connection or no connection may not include an AS security configuration. Alternatively, the above-described preset radio bearer configuration information may include configuration information applied to the last used DRB or the non-GBR bearer, or configuration information applied to the DRB used after the AS security was last activated. Can be used.

In addition, the radio bearer configuration information according to an embodiment of the present invention may be included in dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.

The procedure for small data transmission in a short connection or no connection manner may include a radio bearer configuration.

Specifically, the above-described radio bearer may be Signaling Radio Bearer 1 (SRB1).

Here, signaling radio bearers (SRBs) may be defined as radio bearers used to transmit radio resource control (RRC) and non-access stratum (NAS) messages as follows.

SRB0: SRB for RRC message using Common Control Channel (CCCH) logical channel.

SRB1: This is an SRB that uses a Dedicated Control Channel (DCCH) logical channel for both RRC and NAS messages before setting up SRB2.

SRB2: For both RRC and NAS messages, both SRBs that use DCCH logical channels can always be configured after security activation.

Alternatively, the above-described radio bearer may be a new type of SRB for short data transmission in a short connection or no connection without transition from IDLE state to CONNECTED state.

A new type of SRB may use a CCCH logical channel, a DCCH logical channel, or a new type of logical channel as a signaling radio bearer for transmitting a small amount of data in a short connection or no connection.

The new type of logical channel may be, for example, a channel for a terminal without an RRC connection, but a logical channel having a lower priority in logical channel prioritization (LCP) processing than the CCCH. Or it may be a new channel for temporary RRC connection of a short connection or no connection.

In another method, the above-described procedure for transmitting a small amount of data in a short connection or a connectionless manner may be performed in addition to a signaling radio bearer configuration. Radio Bearer (DRB) configuration may be included.

After generating the radio bearer configuration information, the base station according to an embodiment of the present invention transmits an RRC connection setup message including radio bearer configuration information to the terminal.

In addition, the radio bearer configuration information according to an embodiment of the present invention may include dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.

Specifically, for example, when the base station determines to accept the request by receiving the aforementioned RRC connection request message, the base station may transmit an RRC connection setup message to the terminal.

The above-described RRC connection setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal for SRB1 configuration.

Alternatively, the RRC connection setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied for the new SRB configuration to the terminal.

As another method, the RRC connection setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to configure a data radio bearer (DRB) for transmitting a small amount of data in a short connection or no connection to the terminal.

Referring to FIG. 6, the radio bearer dedicated radio resource configuration information may be included in a RadioResourceConfigDedicated information element or may be included in an additional information element.

Specifically, the dedicated radio resource configuration information included in the RRC connection setup message is applied wirelessly when the base station and the terminal are initially configured to transmit a small amount of data in a short connection method or a connectionless method (for example, a PDN connectivity procedure and an attach procedure). It is possible to use radio bearer configuration information that is set up to use the bearer configuration information or to transmit a small amount of data in a short connection or no connection by local configuration. A radio bearer for transmitting a small amount of data in a short connection or no connection may not include an AS security configuration.

Alternatively, the dedicated radio resource configuration information may use radio bearer configuration information applied to the DRB used last of the DRB or non-GBR bearer last used for the terminal.

Alternatively, the dedicated radio resource configuration information may use radio bearer configuration information applied to the DRB used after the AS security was last activated.

Alternatively, the RRC connection setup message may include SRB1 (or a new SRB) for short data transmission or a short connectionless connection to the UE and dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied for DRB configuration. .

Alternatively, the dedicated radio resource configuration information may be information generated by a value set by default for a small amount of data transmission.

For example, with reference to FIG. 7, the data radio bearer dedicated radio resource configuration information may include an SRB-ToAddMod field and a DRB-ToAddMod field as shown in FIG. 7.

In addition, each field may include information elements such as EPS bearer identification information and DRB identification information as shown in FIG. 7.

The terminal may receive the RRC connection setup message and configure the data radio bearer based on the radio bearer configuration information included in the RRC connection setup message.

In detail, the terminal may stop the cell reselection process by receiving the aforementioned RRC connection setup message and entering the RRC CONNECTED state based on the radio bearer configuration information included in the message.

A terminal according to an embodiment of the present invention may operate in an RRC connected (RRC_CONNECTED) state and a NAS idle (NAS_IDLE) state while a small amount of data transmission through a data radio bearer is maintained.

That is, the terminal enters the RRC CONNECTED state during the small amount of data transmission procedure and stops the reselection process. However, in a higher layer (e.g., NAS or application), a small amount of data transfer procedure is not performed through the existing initial NAS message (e.g., Service Request), so that a higher layer (e.g., NAS) between the terminal and the MME is not performed. ) May be maintained in the ECM-IDLE state.

Alternatively, if a small data transfer procedure is performed at an upper layer (e.g., a NAS or an application) through an existing initial NAS message (e.g., Service Request), the upper layer (e.g., NAS) may enter the ECM-CONNECTED state.

Alternatively, the terminal receives the RRC connection setup message and applies the configuration included in the message, but may maintain the RRC IDLE state when a procedure for transmitting a small amount of data in a short connection or no connection method is started. Accordingly, the terminal may continue the cell reselection process. Alternatively, the terminal may temporarily stop the cell reselection process during the small amount of data transmission procedure.

The terminal may configure SRB1 according to the radio bearer configuration information included in the RRC connection setup message.

Alternatively, the terminal may configure a new SRB or DRB (eg, DRB-ToAddMod) according to the radio bearer configuration information included in the RRC connection setup message.

Alternatively, the SRB1 (or the new SRB) and the DRB may be configured according to the radio bearer configuration information included in the RRC connection setup message.

As described above, the terminal configures the data radio bearer based on radio bearer configuration information or dedicated radio resource configuration information included in the RRC connection setup message.

The RRC setup message described above may be a new RRC message that includes radio bearer configuration information.

Thereafter, the terminal transmits an RRC connection setup complete message to the base station in response to the RRC connection setup message.

The terminal configures SRB1 (or new SRB) and / or DRB based on the radio bearer configuration information included in the aforementioned RRC connection setup message, and then transmits an RRC connection setup complete message to the base station.

As illustrated in FIG. 8, the UE transmits an RRC connection setup complete message including information indicating setup for the small amount of data transmission and setup radio bearer related information to the base station.

Alternatively, the aforementioned RRC connection setup message may be a new RRC message including setup completion information for small amount of data transmission.

The terminal transmits a small amount of data that satisfies a specific small amount of data criteria to the base station through a short or no connection radio bearer.

The operation of the terminal according to an embodiment of the present invention described above will be described in detail with reference to FIG. 9.

The terminal according to an embodiment of the present invention transmits an RRC connection request message including a small amount of data indication information to the base station for transmitting a small amount of data (S910).

The small amount of data indication information may be included in an additional field of the RRC connection request message or may be added as an value of an additional information element to an existing field.

In addition, the terminal according to an embodiment of the present invention may include at least one or more information of the terminal identifier information and the small data transmission setting source information in the RRC connection request message.

The terminal receives an RRC connection setup message including radio bearer configuration information to the base station (S920).

The RRC connection setup message may include radio bearer configuration information for a small amount of data transmission, and the radio bearer configuration information may include dedicated radio resource configuration information for data radio bearer configuration. Alternatively, as described above, information required for SRB1 or new SRB configuration may be included.

The dedicated radio resource configuration information may include a data radio bearer value previously configured in the terminal or configured for small amount of data transmission.

The terminal configures and activates a radio bearer for small data transmission based on the received RRC connection setup message (S940).

Thereafter, the terminal transmits an RRC connection setup complete message including the configured data radio bearer (DRB) or signal radio bearer (SRB) related information and RRC setup completion information to the base station (S940).

The terminal transmits a small amount of data to the base station using the configured bearer (S950).

The present invention described above will be described with reference to the operation of the base station.

Referring to FIG. 10, the base station receives an RRC connection request message including a small amount of data indication information from the terminal (S1010). Based on the received RRC connection request message including the small amount of data indication information, the base station determines whether to configure a radio bearer, and generates radio bearer configuration information (S1020).

The radio bearer configured as described above may be SRB1 or new SRB and / or DRB.

The base station transmits an RRC connection setup message including the generated radio bearer configuration information (S1030). The radio bearer configuration information may include dedicated radio resource configuration information for data radio bearer configuration. Alternatively, dedicated radio resource configuration information for SRB1 or new SRB configuration may be included. Alternatively, dedicated radio resource configuration information for configuring the DRB and SRB1 (or a new SRB) may be included.

The base station may receive an RRC connection setup complete message from the terminal (S1040), and may receive a small amount of data from the terminal (S1050).

The terminal 1101 according to an embodiment of the present invention includes an upper layer including a small amount of data transmission timer information related to a time for transmitting a small amount of data from the base station 1102 before the RRC connection request message transmission step. Receiving the signaling may further include (S1100).

For example, with reference to FIG. 11, the terminal receives small amount of data transmission timer information including information on a time when small amount of data can be transmitted (S1100).

Thereafter, the terminal transmits the RRC connection request message described above (S1110), receives the RRC connection setup message (S1130), configures a radio bearer (S1140), and transmits an RRC connection setup complete message (S1150).

In transmitting the small amount of data to the base station 1102 (S1160), the terminal 1101 may use the small amount of data transmission timer information described above.

For example, after the RRC signaling (S1110 to S1150) for initiating a procedure for transmitting a small amount of data in a short connection or a connectionless manner, the time for transmitting a small amount of data through a radio bearer in a short or connectionless manner is It may be the same time as the enabled time of the aforementioned short connection method or no connection method. Alternatively, the time may be different from each other.

If the amount of time that a small amount of data can be transmitted through a short connection or no connection radio bearer is different from the enabled time of a short connection or no connection method, the small amount of data through the radio bearer When the transmittable time ends, it may fall within the enabled time of the aforementioned short connection method or connectionless method. In this case, a small connection or a connectionless data transmission can be performed through RRC signaling for initiating a procedure for a small connection or a connectionless data transmission.

After the RRC signaling, the UE may transmit a small amount of data through a radio bearer of a short connection or no connection method, using an RRC connection release message, an RRC reconfiguration message, or an RRC connection setup. Can be set by message or local configuration.

With respect to the small amount of transmission time briefly described above will be described in more detail with respect to the transmission time setting method below.

The terminal may initiate RRC signaling for using a short connection method or a connectionless method for data transmission that satisfies a specific small amount of data criteria. A possible time for transmitting a small amount of data to the terminal in the IDLE state in the above-described short connection method or no connection method can be set as follows.

Hereinafter, a method of setting a small amount of data transmission time using a short connection method or a connectionless method will be described.

1. How to set up using RRC Connection Release message.

The time when a terminal configured to transmit a small amount of data in a short connection method or a connectionless method in the IDLE state can transmit a small amount of data using a short connection method or a connectionless method is set through an RRC connection release message. Can be.

That is, the base station may include information on a time (for example, small data enabled timer) capable of transmitting a small amount of data in a short connection or no connection in an IDLE state in an RRC connection release message.

The UE transitioned to the IDLE state through the RRC connection release message starts a time timer capable of transmitting a small amount of data. If the short data transfer method described above is performed before the timer expires, a short time data transfer method for short data transfer is restarted.

2. How to set up using RRC Connection Reconfiguration messages.

The time when a terminal configured to transmit a small amount of data by using a short connection method or a connectionless method in the IDLE state can transmit a small amount of data by using a short connection method or a connectionless method is set through an RRC connection reconfiguration message. Can be.

That is, the base station may include information on a time (for example, small data enabled timer) for transmitting a small amount of data in a short connection or no connection in an IDLE state in an RRC connection reconfiguration message.

The UE transitioned to the IDLE state through the RRC connection release message starts a time timer capable of transmitting a small amount of data. In the case of performing a short connection or a small amount of data transmission before the timer expires, the timer for restarting a small amount of data is restarted.

3. How to apply small data transfers with short or no connection whenever configured.

When the terminal is configured to transmit a small amount of data in the above-described short connection method or no connection method in the IDLE state, the terminal may always be able to transmit a small amount of data using a short connection method or a connectionless method.

That is, the terminal receives information for configuring to not transmit a small amount of data in a short connection method or a connectionless method in the IDLE state, or a general RRC connection that does not transmit a small amount of data in a short connection method or a connectionless method in the IDLE state. After setting, if the device transitions to the IDLE state, the small amount of data is not transmitted in the above-described manner in the IDLE state. In this case, the RRC connection configuration by the existing service request procedure can be used.

Accordingly, as described above, in order to release the radio bearer set up after the RRC connection setup, the base station receives an RRC connection setup complete message and then operates an inactivity timer. The bearer can be released. That is, it is possible to release the radio bearer without transmission for a certain time.

Hereinafter, a description will be given with respect to encryption of a small amount of data transmitted according to an embodiment of the present invention.

The terminal according to an embodiment of the present invention may not apply encryption to a small amount of data transmitted to the base station (for example, applying encryption between the terminal and the S-GW).

Alternatively, when the terminal continues to be located in the base station to which the last RRC connection is established, the terminal may be used when applying an existing encryption key (eg, K _UPenc ) between the base station.

To this end, the terminal and the base station configured to transmit a small amount of data in a short connection method or a connectionless method according to an embodiment of the present invention described above in the IDLE state are encrypted during a enabled time of a short connection method or a connectionless method. A key and an associated UE context can be maintained.

In addition, the UE identifier (ue-Identity) of the RRC connection request message may use the C-RNTI to check whether the terminal continues to be located in the base station that established the last RRC connection.

Alternatively, the UE identifier (ue-Identity) of the RRC connection request message may use an S-TMSI or a random number, such as the UE identifier included in the existing RRC connection request message.

When a terminal moves out of a base station (or cell) that has established a last RRC connection, the new base station (or cell) has an existing encryption key (e.g., K _UPenc ) and related terminal context (or PDCP configuration information) can be inquired to apply encryption.

Or a new base station (or cell) _{shares an} existing encryption key (eg, K _UPenc ) and associated terminal context (or PDCP configuration information) between the base station (or cell) that established the last RRC connection and the terminal-base station. You can also apply.

To this end, the terminal and the base station configured to transmit a small amount of data in the above-described short connection or no connection method in the IDLE state, the encryption key and the associated UE context (UE Context) during the enabled time of the short connection or connectionless method ) Can be maintained.

Second Embodiment: Method 2 for Setting Up a Short or No Connection Radio Bearer for Small Data Transmission in IDLE Mode 2.

12 shows another example of an RRC signaling procedure for transmitting a small amount of data in a short connection or no connection method according to the present invention.

The purpose of this procedure is to transfer small amount of data by short connection without transition from IDLE state to CONNECTED state or small amount of data transmission without connection.

The procedure for a small amount of data transmission in a short connection or no connection method according to the present invention may include a radio bearer setup.

The aforementioned radio bearer may be SRB1. In this case, the message transmitted through the radio bearer may transmit a small amount of data through an RRC connection setup complete message or a new RRC message.

Alternatively, the radio bearer may be a new type of SRB for transmitting a small amount of data in a short connection or no connection without a transition from the IDLE state to the CONNECTED state.

The new type of SRB is a signaling radio bearer for short data connection or small amount of data transmission. The CCB logical channel or the DCCH logical channel or the new type of logical channel may be used. For example, a new type of logical channel may be a channel for a terminal without an RRC connection, but may mean a new channel for a temporary RRC connection of a logical channel prioritization (LCP) or a short connection or no connection method compared to a CCCH.

Alternatively, the above-described procedure for transmitting a small amount of data in a short connection or a connectionless manner may include setting up a data radio bearer for transmitting a small amount of data in a short connection or a connectionless manner.

A small amount of data transmission method according to another embodiment of the present invention will be described with reference to FIG. 12.

1) When a terminal configured to transmit a small amount of data in a short connection or no connection method is in an IDLE state, when the upper layer (for example, NAS or application) determines data transmission that satisfies a specific small amount of data criteria, The terminal initiates the procedure of the present invention.

The terminal 1201 transmits a small data transmission request message to the base station 1202 (S1210).

The small data transfer request message may include information such as a terminal identifier (ue-Identity) and establishment cause (establishmentCause).

The setting cause information may include small data indication information for indicating that a small amount of data is to be transmitted in a short connection method or a connectionless method.

In order to transmit a small data transfer request message, the MAC layer in the terminal performs a random access procedure. If the terminal reselects the cell during the random access procedure, the RRC layer in the terminal may inform the upper layer that a small amount of data transmission procedure has failed.

2) When the base station 1202 determines to accept the request by receiving the above-mentioned Small Data Transfer Request message, the base station 1202 transmits the small data transfer setup to the terminal 1201. ) A message is transmitted (S1230).

The small data transfer setup message described above may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal 1201 for the new SRB configuration described above.

Alternatively, the small data transfer setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied for the DRB configuration for the small amount of data transmission in a short connection or no connection method to the terminal 1201. And / or dedicated RadioResourceConfigDedicated to be applied for SRB1 configuration.

The dedicated radio resource configuration information described above is a radio bearer applied when the base station 1202 and the terminal 1201 are initially configured to transmit a small amount of data in a short connection or no connection method (for example, a PDN connectivity procedure and an attach procedure). Radio bearer configuration information set for transmitting small amount of data in a short or no connection manner using the configuration information or by local configuration may be used. A radio bearer for transmitting a small amount of data in a short connection or no connection may not include an AS security configuration.

Alternatively, the dedicated radio resource configuration information may use radio bearer configuration information applied to the last used DRB of the DRB or non-GBR bearer last used in the terminal.

The base station 1202 may generate radio bearer configuration information including the dedicated radio resource configuration information described above (S1220), and may include the small data transmission setup message in transmission (S1230).

The terminal 1201 receives the above-described Small Data Transfer Setup message and applies the configuration (eg, SRB-ToAddMod, DRB-ToAddMod) included in the message (S1240), and in an RRC CONNECTED state. The cell reselection process can be stopped by entering.

The terminal 1201 enters the RRC CONNECTED state and stops the reselection process during the aforementioned small amount of data transmission procedure. However, in the upper layer (for example, NAS or application), a small amount of data transmission procedure is not performed through the existing initial NAS message (for example, Service Request), so that the upper layer (for example, between the terminal 1201 and the MME) is not performed. For example, NAS) may be maintained in the ECM-IDLE state.

Alternatively, the terminal 1201 receives a small data transfer setup message and applies a configuration included in the message, but the procedure for transmitting a small amount of data in a short connection or no connection method is started. RRC IDLE state can be maintained. In this case, the terminal 1201 may continue the cell reselection process. Alternatively, the terminal may temporarily stop the cell reselection process during the small amount of data transmission procedure.

3) The terminal 1201 transmits data that satisfies a specific small amount of data criteria to the base station 1202 through a radio bearer of a short connection method or no connection method (S1250).

After RRC signaling (S1210, S1230) for initiating a procedure for transmitting a small amount of data in a short connection or no connection method, the time for transmitting a small amount of data through a radio bearer in a short connection or no connection method is described in the first embodiment. As such, it may be the same time as the enabled time of the short connection method or the connectionless method or may be a separate time.

If the amount of time that a small amount of data can be transmitted over a short or no connection radio bearer is separate from the enabled time of the short or no connection method, then the short or no connection method When the time for transmitting a small amount of data through the radio bearer of the end of time can be entered within the enabled time (short or no connection method). In this case, a small connection or a connectionless data transmission can be performed through RRC signaling for initiating a procedure for a small data transmission or a short connectionless data transmission.

After the RRC signaling, the UE 1201 may transmit an RRC connection release message, an RRC reconfiguration message, or a small data set-up time for transmitting a small amount of data through a short or no connection radio bearer. Setup) message or local configuration.

The method described with reference to FIG. 11 may be applied to a method for setting a small amount of data transmission time using a short connection method or a connectionless method.

The method for transmitting a small amount of data according to the second embodiment of the present invention does not apply encryption (for example, encryption between UE and S-GW) or when the UE continues to be located in the base station where the last RRC connection was established. It may be used when applying an existing encryption key (for example, K _UPenc ) between base stations. To this end, the terminal and the base station configured to transmit a small amount of data in the above-described short connection or no connection method in the IDLE state, the encryption key and the associated UE context (UE Context) during the enabled time of the short connection or connectionless method ) Can be maintained.

In addition, in order to check whether the terminal continues to be located in the base station which established the last RRC connection, the UE identifier (ue-Identity) of the aforementioned Small Data Transfer Request message may use C-RNTI.

Alternatively, the UE identifier of the small data transfer request message may use S-TMSI or a random number as the UE identifier included in the existing RRC connection request message. have.

When a terminal moves out of a base station (or cell) that has established a last RRC connection, the new base station (or cell) has an existing encryption key (for example, between terminal-base stations through the base station (or cell) that has established a last RRC connection). K _UPenc ) and related terminal context (or PDCP configuration information) can be inquired to apply encryption.

Or a new base station (or cell) _{shares an} existing encryption key (eg, K _UPenc ) and associated terminal context (or PDCP configuration information) between the base station (or cell) that established the last RRC connection and the terminal-base station. Applicable

To this end, the terminal and the base station configured to transmit a small amount of data in the above-described short connection or no connection in the IDLE state can maintain the encryption key and the associated terminal context for the enabled time of the short connection or no connection. have.

Third embodiment: A method of using an RRC reconfiguration message for setting up a short or no connection radio bearer for a small amount of data transmission.

A small data transmission procedure according to another embodiment of the present invention will be described in detail with reference to FIG. 13.

1) When the terminal 1301 configured to transmit a small amount of data in a short connection or no connection method is in an IDLE state, the upper layer (for example, a NAS or an application) performs data transmission that satisfies a specific small amount of data criteria. If determined, the terminal transmits a small data transfer request message to the base station 1302 (S1310).

The small data transfer request message may include information such as a terminal identifier (ue-Identity), a cause of establishmentCause, and the like.

The small data transfer request message described above may be an RRC connection request message.

Alternatively, the small data transfer request message may be a new RRC message.

2) When the base station 1302 receives the small data transfer request message and determines to accept the request, the base station 1302 sends a small data transfer setup message to the terminal 1301. Send (S1320).

The small data transfer setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal 1301 to configure the SRB1.

Alternatively, the small data transfer setup message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal 1301 for the new SRB configuration described above. The new SRB configuration is, for example, a channel for a terminal without an RRC connection, but a new channel for a temporary RRC connection of a logical channel having a lower priority in logical channel prioritization (LCP) processing than a CCCH, or a short connection or no connection method. It may mean a channel.

The terminal 1301 may receive a small data transfer setup message, apply a configuration included in the message (S1330), and stop the cell reselection process by entering the RRC CONNECTED state.

The terminal 1301 may enter the RRC CONNECTED state during the small amount of data transmission procedure and stop the reselection process. However, in a higher layer (e.g., NAS or application), a small amount of data transfer procedure is not performed through the existing initial NAS message (e.g., Service Request), so that a higher layer (e.g., NAS) between the terminal and the MME is not performed. ) May be maintained in the ECM-IDLE state.

That is, the procedure for transmitting a small amount of data in a short connection or no connection method is an RRC connection for transmitting a small amount of data between the terminal and the base station (E-UTRAN) with or without the initial NAS message in the terminal 1301. Can be set.

In another method, the terminal 1301 receives a small data transfer setup message and applies a configuration included in the message, but indicates that the terminal 1301 is for transmitting a small amount of data in a short connection or no connection method. If the procedure is started with a small amount of data indication, the RRC IDLE state can be maintained. In this case, the terminal 1301 may continue the cell reselection process. Alternatively, the terminal 1301 may temporarily stop the cell reselection process during the small amount of data transmission procedure.

The small data transfer setup message may be an RRC connection setup message.

Alternatively, the small data transfer setup message may be a new RRC message.

3) The terminal 1301 transmits a small data transfer setup complete message to the base station 1302 in response to the small data transfer setup message (S1340).

The terminal 1301 configures SRB1 according to the above-described radio resource configuration information included in the small data transfer setup message (S1330).

Alternatively, the terminal 1301 configures a new SRB according to the radio resource configuration information included in the small data transfer setup message (S1330).

The small data transfer setup complete message may be an RRC connection setup complete message.

Alternatively, the Small Data Transfer Setup Complete message may be a new RRC message.

4) The base station 1302 sends a data radio bearer reconfiguration message to the terminal 1301 (S1350).

The above-described data radio bearer reconfiguration (DRB reconfiguration) message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied for the DRB configuration for a small connection or a small amount of data transmission to the terminal 1301.

The above-described dedicated radio resource configuration information is a radio bearer applied when the base station 1302 and the terminal 1301 are initially configured to transmit a small amount of data in a short connection or no connection method (for example, a PDN connectivity procedure and an attach procedure). It is possible to use radio bearer configuration information that is set up to use the configuration information or to transmit a small amount of data in a short connection or no connection by local configuration.

If a small data transfer procedure is performed at an upper layer (for example, a NAS or an application) through an existing initial NAS message (for example, a service request), the base station 1302 transmits an initial terminal message to the MME. K _RRCint , user data encryption for RRC integrity protection in DRB using security context information (eg K base station or Next Hop Key) included in initial context setup request message received through MME We can derive K _UPenc for.

The AS security may be activated through a data radio bearer reconfiguration message.

To this end, the data radio bearer reconfiguration (DRB reconfiguration) message may include a security algorithm configuration information (securityAlgorithmConfig).

The security algorithm configuration information includes an encryption algorithm (integrityProtAlgorithm) and an integrity protection algorithm (cipheringAlgorithm).

In this case, the data radio bearer reconfiguration message may only apply integrity protection.

The data radio bearer reconfiguration message may be an RRC connection reconfiguration message.

Alternatively, the data radio bearer reconfiguration message may be a new RRC message.

5) The terminal 1301 performs a radio resource configuration procedure (S1360), and sends a data radio bearer reconfiguration complete (DRB reconfiguration complete) message (S1370).

If the AS security is activated through the above-described data radio bearer reconfiguration message, the data radio bearer reconfiguration complete message includes indication information on security success / failure or the security fails. It may include cause information about the failure.

The data radio bearer reconfiguration complete message may be an RRC connection reconfiguration complete message.

Alternatively, the data radio bearer reconfiguration complete message may be a new RRC message.

6) The terminal 1301 transmits data that satisfies a specific small amount of data reference to the base station 1302 through a radio bearer of a short connection method or a connectionless method (S1380).

After the RRC signaling for initiating a procedure for transmitting a small amount of data in a short connection or a connectionless manner, a time period in which a small amount of data can be transmitted through a short connection or a connectionless radio bearer is possible. It may be the same time as the enabled time or may be a separate time.

If the amount of time that a small amount of data can be transmitted through a short or no connection radio bearer is separate from the enabled time of the short or no connection method, then the short or no connection method is used. When the time for transmitting a small amount of data through the radio bearer of the end of time can be entered within the enabled time of a short connection method or a connectionless method, in which case the procedure for the small data transmission of a short connection or connectionless method is initiated Through RRC signaling for a small amount of data transmission in a short connection or no connection can be performed.

After the RRC signaling, the UE may transmit a small amount of data through the RB of a short connection or no connection method, using an RRC connection release message or an RRC reconfiguration message or the aforementioned data radio bearer reconfiguration (DRB). Can be set by reconfiguration message or local configuration.

The small data transmission scheme according to another embodiment of the present invention described above does not apply encryption to a small amount of data transmitted by the terminal to the base station (for example, applying encryption between the UE and the S-GW), or when the terminal It can be used when applying the existing encryption key (for example, K _UPenc ) between the terminal and the base station when continuing to the base station where the RRC connection was established.

To this end, the terminal and the base station configured to transmit a small amount of data in the above-described short connection or no connection method in the IDLE state, the encryption key and associated terminal context ( UE Context) can be maintained.

In order to check whether the UE continues to be located in the base station which established the last RRC connection, the UE identifier (ue-Identity) of the aforementioned Small Data Transfer Request message may use C-RNTI.

Alternatively, the ue-Identity of the Small Data Transfer Request message may use S-TMSI or a random number, such as the UE identifier included in the existing RRC connection request message. It may be.

When a terminal moves out of a base station (or cell) that has established a last RRC connection, the new base station (or cell) has an existing encryption key (e.g., K _UPenc ) and related terminal context (UE Context or PDCP configuration information) can be inquired and encryption can be applied.

Alternatively, a new base station (or cell) may share an existing encryption key (eg, K _UPenc ) and an associated terminal context (UE Context or PDCP configuration information) between the base station (or cell) that has established the last RRC connection and the terminal-base station. Encryption can be applied.

Referring to FIG. 14, the small data transmission method according to another embodiment of the present invention specifically illustrates an example of using the existing RRC message among the small data transmission methods described with reference to FIG. 13.

For example, a brief description will be given with reference to FIG. 14.

1) When the terminal 1401 configured to transmit a small amount of data in a short connection or no connection method is in an IDLE state, the upper layer (for example, a NAS or an application) performs data transmission that satisfies a specific small amount of data criteria. If determined, the UE sends an RRC connection request message to the base station 1402 (S1410). The RRC connection request message may include information such as a terminal identifier (ue-Identity), establishment cause (establishmentCause), and the like.

2) When the base station 1402 receives the RRC connection request message and determines to accept the request, the base station 1402 sends an RRC connection setup message to the terminal 1401 (S1420). ).

3) The terminal 1401 transmits an RRC connection setup complete message to the base station 1402 in response to the RRC connection setup message (S1440).

4) The base station 1402 sends an RRC connection reconfiguration message to the terminal 1401 (S1450).

5) The UE 1401 performs a radio resource configuration procedure (S1460), and sends a RRC connection reconfiguration complete message (S1470).

6) The terminal 1401 transmits data satisfying a specific small amount of data criteria to the base station 1402 through a radio bearer of a short connection method or a connectionless method (S1480).

Fourth Embodiment: A method of using an RRC connection re-establish message for setting up a short or no connection radio bearer for a small amount of data transmission.

The RRC connection re-establishment procedure is used to recover the connection between the terminal and the base station from various failures in the air interface and resets the RRC connection.

RRC connection reconfiguration includes resumption of signaling radio bearer (SRB1), security reactivation, and cell configuration.

When the terminal and the base station are configured to transmit a small amount of data in a short connection or no connection method according to another embodiment of the present invention, a short connection or no connection using an RRC connection re-establishment procedure A radio bearer of the scheme may be configured.

Each step will be described in detail with reference to FIG. 15.

1) When the terminal 1501 configured to transmit a small amount of data in a short connection or no connection method is in an IDLE state, the upper layer (for example, a NAS or an application) performs data transmission that satisfies a specific small amount of data criteria. Upon determining, terminal 1501 initiates this procedure.

The terminal 1501 transmits an RRC connection reestablishment request message to the base station 1502 (S1510).

The RRC connection reestablishment request message may include information such as a terminal identifier (ReestabUE-Identity), a cause of establishment (reestablishmentCause), and the like.

The above-mentioned setting cause information may include a small amount of data indication information for indicating that the small amount of data is to be transmitted in a short connection method or a non-connection method.

2) When the base station 1502 determines to accept the request by receiving an RRC connection reestablishment request message, the base station 1502 sends an RRC connection reestablishment message to the terminal 1501. (S1520).

The RRC connection reestablishment message may include radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal 1501 for SRB1 configuration.

Alternatively, the RRC connection reestablishment message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied to the terminal 1501 for the new SRB configuration described above.

Alternatively, the RRC connection reestablishment message may include dedicated radio resource configuration information (RadioResourceConfigDedicated) to be applied for DRB configuration for transmitting a small amount of data in a short connection or no connection method to the terminal 1501.

The above-described dedicated radio resource configuration information is a radio bearer applied when the base station 1502 and the terminal 1501 are initially configured to transmit a small amount of data in a short connection or no connection method (for example, a PDN connectivity procedure and an attach procedure). It is possible to use radio bearer configuration information that is set up to use the configuration information or to transmit a small amount of data in a short connection or no connection by local configuration.

Alternatively, the dedicated radio resource configuration information may use radio bearer configuration information applied to the last used DRB of the last used DRB or non-GBR bearer. A radio bearer for transmitting a small amount of data in a short connection or no connection may not include an AS security configuration.

As another method, the RRC connection reestablishment message may be transmitted to the terminal 1501 for the purpose of SRB1 (or new SRB) and DRB configuration for transmitting a small amount of data in a short connection or no connection. RadioResourceConfigDedicated) may be included.

The terminal 1501 receives an RRC connection reestablishment message and configures a radio bearer based on configuration information included in the message (S1530).

The terminal 1501 may stop the cell reselection process by entering the RRC CONNECTED state.

The terminal 1501 enters the RRC CONNECTED state during the small amount of data transmission procedure and stops the reselection process. However, in a higher layer (e.g., NAS or application), a small amount of data transfer procedure is not performed through the existing initial NAS message (e.g., Service Request), so that a higher layer (e.g., NAS) between the terminal and the MME is not performed. ) May be maintained in the ECM-IDLE state.

Alternatively, the terminal 1501 receives the RRC connection reestablishment message and applies the configuration included in the message, but if the procedure for transmitting a small amount of data in a short connection or no connection method is started, RRC IDLE State can be maintained. In this case, the terminal 1501 may continue the cell reselection process. Alternatively, the terminal 1501 may temporarily stop the cell reselection process during the small amount of data transmission procedure.

3) The terminal 1501 transmits an RRC connection reestablishment Complete message to the base station 1502 in response to the RRC connection reestablishment message (S1540).

Before step S1540, the terminal 1501 configures SRB1 according to the radio resource configuration included in the RRC connection reestablishment message (S1530).

Alternatively, the terminal 1501 configures a new SRB according to radio resource (radio bearer) configuration information included in an RRC connection reestablishment message.

Alternatively, the terminal 1501 configures a DRB (eg, DRB-ToAddMod) according to radio resource (radio bearer) configuration information included in an RRC connection reestablishment message.

Alternatively, the terminal 1501 may configure the SRB1 (or the new SRB) and the DRB according to the radio resource (radio bearer) configuration information included in the RRC connection reestablishment message.

4) The terminal 1501 transmits data that satisfies a specific small amount of data criterion to the base station 1502 through a radio bearer of a short connection method or a connectionless method (S1550).

If the amount of time that a small amount of data can be transmitted through a short or no connection radio bearer is separate from the enabled time of the short or no connection method described above, a short connection or connection When the time for transmitting a small amount of data through the radio bearer of no end is terminated, it may fall within the enabled time of a short connection or no connection method. In this case, a small connection or a connectionless data transmission can be performed through RRC signaling for initiating a procedure for a small connection or a connectionless data transmission.

After the RRC signaling, the UE 1501 may transmit an RRC connection release message or an RRC reconfiguration message or the above-described RRC connection for a time for transmitting a small amount of data through a radio bearer of a short connection or no connection method after the RRC signaling. Can be set by RRC connection reestablishment message or local configuration.

As described above, the method for transmitting small amount of data according to another embodiment of the present invention does not apply encryption to the small amount of data transmitted by the terminal to the base station (for example, applying encryption between the UE and the S-GW) or when the terminal It may be used when applying an existing encryption key (for example, K _UPenc ) between the terminal and the base station when continuing to be located in the base station to establish the RRC connection.

In addition, the UE identifier (ue-Identity) of the above-described RRC connection reestablishment request message may use C-RNTI to check whether the UE continues to be located in the base station which established the last RRC connection.

As described above, the terminal according to the embodiment of the present invention may configure the above-described data radio bearer and transmit a small amount of data through the configured data radio bear. While the terminal is transmitting a small amount of data through the configured data radio bearer, the terminal may operate in an RRC connected (RRC_CONNECTED) state and NAS idle (NAS_IDLE) state.

Therefore, a small amount of data can be transmitted quickly without going through many unnecessary signaling procedures.

In the above, the embodiments of the present invention have been described in detail as a method for the terminal to transmit a small amount of data.

Hereinafter, the configuration of a base station and a terminal in which both of the present invention described with reference to FIGS. 3 to 15 can operate will be described.

The base station according to another embodiment of the present invention is a control unit for receiving the RRC connection request (RRC connection request) message including a small amount of data indication information from the terminal 1630 and the control unit for generating radio bearer configuration information for the small amount of data transmission 1610 and a transmitter 1620 for transmitting an RRC connection setup message including radio bearer configuration information, wherein the receiver 1630 includes an RRC connection setup including setup completion information for small amount of data transmission. A RRC connection setup complete message may be received and a small amount of data may be further received through the data radio bearer configured based on the radio bearer configuration information.

Referring to FIG. 16, a base station 1600 according to another embodiment of the present invention includes a controller 1610, a transmitter 1620, and a receiver 1630.

The controller 1610 performs operations of the entire base station according to the generation of the RRC signaling required to transmit a small amount of data in a short lived connection or a connectionless manner in the mobile communication network required to perform the above-described present invention. To control.

In detail, the controller 1610 may generate radio bearer configuration information necessary for receiving a small amount of data.

In addition, SRB1, new SRB and DRB configuration information and dedicated radio resource configuration information according to each embodiment of the present invention may be generated.

The transmitter 1620 may transmit an RRC connection setup message or a small data transmission setup message or an RRC connection reset message transmitted to the terminal according to each embodiment of the present invention.

In addition, the transmitter 1620 may further transmit a DRB reconfiguration message or an RRC connection reconfiguration message.

The receiver 1630 may receive an RRC connection request message or a small data transmission request message or an RRC connection reset request message.

In addition, the receiver 1630 may receive an RRC connection setup complete message or a small data setup complete message or a DRB reconfiguration complete message or an RRC connection setup complete message or an RRc connection reconfiguration complete message or an RRC connection reset complete message.

The receiver 1630 receives a small amount of data from the terminal.

In addition to the above-described message, the transmitter 1620 and the receiver 1630 are used to transmit and receive signals, messages, and data necessary for performing each embodiment of the present invention.

A terminal according to another embodiment of the present invention includes a transmitter 1730 for transmitting an RRC connection request message including a small amount of data indication information to a base station and radio bearer configuration information for transmitting a small amount of data from the base station. And a receiver 1720 configured to receive an RRC connection setup message and a controller 1720 configured to configure a data radio bearer for data transmission based on radio bearer configuration information. The 1730 may transmit an RRC connection setup complete message including setup complete information for transmitting a small amount of data to the base station, and may transmit the small amount of data to the base station through the data radio bearer.

Referring to FIG. 17, a user terminal 1700 according to another embodiment of the present invention includes a receiver 1710, a controller 1720, and a transmitter 1730.

In detail, the controller 1720 generates an RRC signaling and configures a radio bearer for transmitting a small amount of data in a short lived connection or connectionless manner in a mobile communication network required to perform the above-described present invention. Control the overall operation of the terminal according to.

In addition, the controller 1720 may configure a radio bearer based on radio bearer configuration information, and may control a procedure such as a transmission time timer and encryption.

The receiver 1710 receives downlink control information, data, and a message from a base station through a corresponding channel.

In addition, the receiver 1710 may receive an RRC connection setup message or a small data transmission setup message or an RRC connection reset message received from a base station according to each embodiment of the present invention.

In addition, the receiver 1710 may further receive a DRB reconfiguration message or an RRC connection reconfiguration message.

The transmitter 1730 transmits uplink control information, data, and messages to the base station through a corresponding channel.

In detail, the transmitter 1730 may transmit an RRC connection request message or a small data transmission request message or an RRC connection reestablishment request message according to each embodiment of the present invention.

Also, the transmitter 1730 may transmit an RRC connection setup complete message or a small data setup complete message or a DRB reconfiguration complete message or an RRC connection setup complete message or an RRC connection reconfiguration complete message or an RRC connection reset complete message according to each embodiment of the present invention. You can also send.

The transmitter 1730 transmits a small amount of data to the base station.

As described above, the present invention provides an RRC signaling method between a terminal and a base station for transmitting a small amount of data in a short lived connection or connectionless method in an LTE mobile communication network, thereby connecting to an IDLE state and a CONNECTED state. There is an effect that can transmit a small amount of data while reducing the signaling load according to the transition of the state.

In addition, when applying the present invention, there is an effect that the terminal provides a method and apparatus for transmitting a small amount of data in a short connection or no connection method.

In addition, when applying the present invention, by reducing the signaling load of the terminal and the base station in transmitting a small amount of data, there is an effect that can reduce the power consumption of the terminal.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application is related to the patent application No. 10-2013-0030567 filed in Korea on March 21, 2013 and the patent application No. 10-2013-0132143 filed in Korea on November 01, 2013. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

In the method for the terminal to transmit a small amount of data,

Transmitting an RRC connection request message including a small amount of data indication information to a base station;

Receiving an RRC connection setup message including radio bearer configuration information for the small amount of data transmission from the base station;

Configuring a data radio bearer for the small amount of data transmission based on the radio bearer configuration information;

Transmitting an RRC connection setup complete message including setup completion information for small amount of data transmission to the base station; And

Transmitting the small amount of data to the base station via the data radio bearer.
The method of claim 1,

The RRC connection request message is,

And at least one or more of the terminal identifier information and the information for setting the small amount of data transmission.
The method of claim 1,

The radio bearer configuration information,

And a dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.
The method of claim 3, wherein

The dedicated radio resource configuration information (RadioResourceConfigDedicated),

And a data radio bearer value previously configured for the terminal or configured for the small amount of data transmission.
The method of claim 1,

The terminal,

Operating in an RRC_CONNECTED state and a NAS idle state, while the small amount of data transmission over the data radio bearer is maintained.
In the method for the base station to control the small amount of data transmission of the terminal,

Receiving an RRC connection request message including a small amount of data indication information from the terminal;

Generating radio bearer configuration information for the small amount of data transmission;

Transmitting an RRC connection setup message including the radio bearer configuration information;

Receiving an RRC connection setup complete message including setup completion information for the small amount of data transmission; And

Receiving the small amount of data via a data radio bearer configured based on the radio bearer configuration information.
The method of claim 6,

The RRC connection request message is,

And at least one or more of the terminal identifier information and the information for setting the small amount of data transmission.
The method of claim 6,

The radio bearer configuration information,

And a dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.
The method of claim 8,

The dedicated radio resource configuration information (RadioResourceConfigDedicated),

And a data radio bearer value previously configured for the terminal or configured for the small amount of data transmission.
The method of claim 6,

Before the step of receiving the RRC connection request message,

And transmitting higher layer signaling including a small amount of data transmission timer information related to a time at which the small amount of data can be transmitted to the terminal.
In the terminal for transmitting a small amount of data,

A transmitter for transmitting an RRC connection request message including a small amount of data indication information to a base station;

A receiver configured to receive an RRC connection setup message including radio bearer configuration information for the small amount of data transmission from the base station; And

And a controller configured to configure a data radio bearer for transmitting the small amount of data based on the radio bearer configuration information.

The transmitter transmits an RRC connection setup complete message including setup complete information for transmitting a small amount of data to the base station, and transmits the small amount of data to the base station through the data radio bearer.
The method of claim 11,

The RRC connection request message is,

And at least one or more of the terminal identifier information and the information for setting the small amount of data transmission.
The method of claim 11,

The radio bearer configuration information,

And a dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.
The method of claim 13,

The dedicated radio resource configuration information (RadioResourceConfigDedicated),

And a data radio bearer value previously configured in the terminal or configured for the small amount of data transmission.
The method of claim 11,

The terminal,

And while the small amount of data transmission through the data radio bearer is maintained, the terminal operates in an RRC connected (RRC_CONNECTED) state and a NAS idle (NAS_IDLE) state.
In the base station for controlling a small amount of data transmission of the terminal,

A receiver configured to receive an RRC connection request message including a small amount of data indication information from the terminal;

A controller configured to generate radio bearer configuration information for the small amount of data transmission; And

A transmitter for transmitting an RRC connection setup message including the radio bearer configuration information,

The receiver receives an RRC connection setup complete message including setup completion information for transmitting the small amount of data, and further receives the small amount of data through a data radio bearer configured based on the radio bearer configuration information. Base station.
The method of claim 16,

The RRC connection request message is,

The base station further comprises at least one or more information of the terminal identifier information and the information of the small data transmission setting cause.
The method of claim 16,

The radio bearer configuration information,

A base station comprising dedicated radio resource configuration information (RadioResourceConfigDedicated) for data radio bearer configuration.
The method of claim 18,

The dedicated radio resource configuration information (RadioResourceConfigDedicated),

And a data radio bearer value previously configured in the terminal or configured for the small amount of data transmission.
The method of claim 16,

The transmitting unit,

Before receiving the RRC connection request message,

And a base station further transmitting higher layer signaling including a small amount of data transmission timer information related to the time when the small amount of data can be transmitted.