KR102005910B1 - Methods for changing connection status of UE and Apparatuses thereof - Google Patents
Methods for changing connection status of UE and Apparatuses thereof Download PDFInfo
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- KR102005910B1 KR102005910B1 KR1020170045815A KR20170045815A KR102005910B1 KR 102005910 B1 KR102005910 B1 KR 102005910B1 KR 1020170045815 A KR1020170045815 A KR 1020170045815A KR 20170045815 A KR20170045815 A KR 20170045815A KR 102005910 B1 KR102005910 B1 KR 102005910B1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/20—Manipulation of established connections
- H04W76/27—Transitions between radio resource control [RRC] states
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/0215—Traffic management, e.g. flow control or congestion control based on user or device properties, e.g. MTC-capable devices
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/30—Connection release
- H04W76/34—Selective release of ongoing connections
Abstract
The present invention relates to a control plane signaling method and apparatus for reducing signaling due to terminal state change, and more particularly, to a method for efficiently changing a terminal connection state in a wireless network without changing mobility or state transition of the terminal in the core network. In one embodiment, a method for a terminal to change a connection state includes receiving a Radio Resource Control (RRC) connection release message including indication information for instructing a state change from a base station to a light connection state, Configuring the connection state of the terminal to the right connection state based on the instruction information, and transmitting the RRC connection resumption request message to the base station without access class barring operation when the state change to the RRC connection state is triggered And to provide a method and apparatus.
Description
The present invention relates to a control plane signaling method and apparatus for reducing signaling due to terminal state change, and more particularly, to a method for efficiently changing a terminal connection state in a wireless network without changing mobility or state transition of the terminal in the core network.
As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals. In a mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the current 3GPP series, a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data outside a voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method.
In addition, due to the increase of terminals using machine type communication (hereinafter referred to as "MTC" communication), data transmission / reception through a mobile communication system is rapidly increasing. Meanwhile, in the case of MTC communication, it is necessary to periodically transmit and receive a small amount of data, and a low-power low-cost terminal can be used.
Therefore, there is a demand for a technology for transmitting and receiving data by a plurality of terminals while reducing power consumption.
In particular, in the case of a terminal that transmits a small amount of data periodically or aperiodically, it is necessary to change the RRC connection state in order to transmit a small amount of data. However, in order to change the RRC connection state by the conventional method, the data transmission / reception procedure of the terminal, the base station, the base station, and the core network has been complicated.
Such a transmission / reception procedure causes a relatively high data load compared to a small amount of data to be transmitted by the terminal. That is, there is a problem that unnecessary data overload occurs in the RRC connection state change procedure for transmitting a small amount of data.
This problem is likely to result in an increase in data load throughout the communication system as the number of terminals for transmitting a small amount of data periodically increases.
Therefore, it is necessary to study a method and a procedure for changing the terminal connection state, which can transmit and receive a small amount of data without seriously increasing the data load of the entire communication system according to the change of the wireless communication environment.
In the above-described background, a connection state of a terminal is added to a RRC connection and a RRC idle, and a light connection state is additionally provided to reduce the load on the entire communication system, And a method and an apparatus for configuring the system to be implemented.
In addition, one embodiment of the present invention specifically proposes whether or not to perform an operation for congestion control and a paging method for a transition when a terminal transitions from a light connection state to an RRC connection state.
According to an embodiment of the present invention, there is provided a method of changing a connection state of a terminal, the method comprising: receiving a Radio Resource Control (RRC) message including instruction information for instructing a state change from a base station to a light connection state; ) Receiving a connection release message, configuring the connection state of the terminal into a light connection state based on the instruction information, and, when the state change to the RRC connection state is triggered, the RRC connection And sending a resume request message to the base station.
According to another aspect of the present invention, there is provided a method of changing a connection state of a terminal in a base station, the method comprising: transmitting a Radio Resource Control (RRC) connection release message including instruction information for instructing a state change to a light connection state; Changing a connection state between the RRC connection state and the terminal to a light connection state, and receiving a RRC connection resumption request message according to a state change trigger to the RRC connection state of the terminal.
In an exemplary embodiment of the present invention, a terminal for changing a connection state includes a receiver for receiving an RRC (Radio Resource Control) connection release message including instruction information for instructing a state change from a base station to a light connection state, And a transmitter for transmitting an RRC connection resumption request message to a base station without access class barring if the state change to the RRC connection state is triggered, And a terminal device.
According to another aspect of the present invention, there is provided a base station for changing a connection state of a terminal, the base station including a transmitter for transmitting an RRC (Radio Resource Control) connection release message including instruction information for instructing a state change to a light connection state, And a receiver for receiving an RRC connection resumption request message according to a state change trigger to the RRC connected state of the terminal.
The embodiments described above provide a reduced signaling procedure for a terminal performing frequent connection state changes, thereby reducing the data load of the entire communication system.
In addition, the present embodiments provide data load reduction through quick connection state change of the terminal and reduction of core network signaling.
1 is a diagram illustrating a specific procedure for changing a connection state of a conventional terminal.
2 is a flowchart illustrating a terminal operation according to an exemplary embodiment.
3 is a flowchart illustrating an operation of a base station according to an exemplary embodiment.
4 is a diagram illustrating exemplary configuration information for RAN initiation paging according to an exemplary embodiment of the present invention.
5 is a diagram for explaining a terminal configuration according to an embodiment.
6 is a view for explaining a base station configuration according to an embodiment.
Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.
Herein, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In this specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, the MTC terminal may refer to a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.
In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. Alternatively, the MTC terminal may support enhanced coverage over the existing LTE coverage or a UE category / type defined in the existing 3GPP Release-12 or lower that supports low power consumption, or a newly defined Release-13 low cost low complexity UE category / type.
The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.
A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.
That is, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.
Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.
Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.
Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .
There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.
A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.
In systems such as LTE and LTE-advanced, a standard is constructed by configuring uplink and downlink based on a single carrier or carrier pair. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.
On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).
In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .
The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.
The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >
Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.
Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.
In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.
That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.
Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.
Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.
The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.
The connection state transition procedure of the terminal
In the conventional mobile communication technology, a terminal and a network state are classified into a terminal idle state and a connected state. The terminal and the network state coincide. For example, the states in the radio network (E-UTRAN) and the core network (for example, the RRC state and the ECM state) coincide. That is, when the UE transits to the RRC-IDLE state, the UE enters the ECM-IDLE state. When the UE transitions to the RRC-CONNECTED state, the UE enters the ECM-CONNECTED state. The terminal in the idle state has to perform a complicated signaling process as shown in FIG. 1 in order to transmit data according to the terminal state. In particular, when a terminal transmits a small amount of data, it becomes a large overhead.
1 is a diagram illustrating a specific procedure for changing a connection state of a conventional terminal.
Referring to FIG. 1, the
The
When the RRC connection setup is completed, the
The
Thereafter, the
The terminal 100 transmits a UDP / IP packet to the
Through this procedure, the
Thereafter, the terminal 100 transmits a measurement report to the
After releasing the RRC connection of the terminal 100, the
Through this procedure, the RRC connection terminal can be transited to the RRC idle state.
As described above, in the prior art, a plurality of signaling procedures are required between the UE, the BS, the BS, and the core network in order for the UE to transition from the RRC idle state to the RRC connected state or from the RRC connected state to the RRC idle state. In this procedure, when the UE periodically transmits a small amount of data, the overhead continuously occurs. Meanwhile, in order to reduce the overhead due to the state transition, the UE can be maintained in a connected state. In this case, even when there is no data transmission, it is necessary to periodically measure the network status according to the measurement configuration, Consumption may be caused. In addition, when the RRC connection state is maintained, the handover signaling overhead due to the movement of the UE increases.
Connection state transition procedure for NB-IoT terminal
A narrow band IoT terminal may be operated in a fixed state and may be installed in a specific location or located within a certain range. Due to this characteristic, the NB-IoT terminal and the base station support the Suspend / Resume procedure. In the RRC connection release message, the base station can request the terminal to maintain an AS context in the RRC_IDLE state. When the UE receives the RRC connection release message including the RRC suspend information and transitions to the RRC IDLE state (or before the BS sends the message to the UE), the BS transmits an S1 message to the core network The ECM enters the IDLE state.
The RRC connection resume procedure is used for the RRC Connected transition in the RRC IDLE used to resume the RRC connection previously stored in the terminal and the base station. When the MS initiates the RRC connection resume procedure and transitions to the RRC Connected state (after the BS sends an RRC connection resume message to the MS), the BS sends an S1 message requesting state transition of the MS to the core network to transmit the ECM CONNECTED state ≪ / RTI >
However, even in this case, the RRC connection state and the ECM connection state are made the same, and thus unnecessary overhead is generated between the base station and the core network. That is, as described above, in the conventional mobile communication technology, there is a signaling overhead problem due to state transition, and in the case of the Suspend / Resume procedure for the terminal in the fixed location which can reduce the overhead, the NB-IoT terminal can be applied . Accordingly, when the UE moves out of a cell (or a base station) providing the previously stored AS Context, the UE has to perform the service request procedure as shown in FIG. 1 to transmit the uplink data. In addition, since the transition between the Suspend state and the Resume state is the same as the transition between the IDLE state and the CONNECTED state, the core network signaling (S1 signaling) is continuously generated.
In order to solve this problem, we propose a concrete procedure for transiting only the wireless network connection state without core network signaling.
In the prior art, since a terminal and a base station have undergone a wireless network connection state transition based on signaling and user data generated in an upper layer (for example, Non Access Stratum, IP, GTP, etc.) of an AS (Access Stratum) In order to transit only the wireless network connection without signaling, detailed operation procedure is necessary.
Also, if only the wireless network connection state is transited without core network signaling, incoming data for the terminal can not be received properly. As a method to solve this problem, it is possible to consider a method of self-triggering paging in a wireless network, but no concrete method has been proposed. In particular, paging according to the prior art is triggered through the core network. Therefore, there is a problem that the method of triggering paging in the wireless network can not sufficiently provide the paging function triggered through the core network.
In the conventional mobile communication technology, there has been a problem of signaling overhead due to state transition. The Suspend / Resume procedure, which can reduce this, could not reduce core network signaling (S1 signaling). In order to solve this problem, it is possible to consider a method of transiting only the wireless network connection state without core network signaling, but there is no concrete method for this. In particular, there was no way to provide connection control / congestion control for RRC connected state terminals. Also, if only the wireless network connection state is transited without core network signaling, incoming data for the terminal can not be properly received.
In order to reduce the overhead of core network signaling, the present embodiment, which has been devised to solve the above-described problems, proposes a specific method of a UE and a base station for performing a radio network state transition without core network signaling. In addition, the present invention provides a specific procedure in which the UE transits between the RRC connection state and the right connection state, and a UE access control or congestion control method in the state transition process. It is another object of the present invention to provide a specific method and apparatus for providing paging for a terminal in a light connection state.
The embodiments described below can be applied to terminals using all mobile communication technologies. For example, the present embodiments can be applied not only to mobile communication terminals to which LTE technology is applied but also to next generation mobile communication (for example, 5G mobile communication) terminals. For convenience of description, the base station may represent an eNode-B of an LTE / E-UTRAN, a base station (CU, DU, or CU) in a 5G wireless network in which a CU (Central Unit) And DU is an entity implemented as a single logical entity).
A method for performing a wireless network state transition without core network signaling
In order to reduce the signaling due to the state transition of the MS, the BS maintains a connection between the BS and the core network for the MS (for example, S1 connection in LTE or interface connection between the BS and the core network in 5G) (E.g., cell reselection, paging, radio resource release / suspend / suspend, and / or at least one operation of some radio resource maintenance / standby) in the RRC idle state so that terminal power similar to the idle state is consumed. As shown in FIG.
For convenience of description, a state in which a control plane or user plane connection is maintained on a base station and a core network interface to a terminal is referred to as a light connection state, in which a part or all of operations of the RRC idle state are performed. The light connection state includes a new RRC state, a sub-state of the RRC connection, a terminal mobility providing connection state, a wireless network paging state, a connection standby state, an RRC idle state for maintaining the S1 connection, an RRC idle state for maintaining the core network connection, Standby state, light connection state, and the like, and the name is not limited.
Also, when the base station instructs to switch the RRC Connected terminal to the light connection state in the light connection state, it may not send the terminal context release request message to the core network. That is, signaling is not performed to release the connection on the interface between the core network and the base station. Or (S1) connection on the interface between the core network and the base station is maintained. For reference, in the prior art, when releasing the RRC connection state to the terminal, the base station sends a terminal context release request message to request the MME to release the logical S1 connection associated with the terminal.
As described above, the newly connected connection state of the terminal is described as a write connection state. As described above, in the write connection state, the connection between the base station and the core network for the terminal is maintained and the terminal is in the RRC idle state But the present invention is not limited to the exemplary names corresponding to the exemplary names indicating the states performing some operations.
Hereinafter, a state transition to the light connection of the terminal and a state transition to the RRC connected state from the light connection state according to the present embodiment will be described with reference to the drawings.
2 is a flowchart illustrating a terminal operation according to an exemplary embodiment.
Referring to FIG. 2, the UE performs a step of receiving a Radio Resource Control (RRC) connection release message including indication information indicating a state change from a base station to a light connection state (S210). The instruction information for instructing the terminal to change the connection state to the right connection state can be transmitted by the base station. In the above, the instruction information is described as being included in the RRC connection release message, but may be included in the RRC connection reconfiguration message if necessary.
When the terminal receives the indication information, it must perform an operation to change the connection state between the terminal and the base station to the light connection state.
The RRC connection release message may further include configuration information for RAN (Radio Access Network) initiation paging for the terminal in the light connection state. For example, the configuration information for RAN initiation paging may include at least one of paging cycle information and cell area information for paging update. As another example, the configuration information for RAN initiation paging may include information of at least one of the UE identification information, the source cn-domain of paging, UE specific DRX information, and cell area information indicating light connection. As another example, the RRC disconnect message may include period / timer information to trigger an update to the configuration information for RAN initiation paging, cell reselection number to trigger the update, and cell area information And a surface trigger).
However, the base station needs to know whether the corresponding terminal supports the light connection state. To this end, the terminal may transmit the terminal capability information to the base station prior to step S210 to inform whether the terminal supports the light connection state.
On the other hand, the terminal performs a step of configuring the connection state of the terminal into the right connection state based on the instruction information (S220). For example, when the UE receives the instruction information indicating the state change from the base station to the light connection state, it stops all SRBs and DRBs for the base station. However, unlike the RRC idle state, the terminal can store the terminal context. In this case, the base station also stores the terminal context for that terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception. Herein, the RAN initiation paging message means a paging message triggered in the RAN layer, not a paging message triggered by an upper layer.
In addition, the terminal in the light connection state can perform the cell reselection operation instead of the handover when moving. That is, since the RRC connection of the UE is similar to the released state of the BS, the UE can perform a process of reselecting the cell when the UE moves.
In addition, when the UE changes its state to the RRC connection state, the UE transmits an RRC connection resumption request message to the BS without performing access class barring (S230). For example, when the transition to the RRC connection state is triggered, the terminal in the right connection state can perform the transition from the light connection state to the RRC connection state by transmitting an RRC connection resumption request message to the base station.
In one example, a change of state to an RRC connected state may be triggered by receiving a radio access network (RAN) initiating paging message or by detecting outgoing data. Specifically, when the paging message for the terminal in the light connection state is received, the terminal can perform the transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state. Alternatively, if outgoing signaling to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state.
Meanwhile, the RRC connection resumption request message may include the cause information that causes the state change trigger to the RRC connection state. The cause information of the trigger cause may include information on whether it is due to the above-described paging or detection of origination data or detection of origination signaling.
In addition, when the light connection terminal changes the connection state in the RRC connection state, the terminal may not perform access class barring operation. For example, when a state transition to an RRC connected state is triggered, the terminal can determine whether to perform a connection class limiting operation based on a connection state of the current terminal. For example, when the UE is in the RRC Idle state at the time of triggering the RRC connection state, the UE controls the connection class limiting operation to be performed for congestion control. In another example, if the terminal connection state at the time of triggering the RRC connection state is the right connection state, the terminal controls to transmit the RRC connection restart message to the base station immediately without performing the connection class restriction operation for congestion control. This treats the light connection state as similar to the RRC connection state, and congestion control is not performed, thereby solving the problem of the state transition failure to the RRC connection state.
Meanwhile, the terminal can perform various operations for access class restriction (Access Class Barring). For example, the terminal checks whether the system information includes an access prohibition parameter for congestion control. If the access prohibition parameter is included in the system information, the terminal performs an access prohibition check. As a result of the access prohibition check, when the corresponding terminal meets the access prohibition condition, it informs the upper layer of the failure of the RRC connection setup, and then retries the RRC connection setup in the upper layer.
3 is a flowchart illustrating an operation of a base station according to an exemplary embodiment.
3, in a method of changing a connection state of a mobile station, a base station transmits a Radio Resource Control (RRC) connection release message including instruction information for instructing a state change to a light connection state to a mobile station (S310). In the above, the instruction information is described as being included in the RRC connection release message, but may be included in the RRC connection reconfiguration message if necessary.
The RRC connection release message may further include configuration information for RAN (Radio Access Network) initiation paging for the terminal in the light connection state. For example, the configuration information for RAN initiation paging may include at least one of paging cycle information and cell area information for paging update. As another example, the configuration information for RAN initiation paging may include information of at least one of the UE identification information, the source cn-domain of paging, UE specific DRX information, and cell area information indicating light connection. As another example, the RRC disconnect message may include period / timer information to trigger an update to the configuration information for RAN initiation paging, cell reselection number to trigger the update, and cell area information And a surface trigger).
However, the base station needs to know whether the corresponding terminal supports the light connection state. To this end, the base station may receive the terminal capability information from the terminal before step S310, and confirm whether the terminal supports the light connection state. For example, the terminal capability information may be transmitted to the base station or the core network through the AS capability or the NAS capability. As another example, the terminal capability information may be included in terminal wireless connection capability or terminal core network capability. The base station can receive the terminal capability information through RRC signaling.
Meanwhile, the base station performs a step of changing the connection state from the RRC connection state to the light connection state (S320). For example, when a terminal transitions to a light connection state, the base station stops all SRBs and DRBs for that terminal. However, unlike the RRC idle state, the base station can store the terminal context of the corresponding terminal. In this case, when the terminal in the right connection state transits to the RRC connection state, the terminal and the base station can use the stored terminal context again to perform fast data transmission / reception.
Meanwhile, the base station performs a step of receiving an RRC connection resumption request message according to a status change trigger to the RRC connected state of the terminal (S330). For example, if a transition to the RRC connection state for a terminal in the right connection state is triggered, the base station can perform an RRC connection state transition operation of the corresponding terminal by receiving the RRC connection resumption request message.
In one example, a change of state to an RRC connected state may be triggered by receiving a radio access network (RAN) initiating paging message or by detecting outgoing data. Specifically, when the paging message for the terminal in the light connection state is received, the terminal can perform the transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state. Alternatively, if outgoing signaling to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state.
Meanwhile, the RRC connection resumption request message may include the cause information that causes the state change trigger to the RRC connection state. The cause information of the trigger cause may include information on whether it is due to the above-described paging or detection of origination data or detection of origination signaling.
In addition, when the light connection terminal changes the connection state to the RRC connection state as described above, the terminal may not perform the access class barring operation. For example, when a state transition to an RRC connected state is triggered, the terminal can determine whether to perform a connection class limiting operation based on a connection state of the current terminal. For example, when the UE is in the RRC Idle state at the time of triggering the RRC connection state, the UE controls the connection class limiting operation to be performed for congestion control. In another example, if the terminal connection state at the time of triggering the RRC connection state is the right connection state, the terminal controls to transmit the RRC connection restart message to the base station immediately without performing the connection class restriction operation for congestion control. This treats the light connection state as similar to the RRC connection state, and congestion control is not performed, thereby solving the problem of the state transition failure to the RRC connection state.
Meanwhile, the terminal can perform various operations for access class restriction (Access Class Barring). For example, the terminal checks whether the system information includes an access prohibition parameter for congestion control. If the access prohibition parameter is included in the system information, the terminal performs an access prohibition check. As a result of the access prohibition check, when the corresponding terminal meets the access prohibition condition, it informs the upper layer of the failure of the RRC connection setup, and then retries the RRC connection setup in the upper layer.
As described above, the terminal and the base station can perform the terminal state transition to the light connection state and the state transition operation to the RRC connected state from the light connection state.
Hereinafter, an individual embodiment of each step will be described in detail with respect to a specific procedure for performing a state transition to a light connection state and a state transition from a light connection state to an RRC connected state.
Light of terminal connection Communicate Support Example
In order to provide a proper configuration to the UE, the BS must correctly recognize the capability (hereinafter, referred to as a UE or a UE for convenience of description, but it may mean a 5G UE as well as an LTE UE). RRC signaling carries AS capabilities and NAS signaling carries NAS capabilities. The core network control plane entity (for example, MME, hereinafter denoted as MME, core network control plane entity) stores UE capabilities (or terminal capability configured with UE Radio Access Capability and UE Core Network Capability).
For example, the UE Core Network Capability can be indicated by the UE through NAS signaling (attach procedure, etc.). As another example, the UE Radio Access Capability may be transmitted from the UE to the Node B using the UE capability transfer procedure and transmitted through the S1 interface. As another example of this, the UE Radio Access Capability can be indicated to the MME through the NAS signaling (attach procedure, etc.) by the UE and transmitted to the base station via the S1 interface.
If available, the MME transmits UE Radio Access Capability to the base station whenever the UE enters RRC Connected. For example, the MME may transmit the UE radio capability to the base station through the S1 Initial context setup request message.
The base station may request UE capability information if necessary. For example, after the handover is completed, the base station may obtain the UE capability information from the UE using the UE capability transfer procedure, and then transmit the UE capability information to the MME.
As an example, information for instructing to support a light connection may be defined in the UE capability information (e.g., UE radio capability information). As another example, the information for indicating that the WLAN connection is supported may be defined by modifying / extending the UE capability information for NB-IoT suspend / resume (or AS context caching).
The base station may receive information to indicate that the terminal supports the light connection using the methods described above.
light connection Change the state of a connection to a state Example
As described above, the base station can use the terminal capability information to confirm whether the corresponding terminal supports the light connection. The base station can transmit the instruction information for changing the connection state of the terminal to the light connection state as needed.
Hereinafter, an embodiment in which the BS transmits instruction information and an embodiment in which the UE configures the light connection state will be described for each of the embodiments. Each embodiment can be performed individually or in combination.
1) Define a new release cause in the RRC Connection Release message
When the base station recognizes that the terminal supports the write connection, the base station may send an RRC disconnect message to the terminal indicating the release connection as a releasecause.
The terminal that has received the RRC connection release message indicating the cause of releasing the light connection can perform the operation for the light connection state.
The terminal operation for the light connection state indicates performing one or more of the following operations.
- Store terminal context
- Save light connection status terminal identification information
- Perform some or all of the operations of the RRC IDLE terminal (eg, cell reselection, paging, radio resource release / suspension / suspend)
1-1) An embodiment in which the upper layer does not indicate the write connection state
Upon receiving the RRC connection release message indicating the cause of the release of the write connection, the UE transmits a write connection state to the upper layer in order to hide the state transition in the upper layer (NAS: Non Access Stratum and / or user plane radio bearer upper layer) May not be indicated. In this case, the upper layer can not distinguish the light connection state.
For example, when originated data (MO data) to be transmitted in the light connection state is generated, it is considered to be in the RRC Connected state and transmitted to the PDCP buffer mapped to the corresponding bearer. If the suspend PDCP entity is suspended due to the radio resource suspend operation according to the change of the light connection state, data transmission can not be performed. Therefore, if the terminal receiving the RRC disconnect message indicating the cause of the release of the light connection does not indicate the light connection state to the upper layer, it must maintain the PDCP in the light connection state (or keep the PDCP the same as the connection state do). When data is received in the PDCP buffer, it must be able to initiate a transition to the RRC connection state. For example, if the terminal receives a PDCP SDU in the PDCP entity in the light connection state, it can request the RRC to transition from the light connection state to the connection state.
As another example, when an originating signaling (MO signaling, NAS signaling, for example) to be transmitted in the light connection state occurs, the UL information transfer RRC message can be transmitted to the base station in consideration of the RRC Connected state. Since the terminal RRC entity knows that it is in the right connection state, it can initiate a transition to the RRC connection state when origination signaling (e.g., MO signaling or NAS signaling) to be transmitted occurs.
1-2) An example of directing the light connection state to the upper layer and switching only the RRC connection state
The terminal receiving the RRC connection release message indicating the cause of the release of the light connection can indicate the write connection state to the upper layer. In this case, the upper layer can distinguish the light connection state.
For example, when the MO data is transmitted in the light connection state, the upper layer (e.g., NAS) of the terminal may not trigger the service request procedure. When the MO data is transmitted in the light connection state, the upper layer (e.g., NAS) of the UE transmits the RRC connection state (for example, RRC) from the light connection state to the lower layer Lt; / RTI > Upon receiving a transition instruction from the upper layer to the RRC connection state from the light connection state, the RRC can start the transition from the light connection state to the RRC connection state.
As another example, when an originating signaling (for example, MO signaling or NAS signaling) to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the terminal may not trigger the service request procedure. When origination signaling to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the terminal can instruct the lower layer (e.g., RRC) to transition from the light connection state to the RRC connection state. Upon receiving a transition instruction from the upper layer to the RRC connection state from the light connection state, the RRC can start the transition from the light connection state to the RRC connection state. That is, upon receiving a transition instruction from the upper layer to the connection state in the write connection state on the RRC, the RRC can start the transition from the write connection state to the connection state.
When a transition from a light connection state to a connection state is received from an upper layer and a transition to the RRC connection state is started, the terminal transmits the corresponding NAS signaling information (e.g., a transition instruction to the light connection state) There is no need to pass it through the core network.
1-3) An example in which the upper layer indicates the write connection state and the upper layer procedure is performed
The terminal receiving the RRC connection release message indicating the cause of the release of the light connection can indicate the write connection state to the upper layer. In this case, the upper layer can distinguish the light connection state.
For example, when the MO data to be transmitted in the light connection state occurs, the upper layer (e.g., NAS) of the MS may trigger the service request procedure.
As another example, when an MO data to be transmitted in a light connection state occurs, a higher layer (e.g., NAS) of the terminal may trigger a NAS procedure (e.g., an attach procedure or a TAU procedure).
As another example, when the MO data to be transmitted in the light connection state occurs, the upper layer (for example, NAS) of the terminal may trigger a new NAS procedure for transition from the light connection state to the RRC connection state .
When starting the NAS procedure (one of the service procedure, the attach procedure, the TAU procedure and the new NAS procedure) from the upper layer, the RRC of the terminal can recognize that it is in the write connection state, Can be performed. For example, the above-described NAS procedure can be performed between the terminal and the core network entity. As another example, the above-described NAS procedure is not performed between the UE and the core network entity, and only the transition to the RRC connection state occurs, and then the RRC may respond to the NAS. For example, only the transition to the RRC connection state is performed and the terminal does not need to transmit the corresponding NAS signaling information (for example, a transition instruction to the light connection state) to the core network through the base station.
2) Write RRC Connection Reconfiguration message Connection How to Define and Direct Information for Instruction
When the base station recognizes that the terminal supports the write connection, the base station can define information for indicating the write connection to the RRC connection reconfiguration message and instruct the terminal to the information.
The terminal receiving the RRC connection reconfiguration message indicating the light connection can perform the operation for the light connection state.
The terminal operation for the light connection state indicates performing one or more of the following operations.
- Store terminal context
- Save light connection status terminal identification information
- Perform some or all of the operations of the RRC IDLE terminal (eg, one or more of cell reselection, paging, and suspend radio resources)
Meanwhile, the base station may include additional configuration information for instructing the terminal to perform additional detailed operations in the light connection state.
If the UE receives the RRC Connection Reconfiguration message indicating the light connection state and suspends the radio resource according to the indication information, the UE can not transmit the RRC Connection Reconfiguration Complete message to the BS. For example, if the SRB for delivering an RRC message is suspended, it can not deliver the RRC signaling. Or if the MAC is reset, or if the radio configuration information of the cell is suspended, an RRC connection reconfiguration acknowledgment message can not be delivered to the base station.
2-1) Light Connection Reconfiguring RRC Connections Reconfirmation of messages Embodiments that do not send messages
For example, the UE receiving the RRC connection reconfiguration message including the information for indicating the light connection may not transmit the RRC connection reconfiguration acknowledgment message to the base station.
2-2) Light Connection Upon receiving the RRC connection reconfiguration message instructing to send a reconfirmation confirmation message and transition to the light connection,
For example, the MS having received the RRC connection reconfiguration message including the information for indicating the right connection may first reply to the RRC connection reconfirmation confirmation message to the base station and then apply the right connection.
2-3) Example of transition to a light connection through a new RRC connection configuration message different from the RRC connection reconfiguration message
As an example, information for indicating a light connection may be received via a downlink RRC message that is distinct from the RRC connection reconfiguration message. This downlink RRC message may be defined as a message that does not require a success or acknowledgment message. The terminal can receive the downlink message and enter the light connection state.
The terminal does not need to forward acknowledgment or failure messages for this downlink RRC message to the base station.
2-4) Light Connection An embodiment that receives some RRC connection reconfiguration message indicating that it supports some communication function when applying the operation
For example, when a terminal that has received an RRC connection reconfiguration message including information for indicating a light connection transitions to a light connection state, a function for performing an operation to instruct an RRC connection reconfiguration confirmation message to the base station , L2 entity, and MAC maintenance) can be maintained for a predetermined time or until a predetermined criterion is satisfied.
2-5) Light Connection Upon receipt of the RRC connection reconfiguration message indicating that a corresponding timer is in effect when applying the action, By connection Conversion Example
As an example, a terminal receiving an RRC connection reconfiguration message including information for indicating a light connection may operate a timer for transition to a light connection. When the terminal receives an RRC connection reconfiguration message containing information for indicating a write connection, the terminal starts the corresponding timer. When the timer expires, it transitions to the light connection state. The UE may transmit an RRC connection reconfiguration acknowledgment message to the Node B until the timer expires.
As described above, the base station transmits indication information to the terminal through the RRC message, and the terminal can construct a write connection based on the indication information.
Light connection status terminal identification information
On the other hand, the terminal in the light connection state does not perform the handover operation since it is not in the RRC connection state. Therefore, the light connection state terminal can perform the cell re-selection operation according to the movement of the terminal.
For this, even if the light connection state terminal moves, it must be able to identify the corresponding terminal in the network. In addition, when the terminal moves, the base station identification information and / or the cell identification information constituting the terminal in a light connection state may be required to process / fetch / interrogate the terminal context for the terminal.
The following information can be used individually or in combination as the light connection state terminal identification information in order to effectively perform state transition and data transmission for the corresponding terminal.
1) The terminal identification information of the core network is stored as the terminal identification information
The terminal identification information of the core network consists of the core network entity code and the identification information temporarily assigned by the core network entity. Therefore, it is possible to uniquely identify the UE within the core network entity.
2) Cell identification information, wireless network temporary identification information is stored as terminal identification information
If the cell in the network can be uniquely identified through the cell identification information, it can be uniquely identified by combining the cell identification information and the wireless network provisional identification information temporarily allocated by the base station accommodating the cell.
3) Store base station identification information and wireless network temporary identification information as terminal identification information
If the base station in the network can be uniquely identified through the base station identification information, the terminal can be uniquely identified by combining the base station identification information and the wireless network provisional identification information temporarily allocated by the base station.
4) CU identification information, wireless network temporary identification information is stored as terminal identification information
If the CU in the network can be uniquely identified through the CU identification information, the terminal can be uniquely identified by combining the CU identification information and the wireless network provisional identification information temporarily assigned by the corresponding CU.
Terminal paging Example
As described above, the UE can receive the paging message and perform the state transition to the RRC connection state. For example, the terminal in the light connection state can be transited to the RRC connection state according to the paging procedure. Therefore, a terminal paging method for a light connection terminal is proposed.
Cell reselection can be triggered as the light connection state terminal moves.
When the terminal is in the light connection state, a connection (for example, S1 connection) between the core network CN and the radio network RAN is maintained. Therefore, when the downlink data arrives, the core network delivers the data to the base station.
When the light connection state terminal moves, if the light connection state terminal does not update the location of the terminal to the base station, the base station can not know in which cell the terminal is located.
When the downlink data has arrived at the base station, the data (user data or signaling data) transmitted to the base station (indicated as an anchor base station for the sake of convenience in the following description) , The anchor base station needs to perform paging to the terminal so that the terminal transits to the RRC connected state. An anchor base station can perform paging by using the following detailed embodiments individually or in combination.
1) Embodiment for requesting paging through the core network
In the light connection state, the core network does not know that the terminal is in the light connection state, and considers that the terminal is in a connected state as the S1 connection is maintained. Therefore, when the core network entity has a signaling message to be transmitted to the mobile station, the core network entity transmits the downlink data to the anchor base station.
For example, if an anchor base station receives a downlink NAS message (e.g., a DOWNLINK NAS TRANSPORT message) from a control plane core network entity (e.g., MME), the anchor base station may request paging by the MME.
The MME initiates a paging procedure to perform paging to the terminal.
When the light connection state terminal receives the paging, it performs an RRC connection resumption operation (for example, transmits an RRC connection resume message) to transition from the light connection state to the RRC connection state.
If the base station (referred to as a remote base station hereinafter) for performing the RRC connection resumption in order to transit from the light connection state to the RRC connection state is not an anchor base station, Fetch / interrogate, and transit to RRC connection state. The remote base station can establish a connection with the anchor base station. When a connection is established between an anchor base station and a remote base station, the anchor base station delivers the downlink NAS message to the remote base station. The remote base station delivers this to the terminal.
The remote base station that has performed the RRC connection resumption in order to transition from the light connection state to the RRC connection state by the paging may forward the paging success confirmation message to the core network entity.
As another example, if an anchor base station receives downlink data from a user plane core network entity (e.g., Serving GW), the anchor base station can request paging by the MME.
The MME initiates a paging procedure to perform paging to the terminal.
When the light connection state terminal receives the paging, it performs an RRC connection resumption operation (for example, transmits an RRC connection resume message) to transition from the light connection state to the RRC connection state.
If the remote base station that has performed the RRC connection resumption in order to transit from the light connection state to the RRC connection state is not an anchor base station, the remote base station inquires / fetches / interrogates the terminal context from the anchor base station and enters the RRC connection state You can transit. The remote base station can establish a connection with the anchor base station. When a connection is established between an anchor base station and a remote base station, the anchor base station transmits the downlink data to the remote base station. The remote base station delivers this to the terminal.
The remote base station that has performed the RRC connection resumption in order to transition from the light connection state to the RRC connection state by the paging may forward the paging success confirmation message to the core network entity.
As another example, an anchor base station may perform paging directly into a corresponding base station cell or a corresponding terminal location expected area. When an anchor base station reaches a certain criterion, it can request paging with a core network entity.
The anchor base station can release the stored terminal context.
The anchor base station can consider the terminal to be in the RRC IDLE state.
2) Embodiment for receiving information for paging from the core network
In the light connection state, the core network can not know that the terminal is in the light connection state, and the terminal considers the connection state as the S1 connection is maintained. Therefore, when the core network entity has a signaling message to be transmitted to the mobile station, the core network entity transmits the downlink data to the anchor base station.
For example, when an anchor base station receives a downlink NAS message (e.g., a DOWNLINK NAS TRANSPORT message) from a control plane core network entity (e.g., MME), it may initiate paging by an anchor base station Paging can be started with a cell capable of being activated.
Since the anchor base station does not receive the paging message from the control plane core network entity, the anchor base station must store information for paging to directly initiate paging to the terminal. That is, since paging is started in the RAN layer, information for RAN initiation paging must be stored. Hereinafter, information for RAN initiation paging will be described as information for paging or configuration information for RAN initiation paging.
Various embodiments in which an anchor base station obtains information for starting paging will be described below.
2-1) Anchor base station lights on terminal connection Mode When instructed, Core network How to view through
For example, an anchor base station may transmit information indicating a light connection state to a terminal and request information for paging to a core network entity when the terminal transitions to a light connection state. For example, the information received by the anchor base station through the core network entity may include at least one of the terminal identification information, the source cn-domain of the paging, the UE specific DRX information, and the cell area information indicating / configured with the right connection.
Hereinafter, the UE specific DRX indicates DRX information signaled by the UE to the core network entity (MME) or DRX information configured to the UE by the core network entity during a core network procedure (for example, a network registration procedure) . The UE specific DRX may be modified by the base station and the base station may inform the MME of the UE specific DRX. Or can be made transparent to the MME.
2-2) Light connection In state Core network By object Downlink How to query through the core network when data is received
For example, an anchor base station may transmit downlink data (for example, DOWNLINK NAS TRANSPORT) to a terminal configured in a light connection state in a connection of the corresponding terminal (connection between a control plane core network entity and a base station, Message), it can request information for paging through the control plane core network entity (e.g., MME). For example, the information that the anchor base station requests through the core network entity may include at least one of the terminal identification information, the source cn-Domain of the paging, UE specific DRX information, and / have.
As another example, the anchor base station may transmit the downlink data (e.g., user plane data) in the connection of the corresponding terminal (connection between the user plane core network entity and the base station, for example, S1-U connection) The base station can request information for paging through the control plane core network entity (for example, MME). The information requested by the anchor base station through the core network entity may include at least one of the terminal identification information, the source cn-Domain of the paging, the UE specific DRX information, and the cell area information indicating / configured as the right connection.
Meanwhile, the base station can buffer the downlink data until it receives the paging information by inquiring / fetching / interrogating / requesting it. The base station may monitor data reception on the S1 connection associated with the terminal when configuring the light connection state with the terminal.
2-3) Light Connection Initial support for supported terminals Context A method for receiving information for paging when transmitting to a base station
As described above, the base station can know the terminal supporting the light connection through the terminal capability information. The base station may transmit information including information for paging when transmitting the corresponding terminal context to the base station supporting the light connection.
For example, the control plane core network entity may transmit initial context setup request message including information for paging to the base station. The information for paging included in the initial context setup request message may include at least one of the UE identification information, the source cn-Domain of the paging, the UE specific DRX information, and the cell area information indicating / configured as the right connection.
3) An example in which paging related information is updated from the terminal
3-1) Light Connection RRC directing In a confirmation message How to include
For example, when the MS receives the RRC message indicating the write connection from the BS, the MS may transmit the response message including the information for paging to the BS.
For example, the information for paging may include one or more of terminal identification information, a source cn-Domain of paging, UE specific DRX information, and cell area information indicated / configured for a light connection.
3-2) Light connection RRC < / RTI > In a confirmation message How to include
For example, a terminal configured in a light connection state may transmit information to a base station including information for paging when requesting an RRC connection resumption to transition from a light connection state to an RRC connection state. For example, the information for paging may include one or more of terminal identification information, source cn-Domain of paging, and UE specific DRX information.
As another example, a terminal configured in a light connection state can request an RRC connection resumption in order to transition from a light connection state to an RRC connection state and receive an acknowledgment or response message thereto. The MS may transmit the RRC message for transition to the right connection state to the BS including information for paging. The information for paging may include at least one of the UE identification information, the source cn-Domain of paging, and the UE specific DRX information.
As another example, a terminal configured in a light connection state requests an RRC connection restart to transition from a light connection state to an RRC connection state. In addition, information request indication information for paging can be received in an acknowledgment / response message for the RRC connection resumption request. The MS can forward the RRC message (or the RRC message for transitioning to the right connection state) to the BS including the information for paging in response thereto. The information for paging may include at least one of terminal identification information, source cn-domain of paging, UE specific DRX information, and cell area information indicating / configured as a write connection.
3-3) Light connection Cell in state Reselection To update the terminal information and to transmit it
A terminal configured in a light connection state can perform cell reselection according to movement.
For example, when the UE performs the cell reselection in the light connection state, the UE can transmit configuration information for RAN initiation paging to the anchor BS. The base station can configure the terminal with information for instructing such operation. The configuration information for RAN initiation paging may include at least one of the UE identification information, the source cn-Domain of the paging, the UE specific DRX information, and / or the cell area information to which the right connection is directed / configured.
As another example, when the terminal transits to the light connection state, the base station can transmit the configuration information for RAN initiation paging to the anchor base station in the light connection state. The configuration information for RAN initiation paging may include at least one of the UE identification information, the source cn-Domain of the paging, the UE specific DRX information, and / or the cell area information to which the right connection is directed / configured. The base station can configure the terminal with additional information for instructing this operation. For example, the UE can configure period / timer information for triggering an update, cell reselection number information for triggering an update, and cell area information for triggering an update (trigger if the cell area information is out of the range). The UE can transmit information for paging to the anchor BS when the trigger condition is satisfied.
The embodiments of the paging method, which is one of the trigger conditions for performing the state transition to the RRC connected state, of the terminal in the light connection state have been described above. When the paging is started, the light connection terminal can perform the transition operation to the RRC connected state. In this case, as described above, the terminal needs to determine whether or not to perform the operation for congestion control in the transition operation to the RRC connected state.
Hereinafter, detailed operation of the operation for congestion control in the case where the UE performs the transition operation to the RRC connection state will be described in detail.
ACB (Access Class Barring)
The terminal can enter the light connection state by the base station instruction. The terminal in the light connection state can be located in the cell indicating the light connection state. Alternatively, the terminal can reselect another cell out of the cell indicating the light connection state in accordance with the movement. The following methods can be used independently or in combination for congestion control for terminals that are configured in the light connection state.
1) How to resume RRC connection without applying ACB
The light connection state can also be regarded as a sub state belonging to the RRC connection state, so that the ACB may not be applied when the terminal is in the light connection state.
For example, when the terminal resumes the RRC connection for the mobile origination data or the mobile origination signaling in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal transmits a check for congestion control For example, an RRC connection can be resumed without performing an access barring check.
Specifically, the terminal applies the default physical channel configuration. The terminal applies the default MAC main configuration. The terminal applies the default CCCH configuration (for example, as specified in 3GPP TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The MS starts the RRC connection resumption (transition from the right connection state to the RRC connection state) message.
As another example, when the terminal resumes the RRC connection for mobile terminated calls in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal checks for congestion control (For example, transition from a light connection state to an RRC connection state) without performing an access barring check.
If the RRC Connection Reject message is received, the RRC restart procedure is terminated.
Otherwise, the terminal applies the default physical channel configuration. The terminal applies the default MAC main configuration. The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2). The terminal starts the corresponding timer.
The MS starts the RRC connection resumption (transition from the right connection state to the RRC connection state) message.
To this end, the base station may broadcast information for instructing the terminal configured in the light connection state to initiate the connection without performing the congestion control (for example, ACB) through the system information. Alternatively, the base station can configure the terminal with dedicated signaling information for instructing the terminal configured in the light connection state to initiate the connection without performing congestion control (e.g., ACB). Alternatively, a procedure for transitioning from the light connection state to the connection state may be predefined and stored or contracted so as not to perform congestion control (for example, ACB).
2) Applying ACB and waiting for the grant of the cell from the AS layer when access is prohibited
The light connection state terminal can perform the cell re-selection according to the movement of the light connection state terminal. When congestion occurs in the reselected cell, information (for example, ACB information) for congestion control can be broadcast through the system information. If there are many light connection state terminals, congestion may be increased by these terminals, and ACB may be applied to the light connection state terminal.
For example, when the terminal resumes the RRC connection for the mobile originated data in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal sends a check for congestion control barring check.
If it contains access barring information for mobile origination data, it is considered that access to that cell is prohibited.
If access to the cell is barred, the terminal can resume the RRC connection for mobile origination data when mobile origination data is allowed on the current cell or when the terminal moves to a cell where mobile origination data is allowed have.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The MS initiates the RRC connection resumption message transmission.
As another example, if origination data (MO data) to be transmitted in the write connection state occurs, the terminal may consider the RRC Connected state and may transmit the origination data to the PDCP buffer mapped to the bearer. In order to be able to wait for the transmission of the corresponding cell in the AS layer, if the source data to be transmitted to the terminal in the light connection state occurs, the corresponding data must be buffered in the AS layer. For example, when the outgoing data to be transmitted reaches the light connection state, the terminal performs the ACB. If access is prohibited, the terminal may buffer the data until the mobile originating data is allowed on the current cell or until the terminal moves to the cell where the mobile originating data is allowed.
As another example, when the terminal resumes the RRC connection for the mobile origination signaling in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal sends a check for congestion control access barring check.
If it includes access barring information for mobile origination signaling, it is considered that access to the cell is prohibited.
If access to the cell is barred, the terminal can resume the RRC connection for mobile origination signaling when mobile origination signaling is allowed on the current cell or when the terminal moves to a cell where mobile origination signaling is allowed have.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The MS initiates the RRC connection resumption message transmission.
Meanwhile, the base station can configure information for instructing the operation of the above-described terminal through the RRC message in the terminal.
3) Applying ACB and instructing it to the upper layer when access is prohibited, and waiting for the upper layer to allow the outgoing signaling of the corresponding cell
The light connection state terminal can perform the cell re-selection according to the movement of the light connection state terminal. When congestion occurs in the reselected cell, information (for example, ACB information) for congestion control can be broadcast through the system information. If there are many light connection state terminals, congestion may be increased by these terminals, and ACB may be applied to the light connection state terminal.
For example, when the terminal resumes the RRC connection for the mobile originated data in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal sends a check for congestion control barring check.
If it contains access barring information for mobile origination data, it is considered that access to that cell is prohibited.
If access to the cell is barred, the terminal informs the upper layer that the RRC connection has failed to resume (transition from the write connection to the RRC connection state) and that the access barring is applicable when the procedure terminates .
When the UE is allowed mobile origination data on the current cell or when the UE moves to a cell where the mobile origination data is allowed, the upper layer may instruct the lower layer to retry or retransmit the RRC connection for mobile originating data .
The terminal may resume the RRC connection for mobile originating data.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The MS initiates the RRC connection resumption message transmission. If successful, the RRC connection resume procedure ends and informs the upper layer.
As another example, when the terminal resumes the RRC connection for the mobile origination signaling in the light connection state (transitions from the light connection state to the RRC connection state), the terminal checks for congestion control barring check.
If it includes access barring information for mobile origination signaling, it is considered that access to the cell is prohibited.
If access to the cell is barred,
The MS informs the upper layer that the RRC connection has failed to resume and that the access barring has been applied when the procedure is terminated.
When a mobile is allowed to originate a signal on a cell in the current cell or when a mobile station moves to a cell where mobile origination signaling is allowed, the upper layer can instruct the lower layer to retry or retransmit the RRC connection for mobile origination signaling .
The terminal may resume the RRC connection for mobile origination signaling.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The MS initiates the RRC connection resumption message transmission.
4) Applying ACB and switching to RRC idle mode when access is disabled
The light connection state terminal can perform the cell re-selection according to the movement of the light connection state terminal. When congestion occurs in the reselected cell, information (for example, ACB information) for congestion control can be broadcast through the system information. If there are many light connection state terminals, congestion may be increased by these terminals, and ACB may be applied to the light connection state terminal.
For example, when the terminal resumes the RRC connection for the mobile originated data in the light connection state (when transitioning from the light connection state to the RRC connection state), the terminal sends a check for congestion control barring check.
If it contains access barring information for mobile origination data, it is considered that access to that cell is prohibited.
If access to the cell is barred, the terminal informs the upper layer that the RRC connection has failed to resume and that access barring is applicable when the procedure terminates.
The terminal leaves the light connection state. Or the terminal transits from the light connection state to the RRC IDLE state. Or the UE enters the RRC IDLE state.
When the mobile originating data is allowed on the current cell or when the mobile station moves to the cell where the mobile originating data is allowed, the upper layer can instruct the lower layer to establish an RRC connection for the mobile originating data. RRC From the IDLE state to the RRC connection state, it can indicate a transition attempt, retry or retransmission.
The terminal may establish an RRC connection for mobile origination data.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The terminal initiates transmission of the RRC connection setup message. If successful, the RRC connection establishment procedure ends and informs the upper layer.
As another example, when the terminal resumes the RRC connection for the mobile origination signaling in the light connection state (transitions from the light connection state to the RRC connection state), the terminal checks for congestion control barring check.
If it includes access barring information for mobile origination signaling, it is considered that access to the cell is prohibited.
If access to the cell is barred, the terminal informs the upper layer that the RRC connection has failed to resume and that the access barring has been applied when the procedure is terminated.
The terminal leaves the light connection state. Or the terminal transits from the light connection state to the RRC IDLE state. Or the UE enters the RRC IDLE state.
When the mobile originating data is allowed on the current cell or when the mobile station moves to a cell where mobile origination data is allowed, the upper layer can instruct the lower layer to establish an RRC connection for mobile origination signaling. RRC From the IDLE state to the RRC connection state, it can indicate a transition attempt, retry or retransmission.
The terminal may establish an RRC connection for mobile origination data.
The terminal applies the default physical channel configuration.
The terminal applies the default MAC main configuration.
The terminal applies the default CCCH configuration (for example, as specified in TS 36.331 9.1.1.2).
The terminal starts the corresponding timer.
The terminal initiates transmission of the RRC connection setup message. If successful, the RRC connection establishment procedure ends and informs the upper layer.
As described above, the embodiments of the present invention allow less processing effort for terminals that perform frequent connection setups and allow more capacity to be used for network nodes. Also, power consumption of the terminal can be reduced. In addition, congestion control can be effectively performed.
Hereinafter, a terminal device and a base station device capable of performing a part or all of the operations of the embodiments described with reference to Figs. 1 to 4 will be described.
5 is a diagram for explaining a terminal configuration according to an embodiment.
5, the
Meanwhile, the RRC connection release message may further include configuration information for RAN (Radio Access Network) initiation paging for the terminal in the light connection state. For example, the configuration information for RAN initiation paging may include at least one of paging cycle information and cell area information for paging update. As another example, the configuration information for RAN initiation paging may include information of at least one of the UE identification information, the source cn-domain of paging, UE specific DRX information, and cell area information indicating light connection. As another example, the RRC disconnect message may include period / timer information to trigger an update to the configuration information for RAN initiation paging, cell reselection number to trigger the update, and cell area information And a surface trigger).
The
When the
In addition, the
When the transition to the RRC connection state is triggered, the
In addition, the
Also, the
In addition, when the light connection terminal changes the connection state in the RRC connection state, the
Meanwhile, the
6 is a view for explaining a base station configuration according to an embodiment.
6, the
The RRC connection release message may further include configuration information for RAN (Radio Access Network) initiation paging for the terminal in the light connection state. For example, the configuration information for RAN initiation paging may include at least one of paging cycle information and cell area information for paging update. As another example, the configuration information for RAN initiation paging may include information of at least one of the UE identification information, the source cn-domain of paging, UE specific DRX information, and cell area information indicating light connection. As another example, the RRC disconnect message may include period / timer information to trigger an update to the configuration information for RAN initiation paging, cell reselection number to trigger the update, and cell area information And a surface trigger).
The base station needs to know whether the corresponding terminal supports the light connection state. The receiving
When the terminal transitions to the light connection state, the
In addition, if a transition to the RRC connection state for the terminal in the light connection state is triggered, the
In one example, a change of state to an RRC connected state may be triggered by receiving a radio access network (RAN) initiating paging message or by detecting outgoing data. Specifically, when the paging message for the terminal in the light connection state is received, the terminal can perform the transition operation to the RRC connected state. Alternatively, when the outgoing data to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state. Alternatively, if outgoing signaling to be transmitted from the terminal in the light connection state to the base station is detected, the terminal can perform the transition operation to the RRC connected state.
Meanwhile, the RRC connection resumption request message may include the cause information that causes the state change trigger to the RRC connection state. The cause information of the trigger cause may include information on whether it is due to the above-described paging or detection of origination data or detection of origination signaling.
In addition, the
The transmitting
The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.
The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.
Claims (20)
Receiving a Radio Resource Control (RRC) disconnect message including indication information indicating a change of state from a base station to a light connection state;
Configuring the connection state of the terminal into the light connection state based on the instruction information; And
And transmitting an RRC connection resumption request message to the base station when the state change to the RRC connection state is triggered,
Before the step of receiving the RRC connection release message
Further comprising the step of transmitting, to the base station, terminal capability information indicating that the terminal supports the light connection state,
The RRC disconnection message may include:
Further comprising paging cycle information for RAN (Radio Access Network) initiation paging for the terminal in the light connection state and cell area information for paging update,
The step of configuring in the light connection state comprises:
(SRB) and a data radio bearer (DRB) of the mobile station, storing a terminal context, instructing an upper layer to transition to the write connection state,
Wherein the upper layer comprises:
When the state change to the RRC connected state is triggered after a transition to the light connection state is instructed, a transition to the RRC connected state is instructed without triggering a service request procedure,
The terminal in the light connection state,
Identified by the light connection state terminal identification information,
The light connection state terminal identification information includes:
And a combination of base station identification information constituting the terminal in the light connection state and wireless network temporary identification information temporarily allocated by the base station.
The state change to the RRC connection state may include:
Characterized in that it is triggered by receiving a Radio Access Network (RAN) start paging message or by detecting outgoing data.
The step of configuring in the light connection state comprises:
And performing a cell re-selection operation when the terminal moves.
Transmitting an RRC (Radio Resource Control) connection release message including instruction information for instructing a terminal to change a state to a light connection state;
Changing a connection state from the RRC connection state to the light connection state; And
Receiving an RRC connection resumption request message according to a state change trigger to the RRC connected state of the terminal,
Prior to transmitting the RRC disconnect message,
Further comprising receiving, from the terminal, terminal capability information indicating that the terminal supports the light connection state,
The RRC disconnection message may include:
Further comprising paging cycle information for a radio access network (RAN) start paging for the terminal in the light connection state and cell area information for paging update,
The terminal,
Upon receiving the RRC connection release message, instructs an upper layer to transition to the write connection state,
The upper layer of the terminal,
When the state change to the RRC connected state is triggered after a transition to the light connection state is instructed, a transition to the RRC connected state is instructed without triggering a service request procedure,
The terminal in the light connection state,
Identified by the light connection state terminal identification information,
The light connection state terminal identification information includes:
And a combination of base station identification information constituting the terminal in the light connection state and wireless network temporary identification information temporarily allocated by the base station.
A receiving unit for receiving an RRC (Radio Resource Control) connection release message including instruction information for instructing a state change from a base station to a light connection state;
A controller configured to configure the connection state of the terminal to the light connection state based on the instruction information; And
And a transmitter for transmitting an RRC connection resumption request message to the base station without a connection class restriction (Access Class Barring) operation when the state change to the RRC connection state is triggered,
The transmitter may further comprise:
Further transmitting, to the base station, terminal capability information indicating that the terminal supports the light connection state,
The RRC disconnection message may include:
Further comprising paging cycle information for a radio access network (RAN) start paging for the terminal in the light connection state and cell area information for paging update,
Wherein,
The method comprising: stopping all Signaling Radio Bearers (SRBs) and a data radio bearer (DRB) of the UE, storing a terminal context, instructing an upper layer to transition to the write connection state,
Wherein the upper layer comprises:
When the state change to the RRC connected state is triggered after a transition to the light connection state is instructed, a transition to the RRC connected state is instructed without triggering a service request procedure,
The terminal in the light connection state,
Identified by the light connection state terminal identification information,
The light connection state terminal identification information includes:
A base station identification information in which the terminal is configured in the light connection state, and a wireless network temporary identification information that is temporarily allocated by the base station.
The state change to the RRC connection state may include:
(RAN) start paging message or detection of outgoing data.
Wherein,
And performs a cell re-selection operation when the UE moves.
A transmission unit for transmitting an RRC (Radio Resource Control) connection release message including instruction information for instructing a state change to a state of a light connection to the terminal;
A controller for changing a connection state from the RRC connection state to the light connection state; And
And a receiver for receiving an RRC connection resumption request message according to a state change trigger to the RRC connected state of the terminal,
The receiver may further comprise:
The terminal further receives terminal capability information indicating that the terminal supports the light connection state from the terminal,
The RRC disconnection message may include:
Further comprising paging cycle information for a radio access network (RAN) start paging for the terminal in the light connection state and cell area information for paging update,
The terminal,
Upon receiving the RRC connection release message, instructs an upper layer to transition to the write connection state,
The upper layer of the terminal,
When the state change to the RRC connected state is triggered after a transition to the light connection state is instructed, a transition to the RRC connected state is instructed without triggering a service request procedure,
The terminal in the light connection state,
Identified by the light connection state terminal identification information,
The light connection state terminal identification information includes:
Wherein the base station comprises a combination of base station identification information constituting the terminal in the light connection state and wireless network temporary identification information temporarily allocated by the base station.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710291278.2A CN107343299B (en) | 2016-05-03 | 2017-04-28 | Method and apparatus for changing connection state of UE |
| US15/582,906 US10159025B2 (en) | 2016-05-03 | 2017-05-01 | Method and apparatus for changing connection state of UE |
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| KR1020160054930 | 2016-05-03 | ||
| KR20160054930 | 2016-05-03 |
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| KR102008886B1 (en) * | 2017-12-28 | 2019-08-08 | 에스케이텔레콤 주식회사 | Method for controlling state transition of terminal and estimating load of mobile network using inactive state, and apparatus for mobile communication applying same |
| KR102425581B1 (en) * | 2018-02-23 | 2022-07-27 | 삼성전자주식회사 | Method and apparatus for performing communication in mobile communication system |
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Non-Patent Citations (4)
| Title |
|---|
| 3gpp R2-162885 |
| 3gpp S2-161008* |
| 3gpp S2-161625 |
| 3GPP TR 23.799 v0.4.0 |
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