WO2014073781A1

WO2014073781A1 - Method of controlling rf resource of base station, base station, and terminal

Info

Publication number: WO2014073781A1
Application number: PCT/KR2013/007968
Authority: WO
Inventors: 홍성표; 이경준
Original assignee: 주식회사 케이티
Priority date: 2012-11-07
Filing date: 2013-09-04
Publication date: 2014-05-15

Abstract

The present invention relates to a method of controlling RF resources of a base station in order to decrease the idle-connection transition of a terminal, and includes receiving core network assistance information while an RRC connection is set up, and setting up an RAN parameter for setting up a connection by using the core network assistance information. The present invention provides the method of controlling the RF resources of a base station, a base station and a terminal.

Description

Radio resource control method of base station, base station and terminal thereof

The present invention relates to a radio resource control method of a base station, a base station and a terminal thereof.

With the proliferation of smartphones, the use of mobile data applications (for example, MSN, Skype, google talk, facebook, etc.) is increasing rapidly.

Mobile data applications frequently generate a small amount of background traffic (e.g., instant messenger) between a mobile application server and a mobile device providing services to the mobile data application, even when there is no direct interaction between the terminal and the user. Chat, heartbeat, keep-alive, status update, and the like. That is, an application installed on the mobile application server and the terminal periodically exchanges heartbeat, keep-alive, or status update messages for the purpose of keeping the application session alive or for presence status updates. do.

This frequently occurring background data traffic repeatedly causes Radio Resource Control (RRC) signaling to the wireless network, which causes network load and terminal battery consumption. Here, the RRC is divided into an RRC connected state and an RRC idle state according to whether a logical connection is made between the RRC of the UE and the RRC of the E-UTRAN.

In order to solve the above-mentioned problem, that is, to reduce the RRC state transition caused by a small amount of background data traffic, the following methods have been proposed.

The first method is a method in which a terminal transmits a background data traffic to a base station by including a non-access stratum (NAS) signaling message without a transition from an idle state to a connected state. Then, when the terminal transmits a message to the mobility management entity (MME) through the control plane connection (Control plane connection), the MME delivers to the base station through the S-GW. In this method, the UE and the base station sends a NAS signaling message including background data in the RRC connection establishment message, and the base station releases the RRC connection by sending an RRC connection release message without transitioning to the connected state.

Secondly, the UE transmits to the base station without the transition from the idle state to the base station, including the fully-qualified tunnel end point identifier (F-TEID) of the S-GW in the background data traffic, without the control plane connection between the base station and the MME There is a way to pass data through the user plane.

When using the first method and the second method, there is a problem that requires a significant change in the function of the current mobile communication terminal, base station, core network entity. In addition, there is a problem that it is difficult to cause overload or mobility support to the existing core network signaling entity (MME).

Third, to reduce the RRC state transition, there is a method of keeping the connected state long. In this method, in order to reduce the RRC state transition, the base station sets a user inactivity timer longer than a normal user idle timer to keep the RRC connected state long. This method can be applied without major modification of the current mobile communication network function. However, if the RRC connection state is kept long, handover signaling for supporting more battery consumption and mobility than the RRC idle state may be caused.

Accordingly, the present invention provides a method and apparatus for preventing frequent state transitions through states of background traffic that occur periodically in the absence of actual interaction by a user.

In addition, the present invention provides a method and apparatus for reducing the load of the wireless section or the battery consumption of the terminal caused by frequent state transitions.

In one aspect, the present invention is a method of controlling a radio resource of a base station to reduce the terminal idle-connection state transition, during the RRC connection establishment, receiving the core network assistance information (Core Network assistance information) and the core network assistance information It includes a radio resource control method of a base station comprising the step of setting a RAN parameter (RAN parameter) for connection establishment using.

In this case, the RAN parameter may be at least one of a user inactivity timer (RRC inactivity timer) and a downlink DRX cycle.

Meanwhile, the core network assistance information may be generated based on at least one of subscription information of the terminal, data traffic state of the terminal, and mobility of the terminal.

Meanwhile, in the step of receiving the core network assistance information, the core network assistance information may be received through an initial context setup request message.

Meanwhile, when the RAN parameter is a downlink DRX cycle, in the step of setting the RAN parameter using core network assistance information, the downlink DRX cycle is transmitted to the terminal through an RRC connection reconfiguration message. Can transmit

Meanwhile, in the step of receiving core network assistance information, core network assistance information may be received from a mobile management entity (MME).

In another aspect, the present invention is a base station for controlling radio resources to reduce the terminal idle-connection state transition, during the RRC connection establishment, the receiver and the core network assistance information receiving the core network assistance information (Core Network assistance information) It includes a base station including a control unit for setting a RAN parameter (RAN parameter) for connection establishment using.

Meanwhile, the receiver may receive the core network assistance information through an initial context setup request message.

Meanwhile, when the RAN parameter is a downlink DRX cycle, the downlink DRX cycle is transmitted to the UE through an RRC connection reconfiguration message to configure the RAN parameter using core network assistance information. The request unit may further include.

Meanwhile, the receiver may receive core network assistance information from a mobile management entity (MME).

In another aspect, the present invention, in order to reduce the terminal idle-connection state transition, the radio resource control method of the terminal, during the RRC connection establishment, the connection configuration using the received Core Network assistance information (Core Network assistance information) Receiving a message including a RAN parameter for the RAN parameter from the base station and changing a reception period of the RAN parameter according to the RAN parameter of the message received from the base station. It includes.

In this case, the RAN parameter is a downlink DRX cycle, and the downlink DRX cycle may be transmitted to the UE through an RRC connection reconfiguration message.

Meanwhile, the core network assistance information may be received from a mobile management entity (MME).

In another aspect, the present invention, in order to reduce the terminal idle-connection state transition, during the RRC connection setup, using the received Core Network assistance information (RAN network) for setting the RAN parameters (RAN parameters) Receiving unit for receiving a message containing from the base station; And a controller for changing the RAN parameter according to the RAN parameter of the message received from the base station.

According to the present invention, it is possible to prevent frequent state transitions through the state of background traffic that occurs periodically in the absence of actual interaction by the user.

In addition, according to the present invention it is possible to reduce the load of the wireless section or the battery consumption of the terminal caused by the frequent state transition.

1 is a diagram illustrating an RRC state transition between a general terminal and a base station.

2 is an exemplary diagram of an environment for an RRC state transition according to the first embodiment of the present invention.

3 is a structural diagram of a state transition control system according to a first embodiment of the present invention.

4 is a structural diagram of an MME according to an embodiment of the present invention.

5 is a flowchart illustrating a state transition method according to a first embodiment of the present invention.

6 is a flowchart illustrating another state transition method according to the first embodiment of the present invention.

7 is an exemplary diagram of an environment for an RRC state transition according to a second embodiment of the present invention.

8 is a flowchart illustrating a state transition method according to a second embodiment of the present invention.

9 is a flowchart illustrating another state transition method according to a second embodiment of the present invention.

10 is a flowchart illustrating a method of processing a mobile terminal having high mobility according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

In the present specification, a terminal is a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user device (User). It may also refer to an Equipment (UE), an Access Terminal (AT), or the like, and may include all or some functions of a mobile terminal, a subscriber station, a portable subscriber station, a user device, and the like.

In the present specification, a base station (BS) may include an access point (AP), a radio access station (RAS), a node B (Node B), an eNodeB, a base transceiver station (BTS), MMR (Mobile Multihop Relay) -BS, etc. may be referred to, and may include all or part of the functions of an access point, a radio access station, a NodeB, an eNodeB, a base transceiver station, an MMR-BS, and the like.

In the present specification, the RAN parameter means a parameter of a terminal and / or a base station. For example, the RAN parameter may be a user inactivity timer (RRC inactivity timer), a downlink DRX cycle, or the like.

Hereinafter, an RRC state transition control system and method according to an embodiment of the present invention will be described with reference to the accompanying drawings. Before describing an embodiment of the present invention, a general RRC state transition will be described first.

As shown in FIG. 1, in an LTE mobile communication network, a terminal and an E-UTRAN enter an RRC connection state through an initial network registration process. If no user data traffic is generated in the RRC connected state and a user inactivity time elapses for a predetermined time, the UE and the E-UTRAN transition from the RRC connected state to the RRC idle state. After the background data is generated by the mobile data application of the terminal in the RRC idle state, the terminal operates a service request procedure in the Non Access Stratum (NAS) layer.

Through this, an RRC connection establishment procedure of an access stratum (AS) layer is initiated, and the terminal and the base station are each transitioned to the RRC connection state. Therefore, even while there is no direct interaction between the terminal and the user, the background data traffic is periodically generated by the mobile data application, so that the terminal and the base station continuously repeat the state transition. Frequent state transitions due to background data traffic may cause frequent RRC signaling to the wireless network and consume battery of the terminal.

Therefore, an embodiment of the present invention describes a system and method for controlling a state transition so that a frequent state transition does not occur. In the embodiment of the present invention, the first method of controlling the state transition through the base station-MME connection and the second method of controlling the state transition through the digital unit (DU) -virtualization server connection will be described. Can be. First, an example of controlling the state transition through the base station-MME connection will be described.

As shown in FIG. 2, the MME 400 interworks with the base station 300 and transmits background traffic state information generated in the terminal 200 located in the cell area formed by the base station 300 to the base station 300. Transfer the control system 100 (not shown) to control the state transition of the terminal 200. In the first embodiment of the present invention, the control system 100 is included in the base station 300 as an example.

The control system 100 determines the adjusted connection state in which the parameter value is changed according to the service request message requested by the terminal 200 to the base station 300, bearer setting information of the current terminal 200, or data traffic state estimation information. This informs the terminal 200. Herein, the adjusted connection state (hereinafter referred to as 'second connection state' for convenience of description) is set in a general RRC connection state (hereinafter referred to as 'first connection state' for convenience of description). It means that the connection status is set to different parameters from the existing parameters.

The structure of the control system 100 for controlling the RRC state transition in such an environment will be described in detail with reference to FIG. 3. Here, when the terminal 200 and the base station 300 perform the initial network registration procedure, it is assumed that the first RRC connection state is maintained as a parameter value of a general connection state.

As shown in FIG. 3, the control system 100 for controlling the RRC state transition includes a background state information receiver 110, an RRC state controller 120, and a state setting requester 130.

The background state information receiver 110 receives background state information transmitted from the MME 400 connected to the base station 300 including the control system 100. The background state information includes help information for estimating the background state by the RRC state controller 120 and / or data traffic state estimation information.

In this case, the assistance information for estimating the background state is information determined by considering the number of RRC connection-idle state transition times in the MME 400. If the MME 400 determines that the number of state transitions for a predetermined time exceeds a certain criterion based on the reference information, the MME 400 indicates that the help information indicates that the second connection state is preferred according to the background data traffic state estimation. Sending to the control system 100 including. Otherwise, the help information is not sent, or the help information is sent to the control system 100 including information indicating that the first connection state is preferred according to the background data traffic state estimation. This will be described later in detail. The data traffic state estimation information may indicate information for estimating a traffic pattern. The data traffic state estimation information may be expressed as "high", "medium", "low". As an example of this, the data traffic state information may include a recent signaling transition frequency value (e.g., a number of transitions within a recent specific time (e.g., 1 minute), or a frequency specified within a recent specific time (e.g., a minute). For example, five times or more is represented by a "high", and another specific number (eg, two times) or less is represented by a "low" and between the specific number and another specific number. (Eg, 2 to 5 times) may be expressed as “medium.” As another example of this, the data traffic state information may include an interval between recent signaling transitions or a connection duration (eg, a last signaling transition). Interval / connection duration, average of the last three signaling transition intervals / connection duration).

The RRC state control unit 120 determines the RRC state of the terminal 200 in the idle state or the first connection state based on the RRC state of the terminal 200 based on the background state information received by the background state information receiving unit 110. 2 Determine whether to set the connection state or the RRC first connection state.

The RRC state controller 120 may determine whether to make the RRC connection state as the first connection state or the second connection state by receiving information on the number of terminals currently in the RRC connection state from the base station 300. In this case, the terminal number information includes consensus information (hereinafter, referred to as 'first terminal number information') of the number of terminals in an RRC first connected state and the number of terminals in an RRC second connected state, and the number of terminals set in an RRC second connection (hereinafter, The number of any one of 'terminal number information') or the number of terminals (hereinafter, referred to as 'third terminal number information') set as the RRC first connection.

That is, a load is applied to the base station 300 in which the number of terminals according to any one of the number of terminals according to the first terminal number information, the number of terminals according to the second terminal number information or the number of terminals according to the third terminal number information is preset. When the number of terminals set not to be given is exceeded, the RRC state controller 120 does not set the RRC connection of the terminal 200 to the RRC second connection state.

When the RRC connection of the terminal 200 is set to the RRC second connection state, the RRC state controller 120 sets a timer to maintain the RRC connection for a longer time than the user idle timer value set in the RRC first connection. . In addition, it is set to a parameter different from the parameter set in the RRC first connection state. This will be described later.

The state setting requester 130 transmits to the terminal 200 to set the state to the RRC connection state determined by the RRC state control unit 120.

Next, a structure of the MME 400 that provides status information to the control system 100 to be used as information when controlling the state transition will be described with reference to FIG. 4.

As shown in FIG. 4, the MME 400 includes a message receiver 410, a background state information generator 420, and a state transition number managing unit 430.

The message receiving unit 410 receives an encapsulated initial terminal message (S1-AP initial UE message) including a NAS message transmitted from the base station 300. The initial terminal message includes a tracking area (TAI) of a base station to which the terminal 200 is connected, and an Enhanced Cell Global Identifier (ECGI) indicating which cell of which base station the terminal 200 is attached to, and the MME 400. Generates a TAI list of subscribers based on this information. Details of the initial terminal message are already known, and detailed descriptions thereof will be omitted in embodiments of the present invention.

When the base station 300 transmits an S1 context release message (S1-AP UE Context Release Request) after the user idle time elapses, the message receiver 410 receives the S1 context release request. The S1 context message is already known and the detailed description is omitted in the embodiment of the present invention.

The state transition number managing unit 430 manages the number of state transitions for the terminal 200 through the message receiving unit 410. That is, when the message receiver 410 receives the initial terminal message, it may detect a state transition. In addition, the background state information generator 420 provides to generate help information when generating the state information.

When the message receiver 410 receives the encapsulated initial terminal message, the background state information generator 420 generates background state information to be included in the initial context setup request message. The initial context setup request message including the generated background state information is transmitted to the base station 300.

The background state information may include help information and / or data traffic state estimation information for the control system 100 to estimate the background traffic state. The help information is determined in consideration of the number of connection-idle state transitions and the like in the MME 400.

For example, before the MME 400 sends the initial context setup request message to the base station 300, if the number of state transitions exceeds a predetermined predetermined criterion for a preset time, the MME 400 may request help information. According to the background data traffic state estimation, information indicating that the second connection state is preferred is sent to the control system 100. Otherwise, the help information is not sent, or the help information is sent to the control system 100 including information indicating that the first connection state is preferred according to the background data traffic state estimation.

Here, an example of exceeding a predetermined criterion is a case where a state transition occurs more than a predetermined number of times, for example, 1 minute, for a predetermined time before sending a message to the base station 300. Alternatively, n state transitions occur during a time in which n times the user idle time set in the base station 300 (where n is any integer) plus a predetermined additional time before sending a message. Assuming that 10 seconds, the schedule addition time is 5 seconds, and n is 5 seconds, for example, five state transitions occur for a total of 55 seconds (5 times 10 seconds + 5 seconds).

In this case, the assistance information including information indicating that the second connection state is preferred is part of subscription information of a terminal included in a home subscriber server (HSS) and is set in a terminal context of the MME 400. It can also be created based on specific subscription information.

A method of controlling the state transition through the control system 100 and the MME 400 described above will be described with reference to FIGS. 5 and 6.

5 is a flowchart illustrating a state transition method according to the first embodiment of the present invention, and FIG. 6 is a flowchart illustrating another state transition method according to the first embodiment of the present invention.

First, as shown in FIG. 5, the terminal 200 transmits an encapsulated service request NAS message to the base station 300 to the MME 400 in an RRC message (S100). The base station 300 encapsulates the NAS message in an initial UE message (S1-AP) and sends it to the MME 400 (S110). Since methods for encapsulating messages are already known, detailed descriptions are omitted in embodiments of the present invention.

The background state information generator 420 of the MME 400 transmits an initial context setup request message (S1-AP Initial Context Setup Request) to the base station in response to the initial terminal message received by the message receiver 410 in step S110. 300 is sent to the control system 100 (S120). At this time, the MME 400 may include help information for estimating a background traffic state in a message.

The help information for estimating the background traffic state is determined by the background state information generator 420 of the MME 400 taking into account the number of connection-idle state transitions stored in the state transition number management unit 430. If the MME 400 serving the terminal 200 is changed due to a tracking update or the like, the new MME requests a context request from the previous MME 400 for the number of state transitions for a preset time for estimating the state of the background data traffic. Can be obtained via the context response message.

When the background state information receiving unit 110 of the control system 100 receives an initial context setup request message including the background state information from the MME 400, the RRC state control unit 120 based on the background state information in the message. It is determined whether the RRC connected state of the terminal 200 is set to an RRC first connected state or an RRC second connected state (S130).

In addition, the RRC state controller 120 may determine the RRC connection state in order to prevent the overload of the base station 100 in addition to the background state information. That is, if the number of terminals according to any one of the first terminal number information, the second terminal number information, or the third terminal number information exceeds the preset number of terminals, the RRC state controller 120 performs the RRC connection with the RRC connection. 2 Do not decide to be connected.

When the RRC state controller 120 sets the RRC connection state to the RRC second connection state through step S130, the RRC state control unit 120 sets a user idle time and a parameter value according to the RRC second connection state.

That is, in the case of the user idle time, a timer is set so that the RRC connected state can be maintained for a longer time than the user idle time value set in the RRC first connection state. For example, the user idle time of the RRC second connected state is set to a value n times (where n is any integer) of the user idle time value of the RRC first connected state. At the same time, in order to increase the downlink reception (DRX) period, a DRX period value in which the DRX period set in the RRC first connection state is increased is set.

In the case of the measurement parameter value, the measurement parameter is set to a value different from the measurement parameter set in the RRC first connection state. The measurement parameter includes a reporting configuration, a measurement gap, and a signal strength reported by the terminal. The reporting configuration is composed of a criterion and a reporting format for triggering the terminal 200 to send a measurement report. The reporting criterion is either periodic or single event description.

In addition, the measurement gap represents a period that the terminal 200 uses to perform the measurement. For example, if the terminal 200 is set to periodically send a measurement report, the terminal 200 is set to report the measurement report at a longer period than the RRC first connection state. When the measurement report is to be sent based on the event, the signal strength reported by the terminal 200 is set to a value smaller than the value set in the RRC first connection configuration.

For example, for Event A3, where neighbor is a better offset amount than PCell, set the a3-offset value to a larger value; for Event A4, where neighbor is better than an absolute threshold, a4- Set the threshold to a larger value. You can also set the S-Measure value in the measurement configuration (MeasConfig) to a smaller value. S-Measure controls whether the UE is required to perform measurements of intra-frequency, inter-frequency, and inter-RAT neighboring cells (inter-RAT neighboring cells). Means a PCell quality threshold.

As another method, the RRC state controller 120 sets one or more parameters of the measurement parameters to a value different from the value set in the RRC first connection state. In this case, in order for the terminal 200 to multiply and set the above-mentioned various measurement parameter values by an arbitrary multiple of the value set in the RRC first connection state, the measurement parameter value is n times (where n is an arbitrary integer). Sends a scaling parameter to the terminal.

The state control request unit 130 transmits the RRC connection reconfiguration information including the values set above to the terminal 200 (S140), and the terminal 200 reconfigures the RRC connection based on the information received in step S140. The RRC connection reconfiguration completion information indicating that the reconfiguration is completed is transmitted to the base station 300 (S150), and the base station 300 sends the initial context setup response to the configuration information currently set in the terminal 200 to the MME 400. It is transmitted in a S1-AP Initial Context Setup Response message (S160).

In the above description, the method for controlling the RRC connection state has been described through one example of the first embodiment of the present invention. Referring to FIG. 6, the method for controlling the RRC connection state in another method according to the first embodiment of the present invention will now be described. Describe the method.

Next, another RRC state transition method according to the first embodiment of the present invention will be described with reference to FIG. 6.

As shown in FIG. 6, the terminal 200 transmits the encapsulated service request NAS message to the base station 300 to the MME 400 in an RRC message (S200). The base station 300 encapsulates the NAS message in an initial UE message (S1-AP) and sends it to the MME 400 (S210). Since methods for encapsulating messages are already known, detailed descriptions are omitted in embodiments of the present invention.

The background state information generator 420 of the MME 400 transmits an initial context setup request message (S1-AP Initial Context Setup Request) to the base station in response to the initial terminal message received by the message receiver 410 in step S110. 300 is sent to the control system 100 (S220). At this time, the MME 400 may include help information for estimating a background traffic state in a message.

The help information for estimating the background traffic state is determined by the background state information generator 420 of the MME 400 taking into account the number of connection-idle state transitions stored in the state transition number management unit 430. If the MME 400 serving the terminal 200 is changed due to a tracking update or the like, the new MME contacts the number of state transitions during the predetermined time for estimating the background data traffic state from the previous MME 400. Can be obtained through request / context response message.

The state control requester 130 first sends an RRC connection reconfiguration message to the terminal 200 to establish a radio bearer in the RRC first connection state (S230). The terminal 200 transmits an RRC connection reconfiguration complete message to the base station 300 (S240).

The RRC state controller 120 determines whether to set the RRC first connection state to the RRC second connection state after the terminal 200 sets the state to the RRC first connection state after step S230. That is, in step S220, the background data traffic state estimation information is received through the MME 400, and when the state transitions to the RRC first connection state for a predetermined time, for example, when the state transitions to the RRC first connection state according to step S230. From the initial data transmission until the end of the user idle timer, if there is no transmission of user data traffic and the dedicated bearer that requires QoS currently is not set, the RRC state control unit 120 is connected to the terminal 200 in the RRC second connection state. Determine (S250).

When the background state information receiving unit 110 of the control system 100 receives the initial context setup message including the background state information from the MME 400, the RRC state control unit 120 may terminal based on the background state information in the message. It is determined whether the RRC connected state of the 200 to the RRC first connected state or the RRC second connected state (S250).

When the RRC state control unit 120 sets the RRC connection state to the RRC second connection state through step S250, the RRC state control unit 120 sets a user idle timer and a parameter value according to the RRC second connection state.

That is, in the case of the user idle timer, the timer is set so that the RRC connected state can be maintained for a longer time than the user idle timer value set in the RRC first connection state. For example, the user idle timer of the RRC second connected state is set to a value of n times (where n is an arbitrary integer) of the user idle timer value of the RRC first connected state. At the same time, in order to increase the downlink reception (DRX) period, a DRX period value with a longer DRX period set in the RRC first connection state is set.

In the case of a parameter value, the measurement parameter is set to a value different from the measurement parameter set in the RRC first connection state. Here, the measurement parameter includes a reporting configuration, a measurement gap, and a signal strength reported by the terminal.

As another method, the RRC state controller 120 sets one or more parameters of the measurement parameters to a value different from the value set in the RRC first connection state. In this case, in order to multiply and set the various parameter values mentioned above by an integer multiple of the value set in the RRC first connection state, the terminal 200 multiplies the measured value by n times (where n is an arbitrary integer). A scaling parameter that can be scaled can be sent to the terminal.

The state control request unit 130 transmits the RRC connection reconfiguration information including the values set above to the terminal 200 (S260), and the terminal 200 reconfigures the RRC connection based on the information received in step S260. The RRC connection reconfiguration completion information indicating that the reconfiguration is completed is transmitted to the base station 300 (S270).

In the RRC state transition method according to the first embodiment of the present invention, the RRC state controller uses the RRC agent by using UE Assistance Information defined in Section 5.3.15 of 3GPP TS 36.331 V11.1.0 (2012-09). 1 Determine whether to set the connection state to the RRC second connection state. The purpose of the UE help information procedure is to inform the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) of the power saving preference of the UE. That is, when the terminal prefers low power according to the background data traffic state, the terminal may transmit a low power preference indication to the base station.

In a state where the base station is configured to configure and process the power preference indication, the UE capable of providing power preference indication may detect a background traffic state in the RRC first connection state. UE assistance information (powerPrefIndication = lowpower consumption) for a low power preference can be sent. When the base station receives the terminal assistance information for the low power preference, the base station may determine the setting as the RRC second connection state. If the RRC state controller determines the setting to the RRC second connection state, the RRC state control unit performs the setting procedure to the RRC second connection state according to the above-described procedure.

In a state where the base station is set to the RRC second connection state, the terminal may detect the general traffic state and send terminal assistance information (powerPrefIndication = default) for the default power preference. When the base station set to the RRC second connection state receives the terminal assistance information for the default power preference, the base station may determine the setting to the RRC first connection state. When the RRC state controller 120 determines the setting to the RRC first connected state, the RRC state control unit 120 performs the setting procedure to the RRC first connected state according to the above-described procedure.

Next, an environment for an RRC state transition according to a second embodiment of the present invention will be described with reference to FIG. 7. In the first embodiment of the present invention, the RRC state transition is controlled by the control system 100 in the base station 300 by transmitting and receiving information between the base station 300 and the MME 400, but the second embodiment of the present invention. In an example, in a virtualization environment in which a radio unit (RU) 700 or 700 ′ and a digital signal processor 600 are separated, the digital signal processor is included in the digital signal processor through information transmission and reception between the digital signal processor and the virtualization server. An example of controlling an RRC state transition in a control system.

Unlike the general base station system, the virtualization structure of the wireless access network according to the second embodiment of the present invention separates the digital signal processing unit and the wireless signal processing unit of the base station, and the digital signal processing unit is disposed in the central station, and the wireless signal processing unit is remotely located. Represents a wireless network technology installed in a service area located. In the virtualization structure of the wireless access network, the digital signal processing unit is centralized and operated through the virtualization server. The virtualization server can operate by centralizing a plurality of digital signal processing units, thereby facilitating integrated information sharing for a considerably wider coverage area than a conventional base station system.

As shown in FIG. 7, the virtualization server 500 interworks with one or more digital signal processing units 600 and is located in a geographic area formed by radio

signal processing units

700 and 700 ′ accommodated by the digital signal processing unit 600. Background traffic state information generated in the located terminal 200 is transmitted to the control system 100 ′ in the digital signal processor 600 to control the state transition of the terminal 200.

In the second embodiment of the present invention, the control system 100 'is included in the digital signal processing unit 600 as an example. The virtualization server 500 may accumulate and manage state transitions of the terminal 200 accommodated in the plurality of digital signal processing units 600 in a virtualization server environment in which the plurality of digital signal processing units 600 is concentrated.

The control system 100 ′ according to the service request message requested by the terminal 200 to the digital signal processing unit 600, help information for estimating a background state of the current terminal 200, and / or data traffic state estimation information, Determines the adjusted connection state with the changed value, and informs the terminal 200 of this. Herein, the adjusted connection state (hereinafter referred to as 'second connection state' for convenience of description) is set in a general RRC connection state (hereinafter referred to as 'first connection state' for convenience of description). A connection state that is set to a parameter different from the existing one is called a second connection state.

A method of controlling the RRC state transition in such an environment will be described in detail with reference to FIG. 8. To this end, it is assumed that the structure of the control system 100 included in the digital signal processor 600 is the same as that of the control system 100 of FIG. 3. In addition, it is assumed that the structure of the virtualization server 500 is the same as that of the MME 400 of FIG. 4. At this time, the state transition number management unit 430 included in the virtualization server 500 manages the number of handovers of the terminal 200 together.

In addition, when the terminal 200 and the digital signal processing unit 600 performs the initial network registration procedure, it will be described on the assumption that the RRC first connection state is maintained as a parameter value of a general connection state.

As shown in FIG. 8, the terminal 200 and the digital signal processing unit 600 set to an RRC first connection state through an initial network registration process. When the user idle time has elapsed while the user data traffic has not been generated for a predetermined time, the terminal 200 and the digital signal processor 600 transition from the connected state to the idle state.

When the user data is generated by the mobile data application of the terminal 200 in the RRC idle state, the terminal 200 initiates a service request procedure in a non-access stratum (NAS) layer and sends a service request NAS message directed to the MME to the RRC message. Encapsulated in and sent to the digital signal processing unit 600 (S300). The digital signal processing unit 600 encapsulates the NAS message in the initial terminal message and sends it to the MME, after receiving the initial context setup response message or before or after the radio bearer setup procedure. Notifies the terminal 200 and the transition from the RRC idle state to the RRC connection state in the network, the virtualization server 600 manages the state transition information received from the digital signal processing unit 600.

In managing the state transition information for estimating the background data traffic state, the virtualization server 500 may manage only state transition information generated for a predetermined time period, and may remove state transition information after a predetermined time period. For example, when the virtualization server 500 receives the state transition information from the digital signal processing unit 600, the digital signal processing unit performs a predetermined number of times or more (for example, when five state transitions occur for 1 minute) for a predetermined time. N state transitions occur (e.g., n is any integer) for n times the user idle time set in (600), where n is any integer, Assuming a user idle time of 10 seconds, an additional time of 5 seconds, and n of 5, five state transitions occur for 55 seconds (5 * 10 seconds + 5 seconds)), and the virtualization server 500 may be The previous state transition information may be stored only for a time obtained by multiplying n by a user idle time set in the digital signal processor 600. The same may be applied to the MME of the first embodiment described above.

When the terminal 200 moves to the digital signal processing unit 600 accommodated in the virtualization server other than the virtualization server 500 currently accommodated, the currently accepted virtualization server transfers the state transition information of the terminal 200 to the previously accepted virtualization server 500. To receive).

The virtualization server 500 transmits help information for estimating a background traffic state to the digital signal processor 600 (S320). The information for estimating the background traffic state is determined in consideration of state transition information managed by the virtualization server 600.

When the digital signal processing unit 600 receives help information and / or data traffic state estimation information for estimating a background state from the virtualization server 500, the digital signal processing unit 600 transitions to the RRC first connection state for a predetermined time after a predetermined time. For example, if there is no user data traffic transmission and there is no dedicated bearer currently requesting QoS, from the time when the RRC transitions to the first connection state to the end of the user idle timer after the initial data transmission, the digital signal processing unit 600 Determines to remain connected to the RRC second connected state.

The digital signal processing unit 600 may select one of the first terminal number information, the second terminal number information, or the third terminal number information in order to prevent overloading or not to maintain the connected number of terminals. Based on this, the RRC connected state is determined as the RRC first connected state or the RRC second connected state. This is the same as mentioned in the description of step S130 of FIG.

When the digital signal processor 600 determines the RRC second connection state (S330), the digital signal processor 600 requests the terminal 200 to reconfigure the RRC connection (S340). When the terminal 200 reconfigures the RRC connection state to the second RRC connection state, the terminal 200 transmits an RRC connection reconfiguration complete message indicating that the reconfiguration is completed to the digital signal processor 600 (S350).

Next, in the virtualization structure according to the second embodiment of the present invention, the terminal 200 and the digital signal processing unit 600 refer to FIG. 9 for a method of switching from the RRC second connected state to the idle state or the RRC first connected state. Explain.

As shown in FIG. 9, when the terminal 200 and the digital signal processing unit 600 are configured in the RRC second connection state, the digital signal processing unit 600 exceeds a predetermined amount of data traffic transmitted through the user plane bearer. Or when receiving a dedicated bearer setup / modification request requesting QoS through the control plane (S400), the digital signal processing unit 600 uses a user idle time value used to detect a user idle state of the RRC first connection state. To set the time information.

The digital signal processor 600 transmits the measurement configuration information value of the RRC first connection state to the terminal 200 by including it in the RRC connection reconfiguration request message (S420). In this case, the digital signal processor 600 also includes the DRX cycle information value of the RRC first connected mode in the message and sends the same to the terminal 200.

The terminal 200 changes the parameter value for setting the RRC connection to the parameter value included in the message received in step S420 (S430). Then, the terminal 200 transmits an RRC connection reconfiguration complete message to the digital signal processor 600 (S440).

Next, a method of processing a mobile terminal having high mobility will be described with reference to FIG. 10.

As shown in FIG. 10, it may be preferable to switch to the idle state in the case of the terminal 200 having high mobility as compared to the RRC second connection state. Therefore, the virtualization server 500 manages the number of handovers that occur during a certain time. Then, it is checked whether the number of handovers managed exceeds a predetermined number of times.

If the number of handovers managed exceeds a certain number of times, it is transmitted to the digital signal processor 600 in the state information. Then, in the RRC second connection state, the digital signal processing unit 600 switches to the RRC idle state without performing the handover, or includes the parameter information for switching to the RRC first connection state in the RRC connection reconfiguration message upon handover. In step 200, the RRC connection state set to the RRC second connection state is switched to the RRC first connection state.

To this end, when the source digital signal processing unit 600 to which the terminal 200 to be handed over is currently connected determines the handover to the terminal 200, or the target digital signal to be handed over by the source digital signal processing unit 600 to be connected. When receiving an ACK for the handover request from the processor 600 (S500), the source digital signal processor 600 notifies the virtualization server 500 that the handover occurs (S510). In addition, the virtualization server 500 manages the handover information received from the digital signal processor 600 and may check the number of handovers (S520).

The virtualization server 500 manages only handover information generated for a predetermined time in order to estimate the state of the mobile terminal 200 having high mobility. In addition, the handover information which has passed a certain time is removed.

For example, when the virtual server 500 generates a predetermined number of handovers for a predetermined time in the corresponding terminal 200 before the time when the handover information is received from the digital signal processor 600, for example, 1 If it is determined that the handover occurs five times per minute and is estimated to be a mobile terminal, the virtualization server 500 stores the previous handover information only for one minute. When the terminal 200 moves to a digital signal processing unit accommodated in a virtualization server other than the virtualization server 500 currently accommodated, the virtual server accommodated by the terminal 200 moves and receives the handover information of the terminal 200 to the previously received virtualization. Obtained via server 500.

The virtualization server 500 transmits help information for estimating the state of the mobile terminal 200 having high mobility to the digital signal processor 600. Information for estimating the state of the mobile terminal 200 having high mobility is determined in consideration of the handover frequency information managed by the virtualization server 500. For example, when the handover count information exceeds a predetermined criterion for a predetermined time from before the virtualization server 500 receives the handover count information information, the virtualization server 500 may provide state estimation information of the terminal 200 having high mobility. To the digital signal processor 600.

The digital signal processor 600 is configured to the terminal 200 and the digital signal processor 600 in an RRC second connection state, and the digital signal processor 600 estimates the state of the mobile terminal 200 having high mobility from the virtualization server 500. When receiving the information, if there is no user data traffic transmission for a predetermined time after a predetermined time from the time when the transition to the RRC first connection state, that is, the data signal until the handover decision by the digital signal processing unit 200 after the state transition initial data transmission If not, the digital signal processing unit 600 executes the terminal context release procedure to the MME to switch to the idle state and sends an RRC connection release message to the terminal (S540).

Alternatively, when the handover includes a parameter for switching to the RRC first connection state in the RRC connection reconfiguration message, it is sent to the terminal 200 to switch to the RRC first connection state. The terminal 200 reconfigures the RRC connection according to the request message received through step S540 and transmits a completion message to the digital signal processor 600 (S550).

As described above, the terminal 200 and the digital signal processor 600 may use help information in the process of switching from the RRC second connection state to the idle state or the RRC first connection state.

That is, when the terminal 200 and the digital signal processing unit 600 are configured in the RRC second connection state, the digital signal processing unit 600 controls the control plane when the data traffic transmitted through the user plane bearer exceeds a predetermined amount. When receiving a dedicated bearer setup / modification request requesting QoS through the digital signal processor 600, the digital signal processor 600 sets a time value used to detect a user idle state of the RRC first connection state.

The digital signal processor 600 transmits the measurement configuration information value of the RRC first connection state to the terminal. In addition, the digital signal processor 600 transmits the DRX cycle information value of the RRC first connection state to the terminal. If the RRC connection reconfiguration message is transmitted including the parameter for setting the RRC first connection state, the terminal 200 changes the parameter value to the received parameter value.

The processing method for the mobile terminal mentioned in FIG. 10 may be equally applied to the first embodiment through the MME 400 and the base station 300.

In the RRC state transition method according to the second embodiment of the present invention, the RRC state controller uses UE Assistance Information defined in Section 5.3.15 of 3GPP TS 36.331 V11.1.0 (2012-09). It may be determined whether to set the RRC first connection state to the RRC second connection state.

With the digital signal processing unit configuring the power preference indication and being capable of processing, the UE capable of providing power preference indication (UE capable of providing power preference indications) in the RRC first connection state, the terminal detects the background traffic conditions UE assistance information (powerPrefIndication = lowpower consumption) for a low power preference may be transmitted. When the digital signal processor receives the terminal assistance information for the low power preference, the digital signal processor may determine the setting as the RRC second connection state. If the RRC state controller determines the setting to the RRC second connection state, the RRC state control unit performs the setting procedure to the RRC second connection state according to the above-described procedure.

In a state where the digital signal processor is set to the RRC second connection state, the terminal may detect the general traffic state and send terminal assistance information (powerPrefIndication = default) for the default power preference. When the digital signal processor configured as the RRC second connection state receives the terminal assistance information for the default power preference, the digital signal processor may determine the setting as the RRC first connection state. If the RRC state controller determines the setting to the RRC first connected state, the RRC state control unit performs the setting procedure to the RRC first connected state.

Determining whether to set the RRC connection state to the first connection state or the second connection state, the terminal help information, the background state information of the virtualization server or the base station, user data traffic, information on whether or not to set up a dedicated bearer requesting QoS, a mobile terminal It may be determined when one or more pieces of information are received.

According to one aspect of the present invention, a method for controlling a state transition of a radio resource control state by a control system, when receiving a service request message generated from a terminal, transmits an initial terminal message to a mobile management entity (MME) to which the control system is connected. step; Determining a radio resource control connection state as either a first connection state or a second connection state based on the background state information when receiving a message including background state information from the MME; And requesting reconfiguration of a radio resource control connection state to the terminal.

According to another aspect of the present invention, a method for controlling a transition of a radio resource control state by a control system includes receiving an service request message generated from a terminal and sending an initial terminal message to a virtualization server to which a digital signal processor including the control system is connected. Transmitting; Determining a radio resource control connection state based on the background state information when receiving a message including background state information from the virtualization server; And requesting reconfiguration of a radio resource control connection state to the terminal.

In another aspect of the present invention, a system for controlling a radio resource control state transition in conjunction with an MME or a virtualization server may receive background state information including help information transmitted from either the MME or a virtualization server. A background state information receiving unit; A state controller configured to set a connection state to be set to one of a first connection state and a second connection state based on the background state information received by the background state information receiver; And a state setting request unit transmitting a connection reconfiguration request message including the connection state information set by the state control unit to the terminal.

Although the present invention has been described above with reference to the drawings, the present invention is not limited thereto. For example, the background state information is described as an example in the above embodiment, but the present invention is not limited thereto and may include some form of state information.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application is related to the patent application No. 10-2012-0125211 filed in Korea on November 07, 2012 and the patent application No. 10-2012-0151329 filed in Korea on December 21, 2012. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

In order to reduce the terminal idle-connection state transition, the radio resource control method of the base station,

During the RRC connection establishment, receiving Core Network assistance information; And

And setting a RAN parameter for establishing a connection using the core network assistance information.
The method of claim 1,

The RAN parameter is a radio resource control method of a base station, characterized in that at least one of a user idle time (RRC inactivity timer), a downlink DRX cycle (downlink DRX cycle).
The method of claim 1,

The core network assistance information is generated based on at least one of the subscription information of the terminal, the data traffic state of the terminal, and the mobility of the terminal.
The method of claim 1,

Receiving the core network assistance information through an initial context setup request message (Initial Context Setup Request).
The method of claim 2,

If the RAN parameter is a downlink DRX cycle, in the step of setting the RAN parameter using the core network assistance information,

And transmitting the downlink DRX cycle to the UE through an RRC connection reconfiguration message.
The method of claim 1,

And receiving the core network assistance information from a mobile management entity (MME) in the step of receiving the core network assistance information.
In order to reduce the terminal idle-connection state transition, to a base station for controlling radio resources,

A receiving unit which receives Core Network assistance information during the RRC connection establishment; And

And a controller configured to set a RAN parameter for establishing a connection using the core network assistance information.
The method of claim 7, wherein

The RAN parameter is at least one of a user idle time (RRC inactivity timer), a downlink DRX cycle (base station).
The method of claim 7, wherein

The core network help information is generated based on at least one of the subscription information of the terminal, the data traffic state of the terminal, and the mobility of the terminal.
The method of claim 7, wherein

And the receiving unit receives the core network assistance information through an initial context setup request message.
The method of claim 8,

If the RAN parameter is a downlink DRX cycle,

And a request unit for transmitting the downlink DRX cycle to the terminal through an RRC connection reconfiguration message to set RAN parameters using the core network assistance information.
The method of claim 7, wherein

And the receiving unit receives core network assistance information from a mobile management entity (MME).
In order to reduce the terminal idle-connection state transition, the radio resource control method of the terminal,

During the RRC connection establishment, receiving a message from the base station including RAN parameters for connection establishment using the received Core Network assistance information; And

And changing the RAN parameter according to the RAN parameter of the message received from the base station.
The method of claim 13,

The RAN parameter is a downlink DRX cycle, and the downlink DRX cycle receives the downlink DRX cycle from the base station through an RRC connection reconfiguration message.
The method of claim 13,

And receiving a RAN parameter from the base station that has received the core network assistance information from a mobile management entity (MME).
In order to reduce the terminal idle-connection state transition,

During the RRC connection establishment, the receiving unit for receiving a message from the base station including the RAN parameter for establishing the connection using the received Core Network assistance information (Core Network assistance information); And

And a control unit for changing the RAN parameter according to the RAN parameter of the message received from the base station.
The method of claim 16,

The RAN parameter is a downlink DRX cycle, and the downlink DRX cycle is received from the base station through the RRC connection reconfiguration message.
The method of claim 16,

And receiving the RAN parameter from the base station, which has received the core network assistance information from a mobile management entity (MME).