KR102176114B1 - Synchronization Method and Apparatus for Changing Radio Configuration - Google Patents

Abstract

In the present invention, in a dual connectivity environment in which one terminal transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB), the latency between the MeNB and the SeNB is By measuring and using the first activation time information included in the RRC reconfiguration message and/or the second activation time information included in the reconfiguration application time indication message accordingly, the radio configuration for a specific terminal at the same time between the terminal and the SeNB ( Radio Configuration) can be changed, and thus synchronization between the UE and the SeNB is possible when changing the radio configuration or reconfiguring the RRC.

Description

Synchronization Method and Apparatus for Changing Radio Configuration}

The present invention relates to a synchronization method and apparatus for radio resource control (Radio Resource Control; hereinafter referred to as “RRC”) connection reconfiguration or radio configuration change in a wireless communication system.

In order to provide more diverse services to users and increase communication capacity through more efficient use of bands, terminals or UEs (users) within the wireless communication system such as LTE (Long Term Evolution), LTE-Advanced, and WCDMA. Equipment) can be a communication environment in which radio resources of transmission points such as two or more base stations or eNBs are used together, and this can be expressed as dual connectivity.

In such a dual connectivity environment, the transmission points or base stations may be connected to each other through an ideal backhaul without any delay or time required for signal transmission between each other. The time, delay or latency required for signal transmission between the two is connected by a non-ideal backhaul ranging from several ms to tens of ms.

With the current technology, when RRC reconfiguration is performed in a dual connectivity environment in which transmission points or base stations are connected through a non-ideal backhaul, RRC reconfiguration synchronization between the terminal or the UE and the transmission point is not performed. There is a problem that you can.

An object of the present invention is to provide a method and apparatus for enabling synchronization during RRC reconfiguration between a terminal and a base station in a dual connectivity environment.

Another object of the present invention is to change the radio configuration or RRC reconfiguration (Radio Resource Control Reconfiguration) between the terminal and the secondary base station (Secondary eNB; SeNB) in a dual connectivity state such as bearer split. If so, it is to provide a method and apparatus for performing synchronization.

Another object of the present invention is in a communication environment in which a master base station (MeNB) and a secondary base station (SeNB) communicate with one terminal at the same time, an activation time in which the master base station considers the latency between the two base stations. Time) A method of synchronizing RRC reconfiguration or radio configuration change between the terminal and the secondary base station by transmitting information to one or more of the terminal and the secondary base station, and simultaneously changing the radio configuration by the terminal and the secondary base station using such activation time information And an apparatus.

According to an embodiment of the present invention, in a wireless communication system in which one terminal transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB), synchronization of radio configuration changes by the master base station As a method, the MeNB receiving a reconfiguration request message requesting a radio configuration change of a corresponding terminal from the SeNB, and an RRC including first activation time information indicating a time value at which the corresponding terminal applies a radio configuration change by the MeNB A radio configuration change comprising the steps of generating a reconfiguration message (RRCConnectionReconfiguration) and transmitting it to the terminal, and receiving a reconfiguration completion message transmitted after the MeNB applies the change of the radio configuration according to the first activation time information from the terminal. Provides a synchronization method.

Another embodiment of the present invention is a radio configuration in which one terminal is a master base station (MeNB) in a wireless communication system that transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB). As a change synchronization device, after receiving a reconfiguration request message stating that a radio configuration change or RRC reconfiguration is required for a specific terminal from the SeNB, the corresponding terminal generates an RRC reconfiguration message including first activation time information indicating when to change the radio configuration Provides a radio configuration change synchronization device comprising an RRC reconfiguration message processing unit that is transmitted to the terminal and a reconfiguration response message processing unit that generates a reconfiguration response message after receiving an RRC reconfiguration completion message from the terminal and delivers it to the SeNB. .

In another embodiment of the present invention, in a wireless communication system in which one terminal transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB), synchronization of radio configuration change by the terminal As a method, receiving an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information, which is a time value at which a radio configuration change should be applied at the request of the SeNB, from the MeNB, and designated by the first activation time information. It provides a radio configuration change synchronization method including the step of applying a change of the radio configuration corresponding to the time point, and generating an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) indicating that the radio configuration change has been completed and transmitting it to the MeNB.

Another embodiment of the present invention is a wireless configuration change synchronization device in which one terminal is the terminal in a wireless communication system that transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB). As, according to the RRC reconfiguration message receiving unit for receiving from the MeNB an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information, which is a time value at which radio configuration change should be applied according to the request of the SeNB, and the first activation time information A radio configuration including a reconfiguration processing unit that applies a radio configuration change corresponding to a specified time point, and an RRC reconfiguration completion message processing unit that generates an RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) indicating that the radio configuration change has been completed and transmits it to the MeNB Provides a change synchronization device.

According to an embodiment of the present invention, in a dual connectivity environment in which a master base station and a secondary base station simultaneously transmit a signal (i.e., simultaneously service data transmission/reception) with one terminal, one of the eNBs Transmits RRC reconfiguration activation time information considering the latency between multiple base stations to one or more of the terminal and counterpart base station to synchronize the RRC reconfiguration, so that the time or phenomenon that the RRC reconfiguration state is asynchronous between the secondary base station (SeNB) and the terminal does not occur. This has the effect of preventing a problem in data transmission/reception service from occurring.

1 shows an example of a wireless communication system in which a terminal communicates with a base station.
2 is a diagram illustrating a structure of an evolved packet system (EPS) bearer.
3 is a diagram illustrating a state of splitting a bearer, which is an example of a dual connectivity environment to which an embodiment of the present invention can be applied.
4 shows a structure of a control plane in a dual connectivity environment to which an embodiment of the present invention is applied.
5 is a flowchart illustrating an example of a process of reconfiguring an RRC connection or changing a radio configuration by the SeNB in a dual connectivity communication system.
6 is a flowchart showing the overall flow of a synchronization method when changing a radio configuration or reconfiguring an RRC according to an embodiment of the present invention.
7 is a signal flow diagram showing a radio configuration change or RRC reconfiguration method according to the first embodiment of the present invention.
8 is a signal flow diagram illustrating a radio configuration change or RRC reconfiguration method according to a second embodiment of the present invention.
9 shows an example of an internal configuration of a MeNB among a radio configuration change device or an RRC reconfiguration device according to an embodiment of the present invention.
10 shows an example of an internal configuration of a secondary base station (SeNB) among a radio configuration changing apparatus or an RRC reconfiguration apparatus according to an embodiment of the present invention.
11 illustrates an internal configuration diagram of a terminal device for changing a radio configuration or reconfiguring an RRC between a specific SeNB according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 shows an example of a wireless communication system in which a terminal communicates with a base station.

Referring to FIG. 1, a wireless communication system includes a user equipment (UE) 10 and a base station (BS) 20 that performs uplink and downlink communication with the terminal 10.

In the present specification, the terminal 10 is a comprehensive concept that means a terminal in wireless communication, as well as UE (User Equipment) in WCDMA, LTE, HSPA, etc., as well as MS (Mobile Station) and UT (User Terminal) in GSM. , SS (Subscriber Station), wireless device (wireless device) will be interpreted as a concept including all.

The base station 20 may generally be a station that communicates with the terminal 10, and may be a Node-B, an evolved Node-B (eNodeB), a sector, a site, and a BTS. (Base Transceiver System), access point (Access Point), relay node (Relay Node), RRH (Radio Resource Head) may be referred to as other terms.

In addition, the base station 20 is meant to cover all various coverage areas such as a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a radio resource head (RRH), and a communication range of a relay node.

On the other hand, the communication environment to which an embodiment of the present invention is applied is a dual connectivity environment in which a terminal or a UE uses radio resources of two or more base stations or transmission points such as an eNB together, and related technologies are detailed below. Explain clearly.

2 is a diagram illustrating a structure of an evolved packet system (hereinafter referred to as “EPS”) bearer.

As shown in Fig. 2, in order for a single terminal to transmit and receive user data (eg, IP packet) with an external Internet network, the mobile communication network entities (elements) existing between the terminal and the external Internet network Resources must be allocated to several paths. The path in which data transmission/reception is possible because resources are allocated to the data transmission/reception path is called a bearer.

In order to transfer data from the terminal to the external Internet network, the terminal must first be able to transmit data to the base station or the eNB through a data radio bearer over the radio, and the data is sent back to the serving gateway from the base station through the S1 bearer. (Serving Gateway; hereinafter also referred to as “S-GW”) must be able to be delivered. And again, the data must be delivered to the packet data network gateway (hereinafter referred to as “P-GW” or “PDN-GW”) through the S5/S8 bearer, and finally, the P-GW and the external Internet network It must be able to be delivered through an external bearer to the destination that exists in.

Likewise, in order to transfer data from the external Internet network to the terminal, it can be transferred to the terminal through each bearer in the reverse direction as described above.

In this case, the types and meanings of various constituent bearers as shown in FIG. 2 will be described as follows.

First of all, the end-to-end service is an EPS bearer that is a path between the terminal and the P-GW, and an external bearer (which is a path between the P-GW and the Internet network) for the terminal to provide Internet network and data services. External Bearer) is required. In this case, the external bearer means a bearer between the P-GW and the Internet network.

The EPS bearer is a transmission path established between the terminal and the P-GW in order to transmit IP traffic with a specific QoS (Quality of Service).Each EPS bearer can be configured with QoS parameters indicating the characteristics of the transmission path. The EPS bearer uniquely expresses the concatenation of one E-RAB and one S5/S8 bearer.

In this case, the S5/S8 bearer is a bearer in the S5/S8 interface, and both S5 and S8 are bearers present in the interface between the S-GW and P-GW. The S5 interface is when S-GW and P-GW belong to the same operator, S8 interface belongs to the service provider (i.e., Visited PLMN) and P-GW belongs to the service provider (i.e. , Home PLMN). In addition, one E-RAB uniquely represents the sum of the S1 bearer and the corresponding data radio bearer (Radio Bearer of Fig. 2), and when one E-RAB exists, the E-RAB and one EPS bearer There is a one-to-one mapping between them.

Meanwhile, a radio bearer or a data radio bearer is a path or bearer through which user data is transmitted, and is distinguished from a signaling radio bearer. A signaling radio bearer is a path through which RRC and NAS control messages are transmitted. When there is one data radio bearer, there is a one-to-one mapping between the data radio bearer, the E-RAB, and the EPS bearer.

Meanwhile, dual connectivity means that one terminal uses radio resources of at least two or more base stations (eNB) together. The base stations may be connected through an ideal backhaul, which takes little time for transmission between base stations, or may be connected through a non-ideal backhaul, where the time required for transmission between base stations ranges from several ms to tens of ms. In addition, in an embodiment of the present invention, a non-ideal backhaul connection is assumed.

In such dual connectivity, two or more base stations through which one terminal transmits and receives data may include a master eNB (Master eNB; hereinafter referred to as “MeNB”) and a secondary eNB (Secondary eNB, hereinafter referred to as “SeNB”), but may include , Is not limited thereto, and is not particularly limited to the expressions MeNB and SeNB.

Among them, the master eNB or MeNB is a terminal base station having at least an S1-MME (Mobility Management Entity) interface in a dual connectivity environment, and a base station that serves as a mobility anchor for a core network (CN). As, it means a base station that can directly perform RRC configuration and reconfiguration with the terminal.

In addition, the secondary eNB or SeNB is a base station that provides additional radio resources to the terminal in a dual connectivity environment, and means a base station other than the MeNB, and the SeNB is a radio configuration such as RRC (re)configuration directly with the terminal. It is common to not be able to make changes to. In other words, the SeNB means that the RRC message for changing the radio configuration may not be directly generated because the RRC layer for the terminal receiving the service may not exist.

Meanwhile, the dual connectivity environment can be further divided into a case with and without a bearer split, and a case in which there is a bearer split is illustrated in FIG. 3.

3 is a diagram illustrating a state of splitting a bearer, which is an example of a dual connectivity environment to which an embodiment of the present invention can be applied.

Bearer Split means that one EPS bearer provides a data transmission service through two or more different base stations, that is, one EPS bearer #2 and a master eNB (MeNB) as shown in FIG. It shows that data transmission/reception service is available through a secondary eNB (SeNB).

However, bearer partitioning is an example of a dual connectivity environment to which an embodiment of the present invention is applied, and an embodiment of the present invention is not limited to such bearer partitioning.

4 shows a structure of a control plane in a dual connectivity environment to which an embodiment of the present invention is applied.

4, in the dual connectivity communication system to which an embodiment of the present invention is applied, a MeNB having an RRC layer and a terminal are connected through a Uu interface, and a SeNB without an RRC layer is also connected to a terminal through a Uu interface. . In addition, MeNB and SeNB are connected to each other through an Xn interface.

As described above, in a dual connectivity communication system to which an embodiment of the present invention is applied, an RRC layer exists only in the MeNB. Therefore, the SeNB may not directly generate an RRC message related to the terminal and transmit it to the terminal. However, it is possible to receive the RRC message generated by the MeNB from the MeNB and transmit it to the UE.

5 is a flowchart illustrating an example of a process of reconfiguring an RRC connection or changing a radio configuration by the SeNB in a dual connectivity communication system.

As described above, in a dual connectivity environment to which an embodiment of the present invention is applied, since the SeNB does not have an RRC layer, it is not possible to directly signal RRC reconfiguration between specific terminals to the terminal.

Accordingly, the SeNB, which determines that RRC reconfiguration is necessary, generates a terminal information request message containing the intention to change the radio configuration and transmits it to the MeNB. (S510) This terminal information request message is intended to change the radio configuration of a specific terminal. Therefore, it is a message that requests information necessary to perform the corresponding operation, in particular, the capability information of the terminal.

Upon receiving the terminal information request message, the MeNB extracts terminal information such as terminal capability information that should be considered when determining the change of the radio configuration and transmits it to the SeNB (S520).

Next, the SeNB generates a radio configuration change of the corresponding terminal, that is, a reconfiguration request message for requesting an RRC reconfiguration or radio configuration change, and transmits it to the MeNB (S530). Then, the MeNB of the corresponding terminal An RRC reconfiguration message (RRCConnectionReconfiguration) instructing a radio configuration change is generated and transmitted to the corresponding terminal (S540).

After receiving the RRC reconfiguration message (RRCConnectionReconfiguration), the UE applies the radio configuration change immediately or as quickly as possible. That is, the RRC configuration is changed according to the RRC configuration parameter requested to be changed. As soon as the application of the change is completed, the UE generates an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) and transmits it to the MeNB (S550).

Upon receiving the RRC reconfiguration complete message (RRCConnectionReconfigurationComplete), the MeNB generates an RRC reconfiguration response message (Reconfiguration response message) indicating that the radio configuration change of the corresponding terminal has been completed and transmits it to the SeNB. (S560) Receiving an RRC reconfiguration response message from the MeNB One SeNB confirms that the wireless configuration change of the corresponding terminal has been applied, and provides the service by changing the service according to the changed wireless configuration for the corresponding terminal. That is, after changing the RRC configuration parameter, etc., after RRC connection with the corresponding terminal, signals or data are transmitted and received.

If the above RRC reconfiguration process is used, the radio configuration for the corresponding terminal is changed and applied immediately after the SeNB generates an RRC reconfiguration request message and transmits it to the MeNB (S530). In this case, the interface between the SeNB and the MeNB is not Since it is connected through an ideal backhaul, there may be a latency of about 15 to 60 ms, and therefore, a certain time may be delayed between the MeNB and the UE. Therefore, although the SeNB has already applied the radio configuration change, the UE receives an RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB in step S540 and changes the radio configuration of the UE accordingly. Will be. Due to the wireless configuration asynchronous phenomenon between the SeNB and the terminal, there is a problem that data transmission/reception service may not be properly performed.

To solve this, the SeNB may change and apply the radio configuration immediately after receiving the RRC reconfiguration response message (Reconfiguration response message) in step S560, but in this case, the UE sends the RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) to the MeNB in step S550. Transmitted to means that the terminal has already applied the radio configuration change. From the SeNB's point of view, the changed radio configuration only after the time required between the terminal and the MeNB and the time between the MeNB and the SeNB (about 15-60 ms). Because of the change, the UE and the SeNB are in different radio configuration states for a certain period of time. That is, a state in which the radio configuration of the terminal and the SeNB is asynchronous for a certain period of time occurs, and thus, a problem may occur in the data transmission/reception service during this period.

In an embodiment of the present invention, in order to overcome this drawback, in a wireless communication system in which one terminal is connected to a master base station (MeNB) and a secondary base station (SeNB), the MeNB or SeNB is the latency or delay between the MeNB and the SeNB. After the MeNB receives the RRC reconfiguration request message requesting the radio configuration change of the corresponding terminal from the SeNB, first activation time information indicating a time value at which the corresponding terminal applies the radio configuration change (1 ^st Activation Time Information) and transmits the RRC reconfiguration message (RRCConnectionReconfiguration) to the terminal, and the terminal may include a configuration in which the terminal applies the change of the radio configuration according to the first activation time information.

In addition, the MeNB generates and transmits an RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information to the terminal, and at the same time, the SeNB is information about the time when the changed radio configuration is applied to the terminal. 2 A reconfiguration application time indication message including activation time information is generated and transmitted to the SeNB, and the SeNB may apply a change of radio configuration for the corresponding terminal according to the second activation time information.

Hereinafter, the first activation time information provided by the MeNB to the terminal and the second activation time information provided to the SeNB are separately described, but in some cases, the first and second activation time information may be the same piece of information.

Accordingly, the SeNB and the UE can apply the newly changed radio configuration from the same point in time, thereby solving the problem caused by the asynchronous phenomenon of the radio configuration.

6 is a flowchart showing the overall flow of a synchronization method when changing a radio configuration or reconfiguring an RRC according to an embodiment of the present invention.

In a wireless communication system in which the UE is connected to the MeNB and the SeNB, the MeNB or SeNB measures the latency or delay between the MeNB and the SeNB (S610), and the MeNB requests a radio configuration change of the UE from the SeNB Receiving a request message (S620), and the MeNB generating and transmitting an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information indicating a time value at which the corresponding terminal applies a radio configuration change to the terminal (S630) and receiving a reconfiguration completion message transmitted after the terminal applies the change of the radio configuration according to the first activation time information (S640).

In addition, apart from the MeNB generating an RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information and transmitting it to the terminal, the MeNB is the second information on the time when the SeNB applies the changed radio configuration to the terminal. Generating and transmitting a reconfiguration application time indication message including activation time information to the SeNB (S650), and the SeNB applying a radio configuration change at the same time as the terminal using the second activation time information (S660). It may contain additionally.

The first activation time information included in the RRC reconfiguration message (RRCConnectionReconfiguration) and the second activation time information included in the reconfiguration application time indication message may be values indicating the same time point. Alternatively, each activation time information includes a relative value, but the absolute time point may represent the same time point. That is, only when the first and second activation time information indicate the same point in time, the SeNB and the terminal can apply the newly changed radio configuration from the same point in time, and only then can different radio configurations be applied. It is possible to prevent the problem caused by the asynchronous phenomenon of the wireless configuration.

7 is a signal flow diagram showing a radio configuration change or RRC reconfiguration method according to the first embodiment of the present invention.

First, when the SeNB needs to change the radio configuration of a specific terminal it serves, that is, when RRC reconfiguration is required, the SeNB requests the MeNB to measure the latency to know the latency value between the SeNB and the MeNB. Send a message (S710)

At this time, the latency measurement request message may include first time stamp information, which is a time value at which the SeNB sends a latency measurement request message to the MeNB, and the MeNB receiving the latency measurement request message sends the latency measurement request message. By comparing the received time and the first time stamp information value, a latency value taken from the SeNB to the MeNB is calculated.

The MeNB that calculated the latency value generates a latency measurement response message and delivers it to the SeNB (S720), and in the latency measurement response message, the inter-base station latency information (SeNB-to-MeNB Latency), which is the time it took for the message to be transmitted from the SeNB to the MeNB. Information) and second time stamp information, which is a time value at which the MeNB transmits the latency measurement response message to the SeNB, but is not limited thereto.

Upon receiving the latency measurement response system including such information, the SeNB can calculate the time required to transmit the message from the MeNB to the SeNB, that is, the latency, using the time value at which the message is received and the second time stamp information. The time required for a message to be transmitted from the SeNB to the MeNB may also be determined using SeNB-to-MeNB Latency Information included in the latency measurement response system. That is, it is possible to calculate both the latency from the MeNB to the SeNB and the latency from the SeNB to the MeNB.

Of course, the measurement of the latency between the MeNB and the SeNB does not necessarily consist of a process in which the SeNB transmits a lane measurement request message (S710) and the MeNB returns a measurement response message thereto (S720). Latency may be measured in other ways as in the second embodiment to be described.

That is, the latency measurement method according to the S710 and S720 is only an example, and another latency measurement method may be used.

After the SeNB calculates the latency between itself and the MeNB in this way, the SeNB generates a reconfiguration request message for changing the radio configuration for a specific terminal and transmits it to the MeNB (S730). In the message, in addition to the identification information (UE Identity) of the terminal that is the object of the radio configuration change, and information on the radio configuration parameter to be changed, when the radio configuration change will be applied after the terminal receives the RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB It may include first activation time information, which is a time value for the time value.

This first activation time information may be an absolute time value, or may be a relative time value or a time difference value for when to apply the change of the radio configuration after the corresponding terminal receives the RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB. In the case of an absolute time value, it may be, for example, in the form of [System Frame Number (SFN) + Subframe Number].

In addition, the above-described changeable radio configuration parameter information may include a parameter related to a measurement method, a parameter controlling mobility, a dedicated radio configuration parameter, a security related parameter, etc. It is not limited to that.

On the other hand, since the SeNB already knows the first activation time information, it can know at which point the corresponding terminal will apply the change of the radio configuration, and thus itself can apply the change of the radio configuration to the corresponding terminal at the same time. . In this way, synchronization of the radio configuration change can be made between the SeNB and the terminal.

Next, the MeNB, which received a reconfiguration request message including first activation time information from the SeNB, includes information (first activation time information, information on a radio configuration parameter to be changed, etc.) included in the reconfiguration request message. A RRC reconfiguration message (RRCConnectionReconfiguration) is generated and transmitted to the corresponding terminal (S740).

On the other hand, the terminal receiving the RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information does not immediately apply the change of the radio configuration parameter, and is designated by the first activation time information after checking the first activation time information. The radio configuration parameter change is applied at a specific point in time, and an RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) is generated and transmitted to the MeNB immediately after the application of the radio configuration parameter change is completed (S750).

After receiving the RRC reconfiguration completion message (RRCConnectionReconfigurationComplete), the MeNB generates a reconfiguration response message (Reconfiguration response message) indicating that the radio configuration change of the corresponding terminal has been completed and transmits it to the SeNB. (S760) Reconfiguration response message received from the MeNB The SeNB confirms that the wireless configuration change of the corresponding terminal has been applied, and the service is changed and provided according to the changed wireless configuration for the corresponding terminal. However, the time at which the SeNB applies the changed radio configuration does not necessarily need to be after step S760 of receiving the reconfiguration response message from the MeNB, but may be before, and the time at which the radio change is applied is the time indicated by the first activation time information. .

As described above, according to the first embodiment of the present invention, when the latency between the SeNB and the MeNB is measured, and when a radio configuration change between the SeNB and a specific terminal is required, the first activation time information indicating the application time of the radio configuration change of the corresponding terminal The MeNB provides to the terminal, the terminal applies a change to the radio configuration corresponding to the time specified by the first activation time information, and the SeNB also changes the radio configuration by changing the radio configuration for the terminal at the same time. Synchronization of RRC reconfiguration becomes possible.

8 is a signal flow diagram illustrating a radio configuration change or RRC reconfiguration method according to a second embodiment of the present invention.

The second embodiment illustrated in FIG. 8 does not limit the measurement of the latency between the SeNB and the MeNB in a specific manner, and the MeNB transmits an RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information to the terminal. , The first embodiment in that the SeNB additionally includes a configuration in which a reconfiguration application time indication message including second activation time information, which is information on the time when the changed radio configuration is applied to the corresponding terminal, is generated and transmitted to the SeNB. And differentiated.

Hereinafter, a radio configuration change or RRC reconfiguration method according to a second embodiment of the present invention will be described with reference to FIG. 8.

First, at least one of the MeNB and the SeNB measures the latency between the base stations, which is the time required for signal or data transmission between itself and the counterpart (S810).

The method of measuring latency between base stations may be standardized matters, but may include various methods according to a specific technology implementation method, and the present invention is not limited to a specific latency measurement method.

When the inter-base station latency is determined in step S810, information on the inter-base station latency may be stored/managed in the MeNB and/or SeNB.

Next, the SeNB generates a reconfiguration request message for changing the radio configuration for a specific terminal and transmits it to the MeNB (S820). In the reconfiguration request message, the identification information of the terminal that is the object of the radio configuration change (UE Identity) and information on a radio configuration parameter to be changed, etc. may be included, and the above-described radio configuration parameter information to be changed includes a parameter relating to a measurement method, a parameter controlling mobility, and a dedicated radio configuration parameter. (Dedicated Radio Configuration Parameter) and security-related parameters may be included, but are not limited thereto.

Next, the MeNB receiving the reconfiguration request message from the SeNB generates an RRC reconfiguration message (RRCConnectionReconfiguration) and transmits it to the corresponding terminal (S830). In the RRC reconfiguration message (RRCConnectionReconfiguration), the first activation time information, which is a time value for applying the change of the radio configuration from when the corresponding terminal receives the RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB, may be included.

This first activation time information may be an absolute time value, or may be a relative time value or a time difference value for when to apply the change of the radio configuration after the corresponding terminal receives the RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB. In the case of an absolute time value, it may be, for example, in the form of [System Frame Number (SFN) + Subframe Number].

Further, unlike the first embodiment, in the second embodiment of the present invention, in addition to step S830 in which the MeNB transmits an RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information to the terminal, the MeNB corresponds to the SeNB. And generating a reconfiguration application point indication message including second activation time information, which is information on a point in time to apply the changed radio configuration to the terminal, and transmitting it to the SeNB (S840).

Step S830 in which the MeNB transmits an RRC reconfiguration message (RRCConnectionReconfiguration) to the terminal and step S840 in which the MeNB generates a reconfiguration application time indication message and transmits it to the SeNB are generally performed simultaneously, but may be performed sequentially.

The above-described second activation time information is a time value indicating from when the SeNB receiving the reconfiguration application time indication message to apply the radio configuration change to the corresponding terminal, and may be an absolute time value, a relative time value, or a time difference value. In the case of an absolute time value, it may be, for example, in the form of [System Frame Number (SFN) + Subframe Number].

In addition, according to the second embodiment of the present invention, since the UE and the SeNB must simultaneously apply the radio configuration change to the other party, the time values indicated by the above-described first activation time information and the second activation time information are the same In some cases, the first and second activation time information may be separate information, or may be the same type of information.

As described above, the UE uses the first activation time information included in the RRC reconfiguration message (RRCConnectionReconfiguration), and the SeNB is the radio configuration between the UE-SeNB at the same time according to the second activation time information included in the reconfiguration time indication message. Since the change is applied, synchronization of the radio configuration change can be achieved between the SeNB and the terminal.

Next, the terminal receiving the RRC reconfiguration message (RRCConnectionReconfiguration) including the first activation time information does not immediately apply the change of the radio configuration parameter, and checks the first activation time information and then according to the first activation time information. The radio configuration parameter change is applied at a specific time point specified, and immediately after the radio configuration parameter change application is completed, an RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) is generated and transmitted to the MeNB (S850).

After receiving the RRC reconfiguration completion message (RRCConnectionReconfigurationComplete), the MeNB generates an RRC reconfiguration response message (Reconfiguration response message) indicating that the radio configuration change of the corresponding terminal has been completed and transmits the RRC reconfiguration response message to the SeNB (S860). The received SeNB confirms that the wireless configuration change of the corresponding terminal has been applied, and provides the service by changing the service according to the changed wireless configuration for the corresponding terminal. However, the time at which the SeNB applies the changed radio configuration does not necessarily need to be after the step S860 of receiving the reconfiguration response message from the MeNB, but may be before, and the time at which the radio change is applied is the first activation time information or the second activation. This is the time indicated by the time information.

As described above, according to the first embodiment of the present invention, when a radio configuration change is required between the SeNB and a specific terminal by measuring the latency between the SeNB and the MeNB, the terminal performs the first activation included in the RRC reconfiguration message (RRCConnectionReconfiguration). According to the time information, the SeNB applies the radio configuration change between the UE and the SeNB at the same time according to the second activation time information included in the reconfiguration time indication message, so that the synchronization of the radio configuration change between the SeNB and the UE is made. Can be.

9 shows an example of an internal configuration of a MeNB among a radio configuration change device or an RRC reconfiguration device according to an embodiment of the present invention.

The MeNB according to an embodiment of the present invention largely includes an RRC reconfiguration message processing unit 910 and a reconfiguration response message processing unit 920, and additionally, a latency measurement unit 930 that measures a latency between the SeNB and itself, and , It may further include a reconfiguration application time message processing unit 940.

Hereinafter, the internal components of the MeNB will be described in more detail.

The RRC reconfiguration message processing unit 910 receives a reconfiguration request message stating that a radio configuration change for a specific terminal or an RRC reconfiguration is required from the SeNB, and then RRC reconfiguration including first activation time information indicating the time when the corresponding terminal changes the radio configuration. Generates a message and transmits it to the terminal.

The first activation time information may be an absolute time value, or may be a relative time value or a time difference value for when to apply the radio configuration change from when the corresponding terminal receives an RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB. In the case of an absolute time value, for example, it may be in the form of [System Frame Number (SFN) + subframe number], but is not limited thereto.

In addition, in addition to the above-described first activation time information, the RRC reconfiguration message may further include radio configuration parameter information to be changed and applied by the corresponding terminal, and the changed radio configuration parameter information includes a parameter related to a measurement method, A parameter for controlling mobility, a dedicated radio configuration parameter, a security related parameter, and the like may be included, but are not limited thereto.

In addition, the reconfiguration response message processing unit 920 performs a function of receiving an RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) from the terminal, generating a reconfiguration response message, and transmitting it to the SeNB.

In addition, the latency measurement unit 930 performs a function of measuring the latency between the SeNB and itself (MeNB) or the time required for signal transmission, and is a first timestamp that is a time value at which the SeNB sends a latency measurement request message to the MeNB. Time Stamp) After receiving the latency measurement request message including information, the latency value taken from the SeNB to the MeNB can be calculated by comparing the time at which the message is received and the first time stamp information value, but this is an example. It is not limited to that. Such a latency measurement unit can calculate the latency from MeNB to SeNB, and the like, as opposed to the latency from SeNB to MeNB.

In addition, after receiving the reconfiguration request message from the SeNB, the reconfiguration application time message processing unit 940 generates a reconfiguration application time indication message indicating the time at which the SeNB performs radio configuration change or RRC reconfiguration for the corresponding terminal and transmits it to the SeNB. The reconfiguration application time indication message may include second activation time information, which is information about a time when the SeNB applies the changed radio configuration to the corresponding terminal.

The second activation time information is a time value indicating from when the SeNB receiving the reconfiguration application time indication message to apply the radio configuration change to the corresponding terminal, and may be an absolute time value, a relative time value, or a time difference value. In the case of an absolute time value, for example, it may be in a format such as [System Frame Number (SFN) + subframe number], but is not limited thereto, and is the same as the time point specified by the first activation time information. It is desirable to indicate the point of view.

10 shows an example of an internal configuration of a secondary base station (SeNB) among a radio configuration changing apparatus or an RRC reconfiguration apparatus according to an embodiment of the present invention.

Unlike the MeNB, which can directly perform radio configuration changes, such as RRC reconfiguration for a specific terminal, the SeNB according to an embodiment of the present invention does not have an RRC layer, so it can directly change the radio configuration for the terminal. It means a base station that cannot be performed.

10, the SeNB according to an embodiment of the present invention largely changes the reconfiguration request message processing unit 1010, the reconfiguration response message receiving unit 1020 for receiving the reconfiguration response message from the MeNB, and the radio configuration related to the corresponding terminal It may include a radio configuration change unit 1030 to be applied, and additionally, a latency measurement unit 1040 that measures the latency between the MeNB and itself, and indicates a point in time to perform radio configuration change or RRC reconfiguration for the corresponding terminal. It may further include a reconfiguration application time message receiver 1050 for receiving a reconfiguration application time indication message from the MeNB.

Hereinafter, the internal components of the SeNB will be described in more detail.

The reconfiguration request message processing unit 1010 generates and transmits a reconfiguration request message to the MeNB when a radio configuration change or RRC reconfiguration for a specific terminal is required.

On the other hand, the reconfiguration request message includes the identification information (UE Identity) of the terminal to be the object of the radio configuration change and information on the radio configuration parameter to be changed, and in addition to the information, after the terminal receives the RRC reconfiguration message (RRCConnectionReconfiguration) from the MeNB. It may include first activation time information, which is a time value for when to apply the change of the radio configuration, and detailed descriptions of the radio configuration parameter information to be changed and the first activation time information are omitted to avoid redundancy.

The reconfiguration response message receiving unit 1020 sends a reconfiguration response message indicating that the terminal has applied the change to the radio configuration according to the first activation time information included in the RRC reconfiguration message (RRCConnectionReconfiguration) transmitted from the MeNB to the terminal. It performs the function of receiving.

That is, the reconfiguration response message is a message generated and transmitted by the MeNB to notify the SeNB of the RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) from the UE.

The radio configuration change unit 1030 performs a function of changing and applying the radio configuration related to the corresponding terminal, and applying the radio configuration change means appropriately changing and resetting the radio configuration parameter to be changed requested by the SeNB. do.

Regarding the point at which the radio configuration changer 1020 applies the change, according to the first embodiment of the present invention, the SeNB itself has already generated the first activation time information and transmitted it to the terminal via the MeNB. The time information is known, and accordingly, the wireless configuration change unit 1030 also applies the wireless configuration change to the corresponding terminal at the same time as when the terminal changes the wireless configuration according to the first activation time information.

In addition, according to the second embodiment of the present invention, the radio configuration changing unit 1020 is a second unit indicating a point in time when the reconfiguration application time message receiving unit 1050 will perform radio configuration change or RRC reconfiguration for a corresponding terminal, which will be described below. 2 After receiving a reconfiguration application time indication message including activation time information from the MeNB, a radio configuration change for the corresponding terminal is applied at a specific time point indicated by the second activation time information.

In addition, the reconfiguration application time message receiving unit 1050 performs a function of receiving a reconfiguration application time indication message from the MeNB indicating the time to perform radio configuration change or RRC reconfiguration for the corresponding terminal, and the SeNB in the reconfiguration application time indication message Second activation time information, which is information on a time point at which the changed radio configuration is applied to the corresponding terminal, may be included.

Detailed descriptions of the first activation time information, the second activation time information, and the like are omitted to avoid redundancy.

11 illustrates an internal configuration diagram of a terminal device for changing a radio configuration or reconfiguring an RRC between a specific SeNB according to an embodiment of the present invention.

11, the terminal device according to an embodiment of the present invention transmits and receives signals or data with at least two base stations including MeNB and SeNB, and largely, an RRC reconfiguration message receiving unit 1110 and a radio requiring actual change It may be configured to include a reconfiguration processing unit 1120 for changing a configuration parameter, and an RRC reconfiguration completion message processing unit 1130 for generating an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) and transmitting it to the MeNB.

Below, with reference to FIG. 11, the internal components of such a terminal will be described in more detail.

The RRC reconfiguration message receiving unit 1110 performs a function of receiving an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information, which is a time value to which the radio configuration change is applied, from the MeNB.

In addition, the reconfiguration processing unit 1120 performs an actual change of a radio configuration parameter that needs to be changed at a time point designated by the first activation time information included in the RRC reconfiguration message.

The RRC reconfiguration completion message processing unit 1130 generates an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) indicating that the radio configuration in the terminal has been changed at the time specified by the first activation time information or that RRC reconfiguration has been completed, and transmits it to the MeNB. Perform.

Meanwhile, the SeNB is the SeNB's own radio configuration at the same time as the UE changes the radio configuration according to the first activation time information included in the RRC reconfiguration message and/or the second activation time information included in the reconfiguration application point indication message. Since the change is also in progress, synchronization between the UE and the SeNB can be achieved during radio configuration change or RRC reconfiguration.

As described above, according to an embodiment of the present invention, one terminal transmits and receives signals or data to and from at least two base stations including a master base station (MeNB) and a secondary base station (SeNB). In the environment, by measuring the latency between the MeNB and the SeNB, and using the first activation time information included in the RRC reconfiguration message and/or the second activation time information included in the reconfiguration application time indication message accordingly, the UE and the SeNB The radio configuration for a specific terminal can be changed at the same time, and thus synchronization between the terminal and the SeNB is possible when the radio configuration is changed or RRC reconfigured.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, 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 interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (14)

Radio configuration change by the master base station in a wireless communication system supporting dual connectivity in which one terminal transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB) As a synchronization method,
Receiving, by the MeNB from the SeNB, a reconfiguration request message requesting a radio configuration change of a corresponding terminal;
Generating, by the MeNB, an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information indicating a time value at which a radio configuration change is to be applied by the corresponding terminal and transmitting it to the terminal;
Generating, by the MeNB, a reconfiguration application time indication message including second activation time information, which is information on a time point at which the changed radio configuration is applied to a corresponding terminal, and transmitting it to the SeNB; And
Receiving, by the MeNB, a reconfiguration completion message transmitted after applying a change of a radio configuration according to the first activation time information from the terminal;
Wireless configuration change synchronization method comprising a. The method of claim 1,
Wherein the SeNB changes the radio configuration associated with the terminal at the same time that the terminal applies the radio configuration change according to the second activation time information. delete delete delete delete delete delete Radio as a master base station (MeNB) in a wireless communication system in which one terminal supports dual connectivity for transmitting and receiving signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB) As a configuration change synchronization device,
After receiving a reconfiguration request message stating that a radio configuration change or RRC reconfiguration is required for a specific terminal from the SeNB, the corresponding terminal generates an RRC reconfiguration message including first activation time information indicating the time to change the radio configuration and transmits it to the terminal An RRC reconfiguration message processor;
A reconfiguration response message processing unit for receiving an RRC reconfiguration completion message (RRCConnectionReconfigurationComplete) from the terminal, generating a reconfiguration response message, and transmitting it to the SeNB; And
After receiving the reconfiguration request message from the SeNB, the SeNB generates a reconfiguration application time indication message including second activation time information indicating a time point to perform radio configuration change or RRC reconfiguration for the corresponding terminal and transmits it to the SeNB. Reconfiguration application point message processing unit
Including, wherein the SeNB changes the radio configuration associated with the terminal at the same time as when the terminal applies the radio configuration change according to the second activation time information. delete delete Synchronization of wireless configuration change by the terminal in a wireless communication system that supports dual connectivity in which one terminal transmits and receives signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB) As a method,
Receiving an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information, which is a time value for applying a radio configuration change, from the MeNB according to the request of the SeNB;
Applying a change in a radio configuration corresponding to a time point designated by the first activation time information;
Generating an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) indicating that the radio configuration change has been completed and transmitting the message to the MeNB;
Including, wherein the time at which the change of the radio configuration is applied is the same time point at which the SeNB applies the radio configuration change according to the second activation time information received by the MeNB. . delete A wireless configuration change synchronization device in which one terminal is the terminal in a wireless communication system that supports dual connectivity for transmitting and receiving signals or data with at least two base stations including a master base station (MeNB) and a secondary base station (SeNB) as,
An RRC reconfiguration message receiver for receiving an RRC reconfiguration message (RRCConnectionReconfiguration) including first activation time information, which is a time value for applying a radio configuration change according to the request of the SeNB, from the MeNB;
A reconfiguration processing unit for applying a change in a radio configuration corresponding to a time point designated by the first activation time information;
RRC reconfiguration completion message processing unit that generates an RRC reconfiguration complete message (RRCConnectionReconfigurationComplete) indicating that the radio configuration change has been completed and transmits it to the MeNB
Including, wherein the time when the change of the radio configuration is applied is the same time as when the SeNB applies the radio configuration according to the second activation time information received by the MeNB.

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