KR100678146B1 - Method for combinimg selective in a mobile communication system - Google Patents

Abstract

The present invention relates to a method for selectively combining the same broadcast data received through a plurality of paths in a mobile communication system. To this end, in the present invention, the selective association assistance data is periodically provided by the radio network controller through a common control channel for each cell. On the other hand, the mobile terminal checks by the selective combining auxiliary data whether duplicate broadcast data is received from the plurality of cells in a situation where the same broadcast service is provided from the plurality of cells. The selective combining may be performed based on a result of the check by the selective combining assistance data.

Broadcast Service, MBMS Service, Selective Combined, RLC PDU, Sequence Number, Selective Combined Auxiliary Data

Description

Selective coupling method in mobile communication system {METHOD FOR COMBINIMG SELECTIVE IN A MOBILE COMMUNICATION SYSTEM}             

1 is a diagram showing a wireless access network structure in an asynchronous mobile communication system for applying an embodiment of the present invention.

2 illustrates signaling for providing selective combining assistance data according to an embodiment of the present invention.

3 is a diagram illustrating a control flow performed in a mobile terminal according to an embodiment of the present invention.

4 is a view showing the structure of a mobile terminal according to an embodiment of the present invention.

FIG. 5 shows an example of the operation of the select coupler in FIG. 4. FIG.

6 is a diagram illustrating an example of a network in which only one serial number assigning device is configured to apply the second exemplary embodiments of the present invention.

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7 is a diagram illustrating an example of a network including a plurality of serial number assigning devices for applying second embodiments of the present invention.

FIG. 8 is a diagram illustrating a control flow according to operation of a UE in a network having the structure of FIG. 7. FIG.

9 is a view showing the structure of a mobile terminal according to a third embodiment of the present invention.

10 is a view showing the structure of a radio link controller of a mobile terminal according to a fourth embodiment of the present invention;

FIG. 11 is a view showing the structure of an SCR-window in FIG.

12 is a view showing the operation of the selective coupler according to the fourth embodiment of the present invention.

The present invention relates to a data combining method in a mobile communication system, and more particularly, to a method for selectively combining the same broadcast data received through a plurality of paths.

Today, due to the development of communication technology, a code division multiple access (CDMA) mobile communication system provides a service for transmitting a large amount of data such as packet data and circuit data as well as voice service. Furthermore, it is developing into multimedia broadcasting / communication capable of transmitting multimedia services. However, in a typical mobile communication system, since radio transmission resources are limited, it is not very efficient to transmit high-speed data one-to-one. For example, in order to provide a 64 kbps video streaming service to a user equipment (hereinafter referred to as "UE"), a radio resource capable of transmitting 64 kbps data should be allocated to the UE. However, if there are n such UEs, the demand for radio resources to allocate will also increase n times. Alternatively, if multiple UEs wish to receive the same service, a method of providing the same service through a common channel is possible. In this case, a service may be provided using the same radio resource regardless of the number of UEs located in the same cell and wishing to receive the same service. This enables efficient use of radio resources.

Accordingly, a broadcast service for serving a plurality of UEs from one or several multimedia data sources has been discussed to support multimedia broadcasting / communication. A representative example thereof will be referred to as a multimedia broadcast / multicast service (hereinafter referred to as an MBMS service) proposed in 3GPP (3rd Generation Project Partnership: hereinafter referred to as "3GPP").

The MBMS service supports multimedia transmission forms such as real-time video, audio, still images, text, etc., and is capable of simultaneously providing audio data and video data according to the application of the multimedia transmission format. Therefore, the MBMS service requires a large amount of transmission resources. In addition, the MBMS service may be provided through a broadcast channel in that multiple UEs may request the same MBMS service.

The MBMS service can be provided in two types of services. First, there is a point-to-point (hereinafter referred to as "PtP") service that provides a desired MBMS service for each UE. In this case, dedicated channels should be allocated to the UEs. Secondly, there is a point-to-multi-point (hereinafter referred to as "PtM") service that provides an MBMS service for a plurality of UEs that request the same MBMS service. In this case, a common channel should be allocated for UEs that request the same MBMS service.

The aforementioned MBMS service is a service for efficiently transmitting the same data to multiple UEs in an asynchronous mobile communication system (hereinafter referred to as a "UMTS mobile communication system"). In particular, the MBMS service is advantageous for multimedia transmission with a large demand for radio transmission resources. Therefore, as the MBMS service may be used not only for high speed multimedia services but also for various purposes, applications suitable for the MBMS service will increase further in the future.

Even if the same MBMS service is provided to multiple UEs using the common channel, there are still limitations on radio resources. According to a simulation or the like, in order to maintain a predetermined block error rate on 80-90% of a cell while transmitting 64kbps data through a common channel, more than 30% of the available cell output power should be used.

These findings suggest that the following points should be considered.

First, in order to provide MBMS service of satisfactory quality for all UEs located in one cell, most of the available transmission outputs of the cell should be used for one service.

Secondly, when limiting the available transmit power of a cell, UEs located at the cell boundary are likely to experience quality degradation.

In order to alleviate these points, it has been proposed that a UE located at the boundary of a cell receives data from two or more cells when a particular service is simultaneously transmitted in several neighboring cells. However, only the discussion of the concept was carried out, and no concrete way to realize it was presented. Therefore, when a specific service is simultaneously transmitted in several neighboring cells, a proper scheme for exchanging control signals between the base station and the UE and by installing a new device in the UE to receive data transmitted from the various cells and then use the data appropriately This desperation will be desired.

Accordingly, an object of the present invention to solve the above problems is to provide a selective combining method for a mobile terminal located at a cell boundary to smoothly receive a broadcast service.                         

Another object of the present invention is to provide a selective combining method for maximizing the efficient use of forward wireless transmission resources.

It is still another object of the present invention to provide a method of selecting and combining only data having no error among the same data received through a plurality of paths.

It is still another object of the present invention to provide a method of performing selective combining using serial numbers assigned to data.

Another object of the present invention is to provide a method for performing selective combining using a serial number of a radio link control (RLC) layer.

It is still another object of the present invention to provide a method for identifying data received through different paths by serial numbers of a radio link control (RLC) layer and performing selective combining based on the identification result. .

It is still another object of the present invention to provide a method of transmitting a serial number identifier for each cell in a network in which a plurality of serial number assigners exist.

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Still another object of the present invention is to provide a method for determining whether to perform selective combining by a serial number identifier transmitted from a mobile terminal by a network.

It is still another object of the present invention to provide a method of performing selective combining of data from the serving cell and the target cell when the serial number identifier from the target cell and the serial number identifier from the serving cell match. Is in.

It is still another object of the present invention to provide a method of not performing selective combining of data from the serving cell and the target cell if the serial number identifier from the target cell and the serial number identifier from the serving cell do not match. In providing.

In a first aspect for achieving the above object, the present invention provides a method of selectively combining broadcast data from a plurality of cells in a mobile terminal, comprising the steps of: receiving broadcast data from the plurality of cells; If the serial number of the received broadcast data does not belong to the reception window, storing the broadcast data in a buffer, updating the reception window by the serial number, and the serial number of the received broadcast data is in the reception window. Belonging to, if it is stored in the buffer, discarding the broadcast data if stored in the buffer, and if not stored in the buffer, And storing the data in the buffer.

In a second aspect for achieving the above object, the present invention provides a device for selectively combining broadcast data from a plurality of cells in a mobile terminal, comprising: a buffer and a series of broadcast data received from the plurality of cells Storing the received broadcast data in the buffer if the number does not belong to the reception window, and storing the received broadcast data in the buffer if the serial number of the received broadcast data is within the reception window and is not stored in the buffer. An optional combiner, wherein the optional combiner updates the receive window if the serial number of the received broadcast data does not fall within the receive window, and wherein the serial number of the received broadcast data belongs to the receive window but does not belong to the buffer. Is stored in the Characterized in a waste box.

In a third aspect for achieving the above object, the present invention provides a mobile terminal, a serving cell for providing an arbitrary broadcast service through a primary link established by the mobile terminal, and an auxiliary set by the mobile terminal. At least one target cell providing the arbitrary broadcast service through a link, and a wireless network controller providing broadcast data according to the arbitrary broadcast service to the serving cell and the at least one target cell. The method of the mobile terminal for selectively combining broadcast data from the serving cell and the at least one target cell, the method comprising: receiving broadcast data from the serving cell and the at least one target cell; Checking whether broadcast data identical to broadcast data has already been received; If the broadcast data is already received broadcast data, discarding the received broadcast data; if the received broadcast data is not already received broadcast data, storing the received broadcast data in a buffer; and And rearranging the broadcast data stored in the serial number and transmitting the broadcast data having a serial number preceding the serial number not received among the rearranged broadcast data to a higher layer. The serial number is an identifier for distinguishing the broadcast data, and the same serial number is assigned to the serving cell and the at least one target cell with respect to the same broadcast data.

In a fourth aspect for achieving the above object, the present invention provides a mobile terminal, a serving cell for providing an arbitrary broadcast service through a primary link established by the mobile terminal, and an auxiliary set by the mobile terminal. At least one target cell providing the arbitrary broadcast service through a link, and a wireless network controller providing broadcast data according to the arbitrary broadcast service to the serving cell and the at least one target cell. The apparatus for selectively combining broadcast data from the serving cell and the at least one target cell by the mobile terminal, wherein the same broadcast data as the broadcast data received from the serving cell and the at least one target cell has already been received. Examines and discards broadcast data already received by the inspection. If it is not received broadcast data, the redundancy check unit for storing in the reconstruction buffer, and the stored broadcast data rearranged by the serial number, and has a serial number preceding the serial number not received among the rearranged broadcast data And a reconstruction buffer for transmitting broadcast data to a higher layer, wherein the serial number is an identifier for distinguishing the broadcast data, and the same serial number in the serving cell and the at least one target cell for the same broadcast data. Said device characterized in that it is given.
In a fifth aspect for achieving the above, the present invention provides a method of selectively combining broadcast data from a plurality of cells in a mobile terminal, the serial number of the first broadcast data received from the plurality of cells, and Allocating a reception window according to the determined reception window size, checking whether a serial number of broadcast data received from the plurality of cells falls within the reception window, and if the serial number is within the reception window, Check whether the broadcast data of the same serial number as the number is already stored in the buffer, and if the broadcast data of the same serial number as the serial number is already stored in the buffer, discard the received broadcast data and the serial number. Broadcast data of the same serial number as is not stored in the buffer Storing the received broadcast data in the buffer, and if the serial number is not within the reception window, storing the received broadcast data in the buffer, by the serial number and the predetermined reception window size. And updating the reception window, and transmitting broadcast data having a serial number out of the updated reception window among the broadcast data stored in the buffer to a higher layer.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. DETAILED DESCRIPTION In the following detailed description, one exemplary embodiment of the present invention will be presented to accomplish the above technical problem. And other embodiments that can be presented with the present invention are replaced by the description in the configuration of the present invention. Meanwhile, in the embodiment of the present invention to be described below, only the MBMS service is limited, but it is obvious that the same may be applied to all broadcast services.

Before examining the present invention in detail, the terms to be frequently used are briefly summarized as follows.

Common Control Channel (MCCH): A channel in which information related to MBMS service is broadcast for each cell. The type of MBMS service provided for each cell and configuration information of a radio bearer for which the MBMS service is provided may be broadcast through the channel. In addition, various information that a UE needs to know in order to receive MBMS service may be transmitted through the common control channel.

Radio Link Control Packet Data Unit (RLC PDU): In the UMTS mobile communication system, the second layer is composed of a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer. The RLC layer configures the data delivered by the upper layer to an appropriate size, and then inserts a header and delivers the data to the lower layer (MAC layer) or interprets the header of the data delivered by the lower layer (MAC layer) and takes appropriate action. It serves to convey. In this case, data exchanged between the RLC layer and a lower layer (MAC layer) is called an RLC PDU. In an embodiment of the present invention, it is referred to as "PDU".

RLC PDU SN (Radio Link Control Packet Data Unit Sequence Number): A serial number included in the header of the RLC PDU, which is monotonically increased in sequence according to the transmission order. It is used as information for distinguishing RLC PDUs for selective combining proposed in the present invention. In the present invention, it is referred to as "SN".

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Selective Combined Auxiliary Data: Data used together with the RLC SN to perform selective combining by dividing the same broadcast data among broadcast data received from a plurality of cells. The present invention proposes an RLC SN version and a Selective Combining Indicator (hereinafter referred to as an "SC identifier") as the selective combining assistant data.

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RLC SN version: This is a count of the number of times the RLC SN is reset by the transmission of the RLC PDU, and is used when the RLC SN cannot determine whether the same RLC PDUs are received from different cells due to a transmission delay. In the present invention, it is referred to as "SN version".

SC identifier: Information indicating whether a specific MBMS service provided in an arbitrary cell supports selective combining.

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In general, broadcast services often have one broadcast service provided simultaneously in adjacent cells. In particular, the MBMS service, which is one of broadcast services, is even more so. Therefore, when the broadcast data according to the same broadcast service are received from a plurality of cells, the present invention uses only broadcast data in which no error occurs among the broadcast data. This is referred to as selective combining in the present invention. By using the selective coupling, a selective coupling gain can be obtained. For example, assume that the UE receives broadcast data according to a specific broadcast service from both Cell # 1 and Cell # 2. In this case, when an error occurs in the broadcast data received in the cell # 1 and no error occurs in the same broadcast data received in the cell # 2, only the broadcast data received in the cell # 2 is used. As a result, it is possible to obtain broadcast data in which no error occurs.

In order to perform such selective combining, the UE must establish a radio link with a plurality of cells, and must be able to determine the same data among broadcast data received through different radio links. The present invention proposes a method of using selective combining auxiliary data and SN to identify the same broadcast data.

A. First Embodiment

First, in order to identify RLC PDUs by using an SN of PDUs received from multiple links, the UE must satisfy the followings.

First, PDUs of the same size must be transmitted on the links to be subjected to selective aggregation. This is possible by setting the same PDU size for the links that will perform the selective aggregation.

Secondly, the same SN should be assigned to PDUs that are sent on links that will be subject to selective aggregation. That is, if the PDU received on the primary link and the PDU received on the secondary link have the same SN, they should be the same PDU. It is automatically met if the first condition is met. That is, the PDUs transmitted through the primary link and the secondary link are PDUs with the same SN after the same MBMS data transmitted from the core network is composed of PDUs of the same size.

Thirdly, the UE should be able to identify PDUs of the links to be subjected to selective aggregation by using the SN. Since the SN has a value between 0 and 127, the SNs of PDUs received at the same time through the primary link and the secondary link by the UE should not differ by more than 128/2 = 64. If the difference is greater than 64, the UE cannot determine the exact order of PDUs received on the secondary link. For example, if at any point in time a PDU with an SN is received from the primary link and a PDU with an SN from (a + 64) is received from the secondary link, then the UE may receive a PDU to receive from the secondary link. It is not possible to determine whether the PDU is transmitted before by 64 PDUs or the PDU to be transmitted after 64 PDUs.

On the other hand, as a method of satisfying the third condition described above, two can be proposed. The first is to synchronize the data transmission per link in the network to some extent. Second, there is no restriction on data transmission per link, but a method of transmitting auxiliary data, which can be used as identifiers of PDUs, for each cell.

The present invention to be described below is constructed based on the second solution. However, even if the first solution is used, the essential part of the present invention is the same. For example, the operation of detecting the duplicately received data and the reconfiguring order of the selective combiner are the same.

In order to apply the second scheme, in the present invention, a UE periodically broadcasting selective combining assistance data for each cell and receiving broadcast data from two or more cells uses the selective combining assistance data and an SN assigned to the broadcasting data. To perform the selective combining.

In general, what is proposed in the present invention, the RNC providing any MBMS service announces the selective association assistance data for the MBMS service for each cell in which the MBMS service is provided. The selective association assistance data means data that the UE should recognize in order to perform selective association, for example, data indicating whether a specific MBMS service is capable of selective combining in the cell (SC identifier) or transmitted in the cell. May be ancillary data (SN version) used to identify a PDU. When the UE finds another cell providing the MBMS service that it desires in a good wireless environment while receiving the MBMS service from any cell, the UE acquires the optional combined assistance data known from the found cell. The selective combining assistance data is used to perform a selective combining operation on MBMS data transmitted from the plurality of cells. As described above, the selective combining operation refers to an operation of discarding duplicated PDUs among the PDUs received through the primary link and the secondary link, and delivering the reconfigured PDUs to the RLC entity in the order of transmission. The optional combined assistance data may be used for PDU identification received through the primary link and the secondary link in the process.

In the present invention, an optional combiner is provided as a device for performing the selective combining operation, and the selective combiner is located between the MAC layer and the RLC layer. The optional combiner is configured with the setting of the secondary link and is not used in the situation where only one of the plurality of links currently set exists. The secondary link indicates a physical layer / MAC layer to process MBMS data transmitted in a new cell.

As a preferred embodiment of the present invention, an operation of performing selective combining using the SN version and the SC identifier as the selective combining auxiliary data will be described.

1 is a view showing the structure of a radio access network (hereinafter referred to as "UTRAN") in a UMTS mobile communication system for applying an embodiment of the present invention. In FIG. 1, a UTRAN is composed of a cell, a base station (hereinafter referred to as "Node B"), and a radio network controller (RNC). There may be a plurality of RNCs in the UTRAN, and each of the RNCs may control a plurality of Node Bs. Each Node B controls a plurality of cells. One RNC, Node Bs controlled by the RNC, and a plurality of cells controlled by the Node Bs are collectively referred to as a Radio Network Subsystem (RNS). In FIG. 1, only the structure of one RNS among a plurality of RNSs constituting the UTRAN is shown, and it is assumed that each of the two Node Bs constituting the RNS controls one cell. On the other hand, the cell typically only serves as a physical layer of the Node B to which it belongs. Therefore, in the embodiment of the present invention to be described later it should be noted that the Node B and the cell can be used interchangeably.

Referring to FIG. 1, the RNC 110 configures MBMS data provided from a core network into PDUs and provides them to two adjacent cells 112 and 114. In addition, the RNC 110 periodically transmits selective combining assistance data for each MBMS service through the MCCH for each of the two neighbor cells 112 and 114. The optional association assistance data includes an SN version and an SC identifier. The SN version is auxiliary data used by the UE 116 to identify the back and forth relationship between PDUs received on the primary link and PDUs received on the secondary link. The SN of the PDU is primarily used to identify the back and forth relationships between the PDUs received from each link. However, since the SN is only 7 bits, it may not reflect the transmission situation difference that may occur between links. For example, if there is a transmission difference of several hundred PDUs between the primary link and the secondary link, the SN is of no help in identifying the back and forth relationships of the received PDUs. In other words, if the x-th PDU is being transmitted on the primary link but the x + 500th PDU is being transmitted on the secondary link, an SN having a value between 0 and 127 is of no help in identifying the back and forth relationships of the received PDUs. The SN version is a parameter that creates an effect of extending the SN so that the UE can identify the PDUs even when the transmission situation difference occurs. Each time the SN of the PDU configured for each link wraps, the RNC 110 increments the SN version by 1 and periodically broadcasts the SN version. It can be assumed that the example of recursion of the SAN returns to zero at 127.

The SC identifier constituting the selective coupling assistance data is a value indicating whether selective coupling of PDUs transmitted on the link with PDUs on another link is possible. The SC identifier may be determined based on whether the RLC configuration of the link satisfies the aforementioned preconditions 1 and 2. For example, if a particular link is driven later than links in an adjacent cell, the second precondition that the SN grants of the PDUs must be the same is not met. For such a link, the SC identifier can be set to 'enabled' to instruct the UEs not to perform selective combining. To illustrate the situation in which the above case actually occurs, the number of UEs that want to receive the MBMS service in any cell was not large enough to set the PtM service at the time when any MBMS service was started. However, the UE may start the PtM service by moving several UEs to the cell while the MBMS service is in progress. In this case, since the SN scheme is different between the link of the cell and the link of another cell, the UE cannot perform selective coupling between the link of the cell and the link of another cell.

Any UE 116 detects that the wireless signal of the new cell 114 satisfies certain requirements, such as meeting the above threshold value, while receiving the MBMS service through the serving cell 112. The UE 116 then establishes a radio link capable of receiving MBMS service from the new cell 114. In order to establish a radio link with the new cell 114, the UE 116 must interpret the control information transmitted on the MCCH from the new cell 114. The control information includes optional combining assistance data. The UE 116 interprets the control information to determine whether the MBMS service desired by the new cell 114 is provided through a common channel. If the desired MBMS service is provided, check whether the selective combination is possible. If the selective combining is possible, the UE 116 interprets radio bearer information for the MBMS service from the control information to establish a secondary link capable of receiving the MBMS service. The radio bearer is composed of an RLC / MAC / PHY layer, and the link is composed of a MAC and a PHY layer. Accordingly, the UE 116 sets the radio link configured for the new cell 114 as the secondary link and the radio link configured for the serving cell 112 as the primary link.

The UE 116 configures an optional combiner to perform selective combining of PDUs received on the primary link and PDUs received on the secondary link. The UE 116 provides the optional combiner with SN version information corresponding to the primary link and SN version information corresponding to the secondary link. The selective combiner combines the SN and the SN version, thereby obtaining an extended SN effect. In the present invention, as described above, the value in which the SN version and the SN are combined is called an extended SN of the corresponding PDU. The UE 116 uses the extended SN to identify duplicated received PDUs among the PDUs received on the primary link and the secondary link. In addition, one of the duplicated PDUs is discarded, and the remaining PDU performs a duplication check operation. In addition, the PDUs are sequentially reconfigured for the PDUs provided through the redundancy check so that the PDUs may be sequentially transmitted to the RLC layer. The duplicate check operation and the sequence reconstruction operation are selective combining operations proposed by the present invention.

For the embodiment of the present invention as described above the following operations will be described in detail.

First, signaling between the RNC and the cell and the UE should be proposed to provide selective combined assistance data.

Second, the operation of the RNC to manage and optionally transmit the optional joint assistance data should be proposed.

Third, an operation of performing selective combining by the UE using selective combining assistance data should be proposed.

1. Signaling

Hereinafter, signaling for transmitting selective combining assistance data according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 illustrates a process in which an RNC announces selective combining assistance data for each cell and receives the same by a UE for an embodiment of the present invention. The signaling illustrated in FIG. 2 assumes that the UE starts to receive a good signal through the target cell in a situation where an MBMS service is provided through the serving cell. The serving cell refers to a cell previously providing any MBMS service to the UE, and the target cell refers to a cell newly providing the MBMS service due to the movement of the UE.

Referring to FIG. 2, the UE receives the MCCH from the serving cell in step 210. The UE, by receiving the MCCH, acquires selective association assistance data along with radio bearer information currently provided through the serving cell and for the type and link establishment of an MBMS service. The selective combining assistance data consists of an SC identifier for identifying whether the serving cell supports selective combining and an SN version for identifying a PDU currently being transmitted.

The UE checks whether the desired MBMS service is provided from the serving cell according to the type of the MBMS service. If the desired MBMS service is provided, the UE establishes a radio bearer using radio bearer information corresponding to the MBMS service. The radio bearer may be composed of an RLC layer, a MAC layer, and a PHY layer. The MAC layer and the PHY layer may be defined by the term "link". In the description below, the MAC layer and the PHY layer configured for the serving cell are referred to as a "main link".

Thereafter, the UE checks whether the serving cell supports selective combining by the SC identifier configuring the selective combining assistance data. If the serving cell does not support selective combining, the UE does not perform the selective combining proposed in the present invention. However, if the serving cell supports selective combining, the UE stores an SN version that constitutes the selective combining assistance data.

The UE receives a PDU from the serving cell on the primary link. The UE checks the SN from the received PDU, and increments the SN version by one if the SN is determined to be an initial value. For example, if a previously received PDU with an SN of 127 is received and the SN of the currently received PDU returns to 0, the UE increments the SN version currently stored by one.

The UE monitors whether a good signal is received from neighbor cells in a situation where an MBMS service is provided from the serving cell. Receiving the good signal means having a good wireless environment. When a good signal is detected, the UE recognizes an adjacent cell transmitting the signal as a target cell. In step 220, the UE receives the MCCH from the target cell, thereby obtaining selective coupling assistance data along with radio bearer information for the type and link setting of the MBMS service currently provided through the target cell. Done.

The UE checks whether the desired MBMS service is provided from the target cell according to the type of the MBMS service. The desired MBMS service is an MBMS service currently provided from the serving cell. If the desired MBMS service is being provided, the UE checks whether the target cell supports selective combining by the SC identifier constituting the selective combining assistance data. If the target cell does not support selective combining, even if the serving cell supports selective combining, the UE does not perform the selective combining proposed by the present invention. In other words, if the target cell does not support selective aggregation, the UE does not configure a secondary link for the target cell. However, if the target cell supports selective combining, the UE configures a radio bearer using radio bearer information corresponding to the MBMS service. The radio bearer may be composed of an RLC layer, a MAC layer, and a PHY layer. In the description below, the MAC layer and the PHY layer configured for the target cell are referred to as "secondary links". When the secondary link is configured, the UE stores an SN version that constitutes the selective association assistance data.

The UE receives a PDU from the target cell on the secondary link. The UE identifies the SN from the received PDU and increments the SN version by one when the SN changes to an initial value.

2. Operation of RNC

In order to implement the present invention, the RNC manages selective combining assistance data and periodically provides it for each cell. Hereinafter, an operation for periodically transmitting selective combining auxiliary data in the RNC will be described in detail.

The RNC periodically transmits selective association assistance data through the MCCH configured for each cell managed by the RNC. The optional combined assistant data is set for each MBMS service. Therefore, if n MBMS services are provided in one cell, n selective coupling assistant data may be periodically transmitted through the MCCH configured for the cell.

First, the SN version constituting the selective association assistance data is managed and transmitted as follows by the RNC.

The RNC configures an RLC entity to process MBMS data according to the MBMS service when an arbitrary MBMS service is first requested from cells managed by the RNC. The SN version corresponding to the random MBMS service is initialized to zero. Thereafter, PDUs according to the MBMS service are sequentially transmitted through the RLC entity. In this case, the PDU includes a SN that monotonically increases in sequence according to the transmission order. The SN is monotonically increased starting from zero and up to any predetermined number. As an example, the SN increases from 0 to 127, and returns to 0 after 127. The RNC increments the SN version by one when the SN returns to zero.

The SN version of each cell managed by the above is periodically informed of the cell where the arbitrary MBMS service is being provided, so that UEs wishing to perform selective combining for the arbitrary MBMS service in the cell may receive the SN version. Be aware of this.

Next, the SC identifier constituting the optional association assistance data is managed and transmitted by the RNC as follows.

The RNC manages an SC identifier indicating whether selective combining is supported for each MBMS service provided through cells controlled by the RNC. In this case, even a cell providing the same MBMS service may be divided into a cell supporting selective combining and a cell not supporting selective combining. In addition, a specific MBMS service may not provide a selective coupling regardless of the cell. By this information the SC identifier is managed by the RNC. The RNC periodically transmits SC identifiers set for each MBMS service. For example, if any MBMS service provided through cell # 1 can be selectively combined, the RNC sets the SC identifier for the arbitrary MBMS service to 'enabled' and periodically broadcasts through the cell # 1. On the other hand, if any MBMS service provided through cell # 2 cannot be selectively combined, the RNC sets the SC identifier for the arbitrary MBMS service to 'disabled' and periodically broadcasts through the cell # 2.

3. Operation of the UE

Hereinafter, an operation of a UE performing selective combining according to an embodiment of the present invention will be described in detail.

3 is a diagram illustrating a control flow for a UE to perform selective combining according to an embodiment of the present invention. The control flow of FIG. 3 assumes a situation in which a radio link is established between a UE and a serving cell and a specific MBMS service is provided through the radio link.

Referring to FIG. 3, in step 301, the UE receives a signal from neighbor cells and detects whether a good signal among the received signals exists. The definition that the received signal is good can be made in various ways. For example, as a method of using the received signal strength, if the received signal intensity exceeds a predetermined threshold, it may be determined that the signal is good. The presence of the good signal implies that the UE is in close proximity to any neighbor cell (hereinafter referred to as the "target cell") that transmitted the good signal. Accordingly, the UE can simultaneously receive signals from the serving cell and the target cell. Meanwhile, the target cell may be one or more cells.

When the target cell is assumed to be plural, the UE receives MCCHs from the target cells in step 303 and selects the MCCH from the target cell where the best signal is received. Through the MCCH, identifiers of the MBMS service provided by the target cell, radio bearer information of the provided MBMS service, selective coupling assistance data, and the like are transmitted. The UE checks the information received through the selected MCCH and proceeds to step 305. In step 305, the UE checks whether the desired MBMS service is provided by the target cell. If the desired MBMS service is provided, the process proceeds to step 307. Otherwise, if the desired MBMS service is not provided, the process proceeds to step 309.

In step 307, the UE determines whether the target cell supports selective combining based on the SC identifier among the checked selective combining assistance data. If it is determined by the SC identifier that the target cell supports selective combining, the process proceeds to step 311. Otherwise, if it is determined that the target cell does not support selective combining, the process proceeds to step 309.

In step 309, the UE selects an MCCH from the target cell to which a good signal is received, checks information received through the selected MCCH, and returns to step 305. However, in step 311, the UE establishes a radio link, that is, a secondary link, with the target cell in order to receive the MBMS service desired by the UE. The secondary link is established by radio bearer information received through the MCCH. The radio bearer information includes physical layer information, MAC layer information, and the like. The physical layer information is information about a transport channel, and includes code information corresponding to a physical channel, a type of channel coding applied to a physical channel, a channel coding rate, a transmission time interval (TTI), and the like. The MAC layer information includes multiplexing information according to whether multiplexing is applied in the MAC layer and service identifier information according to whether a service identifier is used in the MAC layer. The UE sets a new physical layer by the physical layer information, and sets a new MAC layer by the MAC layer information. The secondary link refers to the newly configured physical layer and MAC layer.

When the secondary link is configured as described above, the UE configures an optional combiner for selective combining in step 313. Thereafter, the selective combiner is connected to the primary link and the secondary link, and performs selective combining on broadcast data received through the primary link and the secondary link. A detailed description of the selective coupler will be described later with reference to FIG. 4.

In step 315, the UE continuously monitors whether a situation in which release of the primary link or the secondary link is required occurs. The situation in which the release is required corresponds to a situation in which a signal having an intensity less than a predetermined threshold is received. If such a situation is detected, the UE releases the link with the corresponding cell. For example, if the desired signal is not received through the primary link, the primary link is released. Otherwise, if the desired level of signal is not received through the secondary link, the secondary link is released. If only one link exists in step 315, the UE terminates the selective combining operation by releasing the selective combiner configured in step 317.

4 is a diagram illustrating a structure of a UE for performing an embodiment of the present invention. The structure of the UE shown in FIG. 4 assumes a situation where an optional combiner is configured for selective combining. However, since only the primary link with the serving cell exists, only a configuration of processing a signal received from the serving cell will exist in a situation in which selective coupling is not performed. Therefore, the structure of the UE consists of only the main link 410 composed of the physical layer 412 and the MAC layer 414, and the RLC layer 440 only. Thereafter, when a new MBMS service provided from the serving cell is to be newly provided from a target cell, the UE configures a secondary link with the target cell. The structure of the UE configured with the secondary link is shown in FIG. 4.

Referring to FIG. 4, the UE obtains physical layer information and MAC layer information from the target cell to which the secondary link is to be configured through the MCCH. Thereafter, a new physical layer 422 is set by the physical layer information, and a new MAC layer 424 is set by the MAC layer information. The configuration of the physical layer 422 and the MAC layer 424 means that a new secondary link has been established. The UE then sets up an optional combiner 430 according to the present invention. Thereafter, the primary link 410 and the secondary link 420 are connected to the lower layer, and the RLC layer 440 is connected to the upper layer.

The selective combiner 430 includes a duplication checker 432 and a reordering buffer 434. The selective combiner 430 discards the duplicated PDUs among the PDUs received through the primary link 410 and the secondary link 420, and reconstructs the duplicated PDUs in the order of transmission. It serves to deliver to the layer 440. That is, the same PDU may be received through the primary link 410 and the secondary link 420. In this case, the redundancy checker 432 constituting the selective combiner 430 discards one of the PDUs received through the primary link 410 and the PDUs received through the secondary link 420 and discards the other PDU. Output only. Meanwhile, the PDUs output from the duplication checker 432 may not be regarded as having the same order as the transmission order. Accordingly, the PDUs output from the redundancy checker 432 are temporarily stored in the reconfiguration buffer 434 and then reconfigured in the transmission order to the RLC layer 440.

In order to determine whether the duplication checker 432 overlaps the PDU provided from the primary link 410 and the PDU provided from the secondary link 420, separate information is required. As an example of the information, the SN of the PDU may be used. However, since the SN is the same, it may not necessarily be determined as a duplicate PDU. The reason is that the SN is given with a predetermined period. When the PDUs provided through the primary link 410 and the PDUs provided through the secondary link 420 have a delay difference deviating from one period, the two PDUs are provided. These are not duplicates. This can be confirmed via the SN version. As defined above, the SN version is a value changed by the period. Therefore, even if the SN is the same, if the SN version is different it can not be determined as a duplicate PDU. In order to solve such a problem, the present invention proposes an extended SN (Extended SN) as separate information for identifying the duplication. The extended SN is defined as in Equation 1 below.

Extended SN_x = [RLC SN Version_x II SN_x]

As shown in Equation 1, the extended SN_x of the PDU provided through the link x is a value obtained by concatenating the SN version (SN version_x) and the SN (RLC SN_x) corresponding to the link x. For example, if the SN version of the primary link is "001" and the SN of the PDU received on the primary link is "0000111", the extended SN is "0010000111".

Accordingly, the redundancy checker 432 obtains extended SNs for each of the PDUs provided from the primary link 410 and the PDUs provided from the secondary link 420, and compares the extended SNs to determine whether they overlap. have. However, it does not replace the SN of PDUs with the extended SN. The extended SN is used only to grasp the back and forth relationship between the PDUs received from the primary link 410 and the secondary link 420.

Specific Behavior of Selective Coupling at the UE

Hereinafter, the operations of the redundancy checker and the reconfiguration buffer for selective coupling in the UE according to an embodiment of the present invention will be described in detail.

Example of operation of redundancy check unit

The redundancy checker 432 discards the PDUs that have been repeatedly received through the primary link and the secondary link, or checks the PDUs (hereinafter, referred to as "final lost PDUs") that were not finally received. That is, the redundancy checker 432 delivers only one PDU of the plurality of PDUs received from both the primary link and the secondary link to the upper layer, and discards the remaining PDUs. In this case, the plurality of PDUs may be received with a predetermined delay. Meanwhile, 'final lost PDU' not received through any one of the primary link and the secondary link is identified and notified to the upper layer. There may be various ways to implement the above-described operation of the redundancy checker 432. The following description may be one of the implementation examples.

First, variables to be used in the implementation example to be described below are as follows.

V [Delivered]: The largest value of SNs of PDUs delivered to the reconfiguration buffer 434, and is denoted V [D] thereafter.

S [Not Received]: SN set of PDUs (hereinafter referred to as "lost PDUs") first lost from either one of the primary link or the secondary link, and then referred to as S [NR]. The S [NR] is initially initialized to an empty set. Thereafter, if a lost PDU occurs from the primary link or the secondary link, it is checked whether the lost PDU has been delivered to the reconfiguration buffer 434 before that time. If it was never delivered to the reconfiguration buffer 434, the SN of the lost PDU is registered in S [NR]. However, if it was previously delivered to a higher layer, the lost PDU is ignored. On the other hand, if the SN of the lost PDU is already registered in S [NR], the SN of the lost PDU is erased in S [NR] as it is a lost PDU on both the primary and secondary links. Finally, if a PDU having an SN registered in S [NR] is normally received over the remaining link, the SN of the normally received PDU is erased in S [NR].

S [Missing]: An SN set of PDUs that are both lost and not normally received on either the primary link or the secondary link, hereinafter referred to as S [M]. That is, the SN registered in the S [M] is an SN lost in both the primary link and the secondary link and erased in S [NR].

Looking at the operation of the redundancy check unit 432 using the defined variables as follows.

When the redundancy checker 432 receives the first PDU through the newly configured secondary link, it initializes V [D] with the SN of the PDU most recently received from the primary link and delivered to the reconfiguration buffer 424. Initialization of the V [D] is not performed by a separate procedure, and V [D] is set to the highest SN among SNs of PDUs received through the primary link and delivered to the upper layer before the secondary link is configured. You can also update. The redundancy checker 432 then compares the SN of the PDU first received on the secondary link with the SN recorded in the V [D]. If the SN of the PDU is greater than the SN recorded in V [D], the PDU is delivered to the reconfiguration buffer 424. At this time, the V [D] is updated with the SN of the PDU delivered to the reconstruction buffer 424. The redundancy checker 432 then performs the same operation when a PDU having an SN greater than the SN recorded in the V [D] is received through the primary link and the secondary link.

However, the redundancy checker 432 checks whether the SN of the first PDU received through the secondary link or after that is received through the primary link or the secondary link is less than or equal to the SN recorded in V (D). do. If the SN of the PDU is equal to or less than the SN recorded in the V [D], the duplicate detection unit 432 checks whether there is an SN that matches the SN of the PDU as an element of S [NR]. If not present in the S [NR], the duplicate detection unit 432 discards the PDU in consideration of duplicate reception. This is a case where the same PDU is repeatedly received through the primary link and the secondary link. However, if the SN of the PDU is present as an element in the S [NR], the redundancy checker 432 transfers the PDU to the reconstruction buffer 434. And SN of the PDU existing as an element in S [NR]. This corresponds to a case where the PDU was previously lost on either the primary link or the secondary link, but the lost PDU is received on the remaining link.

Meanwhile, when the lost PDU is generated through the primary link or the secondary link, the redundancy checker 432 checks whether the SN of the lost PDU exists as an element of the S [NR]. If the SN of the lost PDU exists as an element in the S [NR], the redundancy check unit 432 deletes the SN of the lost PDU from the S [NR]. The SN of the lost PDU is registered as an element of S [M], and the SN registered as an element of S [M] is notified to the reconstruction buffer 434 for reference in reconstructing the received PDUs. do. Meanwhile, the redundancy checker 432 removes the SN notified to the reconstruction buffer 434 from the S [M]. This is the case when the corresponding PDU is lost on both the primary link and the secondary link. However, if the SN of the lost PDU does not exist as an element of S [NR], the redundancy check unit 432 registers the SN of the lost PDU as an element of S [NR].

The redundancy checker 432 considers the PDU to be lost for the following situations.

First, if there is a situation in which the difference between the SN of the PDU received at an arbitrary time point per link and the SN of the immediately received PDU is 1 or more, the PDU having an unreceived SN is regarded as a lost PDU. For this purpose, the SN of a previously received PDU must be managed for each link. For example, if a PDU having 13 as a SN is received from a primary link at any time, but the SN of the PDU received immediately before is 10, PDUs having 11 and 12 as SNs are considered as unreceived PDUs. Meanwhile, as another example, a method of managing an SN of a PDU to be received may also be proposed. For example, if a PDU having a SN of 10 is received from a primary link at any time, but the SNs of consecutive PDUs received are 13, PDUs having 11 and 12 of SN may be regarded as unreceived PDUs.

Secondly, when a PDU is first received on the secondary link, the missing PDU may be identified by considering both the primary link and the secondary link. That is, if the SN of the PDU first received on the secondary link after V (D) is initialized is larger than the initial value of V (D), it exists between the initial value of V (D) and the SN of the first PDU. PDUs with SNs are considered lost PDUs. For example, in a situation where V (D) is initialized to 5, if the SN of the first PDU received through the secondary link is 10, PDUs having 6, 7, 8, and 9 as SNs are regarded as lost PDUs. The situation is that the secondary link is transmitted 5 PDUs ahead of the primary link. However, if the difference between the initial value of the V (D) and the SN of the first PDU of the secondary link is less than 1, it is considered that no lost PDU has occurred.

Example of the behavior of the reconfiguration buffer

The reconfiguration buffer 434 according to an embodiment of the present invention reconfigures PDUs transmitted from the redundancy checker 432 in SN order, and delivers the PDUs to a higher layer by a predetermined rule. Referring to the operation of the reconstruction buffer 434 specifically for this, the reconstruction buffer 434 stores the PDUs delivered from the redundancy check unit 432 in the order of SN. Then, check the SNs of the stored PDUs. The check considers missing PDUs for the gap of the SN. The reconfiguration buffer 434 stores the smallest SN among the SNs of the lost PDUs in a variable called V (First Gap). When the first gap is determined, the reconfiguration buffer 434 transfers PDUs having an SN smaller than the first gap to a higher layer. When delivery of the target PDU is made, the reconfiguration buffer 434 updates the V (First Gap) with a new SN. The update of the first gap applies the same criteria as described above. When the first gap is updated, the reconfiguration buffer 434 transfers PDUs having an SN smaller than the updated first gap to a higher layer. The update of the first gap is limited to when a PDU corresponding to a first gap is received and a PDU corresponding to a first gap is notified as a final unreceived PDU.

As described above, in the present invention, the redundancy checker transfers only one of the PDUs received from the primary link and the secondary link to the reconfiguration buffer, and discards the remaining received PDUs. The redundancy checker also determines the last lost PDU and notifies the reconstruction buffer. The reconfiguration buffer is delivered to the upper layer when the order of the PDUs delivered by the redundancy checker is corrected, so that the selective combining gain can be obtained without affecting the operation of the RLC layer.

Example of Selective Combination

5 is a diagram illustrating an example of an operation of a selective combiner of a UE performing selective combining according to an embodiment of the present invention. In this case, it is assumed that PDUs having 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 as SNs are sequentially received at the reception points T (1) to T (9), respectively. Doing. It is assumed that PDUs having 15, 16, 17, 18, 19, 20, 21, 22, 23, and 24 as SNs are sequentially received through the secondary link at reception points T (1) to T (9), respectively. have. On the other hand, it is assumed that a secondary link is set at an arbitrary time T (0), and V (D) is initialized to 10 at this time.

Referring to FIG. 5, the redundancy check unit 432 receives a PDU having a SN of 11 (hereinafter referred to as “SN 11”) through the primary link to the T 1, and has an SN of 15 through the secondary link. Receive a PDU (hereinafter referred to as "SN 15"). Thereafter, the redundancy checker 432 updates V [D] to 15 and registers 12, 13, and 14, SNs existing between 11 and 15, to S [NR]. The SN 11 and the SN 15 are transferred to the reconfiguration buffer 434. The reconfiguration buffer 434 sets V (First Gap) to 12 and delivers SN 11, which is a PDU having an SN lower than V (FIRST GAP), to the RLC layer.

At any point in time T (2), the redundancy check section 432 receives the SN 12 on the primary link and the SN 16 on the secondary link. The redundancy check unit 432 updates the V [D] to 16 based on the SN received through the secondary link, and selects 12 which is an element of the S [NR] based on the SN received through the primary link. Delete it. The SN 12 and the SN 16 are transferred to the reconstruction buffer 434. The reconfiguration buffer 434 updates the V (FIRST GAP) to 13 and forwards the SN 12 to a higher layer.

At any time point T (3), the redundancy check unit 432 receives the SN 13 on the primary link and the SN 17 on the secondary link. The redundancy checker 432 updates the V [D] to 17 based on the SN received through the secondary link, and selects 13 which is an element of the S [NR] based on the SN received through the primary link. Delete it. The SN 13 and the SN 17 are transferred to the reconstruction buffer 434. The reconfiguration buffer 434 updates the V (FIRST GAP) to 14 and delivers the SN 13 to a higher layer.

At any point in time T (4), the redundancy check unit 432 receives the SN 14 on the primary link and does not receive a PDU on the secondary link. The redundancy check unit 432 maintains V (D) at 17 and deletes 14, which is an element of S [NR], based on the SN received through the primary link. The SN 14 is then transferred to the reconstruction buffer 434. The reconstruction buffer 434 updates the V (FIRST GAP) to 18 and transfers the SN 14, SN 15, SN 16, and SN 17 to a higher layer.

At any point in time T 5, the redundancy check unit 432 receives the SN 15 over the primary link and the SN 19 over the secondary link. The redundancy checker 432 updates the V (D) to 19 based on the SN received through the secondary link, and adds 18 to the S [NR] based on the SN received from the T (4). Register. Since the SN of the SN 15 received through the primary link is smaller than the V (D) and is not an element of the S [NR], it may be determined that the received PDU is duplicated. Therefore, the redundancy checker 432 discards the SN 15 without being transferred to the reconstruction buffer 434. The SN 19 is delivered to the reconstruction buffer 434. The SN 19 is stored in the reconstruction buffer 434 until the SN 18 corresponding to the V (FIRST GAP) is received.

At any time point T 6, the redundancy check unit 432 does not receive an RLC PDU on the primary link, but receives an SN 20 on the secondary link. The redundancy checker 432 updates the V (D) to 20 based on the SN received through the secondary link, and the SN 20 is transferred to the reconstruction buffer 434.

At any point in time T 7, the redundancy check unit 432 receives the SN 17 over the primary link and the SN 21 over the secondary link. The redundancy checker 432 updates the V (D) to 21 based on the SN received through the secondary link, and discards the SN 17 as a duplicately received RLC PDU. The SN 21 passes to the reconstruction buffer 434. The redundancy checker 432 confirms that the SN 16 is a lost PDU at T (7). However, since the SN 16 has already been received over the secondary link and delivered to the higher layer, it is discarded without being registered in the S [NR].

At any point in time T 8, the redundancy check unit 432 does not receive any PDUs on the primary and secondary links.

At any point in time T 9, the redundancy check unit 432 receives the SN 19 over the primary link and the SN 23 over the secondary link. The redundancy checker 432 updates V (D) to 23 based on the SN received through the secondary link, and discards the SN 19 received through the primary link as it has already been delivered to a higher layer. . The SN 23 is delivered to and stored in the reconstruction buffer 434. On the other hand, based on the SN received through the primary link to the T (9), it is confirmed that the SN (18) is a lost PDU. Since the SN 18 is already registered in S [NR] at that time, the 18 is removed from S [NR] and 18 is registered in S [M] as a new element. The redundancy checker 432 notifies the reconstruction buffer 434 that a new element is registered in S [M], so that the PDU having SN 18 is the last lost PDU. And 18 registered in S [M]. The reconfiguration buffer 434 updates the V (FIRST GAP) to 22, which is the location of the next lost PDU, by being informed that the SN 18 is the last lost PDU, and SN (PDUs having an SN earlier than 22). 19), the SN 20 and the SN 21 are delivered to the upper layer.

B. Second Embodiment

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The first embodiment of the present invention describes the operation of the UE and the operation of the network when there are entities for constructing data to be selectively combined in an appropriate size and there are entities for granting SNs. In the first embodiment, an entity granting SN after configuring data to an appropriate size was an RLC layer. For convenience of explanation, an entity granting SN after configuring data to an appropriate size will be referred to as a 'serial numbering device'.

From the network's point of view, another way to provide selective combining is to configure only one serial numbering device and allow the cells to share the device to allow selective combining. As described above, in a situation where multiple cells share a single serial numbering device, a network manages an SN version. For reference, the operation of the UE for the case where the serial number assigning device is configured for each cell and the case where several cells share the same serial number assigning device is the same. Therefore, the description to be described later is limited to the operation of the network.

6 shows an example of a network in which only one serial number assigning device is configured. For example, any MBMS service is provided to cell 1 615-1, cell 2 615-2, cell 3 615-3, cell 4 615-4, and cell 5 615-5. In order to provide the MBMS service, the RNC configures one serial number assigning device 605 and storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 for each cell. It was.

The serial number assigning device 605 may be an RLC layer as in the first embodiment. In the serial number assigning device 605, data to which SN is assigned is transmitted for each cell. At this time, before being transmitted to each cell, it is stored in the storage devices (610-1, 610-2, 610-3, 610-4, 610-5). As described above, an entity storing data before being transmitted for each cell may be a MAC layer. Data stored in the storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 are transmitted for each cell at an appropriate time. Therefore, even though the data is given SN through one serial number assigning device 605, the transmission time may be different for each cell.

As shown in FIG. 6, when a single serial number providing device provides data to a plurality of storage devices 610-1, 610-2, 610-3, 610-4, and 610-5, SN version information is provided for each device. The storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 configured for each cell are managed as follows.

First, the storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 providing data to an arbitrary cell initially set the SN version to zero. Thereafter, the storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 store the number of PDUs transmitted to the cell in a variable called N (PDU). The N (PDU) increases monotonically between 0 and 127, and then returns to zero after 127. If the SN has a different size, the size of N (PDU) is adjusted accordingly. As soon as the N (PDU) becomes 0 at 127, the storage devices 610-1, 610-2, 610-3, 610-4, 610-5 increase the SN version by one. In other words, the SN version is increased by one when N (PDU) returns from the maximum value to zero. The storage devices 610-1, 610-2, 610-3, 610-4, and 610-5 periodically transmit the SN version through the MCCH.

In the selective combining operation proposed in the present invention, the serial numbering device is established only in the same cells. However, the current standard does not define a method by which a UE can know which serial numbering device receives a cell. Therefore, the present invention defines a new parameter, called a serial number identifier, and proposes a method in which the parameter is transmitted periodically for each cell.

7 illustrates an example of a network in which a serial number assigning device is configured in plural, and shows an example of periodically transmitting the serial number assigning device identifier for each cell.

Referring to FIG. 7, an arbitrary serial number assigning device 705-1 provides data to cells 1 715-1, cells 2 715-2, and cells 3 715-3, and another serial number. The numbering device 705-2 provides the data to the cell 4 715-4 and the cell 5 715-5. The network assigns unique identifiers to the serial numbering devices 705-1 and 705-2. At this time, the identifier assigned to the serial numbering device should not overlap with the identifiers assigned to the peripheral serial numbering device. For example, the size of the serial number identifier may be about 5 bits. An operation of assigning an identifier to each of the serial number assigning devices 705-1 and 705-2 may be performed by an operator using O & M or the like.

The network periodically transmits the serial number identifiers for each cell, thereby allowing the UE to determine whether to perform selective association. For example, when UE # 1 720-1 recognizes that the serial number assigning device identifier of cell 1 715-1 and the serial number identifier of cell 3 715-3 are identical to each other, the cell 1 715 is recognized. -1) or attempt to selectively combine by setting the secondary link to the cell 3 (715-3). On the other hand, if UE # 2 720-2 recognizes that the serial number identifier of cell 3 715-3 and the serial number identifier of cell 4 715-4 are different, it does not attempt selective combining. . That is, a UE moving between cells assigned serial numbers by different serial number assigning devices does not perform the selective combining proposed by the present invention. However, for a UE moving between cells assigned a serial number by the same serial number assigning device, the selective combining proposed in the present invention is performed.

FIG. 8 is a diagram illustrating a control flow according to operation of a UE in a network having the structure of FIG. 7. 8 is essentially the same as the operation of the UE according to the first embodiment described with reference to FIG. 3. However, in determining whether the UE performs selective combining, there will be a difference in that it refers to whether the serial number identifier of the target cell matches the serial number identifier of the serving cell. The control flow of FIG. 8 assumes a situation in which a radio link is established between a UE and a serving cell, and a specific MBMS service is provided through the radio link.

Referring to FIG. 8, the UE receives signals from neighbor cells in step 801 and detects whether a good signal among the received signals exists.

When the target cell is assumed to be plural, the UE receives the MCCH from the target cells in step 803 and selects the MCCH from the target cell where the best signal is received. Through the MCCH, identifiers of the MBMS service provided by the target cell, radio bearer information of the provided MBMS service, selective coupling assistance data, and the like are transmitted. The UE checks the information received through the selected MCCH and proceeds to step 805. In step 805, the UE checks whether the desired MBMS service is provided by the target cell. If the desired MBMS service is provided, the process proceeds to step 807. Otherwise, if the desired MBMS service is not provided, the process proceeds to step 809.

In step 807, the UE determines whether the target cell supports selective combining based on the SC identifier among the checked selective combining assistance data. If it is determined by the SC identifier that the target cell supports selective combining, the process proceeds to step 811. Otherwise, if it is determined that the target cell does not support selective combining, the process proceeds to step 809.

In step 811, the UE compares the serial number assigning device identifier obtained from the serving cell with the serial number assigning device identifier obtained from the target cell. If the serial number identifier acquired from the serving cell and the serial number assigning device identifier obtained from the target cell are the same by the comparison, the flow proceeds to step 813. Otherwise, if the serial number assigning device identifiers from the target cell and the serving cell do not match, the process proceeds to step 809.

In step 809, the UE selects an MCCH from a target cell in which a good signal is received, checks information received through the selected MCCH, and returns to step 805. However, in step 813, the UE establishes a radio link, that is, a secondary link, with the target cell in order to receive the desired MBMS service. The secondary link is established by radio bearer information received through the MCCH. The radio bearer information includes physical layer information, MAC layer information, and the like. The physical layer information is information about a transport channel, and includes code information corresponding to a physical channel, a type of channel coding applied to a physical channel, a channel coding rate, a transmission time interval (TTI), and the like. The MAC layer information includes multiplexing information according to whether multiplexing is applied in the MAC layer and service identifier information according to whether a service identifier is used in the MAC layer. The UE sets a new physical layer by the physical layer information, and sets a new MAC layer by the MAC layer information. The secondary link refers to the newly configured physical layer and MAC layer.

As described above, when the secondary link is configured, the UE configures an optional combiner for selective combining in step 815. Thereafter, the selective combiner is connected to the primary link and the secondary link, and performs selective combining on broadcast data received through the primary link and the secondary link.

In step 817, the UE continuously monitors whether a situation requiring release of the primary link or the secondary link occurs. The situation in which the release is required corresponds to a situation in which a signal having an intensity less than a predetermined threshold is received. If such a situation is detected, the UE releases the link with the corresponding cell. For example, if the desired signal is not received through the primary link, the primary link is released. Otherwise, if the desired level of signal is not received through the secondary link, the secondary link is released. If only one link exists in step 817, the UE terminates the selective combining operation by releasing the selective combiner configured in step 819.

C. Third Embodiment

9 is a diagram showing the structure of a UE for performing another embodiment of the present invention. The structure of the UE shown in FIG. 9 assumes a situation where an optional combiner is configured for selective combining when receiving data from two or more links. Here, selective combining is a technique for receiving data over multiple cells (or links) to reduce the likelihood of data loss. Therefore, how many cells (or links) the terminal receives from does not have an essential effect on the operation of the terminal. However, for convenience of description, it is assumed that the data is received from only two cells.

Referring to FIG. 9, the optional combiner 920 includes a duplication checker 915 and a reordering buffer 910, and the duplication checker 915 includes a plurality of links. Are connected to the fields 925 and 930. The reordering buffer 910 is connected to the serial number assigning device 905.

Specific Behavior of Selective Coupling at the UE

Hereinafter, the operations of the redundancy checker and the reconfiguration buffer for selective coupling in the UE according to an embodiment of the present invention will be described in detail.

Examples of variables managed by the duplicate checker

The duplication checker 915 manages the following variables for each cell in which a link is established. In this case, the UE establishes a link with n cells, and names each cell c_1 925,..., And c_n 930.

Variables managed by the duplicate checker 915 for any cell x include the following.

VR (c_x): SN of a PDU expected to be received next from cell x, which is 1 plus the SN of the most recently received PDU from cell x.

VM (c_x): A set of SNs of an unreceived PDU from cell x.

On the other hand, the duplicate checker (Duplication Checker) 915 manages the following variables in common for all the cells.

VD: A set of SNs of PDUs that the duplication checker 915 has delivered to the reordering buffer 910. This is used for duplicate acknowledgments.

Highest_delivered_SN: Among the SNs of PDUs that the duplicate checker 915 has delivered to the reordering buffer 910, it represents the highest SN.

Permanently_missing_SN: The set of SNs of the final unreceived PDUs.

Variables Managed by Reconfiguration Chopper

The reordering buffer 910 manages the following variables.

First_missing_SN: The reconstruction buffer considers the PDUs corresponding to the gap of the SN as unreceived PDUs, and recalls the SN of the unreceived PDU with the lowest SN (or corresponding to the earliest occurrence of the earliest point). Save it to a variable.

Example of operation of redundancy check unit

The duplication checker 1215 manages each variable and performs the duplication check as follows. Unlike the previous embodiment, it is assumed that the optional combiner 1220 is configured at the time when the initial link is established. That is, it is assumed that the optional combiner 1220 is also configured when the UE configures a physical layer / MAC layer / RLC layer to receive MBMS service in any cell 1. In the previous embodiment, it is assumed that the UE configures this new link with another cell, thereby configuring the optional combiner 1220 when there is more than one link with the UE. The difference derived from the two situations is the initialization operation of the V (D) variable or Highest_delivered_SN. In other words, if there is an optional combiner even in a single link situation, the initialization of V (D) described in the previous embodiment is not necessary.

1. The duplication checker (Duplication Checker) 915 receives the PDU from any cell x.

2. The duplication checker 915 compares the SN of the received PDU with VR (c_x).

3. If the SN of the received PDU is larger than VR (c_x), the process proceeds to 4;

4. The duplication checker 915 adds SNs corresponding to the SNs of the received PDUs and the VRs c_x to the VM c_x. The SN to be included in the VM c_x also includes a VR c_x.

5. The duplication checker 915 updates the SN of the PDU that received the VR (c_x) by adding 1 to it.

6. The duplication checker 915 compares the SN of the received PDU with Highest_delivered_SN. If Highest_delivered_SN is larger than the SN of the received PDU, the process proceeds to 7. If not, proceed to 11.

7. Update Highest_delivered_SN to the SN of the received PDU.

8. The received PDU is transferred to the reconfiguration buffer 910.

9. Add the SN of the delivered PDU to the VD.

10. End the process and wait for the next PDU to be received.

11. Verify that the SN of the received PDU is included in the VD. If the SN of the received PDU is included in the VD, the process proceeds to 12. On the other hand, if the SN of the received PDU is not included in the VD proceeds to 14.

12. Discard the received PDU.

13. End the process and wait for the next PDU to be received.

14. Deliver the received PDU to the reconfiguration buffer.

15. Add SN of delivered PDU to VD.

16. End the process and wait for the next PDU to be received.

On the other hand, the operation of the duplicate checker (Duplication Checker) 915 manages the VM variable and confirms the final unreceived PDU is as follows.

1. The duplication checker (Duplication Checker) 915 monitors the SNs stored in the VM variables managed for each cell.

2. If a duplicate SN 915 stores any SN in all VM variables, the duplicate checker 915 stores the SN in Permanently_missing_SN. For example, any UE is receiving PDUs from Cell 1, Cell 2, and Cell 3, VM (c_1) = [10, 15, 18], VM (c_2) = [10, 13, 15], VM ( c_3) = [10, 15], SN 10 and 15 are stored in Permanently_missing_SN.

3. The duplication checker 915 reports the SNs stored in Permanently_missing_SN to the reordering buffer 910.

4. The duplicate checker 915 removes the SNs reported to the reordering buffer 910 from the Permanently_missing_SN.

5. The duplication checker 915 removes the SNs reported to the reordering buffer 910 from the VM variables.

Example of the behavior of the reconfiguration buffer

In this case, the operation of the reordering buffer 910 is as follows. The reordering buffer 910 stores the PDUs delivered by the duplication checker 915 in SN order, and considers PDUs corresponding to a portion where the increment of SN is 1 or more as unreceived PDUs. . The operation of the reordering buffer 910 will be described in more detail as follows.

1. The PDU delivered by the duplication checker 1215 arrives at the reordering buffer 910.

2. Reordering Buffer 1210 stores the PDUs in order based on SN.

3. If the SN of the received PDU is the same as First_missing_SN, it means that the PDU corresponding to First_missing_SN is no longer an unreceived PDU. Therefore, First_missing_SN is updated with the SN of the unreceived PDU having the lowest SN among the remaining unreceived PDUs.

4. Forward PDUs with SN lower than the updated First_missing_SN to the upper layer.

5. When the redundancy checker 915 reports the SNs of the final unreceived PDUs, the reordering buffer 910 considers that the unreceived PDUs corresponding to the SNs have been received.

6. If one of the SNs of the last unreceived PDUs matches First_missing_SN, it means that the PDU corresponding to First_missing_SN is no longer an unreceived PDU. Therefore, First_missing_SN is updated with the SN of the unreceived PDU having the lowest SN among the remaining unreceived PDUs.

7. The PDUs having the SN lower than the updated First_missing_SN are delivered to the upper layer.

D. Fourth embodiment

The fourth embodiment of the present invention provides an operation of a selective combiner that implements the functions of a re-ordering buffer and a duplication check.

UE structure

FIG. 10 is a diagram illustrating an RLC structure of a UE when a selective coupling function is included in an RLC entity according to a fourth embodiment of the present invention.

Referring to FIG. 10, the selective combiner 1035 receives PDUs from a plurality of cells through a lower layer. The redundant PDUs are discarded from the PDUs, and the order of the remaining PDUs is reconfigured. The reconstructed PDUs are delivered to an RLC layer 1030.

The selective combiner 1035 manages the SCR-window to perform the above-described operation. Meanwhile, the SCR-window identifies a front and rear relationship between PDUs received from various cells and performs a function for managing PDUs stored in a re-ordering buffer. In order to perform the operation of the re-ordering buffer, the SCR-window manages variables next_expect_SN and ScrWindow_UpperEdge.

Structure and Operation Example of SCR-window

11 shows the structure of the SCR-window.

Referring to FIG. 11, the SCR-window 1165 includes an ScrWindow_UpperEdge 1150 and an SCR_WINDOW_SIZE 1155.

The ScrWindow_UpperEdge 1150 means the highest SN among SNs of PDUs received by the UE to the present time. Therefore, if the SN of the newly received PDU is higher than the existing ScrWindow_UpperEdge, the ScrWindow_UpperEdge is updated with the new SN. That is, the ScrWindow_UpperEdge is updated with the SN of the newly received PDU.

The SCR_WINDOW_SIZE 1155 is a parameter set by the RNC and notified to the UEs. The SCR_WINDOW_SIZE 1155 means a maximum value of a transmission difference that may occur between two adjacent cells. If the RNC informs UEs by setting SCR_WINDOW_SIZE between any two cells to x, the RNC must ensure that the transmission difference between the two cells is no more than x PDUs.

The SCR-window 1165 is formed by an upper end point and a lower end point. In the SCR-window 1165, the ScrWindow_UpperEdge 1150 is used as an upward endpoint. Meanwhile, the downward end point is determined by a result of modulo operation of ScrWindow_UpperEdge SCR_WINDOW_SIZE to 128. The SCR-window 1165 proceeds in the same direction each time the ScrWindow_UpperEdge 1150 is updated.

If the SN of the PDU received at any time is located within the SCR-window 1165, the SN of the PDU is considered to be smaller than ScrWindow_UpperEdge 1150, and if it is located outside the SCR-window 1165, The SN of the PDU is considered to be larger than ScrWindow_UpperEdge 1150.

For example, suppose ScrWindow_UpperEdge (1150) is 100 and SCR_WINDOW_SIZE (1155) is 64 at any point in time.

At this point, the SCR-window 1165 has an upward endpoint of 100 and a downward endpoint of 36. If a PDU with an SN of 50 arrives at any point after the point in time, the 50 is located in the SCR-window 1165. Therefore, SN is a value smaller than 100, which is ScrWindow_UpperEdge (1150).

In addition, when a PDU having an SN of 30 arrives at any point after the time, the 30 is located outside the SCR-window 1165. Therefore, the SN is greater than 100, which is ScrWindow_UpperEdge 1150. Therefore, the ScrWindow_UpperEdge 1150 is updated to 30, and the new downward endpoint of the SCR-window 1165 is 96, calculated as -34 by 128 modules.

On the other hand, if a PDU with an SN of 120 arrives at any point after the point in time, the 120 is located in the SCR-window 1165, and thus 120 is smaller than the ScrWindow_UpperEdge 1150.

As described above, the SCR-window 1165 moves with the update of the ScrWindow_UpperEdge 1150 and is used to determine whether the SN of the received PDU is larger or smaller than the ScrWindow_UpperEdge 1150. In addition, only PDUs having an SN on the SCR-window 1165 may be stored in the re-ordering buffer. For example, if the SCR-window 1165 is [downward endpoint = 0, upward endpoint = 64], only PDUs having an SN between 0 and 64 are stored in the re-ordering buffer. As the SCR-window 1165 moves, the SNs of the PDUs stored in the re-ordering buffer change.

Meanwhile, as another variable used in the optional combiner, next_expect_SN is a variable in which the SN of the first unreceived PDU is stored. That is, it is the same variable as first_Gap in the previous embodiment. The initial value of the ScrWindow_UpperEdge 1150 is one less than the SN of the PDU initially received by the selective combiner. The initial value of next_expect_SN is the SN of the PDU initially received by the selective combiner.

Example of operation of the optional combiner

12 illustrates the operation of the selective coupler according to the fourth embodiment.

The operation of the selective combiner shown in FIG. 12 includes forming or changing a window (SCR_Window), storing broadcast data (PDU) received by the window in a rearrange buffer, or transmitting the same to a higher layer. After updating the SN (nex_expected_SN) of the received broadcast data, the broadcast data stored in the rearrangement buffer is transferred to a higher layer.

Referring to FIG. 12, the selective combiner receives an arbitrary PDU in step 1205. The selective combiner checks whether the SN of the received PDU is located in the SCR-window in step 1207. If the SN is located in the SCR-window, the flow proceeds to step 1225. If not, proceed to step 1210. The fact that the SN is not located in the SCR-window means that the SN is greater than ScrWindow_UpperEdge.

In step 1210, the selective combiner stores the previously received PDU in a re-ordering buffer. The optional combiner then updates the ScrWindow_UpperEdge to the SN in step 1212. In step 1215, the optional combiner newly sets the SCR-Window by the updated ScrWindow_UpperEdge. That is, the SCR-window is updated by moving the downward end point of the SCR-window by the size moved by the ScrWindow_UpperEdge. For example, if ScrWindow_UpperEdge is 10 and SN is 15 in step 1207, the ScrWindow_UpperEdge is moved to 15 by 5. In operation 1215, the lower endpoint of the SCR-Window is also moved by five. That is, the upper end point of the SCR-Window is moved by five.

In step 1217, the selective combiner transfers PDUs whose SN is located outside the new SCR-window to the upper layer among the PDUs stored in the re-ordering buffer. For example, suppose a PDU with an SN of 75 is stored in a re-ordering buffer. At this time, 75 was located in the window before the SCR-window moved (74 to 10). However, after the SCR-Window is moved (79 to 15), it is positioned outside the window. Therefore, the PDU whose SN corresponds to 75 is delivered to the RLC layer. Here, the fact that the PDU having the SN 75 is stored in the re-ordering buffer means that there is a PDU that has not been received before. In addition, the fact that 75 is located outside the SCR-window means that there is no possibility of receiving the unreceived PDU. Therefore, the PDU with the SN 75 is delivered to the higher layer even though the sequence reconstruction is not completed.

The optional combiner checks whether next_expect_SN is located outside the SCR-window in step 1220. If the next_expect_SN is located outside the SCR-window, the process proceeds to step 1260. Otherwise, if the next_expect_SN is located inside the SCR-window, the optional combiner proceeds to step 1295 and waits for the next PDU to arrive.

The location of the next_expect_SN outside the SCR-window means that there is no possibility of receiving an unreceived PDU corresponding to the next_expect_SN. Therefore, a new next_expect_SN should be set and PDUs having SNs smaller than the new next_expect_SN among the PDUs stored in the re-ordering buffer should be delivered to the upper layer. Steps 1260 and 1265 are steps for the above-described operation.

In step 1260, the selective combiner updates next_expect_SN with the SN of the first unreceived PDU of the re-ordering buffer. For example, if there are unreceived PDUs with SN 100, 120, 10 in the re-ordering buffer, update 100 with a new next_expect_SN.

Thereafter, the selective combiner proceeds to step 1265 and delivers PDUs having an SN smaller than the next_expect_SN to a higher layer. The PDUs are PDUs whose order has been successfully reconstructed. When the delivery is complete, the selective combiner completes all processes in step 1295 and waits for a new PDU to arrive.

However, if the SN is included in the SCR-window in step 1207, the flow proceeds to step 1225.

The selective combiner determines whether the PDU has been previously received in step 1225. This is possible by checking whether the SN of the PDU is already stored in the re-ordering buffer. That is, if the PDU of the SN is already stored in the re-ordering buffer, it means that the PDU is duplicated and proceeds to step 1240. In step 1240, the selective combiner discards the redundantly received PDU. Proceed to step 1295 to complete the process and wait for the next PDU to arrive.

However, if the PDU of the SN is not stored in the re-ordering buffer, the PDU is not duplicated. Therefore, the selective combiner proceeds to step 1230 to store the PDU in the re-ordering buffer, and proceeds to step 1235.

In step 1235, the selective combiner checks whether the SN of the PDU is equal to next_expect_SN. If it is not the same, proceed to step 1295 to complete all processes and wait until the next PDU arrives.

However, if the SN of the received PDU is the same as next_expect_SN, the flow proceeds to step 1245. In step 1245, the selective combiner updates next_expect_SN with the SN of the first unreceived PDU of the re-ordering buffer.

In operation 1250, the selective combiner delivers PDUs having an SN smaller than the next_expect_SN to a higher layer. The PDUs are PDUs whose order has been successfully reconstructed.

After completing the step 1250, the selective combiner proceeds to step 1295 and finishes all processes and waits for the arrival of the next PDU.

As described above, the present invention enables taking advantage of selective binding by using selective binding based on SN. Therefore, the UE has an effect of receiving a higher quality service from the same radio resource.

Claims (36)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A method for combining broadcast data from a plurality of cells in a mobile terminal, the method comprising: Receiving broadcast data from the cells; If the serial number of the received broadcast data does not belong to a reception window, storing the broadcast data in a buffer and updating the reception window by the serial number; If the serial number of the received broadcast data belongs to the reception window, checking whether broadcast data having the serial number is already stored in the buffer; Discarding the broadcast data if already stored in the buffer; Storing the broadcast data in the buffer if it is not already stored in the buffer. 21. The method of claim 20, further comprising transmitting broadcast data of a serial number out of a range of the reception window to an upper layer due to updating of the reception window among broadcast data stored in the buffer. . 21. The method of claim 20, further comprising reconstructing the broadcast data stored in the buffer by a sequence number sequence and delivering broadcast data having a serial number preceding the received serial number to a higher layer. Said method. 21. The method as claimed in claim 20, wherein the reception window is determined by a most recent serial number and a predetermined window size among serial numbers of received broadcast data. The method as claimed in claim 23, wherein the predetermined window size is determined by a maximum error range due to reception points of broadcast data having the same serial number transmitted from different cells. An apparatus for combining broadcast data from a plurality of cells in a mobile terminal, the apparatus comprising: Buffers, If the serial number of the broadcast data received from the plurality of cells does not belong to the reception window, the received broadcast data is stored in the buffer, and the serial number of the received broadcast data is already stored in the buffer while belonging to the reception window. Or an optional combiner for storing the received broadcast data in the buffer, Wherein the selective combiner updates the reception window if the serial number of the received broadcast data does not belong to the reception window, and if the serial number of the received broadcast data belongs to the reception window but is already stored in the buffer, Discarding the received data. 27. The apparatus of claim 25, wherein the selective combiner delivers broadcast data having a serial number out of range of the reception window due to updating of the reception window among broadcast data stored in the buffer to a higher layer. . 26. The method of claim 25, wherein the selective combiner reconstructs the broadcast data stored in the buffer by a serial number order and delivers broadcast data having a serial number preceding the received serial number to a higher layer. Said device. The apparatus as claimed in claim 25, wherein the reception window is determined by a most recent serial number of the serial numbers of the received broadcast data and a predetermined window size. 29. The apparatus as claimed in claim 28, wherein the predetermined window size is determined by a maximum error range due to reception points of broadcast data having the same serial number transmitted from different cells. A serving cell providing an arbitrary broadcast service through a mobile terminal, a primary link established by the mobile terminal, at least one target cell providing the arbitrary broadcast service through an auxiliary link established by the mobile terminal, In a mobile communication system comprising a radio network controller for providing broadcast data according to the broadcast service to the serving cell and the at least one target cell, the mobile terminal broadcasts from the serving cell and the at least one target cell In the method of combining data, Receiving broadcast data from the serving cell and the at least one target cell; Checking whether the received broadcast data has already been received; If the broadcast data has already been received, discarding the received broadcast data; If it is not already received broadcast data, storing the received broadcast data in a buffer; Rearranging broadcast data stored in the buffer by a serial number; Transmitting broadcast data having a serial number preceding the serial number not received among the rearranged broadcast data to a higher layer; Wherein the serial number is an identifier for distinguishing the broadcast data, and the same serial number is assigned to the serving cell and the at least one target cell with respect to the same broadcast data. The method as claimed in claim 30, wherein if the broadcast data having the same serial number as the serial number of the received broadcast data is stored in the buffer, the received broadcast data is determined to be already received broadcast data. A serving cell providing an arbitrary broadcast service through a mobile terminal, a primary link established by the mobile terminal, at least one target cell providing the arbitrary broadcast service through an auxiliary link established by the mobile terminal, In a mobile communication system comprising a radio network controller for providing broadcast data according to the broadcast service to the serving cell and the at least one target cell, the mobile terminal broadcasts from the serving cell and the at least one target cell In a device for combining data, A redundancy check unit which checks whether broadcast data received from the serving cell and the at least one target cell has already been received, discards broadcast data that has already been received, and stores it in a reconstruction buffer if not already received broadcast data; Reconstructing the stored broadcast data by a serial number, and including the reconstruction buffer for transmitting broadcast data having a serial number preceding the serial number not received among the rearranged broadcast data to an upper layer; Wherein the serial number is an identifier for distinguishing the broadcast data, and the same serial number is assigned to the serving cell and the at least one target cell with respect to the same broadcast data. 33. The method of claim 32, wherein the redundancy checker determines that the received broadcast data is already received broadcast data when the broadcast data having the same serial number as the serial number of the received broadcast data is stored in the reconstruction buffer. The device, characterized in that. A method for combining broadcast data from a plurality of cells in a mobile terminal, the method comprising: Allocating a reception window by a serial number of broadcast data first received from the plurality of cells and a predetermined reception window size; Checking whether a serial number of a next broadcast data received from the plurality of cells falls within the reception window; If the serial number is in the reception window, it is checked whether broadcast data having a serial number equal to the serial number of the next broadcast data is already stored in the buffer, If broadcast data having the same serial number as the serial number of the next broadcast data is already stored in the buffer, the received next broadcast data is discarded, If the broadcast data having the same serial number as the serial number of the next broadcast data is not stored in the buffer, storing the received next broadcast data in the buffer; If the serial number of the next broadcast data is not within the reception window, the received next broadcast data is stored in the buffer, Updating the reception window by the serial number of the next broadcast data and the predetermined reception window size; Transmitting broadcast data having a serial number out of the updated reception window among the broadcast data stored in the buffer to a higher layer. 35. The method of claim 34, further comprising reconstructing the broadcast data stored in the buffer by a sequence number sequence and delivering broadcast data having a serial number preceding the received serial number to the upper layer. Said method. 35. The method of claim 34, wherein the predetermined window size is determined by a maximum error range due to reception points of broadcast data having the same serial number transmitted from different cells.

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