KR20110124710A - Apparatus and method for setting up communication relationship in mobile communication system - Google Patents

Abstract

PURPOSE: A device and method for setting up communication relationship in a mobile communication system are provided to set X2 interface between network nodes of an eNB and a neighboring cell in which a relay cell is included. CONSTITUTION: A control unit(840) obtains information about a new neighboring cell. A modem(820) reports the information about the new neighboring cell to a DeNB(Donor eNB) which is a base station that relay node is included. The control unit determines whether the physical layer identification information of a neighboring cell which is included in a measure report message is included in the neighboring cell list of the relay node or not. If the physical identification information of the neighboring cell is not included in the neighboring cell list of the relay node, the control unit determines the neighboring cell as a new neighboring cell.

Description

Apparatus and method for establishing a communication connection in a mobile communication system {APPARATUS AND METHOD FOR SETTING UP COMMUNICATION RELATIONSHIP IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system, and more particularly, to an apparatus and method for establishing a communication connection in a mobile communication system.

SAE (System Architecture Evolution) is a 3rd generation (3G) mobile communication technology under development. It is composed of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and core network, reducing system time delay and It has the advantage of increasing the capacity (cell capacity).

1 shows a schematic configuration of a SAE. Referring to FIG. 1, an evolved Node B (eNB) 110, which is a macro base station, is located in an E-UTRAN and is used to provide a user equipment (UE) with a radio interface for accessing a SAE system. The Mobile Management Entity (MME) 120 and the Serving Gateway (S-GW) 130 are located in the core network and are connected to the eNB 110 through the S1 interface. In detail, the MME 120 manages a mobile context, a session context of the UE, and stores security-related information. The S-GW 130 provides a user-plane function and transmits data to the eNB 110 through a General Packet Radio Service (GPRS) tunnel protocol channel. The data is delivered by the eNB 110 to the UE. The MME 120 and the S-GW 130 may be included in the same physical object. In addition, each eNB 110 may be connected with a plurality of MMEs 120 and may be connected with a plurality of S-GWs 130. The eNBs 110 are connected to each other via an X2 interface.

The UE in the connected state may move from eNB to another eNB. For convenience of description below, assume a situation of moving from the first eNB to the second eNB. If there is an X2 interface between the first eNB and the second eNB, the first eNB starts a handover procedure based on the X2 interface. In detail, the first eNB transmits a message including information (eg, UE context) necessary for handover to the second eNB. The second eNB allocates resources to the UE and informs the UE of the configuration of a destination cell. The UE synchronizes to the destination cell and informs the destination cell of the completion of synchronization. The second eNB transmits a message to the MME and performs a handover from the old cell to the new cell for the downlink data tunnel. If there is no X2 interface between the first eNB and the second eNB, the first eNB starts a handover procedure based on the S1 interface. That is, the first eNB sends a message first to the MME, and the message between the first eNB and the second eNB is forwarded by the MME.

In order to enhance coverage at cell boundaries, new network nodes, such as relay nodes, have been proposed. 2 shows a schematic configuration of a SAE with an additional relay node. Referring to FIG. 2, an eNB connected to a relay node 200 is called a DoNB (Denor eNB) 215, and there is a wireless connection between the DeNB 215 and the relay node 200. After the power is turned on, the relay node 200 first establishes a Radio Resource Control (RRC) connection with the DeNB 215. At this time, in the DeNB 215, the relay node 200 is treated the same as the UE. Based on the RRC connection, an S1 interface and an X2 interface may be set, and the S1 interface and the X2 interface of the relay node 200 terminate at the relay node 200. The DeNB 215 provides an intermediate proxy function for the S1 interface and the X2 interface between the relay node 200 and other network nodes. In the relay node 200, the DeNB 215 functions like the S-GW 230 and the Packet Data Network Gateway (P-GW).

The relay node 200 may establish an X2 interface with the DeNB 215, and the relay node 200 may establish an X2 interface with another neighbor node. For example, the other neighbor node may be a network node belonging to the neighbor cell of the relay node 200. It is assumed that a network node belonging to the neighbor cell of the relay node 200 is a third eNB. According to the prior art, if the DeNB 215 has set up the X2 interface with the third eNB and the relay node 200 has set up the X2 interface with the DeNB 215 after powering on, the relay node 200 as a result. ) Also sets the X2 interface with the third eNB. Accordingly, the relay node 200 may communicate with the third eNB through forwarding of the DeNB 215.

In general, depending on the scheme of the network configuration, the X2 interface may be established with the DeNB and other neighbor nodes of the relay node. However, if the relay node discovers a new neighbor cell and the X2 interface is not configured with the network node belonging to the DeNB and the new neighbor cell, the relay node first requests the DeNB to configure the X2 interface. Send. However, according to the related art, information on a target for which the X2 interface is to be set may not be included in the message. The DeNB, having received the message, recognizes that the message has been sent to itself and may not establish an X2 interface with the other network node. As a result, the relay node cannot communicate with the network node belonging to the new neighbor cell.

It is therefore an object of the present invention to provide an apparatus and method for establishing a communication connection in a broadband wireless access system.

Another object of the present invention is to provide an apparatus and method for configuring an X2 interface between an eNB to which a relay node depends and a network node of a neighboring cell in a broadband wireless access system.

Another object of the present invention is to provide an apparatus and method for providing changed information of a relay node to a network node of a neighbor cell in a broadband wireless access system.

Another object of the present invention is to provide an apparatus and method for providing changed information of a network node of a neighbor cell to a relay node in a broadband wireless access system.

According to a first aspect of the present invention for achieving the above object, a method for establishing a communication connection in a communication system, at the relay node, obtaining information about a new neighbor cell, and at the relay node, Reporting information about a neighbor cell to a DeNB, the base station to which the relay node is dependent, discovering a network node to which the new neighbor cell belongs in the DeNB, and in the DeNB, the new neighbor cell belongs to the DeNB Determining whether an X2 interface is established with a network node, and if the X2 interface is not configured in the DeNB, establishing an X2 interface with the network node to which the new neighbor cell belongs. .

According to a second aspect of the present invention for achieving the above object, a method of operating a relay node in a communication system includes: obtaining information about a new neighbor cell, and the relay node is dependent on information about the new neighbor cell; It is characterized in that it comprises a process of reporting to the base station DeNB.

According to a third aspect of the present invention for achieving the above object, in the method of operation of an eNB in a communication system, if information on a new neighbor cell is reported from a relay node dependent on the eNB, the network node to which the new neighbor cell belongs; Determining whether the X2 interface is set with the network node to which the new neighbor cell belongs, and if the X2 interface is not set, setting the X2 interface with the network node to which the new neighbor cell belongs Characterized in that it comprises a process.

According to a fourth aspect of the present invention for achieving the above object, in a communication system, a relay node device includes a control unit for obtaining information about a new neighbor cell, and a base station to which the relay node is dependent on information about the new neighbor cell. It is characterized by including a modem to report to the DeNB.

According to a fifth aspect of the present invention for achieving the above object, an eNB device in a communication system includes a modem for receiving information on a new neighbor cell from a relay node dependent on the eNB, and a network node to which the new neighbor cell belongs. And a controller configured to determine whether an X2 interface is set with the network node to which the new neighbor cell belongs, and if the X2 interface is not set, setting a X2 interface with the network node to which the new neighbor cell belongs. Characterized in that.

In a mobile communication system, a relay node can communicate with a network node to which a new neighbor cell belongs via DeNB. In addition, when at least one of configuration information and load information of the relay node is changed, the neighbor node may be notified in a timely manner through the DeNB. When at least one of configuration information and load information of the neighbor node is changed, the relay node may also be notified through the DeNB.

1 is a diagram showing a schematic configuration of a SAE;
2 is a diagram showing a schematic configuration of a SAE with a relay node added;
3 is a diagram illustrating a signal exchange for establishing a communication connection in a mobile communication system according to an embodiment of the present invention;
4 is a diagram illustrating a signal exchange for notifying change of information for a relay node in a mobile communication system according to an embodiment of the present invention;
5 is a diagram illustrating a signal exchange for notifying a change of information for an eNB in a mobile communication system according to an embodiment of the present invention;
6 is a diagram schematically illustrating a network structure of a mobile communication system according to an embodiment of the present invention;
7A and 7B illustrate a procedure after a DeNB receives an eNB status update message in a mobile communication system according to an embodiment of the present invention;
8 is a block diagram of a relay node in a mobile communication system according to an embodiment of the present invention;
9 is a block diagram of an eNB in a mobile communication system according to an embodiment of the present invention;
10 is a block diagram of an MME in a mobile communication system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The present invention describes a technique for establishing a communication connection in a mobile communication system. For convenience of description below, the present invention uses the terms and names defined in the LTE standard. However, the present invention is not to be limited by the above terms and names.

Briefly, when a relay node according to an embodiment of the present invention finds a new neighbor cell, it transmits information about the new cell to a DeNB to which the relay node belongs. The DeNB discovers a network node belonging to the neighbor cell, determines whether an X2 interface is set with the network node, and if the X2 interface is not configured, sets the X2 interface with the network node.

3 illustrates a signal exchange for establishing a communication connection in a mobile communication system according to an embodiment of the present invention. In the following description, it is assumed that a relay node sets up an X2 interface with a DeNB to which the relay node belongs after powering on.

Referring to FIG. 3, in step 301, the relay node receives a measurement report message transmitted from a connected UE and uses physical layer identification information of a neighbor cell transmitted through the measurement report message. Determine whether a new neighbor cell is found. According to an embodiment of the present disclosure, all UEs may transmit a measurement report message to a relay node to which they depend, periodically or when a predefined condition is met. After receiving the measurement report message from the UE, the relay node obtains the physical layer identification information of the neighbor cell transmitted through the measurement report message, and the neighbor cell list in which the physical layer identification information of the neighbor cell is stored in advance Check if it is included in the. As a result of the check, if the neighbor cell list does not include the physical layer identification information of the neighbor cell transmitted through the measurement report message, the relay node selects a neighbor cell corresponding to the identification information not included in the neighbor cell list. It is determined as a new neighbor cell. For example, cells that depend on different relay nodes that depend on the same DeNB may or may not be neighbor cells to each other. In addition, a cell dependent on a normal eNB may also be a neighbor cell of the relay node. Furthermore, the cell subordinate to the DeNB may also be a neighbor cell of the relay node subordinate to the DeNB. Furthermore, the cell dependent on the relay node may be a neighbor cell of the DeNB to which the relay node belongs, and may be stored in the neighbor cell list of the DeNB.

In step 302, the relay node informs the UE to report information about the new neighbor cell by sending a measurement report control message to the UE. In other words, the relay node requests information about the new neighbor cell. Specifically, the relay node transmits the physical layer identification information of the new neighbor cell to the UE, thereby providing information about the new neighbor cell, for example, an E-UTAN Cell Global Identifier (ECGI) or a tracking area code (TAC). ), And report the PLMN ID (Public Land Mobile Network Identifier). The UE may obtain such information by receiving a broadcast message of the neighbor cell.

In step 303, the UE transmits information of the new neighbor cell to the relay node through a measurement report message. In other words, the UE transmits a measurement report message including information about the new neighbor cell to the relay node.

In step 304, the relay node adds information about the new cell to the neighbor cell list, and transmits the neighbor cell message report message to the DeNB to which the relay node depends. To provide. Specifically, the relay node reports that the new neighbor cell is found by transmitting the neighbor cell message report message to the DeNB and conveys information about the neighbor cell. For example, the information may include ECGI, TAC, PLMN, and the like.

In step 305, the DeNB stores the received information about the new neighbor cell and discovers a network node to which the new neighbor cell belongs. For convenience of description below, the present invention refers to the 'network node to which the new neighbor cell belongs' 'eNB_N'. The DeNB determines whether an X2 interface is established with the eNB_N. If the X2 interface is set, the following step 312 proceeds, and the procedure ends. On the other hand, if the X2 interface is not set, step 306 is performed below. According to an embodiment of the present invention, in addition to the neighbor cell list of the DeNB, neighbor cell lists of each of all relay nodes subordinate to the DeNB may also be stored in the DeNB. In this step, after receiving the information on the new neighbor cell, the DeNB may store the information on the new neighbor cell in the neighbor cell list of the relay node that has transmitted the information on the new neighbor cell. The DeNB finds a network node to which the new neighbor cell belongs. Here, the network node may be a relay node dependent on the same DeNB, another relay node dependent on another DeNB, or a normal eNB. In the following description, it is assumed that the network node is 'eNB_N'. The DeNB determines whether an X2 interface with the eNB_N is configured. If the X2 interface is not set, step 306 proceeds, i.e., the procedure for setting the X2 interface is started. The process of finding the eNB_N and determining whether to set the X2 interface may be performed according to the prior art.

In step 306, the DeNB transmits an eNB configuration transmission message to the MME. The eNB configuration transmission message includes a base station identifier of the DeNB, a PLMN ID, a TAC, a base station identifier of the eNB_N, a PLMN ID, a TAC, and includes an indicator requesting a transport layer address of the eNB_N.

In step 307, the MME transmits an MME configuration transmission message to the eNB_N. The MME configuration transmission message carries the same information as the eNB configuration transmission message transmitted in step 306. That is, the MME configuration transmission message includes a base station identifier of the DeNB, a PLMN ID, a TAC, a base station identifier of the eNB_N, a PLMN ID, and a TAC, and includes an indicator requesting a transport layer address of the eNB_N.

In step 308, the eNB_N transmits an eNB configuration transmission message as a response message to the MME. The eNB configuration transmission message includes a base station identifier, a PLMN ID, a TAC, a base station identifier, a PLMN ID, a TAC of the eNB_N, and a transport layer address of the eNB_N.

In step 309, the MME sends an MME configuration transmission message to the DeNB. The MME configuration transmission message carries the same information as the eNB configuration transmission message transmitted in step 308. That is, the MME configuration transmission message includes a base station identifier, a PLMN ID, a TAC, a base station identifier, a PLMN ID, a TAC of the eNB_N, and a transport layer address of the eNB_N.

In step 310, the DeNB transmits an X2 setup request message to the eNB_N. Upon obtaining the transport layer address of the eNB_N, the DeNB transmits an X2 setup request message to the eNB_N. The X2 setup request message may include information on a cell dependent on the DeNB, and optionally, may include information on a neighbor cell of the DeNB and a pool to which the DeNB belongs.

In step 311, the eNB_N transmits an X2 setup response message to the DeNB. The X2 configuration response message may include information about a cell that is dependent on the eNB_N, and optionally, may include information about a neighbor cell of the eNB_N and a pool to which the eNB_N belongs.

In step 312, the DeNB transmits a neighbor cell information notification message to the relay node. Information about the cells dependent on the eNB_N obtained in the process of configuring the X2 interface may also include information about a neighbor cell of the eNB_N, a pool to which the eNB_N belongs, etc., to be provided to the relay node. Can be.

According to the embodiment of the present invention described above, after discovering the new neighbor cell, the relay node reports to the DeNB to which the relay node belongs. Accordingly, the DeNB finds a network node to which the new neighbor cell belongs and determines whether an X2 interface is configured. If the X2 interface is not configured, the DeNB establishes an X2 interface with the network node. As a result, the relay node can communicate with the network node to which the new cell belongs via the DeNB.

Additionally, according to the related art, when at least one of configuration information and load information of a relay node is changed, for example, when a load of a specific resource block exceeds a limit, the neighbor of the relay node It is required to notify the node (eg eNB_N) not to schedule the support block. According to the prior art, the relay node first sends a message to the DeNB in anticipation of the DeNB forwarding. However, the DeNB only considers the message sent to itself. That is, the DeNB may recognize that the relay node informs the DeNB that the load of the corresponding resource block has exceeded a limit, and may not transmit the message to the eNB_N. As a result, the eNB_N performs scheduling for the resource block, which affects the performance of the relay node, the eNB_N, and the UEs dependent thereto. In addition, when at least one of configuration information and load information of the eNB_N is changed, it is required to notify the relay node, but the same problem as described above occurs.

As mentioned above, the object of the present invention can be achieved. In addition, the neighbor cell list of the DeNB and the neighbor cell list of all subordinate relay nodes may also be stored in the DeNB. Using this, the above-described problems can be solved through the same process as in FIGS. 4 to 7B.

4 illustrates a signal exchange for notifying change of information for a relay node in a mobile communication system according to an exemplary embodiment of the present invention. In the following description, eNB_N is just an example, and there may be a neighbor node of a type such as a relay node.

Referring to FIG. 4, in step 401, at least one of configuration information and load information of a relay node is changed, and the relay node transmits an eNB configuration update message to a DeNB to which the relay node belongs. Specifically, when configuration information such as cell frequency of the relay node is changed, or when load information is changed, or when both the configuration information and the load information are changed, the relay node updates eNB status (eNB). state update) message. Here, the eNB status update message transmits interference information on at least one of changed configuration information and changed load information or other resource blocks by a neighbor cell to a DeNB to which the relay node belongs. The eNB status update message may be referred to as an 'eNB configuration update message' or an 'eNB load status message', which is one of X2 messages. In addition, step 401 may be performed through another message. The embodiment of FIG. 4 assumes an eNB configuration update message.

In step 402, the DeNB updates the neighbor cell list of the DeNB according to the received eNB configuration update message. The DeNB discovers all neighbor cell network nodes included in the neighbor cell list of the relay node that has transmitted the eNB status update message. Here, assume that the network node is eNB_N. In this step, since the cell of the relay node is a neighbor cell of the DeNB to which the relay node belongs, the DeNB needs to update the neighbor cell list of the DeNB. In addition, from the neighbor cell list of all the relay nodes, the DeNB checks the neighbor cell list of the relay node that has transmitted the eNB configuration update message, and finds the relay node to which all neighbor cells in the neighbor cell list belong.

In step 403, the DeNB forwards the eNB configuration update message to the eNB_N. In step 404, the eNB_N updates the neighbor cell list of the eNB_N according to the received eNB configuration update message. After updating the neighbor cell list, the eNB_N transmits an eNB configuration update response message to the DeNB.

In step 405, the DeNB transmits an eNB configuration update response message to the relay node. That is, the eNB configuration update response message is transmitted to the relay node that sent the eNB configuration update message. This step may be performed before step 402. In other words, when the eNB configuration update message is received from the relay node, the eNB configuration update response message may be returned to the relay node as a response thereto.

5 illustrates a signal exchange for notifying a change of information for an eNB in a mobile communication system according to an embodiment of the present invention. In the following description, eNB_N is just an example, and there may be a neighbor node of a type such as a relay node.

Referring to FIG. 5, in step 501, at least one of configuration information and load information of the eNB_N is changed, and the eNB_N transmits an eNB configuration update message to the DeNB. The DeNB can recognize a neighbor cell of the DeNB or a neighbor cell of a relay node that is dependent on the DeNB as a cell that is dependent on the eNB_N. In this step, the eNB_N may transmit an eNB status update message. The eNB status update message conveys at least one of changed configuration information and changed load information, or transmits information on interference generated for other resource blocks by a neighbor cell to the DeNB. The eNB status update message may be referred to as an 'eNB configuration update message' or an 'eNB load status message', which is one of X2 messages. In addition, step 501 may be performed through another message. The embodiment of FIG. 5 assumes an eNB configuration update message.

In step 502, the DeNB determines whether a cell belonging to the eNB_N is included in the neighbor cell list of the DeNB. If the cell belonging to the eNB_N is included in the neighbor cell list of the DeNB, the DeNB updates the neighbor cell list according to the received eNB configuration information message, and proceeds to step 503. On the other hand, if the cell belonging to the eNB_N is not included in the neighbor cell list of the DeNB, the DeNB proceeds directly to step 503.

In step 503, with respect to the neighbor cell list of each subordinate relay node stored by the DeNB, the DeNB determines whether the cell dependent on the eNB_N is the neighbor cell of the relay node. If the cell dependent on the eNB_N is a neighbor cell of the relay node, the DeNB proceeds to step 504. If the cell dependent on the eNB_N is not a neighbor cell of the relay node, the procedure is terminated.

In step 504, the DeNB forwards the received eNB configuration update message to the relay node. In step 505, the relay node updates the neighbor cell list of the relay node according to the received eNB configuration update message. After updating the neighbor cell list, the relay node sends an eNB configuration update response message to the DeNB. In step 506, the DeNB transmits an eNB configuration update response message to the eNB_N. This step may be performed before step 502.

In the embodiments described with reference to FIGS. 4 and 5, both aspects, that is, the relay node and the eNB_N, have been described. Hereinafter, the procedure at the DeNB is described.

6 schematically illustrates a network structure of a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 6, two relay nodes, a relay node A 611 and a relay node B 612 are dependent on the DeNB 620. The cell depends on each relay node. The identifier of the cell of the DeNB is 'ECGI-1', the identifier of the cell of the relay node A 611 is 'ECGI-2', and the identifier of the cell of the relay node B 612 is 'ECGI-3'. The identifier of the cell of eNB_N 630 is 'ECGI-4'. The neighbor cell lists of each of the DeNB 620, the relay node A 611, and the relay node B 612 are shown in Table 1, Table 2, and Table 3 below.

Serial Number Identifier of a neighbor cell Information about neighbor cells One ECGI-4 TAC 1, PLMN 1,... 2 ECGI-2 TAC 2, PLMN 1,... 3 ECGI-3 TAC 3, PLMN 1,...

Serial Number Identifier of a neighbor cell Information about neighbor cells One ECGI-1 TAC 1, PLMN 1,... 2 ECGI-4 TAC 4, PLMN 1,... 3 ECGI-3 TAC 3, PLMN 1,...

Serial Number Identifier of a neighbor cell Information about neighbor cells One ECGI-1 TAC 1, PLMN 1,... 2 ECGI-1 TAC 2, PLMN 1,...

7A and 7B illustrate a procedure after a DeNB receives an eNB status update message in a mobile communication system according to an embodiment of the present invention.

7A and 7B, the DeNB receives an eNB status update message in step 701. The eNB status update message includes at least one of changed configuration information and changed load information.

In operation 702, the DeNB determines whether the eNB status update message is received from the relay node A, the relay node B, or the eNB_N. When the eNB status update message is received from the relay node A or the relay node B, step 703 is performed. When the eNB status update message is received from the eNB_N, step 706 is performed.

When the eNB status update message is received from the relay node A or the relay node B, the flow proceeds to step 703 where the DeNB updates the neighbor cell list of the DeNB according to the received eNB status update message.

In step 704, the DeNB forwards the received eNB status update message to a network node to which all neighbor cells included in the neighbor cell list of the relay node A or the relay node B stored by the DeNB belong. If the relay node A transmits the eNB status update message, it is required to forward the eNB status update message to the relay node B and eNB_N according to the information as shown in Table 2 below. If the relay node B transmits the eNB status update message, it is required to forward the eNB status update message to the relay node A according to the information as shown in Table 3 below.

In operation 705, each network node updates its neighbor cell list according to the received eNB status update message, transmits a response message to the DeNB, and terminates this procedure.

In step 702, when the eNB status update message is received from the eNB_N, the flow proceeds to step 706, wherein the DeNB determines whether a cell belonging to the eNB_N is included in the neighbor cell list of the DeNB. If the cell belonging to the eNB_N is included in the neighbor cell list of the DeNB, step 707 is performed. If the cell belonging to the eNB_N is not included in the neighbor cell list of the DeNB, step 708 is performed. For example, when the neighbor cell list of the DeNB is as shown in Table 1, it can be seen that a cell belonging to the eNB_N is included in the neighbor cell list of the DeNB. If the cell belonging to the eNB_N is included in the neighbor cell list of the DeNB, the flow proceeds to step 707 where the DeNB updates the neighbor cell list of the DeNB according to the received eNB status update message. Thereafter, step 708 is performed.

In step 708, the DeNB determines whether the cell belonging to the eNB_N is included in the neighbor cell list of the relay node A. For example, when the neighbor cell list of the relay node A is as shown in Table 2, it can be seen that the cell belonging to the eNB_N is included in the neighbor cell list of the relay node A. If it is included in the neighbor cell list of the relay node A, the flow proceeds to step 709 where the DeNB forwards the received eNB status update message to the relay node A. Accordingly, in step 710, the relay node A updates the neighbor cell list of the relay node A according to the received eNB status update message, and transmits a response message to the DeNB. Thereafter, step 711 is performed.

In step 711, the DeNB determines whether the cell belonging to the eNB_N is included in the neighbor cell list of the relay Node B. If the cell belonging to the eNB_N is included in the neighbor cell list of the relay node B, step 712 is performed, and if the cell belonging to the eNB_N is not included in the neighbor cell list of the relay node B, the procedure It ends. For example, when the neighbor cell list of the relay node B is as shown in Table 3, it can be seen that the cell belonging to the eNB_N is not included in the neighbor cell list of the relay node B. In this case, step 712 and step 713 are not performed. If the cell belonging to the eNB_N is included in the neighbor cell list of the relay node B, the process proceeds to step 712, and the DeNB forwards the received eNB status update message to the relay node B. Accordingly, in step 713, the relay node B updates the neighbor cell list of the relay node B according to the received eNB status update message, and transmits a response message to the DeNB. The procedure then ends.

The above-described embodiment is an example, and according to a specific embodiment, the order of steps 708 to 710 and steps 711 to 713 may be changed.

8 is a block diagram of a relay node in a mobile communication system according to an embodiment of the present invention.

As illustrated in FIG. 8, the relay node includes a radio frequency (RF) processor 810, a modem 820, a storage 830, and a controller 840.

The RF processor 810 performs a function for transmitting and receiving a signal through a wireless channel, such as band conversion and amplification of the signal. That is, the RF processor 810 up-converts the baseband signal provided from the modem 820 to an RF band signal and transmits the signal through an antenna, and downlinks the RF band signal received through the antenna to a baseband signal. To convert. For example, the RF processor 810 may include an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like.

The modem 820 performs a baseband signal and bit string conversion function according to the physical layer standard of the system. For example, in the Orthgonal Frequency Division Multiplexing (OFDM) scheme, during data transmission, the modem 820 generates complex symbols by encoding and modulating a transmission bit stream, and maps the complex symbols to subcarriers. OFDM symbols are constructed through IFFT operation and CP insertion. In addition, upon receiving data, the modem 820 divides the baseband signal provided from the RF processor 810 in OFDM symbol units, restores signals mapped to subcarriers through an FFT operation, and then demodulates and decodes the signal. Restore the received bit string through.

The storage unit 830 stores data such as a basic program and system information for the operation of the relay node. In addition, the controller 830 temporarily stores the relay data. The storage unit 830 provides stored data at the request of the controller 840.

The controller 840 controls the overall function of the relay node. For example, the controller 840 relays the traffic received from the lower node to the upper node, and relays the traffic received from the upper node to the lower node. In particular, according to an embodiment of the present disclosure, when the new neighbor cell is found, the controller 840 controls the relay node to report the discovery of the new neighbor cell to the subordinate eNB, and updates the neighbor cell list. For example, the controller 840 controls the relay node to operate as shown in FIGS. 3, 4, 5, 7A, and 7B.

9 is a block diagram of an eNB in a mobile communication system according to an embodiment of the present invention.

As shown in FIG. 9, the eNB includes a radio frequency (RF) processor 910, a modem 920, a backhaul communication unit 930, a storage unit 940, and a controller 950.

The RF processor 910 performs a function for transmitting and receiving a signal through a wireless channel such as band conversion and amplification of the signal. That is, the RF processor 910 up-converts the baseband signal provided from the modem 920 to an RF band signal and transmits the signal through an antenna, and downlinks the RF band signal received through the antenna to a baseband signal. To convert. For example, the RF processor 910 may include an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

The modem 920 performs baseband signal and bit string conversion function according to the physical layer standard of the system. For example, according to the OFDM scheme, during data transmission, the modem 920 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then IFFT operation and CP insertion. Through OFDM symbols are configured. In addition, upon receiving data, the modem 920 divides the baseband signal provided from the RF processor 910 in OFDM symbol units, restores signals mapped to subcarriers through an FFT operation, and then demodulates and decodes the signal. Restore the received bit string through.

The backhaul communication unit 930 provides an interface for the eNB to communicate with other nodes (eg, another eNB, MME, etc.). The backhaul communication unit 930 converts a bit string transmitted from the eNB to the other node into a physical signal, and converts a physical signal received from the other node into a bit string. For example, the backhaul communication unit 930 supports an X2 interface. The storage unit 940 stores data such as a basic program and system information for the operation of the eNB. The storage unit 940 provides the stored data at the request of the controller 950.

The controller 950 controls the overall function of the eNB. For example, the controller 950 generates and transmits a transmission traffic packet and a message to the modem 920, and interprets the reception traffic packet and the message provided from the modem 920. In addition, the controller 950 generates and interprets a message for signaling with other nodes. In particular, according to an embodiment of the present invention, when there is a relay node dependent on the eNB, the controller 950 controls to set an X2 interface with a network node to which a new neighbor cell found by the relay node belongs. do. In addition, the controller 950 controls to add information about the new neighbor cell to the neighbor cell list. For example, the controller 950 controls the eNB to operate as shown in FIGS. 3, 4, 5, 7A, and 7B.

10 is a block diagram of an MME in a mobile communication system according to an embodiment of the present invention.

As shown in FIG. 10, the MME includes a communication unit 1010, a storage unit 1020, and a control unit 1030.

The communication unit 1010 provides an interface for communicating with another object (eg, eNB) in a network. The storage unit 1020 stores a basic program for operating the MME, system setting information, and the like.

The controller 1030 controls the overall functions of the MME. For example, the controller 1030 controls control signaling of eNBs connected to the MME. In particular, according to an embodiment of the present disclosure, the controller 1030 controls a procedure for setting an X2 interface between an eNB and a network node. For example, the controller 1030 controls the MME to operate as shown in FIG. 3.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

Claims (33)

A method for establishing a communication connection in a communication system, the method comprising:
Obtaining information about a new neighbor cell at the relay node;
Reporting, at the relay node, information on the new neighbor cell to DeNB, which is a base station to which the relay node depends;
Discovering, at the DeNB, a network node to which the new neighbor cell belongs;
Determining, at the DeNB, whether an X2 interface is established with the network node to which the new neighbor cell belongs;
In the DeNB, if the X2 interface is not configured, establishing an X2 interface with the network node to which the new neighbor cell belongs.
The method of claim 1,
Obtaining information about the new neighbor cell,
Receiving, at the relay node, a measurement report message from a UE subordinate to the relay node;
Determining, at the relay node, whether physical layer identification information of a neighbor cell included in the measurement report message is included in a neighbor cell list of the relay node;
And determining, by the relay node, the neighbor cell as the new neighbor cell if the physical layer identification information of the neighbor cell is not included in the neighbor cell list of the relay node.
The method of claim 1,
The information on the new neighbor cell, characterized in that at least one of the ECGI, TAC, PLMN ID.
The method of claim 1,
The process of setting an X2 interface with the network node to which the new neighbor cell belongs,
Transmitting, at the DeNB, an eNB configuration transmission message to an MME;
Transmitting, at the MME, an MME configuration transmission message to the network node to which the new neighbor cell belongs;
Transmitting, at the network node, the eNB configuration transmission message to the MME;
Transmitting, at the MME, an MME configuration transmission message to the DeNB;
Transmitting, at the DeNB, an X2 configuration request message to the network node to which the new neighbor cell belongs;
Transmitting, at the network node, an X2 configuration response message to the DeNB;
At the DeNB, transmitting a neighbor cell information notification message to the relay node.
The method according to any one of claims 1 to 4,
The neighbor cell list of the relay node is stored in the DeNB,
At the DeNB, adding information about the new neighbor cell to a neighbor cell list of the relay node that has found the new neighbor cell.
The method according to any one of claims 1 to 4,
And if the X2 interface is set between the DeNB and the network node, transmitting, at the DeNB, a neighbor cell information notification message to the relay node.
The method of claim 5,
At the DeNB, when an eNB status update message is received, determining whether at least one of changed configuration information and changed load information is included in the eNB status update message;
Determining, at the DeNB, whether at least one of the changed configuration information and the changed load information is included, whether the eNB status update message is received from a subordinate relay node or another network node;
If the eNB status update message was received from the subordinate relay node,
Forwarding, by the DeNB, the eNB status update message to a network node to which all neighbor cells included in the neighbor cell list of the relay node that has transmitted the eNB status update message belong;
If the eNB status update message was received from the other network node,
Determining, at the DeNB, whether a cell belonging to the network node which has transmitted the eNB status update message is included in a neighbor cell list of the DeNB;
If a cell belonging to the network node is included in the neighbor cell list of the DeNB,
In the DeNB, the neighbor cell list of the DeNB is updated according to the eNB status update message, and if the cell belonging to the network node that has sent the eNB status update message is included in the neighbor cell list of the relay node, the eNB status update is performed. Forwarding a message to the relay node;
If a cell belonging to the network node is not included in the neighbor cell list of the DeNB,
And forwarding the eNB status update message to the relay node when the cell belonging to the network node that has transmitted the eNB status update message is included in the neighbor cell list of the relay node in the DeNB. Way.
In the method of operating a relay node in a communication system,
Obtaining information about a new neighbor cell,
Reporting the information about the new neighbor cell to DeNB, the base station to which the relay node is dependent.
The method of claim 8,
Obtaining information about the new neighbor cell,
Receiving a measurement report message from a UE subordinate to the relay node;
Determining whether the physical layer identification information of the neighbor cell included in the measurement report message is included in the neighbor cell list of the relay node;
If the physical layer identification information of the neighbor cell is not included in the neighbor cell list of the relay node, determining the neighbor cell as the new neighbor cell.
The method of claim 8,
The information on the new neighbor cell, characterized in that at least one of the ECGI, TAC, PLMN ID.
The method of claim 8,
And when at least one of configuration information and load information of the relay node is changed, transmitting the status update message to the eNB to which the relay node depends.
The method of claim 8,
If a status update message including at least one of changed configuration information and changed load information of a neighbor cell is received from an eNB to which the relay node is dependent, further updating the neighbor cell list of the relay node according to the status update message. Method comprising a.
In the method of operation of the eNB in a communication system,
If information on a new neighbor cell is reported from a relay node dependent on the eNB, discovering a network node to which the new neighbor cell belongs;
Determining whether an X2 interface is established with the network node to which the new neighbor cell belongs;
If the X2 interface is not configured, establishing an X2 interface with the network node to which the new neighbor cell belongs.
The method of claim 13,
The information on the new neighbor cell, characterized in that at least one of the ECGI, TAC, PLMN ID.
The method of claim 13,
The process of setting an X2 interface with the network node to which the new neighbor cell belongs,
Transmitting an eNB configuration transmission message including an indicator requesting a transport layer address of the network node to an MME;
Receiving an MME configuration transmission message including a transport layer address of the network node from the MME;
Transmitting an X2 setup request message to the network node using a transport layer address of the network node;
Receiving an X2 setup response message;
Transmitting a neighbor cell information notification message to the relay node.
The method of claim 13,
And transmitting the neighbor cell information notification message to the relay node when the X2 interface is established between the DeNB and the network node.
The method of claim 13,
The neighbor cell list of the relay node is stored in the DeNB,
And adding information on the new neighbor cell to the neighbor cell list of the relay node that has found the new neighbor cell.
The method of claim 17,
Receiving a status update message including at least one of changed configuration information and changed load information from the first node;
Determining whether the first node is a relay node dependent on the eNB or a network node of a neighboring cell;
If the first node is the relay node, further comprising forwarding the status update message to a network node to which all neighbor cells included in the neighbor cell list of the relay node that has transmitted the status update message belong. How to.
The method of claim 18,
When the first node is a network node of the neighbor cell, if the cell belonging to the network node that has transmitted the status update message is included in the neighbor cell list of at least one relay node dependent on the eNB, the status update And forwarding a message to the at least one relay node.
The method of claim 18,
If the first node is a network node of the neighbor cell, if a cell belonging to the network node that has transmitted the status update message is included in the neighbor cell list of the eNB, the neighbor cell of the eNB according to the status update message The method further comprises the step of updating the list.
In a relay node device in a communication system,
A controller for obtaining information about a new neighbor cell;
And a modem for reporting the information on the new neighbor cell to DeNB, the base station to which the relay node depends.
The method of claim 21,
The control unit receives a measurement report message from a UE subordinate to the relay node, and determines whether physical layer identification information of a neighbor cell included in the measurement report message is included in the neighbor cell list of the relay node. And if the physical layer identification information of the neighbor cell is not included in the neighbor cell list of the relay node, determine the neighbor cell as the new neighbor cell.
The method of claim 21,
The information on the new neighbor cell, characterized in that at least one of the ECGI, TAC, PLMN ID.
The method of claim 21,
The control unit, if the at least one of the configuration information and load information of the relay node is changed, characterized in that the relay node controls to transmit a status update message to the subordinate eNB.
The method of claim 21,
The controller, when receiving a status update message including at least one of changed configuration information and changed load information of a neighbor cell from an eNB to which the relay node depends, updates the neighbor cell list of the relay node according to the status update message. Device characterized in that.
In an eNB device in a communication system,
A modem for receiving information on a new neighbor cell from a relay node dependent on the eNB;
Discover a network node to which the new neighbor cell belongs, determine whether an X2 interface is established with the network node to which the new neighbor cell belongs, and if the X2 interface is not configured, if the X2 interface is not configured; And a control unit for setting the X2 interface.
The method of claim 26,
The information on the new neighbor cell, characterized in that at least one of the ECGI, TAC, PLMN ID.
The method of claim 26,
The control unit controls to transmit an eNB configuration transmission message including an indicator requesting a transport layer address of the network node to an MME in order to establish an X2 interface with the network node to which the new neighbor cell belongs, and from the MME Control to receive an MME configuration transmission message including a transport layer address of the network node, control to transmit an X2 configuration request message to the network node using the transport layer address of the network node, and receive an X2 configuration response message Control to transmit a neighbor cell information notification message to the relay node.
The method of claim 26,
And the controller controls to transmit a neighbor cell information notification message to the relay node when the X2 interface is set between the DeNB and the network node.
The method of claim 26,
The neighbor cell list of the relay node is stored in the DeNB,
And the control unit adds information on the new neighbor cell to the neighbor cell list of the relay node that has found the new neighbor cell.
The method of claim 30,
The control unit receives a status update message including at least one of changed configuration information and changed load information from a first node, and determines whether the first node is a relay node dependent on the eNB or a network node of a neighbor cell. And after the determination, if the first node is the relay node, forwarding the status update message to a network node to which all neighbor cells included in the neighbor cell list of the relay node that has transmitted the status update message belong. .
32. The method of claim 31,
If the first node is a network node of the neighbor cell, if the cell belonging to the network node that has transmitted the status update message is included in the neighbor cell list of at least one relay node dependent on the eNB, And forwarding the status update message to the at least one relay node.
32. The method of claim 31,
The controller, when the first node is a network node of the neighbor cell, if a cell belonging to the network node that has transmitted the status update message is included in the neighbor cell list of the eNB, the controller according to the status update message. and update the neighbor cell list of the eNB.

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