KR20160031473A - Method and System for Controlling the Packet Data Transmission Using Relay Technology - Google Patents

Abstract

The present invention relates to a relay system in a wireless network. A method for transmitting data in a medium access control (MAC) layer of a donor base station comprises the following steps: confirming whether data received from an upper layer is to be transmitted to a relay node; constituting a MAC frame including a particular relay node identifier when the data is to be transmitted to a relay node as a result of confirmation; and transmitting the MAC frame to a relay node corresponding to the relay node identifier through a particular physical channel. Accordingly, a relay node may confirm whether given data is to be received therefrom through a relay node identifier.

Description

TECHNICAL FIELD [0001] The present invention relates to a packet data transmission control method using relay technology,

The present invention relates to a method and system for controlling packet data transmission in a wireless network, and more particularly, to a method and system for controlling packet data transmission between terminals in a mobile communication system to which relay technology is applied .

The 3GPP (3 ^rd Generation Partnership Project) and the 3GPP2 (3 ^rd Generation Partnership Project 2), which are oriented toward synchronous services, are largely classified into standardization organizations representing 3G mobile communication.

In particular, 3GPP is an international standardization organization related to asynchronous IMT-2000 service. It is an organization that establishes international standards by participating mobile telecommunication companies from all over the world including Europe, Korea, USA, Japan, Generation HSDPA / HSUPA standard with a maximum data transmission rate of 14.4 kbps, which is intended for high-speed packet data communication, has been established.

Currently, 3GPP is actively promoting standardization of Long Term Evolution (LTE) projects with the main goal of providing packet data transmission speeds of up to 100 Mbps and 50 Mbps for the uplink and downlink within the 20 MHz bandwidth, respectively.

An object of the present invention is to provide a method of controlling packet data transmission in a wireless network using relay technology.

It is another object of the present invention to provide a handover control method in a wireless network to which relay technology is applied.

It is another object of the present invention to provide a method for controlling maximum terminal transmission power in a wireless network using relay technology.

Other objects of the present invention will become readily apparent from the following description of the embodiments.

According to an aspect of the present invention, a method of transmitting data in a medium access control (MAC) layer of a donor base station is disclosed.

According to an embodiment of the present invention, a method of transmitting data in a medium access control (MAC) layer of a donor base station includes: checking whether data received from an upper layer is data to be transmitted to a relay node; If it is determined that the data is to be transmitted to the relay node, constructing a MAC frame including a predetermined relay node identifier, transmitting the MAC frame to a relay node corresponding to the relay node identifier through a predetermined physical channel .

An advantage of the present invention is to provide a packet data transmission control method in a wireless network using relay technology.

An advantage of the present invention is to provide a handover control method in a wireless network to which relay technology is applied.

An advantage of the present invention is to provide a method for controlling maximum terminal transmission power in a wireless network using relay technology.

Other advantages of the present invention will become readily apparent from the following description of the embodiments.

1 is a network structure of an evolved universal mobile telecommunications system (E-UMTS), which is a conventional mobile communication system to which the present invention is applied.
FIG. 2 shows a structure of a radio interface protocol between a UE and an E-UTRAN based on the 3GPP radio access network standard.
3 is an LTE-Advanced relay network structure according to the present invention.
4 is a hierarchical structure of a bearer service according to the present invention;
5 is a user plane structure in a relay system according to the present invention;
6 is a user plane structure in a relay system according to the present invention;
7 is a PDCP structure according to the present invention.
8 is a protocol layer structure for data transmission in a relay system according to an embodiment of the present invention.
9 is a second hierarchical structure of DeNB in the downlink according to the present invention;
10 is a two-layer structure of a downlink direction DeNB according to an embodiment of the present invention.
11 is an RN second hierarchical structure in a downlink according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a packet data transmission control method and system using the relay technology according to the present invention will be described in detail with reference to the drawings.

1 is a diagram illustrating a network structure of an Evolved Universal Mobile Telecommunications System (E-UMTS), which is a conventional mobile communication system to which the present invention is applied.

The E-UMTS system evolved from the existing UMTS system. The E-UMTS system is called an LTE (Long Term Evolution) system.

The E-UMTS network can be divided into E-UTRAN and CN. The E-UTRAN includes a User Equipment (hereinafter abbreviated as UE), a base station (hereinafter abbreviated as eNode B), a Serving Gateway (S-GW) And a Mobility Management Entity (MME) for managing the mobility of the UE. One eNode B may have more than one cell.

2 shows a structure of a radio interface protocol between a terminal based on the 3GPP radio access network standard and an E-UTRAN.

The wireless interface protocol is horizontally composed of a physical layer, a data link layer, and a network layer, and vertically includes a user plane for user data transmission and a control plane And a control plane for signal transmission.

The protocol layers are classified into L1 (first layer), L2 (second layer) and L3 (third layer) based on the lower three layers of the Open System Interconnection (OSI) .

Hereinafter, each layer of the radio protocol structure of FIG. 2 will be described in detail.

The physical layer as the first layer provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to a medium access control layer (upper layer) through a transport channel, and data transmission / reception is performed between the medium access control layer and the physical layer through the transport channel. Data is transmitted and received between the different physical layers, that is, the physical channel between the transmitting side and the receiving side physical channel.

The Medium Access Control (MAC) of the second layer provides a service to a radio link control layer that is an upper layer through a logical channel. The second layer of Radio Link Control (RLC) layer supports the transmission of reliable data. The PDCP layer of the second layer is a header compression that reduces the IP packet header size, which is relatively large and contains unnecessary control information, in order to efficiently transmit the IP packet, such as IPv4 or IPv6, Compression function. The PDCP layer handles the packet data ciphering function.

A radio resource control (RRC) layer located at the bottom of the third layer is defined only in the control plane and is configured by a configuration of a radio bearer (RB) And is responsible for controlling logical channels, transport channels, and physical channels in connection with Re-configuration and Release.

At this time, the RB means a service provided by the second layer for data transmission between the UE and the UTRAN. In this case, the RB means a logical path provided by the first and second layers of the wireless protocol for data transmission between the terminal and the UTRAN. Generally, the RB is set to a wireless protocol layer and a channel And setting the respective specific parameters and operating methods.

When the RRC layer of a specific UE and the RRC layer of the UTRAN are connected to each other so that RRC messages can be exchanged with each other, the UE is in an RRC connected state. When the UE is not connected, ) State.

A logical channel is a channel defined between an RLC entity and a MAC entity, and may be classified according to the characteristics of data on the logical channel. A transport channel is a channel defined between a physical layer and a MAC entity, and can be distinguished according to how data on the transport channel is transmitted.

Hereinafter, a method and an apparatus for transmitting data using a relay technique in a mobile communication system according to the present invention will be described in detail with reference to the accompanying drawings.

Relay technology has been introduced for the purpose of coverage expansion for high-speed data transmission and improvement of transmission rate at the cell edge. LTE-Advanced technology has been adopted as a standard task and research is ongoing. However, in the present 3GPP standard, there is no specific decision about protocol structure and functional elements related to a relay node (RN).

 Therefore, in the present invention, a protocol layer structure for an RN, wherein a protocol layer structure includes a structure of a user plane and a control plane, and a radio bearer between a donor eNB (DeNB) ) Setting method will be described in detail. In addition, a method of transmitting data to the UE through the RN is described in detail.

The DeNB according to the present invention can perform the operation, control, and radio resource allocation functions of the RN that is a remote base station. In addition, the DeNB can perform radio signal transmission / reception with the RN. The RN can use the same frequency band as DeNB and transmits relatively low power compared to DeNB to expand the cell coverage of DeNB and improve the transmission rate at the cell edge.

3 is an LTE-Advanced relay network structure according to the present invention.

Referring to FIG. 3, the S1 interface 301 is a signaling protocol between a donor Node B 320 to 321 (hereinafter referred to as a DeNB) and an MME / SAE Gateway 310, and an X2 interface 302 is a DeNB Lt; / RTI > The Un interface 303 is a radio transmission protocol for exchanging information between the donor base station 320 and the RN 330. Uu interface 304 is a wireless transport protocol defined for the exchange of information between UEs 340 to 341 and DeNBs 320 to 321 / RN 330, and includes a wireless backhaul for UEs connected to the RN Function.

4 is an EPS bearer service hierarchical structure according to the present invention.

Referring to FIG. 4, an end to end service 410 refers to a data transfer service provided between the UE 401 and an end entity (Peer Entity) 406 connected to the Internet network.

The Evolved Packet System Bearer 420 is a part of the end-to-end service 410. The Evolved Packet System Bearer 420 is an Evolved Packet Core (EPC), in which the EPC is an S-GW (Serving Gateway) 404 and a P- , 405), and transmits the packet between the UE 401 and the UE 401.

An Evolved-Radio Access Bearer (E-RAB) 430 transmits an EPS bearer packet between the S-GW 404 and the UE 401. If there is an E-RAB, a 1: 1 mapping relationship can be established between the E-RAB and the EPS bearer.

A radio bearer (hereinafter referred to as 'RB') 450 transmits an EPS bearer packet between the DeNB 403 and the UE 401 over the radio. If there is a radio bearer, the EPS Bearer / E-RAB and RB may have a 1: 1 mapping relationship.

The S1 bearer (S1 bearer) 460 transmits an E-RAB packet between the DeNB 403 and the S-GW 404. The S5 / S8 bearer (S5 / S8 Bearer) 440 transmits the EPS bearer packet between the S-GW 404 and the P-GW 405. If there is an RN 402 between the DeNB and the UE, the RB transmits an Un Radio Bearer (Un Radio Bearer) 470 (hereinafter referred to as 'Un RB') for transmitting the EPS bearer packet between the DeNB and the RN And a Uu radio bearer (UU Radio Bearer, 480, hereinafter referred to as "Uu RB") for transmitting an EPS bearer packet between the RN and the UE.

5 is a user plane structure in a relay system according to the present invention.

As shown in FIG. 5, the Un bearer may be configured as a pure L2 link between the DeNB and the RN. In detail, each of the LTE PHY, the LTE MAC, the LTE RLC and the LTE PDCP layer of the RN and the DeNB performs end-to-end communication with the corresponding layer of the RN. Referring to FIG. 5, the GTP-U (GPRS Tunneling Protocol-User plane) message is exchanged between the P / S-GW and the RN. In addition, DeNB and P / S-GW exchange packets through pure IP communication. That is, the DeNB may not have a GTP-U layer and a UDP (User Datagram Protocol) layer.

6 is a user plane structure in a relay system according to the present invention.

The user plane of the relay system according to another embodiment of the present invention may be part of an Evolved Packet System (EPS) bearer established between the RN and the P / S-GW (Packet Data Network (PDN) / Serving Gateway). Here, EPS is a connection-based transmission network, and it is required to set up a virtual connection (hereinafter referred to as an EPS bearer) before data transmission between two terminals - for example, a UE and a P-GW- That is, the EPS bearer provides a data transmission service between the two ends - for example, between the UE and the P-GW-.

6, the P / S-GW and the RN horizontally communicate with each other using the GTP-U / UDP / IP / L2 / L1 hierarchical structure, and DeNB and RN horizontally transmit L2 / End-to-end communication is accomplished using L1 Link - that is, LTE PDCP / RLC / MAC / PHY-.

Hereinafter, a method of transmitting and receiving data between the DeNB and the RN according to the present invention will be described in detail.

The DeNB and the RN transmit and receive through the air interface, and the DeNB can operate the RN as a single terminal. Therefore, the DeNB transmits data including the predetermined RN identifier information identifying the RN to the corresponding RN. For example, the RN identifier information may be included in one side of the MAC header in the MAC layer of the DeNB. The RN may decode the radio signal received from the DeNB and receive the packet only if the RN identifier included in the MAC header is the same as the pre-assigned RN identifier. Otherwise, the RN may discard the packet.

Data transmission between DeNB and RN may be different from data transmission from existing eNB to UE because data transmission is performed considering RN as one terminal in DeNB position. For example, the RN may establish a radio link with one or more UEs located within the RN region.

Therefore, the DeNB according to an embodiment of the present invention can multiplex at least one UE packets connected to the RN and transmit them to the RN. When the RN receives the multiplexed packet, it can demultiplex it and transmit it to each UE on the radio. To this end, the DeNB may include a predetermined terminal identifier for identifying the UE on one side of the multiplexed packet. Here, the multiplexed packet may be a MAC PDU generated in the MAC layer of the DeNB. The RLC layer of the DeNB according to another embodiment of the present invention may insert a terminal identifier into one side of the RLC PDU.

DeNB and RN create protocol entities for each RB (Radio Bearer). At this time, the RB may be configured for each UE connected to the RN, or may be configured for each service priority or QoS (Quality of Service). For example, a delay-sensitive voice service may be configured as a separate radio bearer since it may have a relatively high priority over e-mail or text messaging services.

7 is a structure diagram of a PDCP according to the present invention.

As shown in FIG. 7, at least one protocol entity is created in each protocol layer, and user data is transmitted through the protocol entity.

A PDCP entity existing between the DeNB and the RN may exist for each radio bearer. In addition, the PDCP entity that processes the user plane data may use a header compression technique to increase data transmission efficiency according to a predetermined control signal.

Hereinafter, a procedure of generating a protocol entity in the relay system according to the present invention will be described in detail.

The radio resource management layer located in each of the DeNB and the RN can set each protocol layer required for user plane data transmission through a predetermined radio bearer establishment procedure. That is, the DeNB and RN each generate a PDCP entity, an RLC entity, and a MAC entity through a radio bearer configuration procedure. The above entities can be generated one by one for a specific UE. A protocol entity according to another embodiment of the present invention includes a combination of various Quality of Service (QoS) parameters, for example, a QoS parameter may include delay, transmission rate, transmission error rate, transmission priority, Lt; RTI ID = 0.0 > QoS < / RTI > Or a radio bearer is generated for each service in the UE, and a radio bearer (UE-RN Radio bearer) between the UE and the RN and a radio bearer (RN-DeNB Radio Bearer) between the RN and the DeNB may be 1: 1 mapped .

8 is a protocol layer structure for data transmission in a relay system according to an embodiment of the present invention.

As shown in FIG. 8, one protocol entity per layer can be created between DeNB and RN. The DeNB and the RN may provide data transmission services for one or more UEs connected to the RN using the established protocol entity. That is, the DeNB can multiplex the data of the UEs connected to the RN and transmit the multiplexed data to the RN. The RN generates a protocol entity for each UE, divides the multiplexed data received from the DeNB into individual UEs, and transmits the corresponding data through a protocol entity generated for each UE.

The DeNB and the RN create respective protocol entities required for data transmission through a radio bearer setup procedure. If the PDCP protocol entity located in the RN uses a header compression scheme, the PDCP protocol entity may be configured for each UE. If a protocol entity is generated for each UE and a plurality of services having different QoSs are provided to the corresponding UE, it may be difficult to provide a differentiated priority service considering QoS. For example, since a service with a high QoS standard is processed together with a service with a low QoS standard, there is a problem in that it is difficult to maintain the QoS quality set for each service.

The PDCP protocol entity according to an embodiment of the present invention may be configured for each QoS. In the case of transmitting data including predetermined user identification information in the RN, the UE receives the data and performs the following process when it is related to itself, and discards the data if the information is unrelated to itself have.

A PDCP protocol entity according to another embodiment of the present invention may be generated for each service in the UE. For example, when the number of terminals existing in the RN area is two, the services corresponding to each terminal may be two or three, respectively. At this time, the number of PDCP protocol entities generated in the RN may be five. That is, the PDCP protocol entity can be mapped 1: 1 with the RB. Here, the PDCP protocol entity located in the RN can perform the PDCP sequence number maintenance function related to the sequential delivery of the PDCP packet without performing the header compression and encryption function.

Hereinafter, the bearer mapping method in the RN will be described in detail.

The bearer mapping method between the Uu interface and the Un interface in the RN may include at least one of the following four methods.

Method 1: Match 1: 1 Uu Bearer and Un Bearer

Method 2: Grouping by UE

Method 3: Group by QoS

Method 4: Map all data received from the RN to a single bearer.

In the UE-specific grouping method, data received through the Uu interface includes predetermined UE identification information for identifying the UE, and the RN configures the received data as one transmission data unit for each UE and transmits the data to the DeNB do.

In the QoS-based grouping method (method 3), data received from the UE via the Uu interface may include predetermined QoS identification information capable of identifying the QoS. The RN may acquire the QoS identification information through the data received from the UE or acquire the signaling message exchange with the DeNB before setting the data channel. The RN may identify the data received from the UE by QoS and then transmit the data having the same QoS as one transmission data unit to the DeNB. In the case of the method 3, a Hybrid Automatic Request (HARQ) operation between the DeNB and the RN can be performed in units of radio bearers having the same QoS for all UEs connected to the RN.

In the case of mapping all the data received from the RN to one bearer, the RN can construct the data received from the UEs as one transmission data unit and transmit the data to the DeNB. Here, a Hybrid Automatic Request (HARQ) operation between the DeNB and the RN may be performed for one radio bearer set for all UEs connected to the RN. That is, the HARQ operation is performed on a radio bearer established between the RN and the UE, and between the DeNB and the RN, HARQ operation can be performed on one radio bearer to which all UEs connected to the RN are mapped. The data received from the UE may include predetermined RN identification information. The RN can identify the data from the UE located in its cell area using the RN identification information.

In the bearer mapping method in the above RN, concatenation of data received via the Uu interface may be performed in the MAC or RLC layer in the RN. When data received from the MAC layer or the RLC layer of the RN is concatenated, predetermined control information indicating the concatenation may be included in one side of the MAC header or the RLC header. The DeNB can distinguish data by UE / QoS / service using the received connec- tion control information.

Hereinafter, the encryption scheme in the RN and the multiplexing scheme in the MAC layer will be described in detail. Since data is transmitted over the radio link between the DeNB and the RN, ciphering must be performed for each transport block. Here, the transport block means a data unit of the PDCP layer located in the DeNB or the RN. For example, if the DeNB desires to transmit data to the UE through the RN in the downlink direction, the DeNB may multiplex the at least one UE data and transmit the multiplexed data to the RN. In this case, the RN divides the data received from the DeNB into individual UEs and transmits the data to the corresponding UEs.

In this case, the RN may decrypt the data encrypted by the DeNB and classify the data according to the UE. Data classified by UE can be encrypted by the PDCP layer of the RN and then transmitted to the final UE. The PDCP layer of the UE decrypts the data encrypted by the PDCP layer of the RN and transfers the decrypted data to the upper layer. Therefore, as shown in FIG. 8, the RN can set only one protocol layer required for transmission / reception with the DeNB. On the other hand, a protocol layer required for transmission / reception with the UE should be provided by the number of terminals connected to the corresponding RN. At this time, the PDCP layer and the RLC layer may have one or more entities.

Hereinafter, the second hierarchical structure of the DeNB with respect to the downlink direction will be described in detail with reference to FIG. 9 is a second hierarchical structure of DeNB in the downlink according to the present invention. As shown in FIG. 9, the MAC layer of the DeNB may include one MAC entity for multiplexing by RN. Here, the corresponding MAC layer of the RN may include one MAC entity that performs demultiplexing.

More specifically, the MAC layer of the DeNB may multiplex the service data for each UE, multiplex the RN by RN for the UEs located in the RN area, and transmit the multiplexed data to the RN. However, for UEs directly processed by DeNB, service data is multiplexed and transmitted for each UE as in the conventional manner.

10 is a two-layer structure of a downlink direction DeNB according to an embodiment of the present invention.

As shown in FIG. 10, the MAC layer of the DeNB may not multiplex service data for UEs located in the RN in two steps, but may include a predetermined terminal identifier in the MAC header, and multiplex the service data for each RN to transmit to the RN . Here, the header of the MAC may include a predetermined header field for identifying the RN.

The MAC layer of the RN responsible for transmission / reception with the UE analyzes the MAC header of the data received from the DeNB, extracts data for each UE, multiplexes the data, and transmits the multiplexed data to the radio.

In order to configure the second hierarchical structure of the DeNB as in the embodiments of FIGS. 9 to 10, it is necessary to determine whether the RN between the DeNB and the RN is multiplexed by UE, multiplexed by RN or multiplexed by UE and RN It may be necessary to provide predetermined control information that can distinguish whether the data is multiplexed or multiplexed in order to perform multiplexing sequentially, hereinafter referred to as a multiplexing delimiter. The multiplex separator may be transmitted to the RRC layer of the RN through a predetermined 3-layer (RRC) message at the RRC layer of the DeNB. The RRC layer of the RN receiving the 3-layer message delivers the multiplexing delimiter to the MAC layer. The MAC layer of the RN may configure an RN MAC layer corresponding to the downlink MAC layer of the DeNB according to the received multiplex identifier.

The MAC layer of the DeNB according to an embodiment of the present invention includes a MAC PDU including a terminal identifier and RN identifier information when the data is multiplexed, wherein the terminal identifier and the RN identifier are included in a header field of the MAC PDU, To the RN over a predetermined radio channel. The MAC layer of the RN checks whether the packet is a packet to be processed by the RN identifier included in the received MAC PDU. If it is determined that the packet is a packet to be processed by itself, the MAC layer of the RN may construct a MAC PDU including the terminal identifier and transmit the MAC PDU to the wireless terminal.

11 is an RN second hierarchical structure in the downlink according to an embodiment of the present invention.

As shown in FIG. 11, the MAC layer of the RN multiplexes the data received from the DeNB on a UE-by-UE basis, and then transmits the multiplexed data to the corresponding UE. At this time, the MAC layer of the RN can include a predetermined terminal identifier in the header of the MAC PDU.

Hereinafter, the RN identifier and the terminal identifier according to the present invention will be described in detail.

A DeNB according to an embodiment of the present invention can recognize an RN as one terminal, and one or more terminals can be located in one RN. Therefore, the DeNB needs to know information about the RN identifier capable of distinguishing the RN and the terminal identifier capable of identifying the terminal. Hereinafter, a method of identifying the RN and the UE by the DeNB will be described in detail.

The RN according to an embodiment of the present invention receives an RRC Connection Request message generated by the RRC layer of the UE, inserts an RN identifier in one side of the received message, and transmits the message to the DeNB do. To this end, the RRC layer located in the RN must reconfigure the RRC connection request message to include the RN identifier after receiving the message.

The RN and DeNB according to another embodiment of the present invention may share the RN identifier through a predetermined pre-configuration procedure. When the RN receives the RRC connection request message from the UE, the MAC layer of the RN inserts a pre-stored RN identifier into one side of the MAC header, and then transmits the RN identifier to the DeNB. The MAC layer of the UE and the MAC layer of the RN can not identify which message the RRC message is. That is, the RRC message is transmitted transparently to the MAC layer. Accordingly, the RRC layer of the UE transmits a predetermined indication signal indicating that it is an RRC connection request message to its MAC layer. If the indication information is transmitted from the MAC layer of the UE to the MAC layer of the RN, the MAC layer of the RN recognizes that the received message is an RRC connection request message based on the received indication information. Here, the MAC layer of the RN includes the RN identifier in the MAC header, and then transmits the RN identifier to the DeNB. Based on the pre-configuration between the RN and the DeNB, the DeNB determines that the received message is received from the terminal located in the corresponding RN Can be identified.

According to another embodiment of the present invention, when the UE attempts to transmit a Random Access Preamble, the RN transmits a predetermined message indicating that data transmission is possible to the UE. At this time, the RN transmits a predetermined RN identifier (or information capable of identifying the RN) in the corresponding message. The RRC layer of the UE transmits an RRC connection request message including the UE identifier and the received RN identifier (or identifiable information) to the RN. The RN transparently transmits the RRC connection request message to the DeNB.

In this way, the DeNB having the RN identifier and the information on the terminals located in the RN area can transmit data in the downlink direction, including the RN identifier (or identifiable information) and the terminal identifier information, And the RN transmits the received data to the UEs based on the UE identifier information.

In addition, the RN and the DeNB can update UE information (UE List) located in the RN area periodically or non-periodically (event triggering).

At this time, at least one terminal identifier information related to the updated RN identifier and the corresponding RN identifier may consist of one set and may be maintained in a predetermined recording area.

Hereinafter, a handover method in a relay system according to the present invention will be described in detail.

When the UE located in the DeNB moves to the RN controlled by the DeNB, the DeNB can recognize this. For example, the DeNB may receive the data or the pilot signal transmitted from the UE, where the received signal strength of the pilot signal may be measured by the RN and reported to the corresponding DeNB, a measurement report of the UE, The user can recognize the movement to the corresponding RN. In this way, the DeNB recognizing that the UE moves from the area directly managed by the DeNB to the area of the RN transmits the information related to the UE to the RN in advance before transmitting the message for instructing the handover to the UE . In this case, the information to be transmitted may be a UE Context including a UE ID (U-RNTI, C-RNTI, etc.), a UE category, and the like.

That is, when the UE is in a connected mode, the DeNB allocates a resource for establishing an environment capable of directly communicating with the UE through a target RN before transmitting a handover request message to the UE, . Then, the target RN transmits a predetermined message for performing a handover (e.g., a handover command message) to the UE. At this time, the handover message may be transmitted directly from the target RN to the UE, or from the target RN to the UE via the DeNB. The UE having received the handover message performs a bearer and channel configuration procedure for data transmission / reception while performing a radio bearer reconfiguration or a radio link reconfiguration operation for data transmission / reception with the target RN or transmitting a handover complete message to the target RN .

After the handover between the UE and the target RN is successfully completed, the UE resets the RLC and PDCP entities for data transmission / reception with the target RN. At this time, parameters used for header compression and encryption are also reset. For example, a Hyper Frame number (HFN) and a PDCP sequence number (hereinafter referred to as a PDCP SN) used for encryption may be reset.

However, if a packet is lost, such as a file download, if the entire data is meaningless, it is desirable to use the AM RLC entity to prevent packet loss. Accordingly, in the case of data transmitted through the AM RLC entity, the HFN and the PDCP SN, which are related to the data, are transmitted from the DeNB to the target RN through the Un interface.

The RN according to an embodiment of the present invention may simply amplify and transmit signals transmitted and received from DeNB and UE according to QoS or service type, or may decode and re-encode a received signal and transmit the decoded signal to DeNB and UE. For example, if a voice channel is established between the DeNB and the UE, the RN can amplify the voice signal received from the UE and transmit the voice signal to the corresponding DeNB. Here, the RN can control the amplification gain using at least one of the strength of the reference signal received from the DeNB, e.g., the pilot signal, the radio quality of the measured uplink and downlink, and predetermined system parameters. Therefore, the RN can minimize the processing delay by omitting the decoding and re-encoding procedure in case of voice call. On the other hand, data services such as Internet browsing are characterized by transmission speed and data error rate rather than transmission delay. Thus, the RN can decode the received signal to recover the erroneous signal for more accurate data transmission, and re-encode and transmit the erroneous signal.

The cell coverage of DeNB and RN of the relay system according to the present invention may be different from each other. For example, the cell coverage of DeNB may be relatively larger than the coverage of RN. Therefore, it is necessary to set the maximum transmission power of the terminal to be different according to the cell area where the terminal is located. If a UE located in the cell coverage of the RN transmits a signal with the maximum transmission power corresponding to the cell coverage of the DeNB, the corresponding signal may cause interference to the UE located in the cell coverage of the DeNB. Therefore, it may be desirable to set the maximum transmission power of the terminal located in the RN area smaller than that directly controlled by the DeNB. Hereinafter, a method of controlling the maximum transmission power of a terminal in a wireless network in which DeNB and RN are mixed will be described in detail.

When the RN receives a call setup request message from the UE, the RN transmits a call setup request message including the predetermined RN identification information to the corresponding DeNB. When the received call setup request message is received via the RN, the DeNB transmits a call setup message to the RN including the UE maximum transmission power information set in advance corresponding to the RN. The RN sends the received call setup message to the corresponding terminal. The UE controls the transmission power according to the received maximum transmission power information.

For example, the maximum transmission power of a terminal located in a specific RN region may be set differently according to the cell radius of the RN and the geographical feature in which the RN is located. Herein, the DeNB is information about the size information of the cell radius and the geographical characteristic of the RN under its own control, for example, the geographical characteristic is identified by the mountainous terrain, the plain terrain, the urban terrain, the sea terrain, May be stored in a predetermined recording area, and the maximum transmission power of the user equipment may be calculated by referring to the predetermined recording area or by referring to a pre-stored predetermined table.

If the RN is equipped with a radio resource control function, the RN may transmit the maximum transmission power information of the UE included in the call setup message received from the DeNB to a value corresponding to its own cell coverage and transmit the same to the corresponding UE. At this time, the DeNB can set the maximum UE transmission power corresponding to the cell coverage of the DeNB irrespective of whether the UE is located in the RN area.

In the above embodiment, the maximum transmission power of the UE is determined according to the cell coverage of the corresponding base station. However, in another embodiment of the present invention, the maximum transmission power of the UE is minimized in the interference between the RN and DeNB areas Lt; / RTI > For example, the DeNB can calculate the maximum transmission power of a corresponding terminal by referring to various radio environment variables, a service type, mobile capability information, and the like. Here, the radio environment variable may include uplink interference information, a downlink reference signal reception level, and the like.

Also, the DeNB can determine the maximum UE transmission power in consideration of a path loss between the RN and the UE, a link budget for the RN, and the like. Here, the link budget refers to a task of setting or adjusting a standard so that the transmitter and the receiver can successfully communicate with each other in consideration of attenuation of an intermediate signal transmission channel (air) in a wireless communication system, or a calculation result thereof. The terminal capability information may include information on a predefined terminal power class (Power Class), where the terminal transmission power class is the maximum transmission power information of the terminal.

It will be apparent to those skilled in the relevant art that various modifications, additions and substitutions are possible, without departing from the spirit and scope of the invention as defined by the appended claims. The appended claims are to be considered as falling within the scope of the following claims.

320: Donor eNodeB (DeNB)
330: Relay Node (RN).

Claims (1)

A signal reception method in a relay-type mobile communication system,
Measuring the strength of the received signal from the base station and the strength of the received signal from the repeater;
Calculating a received signal strength ratio of the base station to the repeater by dividing the strength of the received signal from the base station by the received signal strength from the repeater;
Determining whether interference occurs using the received signal strength ratio;
Transmitting a control message indicating whether or not the interference has occurred; And
A reception signal from the base station is received through channel 1, and a reception signal from the repeater is received through channel 2
Wherein the signal is received by the receiver.

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