TWI429311B - Method for transmitting random access channel message and response message, and mobile communication terminal - Google Patents

Description

Method and mobile communication terminal for transmitting random access channel information and response messages

The invention relates to a random access of a mobile communication system, in particular to a transmission of a random access channel (RACH) response message according to a channel measurement result of a mobile communication terminal transmitting data using an uplink channel. A method of power to efficiently use a radio resource and to support one of the methods.

Figure 1 shows the network structure of a Universal Mobile Telecommunication System (UMTS).

The UMTS generally includes a User Equipment (UE), a UMTS Terrestrial Radio Access Network (hereinafter referred to as UTTS, UMTS Terrestrial Radio Access Network), and a core network (hereinafter referred to as CN, Core Network). The UTRAN includes at least one radio network subsystem (hereinafter referred to as RNS, Radio Network Sub-system). Each RNS includes a radio network controller (hereinafter referred to as RNC, Radio Network Controller), and at least one base station (hereinafter referred to as a node B) managed by the RNC. A node B includes at least one unit.

Figure 2 shows the structure of a radio interface agreement between the UTRAN and the UE based on the 3GPP radio access network standard.

As shown in FIG. 2, the radio access interface protocol includes a horizontal layer including a physical layer, a data link layer and a network layer, and a vertical plane including a user plane for transmitting data information. And for transmission control One of the signals controls the plane. In Figure 2, the protocol layer can be divided into L1 (first layer) and L2 (second layer) based on three lower layers of the Open System Interconnection (OSI) standard model well known in the art of communication systems. ), and L3 (third layer).

The laminate shown in Fig. 2 will be described below. The physical layer as the first layer provides an information transmission service to an upper layer by using a physical channel. The physical layer is connected to a media access control layer via a transport channel, which is an upper layer, and data is transferred between the media access control layer and the physical layer via the transport channel. In addition, the data is transmitted via a physical channel between different physical layers (ie, a transport side and a physical layer on the receiving side).

The medium access control (hereinafter referred to as MAC, Medium Access Control) layer is the second layer, which provides a service to a radio link control layer via a logical channel, which is an upper layer. The radio link control (hereinafter referred to as RLC, Radio Link Control) layer, which is the second layer, provides support for reliable data transmission, and can implement an RLC service data unit (SDU, Service Data) from a higher layer. Unit) segmentation and combined functions.

a radio resource control (hereinafter referred to as RRC, Radio Resource Control) layer located at the lowest part of the third layer, which is defined only in the control plane, and controls the setting, the reset, and a radio The logical channels, the transport channels, and the physical channels released by the carrier (hereinafter referred to as RB, Radio Bearer). At this time, RB represents a service provided by the second layer for data transmission between the UE and the UTRAN. In summary, the setting of the RB means specifying a protocol layer and A program that provides the characteristics of a channel required for a particular service, and sets the parameters and operating methods of individual details.

A RACH of Wideband Code Division Multiple Access (WCDMA) will be described in detail below. RACH is used to transmit short lengths of data on an uplink. In more detail, the RACH is used when the UE obtains initial uplink synchronization. The RACH is used when the UE is initially turned on or switched from a long standby mode to an enabled mode, so that the uplink synchronization is set again and can be used without establishing time synchronization or frequency synchronization. The RACH basically supports multiple users. Each UE transmits a specific preamble sequence when accessing the RACH, the Node B identifies the preamble sequence, and transmits a signal to the lower chain, and the UE uses the information to update its own time synchronization information. At this time, if the frequency synchronization information is transmitted together, the frequency synchronization information can be used in the information of the UE.

The RACH is the transport channel, which is mapped to the physical random access channel (PRACH).

Figure 3 shows a conventional PRACH transmission.

As shown in Figure 3, the PRACH is divided into a preamble and a message part. The preamble partially implements a power boost function for appropriately controlling the transmission power for message transmission and a function for avoiding collision between several UEs. The message part is implemented for transmitting a function of the MAC protocol data unit (hereinafter referred to as a PDU, Protocol Data Unit) transmitted by the MAC to the physical channel.

When the MAC of the UE indicates that a PRACH is transmitted to the physical layer of the UE, the physical layer of the UE first selects an access slot and a signature, and transmits the preamble to an uplink on the PRACH. The preamble is transmitted during the duration of the access slot of length 1.33 ms, and a signature is selected and transmitted by 16 signatures within the first specific length of the access slot. When the UE transmits the preamble, the Node B transmits a response signal by using an AICH (Acquisition Indicator Channel) for one of the downlink physical channels. In response to the preamble, the AICH transmits the signature, which is selected by the preamble and is within a first particular length of the access slot corresponding to the access slot for transmitting the preamble. At this time, the Node B transmits an acknowledgement (ACK) response or an unacknowledged (NACK) response to the UE via the signature transmitted by the AICH.

When the UE receives the ACK response, the UE transmits a message portion having a length of 10 ms or 20 ms using an Orthogonal Variable Spreading Factor (OVSF) corresponding to the transmitted signature.

When the UE receives the NACK response, the MAC of the UE indicates a PRACH retransmission to the physical layer of the UE after a certain period of time. Conversely, if the UE does not receive an AICH corresponding to the transmitted preamble, the UE transmits a new preamble with a higher power than the previous preamble after a predetermined access slot.

Figure 4 shows an exemplary structure of an AICH, one of the traditional downlink physical channels.

A 16-symbol signature (Si, i = 0...15) is transmitted for the AICH of the downlink physical channel for an access slot having a length of 5120 chips. Here, the UE Any signature (Si) can be selected from the S0 signature to the S15 signature, and the selected signature is transmitted during the first 4906 wafer lengths. The remaining 1024 wafer length is set to a transmission power off period during which no symbols are transmitted. At the same time, similar to Fig. 4, the preamble portion of the PRACH for the uplink physical channel transmits 16 symbol signatures (Si, i = 0...15) during the first 4096 wafer length.

However, in the conventional RACH transmission, the downlink message transmitted due to the transmission of the uplink RACH message utilizes high power transmission, so that the downlink message can be received even on a cell boundary, so it is not efficient. Use a radio resource.

Accordingly, the present invention is directed to a method of transmitting a random access channel message and a response message, and a mobile communication terminal that substantially obviates one or more problems due to the limitations and disadvantages of the related art.

An object of the present invention for solving the problem is to provide a method for responding to a random access channel message, which can use a measurement information of a user equipment (UE) to appropriately control transmission power and transmit a message to the UE. .

Another object of the present invention for solving the problem is to provide a method for transmitting a random access channel message, which can include measurement information of a UE in an uplink message, thereby appropriately controlling the transmission power of a base station.

Another object of the present invention for solving the problem is to provide a mobile communication terminal that implements a method of transmitting a random access channel message to efficiently use a radio resource.

The object of the present invention can be achieved by providing a method for responding to a random access channel message, the method comprising the following steps: from a second layer of a random access channel (RACH) message (hereinafter referred to as L2) The header reads the quality measurement information of the link channel, which is transmitted by a user equipment to an uplink; the transmission power of the response message for one of the RACH messages is controlled according to the quality measurement information; and the response message is transmitted to The user device.

Preferably, the L2 header can be a Media Access Control (MAC) header that sets a MAC Protocol Data Unit (PDU).

Preferably, the control of the transmission power may include the following procedure when the upper layer information is included in the MAC PDU of the RACH message. That is, the process of controlling the transmission power may include removing the quality measurement information from the MAC PUD and transmitting the MAC PDU to a MAC of a Radio Network Controller (RNC). In this case, the upper layer information may be transmitted through at least one channel in a common control channel (CCCH), a dedicated control channel (DCCH), and a dedicated traffic channel (DTCH). A Radio Resource Control (RRC) message, which is a logical channel.

Preferably, the response message may include an acknowledgment (ACK) response for notifying that the RACH message was successfully received, and an unacknowledged (NACK) response for notifying that the RACH message was not successfully received. .

For another aspect of the present invention, there is provided a method for responding to a random access channel message, the method comprising the steps of: reading an L2 header adjacency included in a message from a random access channel (RACH) One has The quality measurement information of the downlink channel in the payload, wherein the random access channel information is transmitted by a user equipment to an uplink; and the transmission power for the response message of the one of the RACH messages is controlled according to the quality measurement information; And transmitting the response message to the user device.

Preferably, the RACH message can store information in a target channel type field (TCTF) of the L2 header, wherein the information indicates whether the quality measurement information is included in the payload.

For another aspect of the present invention, there is provided a method for transmitting a random access channel message, the method comprising the steps of: measuring a quality of a link channel at a user equipment, and generating a quality of the downlink channel Measuring information; and including the quality measurement information in a L2 header of one of the random access channel (RACH) messages, and transmitting the RACH message to an uplink.

Preferably, the step of transmitting the RACH message to the uplink may include transmitting a preamble to the uplink, and if the response of the preamble does not receive or receive an unacknowledged response, retransmitting the preamble to The step of winding up. At this point, the RACH message can be transmitted to the uplink when a confirmation response to the preamble is received.

Preferably, the L2 header can be a Media Access Control (MAC) header that sets a MAC Protocol Data Unit (PDU).

Preferably, the L2 header stores information indicating whether the quality measurement information is included in an L2 header in a target channel type field (TCTF).

For another aspect of the present invention, there is provided a transmission random access a method for channel information, the method comprising the steps of: measuring a quality of a link channel at a user device, and generating quality measurement information of the downlink channel; and including the quality measurement information adjacent to a random access channel ( The RACH message is one of the payloads of the L2 header and transmits the RACH message to an uplink.

Preferably, the RACH message stores information indicating whether the quality measurement information is included in a payload in a target channel type field (TCTF) of the L2 header.

For another aspect of the present invention, there is provided a mobile communication terminal for randomly accessing a transmission data to an uplink via a mobile communication system, the mobile communication terminal comprising: a downlink channel measurement unit, which measures a quality of the link channel and generating quality measurement information of the downlink channel; and a message transmission unit including the quality measurement information in a L2 header of a random access channel (RACH) message and transmitting the RACH message Go to the winding.

For another aspect of the present invention, there is provided a mobile communication terminal for randomly accessing a transmission data to an uplink via a mobile communication system, the mobile communication terminal comprising: a downlink channel measurement unit, which measures a quality of the link channel and generating quality measurement information of the downlink channel; and a message transmission unit including the quality measurement information in a payload adjacent to the L2 header of one of the random access channel (RACH) messages, and Transmitting the RACH message to the uplink.

Favorable effect

According to a specific embodiment of the present invention, since the transmission power can be adaptively controlled according to one of the user equipment (UE) channel measurement results, a radio resource can be used efficiently. In a method, since the information indicates whether the quality measurement information is included, or whether the upper layer information is included, the information is notified to a base station via a header, so the compatibility between the existing UE and a radio network is Can be maintained.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments embodiments However, the scope of the invention is not limited to the specific embodiments described below.

Figure 5 is an illustration of a mobile communication terminal 510 in accordance with the present invention.

The lower chain channel measuring unit 511 measures the quality of the chain channel by one of the downlink signals of the node B 520, and generates quality measurement information of the downlink channel.

A message transmission unit 512 includes the quality measurement information in a random access message, that is, a RACH message, and transmits the RACH message to the Node B 520 via an uplink signal. This particular embodiment may vary depending on where the quality measurement information is included in the portion of the RACH message. That is, in the mobile communication terminal 510 according to an embodiment of the present invention, the message transmission unit 512 includes the quality measurement information in the header of the second layer L2 of the RACH message. In addition, in the mobile communication terminal 510 according to another embodiment of the present invention, the quality measurement information may be included in a payload adjacent to the header of the second layer L2 of the RACH message.

The downlink channel measurement unit 511 and the message transmission unit 512 may be implemented in the form of a program installed in the firmware of the mobile communication terminal 510, or may be implemented by manufacturing individual chips for implementing individual logic. The downlink channel measurement unit 511 and the message transmission unit 512 can be implemented by a single chip for implementing all logic.

Figure 6 is a random access procedure in accordance with an embodiment of the present invention.

In an embodiment of the present invention, in order to efficiently use a radio resource, a radio user equipment (UE) includes quality measurement information of the downlink channel to a second layer L2 of the RACH message transmitted to an uplink. In the header. A radio network controls the transmission power of a response message of the RACH message using quality measurement information included in the header of the second layer L2, and transmits the response message to the UE.

In another embodiment of the present invention, in order to efficiently use a radio resource, the UE includes the quality measurement information of the downlink channel validly adjacent to the header of the second layer L2 of the RACH message transmitted to an uplink. In the load. The radio network controls the transmission power of a response message of the RACH message using quality measurement information included in the payload, and transmits the response message to the UE. In this example, the radio UE may include the quality measurement information in an L2-PDU in a load manner and transmit the RACH message to the radio network.

This specific embodiment will be explained below with reference to Fig. 6.

The UE 510 may transmit the RACH message after a RACH preamble transmission step and a step back to the RACH preamble, as shown in FIG. Therefore, the UE 510 first transmits the preamble of the RACH to the Node B 520 (610).

Next, when the preamble is correctly received, Node B 520 transmits an ACK response to the RACH preamble to UE 510 (620). Conversely, when the preamble is not received or received incorrectly, Node B 520 transmits one of the RACH preamble NACK responses to UE 510 (620).

Next, the UE 510 transmits quality measurement information of the link channel below the Node B 520 to the Node B 520 (630). For example, the RACH message includes a Channel Quality Indication (CQI). At this time, the RACH message may include at least one L2-PDU. If the L2-PDU includes the quality measurement information, the header of the L2-PDU, that is, the L2 header, may inform whether the quality measurement information is included in the L2 header or the L2-PDU includes the header of the L2. For example, the L2 header can be a MAC header that sets one of the MAC PDUs. In more detail, information indicating whether the CQI is included in the MAC PDU may be stored in a target channel type field (TCTF) of the MAC header.

The MAC PDU may include an RRC message transmitted to a Common Control Channel (CCCH), a Dedicated Control Channel (DCCH), or a Dedicated Traffic Channel (DTCH), all of which are such logical channels.

When the UE is powered on and then accesses a new unit, the UE establishes downlink synchronization and receives system information of the unit to be accessed. After receiving the system information, the UE transmits an access request message for an RRC connection. However, since the UE is not synchronized with a current network setup time, and An uplink radio resource is not guaranteed, so the RACH can be used. That is, the UE requests the radio resource for transmitting the connection request message to the network using the RACH. The Node B receiving the request for the radio resource configures an appropriate radio resource to the UE. Then, the UE can transmit an RRC connection request message to the network via the radio resource.

In the state in which the UE is RRC connected to the network, the UE in the RRC connected mode can use the RACH. In this example, the UE receives radio resources configured according to the radio resource schedule of the network and transmits data to the network via the configured radio resources. However, if the data to be transmitted is no longer left in the buffer of the UE, the network no longer configures the uplink radio resource to the UE. This is because configuring the uplink radio resource to a UE that does not have the data to be transmitted is not efficient. If new data occurs in the buffer of the UE that does not have the radio resource, the UE can use the RACH because the uplink radio resource is not configured for the UE. That is, the UE can request the radio resource as needed to transmit the data to the network using the RACH.

That is, some RRC messages, such as an RRC connection request message, a unit update message, and a URA update message, may also be transmitted via the RACH. At this time, the CCCH, DCCH, and DTCH, which are all the logical channels, can be mapped to the RACH of the transport channel.

The quality measurement information of the downlink channel may be included in the L2 header, such as the MAC header, or may be included in a front end portion of a MAC payload, or included in a load mode adjacent to the L2 header. One of the MAC payloads of the backend portion.

Next, Node B 520 performs adaptive modulation control (AMC) or power control (640) using the quality measurement information of the downlink channel. At this time, the second layer, that is, the MAC layer of the Node B 520 receives the MAC PDU of the RACH message, checks the MAC header, and checks whether the quality measurement information of the downlink channel is included in the MAC PDU. At this time, if the MAC header notification does not include the quality measurement information of the downlink channel, the Node B 520 controls the quality measurement information without connecting the transmission power.

Finally, Node B 520 transmits a RACH Response message to UE 510 (650) using the transmission power controlled according to the quality measurement information of the downlink channel.

The UE 510 may include L3 information and L2 information in the RACH message, which is transmitted to the uplink, and includes quality measurement information of the downlink channel in the L2 information. At this time, the L3 information may be the RRC message. In addition, the L2 information can notify the Node B 520 that the quality measurement information is included in the L2 information. In particular, the L2 information may be MAC control information included in the MAC header or MAC PDU in a load manner, and may be MAC control information included in a payload of the MAC PDU.

In this step 650, three or lower instances may be implemented based on whether the L3 information is included or whether the quality measurement information is included in the L2 information.

First, if the upper layer information is included in the MAC PDU, and the MAC header notifies that the quality measurement information of the downlink channel is included, the Node B 520 removes the quality measurement information from the MAC PDU and resets The MAC PDU. Node B 520 transmits the reset MAC PDU The MAC to the RNC. In addition, Node B 520 transmits a response message of the RACH message received from UE 510 to UE 510.

Secondly, if the upper layer information is not included in the MAC PDU, and the MAC header notifies that the quality measurement information of the downlink channel is included, the Node B 520 does not transmit the MAC PDU to the RNC. In this example, Node B 520 transmits only the response message for the RACH message to UE 510. At this time, the response message includes the ACK response to notify that the RACH message is successfully received, and the NACK response is used to notify that the RACH message has not been successfully received. The response message includes information indicating the RACH preamble or information indicating the RACH message. At this time, the indication information included in the response message may be coded information for transmission of the message or the signature of the preamble.

Third, if the MAC header does not notify the quality measurement information of the downlink channel to be included, the Node B 520 transmits only the MAC PDU to the MAC of the RNC, and transmits the response message to the UE 510.

The RACH echo message of Node B 520 may be transmitted via the L2-PDU, for example, the MAC PDU may be transmitted via a physical layer control signal. If the response message is transmitted via the MAC PDU, the header of the MAC PDU including the response message notifies the UE 510 that the response message is included in the MAC PDU. In particular, the UE can be notified that the response message is included in the MAC PDU, which uses the TCTF of the header of the MAC PDU.

Figure 7 is an example of the random access procedure shown in Figure 6.

After the RACH preamble transmission (AP) and the RACH preamble response (AICH), the UE 510 measures the link channel below the Node B 520, including the The quality measurement information is in the MAC payload or in the MAC header of the MAC PDU, and the RACH message is transmitted to the uplink.

The response message MSG-ACK/NACK of the Node B 520 of the RACH message is the ACK signal for notifying that the RACH message is successfully received, or for the NACK signal to notify that the RACH message has not been successfully received.

Meanwhile, when the UE 510 receives the MAC PDU from the Node B 520 and checks that the response message MSG-ACK/NACK is included in the MAC PDU through the header of the MAC PDU, the UE 520 according to the response message MSG-ACK/NACK The RACH message can be retransmitted to Node B 520. In particular, the UE 510 does not retransmit the RACH message if the response message MSG-ACK/NACK received from the Node B 520 responds to the ACK, and retransmits the RACH message to the node if the response message is the NACK response. B 520.

Figure 8 is an illustration of the MAC PDU set up in accordance with an embodiment of the present invention.

In Figure 8, the TCTF is included in the MAC header. The TCTF can notify whether the quality measurement information (ie, CQI) is included in the MAC PDU, as described above. The MAC PDU may further include other information such as UE-Id, C/T, and a MAC Service Data Unit (SDU).

In the present invention, the mobile communication terminal includes quality measurement information of the downlink channel in the L2 header or payload of the RACH message transmitted to the uplink, and the radio network usage is included in the L2 header or The quality measurement information in the payload controls the response message of the RACH message. Transmit power and transmit the response message to the UE. Therefore, it is possible to use the radio resource efficiently.

It will be appreciated by those skilled in the art that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention. Therefore, it is intended that the present invention cover the modifications and variations of the invention, if they are within the scope of the appended claims and their equivalents.

Industrial applicability

According to the present invention, it is possible to provide a method for controlling the transmission power of a RACH response message based on a channel measurement result of a mobile communication terminal for transmitting data using an uplink channel. The method can be applied to an algorithm of a random access procedure of a mobile communication system, and a user equipment and a base station for supporting it.

510‧‧‧Mobile communication terminal

511‧‧‧Underline channel measurement unit

512‧‧‧ message transmission unit

520‧‧‧Node B

Preface to 610‧‧‧RACH

620‧‧‧RACH Preface Response

630‧‧‧RACH message

640‧‧‧Power control

650‧‧‧RACH response message

The drawings and illustrations are included to provide a further understanding of the invention and the embodiments of the invention.

In the figure: Figure 1 shows the network structure of a Universal Mobile Telecommunications System (UMTS); Figure 2 shows the UMTS Terrestrial Radio Access Network (UTRAN) based on the 3GPP radio access network standard and a use a radio interface protocol between devices; Figure 3 is a conventional physical random access channel (PRACH) transmission; Figure 4 is a diagram showing an exemplary structure of an indicator channel (AICH) for one of the following chain physical channels; Figure 5 is an example of a mobile communication terminal according to the present invention; and Figure 6 is a random access procedure according to the present invention. Example; Figure 7 is an example of a random access procedure shown in Figure 6; and Figure 8 is an example of a Media Access Control (MAC) Protocol Data Unit (PDU) set in accordance with an embodiment of the present invention. .

510‧‧‧Mobile communication terminal

520‧‧‧Node B

Preface to 610‧‧‧RACH

620‧‧‧RACH Preface Response

630‧‧‧RACH message

640‧‧‧Power control

650‧‧‧RACH response message

Claims (16)

A method for responding to a random access channel message, the method comprising the steps of: receiving a random access channel (RACH) from a user equipment at a base station; at the base station Transmitting a RACH preamble to the user equipment; after transmitting the RACH preamble response, receiving a RACH message from the user equipment at the base station; reading a media save from the RACH message at the base station Taking channel quality measurement information of the downlink channel of the control (MAC) layer header, wherein the channel quality of the downlink channel is measured by the user equipment; and according to the quality measurement information of the channel, the base station determines that One of the RACH messages responds to the transmission power of the message; and uses the determined transmission power to transmit the response message to the user equipment at the base station. The method of claim 1, wherein the MAC layer header is a MAC header of one of a MAC protocol data unit (PDU). The method of claim 2, wherein the step of determining the transmission power comprises removing the channel quality measurement from the MAC PDU. Information, and if the upper layer information is included in the MAC PDU of the RACH message, the MAC PDU is transmitted to the MAC layer of a radio network controller (RNC). The method of claim 3, wherein the upper layer information is via a common control channel (CCCH), a dedicated control channel (DCCH), and a dedicated traffic channel (DTCH, At least one channel in the dedicated traffic channel transmits one radio resource control (RRC) message, which is a logical channel. The method of claim 1, wherein the response message includes an acknowledgement (ACK) response for notifying that the RACH message was successfully received, and an unacknowledgment for notifying that the RACH message was not successfully received ( NACK) responded to any of them. A method for responding to a random access channel message, the method comprising the steps of: receiving a random access channel (RACH) preamble from a user equipment at a base station; transmitting a RACH preamble at the base station Responding to the user equipment; receiving a RACH message from the user equipment at the base station; Reading, at the base station, channel quality measurement information included in a downlink channel in a paylord, the payload being adjacent to a media access control (MAC) layer header of the RACH message, wherein the payload is borrowed Measuring, by the user equipment, a channel quality of the downlink channel; determining, according to the channel quality measurement information, a transmission power corresponding to the response message of the RACH message at the base station; and using the determined transmission power, The base station transmits the response message to the user equipment. The method of claim 6, wherein the RACH message storage information is in a target channel type field (TCTF) of the MAC layer header, the information indicating whether the channel quality measurement information is Is included in the payload. A method for transmitting a random access channel message, the method comprising the steps of: measuring a channel quality of a link channel at a user equipment, and generating channel quality measurement information of the downlink channel; and at the user The device includes the channel quality measurement information in a media access control (MAC) layer header of a random access channel (RACH) message, and transmits the RACH message to a base station via an uplink. The method of claim 8, wherein the winding is performed via the winding The step of transmitting the RACH message includes the steps of: transmitting a preamble at the user equipment via the uplink, and if the one of the preamble is not received or an unacknowledged response is received, then the uplink is The preamble is retransmitted at the user equipment, and if a confirmation response for the preamble is received, the RACH message is transmitted at the user equipment via the uplink. The method of claim 8, wherein the MAC layer header is a MAC header that sets a MAC Protocol Data Unit (PDU). The method of claim 8, wherein the MAC layer header stores information in a target channel type field (TCTF), the information indicating whether the channel quality measurement information is included in the MAC layer header. . The method of claim 8, further comprising the step of retransmitting the RACH message via the uplink if the response message corresponding to the RACH message is an unacknowledged response. A method for transmitting a random access channel message, the method comprising the steps of: measuring a channel quality of a link channel at a user equipment, And generating channel quality measurement information of the downlink channel; and including the channel quality measurement information in the user equipment in a payload, the payload is adjacent to a random access channel (RACH) message Controlling (MAC) layer headers and transmitting the RACH message to a base station via an uplink. The method of claim 13, further comprising the step of retransmitting the RACH message via the uplink if the response message corresponding to the RACH message is an unacknowledged response. A mobile communication terminal for transmitting data via a link through random access in a mobile communication system, the mobile communication terminal comprising: a downlink channel measurement unit, which measures channel quality of the link channel and generates the downlink Channel quality measurement information of the channel; and a message transmission unit including the channel quality measurement information in a media access control (MAC) layer header of a random access channel (RACH) message and transmitted through the uplink The RACH message is sent to a base station. A mobile communication terminal for transmitting data via a link through random access in a mobile communication system, the mobile communication terminal comprising: a downlink channel measurement unit, which measures channel quality of the link channel and generates the downlink Channel quality measurement information of the channel; and a message transmission unit including the channel quality measurement information In a payload, the payload is adjacent to a Media Access Control (MAC) layer header of a random access channel (RACH) message, and the RACH message is transmitted to a base station via the uplink.