KR101488525B1 - Random access procedure practice method and apparatus in mobile communication system - Google Patents

Abstract

A method for performing a random access procedure by a terminal in a mobile communication system, the method comprising: transmitting a preamble for identifying the terminal through a first message; A transparent RRC message which is an RRC message initially transmitted by a UE having no RRC control connection or reverse transmission resource information for transmitting buffer status report information indicating the amount of reverse data, A format indicator for indicating whether the Transparent RRC message or the buffer status report information is included in the third message, and configuring the third message according to the format indicator, And transmits it according to the reverse transmission resource information.

Long Term Evolution (LTE), Buffer Status Report, MAC container

Description

TECHNICAL FIELD [0001] The present invention relates to a method and an apparatus for performing a random access procedure in a mobile communication system,

The present invention relates to a method and apparatus for performing a random access procedure in a mobile communication system.

In LTE (Long Term Evolution), which is one of the next generation mobile communication systems and under standard operation in 3GPP, the base station is responsible for forward and reverse traffic scheduling. The step of transmitting reverse data in the communication system in which the base station is responsible for scheduling generally comprises the following five steps.

Step 1: The user equipment (UE) transmits a signal to the evolved Node B (eNB) that the reverse data is generated

Step 2: The base station allocates transmission resources to the terminal so as to report more accurate information on the generated data, for example, the amount and priority of data

Step 3: The UE transmits a Buffer State Report (BSR) message containing the amount of data stored in its buffer and priority information to the BS

Step 4: Based on the buffer status reporting message, the BS allocates transmission resources required for actual data transmission to the MS

Step 5: The UE transmits data using the allocated transmission resources

Hereinafter, a process of transmitting a scheduling request message to a Node B and reporting a buffer status in a LTE system will be described with reference to FIG. 1A.

In step 1, a message transmitted by the UE is referred to as a scheduling request message, a resource to which a scheduling request message is transmitted is referred to as a scheduling request resource, and a periodically repeated scheduling request resource is referred to as an RRC Radio Resource Control (RRC) connection is established. For example, a specific transmission resource may be given as a scheduling request transmission resource to a specific UE every 10 msec. If the UE 105 periodically transmits data in the reverse direction, the UE 105 having the scheduling request transmission resource transmits a scheduling request message to the Node B 110 through the scheduling request resource in step 115.

The scheduling request message can be represented by 1-bit information, and requests transmission resource allocation for buffer status reporting using 1-bit information. The BS 110 allocates a transmission resource sufficient to transmit a buffer status report message for reporting a buffer status to the MS 105 by transmitting an UL grant message in step 120. In step 125, Transmits the buffer status report message containing the type and size of the generated data to the base station 110 through the transmission resource allocated through the UL grant message.

Based on the buffer status report message, the BS 110 measures the importance of the data, comprehensively considers the channel state of the AT 105 and the traffic state of the current cell, ) To transmit reverse data.

1B is a diagram illustrating an example of a buffer status report message used in an LTE system.

Since the buffer status report message is a MAC control message generated by a Medium Access Control (MAC) layer, it is a type of MAC control SDU (Service Data Unit), and is stored in a typical MAC PDU (Packet Data Unit) The MAC PDU 140 includes a MAC header 130 and a MAC SDU 135. The MAC header 130 stores the type and size of the MAC SDU 135. A PDU and an SDU are terms used to refer to data that has undergone a specific operation step in an arbitrary protocol apparatus. When data generated in an upper layer is transferred to an arbitrary protocol apparatus, the upper layer data is referred to as an SDU. Alternatively, as in the above example, when the protocol apparatus itself generates control information, the control information is also referred to as an SDU. On the other hand, the addition of a predetermined protocol header to the SDU is referred to as a PDU.

Since the base station can not allocate the scheduling request resource to all the UEs with the RRC connection established, the scheduling request resource is not allocated to the UEs having a relatively low data transmission frequency. Since the only reverse channel that can be used by a UE that is not allocated with a scheduling request resource is an Random Access Channel (Random Access Channel) in which the RRC connection is established, the UE, which has not been allocated the scheduling request resource, However, a method of transmitting a buffer status report message to a base station through a random access procedure in a state where an RRC connection is established is not yet defined.

The present invention provides a method and apparatus for a UE to which a RRC connection is established but a UE for which a scheduling request resource is not allocated transmits a buffer status report message to a base station through a random access procedure and receives a buffer status report message from the base station.

The present invention provides a method and apparatus for transmitting a buffer status report message to a base station through a random access procedure and receiving the buffer status report message from the terminal while the RRC connection is established, Lt; / RTI >

The present invention provides a method and apparatus for transmitting and receiving messages for performing a random access procedure between a terminal and a base station.

A method according to an embodiment of the present invention is a method for a UE to perform a random access procedure in a mobile communication system, the method comprising: transmitting a preamble for identifying the UE through a first message; In response to the first message, a transparent RRC message, which is an RRC message initially transmitted from a terminal that does not have an RRC (Radio Resource Control) control connection, or buffer status reporting information indicating the amount of reverse data, The method comprising the steps of: receiving a second message including reverse transmission resource information for transmission; setting a format indicator indicating whether the transparent RRC message or the buffer status report information is included in a third message; And configures the third message according to the set format indicator to transmit the uplink transmission resource information It includes a step of transmitting along.

A method according to another embodiment of the present invention is a method for a UE to perform a random access procedure in a mobile communication system, the method comprising the steps of: determining, when performing the random access procedure, The method comprising the steps of: transmitting a preamble including at least one of information indicating a downlink transmission resource to a base station through a first message; and transmitting reverse transmission resource information for transmitting the third message from the base station in response to the first message, Receiving a second message including at least one of a size of the third message indicated by the base station and a size of the third message instructed by the base station; Indicating a format of the third message; configuring the third message according to the format instructed; Wherein the third message is a transparent message that is an RRC message initially transmitted from a mobile station having no RRC control connection from the base station to the third message according to the format, RRC message or a general MAC (Medium Access Control) PDU (Packet Data Unit).

A method according to another embodiment of the present invention is a method for a base station to perform a random access procedure in a mobile communication system, the method comprising: receiving a preamble for identifying the terminal from a terminal through a first message; 1 RRC message, which is an RRC message originally transmitted by a UE that does not have an RRC (Radio Resource Control) control connection, or a reverse transmission resource for transmitting a buffer status report indicating the amount of reverse data Receiving a third message transmitted through the reverse transmission resource; and transmitting the third message through the reverse transmission resource, if the received third message includes the transparent RRC message or the buffer status report The method comprising the steps of: checking a format indicator indicating whether the format And processing the third message in the RRC layer or MAC (Medium Access Control) layer according to the value set by the indicator.
A method according to another embodiment of the present invention is a method for a base station to perform a random access procedure in a mobile communication system, the method comprising: receiving at least one of information indicating a size of a third message to be transmitted from the terminal and a channel status The method comprising: receiving a preamble including a preamble including a preamble including a first message and a second message from a first message; Receiving a third message transmitted through the reverse transmission resource; and transmitting the third message to the RRC layer according to the format of the received third message. Or a MAC layer, and the format of the third message includes a format of the third message, 3 message or a comparison result between a size of the third message received by the base station and a preset size, and the third message is set according to the format, from the base station to a Radio Resource Control RRC message or a general MAC (Medium Access Control) PDU (Packet Data Unit), which is an RRC message initially transmitted by a UE having no control connection.

An apparatus for performing a random access procedure in a mobile communication system includes a physical layer processor for transmitting and receiving messages to and from a base station, (RRC) message or an amount of reverse data, which is an RRC message initially transmitted by a UE having no RRC (Radio Resource Control) control connection, in response to the first message from the base station Acquires reverse transmission resource information for transmitting the buffer status report information indicating the buffer status report information through the second message received by the physical layer processing unit, generates a Medium Access Control (MAC) control message including the buffer status report information, The third message transmitted using the reverse transmission resource information is transmitted to the third RRC A MAC controller for outputting a format indicator indicating whether the buffer status report is included or not, and a MAC control unit including a buffer status reporting information transmitted from the upper layer and the buffer status report information transmitted from the MAC controller, And a MAC multiplexer for multiplexing the message and configuring the third message according to the format indicator indicated by the MAC controller.

According to another aspect of the present invention, there is provided an apparatus for performing a random access procedure in a mobile communication system, the apparatus comprising: a physical layer processor for transmitting and receiving messages to and from a base station; Wherein the control unit controls the terminal apparatus to transmit a preamble including at least one of a size of a third message to be transmitted and information indicating a channel status to a base station through a first message, Acquires at least one of the reverse transmission resource information for transmitting the third message and the size of the third message indicated by the base station through the second message received from the base station through the physical layer processing unit, Comparing the size of the third message with a preset size, A Medium Access Control (MAC) controller for outputting a format indicator indicating a format of the third message, a Transparent RRC (Radio Resource Control) message transmitted from an upper layer, or a buffer status report And a MAC multiplexer for multiplexing the MAC control message including the MAC message and the third message according to the format indicator indicated by the MAC controller and delivering the third message to the physical layer processor, And the buffer status report information indicates the amount of the reverse data.

The apparatus according to another embodiment of the present invention is a base station apparatus for performing a random access procedure in a mobile communication system, the apparatus comprising: a preamble for identifying the terminal from the terminal to perform the random access procedure; A MAC (Medium Access Control) processing unit for transmitting a second message including the uplink resource information to the UE corresponding to the preamble and processing the buffer status report information included in the third message received from the UE, A physical layer processing unit for transmitting and receiving the first message, the second message and the third message to and from the terminal, and a format indicator of the third message received from the physical layer processing unit, If a transparent RRC (Radio Resource Control) message is included or if the buffer status report And if the buffer status report information is included in the third message, transfers the buffer status report information to the MAC controller, and if the third message includes the transparent RRC message, And a MAC demultiplexer for transmitting a parent RRC message to a 2-tier processor, wherein the transparent RRC message is an RRC message initially transmitted from a terminal having no RRC (Radio Resource Control) control connection from the base station, And the buffer status report information indicates the amount of reverse data.
An apparatus according to another embodiment of the present invention is a base station apparatus for performing a random access procedure in a mobile communication system, the base station apparatus including at least one of information indicating a size of a third message to be transmitted from the terminal and a channel status Wherein the mobile station receives at least one of a reverse transmission resource information for transmitting the third message and a size of the third message that the base station desires to receive in response to the first message, (RRC) layer or a Medium Access Control (MAC) layer according to a format of the received third message, and transmits the third message to the RRC layer or the MAC (Medium Access Control) layer according to the format of the received third message. A MAC controller for processing the first message, the second message, and the third message, Wherein the format of the third message is set according to a size of the third message to be transmitted by the mobile station or a comparison result of a size of the third message received by the base station and a preset size, And a MAC de-multiplexer for transmitting the information included in the third message to the MAC controller or the 2-layer processor, wherein the third message is transmitted from the base station to the third message according to the format, the RRC (Radio Resource Control) A transparent RRC message, or a general MAC (Medium Access Control) PDU (Packet Data Unit), which is an RRC message transmitted first by a terminal having no connection.

According to the present invention, when a UE that is not allocated a scheduling request resource transmits a buffer status report message to a base station, it does not use a 2-layer header or reduces a size of a header, so that an uplink transmission resource can be more efficiently used.

Also, according to the present invention, a UE performing a random access procedure can efficiently transmit a MAC PDU or a transparent RRC message through a message 3.

The present invention provides a method and an apparatus for reporting a buffer status to a base station through a random access procedure, the base station being in a connected state but not being allocated a scheduling request resource.

Prior to describing the embodiments of the present invention, the random access procedure will be briefly described with reference to FIG.

2 is a diagram for explaining a random access procedure between a terminal and a base station in an LTE system.

The random access procedure is a process in which the UE 205 in the idle mode transits to the connection state in which the RRC connection is established, and the UE 205 establishes the reverse synchronization through the random access procedure and transmits the RRC control message . Here, the RRC control message is a message processed in the RRC layer, and may be an RRC connection request message in the embodiment of the present invention. The idle terminal 205 selects one code from a known code set at a predetermined time, such as 215, and transmits the selected code to a predetermined base station 210 through a predetermined reverse transmission resource. This is expressed as transmitting a preamble, which is transmitted via message 1. The Node B 210 can identify which UE is requesting the uplink resource allocation to the Node B 210 by transmitting the preamble in this manner, It is possible to establish synchronization. When the Node B 210 receives the message 1 including the preamble transmitted by the UE 205, the Node B 210 transmits the RRC control message including the uplink transmission resource information to which the UE 205 transmits the RRC control message And transmits the message 2 containing the UL grant information and the TA (Timing Adjustment) information to the terminal 205.

In a communication system based on OFDM such as LTE, the reverse signal transmitted by the terminal 205 must arrive at the base station 210 within a predetermined time period. The base station 210 calculates the reverse transmission timing adjustment degree of the terminal 205 based on the reception timing of the preamble transmitted by the terminal 205 (the degree to which the terminal can adjust the transmission timing in the reverse direction) (Timing Adjustment) refers to an uplink transmission time adjustment value of the UE.

The UE 205 transmits the message 3 including the RRC control message to the Node B 210 in step 225 using the transmission resource allocated through the UL grant included in the message 2 in step 220. [ In step 225, the RRC control message transmitted through the message 3 may be an RRC connection request message. Upon receiving the RRC control message, the BS 210 stores information related to the MS, such as a predetermined operation for transitioning the MS 205 into a state in which the RRC connection is established, and establishes a connection between the upper node and the MS Lt; / RTI >

In step 225, a message 3 transmitted from the AT 205 to the BS 210 is generated and processed in a control layer called RRC (Radio Resource Control), and classified into an RRC message. For convenience of explanation, the messages transmitted and received in each step of the random access procedure (steps 215 through 225) will be referred to as message 1, message 2, and message 3, respectively.

The base station 210 sets the size of the message 3 to a small size because it does not know the channel state of the terminal 205 transiting from the idle mode to the connected state. In the current standard conference, the size of message 3, such as reference numeral 230, is referred to as 9 bytes. A Transparent mode is applied to the RRC connection request message 230, which is an RRC control message transmitted through the message 3, in order to provide as much information as possible to a message of a limited size. Transparent mode is a mode in which only a payload is transmitted without a header, and can be used when a receiver can deduce information to be provided by a header through a reception context.

As described above, information indicating the destination and size of data is stored in the MAC header 130. The destination of the data indicates a certain logical channel or a hierarchical device, and the receiving device refers to the destination information of the data and transmits the data to the appropriate hierarchical device. If only the RRC connection request message is transmitted through the message 3, the destination information does not need to be explicitly signaled. If only one MAC SDU is stored in the message 3, the size information of the data also needs to be explicitly signaled none.

For the above reason, the standardization conference has decided to apply the transparent mode to the MAC PDUs transmitted and received through the message 3. In other words, in the message 3, only the RRC control message is transmitted without the MAC header like the reference numeral 230.

3 is a diagram illustrating a process of performing buffer status reporting through a random access procedure according to an embodiment of the present invention.

In order to transmit the buffer status report message of the connected state terminal through the random access procedure in FIG. 3, the terminal 305 selects an arbitrary code in step 315 and transmits a preamble through the message 1. In step 320, In step 325 using the UL grant allocated through the message 2 received from the mobile station UE. At this time, in the message 3, a buffer status report (BSR) message is stored instead of an RRC control message. Since the UE 305 does not attach the MAC header to the MAC PDU transmitted through the message 3, the BS 310 can not know whether the MAC PDU received through the message 3 is an RRC control message or a buffer status report message. In other words, since the RRC control message as well as the buffer status report message are transmitted through the message 3 transmitted in step 325 of the random access procedure, the receiving apparatus should provide appropriate information to distinguish it.

Hereinafter, a method and apparatus for transmitting / receiving a buffer status report message according to the first and second embodiments of the present invention through a random access procedure will be described. In other words, a method and apparatus for transmitting / receiving messages between a terminal and a base station when performing a random access procedure through the first and second embodiments of the present invention will be described.

≪ Embodiment 1 >

In the first embodiment of the present invention, in transmitting a MAC PDU through a message 3, a MAC PDU is inserted into the MAC PDU so that a device receiving the MAC PDU transmits an RRC control message or a buffer Allows status reporting messages to be delivered to the appropriate device. The MAC header may be a conventional MAC header or a MAC header having a shortened format.

4 is a diagram illustrating an operation of transmitting a status report message by a UE according to the first embodiment of the present invention.

In FIG. 4, attached message 2 and message 3 are respectively defined as follows.

Message 2: In a random access procedure, a control message in which the UE stores transmission resource allocation information and TA information for transmitting an uplink message

Message 3: In a random access procedure, a reverse message transmitted by a UE using an uplink resource allocated through a message 2.

In step 405, if there is a need to transition to a connection state, for example, or when reverse data is generated in a state where a connection request is not allocated, the UE starts a random access procedure.

In step 410, the UE selects one of 64 codes through a predetermined procedure, transmits the preamble coded with the selected code, and monitors the control channel to receive the message 2 from the base station.

In step 415, the UE receives an UL transmission resource by receiving a message 2 from a base station, and recognizes an uplink transmission resource to which the message 3 is to be transmitted.

In step 420, the MS examines the type of data to be transmitted in the message 3, proceeds to step 430 if the message to be transmitted to the message 3 is an RRC message, and proceeds to step 425 if the message is a buffer status report, which is a MAC control message. In the embodiment of the present invention, a buffer status report message is exemplified as a MAC control message, but other messages processed in the MAC layer may be used.

In step 425, the UE attaches a MAC header to the buffer status report message. The MAC header includes information indicating a MAC control message, which is a message that the received data is processed in the MAC layer.

In the first embodiment of the present invention, since the RRC message or the MAC control message can be transmitted through the message 3, a MAC header is required to know whether the RRC message or the MAC control message is received through the third message .

In step 430, the UE attaches a MAC header to the RRC message. The MAC header includes information indicating that the received data is a message processed in the RRC layer. The MS proceeds to step 435 and transmits the MAC PDU with the MAC header to the BS in step 425 or step 430 and performs a predetermined subsequent operation.

The MAC header used in the message 3 may have the same format as a normal MAC header, but a separate format having a smaller size than a normal MAC header can be used for the following reason.

FIG. 5 shows three MAC PDU formats used in message 3 of the first embodiment of the present invention. In the first embodiment of the present invention, a terminal and a base station use one of the following three formats.

Reference numeral 500 shows that Message 3 can use a MAC header in the same format as a conventional MAC header. In this case, the MAC PDU 500 includes an LCH (Logical Channel) ID 505, a LF (Length Field) 510, and a MAC SDU 515. The LCH ID 505 is an identifier of a logical channel to which the MAC SDU 515 contained in the MAC PDU 500 belongs. If the MAC SDU 515 is an RRC message, the logical channel identifier of the RRC device is used as the LCH ID 505. If the MAC SDU 515 is a buffer status report message (BSR), the LCH ID 505 is a predetermined logical channel identifier designated for MAC control information. The LF 510 is information indicating the size of the MAC SDU 515.

Reference numeral 501 shows that the MAC header optimized for message 3 can also be used. Since only one MAC SDU is always transmitted through Message 3, LF is virtually unnecessary information. In the MAC PDU of reference numeral 501, only the LCH ID 520 is included in the MAC header to reduce the overhead, and LF is omitted. In this case, only the LCH ID 520 and the MAC SDU 525 are stored in the MAC PDU 501 transmitted through the message 3.

The LCH ID 520 of reference numeral 501 should have a size that can identify the maximum number of logical channels that can be set in one terminal, and five bits are currently being discussed. However, since only two types of data, i.e., an RRC message or a MAC control message, are transmitted through the message 3, it is possible to distinguish sufficiently by 1 bit. That is, as shown in reference numeral 502, it is also possible to include only a short LCH ID (short LCH ID) field 525 which is information for identifying the logical channel of the MAC SDU 530 with the 1-bit information in the MAC header. For example, a short LCH ID field 525 may indicate that an RRC message has been received, and 1 indicates that a MAC control message has been received. If there is a possibility that not only the two types of messages but also other types of messages are transmitted through the message 3, the short LCH ID 525 may be extended according to the type of data that can be transmitted.

6 is a flowchart illustrating an operation of receiving a buffer status message from a mobile station according to a first embodiment of the present invention.

In step 600, the BS receives a preamble from the MS to which the buffer status report message is to be transmitted, and transmits the message 2 to the MS in step 605. In step 605, At this time, the message 2 contains TA information about the UE and reverse transmission resource information for the UE to transmit the buffer status report message in the reverse direction. In step 610, the BS receives the message 3 from the MS through the reverse resource allocated through the message 2.

In step 615, the BS analyzes the multiplexing information included in the message 3 and checks whether the RRC control message is stored in the message 3 or a buffer status report message, which is a MAC control message, is received. As described above, the conventional multiplexing information format may be used as the multiplexing information of the message 3, the optimized multiplexing information format may be used, and the terminal and the base station apply the multiplexing information format common to the message 3. [

If it is determined in step 615 that the RRC message is included in the message 3, the BS proceeds to step 625 and controls to process the RRC message in the RRC block, and a buffer status report message is included in the message 3 The control proceeds to step 620 to control the MAC control unit to process the buffer status report message.

≪ Embodiment 2 >

In the second embodiment of the present invention, instead of transmitting only the RRC message through the message 3, a method of receiving and storing the buffer status report message in the RRC message is proposed.

In the case where the UE with the RRC connection, which is a connection that does not have the scheduling request transmission resource, transmits the buffer status report message through the message 3, the RRC message contains the buffer status report message so that only the RRC message is always stored in the message 3 do. When the second embodiment of the present invention is used, the overhead due to the MAC header can be avoided by applying the transparent mode to the message 3.

In the second exemplary embodiment of the present invention, in transmitting a buffer status report message, a UE having an RRC connection connection first confirms availability of a scheduling request resource, and transmits a buffer status report message to a MAC control message And stores the RRC message in the RRC message. That is, if a scheduling resource is available, a buffer status report message is received and transmitted in a MAC control message, and if the scheduling resource is not available, a buffer status report message is received and transmitted in an RRC message.

FIG. 7 illustrates a format of a buffer status report message stored in a MAC control message and a structure of a buffer status report message stored in an RRC message according to a second embodiment of the present invention.

The MAC control SDU 720 includes a MAC control message header 710 indicating the type of a control message stored in the MAC control message and a buffer status report message 715 configured in a predetermined format. In the buffer status report message 715, information related to the buffer status of the UE and other scheduling information, for example, available transmission power information of the UE, and the like are stored.

Multiplexing information for the MAC control message 720 is stored in the header 705 of the MAC PDU 723 that stores the MAC control message. Reference numeral 723 in FIG. 7 is a MAC PDU format for transmitting a general buffer status report rather than a MAC PDU according to the second embodiment of the present invention. When a buffer status report message is received and transmitted in the RRC message 725, the MAC control SDU includes a predetermined IE (Information Element) of the RRC message 725, which is a MAC container 740, Lt; / RTI > The IE is meaningful information constituting the RRC message, and one RRC message is composed of a plurality of IEs.

When the UE with the RRC connection set to which the scheduling request resource is not allocated reports a buffer status report message through the message 3, a predetermined RRC message is stored in the message 3, and the MAC bearer of the RRC message container 740 stores a MAC control SDU in the IE, and a buffer state report message is stored in the MAC control message. The MAC transceiver 740 is an IE defined for the purpose of transmitting information to be processed by the MAC layer to the other MAC layer through the RRC message 725.

Generally, the IE stored in the RRC message 725 is generated in a radio resource control (RRC) block, which is the RRC layer of the transmitting side, and is interpreted in the RRC layer of the receiving side. However, the information included in the MAC transceiver 740 is not generated by the radio resource control block but is generated by the MAC control unit, which is the MAC layer of the transmission side, and is interpreted by the MAC control unit, which is the MAC layer of the reception side. In the second embodiment of the present invention The radio resource control block only provides a path for transmitting and receiving the MAC carrier 740, which is MAC information. Conventionally, there is an upper layer transporter, and an upper layer message is stored in a specific IE of the RRC message 725 and transmitted. However, since the upper layer message is originally transmitted and received via the RRC layer, it is natural that the upper layer message is received and transmitted to an upper layer carrier of the RRC message.

On the other hand, there is no need to define that it is a MAC carrier because there is a direct path called MAC control message 720 for transmission and reception of control information between MAC layers. However, if it is necessary to transmit the MAC control message through a channel defined only to transmit / receive only the RRC message 725 as in message 3, a MAC transceiver 740 is defined, and the MAC transceiver 740 The MAC control message can be received and transmitted / received through the RRC message. By transmitting and receiving the MAC control message through the MAC transporter 740, it is possible to avoid adding a separate MAC header to the message 3. In FIG. 7, the RRC message type 730 is information indicating the type of the RRC message 725, and the other information 735 indicates other IEs stored in the RRC message 725. In the RRC message 725, information indicating an IE for each IE is explicitly or implicitly included, so that the RRC of the receiving apparatus transmits the MAC Transmitter IE in the process of processing the IEs of the received RRC message Can be identified.

FIG. 8 is a flowchart illustrating a method of transmitting a status report message to a base station according to a second embodiment of the present invention. A buffer status report is generated in the terminal 805 at an arbitrary point in time at step 815. The buffer status report occurs at step 815 when, for example, data is suddenly generated in the buffer of the terminal. In step 820, the UE 805 checks whether a scheduling request resource is allocated to the UE 805. If the scheduling request transmission resource is allocated, the UE 805 starts a normal buffer status reporting procedure.

That is, in step 825, the UE 805 transmits a scheduling request message to the Node B 810 through the allocated scheduling request transmission resource.

On the other hand, if it is determined in step 820 that the UE 805 has not allocated the scheduling request resource to the UE 805, the UE 805 transmits a status report message through a random access procedure in step 850.

If the BS 805 receives the scheduling request message and the UE 805 allocates a transmission resource for transmitting a status report message through the UL grant message in step 830, the UE 805 allocates the UL grant message in step 835 And transmits a MAC control message (MAC control SDU) containing a buffer status report message using the transmitted transmission resource. The MAC control message is configured according to the format of a conventional MAC PDU as shown in reference numeral 723, and is transmitted and received directly between the MAC controller as a transmitting MAC layer and the MAC controller as a receiving MAC layer. That is, when receiving the MAC PDU, the MAC controller 1160 that handles the MAC layer of the BS 810 directly processes the MAC control SDU contained in the MAC PDU.

Thereafter, in step 840, another buffer status report is generated in the terminal at an arbitrary point in time. In step 845, the UE 805 checks whether a scheduling request transmission resource is allocated to the UE 805. [ If the scheduling request transmission resource is released for any reason and the UE does not have a scheduling request transmission resource available in step 845, the UE 805 starts the random access procedure in steps 850 through 860. On the other hand, if it is determined in step 845 that the scheduling request resource is allocated to the UE 805, the step 805 proceeds to step 825.

However, if it is determined in step 845 that the UE 805 has not allocated a scheduling request resource, the UE 805 transmits a buffer status report message through a random access procedure. Accordingly, the preamble code is selected according to a predetermined procedure in step 850, The base station 810 receives the reverse transmission resource through the message 2. In step 860, the terminal 805 transmits the message 3 through the reverse transmission resource allocated through the message 2. In step 860, the MS 805 receives the RRC message according to the second exemplary embodiment of the present invention.

The terminal 805 receives a MAC carrier IE in which a buffer status report message is stored in an RRC message according to the second embodiment of the present invention. Upon receiving the message 3 transmitted from the UE 805 in step 860, the MAC demultiplexing unit 1150 of the BS 810 transmits the RRC message stored in the message 3 to the radio resource control block (1140). If the MAC bearer is included in the IE of the RRC message, the radio resource control block 1140 extracts the MAC control SDU from the RRC message and receives the MAC control message from the MAC controller 1160). The MAC controller 1160 processes the MAC control message received from the radio resource control block 1140. At this time, the MAC header is not added to the message 3.

9 is a flowchart illustrating an operation of a UE for transmitting a buffer status report message according to a second embodiment of the present invention. If a buffer status report is generated in step 905 and a buffer status report message is generated, the terminal proceeds to step 910.

In step 910, the MS determines whether a scheduling request resource is available. If the MS is available, the MS proceeds to step 915. Otherwise, the MS proceeds to step 935.

In step 915, the UE starts a normal buffer status report procedure. That is, in step 915, a scheduling request message is transmitted through a scheduling request resource. If an uplink resource is allocated in step 920, a buffer status report message is generated in step 925.

The buffer status report message includes MAC control information having a predetermined structure, including the amount and priority of data stored for each buffer of the UE, and the available transmission output information of the UE. In step 930, the UE receives the buffer status report message in the MAC control information and transmits the buffer status report message to the BS.

On the other hand, if it is determined in step 910 that the UE does not have a scheduling request resource, the UE proceeds to step 935 and starts a random access procedure. That is, the preamble code is selected by applying a predetermined rule in step 935, the preamble coded by the code is transmitted to the base station, and the uplink transmission resource for message 3 transmission is allocated from the base station in step 940. In step 945, Generates a status report message. In step 950, the MAC controller 1130 of the UE transmits a MAC control message containing the buffer status report message or the buffer status report message to the radio resource control block 1110, and the radio resource control block 1110 transmits a message 3 and stores the MAC control message in which the buffer status report or the buffer status report is received in the MAC carrier IE of the RRC message. Thereafter, the UE transmits the RRC message received by the MAC Carrier IE to the BS.

10 is a flowchart illustrating an operation of a base station receiving a buffer status report message from a mobile station through a random access procedure according to a second embodiment of the present invention.

In step 1000, the base station receives the preamble from the terminal through the message 1 and transmits the reverse transmission resource information through the message 2 to the terminal corresponding to the preamble received through the message 1 in step 1005. In step 1010, the base station receives the message 3 transmitted by the UE on the uplink transmission resource information, and the MAC de-multiplexer 1150 of the base station receives the RRC control message to be processed by the RRC layer, And transmits it to the radio resource control block 1140 through the processing unit 1145. In step 1015, the radio resource control block 1140 of the base station checks whether the message 3 includes MAC control information such as a buffer status report message.

If it is determined in step 1015 that the MAC control message is included in the message 3, the base station radio resource control block 1140 transmits the MAC control message to the MAC controller 1160 in step 1025, 1160 interpret the MAC control message and perform appropriate operations.

On the other hand, if it is determined in step 1015 that the MAC control message is not included in the message 3, the radio resource control block 1140 proceeds to step 1020 and analyzes the RRC control information stored in the RRC control message, do.

11 is a block diagram of a terminal and a base station transmitting and receiving a buffer status report message according to an embodiment of the present invention. The transmitting apparatus 1105 is comprised of a radio resource control block 1110, a 2-layer processing unit 1115, a MAC multiplexing unit 1120, a MAC control unit 1130, and a physical layer processing unit 1125 .

The radio resource control block 1110 is a device for processing a control message related to a radio access network. The radio resource control block 1110 transmits a buffer status report message, which is a MAC control message delivered from the MAC controller 1130, to a MAC Container of the RRC message as shown in FIG. 7, as in the second embodiment of the present invention It is stored in IE and transferred to lower layer. As an example, in the first embodiment of the present invention, the MAC SDU included in the third message is generated, and in the second embodiment of the present invention, an RRC message including the third message is generated.

The second layer processor 1115 plays a role of framing the RRC message generated by the radio resource control block 1110 to a size suitable for transmission over a wireless channel. The MAC multiplexer 1120 multiplexes the MAC SDUs transmitted from the second layer processor 1115 and the MAC control message transmitted from the MAC controller 1130 and attaches an appropriate MAC header to the MAC PDU to form a MAC PDU, The MAC multiplexer 1120 according to the first embodiment of the present invention receives the RRC message received from the second layer processor 1115 and the MAC SDU received from the MAC controller 1130 And multiplexes the MAC SDU including the BSR message. For example, the MAC multiplexer 1120 multiplexes the RRC message generated by the RRC 1110 and transmits the RRC message.

According to the first embodiment of the present invention, the MAC SDU included in the message 3 is generated in the radio resource control block 1110, the MAC header is generated in the MAC multiplexing unit 1120, and in the second embodiment of the present invention, Is generated in the radio resource control block 1110.

In the first embodiment of the present invention, the MAC multiplexer 1120 attaches an appropriate MAC header to a MAC SDU transmitted through a message 3 when performing a random access procedure. That is, if the RRC message is transmitted through the message 3, that is, if the MAC SDU is received from the 2 nd layer processing unit 1115 connected to the RRC 1110, it is indicated that the message included in the MAC SDU is an RRC message And the MAC demultiplexing unit 1150 of the receiving apparatus 1135 of the base station transmits the MAC SDU to the second layer processing unit 1145 connected to the radio resource control block 1140. On the other hand, if a MAC control message is transmitted through the message 3, the MAC multiplexer 1120 attaches an appropriate MAC header indicating that the message included in the MAC control message is a BSR message, And causes the multiplexer 1150 to transmit the MAC control message to the MAC controller 1160.

As shown in FIG. 5, the MAC PDU transmitted through the message 3 includes a modified MAC header, that is, a MAC header having only a logical channel identifier such as reference numeral 501, or a shortened logical channel identifier such as reference numeral 502 The MAC multiplexer 1120 checks whether the MAC PDU is transmitted in the message 3 and transmits the modified MAC header when the MAC PDU is transmitted in the message 3. In this case, .

In the third embodiment of the present invention, the MAC multiplexer 1120 multiplexes the MAC SDUs transmitted from the upper layer or the MAC control message generated by the MAC controller 1130, and attaches an appropriate MAC subheader to generate a MAC PDU do. In particular, if the initial RRC message is not stored in the MAC PDU but is transmitted through the message 3, the MAC multiplexer 1120 allocates the first bit of the MAC PDU, i.e., the first bit of the first MAC subheader, Message 3, it is used as an appropriate format indicator to indicate whether the initial RRC message is received in the MAC PDU, and after the first bit of the MAC PDU, the first bit of the first MAC sub- And stores the MAC PDU. On the other hand, if the initial RRC message is received in the MAC PDU and is transmitted through the message 3, the MAC multiplexer 1120 adds the first bit of the MAC PDU to the MAC PDU in order to indicate whether the initial RRC message is received Format indicator, and stores the first RRC message after the first bit.

In the fourth embodiment of the present invention, the MAC multiplexer 1120 multiplexes the upper layer data into the MAC PDU using the MAC PDU format specified by the MAC controller 1130. That is, when the MAC control unit 1130 instructs to use the format 1, the MAC multiplexing unit 1120 constructs an MAC PDU using a general format composed of MAC subheaders and MAC SDU / MAC control information, When the control unit 1130 instructs to use format 2, the MAC PDU is configured using a special format including a 1-bit indicator. In the fourth embodiment of the present invention, the MAC multiplexer 1120 adds the header of the message 3 according to the message 3 header setting scheme indicated by the MAC controller 1130.

The MAC controller 1130 controls the MAC multiplexer 1120 and processes a MAC control message. When the random access procedure starts, the MAC controller 1130 determines a code to be used for the preamble, and controls the physical layer processor 1125 to transmit the preamble coded with the code. The MAC control unit 1130 generates a MAC control message, for example, a buffer status report message, and transmits the generated MAC control message to the MAC multiplexing unit 1120. According to the embodiment of the present invention, the MAC controller 1130 transmits a format indicator indicating the format of the message 3 to the MAC multiplexer 1120 so that the MAC multiplexer 1120 configures the message 3 with the format indicator I can do it. In the first embodiment of the present invention, when a buffer status report message is generated, the MAC control unit 1130 stores the MAC SDU in the MAC SDU, and the MAC multiplexing unit 1120 receives the MAC SDU from the MAC control unit 1130 , And attaches a MAC header indicating that the MAC layer should be processed.

The MAC controller 1130 according to the second embodiment of the present invention checks whether the scheduling request resource is available and controls the scheduling request resource to send a scheduling request to the physical layer processor 1125 if the scheduling request resource is available. When the uplink transmission resource is allocated from the base station, the MAC controller 1130 delivers the MAC control message containing the buffer status report message to the MAC multiplexer 1120. If the scheduling request resource is not available, , Controls the physical layer processing unit 1125 to transmit the coded preamble with the selected code, and delivers the MAC control message containing the buffer status report message to the radio resource control block 1110. Here, the reverse transmission resource can be known through the reverse transmission resource information included in the message 2 received by the physical layer processing unit 1125 from the base station.

The MAC control unit 1130 according to the third embodiment of the present invention instructs the MAC multiplexing unit 1120 to use the format indicator. That is, the MAC controller 1130 instructs the MAC multiplexer 1120 to use the format indicator if the message 3 is a random access procedure, and otherwise instructs the MAC multiplexer 1120 not to use the format indicator. In addition, the MAC controller 1130 acquires the reverse transmission resource information through the message 2 received through the physical layer processor 1125, generates the MAC control message containing the buffer status report information, and transmits the MAC control message to the MAC multiplexer 1120, .

On the other hand, the MAC controller 1130 according to the fourth embodiment of the present invention compares the size of the message 3 recognized through the message 2 with a predetermined reference value X 'to determine the format or header setting method of the message 3, Format or header setting method to the MAC multiplexing unit 1120.

The physical layer processor 1125 converts the MAC PDU into a physical layer signal through a predetermined physical layer procedure, transmits the preamble, coded with a predetermined code, or transmits a scheduling request message. In order to perform the random access procedure, the MAC controller 1130 according to the fourth embodiment of the present invention transmits a preamble including at least one of the size of the third message to be transmitted by the terminal and the information indicating the channel status 1 message to the base station. In response to message 1, the MAC controller 1130 transmits at least one of the reverse transmission resource information for transmitting the message 3 and the size of the message 3 indicated by the base station to the physical layer processor 1125 Through the received message 2, compares the size of the message 3 indicated by the base station with a preset size, and indicates a format indicator indicating the format of the message 3 according to the comparison result. The MAC multiplexing unit 1120 multiplexes the transport RRC message transmitted from the upper layer or the MAC control message including the buffer status report information transmitted from the MAC control unit, And transmits the third message to the physical layer processor 1125 according to a format indicator.

The receiving apparatus 1135 includes a radio resource control block 1140, a two-layer processing section 1145, a MAC de-multiplexing section 1150, a MAC control section 1160, and a physical layer processing section 1155.

The radio resource control block 1140 is a device for processing a control message related to a radio access network. According to the second embodiment of the present invention, when the MAC carrier IE is received in the RRC message received from the 2 nd layer processing unit 1145, the radio resource control block 1140 transmits the MAC carrier IE to the MAC controller 1160 .

The 2-layer processing unit 1145 performs a role of reversing the RRC message received from the MAC demultiplexing unit 1150 and restoring the MAC SDU into the original packet. The MAC demultiplexing unit 1150 demultiplexes the MAC SDU and the MAC control message from the MAC PDU delivered by the physical layer processing unit 1155. The MAC SDU as the RRC message is transmitted to the second layer processing unit 1145 for proper processing, Message to the MAC controller 1160. The physical layer processing unit 1155 transmits and receives messages to and from the terminal.

In the first embodiment of the present invention, the MAC demultiplexer 1150 analyzes the MAC header of the MAC PDU received through the message 3 when performing the random access procedure, and determines whether the MAC PDU contains the MAC SDU It is determined whether the acknowledged buffer status report message is a received MAC control message and is transmitted to an appropriate device. That is, if the message stored in the MAC PDU is an RRC message, the MAC demultiplexer 1150 transmits the RRC message to the radio resource control block 1140 through the second layer processor 1145, And transmits it to the control unit 1160.

That is, if a MAC header having a logical channel identifier such as reference numeral 501 or a shortened logical channel identifier such as reference numeral 502 is used in the MAC PDU received through the message 3 , The MAC demultiplexing unit 1150 checks whether the MAC PDU is received in the message 3 in processing an arbitrary MAC PDU. If the MAC PDU is transmitted in the message 3, the MAC de-multiplexer 1150 applies the modified MAC header format, .

In the third embodiment of the present invention, the MAC demultiplexing unit 1150 analyzes the first bit of the received message 3 when performing the random access procedure, determines whether only the first RRC message is stored in the message 3, And performs multiplexing. That is, if only the first RRC message is stored in the message 3, the remaining bits except for the first bit of the first MAC subheader of the message 3 are transmitted to the RRC 1140. If the first bit indicates that only the initial RRC message is not stored in the message 3, the MAC demultiplexer 1150 interprets the MAC subheaders including the first bit, and stores the MAC SDU or MAC control information accordingly And demultiplexes it to the appropriate higher layer device. The MAC demultiplexer 1150 examines the format indicator of the message received from the physical layer processor 1155 and determines whether the message 3 includes the transparent RRC message or the buffer status report information And transmits the buffer status report information to the MAC controller 960 if the buffer status report information is included in the message 3. If the message 3 includes the transparent RRC message, And transmits the RRC message to the second layer processing unit 1145.
The MAC controller 1160 is a device that processes a MAC control message. The MAC controller 1160 may interpret the buffer status report message stored in the MAC control message, for example, to make an appropriate scheduling decision. In the first embodiment of the present invention, the MAC control message is transmitted by the MAC demultiplexing unit 1150, but in the second embodiment of the present invention, the MAC control message may be received from the radio resource control block 1140 receiving the RRC message. The MAC controller 1160 receives a preamble for identifying the MS from the MS in order to perform the random access procedure through a message 1, and transmits the preamble including the uplink resource information to the MS Transmits the message 2, and processes the buffer status report information included in the message 3 received from the terminal.

Hereinafter, the third and fourth embodiments of the present invention for performing the random access procedure will be described with reference to FIGS. 12 to 17 attached hereto.

≪ 3 Examples &

The third embodiment of the present invention proposes a method of displaying whether message 3 contains only a transparent RRC message or a general MAC PDU using the first bit or the first two bits of message 3.

Transparent RRC messages can be transmitted through Message 3 or general MAC PDUs can be transmitted. The general MAC PDU may be in a 'connected state, but the UE does not have a scheduling request resource', and the MAC PDU may include a buffer status report. Since data of totally different format having different characteristics from each other is transmitted through the message 3 as described above, it is necessary to include separate control information in the header so that the receiver can distinguish it.

In the first embodiment of the present invention described above, the shortened LCH ID is defined as the separate control information. However, in the third embodiment of the present invention, a 1-bit or 2-bit format indicator is defined as control information separate from the LCH ID described in the first embodiment.

In the present invention, the format indicator is information indicating whether an initial RRC message is received in the MAC PDU when the MAC PDU is transmitted through the message 3.

The Format Indicator is the most significant bit (MSB) or the first two bits (2MSB) of the message 3, and when the Transparent RRC message is transmitted through the message 3, Transparent RRC message to be transmitted is received. When transmitting a general MAC PDU containing a buffer status report or the like via the message 3, the first bit (MSB) or the first two bits (2MSB) of the first MAC subheader among the MAC subheaders constituting one MAC PDU, And the remaining MAC PDUs except for the first bit or the first two bits of the first MAC subheader are stored after the format indicator. The bit in which the format indicator is stored is used as a format indicator when a certain condition is satisfied, otherwise it is used for a conventional purpose. The specific condition is a case where a general MAC PDU is transmitted through a message 3. Therefore, when configuring the MAC subheader, the MAC multiplexing unit 1120 of the transmitting apparatus 1105 checks whether the MAC PDU is transmitted through the message 3, and if the MAC PDU is transmitted through the message 3, Th bit, or the first two bits, as the format indicator.

The MAC controller 1160 of the receiving apparatus 1135 also checks the first bit or the first two bits of the data received via the message 3 and the first bit or the first two bits indicate that the transparent RRC message has been received And recognizes the remaining part of the message 3 as an RRC message, and transfers the message to the radio resource control block 1140. On the other hand, if the first bit or the first two bits of the message 3 indicate that a general MAC PDU is received, the MAC controller 1160 of the receiving apparatus 1135 transmits the entire first message including the first bit or the first two bits MAC PDU, and performs a normal MAC PDU process from the first MAC subheader including the first bit or the first two bits. In order to perform the random access procedure, the MAC controller 1160 according to the third embodiment of the present invention receives a first message including a preamble for identifying the MS from the MS through a physical layer processor 1155 Transmits a second message including the uplink transmission resource information to the terminal corresponding to the preamble through the physical layer processor 1155 and processes the buffer status report information included in the third message received from the terminal do. The physical layer processor 1155 according to the third exemplary embodiment of the present invention transmits and receives the first message, the second message, and the third message to and from the terminal device 1105.
The MAC demultiplexing unit 1150 of the receiving apparatus 1135 checks the format indicator of the third message received from the physical layer processing unit 1155 to determine whether the third message includes the transparent RRC message or the buffer And if the buffer status report information is included in the third message, transfers the buffer status report information to the MAC controller, and if the third message includes the transparent RRC message , And transfers the transparent RRC message to the second layer processing unit 1145.

As described above, the first bit (MSB) or the first two bits (2MSB) are used as a format indicator. In order to allow the format indicator to be included in a normal MAC subheader, a conventional MAC header structure must be modified. Hereinafter, a structure of a MAC PDU in a system to which the present invention is applied will be described with reference to FIG.

12 is a structure diagram of a MAC PDU format defined in an LTE system to which the present invention is applied.

Referring to FIG. 12, the MAC PDU 1200 includes a plurality of MAC subheaders 1205 and 1210 and a plurality of MAC SDUs or MAC control information 1215 and 1220. The MAC subheader stores multiplexing information for MAC SDU or MAC control information. In other words, MAC SDUs stored in the MAC PDU or MAC subheaders corresponding to the number of MAC control information are stored in the MAC PDU 1200 together. The relationship between the MAC subheader and the MAC SDU or MAC control information is determined according to the received order. For example, the first MAC subheader 1205 is associated with the first MAC SDU or MAC control information 1215, and the second MAC subheader 1210 is associated with the second MAC SDU or MAC control information 1220.

In one MAC subheader, LCID 1225, E 1230, and LEN 1245 fields and R fields 1235 and 1240 not yet defined are stored. The LCID 1225 is information similar to the above-described LCH ID, indicating the logical channel identifier of the MAC SDU and the type of the MAC control information. E 1230 is a field indicating whether the MAC subheader is the last MAC subheader, and LEN 1245 is a field indicating the size of MAC SDU or MAC control information. The MAC subheader is byte aligned in order to reduce the processing load of the transceiver. For this purpose, the RB bits 1235 and 1240 (hereinafter referred to as "R bit" ) Is added.

In the third and fourth embodiments of the present invention, one or both of the R bits are used as a format indicator (FI), and the format indicator indicates the first bit or the first two bits of the MAC PDU 12, the structure of the MAC subheader is changed as shown in FIG.

13 is a diagram illustrating a MAC PDU format according to a third embodiment of the present invention.

13, in the third embodiment of the present invention, the R bits are shifted to the beginning of the MAC subheader and the first R bits 1310 of the first MAC subheader 1305 or the first R bits Bits 1310 and 1312 are used as format indicators. The first R bits 1320 or the first and second R bits 1320 and 1322 of the MAC subheaders other than the first MAC subheader, e.g., the second MAC subheader 1315, do. If the R bit is not used for future but is empty after the difference, the first R bits or the first and second R bits of the remaining MAC subheaders other than the first MAC sub header 1305 Will be used for this new use.

For example, the R bits may be defined to store information that briefly reports the buffer status of the UE, but in the third embodiment of the present invention, the first R bits or the first and second R bits of the first MAC sub- The format indicator is stored in place of the above-described information. The format indicator may be applied only to the MAC PDUs transmitted through the message 3 instead of applying the format indicator to all the MAC PDUs so that the R bit can be used more frequently for a specific purpose. That is, the first R bits or the first and second R bits of the first MAC subheader of the MAC PDU transmitted through the message 3 are used as a format indicator, but the first R Bits or the first and second R bits will be used to the originally defined purpose. For example, if the MAC PDU is not transmitted through the message 3, it may be used as an unused bit or information indicating the buffer status of the terminal may be stored.

FIG. 14 is a diagram illustrating an example of use of the format indicator according to the third embodiment of the present invention.

In the case of transmitting the transparent RRC message through message 3 in FIG. 14, the format indicator is set to "0" or set to a predetermined value other than "11" as indicated by reference numeral 1405, Runt RRC message 1410 is received and message 3 is constructed. If the general MAC PDU is transmitted through the message 3, the format indicator is set to '1' or '11' as indicated by reference numeral 1415. The format indicator indicates the first bit (MSB) of the first MAC sub- Or the first two bits (2 MSB). In the general MAC PDU, MAC control information storing a buffer status report of the UE can be stored.

That is, a general MAC PDU is an MAC PDU storing MAC control information that stores a buffer status report. In this case, it is set to "1" or "11 "

15 is a flowchart illustrating an operation of the UE according to the third embodiment of the present invention.

If it is determined in step 1505 that an MAC PDU should be generated, the terminal proceeds to step 1510 and determines whether the MAC PDU should be transmitted as the message 3. That is, it is determined whether the generation of the MAC PDU is caused by the transmission of the message 3 during the random access procedure. If the UE transmits the configured MAC PDU in step 1510, the process proceeds to step 1520. Otherwise, In step 1515, the UE configures an MAC PDU according to a conventional technique, and proceeds to step 1550 to transmit the MAC PDU to a lower layer and ends the process.

On the other hand, if it is determined in step 1510 that the MAC PDU has been generated due to the transmission of the message 3, the UE determines whether to transmit the transparent RRC message through the message 3 in step 1520. Transparent RRC message means an RRC message in which an RLC / MAC header is not added, and is used in the same sense as the first RRC message in this specification. The first RRC message is an RRC message initially transmitted by a UE that does not have an RRC control connection, and may be expressed as an RRC message transmitted through a CCCH because it is transmitted through a common control logical channel called CCCH (Common Control Channel).

Therefore, in step 1520, if the data to be transmitted through the message 3 is the same as the above-mentioned condition (i.e., the RRC message in which the RLC / MAC header is not added or the RRC message or CCCH originally transmitted by the UE, If the condition is met, the process proceeds to step 1525. Otherwise, the process proceeds to step 1535. If it is determined that the RRC message is an RRC message, In step 1525, the terminal sets the format indicator to "0" or to a predetermined value excluding "11 ". As described above, the format indicator is 1-bit or 2-bit information and has the following meanings when the format indicator is "0" and "1", or when the format indicator is a predetermined value other than "11"

0 (or a predetermined value other than 11): Only the first RRC message is stored in the MAC PDU, and the first RRC message is from the next bit of the format indicator.

1 (or 11): The MAC PDU contains data other than the first RRC message, and follows the general MAC PDU format. The format indicator is the first bit or the first two bits (2MSB) of the first MAC subheader, and the remaining MAC PDUs except the first bit or the first two bits of the first MAC subheader are stored from the next bit of the format indicator.

In step 1530, the MS receives the first RRC message and constructs a MAC PDU. In step 1550, the MS transmits the MAC PDU containing the first RRC message to the lower layer, and ends the process.

On the other hand, the UE, which branches from step 1520 to step 1535, determines information to be stored in the message 3 (or the MAC PDU) according to the size of the message 3. That is, if it is necessary to store MAC control information such as a buffer status report in the MAC PDU in step 1535, the UE generates MAC control information and stores the MAC SDU, which is upper layer data, in the MAC PDU. MAC SDU is received.

In step 1540, the UE configures MAC subheaders for MAC SDUs or MAC control information to be stored in the MAC PDU. In this case, the first bit or the first two bits of the first MAC subheader is used as a format indicator, and it is set to an appropriate value, for example, 1 or 11 according to the meaning of the defined format indicator.

In step 1545, the UE concatenates MAC subheaders and MAC SDU or MAC control information to form a MAC PDU, and proceeds to step 1550 to transmit the MAC PDU to a lower layer and then terminates the process.

<Fourth Embodiment>

Hereinafter, as a fourth embodiment of the present invention, a method of implicitly selecting a format of a message 3 by a base station and a terminal according to the size of the message 3 is presented.

As described above, in the random access procedure, the UE randomly selects one code from a set of known codes and transmits the preamble. However, the preamble may contain 1-bit information indicating the amount of data to be transmitted by the UE, and the BS may allocate more transmission resources to the UE based on the information. That is, the BS may allocate more transmission resources for the message 3 transmission and allow the size of the message 3 to be larger for the MSs reporting that there is a large amount of data to be transmitted. The 1-bit information stored in the preamble and transmitted is as follows.

0: the size of the message 3 to be transmitted exceeds a predetermined reference value X ', and the channel condition is better than a predetermined reference value Y;

1: The channel condition is worse than the predetermined reference value Y even if the size of the message 3 to be transmitted is less than or equal to the predetermined reference value X 'or the amount of data to be transmitted is equal to or larger than the predetermined reference value X'.

The reference value X 'is usually set based on the size of the initial RRC message. When receiving the preamble with the bit set to '1', the base station allocates a transmission resource capable of transmitting data of X 'or more bytes to the terminal. However, if the preamble is set to' 1 ' Quot ;, or &quot; X &quot; bytes.

However, since the UE transmitting the first RRC message can transmit only the first RRC message through the message 3, the 1 bit information to be transmitted through the preamble is always set to 1, and the UE, which confirms that the predetermined bit in the preamble is set to 1 Allocates transmission resources for transmitting data smaller than X 'bytes or X' bytes to the terminal through message 2. In other words, since a transmission resource to transmit data smaller than X 'bytes or X' bytes is always allocated to a terminal that transmits the first RRC message, conversely, a transmission resource to transmit data larger than X ' , It means that the initial RRC message is not transmitted through the message 3.

That is, if the amount of data to be transmitted by the MS exceeds the reference value X ', and the BS reports to the BS through the message 1 that the channel condition is better than the predetermined reference value, the MS will transmit a general MAC PDU through the message 3 , The format of the message 3 follows the general MAC PDU format. On the other hand, if the amount of data to be transmitted by the MS is greater than or equal to the reference value X ', and the channel status is less than the predetermined reference value Y, the first RRC message or the general MAC PDU All can be transmitted. Accordingly, in the fourth embodiment of the present invention, 'format in which the receiving apparatus stores only the first RRC message in the message 3 or whether a general MAC PDU is stored' is used as the format of the message 3. For convenience of explanation, the following two formats are defined as the format of the message 3.

Format 1: A generic MAC PDU format defined in the LTE system.

Format 2: A format in which information indicating whether only the first RRC message is stored in the message 3 or a general MAC PDU is stored is contained in the message 3. May be a format presented in the first embodiment or the third embodiment of the present invention, or another format meeting the above-described purpose.

In addition, in the fourth embodiment of the present invention, the message format of the message 3 is changed according to the predetermined condition, the message header of the message 3 is set according to the predetermined condition in addition to the changed format, .

For example, if the terminal reports to the base station through message 1 that the amount of data to be transmitted exceeds the reference value X 'and that the channel condition is better than Y, which is a predetermined reference value, It means that the MAC header setting method of message 3 follows a general MAC header setting method defined in the LTE system. On the other hand, if the amount of data to be transmitted by the UE does not exceed the reference value X 'or if the channel condition is worse than Y, which is a predetermined reference value, to the base station through the message 1, the UE sends an initial RRC message All the general MAC PDUs can be transmitted.
Therefore, according to the fourth exemplary embodiment of the present invention, a terminal, which is a transmitting apparatus, sets a header of a message 3 so as to distinguish whether only the first RRC message is stored in the message 3 or a general MAC PDU is received, It follows a setting method in which a predetermined limitation is imposed. For convenience of explanation, the following two methods are defined as the header setting method of the message 3.

Header setting method 1: Generally, the method of setting the MAC PDU header. There is no restriction in using LCH ID or R bit.

Header setting method 2: Header setting method applied only when the first RRC message or general MAC PDU is likely to be transmitted through message 3. There are restrictions on setting LCH ID or R bit. In the header setting method 2, by limiting the use of the first bit of the MAC PDU, it is discriminated whether the first RRC message is stored in the message 3 or the general MAC PDU is received. In the following description, it is assumed that the header setting method 2 restricts the use of the first 1 bit of the MAC PDU.

For example, in the third embodiment of the present invention, the first bit of the MAC PDU is used as an R bit according to the header setting scheme 1 of the two header setting schemes described above, but is used as a format indicator according to the header setting scheme 2 . As another example, if the MAC PDU header is made in the order of LCH ID, E, R, and R as shown in FIG. 12, whether to store a general MAC PDU or the first RRC message using the first bit of the 5 bits of the LCH ID You can tell. At this time, if the first bit is set to "0 " to indicate that the first RRC message has been received in message 3, if the transmitting apparatus in accordance with header setting method 2 transmits a general MAC PDU through message 3, It is necessary to comply with the constraint that the first bit of the LCH ID of the MAC subheader is 1, that is, the MAC SDU having the LCH ID of 16 to 31 as the first MAC SDU of the MAC PDU. To summarize the fourth embodiment of the present invention, if the terminal and the BS have reported that the amount of data to be transmitted exceeds a predetermined reference value and the channel condition is better than a predetermined reference value in the preamble transmitted by the UE, Use Format 1, or use Header Format 1, otherwise use Format 2 for Message 3 or Header Format 2.

According to yet another method of the fourth embodiment of the present invention, the terminal transmits the size of the message 3 to be transmitted through the message 1, and the base station that has received the message 1 transmits the size of the message 3 to the terminal If more than the reference value is specified, the terminal and the base station use the format 1 in the format of the message 3 or the header 3 of the message 3 using the header setting method 1. Otherwise, the format 2 is used in the format of the message 3, 2 to set the header of message 3.

The UE determines the format of the message 3 based on the size of the message 3 reported through the preamble, rather than the first method in which the base station determines the format of the message 3, The second method of implicitly determining the format may be more robust, and the fourth embodiment of the present invention takes both of these methods into account.

16 is a flowchart illustrating an operation of a terminal and a base station according to the fourth embodiment of the present invention.

In step 1615, the terminal 1605 starts a random access procedure when a predetermined condition is satisfied. That is, if a predetermined condition is satisfied, the terminal selects a code from a set of known codes and transmits a preamble. At this time, the preamble stores the size of the data to be transmitted through the message 3 and the 1-bit information on the channel status together with the preamble.

Upon receipt of the message 1 including the preamble transmitted by the terminal 1605 in step 1615, the base station 1610 transmits the message 1 in the reverse direction for transmitting the message 3, as in step 1620, To the UE 1605, the UL Grant information including the resource information and the size of the message 3 and the message 2 containing the TA (Timing Adjustment) information. The MS receiving the message 2 in step 1620 recognizes the transmission resource to transmit the message 3 and the size of the message 3, and determines the format of the message 3 or the header setting method of the message 3 in step 1625. As described above, the format of the message 3 or the header setting method of the message 3 is implicitly determined according to the information reported by the terminal through the message 1 or the size of the message 3. If the size of the message 3 is equal to or larger than the predetermined reference value, the terminal 1 confirms the size of the message 3 that the base station desires to receive through the message 2 if the format 1 or the header setting method 1 is agreed between the terminal and the base station , And compares the size of the confirmed message 3 with a predetermined reference value. If the size of the message 3 confirmed through the message 2 is larger than the reference value, the format 1 is used in the format of the message 3 or the header setting method 1 is used in the header setting method of the message 3, Format 2, or header format 2.

The information reported through the message 1 is the size of the message 3 that the terminal desires to transmit and the size of the message 3 transmitted by the base station through the message 2 is the size of the message 3 instructed by the base station to transmit.

On the other hand, if the size of the message 3 to be transmitted through the message 1 is greater than or equal to a predetermined reference value and the channel status reports to the base station that the channel status is better than the predetermined reference value, the terminal uses the format 1 or uses the header setting method 1 If it is agreed between the UE and the BS, the UE determines the format of the message 3 or the header setting method according to the channel status and the size of the message 3 reported through the message 1.

In step 1630, the UE configures the message 3 using the format determined in step 1625 or constructs the message 3 using the header setting method determined in step 1625, and transmits the message 3 to the BS. The base station also determines the format of the message 3 or the header setting method applied to the message 3 by applying the same rule as the terminal and processes the MAC PDU or the first RRC message stored in the message 3 using the format or the header setting method do.

17 is a flowchart illustrating an operation of the UE according to the fourth embodiment of the present invention.

In step 1705, if the terminal satisfies a predetermined condition, for example, transitions from the idle state to the connected state or starts the random access procedure when transmitting the reverse data. In step 1710, the UE transmits a preamble to the base station through a predetermined procedure such as selecting one code from a set of previously known codes to perform a random access procedure. In the preamble, the size of the message 3 to be transmitted by the mobile station and 1-bit information indicating the channel status may be included together.

In step 1710, the terminal that has transmitted the preamble waits to receive the message 2 to be transmitted in the forward direction from the base station through a predetermined procedure. Upon receiving the message 2 from the base station in step 1715, the UE confirms the reverse transmission resource information to transmit the message 3 stored in the message 2 and the size information of the message 3 that the base station desires to receive. In step 1720, the terminal selects a message 3 format or a header setting method to be applied to the message 3. That is, if the size of the message 3 desired to be received by the base station confirmed through the message 2 in step 1720 exceeds a predetermined reference value X ', the terminal proceeds to step 1725 to configure the message 3 using the format 1, Configure message 3 using scheme 1. On the other hand, if the size of the message 3 confirmed through the message 2 received in step 1715 is less than or equal to the predetermined reference value X ', the terminal proceeds to step 1730 and uses format 2, 2 to configure message 3.

Alternatively, if the UE reports that the size of the message 3 exceeds the predetermined reference value X 'using the preamble in step 1710 and that the channel condition is better than the predetermined reference value Y, the UE proceeds to step 1725, Message 3 is configured by setting header of message 3 using header setting method 1, and if not, proceeding to step 1730 to configure message 3 using format 2. In the present invention, X 'is determined to be a message size that can be received by a base station from a terminal located at a cell boundary without difficulty, and is determined through an experiment such as a field test.

In step 1725, the MS configures the message 3 using a general MAC PDU format, i.e., a general MAC PDU format that does not include the 1-bit indicator to be described in step 1730, and proceeds to step 1735 to transmit the configured message 3 in step 1725 . Otherwise, in step 1725, the header of the message 3 is set using the header setting method 1, that is, the header is set in a conventional manner without any restriction. Then, the message 3 is configured and transmitted in step 1735.

In step 1730, the UE configures the message 3 using format 2, for example, using the MAC PDU format proposed in the fourth embodiment of the present invention including a 1-bit indicator, proceeds to step 1735, Message 3 is transmitted. The 1-bit indicator is a value indicating whether only the first RRC message is stored in the message 3 (or the MAC PDU). If the 1-bit indicator indicates that only the first RRC message is stored in the message 3 or the MAC PDU, Only the 1-bit indicator and the first RRC message are stored in the message 3 or the MAC PDU, and the RRC message is stored immediately after the 1-bit indicator. On the other hand, if the 1-bit indicator indicates that only the first RRC message is not stored in the message 3 or the MAC PDU, the first bit of the message 3 or the MAC PDU is the 1-bit indicator, and a general MAC PDU is stored in the remaining part . Alternatively, as shown in the third embodiment of the present invention, the first bit of the message 3 may be the 1-bit indicator, which is the first bit of the first MAC subheader, The remaining MAC PDUs except for the first bit of the subheader can be received.

In step 1730, the UE configures the header of the message 3 using the header setting method 2, and proceeds to step 1735 to transmit the configured message 3 in step 1730.

1A is a diagram for explaining a process of a UE transmitting a scheduling request message to a Node B and reporting a buffer status in an LTE system;

1B shows an example of a buffer status report message used in an LTE system,

2 is a diagram illustrating a random access procedure between a terminal and a base station in an LTE system,

FIG. 3 illustrates a process of performing a buffer status report through a random access procedure according to an embodiment of the present invention; FIG.

4 is a diagram illustrating an operation of transmitting a status report message by a UE according to the first embodiment of the present invention;

5 is a diagram illustrating a format of a message 3 transmitted and received through a message 3 according to the first embodiment of the present invention,

6 is a flowchart illustrating an operation of a BS receiving a buffer status message from a UE according to the first embodiment of the present invention;

7 is a diagram illustrating a format of a buffer status report message stored in a MAC control message and a structure of a buffer status report message stored in an RRC message according to a second embodiment of the present invention;

FIG. 8 is a flowchart illustrating a method of transmitting a status report message to a base station according to a second embodiment of the present invention;

FIG. 9 is a flowchart illustrating an operation of a terminal for transmitting a buffer status report message according to a second embodiment of the present invention;

10 is a flowchart illustrating an operation of a BS receiving a buffer status report message from a UE through a random access procedure according to a second embodiment of the present invention.

11 is a block diagram of a terminal and a base station transmitting and receiving a buffer status report message according to an embodiment of the present invention;

FIG. 12 is a structure diagram of a MAC PDU format defined in an LTE system to which the present invention is applied,

13 is a diagram illustrating a MAC PDU format according to an embodiment 3 of the present invention.

FIG. 14 is a diagram illustrating an example of using a format indicator according to a third embodiment of the present invention; FIG.

15 is a flowchart illustrating an operation of a terminal according to a third embodiment of the present invention.

16 is a flowchart illustrating an operation of a terminal and a base station according to the fourth embodiment of the present invention,

17 is an operational flowchart of a terminal according to the fourth embodiment of the present invention.

Claims (38)

delete delete delete delete delete A method for performing random access in a mobile communication system, Transmitting a first message including a preamble selected from a predefined code set to a base station, Receiving, from the base station, a second message including uplink transmission resource information for transmitting a third message; And generating and transmitting the third message based on a type of data transmitted by the terminal, The third message includes a logical channel identifier (LCH ID) and a medium access control (MAC) service data unit (SDU), and the MAC SDU includes a radio resource control (RRC) wherein the LCH ID includes at least one of a radio resource control message and a buffer status report (BSR), and the LCH ID is an identifier of a logical channel of the MAC SDU included in the third message. &Lt; / RTI &gt; The method according to claim 6, If the size of the third message is smaller than or equal to a predetermined size, the third message further includes a format indicator indicating whether the RRC message is included or the BSR is included. A method for performing random access. 8. The method of claim 7, Wherein the format indicator is a first bit or a first two bits of a MAC (Packet Data Unit) packet data unit (PDU). 8. The method of claim 7, And if the format indicator indicates that the third message includes the RRC message, the RRC message is included after the format indicator. 8. The method of claim 7, If the format indicator indicates that the RRC message is not included in the third message, the first bit or the first two bits of the third message are the format indicator, and the portion excluding the format indicator includes a MAC Packet Data Unit And a packet data unit (PDU). The method according to claim 6, Wherein when the size of the third message is larger than a predetermined size, the third message includes only a MAC packet data unit (PDU). delete delete delete delete delete A terminal for performing random access in a mobile communication system, A physical layer processing unit for transmitting and receiving messages to and from the base station, Wherein the control unit controls the base station to transmit a first message including a preamble selected from a predefined code set to a base station and to acquire reverse transmission resource information for transmitting a third message from the base station through a second message received by the physical layer processing unit A medium access control (MAC) controller, And a MAC multiplexer for generating the third message based on a type of data transmitted by the MS and transmitting the third message to the physical layer processor, The third message includes a logical channel identifier (LCH ID) and a medium access control (MAC) service data unit (SDU), and the MAC SDU includes a radio resource control (RRC) wherein the LCH ID includes at least one of a radio resource control message and a buffer status report (BSR), and the LCH ID is an identifier of a logical channel of the MAC SDU included in the third message. A terminal for performing random access in a mobile station. 18. The method of claim 17, If the size of the third message is smaller than or equal to a predetermined size, the third message further includes a format indicator indicating whether the RRC message is included or the BSR is included. Terminal for performing random access. 19. The method of claim 18, Wherein the format indicator is a first bit or a first two bits of a MAC (Packet Data Unit) packet data unit (PDU). 19. The method of claim 18, And if the format indicator indicates that the third message includes the RRC message, the RRC message is included after the format indicator. 19. The method of claim 18, If the format indicator indicates that the RRC message is not included in the third message, the first bit or the first two bits of the third message are the format indicator, and the portion excluding the format indicator includes a MAC Packet Data Unit And a PDU (Packet Data Unit). The terminal for performing random access in a mobile communication system. 18. The method of claim 17, Wherein if the size of the third message is larger than a predetermined size, the third message includes only a MAC packet data unit (PDU). delete delete delete delete delete A method for performing random access in a mobile communication system, Receiving a first message including a preamble selected from a predefined code set from a terminal; Transmitting, by the terminal, a second message including uplink transmission resource information for transmitting a third message to the terminal; Receiving the third message generated based on a type of data transmitted by the terminal; And processing the received third message, The third message includes a logical channel identifier (LCH ID) and a medium access control (MAC) service data unit (SDU), and the MAC SDU includes a radio resource control (RRC) wherein the LCH ID includes at least one of a radio resource control message and a buffer status report (BSR), and the LCH ID is an identifier of a logical channel of the MAC SDU included in the third message. &Lt; / RTI &gt; 29. The method of claim 28, If the size of the third message is smaller than or equal to a predetermined size, the third message further includes a format indicator indicating whether the RRC message is included or the BSR is included. A method for performing random access. 30. The method of claim 29, Wherein the format indicator is a first bit or a first two bits of a MAC (Packet Data Unit) packet data unit (PDU). 29. The method of claim 28, Wherein when the size of the third message is larger than a predetermined size, the third message includes only a MAC packet data unit (PDU). delete delete delete 1. A base station for performing random access in a mobile communication system, A physical layer processing unit for transmitting and receiving messages to and from the terminal, Receiving a first message including a preamble selected from a predefined code set from a terminal, and transmitting, in response to the first message, a second message including reverse transmission resource information for transmitting the third message, A medium access control (MAC) controller for controlling transmission to the MS, receiving the third message generated based on the type of data transmitted by the MS, and processing the received third message; , And a MAC demultiplexer for verifying the format indicator of the third message and transmitting the information included in the third message to the MAC controller or the L2 (Layer 2) processor, The third message includes a logical channel identifier (LCH ID) and a service data unit (SDU), and the MAC SDU includes a radio resource control (RRC) message and a buffer status And a buffer status report (BSR), and the LCH ID is an identifier of a logical channel of the MAC SDU included in the third message. 36. The method of claim 35, If the size of the third message is smaller than or equal to a predetermined size, the third message further includes a format indicator indicating whether the RRC message is included or the BSR is included. A base station for performing random access. 37. The method of claim 36, Wherein the format indicator is a first bit or a first two bits of a MAC (Packet Data Unit) packet data unit (PDU). Base station. 36. The method of claim 35, Wherein when the size of the third message is larger than a predetermined size, the third message includes only a MAC packet data unit (PDU).

Images