KR102067865B1 - Method for transmitting scheduling request effectively in wireless communication system - Google Patents

Abstract

The present invention relates to a wireless communication system and a wireless terminal for providing wireless communication. In the process of exchanging data between a base station and a terminal in a long term evolution system (LTE system), the terminal requests a radio resource allocation to the base station (RACH ( The present invention relates to a method of increasing the waste and efficiency of radio resources by appropriately selecting a radio resource when a radio resource is allocated through its own radio terminal identifier during a random access channel process.

Description

How to efficiently transmit scheduling request in mobile communication system {METHOD FOR TRANSMITTING SCHEDULING REQUEST EFFECTIVELY IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a method for transmitting and receiving data between a base station and a terminal in a long term evolution system (LTE). In particular, when a terminal requests allocation of radio resources to a base station, the terminal performs its RACH process. When radio resources are allocated through an identifier, the present invention relates to a method of increasing radio resource waste and efficiency by selecting radio resources appropriately.

1 is a diagram illustrating a network structure of an E-UMTS (Evolved Universal Mobile Telecommunications System) which is a mobile communication system to which the present invention and the present invention are applied. The E-UMTS system is an evolution from the existing UMTS system and is currently undergoing basic standardization in 3GPP. The E-UMTS system may be referred to as a Long Term Evolution (LTE) system.

E-UMTS networks can be largely divided into E-UTRAN and CN. E-UTRAN is a user equipment (hereinafter abbreviated as UE) and a base station (hereinafter abbreviated as eNode B), a serving gateway (abbreviated as S-GW) located at the end of the network and connected to an external network. It consists of a Mobility Management Entity (hereinafter referred to as MME) that manages the mobility of. One or more cells may exist in one eNode B.

2 and 3 illustrate a structure of a radio interface protocol between a terminal and a base station based on the 3GPP radio access network standard. The wireless interface protocol consists of a physical layer, a data link layer, and a network layer horizontally, and vertically, a user plane and control for transmitting data information. It is divided into a control plane for signal transmission. The protocol layers are based on the lower three layers of the Open System Interconnection (OSI) reference model, which are well known in communication systems. L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) It can be divided into.

Hereinafter, each layer of the wireless protocol control plane of FIG. 2 and the wireless protocol user plane of FIG. 3 will be described.

The physical layer, which is the first layer, provides an information transfer service to an upper layer by using a physical channel. The physical layer is connected to the upper medium access control layer through a transport channel, and data between the medium access control layer and the physical layer moves through the transport channel. Then, data is moved between different physical layers, that is, between physical layers of a transmitting side and a receiving side through physical channels.

Medium access control (hereinafter referred to as MAC) of the second layer provides a service to a radio link control layer, which is a higher layer, through a logical channel. The radio link control layer (hereinafter referred to as RLC) layer of the second layer supports reliable data transmission. The PDCP layer of the second layer is a header compression that reduces the IP packet header size, which contains relatively large and unnecessary control information, for efficient transmission in a wireless bandwidth where bandwidth is low when transmitting an IP packet such as IPv4 or IPv6. Compression) function. The PDCP layer is also used to perform encryption of C-plane data, for example RRC messages. PDCP also performs encryption of U-plane data.

The radio resource control layer (hereinafter abbreviated as RRC) layer located at the bottom of the third layer is defined only in the control plane, and the configuration and resetting of radio bearers (abbreviated as RB) are performed. It is responsible for the control of logical channels, transport channels and physical channels in relation to configuration and release. In this case, RB means a service provided by the second layer for data transmission between the terminal and the E-UTRAN.

The following is a detailed description of the RACH (Random Access Channel). The RACH channel is used for transmitting a short length of data upward. In particular, the RACH channel is used when there is a signaling message or user data to be transmitted upward by a terminal that has not been allocated a dedicated radio resource. Or, it may be used when the base station instructs the terminal to perform the RACH process.

The following is a description of the random access procedure provided by the LTE system. The random access process provided by the LTE system is classified into a contention based random access procedure and a non-contention based random access procedure. The division between the contention-based random access process and the contention-free random access process is determined according to whether the UE directly selects a random access preamble used in the random access process or the base station.

In the contention-free random access procedure, the terminal uses a random access preamble allocated by the base station directly to the base station. Therefore, when the base station allocates the specific random access preamble only to the terminal, the random access preamble uses only the terminal, and other terminals do not use the random access preamble. Therefore, since a 1: 1 relationship is established between the random access preamble and the terminal using the random access preamble, it can be said that there is no collision. In this case, as soon as the base station receives the random access preamble, the base station can know the terminal that has transmitted the random access preamble.

In contrast, in the contention-based random access procedure, since a random access preamble is randomly selected and transmitted from the random access preamble available to the terminal, there is a possibility that a plurality of terminals always use the same random access preamble. Therefore, even if a base station receives a certain random access preamble, it is not possible to know which UE transmits the random access preamble.

In general, the UE may perform a random access procedure in the following cases. 1) When the terminal does not have an RRC connection with the base station (initial access) 2) When the terminal is initially connected to the target cell during the handover process 3) When requested by the command of the base station 4 5) Radio link failure or handover when uplink data occurs in a situation in which uplink time synchronization is not correct or a designated radio resource used for requesting a radio resource is not allocated. In case of recovery in case of handover failure.

Based on the above description, Figure 4 shows the operation of the terminal and the base station in the contention-based random access process.

First, in contention-based random access, the UE may randomly select one random access preamble from a set of random access preambles indicated by system information or a handover command, and transmit the random access preamble. The PRACH resource is selected and transmitted to the base station. (Step 1) The preamble at this time is called RACH MSG 1.

After the terminal transmits the random access preamble as described above, the terminal attempts to receive a response to its random access preamble within the random access response reception window indicated by the system information or the handover command (step 2). In more detail, the random access response information is transmitted in the form of a MAC PDU, and the MAC PDU may be delivered in a physical downlink shared channel (PDSCH). In addition, the physical downlink control channel (PDCCH) is also delivered in order for the terminal to properly receive the information delivered to the PDSCH. That is, the PDCCH may include information of a terminal that should receive the PDSCH, frequency and time information of radio resources of the PDSCH, a transmission format of the PDSCH, and the like. In this case, if the UE succeeds in receiving the PDCCH coming to it, the UE properly receives a random access response transmitted to the PDSCH according to the information of the PDCCH. The random access response includes a random access preamble identifier (ID), an UL grant (uplink radio resource), a temporary C-RNTI (temporary cell identifier), and a time alignment command. The reason why the random access preamble identifier is needed is that since one random access response may include random access response information for one or more terminals, which terminal the UL Grant, Temporary C-RNTI and Time Alignment Command information are valid for It is to inform. The random access preamble identifier corresponds to the random access preamble selected by the user in step 1.

In this case, when the terminal receives a valid random access response to the terminal, the terminal processes the information included in the random access response. That is, the terminal applies a Time Alignment Command and stores a Temporary C-RNTI. In addition, by using the UL Grant, data stored in the buffer of the terminal or newly generated data is transmitted to the base station (step 3). At this time, among the data (hereinafter referred to as message 3) included in the UL Grant, the identifier of the terminal must be included. This is because, in the contention-based random access process, it is not possible to determine which terminals perform the random access process in the base station, because the terminal needs to be identified for future collision resolution. Here, there are two methods for including the identifier of the terminal. In the first method, if the UE already has a valid cell identifier assigned to the cell before the random access procedure, the UE transmits its cell identifier through the UL Grant. On the other hand, if a valid cell identifier has not been allocated before the random access procedure, the terminal transmits its own unique identifier (eg, S-TMSI or Random Id). In general, the unique identifier is longer than the cell identifier. In step 3, if the UE transmits data through the UL Grant, the UE starts a contention resolution timer.

After the terminal transmits data including its identifier through the UL Grant included in the random access response, the terminal waits for instructions from the base station to resolve the collision. That is, it attempts to receive the PDCCH to receive a specific message (step 4). Here, there are two methods for receiving the PDCCH. As mentioned above, when its identifier transmitted through the UL Grant is a cell identifier, it attempts to receive a PDCCH using its cell identifier, and when the identifier is a unique identifier, it is included in the random access response. Attempt to receive the PDCCH using the Temporary C-RNTI. Then, in the former case, if the PDCCH (hereinafter referred to as message 4) is received through its cell identifier before the conflict resolution timer expires, the terminal determines that the random access procedure has been normally performed, and random access End the process. In the latter case, if the PDCCH is received through the temporary cell identifier before the conflict resolution timer expires, the data (hereinafter referred to as message 4) transmitted by the PDSCH indicated by the PDCCH is checked. If the unique identifier is included in the content of the data, the terminal determines that the random access procedure is normally performed, and ends the random access procedure. Here, the message or MAC PDU received in this fourth step is often called RACH MSG 4.

The following describes a method for the UE to receive data in the downward direction in the LTE system. 5 is an exemplary diagram illustrating a radio resource allocation according to the prior art.

In the downward direction, physical channels are divided into two types, which are a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH). PDCCH is not directly related to transmission of user data, and control information necessary for operating a physical channel is transmitted. In the simplest case, the PDCCH may be used to control other physical channels. In particular, the PDCCH is used to transmit information necessary for the UE to receive the PDSCH. At any particular point in time, information on which UE is transmitted using which specific frequency band, for which UE, what size of data is transmitted, and the like are transmitted through the PDCCH. Accordingly, each UE receives a PDCCH at a specific TTI, checks whether data to be received is transmitted through the PDCCH, and if it is informed that data to be received is transmitted, a frequency indicated by the PDCCH. PDSCH is further received using information such as the above. Data of the PDSCH is transmitted to which UE (one or a plurality of UEs), and information on how the UEs should receive and decode the PDSCH data includes physical channel physical downlink control channel (PDCCH). It can be said that it is included in the transmission.

For example, in a specific subframe, radio resource information A (e.g., frequency position) and transmission type information (e.g., transport block size, modulation and coding information, etc.) of B are RNTI (Radio Network) Assume that CRC is masked as a Temporary Identity and transmitted through PDCCH. One or more terminals in the cell monitor the PDCCH using their own RNTI information. In the above assumption, a CRC error does not occur when the terminal decodes the PDCCH with an RNTI of C. Will not. Accordingly, the terminal receives the data by decoding the PDSCH using the transmission type information of B and radio resource information of A. FIG. On the other hand, in the above assumption, a CRC error occurs when the PDCCH is decoded in a terminal that does not have an RNTI of C. Therefore, the terminal does not receive the PDSCH.

In the above process, in order to indicate to which UEs a radio resource is allocated through each PDCCH, a Radio Network Temporary Identifier (RNTI) is transmitted, which includes a dedicated RNTI and a common RNTI. The dedicated RNTI is allocated to one terminal and used for transmitting and receiving data corresponding to the terminal. The dedicated RNTI is allocated only to a terminal whose information is registered in the base station. On the contrary, the common RNTI is used for transmitting or receiving data commonly applied to a plurality of terminals, such as system information, when terminals that do not have a dedicated RNTI assigned because information is not registered in the base station.

As mentioned above, two axes constituting the E-UTRAN are a base station and a terminal. A radio resource in one cell consists of an uplink radio resource and a downlink radio resource. The base station is responsible for allocating and controlling uplink and downlink radio resources of the cell. That is, the base station determines which radio resource is used by which terminal at any moment. For example, the base station may determine that after 3.2 seconds, the frequency 100Mhz to 101Mhz is allocated to user 1 for downlink data transmission for 0.2 second. After the base station makes this determination, the base station notifies the corresponding terminal of the fact so that the terminal receives downlink data. Similarly, the base station determines when and which terminal to transmit data upward using what radio resources, and the base station informs the terminal of this decision, so that the terminal transmits data using the radio resources during the time. Do it.

Unlike the prior art, the base station dynamically manages radio resources to enable efficient use of radio resources. The prior art allows one terminal to continue using one radio resource while the call is connected. This is particularly unreasonable considering that many services in recent years are based on IP packets. This is because most packet services do not steadily generate packets during the connection time of the call, but there are many sections in which nothing is transmitted during the call. In this case, it is inefficient to continuously allocate radio resources to one UE. In order to solve this problem, the E-UTRAN system uses a method of allocating radio resources to the terminal in the same manner as above only when there is service data when the terminal is needed.

More specifically, in the LTE system, in order to use radio resources efficiently, the base station needs to know how much data to transmit for each user. In the case of downlink data, this downlink data is transferred from the access gateway to the base station. Therefore, the base station knows how much data should be transmitted to the downlink to each user. On the contrary, in the case of uplink data, the base station cannot know how much uplink radio resources each terminal needs unless the terminal directly informs the base station of information about data to be transmitted on the uplink. Therefore, in order for the base station to properly allocate uplink radio resources to the terminal, each terminal should provide the base station with information necessary for the base station to schedule radio resources.

To this end, the terminal informs the base station when there is data to be transmitted, and the base station transmits a radio resource allocation message to the terminal based on this information.

In the above process, that is, when the terminal informs the base station when there is data to be transmitted, the terminal informs the base station of the amount of data accumulated in its buffer. This is called Buffer Status Report (BSR).

However, the buffer state information is generated in the form of MAC Control Element (MAC CE) and included in a MAC Protocol Data Unit (PDU) to be transmitted from the terminal to the base station. That is, uplink radio resources are required to transmit buffer status information. This means that uplink radio resource allocation request information for transmitting buffer status information should be transmitted. When the buffer state information is generated, if there is an allocated uplink radio resource, the terminal immediately transmits the buffer state information by using the uplink radio resource. However, when the buffer status information is generated, if there is no allocated uplink radio resource, the terminal performs a resource allocation request (SR) process.

There are two main SR processes: a method of using a dedicated scheduling request (D-SR) channel set to a physical uplink control channel (PUCCH) resource, and a method of using a random access channel (RAC) process. That is, if the SR process is triggered, the UE sends a radio resource allocation request using the D-SR channel if the D-SR channel is allocated. If the D-SR channel is not allocated, the UE performs the RACH process. To start. In the case of using the D-SR channel, a resource request allocation signal is transmitted in an upward direction through the D-SR channel.

The SR process continues until the terminal is allocated UL-SCH resources.

In the above process, the buffer status information transmitted by the terminal does not send information about the amount of buffer for each logical channel, but informs the amount of buffer for each logical channel group (LCG). That is, for each group designated by the base station, the amount of buffer is calculated. Up to four LCGs are defined for one UE. In the above process, there are two types of buffer status information. One is the Long Buffer Status Report (Long BSR) and the other is the Short Buffer Status Report (Short BSR). The Long BSR contains information about the amount of buffers for all four LCGs, and the Short BSR contains information about the amount of buffers for only one LCG.

The conventional radio resource allocation request method described above has the following problems. In general, a plurality of terminals exist in one cell, and the base station allocates radio resources from a terminal having a higher priority and a channel having a higher priority. Therefore, in some cases, even though the base station receives a radio resource request message or buffer status information from a specific terminal, the base station may not allocate a radio resource to the terminal. In this case, if the UE continuously sends a radio resource allocation request, this causes a waste of uplink radio resources and only causes interference of radio resources. In addition, in the above case, while the terminal performs the RACH process, the base station may directly allocate radio resources to the terminal. For example, in the state in which the second step of the RACH process is completed, the terminal may be allocated radio resources using its own dedicated identifier from the base station. However, the second message of the RACH process also has information for allocating radio resources to the terminal that performed the RACH process. In this case, if the UE continuously performs the RACH process, radio resources allocated using the dedicated identifier are wasted. In addition, the D-SR channel is effective only when the terminal is synchronized with the uplink (Synchronized). That is, if the terminal is not synchronized in the upward direction, even if the terminal uses the D-SR channel, the base station can not properly receive the radio resource allocation request of the terminal. In this case, if the UE continuously transmits the radio resource allocation request transmission without considering such a situation, only the interference of radio resources occurs.

Accordingly, an object of the present invention is to provide a method for efficiently requesting radio resources to a base station while minimizing interference of radio resources.

In order to solve the above problems of the present invention, a method for processing a scheduling request (SR) in a wireless communication system according to the present invention, comprising: determining whether the scheduling request is triggered; If an uplink control channel is configured for transmitting the scheduling request, transmitting the scheduling request on the uplink control channel; or if an uplink control channel is configured for transmitting the scheduling request. If not, initiating a random access channel procedure; Monitoring a downlink control channel; Determining whether an identifier of a terminal is received through the downlink control channel; And if it is determined that the identifier of the terminal has been received, stopping the scheduling request triggering.

Preferably, the uplink control channel is characterized in that the Physical Uplink Control Channel (PUCCH).

Preferably, the downlink control channel is characterized in that the Physical Downlink Control Channel (PDCCH).

Preferably, the step of transmitting the scheduling request on the uplink control channel or initiating the random access channel process is performed when it is determined that the scheduling request is triggered.

Preferably, the identifier of the terminal is characterized in that the Cell-Radio Network Temporary Identifier (C-RNTI).

Preferably, if it is determined that an identifier of the terminal has not been received, the scheduling request triggering is continuously performed.

In addition, to solve the problems of the present invention as described above, as a method of performing a random access channel (RACH) procedure in a wireless communication system according to the present invention, transmitting a random access channel preamble (RACH preamble) Doing; Monitoring a downlink control channel after the RACH preamble is transmitted; Determining whether an uplink allocation resource has been received together with an identifier of a terminal through the downlink control channel, wherein the uplink allocation resource is used to transmit the next scheduled data; And if it is determined that the uplink allocated resource is received together with the identifier of the terminal, stopping the random access channel process.

Preferably, the downlink control channel is characterized in that the Physical Downlink Control Channel (PDCCH).

Preferably, the uplink allocated resource is characterized in that the UL-GRANT.

Preferably, the identifier of the terminal is characterized in that the Cell-Radio Network Temporary Identifier (C-RNTI).

Preferably, if it is determined that the uplink allocated resource is not received together with the identifier of the terminal, the RACH process is continuously performed.

Preferably, the step of receiving a response message (response message) in response to the transmitted RACH preamble, characterized in that the response message further comprises a different always allocated resources.

Preferably, if it is determined that the uplink allocated resource is received together with the identifier of the terminal, the other uplink allocated resource may be discarded.

In the present invention, when the terminal performs the buffer status information or the scheduling request (SR) process to the base station, by presenting a method for effectively using the radio resources, the terminal has the effect of allowing the terminal to be allocated radio resources from the base station more quickly and accurately.

1 is a network structure of E-UMTS, which is a mobile communication system to which the present invention and the present invention are applied.
2 is a control plane structure of a radio interface protocol between a UE and a UTRAN (UMTS Terrestrial Radio Access Network) based on the 3GPP radio access network standard.
3 is a user plane structure of a radio interface protocol between a terminal and a UTRAN (UMTS Terrestrial Radio Access Network) based on the 3GPP radio access network standard.
4 is an exemplary diagram illustrating a contention based random access procedure.
5 is an exemplary diagram illustrating a radio resource allocation according to the prior art.
6 is an exemplary diagram illustrating an operation method used to send buffer status information to a base station by a terminal according to the present invention.
7 is an exemplary diagram illustrating a method of transmitting buffer status information to a base station by a terminal in a random access process according to the present invention.

The present invention is applied to 3GPP communication technology, in particular UMTS (Universal Mobile Telecommunications System) system, communication device and communication method. However, the present invention is not limited thereto and may be applied to all wired and wireless communication to which the technical spirit of the present invention can be applied.

A basic concept of the present invention is a method of processing a scheduling request (SR) in a wireless communication system, comprising: determining whether the scheduling request is triggered; If an uplink control channel is configured for transmitting the scheduling request, transmitting the scheduling request on the uplink control channel; or if an uplink control channel is configured for transmitting the scheduling request. If not, initiating a random access channel procedure; Monitoring a downlink control channel; Determining whether an identifier of a terminal is received through the downlink control channel; And if it is determined that an identifier of the terminal is received, stopping the scheduling request triggering. The method proposes a method of processing a scheduling request (SR) in a wireless communication system, and performs the method. A wireless mobile communication terminal capable of doing so is proposed.

According to the present invention, there is also provided a method of performing a random access channel (RACH) procedure in a wireless communication system, comprising: transmitting a random access channel preamble (RACH preamble); Monitoring a downlink control channel after the RACH preamble is transmitted; Determining whether an uplink allocation resource has been received together with an identifier of a terminal through the downlink control channel, wherein the uplink allocation resource is used to transmit the next scheduled data; And if it is determined that the uplink allocation resource is received together with the identifier of the terminal, stopping the random access channel process (random access channel (RACH) procedure) in a wireless communication system, characterized in that the step of stopping. We propose a method to perform the method and a wireless mobile communication terminal capable of performing such a method.

Hereinafter, the configuration and operation of embodiments according to the present invention will be described with reference to the accompanying drawings.

As described above, the present invention is to propose a method for efficiently requesting radio resources to a base station while minimizing interference of radio resources. To this end, the present invention, when the terminal requests a radio resource to the base station using the D-SR channel, from the base station until the radio resource request to the base station using the D-SR channel for a predetermined number of times or a predetermined time If the uplink radio resource is not allocated, the radio resource request process using the D-SR channel is no longer performed. Preferably, in this process, the terminal transitions to the radio resource request process using the RACH process. In the above process, when the radio resource is allocated to the base station while the D-SR channel is not used for a predetermined number of times, the terminal immediately stops the radio resource request process. In this case, the setting of the D-SR channel is canceled and no longer used.

In addition, in the present invention, in order for the terminal to efficiently send buffer status information to the base station, when the new data arrives on a certain logical channel, the terminal considers the priority of the logical channel and other logical channels, It is proposed to decide whether or not to send status information.

Specifically, the first operation method Approach 1 according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority A of the logical channel. The terminal checks the logical channel group to which the logical channels belong with respect to all other logical channels having data in the buffer. For each logical channel belonging to the identified logical channel group, the priority B of each of the logical channels is checked, whether or not there is data in the buffer of the logical channels. The terminal compares the priorities A and B, and when the priority A is higher than any of the priorities B, triggers buffer status information and transmits the buffer status information to the base station. . Preferably, in this process, only the priority of the logical channels having the highest priority in the logical channel groups may be considered and compared.

Specifically, the second operation method Approach 2 according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority A of the logical channel. The terminal checks the priority B of each of the logical channels with respect to all other logical channels having data in the buffer. The terminal compares the priorities A and B, and when the priority A is higher than any of the priorities B, triggers buffer status information and transmits the buffer status information to the base station. .

The result difference by the first operation method and the second operation method is illustrated in FIG. 6.

That is, according to the first operation method, if new data arrives in the first logical channel, the priority of the first logical channel is not higher than that of any other logical channel (fourth logical channel), and thus the buffer state. It does not trigger information. However, if data newly arrives on the first logical channel according to the second operation method, the priority of the first logical channel is the priority of the other driving logical channel (third logical channel) in which there is data in the buffer. Higher than it will trigger the buffer status information.

 Specifically, the third operation method (Approach 3) according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority (A) of the logical channel and also identifies what logical channel group the logical channel belongs to. do. The terminal identifies logical channels having data in a buffer among logical channels belonging to the logical channel group. If the buffer information has already been delivered to the base station for the logical channel group or logical channels, the terminal does not trigger new buffer status information.

Specifically, the fourth operation method (Approach 4) according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority (A) of the logical channel and also identifies what logical channel group the logical channel belongs to. do. The terminal identifies logical channels having data in a buffer among logical channels belonging to the logical channel group. If the buffer information for the logical channel group or logical channels has already been transmitted to the base station, the terminal has exceeded the reference value if the amount of buffer newly accumulated in the logical channel group after the buffer status information has been transmitted to the base station. Check and trigger new buffer status information only when the reference value is exceeded.

Specifically, the fifth operation method (Approach 5) according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority (A) of the logical channel and also identifies what logical channel group the logical channel belongs to. do. The terminal then checks the priority B of the logical channels having data in the buffer among the logical channels belonging to the logical channel group. When the priority A is higher than the priority B, the terminal triggers new buffer state information.

Specifically, the sixth operation method (Approach 6) according to the present invention is as follows. For any logical channel that previously had no data in the buffer, when new data arrives in the logical channel, the terminal checks the priority (A) of the logical channel and also identifies what logical channel group the logical channel belongs to. do. The UE checks the priority (B) of each logical channel among all logical channels belonging to the logical channel group regardless of whether there is data in the buffer. When the priority A is higher than the priority B, the terminal triggers new buffer state information.

Specifically, the seventh operating method (Approach 7) according to the present invention is as follows. When a new data arrives at the logical channel for a certain logical channel that has no data in the buffer before, the terminal may select the priority of the logical channel having the highest priority among the logical channels belonging to the logical channel group to which the logical channel belongs. Check A). For each of the configured logical channel groups, the priority B of the logical channel having the highest priority among the logical channels belonging to each logical channel group is checked. The terminal compares the priorities A and B, and when the priority A is higher than any priority B, triggers buffer status information and transmits the buffer status information to the base station. Preferably, in this process, logical channels without data can be excluded from the comparison.

In the above process, when the buffer status information for another logical channel group is the same and only the buffer status information for a specific logical channel group is changed, the terminal may use a short BSR.

In addition, in the present invention, in order for the terminal to efficiently send buffer status information to the base station, when the SR process is started, the terminal starts the RACH process when there is no D-SR channel allocated thereto. In the second step of the RACH process, the UE is allocated a UL-SCH resource to be used in the third step. However, in the case of a competitive RACH process, until the contention resolution is successfully completed in the fourth step, the UE cannot know whether the data transmitted by the UE is successfully delivered to the base station in the third step. Therefore, even if the UE which started the SR process does not stop the SR process even if it is allocated radio resources in the upward direction through the third step of the RACH process. 7 is an exemplary view illustrating a method of transmitting buffer status information to a base station by a terminal in a random access process according to the present invention. That is, as shown in FIG. 7, the terminal is considered to have successfully completed the SR process only when receiving the GRANT using its C-RNTI in the fourth step of the RACH. That is, if the C-RNTI of the asset is received through the physical downlink control channel (PDCCH), the SR process is considered to have been successfully completed and the SR process is stopped. If the UE has not received the GRANT using its C-RNTI in the fourth step of the RACH, the SR process is continuously stopped without being stopped.

According to the amount of available radio resources present in one cell or the scheduling algorithm used by the eNB (e-NodeB), the base station knows that there is data to be transmitted by a specific terminal, There is a case where a radio resource is not allocated to a mobile station. Therefore, in this case, the terminal hastily sending another buffer status information or performing the SR process causes a waste of radio resources. Or, even if the SR process or the transmission of the buffer status information should be properly stopped. Therefore, in the present invention, when the UE is allocated a dedicated radio resource from the base station while performing the RACH process due to the buffer state information transmission or the SR process, that is, when the radio resource in the upward direction is allocated through the C-RNTI The UE proposes to immediately stop the RACH process. In addition, in the present invention, if the dedicated radio resource is allocated from the base station when the SR process is started, that is, the terminal continues to perform the SR process until the radio resource in the uplink direction is allocated through the C-RNTI. do. Preferably, when the UE is allocated radio resources to be used in the third stage of the RACH in the second stage of the RACH, and at the same time, if the radio resources are allocated through the PDCCH through its C-RNTI, the terminal is allocated through the C-RNTI. It is suggested to use the received radio resource. At this time, if necessary, the BSR is transmitted using the radio resource. Preferably, when the UE is allocated radio resources to be used in the third stage of the RACH in the second stage of the RACH, and at the same time, the radio resources are allocated through the PDCCH through its C-RNTI, the second stage of the RACH process Proposes to use the allocated radio resources. At this time, if necessary, the BSR is transmitted using the radio resource.

Hereinafter, a terminal according to the present invention will be described.

The terminal according to the present invention includes all types of terminals that can use a service that can exchange data with each other over the air. That is, the terminal according to the present invention is a mobile communication terminal capable of using a wireless communication service (for example, user equipment (UE), mobile phone, cellular phone, DMB phone, DVB-H phone, PDA phone, and PTT phone, etc.) A broader meaning, including laptops, laptops, laptops, digital TVs, GPS navigation, handheld game consoles, MP3s, and other consumer electronics.

The terminal according to the present invention may include a basic hardware configuration (transmitter / receiver, processor or control unit, storage unit, etc.) required to perform functions and operations for using radio resources more efficiently as illustrated in the present invention.

The method according to the invention described thus far can be implemented in software, hardware, or a combination thereof. For example, the method according to the present invention may be stored in a storage medium (eg, internal memory of a mobile terminal or base station, flash memory, hard disk, etc.), and may be stored in a processor (eg, mobile terminal or base station). Code or instructions in a software program that can be executed by an internal microprocessor).

In the above, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary and will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (5)

Identifying new data on a first logical channel belonging to a logical channel group; And
When a second logical channel belonging to the logical channel group stores data in a buffer,
Comparing a first priority of the first logical channel with a second priority of the second logical channel; And
If the first priority of the first logical channel is higher than the second priority of the second logical channel,
Triggering Buffer Status Report (BSR); And
Transmitting the triggered BSR to a base station
How to include. 2. The method of claim 1 wherein the first logical channel does not store data in the buffer prior to arrival of the new data. The method of claim 1,
Comparing the first priority with priorities of all other logical channels including data in the buffer, including the second logical channel; And
Triggering the BSR if the first logical channel has a higher priority than all other logical channels storing data in the buffer.
How to include more. The method of claim 1,
If there is no logical channel storing data in the buffer other than the first logical channel,
Triggering the BSR; And
Transmitting the triggered BSR to the base station
How to include more. A terminal for providing a BSR in a wireless communication system, the terminal comprising:
A transceiver;
buffer; And
A processor connected to the transceiver and the buffer
Including, the processor,
Receive new data for a first logical channel not storing data in the buffer, the first logical channel belonging to a logical channel group;
Compare the priority of the first logical channel with the priorities of all other logical channels belonging to the logical channel group and storing data in the buffer,
If the first logical channel has a higher priority than all the other logical channels storing data in the buffer,
Trigger the BSR,
Send the triggered BSR to a base station
Terminal configured to.

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