KR20160081744A - Method of Transferring Data Based on Limited Contention - Google Patents

Abstract

A data transmitting method according to one embodiment of the present invention comprises the steps of: performing between a terminal and a base station, and the terminal being assigned a scheduling request identifier (SRID) through a connection with the base station; when an uplink traffic occurs, the terminal configuring a scheduling request (SR) message and transmitting the same to the base station; the base station assigning uplink resources on the basis of the SR message; and the terminal transmitting data by using the uplink resources.

Description

TECHNICAL FIELD [0001] The present invention relates to a contention-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method for scheduling requests (SRs) for a mobile station to request uplink resources from a base station in a mobile communication system.

In a mobile communication system, in order for a UE to transmit data in an uplink, uplink resources must be allocated from a base station. To this end, the terminal can request the uplink resource to the base station and transmit data through the allocated resource.

1 shows an uplink resource request procedure according to the related art. The BS allocates a scheduling request period in which a UE can perform a scheduling request in an uplink and a resource capable of transmitting a scheduling request signal. When an uplink traffic is generated (101), the UE transmits a Scheduling Request (SR) signal to the base station in an allocated scheduling request period (102). The base station receives the SR signal and allocates uplink resources for transmitting buffer state information of the UE (103). The UE transmits buffer status information to the BS using the allocated uplink resources (104). The buffer status information indicates size information of data stored in the buffer for uplink transmission. When the BS allocates the uplink resources according to the buffer status information (105), the MS transmits the uplink data to the BS using the allocated uplink resources (106).

The conventional technique as described above has a problem that an uplink resource requesting procedure becomes long and a delay from a scheduling request to a data transmission increases. The prior art may not be suitable for a mobile communication system requiring low-delay data transmission.

An object of the present invention is to provide a method for reducing an uplink data transmission delay through a fast scheduling request in a mobile communication system.

The technical objects of the present invention are not limited to the technical matters mentioned above, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the following description.

A data transmission method according to an embodiment of the present invention is performed between a mobile station and a base station and includes receiving a Scheduling Request Identifier (SRID) through a connection with the base station in the mobile station, The method comprising the steps of: forming a scheduling request (SR) message when link traffic is generated and transmitting the scheduling request message to the base station; allocating uplink resources based on the scheduling request message in the base station; And transmitting the data using the resource.

In one embodiment, the step of receiving the scheduling request identifier may include receiving an uplink resource request related parameter broadcast in the base station. The receiving of the parameter may include receiving at least one of the number of frames, the number of subframes, the number of SR channels per subframe, and the number of opportunities to transmit SR messages per SR channel.

In one embodiment, the step of configuring the scheduling request message uses a CRC (Cyclic Redundancy Check) value for the designated bit value of the scheduling request identifier, the buffer size for storing the uplink traffic, the bit value, and the buffer size And configuring a scheduling request message.

In one embodiment, the step of transmitting the scheduling request message may include transmitting the scheduling request message based on an opportunity index indicating a scheduling request channel. The step of transmitting the scheduling request message may include determining the Opportunity Index based on the following equation.

 [Mathematical Expression]

Opportunity Index = M% N_to

M is a MSB (Most Significant Bit) (Nsr - u) bits; Nsr is the length of the scheduling request identifier; U is a designated bit value of the scheduling request identifier; N_to is N * Nc * Ns (when Nf is 1) or No * Nc * Ns * Nf (Nf is greater than 1), Nf is the number of frames; Ns is the number of subframes; Nc is the number of SR channels per subframe; No is the number of the opportunity to transmit the SR message per SR channel

In one embodiment, transmitting the scheduling request message may include driving a response timer corresponding to the scheduling request message.

In one embodiment, the step of allocating the uplink resource comprises the steps of: configuring a Radio Network Temporary Identifier (SRNTI) in the base station; and allocating uplink resources through a Physical Downlink Control Channel (PDCCH) Step < / RTI > The step of configuring the SR RNTI may further comprise performing a CRC for the scheduling request message. The step of allocating the uplink resource may include allocating the uplink resource based on the size of the buffer storing the uplink traffic.

In one embodiment, configuring and transmitting the scheduling request message to the base station may include forming a scheduling request channel for transmitting the scheduling request message using a CQI message.

According to the present invention, delay in uplink data transmission in a terminal can be effectively reduced through a shortened resource request procedure when an uplink resource is needed in a terminal.

1 shows an uplink resource request procedure according to the related art.
2 is a signal flow diagram illustrating an uplink resource requesting step according to various embodiments.
3 is a flowchart illustrating an uplink resource request procedure in a UE according to various embodiments.
4 shows a buffer size table according to various embodiments.
5 illustrates the configuration of an SR RNTI according to various embodiments.
FIG. 6 is a block diagram illustrating a method of configuring an SR channel using a CQI channel according to various embodiments. Referring to FIG.
7 is a flowchart illustrating a procedure for processing uplink resources in a base station according to various embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

2 is a signal flow diagram illustrating an uplink resource requesting step according to various embodiments.

Referring to FIG. 2, in step 210, the terminal 201 can establish a connection with the base station 202 and receive an SR Identifier (SRID).

In step 220, the terminal 201 can confirm whether or not uplink traffic occurs.

In step 230, if uplink traffic occurs, the MS 201 may configure an SR message and transmit the SR message to the BS 202. In various embodiments, the SR message may be configured as follows.

SR message = u-bits UEID | b-bits buffer size index | c-bits CRC

The u-bits UEID may be mapped to a value corresponding to the u-bits of the LSB (Least Significant Bit) of the SRID received in step 210. The b-bits buffer size index may be the size of the buffer in which the terminal 201 stores the current data. The buffer size index can be mapped by finding the index corresponding to the buffer size of the terminal in the buffer size table. c-bits CRC is u-bits UEID | A cyclic redundancy check (CRC) value for the b-bits buffer size index may be assigned. The length of the SR message may be determined as (u + b + c).

According to various embodiments, the terminal 201 may determine the opportunity index corresponding to the SR channel to transmit the configured SR message. The UE 201 may receive the uplink resource request related parameter broadcasted in the base station 202 in advance. The terminal 201 can determine the opportunity index based on the received parameters. The MS 201 can transmit an SR message on the SR channel indicated by the determined opportunity index. Information on how to derive the opportunity index can be provided through FIG.

In step 240, the base station 202 may configure a Radio Network Temporary Identifier (SR RNTI) and allocate uplink resources to the PDCCH through the SR RNTI.

In step 250, the terminal 201 can transmit the status link data using the allocated resources.

3 is a flowchart illustrating an uplink resource request procedure in a UE according to various embodiments.

Referring to FIG. 3, in step 301, the UE 201 may receive an uplink resource request related parameter broadcast from the Node B 202. In various embodiments, the terminal 201 may obtain Nf, Ns, Nc, and No in the system information channel broadcasted at the base station 202. [ Nf denotes the number of frames, Ns denotes the number of subframes, Nc denotes the number of SR channels per subframe, and No denotes the number of opportunities to transmit SR messages per SR channel.

In step 302, the UE 201 establishes a connection with the BS and can receive an SRID of Nsr bits.

In step 303, the terminal 201 can confirm whether uplink traffic is generated or not.

In step 304, when the uplink traffic occurs, the terminal 201 can construct an SR message. The SR message can be configured as follows.

SR message = u-bits UEID | b-bits buffer size index | c-bits CRC;

The terminal 201 can map the LSB u-bits value of the SRID to the UE ID. Also, the terminal 201 can determine a b-bits buffer size index based on the buffer size in which the uplink traffic is stored. Then, the UE 201 transmits the u-bits UEID | b-bits buffer size The c-bits CRC value can be calculated based on the index.

In step 305, the terminal 201 may determine an opportunity coefficient. The opportunity coefficient may vary according to the SR period. The SR period is a period in which a UE can transmit an SR message, and may be determined as Ns when Nf is 1. In this case, the total opportunity coefficient N_to that can transmit the SR message during the SR period can be determined as follows.

N_to = No * Nc * Ns;

If Nf is greater than 1, the SR period can be determined as Ns * Nf. In this case, the opportunity coefficient N_to that can transmit the SR message during the SR period can be determined as follows.

N_to = No * Nc * Ns * Nf;

In step 306, the UE 201 may determine the opportunity index Tx_o to transmit the SR message as follows.

Tx_o = M% N_to

Here, N_to is an opportunity coefficient, and M is determined by the following equation when the length of the SRID is Nsr bits.

M = Most Significant Bit (MSB) (Nsr - u) bits;

Where u represents the length of u-bits UEID in the SR message configuration.

In step 307, the terminal 201 transmits an SR message and can drive T_rsp, which is a response timer for the SR message. The MS 201 can transmit the SR message in the SR channel indicated by the opportunity index determined in step 306. [

In step 308, the terminal 201 may configure a Radio Network Temporary Identifier (SR RNTI). The SR RNTI can be calculated as (SR RNTI indicator | opportunity index Tx_o | UEID).

In step 309, the UE 201 can confirm whether or not the UE receives the uplink resource allocated to the SR RNTI in the PDCCH before the response timer T_rsp expires. If the response timer T_rsp expires, it can be retried after a backoff for a specified time.

In step 310, upon receiving the uplink resource allocated to the SR RNTI, the MS 201 can terminate the response timer T_rsp and transmit data using the allocated resources.

4 shows a buffer size table according to various embodiments.

Referring to FIG. 4, when uplink traffic occurs, the terminal 201 can determine a b-bits buffer size index based on a buffer size of the corresponding traffic. The determined b-bits buffer size index can be used to construct the SR message.

The terminal 201 can find an index corresponding to the size of the traffic in the buffer size table 401 and map it to a buffer size index.

For example, if the buffer size that stores the data is 121 bytes, you can map 14 values to the buffer size index. As another example, if the buffer size for storing the data is 109776 bytes, the value 47 can be mapped to the buffer size index. If the buffer size for storing the data exceeds 3000000 bytes, the value 63 is mapped to the buffer size index .

5 illustrates the configuration of an SR RNTI according to various embodiments.

Referring to FIG. 5, the MS 201 may transmit an SR message and configure an SRN (Radio Network Temporary Identifier) 501. SR RNTI 501 may include UE ID 510, SR opportunity index 520 and SR RNTI indicator 530 in the SR message.

The UE ID 510 may be a value corresponding to the LSB u-bits of the SRID.

The SR opportunity index 520 may be a value indicating an SR channel through which an SR message can be transmitted.

The SR RNTI indicator 530 may indicate that it is allocated for SR in the 16 bits RNTI.

According to various embodiments, the base station 202 may allocate uplink resources to the PDCCH through the SR RNTI after receiving the SR message from the terminal 201. [ The base station 202 can perform the CRC check by receiving the SR message. If the CRC check is successful, the base station 202 can allocate uplink resources by the size indicated by the buffer size index. In addition, the base station 202 can determine the SR RNTI through the SR message and the opportunity index received therefrom, and transmit the uplink allocation information to the MS 201 using the PDCCH.

The MS 201 can check whether there is an uplink resource allocated to the SR RNTI in the PDCCH using the SR RNTI obtained from the BS 202. [ If there is an allocated resource, the terminal 201 can transmit uplink data using it.

FIG. 6 is a block diagram illustrating a method of configuring an SR channel using a CQI channel according to various embodiments. Referring to FIG.

Referring to FIG. 6, a resource for transmitting an SR message may use a channel structure used for transmitting a 10-bit CQI message in LTE-A. One RB (Resource Block) 605 may be composed of 12 subcarriers and 7 OFDM symbols. One RB 605 of two consecutive slots can constitute one CQI channel. The 10 bits CQI message can be transmitted by being multiplied by a cell-based cyclically shifted base sequence of length 12 after being coded and modulated with QPSK 1/2. At this time, since the base sequence can be rotated 12 times in one CQI channel, up to 12 CQI messages can be simultaneously transmitted.

SR message is u-bits UEID | b-bits buffer size index | c-bits CRC, the length of the SR message is u + b + c, which may be equal to the number of symbols except for the symbols allocated for transmission of the DM-RS 606.

7 is a flowchart illustrating a procedure for processing uplink resources in a base station according to various embodiments.

Referring to FIG. 7, in step 701, the BS 202 may transmit a scheduling request related broadcast message. In various embodiments, base station 202 may transmit parameters No, Nc, Ns, and Nf for scheduling requests through broadcast information. Nf denotes the number of frames, Ns denotes the number of subframes, Nc denotes the number of SR channels per subframe, and No denotes the number of opportunities to transmit SR messages per SR channel.

In step 702, the base station 202 may assign the SRID to the terminal 201 in the connection procedure with the terminal 201.

In step 703, the base station 202 can confirm receipt of the SR message from each SR opportunity index.

In step 704, the base station 202 may perform a CRC check if the received SR message is present.

In step 705, if the CRC check of the SR message is successful, the BS 202 can allocate uplink resources based on the buffer size index of the SR message.

In step 706, the base station 202 may determine the SR RNTI using the opportunity index on which the SR message was received and the UE ID in the SR message.

In step 707, the base station 202 may transmit the SR RNTI and the allocated uplink information. In various embodiments, base station 202 may use SR RNTI to transmit uplink allocation information to terminal 201 on the PDCCH.

In step 708, the base station 202 may receive uplink data to the terminal 201.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

201: terminal
202: base station
401: Buffer size table
410: buffer size index
420: buffer size value
501: SR RNTI
510: UEID
520: SR opportunity index
530: SR RNTI indicator
605: RB
606: DM_RS

Claims (11)

A method of transmitting data between a terminal and a base station,
Receiving, at the UE, a Scheduling Request Identifier (SRID) through a connection with the BS;
Transmitting a Scheduling Request (SR) message to the BS when an uplink traffic occurs in the MS;
Allocating an uplink resource on the basis of the scheduling request message; And
And transmitting, at the UE, data using the uplink resource. The method of claim 1, wherein the step of allocating the scheduling request identifier comprises:
And receiving an uplink resource request related parameter broadcast by the base station. 3. The method of claim 2, wherein receiving the parameter comprises:
Receiving at least one of the number of frames, the number of subframes, the number of SR channels per subframe, and the number of opportunities for transmitting an SR message per SR channel. 2. The method of claim 1, wherein configuring the scheduling request message comprises:
Configuring a scheduling request message using a CRC (Cyclic Redundancy Check) value for a designated bit value of the scheduling request identifier, a buffer size for storing the uplink traffic, the bit value, and the buffer size; Way. The method of claim 1, wherein transmitting the scheduling request message comprises:
And transmitting the scheduling request message based on an opportunity index indicating a scheduling request channel. 6. The method of claim 5, wherein transmitting the scheduling request message comprises:
And determining the Opportunity Index based on the following equation.
[Mathematical Expression]
Opportunity Index = M% N_to

M is a MSB (Most Significant Bit) (Nsr - u) bits;
Nsr is the length of the scheduling request identifier;
U is a designated bit value of the scheduling request identifier;
N_to is No * Nc * Ns (when Nf is 1)
Or No * Nc * Ns * Nf (where Nf is greater than 1);
Nf is the number of frames;
Ns is the number of subframes;
Nc is the number of SR channels per subframe;
No is the number of the opportunity to transmit an SR message per SR channel;
The method of claim 1, wherein transmitting the scheduling request message comprises:
And driving a response timer corresponding to the scheduling request message. The method of claim 1, wherein allocating the uplink resource comprises:
Configuring an SR RNTI (Radio Network Temporary Identifier) at the base station; And
And allocating uplink resources through a physical downlink control channel (PDCCH) at the base station. 9. The method of claim 8, wherein configuring the SR RNTI comprises:
And performing a CRC for the scheduling request message. 9. The method of claim 8, wherein allocating the uplink resource comprises:
And allocating uplink resources based on a size of a buffer for storing the uplink traffic. The method of claim 1, wherein the step of transmitting the scheduling request message to the base station comprises:
And forming a scheduling request channel for transmitting the scheduling request message using a CQI message.

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