KR20160056771A - Method and apparatus for requesting uplink resource allocation - Google Patents

Abstract

The UE allocates a resource for transmitting at least one scheduling request indicating a resource amount of data to be transmitted from the BS and transmits the at least one scheduling request indicating the amount of resources required for transmission of the data to the BS.

Description

[0001] METHOD AND APPARATUS FOR REQUESTING UPLINK RESOURCE ALLOCATION [0002]

The present invention relates to a method and apparatus for requesting uplink resource allocation, and more particularly, to a method and apparatus for requesting uplink resource allocation for a service requiring a short transmission delay.

Long Term Evolution (LTE) systems are designed to meet the data traffic transmission delay requirement of 10ms or less, but depending on various conditions such as system load condition, packet size, and channel condition, actual data transmission experiences a longer transmission delay do. Also, the delay time from the uplink to the data transmission is variable depending on the connection with the base station of the UE and the uplink resource allocation state.

In a conventional LTE (Long Term Evolution) / LTE-A (LTE Advanced) system, when a UE needs allocation of resources for uplink data transmission to a base station, the UE determines whether uplink synchronization is maintained, Or requests an uplink resource allocation to a base station using a random access procedure or an already allocated Physical Uplink Control Channel or a Physical Uplink Shared Channel.

If there is no uplink shared channel allocated to the UE and only the uplink control channel is allocated, the UE transmits a Scheduling Request (SR) through the allocated uplink control channel to inform the BS of the necessity of resource allocation . However, the SR indicates that the UE has data to be transmitted, but does not include other information on the data to be transmitted by the UE. Therefore, the base station receiving the SR only allocates resources of a fixed size to the terminal that transmitted the SR.

The MS transmits a buffer status report (BSR) to the BS using uplink resources allocated from the BS.

After receiving the BSR from the terminal, the base station can check the buffer status information of the terminal and allocate resources to the terminal using the buffer status information.

In the uplink resource allocation procedure through the SR and BSR transmission of the existing LTE / LTE-A system, a delay time of data transmission occurs due to the SR allocation period of the UE and additional transmission of the BSR thereafter. A delay time of 20.5 ms occurs from SR transmission to uplink data transmission even if a minimum value of the SR allocation period is 1 ms and a processing time is 3 ms and there is no transmission error. This is not only larger than 10ms, which is a requirement for LTE data traffic transmission delay, but also requires increased transmission capacity and radio range delay reduction technology compared to 4G mobile communication so that people / objects / information can be connected at any time and anywhere organically. It is not suitable for 4G or later mobile communication.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an uplink resource allocation requesting method and apparatus which can reduce a delay time required for performing a procedure of requesting resource allocation in an uplink and allocating resources from a base station.

According to an embodiment of the present invention, a method is provided in which a terminal requests an uplink resource allocation to a base station. A method for requesting an uplink resource allocation comprises the steps of: allocating, from a base station, a resource for transmitting at least one scheduling request indicating a resource amount of data to be transmitted; and transmitting the at least one scheduling request To the base station.

According to the embodiment of the present invention, it is possible to reduce a delay time required to perform a procedure for requesting resource allocation in an uplink and allocating resources from a base station, and it is possible to support a low-delay service between a base station and a terminal.

FIG. 1 is a diagram illustrating an uplink resource request and allocation procedure when only a PUCCH is allocated in a state where a terminal is registered in a base station in an LTE / LTE-A system.
2 is a diagram illustrating an uplink resource allocation request and an uplink allocation procedure in a mobile communication system according to an embodiment of the present invention.
3 is a diagram illustrating a resource allocation method for SR transmission in the uplink resource allocation procedure shown in FIG.
FIGS. 4, 5, and 6 are diagrams illustrating a method of allocating resources for a plurality of SR allocation and transmission according to an embodiment of the present invention. Referring to FIG.
7 is a flowchart illustrating an uplink resource allocation request method of a UE according to an embodiment of the present invention.
8 is a diagram illustrating an uplink resource allocation apparatus according to an embodiment of the present invention.
9 is a diagram illustrating an apparatus for requesting uplink resource allocation according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification and claims, when a section is referred to as "including " an element, it is understood that it does not exclude other elements, but may include other elements, unless specifically stated otherwise.

Throughout the specification, a terminal is referred to as a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR- A subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE) , HR-MS, SS, PSS, AT, UE, and the like.

Also, a base station (BS) is an advanced base station (ABS), a high reliability base station (HR-BS), a node B, an evolved node B, eNodeB), an access point (AP), a radio access station (RAS), a base transceiver station (BTS), a mobile multihop relay (MMR) (RS), a relay node (RN) serving as a base station, an advanced relay station (ARS) serving as a base station, a high reliability relay station (HR) A femto BS, a home Node B, a HNB, a pico BS, a metro BS, a micro BS, ), Etc., and may be all or part of an ABS, a Node B, an eNodeB, an AP, a RAS, a BTS, an MMR-BS, an RS, an RN, an ARS, It may include a negative feature.

Now, a method and apparatus for requesting an uplink resource allocation according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating an uplink resource request and allocation procedure when only a PUCCH is allocated in a state where a terminal is registered in a base station in an LTE / LTE-A system.

In the existing LTE / LTE-A system, the resource request and resource allocation procedure for data transmission in the uplink varies depending on the connection status of the subscriber station 100 with the base station 200 and the uplink resource allocation state. When there is data to be transmitted to the mobile station in a state of no active connection between the base station 200 and the mobile station 100 (RRC_IDLE), the mobile station 100 performs a random access (RA) procedure to access the base station 200 After that, the base station 200 requests resource allocation from the base station 200, allocates resources from the base station 200, and transmits uplink data. Meanwhile, if there is an active connection between the base station 200 and the UE 100 and there is a PUSCH allocated to the UE in a state (RRC_CONNECTED) in which uplink synchronization is maintained, data can be transmitted using the allocated resources.

The uplink resource allocation procedure shown in FIG. 1 is performed in a state (RRC_CONNECTED) where there is an active connection between the base station 200 and the terminal 100 and the uplink synchronization is maintained in the existing LTE / LTE- PUCCH and the PUSCH required for data transmission is not allocated, a UL resource allocation request of the AT 100 and a resource allocation procedure of the BS 200 are shown.

Referring to FIG. 1, the MS 100 transmits a scheduling request (SR) through an allocated PUCCH in order to request an uplink resource allocation for data transmission to the BS 200 (S110). The SR is used to indicate that there is data to be transmitted by the UE, and has a value of 1 bit indicating whether resource allocation is necessary.

Upon receiving the SR from the terminal 100, the base station 200 determines whether resource allocation is possible, and allocates the uplink resource to the terminal 100 when resource allocation is possible. At this time, since the base station 200 does not have information on the amount and priority of resources requested by the MS 100, the BS 200 allocates a fixed minimum UL resource in consideration of resource utilization efficiency.

The base station 200 transmits UL grant including resource allocation information to the terminal 100 (S120).

When the UE 100 can not transmit all the data to be transmitted by the UL resource, the UE 100 requests UL resource allocation to the BS 200 using the UL resource allocated thereto A buffer status report (BSR) is transmitted (S130).

The base station 200 then allocates uplink resources to the subscriber station 100 based on the information included in the BSR received from the subscriber station 100 and transmits UL grant including resource allocation information to the subscriber station 100. [ (S140).

The terminal 100 transmits the uplink data using the uplink resource allocated through the UL grant (S150).

1, the delay time from transmission of the SR to transmission of the uplink data through the BSR transmission procedure depends on the period of the SR allocated to the AT 100 and the period of the SR allocated to the AT 100 Is determined according to the time until resource allocation of the mobile station 200. The SR allocation period means a resource allocation period of a PUCCH in which an MS can transmit an SR in the base station 200 so that the MS 100 can transmit an SR. The SR allocation period for each UE can be set in the RRC layer and has a value within 1 ms to 80 ms. It is assumed that the SR allocation period is 5 ms and that there is no transmission error between the UE 100 and the BS 200. After the SR and BSR are transmitted, the delay time until the BS 200 receives the uplink data transmission of the actual UE 100 The time needs to be at least 22.5 ms.

In order to support low-delay services requiring a minimum transmission delay in the radio section, the delay time required for uplink data transmission through the additional transmission procedure of the BSR after the SR transmission is reduced, Will be described in detail with reference to FIG.

2 is a diagram illustrating an uplink resource allocation request and an uplink allocation procedure in a mobile communication system according to an embodiment of the present invention.

2, the MS 100 includes information on a BSR corresponding to information on a resource allocation requested by the MS 100 to the SR in the SR, and transmits an SR including information on the BSR to the BS 200 (S210). SR has a value of 1 bit. The base station 200 allocates a PUCCH to the AT 100, which can transmit a plurality of SRs so that the AT 100 can display information of the BSR. The MS 100 transmits a plurality of SRs through the PUCCH allocated from the BS 200 to not only determine whether resource allocation is required, but also transmit BSR information. At this time, the transmission of the PUCCH can use the same format as the SR transmission of the LTE / LTE-A system (for example, PUCCH format 1).

The base station 200 then allocates uplink resources to the subscriber station 100 based on information corresponding to the BSR received from the subscriber station 100 and transmits UL grant including resource allocation information to the subscriber station 100. [ (Step S220).

The MS 100 transmits uplink data using uplink resources allocated through UL grant (S230).

That is, in the existing LTE / LTE-A system, the MS 100 transmits 1-bit information to the BS through a resource (PUCCH) capable of transmitting an SR allocated with a predetermined periodic value. The 1-bit information can indicate only the necessity of resource allocation and can not transmit information on the resource requested to the base station 200. [ Meanwhile, according to the embodiment of the present invention, the MS 100 transmits the BSR information indicating the requested resource amount to the BS 200 at the time of SR transmission, thereby omitting the BSR transmission procedure performed after the existing SR transmission .

A method of transmitting BSR information through a plurality of SR assignments will be described below.

3 is a diagram illustrating a resource allocation method for SR transmission in the uplink resource allocation procedure shown in FIG.

Referring to FIG. 3, the BS 200 allocates a PUCCH resource, which can transmit SRs, to the MS 100 at a predetermined interval. The PUCCH resource is a resource amount enough to transmit one bit of information. The MS 100 transmits the SR through the allocated PUCCH.

FIGS. 4, 5, and 6 are diagrams illustrating a method of allocating resources for a plurality of SR allocation and transmission according to an embodiment of the present invention. Referring to FIG. At this time, each SR uses the PUCCH format 1 of the PUCCH transmission format for transmitting 1-bit information in the same manner as in FIG.

As shown in FIG. 4, the base station 200 may allocate a PUCCH resource to the AT 100, which can transmit a plurality of SRs continuously in time. A plurality of SRs allocated to the UE 100 indicate respective specific resource requirement information values.

The MS 100 selects an appropriate SR according to the requested resource information among the PUCCH resources allocated in time and transmits the corresponding SR to the BS 200 to indicate not only the necessity of resource allocation but also the BSR information send.

As shown in FIG. 5, the base station 200 can allocate a plurality of PUCCH resources, which can transmit a plurality of SRs to different frequency bands, to the terminal 100. [ A plurality of SRs allocated to the UE 100 indicate respective specific resource requirement information values.

The UE 100 selects an appropriate SR according to requested resource information among a plurality of PUCCH resources allocated consecutively in frequency and transmits the corresponding SR to thereby transmit the SR indicating not only the necessity of resource allocation but also the information of the BSR to the base station 200 .

The resource allocation method of FIGS. 4 and 5 can minimize the influence on the LTE system standard since the SR allocation period for each UE can be the same value as that of the existing (for example, FIG. 1).

Also, as shown in FIG. 6, the base station 200 allocates a PUCCH resource capable of transmitting an SR to the terminal 100 at a predetermined period.

The UE 100 subdivides the allocated PUCCH resources and divides the PUCCH resource into a plurality of SRs using different periods to select SRs indicating not only the necessity of resource allocation but also the BSR information and transmits the selected SRs to the BS 200. [

In the resource allocation method shown in FIG. 6, the SR related overhead of the LTE system is maintained at the same level, while the delay decreasing performance may be variable according to the SR allocation period value.

Meanwhile, the terminal 100 and the base station 200 can negotiate in advance that a certain sequence generated by combining a plurality of allocated SRs represents specific resource request information. In this case, the terminal 100 may combine a plurality of allocated SRs to generate a predetermined sequence representing the resource request information of the terminal 100, and the base station 200 may transmit the resource of the terminal 100 The request information can be confirmed. For example, if three SRs can be allocated to the terminal 100, the terminal 100 can generate a 3-bit sequence indicating the resource request information of the terminal 100 using each of the three SRs . In this case, the 3-bit sequence can represent 8 resource request information. The resource request information for each SR may be provided to the UE 100 by the LTE RRC signaling for each UE when the SR is allocated to the UE 100 or may be provided as common information to all UEs with system information.

According to another embodiment of the present invention, the UE 100 transmits SR information with N bits (for example, N < 10 or 20) increased to 1 bit of information in order to display BSR information at the time of SR transmission Can be changed. At this time, the terminal 100 may use the PUCCH format 2 or the PUCCH format 3 instead of the PUCCH format 1 used in the 1-bit transmission of the PUCCH transmission format in order to transmit the increased bit number information. PUCCH Format 2 can transmit 10 bits / 20 bits CSI or 11 bits (1 bit SR + 10 bits CSI) / 21 bits (1 bit SR + 20 bits CSI) according to FDD / TDD. PUCCH format 3 is a transmission format for transmission of HARQ ACK information of 4 bits or more in the CA.

In case of transmitting N-bit SR using PUCCH format 2 or PUCCH format 3 instead of PUCCH format 1, the terminal 100 may be configured to use an extended (shortened) BSR, A new N-bit SR can be constructed to convey the information of the BSR. First, a new N-bit SR is a 1-bit D [dynamic (one time request)] / S (1), which is information indicating whether the resource request of the UE 100 corresponds to a resource allocation request having a predetermined interval semi-persistent) indicator and (N-1) bits of request resource size. When the requested resource information is configured with a shortened BSR or short BSR format, the requested resource information includes one LCG (Logical Channel Group) ID (2 bits) and a buffer size (e.g., 4 or 6 bits). Or the requested resource information may include a plurality of LCG IDs and respective buffer sizes.

7 is a flowchart illustrating an uplink resource allocation request method of a UE according to an embodiment of the present invention.

Referring to FIG. 7, if there is data to be transmitted to the buffer in the terminal 100 (S702), the terminal 100 checks whether there is an allocated PUSCH (S704). If there is a PUSCH allocated to the terminal 100, it is confirmed whether the allocated PUSCH is enough to transmit data (S724).

If the PUSCH is allocated to the terminal 100, the terminal 100 transmits the data using the assigned PUSCH (S730).

Meanwhile, if the allocated PUSCH is not enough to transmit data, the terminal 100 triggers the BSR (S726). The MS 100 transmits the triggered BSR and transmittable data to the BS 200 through the PUSCH (S728). The terminal 100 can repeat the procedure shown in FIG. 7 until the transmission of the data to be transmitted is completed.

On the other hand, if there is no PUSCH allocated to the terminal 100, the terminal 100 triggers the BSR (S706). When the BSR is triggered, the terminal 100 checks whether there is a PUCCH resource allocated in advance (S708). If there is no PUCCH resource allocated in advance, the terminal 100 performs a random access procedure (S722).

Meanwhile, if there is an allocated PUCCH resource, the UE 100 transmits an SR according to an embodiment of the present invention that can display BSR information using the PUCCH allocated as described in FIG. 2 (S710) .

In step S712, the SS 100 determines whether the PUSCH resource of the BS 200 for the SR transmitted for a predetermined time after the SR transmission according to the embodiment of the present invention is allocated. Terminal 100 if it is not the PUSCH resource assignment done, the number of retransmissions (N _SR) of the SR maximum number of retransmissions (N _MAX) as compared to (S720), the maximum retransmission number of retransmissions (N _SR) of the SR ( N _MAX ) of the BS according to the embodiment of the present invention, which can display the BSR information in consideration of the SR allocation period (S710).

The UE 100 performs a random access procedure if the PUSCH resource allocation is not performed from the base station 200 until the number of retransmissions N _{SR of the SR} reaches the maximum retransmission count N _MAX at step S722.

When the PUSCH resource allocation is performed in the base station 200 receiving the SR according to the embodiment of the present invention, the MS 100 determines whether the allocated PUSCH is enough to transmit data (S714). When the allocated PUSCH is enough to transmit data, the terminal 100 transmits data through the allocated PUSCH (S718). On the other hand, if the allocated PUSCH resource is not enough to transmit data, the terminal 100 transmits the BSR indicating the necessary resource allocation information and the transmittable data through the allocated PUSCH resource (S716). The terminal 100 can repeat the procedure shown in FIG. 7 until the transmission of the data to be transmitted is completed.

8 is a diagram illustrating an uplink resource allocation apparatus according to an embodiment of the present invention.

8, the uplink resource allocation apparatus 800 includes a processor 810, a transceiver 820, and a memory 830. [ The uplink resource allocation apparatus 800 may be implemented in the base station 200.

The processor 810 performs the uplink resource allocation function described with reference to FIGS. 2, 4 to 6. 4 to 6, the processor 810 can allocate PUCCH resources for a plurality of SR transmissions and allocate PUSCH resources based on BSR information included in SRs transmitted from the AT 100 . In the LTE / LTE-A system, a packet scheduler of the base station 200 is responsible for resource allocation, and performs HARQ (Hybrid Automatic Repeat reQuest) retransmission related information, discontinuous reception (DRX) Persistent scheduling pattern, QoS requirements, CQI report, buffer / queue information, and so on. Processor 810 performs the functions of this packet scheduler.

 The transceiver 820 transmits and receives messages, signals, and data to and from the terminal 100. In particular, the transceiver 820 receives the SR from the terminal 100 and transmits the uplink grant including the resource allocation information to the terminal 100. [ The transceiver 820 can also receive uplink data from the terminal 100. [

The memory 830 stores instructions for execution in the processor 810 or temporarily loads and stores instructions from a storage device (not shown), and the processor 810 is stored in the memory 830 The loaded instruction can be executed.

The processor 810 and the memory 830 are connected to each other through a bus (not shown), and an input / output interface (not shown) may also be connected to the bus. At this time, a transceiver 820 is connected to the input / output interface, and peripheral devices such as an input device, a display, a speaker, and a storage device may be connected.

9 is a diagram illustrating an apparatus for requesting uplink resource allocation according to an embodiment of the present invention.

9, the uplink resource allocation requesting apparatus 900 includes a processor 910, a transceiver 920, and a memory 930. [ The uplink resource allocation requesting apparatus 900 may be implemented in the terminal 100.

The processor 910 performs the functions described in FIG. 7 when there is data to be transmitted to the base station 200. FIG. The processor 910 generates an SR including the BSR information from the base station 200 and transmits the SR through the transceiver 920 using the allocated PUCCH resources. The processor 910 may display information of the BSR using a plurality of SRs.

The transceiver 920 transmits and receives messages, signals, and data to and from the base station 200. In particular, the transceiver 920 transmits the SR to the base station 200 and receives the uplink grant including the resource allocation information from the base station 200. The transceiver 920 also transmits uplink data to the base station 200.

The memory 930 stores instructions for executing in the processor 910 or temporarily stores the instructions loaded from the storage device (not shown), and the processor 910 is stored in the memory 930 The loaded instruction can be executed.

The processor 910 and the memory 930 are connected to each other via a bus (not shown), and an input / output interface (not shown) may be connected to the bus. At this time, a transceiver 920 is connected to the input / output interface, and peripheral devices such as an input device, a display, a speaker, and a storage device may be connected.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, Such an embodiment can be readily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (1)

A method for requesting an uplink resource allocation from a terminal to a base station,
Allocating, from a base station, a resource for transmitting at least one scheduling request indicating a resource amount of data to be transmitted; and
Transmitting the at least one scheduling request indicating the amount of resources required for transmission of the data to the base station
And transmitting the uplink resource allocation request message.

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