CA2777037A1 - Method and apparatus for transmitting scheduling request signal in mobile communication system - Google Patents

Method and apparatus for transmitting scheduling request signal in mobile communication system Download PDF

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Publication number
CA2777037A1
CA2777037A1 CA2777037A CA2777037A CA2777037A1 CA 2777037 A1 CA2777037 A1 CA 2777037A1 CA 2777037 A CA2777037 A CA 2777037A CA 2777037 A CA2777037 A CA 2777037A CA 2777037 A1 CA2777037 A1 CA 2777037A1
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bsr
transmission
transmitting
scheduling request
canceled
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CA2777037C (en
Inventor
Soeng-Hun Kim
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Samsung Electronics Co Ltd
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Samsung Electronics Co Ltd
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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/02Traffic management, e.g. flow control or congestion control
    • H04W28/0278Traffic management, e.g. flow control or congestion control using buffer status reports
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/12Wireless traffic scheduling
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/12Wireless traffic scheduling
    • H04W72/1263Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W74/00Wireless channel access, e.g. scheduled or random access
    • H04W74/08Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access]
    • H04W74/0833Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access] using a random access procedure
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/12Wireless traffic scheduling
    • H04W72/1263Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
    • H04W72/1268Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows of uplink data flows
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W8/00Network data management
    • H04W8/22Processing or transfer of terminal data, e.g. status or physical capabilities
    • H04W8/24Transfer of terminal data

Abstract

The present invention relates to a method and an apparatus for transmitting a scheduling request signal of a terminal in a mobile communication system. The method for transmitting the scheduling request signal of the terminal in the mobile communication system of the present invention comprises the steps of: triggering a Dedicate Scheduling Request (D-SR) process for requesting a resource for Buffer State Report (BSR) transmission when the BSR is triggered; checking whether the BSR is cancelled; and triggering the D-SR process when the BSR is not cancelled. Accordingly, in the present invention, the terminal can efficiently receive the resource for BSR transmission.

Description

Invention Title METHOD AND APPARATUS FOR TRANSMITTING SCHEDULING
REQUEST SIGNAL IN MOBILE COMMUNICATION SYSTEM

Detailed Description of the Invention Technical Field The present invention relates to scheduling in a mobile communication system. More particularly, the present invention relates to a method and apparatus for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system.

Background Art Generally, mobile communication systems are for providing communication services while securing mobility of users. Thanks to technology breakthroughs, the mobile communication systems have evolved to provide not only voice communication services but also high-speed data communication services.

Recently, standardization for Long Term Evolution (LTE) is in progress in 3rd Generation Partnership Project (3GPP) as one of the next-generation mobile communication systems. LTE, aiming at commercialization around 2010, is technology that can implement high-speed packet-based communication having a data rate of a maximum of 100 Mbps, which is higher than the currently available data rate. In order to support this high-speed communication, several methods have been discussed, such as a method of reducing the number of nodes in a communication link by simplifying the network structure and a method of approximating wireless protocols to wireless channels if possible.

Unlike in voice service, in data service, the amount of wireless resources allocated to one UE is determined depending on the amount of transmission data and the channel conditions. Therefore, a wireless communication system like the mobile communication system manages a scheduler to allocate transmission resources taking into account the amount of transmission resources, the channel conditions, and the amount of transmission data. This is done in the same way even in LTE, one of the next-generation mobile communication systems, and for that purpose, a scheduler located in an Evolved Node B (ENB) manages wireless transmission resources and properly allocates them to UEs.

In the wireless communication system like the mobile communication system, data transmission is classified into downlink transmission and uplink transmission depending on the direction of data transmission. The term `downlink transmission' refers to transmission from an ENB to a UE, while the term `uplink transmission' refers to transmission from a UE to an ENB.

In the case of downlink transmission, since an ENB may pinpoint the current channel conditions, the amount of allocable wireless resources, and the amount of transmission data, a scheduler in the ENB may smoothly perform scheduling based on the above information. However, in the case of uplink transmission, the scheduler in the ENB may not properly allocate wireless resources to UEs since the uplink transmission may be performed with the scheduler not pinpointing the current buffer status of UEs, causing difficulties in the uplink transmission.

In order to solve the difficulties in uplink transmission, in the LTE
system, a UE reports its current buffer status to an ENB using `Buffer Status Report Control Element'.

The `Buffer Status Report Control Element' is set to be transmitted to an ENB by a UE if certain conditions are satisfied, such as if transmission data with a high priority is newly generated and if a predetermined timer expires.
A Buffer Status Report (BSR) occurring when new data with a high priority is generated may be referred to as a regular BSR. In order to transmit the regular BSR to the ENB as quickly as possible, upon occurrence of a regular BSR, a UE requests transmission resources for BSR transmission by transmitting 1-bit information called Dedicated-Scheduling Request (D-SR) to the ENB. In other words, the D-SR is used to request, from the ENB, wireless resources for transmitting a regular BSR.

Disclosure Technical Problems An aspect of the present invention is to provide a method and apparatus for efficiently transmitting a scheduling request signal by a UE in a mobile communication system.

Another aspect of the present invention is to provide a method and apparatus for allowing a UE to be efficiently allocated resources for transmission of a Buffer Status Report (BSR) in a mobile communication system.

Technical Solutions In accordance with an aspect of the present invention, there is provided a method for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system. The method includes, if a Buffer Status Report (BSR) is triggered, triggering a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of the BSR; checking whether the BSR is canceled; and if the BSR is not canceled, triggering the D-SR
process.
In accordance with another aspect of the present invention, there is provided an apparatus for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system. The apparatus includes an SR/BSR controller for, if a Buffer Status Report (BSR) is triggered, triggering a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of the BSR, checking whether the BSR is canceled, and triggering the D-SR process if the BSR is not canceled.

In accordance with further another aspect of the present invention, there is provided a method for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system. The method includes initializing a counter value if a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of Buffer Status Report (BSR) is triggered; increasing the counter value by 1 at a time a predetermined time ahead of an allowable transmission time of the D-SR; and transmitting the D-SR at the allowable transmission time of the D-SR.

In accordance with yet another aspect of the present invention, there is provided an apparatus for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system. The apparatus includes an SR/BSR controller for initializing a counter value if a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of Buffer Status Report (BSR) is triggered, and increasing the counter value by 1 at a time a predetermined time ahead of an allowable transmission time of the D-SR; and a transceiver for transmitting the D-SR at the allowable transmission time of the D-SR.

Advantageous Effects In a mobile communication system according to an embodiment of the present invention, an unnecessary scheduling request signal is not transmitted, contributing to efficient use of wireless resources, preventing unnecessary power waste by UEs, and reducing uplink interference, thereby making it possible to increase the efficiency of the communication system.

Brief Description of the Drawings FIG. 1 illustrates a configuration of an LTE mobile communication system;
FIG. 2 illustrates a structure of a wireless protocol in an LTE system;
FIG. 3 illustrates Buffer Status Report (BSR) and Dedicated-Scheduling Request (D-SR) in an LTE mobile communication system;
FIG. 4 illustrates problems of the conventional technology related to a first embodiment of the present invention;
FIG. 5 illustrates an operation of transmitting a scheduling request signal in a UE according to the first embodiment of the present invention;
FIG. 6 illustrates problems of the conventional technology related to a second embodiment of the present invention, and a process of transmitting a scheduling request signal in a UE according to the second embodiment of the present invention;
FIG. 7 illustrates an operation of transmitting a scheduling request signal in a UE according to the second embodiment of the present invention; and FIG. 8 is a block diagram of a UE according to the first and second embodiments of the present invention.

Best Mode Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Throughout the drawings, like reference numerals refer to like elements unless otherwise specified. A detailed description of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.

The present invention provides a method and apparatus for preventing a UE from performing unnecessary malfunction in transmitting D-SR.

Prior to a detailed description of the present invention, an LTE mobile communication system will be described in brief.
FIG. 1 illustrates a configuration of an LTE mobile communication system.

Referring to FIG. 1, a radio access network of the LTE mobile communication system includes Evolved Node Bs (ENBs) or Node Bs 105, 110, 115 and 120, a Mobility Management Entity (MME) 125, and a Serving-Gateway (S-GW) 130. A User Equipment (UE) 135 accesses the network through the ENB 105 to whit it is connected, and the S-GW 130.

The ENBs 105 to 120 correspond to Node Bs in the legacy UMTS
system. The ENB 105 is connected to the UE 135 over a wireless channel, and plays a more complex role than the legacy Node B. LTE performs scheduling by collecting status information of UEs, since all user traffic including real time services such as Voice over Internet Protocol (VoIP) is serviced over a shared channel. This scheduling function is managed by the ENBs 105 to 120.
One ENB generally controls a plurality of cells. In order to implement a data rate of a maximum of 100 Mbps, LTE uses Orthogonal Frequency Division Multiplexing (OFDM) in a bandwidth of a maximum of 20 MHz as a wireless access technology. In addition, LTE applies Adaptive Modulation &
Coding (AMC) that adaptively determines a modulation scheme and a channel coding rate depending on channel conditions of UEs.

The S-GW 130, a device for providing a data bearer, generates or removes a data bearer under control of the MME 125. The MME 125, a device responsible for various control functions for wireless connection, is connected to a plurality of ENBs.

FIG. 2 illustrates a structure of a wireless protocol in an LTE system.

Referring to FIG. 2, the wireless protocol of the LTE system includes Packet Data Convergence Protocol (PDCP) 205 and 240, Radio Link Control (RLC) 210 and 235, and Medium Access Control (MAC) 215 and 230. The PDCP 205 and 240 are responsible for, for example, an operation of compressing/decompressing an IP header, and the RLC 210 and 235 perform an Automatic Repeat reQuest (ARQ) operation or the like by reconfiguring PDCP
Packet Data Units (PDCP PDUs) in a proper size. The MAC 215 and 230 are connected to several RLC-layer devices formed in one UE, and perform an operation of multiplexing RLC PDUs to a MAC PDU, and de-multiplexing a MAC PDU into RLC PDUs. Physical (PHY) layers 220 and 225 channel-code and modulate upper layer data into OFDM symbols and transmit the OFDM
symbols over a wireless channel; and/or demodulate and channel-decode OFDM
symbols received over a wireless channel and transfer the decoded OFDM
symbols to their upper layers.

FIG. 3 illustrates Buffer Status Report (BSR) and Dedicated-Scheduling Request (D-SR) in an LTE mobile communication system.

An ENB 310 may set D-SR transmission resources for a UE 305. The term `D-SR transmission resources' as used herein may refer to resources that an ENB allocates to a UE, allowing the UE to transmit D-SR to the ENB. The D-SR transmission resources may be allocated to the UE 305 by the ENB 310 for a predetermined period. Accordingly, in step 315, the ENB 310 sends a control message including D-SR transmission resource setting information to the UE
305.
Based on the control message, the UE 305 may determine in which transmission resources the D-SR transmission resources for the UE 305 are set, and in which subframe the D-SR transmission resources are available.

In step 320, a particular situation is assumed, in which a regular BSR is triggered in the UE 305 at a certain time after step 315. In step 325, a Scheduling Request (SR) transmission process is also triggered after the regular BSR is triggered. The term `SR transmission process' as used herein may refer to a process in which a UE transmits D-SR to an ENB until it is allocated wireless resources for BSR transmission from the ENB. In other words, if the SR transmission process is triggered, the UE 305 transmits D-SR to the ENB 310 until the SR transmission process is canceled.

Since the UE 305 may determine a subframe allocated to its D-SR
transmission resource based on the control message received in step 315, the UE
305 transmits D-SR in the allocated subframe. The UE 305 repeatedly transmits D-SR to the ENB 310 until it is allocated resources for BSR
transmission. Assuming that the UE 305 is allocated resources for BSR
transmission in step 345, the UE 305 transmits BSR to the ENB 310 using the resources for BSR transmission in step 350.

After transmitting the BSR to the ENB 310, the UE 305 cancels the SR
transmission process triggered in step 325, and no longer transmits D-SR.
However, the ENB 310 may not receive the D-SR that the UE 305 transmitted, for some reasons such as uplink transmission power is set wrong during the D-SR transmission. In this case, the UE 305 may infinitely repeatedly transmit D-SR to the ENB 310, causing an increase in power consumption and uplink interference of the UE 305.

In order to solve this problem, the current LTE standard limits the number of UE's D-SR transmissions to a predetermined threshold dsr-transmax or below. If a UE is not allocated resources for BSR transmission from an ENB
even after it transmitted D-SR as many times as the threshold dsr-transmax, the UE stops the D-SR transmission and starts a random access process for BSR
transmission.

The ENB's failing to receive an uplink grant even though a UE
transmitted D-SR to the ENB as many times as the threshold dsr-transmax, i.e., the UE's failing to be allocated resources for BSR transmission, suggests a possible fatal error in setting uplink transmission for the UE. In this case, therefore, the UE releases dedicated uplink transmission resources including D-SR transmission resources. For convenience of description, the UE's failing to receive an uplink grant from an ENB even though the UE transmitted D-SR to the ENB as many times as the threshold dsr-transmax will be referred to herein as `D-SR transmission failure'.

In order to determine whether D-SR transmission is failed, the UE
operates a predetermined counter in which a parameter SR COUNTER is set.
A value of SR_COUNTER is initialized to 0 if SR is triggered, and increases by 1 whenever D-SR is transmitted. If SR COUNTER arrives at the threshold dsr-transmax for D-SR transmission, the UE releases the dedicated uplink transmission resources including D-SR transmission resources and performs a random access process, determining that D-SR transmission failure has occurred.
For convenience of description, a series of operations of releasing the dedicated uplink transmission resources including D-SR transmission resources and starting a random access process will be referred to herein as `D-SR
transmission failure follow-up procedure'.

In the current LTE standard, after transmitting a (dsr-transmax)-th D-SR, a UE immediately performs the D-SR transmission failure follow-up procedure without determining whether an uplink grant is received. In other words, after transmitting the last D-SR, the UE performs the D-SR transmission failure follow-up procedure before the ENB receives the last D-SR and allocates an uplink grant. As a result, the UE performs the D-SR transmission failure follow-up procedure without checking an uplink grant from the ENB for the transmitted last D-SR, so the transmission of the last D-SR may cause unnecessary waste of resources, an increase in uplink interference, and power dissipation of the UE. These problems will be described in more detail in conjunction with FIG. 4.
FIG. 4 illustrates problems of the conventional technology related to a first embodiment of the present invention.

In FIG. 4, one rectangle represents a 1-msec subframe. Subframes for D-SR transmission resources allocated to a UE are shown by arrows 405, 410, 415, 420, and 430.

Assume that an SR transmission process is triggered in a UE at an arbitrary time. This is shown by reference numeral 435 in FIG. 4. If the SR
transmission process is triggered in step 435, the UE initializes SR-COUNTER
to 0 in step 440 and waits until a subframe allocated for available D-SR
transmission resources.

In step 445, the UE compares SR_COUNTER with the maximum allowable number dsr-transmax of D-SR transmissions in order to determine whether to perform D-SR transmission in a subframe 410 allocated to be available as D-SR transmission resources. If SR COUNTER is less than dsr-transmax as a result of the comparison, i.e., if the number of SR
transmissions has not arrived at the maximum allowable number of D-SR transmissions, the UE increases SR_COUNTER by 1 in step 450, and transmits D-SR in step 455.
In this manner, if the SR transmission process is in progress, the UE
repeats an operation of comparing SR-COUNTER with dsr-transmax in every subframe where D-SR transmission resources are available, and if SR COUNTER is less than dsr-transmax, increasing SR-COUNTER by I and transmitting SR. For example, if dsr-transmax is set to 3, the UE transmits SR
and increases SR-COUNTER by 1 in a subframe 420 because SR-COUNTER at the time is 2.

In the next subframe 425, since SR COUNTER is 3 and a value of SR COUNTER is equal to dsr-transmax at this time, the UE performs the D-SR
transmission failure follow-up procedure, i.e., releases the D-SR transmission resources and performs random access for resources for BSR transmission, if SR COUNTER is greater than or equal to dsr-transmax. In other words, the UE performs the D-SR transmission failure follow-up procedure before the ENB
responds to the SR that the UE transmitted in the subframe 420.

This problem occurs because the UE immediately performs the D-SR
transmission failure follow-up procedure in the just next subframe after it transmitted the last D-SR in an operation of the above-described conventional LTE standard, although it is preferably that after transmitting D-SR, a UE
waits for a response thereto from an ENB, i.e., waits for an uplink grant to be received, for a predetermined period of time.

A first embodiment of the present invention is for solving the problems described in conjunction with FIG. 4. Conventionally, after transmitting D-SR, a UE increases SR COUNTER, compares SR-COUNTER with dsr-transmax, and immediately performs the D-SR transmission failure follow-up procedure if SR COUNTER is greater than or equal to dsr-transmax.

However, in the first embodiment of the present invention, unlike in the convention method, a UE increases SR COUNTER in advance at a time a predetermined time ahead of the transmission time of D-SR. Thereafter, the UE
compares SR_COUNTER with dsr-transmax, and performs the D-SR
transmission failure follow-up procedure if SR COUNTER is greater than dsr-transmax as a result of the comparison. In this way, the first embodiment of the present invention may solve the above problems by changing the start time of the D-SR transmission failure follow-up procedure.

In accordance with an operation of the first embodiment of the present invention, a UE transmits D-SR but does not start the D-SR transmission failure follow-up procedure at the time the SR COUNTER value is equal to the dsr-transmax value. In addition, the UE increases SR-COUNTER by 1 at a time a predetermined time ahead of the next subframe available for D-SR transmission resources, satisfying a condition that SR-COUNTER is greater than dsr-transmax. So, the UE may perform the D-SR transmission failure follow-up procedure without transmitting D-SR.

As a result, instead of immediately performing the D-SR transmission failure follow-up procedure after transmitting the last D-SR, the UE
determines whether to perform the D-SR transmission failure follow-up procedure after waiting until the next subframe available for D-SR transmission resources, preventing unnecessary transmission of D-SR.

FIG. 5 illustrates an operation of transmitting a scheduling request signal in a UE according to the first embodiment of the present invention.
If an SR transmission process is triggered due to occurrence of, for example, a regular BSR in step 505, the UE initializes SR-COUNTER to 0 in step 510. In step 515, the UE first waits until a predetermined time close to a subframe available for D-SR transmission resources in order to determine whether to transmit D-SR. The predetermined time may be set as a time that goes ahead of a subframe available for D-SR transmission resources by a UE's processing delay required to determine whether to transmit SR, or whether to perform the D-SR transmission failure follow-up procedure, and this time is subject to change.
In step 520, the UE increases SR_COUNTER by 1 prior to a process of determining whether to transmit D-SR. By increasing SR-COUNTER in advance prior to determining whether to transmit D-SR and performing whether to perform the D-SR transmission failure follow-up procedure as described above, the UE may not unnecessarily transmit D-SR before performing the D-SR
transmission failure follow-up procedure.
For example, in FIG. 4, the UE updates SR COUNTER to 4 and compares SR COUNTER with dsr-transmax at a predetermined time which precedes a subframe 430 and is close to the subframe 430. In this case, the UE
performs the follow-up operation in the subframe 430 because SR-COUNTER is greater than dsr-transmax. In other words, instead of immediately performing the follow-up operation after transmitting the last D-SR, the UE performs the follow-up operation after waiting until the subframe time available for D-SR
transmission resources.
In step 525, the UE compares SR_COUNTER with dsr-transmax. If SR COUNTER is less than or equal to dsr-transmax, the UE proceeds to step 545 for D-SR transmission. If SR COUNTER is greater than dsr-transmax, the UE proceeds to step 530 for D-SR transmission failure follow-up procedure.
Conventionally, the UE performs the operation of step 530 if SR COUNTER is greater than or equal to dsr-transmax. However, in the present invention, the UE proceeds to step 530 if SR COUNTER is greater than dsr-transmax. If dsr-transmax is set to a value which is greater by 1 than the conventional technology, the conventional determination procedure may be used as it is. In other words, in this case, if SR COUNTER is less than dsr-transmax in step 525, the UE proceeds to step 545. If SR_COUNTER is equal to or greater than dsr-transmax, the UE may proceeds to step 530. In this case, however, the UE should set dsr-transmax to a value which is greater by 1 than the conventional method, because (dsr-transmax-1)-th D-SR transmission is the last D-SR transmission.

Proceeding to step 530 means that even though the UE has performed D-SR transmission a predetermined maximum number of D-SR transmissions, the UE has failed to receive a response thereto, i.e., an uplink grant. Thus, the UE
performs the D-SR transmission failure follow-up procedure. In other words, the UE releases various dedicated uplink transmission resources including D-SR
transmission resources in step 530, starts a random access process in step 535, and cancels the entire ongoing SR transmission process in step 540.

Proceeding to step 545 means that the number of D-SR transmissions has not arrived at a predetermined maximum number of D-SR transmissions, so the UE transmits D-SR. In step 550, the UE checks whether the SR transmission process is in progress. The SR transmission process being in progress means that the SR transmission process has not been canceled after being triggered.
The SR transmission process may be canceled by the D-SR transmission failure follow-up procedure like in step 540, and may be canceled as a regular BSR is transmitted.

If the SR transmission process is still in progress, the UE proceeds to step 515 and continues to perform the SR transmission process. However, if the SR transmission process is not in progress, i.e., if the SR transmission process has been canceled as BSR is transmitted after the SR transmission process was triggered, the UE terminates the SR transmission process in step 555.

A process of transmitting a scheduling request signal in a UE according to a second embodiment of the present invention will be described below.

FIG. 6 illustrates problems of the conventional technology related to a second embodiment of the present invention, and a process of transmitting a scheduling request signal in a UE according to the second embodiment of the present invention.

As described above, if a regular BSR is triggered, an SR transmission process is also triggered in order for the UE to be allocated resources for transmission of the regular BSR. However, exceptional situations may occur, in which even though a regular BSR is triggered, D-SR is not transmitted.
For example, in a case where a regular BSR is triggered and an SR
transmission process is triggered at an arbitrary time in step 605 and D-SR is transmitted in a subframe available for D-SR transmission resources in step 610, if the D-SR has been successfully transmitted and received, the UE receives an uplink grant in an arbitrary subframe in step 615. In step 625, the UE
performs uplink transmission 4 subframes after the subframe where the uplink grant was received.

Upon receiving the uplink grant, the UE generates a MAC PDU to be subject to uplink transmission, and the MAC PDU includes BSR. A situation will be assumed in which a new regular BSR is generated in step 635 between a time 620 where the generation of MAC PDU is completed and a time 625 where the generated MAC PDU is actually transmitted.
In this case, the new regular BSR may not be included in the MAC PDU
transmitted at the time 625. However, if MAC PDU with BSR included therein is transmitted at the time 625, the SR transmission process triggered in step is canceled at a time 630. In this case, the SR transmission process for the regular BSR newly generated in step 635 may be canceled without start of D-SR
transmission.

To solve the above problems, the current LTE standard provides that the existing SR transmission process is canceled only when BSR reflecting the latest buffer status is transmitted. This solution allows the UE to access an ENB
with the SR transmission process for the regular BSR newly generated in step 635 without canceling the SR transmission process triggered in step 605 for the previous BSR in the situation described in conjunction with FIG. 6. Therefore, the SR COUNTER used in the SR transmission process for the previous BSR in step 605 is used as it is, with the SR-COUNTER value not initialized. This may cause too early execution of the D-SR transmission failure follow-up procedure because of a reduction in the maximum allowable number of D-SR
transmissions for a new BSR in step 635.

In order to solve this problem, in the second embodiment of the present invention, the UE cancels the current ongoing SR transmission process (i.e., SR
transmission process of step 605 in FIG. 6) at a moment that MAC PDU
containing BSR is transmitted, and triggers a new SR transmission process if there is no current ongoing SR transmission process even though a new regular BSR was triggered.
For example, the UE cancels the ongoing SR transmission process at the time 630 if it transmits MAC PDU containing BSR. The UE triggers a new SR
transmission process if there is no current ongoing SR transmission process even though there is BSR (i.e., BSR in step 635) which is not canceled yet at the time 630. In other words, in step 635, the UE newly triggers an SR transmission process for transmission of a newly generated regular BSR after canceling the existing SR transmission process of step 630.

FIG. 7 illustrates an operation of transmitting a scheduling request signal in a UE according to the second embodiment of the present invention.

If a regular BSR is triggered in step 705, the UE triggers an SR
transmission process in step 710. In other words, the UE transmits D-SR at a time where SR transmission resources are available. Upon receiving an uplink grant, the UE generates and transmits MAC PDU including BSR. Upon failure to receive an uplink grant, the UE performs an operation such as transmitting D-SR.

While performing the operation, the UE monitors in step 715 whether the triggered BSR is canceled. For example, the UE may monitor whether the triggered BSR is not canceled, in every Transmission Time Interval (TTI).
After BSR is triggered, if the BSR, in which the latest buffer status is reflected, is included in MAC PDU (to be transmitted), the triggered BSR process is terminated. If the triggered BSR is canceled, the UE terminates the operation.

On the other hand, if the triggered BSR is not canceled, the UE checks in step 720 whether there is current ongoing SR transmission process. For reference, the triggered BSR process is not canceled, if the BSR, in which the latest buffer status is reflected, is not included in MAC PDU yet, or if BSR
does not reflect the current buffer status of the UE even though the BSR is included in MACPDU.

In the general case, if there is non-canceled BSR, an ongoing SR
transmission process should also exist. However, if an SR transmission process is canceled while the BSR, in which the previous buffer status is reflected, is transmitted like in the operation of steps 625 and 630, there may be no ongoing SR transmission process even though there is non-canceled BSR.

Therefore, if there is the current ongoing SR transmission process in step 720, the UE returns to step 715 and continuously monitors whether the BSR
process is canceled while continuing to perform the SR transmission process.
However, if there is no current ongoing SR transmission process in step 720, the UE triggers a new SR transmission process in step 725. Thereafter, the UE
returns to step 715 and monitors whether BSR is canceled. If BSR is canceled in step 715, the UE terminates the operation.
FIG. 8 is a block diagram of a UE according to the first and second embodiments of the present invention.

It should be noted that in the UE's block diagram of FIG. 8, its upper layer device is not shown.
Referring to FIG. 8, the UE includes a multiplexing/demultiplexing (MUX/DEMUX) unit 805, an HARQ processor 810, an SR/BSR controller 815, a MAC controller 820, and a transceiver 825.

The SR/BSR controller 815 determines whether BSR is triggered by monitoring the occurrence of upper layer data. In accordance with the first embodiment of the present invention, if BSR is triggered, the SR/BSR
controller 815 triggers an SR transmission process, determines whether to transmit D-SR
and whether to perform the D-SR transmission failure follow-up procedure by operating SR_COUNTER and dsr-transmax, and controls the transceiver 825 to transmit D-SR or perform a random access operation based on the determination results. In accordance with the second embodiment of the present invention, the SR/BSR controller 815 determines whether BSR is canceled, and triggers a new SR transmission process if there is no ongoing SR transmission process even though there is non-canceled BSR.

The MAC controller 820 analyzes scheduling information received over downlink and uplink control channels, and controls the transceiver 825 to receive downlink data or transmit uplink data.
The MAC controller 820 controls the MUX/DEMUX unit 805 to generate uplink transmission data. Upon receiving an uplink grant, the MAC
controller 820 notifies the SR/BSR controller 815 of the receipt of the uplink grant so that the SR/BSR controller 815 may determine whether an SR
transmission process is canceled and whether BSR is canceled.

The transceiver 825 is a device for transmitting/receiving MAC PDUs or control information, and HARQ packets over wireless channels. The HARQ
processor 810 is a set of soft buffers configured to perform an HARQ
operation, and is identified with an HARQ process identifier.
The MUX/DEMUX unit 805 configures MAC PDUs by concatenating data carried on a plurality of logical channels, or demultiplexes MAC PDUs into MAC SDUs and delivers them over a proper logical channel.

Claims (12)

1. A method for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system, comprising:
if a Buffer Status Report (BSR) is triggered, triggering a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of the BSR;
checking whether the BSR is canceled; and if the BSR is not canceled, triggering the D-SR process.
2. The method of claim 1, further comprising re-triggering the D-SR process;
wherein the D-SR process is triggered, if the BSR is not canceled and there is no current ongoing D-SR process.
3. The method of claim 1, wherein the checking is performed in every Transmission Time Interval (TTI).
4. An apparatus for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system, comprising:
an SR/BSR controller for, if a Buffer Status Report (BSR) is triggered, triggering a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of the BSR, checking whether the BSR is canceled, and triggering the D-SR process if the BSR is not canceled.
5. The apparatus of claim 4, wherein the SR/BSR controller triggers the D-SR process, if the BSR is not canceled and there is no current ongoing D-SR process.
6. The apparatus of claim 4, wherein the SR/BSR controller checks whether the BSR is canceled, in every Transmission Time Interval (TTI).
7. A method for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system, comprising:
initializing a counter value if a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of Buffer Status Report (BSR) is triggered;
increasing the counter value by 1 at a time a predetermined time ahead of an allowable transmission time of the D-SR; and transmitting the D-SR at the allowable transmission time of the D-SR.
8. The method of claim 7, further comprising stopping the transmission of the D-SR if the increased counter value is greater than a predetermined maximum transmission allowable value.
9. The method of claim 7, further comprising repeating the increasing the counter value by 1 and the transmitting the D-SR, if the transmitting the D-SR is in progress, when the increased counter value is equal to or less than a predetermined maximum transmission allowable value.
10. An apparatus for transmitting a scheduling request signal by a User Equipment (UE) in a mobile communication system, comprising:
an SR/BSR controller for initializing a counter value if a Dedicated-Scheduling Request (D-SR) process for requesting resources for transmission of Buffer Status Report (BSR) is triggered, and increasing the counter value by 1 at a time a predetermined time ahead of an allowable transmission time of the D-SR; and a transceiver for transmitting the D-SR at the allowable transmission time of the D-SR.
11. The apparatus of claim 10, wherein the SR/BSR controller stops the transmission of the D-SR if the increased counter value is greater than a predetermined maximum transmission allowable value.
12. The apparatus of claim 10, wherein the SR/BSR controller repeats the increasing the counter value by 1 and the transmitting the D-SR, if the transmitting the D-SR is in progress, when the increased counter value is equal to or less than a predetermined maximum transmission allowable value.
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Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9967362B2 (en) * 2011-10-27 2018-05-08 Telefonaktiebolaget Lm Ericsson (Publ) Caching in wireless communication networks
WO2013166669A1 (en) * 2012-05-09 2013-11-14 Renesas Mobile Corporation Method and apparatus for prioritizing an uplink resource request
KR101896440B1 (en) 2012-05-14 2018-09-11 삼성전자 주식회사 Method and appratus of handling the buffer status report in mobile communication system using inter-base station-carrier aggregation
WO2014047862A1 (en) * 2012-09-28 2014-04-03 Broadcom Corporation Methods, devices and computer program products for scheduling request transmission
WO2014139156A1 (en) * 2013-03-15 2014-09-18 华为技术有限公司 Information reporting method, apparatus, and system
KR102123434B1 (en) * 2013-08-09 2020-06-17 삼성전자 주식회사 Method and apparatus for scheduling request in wirelee cellular communication systems
US11432305B2 (en) 2014-05-19 2022-08-30 Qualcomm Incorporated Apparatus and method for synchronous multiplexing and multiple access for different latency targets utilizing thin control
US11153875B2 (en) 2014-05-19 2021-10-19 Qualcomm Incorporated Apparatus and method for inter-band pairing of carriers for time division duplex transmit- and receive-switching and its application to multiplexing of different transmission time intervals
US20150341938A1 (en) * 2014-05-22 2015-11-26 Qualcomm Incorporated Uplink operation for rlc communications
US9462607B2 (en) * 2014-08-28 2016-10-04 Intel IP Corporation Apparatus, method and system of multi-user uplink transmission
WO2016048082A1 (en) * 2014-09-25 2016-03-31 Lg Electronics Inc. Method and apparatus for canceling triggered prose bsr in wireless communication system
CN107852638B (en) 2015-07-06 2021-03-12 Lg 电子株式会社 Method for canceling buffer status report or scheduling request in dual connectivity and apparatus therefor
US10390357B2 (en) 2015-07-13 2019-08-20 Lg Electronics Inc. Method and apparatus for transmitting or receiving data in wireless communication system
CN106535246B (en) * 2015-09-11 2021-03-16 中兴通讯股份有限公司 Method, device and system for reporting buffer status report
CN108353039B (en) * 2015-11-05 2022-04-29 Lg 电子株式会社 Method for transmitting and receiving data in wireless communication system and apparatus for supporting the same
WO2017150828A1 (en) * 2016-03-02 2017-09-08 Lg Electronics Inc. Method for transmitting a scheduling request in a wireless communication system and a device therefor
US10244490B2 (en) 2016-04-05 2019-03-26 Qualcomm Incorporated Scheduling request transmission to request resources for a buffer status report
US11387973B2 (en) * 2016-11-17 2022-07-12 Samsung Electronics Co., Ltd. Method and apparatus for transmitting and receiving scheduling requests
CN116437465A (en) 2017-03-24 2023-07-14 北京三星通信技术研究有限公司 Method and device for reporting scheduling request in narrowband internet of things system
CN110915284B (en) * 2017-05-04 2021-08-10 欧芬诺有限责任公司 Wireless device and scheduling request method in wireless network
CN108810925A (en) * 2017-05-04 2018-11-13 夏普株式会社 Method and apparatus for handling scheduling request
US11310810B2 (en) 2017-06-15 2022-04-19 Samsung Electronics Co., Ltd. Method and apparatus for performing scheduling request to support plurality of services efficiently
KR102394123B1 (en) * 2017-06-16 2022-05-04 삼성전자 주식회사 The method of supporting multiple scheduling requests in the next generation mobile communication systems
US20190053264A1 (en) * 2017-08-09 2019-02-14 Mediatek Inc. Apparatuses and methods for a user equipment (ue) to handle multiple scheduling request (sr) procedures
CN116782398A (en) * 2017-08-10 2023-09-19 夏普株式会社 Base station, user equipment and related methods
CN109391408B (en) * 2017-08-10 2021-08-06 普天信息技术有限公司 Scheduling request indication transmission method in orthogonal frequency division multiplexing system
CN109561511A (en) * 2017-09-27 2019-04-02 夏普株式会社 Wireless communications method and equipment
CN109587803B (en) * 2017-09-28 2021-05-18 华为技术有限公司 Communication processing method and device
CN109587770A (en) 2017-09-29 2019-04-05 华为技术有限公司 The processing method and terminal device of scheduling request
BR112020009611A2 (en) * 2017-11-20 2020-11-03 Beijing Xiaomi Mobile Software Co., Ltd. method and device for requesting uplink streaming resource
CN110149674A (en) * 2018-02-13 2019-08-20 华为技术有限公司 A kind of route renewing method and equipment
WO2019191883A1 (en) * 2018-04-02 2019-10-10 Oppo广东移动通信有限公司 Method for triggering scheduling request, and terminal device
US11277193B2 (en) * 2019-05-31 2022-03-15 Qualcomm Incorporated Beam selection procedures for multi-stream environments
CN112566265B (en) * 2019-09-26 2022-08-12 大唐移动通信设备有限公司 Scheduling request triggering method, information configuration method, terminal and network equipment
US11696280B2 (en) * 2020-07-02 2023-07-04 Qualcomm Incorporated On-demand scheduling request design
WO2024010103A1 (en) * 2022-07-04 2024-01-11 엘지전자 주식회사 Method and device for performing resource request in wireless communication system

Family Cites Families (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3895165B2 (en) * 2001-12-03 2007-03-22 株式会社エヌ・ティ・ティ・ドコモ Communication control system, communication control method, communication base station, and mobile terminal
KR100689354B1 (en) * 2003-09-02 2007-03-02 삼성전자주식회사 Method of Offering State Information of Mobile Station in Mobile Communication System
KR101084134B1 (en) 2005-05-03 2011-11-17 엘지전자 주식회사 Method for Transmitting Control Information, in a Mobile Communication System
KR101119104B1 (en) * 2005-08-23 2012-03-19 엘지전자 주식회사 Method of transmitting messages in a mocile communications system and a mobile terminal
CN101473566B (en) * 2006-06-22 2013-01-30 三星电子株式会社 Method and apparatus for transmitting scheduling requests in mobile communication system
CN102883373B (en) * 2006-11-15 2016-01-20 三星电子株式会社 For the method and apparatus of buffer status report in mobile communication system
IL280543B (en) * 2007-06-19 2022-07-01 Optis Cellular Tech Llc Method for transmitting scheduling requests from a mobile terminal to a base station, and a mobile terminal for use therewith
KR100937432B1 (en) 2007-09-13 2010-01-18 엘지전자 주식회사 Method of allocating radio resources in a wireless communication system
TW200926860A (en) * 2007-10-29 2009-06-16 Sunplus Mmobile Inc Method for providing a buffer status report in a mobile communication network
JP5115186B2 (en) * 2007-12-27 2013-01-09 富士通株式会社 Control method in wireless communication system
US8243667B2 (en) 2008-01-28 2012-08-14 Lg Electronics Inc. Method for transmitting scheduling request effectively in wireless communication system
US8483146B2 (en) * 2008-02-01 2013-07-09 Lg Electronics Inc. Method for performing efficient BSR procedure using SPS resource
KR101494907B1 (en) 2008-02-01 2015-02-23 엘지전자 주식회사 Method for performing efficient bsr(buffer status report)procedure using sps(semi-persistent scheduling)resource
EP3048835B1 (en) * 2008-02-20 2020-09-30 Amazon Technologies, Inc. Apparatus and method for constructing a data unit that includes a buffer status report
BRPI0908593B1 (en) * 2008-03-21 2020-12-29 Telefonaktiebolaget Lm Ericsson (Publ) method related to uplink communications from a wireless terminal, apparatus for use in a wireless terminal, and radio communications system
EP2272288B1 (en) * 2008-05-07 2014-03-05 Telefonaktiebolaget L M Ericsson (PUBL) Pdcch monitoring after buffer status report transmission
EP2131517A3 (en) * 2008-06-03 2010-01-20 Innovative Sonic Limited Method and apparatus for improving HARQ uplink transmission
US8873522B2 (en) * 2008-08-11 2014-10-28 Qualcomm Incorporated Processing measurement gaps in a wireless communication system
US9167594B2 (en) * 2008-09-22 2015-10-20 Htc Corporation Method and related device of a trigger mechanism of buffer status report and scheduling request in a wireless communication system
US8649320B2 (en) * 2008-09-22 2014-02-11 Htc Corporation Method and related device of scheduling request behavior in a wireless communication system
US8873474B2 (en) * 2008-10-17 2014-10-28 Telefonaktiebolaget L M Ericsson (Publ) Method and mobile terminal providing priority-based uplink scheduling information
US8559962B2 (en) * 2009-01-22 2013-10-15 Innovative Sonic Limited Method and apparatus for improving reconfiguration procedure for scheduling request
EP2237633A1 (en) * 2009-04-03 2010-10-06 Panasonic Corporation Buffer status reporting in a mobile communication system
CN101932019B (en) * 2009-06-19 2015-06-03 中兴通讯股份有限公司 Method, terminal and network system for reporting buffer status report
US20100329204A1 (en) * 2009-06-29 2010-12-30 Yu-Hsuan Guo Method and Apparatus for Handling Scheduling Information Report in Wireless Communication System
JP5607991B2 (en) * 2009-09-02 2014-10-15 創新音▲速▼股▲ふん▼有限公司 BSR method and communication apparatus
EP2484168B1 (en) 2009-10-01 2021-12-08 Nokia Solutions and Networks Oy A method and apparatus to control scheduling
US20120255492A1 (en) * 2011-04-06 2012-10-11 Atomic Energy Council-Institute Of Nuclear Enetgy Research Large Area Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition Apparatus
US9065545B2 (en) * 2012-03-12 2015-06-23 Blackberry Limited Handling scheduling request collisions with an ACK/NACK repetition signal

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