KR20090120792A - Scheduling apparatus and method for transmitting using uplink in mobile system - Google Patents

Abstract

PURPOSE: A scheduling apparatus and a method thereof for uplink transmission using an AG value are provided to perform normal scheduling in case the terminal does not receive AG value in scheduling for uplink transmission. CONSTITUTION: A transceiver(42) receives scheduling information for uplink transmission from a terminal and transmits AG(Absolute Grant) value. A scheduling controller(44) determines whether the AG value of the terminal is received according to the reference value. If the AG value is not received, the scheduling controller transmits the AG value. The scheduling information includes information indicating a buffer and power state.

Description

SCHEDULING APPARATUS AND METHOD FOR TRANSMITTING USING UPLINK IN MOBILE SYSTEM}

The present invention relates to a scheduling apparatus for uplink transmission in a mobile communication system, and more particularly, to a high speed uplink package access (HSUPA) technology capable of high-speed packet data transmission on an uplink. A scheduling apparatus and method for improving scheduling efficiency when performing scheduling for uplink transmission from a mobile communication terminal to a base station in a mobile communication system.

With the development of internet technology and wireless communication technology, mobile communication systems are able to support internet access and multimedia communication, and provide large capacity high speed data services based on this.

Wideband Code Division Multiple Access (W-CDMA) is a wireless interface for International Mobile Communication (IMT-2000), standardized for use as a third generation wireless mobile communication system. It became. This provides a variety of services, such as voice services and multimedia mobile communication services, flexibly and efficiently. To create a common air interface specification for W-CDMA, Japan, Europe, the United States, and other countries have jointly organized a project called the Third Generation Partnership Project (3GPP).

On the other hand, the standardized European version of IMT-2000 is generally called UMTS (Universal Mobile Telecommunication System). The first standard of the UMTS specification was published in 1999. And improvements to the standard are in progress. In particular, in the improvement, high-speed asymmetry using dedicated channels (DCH: individual channels) and downlink shared channels (DSCH: downlink shared channels) in downlink and uplink Connection technology has recently been introduced and used.

First, high-speed downlink packet access (HSDPA) technology is introduced and used in the forward direction. In this technology, a new high-speed downlink shared channel (HS-DSCH) is used. From the radio access network (RAN: UMTS Radio Access Network) to the terminal called the user equipment in the UMTS specification, the downlink high-speed connection is provided to the user.

In addition, a high speed uplink package access (HSUPA) technology has been introduced and used in the reverse direction. In this technology, a large data set can be obtained from a terminal, which is a user device, using an enhanced-dedicated channel (E-DCH). It is a very efficient protocol to transmit and provides high speed uplink data transmission rate.

In the HSDPA and HSUPA systems as described above, scheduling is performed to efficiently manage data transmission and reception of user terminals. In the HSDPA system, terminals in a cell use one shared channel (HS-PDSCH: High Speed Physical Downlink Shared Channel). Since the scheduling is simple, in the HSUPA system, scheduling is complicated because terminals in a cell use each individual channel (E-DPDCH: E-DCH Dedicated Physical Data Channel). Therefore, the scheduling procedure is an important part of data transmission in HSUPA system.

The scheduling procedure in the HSUPA system is described below.

1 is a diagram illustrating a scheduling procedure in a mobile communication system according to the prior art. Referring to FIG. 1, when the terminal 1 needs to be scheduled (eg, when new data is generated in the terminal buffer), the terminal 1 transmits scheduling information (SI) to the base station controller 5 through the base station. In this case, the scheduling information may include information such as a buffer state, a power state (free power) of the terminal 1, and the like.

When the scheduling information is received from the terminal 1, the base station controller 5 determines the data rate and the available transmission power that the terminal 10 can transmit using the scheduling information (S20).

The base station controller 5 sets an AG grant (Absolute Grant value) according to the data rate and available transmission power (S30) and transmits the set AG value to the terminal 1 (S40). The maximum available power at the time of transmission of 1) is shown.

When the AG value is received, the terminal 1 determines the maximum E-TFCI (E-DCH Transport Format Combination Index) not exceeding the AG value according to the AG value. (S50) In this case, the E-TFCI is determined through the E-DCH. This indicates the size of one unit of packet data (MAC-ePDU: Medium Access Control-enhanced Protocol Data Unit) to be transmitted.

When the size of the packet data to be transmitted is determined as described above, the terminal 1 determines the data rate and transmission power to be transmitted through the E-DCH according to the determined E-TFCI. (S60) And the terminal 1 determines the determined data rate and transmission power. In step S70, data is transmitted.

In short, according to the scheduling procedure as described above, in the HSUPA system, scheduling is performed according to an SI value indicating a state of the terminal 10 and an AG value by the base station controller. Therefore, AG value plays an important role for scheduling.

However, due to various reasons such as instability of the wireless environment, the terminal often does not receive the AG value. If the AG value is not received in this manner, the UE cannot perform scheduling. Therefore, even if the terminal does not receive the AG value, there is a need for a method for scheduling to be performed normally.

To this end, in the related art, when the terminal does not receive an AG value, a method is used to use a SG (Serving Grant) value received from a radio bearer setup message. By the way, the SG value is typically used a low value to prevent excessive interference of the uplink. Therefore, when the SG value is used in this manner, the terminal may have a low transmission rate even though scheduling is possible. In this case, the terminal has a problem in that the terminal user is inconvenient because the data to be transmitted is in the buffer, the power is sufficient, and the base station transmits at a low data rate even when a high data rate is allowed.

Accordingly, as another method, a method of periodically transmitting the AG value and using the AG value of the next period when the terminal does not receive the AG value has been proposed. However, even in this method, if the AG value transmission period is Tmsec, the Txsec maintains a low data rate as described above, and even if the T value is set small, the base station frequently transmits the AG value. In addition, there is a problem that it is very difficult to apply the optimal T value because the number of terminals connected to the HSUPA system or the wireless environment changes from time to time.

Accordingly, an object of the present invention is to provide a scheduling apparatus and method capable of normal scheduling even when a terminal does not receive an AG value when performing scheduling for uplink transmission in a mobile communication system.

In addition, an object of the present invention, even when the mobile station does not receive an AG value when performing scheduling for uplink transmission, the base station determines this and immediately retransmits the AG value. It is to provide a scheduling apparatus and method that does not cause a load.

The present invention for achieving the above object is a scheduling apparatus for uplink transmission in a mobile communication system, receiving scheduling information (SI) for uplink transmission from the terminal, the AG value determined by the scheduling controller ( A transceiver for transmitting an Absolute Grant value) to the terminal, a memory for storing a reference value of the AG value non-receipt determination of the terminal, and whether the AG value of the terminal is not received according to the reference value, and the AG value is not received. If it is determined that the present invention provides a scheduling apparatus including a scheduling control unit for determining and transmitting the AG value.

Here, the scheduling information preferably includes information indicating a buffer state and a power state of the terminal.

In addition, the reference value of the AG grant (absolute grant value) determination is preferably a difference value between the data rate and transmission power according to the scheduling information and the data rate and transmission power at the actual data transmission.

The scheduling controller may determine that the AG value is not received when a difference between the data rate corresponding to the scheduling information and the available transmission power and the data rate and transmission power at the actual packet data transmission is greater than or equal to the reference value.

In this case, if the AG value is not received, the scheduling controller may determine the AG value according to a predetermined period T.

The scheduling apparatus may be provided and operated in any one of a base station and a base station controller.

In addition, the mobile communication system may be a high speed uplink package access (HSUPA) system.

According to another aspect of the present invention, there is provided a scheduling method for uplink transmission in a mobile communication system, comprising: a data rate corresponding to scheduling information (SI) received from a terminal and available transmission power and Calculating a difference between data rate and transmission power during actual packet data transmission, comparing the difference value with a predetermined reference value, and determining whether the terminal does not receive an Absolute Grant value; If it is determined that the AG value has not been received, it provides a scheduling method comprising the step of determining the AG value according to the data rate and the available transmission power by the scheduling information from the terminal and transmitting to the terminal.

In this case, if the AG value of the terminal is not received, it is preferable to further include the step of determining the AG value according to a predetermined period (T) and transmitting to the terminal.

The determining of whether the AG value is not received may include determining whether a difference between the data rate corresponding to the scheduling information and the available transmission power and the data rate and transmission power at the actual packet data transmission is greater than or equal to the reference value; The determination may include determining that the AG value is not received when the difference is equal to or greater than the reference value.

The scheduling method may be performed at any one of a base station and a base station controller.

In addition, the mobile communication system may be a high speed uplink package access (HSUPA) system.

According to another aspect of the present invention, there is provided a difference between a data rate corresponding to scheduling information (SI) received from a terminal, available transmission power, and a data rate and transmission power at the actual packet data transmission of the terminal. Comprising a step of calculating, comparing the difference value and a predetermined reference value to determine whether the AG value (Absolute Grant value) of the terminal is not received, and if it is determined that the AG value of the terminal is not received scheduling information from the terminal And a computer-readable recording medium having recorded thereon a program for executing the step of determining the AG value according to the data transmission rate and the available transmission power to the terminal.

Therefore, the present invention has the advantage that if the UE does not receive the AG value when performing scheduling for uplink transmission in the mobile communication system, the base station determines this and immediately retransmits the AG value so that the data rate does not need to be lowered according to the SG value.

In addition, in the present invention, if the AG value is periodically transmitted in the mobile communication system, even if the UE does not receive the AG value between the periods (T), the AG value may be retransmitted before the AG value is transmitted in the next period. It can be set to a value, thereby reducing the system load.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same components in the drawings are represented by the same reference numerals and symbols as much as possible even if shown in different drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First, FIG. 2 is a diagram illustrating a terminal and a base station system performing uplink transmission according to an embodiment of the present invention. 2, a base station system according to an embodiment of the present invention includes a base station 30 and a base station controller 50.

In such a base station system, signals transmitted by a plurality of user terminals 10 during uplink transmission do not maintain orthogonality with each other, and thus act as interference signals. As a result, as the number of uplink signals received by the base station 30 increases, the amount of interference signals for the uplink signal transmitted by the terminal 10 also increases, and thus the reception performance of the base station 30 is degraded. Therefore, the base station 30 should limit the amount of uplink signals that can be received while guaranteeing the overall reception performance.

To this end, the base station 30 or the base station controller 50 includes a scheduling device. Such a scheduling apparatus is capable of reducing the transmit power of the reverse channel to reduce inter-cell interference (ICI) to other cells while maintaining Rise Over Thermal (ROT) of total radio resources. Scheduling is inversely proportional to strength and data rate.

For example, when a plurality of terminals simultaneously transmit packet data using a high data rate, the total ROT may be higher than a target ROT. In this case, the reception performance of the uplink signal at the base station 30 is degraded. Accordingly, the scheduling apparatus prevents a plurality of terminals from simultaneously transmitting upstream using a high data rate. That is, the scheduling apparatus prevents the total ROT from increasing above the target ROT by allowing a lower data rate to other terminals when allowing a high data rate to a specific terminal. Because, when the data rate of a specific terminal is increased, the reception power received by the base station 30 from the specific terminal is increased, and the ROT of the terminal takes up a large portion of the total ROT. This is because the reception power received by the terminal 30 from the terminal becomes small and the ROT of the terminal occupies a small portion of the total ROT. Therefore, the scheduling apparatus performs scheduling during uplink transmission in consideration of the relationship between the data rate and the radio resource and the data rate requested by the terminal.

The scheduling is performed by the scheduling apparatus using an AG value indicating the maximum available power at the time of transmission using scheduling information (SI) including information on the buffer state, power state (free power), etc. from the terminal 10 ( If an Absolute Grant value) is provided, the UE receives the corresponding AG value and notifies whether the UE can transmit uplink or adjusts the uplink data rate.

However, if the terminal 10 does not receive the AG value due to various reasons such as instability of the wireless environment, the scheduling apparatus cannot perform scheduling because the uplink transmission of the terminal 10 cannot be controlled.

Therefore, in the scheduling apparatus according to the present invention, if the terminal 10 does not receive an AG value when performing scheduling for uplink transmission, the scheduling apparatus determines that the scheduling apparatus (base station or base station controller) retransmits the AG value to the terminal 10 immediately. It is composed.

Hereinafter, the configuration and operation of a scheduling apparatus in a mobile communication system according to an embodiment of the present invention will be described in detail.

First, a configuration of a scheduling apparatus according to an embodiment of the present invention will be described. FIG. 3 is a configuration diagram of a scheduling apparatus according to an embodiment of the present invention. Referring to FIG. 3, a scheduling apparatus according to an embodiment of the present invention includes a transceiver 42, a scheduling controller 44, and a memory 46.

The transceiver 42 receives the scheduling information from the terminal 10, and transmits the determined AG value to the terminal 10 when the AG grant (Absolute Grant value) is determined. In this case, the scheduling information may include information such as a buffer state, a power state (free power), and the like of the terminal 10. The AG value represents the maximum available power at the time of transmission of the terminal 10.

The scheduling controller 44 determines whether the terminal 10 does not receive the AG value according to a predetermined criterion, and if it is determined that the terminal 10 does not receive the AG value, the scheduling controller 44 immediately determines the AG value to correspond to the terminal 10. Send AG value.

More specifically, the scheduling controller 44 may determine the data rate corresponding to the scheduling information received from the terminal 10, the available transmission power, and the data rate and transmission power at the actual packet data transmission from the terminal 10. Calculate the difference. The scheduling controller 44 determines that the terminal 10 has not received the AG value if the difference is greater than or equal to a predetermined value, and according to the data transmission rate and the available transmission power based on the scheduling information from the terminal 10. Determine the value again. In addition, the scheduling controller 44 controls to transmit the determined AG value to the terminal 10.

The memory 46 stores the difference between the data rate and the transmission power based on the scheduling information as a reference for the AG value non-receipt determination of the terminal 10 and the data rate and the transmission power at the actual data transmission. This difference value is found in the case where the terminal 10 transmits data at a lower data rate than the AG value transmitted from the scheduling apparatus to the terminal 10 even though there is data to be transmitted to the terminal 10 buffer and sufficient power. The value to bet.

Hereinafter, the operation of the scheduling apparatus of the present invention configured as described above will be described in detail.

4 is a flowchart illustrating an operation of a scheduling apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 4, the scheduling apparatus monitors scheduling information received from the terminal 10 through the transmission / reception unit 42 to determine a data transmission rate and available transmission power of the terminal 10.

The scheduling apparatus determines the data rate and the transmission power at the time of actual packet data transmission from the terminal 10 (S104).

When the determination is completed, the scheduling apparatus compares the data transmission rate and available transmission power with the scheduling information received from the terminal 10 with the available data transmission rate and the available transmission power at actual packet data transmission (S106).

In operation S108, the scheduling apparatus determines whether the difference is greater than or equal to a predetermined value.

 If the difference is not greater than a predetermined value, the scheduling apparatus determines that the terminal 10 normally receives the AG value, and determines the AG value according to a predetermined period (T).

However, if the difference is greater than or equal to a predetermined value, the scheduling apparatus determines that the terminal 10 has not received the AG value, and determines the AG value according to the data rate based on the scheduling information from the terminal 10 and the available transmission power.

The scheduling apparatus transmits the determined AG value to the terminal 10 through the transceiver 44.

Referring to the AG value transmission time point by the scheduling apparatus of the present invention as described above, Figure 5 is a diagram showing the AG value transmission time point of the scheduling apparatus according to an embodiment of the present invention.

Referring to FIG. 5, when the terminal 10 normally receives an AG value, the scheduling apparatus of the present invention transmits the AG value according to a predetermined period T as shown by reference numeral a, and does not receive the AG value. If not, the AG value is transmitted when the non-receipt occurs between the periods, even if the period (T) as shown in the reference number b.

Therefore, in the present invention, when the scheduling apparatus periodically transmits the AG value, even if the AG value is not received between the periods T, the AG value may be retransmitted at the time point of the non-receipt before the AG value transmission in the next cycle occurs. Can be set to a large value, thereby reducing the system load.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. For example, in the above description of the present invention, the mobile communication system has been described using the HSUPA system as an example, but any mobile communication system is possible if the high-speed uplink access technology is applied. In addition, the above-described scheduling apparatus may be included in a base station and configured as a base station, or may be included in a base station controller and configured as a base station controller. On the other hand, it may be configured as a separate device from the base station and the base station controller. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

The present invention described above may be applied to scheduling between a terminal and a base station in a mobile communication system, and in particular, a mobile communication system to which a high speed uplink package access (HSUPA) technology capable of transmitting high-speed packet data on the uplink is applied. In the packet data transmission using the uplink in the scheduling process can be used to provide the AG value.

2 is a diagram illustrating a terminal and a base station system performing uplink transmission according to an embodiment of the present invention.

3 is a block diagram of a scheduling apparatus according to an embodiment of the present invention

4 is an operation flowchart of a scheduling apparatus according to an embodiment of the present invention.

5 is a diagram illustrating an AG value transmission time of a scheduling apparatus according to an embodiment of the present invention.

1 is a diagram illustrating a scheduling procedure in a mobile communication system according to the prior art.

Claims (13)

In the scheduling apparatus for uplink transmission in a mobile communication system, A transceiver for receiving scheduling information (SI) for uplink transmission from the terminal and transmitting an AG grant (Absolute Grant value) determined for scheduling to the terminal; A memory for storing a reference value of the AG value not received determination of the terminal; And a scheduling control unit for determining whether the AG value is not received by the terminal according to the reference value, and if the AG value is not received, determining and transmitting the AG value. The method of claim 1, wherein the scheduling information,  The scheduling apparatus in the mobile communication system, characterized in that it comprises information indicating the buffer state and the power state of the terminal. The reference value of claim 1, wherein the reference value of the non-receipt determination of the AG grant is: And a difference value between the data rate and the transmission power according to the scheduling information and the data rate and the transmission power at the time of actual data transmission. The method of claim 1, wherein the scheduling control unit, If the difference between the data rate corresponding to the scheduling information, the available transmission power and the data rate and transmission power at the time of actual packet data transmission is greater than or equal to the reference value, the AG value is determined not to be received. Device. The method of claim 4, wherein the scheduling control unit, If the AG value is not received, the scheduling apparatus in the mobile communication system, characterized in that for determining the AG value according to a predetermined period (T). The method according to any one of claims 1 to 5, The scheduling apparatus is a scheduling apparatus in a mobile communication system, characterized in that provided in any one of the base station and the base station controller. The method according to any one of claims 1 to 5, The mobile communication system is a scheduling apparatus in a mobile communication system, characterized in that a high speed uplink packet access (HSUPA) system. In the scheduling method for uplink transmission in a mobile communication system, Calculating a difference between a data rate corresponding to scheduling information (SI) received from the terminal, available transmission power, and a data rate and transmission power during actual packet data transmission of the terminal; Comparing the difference value with a predetermined reference value and determining whether the terminal does not receive an Absolute Grant value; In the mobile communication system, if it is determined that the AG value of the terminal is not received, the AG value is determined and transmitted to the terminal according to the data rate and the available transmission power according to the scheduling information from the terminal. Scheduling Method. The method of claim 8, And if the AG value of the terminal is not received, determining the AG value according to a predetermined period T and transmitting the AG value to the terminal. The method of claim 8, wherein the determining of whether the AG value is not received comprises: Determining whether a difference between the data rate corresponding to the scheduling information and the available transmission power and the data rate and transmission power during actual packet data transmission is greater than or equal to the reference value; And determining that the AG value is not received when the difference is greater than or equal to the reference value. The method of claim 8, wherein the scheduling information, The scheduling method of the mobile communication system, characterized in that it comprises information indicating the buffer state and the power state of the terminal. The method according to any one of claims 8 to 11, The mobile communication system is a scheduling method in a mobile communication system, characterized in that the high speed uplink packet access (HSUPA) system. Calculating a difference between a data rate corresponding to scheduling information (SI) received from the terminal, available transmission power, and a data rate and transmission power during actual packet data transmission of the terminal; Comparing the difference value with a predetermined reference value and determining whether the terminal does not receive an Absolute Grant value; If it is determined that the AG value of the terminal is not received, a computer program recording a program for executing the step of determining the AG value according to the data rate and the available transmission power from the scheduling information from the terminal and transmitting the AG value to the terminal is recorded. Recordable media.

Images