KR20190098035A - Method and apparatus for controlling data scheduling in mobile multimedia transmission system - Google Patents

Abstract

The present invention relates to a data scheduling control apparatus. The data scheduling control apparatus in a mobile multimedia transmission system determines a data modulation and coding scheme (MCS) based on an average data rate of a mobile multimedia service and subframe information allocated for physical multicast channel (PMCH) transmission, and transmits data of a transmission block size determined by the determined data MCS.

Description

METHOD AND APPARATUS FOR CONTROLLING DATA SCHEDULING IN MOBILE MULTIMEDIA TRANSMISSION SYSTEM}

The present invention relates to a data scheduling control method and apparatus in a mobile multimedia transmission system.

The UE may perform a process of acquiring Multicast Control Channel (MCCH) information in order to obtain multimedia broadcast multicast service (MBMS) control information broadcast from an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN including one or more base stations transmits a MBNSN (MBNSN) area configuration message to the UE in the RRC layer to transmit MCCH information. The MBSFN region configuration message may be mapped and transmitted to MCCH, which is a logical channel, and the MCCH may be mapped and transmitted on a physical multicast channel (PMCH), which is a physical channel.

The MBSFN region configuration message includes MBMS control information applicable to the MBSFN region, and the E-UTRAN configures the MCCH for each MBSFN region. MCCH identifies the MBSFN area.

The MBSFN area configuration message includes a PMCH Configuration List Information Element as MBMS control information. The PMCH configuration list information element may include a data MCS (dataMCS) field for defining Modulation and Coding Scheme (MCS) information for a subframe in which the PMCH is transmitted. At this point, the data MCS field may indicate whether 256 QAM is supported for the PMCH and may indicate an MCS index value for indicating the MCS. If the MCS index is high, more data can be transmitted using the same radio resource, but a data reception error may occur in a terminal in a low channel quality environment. In addition, the lower the MCS index, the higher the data reception success rate in a terminal in a low channel quality environment, but the disadvantage is that the amount of data that can be transmitted using the same radio resources.

The data MCS is defined as an integer in the range [0,28]. Therefore, when the data MCS is set to an unnecessarily high MCS index, a subframe resource allocated for PMCH transmission is wasted, and a problem in that data is not received from a terminal in a low channel quality environment occurs. In addition, when the data MCS is set to an unnecessarily low MCS index, there is a problem in that service data of a session list set in PMCH cannot be transmitted in a subframe allocated for PMCH transmission.

An object of the present invention is to provide a data scheduling control method and apparatus for efficiently using radio resources in a mobile multimedia transmission system.

According to an embodiment of the present invention, a data scheduling control method in a mobile multimedia transmission system is provided. The data scheduling control method determines the data modulation and coding scheme (MCS) based on the average data rate of the mobile multimedia service and the subframe information allocated for physical multicast channel (PMCH) transmission, and the determined data MCS. Transmitting the data of the transport block size.

The determining may include calculating a target transmission bit number of a subframe capable of transmitting only data from among subframes allocated for the PMCH transmission, and determining the target transmission bit number based on the number of physical resource blocks (PRBs) of a system band. Determining an index of the transport block size that can be transmitted, and selecting an MCS index mapped to the index of the determined transport block size.

The determining of the transport block size index includes determining an index of the smallest transport block size that can transmit the target number of transmission bits in the number of PRBs in the system band, based on a transport block size table according to the number of PRBs. can do.

The calculating may include defining a PMCH target transmission bit number based on the sum of the average data rates per second of each session included in the session list of the PMCH configuration, and the number of data bits that may be transmitted in a subframe transmitting PMCH scheduling information. Calculating the number of data bits that can be transmitted in the PMCH target transmission bit number and the subframe in which the PMCH scheduling information is transmitted, and the number of subframes in which only data can be transmitted among the subframes allocated for the PMCH transmission. And calculating the number of data bits of a subframe in which only the data can be transmitted.

The number of data bits that can be transmitted in the subframe for transmitting the PMCH scheduling information may be calculated based on the signaling transport block size, the data size of the PMCH scheduling information, and the number of subframes for transmitting the PMCH scheduling information.

According to another embodiment of the present invention, an apparatus for controlling data scheduling in a mobile multimedia transmission system is provided. The data scheduling controller determines a data modulation and coding scheme (MCS) based on the average data rate of the mobile multimedia service and subframe information allocated for physical multicast channel (PMCH) transmission, and transmits data according to the determined data MCS. A processor for determining a block size, and a transceiver for transmitting data of the determined transport block size.

The processor may calculate a target transmission bit number of a subframe capable of transmitting only data among subframes allocated for the PMCH transmission, and transmit the target transmission bit number based on the number of physical resource blocks (PRBs) of a system band. An index of the transport block size may be determined, and an MCS index mapped to the determined transport block size index may be selected.

The processor may determine an index of the smallest transport block size that can transmit the target number of transmission bits in the number of PRBs in the system band based on the transport block size table according to the number of PRBs.

According to the present invention, it is possible to efficiently use radio resources by selecting an MCS index that can efficiently transmit mobile multimedia service data in a subframe allocated for PMCH transmission.

1 is a diagram showing the structure of an evolved Multimedia Broadcast / Multicast Services (eMBMS) system to which the present invention is applied.
2 is a diagram illustrating a method of delivering MBMS scheduling information in an MCE according to an embodiment of the present invention.
3 is a diagram illustrating an MCH scheduling information MAC control element.
4 shows a modulation and transport block size index table for PDSCH shown in Table 7.1.7.1-1 of 3GPP TS 36.213.
5 is a diagram illustrating an apparatus for controlling data scheduling in a mobile multimedia transmission system according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification and claims, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

Now, a method and apparatus for controlling data scheduling in a mobile multimedia transmission system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the structure of an evolved Multimedia Broadcast / Multicast Services (eMBMS) system to which the present invention is applied.

Referring to FIG. 1, the BMSC 160 performs authority verification and service start for an MBMS bearer service, and is responsible for scheduling and transmission in consideration of quality of service for MBMS content provided from the content server 170. The BMSC 160 may deliver its own broadcast content to the LTE network or relay the broadcast content in association with an external content server 170. The BMSC 160 has an SGmb interface for exchanging control messages with the MBMS gateway 150 and an SGi-mb interface for transmitting user traffic (content).

The MBMS gateway 150 performs a control (service start / end) function for the MBMS session and delivers content to the eNBs using an IP multicast transmission scheme. The MBMS gateway 150 has an Sm interface for exchanging control messages for the session with the mobility management entity (MME) 140 and an M1 interface for delivering user traffic to the eNB 120.

The MME 140 is in charge of controlling the MBMS session and has an M3 interface with the MCE 130 to connect the MBMS Coordination Entity (MCE) 130 and the MBMS gateway 150.

The MCE 130 is in charge of management and allocation of radio resources for the eNBs 120 belonging to the MCE 130 and is responsible for admission control for MBMS service. It determines the Modulation and Coding Scheme (MBS) for MBMS services and controls the MBMS session. The MCE 130 has an M2 interface for transmitting control signals with the eNB 120.

The eNB 120 receives information on radio resources allocated by the MCE 130 and performs synchronized transmission for broadcast services scheduled by the MCE 130.

UE 110 receives the synchronized MBMS data.

2 is a diagram illustrating a method of delivering MBMS scheduling information in an MCE according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating an MCH scheduling information MAC control element.

Referring to FIG. 2, the MCE 130 may convert MBNSN single frequency network (MBSFN) area configuration information including radio resource allocation information into an MBMS scheduling information request message (MBMSSchedulingInformation Request) which is an M2AP (M2 Application Protocol) message. To transmit to the eNB 120 using (S210).

The eNB 120 transmits MBSFN area configuration information (MBSFNAreaConfiguration) using a multicast control channel (MCCH) message (S220).

MBSFN means simultaneously transmitting the same data in different eNBs to provide MBMS service. The MBSFN region may mean a set of cells providing the same MBSFN service. One MBSFN region is associated with one MCCH, and one MCCH corresponds to one MBSFN region. The MCCH may be transmitted by being mapped to a PMCH which is a physical channel.

MBSFN area information includes the information shown in Table 1.

PMCH Configuration List
-PMCH Configuration
PMCH-Config
sf-AllocEnd
dataMCS
mch-SchedulingPeriod
mbms-SessionInfoList per PMCH
MBMS Service Identity
-logicalChannelIdentity
-MBSFN Subframe Configuration List
-MBSFN Subframe Configuration
Radio Frame Allocation Period
Radio Frame Allocation Offset
Subframe Allocation (oneframe or fourframe)
Common Subframe Allocation Period
MBSFN Area ID

The PMCH configuration (PMCH-Config) includes an allocation last subframe (sf-AllocEnd), a data MCS (dataMCS), and an MCH scheduling period (mch-SchedulingPeriod). The allocation last subframe (sf-AllocEnd) indicates the last subframe allocated for PMCH transmission in the common subframe allocation period. The data MCS (dataMCS) may indicate whether 256 QAM is supported for the PMCH and may indicate an MCS index value for indicating the MCS. MCH scheduling period (mch-SchedulingPeriod) represents the MCH scheduling period.

The MBSFN subframe configuration may include information such as a radio frame allocation period, a radio frame allocation offset, a subframe allocation, and the like. That is, the MBSFN subframe allocation pattern is defined in the radio period by the MBSFN subframe configuration list including one or more MBSFN subframe configurations.

When the MBSFN subframe allocation pattern is applied in the common subframe allocation period, the number of subframes allocated for MBSFN data transmission is defined in the common subframe allocation period of one MBSFN region. do.

In addition, the number of subframes allocated for PMCH transmission in the common subframe allocation period is defined by the setting of the last subframe (sf-AllocEnd) of the PMCH configuration (PMCH-Config). In the first subframe for each MCH scheduling period (mch-SchedulingPeriod) in the subframe allocated for PMCH transmission, (P) MCH scheduling information [(P) MCH Scheduling Information, MSI] MAC CE (Control Element) is transmitted. The MSI MAC CE is defined as shown in FIG. 3, and the MSI MAC CE data size defining scheduling information of each PMCH is (number of sessions defined in PMCH x 2 bytes).

When transmitting data in a subframe allocated for PMCH transmission, data of a transport block size determined by the data MCS (dataMCS) set in the MBSFN region information is transmitted to the radio section. The data MCS is defined as an integer in the range [0,28]. The MCS that uses MBMS service data in the radio section can transmit more data using the same radio resource as the higher MCS index is allocated, but a data reception error may occur in a terminal in a low channel quality environment. In addition, the lower the MCS index, the higher the data reception success rate in a terminal in a low channel quality environment, but the disadvantage is that the amount of data that can be transmitted using the same radio resources. Therefore, setting the data MCS to an unnecessarily high MCS index wastes subframe resources allocated for PMCH transmission and causes a problem in that data cannot be received by a terminal in a low channel quality environment. In addition, if the data MCS is set to an unnecessarily low MCS index, there is a problem in that service data of a session list configured in PMCH cannot be transmitted in a subframe allocated for PMCH transmission.

An embodiment of the present invention provides a method for selecting data MCS to efficiently transmit MBMS service data in a subframe allocated for PMCH transmission.

The MCE 130 of the mobile multimedia transmission system uses 1024 radios based on the sum of the average data rates (bits / s) per second of each session included in the session list (mbms-SessionInfoList per PMCH) of the PMCH-Config. Defines the number of PMCH target transmission bits during the frame. The PMCH target transmission bit number B1 is expressed by Equation 1 below.

Here, one radio frame is 10ms, and 1024 radio frames are 10240ms.

That is, the session service data of the PMCH should be able to transmit the PMCH target transmission bit number B1 of Equation 1 in the radio period during 1024 radio frames.

The MCE 130 according to the embodiment of the present invention applies the MBSFN subframe allocation pattern in the common subframe allocation period to apply the MBSFN in the common subframe allocation period of one MBSFN region. Defines the subframe allocated for data transmission. In addition, the number of subframes N allocated for PMCH transmission in the common subframe allocation period is defined by setting the last subframe (sf-AllocEnd) of the PMCH configuration (PMCH-Config).

The total number of subframes N0 allocated for PMCH transmission during the 1024 radio frames becomes "(1024 / Common Subframe Allocation Period) x N".

The number of subframes N1 for transmitting the MSI, which is PMCH scheduling information, for 1024 radio frames becomes "1024 / mch-SchedulingPeriod".

In addition, the number of data transmission subframes N2 capable of transmitting only data among subframes allocated for PMCH transmission during 1024 radio frames is "(N0-N1)".

The signaling transport block size is determined using the number of PRBs defined by signaling MCS (signallingMCS) and system bandwidth set in MBSFN area information (MBSFN-AreaInfo). For example, if the system bandwidth is 20 MHz (N _PRB = 100) and signaling MCS (signallingMCS) = 5, the signaling transmission block size is 8760 bits.

Since the MSI MAC CE data size is (number of sessions defined in PMCH x 2 x 8) bits, the number of session service data bits (S1) that can be multiplexed and transmitted in a subframe transmitting an MSI during 1024 radio frames is expressed by Equation 2 and the following. Can be represented as:

That is, the MCE 130 determines the number of data bits (B2) of the PMCH data transmission subframe that can only transmit data among the subframes allocated for PMCH transmission during the 1024 radio frames, as shown in Equation 3, Must be able to transmit

The MCE 130 according to an embodiment of the present invention defines a target transmission bit number B3 of a PMCH data transmission subframe capable of transmitting only data among subframes allocated for PMCH transmission as shown in Equation 4.

The MCE 130 selects as the data MCS (dataMCS) the smallest MCS index capable of transmitting the target transmission bit number B3 of the PMCH data transmission subframe in the system bandwidth resource.

The MCE 130 determines the PRB number (N _PRB ) defined by the system bandwidth and refers to the transport block size table defined in Table 7.1.7.2.1 of 3GPP TS 36.213, and describes the columns of PRB number (N _PRB ). In (column), the smallest transport block size index (I _TBS ) capable of transmitting the target number of transmission bits B3 of the PMCH data transmission subframe is determined.

Next, the MCE 130 determines the MCS index mapped to the determined transport block size index (I _TBS ) with reference to the table shown in Equation 4.

4 shows a modulation and transport block size index table for PDSCH shown in Table 7.1.7.1-1 of 3GPP TS 36.213.

As such, the MCE 130 according to an embodiment of the present invention determines a data MCS (dataMCS) to be used for PMCH data transmission based on the average data rate of the mobile multimedia service and the subframe information allocated for PMCH transmission.

5 is a diagram illustrating an apparatus for controlling data scheduling in a mobile multimedia transmission system according to an embodiment of the present invention.

Referring to FIG. 5, the data scheduling control apparatus 500 includes a processor 510, a transceiver 520, and a memory 530. The data scheduling control apparatus 500 may be implemented in the MCE 130 or may mean the MCE 130 itself.

The processor 510 may operate to implement a function, an operation and a method for determining the data MCS (dataMCS) described with reference to FIGS. 1 to 4. The processor 510 may implement a function, an operation and a method of determining the data MCS (dataMCS) of the MEC 130 described above by executing instructions stored or loaded in the memory 530. The processor 510 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to an embodiment of the present invention are performed.

The transceiver 520 is connected to the processor 510 to transmit and / or receive a radio signal.

The memory 530 is connected to the processor 510 and stores various information for driving the processor 510. The memory 530 stores instructions for execution in the processor 510 or temporarily loads instructions from a storage device (not shown). The memory 530 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage device.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (8)

A data scheduling control method in a mobile multimedia transmission system,
Determining a data modulation and coding scheme (MCS) based on the average data rate of the mobile multimedia service and the subframe information allocated for physical multicast channel (PMCH) transmission, and
Transmitting data of a transport block size determined by the determined data MCS
Data scheduling control method comprising a. In claim 1,
The determining step
Calculating a target transmission bit number of a subframe in which only data can be transmitted among the subframes allocated for the PMCH transmission;
Determining an index of a transport block size that can transmit the target number of transmission bits based on the number of physical resource blocks (PRBs) of a system band, and
Selecting an MCS index mapped to an index of the determined transport block size. In claim 2,
The determining of the transport block size index includes determining an index of the smallest transport block size that can transmit the target number of transmission bits in the number of PRBs in the system band, based on a transport block size table according to the number of PRBs. Data scheduling control method. In claim 2,
The calculating step
Defining the number of PMCH target transmission bits based on the sum of the average data rates per second of each session included in the session list of the PMCH configuration,
Calculating the number of data bits that can be transmitted in a subframe that transmits PMCH scheduling information, and
Only the data based on the number of PMCH target transmission bits, the number of data bits that can be transmitted in a subframe for transmitting the PMCH scheduling information, and the number of subframes that can only transmit data among subframes allocated for the PMCH transmission. Calculating the number of data bits of a subframe that can be transmitted. In claim 4,
The number of data bits that can be transmitted in a subframe transmitting the PMCH scheduling information is calculated based on a signaling transport block size, the data size of the PMCH scheduling information, and the number of subframes transmitting the PMCH scheduling information. An apparatus for controlling data scheduling in a mobile multimedia transmission system,
A data MCS (Modulation and Coding Scheme) is determined based on the average data rate of the mobile multimedia service and subframe information allocated for physical multicast channel (PMCH) transmission, and the transport block size of the data is determined according to the determined data MCS. Processor, and
Transceiver for transmitting the data of the determined transport block size
Data scheduling control device comprising a. In claim 6,
The processor may calculate a target transmission bit number of a subframe capable of transmitting only data among subframes allocated for the PMCH transmission, and transmit the target transmission bit number based on the number of physical resource blocks (PRBs) of a system band. And an MCS index that determines an index of the transport block size and maps the index of the determined transport block size. In claim 7,
And the processor determines an index of the smallest transport block size that can transmit the target number of transmission bits in the number of PRBs in the system band, based on a transport block size table according to the number of PRBs.

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