KR101642148B1 - Method for controlling mbms service of user equipment in mbsfn - Google Patents

Abstract

The present invention relates to a method and apparatus for establishing a communication layer for a service in accordance with a service initiation request, the communication layer comprising a radio link control (RLC) layer and a media access control (MAC) layer, ) Layer to determine whether to receive dynamic scheduling information in a physical multicast channel including the service, and if the reception is unsuccessful, cancel the setting for the MAC layer, (RRC) layer control method comprising the step of stopping reception from a channel.

A single frequency network, a multimedia broadcast / multicast service, a radio resource control (RRC) layer

Description

TECHNICAL FIELD [0001] The present invention relates to a multimedia broadcast / multicast service control method for a mobile terminal in a single frequency network,

The present invention relates to a service method of a mobile terminal, and more particularly, to a method of controlling a multimedia broadcast / multicast service of a mobile terminal in a single frequency network.

The present invention has been derived from research carried out as part of the IT growth engine technology development project of the Ministry of Knowledge Economy and the Korea IT Industry Promotion Agency. [Assignment number: 2008-S-006-02, Title: Open IPTV 2.0) technology development].

In the LTE-Advanced (Long Term Evolution-Advanced) system, a multimedia broadcast / multicast service based on a Multimedia Broadcast Multicast Service Single Frequency Network (MBSFN) And defines a Multimedia Broadcast and Multicast Service (MBMS).

MBSFN is a technique for synchronizing radio resources in all base stations belonging to the MBSFN region and simultaneously transmitting the same data at the same time. Even if the mobile station is located at the cell boundary, the signals of the neighboring base stations do not act as interference, .

Accordingly, in the MBSFN region, the mobile station recognizes that the MBMS data transmitted from all of the base stations is transmitted from one base station. Even if the mobile station moves within the area, the mobile station receives a seamless broadcast service without a separate handover procedure .

In providing the MBSFN-based MBMS service, all the services provided in the network are mapped 1: 1 to one multicast traffic channel (MTCH) among the logical channels.

Also, multiple MTCHs are multiplexed (N: 1) mapped to a multicast channel (MCH) of one of transport channels, and one MCH is mapped to one physical multicast channel (1: 1) with a Physical Multicast Channel (PMCH).

At this time, there may exist several PMCHs according to the characteristics of the service, and PMCHs have different modulation and coding schemes (MCS).

For example, a PMCH in which a low-resolution broadcast service and a high-resolution broadcast service are mapped to different MCHs and a low-resolution service is mapped has a low MCS level, for example, QPSK, The mapped PMCH can have a high MCSH level, for example 64QAM.

By doing so, the network can be multiplexed in various ways according to the characteristics of the service, and the radio resources can be efficiently used, but there arises a problem that the area in which the base station can transmit data differs according to the MCS level.

That is, a mobile station located near a base station can receive both data transmitted at a high MCS level and data transmitted at a low MCS level, but a mobile terminal located far away from the base station can receive only data transmitted at a low MCS level .

Therefore, if the user requests the start of a service having a high MCS level in a state far from the base station, the mobile terminal performs a procedure for receiving the service even though the mobile terminal can not receive the service, .

Accordingly, there is a need to provide an MBMS service to a user regardless of the location of the mobile station in an MBSFN environment in which MBMS data having different MCS levels are transmitted, and to minimize battery consumption of the mobile station.

According to an embodiment of the present invention, when channels for a service requested by a user are set based on multicast control channel information (MCCH) received by the mobile station, battery consumption of the mobile station can be minimized And a method for controlling a multimedia broadcast / multicast service (MBMS) service.

A method for controlling a radio resource control (RRC) layer according to an embodiment of the present invention includes a communication layer for the service according to a service initiation request, wherein the communication layer includes a radio link control (RLC) layer, a media access control - checking if the dynamic scheduling information in the physical multicast channel including the service is received from the media access control (MAC) layer, and if the reception fails, And terminating the setting for the control (MAC) layer to stop receiving from the physical multicast channel.

According to an embodiment of the present invention, even if the user requests the start of a service that can not be provided at the current location, the mobile terminal can reduce unnecessary battery consumption by checking whether the MBMS data can be received periodically.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a method of providing a multimedia broadcast / multicast service (MBMS) service based on a Multimedia Broadcast / Multicast Service Single Frequency Network (MBSFN) in an LTE-Advanced system to which the present invention is applied.

As shown in FIG. 1, an LTE-Advanced system has an MBMS service area 101 and a plurality of MBSFN areas 102 can be configured in the MBMS service area. In the MBSFN area 102, all the base stations 103 synchronize the radio resources and simultaneously transmit the same data at the same time.

Therefore, even if the mobile terminal is located at the cell boundary, the signal of the neighboring base station does not act as an interference but acts as a gain. Therefore, even if all the base stations transmit MBMS data in the MBSFN area 102, the mobile terminal recognizes that the data is transmitted from one base station. In this area, even if the mobile terminal moves, Service can be provided.

In providing MBSFN-based MBMS service, all services provided in the network are mapped 1: 1 to one MTCH 104 among logical channels, and several MTCHs 104 are mapped to one MCH 105, 106, 107 Multiple (N: 1) mapped.

One MCH (105, 106, 107) is 1: 1 mapped to one PMCH (108, 109, 110) in the physical channel. At this time, a plurality of MCHs 105, 106 and 107 may exist according to the characteristics of the service, and the PMCHs 108, 109 and 110 to which the MCHs 105, 106 and 107 are mapped have different MCSs.

For example, the service 1, the service 2, and the service 3 having low resolution are mapped to the MCH # 1 105 and the MCH # 1 105 is mapped to the PMCH # 1 108 having the MCS level of QPSK And is transmitted according to the MCH Subframe Allocation Pattern (MSAP).

The service 5, the service 6, and the service 7 having the intermediate resolution are mapped to the MCH # 2 106. The MCH # 2 106 is mapped to the PMCH # 2 109 having the MCS level of 16QAM, do.

The service 9, service 10, and service 11 having high resolution are mapped to the MCH # 3 107. The MCH # 3 107 is mapped to the PMCH # 3 110 having the MCS level of 64QAM, Therefore, it is transmitted.

By doing so, the network can be multiplexed in various ways according to the characteristics of the service and efficiently use the radio resources, but there arises a problem that the area in which the base station can transmit data differs according to the MCS level.

For example, the mobile station UE1 (User Equipment) 111 can receive Service 1, Service 2, and Service 3, which are located at the edge of the cell and are transmitted at a low level of MCS level.

The mobile terminal UE2 112 is located in the middle of the cell and can receive the service 1, the service 2, and the service 3, and the service 5, the service 6, and the service 7 having the intermediate resolution. Also, the mobile terminal UE3 (113) is located inside the cell and can receive all services.

In this situation, if a user using the UE1 111 requests the start of the service 9 having a high MCH level, the mobile terminal is in a position where it can not receive the service.

However, in order to receive the service, the mobile station must perform decoding of the dynamic scheduling information (DSI) 114 of the PMCH # 3 every MSAP occurrence period (MSAP Occasion Period) Resulting in battery loss.

The DSI 114 is a MAC Control Element indicating information of a subframe in which services transmitted to the PMCH are transmitted, and is scheduling information dynamically allocated differently for each MSAP occurrence period.

In order to match the scheduling timing between the MAC and the PHY, the mobile station must decode the DSI 114 to be able to know the subframe in which the corresponding service is transmitted. In addition to DSI, It is possible to receive it smoothly.

The MCCH 115 is a channel for transmitting multicast control information. Since the MCH 115 exists only in the MBSFN area, the MCCH 115 appears only in a PMCH having a specific MCS level, and is transmitted periodically with a modification period and a repetition period.

The MCCH 115 includes information on services currently being transmitted in the MBSFN region and information on PMCHs to which services are mapped, and is changed each time a service is started or terminated.

2 is a diagram illustrating an internal hierarchical structure of a mobile terminal for receiving a multimedia broadcast / multicast service (MBMS) according to an embodiment of the present invention.

As shown in FIG. 2, a mobile terminal is roughly divided into a TE (Terminal Equipment) 201 and a MT (Mobile Terminal) 202.

The TE 201 may correspond to, for example, a notebook computer or a terminal having a communication function, and may be formed of an MBMS client 203 and an IP layer 204.

Here, the MBMS client 203 may correspond to MBMS software such as DMB software installed in a terminal or the like.

MBMS data received from the IP layer 204 through the MT 202 is shown to the user in the MBMS Client 203. [

The MT 202 may be, for example, a Wibro USB modem installed externally in a notebook computer, a communication terminal, or the like. The MT 202 may include a Radio Resource Control (RRC) A radio access control layer 208, a medium access control (MAC) layer 209, and a physical layer (PHY) layer 210.

The RLC 208 performs functions such as upper layer packet data unit (PDU) transmission, error correction through an automatic repeat request (ARQ), connection / division / reassembly of an RLC SDU (Service Data Unit), duplication detection and retransmission .

delete

delete

The MAC 209 performs functions such as logical channel and transport channel mapping, multiplexing / demultiplexing of MAC SDUs, error correction through HARQ, and dynamic scheduling.

The PHY 210 performs functions such as link adaptation, power control, and cell search.

A control plane (hereinafter referred to as a CP) 212 is constructed between the PHY-MAC-RLC-RRC-MBMS Client and a data plane (UP) IP-MBMS Client.

The RRC 206 controls the RLC 208, the MAC 209 and the PHY 210 through a C-SAP (Control-Service Access Point) interface 211 to perform a radio resource control function.

3 is a flowchart illustrating a method of controlling a radio resource control (RRC) layer according to an embodiment of the present invention.

Referring to FIG. 3, the control method of the radio resource control (RRC) layer includes a step 301 of setting a communication layer, a step 303 of confirming whether dynamic scheduling information is received or not, The step 305 of unsetting the media access control (MAC) layer, and the step 307 of starting the service if the reception of the dynamic scheduling information at step 303 is successful.

In step 301, a radio resource control (RRC) layer sets up a communication layer for providing a requested service according to a service start request from a user.

Wherein the communication layer may comprise a radio link control (RLC) layer, and a media access control (MAC) layer.

Prior to step 301, the radio resource control (RRC) layer can confirm whether or not the service-aware service that can be currently provided can be provided through the MCCH information that has been received according to the service start request.

If the service can not be provided because the service has not been started yet, the service is stored in the list of pending services, the service is started, the MCCH information including the information about the service is received, You can wait.

If the service is started and the service can be provided, the radio resource control (RCC) layer can perform radio link control (RLC) setting and media access control (MAC) layer setting for the corresponding service.

In step 303, the radio resource control (RRC) layer confirms whether dynamic scheduling information is received in the physical multicast channel including the service from the media access control (MAC) layer.

In step 303, the MAC layer may request the physical layer (PHY) to receive the dynamic scheduling information (DSI) of the PMCH to which the corresponding service is mapped in order to schedule the corresponding service.

The physical layer (PHY) performs DSI decoding according to the request, and notifies the media access control (MAC) layer of this fact if the DSI decoding for the PMCH fails.

Accordingly, the media access control (MAC) layer notifies the radio resource control layer (RRC) that the requested service has failed to start, thereby confirming whether the dynamic scheduling information is received in the physical multicast channel.

If the reception of the dynamic scheduling information fails in step 305, the radio resource control layer (RRC) can cancel the setting for the MAC layer and stop the reception from the physical multicast channel.

If the dynamic scheduling information is successfully received in step 303, the RRC initiates a service requested by the user using the dynamic scheduling information (307).

4 is a flowchart illustrating a procedure for receiving multicast control channel information (MCCH) and setting a physical multicast channel (PMCH) in a mobile station according to an embodiment of the present invention.

As shown in FIG. 4, when an initial connection due to power application or a cell change due to movement occurs, the mobile terminal receives system information (S420).

If it is the system information in the cell belonging to the MBSFN area, this system information includes MCCH setting information provided for the MBMS service.

At this time, the MCCH setting information may include the MCCH repeat cycle, the update cycle, the PMCH setting information of the MCCH to be transmitted, and the RLC / MAC setting information.

Accordingly, the mobile terminal acquires information on the received information (S423), performs RLC setting (S429), MAC setting (S432), and PHY setting (S435) for MCCH reception.

In this case, the PHY 413 may include PMCH information on which the MCCH is transmitted, i.e., an MCS level, an MSAP, an MSAP occurrence period, an MCCH update period, a repetition period, and the like. The PHY 413 receives the MCCH based on this information (S438) and transmits it to the RRC 405 (S441).

The RRC 405 receiving the MCCH information updates the service information and the PMCH information included in the MCCH (S444). At this time, the MCCH information may include information of services currently being serviced, RLC / MAC setting information for the service, and PMCH information to which the service is mapped.

The RRC 405 checks whether there is another PMCH other than the PMCH to which the MCCH is transmitted or whether the PMCH information is changed differently from the previously received MCCH information (S447).

If the PMCH information is different from the PMCH information received from the system information or the PMCH information received from the previous MCCH, the RRC 405 sets all changed PMCH information in the PHY 413 (S450) even if the PMCH information does not receive the MBMS service, If there is no changed information, it waits for the next MCCH reception.

The PHY 413 can distinguish between a subframe in which MBMS data is transmitted and a subframe in which unicast data is transmitted, by setting all PMCHs even though the MBMS service is not received.

5 is a flowchart illustrating a method of providing a multimedia broadcast / multicast service (MBMS) in a mobile station according to an embodiment of the present invention.

5, the MBMS Client 501 has a list of all services provided in the MBSFN area in which the mobile terminal is located (S520). Through the service list information, the user can request the mobile terminal to start the service have.

Here, the service list information may be received through an SMS cell broadcast, an MBMS broadcast mode, HTTP, FTP, MMS, WAP, and the like, and may include information such as an identity, a service time, and a service type.

When the MBMS client 501 requests the RRC 505 to start the MBMS service at step S523 according to the user's request, the RRC 505 transmits an acceptance confirmation to the MBMS client 501 (S526) (501) receives this acceptance confirmation message and prepares for service start (S529).

The RRC 505, which is requested to start the MBMS service, determines whether the current service is available through the MCCH information that has been received (S532).

If the service is not yet started, that is, if the service is not available, the RRC 505 stores the service in the pending service list (S535), receives the MCCH information including the information about the service I wait until.

When the RRC 505 receives the MCCH information including the corresponding service information (S538), the RRC 505 updates the service list information and PMCH setting information currently being serviced (S541).

Thereafter, the RRC 505 confirms whether the PMCH information has been changed (S544). If the change is made, the RRC 505 sets the changed PMCH information in the PHY 513 (S547).

The RRC 505 checks whether the MBMS service can be started (S550). If the service can be started, the RRC 505 performs the RLC setting (S556) and the MAC setting (S559) for the corresponding service at the time when the MBMS service can be started. If it is not possible to start the MBMS service in step S550, the RRC 505 returns to step S535 to perform the subsequent procedure.

The MAC layer 511 requests the PHY 513 to receive the DSI of the PMCH to which the corresponding service is mapped in order to schedule the service requested by the user (S562).

The PHY 513 performs DSI decoding in the first subframe of the MSAP occurrence period according to the request (S565), and notifies the MAC 511 of this fact if the DSI decoding for the PMCH fails (S568) .

Then, the MAC 511 notifies the RRC 505 that the requested service has failed to start (S571).

Upon receiving the message, the RRC 505 recognizes that the requested service is a service that can not start at the current location, and releases only the setting of the MAC 511 without revoking the configuration information of the RLC 509 (S574) .

Accordingly, the MAC 511 requests decoding of the DSI decoding in the corresponding PMCH (S577), thereby unnecessarily decoding and preventing the battery from being consumed.

When the RRC 505 reaches a position where the service can be started, the RRC 505 sets a service reset time to request service start (S580). When the reset time expires, the RRC 505 requests the MAC setting for the service again S559).

At this time, the service reset period should be longer than the corresponding PMCH occurrence period, and can be determined in consideration of the moving speed of the user.

When the DSI information of the PMCH is successfully detected by the PHY 513 and the DSI information is received by the MAC 511 at S583, the MAC 511 transmits to the RRC 505 that the service has been started at S586.

Then, the RRC 505 notifies the MBMS client 501 that the service has been started (S589) so that the MBMS service can be activated (S592).

Then, the MAC 511 schedules the subframe information including the corresponding service in the PHY 513 based on the received DSI information (S595), so that the MAC 511 can receive data for the service (S598).

By doing so, the mobile terminal can provide the MBMS service to the user while minimizing the battery consumption, and when the service reaches the position where the service can be started with respect to the requested service at the position where the service can not be started, .

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be construed as being limited to the embodiments described, but should be determined by equivalents to the appended claims, as well as the following claims.

1 is a diagram illustrating a method of providing a multimedia broadcast / multicast service (MBMS) service based on a Multimedia Broadcast / Multicast Service Single Frequency Network (MBSFN) in an LTE-Advanced system.

2 is a diagram illustrating an internal hierarchical structure of a mobile terminal for receiving a multimedia broadcast / multicast service (MBMS) according to an embodiment of the present invention.

3 is a flowchart illustrating a method of controlling a radio resource control (RRC) layer according to an embodiment of the present invention.

4 is a flowchart illustrating a procedure for receiving multicast control channel information (MCCH) and setting a physical multicast channel (PMCH) in a mobile station according to an embodiment of the present invention.

5A and 5B are flowcharts illustrating a method of providing a multimedia broadcast / multicast service (MBMS) in a mobile station according to an exemplary embodiment of the present invention.

Claims (10)

Establishing a communication layer for receiving the service in response to a service initiation request, the communication layer including a radio link control (RLC) layer and a media access control (MAC) layer; Confirming whether or not dynamic scheduling information is received from the media access control (MAC) layer in a physical multicast channel of a physical (PHY) layer including the service; And If decoding of the dynamic scheduling information fails from the physical layer (PHY) according to the confirmation, the RLC layer for the reception of the service is not released to the media access control (MAC) layer without canceling the setting for the RLC layer And stopping reception of the service from the physical multicast channel of the physical layer Lt; / RTI > And if a decoding of the dynamic scheduling information fails, a decoding stop request is generated. The method according to claim 1, If the reception of the dynamic scheduling information is successful, starting the service (RRC) layer control method. The method according to claim 1, Confirming whether or not the service can be provided through the previously received multicast control channel (MCCH) information before establishing the communication layer; (RRC) layer control method. The method of claim 3, If the service can not be provided, waiting until receiving multicast control channel (MCCH) information including information on the service (RRC) layer control method. 5. The method of claim 4, Confirming whether the physical multicast channel (PMCH) information is changed when receiving multicast control channel (MCCH) information including information on the service; And Setting the changed physical multicast channel (PMCH) information in the physical layer (PHY) (RRC) layer control method. The method according to claim 1, Wherein the step of verifying whether the dynamic scheduling information is received comprises: Receiving from the media access control (MAC) layer information indicating failure of initiation of the service (RRC) layer control method. The method according to claim 1, Setting a service reset time for a start request of the service if a condition enabling the start of the service is satisfied; And Resetting the media access control (MAC) layer for the service if the reset time expires (RRC) layer control method. 8. The method of claim 7, The service re- Wherein the RRC layer is longer than a physical multicast channel (PMCH) occurrence period and is determined based on a movement speed of a user who has transmitted the service start request. 8. The method of claim 7, If the media access control (MAC) layer is reset, Wherein the media access control (MAC) layer comprises: a radio resource control (RLC) layer for transmitting dynamic scheduling information (DSI) of a physical multicast channel (PMCH) to which the service is mapped to a physical layer RRC) layer control method. A radio link control (RLC) layer, and a media access control (MAC) layer; Confirming whether or not the start of the multimedia broadcast / multicast service (MBMS) has succeeded at the location of the MS based on the message received from the MAC layer; Releasing the setting of the MAC layer without releasing the setting of the RLC layer when the start of the MBMS fails; Setting a Multicast Control Channel (MTCH) reset timer for requesting initiation of the MBMS if the UE is located in a position where the MBMS can be started; Resetting the MAC layer based on expiration of the MTCH reset timer; And Receiving a message indicating the start of the MBMS from the MAC layer if dynamic scheduling information (DSI) detection of a physical multicast channel (PMCH) is successful based on the re-establishment of the MAC layer Lt; / RTI > The failure of initiation of the MBMS corresponds to a failure of decoding of dynamic scheduling information in a physical multicast channel including the MBMS, And if a decoding of the dynamic scheduling information fails, a decoding stop request is generated.

Images