Method and apparatus for counting multimedia broadcast and multicast services

A method and apparatus for multimedia broadcast and multicast service (MBMS) counting is provided. A user equipment (UE) may transmit selected service information to a multi-cell and multicast coordination entity (MCE) through a target evolved node base station (eNB), every time that a service requiring counting is received or cancelled and thus, the MCE may accurately manage a number of UEs that receive a service for each eNB. Also, the use may transmit selected service information to the MCE through the target eNB every time that the UE enters a new cell and thus, the MCE may accurately manage a number of UEs that receive a service for each eNB.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2010-0131431, filed on Dec. 21, 2010, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a method and apparatus for multimedia broadcast and multicast service (MBMS) counting in a multimedia broadcast and multicast service single frequency network (MBSFN).

2. Description of the Related Art

A long term evolution-advanced (LTE-advanced) system standard defines a multimedia broadcast and multicast service single frequency network (MBSFN) to provide a broadcasting service through a communication network.

The MBSFN refers to a technology that simultaneously transmits the same data, at the same time, by synchronizing radio resources in all E-UTRAN NodeBs (eNBs) included in an MBSFN area. A signal from a neighboring eNB may be a gain to a user equipment (UE), as opposed to being interference, when the MBSFN technology is utilized.

Therefore, in the MBSFN area, the UE may recognize MBMS data transmitted from all eNBs as MBMS data transmitted from a single eNB. In the MBSFN area, although the UE moves, a broadcasting service may be continuously provided without an additional handover process.

An MBSFN-based MBMS service may provide a broadcast and multicast service.

The broadcast service may refer to a service provided over a network, unilaterally. When the broadcast service is provided, the UE may selectively receive a service irrespective of a connection state of a radio resource control (RRC). Therefore, a number of UEs receiving services from a particular eNB may be difficult to be recognized, currently, in a network.

Also, to receive a multicast service, the UE may need to join a multicast service group while the UE is in a radio resource control (RRC)-connected state. Therefore, at the time when the UE joins the multicast service group, counting information associated with a corresponding service may be recognized. However, when the UE moves to a new cell while in an RRC-idle state, it is difficult to maintain the counting information associated with a corresponding eNB, accurately.

When MBMS counting is not accurately performed with respect to the MBMS service, the eNB may continuously provide a service that the UE does not actually receive. Therefore, wireless resources may be wasted.

A wideband code division multiple access (WCDMA) system may solve the drawback by transmitting an MBMS access information message. That is, the WCDMA system may transmit an MBMS access information message to be used for MBMS counting in addition to an MBMS traffic information message, for a single-cell-based MBMS service as opposed to for the MBSFN-based MBMS service. The MBMS access information message may be transmitted via an MBMS control channel (MCCH).

When the MBMS counting is performed based on the MBMS access information, the UE may provide a response within a predetermined time. Therefore, a network load may increase, and performing the MBMS counting may in real time be difficult.

As described in the foregoing, the MBMS counting may not be applicable to the MBSFN-based MBMS service.

Therefore, there is a desire for a method that minimizes a waste of wireless resources by providing accurate MBMS counting information to a network, irrespective of the RRC connection state of the UE and a movement of the UE to a new cell when the MBSFN-based MBMS service is provided in the LTE-advanced system.

SUMMARY

An aspect of the present invention provides a method and apparatus for accurately managing a number of user equipments (UEs) that receive a service for each E_UTRAN NodeB (eNB), by transmitting information associated with a selected service to a multi-cell and multicast coordination entity (MCE) through a target eNB, every time that a UE receives or cancels a service requiring counting.

Another aspect of the present invention also provides a method and apparatus for accurately managing a number of UEs that receive a service for each eNB, by transmitting information associated with a selected service to an MCE through a target eNB, every time a UE accesses a new cell.

According to an aspect of the present invention, there is provided a method of a UE for providing, to a base station, multimedia broadcast and multicast service (MBMS) counting information, the method including receiving, from the base station, a multimedia broadcast and multicast service single frequency network (MBSFN) area configuration message, changing MBMS selected services information during a radio resource control (RRC)-connected state, by selecting or terminating a first service requiring MBMS counting, transmitting, to the base station, an MBMS modification request message including a first list of selected services and a second list of terminated services, changing an RRC connection state from the RRC-connected state to an RRC-idle state, changing the MBMS selected services information during the RRC-idle state, by selecting or terminating a second service requiring MBMS counting, and transmitting, to the base station, an RRC connection request message including a third list of selected services and a fourth list of terminated services.

The MBSFN area configuration message may be a message of a multicast control channel, the MBMS modification request message may be a message of a dedicated control channel (DCCH), and the RRC connection request message may be a message of a common control channel (CCCH).

The RRC connection request message may set a cause for establishment as reception of an MBMS.

The first service requiring the MBMS counting and the second service requiring the MBMS counting may be identified based on the MBSFN area configuration message.

The first list, the second list, the third list, and the fourth list may be included in the MBMS selected services information, and transmitted.

According to another aspect of the present invention, there is provided an MBMS counting method in a long-term evolution (LTE)-advanced system including an eNB and a multi-cell and a multicast coordination entity (MCE), the method including receiving, by the eNB from a first UE, an MBMS modification request message including first MBMS selected services information, transmitting, by the eNB to the MCE, a first MBMS selected services information message including the first MBMS selected services information, increasing and decreasing, by the MCE, counting information associated with second UEs that receive a predetermined service from the eNB, based on the first MBMS selected services information, receiving, by the eNB from the first UE, an RRC connection request message including second MBMS selected services information, transmitting, by the eNB to the MCE, a second MBMS selected services information message including the second MBMS selected services information, and increasing and decreasing, by the MCE, counting information associated with the second UEs that receive the predetermined service from the eNB, based on the first MBMS selected services information.

The method may further include transmitting, by the MCE to the eNB, an MBMS scheduling information message, transmitting, by the eNB to the MCE, an MBMS scheduling information response message, and transmitting, by the eNB to a UE in the LTE-advanced system, a multimedia broadcast and multicast service single frequency network (MBSFN) area configuration message.

When the MBMS scheduling information message is associated with the predetermined service requiring MBMS counting, the MBMS scheduling information message and the MBSFN area configuration message may include an MBMS counting indicator.

The transmitting of the MBSFN area configuration message may be repeatedly performed based on a multicast control channel modification period.

The MBMS scheduling information message may include wireless resource allocation information and service information of an MBMS session being serviced.

The method may further include controlling, by the MCE, whether to continuously provide the predetermined service based on the counting information associated with second UEs.

The method may further include controlling, by the MCE, point-to-point transmission switching of the predetermined service based on the counting information associated with the second UEs.

According to still another aspect of the present invention, there is provided an MBMS counting method in an LTE-advanced system including a first eNB, a second eNB, and an MCE, the method including receiving, by the first eNB from a first UE that accesses a cell of the first eNB, an RRC connection request message including a first MBMS selected services information and a second eNB indicator, transmitting, by the first eNB to the MCE, a first MBMS selected services information message including the first MBMS selected services information, and decreasing, by the MCE, counting information of the first eNB and increasing, by the MCE, counting information of the second eNB, based on the first MBMS selected services information.

The method may further include receiving, by the second eNB from a second UE, a handover completion message including second MBMS selected services information and a first eNB indicator, a connection being set between the second eNB and the second UE, transmitting, by the second eNB to the MCE, a second MBMS selected services information message including the second MBMS selected services information, and decreasing, by the MCE, counting information of the first eNB, and increasing, by the MCE, counting information of the second eNB, based on the second MBMS selected services information.

The method may further include transmitting, by the first eNB to the second UE, a DCCH handover command message.

The method may further include converting, by the MCE based on the counting information of the first eNB and the counting information of the second eNB, a cell that does not include a UE that receives an MBMS service from an MBMS reserved cell.

The method may further include changing, by the cell converted to the MBMS reserved cell, a service being provided by the cell.

EFFECT

Exemplary embodiments may provide a method and apparatus for accurately managing a number of user equipments (UEs) that receive a service for each evolved node base station eNB, by transmitting information associated with a selected service to a multi-cell and multicast coordination entity (MCE) through a target eNB every time a UE receives or cancels a service requiring counting.

Exemplary embodiments may provide a method and apparatus for accurately managing a number of UEs that receive a service for each eNB, by transmitting information associated with a selected service to an MCE through a target eNB every time a UE accesses a new cell.

DETAILED DESCRIPTION

Throughout the specifications, changing of information may include changing of partial information.

FIG. 1illustrates provision of a multimedia broadcast and multicast service single frequency network (MBSFN)-based multimedia broadcast and multicast service (MBMS) service in a long term evolution (LTE)-advanced system100according to an embodiment of the present invention.

The LTE-advanced system100may include an MBMS service area110.

The MBMS service area110may include at least one MBSFN area120

In a single MBSFN area120, all eNBs130may synchronize radio resources and may simultaneously transmit the same data at the same time.

Accordingly, even when a user equipment (UE) exists in a boundary between cells, a signal from a neighboring evolved node base station eNB may be a gain to the UE, as opposed to being interference.

Therefore, although the all eNBs130transmit MBMS data in the MBSFN area120, the UE may recognize that the UE receives data transmitted from a single eNB. In the area, the UE may receive a service irrespective of a radio resource control (RRC) connection state, and the UE may continuously receive a broadcasting service without an additional handover process although the UE moves.

An eNB130in the MBSFN area120may be an MBMS reserved cell140. The MBMS reserved cell140may be included in the MBSFN area120, and may not participate in MBMS transmission. The MBMS reserved cell140may provide another service with a limited power within a scope that does not affect an MBMS service.

The MBMS reserved cell140may be determined based on a cell design. Also, when a UE that receives an MBMS service does not exist in a corresponding cell as a result of MBMS counting, the corresponding cell may be dynamically converted to the MBMS reserved cell140.

The eNB130that participates in the MBMS area120may not use, for the MBMS transmission, a wireless resource allocated to a predetermined service based on the result of the MBMS counting, and may provide another service within a scope that does not affect the MBMS service.

FIG. 2illustrates a logical structure of an MBMS in an LTE-advanced system according to an embodiment of the present invention.

A UE210may be connected with an eNB220, wirelessly. The UE210may receive, from the eNB220, a multicast control channel (MCCH) message corresponding to MBMS control information. The MCCH message may include an MBMS service list.

The UE210may receive an MBMS service by selecting or cancelling the MBMS service based on the MBMS control information, and may receive an MBMS service irrespective of an RRC connection state with the eNB220, for example, an RRC-connected state or an RRC-idle state, and movement of the UE210.

The eNB220may wirelessly transmit MBMS traffic received from an MBMS gateway (GW)250, based on information associated with resource control and information associated with a start and end of an MBMS service provided from a multi-cell and multicast coordination entity (MCE)230

The eNB220may communicate with the MCE230through an M2 interface, and may communicate with the MBMS GW250through an M1 interface.

The MCE230may refer to a multi-cell and multicast coordination entity.

The MCE230may perform admission control and allocation of a wireless resource with respect to all eNBs220included in the MBSFN area120.

For example, the MCE230may not allocate a wireless bearer to the eNB220when a wireless resource for an MBMS service is insufficient.

The MCE230may allocate a time wireless resource and a frequency wireless resource for the allocated wireless bearer, and may control all wireless resources allocated to the wireless bearer, including a modulation and code scheme.

The MBMS GW250between a broadcast and multicast service center (BMSC) and the eNB220, may transmit MBMS traffic to the all eNBs220. The transmission may be performed through internet protocol (IP) multicast.

A mobility management entity (MME)240may perform MBMS session control. The MME240may communicate with the MCE230through an M3 interface.

FIG. 3illustrates a configuration of a control plane of an MBMS according to an embodiment of the present invention.

An M3 interface may perform communication between the MME240and the MCE230, based on an M3AP332. The M3 interface may be a signal interface for MBMS session control, such as a start and an end of an MBMS session.

An M2 interface may perform communication between the MCE230and the eNB220, based on an M2AP322. The M2 interface may be a signal interface for MBMS session control and eNB wireless resource control.

An interface between the UE210and the eNB220may include an RRC312corresponding to a layer 3, a radio link control (RLC)314corresponding to a layer 2, and a medium access control (MAC)316corresponding to the layer 2, and a physical layer (PHY)318corresponding to a layer 1.

The RRC312may perform system information control, paging, managing of RRC connection, control of a dedicated wireless bearer, mobility control, MBMS control, and the like.

The RLC314may perform transmission of an upper layer packet data unit (PDU), connection, division, and reassembly of an RLC service data unit (SDU), and the like.

The MAC316may perform mapping of a logical channel and a transmission channel, multiplexing and demultiplexing of an MAC SDU, synchronous scheduling, and the like.

The PHY318may perform link adaptation, power control, and cell searching, and the like.

FIG. 4illustrates an MBMS counting method based on an RRC connection state of the UE210according to an embodiment of the present invention.

The MCE230may be a start and an end of an MBMS session.

In operation S405, an RRC connection state of the UE210may be an RRC-connected state.

In operation S410, when MBMS scheduling information is changed, the MCE230may transmit an MBMS scheduling information message to all eNBs220in an MBSFN area120, through an M2AP322.

In operation S415, the MCE230may receive an MBMS scheduling information response message from the eNBs220, in response to the MBMS scheduling information message.

When the MBMS scheduling information message is associated with a service requiring MBMS counting, the MCE230may transmit the MBMS scheduling information message by adding an MBMS counting indicator in the MBMS scheduling information message. That is, the MBMS scheduling information message may include the MBMS counting indicator.

The MBMS scheduling information message may include wireless resource allocation information and service information associated with an MBMS session that is currently being serviced.

In operation S420, the eNB220may transmit an MBSFN area configuration message of the MCCH to the UE210, in a next multicast control channel (MCCH) modification period. The MBSFN area configuration message may include an MBMS counting indicator.

The eNB220may repeatedly transmit the MBSFN area configuration message based on an MCCH repetition period.

The UE210that is receiving the MBMS or is interested in receiving the MBMS may receive the MBSFN area configuration message. The UE210may selectively receive an MBMS service by receiving the MBSFN area configuration message. The UE210may identify a service requiring MBMS counting, based on the MBSFN area configuration message or based on the MBSFN area configuration message including the MBMS counting indicator, without receiving an additional message.

In operation S430, the UE210of which an RRC connection state is an RRC-connected state may select or terminate a service requiring an MBMS counting. Therefore, the UE210of which the RRC connection state is the RRC-connected state may change MBMS selected services information by selecting or terminating the service requiring the MBMS counting. The information associated with the MBMS selected services may include information associated with MBMS services selected or cancelled by the UE210.

In operation S440, the UE210may transmit, to the eNB220, an MBMS modification request of a dedicated control channel (DCCH). The eNB220may receive the MBMS modification request message.

The MBMS modification request message may include a list of services selected by the UE210and a list of services terminated by the UE210.

The MBMS modification request message may include the changed MBMS selected services information, and the changed MBMS selected services information may include a list of services selected by the UE210and a list of services terminated by the UE210.

In operation S445, the eNB220may transmit, to the MCE230, an MBMS selected services information message through the M2AP322. The MCE230may receive the MBMS selected services information message.

The MBMS selected services information message may include the changed MBMS selected services information.

In operation S450, the MCE230may increase or decrease counting information associated with UEs210that receive a corresponding service from the eNB220through or based on the received MBMS selected services information message.

In operation S460, the RRC connection state of the UE210may be changed to an RRC-idle state.

In operation S470, the UE210that is in the RRC-idle state may select or terminate a service that requires MBMS counting. Accordingly, the UE210in the RRC-idle state may select or terminate the service requiring the MBMS counting so as to change the MBMS selected services information.

In operation S480, the UE210may transmit an RRC connection request message of a common control channel (CCCH) to the eNB220, and may maintain an RRC connection state to be the RRC-idle state. That is, the UE210may generate a new signaling bearer and may change the RRC connections state to an RRC-connected state and thus, may not transmit a message.

The RRC connection request message may include a list of services selected by the UE210and a list of services terminated by the UE210.

The RRC connection request message may include the changed MBMS selected services information, and the changed MBMS selected services information may include the list of services selected by the UE210and the list of services terminated by the UE210.

The RRC connection request message may set a cause for establishment as reception for MBMS service, so that the eNB220does not set an RRC connection.

The eNB220may receive the RRC connection request message.

That is, in terms of reception of an MBSFN-based MBMS service, when a service requiring MBMS counting is received or cancelled, the UE210may transmit information associated with the reception or cancellation of the service to the eNB220, irrespective of the RRC connection state.

In operation S485, the eNB220may transmit an MBMS selected services information message, to the MCE230through the M2AP322. The MCE230may receive the MBMS selected services information message.

The MBMS selected services information message may include the changed MBMS selected services information.

In operation S490, the MCE403may increase or decrease counting information associated with the UEs210that receive a corresponding service from the eNB220, through or based on the received MBMS selected services information message.

Based on the operations S405through S490described in the foregoing, the MCE230may count a number of the UEs210that receive a service requiring MBMS counting for each eNB220, irrespective of an RRC connection state of a corresponding UE210.

The MCE230may control whether to continuously provide a corresponding service or may control point-to-point transmission switching of a corresponding service. Accordingly, wireless resources may be utilized efficiently.

Exemplary embodiments described with reference toFIGS. 1 through 3will be applicable to this exemplary embodiment and thus, detailed descriptions will be omitted for conciseness.

FIG. 5illustrates an MBMS counting method when the UE210moves to a new cell according to an embodiment of the present invention.

The UE210may be able to move to a new cell through handover while being in an RRC-connected state, and the UE210may be able to move to a new cell through cell reselection while being in an RRC-idle state.

In an MBSFN, when the UE210moves, the moving UE210is capable of continuously receiving a service without an additional process, but may need an additional process to perform MBMS counting.

In operation S505, the UE210may receive an MBMS service from a first eNB220. An RRC connection state of the UE210may be an RRC-connected state.

In operation S510, the first eNB220may determine that handover of the UE210to a second eNB222is required due to movement of the UE210. The first eNB220may be a source eNB, and the second eNB222may be a target eNB.

The first eNB220may transmit a handover command message of a DCCH to the UE210. The UE210may receive the handover command message from the first eNB220.

In operation S520, the UE210may establish a connection with the second eNB222. That is, the connection between the UE210and the second eNB222may be established.

The UE210may transmit a handover completion message of the DCCH to the second eNB222.

When a service requiring MBMS counting is included in a service being received by the UE210, the UE210may transmit information associated with the service that the UE210is currently receiving, by including the information in the handover completion message, for MBMS counting. The handover completion message may include MBMS selected services information corresponding to a list of MBMS services being received by the UE210.

The second eNB222may receive the handover completion message from the UE210.

In operation S530, when the received handover completion message includes the MBMS selected services information, the second eNB222may extract the MBMS selected services information from the handover completion message.

The second eNB222may include information associated with a previous eNB, that is, a first eNB indicator, in the extracted MBMS selected services information.

The second eNB222may transmit an MBMS selected services information message to the MCE230through the M2AP322. The MCE230may receive the MBMS selected services information message from the second eNB222.

The MBMS selected services information message may include changed MBMS selected services information.

In operation S540, when the information associated with the previous eNB, that is, information associated with the first eNB220, is included in the received MBMS selected services information, the MCE230may manage MBMS counting information by decreasing MBMS counting information associated with the first eNB220, and increasing MBMS counting information associated with the second eNB222.

In operation S550, the UE210may receive an MBMS service from the second eNB222, and an RRC connection state of the UE210may be an RRC-idle state.

In operation S560, the UE210that receives an MBMS service and is in the RRC-idle state may move and enter a new cell of the first eNB220. Accordingly, the UE210may perform cell reselection and thus, the UE210may continuously receive the MBMS service from the first eNB220through the cell reselection.

The UE210may not have a connection with an eNB, for example the first eNB220and the second eNB222. Therefore, the UE210may transmit an RRC connection request message of a CCCH to the first eNB220, and maintain the RRC-idle state.

That is, the UE210may generate a new signaling bearer for MBMS counting, and may change the RRC-idle state to an RRC-connected state so as not to transmit a message.

The RRC connection request message may include a list of MBMS services being received by the UE210and information associated with a previous eNB, that is, a second eNB indicator. That is, the RRC connection request message may include MBMS selected services information corresponding to the list of MBMS services being received by the UE210.

The RRC connection request message may set a cause for establishment as reception of an MBMS and thus, the first eNB220does not set an RRC connection.

The first eNB220may receive the RRC connection request message from the UE210.

In terms of reception of an MBSFN-based MBMS service, when the UE210moves to a new cell, the UE210may transmit information associated with an MBMS service being currently received by the UE210, to an eNB, for example, the eNB220or the eNB222.

In operation S570, the first eNB220may transmit an MBMS selected services information message to the MCE230through the M2AP322.

The MBMS selected services information message may include changed MBMS selected services information.

The MCE230may receive the MBMS selected services information message from the eNB220.

The MCE230may manage MBMS counting information based on the MBMS selected services information.

When information associated with a previous eNB, for example, the second eNB222, is included in the received MBMS selected services information message, the MCE230may manage the MBMS counting information by decreasing MBMS counting information associated with the previous eNB, that is, the second eNB222, and increasing MBMS counting information associated with a new eNB, that is, the first eNB220.

Based on the method including operations S505through S580, the MCE230may count a number of UEs210that receive a service requiring MBMS counting for each eNB, irrespective of an RRC connection state of a corresponding UE210, although the UE210moves to a new eNB.

Through the counting, the MCE230may control whether to continuously provide a corresponding service or may control point-to-point transmission switching of a corresponding service. Therefore, wireless resources may be utilized efficiently.

The MCE230may convert, to an MBMS reserved cell, a cell that does not include an UE210that receives an MBMS service, based on counting information associated with the first eNB220and counting information associated with the second eNB222. The cell converted to the MBMS reserved cell may change a service provided by the cell.

Exemplary embodiments described with reference toFIGS. 1 through 4may be applicable to this exemplary embodiment and thus, detailed descriptions thereof will be omitted for conciseness.

When the MBSFN-based MBMS service is provided, a network may count services requiring MBMS counting without transmitting an additional message, irrespective of an RRC connection state of the UE210and movement of the UE210. The network may control whether to continuously provide a corresponding service or may control whether to switch a corresponding service to point-to-point transmission. Therefore, wireless resources may be utilized effectively.

Also, the UE210may transmit counting information to the network every time a service requiring MBMS counting is selected or cancelled, and every time that the UE210moves to a new eNB. Accordingly, the MBMS counting may be managed in real-time. A temporary increase in load of the network may be overcome by transmitting an additional MBMS counting message.

The term of “MBSFN-based” may be replaced with a term “multi-cell-based”, a term “a single frequency network-based”, and the like.