WO2014021462A1

WO2014021462A1 - Mobile communication system, user terminal, and processor

Info

Publication number: WO2014021462A1
Application number: PCT/JP2013/071052
Authority: WO
Inventors: ヘンリーチャン; 憲由福田
Original assignee: 京セラ株式会社
Priority date: 2012-08-03
Filing date: 2013-08-02
Publication date: 2014-02-06

Abstract

This mobile communication system, which supports MBMS functionality, has a user terminal that, if a given condition is satisfied in a connected state, can transmit, to a network, a notification that indicates interest in an MBMS service provided using the aforementioned MBMS functionality. Said notification includes the frequency on which the MBMS service the user terminal is indicating interest in is provided and a priority that indicates whether or not to prioritize reception of the MBMS service over the reception of a unicast service. If said priority is being changed, the user terminal transmits the aforementioned notification to the abovementioned network even if the abovementioned condition is not satisfied.

Description

Mobile communication system, user terminal, and processor

The present invention relates to a mobile communication system that supports an MBMS function.

In 3GPP (3rd Generation Partnership Project), which is a standardization project for mobile communication systems, standardization of eMBMS (evolved MBMS), which is an advanced version of MBMS (Multimedia Broadcast Multiservice), is in progress.

These MBMS functions provide a bearer service (MBMS service) that realizes broadcast distribution. According to the MBMS function, an MBMS service can be provided to a plurality of user terminals interested in the MBMS service all at once using a common bearer.

Also, the user terminal transmits an MBMS interest notification to the network in order to notify the network of interest in the MBMS service (see, for example, Non-Patent Document 1).

However, the trigger (timing) for transmitting the above MBMS interest notification from the user terminal to the network has room for improvement in terms of providing an appropriate service to the user terminal.

Therefore, the present invention provides a mobile communication system, a user terminal, and a processor that can provide appropriate services to the user terminal.

According to an embodiment, a mobile communication system supporting an MBMS function transmits a notification indicating an interest in an MBMS service provided using the MBMS function to a network when a predetermined condition is satisfied in a connected state. It has a user terminal that can. The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service. Even when the predetermined condition is not satisfied, the user terminal transmits the notification to the network when the priority is changed.

According to an embodiment, a user terminal in a mobile communication system supporting an MBMS function may be interested in an MBMS service provided using the MBMS function when a predetermined condition is satisfied in the connection state of the user terminal. It has a transmission part which can transmit the notice which shows to a network. The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service. Even when the predetermined condition is not satisfied, the transmission unit transmits the notification to the network when the priority is changed.

According to an embodiment, the processor is provided in a user terminal in a mobile communication system that supports the MBMS function. The processor performs a process of transmitting a notification indicating an interest in an MBMS service provided using the MBMS function to a network when a predetermined condition is satisfied in the connection state of the user terminal. The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service. Even when the predetermined condition is not satisfied, the processor performs a process of transmitting the notification to the network when the priority is changed.

1 is a configuration diagram of an LTE system. It is a block diagram of UE. It is a block diagram of eNB. It is a protocol stack figure of the radio | wireless interface in a LTE system. It is a block diagram of the radio | wireless frame used with a LTE system. 1 is a block diagram of an MBMS architecture. The mapping of a logical channel, a transport channel, and a physical channel in a downlink is shown. It is an operation | movement sequence diagram which concerns on embodiment. It is a flowchart of the operation | movement flow 1 of UE which concerns on embodiment. It is a flowchart of the operation | movement flow 2 of UE which concerns on embodiment.

(1) Outline of Embodiment A mobile communication system that supports an MBMS (Multimedia Broadcast Multicast Service) function shows interest in an MBMS service provided using the MBMS function when a predetermined condition is satisfied in a connected state. It has a user terminal that can send notifications (ie MBMS interest notifications) to the network. Here, the interest in the MBMS service includes not only the case where the user terminal desires to receive the MBMS service without receiving the MBMS service but also the case where the user terminal is receiving the MBMS service.

The MBMS interest notification is a frequency (hereinafter, referred to as “MBMS frequency”) of the MBMS service that the user terminal is interested in, and a priority (hereinafter, referred to as whether or not the MBMS service is received in preference to the unicast service). "Service priority"). The unicast service is a general service provided by unicast to one user terminal, unlike a service provided by broadcast / multicast to a plurality of user terminals like the MBMS service.

The user terminal transmits an MBMS interest notice to the network when changing the service priority even when the predetermined condition is not satisfied. Here, the “predetermined condition” may be a condition that the MBMS frequency is changed by changing the MBMS service in which the user terminal is interested. In this case, even when the user terminal does not change the MBMS frequency in which the user terminal is interested, the user terminal can transmit the MBMS interest notice to the network when changing the service priority. In other words, the user terminal can notify the network of the change of the service priority by the MBMS interest notification regardless of the change of the MBMS frequency in which the user terminal is interested.

Alternatively, the “predetermined condition” may be a condition that a predetermined time (hereinafter “regulation period”) has elapsed since the user terminal last transmitted the MBMS interest notification. Here, the restriction period is a period during which transmission of the MBMS interest notice is restricted. In this case, the user terminal cannot transmit the MBMS interest notification when changing the MBMS frequency in which the user terminal is interested within the restriction period, but can transmit the MBMS interest notification when changing the service priority. In other words, the user terminal can notify the network of the service priority change by the MBMS interest notification regardless of the regulation period.

Therefore, since the network can always grasp the change of the service priority in the user terminal based on the MBMS interest notification, it can appropriately determine whether to provide the MBMS service or the unicast service for the user terminal. As a result, the network can provide appropriate services to the user terminal.

Hereinafter, an embodiment of a mobile communication system (LTE system) configured according to the 3GPP standard and supporting the MBMS function will be described.

(2) LTE System FIG. 1 is a configuration diagram of an LTE system according to the present embodiment.

As shown in FIG. 1, the LTE system includes a plurality of UEs (User Equipment) 100, an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) 10, and an EPC (Evolved Packet Core) 20. The E-UTRAN 10 and the EPC 20 constitute a network.

The UE 100 is a mobile radio communication device, and performs radio communication with a cell (serving cell) that has established a connection. UE100 is corresponded to a user terminal.

The E-UTRAN 10 includes a plurality of eNBs 200 (evolved Node-B). The eNB 200 corresponds to a base station. The eNB 200 manages a cell and performs radio communication with the UE 100 that has established a connection with the cell.

Note that the “cell” is used as a term indicating the minimum unit of the radio communication area, and is also used as a function of performing radio communication with the UE 100.

The eNB 200 has, for example, a radio resource management (RRM) function, a user data routing function, and a measurement control function for mobility control and scheduling.

The EPC 20 includes MME (Mobility Management Entity) / S-GW (Serving-Gateway) 300 and OAM 400 (Operation and Maintenance).

The MME is a network node that performs various types of mobility control for the UE 100, and corresponds to a control station. The S-GW is a network node that performs transfer control of user data, and corresponds to an exchange.

The eNB 200 is connected to each other via the X2 interface. The eNB 200 is connected to the MME / S-GW 300 via the S1 interface.

The OAM 400 is a server device managed by an operator, and performs maintenance and monitoring of the E-UTRAN 10.

Next, the configuration of the UE 100 and the eNB 200 will be described.

FIG. 2 is a block diagram of the UE 100. As shown in FIG. 2, the UE 100 includes an antenna 101, a radio transceiver 110, a user interface 120, a GNSS (Global Navigation Satellite System) receiver 130, a battery 140, a memory 150, and a processor 160. Have. The memory 150 and the processor 160 constitute a control unit.

The UE 100 may not have the GNSS receiver 130. Further, the memory 150 may be integrated with the processor 160, and this set (that is, a chip set) may be used as the processor 160 '.

The antenna 101 and the radio transceiver 110 correspond to a part of layer 1 and are used for radio signal transmission / reception. The antenna 101 includes a plurality of antenna elements. The radio transceiver 110 converts the baseband signal output from the processor 160 into a radio signal and transmits it from the antenna 101. Further, the radio transceiver 110 converts a radio signal received by the antenna 101 into a baseband signal and outputs the baseband signal to the processor 160.

The user interface 120 is an interface with a user who owns the UE 100, and includes, for example, a display, a microphone, a speaker, and various buttons. The user interface 120 receives an operation from the user and outputs a signal indicating the content of the operation to the processor 160.

The GNSS receiver 130 receives a GNSS signal and outputs the received signal to the processor 160 in order to obtain position information indicating the geographical position of the UE 100.

The battery 140 stores power to be supplied to each block of the UE 100.

The memory 150 stores a program executed by the processor 160 and information used for processing by the processor 160.

The processor 160 includes a baseband processor that modulates / demodulates and encodes / decodes a baseband signal, and a CPU (Central Processing Unit) that executes programs stored in the memory 150 and performs various processes. . The processor 160 may further include a codec that performs encoding / decoding of an audio / video signal.

The processor 160 executes, for example, various processes and various communication protocols described later. Details of the processing performed by the processor 160 will be described later.

FIG. 3 is a block diagram of the eNB 200. As illustrated in FIG. 3, the eNB 200 includes an antenna 201, a radio transceiver 210, a network interface 220, a memory 230, and a processor 240. The memory 230 and the processor 240 constitute a control unit.

The antenna 201 and the wireless transceiver 210 are used for transmitting and receiving wireless signals. The antenna 201 includes a plurality of antenna elements. The wireless transceiver 210 converts the baseband signal output from the processor 240 into a wireless signal and transmits it from the antenna 201. In addition, the radio transceiver 210 converts a radio signal received by the antenna 201 into a baseband signal and outputs the baseband signal to the processor 240.

The network interface 220 is connected to the neighboring eNB 200 via the X2 interface and is connected to the MME / S-GW 300 via the S1 interface. The network interface 220 is used for communication performed on the X2 interface and communication performed on the S1 interface.

The memory 230 stores a program executed by the processor 240 and information used for processing by the processor 240.

The processor 240 includes a baseband processor that performs modulation / demodulation and encoding / decoding of a baseband signal, and a CPU that executes programs stored in the memory 230 and performs various processes.

The processor 240 executes, for example, various processes and various communication protocols described later. Details of the processing performed by the processor 240 will be described later.

FIG. 4 is a protocol stack diagram of a radio interface in the LTE system.

As shown in FIG. 4, the radio interface protocol is divided into layers 1 to 3 of the OSI reference model, and layer 1 is a physical (PHY) layer. Layer 2 is further divided into a plurality of sub-layers, and includes a MAC (Media Access Control) layer, an RLC (Radio Link Control) layer, and a PDCP (Packet Data Convergence Protocol) layer. Layer 3 includes an RRC (Radio Resource Control) layer.

The physical layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. The physical layer provides a transmission service to an upper layer using a physical channel. Data is transmitted between the physical layer of the UE 100 and the physical layer of the eNB 200 via a physical channel.

The MAC layer performs data priority control, retransmission processing by hybrid ARQ (HARQ), and the like. Data is transmitted via the transport channel between the MAC layer of the UE 100 and the MAC layer of the eNB 200. The MAC layer of the eNB 200 includes a MAC scheduler that determines an uplink / downlink transport format (transport block size, modulation / coding scheme, and the like) and an allocated resource block.

The RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and the physical layer. Data is transmitted between the RLC layer of the UE 100 and the RLC layer of the eNB 200 via a logical channel.

The PDCP layer performs header compression / decompression and encryption / decryption.

The RRC layer is defined only in the control plane. An RRC message is transmitted between the RRC layer of the UE 100 and the RRC layer of the eNB 200. The RRC layer controls the logical channel, the transport channel, and the physical channel according to establishment, re-establishment, and release of the radio bearer. When there is an RRC connection between the RRC of the UE 100 and the RRC of the eNB 200, the UE 100 is in a connected state (RRC Connected State). Otherwise, the UE 100 is in an idle state (RRC Idle State).

The NAS (Non-Access Stratum) layer located above the RRC layer performs session management and mobility management.

FIG. 5 is a configuration diagram of a radio frame used in the LTE system. The LTE system employs OFDMA (Orthogonal Frequency Division Multiplexing Access) for the downlink, and SC-FDMA (Single Carrier Frequency Multiple Access) for the uplink.

As shown in FIG. 5, the radio frame is composed of 10 subframes arranged in the time direction, and each subframe is composed of two slots arranged in the time direction. The length of each subframe is 1 ms, and the length of each slot is 0.5 ms. Each subframe includes a plurality of resource blocks (RB) in the frequency direction and includes a plurality of symbols in the time direction. A guard interval called a cyclic prefix (CP) is provided at the head of each symbol. The resource block includes a plurality of subcarriers in the frequency direction.

For example, among radio resources allocated to the UE 100, a frequency resource is specified by a resource block, and a time resource is specified by a subframe. That is, the radio resource allocated to UE 100 can be specified by a combination of resource blocks and subframes.

In the downlink, the section of the first few symbols of each subframe is a control region mainly used as a physical downlink control channel (PDCCH). The remaining section of each subframe is an area that can be used mainly as a physical downlink shared channel (PDSCH).

In the uplink, both ends in the frequency direction in each subframe are control regions mainly used as a physical uplink control channel (PUCCH). Further, the central portion in the frequency direction in each subframe is an area that can be used mainly as a physical uplink shared channel (PUSCH).

(3) MBMS function As described above, the LTE system according to the present embodiment supports the MBMS function. The MBMS function provides a bearer service (MBMS service) that realizes broadcast distribution. According to the MBMS function, an MBMS service can be provided to a plurality of user terminals interested in the MBMS service all at once using a common bearer.

In the LTE system, a plurality of eNBs 200 constitute an MBSFN (MBMS Single Frequency Network) and can deliver multimedia data by the MBSFN transmission method. The eNB 200 configuring the MBSFN transmits the same signal all at once. Thereby, UE100 can carry out RF (Radio Frequency) synthesis | combination of the signal transmitted from each eNB200.

FIG. 6 is a block diagram of the MBMS architecture. As shown in FIG. 6, in addition to the network entity shown in FIG. 1, the LTE system includes BMSC (Broadcast Multicast Service Center), MBMS GW (MBMS Gateway), MCE (Multi-Cell Multicast Coordination, and Coordination Entity). Have

BMSC holds multimedia data to be distributed. The MBMS GW transmits multimedia data held by the BMSC to each eNB by IP (Internet Protocol) multicast. The MCE synchronizes multimedia data to each eNB 200 configuring the MBSFN, and designates radio resources for multimedia data.

FIG. 7 shows mapping of logical channels, transport channels, and physical channels in the downlink. As shown in FIG. 7, the LTE system uses MTCH (Multicast Traffic Channel) and MCCH (Multicast Control Channel) as logical channels for MBMS. Further, MCH (Multicast Channel) is used as a transport channel for MBMS.

ENB 200 transmits multimedia data and MBMS service information for controlling multimedia data distribution via multicast channels (MTCH and MCCH). Moreover, eNB200 transmits broadcast information via a broadcast channel (BCCH; Broadcast Control Channel). Broadcast information is information, such as MIB (Master Information Block) and SIB (System Information Block), for example.

(4) Operation Hereinafter, an operation of the UE 100 according to the present embodiment will be described.

(4.1) Operation Sequence FIG. 8 is an operation sequence diagram according to the present embodiment.

As shown in FIG. 8, in step S11, the UE 100 transmits an MBMS interest indication (MBMS Interest Indication) indicating an interest in the MBMS service provided using the MBMS function to the E-UTRAN 10 (specifically, the serving cell). To do. The MBMS interest notification is one of RRC messages.

In the present embodiment, the MBMS interest notification includes the “MBMS frequency” provided by the MBMS service in which the UE 100 is interested, and the “service priority” indicating whether the MBMS service is received in preference to the unicast service. Including.

Currently, the following two are being studied as triggers for the UE 100 to transmit the MBMS interest notification.

First, the UE 100 interested in the MBMS service transmits an MBMS interest notification when establishing an RRC connection, that is, when transitioning from an idle state (RRC Idle State) to a connected state (RRC Connected State). .

Second, the UE 100 transmits an updated MBMS interest notification when changing the MBMS frequency in which the UE 100 is interested in the connected state. Specifically, the UE 100 transmits the updated MBMS interest notification when the MBMS frequency at which the UE 100 is interested is changed from the last (previous) MBMS interest notification transmission time.

In this embodiment, a trigger (third trigger) for transmitting an MBMS interest notification is defined.

The UE 100 according to the present embodiment transmits an updated MBMS interest notice when changing the service priority in the connected state. Specifically, the UE 100 transmits the updated MBMS interest notification when the service priority of the UE 100 is changed compared to the time when the last (previous) MBMS interest notification is transmitted.

(4.2) Operation flow 1
FIG. 9 is a flowchart of the operation flow 1 of the UE 100 according to the present embodiment. In the initial state of this operation flow, the UE 100 is in a connected state.

As shown in FIG. 9, in step S101, the UE 100 determines whether or not to change its own service priority as compared to the time when the MBMS interest notification was last transmitted.

When the result of step S101 is “NO”, in step S102, the UE 100 determines whether or not to change the MBMS frequency at which the UE 100 is interested compared to the time when the MBMS interest notification was last transmitted.

When the result of step S102 is “NO”, the UE 100 resumes the process from the beginning of the operation flow.

On the other hand, when the result of step S101 is “YES” or when the result of step S102 is “YES”, in step S103, the UE 100 transmits the updated MBMS interest notification to the serving cell. Specifically, when the UE 100 changes its service priority (step S101; YES), the UE 100 transmits an MBMS interest notification including the changed service priority to the serving cell. Moreover, UE100 transmits the MBMS interest notification containing the changed MBMS frequency to a serving cell, when changing the MBMS frequency which self shows interest (step S102; YES).

Thus, even when the UE 100 does not change the MBMS frequency that it is interested in, the UE 100 can transmit the MBMS interest notification to the E-UTRAN 10 when changing the service priority. In other words, the UE 100 can notify the E-UTRAN 10 of the service priority change by the MBMS interest notification regardless of the MBMS frequency change in which the UE 100 is interested.

(4.3) Operation flow 2
FIG. 10 is a flowchart of the operation flow 2 of the UE 100 according to the present embodiment. In this operation flow, in order to prevent frequent transmission of MBMS interest notifications, a case is assumed in which transmission of MBMS interest notifications is restricted within a predetermined period (regulation period) from transmission of MBMS interest notifications. In the initial state of this operation flow, the UE 100 is in a connected state.

As shown in FIG. 10, in step S201, the UE 100 transmits an MBMS interest notification to the serving cell. The transmission of the MBMS interest notice here may be a transmission triggered by establishment of an RRC connection, or a transmission triggered by a change in service priority or MBMS frequency.

In step S202, the UE 100 starts a timer for measuring the regulation period in response to the transmission of the MBMS interest notification. Note that the restriction period may be set in advance in a timer or may be designated by the eNB 200 (serving cell). When eNB200 designates a regulation period, eNB200 transmits the RRC message containing a regulation period to UE100, for example, UE100 sets the regulation period contained in the RRC message received from eNB200 to a timer.

In step S203, the UE 100 determines whether or not to change its service priority as compared to the time when the MBMS interest notification was last transmitted. When the result of step S203 is “YES”, in step S204, the UE 100 transmits an updated MBMS interest notification to the serving cell. After transmitting the MBMS interest notice, the UE 100 resumes the process from step S202.

On the other hand, when the result of step S203 is “NO”, in step S205, the UE 100 determines whether or not to change the MBMS frequency at which the UE 100 is interested compared to the time when the MBMS interest notification was last transmitted. . When the result of step S205 is “NO”, the UE 100 resumes the process from step S203.

When the result of step S205 is “YES”, in step S206, the UE 100 determines whether or not the timer has expired, that is, whether or not the restriction period has expired. When the result of step S206 is “YES”, in step S204, the UE 100 transmits the updated MBMS interest notification to the serving cell. After transmitting the MBMS interest notice, the UE 100 resumes the process from step S202.

On the other hand, when the result of step S206 is “NO”, the UE 100 resumes the process from step S203 without transmitting the MBMS interest notification. That is, the UE 100 stops transmitting the MBMS interest notification.

As described above, the UE 100 cannot transmit the MBMS interest notification when changing the MBMS frequency in which the UE 100 is interested during the regulation period, but can transmit the MBMS interest notification when changing the service priority. In other words, the UE 100 can notify the E-UTRAN 10 of the service priority change by the MBMS interest notification regardless of the regulation period.

(5) Summary As described above, the UE 100 in the connected state transmits an updated MBMS interest notification to the E-UTRAN 10 when the service priority is changed even when the MBMS frequency is not changed. To do. Also, the UE 100 in the connected state transmits an updated MBMS interest notification to the E-UTRAN 10 when changing the service priority even within the restriction period. Therefore, the E-UTRAN 10 can always grasp the change of the service priority in the UE 100 in the connected state based on the updated MBMS interest notification.

Therefore, the E-UTRAN 10 can appropriately determine whether to provide the MBMS service or the unicast service to the UE 100, and thus can provide an appropriate service to the UE 100.

(6) Other Embodiments (6.1) Summary of Embodiments The above-described embodiments are summarized as follows.

Assumption 1: MBMS interest information includes an indication indicating the frequency at which the MBMS to be received is distributed and whether to receive the MBMS service / unicast service.

Assumption 2: There are several mechanisms that regulate the transmission of MBMS interest information by the UE.

[Example 1] Even if the transmission of MBMS "interest information" by the UE is restricted, if the "priority" of MBMS "service" / "unicast" services is changed, the UE can transmit MBMS "interest information".

Example 2: The conditions under which transmission of the MBMS interface information is regulated include, for example, when the MBMS service to be received is replaced, and the frequency at which the MBMS service is distributed is the frequency indicated in the previous MBMS interface information The condition is that transmission is possible in different cases.

Example 3: The condition under which transmission of the MBMS interest information is restricted is a condition that, for example, the UE can transmit if a predetermined time specified from the network has passed since the previous indication was transmitted.

(6.2) Appendix 1
In Release 11 (ReL-11) eMBMS, MBMSInterestIndication is introduced in order for the user equipment (UE) to inform the network of the interest of the UE receiving the MBMS service. The UE notifies the interest to the MBMS at the time of RRC connection establishment, and transmits an update notification every time the frequency set of the MBMS of interest is changed. In the embodiment, even when only the priority between MBMS and unicast reception is changed, the UE can transmit the updated MBMS interest notification. That is, the UE can modify its interest in MBMS based only on MBMS / unicast priority change.

The MBMS interest notice is sent under the following conditions. When the UE establishes an RRC connection (the UE does not need to wait until AS security is activated) and the frequency set that the UE is interested in receiving MBMS services (eg due to user interest or service availability changes) Whenever a change is made in comparison with the last notification sent to, an interest in MBMS is notified.

In this case, the priority between MBMS and unicast reception is changed, but it is unclear what happens to the UE when the interest in receiving the MBMS service remains unchanged. If the UE cannot update its interest in MBMS under this circumstance, the user will have an undesirable experience. For example, the UE has previously notified that the priority of the MBMS service is higher than the unicast service, but the UE is quasi-statistically configured as a service with higher priority than MBMS reception, such as VoLTE When a new unicast service is subsequently activated, if the network does not receive an update interest notification from the UE to change the relative priority between the MBMS and the unicast service, the network unicasts the UE through congestion control. May decide to release a service. Therefore, based on the change of priority between MBMS and unicast reception, regardless of whether the frequency set that the UE is interested in receiving the MBMS service has changed compared to the last notification sent to the network , UE should be able to notify interest in MBMS.

Therefore, every time there is a change in the priority between MBMS and unicast reception, regardless of whether the frequency set the UE is interested in receiving the MBMS service has changed compared to the last notification sent to the network. In addition, the UE should be updated to notify its interest in MBMS.

Also, the following conditions can be considered.

If SystemInformationBlockType15 is broadcasted by PCell and obtained by UE, UE has MBMS interest information and has not yet provided MBMS interest notification, or since UE last provided MBMS interest notification, SystemInformationBlockType15 When the UE is connected to a PCell that has not been notified, or when MBMS interest information is changed, transmission of an MBMSInterestIndication message is started.

Here, “MBMS interest information” includes all fields of MBMSInterestIndication including the priority between MBMS and the unicast service.

(6.3) Appendix 2
The embodiment focuses on the point that “a regulatory mechanism is introduced that allows E-UTRAN to configure the shortest period between successive interest notifications”. The need for the UE to notify the network of the priority change is further considered.

The main reason for requiring a regulation mechanism is to avoid the adverse effect of the UE repeatedly sending notifications to the network when the network does not hand over the UE to the desired MBMS frequency. However, the UE cannot send MBMS Interest Indication randomly. The UE only sends an updated MBMS notification if the source eNB or target eNB does not broadcast SIB15, if there is a change in MBMS interest that requires a change in MBMS frequency, or after completion of the handover. With these constraints, notifications should already be well managed and no regulatory mechanism is required. Furthermore, based on considerations regarding congestion and admission control, the UE should be able to change the MBMS priority for unicast at any time, including the time during network congestion. Therefore, a regulation mechanism that allows E-UTRAN to set up a UE in the shortest period between successive interest notifications should not be introduced.

The regulatory mechanism will prevent the UE from sending MBMS interest when the UE needs to update the priority between the MBMS and the unicast service. In order to prevent the user from having an undesirable experience, the UE should notify the MBMS interest as soon as possible when changing the priority between MBMS and unicast reception. Therefore, even when adopting the use of a regulation mechanism, another mechanism or special provision should be provided so that the UE can notify the network of the priority between MBMS and unicast reception whenever the priority is changed.

(6.4) Appendix 3
The UE should be allowed to change the MBMS / Unicast priority indicator whenever necessary. The need to send an updated MBMS / Unicast priority indicator does not depend on whether the set of MBMS frequencies that the UE is interested in receiving MBMS services has changed compared to the last sent indication to the network.

That is, the UE can transmit the updated MBMS / Unicast indicator whenever the priority between MBMS and unicast reception is changed.

The mobility procedure for MBMS reception makes it possible to start or continue receiving the MBMS service via the MBSFN when the cell is changed. The E-UTRAN procedure provides service continuity for mobility within the same MBSFN area. Within the same geographical area, the MBMS service is provided on one or more frequencies, and the frequency at which the MBMS service is provided at one place in the PLMN and another place is different.

The UE that receives the MBMS service in the RRC idle state or the UE in the RRC connected state acquires the target cell MTCH information from the target cell MCCH. In order to avoid acquiring the MBMS related system information and the MCCH of the adjacent frequency, the UE grasps the frequency for providing the MBMS service via the MBSFN by combining the following MBMS auxiliary information.

・ User service description (USD)
In USD, the application / service layer provides TMGI, session start / end time, frequency, and MBMS service area identifier (SAI) for each service.

・ System information
The MBMS cell and the non-MBMS cell notify the MBMS SAI of the own frequency and each adjacent frequency by SystemInformationBlockType15.

Also, the following procedure is applied to UEs in the RRC idle state and the RRC connected state. The UE does not need to verify the frequency for providing the MBMS service by acquiring the MCCH, and these procedures can be applied even if the MBMS service is not provided via the MBSFN. The UE can consider the service when the service of the session derived from the session start time and the end time in USD is progressing and the frequency provides the service. When the serving cell provides SystemInformationBlockType15, the UE determines that the frequency provides the MBMS service only when the MBMS SAI of the frequency indicated by the SystemInformationBlockType15 of the serving cell indicates the MBMS service in USD.

In RRC connected state, a UE that receives or is interested in receiving MBMS service via MBSFN informs the network about the MBMS interest with an RRC message, and the network should allow the UE to receive MBMS and unicast service. Do your best. The UE notifies its MBMS interest when establishing an RRC connection. Alternatively, the UE notifies its own MBMS interest whenever the MBMS frequency of interest changes since the last notification of MBMS interest to the network. Alternatively, the UE notifies its MBMS interest whenever the priority between MBMS and unicast reception changes.

(6.5) Appendix 4
In the above-described embodiment, the mobile communication system is an LTE system, but may be a system such as a UMTS (Universal Mobile Telecommunications System).

Note that the entire content of US Provisional Application No. 61/679340 (filed on August 3, 2012) is incorporated herein by reference.

As described above, the present invention can provide an appropriate service to a user terminal, and thus is useful in the field of wireless communication such as mobile communication. .

Claims

A mobile communication system supporting MBMS (Multimedia Broadcast Multicast Service) function,
A user terminal capable of transmitting to the network a notification indicating interest in the MBMS service provided using the MBMS function when a predetermined condition is satisfied in the connected state;
The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service,
The mobile communication system according to claim 1, wherein the user terminal transmits the notification to the network when the priority is changed even when the predetermined condition is not satisfied.
The mobile communication system according to claim 1, wherein the predetermined condition is a condition that the frequency is changed by changing the MBMS service in which the user terminal is interested.
A user terminal in a mobile communication system that supports MBMS (Multimedia Broadcast Multicast Service) function,
A transmission unit capable of transmitting a notification indicating an interest in the MBMS service provided using the MBMS function to a network when a predetermined condition is satisfied in the connection state of the user terminal;
The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service,
The transmission unit transmits the notification to the network when the priority is changed even when the predetermined condition is not satisfied.
The user terminal according to claim 3, wherein the predetermined condition is a condition that the frequency is changed by changing the MBMS service in which the user terminal is interested.
An MBMS service that is provided in a user terminal in a mobile communication system that supports an MBMS (Multimedia Broadcast Multicast Service) function and that is provided using the MBMS function when a predetermined condition is satisfied in the connection state of the user terminal A processor that performs a process of sending a notice of interest to the network,
The notification includes a frequency provided by the MBMS service in which the user terminal is interested, and a priority of whether to receive the MBMS service in preference to a unicast service,
The processor performs processing for transmitting the notification to the network when the priority is changed even when the predetermined condition is not satisfied.
The processor according to claim 5, wherein the predetermined condition is a condition that the frequency is changed by changing the MBMS service in which the user terminal is interested.