JP2011147191A - Mobile station, and mobile communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue communication in a second cell even if reception of notified information fails in the second cell when handover from a first cell to the second cell occurs. <P>SOLUTION: A mobile station UE is equipped with a communication unit 14 that is so configured that when it has successfully received SIB1 by means of a notified information receiving unit 12, it starts a first communication using information included in MIB, SIB1, and handover command in a handover destination cell, and when it fails in reception of the SIB1 by means of the notified information receiving unit 12, it starts a second communication using information included in the MIB and the handover command in the handover destination cell. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mobile station and a mobile communication method.

  In a mobile communication system of LTE (Long Term Evolution) system defined by 3GPP, a radio base station eNB in a subordinate cell has an MIB (Master Information Block, main information block) or SIB1 (System Information Block 1, first). Broadcast information including a system information block) is transmitted, and the mobile station UE in the cell is configured to perform predetermined communication based on the information in the MIB and SIB1 included in the broadcast information.

3GPP TS36.331 V8.3.0

  However, in the current LTE mobile communication system, when the mobile station UE fails to receive SIB1 or the like in the second cell when handing over from the first cell to the second cell, the mobile station UE communicates in the second cell. There was a problem that it was impossible to continue.

  Therefore, the present invention has been made in view of the above-described problems, and even when the handover from the first cell to the second cell fails to receive broadcast information in the second cell, the second cell An object of the present invention is to provide a mobile station and a mobile communication method capable of continuing communication in a cell.

  A first feature of the present invention is a mobile station, which receives a main information block included in broadcast information in the second cell when handed over from the first cell to the second cell in response to the received handover command. A broadcast information receiving unit configured to receive a first system information block included in the broadcast information based on information included in the main information block; and the broadcast system information receiving unit configured to receive the first system information When the reception of the block is successful, in the second cell, the first communication using the information included in the main information block, the first system information block, and the handover command is started, and the broadcast information When reception of the first system information block by the receiving unit fails, the main information block and the handover are performed in the second cell. And summarized in that comprises a communication unit configured to perform a second communication using information included in the command.

  A second feature of the present invention is a mobile communication method, which is included in broadcast information in the second cell when the mobile station performs handover from the first cell to the second cell in response to the received handover command. Receiving a main information block, receiving a first system information block included in the broadcast information based on information included in the main information block, and the mobile station successfully receiving the first system information block In the second cell, starting the first communication using the information included in the main information block, the first system information block and the handover command in the second cell, the mobile station, If reception of the first system information block fails, it is included in the main information block and the handover command in the second cell. And summarized in that a step of performing a second communication using the information.

  As described above, according to the present invention, when handing over from the first cell to the second cell, communication is continued in the second cell even when reception of broadcast information in the second cell fails. A mobile station and a mobile communication method can be provided.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. FIG. 3 is a functional block diagram of a mobile station according to the first embodiment of the present invention. It is a figure which shows an example of the alerting | reporting information (MIB) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the alerting | reporting information (SIB1) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the information element (uE-TimersAndConstants) contained in the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the information element (radioResourceConfigCommon) contained in the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the content of the information element (radioResourceConfigCommon) contained in the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the content of the information element (radioResourceConfigCommon) contained in the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the content of the information element (radioResourceConfigCommon) contained in the alerting | reporting information (SIB2) transmitted by the wireless base station which concerns on the 1st Embodiment of this invention. 3 is a flowchart showing an operation of the mobile station according to the first embodiment of the present invention.

(Configuration of mobile communication system according to the first embodiment of the present invention)
The configuration of the mobile communication system according to the first embodiment of the present invention will be described with reference to FIG. 1 to FIG.

  As shown in FIG. 1, the mobile communication system according to the present embodiment is an LTE mobile communication system, in which a cell 1 using a frequency f1, a cell 2 using a frequency f1, and a frequency cell 3 in which f3 is used.

  Here, as shown in FIG. 1, the broadcast information transmitted in the cell 1 includes MIB, SIB1, and SIB2, whereas the broadcast information transmitted in the cell 2 and the cell 3 Does not include SIB1 and SIB2.

  Hereinafter, in the present embodiment, an example in which the mobile station UE performs a handover from the cell 1 (first cell) to the cell 2 (second cell) will be described.

  As shown in FIG. 2, the mobile station UE includes a broadcast information storage unit 11, a broadcast information reception unit 12, a handover processing unit 13, and a communication unit 14.

  The notification information storage unit 11 is configured to store the notification information received by the notification information storage unit 11.

  Here, the broadcast information storage unit 11 receives broadcast information received by the broadcast information storage unit 11 in the cell 1 which is a cell before handover, and received by the broadcast information storage unit 11 in the cell 2 which is a cell after handover. Both notification information may be stored.

  The broadcast information receiving unit 12 is configured to receive broadcast information (for example, MIB, SIB1, SIB2, etc.) transmitted in the cell where the mobile station UE is located and store it in the broadcast information storage unit 11. Has been.

  Specifically, the broadcast information receiving unit 12 receives the MIB included in the broadcast information in the cell 2 when the mobile station UE has handed over from the cell 1 to the cell 2, and broadcasts based on the information included in the MIB. It is configured to receive SIB1 included in the information.

  For example, as shown in FIG. 3, the broadcast information receiving unit 12 is configured to receive “dl-System Bandwidth”, “phich-Configuration”, “system Frame Number”, and the like, which are information included in the MIB. .

  Here, “dl-SystemBandwidth” is information indicating a frequency band used in the downlink of the mobile communication system, and “phich-Configuration” is PHICH (Physical HARQ Indicator Channel) setting information, “systemFrameNumber” is information indicating a system frame number in the mobile communication system.

  Further, as shown in FIG. 4, the broadcast information receiving unit 12 is configured to receive “plmn-IdentityList”, “tracking AreaCode”, “schedulingInformation”, and the like, which are information included in the SIB1.

  Here, “plmn-IdentityList” and “trackingAreaCode” are information not included in the handover command, and the location registration processing (when the mobile station UE is in the “RRC-Connected state (connection state)”) Information used in TAU).

  “SchedulingInformation” is information indicating scheduling information (period information and mapping information) of a plurality of SIs (System Information).

  Further, as shown in FIG. 5, the broadcast information receiving unit 12 is configured to receive “ue-TimersAndConstants”, “radioResourceConfigCommon”, “mbsfn-SubframeConfiguration”, and the like, which are information included in the SIB2. .

  Here, “mbsfn-SubframeConfiguration” indicates setting information for receiving LTE MBMS (Multimedia Multicast Service) information in the cell.

  Such setting information includes, for example, setting information on the position of a subframe allocated for the “MBSFN (MBMS Single Frequency Network) transmission method” for simultaneously transmitting the same information from a plurality of cells using the same frequency resource. included.

  In the subframe to which MBSFN transmission is applied, for example, the mobile station UE applies a channel estimation value different from the channel estimation value in a subframe to which the MBSFN transmission scheme is not applied.

  That is, in a subframe to which the MBSFN transmission scheme is not applied, a cell-specific pilot signal is used to identify signals between cells. Therefore, the mobile station UE performs channel estimation for the cell based on the pilot signal for each cell.

  On the other hand, in the subframe to which the MBSFN transmission scheme is applied, since the same pilot signal is transmitted from a plurality of radio base stations eNB, channel estimation for individual cells cannot be performed. In such a subframe, channel estimation for MBSFN reception is performed.

  Further, in a subframe to which the MBSFN transmission scheme is applied, the mobile station UE can be regarded as not performing unicast transmission.

  Thus, the mobile station UE can perform different operations in subframes to which the MBSFN transmission scheme is applied, compared to subframes to which the MBSFN transmission scheme is not applied.

  “Ue-TimersAndConstants” is information indicating setting values of various timers used in the cell. For example, as illustrated in FIG. 6, “ue-TimersAndConstants” is information indicating a setting value of the timer T300, a setting value of the timer T301, a setting value of the timer T310, a setting value of the timer T311, and the like.

  In addition, as shown in FIG. 7, “radioResourceConfigCommon” is “RACH Configuration” that is RACH (Random Access Channel) setting information, and “BCCH-Configuration and BCCH-ConfigurationPC” that is setting information of BCCH (Broadcast Channel). (Paging Control Channel) setting information “pcch-Configuration”, PRACH (Physical Random Access Channel) setting information “prac-Configuration Information” and PDSCH (Physical Downlink Setting Information) -Configura ion "and includes a setting information PUSCH (Physical Uplink Shared Channel) or" PUSCH-Configuration ", which is the setting information of the PUCCH (Physical Uplink Control Channel)" PUCCH-Configuration "and the like.

  For example, “pcch-Configuration” is an information element included in “MobilityControlInformation (see FIG. 9)” that is an information element included in “RRCConnectionReconfiguration (see FIG. 8)” that is an information element transmitted on the dedicated channel. Information set in “radioResourceConfigCommon” is set (see FIG. 10).

  Specifically, as shown in FIG. 10, “pcch-Configuration” is configured to be set to “defaultPagingCycle” indicating the paging cycle and “nB” indicating the set value of the parameter nB.

  Note that the broadcast information receiving unit 12 may be configured not to perform reception processing on the SIB1 when the MIB notifies that the SIB1 is not transmitted in the cell 2. For example, the notification may be configured to be performed by 1 bit in the MIB.

  Further, the broadcast information receiving unit 12 may be configured not to perform reception processing on the SIB1 when notified by the handover command that the SIB1 is not transmitted in the cell 2. For example, such notification may be configured to be performed by 1 bit in the handover command.

  The handover processing unit 13 is configured to perform processing for the mobile station UE to perform handover from the cell 1 to the cell 2 in accordance with the handover command received from the radio base station eNB.

  Here, the handover command is the SIB1 and SIB2 necessary for performing the operation of the “RRC-Connected state (connection state)” after the handover in preparation for the case where the broadcast information receiving unit 12 fails to receive the SIB1 and SIB2. It may be configured to include information to be transmitted.

  For example, “plmn-IdentityList”, “trackingAreaCode”, “ue-TimersAndConstants”, “pcch-Configuration”, “mbsfn-SubframeConfiguration”, etc. are assumed as such information.

  The communication unit 14 is configured to perform predetermined communication in the cell 2 when the mobile station UE hands over from the cell 1 to the cell 2.

  Specifically, when the broadcast information reception unit 12 has successfully received SIB1 and SIB2, the communication unit 14 performs the first communication using information included in the MIB, SIB1, and the handover command in the cell 2. Configured to start.

  On the other hand, the communication unit 14 is configured to perform the second communication using the information included in the MIB and the handover command in the cell 2 when the broadcast information receiving unit 12 fails to receive the SIB1 and SIB2. ing.

  For example, when performing the first communication, the communication unit 14 is configured to perform periodic location registration processing based on the information “plmn-IdentityList” and “tracking AreaCode” included in the SIB1. Also good.

  On the other hand, when performing the second communication, the communication unit 14 is configured not to perform the location registration process because the information “plmn-IdentityList” and “trackingAreaCode” included in the SIB1 cannot be acquired. May be. Further, in the case where the setting is such that the location registration process is performed periodically, the location registration process may be configured not to be performed.

  In addition, when performing the first communication, the communication unit 14 is configured to use the set value of the timer included in the SIB1 (the set value of the timer included in “ue-TimersAndConstants”). When two communications are performed, the setting value of the timer used in the cell 1 may be used.

  Further, when performing the first communication, the communication unit 14 is configured to receive a paging signal addressed to the mobile station UE based on the information “pcch-Configuration” included in the SIB1. When 2 communication is performed, since the information “pcch-Configuration” included in the SIB1 cannot be acquired, the paging signal addressed to the mobile station UE may not be received.

  Alternatively, when performing the first communication, the communication unit 14 is configured to receive a paging signal addressed to the mobile station UE based on the information “pcch-Configuration” included in the SIB1. In the case of performing two communication, since the information “pcch-Configuration” included in the SIB1 cannot be acquired in the cell 2, the mobile station UE is based on the information “pcch-Configuration” used in the cell 1. It may be configured to receive an addressed paging signal.

  Further, when the first communication is performed, the communication unit 14 regards the predetermined subframe as a subframe to which the MBSFN transmission scheme is applied based on the information “mbsfn-SubframeConfiguration” included in the SIB1. When the second communication is performed, the information “mbsfn-SubframeConfiguration” included in the SIB1 cannot be acquired in the cell 2, and thus the predetermined subframe is not applied to the MBSFN scheme. It may be configured to be regarded as a frame.

  Alternatively, when performing the first communication, the communication unit 14 may regard the predetermined subframe as a subframe to which the MBSFN scheme is applied based on the information “mbsfn-SubframeConfiguration” included in the SIB1. When the second communication is performed and the information “mbsfn-SubframeConfiguration” included in the SIB1 is not acquired in the cell 2, it is based on the “mbsfn-SubframeConfiguration” used in the cell 1. Thus, the predetermined subframe may be regarded as a subframe to which the MBSFN scheme is applied.

(Operation of the mobile communication system according to the first embodiment of the present invention)
Referring to FIG. 11, the operation of the mobile communication system according to the first embodiment of the present invention, specifically, the operation of the mobile station UE used in the mobile communication system according to the first embodiment of the present invention. explain.

  As shown in FIG. 11, in step S101, the mobile station UE hands over from the cell 1 to the cell 2.

  In step S102, the mobile station UE determines whether SIB1 / SIB2 is transmitted in the broadcast information in the cell 2 according to a predetermined flag in the MIB or the handover command.

  When it is determined that SIB1 / SIB2 is transmitted, the operation proceeds to step S103, and when it is determined that SIB1 / SIB2 is not transmitted, the operation proceeds to step S103.

  In step S103, the mobile station UE performs reception processing on SIB1 / SIB2. When the reception process is successful, the operation proceeds to step S104. When the reception process fails, the operation proceeds to step S105.

  In step S104, in the cell 2, the mobile station UE continues the first communication (normal communication) using information included in the MIB, SIB1, SIB2, and the handover command.

  On the other hand, in step S105, the mobile station UE continues the second communication using the information included in the MIB and the handover command (communication that can be performed using the information included in the MIB and the handover command) in the cell 2. To do.

(Operations and effects of the mobile communication system according to the first embodiment of the present invention)
According to the mobile communication system according to the first embodiment of the present invention, the mobile station UE is included in the MIB and the handover command even if reception of SIB1 / SIB2 fails in the handover destination cell. Since the second communication using the existing information can be continued, the continuity of the communication can be guaranteed.

  Moreover, according to the mobile communication system which concerns on the 1st Embodiment of this invention, since each cell does not need to transmit SIB1 and SIB2, it can give a flexibility to cell design.

  For example, the mobile station UE in the “idle-mode” waits only in the cell 1 to which SIB1 and SIB2 are transmitted, and the mobile station UE in the “RRC-Connected state (connected state, connected-mode)” However, it is possible to operate such that communication is performed in both the cell 1 and the cell 2 to which the SIB1 and SIB2 are not transmitted.

  In this way, it is possible to reduce the number of cell reselections between different frequencies when the mobile station UE is in the “idle state”. Also, the paging load can be reduced.

  Furthermore, according to the mobile communication system according to the first embodiment of the present invention, the mobile station UE can detect that SIB1 / SIB2 is not transmitted in a specific cell, and in such a case, the SIB1 / Since communication can be started without performing reception processing for SIB2, time required for handover processing can be reduced.

  The characteristics of the present embodiment described above may be expressed as follows.

  The first feature of the present embodiment is the mobile station UE, which receives the MIB included in the broadcast information in the cell 2 when handed over from the cell 1 to the cell 2 in response to the received handover command, In the cell 2, when the SIB1 is successfully received by the broadcast information receiving unit 12 and the broadcast information receiving unit 12 configured to receive the SIB1 included in the broadcast information based on the included information, the MIB and the SIB1 When the first communication using the information included in the handover command and the broadcast information receiving unit 12 fails to receive the SIB1, the cell 2 stores the information included in the MIB and the handover command. The gist of the present invention is to include a communication unit 14 configured to perform the used second communication.

  In the first feature of the present embodiment, the communication unit 14 is configured to perform location registration processing based on information included in the SIB1 when performing the first communication, and the second communication. However, the location registration process may not be performed. The location registration process may include a periodic location registration process.

  In the first feature of the present embodiment, the communication unit 14 is configured to use the set value of the timer included in the SIB1 when performing the first communication, and performs the second communication. In this case, the setting value of the timer used in the cell 1 may be used.

  In the first feature of the present embodiment, the communication unit 14 is configured to receive a paging signal addressed to the mobile station UE based on information included in the SIB1 when performing the first communication. And when performing 2nd communication, you may be comprised so that the paging signal addressed to the mobile station UE may not be received.

  In the first feature of the present embodiment, the communication unit 14 is configured to receive a paging signal addressed to the mobile station UE based on information included in the SIB1 when performing the first communication. And when performing 2nd communication, based on the information used in the cell 1, you may be comprised so that the paging signal addressed to the mobile station UE may be received.

  1st characteristic of this embodiment WHEREIN: When the communication part 14 is performing 1st communication, based on the information contained in SIB1, the subframe to which the MBSFN transmission system is applied for a predetermined subframe When the second communication is performed, the predetermined subframe may be regarded as a subframe to which the MBSFN transmission scheme is not applied.

  1st characteristic of this embodiment WHEREIN: When the communication part 14 is performing 1st communication, based on the information contained in SIB1, the subframe to which the MBSFN transmission system is applied for a predetermined subframe If the second communication is performed, the predetermined subframe may be regarded as a subframe to which the MBSFN transmission scheme is applied based on the information of the cell 1. Good.

  In the first feature of the present embodiment, the broadcast information receiving unit 12 may be configured not to perform a reception process on the SIB1 when the MIB notifies that the SIB1 is not transmitted in the cell 2. Good.

  In the first feature of the present embodiment, the broadcast information receiving unit 12 is configured not to perform reception processing on the SIB1 when notified by the handover command that the SIB1 is not transmitted in the cell 2. Also good.

  The second feature of the present embodiment is a mobile communication method, in which when the mobile station UE performs handover from the cell 1 to the cell 2 in response to the received handover command, the MIB included in the broadcast information in the cell 2 is changed. And receiving the SIB1 included in the broadcast information based on the information included in the MIB, and when the mobile station UE has successfully received the SIB1, the cell 2 includes the MIB, the SIB1, and the handover command. The first communication using the received information, and the second communication using the information included in the MIB and the handover command in the cell 2 when the mobile station UE fails to receive the SIB1. And a step of performing the above.

  The operations of the mobile station UE and the radio base station eNB described above may be implemented by hardware, may be implemented by a software module executed by a processor, or may be implemented by a combination of both. .

  The software module includes a RAM (Random Access Memory), a flash memory, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electronically Erasable and Programmable ROM, a hard disk, a registerable ROM, a hard disk). Alternatively, it may be provided in a storage medium of an arbitrary format such as a CD-ROM.

  Such a storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Further, such a storage medium may be integrated in the processor. Such a storage medium and processor may be provided in the ASIC. Such an ASIC may be provided in the mobile station UE or the radio base station eNB. Further, the storage medium and the processor may be provided as a discrete component in the mobile station UE or the radio base station eNB.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

UE ... Mobile station 11 ... Broadcast information storage unit 12 ... Broadcast information reception unit 13 ... Handover processing unit 14 ... Communication unit

Claims (1)

When handover is performed from the first cell to the second cell in response to the received handover command, the main information block included in the broadcast information in the second cell is received, and the broadcast is performed based on the information included in the main information block. A broadcast information receiver configured to receive the first system information block included in the information;
When the broadcast information receiving unit successfully receives the first system information block, the information contained in the main information block, the first system information block, and the handover command is used in the second cell. When the broadcast information reception unit fails to receive the first system information block, the information contained in the main information block and the handover command is used in the second cell. And a communication unit configured to perform the second communication.