JP2012231529A - Communication system, mobile station device, wireless link state management method, and integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take linkage of a plurality of frequency bands into consideration and to efficiently manage a wireless link state of the frequency bands, in a communication system including a base station device which performs communication using the plurality of frequency bands and a mobile station device wirelessly connected to the base station device.SOLUTION: The base station device sets, to the mobile station device, downlink state determination information for managing the wireless link state of the frequency band of at least one downlink in order to detect a wireless link problem indicating quality degradation of the frequency band and random access information for managing the wireless link state of the frequency band of at least one uplink. The mobile station device detects the wireless link problem of the frequency band on the basis of the information set by the base station device, and simultaneously changes the wireless link states of the frequency band in which the wireless link problem is detected and another frequency band linked with the frequency band in which the wireless link problem is detected.

Description

  The present invention relates to a communication system, a mobile station apparatus, a radio link state management method, and an integrated circuit, and in particular, a radio link state management method when the mobile station apparatus is wirelessly connected to a base station apparatus using a plurality of frequency bands. About.

  Evolved which realized high-speed communication by adopting OFDM (Orthogonal Frequency-Division Multiplexing) communication method and flexible scheduling of predetermined frequency and time unit called resource block in 3GPP (3rd Generation Partnership Project) which is a standardization project Universal Terrestrial Radio Access (hereinafter referred to as EUTRA) has been studied, and further development of Advanced EUTRA (also referred to as LTE-Advanced) is being promoted.

  In Advanced EUTRA, Carrier Aggregation has been proposed as a technology capable of higher-speed data transmission while maintaining compatibility with EUTRA. Carrier aggregation is a method in which data of a transmitting device transmitted in a plurality of different frequency bands (also referred to as carrier frequency and component carrier) is received by receiving devices corresponding to different frequency bands, respectively. It is a technology that improves the rate. In the following, a receiving device in downlink transmission is referred to as a mobile station device, a transmitting device is referred to as a base station device, a receiving device in uplink transmission is a base station device, and a transmitting device in uplink transmission. Are described as mobile station apparatuses, but the scope of application of the present invention need not be limited to these apparatuses.

  An EUTRA mobile station apparatus determines whether a base station apparatus that is currently wirelessly connected is appropriate as a communication destination by detecting a radio link problem in an upper layer. The radio link problem is a problem that occurs in a lower layer (physical layer and data link layer) (physical layer problem in the physical layer (random layer problem) or random access problem in the data link layer). . The physical layer problem is that a downlink synchronization error (out-of-sync) notification and downlink synchronization recovery (in-sync), which are comparison results between the reception quality of the transmission signal from the base station apparatus and the threshold value of the physical layer. Based on the notification, it is detected by RRC (Radio Resource Control).

  Also, the random access problem is detected by the data link layer MAC (Medium Access Control) when the number of preamble transmissions reaches the maximum number of transmissions, and is notified to the RRC. The MAC mainly performs management of random access transmission, management of deviation in uplink transmission timing, management of buffer status, and the like. RRC mainly performs management of lower layer state, management of radio resource control, mobility control, and the like. Further, the RRC detects a radio link failure indicating that an error has occurred in the radio connection with the base station apparatus based on the detected or notified radio link problem.

  Note that the third generation base station apparatus defined by 3GPP is referred to as a Node B (NodeB), and the base station apparatus in EUTRA and Advanced EUTRA is referred to as an eNodeB (eNodeB). The base station apparatus manages a cell that is an area where the mobile station apparatus can communicate, and the cell is also referred to as a femto cell, a pico cell, or a nano cell depending on the size of the area that can communicate with the mobile station apparatus. In addition, when a mobile station device can communicate with a certain base station device, the cell of the base station device is a serving cell of the mobile station device, and other base station devices or cells of different frequencies are referred to as neighboring cells. Is done.

R2-096505, CATT, 3GPP TSG-RAN WG2 Meeting # 68, Jeju, South Korea, 9th-13th November 2009 R2-096496, Huawei, 3GPP TSG-RAN WG2 Meeting # 68, Jeju, South Korea, 9th-13th November 2009 R2-096845, Nokia Corporation, Nokia Siemens Networks, 3GPP TSG-RAN WG2 Meeting # 68, Jeju, South Korea, 9th-13th November 2009

  Even when the mobile station apparatus receives a plurality of frequency bands, it is necessary to detect a radio link failure from the viewpoint of the utilization efficiency of radio resources. However, with regard to the physical layer problem and random access problem of a mobile station apparatus receiving a plurality of frequency bands, as described in Non-Patent Documents 1 to 3, a plurality of proposals have been made, but in Advanced EUTRA, The operation when a physical layer problem and a random access problem occur in a mobile station device (hereinafter simply referred to as a mobile station device) is not determined. In particular, the mobile station apparatus has not decided how to manage the radio link state of the frequency band (component carrier) in which the radio link problem has occurred.

  Non-Patent Documents 1 to 3 described above disclose that a mobile station apparatus detects a physical layer problem and a random access problem for each component carrier, and a determination method for detecting the occurrence of a radio link failure. When a radio link problem occurs in the component carrier set in the mobile station device, how the mobile station device manages the radio link status (radio connection status) of other downlink component carriers or uplink component carriers. It is not disclosed.

  In view of the above problems, the present invention considers the cooperative relationship between a plurality of frequency bands when the mobile station apparatus is wirelessly connected to the base station apparatus using a plurality of frequency bands, and efficiently uses the frequency bands. An object of the present invention is to provide a communication system, a mobile station apparatus, a radio link state management method, and an integrated circuit capable of managing the radio link state.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the communication system of the present invention is a communication system in which a base station apparatus and a mobile station apparatus perform communication by aggregating a plurality of different frequency bands, and the base station apparatus communicates with the mobile station apparatus. Setting downlink state determination information for managing the radio link state of at least one downlink frequency band, and random access information for managing the radio link state of at least one uplink frequency band, The mobile station apparatus detects, for each frequency band, a radio link problem indicating quality degradation of a frequency band based on information set from the base station apparatus, and the frequency band in which the radio link problem is detected, The wireless link state of another frequency band that is associated with the frequency band in which the wireless link problem has been detected is simultaneously changed.

  (2) Also, in the communication system of the present invention, the mobile station apparatus downlinks a radio link state of one or a plurality of downlink frequency bands in which the downlink state determination information is set from the base station apparatus. In the case of changing to a downlink component carrier failure indicating quality degradation of the frequency band, the radio link state of the uplink frequency band that is linked to the downlink frequency band is simultaneously changed.

  (3) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the uplink frequency band that is linked to the downlink frequency band whose radio link state is changed to a downlink component carrier failure. The state is changed to an uplink component carrier failure indicating quality degradation of an uplink frequency band.

  (4) Further, in the communication system of the present invention, the mobile station apparatus sets a downlink component carrier when the radio link state of the downlink frequency band is a downlink component carrier failure and By changing the radio link state of the uplink frequency band that is linked to the downlink frequency band that has been changed to the failure, all the radio link states of the uplink frequency band become uplink component carrier failures. In this case, a radio resource re-establishment procedure is started.

  (5) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the uplink frequency band that is linked to the downlink frequency band whose radio link state is changed to a downlink component carrier failure. The radio resource re-establishment procedure is started when all the radio link states of the uplink frequency band are uplink component carrier failures due to the change of the state.

  (6) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the uplink frequency band that is linked to the downlink frequency band whose radio link state is changed to a downlink component carrier failure. The radio resource re-establishment procedure is started when the radio link state of the uplink frequency band which is an uplink anchor carrier becomes an uplink component carrier failure due to the change of the state.

  (7) Further, in the communication system of the present invention, the mobile station apparatus sets an uplink frequency to a radio link state of one or a plurality of uplink frequency bands in which the random access information is set from the base station apparatus. The radio link state of the downlink frequency band that is associated with the uplink frequency band is simultaneously changed when the uplink component carrier failure indicating the quality degradation of the band is changed.

  (8) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure. The state is changed to a downlink component carrier failure indicating quality degradation of a downlink frequency band.

  (9) Further, in the communication system of the present invention, the mobile station apparatus sets an uplink component carrier when the radio frequency link state of the uplink frequency band is an uplink component carrier failure and when the radio link status is an uplink component carrier. By changing the radio link state of the downlink frequency band that is associated with the uplink frequency band that has been changed to a failure, all the radio link states of the downlink frequency band become downlink component carrier failures. In this case, a radio resource re-establishment procedure is started.

  (10) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure. The radio resource re-establishment procedure is started when all the radio link states of the downlink frequency band are downlink component carrier failures due to the change of the state.

  (11) Further, in the communication system of the present invention, the mobile station apparatus has a radio link in the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure. The radio resource re-establishment procedure is started when the radio link state of the downlink frequency band which is a downlink anchor carrier becomes a downlink component carrier failure due to the change of the state.

  (12) Further, the mobile station apparatus of the present invention is a mobile station apparatus in a communication system in which a base station apparatus and a mobile station apparatus perform communication by aggregating a plurality of different frequency bands, from the base station apparatus A radio link problem indicating quality degradation of a frequency band is detected for each frequency band based on set information, and the frequency band in which the radio link problem is detected and the frequency band in which the radio link problem is detected are linked. A radio link state management unit that simultaneously changes the radio link states of different frequency bands that are related to each other is provided.

  (13) In addition, in the mobile station apparatus of the present invention, the radio link state of one or a plurality of downlink frequency bands in which the downlink state determination information is set from the base station apparatus is defined as the quality of the downlink frequency band. A radio link state management unit that simultaneously changes a radio link state of the uplink frequency band that is associated with the downlink frequency band when the downlink component carrier failure indicating degradation is changed; And

  (14) In the mobile station apparatus of the present invention, the radio link state of the uplink frequency band that is linked to the downlink frequency band in which the radio link state is changed to a downlink component carrier failure And a radio link state management unit for changing to an uplink component carrier failure indicating quality degradation of the frequency band.

  (15) Further, in the mobile station apparatus of the present invention, when all the radio link states of the downlink frequency band are downlink component carrier failures, and the radio link state is changed to a downlink component carrier failure When the radio link state of the uplink frequency band that is associated with the downlink frequency band is changed, and the radio link state of the uplink frequency band becomes an uplink component carrier failure, A radio link state management unit for starting a resource re-establishment procedure is provided.

  (16) In the mobile station apparatus of the present invention, the radio link state of the uplink frequency band that is linked to the downlink frequency band whose radio link state is changed to a downlink component carrier failure is changed. Thus, a radio link state management unit is provided for starting a radio resource re-establishment procedure when all of the radio link states in the uplink frequency band cause an uplink component carrier failure.

  (17) In addition, in the mobile station apparatus of the present invention, the radio link state of the uplink frequency band that is associated with the downlink frequency band whose radio link state is changed to a downlink component carrier failure is changed. The wireless link state management unit for starting the wireless resource re-establishment procedure when the wireless link state of the uplink frequency band, which is an uplink anchor carrier, causes an uplink component carrier failure. .

  (18) Further, in the mobile station apparatus of the present invention, the radio link state of one or a plurality of uplink frequency bands in which the random access information is set from the base station apparatus is changed to degrade the quality of the uplink frequency band. And a radio link state management unit that simultaneously changes a radio link state of the downlink frequency band that is associated with the uplink frequency band when the uplink component carrier failure is changed. The mobile station apparatus according to claim 12.

  (19) In the mobile station apparatus of the present invention, the radio link state of the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure And a radio link state management unit for changing to a downlink component carrier failure indicating quality degradation of the frequency band.

  (20) Further, in the mobile station apparatus of the present invention, when all the radio link states of the downlink frequency band are downlink component carrier failures, and the radio link state is changed to an uplink component carrier failure When the radio link state of the downlink frequency band that is associated with the uplink frequency band is changed, and the radio link state of the downlink frequency band is all downlink component carrier failure, A radio link state management unit for starting a resource re-establishment procedure is provided.

  (21) In the mobile station apparatus of the present invention, the radio link state of the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure is changed. Thus, a radio link state management unit is provided for starting a radio resource re-establishment procedure when all the radio link states in the downlink frequency band cause a downlink component carrier failure.

  (22) In the mobile station apparatus of the present invention, the radio link state of the downlink frequency band that is linked to the uplink frequency band whose radio link state is changed to an uplink component carrier failure is changed. The wireless link state management unit starts a wireless resource re-establishment procedure when the wireless link state of the downlink frequency band, which is a downlink anchor carrier, causes a downlink component carrier failure. .

  (23) The radio link state management method of the present invention is a radio link state management method in a communication system in which a base station apparatus and a mobile station apparatus perform communication by aggregating a plurality of different frequency bands, In the mobile station device, detecting for each frequency band a radio link problem indicating quality degradation of a frequency band based on information set from the base station device; and the frequency band detecting the radio link problem; The method includes the step of simultaneously changing the state of a radio link in another frequency band that is associated with the frequency band in which the radio link problem has been detected.

  (24) Further, the integrated circuit of the present invention is an integrated circuit that performs radio link state management of a mobile station apparatus in a communication system in which a base station apparatus and a mobile station apparatus perform communication by aggregating a plurality of different frequency bands. A radio link problem indicating quality degradation of the frequency band based on information set from the base station apparatus is detected for each frequency band, and the frequency band in which the radio link problem is detected, and the radio link A radio link state management unit that simultaneously changes a radio link state of another frequency band that is associated with the frequency band in which the problem has been detected is provided.

  As described above, according to the present invention, when the mobile station apparatus is wirelessly connected to the base station apparatus using a plurality of frequency bands, the frequency relationship is efficiently considered in consideration of the cooperative relationship of the plurality of frequency bands. It is possible to provide a communication system, a mobile station apparatus, a radio link state management method, and an integrated circuit that can manage a radio link state of a band.

It is the block diagram which showed an example of the mobile station apparatus 1 which concerns on embodiment of this invention. It is the block diagram which showed an example of the base station apparatus 2 which concerns on embodiment of this invention. It is a figure for demonstrating the radio link management method when a radio link problem is detected. It is the figure which showed the method of the state transition of the radio link state for every component carrier regarding a radio link problem. It is another figure for demonstrating the radio link management method when a radio link problem is detected. It is a figure for demonstrating the radio | wireless link management method at the time of detecting a radio | wireless link problem with the component carrier which has a some cell specific connection, and the component carrier by which cell specific connection was carried out. It is another figure which showed the method of the state transition of the radio link state for every component carrier regarding a radio link problem. It is another figure for demonstrating the radio link management method when a radio link problem is detected. It is another figure which showed the method of the state transition of the radio link state for every component carrier regarding a radio link problem. It is a figure for demonstrating the radio link management method when the radio link problem generate | occur | produces in the component carrier which has a some cell specific connection. It is another figure which showed the method of the state transition of the radio link state for every component carrier regarding a radio link problem. It is a figure for demonstrating the radio link management method when the radio link problem generate | occur | produces in the component carrier with an extended cell specific connection. It is the figure explaining the state transition method of the conventional downlink radio link state. It is a figure which shows an example of the communication network structure which concerns on embodiment of this invention. It is the figure which showed an example of the setting of the component carrier with respect to the mobile station apparatus 1 which concerns on embodiment of this invention. It is the figure shown about an example of the layer structure of the mobile station apparatus 1 which concerns on embodiment of this invention.

  Before describing the embodiment of the present invention, the physical channel and physical layer problem, random access problem, and carrier aggregation related to the present invention will be described.

(1) Physical Channel A physical channel (or physical signal) used in EUTRA and Advanced EUTRA will be described. The physical channel includes a downlink channel in the downlink transmitted from the base station apparatus to the mobile station apparatus, and an uplink channel in the uplink transmitted from the mobile station apparatus to the base station apparatus. The physical channel may be added or changed in the future in EUTRA and Advanced EUTRA. However, even if the physical channel is changed, the description of each embodiment of the present invention is not affected.

  Synchronization signals (Synchronization Signals) are composed of three types of primary synchronization signals and secondary synchronization signals composed of 31 types of codes arranged alternately in the frequency domain. By the combination, 504 kinds of cell identifiers (Cell ID: PCI) for identifying base station apparatuses and frame timing for radio synchronization are shown. The mobile station device specifies the cell ID of the synchronization signal received by the cell search.

  A physical broadcast information channel (PBCH; Physical Broadcast Channel) is transmitted for the purpose of notifying control parameters (broadcast information (system information): System information) commonly used by mobile station apparatuses in a cell. Broadcast information that is not notified by the physical broadcast information channel is transmitted by a layer 3 message using the downlink data channel, in which radio resources are notified by the downlink control channel. As broadcast information, a cell global identifier (CGI) indicating an individual cell identifier, a tracking area identifier (TAI) for managing a standby area by paging, and the like are notified.

  The downlink reference signal is a pilot signal transmitted at a predetermined power for each cell. The downlink reference signal is a known signal that is periodically repeated at a frequency / time position based on a predetermined rule. The mobile station apparatus measures the reception quality for each cell by receiving the downlink reference signal. The mobile station apparatus also uses the downlink reference signal as a reference signal for demodulation of the downlink control channel or downlink data channel transmitted simultaneously with the downlink reference signal. As a sequence used for the downlink reference signal, a sequence that can be identified for each cell is used. In addition, although a downlink reference signal may be described as cell-specific reference signal (RS), the use and meaning are the same.

  A downlink control channel (PDCCH; Physical Downlink Control Channel) is transmitted in several OFDM symbols from the beginning of each subframe. Radio resource allocation information according to the scheduling of the base station device and transmission to the mobile station device Used to indicate the amount of power increase / decrease adjustment. The mobile station apparatus monitors (monitors) the downlink control channel addressed to itself before transmitting / receiving the layer 3 message (paging, handover command, etc.) that is downlink data or downlink control data, and By receiving the downlink control channel, it is necessary to acquire radio resource allocation information called an uplink grant at the time of transmission and a downlink grant at the time of reception.

  A downlink data channel (PDSCH: Physical Downlink Shared Channel) is used to notify paging and broadcast information as a layer 3 message that is downlink control data in addition to downlink data. The radio resource allocation information of the downlink data channel is indicated by the downlink control channel.

  An uplink data channel (PUSCH) mainly transmits uplink data and uplink control data, and can also include control data such as downlink reception quality and ACK / NACK. Similarly to the downlink, the radio resource allocation information of the uplink data channel is indicated by the downlink control channel.

  A random access channel (PRACH) is a channel used for notifying a preamble sequence and has a guard time. The random access channel is used as a means for accessing the base station apparatus of the mobile station apparatus. The mobile station apparatus uses a random access channel for a request for scheduling transmission data when the uplink control channel is not set and a request for transmission timing adjustment information necessary for matching the uplink transmission timing with the reception timing window of the base station apparatus. . The mobile station apparatus that has received the transmission timing adjustment information sets an effective time of the transmission timing adjustment information, and is in a transmission timing adjustment state during the effective time and in a transmission timing non-adjustment state outside the effective period. Since other physical channels are not related to each embodiment of the present invention, detailed description thereof is omitted.

(1) Physical Layer Problem FIG. 13 is an example of a radio link state determination procedure related to a conventionally used physical layer problem, and shows state transition with time. The mobile station apparatus manages the downlink radio link state by comparing the reception quality of any downlink channel being received with a threshold value. The comparison between the reception quality and the threshold is typically performed in the physical layer, and the downlink radio link state is typically managed by RRC.

  FIG. 13 shows that the mobile station apparatus does not recover the downlink reception quality after detecting the downlink synchronization error in the physical layer, and is in an idle state without being reconnected (the mobile station apparatus is not connected to the base station apparatus through radio resources). 6 is an example showing a transition of a downlink radio link state of the mobile station apparatus when transitioning to (state). Here, when the mobile station apparatus determines that the reception quality has deteriorated below a predetermined threshold, the mobile station apparatus transmits a downlink synchronization error from the physical layer to the RRC. When the downlink synchronization error is notified, the mobile station apparatus transitions the downlink radio link state from the synchronization section to the error detection section in RRC, and determines whether or not the downlink synchronization error is temporary.

  Furthermore, if a downlink synchronization error is continuously notified from the physical layer even in the error detection period and a downlink synchronization error is detected for a certain number of times continuously, or if a downlink synchronization error is detected for a certain time continuously, The station apparatus determines that a radio link problem (physical layer problem) has occurred, and then transitions the downlink radio link state to a synchronization protection section that waits for reception quality recovery, and simultaneously performs synchronization protection that measures the synchronization protection section. Start the timer.

  If the reception quality of the downlink channel does not recover even after the synchronization protection timer expires, the mobile station apparatus determines that a radio link failure indicating downlink quality degradation has occurred, and sets the downlink radio link status to that of the radio resource connection. A transition is made to the reconnection section attempting re-establishment, and a reconnection timer is started that simultaneously counts the reconnection section. In the reconnection period, the mobile station apparatus performs a cell reselection procedure for selecting a cell with good reception quality. The mobile station apparatus that has selected a good cell by the cell reselection procedure starts a random access procedure and notifies a reconnection request message (radio resource re-establishment message) to the good cell. The mobile station apparatus determines that the re-establishment of the radio resource connection has failed if the permission for the reconnection request message is not notified from the base station apparatus before the measurement by the reconnection timer expires, and holds it. The radio resource is released, and a transition is made to the idle state section in which the radio resource is not connected to the base station apparatus.

(2) Random access problem The mobile station apparatus manages the random access problem in the data link layer by counting the number of transmission attempts of the random access channel. The counting of the number of transmission attempts of the random access channel in the data link layer is typically performed by the MAC, and the random access problem is managed by RRC.

  When the mobile station apparatus transmits any random access channel transmission reason to the base station apparatus, the mobile station apparatus bases the randomly selected preamble sequence or the preamble sequence assigned by the base station apparatus using the random access channel. Send to station device. At this time, if the base station apparatus does not return a response to the random access channel within a certain time because the base station apparatus cannot identify the random access channel, the mobile station apparatus transmits the random access channel again. The mobile station apparatus counts the number of transmissions of the random access channel, and determines that a random access problem indicating uplink quality degradation is detected when the number of transmissions exceeds a specified value (maximum number of transmissions). Even if the mobile station apparatus detects a random access problem, the mobile station apparatus continues to transmit a random access channel with the same parameters to the base station apparatus until an instruction to stop random access is issued. The instruction to stop random access is typically issued from RRC to MAC.

(3) Carrier aggregation Carrier aggregation is a technology that aggregates (aggregates) a plurality of different frequency bands (component carriers) and treats them as one frequency band. For example, when five component carriers having a frequency bandwidth of 20 MHz are aggregated by carrier aggregation, the mobile station apparatus can access the mobile station apparatus by regarding it as a frequency bandwidth of 100 MHz. The component carriers to be aggregated may be a continuous frequency band, or may be a frequency band in which all or part of them are discontinuous. For example, when the usable frequency band is the 800 MHz band, the 2.4 GHz band, and the 3.4 GHz band, one component carrier is the 800 MHz band, another component carrier is the 2 GHz band, and another component carrier is 3.4 GHz. It may be transmitted in a band.

  It is also possible to aggregate continuous or discontinuous component carriers in the same frequency band, for example, the 2.4 GHz band. The frequency bandwidth of each component carrier may be a frequency bandwidth narrower than 20 MHz, or may be different from each other.

  The base station apparatus determines the number of uplink or downlink component carriers to be allocated to the mobile station apparatus based on various factors such as the amount of retained data buffer, the reception quality of the mobile station apparatus, the load in the cell, and QoS. Can be increased or decreased.

[Example of communication network configuration of the present invention]
FIG. 14 is a diagram illustrating an example of a communication network configuration according to the embodiment of the present invention. When the mobile station apparatus 1 can be wirelessly connected to the base station apparatus 2 by simultaneously using a plurality of frequency bands (component carriers, Band1 to Band3) by carrier aggregation, the communication network configuration has one base The station apparatus 2 includes transmitting apparatuses 11 to 13 (and receiving apparatuses 21 to 23 (not shown)) for each of a plurality of frequency bands, and the configuration in which each frequency band is controlled by one base station apparatus 2 simplifies the control. From the viewpoint of However, the base station apparatus 2 may be configured to transmit a plurality of frequency bands with a single transmission apparatus, for example, because the plurality of frequency bands are continuous frequency bands. The communicable range of each frequency band controlled by the transmission apparatus of the base station apparatus 2 is regarded as a cell and exists in the same spatial area. At this time, the areas (cells) covered by each frequency band may have different sizes and shapes.

  However, in the description to be described later, each area covered by the frequency of the component carrier formed by the base station apparatus 2 is referred to as a cell, and this is the definition of a cell in a communication system that is actually operated. Note that it can be different. For example, in some communication systems, some of the component carriers used by carrier aggregation may be defined simply as additional radio resources rather than cells. By referring to the component carrier as a cell in the present invention, even if a case different from the definition of the cell in the actually operated communication system occurs, the gist of the present invention is not affected. The mobile station device 1 may be wirelessly connected to the base station device 2 via a relay station device (or repeater).

[Component carrier configuration setting example]
FIG. 15 shows the correspondence between the downlink component carrier and the uplink component carrier set by the base station device 2 for the mobile station device 1 when the mobile station device 1 according to the embodiment of the present invention performs carrier aggregation. It is the figure which showed an example of the relationship. In FIG. 15, the downlink component carrier DL_CC1 and the uplink component carrier UL_CC1, and the downlink component carrier DL_CC2, the downlink component carrier DL_CC3, and the uplink component carrier UL_CC2 are cell specific linked (Cell Specific Linkage). The cell-specific connection is, for example, a correspondence relationship (linkage relationship) between uplink and downlink frequency bands accessible to the base station device 2 when the mobile station device 1 is not carrier-aggregated. Is indicated by the notification information. The relationship between uplink and downlink frequency bands is explicitly specified as frequency information in broadcast information, or is defined uniquely for each operating frequency when not explicitly indicated in broadcast information. It is implicitly instructed by using frequency difference information. In addition to these methods, other methods may be used as long as the correspondence relationship between uplink and downlink frequency bands can be shown for each cell. A plurality of component carriers may be connected to a single component carrier in a cell-specific manner.

  On the other hand, the base station apparatus 2 may individually set the correspondence relationship between the downlink component carrier and the uplink component carrier for each mobile station apparatus 1 separately from the cell-specific connection (individual connection: UE Specific Linkage). Is possible. A plurality of component carriers may be individually connected to one component carrier. In the case of FIG. 15, three downlink component carriers DL_CC1 to DL_CC3 correspond to an uplink component carrier UL_CC2 to which a certain mobile station device 1 is wirelessly connected, and DL_CC1 and UL_CC2 are individually connected, and DL_CC2 DL_CC3 is cell-specific connected to UL_CC2. In this case, the mobile station apparatus 1 performs reception processing using DL_CC1 to DL_CC3 and performs transmission processing using UL_CC2. That is, DL_CC1 to DL_CC3 and UL_CC2 are connection component carriers that the mobile station device 1 uses for communication with the base station device 2, and UL_CC1 is a non-connection component that the mobile station device 1 does not use for communication with the base station device 2. It is a career.

[Example of mobile station device layer configuration]
FIG. 16 shows an example of RRC (RRC layer) and MAC (MAC layer), a physical layer layer configuration (protocol stack), and an interface between layers in the mobile station apparatus. RRC is an upper layer of the MAC and the physical layer, MAC is a lower layer of the RRC, and is an upper layer of the physical layer. The layers are connected using control interfaces P1 to P3 and data interfaces P4 to P5. The RRC-physical layer control interface P1 is used for setting a control parameter from the RRC to the physical layer and for notifying a downlink synchronization error from the physical layer to the RRC. The RRC-MAC control interface P2 is used for setting a control parameter from the RRC to the MAC and for notifying the random access problem from the MAC to the RRC.

  The MAC-physical layer control interface P3 is used to set control parameters from the MAC to the physical layer. The MAC-physical layer data interface P4 is used for notifying transmission data from the MAC to the physical layer and for notifying reception data from the physical layer to the MAC. The RRC-MAC data interface P5 is used to notify transmission data from the RRC to the MAC, and to notify reception data from the MAC to the RRC. In addition, as an actual mobile station apparatus configuration, there may be an entity or sublayer having a data control function such as RLC (Radio Link Control) and PDCP (Packet Data Convergence Protocol) between RRC and MAC. Even if it is a case, it does not affect the gist of the present invention.

  Considering the above matters, preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the present invention, when it is determined that a specific description of a known function or configuration related to the present invention obscures the gist of the present invention, a detailed description thereof is omitted.

<First Embodiment>
A first embodiment of the present invention will be described below. The present embodiment relates to a method for managing a radio link state of a component carrier associated with a radio link problem detected by the mobile station device 1 during carrier aggregation.

  FIG. 1 is a block diagram showing an example of a mobile station apparatus 1 according to the embodiment of the present invention. The mobile station apparatus 1 includes a reception unit 101, a demodulation unit 102, a decoding unit 103, a measurement processing unit 104, a control unit 105, a random access processing unit 106, a coding unit 107, a modulation unit 108, a transmission unit 109, and an upper layer 110. Composed. Prior to reception, mobile station apparatus control information is input from the upper layer 110 to the control unit 105, and the mobile station apparatus control information related to reception is received as reception control information, including a reception unit 101, a demodulation unit 102, a decoding unit 103, and a measurement processing unit 104. Is entered appropriately. The reception control information includes information such as demodulation information, decoding information, reception frequency band information, reception timing for each channel, multiplexing method, and radio resource arrangement information as reception schedule information.

  The reception signal is received by the reception unit 101. The receiving unit 101 receives a signal in the frequency band notified by the reception control information. The received signal is input to demodulator 102. Demodulation section 102 demodulates the received signal and inputs the received signal to decoding section 103. The decoding unit 103 correctly decodes the received signal based on the reception control information. Decoding section 103 appropriately separates the received signal into downlink traffic data and downlink control data, and inputs the separated signals to higher layer 110, respectively. In addition, the decoding unit 103 inputs a decoded received signal related to measurement to the measurement processing unit 104. The measurement processing unit 104 performs measurement processing of the reception quality of the downlink reference signal for each cell and measurement processing of the reception error rate of the downlink control channel or the downlink data channel, and averages the measured reception quality for each sample. (Filtered) downlink measurement information is generated, and the downlink measurement information is output to the upper layer 110. In addition, the measurement processing unit 104 compares the obtained reception quality with a threshold (also referred to as Qout) used for detecting a downlink synchronization error, and outputs a downlink synchronization error to the upper layer 110 as necessary.

  Prior to transmission, mobile station apparatus control information is input from the upper layer 110 to the control section 105, and the mobile station apparatus control information related to transmission is transmitted as control information, a random access processing section 106, an encoding section 107, a modulation section 108, An appropriate input is made to the transmission unit 109. The transmission control information includes information such as encoding information, modulation information, transmission frequency band information, transmission timing for each channel, multiplexing method, and radio resource arrangement information as uplink scheduling information of the transmission signal. Random access processing unit 106 receives random access information necessary for transmission of a random access channel such as random access radio resource information and the maximum number of transmissions from upper layer 110. Further, when the random access processing unit 106 detects the random access problem by counting the number of transmissions of the random access channel, the random access processing unit 106 notifies the upper layer 110 of random access problem information indicating that the random access problem has occurred. The encoding unit 107 receives uplink traffic data and uplink control data from the upper layer 110, and random access data from the random access processing unit 106. The encoding unit 107 appropriately encodes each data according to the transmission control information and outputs the data to the modulation unit 108. The modulation unit 108 modulates the input from the coding unit 107.

  The transmission unit 109 maps the output of the modulation unit 108 to the frequency domain, converts the frequency domain signal into a time domain signal, performs power amplification on a carrier wave of a predetermined frequency, and transmits the signal. An uplink data channel in which uplink control data is arranged typically constitutes a layer 3 message (radio resource control message; RRC message). The RRC of the mobile station device 1 exists as part of the upper layer 110. The RRC further includes a radio link status management unit (not shown) that is a sub-block that manages a radio link status indicating a frequency band status for each of a plurality of frequency bands. The random access processing unit 106 exists as part of the MAC of the mobile station device 1. In FIG. 1, the other components of the mobile station apparatus 1 are omitted because they are not related to the present embodiment.

  FIG. 2 is a block diagram showing an example of the base station apparatus 2 according to the embodiment of the present invention. The base station apparatus 2 includes a reception unit 201, a demodulation unit 202, a decoding unit 203, a control unit 204, a coding unit 205, a modulation unit 206, a transmission unit 207, a network signal processing unit 208, a peripheral information management unit 209, and an upper layer 210. Consists of

  Upper layer 210 inputs downlink traffic data and downlink control data to encoding section 205. The encoding unit 205 encodes each input data and inputs the data to the modulation unit 206. Modulation section 206 modulates the encoded signal. Also, in the modulation unit 206, the downlink reference signal is multiplexed with the modulated signal and mapped to the frequency domain. The transmission unit 207 converts the frequency domain signal output from the modulation unit 206 into a time domain signal, places the converted signal on a carrier wave of a predetermined frequency, and performs power amplification and transmission. A downlink data channel in which downlink control data is arranged typically forms a layer 3 message (RRC message).

  The receiving unit 201 converts the received signal from the mobile station device 1 into a baseband digital signal. The digital signal is input to the demodulation unit 202 and demodulated. The signal demodulated by the demodulator 202 is subsequently input to the decoder 203 and decoded. The decoding unit 203 appropriately separates the received signal into uplink traffic data and uplink control data, and inputs each to the higher layer 210.

  Base station apparatus control information necessary for the control of each block is input from the upper layer 210 to the control unit 204, and the base station apparatus control information related to transmission is transmitted from the control unit 204 as transmission control information as a coding unit 205, modulation. Base station apparatus control information related to reception is appropriately input to each block of the reception unit 201, demodulation unit 202, and decoding unit 203 as reception control information in each block of the unit 206 and transmission unit 207.

  On the other hand, the network signal processing unit 208 transmits or receives a control message between the base station devices 2 or between the control station device (or gateway device) and the base station device 2. Control messages are transmitted and received via a network line. The peripheral information management unit 209 manages network information for identifying the transmission destination or transmission source base station device 2 (or control station device, gateway device). Network information can specify the address of each device on the network such as tracking area identifier (TAI), cell global identifier (CGI), cell identifier (PCI), network color code, Internet protocol address (IP address), etc. Consists of information.

  The peripheral information management unit 209 provides network information to the network signal processing unit 208 as necessary. The network signal processing unit 208 and the peripheral information management unit 209 are managed by an upper layer. The RRC of the base station device 2 exists as a part of the upper layer 210. In FIG. 2, the other components of the base station apparatus 2 are omitted because they are not related to the present embodiment.

  Next, a radio link state management method for each frequency band when the mobile station apparatus 1 according to the present embodiment detects a radio link problem will be described with reference to FIGS. The following radio link status management is performed by the radio link status management unit of the mobile station apparatus 1.

  The mobile station device 1 monitors all physical downlink component carriers configured from the base station device 2 or every downlink component carrier that monitors the downlink control channel (PDCCH) or downlink state determination information ( For each downlink component carrier for which a maximum allowable number of downlink synchronization errors and timers used for determination of state transition are set. The mobile station apparatus 1 manages the radio link state (downlink state) of the downlink component carrier in which the downlink state determination information is set. Further, the mobile station apparatus 1 determines the random access problem for each of at least one or more uplink component carriers for which random access information (such as the maximum number of transmissions) is set. The mobile station apparatus 1 manages the radio link state (uplink state) of the uplink component carrier in which random access information is set. The mobile station apparatus 1 does not need to detect a random access problem in an uplink component carrier for which random access information is not set.

  In the following description, the physical layer problem detected in the downlink component carrier is referred to as DL_CC failure (downlink component carrier failure). The random access problem detected in the uplink component carrier is referred to as UL_CC failure (uplink component carrier failure).

  The base station apparatus 2 can also set the downlink state determination information used for detecting the physical layer problem for each downlink component carrier for the mobile station apparatus 1. Typically, the base station apparatus 2 sets the downlink state determination information only for the downlink component carrier that instructs the mobile station apparatus 1 to monitor the downlink control channel. Moreover, the base station apparatus 2 can also set random access information for every uplink component carrier with respect to the mobile station apparatus 1. FIG. Typically, the base station apparatus 2 sets random access information for at least one uplink component carrier for each group of uplink component carriers with different uplink transmission timings set in the mobile station apparatus 1.

  FIG. 3 illustrates a radio link state management method for each component carrier when a radio link problem occurs in a certain downlink component carrier when the mobile station apparatus 1 has a plurality of component carriers set by carrier aggregation. It is a figure for doing.

  In FIG. 3, the mobile station device 1 is configured with a downlink component carrier DL_CC1 and a downlink component carrier DL_CC2, and an uplink component carrier UL_CC1 and an uplink component carrier UL_CC2 as carrier aggregation from the base station device 2. Also, DL_CC1 and UL_CC1, and DL_CC2 and UL_CC2 are cell-specific connected, respectively.

  Returning to FIG. 3, when the mobile station apparatus 1 detects the occurrence of DL_CC failure in DL_CC1, the random access procedure and transmission power adjustment for UL_CC1 are based on the reception quality of the associated DL_CC1, so when DL_CC failure occurs in DL_CC1. In order to continue transmission with UL_CC1, complicated and special control different from the conventional one is required. Therefore, the mobile station apparatus 1 of the present embodiment sets UL_CC failure for UL_CC1 that is cell-specifically connected to DL_CC1 so as not to perform these special controls. That is, RRC that has detected that a physical layer problem has occurred in DL_CC1 updates the radio link state of UL_CC1 corresponding to DL_CC1. Note that the mobile station device 1 does not need to update the radio link state for DL_CC2 and UL_CC2 that are not cell-specifically connected to DL_CC1.

  In the case illustrated in FIG. 3, the radio link state management method of each component carrier performed by the mobile station apparatus 1 will be further described with reference to FIG. 4.

  FIG. 4 is a diagram showing a method of state transition with the passage of time of the radio link state for each component carrier managed by the mobile station apparatus 1. The first level in the figure shows the reception quality of DL_CC1, the second level shows the radio link status of DL_CC1, and the third level shows the radio link status of UL_CC1. The reception quality of the upper DL_CC1 is divided into quality A and quality B. Quality A is a state in which the downlink reception quality is higher than the threshold value Qout and no downlink synchronization error is detected in the physical layer. On the other hand, the quality B represents a state in which the reception quality is lower than the threshold value Qout and a downlink synchronization error is detected in the physical layer.

  When the reception quality of DL_CC1 is in the state of quality A, the mobile station device 1 manages the radio link state of DL_CC1 as a synchronization interval. Moreover, the mobile station apparatus 1 manages the radio link state of UL_CC1 as a random access valid section. The random access valid section is a section in which radio resources (random access information) used for random access transmission are valid, and the mobile station apparatus 1 is in a state in which random access can be transmitted at an arbitrary timing as necessary. Show. The random access valid section can be further divided into a section in which transmission timing adjustment information is valid (transmission timing adjustment state) and a section in which transmission timing adjustment information is invalid (transmission timing non-adjusted state) by using a timer. It is omitted inside.

  Here, when the reception quality of DL_CC1 deteriorates to quality B at a certain timing T41, the mobile station apparatus 1 notifies the downlink synchronization error to the RRC from the physical layer, and error detection is performed on the radio link state of DL_CC1. Transition to the section. The mobile station apparatus 1 receives a radio link problem when a downlink synchronization error is notified from the physical layer for a fixed number of times or when a downlink synchronization error is notified from the physical layer for a fixed time (timing T42). It is determined that a (physical layer problem) has occurred, and the radio link state of DL_CC1 is shifted to a synchronization protection interval waiting for reception quality recovery, and at the same time, a synchronization protection timer for timing the synchronization protection interval is started.

  When the reception quality of the downlink channel does not recover even when the synchronization protection timer expires (timing T43), the mobile station apparatus 1 determines that DL_CC1 has reached DL_CC failure. At this time, the mobile station apparatus 1 changes the radio link state of DL_CC1 to the DL_CC failure section. The DL_CC failure section is a section in which downlink data received by the component carrier is regarded as invalid. In the DL_CC failure section, the mobile station apparatus 1 may stop monitoring the downlink control channel. Also, it is considered that UL_CC failure has occurred for UL_CC1 that is cell-specifically connected to DL_CC1, and UL_CC failure is set for UL_CC1 and the radio link state of UL_CC1 is shifted to the random access invalid section.

  A random access invalid section is a section in which radio resources for random access transmission are regarded as invalid. The mobile station apparatus 1 cannot transmit a random access channel using an uplink component carrier whose radio link state is a random access invalid section. Note that the mobile station apparatus 1 considers that the radio resources of all uplink channels other than the random access channel are invalid in the uplink component carrier whose radio link state is the random access invalid section, and all transmissions are prohibited. warn. The mobile station apparatus 1 may notify the release (release) of radio resource settings of the random access channel of the uplink component carrier (UL_CC1) and other uplink channels at the same time as updating the radio link state of the UL_CC1. The release of the radio resource setting is notified from the RRC to the MAC.

  FIG. 5 illustrates a radio link state management method for each component carrier when a radio link problem occurs in a certain downlink component carrier when the mobile station apparatus 1 is configured with a plurality of component carriers by carrier aggregation. It is another figure for doing.

  In FIG. 5, the mobile station device 1 is configured with a downlink component carrier DL_CC1, a downlink component carrier DL_CC2, and an uplink component carrier UL_CC2 as carrier aggregation from the base station device 2. DL_CC1 and UL_CC2 are individually connected, and DL_CC2 and UL_CC2 are cell-specific connected.

  At this time, when the mobile station apparatus 1 detects the occurrence of DL_CC failure in DL_CC1, the mobile station apparatus 1 is not configured with an uplink component carrier that is cell-specifically connected to DL_CC1, and therefore, the radio of component carriers other than DL_CC1. There is no need to update the link state. That is, the mobile station apparatus 1 does not update the radio link state of DL_CC2 and UL_CC2 that are not cell-specifically connected to DL_CC1.

  FIG. 6 shows a case where the mobile station apparatus 1 has a plurality of component carriers set by carrier aggregation, and a radio link problem occurs between a component carrier having a plurality of cell-specific connections and a downlink component carrier that is cell-specifically connected. It is a figure for demonstrating the state management method of the radio link of each component carrier when this occurs.

  In FIG. 6, the mobile station device 1 is configured with a downlink component carrier DL_CC1, a downlink component carrier DL_CC2, and an uplink component carrier UL_CC1 as carrier aggregation from the base station device 2. Also, DL_CC1 and UL_CC1 are cell-specific connected, and DL_CC2 and UL_CC1 are cell-specific connected. That is, UL_CC1 has a plurality of cell-specific connections.

  At this time, when the mobile station apparatus 1 detects the occurrence of DL_CC failure in DL_CC1, the mobile station apparatus 1 sets UL_CC failure for UL_CC1 that is cell-specific connected to DL_CC1. At the same time, DL_CC failure is similarly set for DL_CC2 that is cell-specifically connected to UL_CC1. That is, the RRC that has detected that a physical layer problem has occurred in DL_CC1 updates both the UL_CC1 radio link status corresponding to DL_CC1 and the DL_CC2 radio link status.

  In the case illustrated in FIG. 6, the radio link state management method of each component carrier performed by the mobile station apparatus 1 will be further described with reference to FIG. 7.

  FIG. 7 is a diagram showing a state transition method with the passage of time of the radio link state for each component carrier managed by the mobile station apparatus 1. The first row shows the reception quality of DL_CC1, the second row shows the DL_CC1 radio link status, the third row shows the UL_CC1 radio link status, and the fourth row shows the DL_CC2 radio link status.

  When the reception quality of DL_CC1 is in the state of quality A, the mobile station device 1 manages the radio link state of DL_CC1 as a synchronization interval. Moreover, the mobile station apparatus 1 manages the radio link state of UL_CC1 as a random access valid section. The radio link state of DL_CC2 may be arbitrary, but is assumed to be a synchronization interval for the sake of simplicity of explanation.

  Here, when the reception quality of DL_CC1 deteriorates to quality B at a certain timing T71, the mobile station apparatus 1 notifies the downlink synchronization error to the RRC from the physical layer, and detects the radio link state of DL_CC1 as an error. Transition to the section. When the downlink synchronization error is notified from the physical layer for a fixed number of times or when the downlink synchronization error is notified from the physical layer for a fixed time (timing T72), the mobile station apparatus 1 It is determined that a (physical layer problem) has occurred, and the radio link state of DL_CC1 is shifted to a synchronization protection interval waiting for reception quality recovery, and at the same time, a synchronization protection timer for timing the synchronization protection interval is started. At timing T71 and timing T72, the radio link state of UL_CC1 or DL_CC2 is not affected by the change of the radio link state of DL_CC1.

  If the downlink channel reception quality does not recover even when the synchronization protection timer expires, the mobile station device 1 determines that DL_CC1 has reached DL_CC failure (timing T73). At this time, the mobile station apparatus 1 transitions the radio link state of DL_CC1 to the DL_CC failure section, considers that UL_CC failure has occurred for UL_CC1 that is cell-specifically connected to DL_CC1, and determines UL_CC failure for UL_CC1. Setting is performed, and the radio link state of UL_CC1 is shifted to the random access invalid section. Further, at the same timing T73, the mobile station apparatus 1 considers that DL_CC failure has occurred for DL_CC2 that is cell-specifically connected to DL_CC1 via UL_CC1, performs DL_CC failure setting for DL_CC2, and sets DL_CC2 for DL_CC2. The radio link state is shifted to the DL_CC failure section.

  As described above, the mobile station apparatus 1 sets the uplink component carrier that is cell-specifically connected to the UL_CC failure for the downlink component carrier in which DL_CC failure has occurred, while the uplink link of the individually connected uplink component carrier. The state is not changed. Furthermore, when another downlink component carrier is cell-specific connected to the uplink component carrier set to UL_CC failure, the downlink component carrier is set to DL_CC failure. Therefore, the mobile station apparatus 1 does not perform the radio link state management related to the component carriers completely for each component carrier, but may manage the component carriers connected in a cell-specific manner as one group.

  FIG. 8 illustrates a radio link state management method for each component carrier when a radio link problem occurs in a certain uplink component carrier when the mobile station apparatus 1 has a plurality of component carriers set by carrier aggregation. It is another figure for doing. The setting of the component carrier in FIG. 8 is the same as that in FIG.

  At this time, when the mobile station apparatus 1 detects the occurrence of UL_CC failure in the UL_CC2, the retransmission procedure of transmission data related to the DL_CC2 is performed in the associated UL_CC2, so when the UL_CC failure occurs in the UL_CC2, the reception is performed in the DL_CC2. To continue, complicated and special control different from the conventional one is required. Therefore, the mobile station apparatus 1 of the present embodiment sets DL_CC failure to DL_CC2 that is cell-specifically connected to UL_CC2 in order not to perform these special controls. Since other component carriers are not cell-specifically connected to UL_CC2, there is no need to update the radio link state of other component carriers. That is, RRC notified from the MAC that a random access problem has occurred in UL_CC2 updates the radio link state of DL_CC2 corresponding to UL_CC2.

  In the case illustrated in FIG. 8, the radio link state management method of each component carrier performed by the mobile station apparatus 1 will be further described with reference to FIG.

  FIG. 9 is a diagram illustrating a state transition method with the passage of time of the radio link state for each component carrier managed by the mobile station apparatus 1. The first row shows the state of random access of uplink component carrier UL_CC2, the second row shows the radio link state of UL_CC2, and the third row shows the radio link state of DL_CC2.

  The mobile station apparatus 1 manages the state of random access performed by UL_CC2. The radio link state of UL_CC2 is a random access valid section. Further, the radio link state of DL_CC2 is a synchronization interval. Since the DL_CC1 radio link state is irrelevant to the UL_CC1 or DL_CC2 radio link state, illustration and description thereof are omitted.

  Here, it is assumed that the mobile station apparatus 1 starts random access at a certain timing T91. The reason for starting random access does not matter. At this time, the mobile station apparatus 1 changes the state of random access of UL_CC2 to the random access retransmission section. The random access retransmission section is a state in which random access is started but random access is not successful, and the number of random access attempts is counted. The mobile station device 1 does not need to update the radio link states of UL_CC2 and DL_CC2 at timing T91. The mobile station apparatus 1 considers that the random access problem has occurred in the UL_CC2 when the number of random access attempts reaches a predetermined number, and notifies the RRC of the random access problem from the MAC. The mobile station apparatus 1 notified of the random access problem from the MAC sets UL_CC failure for UL_CC2 (timing T92).

  The mobile station apparatus 1 changes the radio link state of UL_CC2 to the random access invalid section at the same timing T92. Also, the mobile station apparatus 1 considers that DL_CC failure has occurred for DL_CC2 that is cell-specifically connected to UL_CC2 at timing T92, performs DL_CC failure setting for DL_CC2, and sets the DL_CC2 radio link status to the DL_CC failure section. Transition to.

  FIG. 10 shows a case where the mobile station apparatus 1 has a plurality of component carriers set by carrier aggregation, and each component carrier in the case where a radio link problem occurs in an uplink component carrier having a plurality of cell-specific connections. It is a figure for demonstrating the state management method of a radio link. The setting of the component carrier in FIG. 10 is the same as that in FIG.

  At this time, when the mobile station apparatus 1 detects the occurrence of UL_CC failure in UL_CC1, the mobile station apparatus 1 sets DL_CC failure to DL_CC1 that is cell-specific connected to UL_CC1. At the same time, DL_CC failure is similarly set for DL_CC2 that is cell-specifically connected to UL_CC1. That is, the RRC notified from the MAC that a random access problem has occurred in UL_CC1 updates both the radio link state of DL_CC1 corresponding to UL_CC1 and the radio link state of DL_CC2.

  In the case illustrated in FIG. 10, the radio link state management method of each component carrier performed by the mobile station apparatus 1 will be further described with reference to FIG.

  FIG. 11 is a diagram illustrating a method of state transition with the passage of time of the radio link state for each component carrier managed by the mobile station apparatus 1. The first row shows the state of random access of uplink component carrier UL_CC1, the second row shows the radio link state of UL_CC1, the third row shows the radio link state of DL_CC1, and the fourth row shows the radio link state of DL_CC2. .

  The mobile station apparatus 1 manages the state of random access performed by UL_CC1. The radio link state of UL_CC1 is a random access valid section. In addition, the radio link states of DL_CC1 and DL_CC2 are assumed to be synchronization intervals.

  Here, it is assumed that the mobile station apparatus 1 starts random access at a certain timing T111. The reason for starting random access does not matter. At this time, the mobile station apparatus 1 changes the state of random access of UL_CC2 to the random access retransmission section. The mobile station device 1 does not need to update the radio link states of UL_CC1, DL_CC1, and DL_CC2 at timing T111. The mobile station apparatus 1 considers that a random access problem has occurred in UL_CC1 when the number of random access attempts reaches a predetermined number, and notifies the RRC of the random access problem from the MAC. The mobile station apparatus 1 notified of the random access problem from the MAC sets UL_CC failure for UL_CC1 (timing T112).

  The mobile station apparatus 1 changes the radio link state of UL_CC1 to the random access invalid section at the same timing T112. Also, the mobile station apparatus 1 considers that DL_CC failure has occurred for DL_CC1 and DL_CC2 cell-specifically connected to UL_CC1 at timing T112, performs DL_CC failure settings for both DL_CC1 and DL_CC2, and performs DL_CC1 and DL_CC2 The radio link state of is shifted to the DL_CC failure section.

  FIG. 12 shows a case where the mobile station apparatus 1 has a plurality of component carriers set by carrier aggregation, and a certain downlink component carrier has an extended cell specific connection that is effective only for a specific mobile station apparatus 1. FIG. 10 is a diagram for explaining a radio link state management method for each component carrier when a radio link problem occurs in the downlink component carrier.

  In FIG. 12, the mobile station apparatus 1 is configured with a downlink component carrier DL_CC1, an uplink component carrier UL_CC1, and an uplink component carrier UL_CC2 as carrier aggregation from the base station apparatus 2. Also, DL_CC1 and UL_CC1 are cell-specific connected, and DL_CC1 and UL_CC2 are extended cell-specific connected. The extended cell-specific connection is, for example, a cell-specific connection that is valid only for a specific mobile station apparatus 1 (such as a mobile station apparatus 1 with an expanded function that will be released in the future). Is notified by new broadcast information that can be received or information on the frequency difference between the uplink and the downlink that are valid only for a specific mobile station apparatus 1. That is, a normal mobile station apparatus 1 that has accessed DL_CC1 recognizes that only DL_CC1 and UL_CC1 are connected in a cell-specific manner, but a specific mobile station apparatus 1 adds DL_CC1 and UL_CC2 to an extended cell-specific connection in addition to the above. Recognize that The specific mobile station apparatus 1 is a normal mobile station apparatus except that it receives new broadcast information that is valid only for the specific mobile station apparatus 1 or holds information on the prescribed frequency difference between the uplink and the downlink. 1 may be used.

  At this time, the radio link state management method when the normal mobile station apparatus 1 detects the occurrence of DL_CC failure in DL_CC1 may be the same as in FIG. 6 and FIG.

  On the other hand, when a specific mobile station apparatus 1 capable of recognizing an extended cell specific connection between component carriers detects the occurrence of DL_CC failure in DL_CC1, the specific mobile station apparatus 1 is connected to the DL_CC1 and UL_CC2 that is specific to the extended cell. There is no need to update the radio link status. That is, the specific mobile station apparatus 1 does not update the radio link state of the UL_CC2 that is connected to the DL_CC1 and the extended cell.

  In this way, for the uplink component carrier in which UL_CC failure occurs, the mobile station apparatus 1 sets the downlink component carrier that is cell-specifically connected to DL_CC failure, while the downlink link of the individually connected downlink component carrier The state is not changed. Furthermore, when another downlink component carrier other than the downlink component carrier set to DL_CC failure is connected in a cell-specific manner, the downlink component carrier is set to DL_CC failure. Therefore, the mobile station apparatus 1 does not perform the radio link state management related to the component carriers completely for each component carrier, but may manage the component carriers connected in a cell-specific manner as one group.

  As a result of updating the radio link state of the downlink component carrier that has detected DL_CC failure, or the downlink component carrier that is cell-specifically connected to the uplink component carrier that has detected UL_CC failure, and / or the uplink component carrier. When all downlink component carriers managing the radio link state in the device 1 are set to DL_CC failure, or all uplink component carriers managing the radio link state in the mobile station device 1 are set to the UL_CC failure. When set, the mobile station apparatus 1 determines that a radio link failure has occurred and starts a radio resource re-establishment procedure.

  That is, the RRC (Radio Link Status Management Unit) of the mobile station apparatus 1 sets the radio link status of all downlink component carriers to DL_CC failure, or sets the radio link status of all uplink component carriers to UL_CC failure. If set, start the radio resource re-establishment procedure.

  As described above, in the first embodiment, the mobile station apparatus 1 determines and detects a physical layer problem for each downlink component carrier. Moreover, the mobile station apparatus 1 determines and detects a random access problem for each uplink component carrier with a random access channel setting. When the mobile station apparatus 1 detects a radio link problem (physical link problem or random access problem) as a radio link state management method, the mobile station apparatus 1 uses the component carrier where the radio link problem has occurred as a starting point for cell-specific connection. Update the radio link status of all the component carriers. The update of the radio link state of the downlink component carrier or the uplink component carrier is preferably performed by RRC (radio link state management unit) of the mobile station apparatus 1.

  As described above, even when the mobile station apparatus 1 needs to manage the radio link states of a plurality of component carriers by carrier aggregation, the radio link state of which component carrier is associated with the occurrence of the radio link problem. Since it is only necessary to determine whether or not to update the cell carrier depending on whether or not there is a cell-specific connection between the component carriers, the management of the radio link state is simplified. In addition, since the radio link problem can be managed for each component carrier connected in a cell-specific manner instead of being managed independently for each component carrier, the management method becomes efficient. Also, when a physical layer problem occurs, the mobile station apparatus 1 does not perform transmission on the corresponding uplink, so even when the physical layer problem occurs, the mobile station apparatus 1 performs random access procedures and transmission on the corresponding uplink. There is no need for complicated and special control for power adjustment. In addition, when a random access problem occurs, the mobile station apparatus 1 does not receive data on the corresponding downlink. Therefore, even when the random access problem occurs, retransmission of data received on the corresponding downlink There is no need to perform complicated and special control for the procedure.

<Second Embodiment>
A second embodiment of the present invention will be described below. In this embodiment, a special component carrier is set for a downlink component carrier or an uplink component carrier, and the mobile station apparatus 1 that is performing carrier aggregation has a component when a radio link problem occurs in the component carrier. The present invention relates to a radio link state management method for carriers.

  The configurations of the mobile station device 1 and the base station device 2 used in the present embodiment may be the same as those shown in FIGS.

  The mobile station apparatus 1 sets one of the downlink component carriers set from the base station apparatus 2 as a special downlink component carrier. Here, the downlink component carrier is referred to as a downlink anchor carrier. The downlink anchor carrier may be individually set from the base station apparatus 2 to the mobile station apparatus 1, or information used for security information or the like among the downlink component carriers set in the mobile station apparatus 1. It may be set as a downlink component carrier to be provided.

  Also, the mobile station apparatus 1 sets one of the uplink component carriers set from the base station apparatus 2 as a special uplink component carrier. Here, the uplink component carrier is referred to as an uplink anchor carrier. The uplink anchor carrier may be individually set from the base station apparatus 2 to the mobile station apparatus 1, or reception confirmation information (ACK / NACK) among the uplink component carriers set in the mobile station apparatus 1. Etc. may be set as an uplink component carrier in which an uplink control channel for transmitting is set.

  The mobile station device 1 is a component in which the downlink anchor carrier and / or the uplink anchor carrier are set, and the cells are individually connected according to the first embodiment after the occurrence of the radio link problem As a result of updating the radio link state of the carrier, when the downlink anchor carrier becomes DL_CC failure or the uplink anchor carrier becomes UL_CC failure, the radio links of all the component carriers regardless of the radio link states of other component carriers The state is updated to DL_CC failure or UL_CC failure, it is determined that a radio link failure has occurred, and a procedure for re-establishing radio resources is started.

  Alternatively, the mobile station apparatus 1 is a case where a downlink anchor carrier and / or an uplink anchor carrier is set, and when a physical layer problem occurs in the downlink anchor carrier, or an uplink anchor When a random access problem occurs in a carrier, regardless of the radio link status of other component carriers, it is determined that a radio link failure has occurred by updating the radio link status of all component carriers to DL_CC failure or UL_CC failure, Start the procedure for re-establishing radio resources.

  As described above, in the second embodiment, the mobile station apparatus 1 determines and detects the physical layer problem of the downlink anchor carrier or the random access problem of the uplink anchor carrier separately from the other component carriers. Then, when the mobile station apparatus 1 detects a radio link problem (physical link problem or random access problem) in the downlink anchor carrier or the uplink anchor carrier, the mobile station apparatus 1 updates the radio link states of all other component carriers. The update of the radio link state of the downlink component carrier or the uplink component carrier is preferably performed by RRC of the mobile station apparatus 1.

  As described above, when the mobile station apparatus 1 sets the downlink anchor carrier or the uplink anchor carrier, the downlink anchor carrier becomes DL_CC failure, or the uplink anchor carrier becomes UL_CC failure, Since the radio resource re-establishment procedure has only to be started regardless of the radio link status of the component carrier, the management of the radio link status is further simplified.

  The embodiment described above is merely an example, and can be realized using various modifications and replacement examples.

  For example, DL_CC failure and UL_CC failure in the above-described embodiments may be managed in association with DL_CC Deactivation and UL_CC Deactivation, respectively. DL_CC Deactivation is a state in which information necessary for receiving processing on the downlink component carrier is set from the base station apparatus 2, but at least the downlink data channel receiving process is not performed in the mobile station apparatus 1. . UL_CC Deactivation is a state in which information necessary for performing transmission processing on the uplink component carrier is set from the base station apparatus 2, but at least the uplink data channel transmission processing is not performed in the mobile station apparatus 1. .

  That is, each component carrier has a deactivation (DL_CC Deactivation and UL_CC Deactivation) section as a radio link state instead of DL_CC failure and UL_CC failure. The mobile station device 1 changes the radio link state to deactivation when the component carrier set by the base station device 2 is not used. The condition for the mobile station apparatus 1 to change the radio link state of the component carrier to deactivation may be the same as the condition for determining as DL_CC failure or UL_CC failure in the above embodiment. The transition to deactivation and the return from deactivation may be explicitly notified from the base station apparatus 2 to the mobile station apparatus 1. The base station apparatus 2 can use a downlink control channel, a MAC message (MAC control element), or an RRC message as a method for notifying the mobile station apparatus 1. When the mobile station apparatus 1 sets the radio link state of the component carrier to deactivation (DL_CC Deactivation or UL_CC Deactivation) based on detection of a radio link problem or notification from the base station apparatus 2, as in the above embodiment. The radio link state of another component carrier that is linked to the component carrier set for deactivation may be changed to deactivation at the same time.

  Further, for convenience of explanation, the mobile station device 1 and the base station device 2 of the embodiment have been described using functional block diagrams, but the functions of each part of the mobile station device 1 and the base station device 2 or one of these functions Is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to control the mobile station apparatus and the base station apparatus. Also good. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a semiconductor medium (eg, RAM, nonvolatile memory card, etc.), an optical recording medium (eg, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (eg, , A magnetic tape, a flexible disk, etc.) and a storage device such as a disk unit built in a computer system. Furthermore, the “computer-readable recording medium” means that a program is dynamically held for a short time, like a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In this case, it is intended to include those that hold a program for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client in that case. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. .

  Further, each functional block of the mobile station apparatus 1 and the base station apparatus 2 used in the above embodiments may be realized as an LSI that is typically an integrated circuit. Each functional block may be individually formed into chips, or a part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology can also be used.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design and the like within the scope of the present invention are also within the scope of the claims. include.

DESCRIPTION OF SYMBOLS 1 ... Mobile station apparatus 2 ... Base station apparatus 11-13 ... Transmission apparatus 21-23 ... Reception apparatus 101, 201 ... Reception part 102, 202 ... Demodulation part 103, 203 ... Decoding part 104 ... Measurement processing part 105, 204 ... Control Unit 106 ... Random access processing unit 107, 205 ... Encoding unit 108, 206 ... Modulation unit 109, 207 ... Transmission unit 110, 210 ... Upper layer 208 ... Network signal processing unit 209 ... Peripheral information management unit

Claims (8)

A base station device and a mobile station device are communication systems that perform communication by aggregating cells of different frequencies.
The base station device
When adding cells of different frequencies to the mobile station device, the uplink and downlink frequency information of the cell, and a timer used to change the state of the cell upon expiration, set,
The mobile station device
A communication system, wherein the state of the cell whose timer has expired is changed to deactivation, and uplink transmission processing and downlink reception processing related to the cell indicated by the frequency information are changed. The mobile station device
Stop transmission of uplink data as an uplink transmission process related to the cell in the deactivation state, and stop monitoring a downlink control channel as a downlink reception process related to the cell. The communication system according to claim 1. A base station apparatus and a mobile station apparatus are mobile station apparatuses in a communication system that performs communication by aggregating a plurality of cells having different frequencies,
The frequency information of uplink and downlink of the cell notified from the base station apparatus, and a timer used for changing the state of the cell upon expiration,
The mobile station apparatus, wherein the state of the cell whose timer has expired is changed to deactivation, and an uplink transmission process and a downlink reception process related to the cell indicated by the frequency information are changed. .   Stop transmission of uplink data as an uplink transmission process related to the cell in the deactivation state, and stop monitoring a downlink control channel as a downlink reception process related to the cell. The mobile station apparatus according to claim 3, wherein A radio link state management method for a mobile station apparatus in a communication system in which a base station apparatus and a mobile station apparatus perform communication by aggregating a plurality of cells having different frequencies,
Setting the uplink and downlink frequency information of the cell notified from the base station apparatus, and a timer used for changing the state of the cell upon expiration;
Changing the state of the cell whose timer has expired to deactivation, and changing uplink transmission processing and downlink reception processing related to the cell indicated by the frequency information. Radio link state management method.   As an uplink transmission process related to the cell in the deactivation state, a step of stopping transmission of uplink data, and as a downlink reception process related to the cell, monitoring of a downlink control channel is stopped. The radio link state management method according to claim 5, further comprising: a step. The base station apparatus and the mobile station apparatus are mounted on a mobile station apparatus in a communication system that performs communication by aggregating a plurality of different frequency cells, and an integrated circuit that allows the mobile station apparatus to perform a plurality of functions,
A function of setting uplink and downlink frequency information of the cell notified from the base station apparatus, and a timer used for changing the state of the cell upon expiration;
A function of changing the state of the cell when the timer has expired to deactivation, and changing the uplink transmission processing and downlink reception processing related to the cell indicated by the frequency information, An integrated circuit characterized by causing the mobile station device to exhibit.   As an uplink transmission process related to the cell in the deactivation state, a function of stopping uplink data transmission, and as a downlink reception process related to the cell, monitoring of the downlink control channel is stopped. The integrated circuit according to claim 7, further comprising: a function.

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