Apparatus and method for transmitting and receiving signal in a mobile communication system

This application is a continuation reissue application of U.S. patent application Ser. No. 17/729,396, which is an application for reissue of U.S. Pat. No. 10,708,818.

This application claims the benefit under 35 U.S.C. § 119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Aug. 11, 2010 and assigned Serial No. 10-2010-0077578, the entire disclosure of which is hereby incorporated by reference.

1. Field of the Invention

The present invention relates to a mobile communication system. More particularly, the present invention relates to an apparatus and method for transmitting and receiving signals in a mobile communication system.

2. Description of the Related Art

rd The rapid increase in the number of smart phone subscribers has resulted in a corresponding increase in traffic demand by those subscribers. Despite being in the process of commercialization, an Orthogonal Frequency Division Multiple Access (OFDMA)-based mobile communication system having a relatively high frequency efficiency, such as a 3Generation Partnership Project (3GPP) Long-Term Evolution (LTE) mobile communication system, will likely not have sufficient capacity to meet the increasing traffic demand. Therefore, there is a trend toward adopting a micro cell system and a repeater system to increase overall system capacity.

1 FIG. A configuration of a micro cell system will be described below with reference to.

1 FIG. schematically illustrates a configuration of a micro cell system according to the related art.

1 FIG. 111 1 113 1 115 1 117 1 111 1 111 2 113 1 113 2 115 1 115 2 117 1 117 2 111 1 113 1 115 1 117 1 Referring to, the micro cell system includes a plurality of, for example, 4 micro cells-,-,-, and-. The micro cell-is a service coverage area where a micro evolved Node B (eNB)-provides services. The micro cell-is a service coverage area where a micro eNB-provides services. The micro cell-is a service coverage area where a micro eNB-provides services. The micro cell-is a service coverage area where a micro eNB-provides services. It will be assumed that the four micro cells-,-,-, and-have the same coverage area as the service coverage area where one macro eNB (not shown) provides services.

As described above, in the micro cell system, eNBs are installed more densely to increase the system capacity, thereby causing a decrease in the spatial coverage or size of the split cells. The decrease in the size of the split cells may contribute to increasing the average capacity that users can experience, but in inter-cell boundaries, may decrease the data capacity due to interference between data channels and increase outage probability due to interference between control channels. In addition, the smaller the cell size becomes, the more frequently User Equipments (UEs) may perform handover caused by their movements, thereby increasing overhead and making the communication environment unstable.

2 FIG. A configuration of a repeater system will be described below with reference to.

2 FIG. schematically illustrates a configuration of a repeater system according to the related art.

2 FIG. 211 213 215 217 211 213 215 217 211 213 215 217 211 213 215 217 211 213 215 217 Referring to, the repeater system includes a plurality of, for example, 4 Radio Units (RUs),,, andwithin one cell. The four RUs,,, andtransmit and receive the same signals. Therefore, in the boundaries among the RUs,,, and, signals undergo macro combining, contributing to an improvement in the capacity of UEs located in the boundary areas among the RUs,,, and, and a reduction in the outage probability. In addition, when moving between the RUs,,, and, UEs are not required to perform handover.

The repeater system is mainly used for service coverage area expansion and coverage hole filling, because it expands strong-electric field areas using multiple RUs, which are spatially separated. However, unlike the micro cell system, the repeater system may suffer from a reduction in the resource efficiency and system capacity because multiple RUs transmit and receive the same signals.

In summary, the micro cell system and repeater system may be adopted to increase overall system capacity may have the following shortcomings.

First, in the case of the micro cell system, capacities of UEs located in the inter-cell boundaries are limited, and its outage probability is relatively high. UEs may perform handover more frequently, increasing the overhead and making the communication environment unstable.

Second, the repeater system may improve capacities of UEs located in the inter-cell boundaries because multiple RUs transmit and receive the same signals, but may suffer from a reduction in the overall system capacity due to its low resource efficiency.

Aspects of the present invention are to address the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide an apparatus and method for transmitting and receiving signals in a mobile communication system.

In accordance with an aspect of the present invention, a method for transmitting a signal by an evolved Node B (eNB) in a mobile communication system is provided. The method includes transmitting a same control channel signal to each of a plurality of Radio Units (RUs), and transmitting a different data channel signal to each of the plurality of RUs. A data channel signal transmitted to each of the plurality of RUs may be determined taking into account at least one of a location of a User Equipment (UE) that will receive the data channel signal, and load balancing.

In accordance with another aspect of the present invention, an eNB in a mobile communication system is provided. The eNB includes a digital unit for transmitting a same control channel signal to each of a plurality of RUs, and for transmitting a different data channel signal to each of the plurality of RUs. A data channel signal transmitted to each of the plurality of RUs may be determined taking into account at least one of a location of a UE that will receive the data channel signal, and load balancing.

In accordance with another aspect of the present invention, a method for transmitting and receiving a signal by an RU in a mobile communication system is provided. The method includes receiving a control channel signal and a data channel signal from an eNB. The control channel signal may be equal to control channel signals that the eNB transmits to a plurality of RUs except for the RU. The data channel signal may be different from data channel signals that the eNB transmits to the plurality of RUs except for the RU. A data channel signal transmitted to each of the RU and the plurality of RUs may be determined taking into account at least one of a location of a UE that will receive the data channel signal, and load balancing.

In accordance with another aspect of the present invention, an RU in a mobile communication system is provided. The RU includes a receiver for receiving a control channel signal and a data channel signal from an eNB. The control channel signal may be equal to control channel signals that the eNB transmits to a plurality of RUs except for the RU. The data channel signal may be different from data channel signals that the eNB transmits to the plurality of RUs except for the RU. A data channel signal transmitted to each of the RU and the plurality of RUs may be determined taking into account at least one of a location of a UE that will receive the data channel signal, and load balancing.

In accordance with another aspect of the present invention, a method for receiving a signal by a UE in a mobile communication system is provided. The method includes receiving a control channel signal and a data channel signal from each of a plurality of RUs. A control channel signal received from each of the plurality of RUs may be equal. A data channel signal received from each of the plurality of RUs may be different. A data channel signal received from each of the plurality of RUs may be determined taking into account at least one of a location of the UE, and load balancing.

In accordance with another aspect of the present invention, a UE in a mobile communication system is provided. The UE includes a receiver for receiving a control channel signal and a data channel signal from each of a plurality of RUs. A control channel signal received from each of the plurality of RUs may be equal. A data channel signal received from each of the plurality of RUs may be different. A data channel signal received from each of the plurality of RUs may be determined taking into account at least one of a location of the UE, and load balancing.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features and structures.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

rd Exemplary embodiments of the present invention provide an apparatus and method for transmitting and receiving signals in a mobile communication system. In addition, exemplary embodiments of the present invention provide an apparatus and method for allowing multiple Radio Units (RUs) to transmit/receive control channel signals in a shared way, and to transmit/receive data channel signals independently in a mobile communication system. It will be assumed herein that the mobile communication system is a 3Generation Partnership Project (3GPP) Long-Term Evolution (LTE) mobile communication system. However, it will be understood by those of ordinary skill in the art that the signal transmission/reception apparatus and method proposed by the exemplary embodiments of the present invention may be used not only in the 3GPP LTE mobile communication system, but also in any other mobile communication system, such as an Institute of Electrical and Electronics Engineers (IEEE) 802.16m communication system.

3 FIG. schematically illustrates a configuration of a 3GPP LTE mobile communication system according to an exemplary embodiment of the present invention.

3 FIG. 311 313 315 317 319 311 Referring to, the 3GPP LTE mobile communication system includes an evolved Node B (eNB), at least one, for example, 4 RUs,,, and, and at least one User Equipment (UE, not shown). The eNBmanages control channels and data channels in different ways, thereby increasing overall system capacity and making it possible to reduce the overhead caused by frequent handover of UEs.

311 3 FIG. 4 FIG. A method of managing control channels and data channels by the eNBinwill be described below with reference to.

4 FIG. 3 FIG. 311 schematically illustrates a method of managing control channels and data channels by the eNBinaccording to an exemplary embodiment of the present invention.

4 FIG. 311 313 315 317 319 313 315 317 319 311 311 Referring to, the eNBcontrols the RUs,,, and. The RUs,,, andtransmit the same control channel signals in a shared way under control of the eNB, but transmit data channel signals individually under control of the eNB.

313 315 317 319 311 A method of controlling transmission of control channel signals and data channel signals of the RUs,,, andby the eNBwill be described in detail below.

313 315 317 319 311 First, a method of controlling transmission of control channel signals of the RUs,,, andby the eNBwill be described below.

311 313 315 317 319 313 315 317 319 The eNBcontrols the RUs,,, andto transmit the same control channel signals so that a specific UE may acquire a macro combining gain when receiving the control channel signals. When the RUs,,, andtransmit the same control channel signals in this way, interference between control channels may not occur, so the specific UE may acquire a macro combining gain.

313 315 317 319 311 Second, a method of controlling transmission of data channel signals of the RUs,,, andby the eNBwill be described below.

311 313 315 317 319 311 313 315 317 319 311 313 315 317 319 311 313 315 317 319 The eNBenables the RUs,,, andto transmit data channel signals independently. In other words, the eNBcontrols each of the RUs,,, andto transmit data channel signals only to the UE that the RU itself has selected, thereby making it possible to multiplex data channel signals targeting different UEs during their transmission using the same frequency resources. The eNBmay determine the UE to which each of the RUs,,, andwill transmit data channel signals, taking into account at least one of various parameters, such as locations of UEs, and load balancing. For example, the eNBmay control each of the RUs,,, andto transmit data channel signals to the UE located in the shortest distance.

313 315 317 319 313 315 317 319 313 315 317 319 313 315 317 319 Because the RUs,,, andmay multiplex data channel signals targeting different UEs during their transmission using the same frequency resources, interference may occur between data channels in the boundaries among the RUs,,, and. Therefore, an exemplary embodiment of the present invention minimizes interference between data channels in the boundaries among the RUs,,, andusing an interference control method, thereby increasing capacities of UEs located in the boundaries among the RUs,,, and.

313 315 317 319 As described above, because the RUs,,, andcan multiplex data channel signals targeting different UEs during their transmission using the same frequency resources, their resource efficiency and system capacity are higher than those of the repeater system of the related art.

311 3 FIG. 5 FIG. An internal structure of the eNBinwill be described below with reference to.

5 FIG. 3 FIG. 311 illustrates an internal structure of the eNBinaccording to an exemplary embodiment of the present invention.

5 FIG. 311 511 513 515 517 Referring to, the eNBincludes a Digital Unit (DU), which includes a control channel manager, a data channel manager, and a MUltipleXing (MUX) and connection unit.

513 513 515 The control channel managergenerates DownLink (DL) control channel signals. The control channel managerreceives scheduling information from the data channel managerand generates DL control channel signals based on the scheduling information.

515 513 515 The data channel managerperforms a scheduling operation, generates scheduling information corresponding to the results of the scheduling operation, and transmits the scheduling information to the control channel manager. The data channel managergenerates DL data channel signals based on the scheduling information.

517 513 515 313 315 317 319 313 315 317 319 517 517 311 5 FIG. 3 FIG. The MUX and connection unitmultiplexes the DL control channel signals generated by the control channel managerand the DL data channel signals generated by the data channel manager, and transmits them to the RUs,,, and. Although the RUs,,, andare connected to the MUX and connection unitin the case ofsince the configuration of the 3GPP LTE mobile communication system described inis considered, it will be understood by those of ordinary skill in the art that the MUX and connection unitmay be connected to all RUs in the coverage area serviced by the eNB.

517 313 315 317 319 515 The MUX and connection unittransmits UpLink (UL) data channel signals received from the RUs,,, andto the data channel manager.

313 315 317 319 517 313 315 317 319 311 311 The RUs,,, andperform Radio Frequency (RF) processing on the DL control channel signals and DL data channel signals transmitted by the MUX and connection unit, and transmit them to their associated UEs. The RUs,,, andare connected to the eNBthrough, for example, an optic fiber, and exchange signals with the eNBusing, for example, a Common Public Radio Interface (CPRI).

313 315 317 319 313 315 317 319 313 315 317 319 3 FIG. Preferably, the RUs,,, andmay be installed to contribute to forming strong electric fields in spatially different areas. In other words, the RUs,,, andmay be installed to be spatially separated as illustrated in, if they have, for example, omni-directional antennas. On the other hand, if the RUs,,, andhave directional antennas, they may be installed in the same location. In the latter case, strong-electric field areas may be expanded by setting different bore-sights for the directional antennas.

513 5 FIG. 6 FIG. An internal structure of the control channel managerinwill be described below with reference to.

6 FIG. 5 FIG. 513 illustrates an internal structure of the control channel managerinaccording to an exemplary embodiment of the present invention.

6 FIG. 513 611 613 615 Referring to, the control channel managerincludes a control channel reference signal generator, a control channel signal generator, and a MUX.

613 515 The control channel signal generatorgenerates control channel signals based on the scheduling information received from the data channel manager. The control channels may include, for example, a Physical Broadcast Channel (PBCH), a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICH), etc.

611 The control channel reference signal generatorgenerates control channel reference signals used to demodulate control channel signals for UEs. The control channel reference signals may include, for example, cell-specific reference signals.

615 611 613 517 The MUXmultiplexes the control channel reference signals generated by the control channel reference signal generatorand the control channel signals generated by the control channel signal generator, and outputs them to the MUX and connection unit.

515 5 FIG. 7 FIG. An internal structure of the data channel managerinwill be described below with reference to.

7 FIG. 5 FIG. 515 illustrates an internal structure of the data channel managerinaccording to an exemplary embodiment of the present invention.

7 FIG. 515 711 713 715 717 719 721 Referring to, the data channel managerincludes a channel measurer, a scheduler, a channel quality receiver, a data channel generator, a data channel reference signal generator, and a MUX.

515 515 311 515 The data channel managerenables multiple RUs to transmit data channel signals to different UEs independently. In other words, the data channel managerenables the eNBto transmit different data channel signals to multiple UEs by reusing the same frequency resources. The data channel managerdetermines UEs which are spatially separated if possible, as UEs that transmit data channel signals by reusing the same frequency resources, thereby minimizing interference between data channels.

Because the data channel signals, unlike the control channel signals, are not equally transmitted by all RUs, if a UE receives the data channel signals based on only the channel estimates for the reference signals transmitted equally by all RUs, for example, for the control channel reference signals, its receive success rate may be poor. Therefore, it is preferable that each of the RUs transmits a data channel reference signal to a UE individually, to which the RU itself will transmit data channel signals so that the UE may receive the data channel signals based on a channel estimate for the data channel reference signal, or may estimate a channel for the data channel signals based on both the control channel reference signal and beamforming weight information. For convenience, it will be assumed herein that RUs transmit data channel reference signals independently, and UEs receive data channel signals based on the data channel reference signals. The data channel reference signals may include, for example, dedicated reference signals. The 3GPP LTE mobile communication system may transmit the dedicated reference signals in accordance with Transmission Mode 7 when using the Release 8 standard, and may transmit the dedicated reference signals in accordance with Transmission Mode 7 or Transmission Mode 8 when using the Release 9 standard.

715 517 713 The channel quality receiverreceives channel quality information that each UE has measured and transmitted through the MUX and connection unit, and transmits the received channel quality information to the scheduler.

711 7 FIG. 8 FIG. An internal structure of the channel measurerinwill be described below with reference to.

8 FIG. 7 FIG. 711 illustrates an internal structure of the channel measurerinaccording to an exemplary embodiment of the present invention.

8 FIG. 711 811 1 811 2 811 3 811 4 813 1 813 2 813 3 813 4 Referring to, the channel measurerincludes a plurality of, for example, 4 UE signal detectors-,-,-, and-, and a plurality of, for example, 4 channel information measurers-,-,-, and-.

517 313 811 1 315 811 2 317 811 3 319 811 4 Signals received from RUs through the MUX and connection unit, i.e., signals transmitted by UEs, are delivered to their associated UE signal detectors. For example, a signal received from the RUis delivered to the UE signal detector-. A signal received from the RUis delivered to the UE signal detector-. A signal received from the RUis delivered to the UE signal detector-. A signal received from the RUis delivered to the UE signal detector-.

811 1 811 2 811 3 811 4 517 813 1 813 2 813 3 813 4 811 1 813 1 811 2 813 2 811 3 813 3 811 4 813 4 The UE signal detectors-,-,-, and-detect their associated UE signals from the signals received from the MUX and connection unit, and output the detected UE signals to their associated channel information measurers-,-,-, and-connected thereto. In other words, the UE signal detector-outputs its detected UE signal to the channel information measurer-. The UE signal detector-outputs its detected UE signal to the channel information measurer-. The UE signal detector-outputs its detected UE signal to the channel information measurer-. The UE signal detector-outputs its detected UE signal to the channel information measurer-.

813 1 813 2 813 3 813 4 811 1 811 2 811 3 811 4 713 The channel information measurers-,-,-, and-measure information about channels between associated UEs and RUs based on the UE signals detected by the UE signal detectors-,-,-, and-, respectively, and output the measured channel information to the scheduler. The channel information may include channel powers and channel coefficients between associated UEs and RUs.

711 An operation of the channel measurerwill be described in additional detail below.

517 Signals received from RUs through the MUX and connection unitare output to their associated UE signal detectors. The UE signal detectors, which receive Sounding Reference Signals (SRSs) that UEs have transmitted in a UL, may detect their associated UE signals based on the SRSs transmitted by the UEs, and output the detected UE signals to their associated channel information measurers. The channel information measurers measure channel information based on the UE signals detected by the UE signal detectors.

713 7 FIG. 9 FIG. An operation of the schedulerinwill be described below with reference to.

9 FIG. 7 FIG. 713 illustrates an operation of the schedulerinaccording to an exemplary embodiment of the present invention.

9 FIG. 911 713 913 713 Referring to, in step, the schedulercalculates a scheduling metric for each unit resource based on channel qualities of UEs. The unit resource may include, for example, a sub band. In step, the schedulerdetermines a UE having the maximum scheduling metric, for each unit resource.

915 713 917 713 In step, the schedulercalculates a scheduling metric when in addition to the UE having the maximum scheduling metric, another UE determined based on the channel quality information is additionally assigned to a unit resource, using channel information between UEs and RUs. In step, the scheduleradditionally determines a UE having the maximum scheduling metric, for each unit resource.

919 713 713 921 In step, the schedulerdetermines if the scheduling metric increases due to the additional determination of a UE. If the scheduling metric does not increase, the schedulerfinally determines the determined UEs as UEs to which it will transmit data signals using the unit resource in step, thereby completing the scheduling operation.

919 713 923 915 However, if it is determined in stepthat the scheduling metric increases, the schedulerdetermines the determined UEs as UEs to which it will transmit data signals using the unit resource in step, and then returns to step.

9 FIG. 713 713 713 Referring to, the schedulerdetermines a UE having the maximum scheduling metric when transmitting data channel signals using a relevant unit resource based on the channel qualities of UEs, and determines if the scheduling metric increases when transmitting data channel signals to another UE in addition to the determined UE using a related unit resource based on the channel information between UEs and RUs. If it is determined that the scheduling metric increases, the schedulerdetermines the determined UEs as UEs to which it will transmit data channel signals using the unit resource, and determines again whether to additionally assign a UE to which it will transmit data channel signals using the unit resource. On the other hand, if the scheduling metric does not increase, the schedulerfinally determines the determined UEs as UEs to which it will transmit data channel signals using the unit resource, completing the scheduling operation.

713 717 513 713 713 713 717 717 After completing the scheduling operation, the scheduleroutputs the scheduling information corresponding to the finally determined UEs to the data channel generatorand the control channel manager. The schedulermay determine only one UE or multiple UEs at the same time, for each unit resource. The schedulermay allow one RU to transmit data channel signals to UEs, or allow multiple RUs to transmit data channel signals to UEs together. The scheduleroutputs the channel information to the data channel generatorso that the data channel generatormay determine a beamforming weight it will apply to data channels if necessary.

717 7 FIG. 10 FIG. An internal structure of the data channel generatorinwill be described below with reference to.

10 FIG. 7 FIG. 717 illustrates an internal structure of the data channel generatorinaccording to an exemplary embodiment of the present invention.

10 FIG. 717 1011 1013 1015 Referring to, the data channel generatorincludes a beamforming weight calculator, an encoding/modulation/channelization processor, and a beamforming processor.

717 713 The data channel generatorreceives scheduling information from the scheduler, and receives traffic data targeting a UE, which is assigned to a related unit resource based on the scheduling information, i.e., to which it will transmit data channel signals using the unit resource.

1011 1015 719 The beamforming weight calculatorgenerates a beamforming weight to be used for a data channel based on the scheduling information, and outputs the beamforming weight to the beamforming processorand the data channel reference signal generator.

1013 1015 The encoding/modulation/channelization processorperforms encoding/modulation/channelization on the input traffic data, and outputs the results to the beamforming processor.

1015 1013 721 The beamforming processorperforms beamforming processing on the signals output from the encoding/modulation/channelization processor, and outputs transmission signals for RUs to the MUX.

719 719 1011 517 719 The data channel reference signal generatorgenerates reference signals for data channels, i.e., data channel reference signals. The data channel reference signal generatorperforms the same beamforming processing even on the data channel reference signals, using the beamforming weights output from the beamforming weight calculator, and outputs them to the MUX and connection unit. Instead of generating data channel reference signals as described above, it is also possible to allow a UE to estimate a channel of data channel signals based on the control channel reference signals and beamforming weight information. In this case, the data channel reference signal generatoris allowed not to generate data channel reference signals.

721 717 719 517 The MUXmultiplexes the signals output from the data channel generatorand the data channel reference signal generator, and outputs the results to the MUX and connection unit.

517 5 FIG. 11 FIG. An internal structure of the MUX and connection unitinwill be described below with reference to.

11 FIG. 5 FIG. 517 illustrates an internal structure of the MUX and connection unitinaccording to an exemplary embodiment.

11 FIG. 517 1111 1113 Referring to, the MUX and connection unitincludes a control channel copierand a MUX.

1111 1113 The control channel copiergenerates control channel signals for RUs by copying a control channel signal so that all RUs may transmit the same control channel signals, and then outputs them to the MUXfor RUs individually.

1113 1111 515 1113 515 The MUXreceives the signals output from the control channel copierand the data channel signals generated for RUs by the data channel manager, multiplexes them for RUs individually, and transmits the results to the associated RUs. The MUXoutputs the signals that RUs have received from UEs, to the data channel manager.

Although not illustrated in separate drawings, each of RUs may include a transmitter for transmitting various signals, a receiver for receiving various signals, and a controller for controlling operations of the transmitter and the receiver. The transmitter, the receiver and the controller may be realized as separate units, or integrated in a single unit.

Likewise, a UE may include a transmitter for transmitting various signals, a receiver for receiving various signals, a controller for controlling operations of the transmitter and the receiver, and an estimator for estimating various signals. The transmitter, the receiver, the controller and the estimator may be realized as separate units, or integrated in a single unit.

As is apparent from the foregoing description, the exemplary embodiments of the present invention allow multiple RUs to transmit control channel signals in the same way, and to transmit data channel signals independently, thereby contributing to an increase in the capacity of UEs and a reduction in the outage probability, and preventing overhead due to the frequent handover of UEs.

While the invention has been shown and described below with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.