Technical field
[0001]
　The present application relates to wireless communication systems that the wireless station communicates with a wireless terminal in an unlicensed frequency or shared frequency, in particular to Listen-Before-Talk for uplink transmission (LBT).
Background technique
[0002]
　The following section describes the 3rd Generation Partnership Project (3GPP) Release (called Long Term Evolution (LTE)) 8 and a radio frame (radio frame) structure used in later, then, the 3GPP Release 10 (LTE-Advanced It will be described carrier aggregation introduced in referred to) (carrier aggregation (CA)). Furthermore, Licensed Assisted Access being discussed currently with respect to 3GPP Release 13 (LAA), and associated Licensed Shared Access for (LSA) will be described.
[0003]
　First, LTE time - described frequency resources (radio resources). Figure 21 shows the radio frame structure of LTE. In 3GPP Release 8 and later, two radio frame structure is prepared. One is called a frame structure type 1, it can be applied to frequency division duplex (FDD). The other is called a frame structure type 2, applicable to Time division duplex (TDD). As shown in Figure 21, in any of the frame structure of the type 1 and type 2, the length of one radio frame is 10 ms, from one radio frame 10 subframes (subframe) It is configured. In the case of TDD, the first half of the five subframes (# 0 ~ # 4), referred to as the second half of the five subframes (# 5 to # 9) respectively half-frame. The length of the half-frame is 5 milliseconds. The length of one subframe is 1 ms. One more sub-frames, each of which is decomposed into two slots of 0.5 ms. For Normal Cyclic prefix, 1 single slot, if 7 symbols (uplink in the time domain single carrier frequency division multiple access (SC-FDMA) symbols, if the downlink orthogonal frequency division multiplexing (OFDM) symbol )including. Therefore, one sub-frame includes 14 symbols in the time domain.
[0004]
　Figure 22 illustrates the uplink 7 kinds of TDD LTE supports downlink configuration (TDD UL / DL configuration). For TDD LTE, uplink subframe (UL subframe) and a downlink subframe (DL subframe) coexist in a single radio frame. TDD UL / DL configuration refers to the arrangement of the uplink subframes and downlink subframes in one radio frame. In Figure 22, "D" represents a DL sub-frame, "U" represents a UL sub-frame, "S" denotes a special subframe. In TDD LTE, either TDD UL / DL configuration shown in FIG. 22 is used repeatedly in a cycle of a radio frame (10 ms).
[0005]
　UL subframe is a subframe uplink (UL) transmission to the radio base station (eNodeB (eNB)) is carried out from the wireless terminal (User Equipment (UE)), DL subframe, from the eNB to the UE downlink (DL) is a subframe transmission is performed. Switching from DL transmission (DL subframe) UL transmission to (UL sub-frame) is performed in the second subframe in the half-frame (i.e., sub-frame # 1 and # 6). Figure 23 shows a configuration example of a special sub-frame. Special subframe, up DwPTS the DL transmission is performed (downlink pilot time slot (DwPTS)), guard periods are non-transmission interval (guard period (GP)), where and uplink transmission are performed and a link pilot time slot (uplink pilot time slot (UpPTS)).
[0006]
　Furthermore, carrier aggregation (Carrier Aggregation (CA)) to the eNB and the UE in the 3GPP Release 10 performs communications using a plurality of cells functional specification of it was made. Incidentally, UE cell available in CA is limited to a plurality of cells of one eNB (i.e., multiple cells that operate or managed by eNB). The cells used by the UE in CA, primary cell that is already used as a serving cell at the time of starting the CA (Primary cell: PCell) and, additionally or dependent-used secondary cell (Secondary cell: SCell) It is classified in. In PCell, wireless connection (re) establishment (Radio Resource Control (RRC) Connection Establishment, RRC Connection Re-establishment) during, Non Access Stratum (NAS) mobility information (NAS mobility information) and security information (security input The) There are transmitted and received (see section 7.5 of non-Patent Document 1).
[0007]
　Although functionally the introduction of CA has become possible to realize a high-speed communication, by restriction of frequencies allocated to each operator in actual operation (insufficient), concern for an increase in the future additional mobile traffic the remains at present. Therefore, in the 3GPP standardization, unlicensed frequency (Unlicensed frequency band, Unlicensed spectrum) discuss the Unlicensed LTE that performs the LTE using a (referred to as LTE-U is also. Later called LTE-U or U-LTE) is has been started (non-Patent documents 2 and 3).
[0008]
　The implementation method of the LTE-U, in conjunction with license frequency (e.g. as SCell of CA), and Licensed Assisted Access to eNB at unlicensed frequency to communicate with UE (LAA), the UE only unlicensed frequency communication two ways of Standalone (SA) for performing is considered. Here, as the unlicensed frequency, for example, is assumed 5GHz band, the 5GHz band, radar systems and wireless LAN to other: a frequency which is also used (Wireless LAN WLAN.WiFi also called). Therefore, SA scheme to perform communication only in unlicensed frequency, there is concern about the feasibility of delicate control specified in LTE, feasibility (also referred to as LA-LTE) higher LAA method is studied It has been with the center. In the following, it will be described with attention by the LAA method of performing CA license frequency and non-licensed frequency to LTE-U. Note that the license frequency refers to dedicated frequency assigned to a specific operator. Also, the non-license frequency refers to a shared frequency assigned to a frequency or a plurality of operators, not assigned to a specific operator. In the latter case, the frequency is instead called unlicensed frequency, sometimes also called license sharing frequency, communication using the frequency is also referred to Licensed Shared Access (LSA). Later, the collectively referred to unlicensed frequency of these frequencies other than licensed frequencies licensed only to a specific operator.
[0009]
　LTE-U by LAA method is performed according to the sequence shown in basically Figure 24. Here, eNB is in Cell # 2 of Cell # 1 and unlicensed frequency license frequency, a case of performing data transmission (or reception) with the UE # 1. First, the wireless connection between the eNB and the UE # 1 in Cell # 1 is established (RRC Connection Establishment, 2401), further a core network: bearer is established between the (Evolved Packet Core EPC) and UE # 1 ( not shown). That, Cell # 1 is the PCell of UE # 1. eNB, if there is downlink to be transmitted to UE # 1 (DL) · user data (also referred to as User Plane (UP) data), or UE # 1 If there is uplink (UL) · user data to be transmitted , the user data transmitted and received in Cell # 1 (DL (or UL) UP data transmission, 2402).
[0010]
　Then, eNB, when UE # 1 determines that it is effective to transmit and receive user data in Cell # 2 at some point (Trigger LTE-U for UE # 1, 2403), in Cell # 1 Cell # transmitting control information about the second radio resource configuration to UE # 1 (radio resource Configuration for Cell # 2, 2404). The control information corresponds to RadioResourceConfigDedicated Information Element (IE) and RadioResourceConfigCommon IE transmitted at RRC Connection Reconfiguration message in LTE (Non-Patent Document 4). In this case, Cell # 2 is the SCell of UE # 1. When transmitting user data in downlink, eNB can, Cell # perform sensing at 2, the Cell # 2 determines whether available (Perform channel sensing, 2405). eNB, when judging that Cell # 2 is available, to transmit and receive user data to and from the UE # 1 (DL (or UL) UP data transmission, 2406). Thus, improvement in the unlicensed frequency further by using the throughput, or increase in cell capacity can be expected.
[0011]
　Sensing at block 2405 described above, Listen the Before Talk (LBT) and is also known (Non-Patent Document 2), in a non-licensed frequencies of interest, according to LTE-U or other wireless system (eg WLAN) according to other operators communications intended to determine whether taking place in nearby, Channel for radar system Availability Check (CAC), and corresponds such a Clear Channel Assessment performed in Access Point (AP) in WLAN (CCA) (Patent Document 1).
[0012]
　Incidentally, LBT (sensing) at block 2405 described above is performed by eNB, it is mainly LBT performed on the frequency resources used for DL ​​transmission prior to DL transmission. In the present specification, this is referred to as DL LBT. If LAA in the downlink (LAA DL) is performed, it is reasonable to eNB performs DL LBT prior to the DL transmission.
[0013]
　On the other hand, even if the LAA on the uplink (LAA UL) is performed, to achieve regulatory (regulatory requirements, regulatory requirements) fair coexistence in unlicensed frequency between the compliant and the other system (fair Coexistence) the might be required LBT for. In this specification, the LBT performed on the frequency resources used for UL transmission before UL transmission is called a UL LBT. Non-Patent Document 5, UE is described option (Option 2) eNB and option (option 1) to implement the UL LBT to practice the UL LBT.
[0014]
　More specifically, Option 1, UE performs UL LBT after receiving the uplink grant (UL grant) from eNB. If it is unlicensed frequency channel idle for UL transmission (i.e., if clear, if not busy, or if available (available)) UE starts UL transmission. This approach (way) is in line with the legal regulations in many countries and regions (regulatory requirements), the sensing results can always trust for UE. However, in this manner, if not the channel is available as a result of the LBT, even normally received the UL grant, UE can not perform transmission in accordance with the UL grant. In this case, eNB, although I do not need, may perform link adaptation in order to increase the coding gain of the UL grant.
[0015]
　In Option 2, eNB can, UE performs the LBT (channel sensing) in an unlicensed frequency channel to be used for transmission, and transmits the UL grant to the UE if the channel is Dere idle. UE, in response to receiving the UL grant, to start UL transmission without LBT. In this way, eNB can control the UL transmission of the UE. Since the uplink transmission LTE is scheduled by eNB, the eNB determines the UL transmission may be appropriate from the LTE perspective. However, the delay is large it is not preferable between the LBT and UL transmission. Furthermore, since the sensing result of the eNB side is not accurately reflect the interference condition (interference situation) at the UE side, Option 2 eNB performs LBT, the sensing results compared to Option 1, UE performs LBT it may be less accurate of.
CITATION
Non-Patent Document
[0016]
非特許文献1 : 3GPP TS 36.300 V12.3.0 (2014-09), “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 12)”, 2014年9月
非特許文献2 : 3GPP RP-131635, “Introducing LTE in Unlicensed Spectrum”, Qualcomm, Ericsson, 2013年12月
非特許文献3 : 3GPP workshop on LTE in unlicensed spectrum, RWS-140002, “LTE in Unlicensed Spectrum: European Regulation and Co-existence Considerations”, Nokia, 2014年6月
非特許文献4 : 3GPP TS 36.331 V12.3.0 (2014-09), “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 12)”, 2014年9月
非特許文献5 : 3GPP R1-144970, “Views on issues related to LAA UL”, NTT DOCOMO, 2014年11月
非特許文献6 : 3GPP TS 36.213 V12.3.0 (2014-09) “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 12)”, 2014年9月
非特許文献7 : 3GPP TR 36.842 V12.0.0 (2013-12), “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on Small Cell enhancements for E-UTRA and E-UTRAN; Higher layer aspects (Release 12)”, 2013年12月
Patent Literature
[0017]
Patent Document 1: U.S. Patent No. 7,443,821
Summary of the Invention
Problems that the Invention is to Solve
[0018]
　Each of Option 1 and 2 of UL LBT, as described in Non-Patent Document 5, there are advantages and disadvantages. Therefore, whether to employ both Option 1 or Option 2, or thereof, and balanced against the advantages and disadvantages of these options 1 and 2, for each country or region, or Public Land Mobile Network (PLMN) may be determined for each unknown. In other words, the UE whether to perform UL LBT, where the UE is located (country or region), UE is PLMN, the UE to eNB, may differ depending on the connection connection.
[0019]
　Increasing the specific example, legal restrictions on communications in unlicensed frequency (regulatory requirement) may be different for each country or region. Thus, although in certain countries or regions is a need always UL LBT by the UE, in another country or region might be UL LBT by the UE is not necessarily required. Therefore, UE might be better to either option 2 support LBT is performed by Option 1 and eNB that LBT is performed by UE.
[0020]
　Further, even if the option 1 the UE performs LBT is employed, in certain conditions or circumstances, may be allowed to UE omits LBT. As a specific example, UE, it is necessary to perform the UL LBT if its potential or other systems using unlicensed frequencies near exists, that such other systems are not present it may be possible to omit the UL LBT if it is clear.
[0021]
　Therefore, one of the objective to be achieved is the embodiment disclosed herein, the situation and this is adaptively adaptable wireless terminal unwanted situation LBT wireless terminal is required, the method and, program, and contribute to this device is to provide a method, and a program.
Means for Solving the Problems
[0022]
　In a first aspect, the radio terminal includes a radio transceiver configured to communicate with one or more radio stations using the license frequency and unlicensed frequencies, and at least one processor. Wherein the at least one processor, said recognizes whether it is necessary to perform prior Listen the Before talk with (LBT) in uplink transmission for unlicensed frequencies were the LBT if the LBT is required the later starts the uplink transmission in unlicensed frequency operative to initiate the uplink transmission without the LBT if the LBT is not required.
[0023]
　In a second aspect, a method performed by the wireless terminal to recognize the Listen the Before talk whether it is necessary to perform prior to (LBT) in uplink transmission for unlicensed frequencies, and the LBT are required the starts the uplink transmission in unlicensed frequency after the LBT if that includes initiating the uplink transmission without the LBT if the LBT is not required.
[0024]
　In a third aspect, the program includes the when loaded into a computer, instructions for performing the method according to the second aspect described above to a computer (software code).
[0025]
　In a fourth aspect, the radio station, memory and, coupled to said memory, Listen Before talk (LBT) for recognizing whether or not it is necessary to carry out prior to uplink transmission in a wireless terminal for unlicensed frequency the control information used by the wireless terminal and at least one processor operative to transmit to said radio terminal.
[0026]
　In a fifth aspect, the method by the wireless terminal to recognize whether the Listen the Before talk for unlicensed frequency (LBT) should be performed prior to uplink transmission in a wireless terminal that is performed by the radio station the control information used includes transmitting to the wireless terminal.
[0027]
　In a sixth aspect, the program includes the when loaded into a computer, instructions for performing the method according to the fifth aspect of the above to a computer (software code).
[0028]
　In a seventh aspect, a wireless communication system includes a one or more radio stations, and a radio terminal configured to use the license frequency and unlicensed frequency to communicate with the one or more radio stations. The wireless terminal further said recognizing whether it is necessary to perform a Listen Before talk (LBT) for unlicensed frequencies, said at unlicensed frequency after the LBT went when the LBT is required the starts uplink transmission, the LBT is configured to initiate the uplink transmission without the LBT if not required of.
Effect of the Invention
[0029]
　According to an aspect of the above situation and this is adaptively adaptable wireless terminal unwanted situation LBT wireless terminal is required, method, and program, as well as contributing to this device, method, and provides a program it can.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030]
It is a diagram illustrating a configuration example of a wireless communication system and another wireless system in accordance with FIG. 1A] Some embodiments.
It is a diagram illustrating a configuration example of a wireless communication system and another wireless system according to FIG. 1B] Some embodiments.
It is a diagram illustrating a configuration example of a wireless communication system and another wireless system in accordance with FIG. 2 some embodiments.
3 is a flowchart illustrating an exemplary operation of the wireless terminal according to the first embodiment.
4 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the first embodiment.
5 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the second embodiment.
6 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the second embodiment.
7 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the third embodiment.
[FIG 8A] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
[FIG 8B] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
[FIG 8C] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
[FIG. 8D] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
[FIG. 8E] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
FIG 8F] is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
9 is a table showing a UL grant (PDCCH / EPDCCH) or ACK / NACK reception and PUSCH transmission (PHICH) relations in the TDD LTE.
FIG. 10 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the third embodiment.
11 is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
12 is a diagram for explaining an example of operations performed by a wireless terminal according to the third embodiment.
13 is a sequence diagram showing an example of a wireless base station and the operation of the radio terminal according to the fourth embodiment.
It is a diagram illustrating a configuration example of a wireless communication system and another wireless system in accordance with FIG. 14 with some embodiments.
15 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the fifth embodiment.
16 is a sequence diagram showing an example of operation of the radio base station and a radio terminal according to the fifth embodiment.
17 is a sequence diagram showing an example of a wireless base station and operation of the wireless terminal according to a fifth embodiment.
18 is a sequence diagram showing an example of a wireless base station and operation of the wireless terminal according to a fifth embodiment.
Is a block diagram showing a configuration example of a radio base station according to FIG. 19 with some embodiments.
It is a block diagram showing a configuration example of a radio terminal according to FIG. 20 with some embodiments.
21 is a diagram illustrating a radio frame structure and subframe structure of LTE.
22 is a table showing a UL-DL configuration of seven different defined for TDD LTE.
23 is a diagram showing the structure of a special sub-frames defined with respect to TDD LTE.
It is a sequence diagram showing an example of FIG. 24 of the radio base station and wireless terminal in LTE-U operation.
DESCRIPTION OF THE INVENTION
[0031]
　Hereinafter, specific embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, for clarity of description, repeated explanation is omitted as appropriate.
[0032]
　The following several embodiments shown in will be described an Evolved Packet System (EPS) that houses the LTE and SAE (System Architecture Evolution) as a main target. However, these embodiments are not intended to be limited to EPS, other mobile communication networks or systems, for example 3GPP UMTS, 3GPP2 CDMA2000 systems (1xRTT, HRPD (High Rate Packet Data)), global system for mobile communications ( GSM (TM)) / General packet radio service (GPRS) system, and may be applied to WiMAX systems.
[0033]

　First, unlicensed frequency (Unlicensed frequency band, Unlicensed spectrum) of several embodiments including this embodiment is directed for some examples of Unlicensed LTE utilizing explained. Here, Unlicensed LTE is also referred to as LTE-U or U-LTE, the following discussions describe an LTE-U. Further, the unlicensed frequency, for example at a frequency which is also used in the radar system and a wireless LAN (also called WLAN.WiFi), particular operator (i.e., service provider) frequencies other than licensed frequencies allocated only points. The unlicensed frequencies, for example, 5 GHz band is assumed, which are not limited. Furthermore, a plurality of embodiments described below, a plurality of shared frequency (Shared frequency band, Shared spectrum) allocated in common to the operator it is needless to say also applicable in. In the following, these are collectively of a frequency other than the license frequency is referred to as a non-licensed frequency.
[0034]
　FIG. 1A, FIG. 1B, and FIG. 2 is a diagram showing a configuration example of a radio communication system and other systems of the LTE-U in which a plurality of embodiments is intended to include this embodiment. In the example of FIG. 1A, the wireless communication system includes a LTE radio base station (eNB) 11 and a wireless terminal (UE) 3. eNB11 and UE3 is a licensed frequency (F1) is configured to perform communication by ordinary LTE, employed are configured to perform communication by LTE-U at unlicensed frequency (F2). Meanwhile, the unlicensed frequency (F2), the wireless LAN access point (WLAN AP) 4 and the wireless LAN terminal (WLAN Terminal) is also used to communicate between 5. In the example of FIG. 1B, in addition to the example of FIG. 1A, LTE eNB 11 manages the remote base station (RRH or RRE) 12, performs communication by LTE-U at unlicensed frequency (F2) by the remote base station 12 .
[0035]
　Arrangement of Figure 1A and 1B may coexist on the same system. Further, in FIG. 1A and 1B, shows only a portion of a wireless communication system assumed, actually exists eNB11, RRH / RRE12, and a plurality of eNB and RRH / RRE and a plurality of UE around the UE3 the cell of the plurality of license frequencies is managed by the plurality of eNB and RRH / RRE. Furthermore, eNB11, RRH / RRE12, and there may be a plurality of WLAN AP and WLAN Terminal around the UE3. In the following description, referred to as a wireless base station 1 or LTE-U eNB1 are collectively eNB having the function of LTE-U. In other words, the radio base station 1 or LTE-U eNB1, in the arrangement of FIG. 1A correspond to eNB11, in the configuration of FIG. 1B correspond to eNB11 and RRH / RRE12. For convenience of explanation, sometimes called the radio base station 1 or LTE-U eNB1 points to only the nodes corresponding to the RRH / RRE12 configuration of FIG 1B.
[0036]
　Figure 2 is a configuration example of a LTE-U wireless communication systems and other wireless communication system when focused on unlicensed frequencies. There the operator (service provider) A radio base station having a function of LTE-U of (LTE-U eNB-A) 1A and the operator A network can be connected to the wireless terminal (UE for Operator A. UE-A) 3A is present. Similarly, another operator (service provider) radio base station having a function of LTE-U of B (LTE-U eNB-B) 1B and the operator B network can be connected to the wireless terminal (UE for Operator B. there is UE-B) 3A. Here, LTE-U eNB1A and 1B, for example, corresponds to eNB11 and RRH / RRE12 of FIGS. 1A and 1B, also called LTE-U AP in the sense of access points LTE-U. Further, as in FIG. 1A and 1B, there is WLAN AP 4 and WLAN Terminal5 the periphery of LTE-U eNB1A and 1B and UE3A and 3B.
[0037]
　In the above and following descriptions, it is assumed that LTE-U are realized LAA (also referred to as LA-LTE). As already mentioned, the LAA, the radio base station (LTE-U eNB) 1 and a wireless terminal (UE) 3 is the cells of the cell and unlicensed frequency license frequencies carry aggregation (CA), cells of the license frequency with use as a primary cell (PCell), using a cell of the unlicensed frequency as a secondary cell (SCell). As already mentioned, LTE-U, instead of being performed in an unlicensed frequency sharing frequencies assigned to a plurality of operators (service providers) (Shared frequency band, Shared spectrum) may be performed in. In this case, LTE-U may be implemented by the above LAA or similar manner. Alternatively, LTE-U eNB1 and UE3 includes a plurality of (e.g., two F3 and F4) performs CA using a shared frequency, perform a normal LTE one shared frequency (F3) as PCell, other one shared frequency (F4) may be executed the LTE-U as SCell. As already mentioned, LTE-U in a shared frequency is especially also known as Licensed Shared Access (LSA). Furthermore, LTE-U eNB1 The UE3, use shared frequencies assigned to a plurality of operators (e.g. F3), any operator is not assigned narrow unlicensed frequency (e.g. F2, for example, 5GHz band) to perform a CA, perform a normal LTE shared frequency (F3) as PCell, may execute the LTE-U a narrow unlicensed frequency (F2) as SCell.
[0038]
　Moreover, in embodiments including the present embodiment, for simplification of explanation, communication in unlicensed frequency (or shared frequency) executed by the LTE-U is basically a radio base from the wireless terminal 3 uplink to the station 1 (UL) to assume the transmission. Furthermore, if the communication between the radio base station 1 and the wireless terminal 3 in the unlicensed frequency is possible only uplink, the unlicensed frequency is not substantially free of role as sole cell, the uplink secondary carrier: with only a role as (Secondary Component carrier SCC). However, in the description of the embodiments including this embodiment, and that is whether basically have a role as a cell unlicensed frequency alone described without distinction, a supplementary explanation as necessary to.
[0039]
　Then hereinafter be described UE3 of operation according to the present embodiment. Figure 3 shows an example of operations performed by UE3 (process 300). At block 301, UE3 recognizes whether it is necessary to perform a non-licensed frequency uplink for Listen Before talk (UL LBT). As already explained, the term "UL LBT" as used herein means an LBT performed on the frequency resources used for UL transmission before the UL transmission. Thus, UL LBT is, UL timing (or UL subframe, UL frame, UL frequency, or UL channel) may be performed in, it may be performed in DL timing. Further, as already described, LBT for unlicensed frequencies, another system communication in unlicensed frequency by (eg, LTE-U or other wireless system (eg WLAN) by another operator) is performed in the neighborhood in order to detect whether it is, it includes an act of receiving (sense) unlicensed frequency prior to transmission. LBT, for example, Channel for radar system Availability Check (CAC), Clear on WLAN Channel Assessment (CCA), and corresponds to the preamble detection. The LBT, for example, the detection of the signal power (eg, Power detection, Energy detection), detection of the predetermined sequence (eg, Preamble detection) corresponds to performing at least one of, and may be considered.
[0040]
　If the UL LBT is required (YES at block 301), UE3 starts UL transmission in unlicensed frequency after the UL LBT (block 302). Specifically, UE3 performs UL LBT, starts UL transmission when unlicensed frequency channel for the UL transmission (resource) are available. However, UE3 is, if the corresponding channel is available as a result of the LBT, it does not perform UL transmission.
[0041]
　On the other hand, when recognizing that it is not necessary UL LBT (NO at block 301), UE3 starts UL transmission without UL LBT (block 303). That, UE3 can recognize the necessity of UL LBT by UE3 (decision), and the UL transmission starts after the UL LBT if necessary UL LBT, omit the UL LBT if necessary UL LBT UL to start transmission. Therefore, UE3 can UL LBT by UE3 situation and which is needed to adaptively correspond to unwanted situations.
[0042]
　As already described, whether to UE3 performs UL LBT, where the UE3 is located (country or region), may be different depending on the eNB, PLMN, the UE connects to UE3 is connected Absent. For example, legal regulations (regulatory requirement) related to communication in the unlicensed frequency may be different for each country or region. Thus, although there is in the country or region UL LBT due to the UE3 is always necessary, in another country or region might be the UL LBT due to the UE3 not necessarily required. UE3 according to the present embodiment, for example, applied to accommodate different regulatory countries and regions.
[0043]
　Also, in certain conditions or circumstances, UE3 might be allowed to omit the LBT. As a specific example, UE3, it is necessary to perform the UL LBT if its potential or other systems using unlicensed frequencies near exists, that such other systems are not present it may be possible to omit the UL LBT if it is clear. UE3 according to the present embodiment, for example, can be carried out selectively UL LBT only in situations where the UL LBT by UE3 is required.
[0044]
　In some implementations, UE3 is the necessity of UL LBT recognition (determination) may be for transmission of a particular one or more of UL signals. Alternatively, UE3 may recognize the necessity of UL LBT for all UL transmissions UE3 is performed (determination). That, UE3 is, Physical Uplink Shared Channel (PUSCH) transmission, Physical Random Access Channel (PRACH) transmission (ie, Random Access Preamble), Physical Uplink Control Channel (PUCCH) transmission (eg, HARQ ACK · NACK, CQI reporting), Sounding Reference signal (SRS) transmission, or other control signals (eg, short control signaling (SCS)), or the necessity of UL LBT may be recognized (determined) for these arbitrary combination.
[0045]
　In some implementations, UE3 is whether it is necessary to UL LBT for each UL transmission in unlicensed frequency channel may be recognized (determined). For example, UE3 is, DL control channel UL grant from eNB1 every time it receives through (eg, Physical Downlink Control Channel (PDCCH) or enhanced PDCCH (EPDCCH)), UL for PUSCH transmission corresponding to the UL grant LBT may recognize whether or not there is a need. Additionally or alternatively, for example, UE3 an uplink hybrid automatic repeat request (HARQ) DL control channel ACK / NACK from eNB1 on the process (eg, Physical Hybrid ARQ Indicator Channel (PHICH)) every time it receives through the in may recognize whether it is necessary to UL LBT for PUSCH retransmission corresponding to the ACK / NACK. According to such an operation, UE3, since that allows a fine determination of the UL transmission unit, can be suppressed execution of unnecessary UL LBT more effectively.
[0046]
　In some implementations, UE3 can be recognized whether it is necessary to UL LBT each set of periodic setting or semi-persistent of UL transmission (semi-persistent) of UL resource allocation (decision) good. Periodic UL transmissions and semi persistent UL resource allocation includes a plurality of UL transmissions at predetermined radio resources. For example, UE3, every time it receives an SPS configuration including setting information on Semi-Persistent Scheduling (SPS) from eNB1, recognizes whether it is necessary to UL LBT for periodic UL transmissions in accordance with the SPS it may be. Additionally or alternatively, UE3, every time it receives the SPS grant to enable the SPS (The activate) from eNB1, whether or not it is necessary to UL LBT for periodic UL transmissions in accordance with the SPS it may be recognized. According to such an operation, UE3, if it is determined that the UL LBT respect SPS setting is not required, can be omitted UL LBT in a plurality of UL transmissions are scheduled to UE3 by SPS. SPS is primarily utilized for scheduling of real-time communication packets, such as voice calls (for voice call) services and video services. Therefore, in the UL transmission that is scheduled to UE3 by SPS, it may be particularly desirable to be able to omit an unnecessary UL LBT. In the case of the unnecessary UL LBT respect SPS configuration may be unnecessary LBT only in new transmission (HARQ initial transmission), it may be unnecessary LBT in new transmission and HARQ retransmission.
[0047]
　In some implementations, UE3, the cell or component carriers utilize unlicensed frequency (e.g., Cell # 2 in FIG. 1A and FIG. 1B) recognize whether it is necessary to UL LBT for each setting (determining) it may be. For example, UE3, the cell of the license frequency from eNB1 (e.g., Cell # 1 in FIGS. 1A and 1B) or unlicensed frequency cell (e.g., Cell # 2 in FIG. 1A and FIG. 1B) system information broadcast in ( each time it receives a System Information Block (SIB)), it may be determined whether it is necessary to UL LBT for unlicensed frequencies. Additionally or alternatively, UE3 is dedicated signaling (dedicated signaling) on ​​setting unlicensed frequency cell (or component carrier), for example, RRC Connection Reconfiguration message, each time it receives a necessary UL LBT for unlicensed frequency it may determine whether a. According to such an operation, UE3, in order to perform the determination of the cell (or component carrier) unit, generically can suppress unnecessary UL LBT, due to performing necessity determination of UL LBT frequently the load can be reduced.
[0048]
　UE3 is above UL transmission unit may be performed in combination SPS units, and the UL LBT necessity determination of a cell unit as appropriate.
[0049]
　In some implementations, UE3, based on the control information received from the eNB1, may recognize whether it is necessary to perform the UL LBT by UE3. According to such an operation, eNB1, by adjusting the contents of the control information, it is possible to control whether or not to perform the UL LBT to UE3. Figure 4 shows an example of the operation of the eNB1 and UE3 (process 400). In block 401, eNB1 transmits the control information to the UE3. The control information is used by the UE3 the UL LBT for unlicensed frequencies in order to recognize whether it is necessary to perform the UE3.
[0050]
　eNB1 may, UE3 serving cell in the license frequency (e.g., Cell # 1 in FIGS. 1A and 1B) may transmit the control information via a non-licensed frequency cell (e.g., in FIGS. 1A and 1B Cell # 2) it may transmit the control information via a may send the control information in both. Here, the cell of the unlicensed frequency associated with the UL carriers subject to necessity determination of UL LBT (eg, SIB2 linked) may be a DL carrier.
[0051]
　eNB1 may send the control information via the system information (SIB) or dedicated signaling (eg, MAC-MainConfig or PhysicalConfigDedicated the RRC Connection Reconfiguration message). Additionally or alternatively, eNB1 may transmit the DL control channel (PDCCH / EPDCCH) with scheduling information indicating the radio resource allocated to the control information to the UL signal (UL grant). Additionally or alternatively, eNB1 may transmit the DL control channel (PHICH) with the control information HARQ ACK / NACK. NACK transmission in PHICH triggers retransmission PUSCH by UE3.
[0052]
　At block 402, UE3, based on the control information received from the eNB1, to recognize whether it is necessary to perform the UL LBT by UE3 (determination). If the UL LBT is required, UE3 starts UL transmission in unlicensed frequency after the UL LBT (block 403) (block 404). That, UE3 performs UL LBT (block 403), if unlicensed frequency channel for the UL transmission (resource) is available performs UL transmission in unlicensed frequency (block 404), available without it does not perform UL transmission. On the other hand, when recognizing that it is not necessary UL LBT, UE3 performs UL transmission without UL LBT (block 404). The blocks 403 and 404 of FIG. 4 are indicated by broken lines, meaning that these processes are not carried out in certain conditions.
[0053]
　In some implementations, the control information used by the UE3 to recognize whether the UL LBT should be performed in UE3 for unlicensed frequency network entity located in PLMN or an external network (eg, from OAM server or Regulation Data base) may be sent to the UE3 user plane. Additionally or alternatively, the control information, an entity in the core network control messages from (eg, Mobility Management Entity (MME)) to UE3 (eg, NAS message) may be sent with.
[0054]
　eNB1 or the control information transmitted from other network entities to UE3 also include both "regulation (regulatory requirement) related information for radio communication in an unlicensed frequency" or these or "information on the need for UL LBT" good. Specific examples of these information elements are described in the embodiments to be described later.
[0055]

　In the present embodiment, a specific example of processing performed by the UE and the eNB are described. Configuration example of a wireless communication system according to this embodiment, FIG. 1A described with respect to the first embodiment is the same as FIG. 1B, and FIG. In this embodiment, UE3 recognizes whether it is necessary to UL LBT by UE3 based on the control information received from the eNB1, in unlicensed frequency after UL LBT when UL LBT is required It performs UL transmission, operates to perform UL transmission in unlicensed frequency without UL LBT if UL LBT is not required.
[0056]
　The control information UE3 receives from eNB1 includes information on the need for UL LBT. For example, information on the need for UL LBT may explicitly indicate whether it is necessary to perform the UL LBT. More specifically, information on the need for UL LBT may include at least one of the listed information elements below:
· LBT information indicating whether it is necessary to (eg, Flag);
· information (eg, Boolean) indicating that the LBT is necessary (or unnecessary); and
· LBT information indicating a predetermined condition for determining when it is necessary (or unnecessary).
[0057]
　LBT information indicating a predetermined condition for determining if it is necessary (or unnecessary) is may indicate the need for LBT when a predetermined condition is satisfied (or unnecessary). The predetermined condition is, UE3 capability (UE capability data), UE3 is connected (or registered) to a network to a frequency used in UL transmission, and the periphery of the system or network, or may be related to at least one . That is, in one example, UE3, if applicable in a predetermined condition its UE capability is specified (eg, UE Power class, or support of LBT), recognizes that the LBT is necessary (or unnecessary) it may be. UE3, the network is predetermined condition to which it is connected (or registered) in the case corresponding to (eg, PLMN ID (list of PLMN IDs)), be recognized that it is LBT need (or unnecessary) good. UE3 is the frequency used UL transmission predetermined condition when the true (eg, Absolute Radio Frequency Channel Number (ARFCN), or frequency index), be recognized that it is LBT need (or unnecessary) good. UE3 is other systems or networks predetermined condition that it has detected (eg, WLAN Service Set Identifier (SSID), Basic SSID (BSSID), Extended SSID (ESSID), Homogenous Extended Service Set Identifier (HESSID), or access point If the true name), may recognize that the LBT is necessary (or unnecessary). Incidentally, when the predetermined condition is related to WLAN, the information (eg SSID relates to the aforementioned WLAN, BSSID, ESSID, HESSID,
[0058]
　As understood from the above description, in this embodiment, UE3 recognizes whether it is necessary to perform the UL LBT based on "information on the need for UL LBT" received from the eNB1, UL LBT performs UL transmission in unlicensed frequency after UL LBT when is needed, it operates to perform UL transmission in unlicensed frequency without UL LBT if UL LBT is not required. Therefore, UE3 can UL LBT by UE3 situation and which is needed to adaptively correspond to unwanted situations. Furthermore, eNB1, by adjusting the content of the "information on the need for UL LBT", it is possible to control whether or not to perform the UL LBT to UE3.
[0059]
　Figure 5 is a sequence diagram showing eNB1 and an example of the operation of the UE3 (the processing 500). In block 501, eNB1 transmits information on the need for LBT a (eg, Flag or Boolean), with PDCCH / EPDCCH to UE3 with the scheduling information of the uplink (UL grant). eNB1 may transmit information about the need of LBT in another PDCCH / EPDCCH above the PDCCH / EPDCCH for transmitting UL grant. In this case, eNB1 may send these PDCCH / EPDCCH each other in different cells. eNB1 may transmit one or more PDCCH / EPDCCH in unlicensed frequency cell may transmit the license frequency cell (eg PCell).
[0060]
　At block 502, UE3, based on the information on the need for LBT received from eNB1, to recognize whether it is necessary to perform the UL LBT by UE3 (determination). If the UL LBT is required, UE3 performs UL LBT (block 503), UL data transmission according to UL grant in unlicensed frequency when unlicensed frequency channel for the UL transmission (resource) are available (PUSCH transmission) was carried out (block 504) does not perform the UL data transmission to be available. On the other hand, when recognizing that it is not necessary UL LBT, UE3 performs UL data transmission to (PUSCH transmission) at unlicensed frequency without UL LBT (block 504). The blocks 503 and 504 of FIG. 5 is shown by a broken line means that these processes are not carried out in certain conditions.
[0061]
　UE3, at block 503, LBT may be performed based on the setting information about the LBT defined in advance specification. Alternatively, transmits the setting information about the previously LBT is eNB1 to UE3, it may be performed LBT based UE3 is on the setting information. At this time, eNB1 is the setting information may be transmitted in the system information (SIB) or dedicated signaling (RRC Connection Reconfiguration message).
[0062]
　In the example of FIG. 5, UE3 receives control information (information on the need for LBT) with UL grant. Therefore, UE3 can be whether or not it is necessary to UL LBT for each UL transmission in unlicensed frequency channel to recognize (determine). According to such an operation, UE3, since that allows a fine determination of the UL transmission unit, can be suppressed execution of unnecessary UL LBT more effectively.
[0063]
　In block 501 of FIG. 5, eNB1 may transmit information indicating a predetermined condition for determining if a LBT need (or unnecessary). In this case, UE3, at block 502, determines whether a predetermined condition is satisfied or not specified by eNB1, recognizes that if the predetermined condition is satisfied it is necessary UL LBT by UE3 (or unnecessary) it may be.
[0064]
　The UE3 series of operations associated with the example of FIG. 5 can be summarized as follows.
　If, for this TTI, and, with respect to the serving cell, when I received the uplink grant in (e) PDCCH:
　- (addition) if (e) PDCCH content, indicates the need for LBT and if you are:
　　- UE3 is, to run the LBT.
　　- UE3 is to HARQ entity for this TTI, sending the uplink grant, and the associated HARQ information.
　- Otherwise:
　　UE3 is to HARQ entity for this TTI, sending the uplink grant, and the associated HARQ information.
[0065]
　Alternatively, it is possible to put together a series of operations UE3 related to the example of FIG. 5 as follows.
　If you are shown the (e) PDCCH is a new transmission in unlicensed frequency (UL):
　- (addition) if if is (e) PDCCH content, to the need for LBT:
　　- UE3 is to run the LBT.
[0066]
　Figure 6 is a sequence diagram showing eNB1 and an example of the operation of the UE3 (the processing 600). In block 601, eNB1 transmits information on the need for LBT a (eg, Flag or Boolean), the UE3 System Information (SIB) or dedicated signaling (RRC Connection Reconfiguration message). At block 602, UE3, based on the information on the need for LBT received from eNB1, to recognize whether it is necessary to perform the UL LBT by UE3 (determination).
[0067]
　In block 603, eNB1 transmits UL scheduling information (UL grant) to the UE3 with PDCCH / EPDCCH. eNB1 may transmit the PDCCH / EPDCCH in unlicensed frequency (cell) may transmit license frequency (cell).
[0068]
　If at block 602 UL LBT was aware requires, UE3 performs UL LBT in response to receiving a UL grant (block 604). Then, UE3 performs UL data transmission (PUSCH transmission) at unlicensed frequency according UL grant when unlicensed frequency channel for the UL transmission (resource) is available (block 605), if available It does not perform UL transmission. On the other hand, if you have recognized that it is not necessary UL LBT at block 602, UE3 performs UL data transmission to (PUSCH transmission) at unlicensed frequency without UL LBT (block 605). The blocks 604 and 605 in FIG. 6 is indicated by a broken line means that these processes are not carried out in certain conditions.
[0069]
　In the example of FIG. 6, UE3 receives system information (SIB) or a separate signaling control information via a (RRC Connection Reconfiguration message) (information on the need for LBT). Therefore, UE3, for each set of cells or component carriers utilize unlicensed frequency can whether it is necessary to UL LBT recognize (determine). According to such an operation, UE3, in order to perform the determination of the cell (or component carrier) unit, generically can suppress unnecessary UL LBT, due to performing necessity determination of UL LBT frequently the load can be reduced.
[0070]
　In block 601 of FIG. 6, eNB1 may transmit information indicating a predetermined condition for determining if a LBT need (or unnecessary). In this case, UE3, at block 602, determines whether a predetermined condition is satisfied or not specified by eNB1, recognizes that if the predetermined condition is satisfied it is necessary UL LBT by UE3 (or unnecessary) it may be.
[0071]
　The UE3 series of operations associated with the example of FIG. 6 can be summarized as follows.
　If, for this TTI, and, with respect to the serving cell, when I received the uplink grant in (e) PDCCH:
　- (addition) if the RRC, if the need for LBT is shown :
　　- UE3 is, to run the LBT.
　　- UE3 is to HARQ entity for this TTI, sending the uplink grant, and the associated HARQ information.
　- Otherwise:
　　UE3 is to HARQ entity for this TTI, sending the uplink grant, and the associated HARQ information.
[0072]
　In the specific example described with reference to FIGS. 5 and 6, has been described with respect to UL data transmission. Specific examples of these may be performed for other UL signal transmission other than UL data transmission. For example, UL scheduling information transmitted in block 603 of the block 501 and 6 of FIG. 5 may be replaced by RACH preamble transmission request (PDCCH order) from the eNB1, the block of the block 504 and FIG. 6 in FIG. 5 uplink signals transmitted in 605 (PUSCH) may be replaced by PRACH. Alternatively, UE3 is, UL control signal (eg, SRS, PRACH, or PUCCH) for the transmission of, without the recognition of the need for UL LBT, the always radio resource specified by the eNB1 without LBT it may transmit the control information.
[0073]

　In the present embodiment, a specific example of processing performed by the UE and the eNB are described. Configuration example of a wireless communication system according to this embodiment, FIG. 1A described with respect to the first embodiment is the same as FIG. 1B, and FIG. In this embodiment, UE3 recognizes whether it is necessary to UL LBT by UE3 based on the control information received from the eNB1, in unlicensed frequency after UL LBT when UL LBT is required It performs UL transmission, operates to perform UL transmission in unlicensed frequency without UL LBT if UL LBT is not required.
[0074]
　The control information UE3 receives from eNB1 includes regulatory information (regulation) for wireless communication in unlicensed frequency. Information about the regulation, may indicate the first period to be allowed to send a UL signal without UL LBT. More specifically, information regarding the restriction may include at least one of the listed information elements following:
- maximum continuous use time radio resources is allowed after determining that available in LBT (maximum occupancy period, maximum channel occupancy time, or maximum Transmission duration);
· a predetermined signal continuous use time allowed after receiving the (occupancy period, channel occupancy time, or Transmission duration);
· Duty cycle information (eg, duty cycle [% ], observation period [ms], or duty cycle type (continuous duty or intermittent duty)); and
· LBT determination information (eg, LBT type (eg, energy detection or preamble detection), LBT for LAA only , LBT threshold for LAA , LBT for WLAN only, LBT threshold for WLAN, or CCA time).
[0075]
　First period during which information about the regulation is allowed to transmit a UL signal without UL LBT (eg, the maximum continuous operating time radio resources is allowed after determining that available in LBT, or predetermined when showing the continuous use time) allowed the signal after reception, UE3 may operate as follows.
[0076]
　In some implementations, UE3 the elapsed time is a first period from the previous execution of the UL LBT if (ie, the radio resources are continuously used time allowed after determining that available in LBT) shorter, a new it may recognize that the UL LBT is not required. Here, past UL LBT may be one which is executed by the UE3, or those performed by eNB1. Note that the elapsed time from the previous execution of the UL LBT, for example, the elapsed time from the radio resource is determined to be used by UL LBT, or by UL LBT subframes radio resource is judged next available equivalent of the elapsed time, from the sub-frame. Also, whether the elapsed time is shorter than the first period determination is, for example, actually timing for UL transmission (time, or sub-frame) is not (or first or shorter than the first period whether fall period), or timing of the ready to do UL transmission (time, or sub-frame) whether it falls short whether (or the first period than the first time period) is performed by it may be.
[0077]
　In some implementations, UE3 is (continuous use time allowed ie, after receiving a predetermined signal) period from the reception to the UL transmission of the predetermined signal by the transmission or UE3 predetermined signal is a first period by the eNB1 If shorter, it may recognize that UL LBT is unnecessary. The predetermined signal, (UL grant in eg, PDCCH / EPDCCH), the request message for requesting a UL transmission (eg, HARQ ACK / NACK in PHICH) scheduling information indicating allocation of a radio resource for UL transmission, or predetermined may be beacon the. Note that the period from the reception of the predetermined signal to the UL transmission, for example, the timing of UE3 receives the predetermined signal (time, or sub-frame) period from to UL transmission, or UE3 is the predetermined signal receive, demodulate, corresponding timing recognizing the information contained in the signal (time, or sub-frame) from time to UL transmission, a. The determination that period if shorter or not than the first time period, for example, actually timing for UL transmission (time, or sub-frame) whether shorter than the first period (or the first period fit whether) to, or the timing of the ready to do UL transmission (time, or sub-frame) whether falls short whether (or the first period than the first time period), is carried out by it may be.
[0078]
　In other words, in some implementations, UE3 predetermined signal (eg, PDCCH for UL grant) and are received in sub-frame n (the from that point) times the first period (eg, maximum transmission period (maximum If transmission duration)) or not yet elapsed, UL signals (eg, PUSCH according to UL grant) can be transmitted without performing LBT.
[0079]
　In other words, in some implementations, if UE3 predetermined signal (eg, PDCCH for UL grant) and are received in subframe n and the first period (eg, maximum transmission period (maximum transmission duration)) is k + 1 if smaller, UE3, in the current subframe n + k, must be performed LBT before transmitting UL signals (eg, PUSCH according to UL grant). Here, n is a number indicating the subframe number (any integer from 0 to 9), k is a positive integer.
[0080]
　In other words Additionally, in some implementations, UE3 the transmission or the period until the reception of the predetermined signal by the UE3 is a first period of a predetermined signal by the eNB1 back from the timing of the UL transmission (subframe) (ie, a predetermined the signal is shorter than the continuous operating time) allowed after receiving, may recognize that UL LBT is unnecessary. That, UE3, when having received the predetermined signal to the recent past than the first time period going back from the timing of UL transmissions may recognize that UL LBT is unnecessary.
[0081]
　In other words, in some implementations, if UE3 the first period prior to the current subframe n (eg, maximum transmission period (maximum transmission duration)) is shorter than before a predetermined signal (eg, PDCCH for UL grant) to If has been received, UL signals (eg, PUSCH according to UL grant) can be transmitted without performing LBT.
[0082]
　In other words, in some implementations, if UE3 predetermined signal (eg, PDCCH for UL grant) is received in subframe n-k a and a first time period (eg, maximum transmission period (maximum transmission duration)) There if k + 1 is smaller than, UE3, in the current subframe n, must be performed LBT before transmitting UL signals (eg, PUSCH according to UL grant). Here, n is a number indicating the subframe number (any integer from 0 to 9), k is a positive integer.
[0083]
　As understood from the above description, in this embodiment, UE3 is whether it is necessary to perform the UL LBT based on "Regulatory (regulation) for wireless communication in an unlicensed frequency" received from eNB1 recognizes performs UL transmission in unlicensed frequency after UL LBT when UL LBT is required, performs UL transmission in unlicensed frequency without UL LBT if UL LBT is not required operable. Therefore, UE3 can UL LBT by UE3 situation and which is needed to adaptively correspond to unwanted situations. Furthermore, eNB1, by adjusting the content of the "Regulatory Information (regulation) for wireless communication in an unlicensed frequency", it is possible to control whether or not to perform the UL LBT to UE3.
[0084]
　Figure 7 is a sequence diagram showing eNB1 and an example of the operation of the UE3 (the processing 700). In block 701, eNB1 transmits the information about restriction (regulation) for wireless communication in an unlicensed frequency, the UE3 System Information (SIB) or dedicated signaling (RRC Connection Reconfiguration message).
[0085]
　In block 702, eNB1 transmits UL scheduling information (UL grant) to the UE3 with PDCCH / EPDCCH. eNB1 may transmit the PDCCH / EPDCCH in unlicensed frequency (cell) may transmit license frequency (cell).
[0086]
　In block 703, UE3, based on the UL scheduling information received (UL grant) in the information and block 702 Regulatory received at block 701, to recognize whether it is necessary to perform the UL LBT by UE3 (determination) . If the UL LBT is required, UE3 performs UL LBT (block 704), UL data transmission according to UL grant in unlicensed frequency when unlicensed frequency channel for the UL transmission (resource) are available (PUSCH transmission) was carried out (block 705) does not perform the UL data transmission to be available. On the other hand, when recognizing that it is not necessary UL LBT, UE3 performs UL data transmission to (PUSCH transmission) at unlicensed frequency without UL LBT (block 705). The blocks 704 and 705 of Figure 7 is shown by a broken line means that these processes are not carried out in certain conditions.
[0087]
　Regulatory transmitted at block 701 from eNB1 to UE3 may indicate "Maximum continuous operating time radio resources is allowed after determining that available in LBT (MAX_T)". As an example, eNB1 performs LBT (UL LBT) for UL transmission radio resources before transmitting the UL grant, immediately when UL transmission radio resources are available (i.e., the top of MAX_T) transmits a UL grant assume a case. In this case, the UE3, as shown in Figure 8A, until the timing (802) of the UL data transmission corresponding to the UL grant from the reception timing of the UL grant with the UL grant transmission timing or UE3 of by eNB1 (801) (PUSCH transmission) It recognizes that period is unnecessary UL LBT is shorter than the maximum continuous operating time (MAX_T), may recognize the need for UL LBT otherwise. Maximum continuous use time (MAX_T), the sub-frame number (i.e., ms units) may be specified by.
[0088]
　It will be specifically described with reference to Figure 8A. UE3 responds to receiving the UL grant (801) at subframe n, performs PUSCH transmission (the 802) in subframe n + k. That is, the value of k defines a mapping between subframe sub-frame and UL grant for PUSCH transmission is performed is transmitted. Where k is as defined above, it is a positive integer, or a value of k as defined in section 8 of 3GPP TS 36.213 V12.3.0 (Non-Patent Document 6).
[0089]
　For example, CA primary cell (here, the license frequency cell) (here, unlicensed frequency cell) and the secondary cell when it is both FDD component carrier (CC) (FDD cells), self carrier scheduling (self scheduling ) is a k = 4 regardless of whether it is cross-carrier scheduling is. Here, the self-carrier scheduling is a scheduling method scheduling grant (UL grant and DL grant) is transmitted on the same component on the carrier and the component carriers the UE is utilized for DL ​​data received or UL data transmission. In contrast, cross-carrier scheduling is a scheduling method scheduling grant on different component carriers are transmitted to the component carrier the UE is utilized for DL ​​data received or UL data transmission. That is, in the case of self-carrier scheduling, UE, for the scheduling of a serving cell is configured to monitor the PDCCH / EPDCCH sent within the serving cell. On the other hand, in the case of cross-carrier scheduling, UE is the serving cell (e.g., SCell) for scheduling the other serving cell (e.g., PCell) is set so as to monitor the PDCCH / EPDCCH sent within.
[0090]
　If CA primary cell (license frequency cell) and secondary cell (unlicensed frequency cell) are both TDD component carrier (CC) (TDD cell), the value of k according to the table shown in FIG. Incidentally, TDD UL / DL configuration of the table shown in FIG. 9 refers to the "UL-reference UL / DL configuration". UL-reference UL / DL configuration is determined according to a combination of self-carrier scheduling (self-scheduling) as or cross-carrier scheduling a either, and two serving TDD cell UL / DL configuration.
[0091]
　Furthermore, 3GPP Release 12 and later defines the CA of FDD component carrier (FDD CC) and TDD component carrier (TDD CC). FDD CC (or FDD cell) is a cell using the frame structure type 1 for FDD. TDD CC (or TDD cell) is a cell using the frame structure type 2 for TDD. In this specification, the carrier aggregation "FDD-TDD aggregation", or simply referred to as "FDD-TDD". The FDD-TDD carrier aggregation, to primary cell may be a FDD CC (FDD cells), it may be a TDD CC (TDD cell).
[0092]
　In FDD-TDD, a secondary cell (here, the unlicensed frequency cell) is TDD CC (TDD cell), if the self-carrier scheduling for PUSCH transmission on the secondary cell is set to a UE, the value of k follows the table shown in UL / DL configuration and FIG. 9 of the secondary cell. (Here, unlicensed frequency cell) TDD secondary cell as an example the case UL / DL configuration of configuration 0, according to the definition of the table shown in FIG. 9, corresponding to the UL grant received in subframe # 0 PUSCH transmissions are performed in subframe # 4, PUSCH transmission corresponding to UL grant received in subframe # 1 is performed in subframe # 7.
[0093]
　In FDD-TDD, (in this case, unlicensed frequency cell) secondary cell is TDD CC (TDD cell), cross-carrier referencing the PDCCH / EPDCCH sent in another serving cell for the PUSCH transmission of the secondary cell scheduling is set, and if other serving cells are FDD cell, the value of k is in accordance with the table shown in UL / DL configuration and FIG. 9 of the secondary cell.
[0094]
　Continuing with the description back to FIG. 8A. UE3 responds to receiving the UL grant (801) at subframe n, performs PUSCH transmission (the 802) in subframe n + k. Period from UL grant (801) to PUSCH transmission (802) (i.e., k) is maximum continuous operating time (MAX_T) is smaller than (in other words, when MAX_T it is k + 1 or more), UE3 performs the UL LBT may or may not. On the other hand, the period from UL grant (801) to PUSCH transmission (802) (i.e., k) if it is the maximum continuous operating time (MAX_T) above (in other words, when MAX_T is below k), the UE3 UL LBT to run. For example, as shown in Figure 8A, if and k = a 4 MAX_T = 4ms, UE3 performs PUSCH transmission after the UL LBT. In contrast, if it k = a 4 MAX_T = 8ms, UE3 performs PUSCH transmission without UL LBT.
[0095]
　Here, it is possible to put together a series of operations UE3 related to the example of FIGS. 7 and 8A as follows. If UE3 predetermined signal (eg, UL grant (801)) a and is received in subframe n (from the time) time has not yet elapsed the first period (eg, MAX_T) above, UL signals (eg, PUSCH according to UL grant (801) (802)) can be transmitted without performing LBT.
[0096]
　If other words, if UE3 predetermined signal (ie, UL grant (801)) and is received in subframe n and the first period (eg, MAX_T) is k + 1 is smaller than, UE3 is, UL signals ( eg, PUSCH (802) according to UL grant (801)) must be performed LBT before sending the.
[0097]
　Instead of the example of FIG. 8A, UE3 may operate according to the example of FIG. 8B. That, UE3 a period from the timing of UL transmission reception (subframe) the predetermined signal by the transmission or UE3 predetermined signal by eNB1 back from (812) (eg, UL grant (811)) is first period (ie, continuous use time allowed after receiving a predetermined signal, MAX_T) is shorter than may recognize that UL LBT is unnecessary. In other words, it UE3, when having received the first past predetermined signal closer than the period going back from the timing of the UL transmission (812) (eg, UL grant (811)), UL LBT is unnecessary You may recognize.
[0098]
　In the example of FIG. 8B, UE3 performs PUSCH transmission (the 812) at subframe n. PUSCH transmission or the period until the reception is performed subframe n-k (811) of transmitting UL grant (801) back to (812) (i.e., k) if the maximum continuous operating time (MAX_T) less (in other words If, when MAX_T it is k + 1 or more), UE3 may not perform the UL LBT. On the other hand, time to transmit or receive UL grant (801) back from PUSCH transmission (812) (i.e., k) when is the maximum continuous operating time (MAX_T) above (in other words, when MAX_T is below k ), UE3 is to run the UL LBT. For example, as shown in FIG. 8B, if and k = a 4 MAX_T = 4ms, UE3 performs PUSCH transmission after the UL LBT. In contrast, if it k = a 4 MAX_T = 8ms, UE3 performs PUSCH transmission without UL LBT.
[0099]
　7 and associated UE3 series of operations in the example of FIG. 8B may be summarized as follows. If UE3 has received a first time period prior to the current subframe n (eg, MAX_T) shorter than before a predetermined signal (eg, UL grant (811)), UL signals (eg, UL grant PUSCH according to (811) (812)) can be transmitted without performing LBT.
[0100]
　If other words, if UE3 predetermined signal (eg, UL grant (811)) is received in subframe n-k a and a first time period (eg, MAX_T) is k + 1 is smaller than, UE3 are currently of at subframe n, (PUSCH according to eg, UL grant (811) (812)) UL signal must be performed LBT before sending the.

The scope of the claims
[Claim 1]
　Use license frequency and unlicensed frequencies and radio transceiver configured to communicate with one or more radio stations,
　at least one processor,
comprising a
　at least one processor,
　Listen the Before for said unlicensed frequency recognizes whether it is necessary to perform prior talk with (LBT) in uplink transmission,
　the initiate the uplink transmission in unlicensed frequency after the LBT went when the LBT is required the LBT starts the uplink transmission without the LBT if not required,
to operate as,
a wireless terminal.
[Claim 2]
　Wherein the at least one processor is operative to recognize whether it is necessary to perform the LBT based on the one or more control information received from at least one radio station,
according to claim 1 radio terminal.
[Claim 3]
　Wherein the at least one processor is
　said to operate uplink grant or indicating the allocation of radio resources with the uplink transmission request message to receive the control information for uplink transmission,
　for each of the uplink grant or it operates to recognize whether the it is necessary to perform the LBT for each of the request message,
the wireless terminal according to claim 2.
[Claim 4]
　Wherein the at least one processor is operative to recognize whether it is necessary to perform the LBT whenever the uplink transmission,
the radio terminal according to claim 2.
[Claim 5]
　Wherein the at least one processor, the via the one or more system information is broadcast from one of the radio stations, or the one or more Radio Resource Control, which is transmitted from one radio station (RRC) message operable to receive control information,
the wireless terminal according to claim 2.
[Claim 6]
　Wherein the at least one processor is
　said with the one or more SPS configuration includes configuration information for Semi-Persistent Scheduling (SPS) that is sent from any of the wireless stations, or SPS grant for enabling the SPS operates to receive control information,
　it operates to recognize the whether LBT it is necessary to perform before a periodic uplink transmission according to the SPS,
the wireless terminal according to claim 2.
[Claim 7]
　Wherein the control information indicates explicitly whether it is necessary to perform the LBT,
wireless terminal according to any one of claims 2-6.
[8.]
　Wherein the control information indicates a determination condition for determining whether it is necessary to perform the LBT,
wireless terminal according to any one of claims 2-7.
[Claim 9]
　The determination condition, the wireless terminal capabilities, the network to which the wireless terminal is connected, the uplink frequency used for transmission, and the periphery of the system or network, for at least one,
according to claim 8 wireless terminal.
[Claim 10]
　Wherein the control information includes information about the restrictions on wireless communication in the unlicensed frequency
radio terminal according to any one of claims 2-9.
[Claim 11]
　The regulation relates first period that is allowed to be transmitted without the LBT,
　the at least one processor, the one or more transmission or the wireless terminal of the predetermined signal by any of the wireless station If the period from the reception until said uplink transmission corresponding to the predetermined signal of the predetermined signal is shorter than the first period by operative to recognize that the LBT is not necessary,
according to claim 10 wireless terminal according to.
[Claim 12]
　The predetermined signal, the uplink uplink grant indicating the allocation of radio resources for transmission, or a request message that requests the uplink transmission,
the radio terminal according to claim 11.
[Claim 13]
　The regulation relates first period that is allowed to be transmitted without the LBT,
　the at least one processor, when the elapsed time from the previous execution of the LBT is shorter than the first period, It operates to recognize that new LBT is not necessary,
the radio terminal according to claim 10.
[Claim 14]
　Wherein the first period of time is specified by the number of subframes,
the radio terminal according to any one of claims 11 to 13.
[Claim 15]
　Use license frequency and unlicensed frequencies A method performed by a configured radio terminal to communicate with one or more wireless stations,
　prior Listen the Before talk for said unlicensed frequency (LBT) in uplink transmission recognizing whether it is necessary to perform it, and
　the LBT said initiate the uplink transmission in unlicensed frequency after the LBT went when is needed, when said LBT is not required wherein initiating the uplink transmission without LBT, to
comprise a method.
[Claim 16]
　It involves recognizing whether it is necessary to perform the LBT based on the one or more control information received from at least one radio station, to the recognition
method according to claim 15.
[Claim 17]
　The uplink further comprises an uplink grant indicating the allocation of radio resources for transmission or with the uplink transmission request message to receive the control information,
　to the recognition, for each of the uplink grant or comprising recognizing whether the it is necessary to perform the LBT for each of the request message,
the method according to claim 16.
[Claim 18]
　Wherein the one or SPS configuration includes a plurality of configuration information for Semi-Persistent Scheduling is transmitted (SPS) from any of the wireless stations, or with SPS grants to enable the SPS to receive said control information further comprising,
　to the recognition includes recognizing the whether LBT it is necessary to perform before a periodic uplink transmission according to the SPS,
the method according to claim 16.
[Claim 19]
　The control information is explicitly indicate whether it is necessary to perform the LBT,
the method according to any one of claims 16-18.
[Claim 20]
　Wherein the control information indicates a determination condition for determining whether it is necessary to perform the LBT,
the method according to any one of claims 16-19.
[Claim 21]
　The determination condition, the wireless terminal capabilities, the network to which the wireless terminal is connected, the uplink frequency used for transmission, and the periphery of the system or network, for at least one,
according to claim 20 Method.
[Claim 22]
　Wherein the control information includes information about the restrictions on wireless communication in the unlicensed frequency,
method according to any one of claims 16-21.
[Claim 23]
　The regulation relates first period to transmit without the LBT is allowed
　to the recognition by the transmission or the wireless terminal of a predetermined signal according to any of the one or more radio stations If the period from the reception of the predetermined signal until the uplink transmission corresponding to the predetermined signal is shorter than the first period, including recognizing that the LBT is unnecessary
to claim 22 the method described.
[Claim 24]
　The predetermined signal, the uplink uplink grant indicating the allocation of radio resources for transmission, or a request message that requests the uplink transmission
method according to claim 23.
[Claim 25]
　The regulation relates first period to transmit without the LBT is allowed
　to the recognition, when the elapsed time from the previous execution of the LBT is shorter than the first period, a new such LBT comprising recognizes that it is not necessary,
the method of claim 23.
[Claim 26]
　A memory,
　coupled to the memory, the control information used by the wireless terminal to recognize whether the Listen the Before talk for unlicensed frequency (LBT) should be performed prior to uplink transmission in a wireless terminal and at least one processor operative to transmit to the radio terminal
includes a radio station.
[Claim 27]
　Wherein the at least one processor is operative to transmit the control information together with uplink grant indicating the allocation of radio resources for uplink transmission,
　the control information, performs the LBT for each of the uplink grant used by the wireless terminal to recognize whether it is necessary,
the radio station according to claim 26.
[Claim 28]
　Wherein the at least one processor is operative to transmit the control information together with uplink transmission request message,
　the control information, the to recognize whether it is necessary to perform the LBT for each said request message used by the wireless terminal,
the radio station according to claim 26.
[Claim 29]
　Wherein the at least one processor is operative to transmit the control information using the system information or Radio Resource Control (RRC) message,
the radio station according to claim 26.
[Claim 30]
　Wherein the at least one processor is operative to transmit the control information together with SPS grant for activating SPS configuration, or the SPS including the setting information about the Semi-Persistent Scheduling (SPS),
　the control information, the used by the wireless terminal in order to recognize whether it is necessary to perform the LBT prior to periodic uplink transmission according to the SPS,
the radio station according to claim 26.
[Claim 31]
　The control information is explicitly indicate whether it is necessary to perform the LBT,
radio station according to any one of claims 26-30.
[Claim 32]
　Wherein the control information indicates a determination condition for determining whether it is necessary to perform the LBT,
radio station according to any one of claims 26-31.
[Claim 33]
　The determination condition, the wireless terminal capabilities, the network to which the wireless terminal is connected, the uplink frequency used for transmission, and the periphery of the system or network, for at least one,
according to claim 32 wirelessly station.
[Claim 34]
　Wherein the control information includes information about the restrictions on wireless communication in the unlicensed frequency
radio station according to any one of claims 26-33.
[Claim 35]
　The regulation, for the first time it is allowed to transmit without the LBT,
radio station according to claim 34.
[Claim 36]
　Wherein the first period of time is specified by the number of subframes,
the radio station according to claim 35.
[Claim 37]
　Transmitting the control information used by the wireless terminal to recognize the Listen the Before talk for unlicensed frequency (LBT) whether it is necessary to perform prior to uplink transmission in a wireless terminal to said wireless terminal comprising,
the method performed by the radio station.
[Claim 38]
　That said transmitting includes transmitting the control information together with uplink grant indicating the allocation of radio resources for uplink transmission,
　the control information, necessary to perform the LBT for each of the uplink grant used by the wireless terminal in order to recognize whether there is,
the method of claim 37.
[Claim 39]
　Said transmitting includes transmitting the control information together with uplink transmission request message,
　the control information, the radio in order to recognize whether it is necessary to perform the LBT for each said request message used by the terminal,
the method of claim 37.
[Claim 40]
　It includes transmitting the control information using the system information or Radio Resource Control (RRC) message, to the transmission
method according to claim 37.
[Claim 41]
　Said transmitting includes transmitting the control information with SPS grant for activating SPS configuration, or the SPS including the setting information about the Semi-Persistent Scheduling (SPS),
　the control information, the wherein in order to recognize whether it is necessary before a periodic uplink transmission according to the SPS performs the LBT used by the wireless terminal,
the method according to claim 37.
[Claim 42]
　The control information is explicitly indicate whether it is necessary to perform the LBT,
the method according to any one of claims 37 to 41.
[Claim 43]
　Wherein the control information indicates a determination condition for determining whether it is necessary to perform the LBT,
the method according to any one of claims 37-42.
[Claim 44]
　The determination condition, the wireless terminal capabilities, the network to which the wireless terminal is connected, the uplink frequency used for transmission, and the periphery of the system or network, for at least one,
Method according to claim 43 .
[Claim 45]
　Wherein the control information includes information about the restrictions on wireless communication in the unlicensed frequency,
method according to any one of claims 37-44.
[Claim 46]
　The regulation, for the first time it is allowed to transmit without the LBT,
The method of claim 45.
[Claim 47]
　Non-transitory computer readable medium storing a program comprising software code for performing the method according to the computer in any one of claims 15 to 25.
[Claim 48]
　Non-transitory computer readable medium storing a program comprising software code for performing the method according to the computer in any one of claims 37-46.
[Claim 49]
　And one or more radio stations,
　a wireless terminal configured to communicate with the one or more radio stations using the license frequency and unlicensed frequencies
comprises a,
　the wireless terminal further the unlicensed frequency recognizing whether or not it is necessary to carry out prior to uplink Listen before talk (LBT) in the uplink transmission to the said up in unlicensed frequency after the LBT went when the LBT is required link transmission was started, the LBT is configured to initiate the uplink transmission without the LBT if not needed,
the wireless communication system.
[Claim 50]
　At least one of the one or more radio stations is configured to transmit the control information to the wireless terminal,
　the wireless terminal recognizes whether it is necessary to perform the LBT based on the control information It is configured,
a wireless communication system according to claim 49.