[0001]The present disclosure relates to a wireless communication system that performs communication control for coverage improvement.
BACKGROUND
[0002]In 3rd Generation Partnership Project (3GPP), improvement and standardization of technology for the realization of higher speed communications decrease in communication quality due to rapid increase in recent mobile traffic is being performed. Moreover, are also being standardized technique to avoid an increase in control signaling load due connection to the vast number of Machine to Machine (M2M) terminal of Long Term Evolution (LTE) network or LTE-Advanced network is anticipated . Here, M2M terminal refers to a terminal that performs communication such as a human does not intervening. M2M terminal machine (eg, vending machines, gas meters, electric meters, automobiles, railway vehicles, ships) and the sensor is mounted on a variety of devices such as (eg, environmental, agricultural, sensors about traffic, etc.). In LTE and LTE-Advanced, call communication by M2M terminal and Machine Type Communication (MTC), referred to as terminal MTC terminal for MTC (MTC User Equipment (MTC UE)).
[0003]
　M2M service operators there is a need to distribute a large number of M2M terminals on the market, but there is a limit to the cost applied to the per M2M terminal. For this purpose, M2M terminal to be implemented at low cost, that can communicate with low power consumption, etc. is required. Further, as one use case of MTC UE, when performing communication while being fixed or statically installed in a building (e.g., a building) it is assumed. In this case, there is always less likely radio quality of the MTC UE, usually of the UE, which generally have a mobility compared to (eg, mobile phone, smart phone, tablet computer, a notebook personal computer (notebook PC)) technology for coverage improvement is needed. As the function restriction for cost reduction, for example, the maximum transmission power is small, the number of receiving antennas is small (eg, 1 single receive antenna only), high-order modulation (eg, 64 quadrature amplitude modulation (64QAM)) does not support, the available radio bandwidth narrowband (eg, 1.4 MHz) is, and the like are considered, thereby the maximum transmission rate of the MTC UE is reduced.
[0004]
　Therefore, In 3GPP, communication characteristics of the MTC UE that are normally expected to be inferior to that of the UE (i.e., coverage) improve (Improve) or enhance (* Enhance) standardization of technology for has been performed (Non-patent Document 1). Hereinafter, an example of a technology for improving the coverage of the MTC UE being considered in 3GPP. Note that coverage enhancement techniques (coverage enhancement) for the MTC UE described below, can also be referred to as processing for improving or enhancing the communication characteristics or communication quality of MTC UE. The UE to apply these special coverage enhancement techniques state, coverage improvement mode (Coverage Enhancement (CE) Mode), coverage expansion mode (Coverage Extension (CE) Mode), enhanced coverage mode (Enhanced Coverage Mode ( ECM)), or it is called the extended coverage mode (extended coverage mode (ECM)).
[0005]
　Characteristics are improved by the coverage improvement technique (detection characteristics in other words the wireless base station (evolved NodeB (eNB))) the reception characteristics, Physical Random Access Channel (PRACH) transmission characteristics of the preamble of Physical Broadcast Channel (PBCH), Physical Downlink reception characteristics Control Channel (PDCCH), transmission characteristics of the reception characteristic of the Physical Downlink Shared Channel (PDSCH), transmission characteristics of the Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), and the like. PBCH is a downlink broadcast channel used for transmitting the cell common broadcast information by eNB. PRACH is a physical uplink channel used for initial access to the eNB by UE (ie, random access). The PDCCH, for example, the scheduling information of the downlink data by the eNB (DL assignment), and a downlink physical channel used for transmitting the radio resource allocation information of uplink data (UL grant). PDSCH is a downlink physical channel used for system information and data received by the UE. PUSCH is a physical uplink channel used for data transmission by UE.
[0006]
　One of the process that is being considered to improve the reception characteristics of the PBCH is to repeat the transmission of the notification information by a predetermined number of times extra PBCH than normal (see Non-Patent Document 2). One of the processes has been studied to improve the transmission characteristics of the PRACH is to repeat the transmission of the PRACH (i.e. preamble) a predetermined number of times (see Non-Patent Document 3). The reception characteristics of the PDSCH, and one of the processing that has been studied to improve the transmission characteristics of the PUCCH and PUSCH is to PDSCH over a plurality subframes repeated PUCCH, and a PUSCH transmission (non-patent see reference 4). Furthermore, one of the processing that has been studied to improve the reception characteristics of the M-PDCCH is a PDCCH that transmits the L1 / L2 control information for MTC UE repeatedly transmits the M-PDCCH over a plurality subframes it is. By these processes, it is expected that normally be degraded from UE to improve the communication characteristics of the MTC UE expected. In the case where downlink data are scheduled by the repeated transmission of the M-PDCCH, the data is considered to be transmitted in sub-frame after the sub-frame is the last repeat transmission of M-PDCCH is performed . Further, the downlink control information contained in the M-PDCCH (DL Control Information), has also been considered to include the number of repetitions of the M-PDCCH (number of repetitions that will be actually performed).
[0007]
　Transmitting the repeat count and the reception number of iterations required to improve the communication characteristics, depending on where the MTC UE is installed, it depends on the propagation loss between each MTC UE and eNB (pathloss). Therefore, coverage improved technique provides a plurality of coverage improved level (coverage enhancement (CE) levels). Coverage improved level (coverage enhancement (CE) levels) is, enhanced coverage levels, coverage extension levels, there extended coverage levels, or repetition levels (eg, PRACH repetition levels) sometimes called. Further, between the CE level and Repetition level sometimes one-to-one relationship or a predetermined relative relationship, it is set in advance.
[0008]
　For example, coverage improvement techniques typically coverage (normal coverage, zero coverage extension) was added to provide three CE levels. A plurality of CE levels are associated with different transmission repetition frequency and receiving number of repetitions each other. Transmitting the repeat count and the received number of iterations used in high CE level is larger than those used in low CE level. Each MTC UE is larger propagation loss between the MTC UE and eNB is assigned to a high CE level. In some implementations, MTC UE measures the estimated propagation loss between the received power (Reference Signal Received Power (RSRP)) or MTC UE and eNB of the reference signal from the eNB, the measured RSRP or propagation determine the CE level required based on the loss (estimated), and transmits a random access preamble (RACH) preamble according to the maximum transmission number of iterations associated with the determined CE level (see Patent Document 1) .
CITATION
Patent Document
[0009]
Patent Document 1: International Publication No. WO 2015/021315
Non-patent literature
[0010]
非特許文献1 : 3GPP TR 36.888 V12.0.0 (2013-06), “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on provision of low-cost Machine-Type Communications (MTC) User Equipments (UEs) based on LTE (Release 12)”, 2013年6月
非特許文献2 : 3GPP R1-135943, Vodafone, “Way Forward on P-BCH for MTC enhanced coverage”, 3GPP TSG RAN WG1 #75, San Francisco, USA, 11-15 November 2013
非特許文献3 : 3GPP R1-135944, Vodafone, “Way Forward on PRACH for MTC enhanced coverage”, 3GPP TSG RAN WG1 #75, San Francisco, USA, 11-15 November 2013
非特許文献4 : 3GPP R1-136001, Vodafone et al. “Way forward on PDCCH, PDSCH, PUCCH and PUSCH for MTC enhanced coverage”, 3GPP TSG RAN WG1 #75, San Francisco, USA, 11-15 November 2013
Summary of the Invention
Problems that the Invention is to Solve
[0011]
　eNB needs to inform the radio resource configuration of the plurality of CE levels for MTC UE to support coverage enhancement techniques. For example, eNB is initial access (ie, random access) by MTC UE idle radio resource configuration about the system information for the MTC UE (ie, System Information Block x-bis (SIB x-bis)), for example, SIB 1-bis or SIB 2-bis, transmitted in the cell, including the. If if it is necessary system information explicitly includes a plurality of radio resource configuration for multiple CE level, the data size of the system information is increased.
[0012]
　One objective to be achieved is the embodiment disclosed herein, the data size necessary to inform a plurality of radio resource configuration from the base station to the wireless terminal for a plurality of coverage improved level (ie, contributes apparatus to reduce the signaling overhead) is to provide a method, and a program. Incidentally, this objective should more embodiments disclosed herein is noted that only one of several objects of it and to achieve. Other objects or problems and novel features will become apparent from the description, or the accompanying drawings of this specification.
Means for Solving the Problems
[0013]
　In a first aspect, the base station includes a memory, and at least one processor coupled to said memory. Wherein the at least one processor is configured to transmit a first value associated with the normal coverage or first coverage improvement level for the first radio resource configuration information element and the information about the conversion factor, the wireless terminal It is. The value of the conversion factor obtained from the information on the conversion factor, to derive a second value associated with a second coverage improvement level for the first radio resource configuration information element from said first value used by the wireless terminal.
[0014]
　In a second aspect, a method in a base station, a first value associated with the normal coverage or first coverage improvement level for the first radio resource configuration information element and the information about the conversion factor, the wireless terminal It includes transmitting to. The value of the conversion factor obtained from the information on the conversion factor, to derive a second value associated with a second coverage improvement level for the first radio resource configuration information element from said first value used by the wireless terminal.
[0015]
　In a third aspect, the radio terminal includes a memory, and at least one processor coupled to said memory. Wherein the at least one processor is configured to perform at least one module. Wherein the at least one module includes a receiving module and a calculation module. The receiving module, a normal first value associated with a coverage or first coverage improvement level for the first radio resource configuration information element, and is configured to receive from the base station. Said computing module, by converting the first value using the value of the conversion factor, deriving a second value associated with a second coverage improvement level for the first radio resource configuration information element It is configured to.
[0016]
　In a fourth aspect, a method in a wireless terminal, (a) to the normal first value associated with a coverage or first coverage improvement level for the first radio resource configuration information element is received from the base station , and (b) by converting the first value using the value of the conversion factor, deriving a second value associated with a second coverage improvement level for the first radio resource configuration information element to it, including the.
[0017]
　In a fifth aspect, the program includes the when loaded into a computer, instructions for performing the method according to the second or fourth aspects described above to a computer (software code).
Effect of the invention
[0018]
　According to the embodiments described above, it contributes to reducing multiple data size required multiple radio resource configuration from the base station to inform the wireless terminal for coverage improvement level (ie, signaling overhead) the device, method, and it is possible to provide a program.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
It is a diagram illustrating a configuration example of a wireless communication network according to FIG. 1 with some embodiments.
[2] is a sequence diagram showing an example of a transmission operation of system information according to the first embodiment.
3 is a diagram showing an example of a repeated transmission of the RACH preamble.
Is a diagram illustrating an example of FIG. 4 the value of the radio resource configuration information element for multiple CE levels.
5 is a flowchart illustrating an exemplary operation of the wireless terminal according to the first embodiment.
6 is a diagram showing a first example of a calculation for deriving the radio resource configuration information element by the radio terminal according to the first embodiment.
7 is a diagram showing a second example of calculation for deriving the radio resource configuration information element by the radio terminal according to the first embodiment.
8 is a diagram showing a third example of calculation for deriving the radio resource configuration information element by the radio terminal according to the first embodiment.
9 is a diagram showing a fourth example of calculation for deriving the radio resource configuration information element by the radio terminal according to the first embodiment.
10 is a diagram showing an example of a random access procedure according to the first embodiment.
11 is a block diagram showing a configuration example of a radio terminal according to some embodiments.
Is a block diagram showing an exemplary configuration of a base station according to FIG. 12 with some embodiments.
DESCRIPTION OF THE INVENTION
[0020]
　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.
[0021]
　A plurality of embodiments described below can can either be carried out independently, also be implemented in appropriate combination. These several embodiments have different novel features together. Accordingly, the plurality of embodiments, contribute to solving the different purpose or task to each other, which contributes to achieve different effects from each other.
[0022]
　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.
[0023]

　FIG 1 shows a configuration example of a wireless communication network according to some embodiments including the present embodiment. In the example of FIG. 1, a wireless communications network includes one or more wireless terminals (ie, MTC UE) 1 and a base station (eNB) 2. Each MTC UE1 has at least one radio transceiver, and is configured to perform cellular communications with the eNB2. eNB2 manages cell 21, and is configured to perform each of the cellular communication for multiple MTC UE1 using cellular communication techniques (eg, Evolved Universal Terrestrial Radio Access (E-UTRA) technology).
[0024]
　eNB2 shown in FIG. 1 may be a Centralized Radio Access Network (C-RAN) Baseband Unit used in the architecture (BBU). In other words, eNB2 shown in FIG. 1 may be a RAN node connected to one or more Remote Radio Head (RRH). In some implementations, eNB2 as BBU is responsible for digital baseband signal processing control plane processing and user plane. Meanwhile, RRH is responsible for analog Radio Frequency (RF) signal processing (eg, frequency conversion and signal amplification). Incidentally, C-RAN may also be referred to as the Cloud RAN. Further, BBU may also be referred to as a Radio Equipment Controller (REC) or Data Unit (DU). The RRH, Radio Equipment (RE), Radio Unit (RU), or sometimes referred to as Remote Radio Unit (RRU).
[0025]
　In the example of FIG. 1, MTC UE Ia, in order to away the distance from eNB2 compared to MTC UE1B, larger radio quality propagation loss is to degrade envisioned. MTC UE1C is installed in a building (e.g. building), it is assumed that the radio quality is deteriorated as compared with the case of being installed outdoors. Further, if each MTC UE1, voice and UEs performing human type communication web browsing, etc., for example, when having only smartphones and tablet computers, capacity or function limited compared to, more pronounced deterioration in radio quality of It is expected to be. Thus, MTC UE1 according to the present embodiment supports the coverage improvement techniques described above.
[0026]
　As already explained, in order to improve cell coverage on the downlink (DL), the repetition of DL transmission, for example, may be system information, repeatedly sending the M-PDCCH, and PDSCH used. In order to improve the cell coverage of the uplink (UL), the repetition of UL transmission can RACH preamble, PUCCH, and the repeated transmission of the PUSCH is used.
[0027]
　MTC UE1 may support multiple CE modes (or ECMs). In some implementations, MTC UE1 may support different CE modes (or ECMs) for CE modes (or ECMs) and RRC_CONNECTED state for the RRC_IDLE state. Additionally or alternatively, MTC UE1 may be support multiple CE modes (or ECMs) for RRC_IDLE state, even support multiple CE modes (or ECMs) for RRC_CONNECTED state good. In some implementations, a plurality of Coverage improved levels are defined for each CE mode (or each ECM). Additionally or alternatively, in some implementations, the plurality of CE modes provide different coverage improved levels each other.
[0028]
　Figure 2 is an example of a transmission operation of the system information according to the present embodiment (the processing 200) shown. In step 201, eNB2 transmits the system information (eg, SIB1-bis, SIB2-bis) in the cell 21. eNB2 according coverage improvement set for the DL of the cell 21, system information (SIB1bis, SIB2-bis) may be repeatedly transmitted a.
[0029]
　The system information transmitted in step 201, explicitly or implicitly indicate information that coverage improvement technology (Coverage enhancement solution) is supported by the cell, and control information necessary for coverage improvement technology (Coverage enhancement configuration ) encompasses. In particular, the system information is associated with a normal coverage (normal coverage, zero coverage extension), or first increase coverage (CE) level (eg, CE level 1) for the first radio resource configuration information element (IE) value (hereinafter referred to as the "base value (base value)") encompasses. The first radio resource configuration IE is a necessary IE to be set to a different value for each CE level. For example, the first radio resource configuration IE is, UL message is repeatedly transmitted in a random access procedure, UL physical channels, DL message, and may relate to at least one of the DL physical channel.
[0030]
　In some implementations, the first radio resource configuration IE may include at least one of a plurality of IEs relating listed RACH set below:
· NumberOfRA-preambles;
· MaxNumPreambleAttemptCE;
· EnuyuemuaruipietitionPerPreambleAttempt;
· ra- ResponseWindowSize;
· mac-ContentionResolutionTimer;
· MaxHARQ-Msg3Tx; and
· numRepetitionPerRA-Response.
[0031]
　"NumberOfRA-Preambles" IE indicates the total number of random access preamble (RACH preamble) that can be used for contention based random access. "MaxNumPreambleAttemptCE" IE indicates the maximum number of attempts of PRACH attempt (CE level each). "NumRepetitionPerPreambleAttempt" IE indicates the number of repetitions of the preamble transmission per PRACH attempt (CE per level). "Ra-ResponseWindowSize" IE shows a random access (RA) · response window duration (duration). "Mac-ContentionResolutionTimer" IE, the third message of the random access procedure (Msg3), i.e. the reception of Medium Access Control (MAC) Contention Resolution message for RA Contention Resolution from eNB2 after sending the RRC Connection Request message to the eNB2 the timer value of the MAC contention resolution timer for waiting for the show. "MaxHARQ-Msg3Tx" IE, the third message of the random access procedure (Msg3), i.e. RRC Connection Request message, the Hybrid Automatic Repeat Request indicating the maximum number of (HARQ) retransmissions (retransmissions). "NumRepetitionPerRA-Response" IE, a second message of the random access procedure (Msg2), i.e. the number of repetitions of M-PDCCH transmission to be used for transmission of a random access response (RAR) message (CE level per), or RAR It indicates the number of times of repetition of message transmission. Note that these IE names are exemplary and other names may be used for these IE.
[0032]
　Figure 3 shows an example of a repeated transmission of the RACH preamble to be performed by the MTC UE1 supporting coverage enhancement techniques. In the example of FIG. 3, MTC UE1 is once repeated preamble transmission of 4 times per PRACH attempt on, executes 20PRACH attempt at maximum. MTC UE1 is to increase the transmission power of the RACH preamble to initiate the next attempt in accordance with one of the failure of the attempt and power ramping scheme.
[0033]
　Figure 4 shows an example of values ​​of radio resource configuration information element for multiple CE levels. In the example of FIG. 4, the value of "maxNumPreambleAttemptCE" IE associated with the least CE level (ie, CE level 1) is 20, the value of "numRepetitionPerPreambleAttempt" IE is 4. This corresponds to the example shown in FIG. On the other hand, the higher the CE level, number of repetitions of the preamble transmission maximum number of attempts and PRACH attempt per PRACH attempt to both increase. That is, the value of "maxNumPreambleAttemptCE" IE associated with CE level 2 is 60, the value of "numRepetitionPerPreambleAttempt" IE is 10. Furthermore, the value of "maxNumPreambleAttemptCE" IE associated with CE level 3 is 120, the value of "numRepetitionPerPreambleAttempt" IE is 20.
[0034]
　In some implementations, the first radio resource configuration IE may include at least one of a plurality of IEs relating listed PRACH configuration below:
· prach-ConfigIndex; and
· prach-FreqOffset.
[0035]
　"Prach-ConfigIndex" IE indicates the value for MTC UE1 to define should when transmitting a random access preamble within a frequency / time grids (ie, R_Slot). "Prach-FreqOffset" IE indicates the frequency offset value for identifying the RACH access available physical resource blocks (Physical Resource Block (PRB)).
[0036]
　3GPP specification defines a set or one-dimensional array of values ​​of a predetermined number that can be set in each radio resource configuration IE (eg, 8 pieces). These values ​​are arranged, for example, ascending or descending order, each value associated with the index value of the order of ascending or descending order. Therefore, the radio resource configuration IE indicates the index value representing one of the values ​​contained in these sets or one-dimensional array. For example, in the 3GPP Release 12, RA response window size is in units of subframes can be set to a value of eight of 2,3,4,5,6,7,8, and 10 sub-frames. Thus, "ra-ResponseWindowSize" IE has a 3 bit length, indicating the value of any of these eight index value of 3 bits.
[0037]
　MTC UE1, the first radio resource configuration IE normal coverage (zero coverage extension, CE level 0) for the or the first CE level (eg, CE level 1) the basal value associated with received from eNB2, the other CE level for the first radio resource configuration IE (second CE level (eg, CE level 2)) is derived from the basic value received value (second value) associated with the. Thus, MTC UE1 does not need to receive additional IE that indicates a second value associated with the second CE level for the first radio resources configuration IE explicitly from eNB2.
[0038]
　More specifically, MTC UE1 is converted factors to derive a second value associated with the basal values ​​received from eNB2 to the second CE level (eg, CE level 2) of the (conversion factor) use the value. Conversion factor may be simply expressed as factor. To support the derivation of the second value in the MTC UE1, in some implementations, eNB2 is in the system information transmitted in step 201 of FIG. 2, it may further include a value of the conversion factor. Alternatively, in some implementations, eNB2 is information for deriving the value of indirectly indicates information or conversion factor value of the conversion factor, in the system information transmitted in step 201 of FIG. 2 in addition it may be included in the. For example, information indicating the value of the conversion factor indirectly may be an index for designating any one of the values ​​from a set comprising a plurality of candidate values ​​determined in advance. For example, information for deriving the value of the conversion factor may comprise one or more parameters are substituted into equation predetermined conversion factor. That, eNB2 is information about the conversion factor (eg, the value of the conversion factor per se, information indicating the value of the conversion factor indirectly, information for deriving the value of the conversion factor) may be transmitted to the MTC UE1 to . Information about the conversion factor is used by the MTC UE1 to obtain the value of the conversion factor. In this case, the procedure derived (calculated) conversion factor and a second value for the use of this explicit a second value associated with the CE level for one or more wireless resources configuration IE from eNB2 to MTC UE1 is defined as data size of the information about the conversion factor is smaller than the data size necessary to transmit the.
[0039]
　Prior to step 201, eNB2 may calculate the value of the conversion factor that is sent to the MTC UE1. Specifically, eNB2 is 1 or more second CE level (eg, CE levels 1-3) and first determines the value of radio resource configuration IE, determined IE values ​​for each the basic value of the first radio resources configuration IE value of the conversion factor may be calculated for each second CE level using (eg, IE value for CE level 0).
[0040]
　In other implementations, MTC UE1 is the default value of the conversion factor is configured to previously stored in memory, if the conversion factor from eNB2 is not transmitted explicitly, second from the basic value of the first radio resource configuration IE it may be using the default values ​​to derive the values.
[0041]
　Figure 5 is a flow chart showing an example of the operation of the MTC UE1 (the processing 500). In step 501, MTC UE1 receives system information including the eNB2 basic value for the first radio resource configuration IE. As already explained, the basic value for the first radio resource configuration IE is usually coverage (zero coverage extension) or the first CE level (eg, CE level 1) a first value of the radio resources configuration IE associated it is. The system information may further include a conversion factor used to derive a second value associated with the second CE level for the first radio resources configuration IE from the base value.
[0042]
　In step 502, MTC UE1, by conversion using the normal coverage (or first CE level) the first value of the conversion factor basic value of the radio resources configuration IE associated with a second CE level deriving a value of the first radio resources configuration IE associated with. For example, the first radio resource configuration IE includes one or more RACH setting IE (eg, ra-ResponseWindowSize, and mac-ContentionResolutionTimer) a. In this case, MTC UE1 is a normally associated with the coverage (or first CE level) to one or more RACH configuration IE basal values ​​from the first CE level associated with (or second CE level) using the value of the conversion factor to derive a value of 2.
[0043]
　MTC UE1 is determined CE level required based on the estimated propagation loss measured by, measured RSRP or propagation loss between the received power (RSRP) or MTC UE1 and eNB2 of the reference signal from eNB2 it may be. In step 503, if the MTC UE1 requires second CE level, MTC UE1 is the first radio resources configuration IE, which is derived in step 502 (eg, ra-ResponseWindowSize, and mac-ContentionResolutionTimer) according a value of 2, it performs a random access procedure.
[0044]
　Subsequently below, some examples of procedures that second value is derived (calculated) by using the several examples of the conversion factor, and the conversion factor from the basic value of the radio resources configuration IE is described. In the first example shown in FIG. 6, the conversion factor represents the multiplier (multiplier factor). Further, the in the first example, the value of one conversion factor (multiplier) is associated with a second CE levels for two or more radio resource configuration IE (eg, ra-ResponseWindowSize, and mac-ContentionResolutionTimer) It is also used to derive a value of 2 or more. Thus, the in the first example, eNB2, instead of transmitting the two or more values ​​associated with the second CE levels for two or more radio resource configuration IE, by transmitting the value of one conversion factor good. Thus, the first example, it is possible to reduce the data size required to inform the plurality of radio resource configuration for multiple CE level from the base station to the wireless terminal. The conversion factor of the first example, the scaling factor (factor), Factor (Coefficient), or may also be referred to as scaling factor.
[0045]
　In detail, in the example of FIG. 6, MTC UE1 usually coverage value of "ra-ResponseWindowSize" IE and "mac-ContentionResolutionTimer" IE for (ie, zero coverage extension or CE level 0) in SIB from eNB2 receiving (601). In Figure 6, a RA response window size for the normal coverage (ra-ResponseWindowSize) is 2 subframes (sf2), usually contention resolution timer length (mac-ContentionResolutionTimer) is 8 subframes for coverage it is a (sf8).
[0046]
　MTC UE1 further receives three CE levels (CE level 1, 2, 3) three conversion factors associated with (ie, multiplier) values ​​from eNB2 (602). In Figure 6, the value of the conversion factor for the CE level 1, 2, and 3 (multiplier) are each 2, 3, and 4. Incidentally, MTC UE1 is only the value of conversion factor corresponding to one CE level required of the three CE levels may receive from eNB2.
[0047]
　MTC UE1 typically multiplies the value of each converted into factor of two or more IE value (601) (multiplier) for the coverage (603). Thus, MTC UE1 can derive a value of 2 or more IE for CE level 1, 2 or 3 (604). Incidentally, MTC UE1 can only be calculated value corresponding to one CE level required of the three CE levels.
[0048]
　In the second example shown in FIG. 7, IE values ​​for two or more CE level using the value of a single conversion factor can be calculated. That, MTC UE1 is not only to calculate the second second value of the radio resources configuration IE associated with CE level using the value of the basic value and the conversion factor of the radio resources configuration IE, the basal value further calculating the third third of the value of the wireless resources configuration IE associated with CE level using the value of the conversion factor. Thus, the in the second example, eNB2, instead of transmitting the second and 2 or more values ​​associated with the third CE level for the first radio resource configuration IE, and a value of one conversion factor it may be transmitted. Thus, the second embodiment can reduce the data size necessary to inform a plurality of radio resource configuration for multiple CE level from the base station to the wireless terminal.
[0049]
　In detail, in the example of FIG. 7, MTC UE1 receives normal coverage value of "ra-ResponseWindowSize" IE for (ie, zero coverage extension or CE level 0) from eNB2 in SIB (701). In Figure 7, a RA response window size for the normal coverage (ra-ResponseWindowSize) is 2 subframes (sf2).
[0050]
　MTC UE1 further, eNB2 values ​​of three CE levels (CE level 1, 2, 3) 1 single conversion factor used to determine the IE value for (ie, basic multiplier (base multiplier factor)) received from the (702). In Figure 7, the value of the conversion factor (basic multiplier) is two.
[0051]
　MTC UE1 multiplies the value of the conversion factor (basic multiplier) to the value of the radio resources configuration IE for normal coverage (701) (703). Thus, MTC UE1 can derive the IE value for CE Level 1 (704). Furthermore, when obtaining the IE value for CE level 2, MTC UE1 multiplies the value of the conversion factor (basic multiplier) to IE value for CE level 1. That is, in the example of FIG. 7, the value of the conversion factor (basic multiplier) is usually directly or indirectly specify the scale ratio between the IE value and two or more CE level IE value for coverage. Thus, MTC UE1 can be based on the value of one conversion factors (basic multiplier), to calculate the IE values ​​for two or more CE level.
[0052]
　In the third example shown in FIG. 8, the conversion factor represents an offset. The In a third example, as in the first example described above, one conversion factor value of (offset) is more than one radio resource configuration IE (eg, ra-ResponseWindowSize, and mac-ContentionResolutionTimer) second for It is also used to derive two or more values ​​associated with the CE level. Accordingly, examples of the third, as in the first example described above, it is possible to reduce the data size necessary to inform a plurality of radio resource configuration for multiple CE level from the base station to the wireless terminal it can.
[0053]
　In detail, in the example of FIG. 8, MTC UE1 usually coverage value of "ra-ResponseWindowSize" IE and "mac-ContentionResolutionTimer" IE for (ie, zero coverage extension or CE level 0) in SIB from eNB2 receiving (801). 8, an RA response window size for the normal coverage (ra-ResponseWindowSize) is 2 subframes (sf2), usually contention resolution timer length (mac-ContentionResolutionTimer) is 8 subframes for coverage it is a (sf8).
[0054]
　MTC UE1 further receives the value of the three CE levels (CE level 1, 2, 3) three conversion factors associated with (ie, offset) from eNB2 (802). 8, the value of the conversion factor for the CE level 1, 2, and 3 (offset) are respectively 2, 4 and 6,. Incidentally, MTC UE1 is only the value of conversion factor corresponding to one CE level required of the three CE levels may receive from eNB2.
[0055]
　MTC UE1 usually adds the value of each converted into factor of two or more IE value (801) (offset) for the coverage (803). Thus, MTC UE1 can derive a value of 2 or more IE for CE level 1, 2 or 3 (804). Incidentally, MTC UE1 can only be calculated value corresponding to one CE level required of the three CE levels.
[0056]
　In the fourth example shown in FIG. 9, as in the second example described above, IE values ​​for two or more CE level using the value of a single conversion factor can be calculated. Thus the fourth example, similarly to the second example described above, it is possible to reduce the data size required to inform the plurality of radio resource configuration for multiple CE level from the base station to the wireless terminal . However, in the fourth example, basic offset (base offset) is used as a conversion factor.
[0057]
　In detail, in the example of FIG. 9, MTC UE1 is usually coverage (ie, zero coverage extension or CE level 0) "ra-ResponseWindowSize" SIB value of IE from eNB2 for (eg, SIB2-bis) receiving (901). In Figure 9, a RA response window size for the normal coverage (ra-ResponseWindowSize) is 2 subframes (sf2).
[0058]
　MTC UE1 further receives the value of a single conversion factor used (ie, basic offset) in order to determine the IE values ​​for three CE levels (CE level 1, 2, 3) from eNB2 (902 ). In Figure 9, the value of the conversion factor (basic offset) is 2.
[0059]
　MTC UE1 adds the value of the conversion factor (basic offset) to the values ​​of the radio resources configuration IE for normal coverage (901) (903). Thus, MTC UE1 can derive the IE value for CE Level 1 (904). Furthermore, when obtaining the IE value for CE level 2, MTC UE1 adds the value of the conversion factor (basic offset) to IE value for CE level 1. That is, in the example of FIG. 9, the value of the conversion factor (basic offset) is usually indirectly specify the scale ratio between the IE value and two or more CE level IE value for coverage. Thus, MTC UE1 can be based on the value of one conversion factors (basic offset), calculates the IE values ​​for two or more CE level.
[0060]
　Examples of the 5 is a modification of the first example described above, the conversion factor represents the divisor (divisor factor). The In the fifth embodiment, as in the first example, the value of one conversion factor (divisor) is derived at least two values ​​associated with the second CE levels for two or more radio resources configuration IE It is also used to. In some implementations, MTC UE1 is each of two or more IE values ​​for normal coverage dividing by the value of the conversion factor for each CE level (divisor). Thus, MTC UE1 can derive a value of 2 or more IE for each CE level. Examples of such fifth, IE (eg, maxNumPreambleAttemptCE) that decreases as the CE level becomes higher may be used to determine the value of.
[0061]
　Examples of the 6 is a modification of the second example described above, the conversion factor represents the basic divisor (base divisor factor). The In the sixth example, as in the second example, IE values ​​for two or more CE level using the value of a single conversion factor can be calculated. In some implementations, MTC UE1 divides the IE value for normal coverage conversion factor (ie, basic divisor) by the value of. Thus, MTC UE1 can be based on the value of one conversion factors (basic divisor), calculates the IE values ​​for two or more CE level. Examples of such sixth, IE (eg, maxNumPreambleAttemptCE) that decreases as the CE level becomes higher may be used to determine the value of.
[0062]
　Examples of the 7 is a modification of the first example described above, the conversion factor represents the index (exponent) of the power of an integer m (m are powers). When the conversion factor is a positive integer k, the value of the second radio resource configuration IE is a value obtained basic values ​​of the radio resources configuration IE is multiplied by the multiplication k of m. The value of the power of the bottom m may be defined in the 3GPP specification, and the like. That is, the value of the power of the bottom m may be stored in advance in the memory of the MTC UE1. For example, a power of the base m is 2, when the value of the conversion factor for the CE level 1 is 3, the value of the radio resources configuration IE for the CE level 1, for a normal coverage (CE level 0) of the radio resource configuration base value to a value obtained by multiplying the cube of 2 iE, which is 8 times the value of that is the base value. The In the seventh example, as in the first example, the value of one conversion factor (exponent) is associated with two or more second CE levels for radio resource configuration IE (eg, CE level 1) is also used to derive a value of 2 or more was.
[0063]
　Incidentally, examples of the first to seventh as described above may be modified appropriately. It may also be used different techniques from the first to the sixth example of embodiment to derive a value from a base value by using a conversion factor that second radio resource configuration IE.
[0064]
　For example, in the example of the first to seventh mentioned above, the value of the conversion factor, the multiplication of the basic values ​​of the radio resource configuration IE (ie, index values) specific values ​​are shown (eg, the number of sub-frames), adder, or multiplier for dividing the offset is an index of the divisor, or power. Alternatively, the value of the conversion factor, the multiplication of the basic value its own radio resource configuration IE (ie, index value), the addition or multiplier for dividing the offset, divisor, or even exponent good. For example, the base value itself (ie, the index value) of the radio resources configuration IE may be multiplied by the value of the multiplier as a conversion factor. In this case, specific values ​​represented by the converted index values ​​after (eg, number of sub-frames) are used for each CE level.
[0065]
　Examples of the first to seventh mentioned above may be appropriately combined use. For example, if the value of the plurality of IE with the same conversion factor is calculated, the role of the conversion factor for each IE (ie, the calculation method for deriving the IE value) may have different. For example, the value of the conversion factor to determine the value of certain IE is used as a multiplier for multiplying the value of the conversion factor to determine the value of other IE may be used as an offset for addition .
[0066]
　In some implementations, the value of the conversion factor for determining a second value associated with the CE level of the first radio resource configuration IE includes a second radio that is different from that of the first radio resource configuration IE second value and may be used also associated with a coverage improvement levels for resource configuration IE. For example, MTC UE1 repeats preamble at the second CE level received from eNB2 number (PRACH preamble repetition level) indicating the "numRepetitionPerPreambleAttempt" repetition number of RA response with a value and a second CE level IE (RAR repetition conversion factor to either or both of the values ​​of the "numRepetitionPerRA-Response" IE indicates the level), obtaining a second value associated with the CE level of "ra-ResponseWindowSize" IE and "mac-ContentionResolutionTimer" IE it may be used as. Additionally or alternatively, MTC UE1, the second repetition level value of IE that indicates the (number of repetitions) and the fourth third message of a random access procedure in a CE level (RRC Connection Request message) received from eNB2 either or both of the values ​​of IE indicating the repetition level (repeat number) of the message (Contention Resolution message), as the conversion factor for determining a second value associated with the CE level for "mac-ContentionResolutionTimer" IE it may also be used. In these two examples, PRACH preamble repetition level and RAR repetition
[0067]
　In some implementations, the value of the IE corresponding to the CE level necessary for obtaining the MTC UE1, in addition to the conversion factor may be used other values ​​further. For example, the corresponding signal (preamble, message) may be derived the value of the IE with repetition level (number of repetitions) and the conversion factor. For example, a first CE level (eg, CE level 0) the value of the PRACH preamble repetition level for the second CE level to the value of ra-ResponseWindowSize (eg, CE level 1, 2, or 3) for the multiplying, by further multiplying the value of the conversion factor to this (or addition, division) to may be derived the value of ra-ResponseWindowSize for the second CE level. At this time, the value of the conversion factor may be a value of the interval of the repeat value of the transmission interval of the RACH preamble or repeated transmission of RAR message, (M-PDCCH or PDSCH).
[0068]
　Furthermore, when applying the same transformation factor to the plurality of IE, signals corresponding to (preamble, message) repetition level (repeat number) of and may the be derived the value of the IE with the same conversion factor. For example, a first CE level (eg, CE level 0) the value of the PRACH preamble repetition level for the second CE level to the value of ra-ResponseWindowSize for (eg, CE level 1, 2, or 3) or multiplied by the value of the RAR repetition level, by further multiplying the value of the conversion factor to this (or addition, division) to may be derived the value of ra-ResponseWindowSize for the second CE level. Similarly, the first CE level (eg, CE level 0) the third message (RRC Connection for the second CE level to the value of mac-ContentioResolutionTimer for (eg, CE level 1, 2, or 3) multiplied by either or both of the values ​​of the repetition level values ​​of repetition level of Request message) and the fourth message (Contention Resolution message), further multiplies the same conversion factor to this (or addition by dividing), the the value of mac-ContentioResolutionTimer for 2 CE level may derive.
[0069]
　In some implementations, the value of the conversion factor may be a CE level value. For example, the value of the conversion factor The required CE level (eg, CE level 1) may be a value obtained by converting a value indicating (eg, 1) or which in accordance with a predetermined conversion formula.
[0070]
　In some implementations, some of the CE level of the plurality of CE levels (eg, CE level 1) Derivation of IE values ​​using the conversion factor only with respect to is performed, the remaining CE level (eg, CE level 1 IE values ​​for and CE level 2) is the part of the CE level (eg, may be derived according to a predetermined rule from the IE value for CE level 1). For example, IE value for CE level 2 is twice the value of the IE value for CE level 1, and three times the value of the IE value for IE value of CE level 1 for CE level 3 it may be. Alternatively, IE value for CE level 2 is a value obtained by adding the "Offset +2" in IE value for CE level 1, IE value IE for CE level 1 for CE level 3 it may be a value obtained by adding the "offset +3" to the value. Alternatively, repetition level difference of (number of repetitions) between CE level (eg, ratio, difference) IE value using the corresponding value in may be derived. For example, if the repetition level of CE level 1 is 2, repetition level of CE level 2 is 4, the value of the IE CE level 2 is set to 4/2 times the value, that is twice the value of the value of the CE level 1 it may be.
[0071]
　The first was described above, in the third, of the fifth, and seventh, the value of one conversion factor is set for every two or more radio resource configuration IE (or used) shows an example. Second, the fourth, and the sixth example, the value of one conversion factor is set for every two or more CE level (or used) shows an example. Instead of them, in some implementations, the value of one conversion factor may be set to the radio resource for each configuration IE and each CE level (or use). In this case, conversion factor, preferably the bit length of the IE indicating a conversion factor is defined to be smaller than the bit length of the radio resource configuration IE.
[0072]
　Figure 10 is a diagram showing an example (process 1000) of a random access procedure according to the present embodiment. In step 1001, MTC UE1 reception quality (eg, RSRP) of a signal from eNB2 measurements, or a CE level required based on the UE1 and the measurement value of the propagation loss between the eNB2 (estimate) determining (estimated).
[0073]
　In step 1002, MTC UE1 is coverage enhancement technique corresponding to the determined CE level while applying (eg, repeated transmission of the system information (SIB)), receives the system information (SIB) transmitted from eNB2. The system information, along encompasses normal basal values ​​associated with the coverage or first CE level (eg, CE level 1) for the first radio resource configuration IE (eg, 1 or more RACH setting IE) further includes information about the conversion factors to derive a value of the first radio resources configuration IE associated with a second CE level (eg, CE level 2). As already explained, the information about the conversion factor may be, for example, comprise the value itself of the conversion factor is information for deriving the value of indirectly indicates information or conversion factor value converted factor it may be.
[0074]
　In step 1003, MTC UE1 converts using conventional coverage (or first CE level) the first value of the conversion factor basic value of the radio resources configuration IE associated with. The value of the conversion factor can be obtained from the information about the conversion factor received from eNB2. Thus, MTC UE1 derives a first value of the radio resources configuration IE associated with the required CE level determined.
[0075]
　Thereafter, MTC UE1 is in accordance with the first value of the radio resource configuration IE (eg, 1 or more RACH setting IE) derived performs a random access procedure (step 1004 to 1006).
[0076]
　In step 1004, MTC UE1 is determined (estimated) was CE level (eg, CE level 1) if not successful random access reaches the maximum number of attempts RACH preamble for the next CE level (eg, CE level 2 ) using a setting for, may start the transmission of the RACH preamble. In this case, MTC UE1 is set corresponding to the next CE level (eg, CE level 2), for example, a value of "ra-ResponseWindowSize" IE and "mac-ContentionResolutionTimer" IE, and derive the time of the CE level change may be, it may have been derived collectively a value corresponding to the pre-multiple CE levels.
[0077]
　Incidentally, MTC UE1 may start measuring the RA response window according to the first or last after 3 subframes from "ra-ResponseWindowSize" IE of repeatedly transmitted within one trial of RACH preamble transmission in step 1004. "Ra-ResponseWindowSize" IE is, MTC UE1 indicates the time to wait for the reception of the random access response in step 1006 (RAR) after transmitting the RACH preamble in step 1004. Further, MTC UE1 may start measuring the MAC contention resolution timer according repeating transmission of the first or last one from "mac-ContentionResolutionTimer" IE in the third message of the random access procedure (Msg3). "Mac-ContentionResolutionTimer" IE is, MTC UE1 indicates the time to wait for reception of Contention Resolution message (and confirmation of contents) after sending the third message (Msg3).
[0078]
　In step 1005, eNB2 detects the random access transmitted from MTC UE1 (RA) preamble (RACH preamble). For example, eNB2 determines CE level of MTC UE1 based on the radio resource RA preamble is detected. Then, eNB2 includes a plurality of IE corresponding to CE level of MTC UE1 which is determined according to the value of (eg, "numRepetitionPerPreambleAttempt" IE, "ra-ResponseWindowSize" IE), the repeated transmission of repeated reception and RA response RA preamble performing an operation for the coverage improvement comprising. In some implementations, eNB2, based on the value of the conversion factor for the determined MTC UE1 the CE level may be calculated values ​​of a plurality of IE corresponding to CE level of the MTC UE1. In some other implementations, eNB2, by referring to the look-up table storing values ​​of a plurality of IE for each CE level, corresponding to the CE level of MTC UE1 it is judged more the value of the IE may be calculated.
[0079]
　In the above example, for existing wireless parameters in the random access procedure (IE of RRC message), it described a method of deriving a value corresponding to each CE level. Similarly, the method of deriving the above may be used to derive a value corresponding to the CE level for the newly defined by radio parameter (IE of RRC message) for coverage enhancement techniques . For example, a method of deriving the above, IE (ie, maxNumPreambleAttemptCE) indicating the maximum number of attempts RACH preamble per CE level, and RACH IE (ie, numRepetitionPerPreambleAttempt) indicating the maximum number of repetitions of each trial preamble be applied to good. In this case, eNB2 sends lowest CE levels (eg, CE level 1) to the IE value corresponding to the system information, UE1 in one or more higher CE level (eg, CE level 2 or higher) the corresponding IE value may be derived using the conversion factors mentioned above.
[0080]
　Random access procedure described above, UE not only initial access when consisting RRC_IDLE state in RRC_CONNECTED state (Initial Access), may be applied to random access in RRC_CONNECTED state. Furthermore, in the case of random access by the execution instruction from eNB2 (PDCCH Order), the execution instruction may include at least one of the basic values ​​and conversion factors.
[0081]
　Then hereinafter, a configuration example of the MTC UE1 and eNB2 according to the present embodiment. Figure 11 is a block diagram showing a configuration example of a MTC UE1. Radio Frequency (RF) transceiver 1101 performs an analog RF signal processing to communicate with the eNB2. Analog RF signal processing performed by the RF transceiver 1101 includes a frequency up-conversion, the frequency down-conversion, and amplification. RF transceiver 1101 is coupled to antenna 1102 and the base band processor 1103. That, RF transceiver 1101 receives the modulated symbol data (or OFDM symbol data) from the baseband processor 1103, generates a transmission RF signal and provides a transmit RF signal to the antenna 1102. Also, RF transceiver 1101 to generate a baseband received signal based on the reception RF signal received by an antenna 1102, and supplies it to the baseband processor 1103.
[0082]
　Baseband processor 1103 performs control plane processing and digital baseband signal processing for wireless communication (data plane processing). Digital baseband signal processing, (a) data compression / decompression, (b) segmentation / concatenation of data, generation / decomposition of (c) transmission format (transmission frame), (d) transmission channel coding / decoding , including generation of (e) modulation (symbol mapping) / demodulation, and OFDM symbol data by (f) Inverse Fast Fourier Transform (IFFT) (baseband OFDM signal). On the other hand, the control plane processing, layer 1 (eg, transmission power control), Layer 2 (eg, radio resource management, and hybrid automatic repeat request (HARQ) process), and layer 3 (eg, attach, mobility, and packet communication including communication management signaling) related.
[0083]
　For example, in the case of LTE and LTE-Advanced, a digital baseband signal processing by a baseband processor 1103, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, includes a signal processing of the MAC layer, and a PHY layer But good. Further, the control plane processing by baseband processor 1103, Non-Access Stratum (NAS) protocol, RRC protocol, and may include a process of MAC CE.
[0084]
　Baseband processor 1103, a modem processor that performs digital baseband signal processing (eg, Digital Signal Processor (DSP)) and protocol stack processor for performing control plane processing (eg, Central Processing Unit (CPU), or Micro Processing Unit it may include (MPU)). In this case, the protocol stack processor for performing control plane processing may be shared with an application processor 1104 which will be described later.
[0085]
　The application processor 1104, CPU, MPU, also referred to as a microprocessor or processor cores. The application processor 1104 may include a plurality of processors (multiple processor cores). The application processor 1104 may perform memory 1106 or illustrated which do not result system read from the memory a software program (Operating System (OS)) and various application programs (e.g., the communication application for acquiring metering data or sensing data) by, for realizing various functions of the MTC UE1.
[0086]
　In some implementations, as indicated by the dashed line (1105) in FIG. 11, the baseband processor 1103 and an application processor 1104 may be integrated on a single chip. In other words, the baseband processor 1103 and an application processor 1104 may be implemented as a single System on Chip (SoC) device 1105. SoC devices, sometimes referred to as system Large Scale Integration (LSI) or chipset.
[0087]
　Memory 1106 is a volatile memory or nonvolatile memory, or a combination thereof. Memory 1106 may include a physically independent plurality of memory devices. Volatile memory may be, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM) or a combination thereof. The non-volatile memory, a mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. For example, memory 1106, a baseband processor 1103, an application processor 1104, and may contain accessible external memory device from SoC1105. Memory 1106, within baseband processor 1103, within the application processor 1104, or may include an integrated chip memory device within SoC1105. Furthermore, memory 1106 may include a memory in the Universal Integrated Circuit Card (UICC).
[0088]
　Memory 1106 may store one or more software modules (computer program) 1107 containing instructions and data for processing by the MTC UE1 described in several embodiments described above. In some implementations, the baseband processor 1103 or the application processor 1104, the software modules 1107 and executes from the memory 1106, may be configured to perform processing of MTC UE1 described in the above embodiments good.
[0089]
　Figure 12 is a block diagram showing an exemplary configuration of a base station (eNB) 2 according to the above-described embodiment. Referring to FIG. 12, eNB2 includes an RF transceiver 1201, a network interface 1203, a processor 1204, and memory 1205. RF transceiver 1201 performs an analog RF signal processing for communicating with wireless terminal 1. RF transceiver 1201 may include a plurality of transceivers. RF transceiver 1201 is coupled to antenna 1202 and the processor 1204. RF transceiver 1201 receives the modulated symbol data (or OFDM symbol data) from the processor 1204, generates a transmission RF signal and provides a transmit RF signal to the antenna 1202. Also, RF transceiver 1201 to generate a baseband received signal based on the reception RF signal received by an antenna 1202, and supplies it to the processor 1204.
[0090]
　Network interface 1203 is used to communicate with a network node (eg, Mobility Management Entity (MME) and Serving Gateway (S-GW)). Network interface 1203 may include, for example, a network interface card that complies with the IEEE 802.3 series (NIC).
[0091]
　The processor 1204 performs control plane processing and digital baseband signal processing for wireless communication (data plane processing). For example, in the case of LTE and LTE-Advanced, a digital baseband signal processing by the processor 1204, PDCP layer, RLC layer may include a signal processing of the MAC layer, and the PHY layer. The control plane processing by the processor 1204, S1 protocol, RRC protocol, and may include a process of MAC CE.
[0092]
　Processor 1204 may include multiple processors. For example, the processor 1204 may include a modem processor that performs digital baseband signal processing (eg, DSP) and a protocol stack processor for performing control plane processing (eg, CPU or MPU).
[0093]
　Memory 1205 is constituted by a combination of volatile and nonvolatile memory. Volatile memory is, for example, a SRAM or DRAM, or a combination thereof. The non-volatile memory, for example, MROM, PROM, flash memory, or hard disk drive, or a combination thereof. Memory 1205 may include a storage that is remotely located from the processor 1204. In this case, the processor 1204 may access the memory 1205 via the I / O interfaces that are not network interface 1203 or illustrated.
[0094]
　Memory 1205 may store software modules (computer program) 1206 containing instructions and data for processing by the eNB2 described in several embodiments described above. In some implementations, the processor 1204, the software module 1206 that reads out and executes from the memory 1205 may be configured to perform processing of eNB2 described in the above embodiments.
[0095]
　As described with reference to FIGS. 11 and 12, each of the processors included in the MTC UE1 and eNB2 according to the above embodiment includes instructions for causing the algorithm described with reference to the drawings computer 1 or to run multiple programs. This program is stored using a non-transitory computer readable media of various types (non-transitory computer readable medium), it can be supplied to the computer. Non-transitory computer readable media include with various types of entities (tangible storage medium). Examples of non-transitory computer readable media include magnetic storage media (such as floppy disks, magnetic tape, hard disk drive), magneto-optical recording medium (e.g., magneto-optical disk), Compact Disc Read Only Memory (CD-ROM), CD- R, including CD-R / W, a semiconductor memory (e.g., a mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access memory (RAM)). The program may be provided to a computer using a temporary computer readable media of various types (transitory computer readable medium). Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media, wired communication path such as electrical wires and optical fibers, or via a wireless communication path can provide the program to a computer.
[0096]

　The above-described embodiments have been described mainly radio resource configuration about the random access IE (eg, RACH configuration IE and PRACH configuration IE) with respect. However, techniques for deriving the IE value for a particular CE level using the conversion factor described in the above embodiments, when a radio resource configuration different depending on coverage improvement (CE) level is required it can be widely utilized. Procedures described in the above embodiment, for example, MTC UE1 the RRC_CONNECTED state, UL user data transmission in the PUSCH, the transmission of the L1 / L2 control information in the PUCCH, the system information or DL user data received in the PDSCH, and the values of the radio resources configuration IE required when performing the receiving specific CE level of the L1 / L2 control information in M-PDCCH may be used to derive (eg, transmission (reception) number of repetitions) and .
[0097]
　The above-described embodiments are mainly eNB2 has been described for the case of transmitting the information about the conversion factor system information. However, information about the conversion factor, the signal eNB2 transmits individual control information to the MTC UE1 (eg, RRC signaling, MAC signaling) may be transmitted with. For example, information about the conversion factor may be transmitted from the eNB2 in RRC Connection Reconfiguration messages and MAC Control Element on MTC UE1. Incidentally, if the MTC UE1 receives the information about the conversion factor system information and individual control information, the value of the conversion factor obtained from the information about the conversion factors notified by the individual control information preferentially (i.e., system information the value of the conversion factor obtained from or to be overwritten with) use the value of the conversion factor obtained from individual control information.
[0098]
　Operation of MTC UE1 and eNB2 regarding the derivation of IE values ​​using the conversion factor described in the above embodiment, in order to derive the value of the timer that different lengths depending on the coverage improvement (CE) level is required it may be utilized. Specific examples of a timer using different timer values ​​into a plurality of CE level, for example, (1) control, such as call processing (ie, RRC, NAS) to the associated timer, (2) Layer 2 (ie, PDCP, RLC includes a timer for measuring a timer, and in (3) RRC_IDLE state associated with MAC) control.
[0099]
　For example, the timer of the above-described (1), the timer (ie, the timer T300) which is used to determine the success or failure of the RRC connection establishment may be. MTC UE1 is, RRC Connection Reestablishment Request the timer message from the time of transmitting a (ie, the timer T300) Start response from eNB2 (ie, RRC Connection Setup message or an RRC Connection Reject message) the timer when receiving the a stop.
[0100]
　Additionally or alternatively, the timer in the above (1), the timer (ie, the timer T311) for determining the success or failure of detection of a suitable cell (Suitable cell) may be. MTC UE1 is started the timer from a time point when starting RRC Connection Reestablishment procedure (ie, the timer T311), the timer is stopped when a suitable cell is detected (selected).
[0101]
　Additionally or alternatively, the timer in the above (1), the timer (ie, the timer T304) for determining the success or failure of the handover may be. MTC UE1 is (a i.e. handover indication) including MobilityControlInfo IE RRC Connection Reconfiguration the timer from the time of receiving the message (ie, the timer T304) Start, if completed successfully the random access procedure to the target cell stop the timer.
[0102]
　For example, the timer of the above-described (2) may be a timer which is used to control the MAC layer. Specific examples of a timer that is used to control the MAC layer, discontinuous reception control in UE timer associated with (Discontinuous Reception (DRX)) (eg, OnDurationTimer, drx-InactivityTimer, drx-RetransmissionTimer, HART RTT Timer), scheduling request timer for measuring the period (Scheduling Request (SR)) is inhibited (eg, sr-ProhibitTimer, logicalChannelSR-ProhibitTimer), a timer (eg relating to uplink buffer amount reported (buffer Status report (BSR)), PeriodicBSR -timer, including RetxBSR-timer), and reporting of the remaining amount of uplink transmission power (power Headroom report (PHR) timer associated with) (eg, periodicPHR-timer, the prohibitPHR-timer).
[0103]
　Additionally or alternatively, the timer in the above (2) may be a timer which is used to control the RLC layer. Specific examples of a timer that is used to control the RLC layer detects and sequence used for controlling the timer (T-Reordering) of missing RLC PDU (loss) in the DL data reception, and information (STATUS indicating the reception status of DL data measuring the period during which the transmission of the PDU) is inhibited include a timer (T-StatusProhibit).
[0104]
　Additionally or alternatively, the timer in the above (2) may be a timer which is used to control the PDCP layer. Specific examples of a timer that is used to control the PDCP layer includes a timer (discardTimer) determines whether to discard the unsent data in the UL data transmission.
[0105]
　For example, the timer of the above-described (3) may be a timer used in the process of cell reselection by MTC UE1 in RRC_IDLE state. Specifically, the timer of the above-described (3), the cell duration conditional expression is satisfied for triggering reselection (duration) (ie, T-Reselection) or may be a timer that measures.
[0106]
　Measurement of the above timer is associated with each (the ie trigger) signal repetitions first or last may be initiated from either the transmission of the (message). Alternatively, measurement of the timer may be started from either the first or the last of the recurring received signal associated with each (message).
[0107]
　In the embodiment described above, the wireless terminal 1 may be a non-MTC UE. In other words, the embodiment described above can be widely applied to communication between the UE and the eNB to support coverage enhancement techniques including repeated transmission (or reception).
[0108]
　Furthermore, the above-described embodiments apply, LTE, is not limited to LTE-Advanced and modifications thereof, for communication between the wireless terminal and the base station supporting the coverage improvement techniques in other wireless communication network or system it may be.
[0109]
　For example, the above-described embodiments, Narrow Band has been studied by 3GPP - may be applied to a coverage improvement technology in a system that Internet of Things (NB-IoT). NB-IoT is intended to accommodate the IoT terminal of the low-cost and very low power consumption (e.g. without battery replacement, such as 10 years running) in a cellular network. NB-IoT is studied to reuse objects and in view of the characteristics of the target terminal is very similar to Rel-13 MTC, the 3GPP Release 13 (Rel-13) MTC techniques for NB-IoT ing. Thus, the above-described embodiments may be applied to NB-IoT. Note, Rel-13 MTC UE is transmitting the RACH preamble in the random access, UE in NB-IoT has been studied to transmit a message (eg, contention-based message) instead of the preamble in PRACH. Thus, it has also been studied to a function without the Rel-13 MTC to or Rel-13 MTC improve for NB-IoT introduced into NB-IoT, the above-described embodiment matter the difference It can be applied without NB-IoT.
[0110]
　Furthermore, the above-described embodiments are only examples for the application of technical ideas obtained by the present inventor. In other words, the technical idea is not limited to the embodiments described above, it is needless to say various modifications are possible.
[0111]
　For example, some or all of the above embodiments, can be described as the following notes, not limited to the following.
[0112]
(Supplementary Note A1)
　a base station,
　a memory,
　and at least one processor coupled to said memory,
comprising a
　at least one processor is usually coverage or first for the first radio resource configuration information element a first value associated with a coverage improvement level, and information about the conversion factor, is configured to transmit to the radio terminal,
　the value of the conversion factor obtained from the information on the conversion factor, the first radio wherein the second value associated with a second coverage improvement levels for resource configuration information elements to derive from said first value being used by the wireless terminal,
a base station.
[0113]
(Supplementary Note A2)
　the first radio resource configuration information element includes two or more radio resource configuration information element,
　wherein the second value, the second improvement of the coverage for the two or more radio resource configuration information element comprise two or more values associated with the level,
　the value of the conversion factor, the commonly said two or more values to derive from said first value being used by the wireless terminal,
according to Appendix A1 base stations of.
[0114]
(Supplementary Note A3)
　value of the conversion factor, in addition to the second value, the third value the first being associated with a third coverage improvement level for the first radio resource configuration information element used by the wireless terminal to derive from the value,
the base station according to Appendix A1.
[0115]
(Supplementary Note A4)
　value of the conversion factor, the first value, the second value, and specifying either directly or indirectly the scale ratio between the third value,
the base of statement A3 station.
[0116]
(Supplementary Note A5)
　the value of the conversion factor comprises a multiplier value,
　the second value, said computed by multiplying the multiplier value to the first value,
in any one of Appendices A1 ~ A4 the base station according.
[0117]
(Supplementary Note A6)
　value of the conversion factor includes an offset value,
　said second value, said computed by adding the first of the offset value to the value,
in any one of Appendices A1 ~ A4 the base station according.
[0118]
(Supplementary Note A7)
　value of the conversion factor is also used as the first value associated with the second coverage improvement levels for different second radio resource configuration information element from the radio resource configuration information element,
the base station according to any one of appendices A1 ~ A4.
[0119]
(Supplementary Note A8)
　of the first radio resource configuration information element comprises at least one parameter for random access procedure,
　the at least one parameter,
and available frequencies for the transmission of (a) a random access preamble parameters defining the time resources, (b) a parameter indicating the total number of random access preamble, (c) a parameter indicating the maximum number of transmission attempts of a random access preamble (attempts the), transmission attempts (d) a random access preamble number of repetitions of the random access preamble transmission per, parameter indicating (e) a parameter indicating a random access response window duration (duration), (f) contention resolution timer duration (duration) , ( g) including the maximum number of iterations of the random access response transmitted by the base station, and (h) a parameter indicating the maximum number of retransmissions of the third message in response to receiving the random access response, at least one of,
Appendix A1 the base station according to any one of ~ A7.
[0120]
(Supplementary Note A9)
　at least one processor is further converted to the value of the conversion factor to be transmitted to the radio terminal is calculated using the first value and the second value, which is the calculated the value of the factor is configured to transmit to the wireless terminal,
a base station according to any one of appendices A1 ~ A8.
[0121]
(Supplementary Note B1)
　a wireless terminal,
　a memory,
　and at least one processor coupled to said memory,
comprising a
　at least one processor is configured to perform at least one module,
　said at least one module is
　a normal first value associated with a coverage or first coverage improvement level for the first radio resource configuration information element, a receiving module configured to receive from the base station,
　using the value of the conversion factor by converting the first value Te, a calculation module configured to derive a second value associated with a second coverage improvement level for the first radio resource configuration information element
comprises ,
wireless terminal.
[0122]
(Supplementary Note B2)
　the first radio resource configuration information element includes two or more radio resource configuration information element,
　wherein the second value, the second improvement of the coverage for the two or more radio resource configuration information element comprise two or more values associated with the level,
　the calculation module, wherein is used in common by the value of the conversion factor the value of 2 or more in order to derive from said first value,
according to Appendix B1 wireless terminal.
[0123]
(Supplementary Note B3)
　the calculation module, in addition to the second value, a third value associated with a third coverage improvement level for the first radio resource configuration information element from said first value wherein it is used in common by the value of the conversion factor to derive,
wireless terminal according to Appendix B1.
[0124]
(Supplementary Note B4)
　value of the conversion factor, the first value, the second value, and specifying either directly or indirectly the scale ratio between the third value,
the radio of statement B3 terminal.
[0125]
(Supplementary Note B5)
　the at least one processor, information related to the conversion factor to obtain a value of the conversion factor is configured to receive from the base station,
according to any one of Appendices B1 ~ B4 wireless terminal.
[0126]
(Supplementary Note B6)
　value of the conversion factor comprises a multiplier value,
　the second value, said computed by multiplying the multiplier value to the first value,
in any one of Appendices B1 ~ B5 wireless terminal according.
[0127]
(Supplementary Note B7)
　value of the conversion factor includes an offset value,
　said second value, said computed by adding the first of the offset value to the value,
in any one of Appendices B1 ~ B5 wireless terminal according.
[0128]
(Supplementary Note B8)
　value of the conversion factor is also used as the first value associated with the second coverage improvement levels for different second radio resource configuration information element from the radio resource configuration information element,
wireless terminal according to supplementary note B5.
[0129]
(Supplementary Note B9)
　, wherein said at least one module, further
　wherein the estimation module configured to estimate the coverage improved level to the wireless terminal according,
　the first radio resources associated with the estimated coverage improved level a communication module for communicating with the base station according to the value of the setting information element
comprises a,
　the calculation module, wherein as the value of the estimated coverage improved to the first associated level radio resource configuration information element first calculating a value of 2,
the radio terminal according to any one of appendices B1 ~ B8.
[0130]
(Supplementary Note B10)
　the first radio resource configuration information element comprises at least one parameter for random access procedure,
　the at least one parameter,
and available frequencies for the transmission of (a) a random access preamble parameters defining the time resources, (b) a parameter indicating the total number of random access preamble, (c) a parameter indicating the maximum number of transmission attempts of a random access preamble (attempts the), transmission attempts (d) a random access preamble number of repetitions of the random access preamble transmission per, parameter indicating (e) a parameter indicating a random access response window duration (duration), (f) contention resolution timer duration (duration) , (G) including the maximum number of iterations of the random access response transmitted by the base station, and (h) a parameter indicating the maximum number of retransmissions of the third message in response to receiving the random access response, at least one of,
Appendix wireless terminal according to any one of B1 ~ B9.
[0131]
　This application claims priority based on Japanese Patent Application No. 2015-217963, filed on November 5, 2015, the entire disclosure of which is incorporated herein.
DESCRIPTION OF SYMBOLS
[0132]
1 wireless terminal
(UE) 2 base station
(eNB) 1101 radio frequency (RF) transceiver
1103 baseband processor
1104 application processor
1106 memory
1201 RF transceiver
1204 processor
1205 memory

WE CLAIM

A base station,
　a memory and,
　at least one processor coupled to the memory,
provided with,
　at least one processor is usually coverage or first coverage improvement level for the first radio resource configuration information element a first value associated with, the information about the conversion factor, is configured to transmit to the radio terminal,
　the value of the conversion factor obtained from the information on the conversion factor, the first radio resource configuration information element the used by the wireless terminal a second value associated with a second coverage improved levels to derive from said first value for,
the base station.
[Requested item 2]
　The first radio resource configuration information element includes two or more radio resource configuration information element,
　wherein the second value is associated with said second coverage improvement levels for the two or more radio resource configuration information element two include more values,
　the value of the conversion factor, the commonly said two or more values to derive from said first value being used by the wireless terminal,
a base station according to claim 1 .
[Requested item 3]
　The value of the conversion factor, in addition to the second value, deriving a third value associated with a third coverage improvement level for the first radio resource configuration information element from said first value the are used by the wireless terminal to,
the base station according to claim 1.
[Requested item 4]
　The value of the conversion factor, wherein the first radio resource configuration information element is also used as the value associated with the second coverage improvement levels for different second radio resource configuration information element,
according to claim 1 the base station according to any one of the three.
[Requested item 5]
　Wherein the at least one processor, further wherein the value of the conversion factor to be transmitted to the radio terminal is calculated using the first value and the second value, the value of the computed transform factor wherein being configured to transmit to the radio terminal,
the base station according to any one of claims 1-4.
[Requested item 6]
　A method in a base station,
　a first value associated with the normal coverage or first coverage improvement level for the first radio resource configuration information element and the information about the conversion factor, by sending to the wireless terminal the provided,
　the value of the conversion factor obtained from the information on the conversion factor, from the second of the second of said values first value associated with a coverage improvement level for the first radio resource configuration information element the used by the wireless terminal to derive,
methods.
[Requested item 7]
　The method in the base station A non-transitory computer readable medium storing a program for causing a computer,
　the method comprising the normal coverage or first coverage improvement level for the first radio resource configuration information element a first value associated with the information about the conversion factor comprises transmitting to a wireless terminal,
　the value of the conversion factor obtained from the information on the conversion factor, for the first radio resource configuration information element the second of the second value associated with the coverage improved levels to derive from said first value being used by the wireless terminal, the
non-transitory computer readable media.
[Requested item 8]
　A wireless terminal,
　a memory,
　and at least one processor coupled to said memory,
comprising a
　at least one processor is configured to perform at least one module,
　said at least one module,
　the first Usually coverage or a first value associated with a first coverage improvement level, a receiving module configured to receive from a base station, for the radio resource configuration information element
　of the first using the value of the conversion factor by converting the values, a calculation module configured to derive a second value associated with a second coverage improvement level for the first radio resource configuration information element
comprises,
wireless terminal.
[Requested item 9]
　The first radio resource configuration information element includes two or more radio resource configuration information element,
　wherein the second value is associated with said second coverage improvement levels for the two or more radio resource configuration information element and comprise more than one value,
　the calculation module, the two or more values for use in common the value of the conversion factor to derive from said first value,
the wireless terminal according to claim 8.
[Requested item 10]
　Said computing module, in addition to the second value, a third value associated with a third coverage improvement level for the first radio resource configuration information element to derive from said first value used in common value of the conversion factor,
the wireless terminal according to claim 8.
[Requested item 11]
　Wherein the at least one processor, information related to the conversion factor to obtain a value of the conversion factor is configured to receive from the base station,
the wireless terminal according to any one of claims 8-10.
[Requested item 12]
　The value of the conversion factor is also used as the first value associated with the second coverage improvement levels for different second radio resource configuration information element from the radio resource configuration information element,
to claim 11 wireless terminal according.
[Requested item 13]
　Wherein said at least one module, further
　wherein the estimation module configured to estimate the coverage improved level to the wireless terminal to follow,
　the estimated first associated coverage improvement level of the radio resource configuration information element a communication module for communicating with the base station in accordance with the value
provided with,
　the computing module, the second value as the value of the estimated coverage to the associated first improved level radio resource configuration information element calculations,
wireless terminal according to any one of claims 8-12.
[Requested item 14]
　The first radio resource configuration information element comprises at least one parameter for random access procedure,
　wherein the at least one parameter
defining the available frequency and time resources for the transmission of (a) a random access preamble parameters, (b) a parameter indicating the total number of random access preamble, (c) a parameter indicating the maximum number of transmission attempts of a random access preamble (attempts), (d) random access per transmission attempt of the random access preamble - number of repetitions of the preamble transmission, (e) a parameter indicating a random access response window duration (duration), (f) contention resolution timer duration indicating the (duration) parameter, (g) said base Maximum number of iterations of the random access response transmitted by the station, and (h) a parameter indicating the maximum number of retransmissions of the third message in response to receiving the random access response includes at least one of,
the claims 8 to 13 wireless terminal according to any one.
[Requested item 15]
　A method in a wireless terminal,
　to a normal first value associated with a coverage or first coverage improvement level for the first radio resource configuration information element is received from the base station, and
　the value of the conversion factor by converting the first value using, deriving a second value associated with a second coverage improvement level for the first radio resource configuration information element,
it comprises a method.
[Requested item 16]
　The non-transitory computer readable medium storing a program for causing a method in a wireless terminal to a computer,
　the method comprising
　the normal coverage or first coverage improvement level for the first radio resource configuration information element a first value associated with, receiving from the base station, and
　by converting the first value using the value of the conversion factor, a second coverage for the first radio resource configuration information element deriving a second value associated with the increase level,
comprising a non-transitory computer readable media.