WO2017150601A1 - User device and random access method - Google Patents

Abstract

Provided is a user device for communicating with a base station in a wireless communication system provided with the base station and the user device, wherein the user device is provided with: a selection unit for selecting a random access signal group from among a plurality of random access signal groups by comparing the size of a message transmitted on a prescribed logical channel with a prescribed threshold value, and selecting a random access signal from the random access signal group; and a transmission unit for transmitting the random access signal selected by the selection unit to the base station, the transmission unit transmitting the message on the prescribed logical channel using a resource allocated by a response from the base station to the random access signal.

Description

User device and random access method

The present invention relates to a random access procedure executed between a user apparatus (hereinafter referred to as UE) and a base station (hereinafter referred to as eNB) in a wireless communication system.

In a radio communication system such as LTE, a random access (hereinafter sometimes abbreviated as RA) procedure is executed when a UE establishes a connection with an eNB, or when reconnection (resynchronization) is performed. The RA procedure includes a collision type RA procedure and a non-collision side RA procedure. The collision-type RA procedure can be used for all purposes, and the non-collision-side RA procedure is used for a specific purpose such as handover. Here, the collision type RA procedure is targeted.

In the RA procedure, the UE transmits RA preamble to the eNB, and the eNB returns RA response to the UE. Then, the UE transmits a control message to the eNB using the uplink resource allocated by UL grant in the RA response. This control message is called Message 3 (message 3) (Non-Patent Document 1).

In Message-3, an RRCConnectionRequest message is sent at the time of connection, and an RRCConnectionReestablishmentRequest message is sent at the time of reconnection via CCCH (Common Control Channel), which is a logical channel.

The RRCConnectionRequest message and RRCConnectionReestablishementRequest message are generically called CCCH Service Data Unit (SDU) in the standard specifications. The size of RRCConnectionRequestRRmessage and RRCConnectionReestablishmentRequest message is 48 bits, 8 bits of MAC header are added to this, and the MAC PDU is 56 bits. That is, 56-bit data becomes one Transport block that can be transmitted by the physical layer (PHY), and its size (56 bits) becomes Transport block Size (TBS).

A value larger than 56 bits can be assigned as the TBS of Message IV3. In this case, for example, Padding Buffer Status Report (Padding BSR) is added to the data. In LTE, it is specified that the RA preamble is grouped and the UE performs the RA procedure using the RA preamble selected from the group (Non-Patent Document 2). The eNB can determine whether or not the size of Message 3 is increased depending on the group to which the transmitted RA-preamble belongs, and can notify the UE of the corresponding TBS with RA-response.

Specifically, as described in Non-Patent Document 2, Preamble group A / B is provided. And if Preamble group B exists, if the size of Message 3 is larger than the message size (messageSizeGroupA in RACH-ConfigCommon) set in the system information and the path loss is less than or equal to the predetermined value, Preamble group B RA preamble is selected. Otherwise, RA preamble is selected from Preamble group A.

By the way, there is a mechanism for reducing the amount of signaling for connection by storing the UE context in the eNB / UE when the UE is in an idle state and using the stored UE context when transitioning to the connected state. It is being considered. For example, Non-Patent Document 3 describes an example as solution 18.

In this mechanism, in order to resume RRC connection using the saved UE context, the UE sends a restart request message with Message 3. Since an ID and authentication information used for resuming the connection are added to this message, the message size may exceed the 56 bits of the existing CCCH SDU TBS (for example, Non-Patent Document 4).

Therefore, multiple CCCH SDUs with different message sizes may be specified. When a plurality of CCCH SDUs having different message sizes are defined, the UE transmits CCCH SDUs of different sizes to the eNB according to the procedure. As an example, it is assumed that the UE transmits a normal RRC connection request with a 56-bit TBS and transmits RRC connection resume with a 64-bit TBS.

Conventionally, the message size of CCCH SDU was one (TBS: 56 bits). However, when CCCH SDU with different message size is specified, eNB will assign CCCH by the time of assigning UL grant of Message 3 in RA response. It is necessary to decide the TBS assigned by UL grant considering the size of SDU. However, in the conventional mechanism, since the eNB cannot know the message size of CCCH SDU before sending RA response, the TBS to be assigned by UL grant cannot be determined in consideration of the size of CCCH SDU. For this reason, for example, even if the UE tries to transmit a resume request message, it may occur that TBS is insufficient and cannot be transmitted.

Note that the above-described problem is a problem that may also occur when a control message other than the restart request message is transmitted.

The present invention has been made in view of the above points, and provides a technique for preventing a user apparatus from being unable to transmit a control message due to a lack of uplink resources allocated from a base station in a random access procedure. With the goal.

According to an embodiment of the present invention, in the wireless communication system comprising a base station and a user device, the user device that communicates with the base station,
A random access signal group is selected from a plurality of random access signal groups by comparing the size of a message transmitted on a predetermined logical channel with a predetermined threshold, and a random access signal is selected from the random access signal group. A selection section to select;
A transmission unit for transmitting the random access signal selected by the selection unit to the base station,
The transmission unit transmits the message on the predetermined logical channel using a resource allocated by a response from the base station to the random access signal.

Further, according to an embodiment of the present invention, in the wireless communication system comprising a base station and a user device, the user device that communicates with the base station,
A receiving unit that receives information on a correspondence relationship between a size of a message transmitted on a predetermined logical channel and a resource of a random access signal from the base station;
A selection unit that selects a resource corresponding to the size of a message transmitted on the predetermined logical channel from the information on the correspondence;
There is provided a user apparatus comprising: a transmission unit that transmits a random access signal to the base station using the selected resource.

According to the embodiment of the present invention, there is provided a technique for preventing a user apparatus from being unable to transmit a control message due to a lack of uplink resources allocated from a base station in a random access procedure.

It is a block diagram of the communication system in embodiment of this invention. It is a figure which shows a random access procedure. It is a figure which shows the process sequence of the context holding | maintenance system example 1. FIG. It is a figure which shows the process sequence of the context holding | maintenance system example 1. FIG. It is a figure which shows the process sequence of the context holding | maintenance system example 2. FIG. It is a figure which shows the example of a specification change in Example 1. FIG. It is a figure which shows the example of a specification change in Example 1. FIG. 10 is a flowchart illustrating a processing procedure in the second embodiment. It is a figure which shows the example of a specification change in Example 2. FIG. It is a figure which shows the example of a specification change in Example 2. FIG. It is a figure which shows the example of a specification change in Example 2. FIG. It is a figure which shows the example of a specification change in Example 2. FIG. FIG. 10 is a diagram for explaining a modification of the second embodiment. 10 is a flowchart illustrating a processing procedure in a modification of the second embodiment. It is a figure which shows the example of a specification change in the modification of Example 2. FIG. It is a figure which shows the example of a specification change in the modification of Example 2. FIG. It is a figure which shows the example of a specification change in the modification of Example 2. FIG. It is a figure which shows the example of a specification change in the modification of Example 2. FIG. 10 is a flowchart illustrating a processing procedure in the third embodiment. It is a figure which shows the example of a specification change in Example 3. FIG. It is a figure which shows the example of a specification change in Example 3. FIG. It is a figure which shows the example of a specification change in Example 3. FIG. 10 is a flowchart illustrating a processing procedure in the fourth embodiment. It is a block diagram of UE. It is a HW block diagram of UE. It is a block diagram of eNB. It is a HW block diagram of eNB.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. For example, in the present embodiment, an LTE system is targeted, but the present invention is not limited to LTE and can be applied. Further, in the present specification and claims, the term “LTE” is not limited to a specific Rel (release) of 3GPP unless otherwise specified. “LTE” includes “5G”. In the processing described in the present embodiment, “below” and “smaller” are substantially the same, and either may be used.

(Whole system configuration)
FIG. 1 is a diagram illustrating a configuration example of a communication system according to an embodiment of the present invention. As shown in FIG. 1, the communication system of the present embodiment includes an eNB 10, an eNB 20, an MME 30, a serving gateway (S-GW) 40, and a UE 50.

UE 50 is a user device such as a mobile phone. Each of the eNBs 10 and 20 is a base station. The MME 30 is a node device that accommodates the eNB and performs location control, mobility control such as paging and handover, bearer establishment / deletion, and the like. The S-GW 40 is a node device that relays user data (U-Plane data). A system composed of the MME 30 and the S-GW 40 is called a communication control device. Alternatively, the MME 30 and the S-GW 40 may be configured as a single device and referred to as a communication control device.

As shown in FIG. 1, the MME 30 and the eNBs 10 and 20 are connected by an S1-MME interface, and the S-GW 40 and the eNBs 10 and 20 are connected by an S1-U interface. A dotted connection line indicates a control signal interface, and a solid connection line indicates a user data transfer interface.

The technique according to the present invention can be applied not only to the random access at the time of resuming the connection in the above-described UE context maintaining system, but in this embodiment, as one application example of the present invention, the UE context maintaining system Is used.

In the present embodiment, as an example of the UE context maintenance method, a method for defining a new RRC state called RRC-Suspended (and ECM-Suspended) which is a method described in Non-Patent Document 3 (context maintenance method 1) And a scheme (context holding scheme 2) for reusing the UE context without defining a new RRC state. Examples of these sequences will be described later.

(Random access procedure)
In this embodiment, since a random access procedure between a user apparatus (referred to as UE) and a base station eNB (referred to as eNB) is targeted, first, basic processing of the random access procedure will be described.

Random access (hereinafter referred to as RA) is performed when the UE establishes a connection with the eNB at the time of transmission or the like, and its main purpose is to establish uplink synchronization. As already described, the RA procedure includes a collision-type RA procedure and a non-collision-side RA procedure. The collision-type RA procedure can be used for all purposes, and the non-collision-side RA procedure is used for a specific purpose such as handover. In this embodiment, the collision RA procedure is targeted.

The collision RA procedure will be described with reference to FIG. The UE transmits an RA か ら preamble (selected sequence) through a Physical Random Access Channel (PRACH) using one sequence from a predetermined number of RA preambles (sequence) (step S1). If there is no other UE that performs random access using the same sequence at the same time, no collision occurs.

In step S2, the eNB utilizes DL-SCH (downlink shared channel), TA (timing advance) command for adjusting the transmission timing of the UE, detected RA preamble index, uplink resource allocation information (ULrantgrant ) Including RA) response (response) is transmitted to the UE.

The UE that has received the RA response adjusts the uplink timing and transmits a control message such as RRC connection request to the eNB by CCCH using the allocated resource (step S3).

When the UE that sent the RA preamble fails to receive the RA response (when the random access attempt fails), the UE increases the transmission power by a predetermined step size and performs PRACH each time it fails. Send. Such an operation is called Power Ramping.

In step S4, the eNB transmits contention resolution (contention resolution message). The UE that has received the contention resolution completes the random access process by confirming that its own ID (eg, TC-RNTI, which was used for scrambling in step S3) is included. Send and receive.

(About the sequence example of the context retention method)
Next, as an example of the operation of the system in the present embodiment, the operation related to the context holding method described above will be described. Hereinafter, the context holding method 1 and the context holding method 2 will be described.

<Context retention method 1>
First, the context holding method 1 will be described. In the context maintenance method 1, in addition to the conventional RRC-Idle (RRC idle state) and RRC-Connected (RRC connection state), a state of RRC-Suspended (referred to as RRC suspension state) is added. In the RRC hold state, the UE and the eNB each hold the UE context used for connection in the RRC connection state before entering the RRC hold state. Then, when transitioning from the RRC hold state to the RRC connection state, RRC connection establishment is performed using the held UE context.

First, as a sequence example of the entire communication system in the context holding method 1, a processing sequence when the UE 50 transitions from the RRC idle state to the RRC hold state (and the ECM hold state) will be described with reference to FIG.

In step S11, the eNB 10 determines to suspend the RRC connection. In step S12, the eNB 10 transmits a message indicating that the RRC connection of the UE 50 is suspended to the MME 30. MME10 and eNB30 hold | maintain UE context.

After the messages in steps S13 and S14, in step S15, the MME 30 returns an Ack for step S12. In step S16, the MME 30 enters the ECM-SUSPENDED state.

In step S17, the eNB 10 transmits an RRC connection suspend message to the UE 50 to place the UE 50 in the RRC suspension state (step S18). The RRC connection suspend message includes Resume ID (resumption ID). Resume ID is an identifier used when the RRC connection is resumed next time. In the RRC hold state, the UE 50 and the eNB 10 each store a UE context.

Here, in the present embodiment, the UE context held in each of the UE 50 and the eNB 10 includes, for example, an RRC configuration (RRC configuration), a bearer configuration (including bearer configuration: RoHC state information, etc.), an AS security context. (Access Stratum Security Context), L2 / L1 parameters (MAC, PHY configuration, etc.).

The UE 10 and the eNB 10 each retain the above information as a UE context, so that when transitioning from the RRC hold state to the RRC connection state, the RRC Connection Setup Complete, RRC Security Mode Command, RRC Security Mode Complete, RRC Connection Reconfiguration RRC connection can be established without sending / receiving messages such as RRC ConnectionＲReconfiguration Complete.

Next, a sequence example when the UE 50 transitions from the RRC hold state to the RRC connection state will be described with reference to FIG. FIG. 4 shows a case where the UE 50 in the RRC hold state (step S51) receives an incoming call (steps S52 to S55). However, this is an example, and even when the UE 50 in the RRC hold state makes a call, Similar processing is performed for reusing the UE context.

In the UE that has received paging from the eNB 10, in step S56, an RRC restart procedure (resume procedure) is started from the EMM layer. Random５７Access Preamble is transmitted from the UE 50 to the eNB 10 in step S57, and Random５８Access Response is returned from the eNB 10 to the UE 10 in step S58.

In step S59, the UE 50 transmits an RRC 送信 Connection Resume Request message to the eNB 10 as the message 3.

The RRC Connection Resume Request message includes Resume ID (resumption ID), authentication information, and the like indicating that the UE 50 holds the UE context. The eNB 10 that has received the RRC Connection Resume Request message obtains the UE context of the UE 50 stored in association with the Resume Id included in the message, and performs bearer resumption and the like based on the UE context information. In step S60, the eNB 10 transmits an RRC 送信 Connection Resume Complete message including Resume メ ッ セ ー ジ Id to the UE 50.

In step S61, the UE 50 and the eNB 10 resume the stored security context. In steps S62 to S65, notification of a change in the state of the UE 50 to the MME 30 is performed.

<Context retention method 2>
Next, the context holding method 2 will be described. As described above, the context maintenance method 2 does not define a new state such as RRC-Suspended, and the UE and the eNB hold the UE context in the RRC idle state, and hold it when transitioning to the RRC connected state. In this scheme, the number of signaling can be reduced by reusing the UE context.

As a sequence example of the entire communication system in the context maintaining method 2, a method of paging from the MME 30 when there is an incoming call to the UE 50 in the RRC idle state will be described. More specifically, the processing sequence in the case where the UE 50 connects to the eNB 10 and enters the RRC connection state, enters the RRC idle state in the cell under the control of the eNB 10, and receives an incoming call later in the same cell will be described with reference to FIG. To do.

As a premise of the processing in FIG. 5, the UE 50 is in an RRC connection state in the cell of the eNB 10 and an S1-C / U connection related to the UE 50 is established. In FIG. 5, the S1-C connection includes a connection between the eNB 10 and the MME 30 and a connection between the MME 30 and the S-GW 40, and the S1-U connection includes a connection between the eNB 10 and the S-GW 40. When the connection is established, a signal (data) related to the UE 50 can be transmitted / received between the corresponding node devices without executing a procedure for connection setup such as a connection establishment signal.

Before entering the description of the procedure of FIG. 5, an outline of an example of a procedure when the UE 50 first connects to the eNB 10 will be described. Note that the procedure related to the first connection can also be applied to the context holding method 1. During random access of the UE 50, the eNB 10 transmits RRC 送信 Connection Setup to the UE 50, sets the UE 50 to the RRC connection state, and receives RRC Connection Setup Complete from the UE 50. Thereafter, the eNB 10 receives an Initial Context Setup Request from the MME 30, transmits an RRC Security Mode to the UE 50, receives an RRC Security Mode Complete from the UE 50, and transmits an RRC Connection Reconfiguration to the UE 50, RRC Connection Reconfiguration Complete is received from UE50, and InitialInContext Setup Response is transmitted to MME30. Through such a procedure, the UE context and the UE context are established and held in the UE 50 and the eNB 10.

As shown in FIG. 5, in the RRC connection state, the eNB 10 transmits a connection maintenance instruction signal to the MME 30 (step S71). Also, the MME 30 transmits a connection maintenance instruction signal to the S-GW 40 (step S72).

The connection maintenance instruction signal is a signal that instructs the MME 30 to perform the paging by holding down the downlink data in the S-GW 40 when receiving the call to the UE 50 while maintaining the S1-C / U connection related to the UE 50.

The S-GW 40 that has received the connection maintenance instruction signal transmits a confirmation response indicating that the instruction has been confirmed to the MME 30 (step S73), and the MME 30 transmits a confirmation response to the eNB 10 (step S74).

The transmission of the connection maintenance instruction signal from the eNB 10 to the MME 30 regarding the UE 50 may be triggered by, for example, an event that causes the UE 50 to transition to the RRC idle state in the eNB 10, or the UE 50 is initially under the control of the eNB 10. It may be performed immediately after entering the RRC connection state and establishing the S1-C / U connection for the UE 50.

The event that causes the transition to the RRC idle state is, for example, when it is detected that communication with the UE 50 (uplink / downlink user data communication) does not occur for a certain period of time due to expiration of a predetermined timer (eg, UE ： Inactivity Timer). However, it is not limited to this.

FIG. 5 assumes a case where it is triggered by detecting that communication with the UE 50 (uplink / downlink user data communication) does not occur for a certain period of time. After steps S71 to S74, RRC connection release (RRC Connection) is assumed. Release) is transmitted to the UE 50, and the UE 50 is shifted to the RRC idle state (step S75). Even when the UE 50 transitions to the RRC idle state, the UE context established at the time of RRC connection is maintained in each of the UE 50 and the eNB 10.

Thereafter, downlink data for the UE 50 is generated, and the downlink data arrives at the S-GW 40 (step S76). Here, the S1-U connection has been established, but based on the connection maintenance instruction signal received in step S72, the S-GW 40 holds the downlink data in the buffer without transferring it to the eNB 10.

The S-GW 40 transmits a downlink data incoming notification to the MME 30 (step S77), and the MME 30 transmits an S1-AP paging signal for the UE 50 to the eNB 10 (step S78). This paging itself is the same as the existing paging, and is transmitted to each eNB in the tracking area of the UE 50, but FIG. 5 shows transmission to the eNB 10.

The eNB 10 that has received the S1-AP paging signal transmits the RRC paging signal to the subordinate UE 50 (step S79).

UE50 which received the RRC paging signal performs an RRC connection establishment procedure, and establishes an RRC connection (step S80). Thereafter, the eNB 10 transmits RRC connection establishment completion, which is a signal indicating that establishment of the RRC connection is completed, to the MME 30 (step S81).

The MME 30 transmits an RRC connection establishment completion signal to the S-GW 40 (step S82). Thereby, the S-GW 40 determines that the RRC connection between the UE 50 and the eNB 10 has been established, and uses the S1-U connection related to the UE 50 that has already been established to transfer the pending downlink data to the eNB 10. Start (step S83). The downlink data reaches the UE 50 from the eNB 10 (step S84). In this way, transmission of downlink data to the UE 50 is started.

In the RRC connection establishment procedure in step S80 of FIG. 5, since the UE context held in each of the UE 50 and the eNB 10 is used, the RRC Security Mode Command, RRC Security Mode Complete, and RRC Connection that were necessary in the past are used. RRC connection establishment can be performed without transmitting / receiving messages such as Reconfiguration, RRC 、 Connection Reconfiguration Complete, and the like.

Examples 1 to 4 will be described below as methods for solving the problems in the random access procedure described above. That is, Embodiments 1 to 4 will be described as an example of a method for avoiding that the UE cannot transmit because the TBS is insufficient even if the UE tries to transmit Message 3. The entire random access procedure in each of the following embodiments is as shown in FIG. Hereinafter, the user apparatus is referred to as UE, and the base station is referred to as eNB.

Example 1
First, Example 1 will be described. In Embodiment 1, when the UE selects an RA preamble group from RA preamble group A / B in the random access procedure, the size of the CCCH SDU is not satisfied even if it falls outside the conditions for selecting an existing RA preamble group B. When (size including the MAC header) is larger than messageSizeGroupA, RA preamble group B is selected, and RA preamble is selected from RA preamble group B and transmitted.

The above procedure is performed when RA preamble group B exists. That is, the UE receives an SIB2 message (or RRC dedicated message) from the eNB, and in RACH-ConfigCommon in the message, sizeOfRA-PreamblesGroupA (the number of preambles of Group A) is not equal to numberOfRA-Preambles (the number of all preambles) The UE determines that RA preamble group B exists. messageSizeGroupA is a parameter in RACH-ConfigCommon, and is a threshold value to be compared with the message size (size of Message 3) in the selection determination of RA 判定 preamble group A / B.

FIG. 6 shows a description example (excerpt) of the specification (3GPP TS 36.321) corresponding to the operation of the UE of the first embodiment. In FIG. 6, the changed part from Non-Patent Document 2 is underlined.

As shown in FIG. 6, in the determination condition for selecting one of RA preamble group A / B, the condition that CCCH SDU size is larger than messageSizeGroupA is added to the condition for determining RA preamble group B with OR. .

That is, the UE according to the first embodiment conforming to this specification first determines whether or not RA に preamble group B exists before performing step S1 shown in FIG. I do.

First, the UE determines whether the size of the message (UL data + MAC header, if necessary + MAC CE) to be transmitted as Message 3 is larger than messageSizeGroupA and the path loss is equal to or smaller than a predetermined value. If the determination result is Yes, RA preamble group B is selected.

Also, the UE determines whether CCCH SDU size (size as MAC PDU) is larger than messageSizeGroupA, and if the determination result is Yes, selects RA preamble group B. Note that CCCH SDU size in the present embodiment (examples 1 to 4) means a size to which MAC header is added even if it is not explicitly described that the size is the sum of MAC header. However, instead of this, the size of CCCH SDU not including MAC header may be used.

If any of the above determination results is No, the UE selects RA preamble group A.

Then, the UE randomly selects one RA preamble from the RA preamble in the selected group and transmits it to the eNB (step S1 in Fig. 2).

In the eNB, for example, when it is determined that the RA preamble of RA preamble group B is received, a larger TBS is assigned as a UL resource than when the RA preamble of RA preamble group A is received, and the RA response including UL grant is assigned to the UE. (Step S2 in FIG. 2). Thereby, UE can transmit Message 3 larger than 56 bits to eNB, for example.

FIG. 7 shows another example of the description (excerpt) of the specification (3GPP TS 36.321) corresponding to the operation of the UE of the first embodiment. The example shown in FIG. 7 is an example that clearly describes that the size to be compared with messageSizeGroupA is the size of “CCCH SDU size + MAC header”. That is, the UE executing the operation of the specification determines whether or not “the random access procedure is started for the CCCH logical channel and“ CCCH SDU size + MAC header ”is larger than messageSizeGroupA”. If the result is Yes, RA preamble group B is selected, except for this part, which is the same as in Fig. 6. Note that "the random access procedure is started for the CCCH logical channel" means, for example, RRCConnectionRequest This corresponds to the initiation of a random access procedure for transmitting message, RRCConnectionReestablishmentRequestRemessage, RRC connection resume message, and the like.

In Example 1, the value of messageSizeGroupA notified from the eNB to the UE is not limited to a specific value, but is 56 bits, for example.

Embodiment 1 is particularly suitable when only one additional CCCH SDU size is specified in addition to the current 56-bit TBS. However, the technique of the first embodiment can be used even when two or more additional CCCH 技術 SDU sizes are defined.

(Example 2)
Next, Example 2 will be described. In the second embodiment, a new RA preamble group is provided for a newly added CCCH SDU size. For example, when only one CCCH SDU size is added, Group C is newly added. That is, in this case, a plurality of preambles that can be randomly selected by the UE (e.g., 64, values notified by numberOfRA-Preambles of RACH-ConfigCommon) are divided into three groups (Group C, Group B, and Group C). .

An operation example of the UE RA selection in the second embodiment (operation immediately before step S1 in FIG. 2) will be described with reference to the flowchart in FIG. As a premise of this flowchart, it is assumed that the UE receives the SIB2 message (or RRC individual message), and acquires and holds each parameter such as a threshold by RACH-ConfigCommon in the message. Further, it is assumed that the UE knows that Group C and Group B exist based on the parameters. Also, the following “Group C message size” is one of the parameters notified from the eNB to the UE.

The UE starts a random access procedure when, for example, it wishes to transmit the above-mentioned message for resuming connection to the eNB as Message 3.

In step S101, for example, the UE grasps that the RA-Preamble is not explicitly signaled from the eNB, and starts the RA-preamble selection process in the MAC layer.

In step S102, the UE determines whether or not message size (CCCH SDU + MAC header) to be transmitted is equal to the message size of Group C. If the determination result is Yes, the process proceeds to step S104, Group C is selected, and RA preamble is selected from Group C.

If the determination result in step S102 is No, the process proceeds to step S103. In step S103, the UE determines whether the Potential message size (UL data + MAC header, if necessary, + MAC CE) is larger than the Message message size of Group C, and the path loss is equal to or less than a predetermined value. If the determination result is Yes, the process proceeds to step S105, Group B is selected, and RA preamble is selected from Group B. Note that “Potential message size” is the size of the message scheduled to be sent as Message 3.

If the determination result in step S103 is No, the process proceeds to step S106, where Group A is selected, and RA preamble is selected from Group A.

For example, if the new CCCH SDU + MAC header is 64 bits, the eNB allocates a 64-bit TBS to the UE when the Group C RA preamble is received from the UE. Also, in this case, when the eNB receives the Group B RAmblepreamble from the UE, the eNB allocates a TBS larger than 64 bits (e.g., 80 bits) to the UE. Also, when the Group A RA preamble is received from the UE, a TBS smaller than 64 bits (e.g., 56 bits) is allocated to the UE.

FIG. 9 shows a description example (excerpt) of specifications (3GPP TS 36.321, 5.1.1) corresponding to the operation of the UE of the second embodiment. In FIG. 9, the changed part from Non-Patent Document 2 is underlined.

As shown in FIG. 9, it is specified that the preambles included in RA Preambles group A, RA Preambles group B, and RA Preambles 計算 group C are calculated from parameters of numberOfRA-Preambles, sizeOfRA-PreamblesGroupA, and sizeOfRA-PreamblesGroupC. ing. When RA Preambles Group C exists, the preamble of RA Preamble Group C is from sizeOfRA-PreamblesGroupA to numberOfRA-PreamblesC-1, and the preamble of RA の Preamble Group B is from sizeOfRA-PreamblesGroupC to numberOfRA-Preambles- It is specified that

FIG. 10 shows a description example (excerpt) of specifications (3GPP TS 36.321, 5.1.2) corresponding to the operation of the UE of the second embodiment. In FIG. 10, the changed part from Non-Patent Document 2 is underlined.

The description example shown in FIG. 10 corresponds to the content of the flowchart shown in FIG. As shown in FIG. 10, when Group 、 C does not exist, Group B is selected when potential message size is equal to or larger than message size of Group A and the path loss is equal to or less than a predetermined value, as in the conventional case.

FIG. 11 and FIG. 12 show a description example (extract) of the specification (3GPP TS 36.331) corresponding to the operation of the UE of the second embodiment. In FIG. 11 and FIG. 12, the changed part from the nonpatent literature 5 is underlined.

As shown in FIG. 11, parameters such as sizeOfRA-PreamblesGroupC, messageSizeGroupC, and messagePowerOffsetGroupB are added to RACH-ConfigCommon information element. messageSizeGroupC is a threshold value used for determination (message size of GroupC). As shown in FIG. 12, sizeOfRA-PreamblesGroupC is the size (number of preambles) of GroupC.

In the second embodiment, the case where one group is newly added has been described as an example, but the same processing can be realized even when two or more groups are newly added. In that case, in the flow of FIG. 8, it is determined for each additional group whether message size (CCCH SDU + MAC header) and a parameter (such as message size of Group C) are equal.

(Modification of Example 2)
Next, a modification of the second embodiment will be described. In the modification of the second embodiment, four RA preamble groups are provided so as to be divided into five patterns shown in FIG. In this example, the message size of RA preamble group A is 56 bits and the message size of RA preamble group C is 80 bits, but this is only an example. These values are notified from the eNB to the UE as parameters by RACH-ConfigCommon. In this example, a plurality of preambles that can be randomly selected by the UE are divided into four groups (Group D, Group C, Group B, and Group C).

An example of operation of RA preamble selection of the UE in the modification of the second embodiment (operation immediately before step S1 in FIG. 2) will be described with reference to the flowchart in FIG. As a premise of this flowchart, it is assumed that the UE receives the SIB2 message (or RRC individual message), and acquires and holds each parameter such as a threshold by RACH-ConfigCommon in the message. Further, it is assumed that the UE knows that Group C and Group B exist based on the parameters.

The UE starts a random access procedure when, for example, it wishes to transmit the above-mentioned message for resuming connection to the eNB as Message 3.

In step S201, for example, the UE grasps that the RA-Preamble has not been explicitly signaled from the eNB, and starts the RA-preamble selection process in the MAC layer.

In step S202, the UE determines whether the Potential message size (UL data + MAC header, if necessary, + MAC CE) is larger than the Message message size of Group C, and the path loss is equal to or less than a predetermined value. If the determination result is Yes, the process proceeds to step S204, Group B is selected, and RA preamble is selected from Group B.

If the determination result in step S202 is No, the process proceeds to step S203. In step S <b> 203, the UE determines whether or not message size (CCCH SDU + MAC header) of Message 3 to be transmitted is equal to message８０size (eg, 80 bits) of Group C. If the determination result is Yes, the process proceeds to step S205, Group C is selected, and RA preamble is selected from Group C.

If the determination result in step S203 is No, the process proceeds to step S206. In step S206, the UE determines that “Potential message size (UL data + MAC header, if necessary, + MAC CE) is smaller than Group C message size and PotentialPmessage size (UL data + MAC header, if necessary, It is determined whether + MAC CE) is larger than Group A message５６size (for example, 56 bits) and the path loss is equal to or less than a predetermined value. If the determination result is Yes, the process proceeds to step S207, where Group D is selected, and RA preamble is selected from Group D. If the determination result is No, the process proceeds to step S208, Group A is selected, and RA preamble is selected from Group A.

For example, when the new CCCH SDU + MAC header is 80 bits and the existing (Group A) message size is 56 bits, the eNB receives the Group C RA preamble from the UE. It is conceivable to allocate a bit TBS to the UE. In addition, when the eNB receives RA preamble of Group B from the UE, the eNB allocates a TBS larger than 80 bits to the UE. In addition, when a Group A RA preamble is received from a UE, a 56-bit TBS is allocated to the UE. In addition, when a Group D RA preamble is received from the UE, a TBS larger than 56 bits and smaller than 80 bits (eg, 64 bits) is allocated to the UE.

FIG. 15 shows a description example (excerpt) of a specification (3GPP TS 36.321, 5.1.1) corresponding to the UE operation of the modified example of the second embodiment. In FIG. 15, changes from Non-Patent Document 2 are underlined.

As shown in FIG. 15, the preambles included in RA Preambles group A, RA Preambles group B, RA Preambles group C, and RA Preambles group D are calculated from the parameters of numberOfRA-Preambles, sizeOfRA-PreamblesGroupA, and sizeOfRA-PreamblesGroupC. Is stipulated. In addition, when RA Preambles Group C and RA Preambles Group D exist, the preamble of RA Preamble Group C is from sizeOfRA-PreamblesGroupA to numberOfRA-PreamblesC-1 、, and the preamble of RA Preamble Group D is from sizeOfRA-PreamblesGroupC It is specified that numberOfRA-PreamblesD-1 and the preamble of RA Preamble Group B is from sizeOfRA-PreamblesGroupD to numberOfRA-Preambles-1.

FIG. 16 shows a description example (excerpt) of specifications (3GPP TS 36.321, 5.1.2) corresponding to the operation of the UE according to the modification of the second embodiment. In FIG. 16, the changes from Non-Patent Document 2 are underlined.

The description example shown in FIG. 16 corresponds to the content of the flowchart shown in FIG. As shown in FIG. 16, when Group 、 C does not exist, Group B is selected when potential message size is equal to or larger than message size of Group A and the path loss is equal to or less than a predetermined value, as in the conventional case.

17 and 18 show a description example (excerpt) of a specification (3GPP TS 36.331) corresponding to the operation of the UE according to the modification of the second embodiment. In FIG. 17 and FIG. 18, the changes from Non-Patent Document 5 are underlined.

As shown in FIG. 17, parameters such as sizeOfRA-PreamblesGroupC, messageSizeGroupC, messagePowerOffsetGroupB, and sizeOfRA-PreamblesGroupD are added to RACH-ConfigCommon information element. messageSizeGroupC is a threshold value used for determination (message size of GroupC). As shown in FIG. 18, sizeOfRA-PreamblesGroupC is the size (number of preambles) of GroupC.

In the modification of the second embodiment, the case where two groups are newly added has been described as an example. However, the same processing can be realized even when three or more groups are newly added.

(Example 3)
Next, Example 3 will be described. In the third embodiment, 64 different RA preamble resources (PRACH resources) are prepared for each CCCH SDU size. 64 is an example. The UE can determine the number based on system information from the eNB or RRC dedicated signaling. In the following description, it is assumed that there are 64. The CCCH SDU size and the RA preamble resource do not need to correspond one-to-one, and may correspond to one-to-N (N is an integer of 2 or more), for example.

UE generates RA preamble sequence from Zadoff-chu sequence. The UE can regard the RA preamble sequence as the above RA preamble resource. In this case, each of 64 different RA preamble sequences corresponds to the size of CCCH SDU. For example, when transmitting a 72-bit CCCH SDU message, the UE transmits an RA preamble sequence 1 corresponding to 80 bits, and when transmitting a 56-bit CCCH SDU message, the UE supports an RA corresponding to 56 bits. Transmit preamble series 2.

Also, for example, the RA preamble sequence may be the same regardless of the CCCH SDU size, and the frequency / time resource for transmitting the RA preamble sequence may be associated with the CCCH SDU size. In this case, the frequency / time resource corresponds to the above RA preamblearesource. In this case, for example, when the UE transmits an 80-bit CCCHDUSDU message, the UE transmits an RA preamble with a frequency / time resource 1 corresponding to 80 bits and transmits a 56-bit CCCH SDU message. , Transmit the RA preamble with frequency / time resource 2 corresponding to 56 bits.

Information on the correspondence relationship between CCCH SDU size and RA 通知 preamble resource is notified from the eNB to the UE by system information or RRC dedicated signaling. The UE holds information on the correspondence relationship, and determines RA preamble resource based on the correspondence relationship and CCCH SDU size of Message 3 to be transmitted.

ENB holds the correspondence between CCCH SDU size and RA preamble resource, and based on RA preamble resource received from UE, it can grasp CCCH SDU size that the UE intends to transmit in Message 3. Thereby, the allocation of TBS according to CCCH SDU size can be performed by RA response.

An operation example of the UE RA selection in the third embodiment (operation immediately before step S1 in FIG. 2) will be described with reference to the flowchart in FIG. As a premise of this flowchart, it is assumed that the UE acquires and holds information on the correspondence between CCCH SDU size and RA preamble resource from the system information (or RRC individual message) received from the eNB.

The UE starts a random access procedure when, for example, it wishes to transmit the above-mentioned message for resuming connection to the eNB as Message 3.

In step S301, for example, the UE recognizes that the RA-Preamble has not been explicitly signaled from the eNB, and starts the RA-preamble selection process in the MAC layer.

In step S302, the UE determines whether the CCCH SDU size of Message 3 to be transmitted is equal to the predetermined message size reported in the system information or individual RRC signaling. That is, it is determined whether or not there is a message size equal to CCCH SDU size in the list of message size in the above correspondence relationship notified in the system information or individual RRC signaling.

When the determination result in step S302 is Yes, the process proceeds to step S303, and the UE regards the PRACH resource (generally having a plurality of PRACH resources) corresponding to the message size equal to the CCCH size SDU size as a usable PRACH resource. Then, in step S305, the UE selects an RA-preamble resource from the available PRACH-resources, and transmits the RA-preamble.

If the determination result in step S302 is No, the process proceeds to step S304, the conventional PRACH resource notified by the system information or individual RRC signaling is regarded as a usable PRACH resource, and the process proceeds to step S305.

FIG. 20 shows a description example (excerpt) of specifications (3GPP TS 36.321, 5.1.1) corresponding to the operation of the UE of the third embodiment. In FIG. 20, the changed part from Non-Patent Document 2 is underlined.

As shown in FIG. 20, at the start of the RA procedure, the UE knows a set of usable PRACH resources that are associated with each message size of Message3. This is indicated by prach-ConfigIndex.

FIG. 21 shows a description example (extract) of specifications (3GPPGPTS 36.321, 5.1.2) corresponding to the operation of the UE of the third embodiment. In FIG. 21, changes from Non-Patent Document 2 are underlined.

As shown in FIG. 21, when CC 含 ま SDU is included in Message 3 and CCCH SDU size is indicated by MessageSizeOfMsg3 in MessageSizePrachInfoList (a list of a predetermined size), the UE PRACH-ParametersMsgSize) is considered a usable PRACH resources. Otherwise, the resource indicated by PRACH-ConfigSIB or PRACH-Config is regarded as usable PRACH resources.

FIG. 22 shows a description example (extract) of the specification (3GPP TS 36.331) corresponding to the operation of the UE of the third embodiment. In FIG. 22, the changed part from Non-Patent Document 5 is underlined. As shown in FIG. 22, the above MessageSizePrachInfoList, PRACH-ParametersMsgSize, and the like are added to PRACH-Config-information elements. These pieces of information correspond to the information on the correspondence relationship between CCCH SDU size and RA preamble resource described above.

Example 4
Next, Example 4 will be described. In the fourth embodiment, when the UE resumes the RRC connection (eg, steps S56 to S59 in FIG. 4 and step S80 in FIG. 5), the UE requests a message for resuming at the RRC layer (conventional Msg). At the same time, a conventional RRC Connection request message (or RRC Connection reestablishment request message) of Msg.3 size (56 bits TBS) is also created. The UE then sends both messages to the lower layer.

In the MAC layer, the UE sends a message requesting resumption of a size larger than that of the conventional Msg.3 according to the allocated TBS, or the conventional Msg.3 size RRCRRconnection request message (or RRC Connection reestablishment request) message).

For example, in the case of FIG. 4, when the UE starts RRC connection resumption in step S56, the UE creates RRC connection request message and RRC connection request message. Then, in the MAC layer, the UE determines whether to transmit either RRC connection resume request message or RRC Connection request message according to the TBS assigned by UL grant received in step S58. For example, when the TBS has a size that allows transmission of RRC connection, resume request, and message, RRC connection, resume request, and message are transmitted. In this case, the procedure shown in FIG. 4 is performed thereafter. On the other hand, when the TBS is not of a size that can transmit RRC connection, request, message, RRC connection, request request message (or RRC connection request request message). In this case, the same procedure as that at the time of transmitting the conventional RRC Connection request message (or RRC Connection reestablishment request message) is subsequently executed.

An example of operation of the UE when the RRC connection is resumed in the fourth embodiment will be described with reference to the flowchart of FIG. In FIG. 23, RRC connection resume request message is used as a message for resuming the RRC connection. This may be considered as a new message in FIG. 4 or an extension of an existing message (for example, a message used in step S80 in FIG. 5).

In step S401, the UE creates an RRC connection request message in the RRC layer and also creates an existing RRC connection request message. In step S <b> 402, the UE determines whether or not it is possible to transmit RRC connection resume request using the TBS assigned to Message 3.

If the determination result in step S402 is Yes, RRC connection resume request message is transmitted in step S403. In the case of No, it is assumed that the TBS is 56 bits, and an existing RRC connection request message is transmitted in step S404.

In the fourth embodiment, for example, if the radio quality is good, a large TBS allocation can be expected, and in that case, an RRC connection connection request message can be transmitted. Even when receiving normal TBS allocation, RRC connection request message can be transmitted. That is, in the RA procedure, it is possible to avoid that the UE cannot transmit the control message due to a lack of uplink resources allocated from the eNB.

In the fourth embodiment, an example in which RRC connection request message and RRC connection resume request message are created at the same time is shown, but a plurality of messages of different sizes are created at the same time, and if large messages can be sent, they are sent. The process is applicable not only to RRC connection request message and RRC connection request request message.

All or any one of Embodiments 1 to 4 (including the modified example of Embodiment 2, the same applies below) can be implemented in combination as long as no contradiction occurs.

(Device configuration example)
Next, an apparatus configuration example of the UE and the eNB in the embodiment of the present invention will be described. The configuration of each device described below shows only functional units particularly related to the embodiment of the invention, and has at least a function (not shown) for operating as a device in a communication system compliant with LTE. . Moreover, the functional configuration shown in each figure is only an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

Each device may have all the functions of the first to fourth embodiments, or may have the function of any one of the first to fourth embodiments or the function of a modified example. Alternatively, any one of the functions of the first to fourth embodiments may be provided. In the following description, each device is assumed to have the functions of the first to fourth embodiments.

<User device UE>
FIG. 24 shows a functional configuration diagram of the UE. As shown in FIG. 24, the UE includes a DL signal reception unit 51, a UL signal transmission unit 52, a preamble selection unit 53, an RRC processing unit 54, and a UE context management unit 55. FIG. 24 shows only functional units particularly relevant to the present invention in the UE, and the UE also has a function (not shown) for performing an operation based on LTE.

The DL signal receiving unit 51 includes a function of receiving various downlink signals from the base station eNB and acquiring higher layer information from the received physical layer signal, and the UL signal transmitting unit 52 is transmitted from the UE 50. It includes a function of generating various signals of the physical layer from information on higher layers to be transmitted and transmitting the signals to the base station eNB.

The preamble selection unit 53 selects a preamble in the MAC layer using the logic described in the first and second embodiments. The preamble selection unit 53 may be provided in the UL signal transmission unit 52. Also, the preamble selection unit 53 performs resource selection for RA preamble transmission in the third embodiment.

The RRC processing unit 54 generates and transmits an RRC message (transmission is performed via the UL signal transmission unit 52), interprets the RRC message received by the DL signal reception unit 51, and the like. In the third embodiment, the RRC processing unit 54 acquires / holds correspondence information. In the fourth embodiment, the RRC processing unit 54 simultaneously creates RRC connection request message and RRC connection resume request message. In the fourth embodiment, the UL signal transmission unit 52 includes a function for determining which of RRC connection request message and RRC connection resume request message is to be transmitted based on TBS.

The UE context management unit 55 includes storage means such as a memory, and holds the UE context in the RRC hold state / RRC idle state.

The configuration of the UE shown in FIG. 24 may be entirely realized by a hardware circuit (eg, one or a plurality of IC chips), or a part is constituted by a hardware circuit, and the other part is a CPU and a program. And may be realized.

FIG. 25 is a diagram illustrating an example of a hardware (HW) configuration of the UE. FIG. 25 shows a configuration closer to the mounting example than FIG. As shown in FIG. 25, the UE controls a radio equipment (RE) module 151 that performs processing related to a radio signal, a base band (BB) processing module 152 that performs baseband signal processing, and device control that performs processing such as an upper layer. It has a module 153 and a USIM slot 154 which is an interface for accessing a USIM card.

The RE module 151 should transmit from the antenna by performing digital-to-analog (D / A) conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB processing module 152 Generate a radio signal. In addition, a digital baseband signal is generated by performing frequency conversion, analog to digital (A / D) conversion, demodulation, and the like on the received wireless signal, and the digital baseband signal is passed to the BB processing module 152. The RE module 151 includes functions such as a physical layer in the DL signal receiving unit 51 and the UL signal transmitting unit 52 in FIG. 24, for example.

The BB processing module 152 performs processing for mutually converting an IP packet and a digital baseband signal. The digital signal processor (DSP) 162 is a processor that performs signal processing in the BB processing module 152. The memory 172 is used as a work area for the DSP 162. The BB processing module 152 includes, for example, functions such as layer 2 in the DL signal reception unit 51 and the UL signal transmission unit 52 in FIG. 24, a preamble selection unit 53, an RRC processing unit 54, and a UE context management unit 54. Note that all or some of the functions of the preamble selection unit 53, the RRC processing unit 54, and the UE context management unit 54 may be included in the device control module 153.

The device control module 153 performs IP layer protocol processing, various application processing, and the like. The processor 163 is a processor that performs processing performed by the device control module 153. The memory 173 is used as a work area for the processor 163. The processor 163 reads and writes data with the USIM through the USIM slot 154.

<Base station eNB>
FIG. 26 shows a functional configuration diagram of the eNB. As illustrated in FIG. 26, the eNB includes a DL signal transmission unit 11, a UL signal reception unit 12, an RRC processing unit 13, a UE context management unit 14, and an NW communication unit 15. FIG. 26 shows only functional units particularly related to the embodiment of the present invention in the eNB, and the eNB also has a function (not shown) for performing an operation based on at least the LTE scheme.

The DL signal transmission unit 11 includes a function of generating and transmitting various physical layer signals from higher layer information to be transmitted from the eNB. The UL signal receiving unit 12 includes a function of receiving various uplink signals from the UE and acquiring higher layer information from the received physical layer signals.

The RRC processing unit 13 performs generation / transmission of RRC messages and system information (transmission is transmission via the DL signal transmission unit 11), interpretation of RRC messages received by the UL signal reception unit 12, operation, and the like. The RRC processing unit 13 also includes a function of resuming RRC connection using the UE context held in the UE context management unit 14.

The UE context management unit 14 includes storage means such as a memory and holds the UE context in the RRC hold state / RRC idle state.

The NW communication unit 15 transmits / receives a control signal to / from the MME through the S1-MME interface, a function to transmit / receive data to / from the S-GW through the S1-U interface, and a function of transmitting a connection maintenance instruction signal , A transmission function for transmitting RRC connection establishment completion, and the like.

The configuration of the eNB shown in FIG. 26 may be realized entirely by a hardware circuit (eg, one or a plurality of IC chips), or a part may be configured by a hardware circuit, and the other part may be a CPU and a program. And may be realized.

FIG. 27 is a diagram illustrating an example of a hardware (HW) configuration of the eNB. FIG. 27 shows a configuration closer to the mounting example than FIG. As shown in FIG. 27, the eNB is connected to the network by an RE module 251 that performs processing related to a radio signal, a BB processing module 252 that performs baseband signal processing, a device control module 253 that performs processing such as an upper layer, and the like. And a communication IF 254 which is an interface for the

The RE module 251 generates a radio signal to be transmitted from the antenna by performing D / A conversion, modulation, frequency conversion, power amplification, and the like on the digital baseband signal received from the BB processing module 252. In addition, a digital baseband signal is generated by performing frequency conversion, A / D conversion, demodulation, and the like on the received radio signal, and passed to the BB processing module 252. The RE module 251 includes functions such as a physical layer in the DL signal transmission unit 11 and the UL signal reception unit 12 in FIG. 26, for example.

The BB processing module 252 performs processing for mutually converting an IP packet and a digital baseband signal. The DSP 262 is a processor that performs signal processing in the BB processing module 252. The memory 272 is used as a work area for the DSP 252. The BB processing module 252 includes, for example, functions such as layer 2 in the DL signal transmission unit 11 and the UL signal reception unit 12 in FIG. 25, an RRC processing unit 13, and a UE context management unit 14. Note that all or part of the functions of the RRC processing unit 13 and the UE context management unit 14 may be included in the device control module 253.

The device control module 253 performs IP layer protocol processing, OAM processing, and the like. The processor 263 is a processor that performs processing performed by the device control module 253. The memory 273 is used as a work area for the processor 263. The auxiliary storage device 283 is an HDD, for example, and stores various setting information for the base station eNB itself to operate.

Note that the configuration (functional category) of the apparatus shown in FIGS. 24 to 27 is merely an example of a configuration that realizes the processing described in the present embodiment. As long as the processing described in this embodiment can be realized, the mounting method (specific arrangement of functional units, names, and the like) is not limited to a specific mounting method.

(Summary of embodiment)
As described above, according to the present embodiment, the size of a message transmitted on a predetermined logical channel in the user apparatus that communicates with the base station in a wireless communication system including the base station and the user apparatus. And selecting a random access signal group from a plurality of random access signal groups and selecting a random access signal from the random access signal group, and selecting by the selection unit A transmitter that transmits the random access signal to the base station, and the transmitter uses the resource allocated by the response from the base station to the random access signal to transmit the message to the predetermined logic. A user equipment characterized by transmitting on a channel is provided.

With the above configuration, for example, the base station can grasp the size of the message to be transmitted by the user apparatus before transmitting the RA response, and can allocate an appropriate TBS with the UL response grant. Therefore, it is possible to prevent the user apparatus from being unable to transmit a control message due to a shortage of uplink resources allocated from the base station.

When the size of the message is larger than the predetermined threshold, the selection unit may select a random access signal group corresponding to the predetermined threshold from two random access signal groups. With this configuration, for example, it is possible to notify the base station that the user apparatus uses a new CCCH SDU size using the existing Group B.

In addition, when the size of the message is equal to the predetermined threshold, the selection unit may select a random access signal group corresponding to the predetermined threshold from a plurality of random access signal groups. With this configuration, for example, it is possible to notify the base station that the user apparatus uses a new CCCH SDU size using Group C, which is a new Group. The random access signal group corresponding to the predetermined threshold is, for example, messageSizeGroupC.

In the above example, when the size of the message is larger than the predetermined threshold value and the path loss is smaller than a predetermined value, the selection unit selects the predetermined value from a plurality of random access signal groups. It is also possible to select a predetermined random access signal group different from the random access signal group corresponding to the threshold value. With this configuration, for example, it is possible to notify the base station that the user apparatus uses a message larger than messageSizeGroupC using the existing Group B.

The selection unit determines whether or not a first condition that a size of the message is larger than the predetermined threshold and a path loss is smaller than a predetermined value is satisfied, and the first condition is not satisfied And determining whether or not a second condition that the size of the message is equal to the predetermined threshold is satisfied, and selecting the random access signal group corresponding to the predetermined threshold when the second condition is satisfied It is good to do. With this configuration, for example, it is possible to notify the base station that the user apparatus uses a new CCCH SDU size using Group C, which is a new Group.

In the above example, when the second condition is not satisfied, the selection unit, the size of the message is smaller than the predetermined threshold, and the size of the message is larger than a predetermined second threshold, In addition, it is determined whether or not a third condition that a path loss is smaller than a predetermined value is satisfied, and when the third condition is satisfied, the selection unit determines that the predetermined second threshold value and the predetermined value Selecting a random access signal group corresponding to a size between the threshold and the selection unit selecting a random access signal group corresponding to the predetermined second threshold when the third condition is not satisfied; It is good. With this configuration, for example, as shown in FIG. 12, the message size can be divided into a plurality of patterns, and notification to the base station can be performed for each pattern.

Further, according to the present embodiment, in the radio communication system including a base station and a user apparatus, the user apparatus that communicates with the base station, the size of a message transmitted on a predetermined logical channel, and a random access signal A receiving unit that receives information on a correspondence relationship between the resource and the resource from the base station, and a selection unit that selects a resource corresponding to the size of a message transmitted on the predetermined logical channel from the correspondence information. A user apparatus comprising: a transmission unit that transmits a random access signal to the base station using the selected resource is provided.

With the above configuration, for example, the base station can grasp the size of the message to be transmitted by the user apparatus before transmitting the RA response, and can allocate an appropriate TBS with the UL response grant. Therefore, it is possible to prevent the user apparatus from being unable to transmit a control message due to a shortage of uplink resources allocated from the base station.

The resource is, for example, a random access signal sequence or a resource of time and frequency used for transmission of the random access signal. Thus, flexible resource control becomes possible by using various information as resources.

Further, according to the present embodiment, there is provided a random access method executed by the user apparatus that communicates with the base station in a wireless communication system including the base station and the user apparatus, and a message transmitted on a predetermined logical channel. By selecting a random access signal group from a plurality of random access signal groups by comparing the size and a predetermined threshold, and selecting a random access signal from the random access signal group; and A transmitting step of transmitting the selected random access signal to the base station; and a transmitting step of transmitting the message on the predetermined logical channel using a resource allocated by a response from the base station to the random access signal. Random access with Scan method is provided.

Further, according to the present embodiment, there is provided a random access method executed by the user apparatus that communicates with the base station in a wireless communication system including the base station and the user apparatus, and a message transmitted on a predetermined logical channel. A reception step of receiving information on a correspondence relationship between a size and a resource of a random access signal from the base station; a resource corresponding to a size of a message transmitted on the predetermined logical channel; There is provided a random access method comprising a selection step of selecting from the above and a transmission step of transmitting a random access signal to the base station using the selected resource.

In addition, according to the present embodiment, the user apparatus that communicates with the base station in a wireless communication system including a base station and a user apparatus, the first message and a size smaller than the first message A generating unit that generates a second message, and the first message when the first message can be transmitted according to the amount of resources allocated by a response from the base station to the random access signal transmitted to the base station. There is provided a user apparatus comprising: a transmission unit that transmits one message to the base station and transmits the second message to the base station when the first message cannot be transmitted.

With the above configuration, it is possible to prevent the user apparatus from being unable to transmit a control message due to a lack of uplink resources allocated from the base station.

Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various variations, modifications, alternatives, substitutions, and the like. I will. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The classification of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, or the items described in one item may be used in different items. It may be applied to the matters described in (if not inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to physical component boundaries. The operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components. For convenience of description, each device has been described using a functional block diagram. However, such a device may be implemented in hardware, software, or a combination thereof. Software that is operated by the processor of the apparatus according to the embodiment of the present invention includes random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD It may be stored in any suitable storage medium such as ROM, database, server, etc.

The notification of information is not limited to the aspect / embodiment described in this specification, and may be performed by other methods. For example, notification of information includes physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (for example, RRC signaling, MAC signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or a combination thereof. Further, the RRC message may be referred to as RRC signaling. The RRC message may be, for example, an RRC connection setup (RRCRRConnection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, or the like.

In addition, each aspect / embodiment described in this specification includes Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G, 5G, Future Radio Access (FRA), W -CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-WideBand (UWB) ), Bluetooth (registered trademark), other appropriate systems, and / or next-generation systems extended based on these systems.

The determination or determination may be performed by a value represented by 1 bit (0 or 1), may be performed by a true value (Boolean: true or false), or may be performed by comparing numerical values (for example, (Comparison with a predetermined value).

Note that the terms described in this specification and / or terms necessary for understanding this specification may be replaced with terms having the same or similar meaning. For example, the channel and / or symbol may be a signal. The signal may be a message.

UE is a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal by those skilled in the art , Remote terminal, handset, user agent, mobile client, client, or some other appropriate terminology.

Each aspect / embodiment described in this specification may be used alone, in combination, or may be switched according to execution. In addition, notification of predetermined information (for example, notification of being “X”) is not limited to explicitly performed, but is performed implicitly (for example, notification of the predetermined information is not performed). Also good.

As used herein, the terms “determining” and “determining” may encompass a wide variety of actions. “Judgment”, “decision” can be, for example, calculating, computing, processing, deriving, investigating, looking up (eg, table, database or another (Searching in the data structure), and confirming (ascertaining) what has been confirmed may be considered as “determining” or “determining”. In addition, “determination” and “determination” include receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (accessing) (e.g., accessing data in a memory) may be considered as "determined" or "determined". In addition, “determination” and “decision” means that “resolving”, “selecting”, “choosing”, “establishing”, and “comparing” are regarded as “determining” and “deciding”. May be included. In other words, “determination” and “determination” may include considering some operation as “determination” and “determination”.

As used herein, the phrase “based on” does not mean “based only on”, unless expressly specified otherwise. In other words, the phrase “based on” means both “based only on” and “based at least on.”

Further, the processing procedures, sequences, flowcharts, etc. of the respective embodiments / variants described in this specification may be switched in order as long as there is no contradiction. For example, the methods described herein present the elements of the various steps in an exemplary order and are not limited to the specific order presented.

The input / output information or the like may be stored in a specific place (for example, a memory) or may be managed by a management table. Input / output information and the like can be overwritten, updated, or additionally written. The output information or the like may be deleted. The input information or the like may be transmitted to another device.

The notification of the predetermined information (for example, notification of “being X”) is not limited to explicitly performed, and may be performed implicitly (for example, notification of the predetermined information is not performed). .

The information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, commands, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these May be represented by a combination of

In addition, information, parameters, and the like described in this specification may be represented by absolute values, may be represented by relative values from a predetermined value, or may be represented by other corresponding information. . For example, the radio resource may be indicated by an index. The names used for the parameters described above are not limiting in any way.

The present invention is not limited to the above-described embodiment, and various variations, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

This international patent application claims priority based on Japanese Patent Application No. 2016-042819 filed on March 4, 2016 and Japanese Patent Application No. 2016-105565 filed on May 26, 2016. The entire contents of Japanese Patent Application No. 2016-042819 and Japanese Patent Application No. 2016-105565 are incorporated herein by reference.

10, 20 eNB
11 DL signal transmission unit 12 UL signal reception unit 13 RRC processing unit 14 UE context management unit 15 NW communication unit 30 MME
40 S-GW
50 UE
51 DL signal reception unit 52 UL signal transmission unit 53 Preamble selection unit 54 RRC processing unit 55 UE context management unit 151 RE module 152 BB processing module 153 Device control module 154 USIM slot 251 RE module 252 BB processing module 253 Device control module 254 Communication IF

Claims (9)

1. The user apparatus that communicates with the base station in a wireless communication system including a base station and a user apparatus,
   A random access signal group is selected from a plurality of random access signal groups by comparing the size of a message transmitted on a predetermined logical channel with a predetermined threshold, and a random access signal is selected from the random access signal group. A selection section to select;
   A transmission unit for transmitting the random access signal selected by the selection unit to the base station,
   The transmission apparatus transmits the message on the predetermined logical channel using a resource allocated by a response from the base station to the random access signal.
2. The said selection part selects the random access signal group corresponding to the said predetermined threshold value among two random access signal groups, when the size of the said message is larger than the said predetermined threshold value. The user device according to 1.
3. When the size of the message is equal to the predetermined threshold, the selection unit selects a random access signal group corresponding to the predetermined threshold from a plurality of random access signal groups. The user device according to 1.
4. When the size of the message is larger than the predetermined threshold and the path loss is smaller than a predetermined value, the selection unit selects a random access corresponding to the predetermined threshold from a plurality of random access signal groups. The user apparatus according to claim 3, wherein a predetermined random access signal group different from the signal group is selected.
5. The selection unit includes:
   Determining whether a first condition is satisfied that a size of the message is larger than the predetermined threshold and a path loss is smaller than a predetermined value;
   When the first condition is not satisfied, it is determined whether or not a second condition that the size of the message is equal to the predetermined threshold is satisfied, and when the second condition is satisfied, the predetermined threshold is set. The user equipment according to claim 1, wherein a corresponding random access signal group is selected.
6. When the second condition is not satisfied, the selection unit determines that the size of the message is smaller than the predetermined threshold, the size of the message is larger than a predetermined second threshold, and the path loss is predetermined. Whether or not the third condition of being smaller than the value of is satisfied,
   When the third condition is satisfied, the selection unit selects a random access signal group corresponding to a size between the predetermined second threshold and the predetermined threshold, and the third condition is not satisfied In this case, the selection unit selects a random access signal group corresponding to the predetermined second threshold. The user apparatus according to claim 5,
7. The user apparatus that communicates with the base station in a wireless communication system including a base station and a user apparatus,
   A receiving unit that receives information on a correspondence relationship between a size of a message transmitted on a predetermined logical channel and a resource of a random access signal from the base station;
   A selection unit that selects a resource corresponding to the size of a message transmitted on the predetermined logical channel from the information on the correspondence;
   A user apparatus comprising: a transmission unit that transmits a random access signal to the base station using the selected resource.
8. A random access method executed by the user apparatus that communicates with the base station in a wireless communication system including a base station and a user apparatus,
   A random access signal group is selected from a plurality of random access signal groups by comparing the size of a message transmitted on a predetermined logical channel with a predetermined threshold, and a random access signal is selected from the random access signal group. A selection step to select;
   A transmission step of transmitting the random access signal selected by the selection step to the base station;
   A random access method comprising: a step of transmitting the message on the predetermined logical channel using a resource allocated by a response from the base station to the random access signal.
9. A random access method executed by the user apparatus that communicates with the base station in a wireless communication system including a base station and a user apparatus,
   A receiving step of receiving information on a correspondence relationship between a size of a message transmitted on a predetermined logical channel and a resource of a random access signal from the base station;
   A selection step of selecting a resource corresponding to a size of a message transmitted on the predetermined logical channel from the information on the correspondence;
   And a transmission step of transmitting a random access signal to the base station using the selected resource.

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