WO2014087553A1

WO2014087553A1 - Communication device, communication control method and program

Info

Publication number: WO2014087553A1
Application number: PCT/JP2013/004443
Authority: WO
Inventors: 高志唯木
Original assignee: Ｎｅｃカシオモバイルコミュニケーションズ株式会社
Priority date: 2012-12-06
Filing date: 2013-07-22
Publication date: 2014-06-12

Abstract

[Problem] To circumvent the influence of differences in communication environments while efficiently reducing power consumption. [Solution] A communication device is equipped with: a communication unit (200) that carries out communication using LTE; a communication recording unit (201) that records the communication state of the communication unit (200) with each base station in the form of history information; a determination unit (202) that determines whether the communication unit (200) can or cannot communicate with each base station on the basis of the history information recorded by the communication recording unit (201); and a control unit (203) that controls the communication operation by the communication unit (200) on the basis of the communication possibility determination result made by the determination unit (202).

Description

COMMUNICATION DEVICE, COMMUNICATION CONTROL METHOD, AND PROGRAM

The present invention relates to a communication device, a communication control method, and a program.

In recent years, in communication devices such as mobile phone terminals, smartphones, and wireless routers, LTE (Long Term Evolution) has become a faster communication technology as the amount of data transmitted to and received from a network (hereinafter referred to as NW) increases. ) Is becoming popular. In LTE, there are two states between a communication device and the NW, a connection state in which an RRC connection (Radio Resource Control-Connection) is established and an idle state in which no RRC connection is established. Exists.

In the LTE idle state, similarly to the W-CDMA idle state, the communication apparatus can intermittently monitor the downlink channel. For this reason, it is generally possible to keep current consumption low. On the other hand, in the communication state, in order to secure the uplink / downlink communication channel, the communication apparatus needs to always monitor the downlink communication channel. For this reason, the power consumption of a communication apparatus becomes large compared with an idle state.

Incidentally, in order to reduce the power consumption in a communication apparatus using LTE, it is desirable to release the RRC connection in a shorter time and transition to the idle state when there is no data to be transmitted / received. In this regard, in the case of W-CDMA, when there is no packet communication data for a certain period of time, the communication device voluntarily notifies the NW of the timing for releasing the signaling connection and can effectively save power (signaling A function such as FastDormancy for requesting a transition to an RRC connection in response to a connection release trigger is requested.

However, in LTE, a similar mechanism is not defined, and RRC connection release is performed entirely by the NW side. For this reason, the time from when there is no packet communication data until the RRC connection is released (transition to the idle state) cannot be controlled by the communication device, but is 30 seconds in one LTE cell and 180 seconds in another LTE cell. As described above, there is a possibility that it is different for each LTE cell.

In LTE, there is a state called CDRX (Connected DRX) when there is no uplink / downlink communication instead of the lack of W-CDMA FastDormancy function. In CDRX, intermittent operation is permitted while maintaining the RRC connection, and parameters such as a timer until transition and an intermittent period are defined in 3GPP (Third Generation Partnership Project). These parameters are notified from the NW to the communication device by a message such as RRC Connection Reconfiguration during LTE communication. When there is no uplink / downlink communication with the NW, the communication device transitions to the CDRX state according to the parameter. When uplink or downlink communication occurs in the CDRX state, the communication state (non-intermittent operation) before the CDRX state transition is restored.

Representative examples of the above parameters include drx-InactivityTimer, onDurationTimer, shortDRX-cycle, and longDRX-cycle. The drx-InactivityTimer is the CDRX after the elapse of the drx-InactivityTimer from the time when communication data (including not only the packet communication data but also the Control-Plane (hereinafter referred to as C-Plane) data, etc.) disappears. It is a timer that performs the operation. For this reason, the shorter the drx-InactivityTimer is set, the easier it is to transition to the CDRX state.

Also, shortDRX-cycle and longDRX-cycle are CDRX cycles as the name implies. The onDurationTimer is a timer for designating the time (ON duration) that the communication apparatus is activated for each CDRX cycle for incoming call confirmation (PDCCH confirmation). For this reason, the time during which the communication apparatus sleeps for each CDRX cycle is the difference between them ((short (long) DRX-cycle) -onDurationTimer).

For this reason, the longer the short (long) DRX-cycle or the shorter the onDurationTimer, the longer the sleep time. Since these parameters also depend on the operation of the NW, there is a possibility that the parameters differ for each LTE cell.

In the CDRX state, signaling for state transition does not occur at the time of transition from the normal communication state (non-intermittent state) to the CDRX state (intermittent state). For this reason, it is more effective than the Fast Dormancy function of W-CDMA in that the NW load can be reduced by increasing traffic and the operation can be shifted to an intermittent operation in a short time. However, data other than packet communication data, signals (for example, Control-Plane (hereinafter referred to as C-Plane) for changing uplink channel transmission power setting), and signals for lower layers such as Timing Advance for adjusting uplink transmission timing ), The communication device cannot make a transition to the CDRX state, so that it is practically difficult to reduce power consumption.

Further, in the situation where there is no packet communication data, the extent to which the above-mentioned C-Plane data and lower layer signals are received depends on the state of the LTE cell and the communication device in the area (for example, accommodated in the same cell). For example, whether the uplink channel power adjustment of the communication apparatus is necessary). For this reason, there is a circumstance that the extent to which the communication device is actually in the CDRX state is different for each LTE cell from this viewpoint.

As described above, LTE does not have a mechanism for promoting a transition to a state in which current consumption is lower than that of a communication device, focusing on the presence or absence of packet communication data, such as the Fast Dormancy function of W-CDMA. In other words, the transition to the CDRX state with low power consumption or the idle state depends on the NW, and there is a circumstance that the degree of transition is different for each LTE cell. For this reason, once packet communication occurs in an LTE cell that is difficult to transition and once transits to a communication state, the communication device can maintain a communication state that consumes a large amount of current for a long time even when there is no packet communication data. There is a problem that power consumption cannot be effectively reduced because it must be maintained. Therefore, various techniques for reducing power consumption have been proposed for communication devices in accordance with the amount of data, the communication state, and the like.

For example, in Patent Document 1, a mobile terminal device such as a smartphone is calculated by calculating a data usage amount for each application, and selectively connecting and blocking data communication according to the data usage amount for each application. Technologies that reduce battery consumption have been proposed.

Patent Document 2 relates to a mobile phone terminal capable of receiving terrestrial digital broadcasts, and reduces the power consumption by controlling the digital broadcast reception operation according to the reception status of the digital broadcast in the background. Technology has been proposed.

Further, in Patent Document 3, in order to prevent a ping-pong phenomenon between cells and between TAs (Tracking Areas), cell selection / reselection parameters for user communication devices are adjusted in the active state using history information of the serving cell. Techniques to do this have been proposed.

JP 2012-138904 A JP 2010-004545 A Special table 2011-511488 gazette

However, Patent Documents 1 and 2 described above are not related to communication control by LTE, but are technologies related to connection and blocking of 3G connection and WiFi connection, or technologies related to reception of digital broadcasts. No such issues are taken into account. For this reason, the techniques according to Patent Documents 1 and 2 described above are not directly applicable to communication apparatuses using LTE, and there is a problem that it is difficult to reduce power consumption in communication apparatuses using LTE.

Moreover, although the above-mentioned patent document 3 is related to communication control by LTE, it is a technique for the purpose of preventing a ping-pong phenomenon in which a mobile phone terminal located in or near a boundary region between cells goes back and forth between cells. After all, there is a problem that it is difficult to realize reduction of power consumption in a communication device using LTE.

In addition, in smartphones and the like, background communication that the user is not aware of at any given time occurs frequently depending on the installed application, so it is difficult to maintain an idle state and effectively reduce power consumption. There is a problem that you can not. As a solution to this problem, a mechanism for suppressing background communication is introduced for each specific time zone and each specific application in conjunction with a function such as a schedule. However, with the mechanism, when the background communication is permitted or when packet communication occurs in the application, it is impossible to avoid the influence due to the environment difference for each LTE cell as described above. There is.

Therefore, an object of the present invention is to provide a communication device, a communication control method, and a program that can avoid the influence due to the difference in the communication environment and can efficiently reduce the power consumption.

The communication device of the present invention includes a communication unit that performs communication using LTE, a communication recording unit that records a communication state of each base station by the communication unit as history information, and history information recorded by the communication recording unit. A determination unit that determines whether or not communication by the communication unit is possible for each base station, and a control unit that controls communication operation by the communication unit based on a determination result of whether or not communication is possible by the determination unit. This is a featured communication device.

The communication control method of the present invention is based on a communication step of performing communication using LTE, a communication recording step of recording a communication state using LTE for each base station as history information, and the recorded history information. A determination step for determining whether communication using the LTE is possible for each base station, and a control step for controlling a communication operation using the LTE based on the determination result of the communication permission This is a communication control method.

The program of the present invention is based on a communication function for performing communication using LTE on a computer, a communication recording function for recording a communication state using LTE for each base station as history information, and the recorded history information. A determination function for determining whether or not communication using the LTE is performed for each base station, and a control function for controlling a communication operation using the LTE based on the determination result of the communication permission or not. is there.

According to the present invention, it is possible to avoid the influence due to the difference in the communication environment and efficiently reduce the power consumption.

It is a block diagram which shows the structure of the mobile telephone terminal by embodiment of this invention. It is a flowchart for demonstrating the processing method of the background communication by the mobile telephone terminal of this embodiment. It is a flowchart for demonstrating the recording method of the transition ease (R_cdrx) to the CDRX state of the LTE cell which is located by the mobile telephone terminal of this embodiment. It is a flowchart for demonstrating the recording method of the ease of transition to the idle state (T_rel) of the LTE cell which is located by the mobile telephone terminal of this embodiment. It is a block diagram which shows the structure of Additional remark 1.

The present invention efficiently reduces power consumption by suppressing background communication that the user is not aware of according to the state of the LTE cell in which the packet is transmitted in an LTE-compatible communication device. It is characterized by. Therefore, in the present invention, when packet communication is performed in an LTE cell in an LTE-compatible communication device, the CDRX state and the ease of transition to an idle state are recorded as history information for each LTE cell, and LTE is performed. The power consumption is reduced by controlling the operation of the background communication based on the recorded history information at the timing when the background communication occurs in the cell.

In the present invention, T_rel is defined as the time from when there is no packet communication data until the RRC connection / release is received from the NW and the state transits to the idle state. In other words, T_rel is an index indicating the ease of transition of the serving LTE cell to the idle state. If T_rel is short, even if packet communication data is generated once, it is possible to shift to the idle state soon after the packet communication ends. For this reason, when performing the same packet communication, the power saving efficiency is higher when the packet communication is performed in the LTE cell having a shorter T_rel.

Also, in the present invention, the rate at which intermittent operation is actually performed in a section where there is no packet communication data in the CDRX state, that is, the CDRX operation rate is defined as R_cdrx. In other words, R_cdrx is an index indicating the degree of ease of transition of the serving LTE cell to the CDRX state. Even if the LTE cell has a long T_rel, if the LTE cell has a high R_cdrx, the LTE cell is likely to make a transition to a lower power consumption state. Therefore, the power saving efficiency is higher than that of the LTE cell having a low R_cdrx.

As described above, by using history information that records the actual situation such as T_rel and R_cdrx as the ease of transition to the CDRX state and the idle state in the LTE cell that is in the area, for example, for each LTE cell, Compared with a case where only the 3GPP-defined CDRX parameters are compared, it is possible to efficiently reduce the power consumption suitable for the actual use environment of the user.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a communication apparatus 100 according to an embodiment of the present invention. In the following, it is assumed that the communication device 100 is an LTE-compatible mobile phone terminal, a smartphone, or the like. In FIG. 1, the communication apparatus 100 includes an application unit 101, a control unit 102, and a wireless unit 107. The application unit 101 determines whether or not packet communication data is generated by the user operating various applications, that is, whether or not foreground communication data is generated according to the user's intention.

The control unit 102 includes a communication recording unit 103, a data storage unit 104, a communication determination processing unit 105, and a communication control unit 106. The communication recording unit 103 measures and records values of R_cdrx and T_rel. The communication recording unit 103 stores information on the actual intermittent time (sleep operation time) in the CDRX notified from the communication control unit 106 and the RRC connection from the NW when packet communication is not performed in the LTE cell. -The R_cdrx and T_rel values are classified and recorded for each LTE cell in association with the release timing information of the release (RRC Connection Release).

The data storage unit 104 stores R_cdrx and T_rel notified from the communication recording unit 103 for each LTE cell. The data storage unit 104 also stores reserved background communication data. Note that the communication recording unit 103 and the data storage unit 104 may be a rewritable nonvolatile memory such as a flash memory.

The communication determination processing unit 105 determines whether the packet communication data is foreground communication or background communication, and whether the serving LTE cell is communicable, and determines whether or not the packet communication can be performed. When the communication determination processing unit 105 determines that the background communication is on hold, the communication determination processing unit 105 stores the background communication data in the data storage unit 104 and notifies the application unit 101 that the background communication is on hold. The communication determination processing unit 105 also determines whether or not batch transmission of the suspended background communication data is possible. The communication control unit 106 controls overall communication including packet communication. The wireless unit 107 performs wireless communication with the NW.

Next, an outline of the operation of the communication apparatus 100 according to the above-described embodiment will be described.
(A1) When the packet communication data is generated, the communication apparatus 100 determines whether the packet communication data is foreground communication data or background communication data. If the packet communication data is foreground communication data, the communication apparatus 100 performs packet communication. In the case of background communication data, the following communication determination (A2) is performed.

(A2) The communication device 100 determines whether or not the currently located cell is an LTE cell. In the case of a cell other than LTE, packet communication is started. On the other hand, when the serving cell is an LTE cell, the history information is compared with a predetermined threshold value using the history information of the LTE cell stored in the memory in the operations (A4) to (A8) described later. To determine whether communication is possible. When it is determined that the serving LTE cell is communicable, background communication is performed. When communication is not possible, the background communication data is suspended. In addition, when there is no history information of the serving LTE cell, packet communication is always performed.

(A3) The held background communication data is held at the time of packet communication by the foreground communication data or until the in-zone cell is changed, and when packet communication becomes possible for any reason, Sent.

(A4) In parallel with the above-described operations (A1) to (A3), the communication device 100 can establish an RRC connection with the NW when packet communication occurs due to a user operation or an incoming call in the LTE cell. To establish LTE communication.

(A5) When the packet communication is completed, the communication apparatus 100 regards the packet non-communication state, R_cdrx that is the CDRRX operation rate in the non-communication state, and T_rel that is the time from the last packet communication to the RRC connection / release reception. Start measuring.

(A6) If packet communication occurs again before receiving the RRC connection / release from the NW, the communication apparatus 100 stops measuring R_cdrx and T_rel, and stores the R_cdrx measurement result in the communication apparatus 100. Store in the provided memory. When storing, if there is a measurement history in the LTE cell in the past, the average value of the past measurement result and the new measurement result already stored is stored. In this case, the measurement result of T_rel is not stored in the memory. Thereafter, the process returns to (A5).

(A7) Before the RRC connection / release is received from the NW, if the LTE cell is changed to another cell due to handover or reconnection, the communication apparatus 100 stops measuring R_cdrx and T_rel. , R_cdrx measurement results are stored in a memory provided in the communication device 100. When storing, if there is a measurement history in the LTE cell in the past, the average value of the past measurement result and the new measurement result already stored is stored. Also in this case, the measurement result of T_rel is not stored in the memory. Thereafter, the process returns to (A5).

(A8) When the RRC connection / release is received from the NW, the communication apparatus 100 stops measuring R_cdrx and T_rel, and stores the measurement results of R_cdrx and T_rel in a memory provided in the communication apparatus 100. . When storing, if there is a measurement history in the LTE cell in the past, the average value of the past measurement result and the new measurement result already stored is stored.

(A9) Thereafter, the operations (A1) to (A8) described above are repeated.

(Background communication processing method)
Next, a background communication processing method according to the present embodiment will be described.
FIG. 2 is a flowchart for explaining a background communication processing method performed by the communication apparatus 100 according to the present embodiment.

(B1) The application unit 101 determines whether there is packet communication data (step S10). If there is bucket communication data (YES in step S10), the application unit 101 determines whether the data is foreground communication or background communication. Is determined (step S12), and the communication type information of the packet communication data is provided to the communication determination processing unit 105 together with the packet communication data itself (step S14).

(B2) The communication determination processing unit 105 determines whether or not the packet communication data is provided from the application unit 101 (step S20). When the packet communication data is provided from the application unit 101 (YES in step S20). ), RAT determination is executed based on the current RAT (Radio Access Technology) information 106a notified from the communication control unit 106 (step S22).

(B3) RAT Determination (B3-1) In the RAT determination, the communication determination processing unit 105 first determines whether or not the current RAT is LTE (step S22). If the current RAT is other than LTE (NO in step S22), the communication determination processing unit 105 transmits the provided packet communication data to the communication control unit regardless of the communication type of the provided packet communication data. It transmits to 106 (step S30). At this time, it is determined whether or not there is packet communication data (background) pending in the data storage unit 104 (step S32).

Then, when there is packet communication data (background) on hold in the data storage unit 104 (YES in step S32), the reserved packet communication data (background) 104b is acquired from the data storage unit 104 to perform communication. The data is transmitted to the control unit 106 (step S34), and the application unit 101 is notified that the pending packet communication data (background) 104b has been transmitted (transmission completion notification) (step S36). Thereafter, the process is completed (step S38).

On the other hand, if there is no pending packet communication data (background) in the data storage unit 104 (NO in step S32), the process is completed (step S38).

(B3-2) On the other hand, in the RAT determination, when the current RAT is LTE (YES in step S22), the communication determination processing unit 105 determines that the communication type is the back as the communication type determination of the provided packet communication data. It is determined whether the data is ground communication data (step S24).

(B4) Communication type determination (B4-1) Then, in the communication type determination, when it is determined that the communication type is foreground communication data (NO in step S24), the communication determination processing unit 105 performs the above steps. In step S30, the provided packet communication data is transmitted to the communication control unit 106. Thereafter, in the handling of the reserved background communication data, steps S32 to S38 are executed in the same manner as (3-1) described above.

(B4-2) On the other hand, in the communication type determination, when it is determined that the communication type is background communication data (YES in step S24), the communication determination processing unit 105 is notified from the communication control unit 106. Based on the serving cell information 106b, the history information 104a of the serving cell is acquired from the data storage unit 104, and it is determined whether or not T_rel, which is the history information 104a, is larger than the threshold T_th as communication feasibility determination (step S26). ).

(B5) Communication availability determination (B5-1) Then, in the communication availability determination, when it is determined that T_rel as the history information 104a is equal to or less than the threshold T_th (NO in step S26), the communication determination processing unit 105 In step S30 described above, the provided packet communication data is transmitted to the communication control unit 106. Thereafter, in the handling of the reserved background communication data, steps S32 to S38 are executed in the same manner as (3-1) described above. If there is no T_rel in the history information 104a of the serving cell, it is treated as T_rel = 0 (that is, it is always determined that communication is possible regardless of the threshold T_th).

(B5-2) On the other hand, if it is determined in the communication availability determination that T_rel, which is history information, is greater than the threshold value T_th (YES in step S26), the communication determination processing unit 105 proceeds to communication availability determination for R_cdrx. Then, it is determined whether or not R_cdrx that is history information is smaller than the threshold value R_th (step S28).

(B5-3) When it is determined that the history information R_cdrx is greater than or equal to the threshold value R_th in the communication availability determination (NO in step S28), the communication determination processing unit 105 determines that communication is possible, and In step S30, the provided packet communication data is transmitted to the communication control unit 106. Thereafter, in the handling of the reserved background communication data, steps S32 to S38 are executed in the same manner as (3-1) described above. If there is no R_cdrx in the history information of the serving cell, it is handled as R_cdrx = 100% (that is, it is always determined that communication is possible regardless of the threshold value R_th).

(B5-4) On the other hand, when it is determined in the communication availability determination that R_cdrx, which is history information, is smaller than the threshold value R_th (YES in step S28), the communication determination processing unit 105 determines that communication is not possible, and the packet The communication data is suspended and transmitted to the data storage unit 104 (step S40). The packet communication data is stored in the data storage unit 104 as pending packet communication data 104b. Further, the communication determination processing unit 105 notifies the application unit 101 that the provided packet communication data has been suspended (step S42).

(B6) The communication determination processing unit 105 checks whether or not the background communication data 104b is held at the timing of receiving the RAT information 106a and the cell information 106b from the communication control unit 106, and holds the back If there is the ground communication data 104b, the background communication data is regarded as the packet communication data provided from the application unit 101, and the processes (B3) to (B5) described above are performed.

(Recording method of CDRX state of LTE cell in which it is located and ease of transition to idle state)
Next, the recording method of the CDRX state of the LTE cell in the area and the ease of transition to the idle state according to the present embodiment will be described.

FIG. 3 is a flowchart for explaining a method of recording the ease of transition (R_cdrx) to the CDRX state of the LTE cell located by the communication apparatus 100 according to the present embodiment.

(C1) The communication control unit 106 determines whether or not there is packet communication data (step S40). If there is packet communication data, that is, when various communication states are changed (YES in step S40). ), The communication status information is notified to the communication recording unit 103 (step S40). The communication state information includes transition of idle / connection state, reconnection in connection state, cell movement by handover, presence / absence of packet communication data, and the like. Further, the communication control unit 106 determines whether or not the device is in the CDRX state (step S44). If the communication control unit 106 is in the CDRX state (YES in step S44), the communication control unit 106 actually sleeps in the CDRX state in addition to the communication state information. The start time when the state is started and the stop time when the sleep state is stopped are notified to the communication recording unit 103 as CDRX information (step S46).

(C2) The communication recording unit 103 determines whether or not the current communication state is a connection state in the LTE cell based on the communication state information notified from the communication control unit 106 (step S50). When the communication state is a connection state in the LTE cell (YES in step S50), the presence / absence of packet communication data is confirmed (step S52). If there is no packet communication data (YES in step S52), recording of R_cdrx is started (step S54), the CDRX information notified from the communication control unit 106 is monitored, and whether or not the communication state has changed. Is determined (step S56).

(C3) From the CDRX information notified from the communication control unit 106, the communication recording unit 103 calculates and records R_cdrx indicating the rate of actual CDRX operation (sleep) during no packet communication.

(C4) Further, the communication recording unit 103 determines whether or not the communication state has changed during the R_cdrx recording (step S56). If there is a transition in the communication state such as resumption of packet communication by packet communication data, reconnection by communication disconnection, cell movement by handover during the R_cdrx recording (YES in step S56), the communication recording unit 103 Stops recording R_cdrx (step S58), and notifies R_cdrx (= actual sleep time / no-packet communication time) and LTE cell information (cell ID, etc.) to the data storage unit 104 (step S60). ).

Here, the information to be notified to the data storage unit 104 is R_cdrx after calculation and cell ID information. However, if parameters for collation with the past history and average value calculation are included, the data storage unit 104 The information to be notified may be in any format. For example, the data storage unit 104 may be notified of the sleep time and the no-communication time as R_cdrx.

(C5) The data storage unit 104 collates the LTE cell information notified from the communication recording unit 103 with the past history information 104a (see FIG. 2) stored therein, and whether there is history information of the same cell. Is determined (step S70). If there is history information of the same cell (YES in step S70), the data storage unit 104 calculates an average R_cdrx from the past R_cdrx and the currently recorded R_cdrx (step S72), and stores the stored R_cdrx. The history information is updated (step S74). On the other hand, if there is no history information of the same cell (NO in step S70), the R_cdrx recorded this time is stored as it is as history information (step S74).

The average value of R_cdrx when the LTE cell information notified from the communication recording unit 103 is in the history information stored in the data storage unit 104 is, for example, w (0 ≦ w ≦ 1) as follows: In the present invention, the averaging method is not particularly defined.

R_cdrx (average value) = R_cdrx (current data)
+ W × (R_cdrx (history data up to the previous time) −R_cdrx (current data))

FIG. 4 is a flowchart for explaining a method for recording the ease of transition (T_rel) of the LTE cell in the idle state to the idle state by the communication apparatus 100 according to the present embodiment. 3 is almost the same as the recording method of R_cdrx shown in FIG. 3, but in the case of T_rel, the condition for notifying the data storage unit 104 is that the condition is only the transition to the idle state due to the reception of the RRC connection / release from the NW. Different. Hereinafter, a recording method of T_rel will be described.

(D1) The communication control unit 106 determines whether or not the communication state has changed (step S82), and notifies the communication recording unit 103 of the communication state information when the communication state is changed for some reason. (Step S80). The communication state information includes transition of idle state / connection state, reconnection in communication state, cell movement due to handover, presence / absence of packet communication data, and the like.

(D2) The communication recording unit 103 determines whether the current communication state is a connection state in the LTE cell based on the communication state information (step S90). If the current communication state is a connection state in the LTE cell (YES in step S90), the communication recording unit 103 determines whether or not there is no packet communication data communication state (step S92). . If there is no packet communication data (YES in step S92), recording of T_rel is started (step S94).

(D3) The communication recording unit 103 determines whether or not there has been a transition in the communication state based on the communication state information notified from the communication control unit 106 in step S80 of (D1) (step S96). If there is no transition in the communication state (NO in step S96), the recording of T_rel is continued. On the other hand, when there is a transition in the communication state (YES in step S96), the communication recording unit 103 stops recording T_rel (step S98).

(D4) Next, the communication recording unit 103 determines whether or not the communication state transition in step S96 of (D3) is a transition to the idle state due to RRC connection / release reception (step S100). When the communication state transition is a transition to the idle state by RRC connection / release reception (YES in step S100), the communication recording unit 103 uses the recorded T_rel and LTE cell information (cell ID, etc.) as data. The storage unit 104 is notified (step S104). On the other hand, when the communication state transition is other than the transition to the idle state due to RRC connection / release reception, that is, when packet communication is resumed by packet communication data, reconnection by communication disconnection, cell movement by handover, etc. (NO in step S100), the communication recording unit 103 discards the recorded T_rel (step S102) and notifies the data storage unit 104 of nothing.

(D5) The data storage unit 104 collates the LTE cell information notified from the communication recording unit 103 with the past history information 104a (see FIG. 2) stored therein, and whether there is history information of the same cell. Is determined (step S110). If there is history information of the same cell (YES in step S110), the data storage unit 104 calculates an average T_rel from the past T_rel and the currently recorded T_rel (step S112), and stores the stored T_rel. The history information is updated (step S114). On the other hand, when there is no history information of the same cell (NO in step S110), the T_rel recorded this time is stored as history information as it is (step S114).

The average value of T_rel when the LTE cell information notified from the communication recording unit 103 is in the history information stored in the data storage unit 104 is, for example, w (0) as follows, similarly to R_cdrx: Although it is calculated by weighting such that ≦ w ≦ 1), the present invention does not particularly define an averaging method.

T_rel (average value) = T_rel (current data)
+ W × (T_rel (history data up to the previous time) −T_rel (current data))

According to the above-described embodiment, the ease of transition to the CDRX state and the idle state varies depending on the LTE cell depending on the 3GPP-specified parameters and the state of the communication device 100 in the cell. Instead of performing all packet communication in the LTE cell, the CDRX state and the ease of transition to the idle state (T_rel, R_cdrx) are recorded, and background communication is controlled using the history information. By doing so, power consumption can be reduced efficiently

In particular, since the ratio of actually performing intermittent operation in the CDRX state is affected by data other than packet communication data, the ratio of actually operating (R_cdrx) is used instead of the 3GPP standard parameters. Power consumption can be efficiently reduced according to the user's activity area.

When the user's activity range is mainly the W-CDMA area, the W-CDMA area prompts a transition to an idle state with low power consumption spontaneously from a communication device such as a mobile phone, as in the Fast Dormancy function. There is a mechanism. For this reason, even if packet communication occurs, power consumption other than the minimum necessary amount for transmitting the packet communication data can be suppressed. In such a case, packet communication is performed in the LTE cell that is difficult to transition to the idle state, and after the packet communication data is lost, the packet is transmitted in the W-CDMA cell rather than maintaining the connection state in which the power consumption is large. Communication is more likely to reduce power consumption, and a power saving effect can be expected.

In addition, according to the present embodiment, it is possible to transmit the suspended packet communication data at a time when RAT switching, cell movement, and foreground communication occur, and these packet communication data are generated individually. Compared to the case, the number of RRC connection establishment and release times can be reduced, and the amount of signaling transmission / reception required for the processing is eliminated, so that the power consumption can be reduced by that amount.

In the above-described embodiment, in the background communication processing method, the communication availability determination is performed using a combination of T_rel and R_cdrx. However, the communication availability determination of the serving LTE cell is performed using only one of T_rel and R_cdrx. You may go.

In the embodiment described above, in the background communication processing method, R_cdrx, which is the ratio of the time actually in the sleep state when there is no packet communication, is used as the index of the ease of transition to the CDRX state. Instead of R_cdrx, it is also possible to determine whether or not communication is possible for the serving LTE cell by using CDRX parameters (such as drx-InactivityTimer, onDurationTimer, short (long) DRX-cycle, etc.) notified from the NW.

In the above-described embodiment, in the background communication processing method, when it is determined that communication is impossible by the communication availability determination, background communication is suspended, but RAT is switched instead of suspension (for example, LTE) (→ W-CDMA), packet communication may be performed.

In the above-described embodiment, the communication is limited to the background communication. However, the packet communication data to which the communication feasibility determination is applied is expanded to the foreground communication data, the packet communication data designated in advance by the user, or the like. Also good.

In the present embodiment, the communication device is not limited to a mobile phone / smartphone, but other devices (LTE data communication cards, PCs incorporating LTE data communication card functions (tablet PCs, notebook PCs), wireless routers, and the like) Etc.).

This application claims priority based on Japanese Patent Application No. 2012-267067 filed on Dec. 6, 2012, the entire disclosure of which is incorporated herein.

The features of the present invention will be described below.
A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
FIG. 5 is a configuration diagram of Supplementary Note 1. The correspondence between FIG. 5 and FIG. 1 will be described. A communication unit 200 illustrated in FIG. 5 corresponds to the wireless unit 107 in FIG. 1, and a communication recording unit 201 in FIG. 5 corresponds to the communication recording unit 103 in FIG. 5 corresponds to the communication determination processing unit 105 in FIG. 1, and the control unit 203 in FIG. 5 corresponds to the communication control unit 106 in FIG.

As shown in this figure, the invention described in Appendix 1 is
A communication unit 200 that performs communication using LTE;
A communication recording unit 201 for recording the communication state of each base station by the communication unit 200 as history information;
Based on the history information recorded by the communication recording unit 201, a determination unit 202 that determines whether communication by the communication unit 200 is possible for each base station;
The communication apparatus includes: a control unit 203 that controls a communication operation by the communication unit 200 based on a determination result of the communication unit 200 by the determination unit 202.

(Appendix 2)
The determination unit determines whether or not communication by the communication unit in the visited area is possible based on history information recorded by the communication recording unit at a timing when background communication occurs in the visited area, The control unit is the communication apparatus according to appendix 1, wherein the background communication is controlled based on a determination result by the determination unit.

(Appendix 3)
The control unit performs the background communication when it is determined by the determination unit that communication in the area is possible, and when it is determined that communication is not possible, The communication apparatus according to appendix 2, wherein the background communication data is reserved.

(Appendix 4)
The control unit, when it is determined that communication is impossible, the data of the background communication that has been suspended, at the time of packet communication by foreground communication, or when the area is changed and packet communication becomes possible, The communication apparatus according to attachment 3, wherein transmission is performed in a lump.

(Appendix 5)
The communication recording unit records the ease of transition to the CDRX state and the ease of transition to the idle state for each base station as the history information. Is a communication device.

(Appendix 6)
When the history information in the base station is already recorded when the communication recording unit records the ease of transition to the CDRX state and the ease of transition to the idle state for each base station, The average value of the ease of transition to the previous CDRX state, the ease of transition to the idle state and the measurement results, the ease of transition to the new CDRX state, and the ease of transition to the idle state are recorded. The communication apparatus according to appendix 5, wherein the communication apparatus records the history information in the base station.

(Appendix 7)
The communication recording unit records a CDRX operation rate indicating a rate at which intermittent operation is actually performed in a section where there is no packet communication data in the CDRX state, as the ease of transition to the CDRX state, and enters the idle state. The communication device according to appendix 5 or 6, wherein the time from when the packet communication data is lost until the transition to the idle state is received after the packet communication data is lost is recorded.

(Appendix 8)
A communication step for performing communication using LTE, a communication recording step for recording a communication state using LTE for each base station as history information, and whether communication using LTE is possible based on the recorded history information And a control step for controlling a communication operation using the LTE based on the determination result of the availability of communication.

(Appendix 9)
A communication function for performing communication using LTE in a computer, a communication recording function for recording a communication state using LTE for each base station as history information, and communication using LTE based on the recorded history information A program for executing a control function for controlling a communication operation using the LTE based on a determination function for determining whether or not communication is possible for each base station and a determination result of the communication availability.

DESCRIPTION OF SYMBOLS 100 Communication apparatus 101 Application part 102 Control part 103 Communication recording part 104 Data storage part 105 Communication determination processing part 106 Communication control part 107 Wireless part

Claims

A communication unit that performs communication using LTE;
A communication recording unit for recording the communication state of each base station by the communication unit as history information;
Based on the history information recorded by the communication recording unit, a determination unit that determines whether communication by the communication unit is possible for each base station;
And a control unit that controls a communication operation performed by the communication unit based on a determination result of whether or not communication by the determination unit is possible.
The determination unit determines whether or not communication by the communication unit in the visited area is possible based on history information recorded by the communication recording unit at a timing when background communication occurs in the visited area,
The communication device according to claim 1, wherein the control unit controls the background communication based on a determination result by the determination unit.
The control unit performs the background communication when it is determined by the determination unit that communication in the area is possible, and when it is determined that communication is not possible, The communication device according to claim 2, wherein the background communication data is reserved.
The control unit, when it is determined that communication is impossible, the data of the background communication that has been suspended, at the time of packet communication by foreground communication, or when the area is changed and packet communication becomes possible, The communication apparatus according to claim 3, wherein the communication apparatus transmits a batch.
The said communication recording part records the ease of transition to a CDRX state and the ease of transition to an idle state for every said base station as said log | history information. Any one of Claim 1 to 4 characterized by the above-mentioned. The communication device described.
When the history information in the base station is already recorded when the communication recording unit records the ease of transition to the CDRX state and the ease of transition to the idle state for each base station, The average value of the ease of transition to the previous CDRX state, the ease of transition to the idle state and the measurement results, the ease of transition to the new CDRX state, and the ease of transition to the idle state are recorded. 6. The communication apparatus according to claim 5, wherein the communication apparatus records the history information in the base station.
The communication recording unit records a CDRX operation rate indicating a rate at which intermittent operation is actually performed in a section where there is no packet communication data in the CDRX state, as the ease of transition to the CDRX state, and enters the idle state. 7. The communication device according to claim 5, wherein the time from when the packet communication data is lost to when the RRC connection release is received and the state transits to the idle state is recorded.
A communication step for performing communication using LTE;
A communication recording step of recording a communication state using LTE for each base station as history information;
A determination step of determining for each base station whether or not communication using the LTE is possible based on the recorded history information;
And a control step of controlling a communication operation using the LTE based on the determination result of the communication availability.
On the computer,
A communication function for performing communication using LTE;
A communication recording function for recording a communication state using LTE for each base station as history information;
A determination function for determining, for each base station, whether or not communication using the LTE is possible based on the recorded history information;
A program for executing a control function for controlling a communication operation using the LTE based on the determination result of the communication availability.