JP5586055B2 - Base station control device, radio communication system, and timing correction method - Google Patents

Description

  The present invention relates to a wireless communication system capable of correcting the timing of a frame transmitted from a base station controller to a base station.

  In signal transmission in a mobile communication system, signal transmission delays and fluctuations occur due to environmental influences such as the distance from a transmitter to a receiver and traffic conditions. The transmission delay and fluctuation of these signals change with time as the traffic situation between the base station controller and the base station changes.

  In order to transmit and receive signals and data without error between the base station controller and the base station, in the W-CDMA (Wideband Code Division Multiple Access) system, the base station controller and the base station mutually synchronize the transport channel frame, A frame is transmitted to the transport channel using the reference frame number of each device.

  The base station that has received the frame data from the base station controller transmits the received data to the mobile terminal. Therefore, the base station provides a window corresponding to the timing for transmitting data to the mobile terminal through the radio interface, and performs timing control regarding the timing relationship between the data received from the base station control device and the window (see Patent Document 1).

  For example, when the frame data received from the base station controller does not fall within the window, the base station corrects the transmission timing of the frame data of the base station controller. This timing correction (TA: Timing Adjustment) is performed when the base station requests the base station controller to correct the frame transmission timing. The base station can request timing correction from the base station control device in units of transmission timing period (TTI).

  Upon receiving a timing correction request from the base station, the base station controller corrects the timing by changing the connection frame number (CFN) to be added to the frame for transport channel frame synchronization.

  At that time, if the timing correction is not completed by the next transmission timing, the timing correction request is duplicated from the base station to the base station control device, and the timing correction is performed twice. Therefore, in order to prevent the timing correction from being performed twice, it is common for the base station control apparatus to provide a guard time so that the next timing correction request is not received for a certain period of time after receiving the timing correction request. It is. In general, a fixed value is used for the guard time.

  However, the set Guard Time is too short, and timing correction may take time longer than the Guard Time due to signal transmission delay and fluctuation between the base station controller and the base station. In that case, after the base station control apparatus performs timing correction by the request for timing correction from the base station, the timing correction is performed twice by the request for timing correction issued redundantly from the base station.

  As a result, the frame synchronization of the transport channel between the base station controller and the base station is further lost, so that timing correction is requested from the base station to the base station controller, and the timing correction is repeated. As a result, a silent state or forced disconnection occurs in a voice call, and data cannot be received in data communication.

  On the other hand, if the set guard time is too long, timing correction cannot be performed during the guard time, so the response of the correction is reduced, the timing correction cannot catch up with a sudden change in transmission delay or fluctuation, and the transformer Port channel frame synchronization will not be smooth.

  On the other hand, Patent Document 2 discloses a technique for changing the guard time to a variable value instead of a fixed value. According to Patent Document 2, transmission delay time is periodically measured using ICMP (Internet Control Protocol) ECHO, and Guard Time is determined based on the measured value.

Special table 2007-525080 JP 2009-17118 A

  As described above, in the technique described in Patent Document 2, the transmission delay time is periodically measured, and the Guard Time is determined based on the measured value. However, the transmission delay time always changes or fluctuates. When the transmission delay time changes abruptly, the timing correction may take a time exceeding the Guard Time determined from the measured value of the transmission delay time. If the time required for timing correction exceeds Guard Time, double correction of timing occurs as described above.

  An object of the present invention is to provide a technique for suppressing occurrence of double correction in frame timing correction from a base station controller to a base station.

In order to achieve the above object, the base station controller of the present invention provides:
A data receiving unit for receiving data from the base station device;
A data transmission unit that transmits data to the base station device at a timing corrected according to a timing correction request from the base station device received by the data reception unit;
A transmission delay calculation unit for calculating a round trip transmission delay time including a transmission delay time from the own device to the base station device and a transmission delay time from the base station device to the own device;
A guard time is calculated based on the round-trip transmission delay time and the timing correction amount in the timing correction requested from the base station device, and a timing correction request received from the base station device during the guard time is calculated. A guard time calculation / determination unit to be discarded.

The wireless communication system of the present invention includes:
A base station device that monitors timing of data received from the base station control device and requests the base station control device to perform timing correction so that the timing falls within a predetermined range;
Data is transmitted to the base station device at a timing corrected in response to a timing correction request from the base station device, a transmission delay time from the own device to the base station device, and from the base station device to the own device. A round trip transmission delay time including a transmission delay time is calculated, and a guard time is calculated based on the round trip transmission delay time and a timing correction amount in the timing correction requested from the base station apparatus. And a base station control device that discards the timing correction request received from the base station device.

The timing correction method of the present invention is a timing correction method for correcting a transmission timing for transmitting data from a base station control device to a base station device,
At the timing corrected according to the timing correction request from the base station device, data is transmitted from the base station control device to the base station device,
Calculating a round trip transmission delay time including a transmission delay time from the base station control device to the base station device and a transmission delay time from the base station device to the base station control device;
Based on the round trip transmission delay time and the timing correction amount in the timing correction requested from the base station device, to calculate the guard time,
A request for timing correction received from the base station apparatus during the guard time is discarded.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the double correction | amendment in the timing correction of the flame | frame from a base station control apparatus to a base station can be suppressed.

It is a block diagram which shows the structure of the mobile communication system in schematic embodiment of this invention. It is a block diagram which shows the structure of the base station control apparatus by this embodiment. It is a block diagram which shows the structure of the mobile communication system by a 1st Example. It is a block diagram which shows the structure of the base station control apparatus by a 1st Example. It is a figure for demonstrating operation | movement of the mobile communication system by a 1st Example. It is a flowchart which shows the process in which the base station control apparatus of a 1st Example calculates a transmission delay. It is a flowchart which shows the process of the timing adjustment by the base station control apparatus of a 1st Example. It is a flowchart which shows the process of the timing adjustment by the base station control apparatus of a 1st Example. It is a block diagram which shows the structure of the base station control apparatus by 2nd Example. It is a flowchart which shows the guard time process by a 2nd Example. It is a flowchart which shows the guard time process by a 2nd Example.

  Embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a mobile communication system in a schematic embodiment of the present invention. Referring to FIG. 1, the mobile communication system includes a base station controller 110 and a base station 111. The base station 111 relays data transmitted and received by the mobile terminal 112 via a wireless line. The base station controller 110 is connected to the base station 111 and transmits / receives data transmitted / received by the mobile terminal 112 to / from the base station 111.

  Then, the base station 111 monitors the timing of data received from the base station controller 110 and requests the base station controller 110 to correct the timing so that the timing falls within a predetermined range.

  The base station control device 110 transmits data to the base station 111 at a timing corrected in response to a timing correction request from the base station 111. Further, the base station control device 110 calculates a round trip transmission delay time including a transmission delay time from the own device to the base station 111 and a transmission delay time from the base station 111 to the own device. The base station controller 110 calculates the guard time based on the round trip transmission delay time and the timing correction amount in the timing correction requested from the base station 111, and is received from the base station 111 during the guard time. Discard the timing correction request.

  FIG. 2 is a block diagram showing the configuration of the base station control apparatus according to the present embodiment. Referring to FIG. 2, the base station control apparatus 110 includes a data transmission unit 121, a data reception unit 122, a transmission delay calculation unit 123, and a guard time calculation / determination unit 124.

  The data receiving unit 122 receives data from the base station 111.

  The data transmission unit 121 transmits data to the base station 111 at the timing corrected according to the timing correction request from the base station 111 received by the data reception unit 122.

  The transmission delay calculation unit 123 calculates the round-trip transmission delay time described above.

  The guard time calculation / determination unit 124 calculates the guard time based on the round trip transmission delay time and the timing correction amount in the timing correction requested from the base station 111, and is received from the base station 111 during the guard time. Discard the timing correction request.

  According to the present embodiment, the guard time is determined based on the timing correction amount in addition to the round-trip transmission delay time between the base station controller 110 and the base station 111. Since the timing correction amount is a parameter that is affected by changes in transmission delay time and fluctuations, timing correction does not exceed the guard time even when the transmission delay time changes drastically by using this parameter for calculating the guard time. It is possible to calculate the guard time. As a result, the occurrence of double correction in the data timing correction from the base station control apparatus 110 to the base station 111 can be suppressed.

  As a specific example, the base station control apparatus 110 may calculate the guard time based on the round trip transmission delay time and the maximum value of the past timing correction amount. More specifically, the base station controller 110 may use the total time of the round trip transmission delay time, the maximum timing correction amount, and the predetermined margin as the guard time. Further, the base station controller 110 returns the maximum timing correction amount to zero if there is no request for the next timing correction from the base station 111 until a certain time elapses after the guard time expires. Also good.

  Next, a more specific example of the present embodiment will be described.

(First embodiment)
FIG. 3 is a block diagram showing the configuration of the mobile communication system according to the first embodiment. Referring to FIG. 3, nodes constituting the mobile communication system according to the present embodiment are a base station 11 and a base station control device 10.

  Between the base station controller 10 and the base station 11, transport channel frame synchronization between nodes is established. In order to achieve transport channel frame synchronization, the base station controller 10 measures a round-trip transmission delay time (hereinafter referred to as RTT: Round Trip Time) between the base station controller 10 and the base station 11. RTT is the total time of the frame arrival time from the base station controller 10 to the base station 1 and the frame arrival time from the base station 11 to the base station controller 10.

  The arrival time of the frame from the base station controller 10 to the base station 11 is measured using a DL_NSYNC (Down Link Node Synchronization) 13 of NSYNC (Node Synchronization). The arrival time of the frame from the base station 11 to the base station control apparatus 10 is measured using NSYNC UL_NSYNC (Up Link Node Synchronization) 14.

  In addition, the base station control device 10 determines the timing of sending a frame to the base station 11. In addition, when the transport channel frame synchronization between nodes is shifted, the base station control device 10 corrects the frame transmission timing in response to a request from the base station 11. Specifically, when the frame synchronization is lost, the base station 11 transmits TA15 to the base station control apparatus 10, notifies the base station control apparatus 10 of the frame transmission timing deviation width, and requests timing correction. . When receiving the TA 15 from the base station 11, the base station control device 10 corrects the frame transmission timing according to the request.

  FIG. 4 is a block diagram showing the configuration of the base station control apparatus according to the first embodiment. Referring to FIG. 4, the base station control device 10 includes a data processing device 22, a storage device 23, and a periodic processing device 24.

  The data processing device 22 is a processing device that performs data transmission / reception control, and includes a data transmission unit 25, a data reception unit 26, a transmission delay calculation unit 27, and a guard time calculation / determination unit 28. The storage device 23 is a storage device that records actual control information, and includes a ToA storage unit 2a and a guard time storage unit 2b. The periodic processing device 24 is a processing device that performs each control by periodic activation, and includes a TTI activation unit 2c.

  In the data processing device 22, the data transmission unit 25 transmits data including DL_NSYNC (2d) to the base station 11. The data receiving unit 26 receives data including UL_NSYNC (2e) from the base station 11. The transmission delay calculation unit 27 calculates the RTT between the base station control device 10 and the base station 11. The guard time calculation / determination unit 28 calculates the guard time using DL_NSYNC (2d) and UL_SYNC (2e) according to TA (2f).

  In particular, the transmission delay calculation unit 27 determines the base time based on the time information T1 given to DL_NSYNC (2d), the time information T2 and T3 given to UL_NSYNC (2e), and the time T4 received UL_NSYNC (2e). The transmission delay RTT between the station 11 and the base station control device 10 is calculated, and the calculation result is recorded in the transmission delay storage unit 29 of the storage device 23.

  T1 indicates the time when the base station control apparatus 10 transmits DL_NSYNC (2d). T2 indicates the time when the base station 11 receives DL_NSYNC (2d). T3 indicates the time at which the base station 11 transmits UL_NSYNC (2e). T4 indicates the time when the base station control device 10 receives UL_NSYNC (2e).

  In the storage device 23, the transmission delay storage unit 29 holds the RTT information calculated by the transmission delay calculation unit 27. The ToA storage unit 2a stores the maximum absolute value of Negative ToA based on the value of ToA (Time of Arrival) notified from the guard time calculation / determination unit 28. Negative ToA is a parameter in TA and represents a negative value among ToAs indicating a time difference between frame arrivals.

  The guard time storage unit 2b stores the guard time calculated by the guard time calculation / determination unit 28, and holds the remaining time information of the guard time.

  In particular, the guard time calculation / determination unit 28 calculates the absolute value of Negative ToA from the ToA value of TA (2f) received by the base station controller 10, and the calculated absolute value is stored in the ToA storage unit 2a. If the absolute value of the previous negative ToA is greater than the maximum value, the calculated absolute value is stored in the ToA storage unit 2a as a new maximum value.

  In the periodic processing device 24, the TTI activation unit 2c executes various periodic processes. For example, the TTI activation unit 2c activates transmission of DL_NSYNC (2d). Further, the TTI activation unit 2c monitors the reception timing of UL_NSYNC (2e). Further, the TTI activation unit 2c monitors the reception timing of TA (2f). Further, the TTI activation unit 2c reads the guard time from the guard time storage unit 2b, and performs a guard time timer subtraction process.

  Hereinafter, the operation of the mobile communication system according to the present embodiment will be described.

  FIG. 5 is a diagram for explaining the operation of the mobile communication system according to the first embodiment. Referring to FIG. 5, transmission delay time between nodes (hereinafter referred to as “NSYNC”) is calculated between the base station controller 10 and the base station 11.

  In the base station control device 10, the frame transmission timing T 1 (32) is placed in the DL_NSYNC (36) frame based on the frame timing commonly used in the base station control device 10, and directed to the base station 11. Send.

  The base station 11 uses the timing T2 (33) indicating the time of reception of the DL_NSYNC (36) frame based on the frame timing commonly used in the base station 11, and the timing of frame transmission toward the base station control apparatus 10. T3 (34) is loaded on UL_NSYNC (37) and transmitted to the base station controller 10.

Further, the base station controller 10 measures the timing T4 (35) of UL_NSYNC (37) frame reception from the base station 11, and calculates NSYNC by the following (Equation 1) using T1 to T4. This operation is based on Section 6.1.1 of 3GPP TS25.402 v5.4.0 (2005-06).
(T2-T1) + (T4-T3) (Formula 1)
Next, in this embodiment, transport channel frame synchronization is used.

  According to 7.2 of 3GPP TS25.402 v5.4.0 (2005-06), ToA is the end point of the reception window of the base station 11 (at the timing when the frame data is received from the base station controller 10). This is timing difference information indicating a deviation from ToAE: Time of Arrival Endpoint).

  If the base station 11 receives the frame data from the base station controller 10 before the ToAE in the base station 1, that is, if the frame data arrives early, ToA becomes Positive ToA indicating a positive value. . Conversely, if the timing at which the base station 11 receives the frame data from the base station controller 10 is later than the ToAE at the base station 11, that is, if the frame data arrives late, the ToA indicates a negative value. It becomes.

  When the frame data received from the base station control device 10 is out of the reception window, the base station 11 cannot transmit the frame data to the mobile terminal 12, and therefore the base station control device 10 is provided with a TA with ToA as a parameter. Send to request timing correction. The base station control apparatus 10 that has received the TA corrects the transmission timing based on ToA included in the TA received from the base station 11.

  In addition, the base station controller 10 prevents TA from being duplicated by the TA that arrives in the next TTI period after receiving the TA, and within a certain guard time after receiving the TA. Timing correction is not performed even if received.

  The base station controller 10 of this embodiment calculates the guard time using the transmission delay (RTT) between nodes and ToA based on the above (Equation 1), and dynamically updates it.

  FIG. 6 is a flowchart illustrating a process in which the base station controller of the first embodiment calculates a transmission delay.

  When the base station controller 10 receives UL_NSYNC (2e) from the base station 11, the transmission delay calculation unit 27 extracts parameters T1, T2, and T3 from UL_NSYNC (2e) (step S41). Here, the base station control device 10 acquires the parameter T1 from the UL_NSYNC (2e). However, the base station control device 10 holds the time when the own device transmits the DL_NSYNC (2d) and uses it. Good.

  Furthermore, the base station control apparatus 10 acquires T4 which is the reception timing of UL_NSYNC (2e) in the transmission delay calculation unit 27 (step S42).

  Next, the base station control device 10 calculates an RTT between the base station control device 10 and the base station 11 from T1, T2, T3, and T4 using (Equation 1) (step S43). Then, the base station control device 10 registers the calculated RTT in the transmission delay storage unit 29 (step S44). The transmission delay calculated here is a reference value for determining the guard time.

  7A and 7B are flowcharts illustrating timing adjustment processing by the base station control apparatus of the first embodiment. The guard time update process in FIG. 7B is a process started from the guard time process in FIG. 7A.

  Referring to the guard time processing in FIG. 7A, the frame synchronization of the transport channel between the base station controller 10 and the base station 11 is lost, and the base station controller 10 receives the TA from the base station 11.

  When the TA is received, the base station control device 10 determines whether the guard time is in use at the guard time calculation / determination unit 28 (step S50). During the guard time, the guard time timer subtraction process is activated and the timer has not expired.

  If it is during the guard time, the base station controller 10 discards the received TA and ends the process.

  If it is not during the guard time, the base station control device 10 reads the guard time value from the guard time storage unit 2b, and starts the guard time timer subtraction process (step S51). The base station controller 10 subtracts the count value of the guard time by the timer, and ends the process when the count value becomes 0 (step S52).

  On the other hand, the base station control apparatus 10 also executes a guard time update process (step S53).

As shown in FIG. 7B, when receiving the TA (2f), the base station control device 10 reads the maximum value (ToA ′) of ToA stored in the ToA storage unit 2a (step S54). Next, the base station control device 10 extracts the parameter ToA from the received TA (step S55). Then, the base station control device 10 determines whether or not the ToA extracted from the received TA and the ToA ′ read from the ToA storage unit 2a satisfy (Expression 2) and (Expression 3) (Step S56).
ToA <0 (Equation 2)
(Absolute value of ToA extracted from received TA)> ToA ′ (Equation 3)
Here, (Equation 2) indicates that when the ToA of the received TA is a Negative ToA, that is, when the frame data is late arrival, double correction can occur. Therefore, the ToA in the received TA sets the Negative ToA to It is determined whether or not it is less than 0. If Positive ToA is 1 or more, it means that the frame data arrives early, and therefore no overlap correction can occur.

  Further, in (Expression 3), since ToA satisfying (Expression 2) is a value less than 0, the maximum value is determined by an absolute value.

  When the logical product of (Equation 2) and (Equation 3) does not hold, the base station control apparatus 10 ends the process.

  If the logical product of (Equation 2) and (Equation 3) holds, the base station controller 10 next updates ToA ′ stored in the ToA storage unit 2a to the new maximum value of ToA (step S57). ). Furthermore, the base station controller 10 reads the guard time from the guard time storage unit 2b, updates the value obtained by substituting the maximum value of ToA into (Equation 4), and stores it in the guard time storage unit 2b. The process ends (step S58).

Transmission delay time + ToA + TTI (4)
Note that the addition of TTI has the meaning of adding a margin to the guard time.

  In a general method, when the transport channel frame synchronization correction process between the base station controller 10 and the base station 11 exceeds the guard time due to a transmission delay, the TA process already performed by the base station controller 10 is performed. Overlap correction may occur in which the requested TA is received again and the corrected timing is further corrected. When duplication correction occurs, the transport channel frame synchronization between the base station controller 10 and the base station 11 is further lost, and the timing correction process is repeated.

  On the other hand, in this embodiment, as described above, the maximum value of the timing correction value so far and the time corresponding to the transmission timing period are added to the transmission delay time measured in advance to operate as a guard time. Therefore, it is possible to appropriately suppress the occurrence of duplication correction according to the signal transmission situation.

  Further, preventing duplication correction also efficiently executes processing for recovery from loss of transport channel frame synchronization. As a result, the time required for timing correction can be shortened, and the transmission / reception of useless signals between the base station controller 10 and the base station 11 can be reduced.

  In the above-described embodiment, one base station 11 is shown. However, even if a plurality of base stations 11 are combined, the basic operations of the base station 11 and the base station control device 10 are the same. There is no limit.

  In the present embodiment, a single node synchronization process has been described. Needless to say, the same process may be repeated a plurality of times or periodically.

(Second embodiment)
In the first embodiment, based on the TA parameter ToA received by the base station controller 10, the guard time corresponding to the maximum value of ToA is set using (Equation 4), and the frame transmission timing overlap correction is performed. The ToA used for calculating the guard time remained the maximum value.

  The configuration and operation according to the first embodiment are sufficient as long as the purpose of suppressing the redundant correction of the frame transmission timing against the sudden transmission delay and fluctuation is achieved. However, once a large transmission delay or fluctuation is dealt with, even if the transmission delay or fluctuation thereafter decreases, the correction cannot follow the change in a short time unit.

  Therefore, in the second embodiment, when transmission delay and fluctuation are reduced, the guard time is returned to an appropriate value to realize efficient correction.

  FIG. 8 is a block diagram showing the configuration of the base station control apparatus according to the second embodiment. Referring to FIG. 8, the base station controller 10 of the second embodiment includes a ToA storage unit update ToA storage unit 61 and a ToA in the storage device 23 in addition to those of the first embodiment shown in FIG. The storage unit updating time storage unit 62 is included.

  The guard time calculation / determination unit 28 of the data processing device 22 and the TTI activation unit 2c of the periodic processing device 24 control the ToA storage unit update ToA storage unit 61 and the ToA storage unit update time storage unit 62. 4 is different from that of the first embodiment shown in FIG.

  When the guard time timer expires, the ToA storage unit update time storage unit 62 sets a timer value of the frame timing commonly used in the base station control apparatus 10, and starts a timer subtraction process. As an example of the set Timer value, as an example, a reference frame number (RFN: RNC Frame Number) used for establishing a network synchronization in the base station controller RNC (Radio Network Controller) of the W-CDMA system corresponds to one period. Is used for 40.96 seconds. Hereinafter, this timer is referred to as 40.96 seconds Timer.

  The ToA storage unit update ToA storage unit 61 has a ToA in TA (2f) received from the base station 11 from the time when the 40.96 second Timer is activated until the expiration, and is a Negative ToA (negative value). When the absolute value of ToA is larger than the maximum value of ToA held in the ToA storage unit update ToA storage unit 61, the maximum value of ToA in the ToA storage unit update ToA storage unit 61 is updated.

  Further, the ToA storage update ToA storage unit 61 receives TA (2f) from the base station 11 before the expiration of 40.96 seconds Timer, and the parameter ToA extracted from the TA is stored in the ToA storage. If the ToA value held in the copy updating ToA storage unit 61 is not exceeded, the maximum ToA value among the ToAs extracted from the TA (2f) received from the start of the 40.96 second Timer to the expiration is displayed. Hold.

  In addition, the ToA storage unit 61 for updating the ToA storage unit 61 determines that the ToA storage unit 61 for updating the ToA storage unit 61 when the TA (2f) has never been received from the activation of the 40.96-second Timer. Set the maximum value of to 0.

  By reflecting the ToA value in the ToA storage unit 61 for updating the ToA storage unit as the maximum value of ToA in (Expression 4), the guard time can be controlled to an appropriate value as the transmission delay and fluctuation are reduced.

  9A and 9B are flowcharts showing guard time processing according to the second embodiment. Steps S70, S72, S73, and S74 are the same processes as steps S50, S51, S52, and S53 in the guard time process shown in FIG. 7A. Step 7d is the same process as (S57) of the guard time update process shown in FIG. 7B. The other processes in FIGS. 9A and 9B are processes peculiar to the second embodiment.

  In step S71, the base station controller 10 determines whether or not a 40.96-second timer for updating the next guard time is activated after the guard time timer expires. If the 40.96-second timer is active, the base station control apparatus 10 sets the TA reception flag indicating that the TA has been received during that time (step S77).

  The process of steps S77 to 7a is a process for updating the guard time. The base station control device 10 compares the parameter ToA in the received TA (2f) with the maximum value of ToA stored in the ToA storage update ToA storage unit 61 (step S78).

If the logical product of (Equation 2) and (Equation 5) is established in the determination in step S78, the base station control device 10 overwrites the ToA storage unit 61 for updating the ToA storage unit with the ToA value in TA (2f). Then, the process ends (step S79). In other words, this indicates that a transmission delay has occurred that causes a ToA greater than the previously stored ToA value, and works in the direction of extending the guard time.
(ToA extracted from TA)> (ToA in ToA storage unit for updating ToA storage unit) (5)
If the logical product of (Equation 2) and (Equation 5) does not hold, the base station control device 10 ends the process as it is and retains the previous ToA value.

  In step S71, if the 40.96-second timer is not activated, the base station controller 10 activates the guard time in step S72 and step S73, and performs the guard time update process in step S74 as in the process of FIG. 7A. carry out. And the base station control apparatus 10 starts 40.96 second Timer (step S75).

  Further, the base station controller 10 monitors the expiration of the 40.96 second timer (step S76), and whether or not a new TA (2f) is received while the 40.96 second timer is operating after the expiration. Is determined by the TA reception flag (step 7a).

  If a new TA (2f) has been received while the 40.96 second Timer is operating, the base station control device 10 turns off the TA reception flag (step S7d) and ends the process.

  If a new TA (2f) is not received while the 40.96 second Timer is operating, the base station controller 10 determines that the frame synchronization of the transport channel is stable and turns off the TA reception flag. At the same time, the ToA value in the ToA storage unit updating ToA storage unit 61 is set to 0 (step S7c). Furthermore, the base station control apparatus 10 updates the guard time in the guard time storage unit 2b to the calculation result according to (Equation 4) (step S7d).

  Thus, by reflecting the ToA value updated by 40.96 seconds Timer in the calculation of (Equation 4), the maximum value of ToA used for calculating the guard time once increased is reduced in transmission delay and fluctuation. At the same time, it can be properly controlled.

  In addition, a more stable guard time is calculated by periodically measuring and updating NSYNC, which is a parameter in the calculation of the guard time according to (Equation 4), using DL_SYNC (2d) and UL_SYNC (2e). be able to.

10, 110 Base station control device 11, 111 Base station 12, 112 Mobile terminal 121 Data transmission unit 122 Data reception unit 123 Transmission delay calculation unit 124 Determination unit 22 Data processing device 23 Storage device 24 Periodic processing device 25 Data transmission unit 26 Data Reception unit 27 Transmission delay calculation unit 28 Determination unit 29 Transmission delay storage unit 2a ToA storage unit 2b Guard time storage unit 2c TTI activation unit 61 ToA storage unit update ToA storage unit 62 ToA storage unit update time storage unit

Claims (7)

A data receiving unit for receiving data from the base station device;
A data transmission unit that transmits data to the base station device at a timing corrected according to a timing correction request from the base station device received by the data reception unit;
A transmission delay calculation unit for calculating a round trip transmission delay time including a transmission delay time from the own device to the base station device and a transmission delay time from the base station device to the own device;
A guard time is calculated based on the round trip transmission delay time and the past maximum value of the timing correction amount in the timing correction requested from the base station device, and is received from the base station device during the guard time. A base station control apparatus comprising: a guard time calculation / determination unit that discards a timing correction request. The guard time calculation / determination unit, the if there is the request timing correction before the guard time has elapsed a predetermined time from the expiration of the maximum value of the timing correction amount to zero, according to claim 1 Base station controller. The guard time calculation / determination unit, the total time of the guard time of the maximum value and a predetermined margin of the round trip transmission delay time and the timing correction amount, the base station control apparatus according to claim 1 or 2. The guard time calculation / determination unit detects a shift between an end point of a reception window in the base station device and a data reception timing in the base station device, which is included in the Timing Adjustment information received from the base station device. The time of arrival indicated is a negative value indicating that the reception timing is delayed from the end point, and the absolute value of the time of arrival is the maximum value up to that time. The base station control apparatus according to any one of claims 1 to 3, wherein the base station control apparatus is used as a maximum value. The transmission delay calculation unit includes a time from a first time at which DL_NSYNC information is transmitted from the data transmission unit to a second time at which the DL_NSYNC information is received at the base station device, and the base station device. from the third time UL_NSYNC information is transmitted, the UL_NSYNC information and fourth total time the round trip transmission delay time to the time received by the data receiving unit, of claims 1 to 4, The base station control apparatus according to any one of the above. A base station device that monitors timing of data received from the base station control device and requests the base station control device to perform timing correction so that the timing falls within a predetermined range;
Data is transmitted to the base station device at a timing corrected in response to a timing correction request from the base station device, a transmission delay time from the own device to the base station device, and from the base station device to the own device. Calculating a round trip transmission delay time including a transmission delay time, calculating a guard time based on the round trip transmission delay time and a past maximum value of a timing correction amount in a timing correction requested from the base station device, And a base station control device that discards a timing correction request received from the base station device during the guard time. A timing correction method for correcting a transmission timing for transmitting data from a base station control device to a base station device,
At the timing corrected according to the timing correction request from the base station device, data is transmitted from the base station control device to the base station device,
Calculating a round trip transmission delay time including a transmission delay time from the base station control device to the base station device and a transmission delay time from the base station device to the base station control device;
Calculate the guard time based on the round trip transmission delay time and the past maximum value of the timing correction amount in the timing correction requested from the base station device,
A timing correction method for discarding a timing correction request received from the base station apparatus during the guard time.

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