JP4924322B2 - Frame synchronization method and base station controller - Google Patents

Description

  The present invention relates to a frame synchronization method and a base station control device, and is particularly suitable for use as a frame synchronization method and a base station control device that perform frame synchronization between a base station device and a base station control device.

  A wireless base station installed by a telecommunications carrier secures a communication line with a terminal (mobile device) by transmitting and receiving radio waves, exchanges communications between the base station apparatus and the terminal, and controls the base station apparatus and the base station. Frame synchronization is established with the device.

  FIG. 8 is a configuration diagram of a general mobile communication system (in the case of a W-CDMA system). In the figure, 11 and 12 are mobile terminals (MSs), 2 1 and 2 2 are radio base station devices (NodeB), 3 1, 3n-1 and 3n are radio network controllers (RNCs) 4 Indicates a multimedia processing equipment (MPE), and 5 indicates a mobile multimedia switching system (MMS). Iub and Iu are protocol names, and the Iub protocol is a protocol between the radio base station devices (Node B) 21 and 2 2 and the radio network control devices (RNC) 3 1, 3n-1 and 3n. , A protocol between radio network controllers (RNC) 3 1, 3 n−1, 3 n and mobile multimedia switching system (MMS) 5.

  In the W-CDMA system, synchronization between devices is established in accordance with the timing synchronization rule of 3GPP (Third Generation Partnership Project), which is a project between standardization organizations, for the third generation mobile phone system.

  Although the synchronization method differs depending on the device, the physical delay is measured by node synchronization, and the timing of each user is synchronized by transport channel synchronization.

  The purpose of the frame synchronization between the devices is that the radio network control devices (RNC) 3 1, 3 n-1, 3 n transmit to the radio base station devices (Node B) 2 1, 2 2 in accordance with the radio timing by establishing synchronization between the devices. This is because the buffer amount in the radio base station devices (Node B) 21 and 22 can be reduced.

  Another purpose is that timing synchronization is necessary for concealing user data, which is necessary for matching the start timing of the concealment (secret activation time).

  FIG. 9 is an explanatory diagram of a procedure for establishing frame synchronization between a radio base station and a base station controller according to the prior art.

(A) Node synchronization Node synchronization is used for initial synchronization between the radio network controller (RNC) and the radio base station apparatus (NodeB). That is, the phase difference between the RFN (RNC frame number (counter)) in the radio network controller (RNC) and the BFN (Node B frame number (counter)) in the radio base station device (NodeB) is measured. To do.

  In the figure, the radio network controller (RNC) is T1 (time when the RNC transmits a frame in a downlink node synchronization (DL Node Synchronization) control frame toward the radio base station (NodeB). ) And send. Upon receipt of downlink node synchronization, the radio base station apparatus (NodeB) T2 (time when NodeB receives downlink node synchronization) with respect to T1 (time when RNC transmits a frame) and It responds with an uplink node synchronization (UL Node Synchronization) control frame, indicating T3 (time when NodeB sends downlink node synchronization).

(B) Transport Channel Synchronization Transport Channel Synchronization is used to synchronize each communication on a node synchronization basis. That is, the CFN (connection frame number (counter)) is synchronized between the radio network controller (RNC) and the radio base station apparatus (NodeB).

  In the figure, a radio network controller (RNC) transmits a radio transmission timing (CFN) serving as a reference in a DL node synchronization control frame in the direction of a radio base station apparatus (Node B). Upon reception of the DL node synchronization control frame, the radio base station apparatus (NodeB) measures the phase difference (ToA: Time Of Arrival) between the transmission timing for the CFN and T1 (time when the RNC transmits the frame). To do. The measured phase difference is responded by indicating ToA in the UL node synchronization control frame.

(C) Timing Adjustment Timing adjustment (Timing adjustment) is used to correct when a phase difference occurs due to movement of a terminal or the like as establishment of synchronization during communication.

  In the figure, when the DL DATA frame transmitted from the radio network controller (RNC) in the direction of the radio base station (NodeB) is out of the NodeB reception window, the received DL DATA frame and the NodeB CFN (connection frame) The phase difference (ToA) between the transmission timing for the number (counter) and T1 (time when the RNC transmits a frame) is transmitted to the RNC.

  FIG. 10 is a diagram illustrating a relationship between a master frame counter and a channel card in the base station control apparatus according to the conventional technique. In the figure, 61 and 62 are master frame counter # 1 and master frame counter # 2, respectively, and 71, 72, 73 and 74 are channel card # 1, channel card # 2, channel card # 3 and channel card # 4. It is. The base station control device corresponds to an RNC (Radio Network Controller) of the W-CDMA system shown in FIG.

  That is, the master frame counter has a duplex configuration, and each channel card 71, 72, 73, 74 stores the frame synchronization information data of each channel. The master frame counter 61 sends # 1 system frame counter information and # 1 system control signals to the channel cards 71, 72, 73 and 74, and the master frame counter 62 sends # 2 system frame counter information and #. A 2-system control signal is transmitted to each channel card 71, 72, 73, 74.

  As described above, conventionally, the only reference RFN in the base station controller (the frame number of the RNC obtained from the frame counter held in the RNC device) and the only reference BFN of the radio base station (in the NodeB device) Establishing synchronization by determining CFN (common frame number between RNC device and NodeB determined from the phase of RFN and BFN) that can be commonly used for actual communication from the frame number of NodeB obtained from the owned frame counter) Had gone.

  In this general conventional method, centralized management of frame synchronization can be expected by providing a plurality of base station controllers with a high-accuracy master frame counter in common.

In addition, as a synchronization method between different protocols in the UMTS terrestrial radio access network which is the European standard of the third generation mobile communication system, the timing in the first protocol is controlled by the connection frame number (CFN), There is known an uplink synchronization method in which timing in a protocol is controlled by a frame number (FN), and a frame number is given to a second protocol based on the frame number of the first protocol. (For example, see Patent Document 1)
This conventional method can be expected to reduce the protocol replacement delay and the buffer and the like related thereto.
JP-T-2004-533191

  In the frame synchronization between a radio base station and a base station control device, the present invention performs frame synchronization without having a master frame counter common to the device on the base station control device side. It is an object of the present invention to provide a frame synchronization method and a frame synchronization control mobile communication system that can omit a frame synchronization establishment procedure between apparatuses without requiring a value transmission path and control.

  According to a first aspect of the present invention for solving the above problem, in a frame synchronization method between a radio base station and a base station controller, a self-running counter provided in each channel card in the base station controller is self-run. A step of generating a frame number; a step of extracting a connection phase for each path of a transmission path used by a user from a transmission frame number sent from a transmission source; Establishing self-synchronization using a phase difference with the running frame.

  According to the first aspect of the present invention, the frame synchronization establishment procedure between apparatuses can be omitted, and a frame synchronization method with good synchronization tracking can be provided.

  According to a second invention, in the frame synchronization method according to the first invention, the step of establishing the self-synchronization calculates a user offset value by calculating a phase difference between the self-running frame and the reception frame number for each user. And

  According to the second aspect of the present invention, it is possible to provide a frame synchronization method that sets a user offset value (correction value) for correcting a phase shift, can be updated each time a partner reception frame is received, and can be kept up to date. .

  According to a third aspect of the present invention, in the frame synchronization method according to the first aspect, when there are a plurality of the paths, the step of synchronizing the received frame with the latest path or synchronizing with the earliest path The method further includes performing transmission frame synchronization.

  According to the third aspect of the invention, it is possible to provide a frame synchronization method that enables reception frame synchronization or transmission frame synchronization when a plurality of paths are connected.

  According to a fourth aspect of the present invention, in the frame synchronization method according to the first aspect, when a path is newly added to the path, a step of performing received frame synchronization when adding a path later than the path or adding a path earlier than the path The method further includes a step of performing transmission frame synchronization.

  According to the fourth invention, when the user moves from the own cell to another cell, the frame synchronization is updated depending on whether the new path is delayed from the original path frame synchronization state or not. A possible frame synchronization method can be provided.

  A fifth invention is a base station controller that performs frame synchronization with a radio base station, a self-running counter provided for each channel card in the base station controller, and a transmission path used by a user Means for extracting a connection phase for each path from a transmission frame number sent from a transmission source; means for establishing self-synchronization using a phase difference between the connection phase for each path and the free-running frame of the free-running counter And have.

  According to the fifth aspect of the present invention, the master frame counter of the device, the path for transmitting the counter value to each card and the control device are unnecessary, and a base station control device with easy maintenance can be provided.

  As described above, according to the frame synchronization method and the mobile communication system of the present invention, the master frame counter of the apparatus is not required, and the route and control for transmitting the counter value to each card are not required.

  Since the card on which the master frame counter is mounted is shared by the apparatus, if this fails, the entire apparatus is affected. Therefore, usually a countermeasure such as duplication is taken, and the circuit becomes complicated by the synchronous switching control. In the present invention, since such a card itself is unnecessary, there is no need for duplexing, switching control, or a path for transmitting a frame counter value, and the structure is simplified, so that there is an advantage that design / maintenance is simple and inexpensive.

  In addition, the procedure for establishing frame synchronization between devices can be omitted. That is, there is no establishment of frame synchronization between devices, and synchronization can be obtained only within the own device from the signal of the partner device, so that the number of signals traveling between devices can be reduced. As a result, it is not necessary for the radio base station to mount the synchronization establishment procedure in the application, and the processing can be simplified. The base station control device can speed up the frame synchronization procedure because the synchronization establishment is closed to the processing in the device.

  Furthermore, the synchronization followability is good. That is, in the synchronization establishment procedure so far, after the establishment of synchronization, when a certain amount of phase shift is detected on the radio base station side (to the extent that the reception window deviates), the procedure for correcting the phase is performed. Since the frame synchronization information is updated every time an upstream signal is received, the latest phase state is always maintained, and there is no need to consider the phase correction procedure again. In addition, since there is no large phase change at a time compared to the conventional case, there is no need for signal loss due to timing skip and countermeasures (buffering for delay use) therefor.

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

  FIG. 1 is a block diagram of a channel card according to an embodiment of the present invention. In the figure, reference numeral 7 denotes a plurality of channel cards provided in the base station controller. The configuration of each channel card 7 includes a CPU 71 that performs data transmission / reception and phase management, a memory 72 that stores frame synchronization information data of each channel such as phase information, and a free-running counter 73 that self-runs upon resetting the channel card. , A transmission function unit 74, a reception function unit 75, and another function unit 76, each of which is connected on a common bus.

FIG. 2 is a call connection procedure time chart of the mobile communication system according to the embodiment of the present invention. In the present invention, as shown in the figure, it is not necessary to establish frame synchronization between the radio base station and the radio base station control device, and synchronization can be established only within the own device from the signal of the counterpart device. Hereinafter, a description will be given of a frame synchronization procedure in each connection procedure of communication start on the common control channel, transition to the individual control channel, call setting, and transition to the individual user channel to start a call.
(1) Start communication on the common control channel
(1-1) A call signal is sent from the exchange to the radio base station.
(1-2) In response, the radio base station sends a radio link connection request to the base station controller.
(1-3) The base station controller establishes frame synchronization by receiving the partner frame number (FN).
(Note) The frame number (FN) corresponding to the CFN required at the time of communication is a self-running counter for each subordinate card described above, and a method of subordinately synchronizing with the BFN (CFN) assigned to the signal from the base station apparatus. Take.
(2) Transition to dedicated control channel and call setup
(2-1) A radio link connection setting signal is sent from the base station controller to the radio base station.
(2-2) In response, the radio base station sends a radio link connection setting completion signal to the base station controller.
(2-3) The base station controller establishes frame synchronization (update) by receiving the partner frame number (FN).
(2-4) A call response signal is sent from the exchange to the exchange via the base station controller.
(2-5) The base station controller establishes frame synchronization (update) by receiving the partner frame number (FN).
(2-6) An authentication request signal is sent from the exchange to the radio base station.
(2-7) Upon receiving this, the radio base station sends an authentication response signal to the exchange via the base station controller.
(2-8) The base station controller establishes frame synchronization (update) by receiving the partner frame number (FN).
(2-9) A secret setting signal is sent from the exchange to the radio base station.
(2-10) Upon receiving this, the radio base station sends a concealment setting completion signal to the exchange via the base station controller.
(2-11) The base station controller establishes frame synchronization (update) by receiving the partner frame number (FN).
(2-12) A call setup signal is sent from the exchange to the radio base station.
(2-13) Upon receiving this, the radio base station sends a call setup acceptance signal to the exchange via the base station controller.
(2-14) The base station controller establishes frame synchronization (update) by receiving the partner frame number (FN).
(3) Transition to individual user channel and start calling
(3-1) A radio bearer setting signal is sent from the exchange to the radio base station.
(3-2) Upon receiving this, the radio base station sends a radio bearer setting completion signal to the exchange via the base station controller, and sends an alert signal and a call connection signal to the exchange.
(3-3) The base station control device establishes frame synchronization (update) by receiving the partner frame number (FN) each time it receives a radio bearer setting completion signal, an alert signal, and a call connection signal.
(3-4) A call connection response signal is sent from the exchange to the radio base station.
(3-5) The radio base station and the exchange station enter into a call.

FIG. 3 is an explanatory diagram of a frame synchronization procedure (reception synchronization) in one embodiment of the present invention. (A) In the case of 1-path connection In this example, an example when the user a-path 1 is connected is shown. Note that the frame number (FN) of the user a path 1 is incremented every time data is transmitted.

  The difference between the free-running frame number and the received frame number (FN) (user offset r) = 11-2 = 9 is held as an offset as management information for each user.

Received frame synchronization (user a) = (free-running frame number + user offset r + [system offset r] + FNmax) modFNmax = (2 + 9 + 0 + FNmax) modFNmax = 11
Once the other party reception frame number (FN) is received, the corresponding user is synchronized, and thereafter, it is possible to determine from the self-running frame number, the user offset r, and the system offset r without receiving the reception frame from the other party. It becomes possible. Further, the user offset r is updated every time a partner received frame is received, and is kept in the latest state.
(B) In the case of two-path simultaneous connection In this example, an example of simultaneous connection when a route for a user a-path is added is shown. It is assumed that there is a phase difference between the FNs of path 1 and path 2. Here, FN is set to 1 count (10 ms).

  If there are multiple paths, adjust to the most delayed path. In this example, it is adjusted to pass 2.

  In the figure, the difference from the free-running frame of pass 1 = 11−2 = 9, and the difference from the free-running frame of pass 2 = 10−2 = 8. Here, the one with a sign and a smaller numerical value is determined as a delayed path, and this is set as a user offset r.

Received frame synchronization (user a) = (free-running frame number + user offset r + [system offset r] + FNmax) modFNmax = (2 + 8 + 0 + FNmax) modFNmax = 10
As described above, in the reception synchronization, the base station control device establishes frame synchronization by receiving the partner frame number (FN). At that time, the base station controller stores connection information for each user, and manages which transmission path the user is using in units of paths. Since the connection phase for each path differs depending on the communication path, it is necessary to measure the phase information for each communication path. The phase information is extracted from the transmission frame number (FN) sent from the other party, and self-synchronization is ensured using the phase difference (user offset r) from the self-running frame. The transmission frame numbers (FN) received at this time are shifted in units of mobile units and paths, but if they wait for the path with the longest frame number, they can all be absorbed. When a delay occurs in the system, a settable offset can be given as the system offset r. This frame synchronization method is always asynchronous with the other party because it is synchronized with a free-running frame, but the phase tracking is always performed by performing this synchronization procedure every time it is received.

  FIG. 4 is a flowchart of the most delayed path determination in one embodiment of the present invention.

  S1. It is determined whether there is a change in the self-running frame.

  S2. If there is a change in the free-running frame, it is determined whether or not the reception flag is ON.

  S3. When the reception flag is in the ON state, the user offset r is updated and the user offset r is corrected to the difference r_temp.

  S4. The reception flag is turned off, and the difference r_now and the difference r_temp are cleared.

  S5. Determine whether a frame has been received.

  S6. The difference between the reception frame number (FN) and the free-running frame (difference r_now = reception FN−free-running frame number) is calculated. Actually, the frame crossing correction is performed.

(Correction between frames)
When −FNMAX / 2 <difference r_now ≦ FNMAX / 2, difference r_now = difference r_now. When difference r_now ≦ −FNMAX / 2, difference r_now = difference r_now + FNMAX.
When difference r_now> FNMAX / 2, difference r_now = difference r_now−FNMAX.

  S7. It is determined whether the reception flag is in an ON state.

  S8. When the reception flag is in the ON state, it is determined whether or not the difference r_now <the difference r_temp.

  S9. If difference r_now <difference r_temp, the difference r_temp is updated and corrected to difference r_temp = difference r_now.

  S10. If the reception flag is not ON, the difference r_temp is updated and the difference r_temp = difference r_now is corrected.

  S11. Turn on the reception flag.

FIG. 5 is an explanatory diagram of a frame synchronization procedure (transmission synchronization) in an embodiment of the present invention. Note that the case of one pass is omitted because it is the same image as in the case of reception synchronization.
(A) All-path connection (in the case of 2-path connection)
This example shows an example of simultaneous connection when a route is added to the user a path. It is assumed that there is a phase difference between the FNs of path 1 and path 2. Here, FN is set to 1 count (10 ms). If there are multiple paths, match the earliest path. In this example, it is adjusted to pass 1.

  In the figure, the difference from the free-running frame of pass 1 = 11−2 = 9, and the difference from the free-running frame of pass 2 = 10−2 = 8. Here, it is determined that a path with a sign and a larger numerical value is a delayed path, and this is set as a user offset t.

Transmission / reception frame synchronization (user a) = (free-running frame number + user offset t + [system offset t] + FNmax) modeFNmax = (2 + 9 + 0 + FNmax) modeFNmax = 11
On the transmission side, by synchronizing with the earliest path of the received FN, delay arrival can be prevented by transmission to the earliest path. In this example, if transmission is performed with FN = 12, when transmitting at the point of the self-running frame 3, path 1 can be received just before FN = 12, and path 2 can be received one frame before with FN = 11. Furthermore, it is possible to add a system offset t as an option in consideration of the system delay.
(B) Per-path control (in the case of 2-path connection)
The conditions are the same as the all-path connection (in the case of two-path connection) in the previous section.

Transmission frame synchronization (user a path 1) = (free-running frame number + user offset t1 + [system offset t] + FNmax) modFNmax = (2 + 9 + 0 + FNmax) modFNmax = 11
Transmission frame synchronization (user a path 2) = (free-running frame number + user offset t 2 + [system offset t] + FNmax) modFNmax = (2 + 8 + 0 + FNmax) modFNmax = 10
On the transmission side, the user offset is managed for each path and transmitted at the optimum timing. In this example, when transmitting at the point of the self-running frame 3, the path 1 is transmitted with FN = 12, and the path 2 is transmitted with FN = 11. It is also possible to add a system offset t in consideration of the system delay.

  As described above, transmission synchronization is basically the same as reception synchronization. Frame synchronization is established by receiving the partner frame number (FN). Connection information is stored in units of users, and the transmission path used by the user is managed in units of paths. Since the connection phase for each path differs depending on the communication path, it is necessary to measure the phase information for each communication path. The phase information is extracted from the transmission frame number (FN) sent from the other party, and self-synchronization is ensured using the phase difference (user offset t) from the free-running frame. However, unlike the reception side, the transmission side is adjusted to the earliest path with respect to the deviation for each path. This is because even the transmission to the earliest path does not cause late arrival on the other side. Alternatively, it is also possible to transmit at the optimum timing for each path by managing the user offset tx for each path. It is possible to attach a settable system offset t to adjust the delay time of the system, as in the receiving side. This frame synchronization method is always asynchronous with the other party because it is synchronized with a free-running frame, but the phase tracking is always performed by performing this synchronization procedure every time it is received.

  FIG. 6 is a flowchart of the earliest path determination in one embodiment of the present invention.

  S12. It is determined whether there is a change in the self-running frame.

  S13. If there is a change in the free-running frame, it is determined whether or not the reception flag is ON.

  S14. If the reception flag is ON, the user offset t is updated and the user offset t = difference t_temp is corrected.

  S15. The reception flag is turned off, and the difference t_now and the difference t_temp are cleared.

  S16. Determine whether a frame has been received.

  S17. The difference between the received frame number (FN) and the free-running frame (difference t_now = received FN−free-running frame number) is calculated. Actually, the frame crossing correction is performed.

(Correction between frames)
When -FNMAX / 2 <difference t_now ≦ FNMAX / 2, difference t_now = difference t_now. When difference t_now ≦ −FNMAX / 2, difference t_now = difference t_now + FNMAX.
When difference t_now> FNMAX / 2, difference t_now = difference t_now−FNMAX.

  S18. It is determined whether the reception flag is in an ON state.

  S19. If the reception flag is in the ON state, it is determined whether or not the difference t_now> the difference t_temp.

  S20. If difference t_now> difference t_temp, the difference t_temp is updated and corrected to difference t_temp = difference t_now.

  S21. If the reception flag is not in the ON state, the difference t_temp is updated, and the difference t_temp = the difference t_now is corrected.

  S22. Turn on the reception flag.

FIG. 7 is an explanatory diagram when a path is added according to an embodiment of the present invention.
(A) When a slow path is added A case where a new path 3 is originally added from frame synchronization in two paths and a new path is delayed from a two-pass frame synchronization state is shown.

Received frame synchronization (user a) = (free-running frame number + user offset r + [system offset r] + FNmax) modFNmax = (3 + ((254-3) −256) + (− 1) +256) mod256 = 253
Transmission frame synchronization (user a) = (free-running frame number + user offset t + [system offset t] + FNmax) modFNmax = (3+ (1-3) + 1-256) mod256 = 2
In this case, the received frame synchronization is updated by adding a slow path.

  Note) The system offset r is -10 ms (1 count), and the system offset t is +10 ms (1 count).

In this case, the received frame synchronization is updated by adding a slow path.
(B) A case where an early path is added A case where a new path 3 is originally added from frame synchronization in two paths and a case where the new path is not delayed from the two-pass frame synchronization state is shown.
Received frame synchronization (user a) = (free-running frame number + user offset r + [system offset r] + FNmax) modFNmax = (3 + ((0-3) -256) + (-1) +256) mod256 = 255
Transmission frame synchronization (user a) = (free-running frame number + user offset t + [system offset t] + FNmax) modFNmax = (3+ (2-3) + 1 + 256) mod256 = 3
In this case, the transmission frame synchronization is updated by early path addition.

    Note) The system offset r is -10 ms (1 count), and the system offset t is +10 ms (1 count).

  As described above, when the user moves from the own cell and moves to another cell, it is necessary to resynchronize from the environment in which synchronization has been ensured so far. Since the destination delay time is not measured in advance, it is determined when the path N is added.

The following additional notes are further disclosed with respect to the embodiment including the above examples.
(Supplementary note 1) In a frame synchronization method between a radio base station and a base station controller, a step of generating a free-running frame number of a free-running counter provided for each channel card in the base station controller, and a user Using the phase difference between the connection phase for each path and the free-running frame of the free-running counter, and extracting the connection phase for each path of the transmission path used by the transmission path from the transmission frame number sent from the transmission source Establishing a self-synchronization method.
(Supplementary note 2) In the frame synchronization method according to supplementary note 1, the step of establishing the self-synchronization calculates a phase difference between the self-running frame and the reception frame number for each user to obtain a user offset value. Frame synchronization method.
(Supplementary note 3) In the frame synchronization method according to supplementary note 1, when there are a plurality of the paths, the step of synchronizing the received frame with the latest delayed path or performing the synchronization of the transmission frame with the synchronization of the fastest path is performed. The frame synchronization method further comprising a step.
(Supplementary note 4) In the frame synchronization method according to supplementary note 1, when a new path is added to the path, a step of performing reception frame synchronization when adding a path later than the path or transmission frame synchronization when adding a path earlier than the path. The frame synchronization method further comprising the step of:
(Supplementary Note 5) In a base station controller that performs frame synchronization with a radio base station, a free-running counter provided for each channel card in the base station controller and a path that is a transmission path used by a user Means for extracting the connection phase from the transmission frame number sent from the transmission source, means for establishing self-synchronization using the phase difference between the connection phase for each path and the free-running frame of the free-running counter, A base station control apparatus comprising:
(Supplementary note 6) The base station control device according to supplementary note 5, wherein a phase difference between the self-running frame and the reception frame number is calculated for each user to obtain a user offset value.
(Supplementary note 7) The base station control device according to supplementary note 5, wherein when there are a plurality of the paths, the received frame synchronization is performed by synchronizing with the most delayed path.
(Supplementary note 8) The base station control device according to supplementary note 5, wherein when there are a plurality of the paths, the transmission frame synchronization is performed by synchronizing with the earliest path.

  The present invention is a base station controller that performs frame synchronization with a radio base station, and can eliminate the route and control for transmitting the count value without providing a master frame counter that is conventionally required. The procedure for establishing frame synchronization between devices can be omitted. Furthermore, since the synchronization followability is good, a large phase change does not occur at one time. Therefore, the maintenance is simplified and the present invention can be used in a base station controller of a mobile communication system that requires a high speed frame synchronization procedure.

It is a block block diagram of the channel card in one Embodiment of this invention. It is a call connection procedure time chart of the mobile communication system in one Embodiment of this invention. It is explanatory drawing of the frame synchronization procedure (reception synchronization) in one Embodiment of this invention. It is a flowchart of the most delayed path determination in one embodiment of the present invention. It is explanatory drawing of the frame synchronization procedure (transmission synchronization) in one Embodiment of this invention. It is a flowchart of the earliest path | pass determination in one Embodiment of this invention. It is explanatory drawing when the path | pass in one Embodiment of this invention is added. It is a block diagram of a general mobile communication system (in the case of a W-CDMA system). It is explanatory drawing of the frame synchronization establishment procedure between the wireless base station and base station control apparatus by a prior art. It is a figure which shows the relationship between the master frame counter and channel card in the base station control apparatus by a prior art.

Explanation of symbols

1 Wireless mobile station equipment (MS)
2 Radio base station equipment (NodeB)
3 Radio network controller (RNC)
4 Multimedia signal processing equipment (MPE)
5 Mobile multimedia switching system 6 Master frame counter 7 Channel card 71 CPU
72 Memory 73 Self-running counter 74 Transmission function part 75 Reception function part 76 Other function part

Claims (5)

In a frame synchronization method between a radio base station and a base station controller,
Generating a free-running frame number of a free-running counter provided for each channel card in the base station controller;
Extracting a connection phase for each path of a transmission path used by a user from a transmission frame number sent from a transmission source;
Establishing self-synchronization using a phase difference between the connection phase for each path and the free-running frame of the free-running counter;
Including a frame synchronization method. The frame synchronization method according to claim 1, wherein
The step of establishing the self-synchronization includes calculating a phase difference between the self-running frame and the reception frame number for each user to obtain a user offset value. The frame synchronization method according to claim 1, wherein
When there are a plurality of the paths, the frame synchronization method further includes the step of synchronizing the received frame with the latest path and the step of synchronizing the transmission with the earliest path. The frame synchronization method according to claim 1, wherein
When a path is newly added to the path, the frame synchronization method further includes a step of performing received frame synchronization when adding a path later than the path, or performing a transmission frame synchronization when adding a path earlier than the path. . In a base station controller that performs frame synchronization with a radio base station,
A free-running counter provided for each channel card in the base station controller,
Means for extracting a connection phase for each path which is a transmission path used by a user from a transmission frame number sent from a transmission source;
Means for establishing self-synchronization using a phase difference between a connection phase for each path and a free-running frame of the free-running counter;
A base station control apparatus comprising:

Images