WO2001013667A1

WO2001013667A1 - Method of accepting packet call in mobile communication system

Info

Publication number: WO2001013667A1
Application number: PCT/JP1999/004358
Authority: WO
Inventors: Kumiko Fujimoto; Takashi Murai
Original assignee: Fujitsu Limited
Priority date: 1999-08-12
Filing date: 1999-08-12
Publication date: 2001-02-22

Abstract

A mobile communication system comprises base stations capable of communicating with mobile stations in a cell, and a base station controller for controlling the base stations. Upon receiving a request for a packet call transmission, each base station forecasts the total power required for transmission from the base station to the mobile stations in the cell. If the forecast transmission power is greater than the allowable transmission power of the base station, the base station controller (31) decreases the transmission rate of the current speech or packet call or ends the software handoff control to bring the forecast transmission power below the allowable transmission power, and then connects the packet call.

Description

Specification

Packet call acceptance method in mobile communication system

Technical field

The present invention relates to a packet call accepting method, and more particularly to a bucket call accepting method in a base station communicating with a mobile station in a cell, a CDMA mobile communication system equipped with a base station controller controlling a plurality of base stations, and the like. About.

Background art

In recent years, with the spread of mobile communication systems and the adoption of multimedia, there has been a demand for the efficient use of radio resources and the provision of stable services with an improved call connection rate.

For this reason, in the CDMA mobile communication system, the transmission power control and the maintenance and management of the channel quality and radio resources are performed. FIG. 18 is an explanatory diagram for explaining the necessity of transmission power control, where 1 is a base station (BS),? ~? !! is a mobile station (MSi MSn), which performs CDMA communication. The CDMA system is a multiple access method using a spread spectrum communication system.The base station 1 spreads and modulates transmission information of a plurality of channels or users with different codes, and multiplexes each spread modulation signal. Transmit. Each of the mobile stations 2 to 2n despreads the received signal by using the spreading code allocated at the time of communication to demodulate the transmission information addressed to itself, and spread modulates the transmission information to base station 1 Send to In the mobile radio according to the CDMA system, signals from the mobile stations 2 i to 2 n arrive at the base station 1 overlapping in time. The signal strength (power) arriving at the base station 1 from each of the mobile stations 2 to 2n differs depending on the distance, transmission path environment, and transmission power. Focusing on a certain mobile station, the signal output from another mobile station becomes an interference wave, and communication becomes impossible if the signal strength from the other mobile station is large. For this reason, it is necessary to keep the SIR (signal interference rat io), which is the ratio of the signal power reaching the base station 1 from the predetermined mobile stations 2 to 2η, to the power of the interference wave including thermal noise constant. Power control is performed. FIG. 19 is a processing flow of the transmission power control by the closed loop method. The base station BS measures the SIR, which is the ratio between the power of the received signal from the mobile station MSi (i = 1, 2,... Η) and the power of the interference wave (step S001), and compares the measured SIR with the lower signal. Notify the mobile station MSi (step S002) _{o The} mobile station MSi checks whether the base station BS / SIR notification has been received (step S00 3) The transmission power is determined based on the notified SIR, and a signal is transmitted at the transmission power (step S004).

In a CDMA mobile communication system, when a mobile station (car phone, mobile phone, etc.) moves from a first cell to an adjacent second cell, soft handoff control is performed. The soft handoff control is based on the assumption that when a mobile station moves from the first cell to the second cell and enters the cell boundary area, the mobile station in the second cell remains connected to the base station in the first cell. A wireless line is connected to this base station, and then a base station that can communicate with low power is selected for communication. According to the soft handoff method, (1) uninterrupted handoff is possible, and (2) inter-cell diversity is possible.However, one mobile terminal communicates with two base stations at the same time. Uses a lot of radio resources.

In a CDMA mobile communication system, a packet data service (packet communication) is possible.

By the way, the transmission rate of a bucket call is higher than the transmission rate of a normal voice call, requiring a large transmission power, and increasing the ratio to the transmission power of the entire base station. That is, when a packet call occurs, the base station raises the transmission power to keep the line quality constant, and requires a large transmission power. For this reason, the radio resources within the cell decrease due to the packet call, causing a problem that the call connection rate decreases.

An object of the present invention is to reduce the transmission rate of a voice call during communication or a packet call during communication when the remaining capacity of the radio resources in the cell decreases, or to end the soft hand-off and reduce the transmission power. This is to increase the remaining connection capacity of the radio resources within the recell to improve the call connection rate.

Another object of the present invention is to monitor the remaining capacity of radio resources in a cell, and when a packet call cannot be accepted due to the remaining capacity, (1) the transmission rate of a voice call during communication or a packet call during communication; Or (2) to end the soft handoff and suppress the transmission power, thereby enabling bucket calls to be accepted.

Disclosure of the invention

When the base station receives a request to send a repacket call from the mobile station, the base station predicts (1) the total transmission power from the base station to the mobile station in the cell, and (2) the predicted transmission power is equal to that of the base station. If the transmission power is higher than the transmission power or the threshold, the transmission rate of the voice call communicating with the base station is (3) After that, the connection control of the bucket call is performed.

When the base station receives a repacket call transmission request from the mobile station, the base station predicts (1) the total transmission power from the base station to the mobile station in the cell, and (2) the predicted transmission power is If the transmission power is larger than the possible transmission power or the threshold, a terminal in communication with the base station is searched for a terminal in a soft hand-off state. (4) After that, control the connection of the bucket call.

When the base station receives a repacket call transmission request from the mobile station, the base station predicts (1) the total transmission power from the base station to the mobile station in the cell, and (2) the predicted transmission power is If the transmission power is larger than the possible transmission power or the threshold value, the transmission rate of the bucket call communicating with the base station is reduced to make the predicted transmission power smaller than the possible transmission power or the threshold value of the base station. (3) Performs connection control for packet calls.

In addition, the base station side (1) pre-sets and stores the packet call transmission rate corresponding to the mobile station, and (2) receives a packet call transmission request from the mobile station, and The transmission rate of a packet call is determined. (3) The total transmission power from the base station to the mobile station in the cell is predicted in consideration of the transmission rate. If the power is larger than the power or the threshold value, the transmission rate of the voice call during communication with the base station is reduced to make the predicted transmission power smaller than the possible transmission power or the threshold value of the base station. Perform control.

As described above, when the remaining capacity of wireless resources in a cell decreases, (1) reduce the transmission rate of a voice call during communication or a packet call during communication, or (2) end soft hand-off and reduce transmission power. Therefore, the remaining capacity of the radio resources in the cell can be increased, and the call connection rate can be improved. In particular, when a packet call cannot be accepted due to the remaining capacity of the radio resources in the cell, (1) reduce the transmission rate of a voice call during communication or a bucket call during communication, or (2) end soft handoff to reduce transmission power. Therefore, the remaining capacity of the radio resources in the cell can be increased, and the bucket call can be accepted.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 illustrates the procedure for accepting packet calls while reducing the transmission rate of voice calls during communication. It is.

FIG. 2 is an explanatory diagram of a procedure for setting a threshold value and controlling a transmission rate.

FIG. 3 is an explanatory diagram of a procedure for ending the handoff and receiving a bucket call.

Figure 4 is an explanatory diagram of the procedure for reducing the transmission rate of a bucket call during communication and accepting the bucket call.

FIG. 5 is an explanatory diagram of a procedure for reducing the transmission rate of a voice call during communication and accepting a bucket call at a different transmission rate for each mobile terminal.

FIG. 6 is a configuration diagram of a CDMA mobile communication system to which the present invention can be applied.

FIG. 7 is a system configuration diagram for explaining the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of a control procedure according to the first embodiment.

FIG. 9 is an explanatory diagram of the audio transmission rate.

FIG. 10 is a system configuration diagram of a modification of the first embodiment.

FIG. 11 is an explanatory view of the procedure of the modification.

FIG. 12 is a system configuration diagram for explaining a second embodiment of the present invention.

FIG. 13 is an explanatory diagram of a control procedure according to the second embodiment.

FIG. 14 is a system configuration diagram for explaining a third embodiment of the present invention.

FIG. 15 is an explanatory diagram of a control procedure according to the third embodiment.

FIG. 16 is a system configuration diagram for explaining a fourth embodiment of the present invention.

FIG. 17 is an explanatory diagram of a control procedure according to the fourth embodiment.

FIG. 18 is a diagram for explaining the necessity of transmission power control.

FIG. 19 is a processing flow of the transmission power control by the closed loop method.

BEST MODE FOR CARRYING OUT THE INVENTION

(A) Outline of the present invention

(a) Reduction of transmission rate of voice call during communication

FIG. 1 is an explanatory diagram of a procedure for reducing the transmission rate of a voice call during communication and receiving a bucket call. The base station 11 has a function of predicting the transmission power of the lower link, and the base station controller 31 has a traffic monitoring control function.

The base station 11 keeps the SIR (Eb / (No + Io) constant in order to maximize the subscriber capacity by optimizing the power allocation for each mobile terminal (mobile station) 21 in the upper wireless link. Each The transmission power of the mobile terminal 21 is controlled. Eb is energy per bit, No is thermal noise, and Io is interference noise from other users.

In this transmission power control state, when the base station 11 receives a request for transmitting a bucket call from the mobile terminal 21, (1) the total transmission power on the lower radio line when the call is assumed to be accepted and connected. (2) Notify the base station controller 31 of the occurrence of the packet call and the estimated transmission power. When notified of the occurrence of the call and the predicted transmission power of the downlink radio line, the base station controller 31 checks whether the call is a packet call and the predicted transmission power exceeds a certain radio resource capacity. Click (Step 101). That is, the base station controller 31 determines whether the predicted transmission power is equal to or less than the possible transmission power of the base station.

If the predicted transmission power is <the possible transmission power of the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request.

On the other hand, if it is determined in step 101 that the estimated transmission power is the transmission power of the base station, the base station controller 31 notifies the voice codec processing unit to reduce the transmission rate of the active voice call, Reduce the transmission rate (Step 102). Thereafter, the base station 11 notifies the base station 11 of the acceptance of the bucket call. When the base station 11 receives the acceptance, the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request.

Thereafter, according to the normal sequence, the bucket call is accepted and connection control with the other party is performed.

In the above, the transmission rate was controlled based on the estimated transmission power and the magnitude of the base station's possible transmission power. If the estimated transmission power is higher than the threshold, the transmission rate of the voice call communicating with the base station should be reduced to make the expected transmission power smaller than the threshold, and the connection control of the packet call should be performed. Can also. Fig. 2 is an explanatory diagram of the procedure for setting the threshold and controlling the transmission rate. The difference from Fig. 1 is that the threshold is set in advance by the maintenance device (step 103), the estimated transmission power and The point is that transmission rate control is performed based on the magnitude of the threshold (step 101 ′).

As described above, the remaining capacity of the radio resources in the cell can be increased, and the call connection rate can be improved. In particular, when a packet call cannot be accepted due to the remaining capacity of the radio resources in the cell, the transmission rate of the voice call during communication is reduced and the transmission power is suppressed, so that the remaining capacity of the radio resources in the cell can be increased and the bucket call can be increased. Can be accepted.

(b) Forced termination of handoff

FIG. 3 is an explanatory diagram of a procedure for forcibly terminating the handoff and accepting a bucket call. The base station 11 has a function of estimating the transmission power of the lower link, and the base station controller 31 has a traffic monitoring control function and a Z handoff control function.

The base station 11 controls the transmission power of each mobile terminal 21 so that the SIR is constant in order to maximize the subscriber capacity by optimizing the power allocation for each mobile terminal 21 in the upper wireless link are doing.

In this transmission power control state, if the base station 11 receives a request for transmitting a rebate call from the mobile terminal 21, the base station 11 predicts the total transmission power in the lower radio line assuming that the call is accepted and connected. Then, the base station controller 31 is notified of the occurrence of the bucket call and the estimated transmission power. When notified of the occurrence of the call and the estimated transmission power of the lower radio link, the base station controller 31 checks that the call is a packet call, and the estimated transmission power exceeds a certain radio resource capacity. Check (step 1 1 1). That is, the base station control device 31 determines whether the predicted transmission power is equal to or less than the possible transmission power of the base station.

On the other hand, if it is determined in step 111 that the estimated transmission power ≥ the possible transmission power of the base station, the base station controller 31 switches the mobile terminal that is communicating with the base station 11 to the soft hand-off terminal. Then, the soft handoff of the obtained mobile terminal is forcibly terminated, communication with the base station 11 is stopped, and the predicted transmission power is made smaller than the possible transmission power of the base station (step 112). Thereafter, the base station controller 31 notifies the base station 11 of the permission to accept the bucket call, and the base station 11 notifies the mobile terminal 21 of the transmission response to the transmission request when the base station 11 receives the reception permission. .

After that, the bucket call is accepted according to the normal sequence and the connection with the destination is controlled. I will do it.

If the predicted transmission power is still larger than the possible transmission power of the base station even when the soft handoff of the mobile terminal is forcibly terminated, the transmission rate of the voice call during communication with the base station is reduced and the predicted transmission power is increased. It can be made smaller than the possible transmission power of the station.

Also, soft handoff termination control was performed based on the estimated transmission power and the possible transmission power of the base station.However, instead of the possible transmission power, a lower power was set as the threshold, and the expected transmission power and the threshold were set. The soft handoff termination control can be performed based on the size of the soft handoff.

As described above, the remaining capacity of the radio resources in the cell can be increased, and the call connection rate can be improved. In particular, when a packet call cannot be accepted due to the remaining capacity of the radio resources in the cell, the soft hand-off is terminated and the transmission power is suppressed, so that the remaining capacity of the radio resources in the cell can be increased and packet calls can be accepted. Become.

(c) Reduction of transmission rate of packet call during communication

Figure 4 is an explanatory diagram of the procedure for reducing the transmission rate of a bucket call during communication and accepting the bucket call. The base station 11 has a function of predicting the transmission power of the lower link, and the base station controller 31 has a traffic monitoring control function.

The base station 11 controls the transmission power of each mobile terminal 21 so that the SIR is constant in order to optimize the power allocation for each mobile terminal 21 in the uplink radio channel and maximize the subscriber capacity. ing.

In this transmission power control state, when the base station 11 receives a request for transmitting a rebate call from the mobile terminal 21, the base station 11 predicts the total transmission power in the lower radio line assuming that the call is accepted. Then, the base station controller 31 is notified of the occurrence of the bucket call and the predicted transmission power. When notified of the occurrence of the call and the estimated transmission power of the lower radio line, the base station controller 31 checks that the call is a packet call, and the estimated transmission power exceeds a certain radio resource capacity. Check (Step 1 2 1). That is, the base station control device 31 determines whether the predicted transmission power is equal to or less than the possible transmission power of the base station.

If the predicted transmission power is <the transmission power available for the base station, the base station 11 notifies the base station 11 of the permission to accept the bucket call, and if the base station 11 receives the permission, the base station 11 issues a call request. The mobile terminal 21 is notified of the communication response.

On the other hand, if it is determined in step 122 that the estimated transmission power is equal to or more than the possible transmission power of the base station, the base station controller 31 lowers the transmission rate of the packet call during communication (step 122). Thereafter, the base station 11 notifies the base station 11 of the acceptance of the bucket call. When the base station 11 receives the acceptance, the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request. Thereafter, it accepts the packet call according to the normal sequence and controls the connection with the destination.

In addition, by reducing the transmission rate of the outgoing connection-requested bucket call, acceptance of the bucket call at a low rate can be permitted.

If the predicted transmission power cannot be made smaller than the possible transmission power of the base station by merely reducing the transmission rate of the bucket call, if the transmission rate of the voice call during communication with the base station is reduced, the predicted transmission power is reduced. It can be made smaller than the possible transmission power of the base station. In addition, the transmission rate of the bucket call was controlled based on the estimated transmission power and the magnitude of the possible transmission power of the base station.However, instead of the possible transmission power, a power less than that was set as a threshold, and the expected transmission power and It is also possible to control the transmission rate of the bucket call based on the magnitude of the threshold.

As described above, the remaining capacity of the radio resources in the cell can be increased, and the call connection rate can be improved. In particular, when a packet call cannot be accepted with the remaining capacity of the radio resources in the cell, the transmission rate of the bucket call during communication is reduced and the transmission power is suppressed, so that the requested bucket call can be accepted. Also, by reducing the transmission rate of the requested packet call during the connection, the bucket call can be accepted at a low rate.

(d) Acceptance at different transmission rates for each mobile terminal

The transmission rate of the bucket call (transmission quality of the bucket call) is set in advance for each mobile terminal, and is stored in the subscriber data storage database 51 provided in the exchange. When the base station 11 receives a request for transmitting a rebate call from the mobile terminal 21, the base station 11 obtains the transmission rate of the packet call of the mobile terminal 51. Next, considering the transmission rate, the total transmission power from the base station 11 to the cell 內 mobile station is calculated. Predict and notify the base station controller 31 of the occurrence of the bucket call and the predicted transmission power. When notified of the occurrence of the call and the predicted transmission power, the base station controller 31 determines whether the call is a packet call and the predicted transmission power is equal to or less than the possible transmission power of the base station. Yes (Step 1 3 1).

If the transmission power is higher than the estimated transmission power of the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request.

On the other hand, if it is determined in step 13 1 that the predicted transmission power ≥ the possible transmission power of the base station, the base station controller 31 notifies the voice codec processing unit to reduce the transmission rate of the voice call during communication. Then, lower the transmission rate (step 13 2). Thereafter, the base station 11 notifies the base station 11 of the permission to receive the bucket call, and the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request.

As described above, bucket call communication can be performed at a transmission rate preset for each mobile terminal, and required transmission quality can be maintained.

In the above, the transmission rate control of the bucket call was performed based on the estimated transmission power and the magnitude of the possible transmission power of the base station.However, instead of the possible transmission power, a power less than the possible transmission power was set as a threshold, and It is also possible to control the transmission rate of the bucket call based on the magnitude of the power and the threshold.

(B) Mobile communication system

FIG. 6 is a configuration diagram of a CDMA mobile communication system to which the present invention can be applied, where 11 and 12 are base stations, and 21 to 23 are in wireless zones (cells) corresponding to the base stations 11 and 12. A mobile station that exists and communicates wirelessly with the corresponding base stations 11 and 12, 31 is a base station controller that controls a plurality of base stations 11 and 12, and 41 is an exchange.

Base stations 11 and 12 have the same configuration, AMP section 11a, radio section 11b, baseband processing section 11c, transmission line interface section 11d, call control section 11e, transmission power It has a prediction unit 1 1 f. The AMP section 11a amplifies the transmission / reception signal, and the radio section 11b transmits the high-frequency signal input from the antenna via the re-amplifier section 11a to the baseband signal. The baseband signal is converted to a high-frequency signal and input to the antenna via the amplifier. The baseband processing unit 11c performs processing such as spreading and quadrature modulation on communication signals (call control signals, voice signals, and packet signals), inputs them to the radio unit 1lb, and performs quadrature detection on signals input from the radio unit. Performs processing such as despreading and data demodulation, and inputs the demodulated data to the call control unit and the transmission line interface unit. The transmission line interface section 11d performs signal multiplexing and Z signal separation processing for N channels and signal conversion processing between base stations and base station controllers. When receiving a voice / bucket call origination request from the mobile station, the call control unit 11e notifies the base station control unit 31 of the occurrence of the voice call no-packet call and the predicted transmission power. Whether a call is a voice call or a bucket call is determined by referring to the outgoing call message sent from the mobile station at the time of calling. The transmission power prediction unit 11 f predicts the transmission power of the base station 11 at the time of a transmission request, and inputs the predicted transmission power to the call control unit 11 e.

In the base station controller 31, the base station interface units 31a and 3lb perform signal format conversion and level conversion between the base station and the switch, and the clock generation unit 31c generates a reference clock and various timing signals. . The controller 31d controls the entire base station controller, the ATM switch / processor 31e performs multiplex conversion, and sends signals from the base stations 11 and 12 to a predetermined port on the switching center side. At the same time, the signal from the exchange is sent to a predetermined base station. The handoff processing unit 31 f performs handoff control, the traffic monitoring control unit 31 g monitors traffic for each base station, and the audio codec processing unit 31 h operates the audio in the wireless section (between the terminal and the base station device). It converts between the coding system and the voice coding system (PCM) in the switching network and changes the transmission rate of voice calls. The signal multiplexing processing unit 31 i performs signal multiplexing processing, the transmission power control unit 31 j performs transmission power control, the maintenance monitoring unit 31 k performs various types of maintenance and monitoring, and the switch interface unit 3 1 m performs signal conversion processing between the base station controller and the exchange. The traffic monitoring and control unit 31g is provided with a rate control unit 31p for performing transmission rate determination control, and the voice codec processing unit 31h is a rate change processing unit 31 for changing the transmission rate of voice calls. q is provided.

The traffic monitoring control unit 31g determines the allocation status of each channel to the mobile terminal for each base station, whether it is a packet call or voice call, whether it is a handoff state, the transmission rate of each call, etc. It has a traffic monitoring table TRMT (see Fig. 7) for storage.

(C) First embodiment

In the first embodiment, when the predicted transmission power is larger than the possible transmission power of the base station, the transmission rate of the voice call during communication with the base station is reduced to make the predicted transmission power smaller than the possible transmission power, Thereafter, connection control for packet calls is performed. FIG. 7 is a system configuration diagram for explaining the first embodiment of the present invention. The mobile terminals 21 a to 21 c are communicating with the base station 11 based on a voice call, and the mobile terminal 21 d The figure shows the case where a request is made to send a bucket call from. The mobile terminals 21a to 21c communicate with the base station 11 at the transmission rates Ua, Uc, and Ub in the upward direction and at the transmission rates Da, Db, and Dc in the downward direction.

Upon receiving the request for transmitting a bucket call from the mobile terminal 21d, the base station 11 predicts the total transmission power in the lower radio line assuming that the call is accepted and connected. Since the transmission power increases and decreases according to the transmission rate, the lower transmission powers Pa, Pb, and Pc are obtained from the lower transmission rates Da, Db, and Dc. The transmission power P i is obtained. Therefore, the estimated transmission power Ep is

Ep = (∑, P i) + P f

= (Pa + Pb + Pc) + P f

Given by (∑i P i = Pa + Pb + Pc) is known as the current transmission power, for example, is notified from the base station controller 31 as described later, and is known.

When the predicted transmission power is obtained, the base station 11 notifies the base station controller 31 of the occurrence of the packet call and the predicted transmission power Ep. The control unit 31d of the base station controller 31 determines whether the generated call is a packet call and whether the estimated transmission power Ep is equal to or less than the possible transmission power E of the base station (step 201). .

If the predicted transmission power Ep <the possible transmission power E of the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21d of a transmission response to the transmission request. After that, it accepts the packet call according to the normal connection sequence and controls the connection with the other party. As a result, the mobile terminal 21 d starts communication of a packet call at the upper retransmission rate Ue and the lower retransmission rate Df. In addition, the traffic monitoring controller 31g updates the traffic monitoring table TRMT, and updates the current transmission power (∑i P i = Pa + Pb + Pc + Pf) is notified to the base station 31 so that the base station can estimate the transmission power.

On the other hand, if it is determined in step 201 that the estimated transmission power Ep ≥ the possible transmission power E of the base station, the control unit 31 d instructs the traffic monitoring control unit 31 g to change the transmission rate of the voice call. . As a result, the relay control unit 31p lowers the lower retransmission rate of the voice call during communication, and makes the estimated transmission power Ep smaller than the possible transmission power E of the base station. In other words, the rate control unit 31 P can be expressed by the following equation, where f i is the reduction in the transmission power according to the reduction in the lower transmission rate of each voice call.

Ep = ∑ i (Pi— £ i) + Pf <E

That is, the reduction of the transmission rate of each voice call is determined (step 202). If the amount of reduction in the transmission rate of each voice call is determined, the traffic monitoring control unit 31g notifies the voice codec processing unit 31h, and the rate change processing unit 31q determines the transmission rate of each voice call. Reduce the transmission rate.

FIG. 9 is an explanatory diagram of the audio transmission rate. (1) If the audio information is transmitted at 192 bits / 20 ms, the transmission rate will be 9600 bps. (2) If the audio information is intermittently transmitted at 96 bits / 20 ms, the transmission rate will be 4800 bps, (3) the audio information will be 48 bits / If intermittent transmission is performed at 20 ms, the transmission rate is 2400 bps. (4) If audio information is intermittently transmitted at 24 bits / 20 nis, the transmission rate is 1200 bps. The rate change processing unit 31q changes the voice transmission rate of the specified channel and transmits voice information to the base station 11 according to an instruction from the traffic monitoring control unit 31g. The base station 11 identifies the number of bits of the audio information received from the base station controller 31 and continuously transmits data at any of 9600 bps, 4800 bps, 2400 bps, and 1200 bps.

As described above, it is possible to control the retransmission rate for a voice call of a predetermined channel, and it is possible to reduce the power as a whole by lowering the transmission rate. For details of variable transmission rate control, see the CDMA Cellular System, CDMA Cellular System, CDMA Cellular System, Standard Version ARIB STANDARD, ARIB STD-T53 Version 1.0 (1/3 ) ".

As described above, after lowering the transmission rate of the voice call, the control unit 31 d notifies the base station 11 of the permission to accept the bucket call. If the base station 1 1 receives the acceptance permission, it will call The mobile terminal 21d is notified of the outgoing response to the request. Thereafter, it accepts the packet call according to the normal sequence and controls the connection with the destination. As a result, the mobile terminal 21 d starts the communication of the bucket call at the upper retransmission rate Ue and the lower retransmission rate Di. In addition, the traffic monitoring controller 31g updates the traffic monitoring table TRMT, and notifies the base station 31 of the current transmission power (∑ i P i = Pc + Pc + Pd + P f) and notifies the base station 31 of the transmission power. Enable the station to predict the transmission power.

As described above, according to the first embodiment, even if a packet call occurs, the transmission power of the entire network can be suppressed by lowering the rate of another voice call, and the call connection rate can be improved.

• Modification 1

In the above description, the transmission rate is controlled based on the magnitude of the estimated transmission power Ep and the possible transmission power E of the base station. However, instead of the possible transmission power, a lower power E _T (for example, the possible transmission power Ε If the estimated transmission power Ep is larger than the threshold Ε _τ , the transmission rate of voice calls during communication with the base station is reduced and the estimated transmission power Ep is made smaller than the threshold Ε _τ . However, connection control for packet calls can be performed. FIG. 10 is a system configuration diagram of a modified example, and the same parts as in FIG. 7 are denoted by the same reference numerals. Different that point is that from the maintenance units 61 that are set in the base station control apparatus 3 1 by entering the threshold E _tau. Also, FIG. 11 is a diagram illustrating the procedure of the modified example, and the difference from FIG. 8 is that the maintenance device 61 sets the threshold Ε _τ in advance (step 203), the estimated transmission power Ep and the threshold. The point is that the transmission rate of a voice call is controlled based on the magnitude of E _T (step 201 ′).

As described above, according to the modification, the radio resource capacity in the cell can be controlled by changing the threshold value. Even if a packet call occurs, the transmission power can be reduced by lowering the rate of other voice calls, and the call connection rate can be improved.

• Modification 2

In the above, the base station 11 predicted the transmission power, but the base station controller 31 can predict the transmission power. Further, in the above description, the base station 11 does not have its own traffic management table. However, it is possible to configure so that the base station independently estimates the transmission power.

(D) Second embodiment In the second embodiment, if the predicted transmission power is larger than the possible transmission power of the base station, the soft handoff is terminated and the predicted transmission power is made smaller than the possible transmission power of the base station. I do. FIG. 12 is a system configuration diagram for explaining a second embodiment of the present invention, in which mobile terminals 21 a to 21 b are communicating with base station 11 based on a voice call, and This shows a case in which the mobile terminal 21d issues a bucket call request while the mobile terminal 21c is communicating with the soft base station 11 and 12 simultaneously with the soft handoff control.

Upon receiving the request for transmitting a bucket call from the mobile terminal 21d, the base station 11 predicts the total transmission power in the lower radio line assuming that the call is accepted and connected. Since the transmission power increases and decreases according to the transmission rate, the transmission power below the lower transmission rate for each mobile terminal is determined, and the transmission power P for the packet call is calculated from the lower transmission rate IM for the packet call. i is found. Therefore, the estimated transmission power Ep is

Ep = (∑ i P i) + P f

Given by

When the predicted transmission power is obtained, the base station 11 notifies the base station controller 31 of the occurrence of the bucket call and the predicted transmission power Ep. The control unit 31d of the base station controller 31 determines whether the generated call is a packet call and whether the estimated transmission power Ep is equal to or less than the available transmission power E of the base station (step 301). .

If the predicted transmission power Ep <the possible transmission power E of the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21 d of the transmission response. After that, it accepts the bucket call according to the normal connection sequence and controls the connection with the other party. As a result, the mobile terminal 21 d starts communication of the packet call at the upper retransmission rate Ue and the lower retransmission rate Di. In addition, the traffic monitoring controller 31g updates the traffic table TRMT, notifies the base station 31 of the current transmission power (∑ i P i), and predicts the transmission power when the base station receives the next transmission request. To be able to

On the other hand, in the determination of step 301, if the predicted transmission power Ep ≥ the possible transmission power E of the base station, the control unit 31d instructs the traffic monitoring control unit 21g to change the transmission rate. As a result, the relation control unit 31 P refers to the traffic monitoring table TRMT. The terminal searches for a terminal in the handoff state (mobile terminal 21c in the figure) by referring to the terminal, and instructs the soft handoff processing unit 31f to end the soft handoff control of the terminal. The soft handoff processing unit 31f ends the soft handoff of the mobile terminal 21c in response to the instruction, and stops communication between the mobile terminal 21c and the base station 11. That is, the base station controller 31 and the mobile terminal 21c send and receive (1) a soft handoff end request, (2) a soft handoff end response, and (3) a message response, and the mobile terminal 21c and the base station The communication between the mobile stations 21 and 21 is cut off, and only the communication between the mobile terminal 21c and the base station 12 is left. As described above, the estimated transmission power Ep decreases and becomes smaller than the possible transmission power E of the base station 11. If the estimated transmission power Ep does not become smaller than the possible transmission power E of the base station, control such as terminating the soft handoff of another terminal or reducing the transmission rate of the voice call during communication is performed.

Thereafter, the control unit 31d notifies the base station 11 of the acceptance of the bucket call. When receiving the acceptance permission, the base station 11 notifies the mobile terminal 2Id of a transmission response to the transmission request. After that, it accepts the packet call according to the normal sequence and controls the connection with the destination. As a result, the mobile terminal 21 d starts the communication of the bucket call at the upper transmission rate Ue and the lower transmission rate Di. In addition, the traffic monitoring controller 31g updates the traffic monitoring table TRMT and notifies the current transmission power to the base station 31 so that the base station can predict the transmission power when the next transmission request is accepted. You.

In the above, it was subjected to control of transmission record over preparative based on the magnitude of the transmittable power E of a prediction transmit power Ep and the base station, and set as a threshold less power E _T instead of transmittable power, can be predicted transmit power Ep is controlled to end the handoff larger Li yo threshold E _tau.

As described above, according to the second embodiment, when a packet call is generated, the number of calls during re-communication is reduced by terminating the soft handoff, so that the transmission power can be reduced, and a packet call is generated. Even so, the overall transmission power is suppressed and the call connection rate is improved.

(Ε) Third embodiment

In the third embodiment, when the estimated transmission power Ep is larger than the possible transmission power of the base station, The transmission rate of the bucket call during communication with the base station is reduced to make the predicted transmission power smaller than the possible transmission power, and thereafter, the connection control of the packet call is performed. FIG. 14 is a system configuration diagram for explaining the third embodiment of the present invention, in which mobile terminals 21a to 21c are communicating with base station 11 based on a voice call, and The figure shows a case where a request for transmitting a bucket call is issued from the mobile terminal 21 e while the mobile terminal 21 d communicates with the base station 11 based on the bucket call. The upward transmission rate of mobile terminal 21a to 21c is Ua, Uc, Ud, the downward transmission rate is Da, .Db, Dc, and the upward transmission rate of mobile terminal 21d is Ue, the downlink transmission rate is Df. The upper transmission rate of the packet call for which transmission is requested is Ue, and the lower transmission rate is Df.

Upon receiving the request for transmitting a bucket call from the mobile terminal 21e, the base station 11 predicts the total transmission power in the lower radio line assuming that the call is accepted and connected. Since the transmission power increases or decreases according to the transmission rate, the transmission power under each mobile terminal is determined, and the transmission rate of the packet call is determined by the transmission power P f of the packet call. I get it. Therefore, the estimated transmission power Ep is

Ep = (∑ i P i) + P f

Given by

When the predicted transmission power is obtained, the base station 11 notifies the base station controller 31 of the occurrence of the bucket call and the predicted transmission power Ep. The control unit 31d of the base station controller 31 determines whether the generated call is a packet call and whether the estimated transmission power Ep is equal to or less than the possible transmission power E of the base station (step 401). .

If the predicted transmission power Ep <the possible transmission power E of the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21 e of the transmission response. After that, it accepts the bucket call according to the normal connection sequence and controls the connection with the other party. As a result, the mobile terminal 21e starts packet call communication at the upper retransmission rate Ue and the lower retransmission rate Df. In addition, the traffic monitoring control unit 31g updates the traffic table TRMT, notifies the current transmission power (∑iPi) to the base station 31, and the base station estimates the transmission power when the next transmission request is received. To be able to

On the other hand, in the judgment of step 401, the estimated transmission power Ep ≥ the possible transmission power of the base station If the power is E, the control unit 31d instructs the traffic monitoring control unit 31g to change the transmission rate of the packet call. As a result, the relation control unit 31p searches for the bucket call terminal (mobile terminal 21d in the figure) with reference to the traffic monitoring table TRMT, and checks the bucket call during communication and the bucket call for which transmission is requested. Reduce the lower transmission rate and make the predicted transmission power Ep smaller than the possible transmission power E of the base station. The reduction in transmission power according to the reduction in the lower transmission rate during a communication call is £ i, and the reduction in transmission power in accordance with the reduction in the transmission rate of the bucket call requested to be transmitted. If γ, the rate control unit 3 1 ρ is given by the following equation: Ep = Ep, (P i-£ i) + (P f- γ ΧΕ

Calculate £ i, y that satisfies As a result, the downlink transmission rate Dg (Df> Dg) of each packet call is obtained.

When the amount of reduction in the transmission rate of each bucket call is determined, the traffic monitoring control unit 31g lowers the lower transmission rate of the packet call during communication (Df → Dg, Df> Dg). For example, the base station controller 31 stores the bucket data sent from the exchange 41 in a buffer, reads out the buffer at a read speed corresponding to a predetermined transmission rate, converts the packet into cells, and sends the cells to the base station. . Thus, the traffic monitoring controller 31g switches the speed at which the bucket data is read from the buffer according to the transmission rate.

Thereafter, the control unit 31d notifies the base station 11 of the acceptance of the bucket call. When receiving the acceptance permission, the base station 11 notifies the mobile terminal 21 of a transmission response to the transmission request. Thereafter, it accepts packet calls according to the normal sequence and controls connection with the other party. As a result, the mobile terminal 21e starts packet call communication at the upper transmission rate Ue and the lower transmission rate Dg (Df> Dg).

Further, the traffic monitoring control unit 31g updates the traffic table TRMT and notifies the base station 31 of the current transmission power.

In the above, only the transmission rate of the bucket call was reduced.However, in the reduction of the transmission rate of the bucket call only, if the predicted transmission power Ep does not become smaller than the possible transmission power E of the base station, the transmission rate of the voice call during communication is reduced. Control such as lowering can be performed.

In the above, it was subjected to control of transmission record over preparative based on the magnitude of the transmittable power E of a prediction transmit power Ep and the base station, and set as a threshold less power E _T instead of transmittable power, If the estimated transmission power Ep is larger than the threshold _{τ τ,} control the transmission rate of the bucket call. It can be configured as follows.

As described above, according to the third embodiment, even if a packet call exceeding the possible transmission power of the base station occurs, the transmission data rate of other packets is reduced, and the transmission rate of the packet call during connection is suppressed. In addition, it is possible to reduce the transmission power, to accept a bucket call and to perform bucket communication.

(F) Fourth embodiment

In the fourth embodiment, the transmission rate (transmission quality) of a packet call is stored in a database in advance in correspondence with the mobile terminal, and when a request for originating a bucket call is received from the mobile terminal, the packet call of the mobile terminal is transmitted. The transmission power of the base station is predicted in consideration of the transmission rate (transmission quality). If the predicted transmission power is larger than the possible transmission power of the base station, the transmission rate of voice calls during communication with the base station is reduced. To control the connection of the bucket call.

FIG. 16 is a system configuration diagram for explaining the fourth embodiment of the present invention. The mobile terminals 21a to 21c communicate with the base station 11 based on a voice call while the mobile terminal 2 This shows a case where a bucket call origination request is made from 1d. The mobile terminals 21a to 21c have transmission rates Ua, Uc, and Ub in the upstream direction with the base station 11 and transmission rates in the downward direction.

Communication is using Da, Db, and Dc. The transmission rate of the bucket call, that is, the transmission quality, is set in the database 51 in advance so as to correspond to each mobile terminal.

When the base station 11 receives the request for transmitting a bucket call from the mobile terminal 21 d, the base station 11 predicts the total transmission power Ep on the downlink radio line when the call is accepted and connected. That is, the base station 11 obtains the transmission rate Di 'of the packet call of the database 51 mobile terminal 21 d via the base station controller 31 and the exchange 41 and considers the transmission rate. And the total transmit power from base station 11 to cell 內 mobile terminal is

Ep = (∑ i P + P f

To predict. (∑i P i) is the current lower transmission power and is known from the base station controller. P f ′ is a transmission power according to the transmission rate D i ′.

When the predicted transmission power is obtained, the base station 11 notifies the base station controller 31 of the occurrence of the packet call and the predicted transmission power Ep. The control unit 3 1 d of the base station controller 31 generates It is determined whether the received call is a packet call and whether the predicted transmission power Ep is equal to or less than the possible transmission power E of the base station (step 501).

If the estimated transmission power Ep is the transmission power E possible for the base station, the base station 11 notifies the base station 11 of the acceptance of the bucket call, and the base station 11 notifies the mobile terminal 21 d of the transmission response. After that, it accepts the bucket call according to the normal connection sequence and controls the connection with the other party. As a result, the mobile terminal 21 d starts packet call communication at the upper retransmission rate Ue and the lower retransmission rate Df. Further, the traffic monitoring control unit 31g updates the traffic monitoring table TRMT and notifies the base station 31 of the current transmission power (∑iPi = Pa + Pb + Pc + Pf ').

On the other hand, if it is determined in step 501 that the estimated transmission power Ep ≥ the possible transmission power E of the base station, the control unit 31 d instructs the traffic monitoring control unit 31 g to change the transmission rate of the voice call. I do. As a result, the relay control unit 31p lowers the lower retransmission rate of the voice call during communication, and makes the predicted transmission power Ep smaller than the possible transmission power E of the base station. In other words, the rate control unit 31p calculates the reduction in transmission power according to the reduction in the lower retransmission rate of each voice call as

Ep = ∑ i (P i-ε i) + P f ⁷ <E

Ε i that satisfies the above condition, in other words, the amount of reduction in the transmission rate of each voice call is determined (step 502). If the amount of reduction in the transmission rate of each voice call is determined, the traffic monitoring control unit 31g notifies the voice codec processing unit 31h and the rate change processing unit 31q determines the transmission rate of each voice call. Lower.

Thereafter, the control unit 31d notifies the base station 11 of the acceptance of the bucket call. Upon receiving the acceptance permission, the base station 11 notifies the mobile terminal 21 d of a call response. Thereafter, according to the normal sequence, the bucket call is accepted and connection control with the other party is performed. As a result, the mobile terminal 21d starts communication of the packet call at the uplink transmission rate Ue and the lower retransmission rate Df '. In addition, the traffic monitoring controller 31g updates the traffic monitoring table TRMT and notifies the base station 31 of the current transmission power (∑iPi = Pc + Pc + Pd + Pf '). 11. Enable 1 to predict the transmission power. In the above, the transmission rate was controlled based on the estimated transmission power Ep and the possible transmission power E of the base station.However, instead of the possible transmission power, a lower power Ε _τ was set as the threshold. If the estimated transmission power Ep is greater than the threshold E _T , the transmission rate of the voice call during communication with the base station is reduced to reduce the estimated transmission power Ep by the threshold _{τ τ} , and the connection control of the bucket call is performed. It can also be done.

As described above, according to the fourth embodiment, even when bucket communication that exceeds the transmission power available at the base station occurs, the overall transmission power can be suppressed and packet calls can be accepted at different transmission rates (transmission quality) for each mobile device. Becomes

As described above, according to the present invention, when a bucket call is generated, the transmission power is reduced by lowering the rate of another voice call or by stopping soft handoff. However, it is possible to connect packet calls without reducing the radio resource capacity, and it will greatly contribute to improving the call connection rate.

Claims

The scope of the claims

1. A packet call receiving method in a mobile communication system including a base station that communicates with mobile stations in a cell and a base station control device that controls a plurality of base stations,

When a bucket call origination request is received, the total transmission power from the base station to the mobile station in the cell is predicted,

If the predicted transmission power is larger than the possible transmission power of the base station, the transmission rate of the voice call during communication with the base station is reduced to reduce the predicted transmission power to the possible transmission power, and thereafter, the packet call Control the connection of

A method for receiving a bucket call.

2. Set a power value equal to or less than the possible transmission power as a threshold,

If the predicted transmission power is larger than the threshold, the transmission rate of the voice call communicating with the base station is reduced to make the predicted transmission power smaller than the threshold, and thereafter, connection control of the packet call is performed.

2. The bucket call accepting method according to claim 1, wherein:

3. A packet call receiving method in a mobile communication system including a base station communicating with a mobile station in a cell and a base station control device controlling a plurality of base stations,

If the predicted transmission power is larger than the possible transmission power of the base station or a threshold value equal to or less than the possible transmission power, a terminal in a soft handoff state is obtained,

Ending the soft handoff of the terminal and reducing the estimated transmission power from the possible transmission power or threshold of the base station,

Then, control the connection of the packet call.

A method for receiving a bucket call.

4. If the estimated transmission power is larger than the possible transmission power of the base station or the threshold value even after soft handoff of the terminal is completed, the transmission rate of the voice call communicating with the base station is reduced and the estimated transmission power is increased. 4. The bucket call accepting method according to claim 3, wherein the connection is controlled to be smaller than a possible transmission power or a threshold value of the station, and thereafter, connection control of the bucket call is performed.

5. A packet call receiving method in a mobile communication system including a base station that communicates with mobile stations in a cell and a base station control device that controls a plurality of base stations,

If the predicted transmission power is larger than the possible transmission power or threshold of the base station, the transmission rate of the bucket call communicating with the base station is reduced to make the predicted transmission power smaller than the possible transmission power or threshold of the base station. And

Then, control the connection of the packet call.

A method for receiving a bucket call.

6. Reducing the transmission rate of the bucket call during the communication and reducing the transmission rate of the connection-requested bucket call to make the predicted transmission power smaller than the possible transmission power or threshold value of the base station. 6. The bucket call accepting method according to claim 5, wherein:

7. Even if the transmission rate of the bucket call during communication is reduced, if the estimated transmission power is larger than the possible transmission power or threshold value of the base station, the transmission rate of the voice call communicating with the base station is reduced to estimate the transmission power. 6. The bucket call accepting method according to claim 5, wherein the control is made smaller than a possible transmission power or a threshold value of the base station, and thereafter, connection control of the bucket call is performed.

8. A packet call receiving method in a mobile communication system including a base station that communicates with mobile stations in a cell and a base station control device that controls a plurality of base stations,

The transmission rate of the bucket call is set and stored in advance corresponding to the terminal,

When receiving a request for sending a bucket call from the terminal, the transmission rate of the bucket call of the terminal is obtained, and

The total transmission power from the base station to the mobile station in the cell is estimated in consideration of the transmission rate of the bucket call,

If the predicted transmission power is greater than the possible transmission power or threshold of the base station, the transmission rate of the voice call communicating with the base station is reduced to make the predicted transmission power smaller than the possible transmission power or threshold of the base station. ,

Then, control the connection of the packet call. A method for receiving a bucket call.