JP2004282169A - Transmission rate control method, control station and radio base station - Google Patents

Abstract

An object of the present invention is to provide a transmission rate control method capable of preventing a decrease in overall system throughput by flexibly setting an initial transmission rate when a mobile station starts communication on an individual channel. That is.
A common channel shared between a radio base station and a mobile station includes a radio base station, a mobile station, and a control station that controls communication of the radio base station, and a mobile station. In the transmission rate control method in a mobile communication system using a dedicated channel individually assigned to each of the mobile stations, a situation in which the control station starts the communication when detecting that the mobile station has started communication on the dedicated channel The transmission rate is determined according to the transmission rate, and the determined transmission rate is notified to the radio base station.
[Selection diagram] Fig. 4

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission rate control method, a control station, and a radio base station, and more particularly, to a transmission rate control method for an individual channel individually assigned to each mobile station.
[0002]
The present invention also relates to a control station and a radio base station capable of controlling a transmission rate according to such a transmission rate control method.
[0003]
[Prior art]
In the IMT-2000 mobile communication system, a CDMA (Code Division Multiple Access) system is adopted as a wireless transmission system. In the IMT-2000 mobile communication system employing the CDMA system, two types of channels are used as radio channels used for communication: an individual channel individually assigned to each mobile station and a common channel shared by a plurality of mobile stations. is there. As these two types of channels, a common channel or an individual channel is selected according to the characteristics of the traffic. For example, when traffic is small, a common channel shared and used by a plurality of mobile stations is selected, and when traffic is large, an individual channel individually assigned to each mobile station is selected.
[0004]
By the way, the services provided by the IMT-2000 mobile communication system include a communication service of only packet calls, a communication service of only circuit-switched calls, and a service of simultaneous communication of packet calls and circuit-switched calls (referred to as multi-call). is there. Simultaneous communication of packet call and circuit-switched call occurs when a packet call is added during circuit-switched call communication or when a circuit-switched call is added during packet call communication.
[0005]
In a wireless system in which wireless communication is performed, including the above-mentioned IMT-2000 mobile communication system, valuable radio resources are used and benefited from it, and efficient use of radio resources is essential. Therefore, in the case of the IMT-2000 mobile communication system, when a mobile station performs packet call communication on an individual channel, the mobile station switches the transmission rate according to the communication status to achieve efficient use of wireless resources.
[0006]
In a mobile communication system employing a CDMA system, packet communication is performed using a common channel and an individual channel, and communication traffic in a mobile station is shifting from a sparse state to a dense state during communication. Sometimes, a radio base station or a mobile station has proposed a technology that can improve the communication quality of a mobile communication system and effectively use radio frequencies by making an acceptance determination of transition from a common channel to a dedicated channel. (For example, see Patent Document 1).
[0007]
[Patent Document 1]
International Publication WO00 / 35235 pamphlet
[Problems to be solved by the invention]
As described above, in the conventional IMT-2000 mobile communication system, when a mobile station performs packet call communication on an individual channel in order to use radio resources effectively, the transmission rate is switched according to the communication status.
[0009]
There are several cases where the mobile station starts the communication of the packet call on the dedicated channel. For example, the following case is considered.
[0010]
(1) When setting up a packet call in outgoing / incoming calls (2) When switching to an individual channel due to increased traffic while communicating on a common channel with a packet call (3) Circuit switching call during communication on a common channel In each of the above cases where the mobile station starts packet call communication on the dedicated channel when the mobile station transitions from the common channel to the dedicated channel due to the addition of, the required initial transmission rate is considered to be different. However, in the control of switching the transmission rate in the conventional IMT-2000 mobile communication system, the same initial transmission rate is generally used uniformly in each of the above cases. For this reason, it is impossible to set an initial transmission rate that is appropriate for all of the above cases. On the other hand, if an appropriate initial transmission rate is set for only one of the cases, there is a possibility that the throughput of the entire system is reduced, and that the system capacity is deteriorated due to a waste of radio resources.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to flexibly set an initial transmission rate when a mobile station starts communication on a dedicated channel, thereby providing an overall system. It is an object of the present invention to provide a transmission rate control method capable of preventing a decrease in throughput.
[0012]
Another object of the present invention is to provide a control station and a radio base station capable of controlling a transmission rate according to such a transmission rate control method.
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention includes a radio base station, a mobile station, and a control station that controls communication between the radio base station and the radio base station. In a transmission rate control method in a mobile communication system using a common channel shared between the mobile station and a dedicated channel individually allocated to each mobile station, the control station starts communication by the dedicated channel. When this is detected, a transmission rate is determined according to a situation in which the communication is started, and the determined transmission rate is notified to the radio base station.
[0014]
Further, in the transmission rate control method according to the second aspect of the present invention, in the transmission rate control method, the control station includes a database that stores information on a transmission rate corresponding to a situation when the mobile station starts communication using a dedicated channel, Upon detecting that the mobile station has started communication on an individual channel, the mobile station determines the start status of communication on the individual channel, and transmits information on a transmission rate corresponding to the determined start status of communication from the database. It is characterized in that it is extracted and the extracted transmission rate is determined as a transmission rate for notifying the radio base station.
[0015]
Further, in the transmission rate control method according to the third aspect of the present invention, when the communication start situation on the dedicated channel is a call setup situation, the traffic amount required in the call setup situation The transmission rate information determined in consideration of the above is registered in the database.
[0016]
According to a fourth aspect of the present invention, in the transmission rate control method, when a start state of communication on the dedicated channel is a state of increasing traffic, the communication rate is determined in consideration of an increase amount of the traffic. The transmission rate information is registered in the database.
[0017]
Also, in the transmission rate control method according to the present invention, when the start state of the communication on the dedicated channel is an additional state of a circuit-switched call, the communication rate is controlled by the additional state of the circuit-switched call. The transmission rate information determined in consideration of the required traffic volume is registered in the database.
[0018]
According to the configuration of the present invention, when the mobile station starts communication on the dedicated channel, the control station determines the transmission rate according to the situation in which the communication starts, and notifies the radio base station. It is possible to start communication on the individual channel at an appropriate transmission rate required in each communication start situation when communication is performed. This makes it possible to prevent a decrease in throughput of the entire system and a deterioration in communication capacity.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
A mobile communication system to which a transmission rate control method according to an embodiment of the present invention is applied is configured, for example, as shown in FIG. The mobile communication system according to the present embodiment is, for example, a CDMA mobile communication system that establishes a wireless link with a plurality of mobile stations for communication by code division multiple access.
[0021]
In FIG. 1, the mobile communication system includes a mobile station 101, a radio base station 102, a control station 103 that controls the radio base station 102, and is connected to the control station 103 to perform call control and the like of the mobile station 101. And a core network 104.
[0022]
FIG. 2 is a block diagram showing a configuration of the initial transmission rate application function unit of radio base station 102 according to the present embodiment. In the figure, the initial transmission rate application function unit includes a reception interface unit 201, a transmission rate extraction unit 202, and a transmission rate application unit 203.
[0023]
The reception interface unit 201 receives a signal transmitted from the control station 103. The signal received by the reception interface unit 201 is sent to a transmission rate extraction unit 202, which extracts the transmission rate notified from the control station 103. The information on the transmission rate (hereinafter, referred to as the initial transmission rate) extracted by the transmission rate extracting unit 202 in this manner is applied as the initial transmission rate of the packet call of the individual channel by the transmission rate applying unit 203, Various parameters for starting the individual channel at the set initial transmission rate are set.
[0024]
The mobile station 101 shown in FIG. 1 includes a function unit similar to the initial transmission rate application function unit of the wireless base station 102, and receives information on the initial transmission rate by wireless communication with the wireless base station 102.
[0025]
FIG. 3 is a block diagram showing a configuration of the initial transmission rate notification function unit of control station 103 according to the present embodiment. In the figure, the initial transmission rate notification function unit includes a call state monitoring unit 301, a communication start type determination unit 302, a transmission rate extraction unit 303, a transmission rate notification unit 304, a transmission interface unit 305, a transmission rate It comprises an information management unit (database) 306.
[0026]
The call state monitoring unit 301 monitors the occurrence and attributes of a call. When the same unit 301 detects that the mobile station 101 has started the communication of the packet call on the dedicated channel, the communication start type determining unit 303 determines which case the communication started corresponds to. You. Then, after the case determination is made in the same unit 303, the information of the initial transmission rate corresponding to the case is extracted by the transmission rate information management unit 306 by the transmission rate extraction unit 303. The information on the initial transmission rate extracted by the transmission rate extracting unit 303 is converted into a signal for notifying the radio base station 102 by the transmission rate notifying unit 304 and transmitted to the radio base station 102 through the transmission interface unit 305.
[0027]
Next, the operation of the initial transmission rate setting notification process performed by the control station 103 will be described with reference to the flowchart shown in FIG.
[0028]
In FIG. 4, a call state monitoring unit 301 monitors the occurrence of a call and a change in a call attribute (a packet call or a circuit-switched call) of the mobile station 101 under its control. When the call state monitoring unit 301 detects that the mobile station 101 has started packet call communication on an individual channel (step S1), the detection result is sent to the communication start type determination unit 302. The communication start type determination unit 302 determines which of the plurality of communication start cases the communication started corresponds to (steps S2 and S3).
[0029]
The communication start type determination unit 302 first determines whether or not the trigger for starting the dedicated channel by the mobile station 101 corresponds to the case of call setting (case (1) above) (step S2). If determined to be applicable (YES in step S2), a flag value indicating the result of the determination is set (step S4) and output to transmission rate extracting section 303. In the present embodiment, the flag setting value is 0x01 (0x means a hexadecimal number) when the communication start case using the dedicated channel is call setting.
[0030]
The transmission rate extraction unit 303 accesses the transmission rate information management unit 306 and extracts information on the initial transmission rate corresponding to the flag setting value sent from the communication start type determination unit 302 (step S7), and Output to the notification unit 304 (step S8).
[0031]
In the present embodiment, as shown below, it is assumed that there are four types of transmission rates of packet calls for individual channels (see FIG. 5).
[0032]
1.384 kbps transmission rate
2.256 kbps
3.128 kbps
4.64kbps
As shown in FIG. 6, the initial transmission rate information registered and managed in the transmission rate information management unit 306 is registered and managed for each case where the mobile station 101 starts packet call communication on an individual channel. For example, at the time of call setup (case (1): flag = 0x01), communication is newly started, and a relatively large amount of control traffic for establishing communication is expected. In the example, 256 kbps) is set. Further, in the case of transition from the common channel to the dedicated channel due to traffic increase (case (2): flag = 0x02), it is expected that traffic will continue to increase, and therefore a high transmission rate (384 kbps in this example) Is set. Further, when a transition to an individual channel is forcibly performed by the addition of a circuit-switched call as in the case of a multi-call (case (3): flag = 0x03), the traffic volume of the packet call is considered to be small. A transmission rate (128 kbps in this example) is set.
[0033]
Referring back to FIG. 4, the information of the initial transmission rate extracted by the transmission rate extracting unit 303 and notified to the transmission rate notifying unit 304 is converted into a predetermined signal, and then converted to a predetermined signal via the transmission interface unit 305. Sent to The reception interface unit 201 of the wireless base station 102 receives the signal and sends it to the transmission rate extraction unit 202. The transmission rate extraction unit 202 extracts information on the initial transmission rate from the signal transmitted from the reception interface unit 201, and sends the extracted information on the initial transmission rate to the transmission rate application unit 203. Then, the transmission rate application section 203 performs setting processing of various parameters so that communication at the extracted initial transmission rate becomes possible.
[0034]
The processing in the wireless base station 101 as described above is performed in the mobile station 101 in the same manner. As a result, the wireless base station 102 and the mobile station 101 are set to the initial transmission rate notified from the control station 102, and commence communication of a packet call using a dedicated channel.
[0035]
When the communication start type determination unit 302 determines in step S2 that the call does not correspond to the case of call setting (case of (1)) (NO in step S2), the process proceeds to step S3, in which the individual channel is determined. It is determined whether or not the start trigger is due to a case of traffic increase (case (2) above). Then, when it is determined that this case corresponds to the case of the increase in traffic (YES in step S3), the flag setting value is set to 0x02 and output to the transmission rate extracting unit 303. Subsequent processing is performed in the same manner as in the case of the call setting.
[0036]
On the other hand, if it is determined in step S3 that the traffic does not correspond to the case of increased traffic (NO in step S3), the start of the individual channel is performed during communication on the common channel, and the addition of the circuit switched call causes Is determined to be a case (case (3) above), and a flag corresponding to this case is set (step S6) (the flag setting value in this case is, for example, 0x03), and the transmission rate is extracted. Output to the unit 303. Subsequent processing is performed in the same manner as in the above case (1).
[0037]
As described above, according to the present embodiment, the control station 103 identifies each case where the mobile station 101 starts the communication of the packet call on the dedicated channel, and determines the required transmission rate according to each case. Since the settings are made independently, the transmission rate can be set flexibly in consideration of system capacity and serviceability. As a result, an appropriate transmission rate is set according to each case, so that the setting of the transmission rate starting with the individual channel is lower than in the conventional system in which the transmission rate is set uniformly. And deterioration of communication capacity can be avoided, and wireless resources can be effectively used.
[0038]
In this embodiment, the transmission rate of the packet call of the individual channel is set to four types, and the case where the mobile station starts the communication of the packet call on the individual channel is set to three types (cases (1) to (3)). These types may be increased or decreased without departing from the spirit of the present invention.
[0039]
【The invention's effect】
As described above, according to the present invention, when the mobile station starts communication on the dedicated channel, the control station determines the transmission rate according to the situation of starting the communication and notifies the radio base station Therefore, communication on the individual channel can be started at an appropriate transmission rate required in each communication start situation when communicating on the individual channel. This makes it possible to prevent a decrease in throughput of the entire system and a deterioration in communication capacity.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a mobile communication system to which a transmission rate control method according to an embodiment of the present invention is applied.
FIG. 2 is a block diagram illustrating a configuration of an initial transmission rate application function unit of the wireless base station illustrated in FIG. 1;
FIG. 3 is a block diagram showing a configuration of an initial transmission rate notification function unit of the control station shown in FIG.
FIG. 4 is a flowchart illustrating an operation of an initial transmission rate setting notification process performed by a control station.
FIG. 5 is a diagram showing the types of transmission rates of packet calls for individual channels.
FIG. 6 is a diagram showing initial transmission rate information for each start case registered and managed in the transmission rate information management unit.
[Explanation of symbols]
Reference Signs List 101 mobile station 102 radio base station 103 control station 104 core network 201 reception interface unit 202, 303 transmission rate extraction unit 203 transmission rate application unit 301 call state monitoring unit 302 communication start type determination unit 304 transmission rate notification unit 305 transmission interface unit 306 Transmission rate information management unit

Claims (10)

A common channel shared between the radio base station and the mobile station, including a radio base station, a mobile station, and a control station controlling communication between the radio base station, and an individual channel individually assigned to each mobile station In a transmission rate control method in a mobile communication system using
The control station comprises:
Upon detecting that the mobile station has started communication on the dedicated channel, determine the transmission rate according to the situation to start the communication,
A transmission rate control method, wherein the determined transmission rate is notified to the radio base station. The transmission rate control method according to claim 1,
The control station comprises:
The mobile station includes a database that stores information on a transmission rate corresponding to a situation when starting communication on an individual channel,
When detecting that the mobile station has started communication on a dedicated channel, determine the start status of communication on the dedicated channel,
A transmission rate control method, wherein information on a transmission rate corresponding to the determined communication start status is extracted from the database, and the extracted transmission rate is determined as a transmission rate for notifying the wireless base station. The transmission rate control method according to claim 2,
When the start state of communication on the dedicated channel is a call setup situation, information of a transmission rate determined in consideration of a traffic amount required in the call setup situation is registered in the database. A transmission rate control method. The transmission rate control method according to claim 2,
When the start state of communication on the dedicated channel is a situation of increasing traffic, information of a transmission rate determined in consideration of the increase amount of the traffic is registered in the database. Transmission rate control method. The transmission rate control method according to claim 2,
When the start state of the communication on the dedicated channel is an additional state of a circuit-switched call, information on a transmission rate determined in consideration of a traffic amount required in the additional state of the circuit-switched call. Is registered in the database. In a control station that controls a radio base station that performs communication using a common channel and an individual channel with a mobile station,
Detecting means for detecting that the mobile station has started communication by a dedicated channel,
By the detecting means, when detecting that the mobile station has started communication by a dedicated channel, a transmission rate determining means for determining a transmission rate according to the situation to start the communication,
A control unit for notifying the radio base station of the transmission rate determined by the transmission rate determining unit. In the control station according to claim 1,
Transmission rate information storage means for storing information of the transmission rate corresponding to the situation when the mobile station starts communication on an individual channel,
The detection means, when detecting that the mobile station has started communication on a dedicated channel, a communication start status determination means for determining a start status of communication on the dedicated channel,
Transmission rate information extraction means for extracting information on the transmission rate corresponding to the communication start status determined by the communication start status determination means from the transmission rate information storage means,
A control station for notifying the information of the extracted transmission rate by the notifying means. The control station according to claim 7,
The communication start status determination means,
A control station according to claim 1, wherein the start state of the communication on the dedicated channel is any one of a call setup situation, a traffic increase situation, and a circuit-switched call addition situation. The control station according to claim 7,
The transmission rate information storage means considers the amount of traffic required according to the call setting situation determined by the communication start situation determining means, the traffic increase situation, and the circuit switched call addition situation. A control station in which information on a determined transmission rate is registered. In a radio base station that performs communication using a common channel and an individual channel with a mobile station,
Detecting means for detecting that the mobile station has started communication by a dedicated channel,
Transmission rate determination means for determining a transmission rate according to the situation to start the communication,
A transmission rate setting means for switching to a transmission rate determined by the transmission rate determining means.

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