JP4018563B2 - Transmission rate control method, control station, and radio base station - Google Patents

Description

[0001]
BACKGROUND 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 that is individually assigned to each mobile station.
[0002]
The present invention also relates to a control station and a radio base station that can control the 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) method is adopted as a wireless transmission method. In the IMT-2000 mobile communication system adopting this CDMA system, two types of channels are used as radio channels used for communication: an individual channel assigned to each mobile station and a common channel shared by a plurality of mobile stations. is there. For these two types of channels, a common channel or an individual channel is selected according to the traffic characteristics. For example, a common channel that is shared and used by a plurality of mobile stations is selected when the traffic is low, and an individual channel that is individually assigned to each mobile station is selected when the traffic is high.
[0004]
By the way, the services provided in the IMT-2000 mobile communication system include a communication service for only packet calls, a communication service for only circuit-switched calls, or a service for simultaneous communication of packet calls and circuit-switched calls (referred to as multicall). is there. Simultaneous communication of a packet call and a 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]
Wireless systems that perform wireless communication, including the IMT-2000 mobile communication system as described above, benefit from the use of valuable radio wave resources, and efficient use of radio resources is essential. Therefore, in the case of the IMT-2000 mobile communication system, when the mobile station performs packet call communication on an individual channel, the transmission rate is switched according to the communication status, thereby efficiently using radio resources.
[0006]
Also, a mobile communication system adopting a CDMA system, which performs packet communication using a common channel and a dedicated channel, and communication traffic in the mobile station is shifting from a sparse state to a dense state during communication. In some cases, a technique has been proposed in which radio base stations or mobile stations can accept the transition from a common channel to an individual channel to improve the communication quality of the mobile communication system and effectively use the radio frequency. (For example, refer to Patent Document 1).
[0007]
[Patent Document 1]
International Publication No. WO00 / 35235 Pamphlet [0008]
[Problems to be solved by the invention]
As described above, in the conventional IMT-2000 mobile communication system, the transmission rate is switched according to the communication status when the mobile station performs packet call communication on the dedicated channel for the purpose of effectively using radio resources.
[0009]
There are several cases when the mobile station starts packet call communication on a dedicated channel. For example, the following cases can be considered.
[0010]
(1) When setting up a packet call for outgoing / incoming calls (2) When communicating on a common channel with a packet call, or when switching to an individual channel due to increased traffic (3) During a communication on the common channel, a circuit-switched call In each of the above cases where the mobile station starts packet call communication on the dedicated channel when the common channel is changed from the common channel to the dedicated channel, the required initial transmission rate is considered to be different. However, transmission rate switching control in the conventional IMT-2000 mobile communication system is generally performed using the same initial transmission rate in each case. For this reason, it is impossible to set an initial transmission rate that is appropriate for all the cases described above. On the other hand, if an appropriate initial transmission rate is set for only one of the cases, the throughput of the entire system may be reduced, or the system capacity may be deteriorated due to waste of radio resources.
[0011]
The present invention has been made in view of the above problems, and the problem is that the entire system is configured by flexibly setting an initial transmission rate when a mobile station starts communication on a dedicated channel. The present invention provides a transmission rate control method that can prevent a decrease in throughput.
[0012]
Another object of the present invention is to provide a control station and a radio base station that can control the transmission rate according to such a transmission rate control method.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems , according to the present invention , a wireless base station, a mobile station, and a control station that controls communication of the wireless base station are shared and shared between the wireless base station and the mobile station. In a transmission rate control method in a mobile communication system that uses a channel and an individual channel that is individually assigned to each mobile station, the control station detects that the mobile station has started communication using an individual channel, and A transmission rate is determined according to a situation in which communication is started, and the determined transmission rate is notified to the radio base station.
[0014]
According to 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, and the mobile station When it is detected that a station has started communication on an individual channel, the start status of communication on the individual channel is determined, and information on the transmission rate corresponding to the determined start status of communication is extracted from the database. The extracted transmission rate is determined as a transmission rate to be notified to the radio base station.
[0015]
Further , according to the present invention , in the transmission rate control method, when the communication start status on the dedicated channel is a call setup status, the traffic amount required in the call setup status is considered. The transmission rate information determined in this way is registered in the database.
[0016]
Also, according to the present invention , in the transmission rate control method, when the start state of communication on the dedicated channel is a traffic increase state, the transmission is determined in consideration of the traffic increase amount. Rate information is registered in the database.
[0017]
Further , according to the present invention , in the transmission rate control method, when the start status of communication on the dedicated channel is a status of adding a circuit-switched call, it is necessary for the status of adding the circuit-switched call. The transmission rate information determined in consideration of the amount of traffic to be transmitted 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 of starting the communication and notifies the radio base station. The communication on the dedicated channel can be started at an appropriate transmission rate required in each communication start situation at the time of communication. As a result, it is possible to prevent a decrease in throughput of the entire system and a deterioration in communication capacity.
[0019]
DETAILED DESCRIPTION OF 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 performs communication by setting radio links with a plurality of mobile stations by code division multiple access.
[0021]
1, the mobile communication system is connected to a mobile station 101, a radio base station 102, a control station 103 that controls the radio base station 102, and the control station 103, and performs call control of the mobile station 101. A core network 104.
[0022]
FIG. 2 is a block diagram showing a configuration of an initial transmission rate application function unit of radio base station 102 according to the present embodiment. In this 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 the transmission rate extraction unit 202, and the transmission rate notified from the control station 103 is extracted by the unit 202. Information on the transmission rate (hereinafter referred to as initial transmission rate) extracted by the transmission rate extraction unit 202 in this way is applied as an initial transmission rate of the packet call of the dedicated channel by the transmission rate application unit 203. Various parameters are set to start the individual channel at the initial transmission rate.
[0024]
The mobile station 101 shown in FIG. 1 includes a functional unit similar to the initial transmission rate application functional unit of the radio base station 102, and receives information on the initial transmission rate by radio communication with the radio base station 102.
[0025]
FIG. 3 is a block diagram showing the configuration of the initial transmission rate notification function unit of control station 103 according to the present embodiment. In this 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. An information management unit (database) 306 is included.
[0026]
The call state monitoring unit 301 monitors call occurrence and attributes. When it is detected in the same unit 301 that the mobile station 101 has started communication of a packet call on an individual channel, the communication start type determination unit 303 determines which case the communication start case corresponds to. The Then, after the case determination is made in the same unit 303, the transmission rate extraction unit 303 extracts the information of the initial transmission rate corresponding to the case from the transmission rate information management unit 306. The information on the initial transmission rate extracted by the transmission rate extraction unit 303 is converted into a signal for notifying the radio base station 102 by the transmission rate notification unit 304 and sent 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 of the mobile station 101 under its own station and the change of call attributes (packet call or circuit switched call). When the call state monitoring unit 301 detects that the mobile station 101 has started communication of a packet call 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 case the communication start case corresponds to among a plurality of communication start cases (steps S2 and S3).
[0029]
First, the communication start type determination unit 302 determines whether or not the start timing of the dedicated channel by the mobile station 101 corresponds to the call setting case (case (1) above) (step S2). When it is determined to be applicable (YES in step S2), a flag value indicating the determined result is set (step S4) and output to the transmission rate extraction unit 303. In this embodiment, the flag setting value when the communication start case by the dedicated channel is call setting is 0x01 (0x means a hexadecimal number).
[0030]
The transmission rate extraction unit 303 accesses the transmission rate information management unit 306 to extract information on the initial transmission rate corresponding to the flag set value sent from the communication start type determination unit 302 (step S7), and transmits the transmission rate. It outputs to the notification part 304 (step S8).
[0031]
In the present embodiment, as shown below, it is assumed that there are four types of packet channel transmission rates of dedicated channels (see FIG. 5).
[0032]
Transmission rate 1.384 kbps
2.256 kbps
3.128 kbps
4.64 kbps
Further, 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, when a call is set up (case {circle around (1)}: flag = 0x01), a new communication is started and a relatively large amount of control traffic is expected to establish communication. In the example, 256 kbps) is set. In addition, when a transition is made from a common channel to an individual channel due to traffic increase (case (2): flag = 0x02), it is expected that traffic will continue to increase, so a high transmission rate (384 kbps in this example) Is set. Further, when a transition to a dedicated channel is forcibly made by adding a circuit-switched call as in 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]
Returning to FIG. 4, the initial transmission rate information extracted by the transmission rate extraction unit 303 and notified to the transmission rate notification unit 304 is converted into a predetermined signal, and then transmitted to the radio base station 102 via the transmission interface unit 305. Sent to. The reception interface unit 201 of the radio 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 sent 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 unit 203 performs various parameter setting processing so that communication at the extracted initial transmission rate is possible.
[0034]
The processing in the radio base station 101 as described above is similarly performed in the mobile station 101. As a result, the radio base station 102 and the mobile station 101 are set to the initial transmission rate notified from the control station 102 and start communication of the packet call through the dedicated channel.
[0035]
If the communication start type determination unit 302 determines in step S2 that it does not correspond to the call setting case (case (1)) (NO in step S2), the process proceeds to step S3. It is determined whether the start trigger is due to a traffic increase case (case (2) above). If it is determined that this case corresponds to a traffic increase case (YES in step S3), the flag set value is set to 0x02 and output to the transmission rate extraction unit 303. The subsequent processing is performed in the same manner as in the call setting case.
[0036]
On the other hand, when it is determined in step S3 that the case does not correspond to the traffic increase case (NO in step S3), the common channel is started by adding a circuit-switched call while the start timing of the individual channel is communicating on the common channel. Is determined to be a case of transition to an individual channel (case (3) above), and a flag corresponding to this case is set (step S6) (in this case, the flag set value is, for example, 0x03), and transmission rate extraction is performed. Is output to the unit 303. The subsequent processing is performed in the same manner as in the case (1).
[0037]
As described above, according to the present embodiment, the control station 103 identifies each case in which the mobile station 101 starts communication of a packet call on a dedicated channel, and sets the transmission rate required for each case. Since they are set 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 throughput of the entire system is reduced as compared to the conventional case where the transmission rate starting from the individual channel is set uniformly. And communication capacity can be avoided, and wireless resources can be used effectively.
[0038]
In this embodiment, there are four types of packet call transmission rates for individual channels, and there are three types (cases (1) to (3)) in which the mobile station starts packet call communication on individual channels. 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, it is possible to start communication on the individual channel at an appropriate transmission rate required in each communication start situation when performing communication on the individual channel. As a result, it is 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.
2 is a block diagram showing a configuration of an initial transmission rate application function unit of the radio base station shown in FIG. 1;
3 is a block diagram showing a configuration of an initial transmission rate notification function unit of the control station shown in FIG. 1. FIG.
FIG. 4 is a flowchart showing an operation of initial transmission rate setting notification processing performed in a control station.
FIG. 5 is a diagram showing types of transmission rates of dedicated channel packet calls;
FIG. 6 is a diagram illustrating initial transmission rate information for each start case registered and managed in a transmission rate information management unit.
[Explanation of symbols]
101 mobile station 102 wireless 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 (9)

A common channel that is shared between the radio base station and the mobile station, and an individual channel that is individually assigned to each mobile station, including a radio base station, a mobile station, and a control station that controls communication of the radio base station In a transmission rate control method in a mobile communication system using
The control station
A database for storing information on a transmission rate corresponding to a situation when the mobile station starts communication on an individual channel;
When it detects that the mobile station has started communication on a dedicated channel, it refers to the database , determines the transmission rate according to the situation to start the communication,
Notifying the determined transmission rate to the radio base station ,
In the database, when the start status of communication on the dedicated channel is a traffic increase status, information on a transmission rate determined in consideration of the traffic increase amount is registered. A transmission rate control method. The transmission rate control method according to claim 1,
Said control station,
When the front Symbol mobile station detects that it has started a communication with the dedicated channel, to determine the starting situation of communication in the individual by the channel,
A transmission rate control method, wherein information of 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 to be notified to the radio base station. The transmission rate control method according to claim 2, wherein
If the communication start status on the dedicated channel is a call setup status, information on the transmission rate determined in consideration of the traffic volume required in the call setup status is registered in the database. A transmission rate control method. The transmission rate control method according to claim 2, wherein
Start condition of communication in the dedicated channel, if an additional condition of circuit switching call, the transmission rate is determined in consideration of the Torahi' click amount required by the additional status of the circuit-switched call A transmission rate control method, wherein information is registered in the database. In a control station that controls a radio base station that communicates with a mobile station using a common channel and a dedicated channel,
  Transmission rate information storage means for storing transmission rate information corresponding to the situation when the mobile station starts communication on a dedicated channel;
  Detecting means for detecting that the mobile station has started communication on a dedicated channel;
  A transmission rate determining unit that refers to the database and determines a transmission rate according to a situation of starting the communication when the detecting unit detects that the mobile station has started communication through a dedicated channel;
  A notifying means for notifying a radio base station of the determined transmission rate by the transmission rate determining means;
  Have
  In the transmission rate information storage means, when the start status of communication on the dedicated channel is an increase in traffic, information on the transmission rate determined in consideration of the increase in traffic is registered. A control station. The control station according to claim 5,
  When the detecting means detects that the mobile station has started communication on a dedicated channel Communication start status determining means for determining the start status of communication on the dedicated channel;
  Transmission rate information extracting means for extracting information on the transmission rate corresponding to the communication start status determined by the communication start status determining means from the transmission rate information storage means,
  The control station which notifies the extracted information of the transmission rate by the notification means. The control station according to claim 6,
The communication start status determination means includes
A control station characterized in that the start status of communication on the dedicated channel determines one of a call setup status, a traffic increase status, and a circuit-switched call addition status. The control station according to claim 6 ,
The transmission rate information storage means takes into account the amount of traffic required according to the call setup status, traffic increase status, and circuit-switched call addition status determined by the communication start status determination means. A control station in which information on a transmission rate to be determined is registered. In a radio base station that communicates with a mobile station using a common channel and a dedicated channel,
  The control station that controls the communication of the radio base station includes a database that stores information on a transmission rate corresponding to a situation when the mobile station starts communication on a dedicated channel, and the database includes the dedicated channel. If the start status of the communication is an increase in traffic, information on the transmission rate determined in consideration of the increase in traffic is registered, and the mobile station has started communication on the dedicated channel 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,
  Detecting means for detecting that the mobile station has started communication on a dedicated channel;
  Transmission rate extraction means for extracting the transmission rate notified from the control station;
  Transmission rate application means for setting parameters for starting communication on the dedicated channel at the extracted transmission rate;
  A radio base station characterized by comprising:

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