JP3284998B2 - Call distribution method and wireless switch in wireless switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call distribution method for distributing a processing load among a plurality of processors and avoiding a congestion state in a wireless switching system in which call processing is performed by a plurality of processors.

[0002]

2. Description of the Related Art Similar to a general telephone line exchange, a wireless exchange selects a called side (called side) in response to a request from a calling side in a wireless communication line, and communicates with the calling side. The call processing for connecting the terminals is performed. The transmission path of the mobile communication system is formed by connecting the wireless switch to a plurality of base stations and connecting the wireless switch to other wireless switches.

The number of lines accommodated by one wireless switch is hundreds or thousands, and if a single processor performs call processing, the load becomes too large. Therefore, in a wireless switch, a plurality of processors having the same function are used. It is configured to perform call processing and share the load.

[0004] In such a wireless switching system in which call processing is performed by a plurality of processors, the load state of each processor is detected in accordance with the load state in order to prevent a processing load from being excessively applied to one processor. Therefore, the calls to be processed by each processor are distributed.

[0005]

At present, a plurality of processors need to control (manage) a plurality of types of radio resources. Here, the radio resource means a resource (Resource; means, measure) necessary for connecting a call through a radio communication line.

[0006] The connection mode required by the mobile station is 13 kbps Voice, 8 kbps depending on the amount of signal transmission.
EVRC Voice, 8kbps Voice, D
data, etc., and a radio resource corresponding to such a connection mode is required for the radio exchange. For example, when a signal is transmitted in a wireless section, the signal is coded (coded). At this time, a vocoder (voco) corresponding to the connection mode is used.
der; a coding method based on speech analysis / synthesis), and a corresponding radio resource is also required.

However, the above-described call distribution method in the conventional wireless switching system is effective in a configuration in which a plurality of processors each control one type of wireless resource, but a plurality of processors each include a plurality of different types of wireless resources. Not applicable to configurations that control resources.

That is, if each processor manages only one type of radio resource, it is only necessary to detect an overloaded processor and distribute the call so as to reduce the processing load on the processor. When the processor controls a plurality of different types of radio resources, the processor may not implement the radio resources for performing the call processing. Cannot be sorted.

If the above-described call distribution method is applied to a wireless switching system in which a plurality of processors control a plurality of different types of wireless resources, in order to keep the load of call processing of the processors uniform, It is necessary to mount the same number of radio resources on all processors. Therefore, for example, when the number of processors of the wireless switchboard is increased with the increase in the number of wireless communication lines, different types of wireless resources cannot be implemented (if different types of wireless resources are implemented, the wireless resources implemented by a certain processor are changed ( Additional issues).

[0010] The present invention has been made to solve the above-described problem, and a plurality of different types of radio resources implemented by a plurality of processors can be used evenly (uniformly), and the same type of radio resources can be used. It is an object of the present invention to obtain a call distribution method and a radio switch in a radio switch capable of equally distributing loads among a plurality of processors mounted with the above radio resources.

[0011]

According to a first aspect of the present invention, there is provided a call distribution method in a wireless switching system, wherein a load condition and a radio resource availability condition for each call processor are provided when a call connection request is received from a mobile device. Is determined, and one call processor that implements the corresponding radio resource is searched for each corresponding radio resource.

[0012] According to a second aspect of the present invention, there is provided a call distribution method in a wireless exchange, wherein a radio resource selection process for selecting a radio resource corresponding to a connection mode of a call requested by a mobile device and a radio resource selection process are performed. A radio resource implementation determination process for determining whether or not each call processor implements the corresponding radio resource; a processor congestion state determination process for determining whether each call processor is restricted by congestion; A radio resource vacancy status determination process to determine whether there is a vacancy in the corresponding radio resource implemented by the processor, and a result of the processor congestion status determination process and the radio resource vacancy status determination process,
A processor determining process for causing the one call processor to perform call processing when one call processor is not regulated by congestion and there is a vacant radio resource installed in the one call processor. It is a thing.

According to a third aspect of the present invention, there is provided a call distribution method in a wireless switching system, wherein a wireless resource selection process selects a wireless resource based on an order table stored in a storage unit.

According to a fourth aspect of the present invention, there is provided a wireless switchboard.
A plurality of different types of radio resources for connecting a call, and a plurality of calls implementing the plurality of different types of radio resources and causing the corresponding radio resource corresponding to the connection mode of the call requested by the mobile device to execute the call processing. A processing processor, and a selection processing processor that determines a load processor and a radio resource vacancy status for each of the plurality of call processors, and, for each radio resource, searches for a call processor that implements the radio resource. It is provided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 is a block diagram showing a configuration of a wireless switching system according to an embodiment of the present invention. In the figure, the wireless switch 1 performs a call process of selecting a called side (called side) in response to a request from the calling side and connecting the calling side and the called side. Although not shown in FIG. 1, the wireless switch 1 is connected to a plurality of base stations and other wireless switches.

The selection processor 2 performs call processing according to the load state (congestion state) of the call processors 3A to 3C and the availability of the radio resources 4Aa to 4Ac, 4Ba, 4Bb, 4Ca, and 4Cc. A processor that selects and determines the processors 3A to 3C.

The call processors 3A to 3C are provided with radio resources 4Aa to 4Ac, 4Ba, 4Bb, 4
A processor that executes call processing by controlling Ca, 4Cc. The call processor 3A implements different types of radio resources 4Aa to 4Ac, and the call processor 3B implements different types of radio resources 4Ba, 4Ba.
Bb is implemented, and the call processor 3C implements different types of radio resources 4Ca and 4Cc.

Radio resources 4Aa to 4Ac, 4Ba, 4
Bb, 4Ca, and 4Cc are resources necessary for connecting a call through a wireless communication line. This radio resource 4Aa ~
4Ac, 4Ba, 4Bb, 4Ca, and 4Cc are connection modes (13 kbps Voice, 8k) required by the mobile device.
bps EVRC Voice, 8kbps Voice
e, Data, etc.).
The radio resources 4Aa, 4Ba, 4Ca, the radio resources 4Ab, 4Bb, and the radio resources 4Ac, 4Cc
Are the same type of radio resources (subscripts a, b, and c represent the types of radio resources).

Next, a method of distributing calls in the wireless exchange will be described. FIG. 2 shows each of the call processors 3A to 3A.
It is a flowchart which shows the radio | wireless resource vacancy status notification from 3C to the selection processor 2. As shown in FIG. 2, first, the call processor 3A determines the number of vacant radio resources 4Aa to 4Ac implemented by the call processor 3A, that is, the number of vacant radio communication lines accommodated by the radio resources 4Aa to 4Ac. The selection processor 2 is notified. Upon receiving the notification from the call processor 3A, the selection processor 2 sets the radio resource use status of the call processor 3A based on the notification.

Similarly, the call processors 3B and 3C also
The number of vacant radio resources 4Ba, 4Bb, 4Ca, and 4Cc is notified to the selection processor 2, and the selection processor 2 receives the radio resources of the call processors 3B and 3C based on the notification from the call processors 3B and 3C. Set usage status.

Each of the call processors 3A to 3C transmits the radio resources 4Aa to 4Ac, 4Ba, 4B
The selection processor 2 notifies the number of free spaces b, 4Ca, and 4Cc, and sets the radio resource use status of each of the call processors 3A to 3C every time the selection processor 2 receives this notification.

FIG. 3 shows each call processor 3 when overloaded.
9 is a flowchart showing load notification from A to 3C to a selection processor 2. In addition, each call processor 3A ~
3C has an overload threshold value and an overload release threshold value, respectively, and the selection processing processor 2 has an initial value of the acceptable number. The overload threshold value and the overload release threshold value are determined based on the usage rate of the processing capacity of each of the call processors 3A to 3C.
(Percentage of time during which the CPUs A through 3C operate). Further, the allowable number of receptions is
This is the allowable number of calls to be distributed to A to 3C.

As shown in FIG. 3, each call processor 3
A to 3C indicate that the load state exceeds the overload threshold,
When an overload state occurs, an overload notification indicating the overload state is sent to the selection processor 2 at regular intervals.

When the selection processor 2 receives an overload notification from the call processors 3A to 3C in the normal load state (ie, when the call processors 3A to 3C shift from the normal load state to the overload state), the overload state is determined. The allowable number of calls accepted by the call processors 3A to 3C that have notified the load (call distribution limit value) is greatly reduced. Further, the selection processor 2 receives the overload notification from the overloaded call processors 3A to 3C (that is, the call processors 3A to 3C).
If C remains in the overloaded state), the allowable number of calls (call distribution limit value) of the call processors 3A to 3C that have notified the overload is reduced by a small amount.

FIG. 4 is a flowchart showing a load notification from each of the call processors 3A to 3C to the selection processor 2 under normal load. As shown in FIG. 4, each of the call processors 3 </ b> A to 3 </ b> C is in a normal load state with respect to the selected processor 2 when the load state is below the overload threshold and becomes a normal load state. Is notified at regular intervals.

Upon receiving the normal load notification from the call processors 3A to 3C, the selection processor 2 notifies the normal load notification regardless of whether the call processors 3A to 3C are in the normal load state or the overload state. The call accepting number (call distribution limit value) of the call processors 3A to 3C is increased within a certain range.

FIG. 5 is a flowchart for explaining a call distribution method in the wireless switching device 1. When the wireless switching device 1 receives a call connection request from a mobile device, first,
The selection processor 2 serves as a mobile communication system,
It is confirmed whether or not outgoing / incoming (outgoing / incoming) restrictions are set (step ST1). Here, the reasons why the system is restricted include, for example, when the system is down and outgoing / incoming cannot be performed, when a failure occurs in a system that performs call processing, when the radio resources 4Aa to
4Ac, 4Ba, 4Bb, 4Ca, and 4Cc are all used, and all the call processors 3A to 3C are overloaded.

When the selection processor 2 determines that the system is being restricted as a result of the determination that the outgoing / incoming call is being restricted, the call processing cannot be performed (step ST2). Disconnect.

On the other hand, if the selection processor 2 determines that the system is not under regulation, the selection processor 2 sets the connection mode (for example, 13 kb) requested by the mobile device.
ps Voice, 8 kbps EVRC Voice,
In order to search for wireless resources a, b, and c capable of supporting 8 kbps voice, data, etc., refer to the order table shown in FIG. 6 and select a candidate pattern of wireless resources a, b, and c corresponding to the connection mode. (Step ST3). Incidentally, the order table in FIG. 6 is stored in a memory (not shown) of the wireless switching device 1.

For example, in the case of the order table shown in FIG. 6, the radio resources that can support the connection mode A (13 kbps Voice) are the radio resources a, b, and c.
Let radio resource a be the first candidate and radio resource b be the second candidate
The wireless resource c is set as a candidate, and the wireless resource c is set as a third candidate. Radio resources that can support the connection mode B (8 kbps EVRC Voice) are radio resources b and c,
Let radio resource b be the first candidate and radio resource c be the second candidate
Make it a candidate. In addition, connection mode C (8 kbps Voi
The only radio resource that can support ce) is the radio resource c, and the radio resource c is the first candidate.

Thereafter, the selection processor 2 searches the call processor (eg, 3B) next to the call processor (eg, 3A) to which the call has been distributed at the time of the previous call connection request from the mobile station, and searches for the search start call. It is automatically determined as the processing processor (step ST4), and it is determined whether or not all the call processors 3A to 3C have been searched (step S4).
T5).

If the search for all the call processors 3A to 3C has not been completed, the selection processor 2 determines that the relevant call processor (any of 3A to 3C) to be searched has the corresponding radio resource (any of ac). ) Is implemented (step ST6), and as a result of the determination, the search target call processor (any of 3A to 3C) implements the corresponding radio resource (any of a to c). If not, the next call processor is determined as the call processor to be searched (step ST10). On the other hand, when the call processing processor (any one of 3A to 3C) to be searched has the corresponding radio resource (any one of ac), the selection processing processor 2 determines that the call processing processor is restricted by congestion. It is determined whether or not there is (step ST
7).

Here, the selection processor 2 determines the congestion of the call processors (step ST7) by using the call processors 3A to 3A described with reference to FIGS.
This is performed by an overload notification and a normal load notification periodically notified from C. That is, when the selection processing processor 2 has received an overload notification from the call processing processor (any of 3A to 3C) to be searched, the call processing processor is in an overloaded state, and the allowable number of calls that can be accepted is reduced. Since it is 0, it is determined that there is regulation due to the congestion of the call processor.

As a result of the determination of the congestion of the call processors, if the selection processor 2 determines that there is regulation due to the congestion (overload state) of the search target processor (any of 3A to 3C), Is determined as the call processor to be searched (step S
T10). On the other hand, when the selection processor 2 determines that there is no regulation due to the congestion of the call processor to be searched (any of 3A to 3C), the call is distributed to the call processor (any of 3A to 3C) ( Provisionally determined as a call processor for processing a call (step ST)
8) Next, the selection processor 2 determines whether or not there is a free radio resource for the provisionally determined call processor (step ST9).

Here, the selection processor 2 determines whether or not the radio resources are available, as described with reference to FIG. 2 above, by the radio resources a, b,. This is performed according to the radio resource usage status of each of the call processors 3A to 3C set based on the number of free spaces of c.

As a result of the determination of the radio resource availability, if the selection processor 2 determines that there is no available radio resource in the call processor, the selection processor 2 determines the next call processor as the call processor to be searched. (Step ST10). On the other hand, when the selection processor 2 determines that there is a vacancy in the corresponding radio resource of the call processor, the selection processor 2 determines the call processor as a call processor that distributes (calls) a call (final determination).
(Step ST11). Thereafter, the call processor determined in this way controls the corresponding radio resource to execute call processing.

Determination of the implementation of the radio resource (step ST6), determination of call processor congestion (step ST6)
7), and determination of radio resource availability (step ST
As a result of 9), when the next call processor is determined as the call processor to be searched (step ST10),
Returning to step ST5, it is determined whether or not all the call processors have been searched. If all the call processors have not been searched, the above-mentioned steps ST6 to ST9 are performed.
Is repeated.

On the other hand, when all the call processors have been searched, the selection processor 2 determines the next candidate from the candidate patterns of the order table shown in FIG. 6 (step ST12), and determines whether the next candidate is in the order table. It is determined whether or not it is (step ST13). For example, if the connection mode requested by the mobile device is A, the call cannot be sorted as a result of searching the call processors 3A to 3C that implement the radio resource a (congestion state, empty state).
Then, it is determined to use the second candidate radio resource from the order table of FIG.

If it is determined in step ST13 that a wireless resource is described in the order table for the determined candidate, that there is a next candidate (for example, a second candidate or a third candidate), Returning to step ST4, the processing from step ST5 to step S9 is repeated for the corresponding radio resource.

On the other hand, if the next candidate is described as “none” in the order table, the selection processor 2
The call processors (3A to 3A) provisionally determined in step 8 above
3C) (step ST).
14). As a result of the determination, when there is no provisionally determined call processor (when the call processor is not provisionally determined), the call processing cannot be performed, so that no call distribution is performed (step ST2), and the call is disconnected.

On the other hand, if there is a call processor provisionally determined in the above step 8, the selection processor 2 determines the provisionally determined call processor as a call distribution destination (step ST15), and calls the call processor. Is determined (actually determined) as a call processor for distributing (call processing) (step ST11). As described above, the provisionally determined call processor is determined as the call distribution destination when there is no available radio resource (step ST9). This is because it is anticipated that there may be a vacant radio resource. If there is no vacancy in the radio resource of the provisionally determined call processor, no call distribution is performed.

Thereafter, the call processor determined as described above controls the corresponding radio resource to execute the call processing.

As described above, according to this embodiment,
The selection processor 2 is a call processor 3A-3C
After determining the load status and the radio resource vacancy status for each of the radio resources a, b, and c, the configuration is such that the call processors 3A to 3C for distributing the calls are searched for. 3B can use a plurality of different types of radio resources a, b, c uniformly (uniformly), and use the same type of radio resources a,
The call processing load among the plurality of processors 3A to 3C in the b and c mounted states can be evenly distributed. As a result, traffic congestion can be reduced, and a system with excellent stability can be realized.

Since the radio resource corresponding to the connection mode is selected in the order table, the type of the radio resource usable in the connection mode can be easily determined, and the radio resources can be used more uniformly.

Although the above embodiment has been described with reference to the case where the wireless switchboard 1 is provided with three call processors 3A to 3C, the present invention is not limited to this, and a plurality (three or more) of call processors are provided. May be used. Also, a radio resource a implemented by the call processor
~ C were three types, but are not limited to this.
A plurality of (three or more) wireless resources may be mounted.

[0046]

As described above, according to the first aspect of the present invention, when there is a call connection request from a mobile station, the load status and the radio resource availability status of each call processor are determined. Therefore, for each corresponding radio resource, one call processor that implements the corresponding radio resource is searched, so that a plurality of different types of radio resources implemented by a plurality of call processors can be used evenly, and the same type of radio can be used. There is an effect that the call processing load among the plurality of processors C in the resource mounted state can be evenly distributed.

According to the second aspect of the present invention, a radio resource selection process for selecting a radio resource corresponding to a connection mode of a call requested by a mobile station, and a corresponding radio resource selected by the radio resource selection process, A radio resource implementation determination process that determines whether the call processor is implemented, a processor congestion state determination process that determines whether each call processor is regulated by congestion, and each call processor is implemented. Radio resource availability status determination processing for determining whether or not the radio resource is available;
As a result of the processor congestion state determination processing and the radio resource vacancy status determination processing, if one call processing processor is not regulated by congestion and the corresponding radio resource implemented by one call processing processor has a vacancy, this one And a processor determining process for causing the call processor to perform the call process, so that a plurality of different types of radio resources implemented by the plurality of call processors can be used evenly, as in the invention of claim 1, and There is an effect that the call processing load among a plurality of processors C of the same type of wireless resource mounted state can be evenly distributed.

According to the third aspect of the present invention, the radio resource selection process is configured to select radio resources based on the order table stored in the storage means.
This makes it possible to easily determine the types of radio resources that can be used in the connection mode, and to use radio resources more uniformly.

According to the fourth aspect of the present invention, a plurality of different types of radio resources for connecting a call and the plurality of different types of radio resources are mounted to correspond to the call connection mode requested by the mobile station. A plurality of call processors for executing the call processing on the corresponding radio resources, and determining a load condition and a radio resource vacancy condition for each of the plurality of call processors, and implementing the corresponding radio resources for each corresponding radio resource. A selection processor that searches for one call processor, so that a plurality of different types of radio resources implemented by a plurality of call processors can be used evenly, and a plurality of processors of the same type of radio resource are installed. There is an effect that the call processing load between C can be evenly distributed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless exchange according to an embodiment of the present invention.

FIG. 2 is a flowchart showing wireless resource availability notification from each call processing processor to a selection processing processor;

FIG. 3 is a flowchart showing a load notification from each call processor to a selected processor when an overload occurs.

FIG. 4 is a flowchart showing a load notification from each call processor to a selected processor under a normal load.

FIG. 5 is a flowchart for explaining a call distribution method in the wireless exchange.

FIG. 6 is a diagram showing an order table of candidate patterns for searching for a radio resource corresponding to a connection mode requested by a mobile device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 wireless exchange 2 selection processor 3A-3C call processor 4Aa-4Ac, 4ba, 4Bb, 4Ca, 4Cc wireless resource

Claims (4)

(57) [Claims] 1. When a call connection request is received from a mobile station,
A call distribution method in a radio switch, comprising: determining a load condition and a radio resource availability condition for each call processor; and searching for one call processor implementing the radio resource for each radio resource. . 2. A radio resource selection process for selecting a radio resource corresponding to a connection mode of a call requested by a mobile station, and whether each call processor implements the radio resource selected by the radio resource selection process. Wireless resource implementation determination processing to determine whether or not each of the call processors is constrained by congestion; processor congestion state determination processing to determine whether or not there is regulation due to congestion; The result of the processor congestion state determination process and the radio resource availability condition determination process for determining whether there is a call processor is not regulated by congestion, and the one call processor If there is a vacancy in the corresponding radio resource implemented by the above, the call processing is performed to the one call processor. Call distribution method in a wireless switching system characterized by comprising a processor determining process to. 3. The method according to claim 1, wherein the wireless resource selection process selects a wireless resource based on an order table stored in a storage unit. 4. A plurality of different types of radio resources for connecting a call, and the plurality of different types of radio resources are mounted, and call processing is performed on a corresponding radio resource corresponding to a call connection mode requested by the mobile station. A plurality of call processors to be executed, and a load state and a radio resource availability state of each of the plurality of call processors are determined, and for each of the above radio resources, one call processor that implements the relevant radio resource is searched. And a selection processing processor.