JP3203540B2 - Location registration control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a location registration control method for mobile communication.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing a conventional mobile communication system. As shown in FIG. 1, in a conventional mobile communication system, a location registration area (LA) including a plurality of radio cells is provided.
1, LA2) are fixedly set. Mobile station (M
1) knows that the mobile terminal has moved beyond the boundary of the location registration area by the number given to the location registration area notified from each wireless base station, and sends a location registration request signal so that the simultaneous paging at the time of the incoming call is correctly performed. The transmission is performed in the wireless cell (A1) included in the destination location registration area (LA2).
The location registration information of the mobile station M1 is sent to a database in the network via the radio base station (B1), and the location registration information management database is rewritten.

As an attempt to improve the above-described location registration control method, the location registration area is made variable instead of fixed.
There has been proposed a method of configuring a location registration area so that the number of times a location registration request signal is sent by learning or the like is reduced as much as possible.

However, this improvement has a problem that when the configuration of the location registration area is changed by learning or the like, location registration must be performed again on the network in order to guarantee a correct call upon arrival. However, this causes a temporary explosion in location registration traffic.

On the other hand, as a method effective in preventing the explosive increase in the location registration traffic, Japanese Patent Laid-Open No. 5-3581 has been proposed.
There is a method described in Japanese Unexamined Patent Application Publication No. 2000-205,878. This is because each base station broadcasts all the radio cells included in the location registration area as location registration area information, and the mobile station stores and stores the radio cell (hereinafter referred to as a registered cell) that has performed location registration. This is a method for performing location registration when a wireless cell that has been moved to a wireless cell that has not been notified.

In this method, when an incoming call is generated, the incoming call is made in all the radio cells to which the registered cell is broadcast. Therefore, even if the location registration area configuration changes, if the location registration area information notified after the change includes a registration cell, the call at the time of incoming call is guaranteed, and there is no need to newly register the location. This is effective in reducing the location registration traffic when the location registration area configuration is changed.

[0007]

However, broadcasting all the radio cells included in the location registration area causes an increase in the amount of downlink signals, and cannot be applied to an actual system.

An object of the present invention is to improve a method of notifying a mobile station of a location registration area and to prevent explosive increase in location registration traffic when the location registration area configuration is changed.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a plurality of base stations and a plurality of mobile stations,
A radio cell is assigned to each of the base stations, and a location registration area is formed by combining a plurality of the radio cells,
The mobile station registers its location in the location registration area in which the mobile station is currently located, and when an incoming call to each mobile station occurs, each mobile station receives an incoming call within the radio cell that constitutes the location registration area registered. In the location registration control method of making a call, each base station , each mobile station common location registration area conditional expression is a conditional expression to be satisfied by each radio cell included in the location registration area ,
Each mobile station is notified of location registration area information common to each mobile station provided for each base station , and each mobile station stores registered cell information, which is identification information of a radio cell, and stores location registration area conditions. If the relationship between the registered cell information and the location registration area information assigned to the formula does not satisfy the location registration area condition formula, it is determined that the registered location registration area has left, and location registration is performed again to store the registered cell information. It is a control method.

Further, another aspect of the present invention comprises a plurality of base stations and a plurality of mobile stations, a radio cell is allocated to each of the base stations, and a location registration area is formed by combining a plurality of the radio cells. The mobile station registers its location in the location registration area in which the mobile station is currently located, and when an incoming call to each mobile station occurs, each mobile station receives an incoming call within the radio cell that constitutes the location registration area registered. In the location registration control method for paging, each base station shares with each mobile station provided for each base station.
Each mobile station that has notified the location registration area information to each mobile station, and the location registration area conditional expression is set in advance, stores the registered cell information that is the identification information of the radio cell, and stores the location registration area conditional expression. If the relationship between the registered cell information and the location registration area information does not satisfy the location registration area conditional expression, it is determined that the registered location registration area has left, the location registration is performed again, and the registered cell information is stored. Is the way.

The location registration area conditional expression is a conditional expression using the registration cell information and the location registration area information broadcast by the base station when each mobile station performs location registration as parameters.

Further, each registered cell information is displayed in coordinates, and the position registration area conditional expression is an inequality that satisfies the coordinate-displayed registered cell information and position registration area information.

Further, each registered cell information is displayed as a natural number, and all natural number information, which is a product of all the natural number displays provided for each radio cell included in the same position registration area, is used as the position registration area information. Stores registered cell information in a natural number representation, and in the location registration area conditional expression, the registered cell information stored in each mobile station is a divisor of all natural number information.

[0014]

According to the present invention having the above-described configuration, not only all the radio cells included in the location registration area but the location registration area conditions to be satisfied by the radio cells constituting the location registration area are used as the location registration area information. By reporting the expression, the location registration area information can be reported efficiently (minimizing the information overhead).

Further, it is possible to reduce the location registration traffic at the time of changing the location registration area configuration without notifying all the radio cells included in the location registration area. That is, since the location registration area where the location registration is performed is all the radio cells that broadcast the location registration area conditional expression satisfied by the registration cell, even if the configuration of the location registration area changes,
If the registered cell continuously satisfies the location registration area conditional expression broadcast after the change, the mobile station will also be located in the location registration area where location registration is still being performed, and the incoming call is guaranteed, and This is because there is no need to register.

[0016] The prior art means that, as location registration area information, the number assigned to the location registration area or all wireless cells belonging to the location registration area (the numbers assigned to) are not reported, and the location registration area condition is not notified. The difference is that the formula is reported.

[0017]

FIG. 1 is a system configuration diagram of a first embodiment of the present invention. In the figure, M1 is a mobile station, A1 to A12
Is a wireless cell, B1 to B12 are wireless base stations, C1 is a control station, and D1 is a database. Each wireless cell is provided with coordinates indicating a position. As the coordinates, two-dimensional coordinates using longitude and latitude, two-dimensional coordinates using section numbers dividing the service area into, for example, east, west, south and north are used.

FIG. 3 shows an example of the structure of broadcast information periodically transmitted from each of the base stations B1 to B12. The broadcast information includes identification information of a wireless cell formed by the own base station and location registration area information of a location registration area including the wireless cell of the own base station. In this example, the two-dimensional coordinates (Xc, Yc) given to the wireless cell in the identification information are reported. In the location registration area information, the parameters of the location registration area conditional expression (here, X1, Y1, X2,
Y2. Hereinafter, this is referred to as an area parameter).

FIG. 4 is a flowchart showing a mobile station location registration algorithm according to the present invention.

The location registration operation according to the first embodiment of the present invention will be described below with reference to FIGS. 1, 3 and 4.

Assume that the mobile station M1, which has not been used, is turned on for the first time in the radio cell A1 (step 40).
1). After the power is turned on, the mobile station M1 receives the broadcast information from the base station B1, and recognizes that the coordinates of the wireless cell A1 in which the mobile station M1 is located are (1, 1), and then the database D1 via the base station B1. The position (1, 1) of the wireless cell A1 is registered (step 402). Also, the coordinates (1, 1) of the wireless cell A1 are recorded in its own memory as the coordinates (Xr, Yr) of the registered cell. Next, it is determined whether the registered cell satisfies the following location registration area conditional expression (step 4).
03).

The location registration area conditional expression is given in advance as an inequality including the area parameter reported in the location registration area information. In the present embodiment, (X1, Y1, X2, Y2) are broadcast as area parameters, and the following inequalities including the four area parameters are used as conditional expressions for the location registration area. However, (Xr, Y
r) is the coordinates of the registered cell.

(X1 ≦ Xr ≦ X2) and (Y1 ≦ Yr ≦ Y2)

It is to be noted that the location registration area conditional expression is not satisfied if the coordinates (Xc, Yc) of the radio cell reported by the identification information are substituted into the coordinates (Xr, Yr) of the registration cell. Not to be. This rule is a rule for assuring that the location registration area broadcast by the base station always includes its own wireless cell. For example, base station B
Area parameters (X1, Y1, X
(2, Y2) is (1, 1, 3, 2), and the conditional expression of the location registration area is as follows.

(1 ≦ Xr ≦ 3) and (1 ≦ Yr ≦ 2)

Of course, even if the coordinates (2, 1) of the radio cell A2 are substituted for (Xr, Yr), the above inequality is satisfied as prescribed.

In this embodiment, the base stations B2, B3, B
7, B8, and B9 broadcast the same area parameters as the base station B1, and all have the same location registration area conditional expression. Therefore, the mobile station M whose location is registered in the wireless cell A1
No. 1 satisfies the location registration area conditional expression even if it moves to the above eight base station radio cells, and does not perform location registration.
That is, the mobile station M1 has the radio cells A1, A2, A3, A
It can be considered that an area consisting of 7, A8, and A9 is registered as a position registration area.

Thereafter, when the mobile station M1 whose location is registered in the radio cell A1 moves to the base station 4, the area parameters (X1, Y1, X2, Y2) change to (4, 1, 6, 2). The location registration area conditional expression is as follows.

(4 ≦ Xr ≦ 6) and (1 ≦ Yr ≦ 2)

Since the coordinates (Xr, Yr) of the registered cell (Xr, Yr) = (1, 1) recorded by the mobile station M1 do not satisfy this inequality, it is assumed that the mobile station M1 has left the location registration area registered by itself. Judgment is made and the coordinates (4, 1) of the wireless cell A4 are registered.

As described above, if the recorded coordinates (Xr, Yr) of the registered cell satisfy the location registration area conditional expression reported from the base station by the area parameter, the mobile station M1 registers itself. It is determined that the user is within the registered location registration area, and the location registration is not performed. Conversely, if the location registration area conditional expression is not satisfied, it is determined that the user has left the location registration area registered by himself, and the location of the wireless cell located in the area is registered again.

As described above, (X1,
Although an example using Y1, X2, Y2) has been described, there is also an example in which four area parameters of (X1, Y1, a, b) are reported and the following inequality is used as a location registration area conditional expression. Conceivable.

(X1 ≦ Xr ≦ X1 + a) and (Y1 ≦ Y
r ≦ Y1 + b)

In this conditional expression, the area parameter (X
(1, Y1) indicates the location of the location registration area, and the area parameter (a, b) indicates the size of the location registration area.

In the description, an example has been described in which an inequality (location registration area conditional expression) including an area parameter is determined in advance, and only the area parameter is notified as the location registration area information. A method of notifying the location registration area conditional expression itself including the relational operator as the area information is also conceivable. That is, instead of the base station B1 notifying only the area parameter (1, 1, 3, 2),

(1, ≦, Xr, ≦, 3, ∧, 1, ≦, Yr, ≦, 2)

Then, the location registration area condition expression itself is notified.
In this case, there is no need to determine a location registration area conditional expression including an area parameter between the base station and the mobile station in advance.

Next, the calling operation will be described.

FIGS. 5 and 6 are flowcharts showing the calling algorithm on the network side in the first embodiment of the present invention.

As shown in FIG. 5, when there is an incoming call at the mobile station, the network searches for the coordinates of the registered cell whose position has been registered first (steps 501 and 502). Next, it is determined whether or not all base stations have an inequality that satisfies the coordinates of the registered cell (step 505). If any inequality is satisfied, the base station is recorded (step 506). After the determination of all base stations is completed (step 503), simultaneous paging is performed only to the radio cells of the base stations satisfying the stored conditions (step 504).

In addition to this, as shown in FIG. 6, a method of sequentially calling the radio cells can be considered. That is, after searching for the coordinates of the registered cell (steps 601 and 602), if there is a base station having an inequality that satisfies the coordinates of the registered cell (step 604), a call is immediately made to the wireless cell (step 605). If there is a response from the mobile station, the method stops the call to the radio cell that has not made a call, and if there is no response, determines whether the inequality of the next base station satisfies the coordinates of the registered cell. (Steps 606 and 603).

Next, a case where the location registration area configuration is changed by learning or the like will be described.

In a system in which the location registration area number assigned to the location registration area is used for location registration, if the location registration area number changes with a change in the location registration area configuration, a new location registration area number is registered. I have to do it again.

For example, as shown in FIG.
1, A2, A3, A7, A8, A9, a location registration area LA1, and radio cells A4, A5, A6, A10, A
11 and A12, two location registration areas LA2 are radio cells A1, A2, A3, A4, A
5 and A6, and a wireless cell A
Consider a case in which the location is changed to two location registration areas of a location registration area LA4 including 7, A8, A9, A10, A11, and A12.

FIG. 8 is a diagram showing an example of a change in the position registration area number at this time.

Before the change of the location registration area configuration, the radio cell A
The mobile station M1 whose location has been registered in 1 and the mobile station M2 whose location has been registered in the radio cell A7 have both registered the location registration area number LAN1 of the location registration area LA1. afterwards,
It is assumed that the configuration of the location registration area has changed as described above. At this time, as shown in the correspondence table of FIG. 8A, the new location registration area KA3 has a new location registration area number LAN.
When a new location registration area number LAN4 is assigned to the new location registration area LA4, both the mobile stations M1 and M2 must perform location registration for changing to the new location registration area number.

Therefore, as shown in the correspondence table of FIG. 8B, the old location registration area number L is added to the new location registration area LA3.
AN1 assigns the old location registration area number LAN2 to the new location registration area LA4. With this method,
The mobile station M1 does not need to perform location registration because the location registration area number does not change. However, since the location registration area number of the mobile station M2 changes from LAN1 to LAN2, location registration must be performed.

However, in the present invention, the above-mentioned mobile station M1,
The location registration area is set to L without performing location registration for both M2.
The configuration of A1 and LA2 can be changed to the configuration of LA3 and LA4.

FIG. 9 shows an example of the configuration of the broadcast information of the base station when the above-mentioned location registration area configuration change has occurred.

That is, by changing the notification information as shown in FIG. 3 to FIG. 9, (1, 1, 3, 2) is notified as an area parameter in the location registration area LA1, and the area is registered in the location registration area LA2. (4, 1, 6, 2) was notified as a parameter, but (1, 1, 6, 2) is used as an area parameter (1, 1, 6) in a new location registration area LA3.
(1, 6, 1) is notified, and (1, 2, 6, 2) is notified as an area parameter in the new location registration area LA4.

When the broadcast information changes, the base station B1
Then, the location registration area conditional expression to notify,

(1 ≦ Xr ≦ 3) and (1 ≦ Yr ≦ 2) →
(1 ≦ Xr ≦ 6) and (1 ≦ Yr ≦ 1)

Changes as follows. However, the mobile station M1 whose location is registered in the radio cell A1 has the coordinates (1, 1) of the radio cell A1.
Is registered as a registered cell, and any inequality satisfies the coordinates (Xr, Yr) = (1, 1) of the registered cell, so there is no need to perform position registration.

Similarly, in the base station B7, the inequality of the location registration area to be broadcast is

(1 ≦ Xr ≦ 3) and (1 ≦ Yr ≦ 2) →
(1 ≦ Xr ≦ 6) and (2 ≦ Yr ≦ 2)

Changes. However, the mobile station M2 whose location has been registered in the radio cell A7 has the coordinates (1, 2) of the radio cell A7.
Is registered as a registration cell, and any of the inequalities satisfies the coordinates (Xr, Yr) = (1, 2) to be registered.

Also, if the location registration area configuration changes as described above after the mobile station M1 whose location has been registered in the radio cell A1 moves to the radio cell A2, the base station B2 does not change the area parameter. Since it is the same as the base station B1, the location registration of the mobile station M1 is not performed.

On the other hand, if the location registration area configuration changes as described above after the mobile station M1 whose location has been registered in the radio cell A1 moves to the radio cell A7, the location reported by the base station B7 after the change. Inequality of registration area

(1 ≦ Xr ≦ 6) and (2 ≦ Yr ≦ 2)

The coordinates (Xr, Y) of the registered cell of mobile station M1
Since r) = (1, 1) is not satisfied, the mobile station M1 performs location registration.

That is, when the new location registration area does not include a registration cell, location registration must be performed.

However, as described above, when a new location registration area includes a registration cell, location registration does not have to be performed even if the location registration area configuration changes. Compared with the method used, the number of position registrations can be reduced when the position registration area configuration changes.

The method of using two-dimensional coordinates for the identification information of the radio cell and using the inequality satisfied by the coordinates of the registered cell as the conditional expression of the location registration area has been described above.

In addition, a natural number is used as identification information of a wireless cell, and the product of the natural numbers of the wireless cells included in the location registration area is reported as location registration area information. A position registration control method that is a divisor of the product of the positions is also conceivable.

Next, a second embodiment of the present invention will be described.

In this embodiment, a natural number “prime number” is assigned to each radio cell. The broadcast information of the base station includes, as identification information, a product of a “prime number” of a wireless cell of the own base station and “prime numbers” of all wireless cells included in the location registration area as location registration area information. The mobile station registers the "prime number" of the wireless cell in which the mobile station is located at the time of position registration and, at the same time, records it as the "prime number" of the registered cell. Thereafter, if the “product” of the location registration area information broadcast from the base station is divisible by the “prime number” of the registered cell, the mobile station determines that the mobile station is located in the registered location registration area, does not perform location registration, and must be divisible. In this case, it is determined that the user has left, and the location is registered again. When there is an incoming call to the mobile station, a call is made to the radio cells of all base stations having "product" divisible by the "prime number" of the registered cell in the location registration area information.

In this method, as in the first embodiment using coordinates and inequalities, even if the location registration area configuration changes, location registration is not performed unless the registered cell is included in the new location registration area. Therefore, it is possible to reduce position registration when the position registration area configuration changes.

[0068]

As described above, according to the present invention, the base station notifies the mobile station of the location registration area in the form of a location registration area conditional expression to be satisfied by the radio cell included in the location registration area. By doing so, even if the configuration of the location registration area changes, the location registration does not need to be performed if the registration cell continues to satisfy the location registration area conditional expression notified after the change, and the location generated when the location registration area configuration changes. Registration traffic can be reduced.

Although the location registration traffic reduction effect can also be obtained by a method of broadcasting all the radio cells included in the location registration area, it is not practical in a real system to broadcast all the radio cells.

On the other hand, according to the present invention in which the location registration area is notified by the conditional expression, the effect of reducing the location registration traffic can be easily realized.

[Brief description of the drawings]

FIG. 1 is an example of a system configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram showing location registration in a conventional mobile communication system.

FIG. 3 is a configuration example of broadcast information of a base station according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a location registration algorithm of a mobile station according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a call on the network side according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing a call on the network side according to the first embodiment of the present invention.

FIG. 7 is a change example of a position registration area configuration.

FIG. 8 is an example of a change in a location registration area number when the location registration area configuration changes.

FIG. 9 is a configuration example of broadcast information of a base station according to the first embodiment of the present invention.

[Explanation of symbols]

A1 to A12 Wireless cell B1 to B12 Wireless base station C1 Control station D1 Database M1, M2 Mobile station LA1 to LA4 Location registration area LAN1 to LAN4 Individual location registration area Xc, Yc Two-dimensional coordinates of wireless cell Xr, Yr Location of mobile station Two-dimensional coordinates of registered wireless cell (registered cell) X1, Y1, X2, Y2, a, b Parameters of conditional expression of location registration area

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (5)

(57) [Claims] 1. A system comprising a plurality of base stations and a plurality of mobile stations,
A radio cell is assigned to each of the base stations, a location registration area is formed by combining a plurality of the radio cells, and the mobile station registers the location registration area where its own station is currently located. In a location registration control method for performing an incoming call of each mobile station in the radio cell configuring the location registration area where location registration is performed when an incoming call to each of the mobile stations occurs , each of the base stations includes : It said position said common location registration area condition each mobile station is a condition to be satisfied by the radio cells included in the registration area, each shift of said given for each base station
A dynamic station common location registration area information, the notified to each mobile station, wherein each mobile station stores the identification information is registered cell information of the radio cell, the registration in the location registration area Condition When the relationship between the cell information and the location registration area information does not satisfy the location registration area conditional expression, it is determined that the registered location registration area has left, the location registration is performed again, and the registered cell information is stored. And a location registration control method. 2. A system comprising a plurality of base stations and a plurality of mobile stations,
A radio cell is assigned to each of the base stations, a location registration area is formed by combining a plurality of the radio cells, and the mobile station registers the location registration area where its own station is currently located. In a location registration control method for performing an incoming call of each mobile station in the radio cell configuring the location registration area where location registration is performed when an incoming call to each of the mobile stations is generated, Each mobile station assigned to each base station
The mobile station broadcasts location registration area information to each mobile station, and the mobile station, in which the location registration area conditional expression is set in advance, stores registered cell information that is identification information of the wireless cell, If the relationship of assigning the registration cell information and the location registration area information to a registration area conditional expression does not satisfy the location registration area conditional expression, it is determined that the registered location registration area has left, and the location registration is performed again. A location registration control method characterized by storing registered cell information. 3. The location registration area conditional expression is a conditional expression using, as parameters, the registered cell information and the location registration area information reported by a base station through which each mobile station performs location registration. 3. The location registration control method according to claim 1. 4. The method according to claim 1, wherein said registered cell information is displayed in coordinates, and said location registration area conditional expression is an inequality that satisfies said registered cell information in coordinates and said location registration area information. The location registration control method according to any one of claims 1 to 3. 5. A method of displaying each registered cell information as a natural number, and calculating all natural number information, which is a product of all the natural number displays given for each of the radio cells included in the same position registration area, as the position registration area information. Wherein each mobile station stores the registered cell information in a natural number representation, and the location registration area conditional expression is that the registered cell information stored in each mobile station is a divisor of the total natural number information. Claims 1-3
The location registration control method according to any one of the above.