KR100586600B1 - Asymmetric Adaptive Location Update Method at Intercell Boundary Area - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an asymmetric adaptive location update method in an intercell boundary region and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention provides asymmetric and adaptive size of boundary location area in designing a boundary location area (BLA) and roaming effectively through a boundary location register (BLR) in a system in which heterogeneous wireless communication systems are interworked. By optimizing the increase in the number of location updates according to the introduction of the boundary location area according to the system design, the additional signal traffic of the network caused by the movement of the terminal in the location area or cell boundary area between heterogeneous systems and the resulting signal cost increase problem To provide an asymmetric adaptive location update method for solving the problem and a computer-readable recording medium for realizing the method.

3. Summary of Solution to Invention

The present invention provides a method for updating a location in an intercell boundary area in a system interworking heterogeneous mobile communication networks, wherein the intercellular boundary area is asymmetric and adaptive according to the relative location registration signal cost of each system and the average speed of the mobile terminal. A first step of setting an optimal boundary position area (BLA) with the first step; In order to continuously manage the mobility of roaming subscribers in the boundary location area (BLA) and to reduce unnecessary signal traffic, the boundary location capable of supporting all the signaling methods of the heterogeneous mobile communication networks and supporting the subscriber information form of the system A second step having a register (BLR); And optimizing an increase in the number of position updates according to the introduction of the boundary position region according to the system design by optimizing the position of the mobile terminal crossing the boundary of the boundary position region BLA through the boundary position register BLR according to the system design. Includes a third step of updating automatically.

4. Important uses of the invention

The present invention is used for subscriber roaming services in heterogeneous mobile communication networks.

Boundary Location Register (BLR), Boundary Location Area (BLA), Intercell Boundary Area, Asymmetric Adaptive Update, Roaming

Description

Asymmetric and adaptive location registration method for inter-cell boundary region             

1 is a diagram illustrating a location update and paging method in a boundary area between cells of a conventional heterogeneous mobile communication system.

2 is an exemplary configuration diagram of a hardware system for an asymmetric adaptive location update method in an intercell boundary region according to the present invention.

3 is a diagram illustrating an embodiment of a distance-based location area technique used in the present invention.

4 is a flowchart illustrating an asymmetric adaptive location update method in an intercell boundary region according to the present invention;

* Explanation of symbols for the main parts of the drawings

21: Exchange station a (MSC-a) 22: Visitor location register (VLR-h) in the home network

23: switching center c (MSC-c) 24: home position register of the home network (HLR-h)

25: boundary location register (BLR) 26: visitor location register (VLR-v) of the visit network

27: exchange office b (MSC-b) 28: home location register (HLR-v)

The present invention provides a wireless subscriber network (WLL), a broadband wireless subscriber network (B-WLL), a radio frequency system (TRS), a cell phone network (Cellullar), a personal mobile communication network (PCS), and an intelligent transportation network using different mobile communication protocols. (ITS), wireless data networks, other mobile telephone networks in foreign countries, "International Mobile Telecommunication-2000" (IMTS-2000) and "Universal Mobile Telecommunication Service" (UMTS), which are currently being standardized in northern and European ways. In a system in which heterogeneous wireless communication systems, such as next generation mobile communication networks, are interworked, an asymmetric adaptive location update method in a boundary area between cells adjacent to each other, and a computer-readable recording medium recording a program for realizing the method. It is about. That is, the present invention relates to a location management technique, such as location registration and paging, to transfer a call by tracking and grasping the location of a mobile terminal in a mobile communication system.

Up to now, the technology of this field has been researched and developed mainly on the location management technique in the structure of one system or the cell of the same layer, and the technology for efficient location management in various hierarchical or mixed systems is insufficient research and development. to be.

1 is an explanatory diagram showing a location update and paging method in a boundary area between cells of a conventional heterogeneous mobile communication system, in which "11" is an exchange station a (MSC-a) and "12" is a visitor location register (VLR) of a home network. -h), "13" is the switching center c (MSC-c), "14" is the home location register (HLR-h) of the home network, "15" is the visitor location register (VLR-v), "16" in the visiting network. Are the switching center b (MSC-b), and " 17 " represent the home location register (HLR-v) of the visited network, respectively.

Currently, at the time of updating and paging the current location in the intercell boundary area of the heterogeneous system, location update and paging location management for the mobile terminal are performed by the home location registers 24 and 27 and the visitor location registers 22 and 25. .

However, in the next generation mobile communication system such as IMT-2000, several different systems may overlap, and a global roaming function for allowing a mobile terminal to receive the same service while moving between heterogeneous systems is an essential requirement. . That is, as shown in Figure 1 may be in contact with a system having a heterogeneous signal system, in this case, the location update and paging is the home location register 24 of the home network, the visitor location register 22 of the home network, The home location register 27 and the visitor location register 25 of the visited network.

Here, the home location register 24 of the home network and the visitor location register 22 of the home network represent the location register of the home system to which the subscriber subscribes, and the home location register 27 of the visited network and the visitor location register 25 of the visited network. ) Denotes the location register of the visiting system. When the mobile terminal is located at the boundary area between these two system location areas, location update and paging for the mobile terminal generates unnecessary signal traffic.

For example, when the mobile terminal roams from the location area LA1 of the home system to the location area LA2 of the visited system, the mobile terminal sends a location update message to the visitor location register 25 of the visited network. The visitor location register 25 of the visited network transmits a signal message to the home location register 27 of the visited network in order to obtain information about the mobile terminal and the subscriber. At this time, since the home location register 27 of the visited network does not have information about the mobile terminal, the home location register 24 of the home network is inquired again, and the home location register 24 of the home network reconfirms the authentication of the subscriber. The subscription information is transmitted to the home location register 27 of the visited network.

Thereafter, the home location register 27 of the visited network that receives the information about the mobile terminal from the home location register 24 of the home network transmits it to the visitor location register 25 of the visited network.

Meanwhile, the home location register 24 of the home network instructs the visitor location register 22 of the previous home network to delete the location information of the mobile terminal after storing the location of the roaming mobile terminal.

As such, when the mobile terminal moves back and forth between the location areas LA1 and LA2 of two systems in the cell boundary region, such signal traffic is repeatedly generated, thus increasing the location management cost for the mobile terminal. Occurs.

However, as described above, in a next generation mobile communication system such as IMT-2000, systems having different network protocols may be mixed and installed. In this case, integrated location management for the terminal is performed to provide roaming in any system area. This requires a technique that minimizes the additional signal costs incurred by location management between different systems. In other words, a method for efficiently reducing such a signal cost is required.

The present invention devised to meet the above requirements, in the system interworking heterogeneous wireless communication system, in designing the boundary location area (BLA), roaming effectively through the boundary location register (BLR) In this case, the size of the boundary location area is asymmetrically and adaptively optimized to optimize the increase in the number of location updates due to the introduction of the boundary location area according to the system design. It is an object of the present invention to provide an asymmetric adaptive location update method for solving the additional signal traffic and the resulting increase in signal cost, and a computer-readable recording medium for realizing the method.

In order to achieve the above object, the present invention provides a method for updating a location at an intercell boundary area in a system interworking with a heterogeneous mobile communication network, wherein the relative location registration signal cost of each system and the average speed of the mobile terminal are used at the intercell boundary area. A first step of asymmetrically and adaptively setting an optimal boundary position region (BLA) according to the first and second positions; In order to continuously manage the mobility of roaming subscribers in the boundary location area (BLA) and to reduce unnecessary signal traffic, the boundary location capable of supporting all the signaling methods of the heterogeneous mobile communication networks and supporting the subscriber information form of the system A second step having a register (BLR); And optimizing an increase in the number of position updates according to the introduction of the boundary position region according to the system design by optimizing the position of the mobile terminal crossing the boundary of the boundary position region BLA through the boundary position register BLR according to the system design. It is characterized in that it comprises a third step of updating to the target.

In addition, the present invention is an asymmetric and adaptively optimal boundary position region in a system interworked with a heterogeneous mobile communication network having a processor, in a cell-cell boundary region, depending on the relative location registration signal cost of each system and the average speed of the mobile terminal. Setting a BLA; In order to continuously manage the mobility of roaming subscribers in the boundary location area (BLA) and to reduce unnecessary signal traffic, the boundary location capable of supporting all the signaling methods of the heterogeneous mobile communication networks and supporting the subscriber information form of the system Having a register (BLR); And the position of the mobile terminal crossing the boundary of the boundary position region BLA through the boundary position register BLR and asymmetric by optimizing the increase in the number of position updates according to the introduction of the boundary position region according to the system design. A computer readable recording medium having recorded thereon a program for realizing an adaptive update function is provided.

In the present invention, in order to optimize signal cost for location management in a heterogeneous system boundary region, a distance-based boundary location area (BLA) is determined in performing a location update and paging in an intercell boundary region where the heterogeneous system is in contact with each other. When setting the boundary location register (BLR) for location update and paging in the boundary location area, the size of the boundary location area is asymmetrical according to the relative location registration signal cost of each system and the average speed of the terminal. By adaptively and adaptively setting, it is possible to optimize the increase in the number of position updates according to the introduction of the boundary position region according to the system design.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exemplary configuration diagram of a hardware system for an asymmetric adaptive location update method in an intercell boundary region according to the present invention.

The present invention is characterized by setting a boundary location area (BLA) 2a and a border location register (BLR) 25 for location management in a cell boundary area to perform location update and paging. That is, the boundary position area 2a is set at the boundary of the heterogeneous system position area, and the position update and paging in the boundary position area 2a are performed through the boundary position register 25. At this time, the boundary location area 2a supports both system signaling methods, and supports the subscriber information form of both systems.

As described above, the boundary location area 2a is set at the boundary area between cells of the heterogeneous system, and the location update and paging method through the boundary location register 25 in the set boundary location area 2a are described below.

When the mobile terminal enters the boundary location area 2a from the location area LA-h of the home network, the mobile terminal transmits a location update message to the boundary location area 2a, and the boundary location area 2a is located in the home network. The home location register 24 inquires and stores subscription information for the mobile terminal. At this time, the home location register 24 of the home network sets and stores the location information of the mobile terminal as the boundary location area 2a.

If the mobile terminal moves from the boundary location area 2a to the location area LA-v of the visited network, the mobile terminal transmits a location update message to the visitor location register 26 of the visited network and the visitor location register of the visited network. 26, the boundary location register 25 queries the subscription information for the mobile terminal. At this time, the boundary location register 25 transmits the information to the visitor location register 26 of the visited network to set the location information of the mobile terminal as the location area LA-v of the visited network.

On the other hand, when the mobile terminal enters the boundary location area 2a again, the boundary location register 25 deletes the location information of the mobile terminal from the visitor location register 26 of the visited network and replaces the location information of the mobile terminal with the boundary location area ( 2a).

On the other hand, when the mobile terminal moves from the boundary location area 2a to the location area LA-h of the home network again, the mobile terminal transmits a location update message to the visitor location register 22 of the home network and the home location of the home network. The register 24 sets the location information of the mobile terminal to the location area LA-h of the home network and deletes the location information of the mobile terminal from the boundary location register 25.

Through this procedure, the mobile terminal can reduce unnecessary signal traffic between the home location register 24 of the home network and the home location register 28 of the visited network due to repetitive movement in the border area.

When an incoming call to the mobile terminal occurs, the switching center c 23 inquires to the home location register 24 of the home network, and the home location register 24 of the home network has the location information of the mobile terminal as the boundary location area 2a. If the position information for the mobile terminal is inquired to the boundary location register (25), the boundary location register (25) according to the location information of the mobile terminal stored in its database to the visitor location register (22, 26) Instructs to pass a routing number to and sets up an incoming call by instructing a call to the mobile terminal. That is, the boundary location register 25 performs the same role as the home location register (HLR) with respect to the roaming mobile terminal in the position of the visitor location register 26 of the visited network. In this case, the boundary location area 2a may be set according to a distance-based location registration technique to optimize an additional location update cost generated due to the boundary location area 2a.

In the present invention, the boundary position region 2a and the boundary position register 25 are set in such an intercell boundary region, and the threshold distance is dynamically set when the boundary position region 2a is set by a distance-based position update technique. Allows you to optimize the cost of location management. That is, when the terminal enters the boundary location area 2a by setting the boundary location area 2a at the boundary area between cells, the location registration is performed through the boundary location register 25, and when entering the visiting system, the boundary location register is entered. Through 25, information about roaming terminals and subscribers can be extracted.

As described above, when the boundary position area 2a and the boundary position register 25 are set, the number of position updates due to the boundary position area 2a can be increased, and accordingly, the size of the boundary position area 2a can be changed depending on the situation. There is a need for a method that dynamically adapts to reduce unnecessary location updates. The size of this boundary position region can be adjusted by adjusting the critical distance shown in FIG.

In FIG. 3, location registration performs location registration when the distance d 'from the boundary is smaller than the threshold distance d determined by the system. In this case, the critical distance d for the optimal boundary location area size is determined by the following principle. .

First, relative position is determined by asymmetrically determining the critical distance according to the position update cost increase rate when moving from system i to system j according to the position update cost in different systems and the position update cost rise rate when moving from system j to system i. It is possible to reduce the total location management cost by reducing the location update rate to the boundary location area by reducing the critical distance when roaming from the system with low update cost to the system with high location update cost.

Second, in the case of the terminal with a higher average speed than the average speed of all users, the boundary location area is extended by increasing the critical distance, and conversely, the terminal with a lower average speed compared to the average speed of all users reduces the critical distance to improve the boundary location area. By narrowing, it is possible to determine the effective area of the boundary location area according to the speed of the terminal.

According to this principle, the critical distance d (i, j, m) for determining the area of the boundary location region is determined as in Equation (1).

로 주어지며, c_i는 각 시스템에서의 위치 등록에 소요되는 신호 비용이고, c_i,j는 i시스템 영역에서 j시스템 영역으로 단말이 위치 등록하는데 소요되는 비용이다. 또한, v(i,m)은 m 단말의 i시스템에서의 평균 속도이고, v_i는 i시스템에서의 전체 단말의 평균 속도이며, d₀는 이러한 비대칭 적응형 임계거리를 적용하기 전의 균일한 임계거리이다. At this time,

C _i is a signal cost required for location registration in each system, and c _{i, j} is a cost required for the terminal to register a location from the i system area to the j system area. In addition, v (i, m) is the average speed in the i system of the m terminal, v _i is the average speed of the entire terminal in the i system, d ₀ is a uniform threshold before applying this asymmetric adaptive threshold distance Distance.

4 is a flowchart illustrating an asymmetric adaptive location update method in an intercell boundary region according to the present invention.

As shown in FIG. 4, the asymmetric adaptive location update method in the intercell boundary region according to the present invention calculates average speed information of the terminal at the network side and transmits new threshold distance information to the terminal accordingly (401).

Thereafter, the terminal calculates the distance to the boundary (402) and performs a location update procedure when it is smaller than the new threshold distance (403, 404).

As described above, the present invention sets the boundary location area and the boundary location register in the boundary areas between heterogeneous systems having different location management techniques, and determines the size of the boundary location area according to the relative ratio of the required signal cost and the speed information of the terminal. By dynamically determining, it is possible to minimize the increase in the number of location updates due to the introduction of the boundary location area, thereby reducing the overall location management cost.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains, and the above-described embodiments and accompanying It is not limited to the drawing.

As described above, the present invention can reduce the unnecessary signal traffic caused by the terminal crossing the boundary in the boundary region between the cells or between the location area to perform efficient location management for the terminal, thereby reducing the location management cost of the entire terminal This reduces the maintenance costs of the entire system.

Claims (3)

A location update method in a boundary area between cells in a heterogeneous mobile communication system, A first step of asymmetrically and adaptively setting an optimal boundary location area (BLA) according to the relative location registration signal cost of each system and the average speed of the mobile terminal in the intercell boundary area; In order to continuously manage the mobility of roaming subscribers in the boundary location area (BLA) and to reduce unnecessary signal traffic, the boundary location capable of supporting all the signaling methods of the heterogeneous mobile communication networks and supporting the subscriber information form of the system A second step having a register (BLR); And Through the boundary position register BLR, the position of the mobile terminal crossing the boundary of the boundary position area BLA is asymmetrical and adaptive by optimizing the increase in the number of position updates according to the introduction of the boundary position area according to the system design. Third step to update with Asymmetric adaptive location update method in the inter-cell boundary region comprising a. The method of claim 1, The first step is, The critical distance is calculated according to the relative ratio of the relative location registration signal cost in each system and the signal cost for location registration with the relative system, and is calculated according to the ratio of the average speed of all mobile terminals in the system to the average speed of the corresponding mobile terminal. An asymmetric adaptive position update method in an intercell boundary region is calculated by calculating a critical distance and asymmetrically and adaptively setting an optimal boundary position region (BLA) by the following equation.

(only,

C _i is a signal cost for location registration in each system, c _{i, j} is a cost for location registration of a terminal from a first (i) system area to a second (j) system area, v (i, m) is the average speed in the i-system of terminal m, v _i is the average speed of the entire terminal in the system i, d ₀ is a uniform critical distance before applying this asymmetric adaptive threshold distance) In a system interworking heterogeneous mobile communication network having a processor, At the cell-to-cell boundary, asymmetrically and adaptively setting an optimal boundary position region (BLA) according to the relative location registration signal cost of each system and the average speed of the mobile terminal; In order to continuously manage the mobility of roaming subscribers in the boundary location area (BLA) and to reduce unnecessary signal traffic, the boundary location capable of supporting all the signaling methods of the heterogeneous mobile communication networks and supporting the subscriber information form of the system Having a register (BLR); And Through the boundary position register BLR, the position of the mobile terminal crossing the boundary of the boundary position area BLA is asymmetric and adaptive by optimizing the increase in the number of position updates according to the introduction of the boundary position area according to the system design. To update automatically A computer-readable recording medium having recorded thereon a program for realizing this.

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