KR20070002532A - Method for hand-off of mobile phone using gps and the mobile phone thereof - Google Patents

Abstract

A method for performing hand-off by using a GPS in a mobile terminal and the mobile terminal thereof are provided to enable the mobile terminal, which is moving, to perform the hand-off in a state that the strength of a pilot signal is enough strong to perform the hand-off, thereby reducing possibility that it is failed to establish a backward or forward speech path during the hand-off and decreasing a problem of call disconnection during the hand-off. A mobile terminal(100) performing hand-off by using a GPS(Global Positioning System) comprises the followings: a memory(110) which stores a program for performing the hand-off, information of each base station, transmitted from base stations, and location information of the mobile terminal(100), received from a GPS satellite; a GPS receiving unit(130) which receives information about location of the mobile terminal(100) from the GPS satellite and periodically stores the location information in the memory(110); and a control unit(120) which calculates a movement direction of the mobile terminal(100) by using the location information, stored in the memory(110), through the GPS receiving unit(130) and performs the hand-off if the strength of a pilot signal, received from the base station located in the movement direction, is equal to or larger than that of a pilot signal received from a base station of a cell area, where its own mobile terminal belongs to.

Description

Handoff method of mobile terminal using WPS and its mobile terminal {METHOD FOR HAND-OFF OF MOBILE PHONE USING GPS AND THE MOBILE PHONE THEREOF}

1 is a view for explaining a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

2 is a flowchart illustrating a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

3 is a block diagram of a mobile terminal for performing a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

4 and 5 are flow charts in which the mobile terminal shown in FIG. 3 performs handoff using GPS.

6 is a graph comparing a handoff method of a mobile terminal using GPS according to an embodiment of the present invention and a result of performing a handoff of a mobile terminal according to the related art.

<Description of the symbols for the main parts of the drawings>

1: base station A 2: base station B

3: GPS satellite 100: mobile terminal

110: memory 120: control unit

121: signal strength measurement unit 122: direction calculation unit

123: handoff performing unit 124: call processing unit

130: GSP receiving unit 140: RF unit

150: voice processing unit 160: speaker

170: microphone 180: key input unit

190: display unit

The present invention relates to a handoff of a mobile communication system, and more particularly, to a handoff method of a mobile terminal using GPS for performing a handoff using a GPS and a mobile terminal thereof.

In general, a mobile communication system is a communication between mobile devices capable of communicating with anybody, anytime, anywhere, and anyone using a radio wave in a space, or between a mobile device and a fixed body, and transmits and receives a message to and from a mobile terminal moving in an unspecified area. A base station for managing radio resources, a control station for controlling the base station and sending and receiving messages to and from the base station, and a switching station connected to the control station, another station, and another network to perform a switching role.

One of the most important and big features of the mobile communication system configured as described above is that the mobile terminal guarantees the mobility of the subscriber station, and in order to ensure the mobility of the subscriber, hand-off technology is most important. need.

Hand-off technology is a technology for switching a call path between a mobile station and a base station so that the call can be continuously maintained even if the mobile station leaves the service area of the base station or sector currently being provided with the service.

The hand-off method is divided into softer handoff, soft handoff, and hard handoff.

Softer handoff is a handoff in which a mobile terminal approaches a contiguous sector area in a cell having the same radio channel frequency during a call and talks like two sectors in the cell.

That is, soft handoff occurs when moving between sectors with the same frequency and the same frame offset value in the base station. The processing of the voice packet is performed by setting a new communication channel with the target sector while maintaining the existing communication channel between the mobile station and the base station. Send to multiple call channels. If there is no need to move enough to the destination sector to maintain the existing call channel, the existing call channel is blocked.

Soft handoff is a handoff when a mobile terminal approaches a neighboring cell area having the same radio channel frequency during a call and simultaneously talks with two or three cells.

That is, the soft handoff occurs when the neighboring base stations move with the same frequency and the same frame offset value, and the processing thereof is performed by another call channel between the moving target base station cells while maintaining the call channel of the existing mobile station-base station for a predetermined time. Set to send voice packets to multiple call channels. If the mobile terminal does not need to move enough to the destination cell to maintain the existing call channel, it blocks the existing call channel.

Hard handoff is also a handoff between a system or between networks when a mobile terminal moves to a cell area with a different frequency during a call.

That is, hard handoff occurs when the frame offset is changed during the movement between neighboring base stations, when the frequency is changed, and when moving to another switching system, and the processing thereof is different from the softer handoff and the soft handoff. Otherwise, the existing call channel cannot be maintained, and only the newly established call channel is used to transmit the voice packet.

Referring to the general handoff process, when the mobile station communicates with the base station of the cell A area in the cell A area and moves to the cell B area, and the pilot signal received from the base station of the cell B area reaches a certain reference value, The base station in the cell A area and the base station in the B area perform a preparation operation for handoff from the cell A to the cell B.

While the mobile station performs this handoff preparation operation, the pilot signal received from the base station in the cell A area becomes less than the predetermined value while the signal of the pilot received from the base station in the cell B area exceeds an arbitrary reference value. At the time point, a handoff is performed from the cell A area to the cell B.

That is, when the mobile terminal performs the handoff to the cell B area when the pilot signal received from the base station in the cell A area falls below a certain reference value, the call disconnection may occur when the handoff is not performed properly. have.

For example, the ping-pong phenomenon may occur in which the signal strength of the inter-cell frequency is continuously variable in the handoff processing boundary region, and the connection and disconnection of the call is repeated.

However, conventionally, the handoff is performed in the boundary area between systems due to this ping-pong phenomenon as the handoff is performed when the strength of the pilot signal received from the base station in the cell area communicating before the handoff falls below a reference value. Call truncation is a problem that degrades the call quality.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem in the prior art, and provides a handoff method for a mobile terminal using GPS and a mobile terminal which can determine whether to perform a handoff in consideration of the direction in which the mobile terminal moves during a call. Its purpose is.

According to an aspect of the present invention for achieving this object, a memory for storing the information for each base station and the location information of the mobile terminal received from the GPS satellite and the program for performing the handoff and the base station, the GPS satellite A GPS receiver for receiving the position of the mobile terminal from the mobile station and periodically storing the position of the mobile terminal in the memory; and calculating a movement direction of the mobile terminal by using the position information stored in the memory through the GPS receiver. And a control unit performing a handoff when the strength of the pilot signal received from the base station is equal to or greater than the strength of the pilot signal received from the base station in the cell region to which the mobile station belongs. It provides a mobile terminal to perform the off.

Preferably, the control unit is a signal strength measuring unit for measuring the strength of the pilot signal received from any base station to provide a pilot signal strength of the base station, and the GPS terminal of the mobile terminal periodically stored in the memory The strength of the pilot signal measured by the signal strength measuring unit for the base station located in the moving direction measured by the direction calculating unit and the direction calculating unit for measuring and providing the moving direction of the mobile terminal from the position information And a handoff performer for performing a handoff at a point equal to or greater than the strength of the pilot signal received from the base station in the cell region to which the mobile station belongs.

According to another aspect of the present invention, the base station selection step of selecting a plurality of base stations that can be handed off according to the strength of the pilot signal received from the base station by scanning the base station and the location information received through the GPS satellites Calculate the moving direction of the mobile station using the method, and the intensity of the pilot signal received from the base station located in the moving direction among the selected base stations is the strength of the pilot signal received from the base station of the cell region to which the mobile terminal belongs Provided is a handoff method of a mobile terminal using GPS, including a handoff performing step of performing a handoff at a time equal to or greater than.

Preferably, the base station selection step includes receiving neighboring base station list information from the base station to which it belongs, and whether there is a pilot signal received from any base station through base station scan based on the received neighbor base station list information. And transmitting a signal indicating that the base station whose strength of the pilot signal exceeds the threshold value of the base station can be handoffed to the base station. It may include.

Preferably, the performing of the handoff step may include transmitting its own location information received from the GPS satellite to the corresponding base station, and calculating a moving direction of the own location information received from the GPS satellite. Extracting a base station located in a moving direction of the mobile station from among base stations which the user has placed as a target for handoff; and transmitting a handoff preliminary signal to the extracted base station, the base station transmitting the handoff signal to the mobile station; Preparing a handoff for the handset and performing a handoff if the strength of the pilot signal received from the base station to be handed off is equal to or greater than the strength of the pilot signal received from the base station to which it belongs. can do.

Hereinafter, a handoff method and a mobile terminal of a mobile terminal according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

Referring to FIG. 1, the mobile terminal 100 receives its location information through the GPS satellite 3 and performs handoff while moving from the cell region of the base station A 1 to the cell region of the base station B 2. It is showing what it does.

The base station A 1 and the base station B 2 perform mutual conversion between the wired signal and the wireless signal, cover one cell / sector area, and include a mobile terminal 100 included in the cell / sector area. Preside over)

The GPS satellite 3 communicates with the GPS receiving module of the mobile terminal 100 to periodically transmit the location information of the mobile terminal 100 to the mobile terminal 100.

The mobile station 100 receives neighbor base station list information in the vicinity of the mobile station 100 from the base station A 1 while communicating with the base station A 1 in the cell region of the base station A 1.

The mobile terminal 100 receives a pilot signal received from any base station including base station B 2 through a base station scan based on neighbor base station list information received from base station A 1, and receives a pilot signal received from the base station. For the base stations whose strength of the pilot signal exceeds the reference value, the base station communicates with the base stations and transmits a signal indicating that it is possible to perform handoff to the base station.

The mobile terminal 100 utilizes its own direction of movement calculated by its position information obtained through the GPS satellite 3 as well as the pilot signal strength of each base station 1 and 2 received from the base stations 1 and 2. By performing the handoff is determined by performing the handoff.

Here, the location information transmitted by the mobile terminal 100 may be accurate location information (for example, latitude and longitude information) of the mobile terminal, but the base station is not the exact location of the mobile terminal, but the base station is determined from the information transmitted from the mobile terminal. It can be a positional parameter from which the position can be extracted.

For example, a mobile terminal includes a GPS (Global Positioning System) receiver to determine the coordinate value of the current position based on a signal received from the GPS satellite 3.

Such a technology is disclosed, for example, in Korean Patent Publication No. 1999-18329, published on March 15, 1999, 'Multimedia portable terminal in mobile communication environment', and Korean Patent Publication No. published on April 06, 1999. Korean Patent Publication No. 1999-33792, entitled 'Method for Providing a Positioning Service for Mobile Terminal by Attaching GPS Terminal to Personal Cellular Communication and Mobile Communication' Mobile phone location management system using a telephone, and Korean Patent Publication No. 1999-35271 published on May 15, 1999, "Mobile phone device with location transmission and management function." In addition, according to the Patent Publication No. 1999-24511, Patent Publication No. 1999-33792, Domestic Patent Publication No. 1999-35271, etc., the mobile terminal sends the location information obtained as described above to a base station or a location tracking center. It becomes.

As such, the mobile terminal 100 continuously communicates with the GPS satellite 3 to store its location information in the memory. The mobile terminal 100 transmits its location information obtained through the GPS satellites 3 to the base station A 1 which is in communication with itself and to the base stations which are likely to perform handoffs to the neighbors.

In addition, the mobile terminal 100 periodically receives its location information through the GPS satellites 3, calculates its own direction of movement, finds the base station located in the direction in which it is to move, and calculates the pilot signal received from the base station. When the strength and the strength of the pilot signal received from the base station with which it communicates are the same, handoff is performed to the corresponding base station.

In the figure, since the mobile terminal 100 is moving from the area of the base station A 1 to the area of the base station B 2, the mobile terminal 100 receives the strength of the pilot signal received from the base station A 1 and the base station B 2. At the same time as the strength of the pilot signal received from the base station A, a handoff is performed from the base station A 1 to the base station B 2.

2 is a flowchart illustrating a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

Referring to FIG. 2, the mobile terminal 100 communicates with the base station A 1 in the cell area of the base station A 1 (S1). The mobile station 100 receives neighbor base station list information in the vicinity of the mobile station 100 from the base station A 1 while performing communication with the base station A 1 (S2).

Accordingly, the mobile station 100 moves from within the cell area of the base station A 1 to the cell area of the base station B 2 and performs the base station scan through the base station scan based on the neighbor base station list information received from the base station A 1. It is determined whether there is a pilot signal received from any base station including (2) (S3).

As a result of determination, when there is a pilot signal received from any base station included in the neighbor base station list received from the base station A 1, the mobile station 100 continuously monitors the pilot signal received from the base station. In step S4, it is determined whether there is a base station whose strength of the pilot signal exceeds a reference value for handoff.

As a result of the determination, when there are base stations whose strength of the pilot signal exceeds a reference value, the base station performs communication with the corresponding base stations and transmits a signal indicating that the mobile station may perform handoff to the corresponding base station (S5).

Meanwhile, the mobile terminal 100 receives its location from the GPS satellite 3 and stores it in its memory. Accordingly, when a base station capable of handoff is detected, the mobile terminal 100 transmits its location information to base stations communicating with the mobile station 100 (S6).

The mobile terminal 100 calculates its own moving direction from its positional information received through the GPS satellite 3 (S7).

When the mobile terminal 100 calculates its own moving direction, the mobile terminal 100 extracts a base station located in its own moving direction from the base stations that it places as a target for handoff (S8). In FIG. 1, the base station B 2 is extracted as the mobile terminal 100 moves from the area of the base station A 1 to the area of the base station B 2. Therefore, it is assumed here that the base station B 2 is a predominant base station.

When the base station located in its moving direction is extracted as the base station B 2, the mobile terminal 100 transmits a handoff preliminary signal that informs the base station B 2 that it is likely to perform a handoff to the base station. By transmitting the base station B (2) to prepare the handoff for the mobile terminal 100 (9).

At this time, the mobile terminal 100 maintains communication for handoff that is being performed with other base stations that are targets for handoff.

The mobile terminal 100 finds a time point at which the strength of the pilot signal received from the base station B 2, which is a strong base station capable of performing handoff, and the strength of the pilot signal received from the base station A 1 are the same.

Since the mobile terminal 100 is already communicating with the base station A 1, the strength of the pilot signal received from the base station A 1 is greater than the strength of the pilot signal received from the base station B 2. Moving toward base station B 2, the strength of the pilot signal received from base station B 2 becomes equal to the strength of the pilot signal received from base station A 1 and further, becomes larger.

For this reason, the mobile terminal 100 determines whether the strength of the pilot signal received from the base station B 2 is equal to or greater than the strength of the pilot signal received from the base station A 1 (S10).

When the strength of the pilot signal received from the base station B 2 is equal to or greater than the strength of the pilot signal received from the base station A 1, the mobile terminal 100 receives the base station from the base station A 1. Handoff to B (2) is performed (S11).

Meanwhile, when the strength of the pilot signal received from the base station B 2 is less than the strength of the pilot signal received from the base station A 1, the mobile terminal 100 communicates with the base station A 1. The strength of the pilot signal is continuously monitored until the strength of the pilot signal received from B (2) is greater than that of the pilot signal received from base station A (1).

3 is a block diagram of a mobile terminal for performing a handoff method of a mobile terminal using GPS according to an embodiment of the present invention.

Referring to FIG. 3, a mobile terminal 100 for performing a handoff method of a mobile terminal using GPS according to an embodiment of the present invention includes a memory 110 for storing a program and various data for performing a handoff. A control unit 120 for performing handoff, a GPS receiver 130, an RF unit 140 for performing wireless communication, a voice processing unit 150, a speaker 160, a microphone 170, And a key input unit 180 and a display unit 190.

The memory 110 stores a program for performing a handoff and information of each base station transferred from the base stations A and B (1, 2). In addition, it stores the position information of the mobile terminal 100 received from the GPS satellite (3).

The controller 120 calculates a moving direction of the mobile terminal 100 by using the location information provided from the GPS receiver 130, and the strength of the pilot signal received from the base station located in the moving direction and the cell to which the mobile station belongs. Handoff is performed at the same time as the strength of the pilot signal received from the base station in the region.

Meanwhile, the GPS receiver 130 receives the position of the mobile terminal 100 from the GPS satellite 3 and periodically stores the position of the mobile terminal 100 in the memory 110.

The controller 120 includes a signal strength measuring unit 121, a direction calculating unit 122, a handoff performing unit 123, and a call processing unit 124.

The signal strength measuring unit 121 continuously measures the strength of the pilot signal from the requested base station at the request of the handoff performing unit 123 and provides it to the handoff performing unit 123.

The direction calculator 122 calculates a moving direction of the mobile terminal 100 from the position information of the mobile terminal 100 periodically stored in the memory 110 by the GPS receiver 130, and performs a handoff performing unit 123. To provide.

The handoff performer 123 continuously monitors the pilot signal received from the base station when there is a pilot signal received from any base station through the base station scan based on the neighbor base station list information received from the base station A 1.

In addition, the handoff performing unit 123 receives the strength of the pilot signal received from each base station from the signal strength measuring unit 121 and measures the moving direction of the mobile terminal 100 in the direction calculating unit 122. Let's do it.

The handoff performing unit 123 receives the pilot signal strength of each base station from the signal strength measuring unit 121 and communicates with the base stations whose strength of the pilot signal exceeds the reference value that can be the target of handoff among the base stations. It performs a signal that transmits a signal indicating that it is possible to perform a handoff to the base station.

The handoff performer 123 transmits the location information of the mobile terminal 100 stored in the memory 110 by the GPS receiver 130 to the base stations communicating with the mobile terminal 100 while the mobile terminal 100 moves. When the moving direction of the mobile terminal 100 is calculated by the direction calculating unit 122, the base station located in the moving direction of the mobile terminal 100 is extracted from the base stations which are placed on the target of handoff.

When the base station located in the moving direction of the mobile terminal 100 is extracted, the handoff performing unit 123 transmits a handoff preliminary signal to the base station so that the base station prepares for the handoff.

The handoff performing unit 123 receives the strength of the pilot signal received from the base station B 2, which is a strong base station capable of performing the handoff measured by the signal strength measuring unit 122, and the base station A 1. A time point where the strengths of the pilot signals are equal is found, and a handoff is performed at the same time points.

The call processing unit 124 performs various call processing for the mobile terminal 100 to communicate with the base station A 1. In addition, the call processing unit 124 receives neighboring base station list information in the vicinity of the mobile terminal 100 from the base station A 1 while performing communication with the base station A 1 in the cell area of the base station A 1. When received, it is stored in the memory 110.

4 and 5 are flowcharts in which the mobile terminal shown in FIG. 3 performs handoff using GPS.

4 and 5, the call processing unit 124 of the mobile terminal 100 communicates with the base station A 1 in the cell area of the base station A 1 (S21). The call processing unit 124 receives neighbor base station list information in the vicinity of the mobile station 100 from the base station A 1 while performing communication with the base station A 1 (S22).

Accordingly, while the mobile terminal 100 moves from the cell area of the base station A 1 to the cell area of the base station B 2, the handoff performing unit 123 receives neighboring base station list information received from the base station A 1. Based on the base station scan to determine whether there is a pilot signal received from any base station including the base station B (2) (S23).

As a result of the determination, when there is a pilot signal received from any base station included in the neighbor base station list received from the base station A 1, the handoff performing unit 123 continuously monitors the pilot signal received from the base station ( S24).

The handoff performer 123 continuously monitors the pilot signal received from the base station and causes the signal strength measurement unit 121 to continuously measure the strength of the pilot signal received from each base station (S25).

In addition, the handoff performing unit 123 causes the direction calculating unit 122 to measure the moving direction of the mobile terminal 100 (S26).

Accordingly, the signal strength measuring unit 121 continuously measures the strength of the pilot signal from the base station whose pilot signal is monitored by the handoff performing unit 123 (S27).

The handoff performer 123 receives the pilot signal strength of each base station from the signal strength measuring unit 121 and determines whether there is a base station in the corresponding base station exceeding a threshold that the strength of the pilot signal may be the target of handoff. Determine (S28).

As a result of the determination, when there are base stations whose strength of the pilot signal exceeds a threshold, the handoff performer 123 communicates with the base stations and transmits a signal indicating that there is a possibility that the base station may perform a handoff. (S29).

Meanwhile, the GPS receiver 130 receives the position of the mobile terminal 100 from the GPS satellite 3 and periodically stores the position of the mobile terminal 100 in the memory 110.

The handoff performer 123 communicates the position information of the mobile terminal 100 stored in the memory 110 by the GPS receiver 130 with the mobile terminal 100 while the mobile terminal 100 moves. Send to the base station (S30).

In addition, the direction calculating unit 122 calculates the moving direction of the mobile terminal 100 from the position information of the mobile terminal 100 periodically stored in the memory 110 by the GPS receiver 130 (S31).

The handoff performing unit 123 calculates a moving direction of the mobile terminal 100 by the direction calculating unit 122, and the mobile terminal 100 among the base stations placed by the mobile terminal 100 as a target for handoff. The base station located in the moving direction of is extracted (S32).

In FIG. 1, the base station B 2 is extracted as the mobile terminal 100 moves from the area of the base station A 1 to the area of the base station B 2.

If the base station located in the moving direction of the mobile terminal 100 is extracted as the base station B 2, the handoff performing unit 123 may perform the handoff to the base station B 2 at the base station B 2. By transmitting a handoff preliminary signal indicating that the base station B (2) is able to prepare for the handoff for the mobile terminal (100) (S33).

At this time, the handoff performer 123 maintains communication for handoff that is being performed with other base stations that are targets for handoff.

The handoff performing unit 123 receives the strength of the pilot signal received from the base station B 2, which is a strong base station capable of performing the handoff measured by the signal strength measuring unit 122, and the base station A 1 received. Find the point in time at which the strength of the pilot signal is equal.

As the mobile terminal 100 is already communicating with the base station A 1, the mobile station 100 gradually increases in the state where the strength of the pilot signal received from the base station A 1 is greater than the strength of the pilot signal received from the base station B 2. Moving toward base station B 2, the strength of the pilot signal received from base station B 2 is equal to the strength of the pilot signal received from base station A 1, and further, larger.

For this reason, the handoff performer 123 determines whether the strength of the pilot signal received from the base station B 2 is equal to or greater than the strength of the pilot signal received from the base station A 1 (S34).

If the strength of the pilot signal received from the base station B (2) measured by the signal strength measuring unit 121 is equal to or greater than the strength of the pilot signal received from the base station A (1) The mobile terminal 100 performs a handoff from the base station A 1 to the base station B 2 (S35).

On the other hand, if the strength of the pilot signal received from the base station B (2) measured by the signal strength measuring unit 121 is smaller than the strength of the pilot signal received from the base station A (1) In the state of communicating with the base station A 1, the strength of the pilot signal is continuously monitored until the strength of the pilot signal received from the base station B 2 becomes greater than the strength of the pilot signal received from the base station A 1. do.

6 is a graph comparing a handoff method of a mobile terminal using GPS according to an embodiment of the present invention and a handoff performance of a mobile terminal according to the related art.

Referring to FIG. 6, when the mobile terminal 100 moves from the cell region of the base station A 1 to the cell region of the base station B 2, the mobile terminal 100 passes through P1, P2, and P3, and the base station A (1). ), The pilot signal strength of the base station B 2 becomes increasingly strong.

Here, T_ADD is added to the list of base stations with which the mobile terminal 100, which was communicating with the base station A 1 in the cell region of the base station A 1, may perform the handoff of the base station B 2. It is a threshold indicating the strength of the pilot signal to be a point in time.

T_H is a pilot signal strength at the time of performing a handoff according to an embodiment of the present invention, and is measured by the mobile terminal 100 communicating with the base station A 1 in the cell region of the base station A 1. The pilot signal strength of the base station A 1 and the pilot strength of the base station B 2 are threshold values indicating the strength of the pilot signal at the same point in time.

On the other hand, the T_DROP is a mobile terminal 100 that has been communicating with the base station A (1) in the cell area of the base station A (1) by a method of performing a handoff time by the strength of the pilot signal received from the base station. As the threshold for performing the handoff from the base station A 1 to the base station B 2, the handoff is performed when the strength of the pilot signal received from the base station A 1 falls below the threshold value T_DROP.

According to the handoff method according to an embodiment of the present invention, as shown in the graph of FIG. 5, when the pilot signal strength of the base station A 1 is T_H in the mobile terminal, the hand is transferred from the base station A 1 to the base station B 2. Off is performed. On the other hand, according to the conventional handoff method, when the pilot signal strength of the base station A 1 is T_DROP in the mobile terminal, the handoff is performed from the base station A 1 to the base station B 2.

That is, the handoff method according to an embodiment of the present invention performs the handoff from the base station A (1) to the base station B (2) when the pilot signal strength of the base station A (1) is higher than the conventional hand off method. Will perform. Accordingly, the mobile terminal 100 can perform a handoff in a more stable radio wave environment, thereby ensuring a higher success rate of the handoff than in the related art.

The present invention has been described with reference to preferred embodiments and many specific variations. However, those skilled in the art will understand that many other embodiments other than those specifically described also fall within the spirit and scope of the invention.

According to the present invention, since the mobile station in the mobile station performs the handoff procedure in a state where the strength of the pilot signal is sufficiently high, the possibility of failure in setting up a reverse or forward call during the handoff is reduced, and call connection and disconnection are performed. Since the handoff is performed at a sufficiently high intensity of the pilot signal even in this repeated ping-pong phenomenon, it is possible to effectively reduce the call disconnection problem during the handoff.

Claims (5)

A memory for storing a program for performing a handoff, information of each base station transmitted from the base station, and location information of a mobile terminal received from a GPS satellite; A GPS receiver which receives the position of the mobile terminal from the GPS satellites and periodically stores the position of the mobile terminal in the memory; Calculating a moving direction of the mobile terminal using the location information stored in the memory through the GPS receiver, and the strength of the pilot signal received from the base station located in the moving direction is the base station of the cell area to which the mobile terminal belongs And a control unit that performs handoff when the strength of the pilot signal received from the terminal is equal to or greater than the strength of the pilot signal. The method according to claim 1, wherein the control unit, A signal strength measuring unit which measures the strength of a pilot signal received from an arbitrary base station and provides a pilot signal strength of the corresponding base station; A direction calculator for measuring and providing a moving direction of the mobile terminal from position information of the mobile terminal periodically stored in the memory by the GPS receiver; The strength of the pilot signal measured by the signal strength measuring unit and the strength of the pilot signal received from the base station in the cell area to which the mobile terminal belongs are measured for the base station located in the moving direction measured by the direction calculating unit. A mobile terminal for performing handoff using GPS including a handoff performing unit for performing a handoff at the same or greater time point. A base station selection step of scanning several base stations and selecting a plurality of base stations that can be handed off according to the strength of a pilot signal received from the base station; Calculate the moving direction of the mobile terminal using the location information received through the GPS satellite, and the strength of the pilot signal received from the base station located in the moving direction among the selected base station is the cell area to which the mobile terminal belongs And a handoff performing step of performing a handoff at a time equal to or greater than the strength of a pilot signal received from a base station of the mobile station. The method of claim 3, wherein the base station selection step, Receiving neighbor base station list information from the base station to which the base station belongs; Determining whether there is a pilot signal received from an arbitrary base station through a base station scan based on the received neighbor base station list information; A mobile station using the GPS includes transmitting a signal indicating that the base station whose strength of the pilot signal exceeds the threshold value of the base station may be handoffed to the base station. Handoff method of the terminal. The method according to claim 3, wherein performing the handoff, Transmitting their location information received from the GPS satellites to the corresponding base station; Calculating a moving direction from its own location information received through GPS satellites; Extracting a base station located in a moving direction of the mobile station from among base stations placed as a target for handoff; Transmitting a handoff preliminary signal to the extracted base station to allow the base station to prepare for handoff for the mobile station; And performing a handoff when the strength of the pilot signal received from the base station to be handed off is equal to or greater than the strength of the pilot signal received from the base station to which the base station belongs.

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