KR100288559B1 - Location system and location service request method for mobile communication system - Google Patents

Abstract

A location system and a location service request method for a mobile communication system are disclosed. The method is performed when a subscriber in a call needs location services. When the mobile exchange requests location services from the base station controller, the base station controller requests neighboring base stations located in the vicinity of the mobile terminal to allocate a channel for the mobile terminal. When neighboring base stations allocate a channel and send a response signal to the base station controller, the base station controller instructs the serving base station connecting the mobile terminal to request a PUF signal. The serving base station requests the PUF signal to the mobile terminal through the forward traffic channel, and the mobile terminal emits the PUF signal through the reverse traffic channel. The neighboring base station and the serving base station then receive the PUF signal with different time delays. The mobile exchange receives the parameters detected by the base stations through the base station controller and calculates the location information of the mobile terminal using the parameters.

Description

Location system and location service request method for mobile communication system

The present invention relates to a location system and a location service request method for a mobile communication system, and more particularly, to a method for locating a mobile terminal in a mobile communication network.

A typical cellular wireless communication system includes a mobile station (MS) receiving wireless service, a base station transceiver (BTS) providing wireless service to a mobile terminal within a certain area, and connecting the base station to a mobile switching center. A base station controller (BSC) and a mobile switching center (MSC) for connecting the base station controller to a public switching telephone network (PSTN).

As the mobile communication system developed and the number of subscribers increased, various services were created. Location services provide the geographical location of the current mobile terminal to the mobile communication subscriber using the mobile terminal. This can be useful for emergency calls such as 119 or when illegal user tracking or logistics management is required.

In a conventional mobile communication network, a base station is equipped with a separate receiving device to receive radio waves emitted by a mobile terminal from several base stations, and each radio wave received by the base station is used to generate a time difference of arrival (TDOA) or TDOA. The location of the mobile terminal is calculated by performing the Angle Of Arrival (AOA). In the case of the location service system configured as described above, the mobile terminal emits a separate radio wave for the location search, and the receiving device receives the radio wave. Therefore, the location system is configured separately from the mobile communication network, requiring dual resources in terms of installation cost and operational management.

U.S. Patent No. 5,614,914, "Wireless telephone distribution system with time and space diversity transmission for determining receiver location," uses signals of a mobile terminal received with respective time delays from multiple antennas located in different spatial locations. A method of determining location is disclosed. However, the above-described location services according to the related art require a separate location system. Therefore, there is a need for a method for applying location services in an existing mobile communication network.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art operating as described above, and an object thereof is to provide a location system for calculating and grasping a location of a mobile terminal in a mobile communication system.

It is also an object of the present invention to provide a method in which a mobile exchange requests location services in accordance with a need of a mobile terminal or a network in a mobile communication network.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

1 illustrates a configuration of a location system for a mobile communication system according to the present invention.

2 is an exemplary diagram illustrating a process of receiving a PUF signal by a base station.

3 is an exemplary diagram illustrating a process of receiving a PUF signal by a base station according to a distance.

4 is a message flow diagram illustrating a location service request method of a mobile switching center according to the present invention.

<Explanation of symbols for main parts of drawing>

10,11,12,13: base station (BTS)

20,21: base station controller (BSC)

30: mobile switching center (MSC)

31: Operational Maintenance Center (OMC)

32: location database

40 Public Switched Telephone Network (PSTN)

41: application processor (AP)

A preferred embodiment of a location system for a mobile communication system according to the present invention devised to achieve the above object is at least to receive a particularly strong level PUF signal from a mobile terminal to detect a parameter required for location search. Three base stations;

A mobile switch comprising a system for calculating a position of a mobile terminal by collecting parameter values of the base stations received through a base station controller;

A location database for storing and managing the calculated location data of the mobile terminal;

An operation and maintenance center that provides the operator with configuration, controllability, status, alarms, diagnostics and reporting of the location system; And

It includes a public switched telephone network that accesses data from the location database to obtain the necessary information and is responsible for managing, configuring, and controlling the location system.

A preferred embodiment of the method for requesting location service for a mobile communication system according to the present invention is a mobile terminal which receives a mobile communication service and emits a particularly strong level PUF signal at the request of a base station, and connects communication with the mobile terminal. A mobile communication system comprising a serving base station, a base station controller connecting the base station to a mobile switching center, and a mobile switching station connecting the base station controller to a public switched telephone network (PSTN).

Requesting a location service from a mobile exchange by a base station controller;

Requesting a base station controller to allocate neighboring base stations located around the mobile terminal to a channel for the mobile terminal;

Assigning a channel by the adjacent base stations and sending a response signal to a base station controller;

Instructing a base station controller to request a PUF signal from the serving base station;

The base stations receiving the PUF signal with different time delays;

Transmitting, by a base station controller, a time delay value measured by the base stations to a mobile switching center; And

The mobile switch calculates the location information of the mobile terminal using the time delay value.

In an embodiment of the present invention, the process of requesting the location service is preferably performed when the mobile terminal requests it.

The process of requesting the location service is preferably performed when the location information of the mobile terminal is requested from another network.

The process of requesting the neighboring base stations to allocate a channel for the mobile terminal may include a base station controller assigning a channel for the mobile terminal to two or more base stations included in the neighbor base station list of the serving base station. It is desirable to require

Preferably, the step of instructing the request for the PUF signal includes a step of a base station controller sending information on a PUF signal to a serving base station.

The receiving of the PUF signal may further include releasing a channel when the base station does not receive the PUF signal of the mobile terminal within a predetermined time (second timer).

Preferably, the parameter is a time delay value of a PUF signal measured by each base station.

The transferring of the parameter to the mobile switching center preferably further includes reporting a failure to the mobile switching center when the number of base stations receiving the PUF is two or less.

The method for requesting a location service is a channel for the mobile terminal to the neighboring base stations when the mobile exchange re-requests location service within a predetermined time (first timer) after the mobile exchange requests location service from a base station controller. Preferably, the method further includes the step of returning to the process requiring the allocation of

The location service request method further includes the step of terminating the location service if the mobile exchange does not request the location service until a predetermined time (a first timer) passes after the mobile exchange requests the location service from the base station controller. It is preferable to include as,

The location service request method further includes the step of terminating the location service if the mobile exchange requests the end of the location service within a predetermined time (first timer) after the mobile exchange requests the location service from the base station controller. It is preferable.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

A base station of a code division multiple access (CDMA) cellular system or a personal communications services (PCS) system that satisfies IS-95B as an air interface between the mobile terminal and the base station is a mobile terminal. May request a Power Up Function (PUF) signal. The PUF signal is a specially strong signal transmitted by the mobile terminal at the request of the base station. The PUF signal transmits a pulse that becomes strong at regular time intervals. Since the PUF signal is transmitted at a very strong level compared to the original signal of the mobile terminal, the position of the mobile terminal can be determined using this signal.

The present invention illustrates a method for providing location services in a mobile communication system.

1 illustrates a configuration of a location system for a mobile communication system according to the present invention. As shown, a base station (BTS) (10) (11) (12) (13) for receiving a signal (PUF) coming from the mobile terminal to detect a parameter required for location search; A mobile switching center (MSC) 30 which collects parameter values of various base stations received through the base station controller (BSC) 20 and 21 to calculate the position of the mobile terminal; A location database 32 for storing and managing the calculated location data of the mobile terminal; An Operation and Maintenance Center (OMC) 31 which provides a single-point control function of the location system, ie, the shape, controllability, status, alarms, diagnostics and reporting capabilities of the network to the operator; It includes an application processor (AP) 41 of a public switched telephone network (PSTN) 40 which accesses data from the location database to obtain necessary information and is responsible for the management, configuration and control of the location system.

First, the base station sends a PUF message to the mobile terminal for requesting the PUF signal through a forward traffic channel (base station to mobile terminal) as necessary. The mobile terminal receives this and increases the transmission output level for a short period within a predetermined time (third timer) to transmit a PUF signal including a preamble on a reverse traffic channel (from the mobile terminal to the base station). do. Base stations located around the mobile terminal receive the PUF signal transmitted by the mobile terminal and calculate the position of the mobile terminal by measuring the delay value.

2 is an exemplary diagram illustrating a process of receiving a PUF signal by a base station. As shown, the mobile terminal 50 is in a state of connecting a call with the base station A (10). The base station A 10 sends a PUF message to the mobile terminal 50. The mobile terminal 50 then transmits a PUF signal (1) (2) (3) (4) which gradually increases with a constant level interval and time interval.

Neighbor BTSs 11 and 12 adjacent to base station A 10 then receive the PUF signal. Neighboring base stations have different time delay values (TDOA) depending on the distance from the mobile terminal.

3 is an exemplary diagram illustrating a process of receiving a PUF signal by a base station according to a distance. As shown, the PUF pulses 1, 2, 4 transmitted by the mobile terminal 50 are transmitted at regular power level intervals. Then, the base station A 10 located closest to the mobile terminal 50 first receives the PUF pulse 1. However, the PUF pulse 1 becomes smaller as the distance increases, so that the base station B 11 does not receive the PUF pulse 1. However, since the next PUF pulse 2 is transmitted at a higher level, the base station B 11 may receive the PUF pulse 2. Base station C 12 also receives a higher level PUF pulse 4.

Therefore, if each base station 10, 11, 12 passes the TDOA, which is the time delay value of the measured PUF pulses 1, 2, 4, to the mobile switching center 30 that includes the network's position calculation system, The mobile exchange 30 calculates the position of the mobile terminal 50 by the TDOA algorithm. The calculated position of the mobile terminal 50 is stored in the position database 32.

The invention also relates to a method for enabling a mobile exchange to first request location services.

In order for the base station to send a PUF message to the mobile terminal, the mobile exchange must request location services from the base station through the base station controller. The base station controller, which has received the location service from the mobile exchange, sets up an environment so that neighboring base stations can receive the PUF signal emitted by the mobile terminal.

When a mobile terminal in a traffic state needs location services at the request of a network or a subscriber, the mobile exchange requests location services from a base station controller. The base station controller then delivers an initial message (Primitive) to the base station connecting the call with the mobile terminal through a signal channel that is not in a call. The base station delivers the PUF message to the terminal through the forward traffic channel.

At this time, the base station controller refers to the stored neighbor list to the neighbor base stations around the mobile station, and uses the long pseudo noise (PN) code of the mobile terminal to establish a channel. Command to allocate This is to allow neighboring base stations to receive the PUF signal transmitted by the mobile terminal after a while. When the channel allocation of the neighbor base stations is completed, the mobile terminal emits a PUF signal, and the base stations receive the signal and transmit the measured parameter to the mobile switching center.

4 is a message flow diagram illustrating a location service request method of a mobile switching center according to the present invention. With reference to the drawings will be described in detail the operation according to the preferred embodiment of the present invention.

When the mobile terminal makes an emergency call to 119 or requests the location information of the mobile terminal from other networks, the mobile switching center 30 sends Loc_Svc_rqst to the base station controller 20 through the E1 link to request location service. Service Request) (100)

Then, the base station controller 20 transmits TCE_Asgn to the neighbor base stations 11 and 12 of the mobile terminal according to the request of the mobile switching center to request a traffic channel element assignment (110). Assigns a channel to two or more neighboring base stations by using the neighboring base station list of the service base station 10 to which the call is connected.

The neighbor base station 11 (12), which has been requested to allocate the traffic channel, allocates a traffic channel according to the information of the mobile terminal, and transmits a response message TCE_Asgn_ack to the base station controller.

The base station controller receiving the response from the neighbor base station instructs the serving base station 10 in communication with the mobile terminal to send PUF_msg_rqst to send a PUF_msg (PUF message). Contains.

The serving base station 10 transmits the PUF_msg to the mobile terminal 50 through the traffic channel (140). The mobile terminal emits the PUF signal according to the information included in the received PUF_msg. (150) In the PUF_msg, the power of the PUF signal Contains information such as level intervals, time intervals, and delivery times.

Then, the base stations 10, 11 and 12, which are allocated the traffic channel, recognize the PUF signal with different time delays. If one or more of the neighbor base stations 11, 12 does not receive a PUF signal within a certain time (second timer) for any reason, the base station releases the traffic channel upon termination of the second timer. .

Upon receiving the PUF signal, the base stations 10 (11) 12 transmit the position parameters such as the measured time delay to the mobile switch through the base station controller, and the mobile switch exchanges the position of the mobile terminal through the received position parameters. Calculate (160)

In this case, when the number of signals of the neighboring base stations delivered to the base station controller is less than two, since the position detection is impossible, a fault should be reported to the mobile switching center or a reallocation of the traffic channel should be requested.

Upon receiving Loc_Svc_rqst in step 100, the base station controller starts a first timer. If Loc_Svc_rqst for the same mobile terminal is received from the mobile switchboard before the first timer expires, the channel is allocated to the neighbor base stations again (170), and the above steps (110) to (150) are repeated.

If Loc_Svc_rqst is not received until the first timer expires, the location service terminates with the termination of the first timer. Or, if Loc_Svc_Cmpt indicating Location Service Complete is transmitted from the mobile exchange before the first timer expires, the base station controller sends a TCE_release to an adjacent base station to instruct channel release and terminate the location service.

Types of timers used in the present invention are as follows.

The first timer is located in the base station controller and starts when Loc_Svc_rqst is received from the mobile exchange and ends when Loc_Svc_Complete is received from the mobile exchange. The second timer is located in the base station. The second timer starts when TCE_asgn is received from the base station controller and ends when the PUF signal is received from the mobile terminal. The third timer is located in the mobile terminal and starts when the PUF_msg is received from the base station and ends when the PUF signal is emitted.

The present invention can be variously modified and can take various forms and only the specific embodiments thereof are described in the detailed description of the invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

In the present invention operating as described above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

By presenting a method for requesting location service in a mobile exchange and a method for supporting location service in a base station controller, it is possible to provide a location service to a mobile terminal using a PUF signal proposed in the standard. Therefore, the position of the mobile terminal can be calculated using an existing mobile communication system without using a separate location system.

Claims (12)

A mobile terminal provided with a mobile communication service and emitting a particularly strong level of PUF signal at the request of the base station, a service base station connecting communication with the mobile terminal, a base station controller connecting the base station to a mobile switch and the base station controller A mobile communication system comprising a mobile switch for connecting a PSTN to a public switched switching network, the mobile switch requesting a location service from a base station controller; Requesting a base station controller to allocate neighboring base stations located around the mobile terminal to a channel for the mobile terminal; Assigning a channel by the adjacent base stations and sending a response signal to a base station controller; Instructing a base station controller to request a PUF signal from the serving base station; Detecting, by the base stations, a PUF signal having different time delays to detect a parameter required for position calculation; Transmitting, by a base station controller, the parameters detected by the base stations to a mobile exchange; And calculating, by the mobile exchange, location information of the mobile terminal using the parameter. The method of claim 1, wherein the requesting of the location service is performed when requested by the mobile terminal. The method of claim 1, wherein the requesting of the location service is performed when the location information of the mobile terminal is requested from another network. The method of claim 1, wherein the requesting of the neighboring base stations to allocate a channel for the mobile terminal is performed by a base station controller for the at least two base stations included in the neighbor base station list of the serving base station. Location service request method for a mobile communication system. 2. The method of claim 1, wherein the step of instructing to request the PUF signal comprises the step of a base station controller sending information about the PUF signal to a serving base station. The mobile communication system of claim 1, wherein the receiving of the PUF signal further comprises releasing a channel when the base station does not receive the PUF signal of the mobile terminal within a predetermined time (second timer). Service request method for service. The method of claim 1, wherein the parameter is a time delay value of a PUF signal measured at each base station. The location of claim 1, wherein the step of communicating the parameter to the mobile exchange further comprises reporting a failure to the mobile exchange when the number of base stations receiving the PUF is two or less. Service request method. The method of claim 1, wherein the transmitting of the time delay value to the mobile switching center requires that neighboring base stations allocate a channel for the mobile terminal when the number of time delay values measured by each base station is 2 or less. And returning to the process. The method of claim 1, wherein the method for requesting location service comprises: when the mobile exchange requires location service within a predetermined time (first timer) after the mobile exchange requests location service from a base station controller, And returning to requesting to allocate a channel for the mobile terminal. 12. The method of claim 10, wherein the location service request method further comprises: if the mobile exchange does not request location service until a predetermined time (first timer) passes after the mobile exchange requests location service from a base station controller. Further comprising the step of terminating the location service request method for a mobile communication system. The method of claim 1, wherein the method for requesting location service comprises: terminating location service when the mobile exchange requests end of location service within a predetermined time (first timer) after the mobile exchange requests location service from a base station controller. And further comprising a process.