KR20050027283A - Enhanced method of mobile station terminated call protocol in mobile communication system - Google Patents

Abstract

A method for enhancing a call termination service in a mobile communication system is provided to inform a user about calls received in a shadow area by allowing a network to inform a mobile terminal of the user of the termination-failed calls when the mobile terminal escapes from the shadow area. An MSC(Mobile Switching Center) stores information of a termination-failed call generated in a shadow area in an HLR(Home Location Register). When a mobile terminal escapes from the shadow area, it registers its escape out of the shadow area through an access channel. When the registration of the escape out of the shadow area is detected, the MSC obtains information on the termination-failed call from the HLR and transmits it to a base station system. The base station system transmits a message including the information on the termination-failed call to the mobile terminal. The mobile terminal extracts the information on the termination-failed call from the message and stores it.

Description

How to improve incoming service in mobile communication system {ENHANCED METHOD OF MOBILE STATION TERMINATED CALL PROTOCOL IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a method for improving an incoming service in a mobile communication system, and more particularly, to a method for providing an incoming service for a call occurring in a shadow area.

In general, in a mobile communication system, registration is a procedure of informing the base station of the location, status, etc. of the mobile station in order to make an effective paging when establishing a mobile station terminated call. The types of registration provided by the mobile communication system can be briefly described as follows: power supply / blocking registration performed when the power is turned on / off, reference registration performed at regular time intervals, distance reference registration performed when moved over a certain distance, and a mobile station. Zone-based registrations performed when moving to this new zone, and parameter change registrations performed when the status information of the mobile station changes.

As described above, in the conventional registration form, when a mobile station (or a mobile terminal) enters a shaded area and then moves back to a serviceable area, there is a problem in that an incoming call cannot be received for a call generated in the shaded area. have. That is, there is no way for the mobile terminal user to check the call arrival occurring while staying in the shadowed area.

1 shows a general incoming service processing procedure. 1 is a procedure performed when calling a mobile station in a system, which is described in detail in "CDMA InternetWorking: Deploying the Open A-Interface".

Referring to FIG. 1, first, when a call occurs, a mobile switching center (MSC) acquires location information of a mobile station by accessing a home location register (HLR) / visit location register (VLR). (Step [2]). The mobile exchange transmits a page request message (PageReq) to the base station system (BSC / Base Transceiver System) based on the obtained location information of the mobile station (step [3]). The base station system transmits a call message (PCH_GenPage) to the mobile station through a paging channel (PCH) (step [4]).

Upon receiving the call message, the mobile station transmits a response message (ACH_PgRsp) to the base station system through an access channel (ACH) (step [5]). Upon receiving the response message, the base station system transmits a response message (PCH_BSAck) to the mobile station through a call channel (step [6]). The base station system transmits a response message (PageRsp) for the call request message to the mobile switch (step [7]).

Thereafter, the base station system transmits null frames to the mobile station through a forward traffic channel F_TCH (step [a]). At this time, the mobile exchange transmits a channel connection message (SCCP-CC: Signaling Connection Control Part-Channel Connection) to the base station system (step [8]). Then, the base station system transmits a channel assignment message (PCH_ChanAssign) to the mobile station through the call channel (step [b]). Upon receiving the channel assignment message, the mobile station transmits a preamble signal to the base station system through a reverse traffic channel (R_TCH) (step [c]). The base station system then sends a response message to the mobile station via a forward traffic channel (step [d]). Upon receiving the response message, the mobile station transmits the response message to the base station system through a reverse traffic channel (step [e]).

Meanwhile, the mobile exchange transmits a service allocation request message (AssignReq) to the base station system (step [9]). The base station system transmits a service connection message (FTCH_Serv_Conn) to the mobile station through a forward traffic channel (step [10]). Upon receiving the service connection message, the mobile station transmits a service connection complete message (RTCH_Serv_ConnCmplt) to the base station system through a reverse traffic channel (step [11]). The base station system transmits a service assignment response message (AssignCmplt) to the mobile switch (step 12).

The base station system transmits an alert message (FTCH_AlertWithInfo) including a calling party number and the like to the mobile station through a forward traffic channel (step 13). At this time, the mobile station displays the calling party number received from the base station system on the display window. Upon receiving the alert message, the mobile station transmits a response message to the base station system through a reverse traffic channel (step 14). At this time, when the user inputs a call key, the mobile station transmits a connection message (RTCH_Connect) to the base station system through a reverse traffic channel. Upon receiving the connection message, the base station system transmits a response message through a forward traffic channel (step 16). The base station system transmits a connection message (Connet) to the mobile exchange (step [17]). In this way, the call path is connected.

In the above-described process, when there is no response of the mobile station to the call message PCH_GenPage generated by the base station system, or when the mobile station has received a response, the mobile station does not receive a response (RTCH_MSAck) to the warning message FTCH_AlertWithInfo. If so, the system (or network) considers the mobile station not to handle the call normally. In this case, the mobile station is most likely in the shadowed area, where calls to the mobile station are lost. In addition, the mobile terminal user has no way of identifying a lost call in the shadow area.

Currently, mobile terminal users can check the information (caller number) for the call through the 'caller display service'. However, these services are only possible if the mobile terminal is in the service area. Mobile terminal users are always in need of better service, and from this point of view, there is an increasing demand for users to receive 'caller indication service' for terminated calls occurring in shadowed areas.

Accordingly, an object of the present invention is to provide a method for providing an incoming service for a call occurring while a mobile terminal stays in a shaded area.

Another object of the present invention is to provide a method for performing shadow escape registration in a mobile terminal.

Another object of the present invention is to register the information on the incoming call failed while the mobile terminal stays in the shadowed area in the mobile communication system to the home location register (HLR), and when the mobile terminal escapes the shadowed area, the information of the incoming call failed to move The present invention provides a method for transmitting to a terminal.

It is still another object of the present invention to provide a method for receiving and displaying information on an incoming / failed call generated while staying in a shaded area in a mobile terminal.

According to a first aspect of the present invention for achieving the above objects, in a method for providing an incoming service for a call that occurs while a mobile terminal is located in a shadowed area, the mobile exchange, the incoming call occurs in the shadowed area Storing the failed call information in a home location register; registering the shadow escape through the access channel when the shadow area escapes; and detecting the shadow escape registration by the mobile exchange when the shadow exchange registration is detected. Obtaining information of the unsuccessful call from a location register and transmitting the received information to a base station system; transmitting, by the base station system, a message including information of the unsuccessful call to the mobile terminal; And extracting and storing the information on the unsuccessful call from the receiver.

According to a second aspect of the present invention, in a method for performing shadow escape registration in a mobile terminal, receiving a system parameter message from a base station system, activating a shadow escape registration value (TRUE) based on the message content, Setting a shadow escape timer to a predetermined value, starting a timer having the shadow escape timer value at the time of entering the shadow area, activating a shadow escape indication value when the timer expires, and displaying the shadow escape indication If the shadow area escape is detected after activating the value, it is characterized in that it comprises the step of performing the shadow escape registration to the base station system through the access channel.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 illustrates a schematic network configuration of a mobile communication system according to the present invention. This is a general mobile communication network structure, and the names of the components are different, but they are also common to IS-95A / B, GSM, IS-2000, WCDMA, and UMTS.

2, a mobile station (MS) 5 means a mobile communication terminal. The mobile station 5 may be a legacy voice center that does not support IP or a terminal that supports IP. A base transceiver system (BTS) 4 is a device that manages radio resources and substantially exchanges information with a mobile terminal through a radio link. A base station controller (BSC) 2 is a device for controlling base stations (BTSs) and supports signal protocols such as call setup and release. The base station manager (BSM) 3 provides an initialization, configuration and operator matching function of the base station.

MSC (Mobile Switching Center) / Gateway (GW: Gateway) (1) is a device that connects the mobile communication network and the Internet (Internet), PSTN (Public Switched Telephone Network) and PSDN (Public Switched Data Network), Protocol conversion is supported. The gateway GW may be called a logical name such as a packet data service node (PDSN), an access gateway (AGW) or a media gateway (MGW). The home location register (HLR) / visit location register (VLR) 4 is a database that stores and manages subscriber parameters and location information for all mobile terminals registered in the network. According to the present invention, the home location register / visit location register 4 stores and manages information of a mobile station incoming failure call occurring in a shadowed area.

In the mobile communication network structure, the link between the BSC / BTS and the GW / BSC may be a circuit type network using a dedicated line such as E1 / T1 like the existing mobile communication network, or may be an IP packet network constructed using an IP router. That is, in the former case, IP is used as the upper transport layer while the BSC and BTS are connected by E1 / T1, and the latter case is connected between the BSC and the BTS through equipment such as a router. BTS is not directly connected 1: 1, but each device is connected to IP network.

3 shows a detailed configuration of the mobile terminal 5 according to the present invention.

Referring to FIG. 3, a control unit (MPU: Micro-processor unit) 100 controls the overall operation of the communication terminal. For example, it performs processing and control for voice call and data communication, performs shadow escape registration when escaping shadow area according to the present invention in addition to the usual function, and information of incoming / failed call occurred in shadow area (sender information). Process the operation to receive and store the. Therefore, in the following description, description about the process and control of the normal control part 100 is abbreviate | omitted.

The read only memory (ROM) 102 stores microcode and various reference data of a program for processing and controlling the control unit 100. Particularly, according to the present invention, when the shadow area escapes, the shadow escape registration is performed, and a program for receiving and storing the information of the incoming / failed call occurring in the shadow area is stored. Random Access Memory (RAM) 104 is a working memory of the controller 100. Stores temporary data generated during the execution of various programs. The flash ROM 106 stores various updatable storage data such as a phone book. In particular, the flash ROM 106 stores a recent call number and a recent call number. Here, the recent received number history is to store the calling party number (Calling Party Number) for the call, and stores the caller number for the call (call) that occurred in the shaded area according to the present invention as well as the caller number for the missed call. .

Key pad 108 includes numeric keys 0 through 9, menu, text transfer key, TALK, clear (CLR), end (END), *, #, scroll key (UP /). And a plurality of function keys, such as a DOWN key, and provide the control unit 100 with key input data corresponding to a key pressed by the user. The display 110 displays status information generated during the operation of the mobile communication terminal, a limited number of characters, a large amount of video and still images, and the like. The display unit 100 may use a color liquid crystal display (LCD).

The codec (Coder-Decoder) 112 connected to the control unit 100 and the speaker 116 and the microphone 114 connected to the codec 112 are voice input / output blocks used for phone calls and voice recording. . The codec 112 converts the PCM data provided from the controller 100 into an analog voice signal and transmits the same through the speaker 116 and converts the voice signal received through the microphone 114 into PCM data. Provided to the controller 100.

In addition, the RF unit (Radio Frequency unit) (120) is the frequency of the radio frequency signal received via the antenna 118 is provided to the baseband processing unit 122 by lowering the frequency, the baseband signal from the baseband processing unit 122 The frequency is raised and transmitted through the antenna 118. The baseband processor 122 processes a baseband signal transmitted and received between the RF unit 120 and the controller 100. For example, in case of transmission, channel coding and spreading of data to be transmitted are performed, and in case of reception, despreading and channel decoding of a received signal are performed. . That is, the baseband processor 122 is a block for demodulating various channels (calling channel, traffic channel, etc.) received from the base station or generating various channels (access channel, traffic channel, etc.) transmitted to the base station.

4 is a flowchart illustrating a procedure for performing shadow shadow registration in a mobile terminal according to an embodiment of the present invention.

Referring to FIG. 4, the controller 100 receives a system parameter message from the base station in step 401 and sets a corresponding parameter value based on the contents of the system parameter message. Here, the shadow escape registration (ESCAPE_SHADOW_REG) value is activated as "TRUE", and the shadow escape timer (ESCAPE_SHADOW_TIMER) is set to a predetermined value.

In step 403, the control unit 100 determines whether the mobile terminal enters the shadow area, and whether the shadow escape registration (ESCAPE_SHADOW_REG) is "True." Here, entering the shaded region indicates a state in which the mobile terminal does not receive a signal from the base station. If at least one of the two conditions is not satisfied, the controller 100 proceeds to step 415 to perform general call processing. If the two conditions are satisfied, the control unit 100 proceeds to step 405 to make the value of escaping out (ESCAPE_SHADOW_INDICATOR) to "TRUE", and to start the timer to cycle the value of the shadowing out timer.

In operation 407, the controller 100 checks whether the timer expires. If the timer has not expired, the controller 100 proceeds to step 417 to determine whether the mobile terminal has escaped from the shadow area. If the escape from the shadowed area fails, the control unit 100 returns to step 407 and checks whether the timer expires. In case of escaping the shadow area, the control unit 100 proceeds to step 419 and sets the shadow escape registration value to "FALSE", the shadow escape timer value to "0", and the shadow escape indication value " FALSE ". The controller 100 proceeds to step 421 to perform general call processing. As such, if the user enters the shadow area and escapes the shadow area within a preset time, the shadow escape registration is not performed to the base station.

On the other hand, when the shadow escape timer expires, the controller 100 proceeds to step 409 and sets the shadow escape indication value to "FALSE". The controller 100 determines whether the mobile terminal escapes the shadow area in step 411, the shadow escape registration value is "TRUE", and the shadow escape indication value is "TRUE". If any one of the three conditions is not satisfied, the controller 100 proceeds to step 421 to perform general call processing. If all three conditions are satisfied, the controller 100 proceeds to step 413 to set the shadow escape registration parameter value to "FALSE", the shadow escape timer to "0", and the shadow escape indication value. Is set to "FALSE" and Escape Shadow Registration is performed to the base station through the reverse access channel (R_ACH).

Thereafter, the mobile terminal receives a message including information of incoming call failures occurring in the shadow area. Upon receiving the message, the mobile terminal displays an indication on the display window indicating that there is an incoming call. Then, the information (caller number) of incoming calls is extracted from the notification message and stored in the corresponding area (recently received number storage area) of the memory. The stored caller numbers are displayed on the display window by the user's key operation.

5 is a flowchart illustrating a procedure for registering an incoming call to a home location register in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 5, first, the base station system transmits a system parameter message including shadow escape registration information, shadow escape timer information, and the like to the mobile terminal (step [1]). It is then assumed that the mobile terminal has moved to the shaded area. When a call is received from a mobile terminal in the shaded area, the mobile exchange accesses a home location register (HLR) / visit location register (VLR) to obtain location information of the mobile terminal ([ Step 2). The mobile exchange transmits a page request message (PageReq) to the base station system (BSC / Base Transceiver System) based on the obtained location information of the mobile terminal (step [3]). . The base station system transmits a call message (PCH_GenPage) to the mobile terminal through a paging channel (PCH) (step [4]). However, the mobile terminal cannot receive the call message because it is in a shaded area. Therefore, the procedure of steps [5] to [14] cannot be performed in the incoming service processing procedure described with reference to FIG. 1.

On the other hand, the mobile exchange transmits the call request message (PageReq) to the base station system, and checks whether a response message (PageRsp) for the call request message is received for a predetermined time. Here, if the response message is not received within the preset time, the mobile exchange transmits an incoming failure message to the home location register (step [15]). Then, the home location register stores information on a call failure history (Call Failed History) in a database (MS-Terminated Call Pending DB). Then, when the mobile terminal escapes from the shadowed area, information (caller number) for the incoming call failure stored in the database is transmitted to the mobile terminal.

When receiving a message including the information of the incoming call, the mobile terminal displays an indication on the display window indicating that the incoming call failed. Then, the information of the unsuccessful call (caller number) is extracted from the message and stored in the corresponding area (recently received number storage area) of the memory. The stored caller numbers are displayed on the display window by the user's key operation.

6 is a flowchart illustrating a procedure for transmitting information of an unsuccessful call to a mobile terminal in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 6, first, the base station system transmits a system parameter message including shadow escape registration information, shadow escape timer information, etc. to the mobile terminal (step [1]). It is then assumed that the mobile terminal has moved to the shaded area. When a call is received by the mobile terminal, the mobile switch accesses a Home Location Register (HLR) / Visit Location Register (VLR) to obtain location information of the mobile terminal, and obtains the obtained mobile terminal. The call request message (PageReq) is transmitted to the base station system (BSC / Base Transceiver System) based on the location information of the terminal. The base station system transmits a call message (PCH_GenPage) to the mobile terminal through a paging channel (PCH). However, the mobile terminal cannot receive the call message because it is in a shaded area. The figure shows that N incoming calls failed. As described above, the home location register / visit location register stores and manages information about incoming call failures in a database.

Thereafter, when the mobile terminal escapes the shadow area, the mobile terminal transmits a shadow escape registration message (REG_TYPE = ESCAPE_SHADOW_REG) to the base station system through an access channel (step [2]). Then, the base station system sends a location update request message (LocUpdateReq) to the mobile switch (step [3]). Upon receiving the location update request message, the mobile exchange sends a registration request message (IS41_REGNOT: Registration Notification) according to the IS41 protocol to the home location register / visit location register (step [4]). The home location register / visit location register then updates and stores the location information of the mobile terminal in the database. The home location register / visit location register sends a location registration result message (IS41_regnot: Registration Notification Return Result) informing of the update storage to the mobile switch (step [5]). Then, the mobile exchange sends a location update acceptance message (LocUpdateAccept) to the base station system (step [6]). Upon reception of the location update acceptance message, the base station system transmits the registration acceptance message PCH_RegAccept_Order to the mobile terminal through a call channel (step [7]).

On the other hand, the home location register / visited location register after performing the location update of the mobile terminal, retrieves the information of the failed call to the mobile terminal, the failure call notification message including the information of the failed call (IS41_LostCall_Not ) Is transmitted to the mobile exchange (step [8]). Upon receiving the failed call notification message, the mobile switcher sends a notification message (Feature_Notification) including information of the incoming call failures to the base station system (step [9]). Then, the base station system transmits a notification message (PCH_Feature_Notification) including the information of the unsuccessful call to the mobile terminal through a call channel (step [10]).

When the notification message is received, the mobile terminal displays an indication on the display window indicating that there is an incoming call. Then, the information (caller number) of incoming calls is extracted from the notification message and stored in the corresponding area (recently received number storage area) of the memory. The stored caller numbers are displayed on the display by the user's key operation.

After storing the information of the unsuccessful call, the mobile station transmits a response message (ACH_MSAck) to the base station system through the access channel (step [11]). Upon receiving the response message, the base station system transmits a message Lost_Call_Clr requesting deletion of the incoming call to the mobile exchange (step [12]). Then, the mobile exchange transmits the incoming unsuccessful call deletion request message according to the IS41 protocol to the home location register / visit location register (step [13]). Upon reception of the unsuccessful call deletion request message, the home location register / visit location register deletes the information of the unsuccessful call for the mobile terminal from the database.

Here, the database (Lost MS-Terminated Call DB) may be implemented as a separate server located in the home location register (HLR) or interworking with the home location register. The number of unsuccessful incoming calls managed in the database is regarded as an implementation problem.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, the present invention informs the mobile terminal of the incoming call failures occurring in the shadowed area to the mobile terminal in the network immediately after escaping the shadowed area, so that the user can know what kind of call occurred in the shadowed area. That is, the present invention has the effect of providing an improved incoming service.

1 is a diagram illustrating a general incoming service processing procedure;

2 is a diagram illustrating a network configuration of a schematic mobile communication system according to the present invention.

3 is a view showing a detailed configuration of a mobile terminal 5 according to the present invention.

4 is a diagram illustrating a procedure for performing escape shadow registration in a mobile terminal according to an embodiment of the present invention.

5 is a diagram illustrating a procedure for registering an incoming call to a home location register in a mobile communication system according to an embodiment of the present invention.

6 is a diagram illustrating a procedure for transmitting information of an unsuccessful call to a mobile terminal in a mobile communication system according to an embodiment of the present invention.

Claims (7)

A method for providing an incoming service for a call that occurs while a mobile terminal is located in a shadow area, Storing, by the mobile exchange, information on an unsuccessful call generated in the shadowed area in a home location register; When the shadow area escapes, the mobile terminal performing a shadow escape registration through an access channel; When the shadow escape registration is detected, the mobile switch obtaining the information of the incoming call from the home location register and transmitting the information to the base station system; Transmitting, by the base station system, a message including information on the unsuccessful call to the mobile terminal; And the mobile terminal extracts and stores the information on the unsuccessful call from the message. The method of claim 1, The information of the incoming call failure is characterized in that the calling party number (Calling Party Number). The method of claim 1 And the base station system transmits the message to the mobile terminal through a paging channel. In the method for performing shadow escape registration in the mobile terminal, Receiving a system parameter message from the base station system, activating a shadow escape registration value (TRUE) based on the message content, and setting the shadow escape timer to a predetermined value; Starting a timer to give the shadow escape timer value upon entering the shadow area; Activating a shadow escape indication value when the timer expires; And if shadow exit is detected after activating the shadow exit indication value, performing shadow exit registration with the base station system through an access channel. The method of claim 4, wherein If it is detected that the shadow area escape before expiration of the timer, further comprising performing a general call processing. The method of claim 4, wherein Receiving and storing information on an incoming call failed in the shaded area from the base station system after registering the shadow escape; And when a key operation for confirming the information of the unsuccessful call is detected, displaying the information of the unsuccessful call on the display window. The method of claim 6, The information of the incoming call failure is characterized in that the calling party number (Calling Party Number).