KR100894361B1 - Method for processing call of mobile communication system - Google Patents

Abstract

The present invention relates to a method for processing a call in a mobile communication system, in which, when a mobile communication terminal transmits a call attempt message to a base station, the base station controller requests a call connection from the exchange, and the base station controller resources according to the resource allocation request of the exchange. Transmitting the channel assignment information to the base station controller after the base station performs a channel assignment and service setup process, and the base station controller transmits a channel assignment message to the base station. And transmitting, by the base station, the channel assignment message to the mobile communication terminal by a predetermined number of retransmissions in a preset retransmission period, and repeatedly transmitting the channel assignment message in the wired section and the wireless section in which loss of the channel assignment message may occur. Due to loss of channel assignment messages There is an advantage of reducing the rate of incoming / outgoing calls by minimizing the possibility of call failure.

Channel assignment message, CAM, ECAM

Description

Call handling method of mobile communication system {METHOD FOR PROCESSING CALL OF MOBILE COMMUNICATION SYSTEM}

1 is a signal flow diagram illustrating a call processing method of a mobile communication system according to the prior art;

2 is a block diagram showing an example of a mobile communication system capable of performing a call processing method according to the present invention;

3 is a signal flow diagram illustrating a call processing method of a mobile communication system according to an embodiment of the present invention;

4 is a flowchart illustrating an operation process in a base station for performing a call processing method of a mobile communication system according to an embodiment of the present invention.

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

110: mobile communication terminal 120: wireless access network

121: base station transmitter 123: base station controller

130: exchanger

The present invention relates to a call processing method of a mobile communication system, and more particularly, to a call processing method in which an exchange connects a corresponding call according to a call attempt of a mobile communication terminal.

The call processing method of the conventional mobile communication system will now be described with reference to the signal flow diagram of FIG. 1.

First, when the mobile communication terminal transmits a call attempt message through an access channel (S1), the base station transmits the call attempt message to the base station controller (S3), and the base station controller requests a call connection from the exchange (S5).

After performing the authentication operation on the mobile communication terminal (S7), the exchange requests resource allocation to the base station controller (S9).

The base station controller allocates resources according to the resource allocation request (S11) and requests channel allocation from the base station (S13).

The base station allocates a channel to the corresponding mobile communication terminal according to the channel allocation request (S15) and after performing a service setup process (S17), transmits configuration information of the allocated channel to the base station controller (S19). The controller checks the traffic path by sending and receiving an idle frame (S21).

The base station controller transmits a channel assignment message, that is, a channel assignment message (CAM) or extended channel assignment message (ECAM) to the base station (S23), and the base station transmits the channel assignment message to the mobile communication terminal to inform the configuration information of the channel ( S25).

The mobile communication terminal transmits a channel assignment response message after receiving the channel assignment message (S27), and the base station transmits a connection status information message to the base station controller to inform that the mobile communication terminal and the base station are connected (S29).

The mobile communication terminal and the base station confirms the service connection state by exchanging messages with each other (S31), and when the base station transmits the service connection confirmation message to the base station controller (S33), the base station controller transmits a channel assignment completion message to the exchange (S35). ). After that, the call connection between the mobile communication terminal and the exchange is completed (S37).

However, the channel assignment message is lost in the wired section (from the base station controller to the base station) or the wireless section (from the base station to the mobile communication terminal) during the call processing. In the wireless section, the channel assignment message may be lost when the signal strength is constantly changed by external force, and in the wired section, the reason for this is not found.

However, according to the call processing method of the mobile communication system according to the prior art, when the channel assignment message is lost, it is immediately treated as a failure of the call connection, which is a factor to increase the call / incoming failure rate.

In this case, the mobile communication user not only has to take the hassle of performing redialing, but also has to bear the delay of the call, which causes a problem of degrading the call quality of the mobile communication system.

The present invention has been proposed to solve such a conventional problem, and it is possible that the call connection will fail due to the loss of the channel assignment message by repeatedly transmitting the channel assignment message in the wired section and the wireless section where the channel assignment message may be lost. The purpose is to reduce the incoming / outgoing failure rate by minimizing

In the call processing method of the mobile communication system according to the present invention for realizing the above object, when the mobile communication terminal transmits a call attempt message to the base station, the base station controller requests a call connection from the switch, and the resource allocation request of the switch is performed. The base station controller allocates resources and requests channel allocation to the base station, and after the base station performs a channel assignment and service setup process, transmitting allocation channel configuration information to the base station controller, and the base station controller sends a channel assignment message. And transmitting, by the base station, the channel assignment message to the mobile communication terminal by a predetermined number of retransmissions in a predetermined retransmission period.

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

2 is a block diagram showing an example of a mobile communication system capable of performing a call processing method according to the present invention.

The mobile communication system for the present invention includes a mobile communication terminal 110, a wireless access network 120 and a switch 130, the wireless access network 120 includes a base station 121 and a base station controller 123 The base station 121 includes a BTS resource control (BRC) 121a, a BTS call control (BCC) 121b, a BTS main control (BMC) 121c, and a channel element control (CEC) 121d. .

The mobile communication terminal 110 is a terminal capable of voice communication and data communication with the other party through a mobile communication network, and generates a corresponding call when a user inputs a phone number for a voice call.

The radio access network 120 serves to guarantee the mobility of the mobile communication terminal 110 and performs handover and radio resource management functions. The radio access network 120 includes a base station 121 and a base station controller 123 and supports both synchronous and asynchronous. Here, in the case of synchronous, the base station 121 will be a base transceiver station (BTS), the base station controller 123 will be a base station controller (BSC), and in the asynchronous case, the base station 121 is a radio transceiver subsystem (RTS), The base station controller 123 may be a radio network controller (RNC). Of course, the wireless access network 120 is not limited thereto, and may include a GSM network other than a CDMA network and an access network of all mobile communication systems to be implemented in the future.

As an example of the synchronous type, the BRC 121a of the base station 121 performs resource allocation and management functions in the base station during call processing by the base station main processor, and the BCC 121b performs channel card resources and the like on the BRC 121a. The BMC 121c is a main processor in charge of the channel card, and the CEC 121d performs a power control function.

The base station 121 having such an example configuration receives a call attempt message from the mobile communication terminal 110 through a traffic channel among signal channels, and transmits the received call attempt message to the base station controller 123. In addition, the base station 121 is a network endpoint device that is directly connected to the mobile communication terminal 110 by performing baseband signal processing, wired and wireless conversion, and transmission and reception of wireless signals.

The base station controller 123 controls the base station 121, and assigns and releases radio channels to the mobile communication terminal 110, transmit power control of the mobile communication terminal 110 and the base station 121, soft handover and inter-cell soft handover. Determination of handover, transcoding and vocoding, global positioning system (GPS) clock distribution, and operation and maintenance functions for the base station are performed.

The exchange 130 performs basic and additional service processing, incoming and outgoing call processing of the subscriber, location registration procedure and handover procedure processing of the mobile communication terminal 110, interworking with other networks, and the like. The exchange 130 is an Access Switching Subsystem (ASS) that performs distributed call processing, an Interconnection Network Subsystem (INS) that performs centralized call processing, and a Central Control Subsystem (CCS) that centralizes operations and maintenance. ), And a subsystem such as a Location Registration Subsystem (RLS) that performs storage and management of information on mobile subscribers.

Call processing of the mobile communication terminal implemented in the mobile communication system configured as described above will be described with reference to FIGS. 2 to 4.

First, when the mobile communication terminal 110 transmits a call attempt message through an access channel (S201), the message is transmitted to the base station controller 123 via the base station 121 (S203), and the base station controller 123 exchanges the switch. In operation S205, the terminal 130 requests a CM (Connection Management) service, that is, a call connection.

The exchange 130 requests resource allocation from the base station controller 123 after performing authentication work on the corresponding mobile communication terminal 110 (S207).

The base station controller 123 allocates resources according to the resource allocation request (S211), and requests the channel allocation from the base station 121 (S213).

The base station 121 allocates a channel to the corresponding mobile communication terminal 110 according to the channel allocation request (S215), and after performing a service setup process (S217), transmits configuration information of the allocated channel to the base station controller 123. Transmitting (S219), the base station 121 and the base station controller 123 exchanges the idle frame to confirm the traffic path (S221).

The base station controller 123 transmits a channel assignment message, that is, CAM or ECAM, to the base station 121 (S223), and the base station 121 transmits the channel assignment message to the mobile communication terminal 110 to inform the channel configuration information. (S225).

The mobile communication terminal 110 transmits a channel assignment response message after receiving the channel assignment message (S227).

In this case, the channel assignment message may be lost in the wired section from the base station controller 123 to the base station 121 or in the wireless section from the base station 121 to the mobile communication terminal 110. If it is lost, it is immediately treated as a failure of call connection, which increases the rate of incoming / outgoing calls.

In the present invention, if the base station 121 does not receive a channel assignment response message from the mobile communication terminal 110 (S229), it recognizes that the channel assignment message is lost in the wired section or the wireless section, and thus the channel assignment message is transmitted to the mobile communication terminal 110. To transmit again (S225).

Thereafter, it is checked again whether a channel allocation response message is received from the mobile communication terminal 110 (S229). If the channel allocation response message is not received again, step S225 is repeated to transmit the channel allocation message to the mobile communication terminal 110. do.

The retransmission of the channel assignment message is performed a predetermined number of times to minimize the failure of the call connection (S231), and even when the channel allocation message is retransmitted a predetermined number of times, a channel assignment response message is received from the mobile communication terminal 110. If not, the call connection is treated as failed (S233).

On the other hand, by applying the steps S229 and S231 to the present invention may be designed to retransmit the channel assignment message when the channel assignment response message does not occur in the mobile communication terminal 110, the number and retransmission cycle of the channel assignment message (I.e., delay time) may be parameterized to design a channel assignment message independent of the channel assignment response message.

Next, the base station 121 transmits a connection status information message to the base station controller 123 to inform that the mobile communication terminal 110 and the base station 121 are connected (S235).

The mobile communication terminal 110 and the base station 121 confirm a service connection state while exchanging messages with each other (S237), and when the base station 121 transmits a service connection confirmation message to the base station controller 123 (S239), the base station controller 123 transmits the channel assignment completion message to the exchange 130 (S241). After that, the call connection between the mobile communication terminal 110 and the exchange 130 is completed (S243).

4 is a flowchart illustrating an operation process in a base station for performing a call processing method of a mobile communication system according to an embodiment of the present invention. The internal operation of the base station will be described with reference to FIGS. 2 and 4. For reference, the following description corresponds to steps S223 to S233 described with reference to FIG. 3.

First, when the base station controller 123 transmits a channel assignment message, ie, CAM or ECAM, to the BCC 121b of the base station 121 (S301), the BCC 121b and the BMC 121c of the base station 121 are corresponding channels. The allocation message is transmitted to the mobile communication terminal 110 to inform the channel configuration information (S303). Here, the BCC 121b to the BMC 121c correspond to the wired section, and the BMC 121c to the mobile communication terminal 110 correspond to the wireless section.

After receiving the channel assignment message, the mobile communication terminal 110 transmits a channel assignment response message to the CEC 121d of the base station 121, and the CEC 121d transmits a normal frame instead of an Adida frame. Send to 123.

In this case, if the channel assignment response message is not received from the mobile communication terminal 110 (S305), the BCC 121b of the base station 121 recognizes that the channel assignment message is lost in the wired section or the wireless section. The number of lost times is compared with the preset reference number of times (S307).

The BCC 121b of the base station 121 retransmits the channel assignment message to the BMC 121c when the number of lost channel assignment response messages is within a preset reference number, and retransmits the channel assignment message to the mobile communication terminal 110. The retransmission information for transmitting is transmitted (S309).

Then, the BMC 121c of the base station 121 retransmits the channel assignment message to the mobile communication terminal 110 based on the retransmission information provided from the BCC 121b. Here, the retransmission information provided from the BCC 121b to the BMC 121c includes the number of retransmissions of the channel assignment message and the retransmission period (ie, delay time). Accordingly, the BMC 121c retransmits the channel assignment message for each retransmission period by the number of retransmissions. That is, whenever the BCC 121b determines retransmission of the channel assignment message, the BMC 121c retransmits the channel assignment message a predetermined number of times (S311).

If, in step S307, the BCC 121b of the base station 121 loses the channel allocation response message beyond the preset reference number, the BCC 121b processes the call connection as a failure without retransmitting the channel allocation message any more (S313). .

As described above with reference to FIG. 3, when the channel assignment response message does not occur from the mobile communication terminal 110, the channel assignment message may be retransmitted through steps S309 and S311. Regardless of whether or not, the BCC 121b and the BMC 121c may be designed to transmit a channel assignment message a predetermined number of times.

It has been described so far limited to one embodiment of the present invention, it is obvious that the technology of the present invention can be easily modified by those skilled in the art. Such modified embodiments should be included in the technical spirit described in the claims of the present invention.

As described above, the present invention minimizes the possibility of a call connection failure due to the loss of the channel assignment message by repeatedly transmitting the channel assignment message in the wired section and the wireless section in which the channel assignment message may be lost.

This not only eliminates the need for the mobile subscriber to redial, but also eliminates unnecessary call delays, thereby providing improved call quality.

In addition, the mobile communication service provider can easily solve the petition task by improving the call quality by reducing the incoming / outgoing call rate by simply updating the operating software without changing complicated hardware.

Claims (5)

delete delete Requesting a call connection from the base station controller when the mobile communication terminal transmits a call attempt message to the base station; A base station controller allocates resources according to a resource allocation request of the exchange and requests channel allocation from the base station; Transmitting allocation channel configuration information to the base station controller after the base station performs a channel allocation and service setup process; Transmitting, by the base station controller, a channel assignment message to the base station; Transmitting, by the base station, the channel assignment message to the mobile communication terminal; Confirming, by the base station, whether a channel assignment response message corresponding to the channel assignment message is received from the mobile communication terminal; If the BCC (BTS Call Control) of the base station does not receive the channel allocation response message from the mobile communication terminal, the channel allocation message transmitted to the mobile communication terminal is lost and the number of lost times and the preset reference number are determined. Comparing with, Retransmitting, by the BCC, the channel assignment message to a BTS Main Control (BMC) of the base station when the number of times of loss is within the reference number of times; The BMC retransmitting the channel assignment message to the mobile communication terminal Call processing method of a mobile communication system comprising a. The method of claim 3, wherein The BMC retransmits the channel assignment message a predetermined number of times each time the BCC retransmits the channel assignment message. Call processing method of mobile communication system. The method of claim 4, wherein The BMC retransmits the channel assignment message based on the number of retransmissions and the retransmission period included in the retransmission information provided from the BCC. Call processing method of mobile communication system.

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