KR101145922B1 - Network sellecting method for dual mode mobile communication terminal - Google Patents

Abstract

The present invention relates to a network selection method of a dual mode mobile communication terminal, comprising: setting a switching condition of a radio access technology (RAT) when selecting a public land mobile network (PLMN) for service use; Requesting registration with the PLMN according to the RAT in the current operation mode; Receiving a reject cause message according to the PLMN registration failure; Determining whether the content of the received reject cause message and the number of receptions satisfy the RAT switching condition based on the preset RAT switching condition; Searching for a PLMN that can be registered by switching to another RAT when the received reject cause message satisfies the RAT switching condition; And requesting registration to the PLMN side of the other RAT. As a result, when the subscriber's network registration is not smooth due to a network failure or the like, it is possible to quickly return to normal service.

Description

NETWORK SELLECTING METHOD FOR DUAL MODE MOBILE COMMUNICATION TERMINAL}

1 is a flowchart of a network selection method of a conventional mobile communication terminal;

2 is a configuration diagram of a mobile communication network to which a dual mode mobile communication terminal according to the present invention is applied;

3 is a flowchart illustrating a network selection method of a dual mode mobile communication terminal according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

100: mobile communication terminal 200: 2G network

300: 3G network 210, 310: base station

220, 320: base station controller 230, 330: mobile switching center

The present invention relates to a network selection method of a dual mode mobile communication terminal.

The International Telecommunication Union (ITU) is a second generation (2Generation, hereinafter called 2G) mobile phone that provides only voice calls, and the third generation (3Generation, hereinafter) is a service that freely sends and receives both voice, data, and video to the wireless Internet. 3G). 2G technology includes CDMA and GSM (Global System for Mobile communication), and 3G technology includes CDMA 2000 based on CDMA, Wide band CDMA (WCDMA) based on CDMA technology and GSM technology, and IMT-2000. Etc. belong to this. Currently, the mobile communication network is a mixture of 2G and 3G network, so the mobile communication terminal also supports the radio access technology (Radio Access Technology, hereinafter referred to as RAT) of each network, which operates in two modes of 2G and 3G. A communication terminal is used.

In the network selection and registration process of the dual mode mobile communication terminal, the 3GPP TS 24.008 standard, which is a mobile radio interface layer 3 specification of the 3rd generation partnership project (3GPP), is applied.

1 is a flowchart illustrating a network selection method according to 3GPP TS 24.008, a related standard, as a network selection method of a mobile communication terminal.

An initial power is applied to the mobile communication terminal or a mobile communication terminal moving between service cells (hereinafter referred to as a PLMN) requests registration to a selected PLMN according to a preset priority (P10). The priority of PLMN selection may be determined according to the electric field strength, whether or not it is a Home-PLMN.

The registration request of the mobile communication terminal may fail to register due to various reasons such as MAC failure (reject cause # 20), sync failure (reject cause # 21), and if registration fails, the mobile communication terminal is rejected. A cause cause message is received (P12). Herein, the operation of the mobile communication terminal upon receiving the rejection cause message is defined in the 3GPP TS 24.008 standard.

For example, when registration fails due to rejection of PLMN registration (reject cause # 11) (P16), the mobile communication terminal reselects the PLMN immediately without retrying registration for the PLMN that failed to register (P24), and reselects the PLMN. Request registration to PLMN (P26).

On the other hand, if registration fails due to a network error (reject cause # 17) (P14), the mobile communication terminal starts to drive the internal timer and once suspends the registration attempt (P18). Thereafter, if it is determined that the hold time has elapsed by more than the reference time through the timer, the mobile communication terminal retries registration to the PLMN which failed to register (P20). If the rejection cause message due to network error (reject cause # 17) is received even after retrying registration, the mobile communication terminal withholds the registration request and repeats the registration retry with the corresponding PLMN up to a predetermined number of times.

Here, when the number of retries is set to 5 times, the mobile communication terminal attempts to register the corresponding PLMN up to 5 times but fails to register (P22). The mobile communication terminal reselects the PLMN (P24) and registers the reselected PLMN. Request (P26).

However, the conventional method for selecting a network of a mobile communication terminal is based on a 3G network and does not separately define a dual mode terminal that can use both 2G and 3G networks. When the dual mode mobile communication terminal is denied registration from a predetermined PLMN, registration is attempted again in the current RAT without a separate RAT change process. Therefore, even though it is possible to register with a PLMN belonging to another RAT, the current RAT is to retry registration, which delays network registration and causes a problem in providing a service.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a network selection method of a dual mode mobile communication terminal that can quickly return to normal service when a subscriber's network registration is not smooth due to a network failure. There is a purpose.

Network selection method of a dual-mode mobile communication terminal according to the present invention for achieving the above object, when the PLMN (Public Land Mobile Network) for the use of the service to set the switching conditions of the radio access technology (Radio Access Technology, RAT) Receiving step; Requesting registration with the PLMN according to the RAT in the current operation mode; Receiving a reject cause message according to the PLMN registration failure; Determining whether the content of the received reject cause message and the number of receptions satisfy the RAT switching condition based on the preset RAT switching condition; Searching for a PLMN that can be registered by switching to another RAT when the received reject cause message satisfies the RAT switching condition; And requesting registration to the PLMN side of the other RAT.

Here, the step of setting the switching condition of the RAT when selecting the PLMN for using the service, the step of setting the switching condition of the RAT in an over the air (OTA) method of setting the RAT phone conditions by wirelessly receiving a setting value It is possible to include.

The determining of whether the content of the received reject cause message and the number of reception of the rejected cause message satisfies the RAT switching condition may include determining that the rejection cause message is a third generation partnership project (GPP). In the case of a network error message (reject cause # 17) according to the 3GPP TS 24.008 standard, which is a mobile radio interface layer 3 specification, the RAT may be switched.

Determining whether the network cause (reject cause # 17) message has been continuously received more than a predetermined number of times; It may be possible to include the step of switching the RAT when the network cause (reject cause # 17) message is received more than a predetermined number of times.

The requesting for registration to the PLMN side of the other RAT may include: searching for a PLMN that has been most recently registered among PLMNs belonging to the other RAT; It is possible to include the step of requesting registration to the most recently successful PLMN retrieved.

Hereinafter, a network selection method of a dual mode mobile communication terminal according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

2 is a configuration diagram of a mobile communication network to which a network selection method of a dual mode mobile communication terminal according to the present invention is applied, a second generation (hereinafter referred to as 2 Generation, 2G) network 200 and a third generation (hereinafter referred to as 3 Generation). , 3G) illustrates a mobile communication network in which the network 300 coexists.

The 2G network 200 is operated by 2G Radio Access Technology (RAT), such as GSM (Grobal System for Mobile communication) technology, and the 3G network 300 is a Universal Mobile Telecommunication System (UMTS) technology. It is operated by 3G-RAT. The two networks 200, 300 each include a base station 210, 310, a base station controller 220, 320, a mobile switching center 230, 330, and a home register (HLR) / visitor register (VLR). The short message service center (SMSC) in the networks 200 and 300 transmits a message on whether the mobile communication terminal 100 is registered to the operator and the mobile communication terminal 100.

The mobile communication terminal 100 of the present invention supports a dual mode function that can selectively use the 2G network 200 and the 3G network 300, 2G- which is a transceiver of the corresponding network (200, 300) according to the operation mode Under the access control of RAT and 3G-RAT.

The mobile communication terminal 100 is equipped with a USIM card including both a subscriber identity module (SIM) application and a universal subscriber identity module (USIM) application for a universal mobile telecommunication system (UMTS), which is a 3G network 300. The USIM card stores control information for operations in different networks 200 and 300, so that the mobile communication terminal 100 can use the 2G network 200 and the 3G network 300 according to the information stored in the USIM card. have. When using each network 200, 300, the mobile communication terminal 100 receives a radio signal from the transceiver (2G-RAT, 3G-RAT) of the network (200, 300), and receives the received signal The data is transmitted to the corresponding transceivers (2G-RAT, 3G-RAT).

Further, the mobile communication terminal 100 according to the present invention is initially supplied with power, or the mobile communication terminal 100 moving between PLMNs registers with the PLMN selected according to a preset priority through RAT in the current operation mode. request. In this case, when the reject cause message is repeatedly received from the currently operating RAT, the mobile communication terminal 100 changes from the 2G network 200 to the 3G network 300, or according to a preset RAT switching condition. The RAT is switched from the 3G network 300 to the 2G network 200 to select a PLMN that can be registered. Accordingly, the PLMN registration can be completed quickly, compared to attempting network registration through a single RAT, thereby providing a smooth service to the user.

A network selection method of a mobile communication terminal according to the present invention having such a configuration will be described in detail with reference to FIG. 3. 3 is a flowchart illustrating a network selection method of a dual mode mobile communication terminal according to the present invention.

First, the RAT switching condition is set in the mobile communication terminal 100 when registering the networks 200 and 300 (S10). RAT switching condition is set by the debug command (DebugCmmand) method of connecting the mobile communication terminal 100 to the PC to store the setting value in the mobile communication terminal 100, or wirelessly receiving the setting value through the network (200, 300) It can be set to the over-the-air (OTA) method to store in the mobile communication terminal 100.

Thereafter, the mobile communication terminal 100 is initially supplied with power, or the mobile communication terminal 100 moving between service cells (Public Land Mobile Network, hereinafter referred to as PLMN) is registered in the selected PLMN according to a preset priority. Request (S12). The priority of PLMN selection may be determined according to electric field strength, Home-PLMN, or the like. If registration fails, a reject cause message is received by the mobile communication terminal 100 (S14).

Accordingly, the mobile communication terminal 100 determines whether the rejection cause message has been received more than a predetermined number N according to the RAT switching condition set in step S10 (S16). Here, the RAT switching condition may be added not only the number of times of rejection cause message but also various conditions. For example, if a network error (reject cause # 17) message, which is a registration failure message due to a network error, is received three or more times in a row, the RAT can be switched. In this case, it is possible to set the switching conditions in such a manner as to switch the RAT. In addition, by setting the RAT switching conditions differently according to each PLMN by setting the mobile communication terminal 100 entering the PLMN in an OTA manner, it can be flexibly set according to the radio environment of each PLMN.

On the other hand, if the rejection cause message is received more than the set number (N), the mobile communication terminal 100 switches the RAT to reselect the PLMN (S18), and requests registration to the reselected PLMN (S20). Here, the process of reselecting the PLMN by switching the RAT may also add various setting conditions. For example, it is possible to switch the RAT only when there is a PLMN that has recently registered a location in another RAT, and when a PLMN that has recently registered a location successfully exists in another RAT, a request for registration can be directly made to the PLMN. Do.

As described above, the dual mode mobile communication terminal according to the present invention re-selects a PLMN that can be registered by switching RAT from 2G network to 3G network or from 3G network to 2G network if a failure message is repeatedly received when attempting to register a network. have. Accordingly, if the subscriber's network registration is not smooth due to a network failure, it is possible to quickly return to normal service.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. I will understand. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

As described above, the network selection method of the dual-mode mobile communication terminal of the present invention registers by switching RAT from 2G network to 3G network or from 3G network to 2G network if a failure message is repeatedly received when attempting to register a network. Reselect the PLMN if possible.

Accordingly, if the subscriber's network registration is not smooth due to a network failure or the like, it can quickly return to normal service.

Claims (5)

Setting a switching condition of a radio access technology (RAT) when selecting a public land mobile network (PLMN) for using a service; Requesting registration with the PLMN according to the RAT in the current operation mode; Receiving a reject cause message according to the PLMN registration failure; Determining whether at least one of the contents of the received reject cause message and the number of receptions meets the RAT switching condition based on the preset RAT switching condition; Searching for a PLMN that can be registered by switching to another RAT when the received reject cause message satisfies the RAT switching condition; Requesting registration to the PLMN side of the other RAT; The determining of whether the RAT switching condition is satisfied may include determining whether the reject cause message has been continuously received more than a preset number of times; and switching the RAT when the reject cause message has been received more than a preset number of times. Network selection method of a dual-mode mobile communication terminal comprising a. The method of claim 1, The step of setting the switching condition of the RAT when selecting the PLMN for using the service, Receiving a setting value wirelessly and setting the switching condition of the RAT in an over-the-air (OTA) method for setting the RAT phone condition; and a network selection method of a dual mode mobile communication terminal. The method of claim 1,  On the basis of the predetermined RAT switching condition, the step of determining whether at least one of the content and the number of reception of the received reject cause message meets the RAT switching condition, If the rejection cause message is a network error (reject cause # 17) message according to the 3GPP TS 24.008 standard of 3GPP (3rd Generation Partnership Project) mobile radio interface layer 3 specification (3GPP) to switch the RAT Network selection method of a dual-mode mobile communication terminal comprising a step. delete The method of claim 1, The requesting registration to the PLMN side of the other RAT may include: Retrieving a PLMN most recently registered among PLMNs belonging to the other RAT; And requesting registration from the most recently found successful PLMN.

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