KR100965384B1 - Method of power-saving in multi-mode mobile telephone - Google Patents

Abstract

A method for searching a cell of a multi-mode mobile communication terminal capable of accessing at least two radio access technologies (RATs), the method comprising: receiving RAT information from a mobile communication network and receiving RAT information accessible from a cell to which the mobile communication terminal is connected; Storage step of associating and storing the unique identification value of the cell to which the cell is connected and the cell's accessible RAT information, and limiting the cell search for the RAT not belonging to the cell's accessible RAT information and belonging to the cell's accessible RAT information. Comprising a cell search for performing a cell search for the RAT to configure a power saving method of a multi-mode mobile communication terminal. Therefore, since the current consumption required for searching for an unnecessary wireless access technology cell is reduced in a region supporting only a single mode, there is an advantage of providing a longer standby time with a single charge.

Mobile Phone, Waiting Time, Kids, Search, Rescan

Description

How to save power in multi-mode mobile terminal {METHOD OF POWER-SAVING IN MULTI-MODE MOBILE TELEPHONE}

The present invention relates to a method of operating a multi-mode mobile communication terminal and a mobile communication terminal using the same. More particularly, a wireless access technology (RAT: Radio) in a mobile communication terminal supporting both second and third generation mobile communication systems. The present invention relates to a power saving method that can reduce power consumption that may occur due to cell search for selecting access technology.

In the case of 3G mobile communication systems (e.g., WCDMA), it is a standard that is adopted in a wider range of countries and regions than the previous generation, so it supports global roaming and makes video calls using large transmission rates. It is possible to make it possible. However, even when such a third generation mobile communication system is adopted, it is difficult to replace all the systems with a new third generation mobile communication system as soon as possible due to the cost and the time required for securing and installing the equipment.

In order to improve the interests and investment of the operator, the existing mobile communication system may be maintained for a long time if it coexists with the existing second generation mobile communication system for a certain period of time or users do not feel great inconvenience. will be.

Therefore, even if a third generation mobile communication system is introduced, since the second and third generation mobile communication systems will coexist for a considerable period of time, the mobile communication terminal also has various radio access technologies (RATs) and various frequency bands. Multi-mode (MM: multi-mode) or multi-band (MB: multi-mode) mobile communication terminals have been provided to support this.

For example, among the 3G mobile communication systems, UMTS, which is a European-led asynchronous method, WCDMA radio access technology representing UMTS, and GSM technology, asynchronous second generation wireless access technology representing Europe, coexist. Can be mentioned.

When power is supplied to the mobile communication terminal, a method for selecting an available Public Land Mobile Network (PLMN) may be divided into an automatic mode and a manual mode (see 3GPP TS 23.122). ). The automatic mode means to automatically select a PLMN determined to be optimal among the PLMNs that can be selected according to an arbitrarily set criterion. On the other hand, manual mode means presenting a list of PLMNs that can be selected once and allowing the user to directly select the desired PLMN. In most cases, the automatic mode operation is preferred for the convenience of the user. When the PLMN is selected, cell searching of the RAT associated with the selected PLMN is performed.

At this time, in the automatic mode, a cell search is performed periodically to check whether another PLMN is available or RAT is available within the selected PLMN. Particularly, in the case of a multi-mode mobile communication terminal supporting WCDMA and GSM at the same time, the GSM cell search is periodically performed at idle time even when operating in the WCDMA mode. It is an operation to automatically select an optimal RAT (mainly, a low-cost RAT or a high-speed RAT automatic selection) in terms of benefits for both users and operators. For example, the transition from WCDMA to GSM may be needed for coverage expansion, and the transition from GSM to WCDMA may be required to complement each other for increased capacity.

Table 1 below is a diagram for explaining a GSM cell search period that is periodically performed in the state of being connected to WCDMA when the multi-mode mobile communication terminal supporting WCDMA and GSM simultaneously operates in the automatic mode.

Table 1

DRX Cycle Length N _serv
(Number of DRX cycles) T _{measure FDD} [S]
(Number of DRX cycles) T _evaluateFDD [S]
(Number of DRX cycles) T _measureGSM [S]
(Number of DRX cycles) 0.08 4 0.64 (8) 2.56 (32) 2.56 (32) 0.16 4 0.64 (4) 2.56 (16) 2.56 (16) 0.32 4 1.28 (4) 5.12 (16) 5.12 (16) 0.64 4 1.28 (2) 5.12 (8) 5.12 (8) 1.28 2 1.28 (1) 6.4 (5) 6.4 (5) 2.56 2 2.56 (1) 7.68 (3) 7.68 (3) 5.12 One 5.12 (1) 10.24 (2) 10.24 (2)

The standard document TS 25.133 of 3GPP defines such a periodic GSM cell search period. For example, in case of DRX64 (Discontinuous Reception), the GSM cell search is performed every 5.12 seconds. When using WCDMA RAT only in manual mode, a current consumption period of about 20 ms occurs every 640 ms.However, when the GSM cell search is repeated every 5.12 seconds in WCDMA mode in auto mode, a current of about 40 ms every 5.12 seconds is set. The consumption period is further generated. This means that the current consumption period is increased by about 20-25% (at 160ms period current consumption per 5.12 seconds, 200ms period current consumption per 5.12 seconds) in the standby state, which means that the standby time is reduced by about 20-25%.

That is, if the current consumption of the WCDMA dedicated mobile communication terminal is only 3.8mA / h in the region where only WCDMA exists (especially in the region where GSM RAT is not supported, such as Korea), the mobile communication terminal supporting WCDMA and GSM together When operating in the automatic mode, the current consumption reaches 4.8mA / H. At this time, if the one-time charging capacity of the battery mounted in the mobile communication terminal is 1100mAH, when the conversion to the standby time has a difference of about 60 hours. Although the capacity of secondary batteries installed in mobile communication terminals has been continuously increasing, and the usage time per charge has been increased due to lower power consumption of components used in mobile communication terminals, it has been consumed by high functionality including multimedia functions. The amount of power is also increasing. Since there is a certain limit to increasing the capacity of the secondary battery, it is urgently needed to increase the time available for one-time charging by minimizing unnecessary current consumption.

An object of the present invention for solving the above problems is to improve the cell search in the mobile communication terminal supporting a multi-mode to reduce the amount of current consumed by repeated unnecessary cell search It is to provide a current saving method.

One embodiment of the present invention for achieving the above object is a multi-mode mobile communication terminal cell search method that can be connected to at least two radio access technology (RAT),

RAT information receiving step of downloading RAT information accessible from a cell connected by a mobile communication terminal from a mobile communication network; RAT information storing the unique identification value of a cell connected by the mobile communication terminal and the accessible RAT information of the cell in association. Power of a multi-mode mobile communication terminal including a storing step and a cell searching step of limiting cell searching for RATs not belonging to the accessible RAT information of the cell and performing cell searching for RATs belonging to the accessible RAT information of the cell Provides savings.

Here, at least two radio access technologies to which the multi-mode mobile communication terminal can access may include wideband code division multiple access (WCDMA) and global system for mobile telecommunication (GSM).

In this case, a cell ID may be used as a unique identification value of a cell currently accessed by the mobile communication terminal.

Here, the unique identification value of the cell connected to the mobile communication terminal and the accessible RAT information of the cell may be stored in a nonvolatile memory installed in the mobile communication terminal. In this case, the nonvolatile memory may be a nonvolatile memory in a user identification module (SIM) card.

Another embodiment of the present invention for achieving the above object is a multi-mode mobile communication terminal having a database that can be connected to at least two radio access technology (RAT), and has a database stored by associating the RAT information accessible by region and region In the cell search method, the RAT information acquisition step of reading the RAT information accessible from the database in the region where the mobile communication terminal is currently located, and limiting the cell search for the RAT not belonging to the accessible RAT information of the cell; Provided is a power saving method of a multi-mode mobile communication terminal including a cell search step of performing a cell search for a RAT belonging to a cell's accessible RAT information.

Here, at least two radio access technologies to which the multi-mode mobile communication terminal can access may include wideband code division multiple access (WCDMA) and global system for mobile telecommunication (GSM).

Here, the database may be updated via over the air (OTA).

Here, the database may be stored in a nonvolatile memory mounted in the mobile communication terminal, where the nonvolatile memory may be a nonvolatile memory in a user identification module (SIM) card.

The RAT information accessible by the region and the region stored by the database may be configured to associate and store the RAT information provided by the PLMN and the PLMN accessible by the mobile communication terminal.

When using the power saving method of the multi-mode mobile communication terminal according to the present invention as described above, it is possible to reduce the current consumption required for searching for unnecessary wireless access technology cells in a region that supports only a single mode. The advantage is that time can be provided.

In particular, in the case of a multi-mode mobile communication terminal which simultaneously supports the third generation mobile communication WCDMA system and the second generation mobile communication GSM system, unnecessary GSM cells are required in an area such as Korea that does not support the second generation mobile communication network. By preventing the search, the battery consumption is reduced and the use time is extended.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating an embodiment of a power saving method of a multi-mode mobile communication terminal according to the present invention.

Referring to FIG. 1, an embodiment of a power saving method of a multi-mode mobile communication terminal according to the present invention includes a RAT information receiving step S110, a RAT information storing step S120, and a cell searching step S130. Can be configured. In the flowchart illustrated in FIG. 1, the essential steps in the power saving method of the multi-mode mobile communication terminal according to the present invention are shown in solid lines, and the procedures necessary to explain the present invention as a procedure defined by technical standards are indicated by dotted lines. It is to be noted that is shown. In addition, the procedures shown in dashed lines are not limited to those in which the procedure is illustrated and may be modified.

A multi-mode mobile communication terminal is defined as a mobile communication terminal that supports at least two radio access technologies (RATs). Examples of the wireless access technology include second and third generations, such as wide-band code-division multiple access (WCDMA) technology, global system for mobile telecommunication (GSM), and code division multiple access (CDMA) technology. Covers mobile communication technologies.

When power is supplied to the mobile communication terminal and powered on (S101), the mobile communication terminal attempts to connect to a public land mobile network (PLMN). The mobile communication network to be connected is selected by the automatic mode or the manual mode as described above in the prior art.

The mobile communication terminal starts a process of searching for a suitable cell in the selected PLMN, and when a cell capable of providing a service is selected (this process is referred to as camping on the 'Camping on the cell'; S102), the system information is obtained. Tuned to the control channel to receive.

The RAT information receiving step S110 is a step of downloading RAT information accessible from a cell to which a mobile communication terminal is connected from a mobile communication network.

In this case, the RAT information may be encoded into a predetermined bit string located in the above-described system information. For example, when a predetermined bit is '1' by allocating one bit to a supportable RAT, the corresponding RAT may be supported. In case of '0', it may be specified to specify that the RAT is not supported. Alternatively, a message indicating whether to support each RAT may be defined to identify a type of a received message to identify an RAT that can be supported or not supported.

The RAT information storage step (S120) is a step of storing the unique identification value of the cell to which the mobile communication terminal is connected in association with the accessible RAT information of the cell.

A cell ID may be used as a unique identification value of a cell to which a mobile communication terminal accesses. Therefore, in the step of storing the RAT information (S120), the ID of the cell to which the mobile communication terminal is connected is stored in association with the accessible RAT information of the cell downloaded in the step of receiving the RAT information (S110).

In this case, a non-volatile memory mounted in the mobile communication terminal may be used as a location where the unique identification value of the cell and the accessible RAT information of the cell are stored. In addition, the nonvolatile memory may be a nonvolatile memory provided in a subscriber identity module (SIM) card installed in a mobile communication terminal. The user identification module (SIM) may include a universal subscriber identity module (USIM) used in conventional SIM cards and third generation mobile communication terminals.

After the RAT information storage step S120, the location registration step S121 may be performed. Location registration may be performed by a GPRS attach or IMSI attach procedure. It is determined whether the location registration has been successfully performed (S122). If the registration has been successfully performed, the process proceeds to the cell search step (S130) to be described below. If not, the exception processing (S123) is performed.

Meanwhile, the mobile communication terminal is configured to continuously search for a more suitable cell in idle time and to reselect a cell if necessary. As described above in the prior art, in the case of DRX64, cell searching is performed for every 20 ms for every 640 ms. In addition, according to the WCDMA standard, it takes 60ms for the GSM cell search every 5.12 seconds to support the multi-mode with GSM.

The cell search step (S130) defines this process and is characterized by using the accessible RAT information of the cell stored in the RAT information storage step (S120).

That is, the cell search for the RAT designated as not supported in the accessible RAT information of the cell is limited, and the cell search for the RAT designated as supported in the accessible RAT information of the cell is performed. For example, in the case of a multi-mode mobile communication terminal supporting WCDMA and GSM at the same time, GSM cell discovery is restricted and only WCDMA cell discovery procedure is performed in a region where GSM is not supported.

In this way, for example, it is possible to save the amount of current consumed for meaningless GSM cell search in a single mode region where GSM is not supported and only WCDMA is supported. Therefore, in terms of standby time alone, when a rechargeable battery of 1100 mAH is used, an increase in standby time of about 60 hours can be brought about. For example, in the case of DRX64, a current consumption time of about 200 ms per 5.12 seconds is reduced to about 160 ms, and when the peak value of the current is the same, the standby time of about 20 to 25% can be increased.

When a more suitable cell is re-discovered in the cell searching step S130, camping-on to a new cell is performed again, and the processes below the RAT information receiving step S110 are repeatedly performed.

2 is a flowchart illustrating another embodiment of a power saving method of a multi-mode mobile communication terminal according to the present invention.

Referring to FIG. 2, another embodiment of the power saving method of the multi-mode mobile communication terminal according to the present invention may include a RAT information acquisition step S210 and a cell search step S220. In the flowchart illustrated in FIG. 2, the essential steps in the power saving method of the multi-mode mobile communication terminal according to the present invention are shown in solid lines, and the procedures necessary to describe the present invention as a procedure defined by technical standards are indicated by dotted lines. It is to be noted that is shown.

Unlike the exemplary embodiment of the present invention described with reference to FIG. 1, the multi-mode mobile communication terminal described with reference to FIG. 2 has a difference in that a database in which the RAT information accessible by region is associated with and stored in advance is provided. Here, the RAT information accessible by region and region may be used by the PLMN to which the corresponding mobile communication terminal is accessible and the RAT information that can be supported by each PLMN. The database may be updated periodically or aperiodically using an Over The Air (OTA) message.

In this case, the database may be stored in a non-volatile memory mounted in the mobile communication terminal. In addition, the nonvolatile memory may be a nonvolatile memory provided in a subscriber identity module (SIM) card installed in a mobile communication terminal. The user identification module (SIM) may include a Universal Subscriber Identity Module (USIM) used in conventional SIM cards and third generation mobile communication terminals.

Since the step S201 and the camping-on step S202 where the mobile communication terminal is powered on are the same processes as the power-on step S101 and the camping-on step S102 illustrated in FIG. 1, description thereof is omitted.

RAT information acquisition step (S210) is a step of reading from the database the RAT information that can be accessed in the area where the mobile communication terminal is currently located. As a method for identifying an area where the mobile communication terminal is currently located, a method using cell positioning or GPS information may be used to determine the current area. If the current location is identified, accessible RAT information corresponding to the current location may be read from the database.

Alternatively, the database may be a database stored in association with a PLMN accessible by the mobile communication terminal and a RAT available in the PLMN. In this case, the mobile communication terminal may read a PLMN and an RAT provided by the PLMN from the database. Can be. At this time, the database can be searched with the currently selected PLMN to obtain supportable RAT information.

The location registration step (S211), the step of determining the location registration success (S212) and the exception processing step (S213) of the mobile communication terminal are the steps (S121), step (S122) and step (S123) illustrated in FIG. The description is omitted because it is an equivalent process.

Cell search step (S220) is characterized in that using the accessible RAT information read from the database in the RAT information acquisition step (S210).

That is, the cell search for the RAT designated as not supported in the accessible RAT information is limited, and the cell search for the RAT designated as supported in the accessible RAT information of the cell is performed. For example, in the case of a multi-mode mobile communication terminal supporting WCDMA and GSM at the same time, GSM cell discovery is restricted and only WCDMA cell discovery procedure is performed in a region where GSM is not supported.

In this way, for example, it becomes possible to save the amount of current consumed for meaningless GSM cell search in a single mode region where GSM is not supported and only WCDMA is supported, according to one embodiment of the invention described in FIG. Same as the case, detailed description is omitted.

When a more suitable cell is re-discovered in the cell searching step S220, camping-on to a new cell is performed again and the process following the RAT information obtaining step S210 is repeatedly performed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

1 is a flowchart illustrating an embodiment of a power saving method of a multi-mode mobile communication terminal according to the present invention.

2 is a flowchart illustrating another embodiment of a power saving method of a multi-mode mobile communication terminal according to the present invention.

Claims (11)

In the power saving method of a multi-mode mobile communication terminal that can be connected to at least two radio access technologies (RAT), A RAT information receiving step of downloading RAT information accessible from a cell connected to a mobile communication terminal from a mobile communication network; A RAT information storing step of associating and storing a unique identification value of a cell to which the mobile communication terminal is connected and accessible RAT information of the cell; And A multi-mode mobile communication including a cell search step of limiting cell search for a RAT designated as unsupportable based on the accessible RAT information of the cell and performing a cell search for a RAT belonging to the accessible RAT information of the cell; How to save power in the terminal. 2. The method of claim 1, wherein the at least two radio access technologies to which the multimode mobile communication terminal is connected include wideband code division multiple access (WCDMA) and Global System for Mobile Telecommunication (GSM). How to save power in the terminal. The method of claim 1, The unique identification value of the cell currently connected to the mobile communication terminal is a cell ID (cell ID) power saving method of the multi-mode mobile communication terminal, characterized in that. The method of claim 1, The unique identification value of the cell connected to the mobile communication terminal and the accessible RAT information of the cell is stored in a non-volatile memory mounted on the mobile communication terminal, the power saving method of the multi-mode mobile communication terminal. The method of claim 1, The RAT information is allocated to a plurality of RATs by one bit, and when the predetermined bit is '1', the RAT can be supported. If the bit is '0', the RAT information is designated as a predetermined bit string to specify that the corresponding RAT is not supported. Power saving method of a multi-mode mobile communication terminal, characterized in that the encoding. In the power saving method of a multi-mode mobile communication terminal having at least two radio access technology (RAT), and having a database stored in association with the RAT information accessible by region and region, Acquiring RAT information from the database to read RAT information accessible in the region where the mobile communication terminal is currently located; And A cell search step of limiting cell search for a RAT designated as unsupportable based on accessible RAT information of a cell to which the mobile communication terminal is connected and performing a cell search for a RAT belonging to the accessible RAT information of the cell; Power saving method of a multi-mode mobile communication terminal including a. 7. The method of claim 6, wherein the at least two radio access technologies to which the multi-mode mobile communication terminal is connected include multi-mode mobile communication (WCDMA) and Global System for Mobile Telecommunication (GSM). How to save power in the terminal. 7. The method of claim 6, wherein the database is updated through over the air (OTA). The method of claim 6, And the database is stored in a nonvolatile memory installed in the mobile communication terminal. The method of claim 6, The RAT information is allocated to a plurality of RATs by one bit, and when the predetermined bit is '1', the RAT can be supported. If the bit is '0', the RAT information is designated as a predetermined bit string to specify that the corresponding RAT is not supported. Power saving method of a multi-mode mobile communication terminal, characterized in that the encoding. The method of claim 6, The area and the RAT information accessible by the region stored in the database is stored by associating the RLM information provided by the PLMN and the PLMN to which the mobile communication terminal is connected, the power saving method of a multi-mode mobile communication terminal.

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