KR20080091636A - Method for searching adaptively the frequency band in the mobile phone mounting the multi-rat(radio access technology) - Google Patents

Abstract

A method for searching adaptively the frequency band in a mobile phone mounting the multi-RAT(Radio Access Technology) is provided to intercept the unnecessary frequency search by means of the system information received from a mobile communication system. A mobile terminal(110) applies plural radio access technologies having WCDMA(Wideband Code Division Multiple Access) as the third generation communication type and GSM(Global System for Mobile communication) as the second generation communication type. A base station(120) is constructed by plural cells. The mobile terminal receives a pilot signal and obtains the reference phase information of all common channel transmitted from the corresponding cell. The mobile terminal decodes the broadcasting channel by means of the obtained reference phase information. The WCDMA includes the MIB(Master Information Block) and SB(Scheduling Block) to the system information in order to offer the scheduling information of the SIB(System Information Block). The mobile terminal compares whether the MCC(Mobile Country Code) included in the MIB is the same as the predetermined mobile country code. When the MCC is the same as the predetermined mobile country code, the mobile terminal intercepts the search of the frequency band corresponding to the predetermined wireless connection technology.

Description

Method for Searching Adaptively the Frequency Band in the Mobile Phone Mounting the Multi-RAT (Radio Access Technology)}

1 is a block diagram of a mobile communication network according to an embodiment of the present invention.

2 is an internal block diagram of a mobile terminal according to an embodiment of the present invention;

3 is a flowchart illustrating an adaptive frequency searching method in a mobile terminal according to an embodiment of the present invention.

4 is a table structure for storing frequency search order information according to an embodiment of the present invention.

* Key Drawing

220: radio frequency transceiver

230: baseband processing unit

240: control unit

250: storage unit

460: Frequency search cutoff identification field

The present invention relates to a frequency searching method in a mobile terminal. More particularly, the present invention relates to a method for adaptively using system information received from a base station in a mobile terminal equipped with a plurality of radio access technologies (RATs). The present invention relates to an adaptive frequency search method in a mobile terminal that saves initial cell search time by searching for a frequency.

Recent mobile operators are beginning to the 3GPP (3 ^rd Generation Partnership Project) (Universal Mobile Telecommunication System) using the WCDMA UMTS radio access scheme adopted by the standardization forum service as a third-generation mobile communication technologies.

In general, the third generation mobile communication technology is oriented toward a global roaming service that can be provided through a single mobile terminal anywhere in the world.

To this end, recently released third generation mobile terminals are launching combined terminals equipped with not only the third generation wireless access technology but also the second generation wireless access technology.

For example, in Korea, a multi-band dual mode (DBDM) terminal supporting both asynchronous technology (Wideband Code Division Multiple Access) and a synchronous technology (CDMA) are introduced.

In addition, mobile terminal manufacturers and mobile carriers are competitively launching mobile terminals that simultaneously support GSM, a third-generation communication method, and WCDMA, the third-generation communication method, with the commercialization of WCDMA service. to be.

However, in a domestic mobile communication environment in which there is no GSM network, when a mobile terminal initially searches for a cell, there is a problem of searching up to a frequency band corresponding to the GSM network.

As a result, in the related art, since the mobile terminal can search for an unnecessary frequency band, the initial cell search time can be lengthened and the battery consumption of the mobile terminal is increased.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art as described above, an object of the present invention is to provide a mobile terminal capable of adaptive frequency searching to selectively attempt frequency searching in accordance with changes in the mobile communication environment.

Another object of the present invention is to block unnecessary frequency searching using system information received from a mobile communication system.

Another object of the present invention is to prevent the mobile terminal from searching for unnecessary frequencies by only changing the software in the mobile terminal without changing the standard and the existing mobile communication system.

In addition, an object of the present invention is to minimize battery consumption by preventing the mobile terminal from searching for unnecessary frequencies.

Other objects of the present invention will be readily understood through the following description of the embodiments.

In order to achieve the above object, according to an aspect of the present invention, a method for adaptively searching for frequencies in a mobile terminal is disclosed.

According to an embodiment of the present invention, a method for adaptively searching a frequency in a mobile terminal may include: (a) searching for a cell according to a predefined frequency search order; (b) decoding system broadcast channels received from the found cells to obtain system information; (c) comparing a first mobile country code obtained from the system information with a second mobile country code preset in the mobile terminal; And (d) if the comparison result is the same, blocking the frequency search corresponding to the preset wireless access technology and transitioning to the idle state, wherein the mobile terminal supports a plurality of wireless access technologies.

According to another aspect of the present invention, a mobile terminal capable of adaptive frequency searching is disclosed.

According to an aspect of the present invention, there is provided a mobile terminal comprising: a storage unit which maintains information on frequency band information and frequency search order in a wireless access technology; A radio frequency processor for transmitting and receiving radio frequency signals for a predetermined frequency band; A baseband processor for searching for a cell by processing a radio frequency signal received from the radio frequency processor and obtaining system information from the found cell; And a control unit for controlling the frequency search by using the mobile country code and the neighbor radio access technology list information included in the system information.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same components have the same number as much as possible even if displayed on different drawings.

Hereinafter, a preferred embodiment of an adaptive frequency searching method in a mobile terminal equipped with a plurality of radio access technologies according to the present invention will be described in detail with reference to the drawings.

1 is a block diagram of a mobile communication network according to an embodiment of the present invention.

As shown in FIG. 1, a mobile communication network according to the present invention may include a mobile terminal 110, a base station 120, a wireless network controller 130, and a mobile switching center (MSC) 140.

The mobile terminal 110 according to the present invention includes a plurality of radio access technologies including wideband code division multiple access (WCDMA), which is a third generation communication method, and global system for mobile communication (GSM), a second generation communication method. Technology).

Here, the wireless access technology may include a P-GSM method of 935 ~ 960MHz band, DCS1800 of 1805 ~ 1880MHz band, PCS1900 of 1930 ~ 1990MHz band, WCDMA method of 2110 ~ 2170MHz band according to the assigned frequency band .

Base station 120 may be composed of a plurality of cells (Cell), each cell is a pilot channel (e.g. Common Pilot Channel (CPICH) in WCDMA) and a broadcast channel (e.g. For example, a primary common control physical channel (PCCPCH) signal in WCDMA is transmitted to the entire cell.

Here, the mobile terminal 110 may receive the pilot signal and obtain reference phase information of all common channels transmitted from the corresponding cell.

Thereafter, the mobile terminal 110 may decode the broadcast channel using the obtained reference phase information. Here, the broadcast channel may include various system information for controlling the operation of the mobile terminal 110.

For example, WCDMA is a plurality of system information blocks (hereinafter, referred to as 'SIBs'), which are scheduled according to the characteristics and purposes of the system information, where each SIB is composed of system information of similar attributes. Transmit-by mapping to PCCPCH.

For example, dynamic system information elements that are variable over time may be included in a different SIB than static system information elements that rarely change in the system.

In addition, the WCDMA is referred to as a master information block (hereinafter referred to as 'MIB (Master Information Block)') and scheduling block (hereinafter referred to as 'SB (Scheduling Block)') to provide scheduling information of the SIB to the mobile terminal 110. ) May be included in the system information.

Here, the MIB may include a scheduling field of a plurality of system information blocks in a cell and a reference field for indicating the presence or absence of a specific SIB.

In addition, the MIB may include scheduling information and reference fields corresponding to one or two SBs that provide scheduling information and reference fields for all additional SIBs.

That is, the mobile terminal 110 may first obtain scheduling information of system information received through the MIB and the SB, and obtain at least one SIB using the obtained scheduling information.

Of course, before the mobile terminal 110 acquires the system information, by using a synchronization channel transmitted in a partial section of the PCCPCH, slot synchronization and frame synchronization of the corresponding cell are acquired. It is apparent to those skilled in the art that a primary scrambling code (PSC) corresponding to a corresponding cell should be obtained.

According to an exemplary embodiment of the present invention, the mobile terminal 110 includes a mobile country code (MCC: Mobile) included in a Public Land Mobile Network (PLMN) identifier (hereinafter, referred to as 'PLMN_ID') included in the MIB. The Country Code (hereinafter referred to as 'MCC1') is compared with the preset mobile country code (hereinafter referred to as 'MCC2').

If the comparison result is the same, the mobile terminal 110 may block the search for the frequency band corresponding to the predefined wireless access technology.

According to another preferred embodiment of the present invention, when the MCC1 and the MCC2 are the same, the mobile terminal 110 is not included in the neighboring RAT list included in the SIB (eg, SIB3). It is possible to block the search for the frequency band corresponding to the access technology.

Here, the neighbor radio access technology list is a list of radio access technologies corresponding to the radio network superimposed on the area to which the cell receiving the system information belongs.

When the mobile terminal 110 no longer receives the service from the currently connected wireless network, the mobile terminal 110 may attempt to access a wireless network belonging to the neighboring wireless access technology list.

That is, the mobile terminal 100 may perform handover between different radio access technologies.

If the GSM method is not included in the neighbor radio access technology list, the mobile terminal 110 according to an exemplary embodiment of the present invention may not search for a frequency band corresponding to GSM.

The radio network controller 130 may control at least one base station 120 and change system information to be transmitted in a corresponding cell by using a system information update message.

For example, if a network using a new radio access technology (eg, including WCDMA service) is added to an area providing a GSM service, the radio network controller 130 may be configured for the added radio access technology. The information may be transmitted to the base station 120 using the system information update message.

The base station 120 may schedule the system information included in the received system information update message, and then map and transmit the system information to the PCCPCH.

In general, when the initial power is turned on, the mobile terminal 110 equipped with a plurality of radio access technologies searches for accessible cells according to a frequency search order for each radio access technology.

For example, if the frequency search order is set to search the WCDMA frequency band first, and then search the GSM frequency band, the mobile terminal 110 first measures the strength of the signal received through the WCDMA downlink frequency band.

If the strength of the received signal satisfies a predetermined threshold, the mobile terminal 110 performs an initial cell search procedure.

Here, the initial cell search procedure may include obtaining phase information from the CPICH, acquiring slot and frame synchronization, and primary scrambling code (PSC) -wherein, the PSC is code information for identifying a cell and includes a mobile terminal 110. May include acquiring the cell may be distinguished using the obtained PSC information.

The mobile terminal 110 can obtain system information by decoding the PCCPCH using the obtained PSC.

The exchange 140 may not only perform general call processing and mobility management functions but also provide system information related to the core network to the wireless network controller 130.

2 is an internal block diagram of a mobile terminal according to an embodiment of the present invention.

As shown in FIG. 2, the mobile terminal 110 according to the present invention includes a transceiver antenna 210, a radio frequency transmitter / receiver 220, a baseband processor 230, a controller 240, a storage 250 and Peripheral device 260 may be included.

In the following description, a physical channel and a transmission channel according to the WCDMA standard are described as an example to help the understanding of the present invention.

The RF transmitter / receiver 220 (hereinafter, referred to as a “radio frequency (RF) transmitter / receiver”) according to the present invention downwards an RF signal received in a preset frequency band according to a control signal of the controller 240 to a baseband signal. The conversion is transmitted to the baseband processor 230.

In addition, the RF transmitter / receiver 220 may up-convert the baseband signal processed by the baseband processor 230 to a preset frequency band and transmit it to the transmit / receive antenna 210.

In particular, the RF transmitter / receiver 220 according to the present invention may set a frequency band corresponding to at least one radio access technology according to a control signal of the controller 240.

For example, the baseband processor 230 transmits and receives signals in frequency bands allocated to various radio access technologies including WCDMA, GSM, PCS, DCS, and wireless Internet (including Wibro and Wimax). Can be processed.

The baseband processor 230 may generate binary data by decoding the baseband signal received from the RF transmitter / receiver 220 using a preset wireless access technology according to a control signal of the controller 240. Can be. Here, the generated binary data may be converted into a predetermined format corresponding to the corresponding radio access technology and transmitted to the controller 240.

For example, the baseband processor 230 according to an embodiment of the present invention may obtain reference phase information by decoding a pilot signal received from a specific cell.

In addition, the baseband processor 230 adjusts the phase with the corresponding cell by using the obtained reference phase information, and the synchronization channel (for example, in the WCDMA scheme, the base station 120 transmits the synchronization channel and the broadcast channel to the PCCPCH). Time multiplexing and broadcasting to a corresponding cell) to obtain slot and frame synchronization with the corresponding cell.

Thereafter, the baseband processor 230 may acquire PSC information scrambled in the pilot channel of the corresponding cell.

In particular, the baseband processor 230 acquires system information included in a broadcast channel (eg, including PCCPCH in WCDMA) using the obtained PSC information, and then acquires the system information acquired in the controller 240. Can transmit

According to another embodiment of the present invention, the baseband processor 230 may store the obtained system information in a predefined area of the storage 250.

The controller 240 may control the baseband processor 230 and the RF transmitter / receiver 220 using frequency band information and frequency band search order information for each wireless access technology stored in the storage 250.

For example, when the radio access technology method having the highest frequency search order is GSM and the frequency band allocated to GSM is 935 to 960 MHz, the controller 240 changes the radio access technology method of the baseband processor 230 to the GSM mode. The predetermined control signal to be set can be transmitted to the baseband processor 230.

In addition, the controller 240 may transmit a predetermined control signal to the RF transmitter / receiver 220 to set the transmission / reception radio frequency band to 935 to 960 MHz.

The controller 240 according to an exemplary embodiment of the present invention may block the search for the frequency band corresponding to the radio access technology that does not need to be searched using the system information obtained by the baseband processor 230.

If, in the domestic network, WCDMA provides the national network service, and the GSM network does not exist, the control unit 240 is a value corresponding to the domestic network of the mobile country code included in the system information (for example, domestic network) If the corresponding mobile country code may be 450), the frequency band search corresponding to the GSM network may be blocked.

To this end, the mobile terminal 110 according to the present invention should maintain a mobile country code value corresponding to the domestic network in a predetermined recording area.

Here, the mobile country code included in the system information is included in the PLMN_ID field of the master information block (MIB) defined in the 3GPP standard.

The PLMN_ID consists of a mobile country code (MCC) and a mobile network code (MNC) for distinguishing a mobile carrier.

The control unit 240 according to another embodiment of the present invention may not search for a frequency band corresponding to a radio access technology that is not included in the neighbor radio access technology list included in the system information.

If the mobile country code included in the system information is different from the mobile country code preset in the mobile terminal 110, the controller 240 may use a frequency band according to a frequency search order for each radio access technology stored in the storage 250. You can explore

The peripheral device 260 may include a device such as a liquid crystal display, a keypad, a microphone, a battery, and the like.

3 is a flowchart illustrating an adaptive frequency searching method in a mobile terminal according to an embodiment of the present invention.

Referring to FIG. 3, when the power of the mobile terminal 110 is turned on (S310), the mobile terminal 100 may obtain terminal setting state information from a predetermined recording area (S320).

Here, the terminal setting state information indicates information on a radio access technology to be searched first, and the mobile terminal 110 may perform frequency searching for each radio access technology according to frequency search order information corresponding to the terminal setting state information. .

For example, the terminal configuration state information may include at least one of WCDMA preferences, GSM preferences, and CDMA preferences, each terminal configuration state information is a predefined value (for example, WCDMA preferences '0', GSM The preference may be defined as '1' and the CDMA preference may be defined as '2'.

In addition, the terminal setting state information may be a value set to be fixed so as not to be changed by the terminal user.

It should be noted that the terminal setting state information according to another embodiment of the present invention may be a value that can be changed through a predetermined user interface.

The mobile terminal 110 may perform an initial cell search procedure according to a frequency search order defined according to the terminal setting state information (S330). The mobile terminal 110 decodes a broadcast channel received from the found cell. Information may be obtained (S340).

The acquired system information may include MCC1 included in the MIB and neighbor radio access technology list information included in a specific SIB (for example, may be SIB3).

The mobile terminal 110 compares whether the MCC1 is equal to the MCC2 preset in the mobile terminal 110 (S350).

As a result of the comparison, if the same, the mobile terminal 110 blocks the frequency search for the radio access technology that is not included in the information in the neighbor radio access technology list (S360) and then transitions to the idle state (S370).

In step 350, when the MCC1 is not the same as the MCC2, the mobile terminal 110 transitions to a dormant state.

Here, the idle state according to the present invention will be defined as a state waiting for a request for a specific service after completing the initial cell search.

4 is a table structure for storing frequency search order information according to an embodiment of the present invention.

As shown in FIG. 4, the frequency search order for each terminal configuration state includes a search order index field 410, a minimum frequency field 420, a maximum frequency field 430, a total frequency allocation number field 440, and a wireless access technology. Field 450 and frequency search blocking identification field 460.

The mobile terminal 110 according to an embodiment of the present invention may refer to frequency search order information corresponding to the terminal setting state information.

The search order index field 410 is a field for indicating the order in which the mobile terminal 110 searches for a frequency band according to the terminal setting state information.

Referring to FIG. 4, when the terminal configuration state is WCDMA preference, the mobile terminal 110 may search for a corresponding frequency band in the order of WCDMA, GSM, DCS1800, and PCS1900 during initial cell search.

The minimum frequency field 420 and the maximum frequency field 430 mean minimum and maximum values of frequency bands allocated to the corresponding radio access technology.

The total frequency allocation number field 440 is a value obtained by dividing the frequency band allocated to the radio access technology by the minimum service frequency band.

For example, according to the 3GPP standard, WCDMA radio access technology can provide services using at least 5 MHz band. That is, when the total frequency band allocated to WCDMA is 60 MHz, the total number of frequency allocations may be 12.

In general, when the mobile terminal 110 initially searches for a cell or performs a hard handover, the mobile terminal 110 may process a signal in units of frequency allocation (hereinafter, referred to as 'Frequency Allocation').

For example, if the frequency band allocated by the government for the WCDMA service is 20 MHz, the mobile operator may manage frequencies allocated to four FAs (eg, 1FA, 2FA, 3FA, 4FA) having a 5 MHz band. Can be.

Here, the hard handover may be performed when the mobile terminal 110 moves to a border area of the FA or moves to an area where different radio access technologies overlap.

The radio access technology field 450 is a field for identifying the type of radio access technology using the corresponding frequency band.

Referring to FIG. 2, the controller 110 according to an embodiment of the present invention refers to a mode of the baseband processor 230 with reference to a radio access technology field 450 value, where the mode is a WCDMA mode, a GSM mode, and a CDMA mode. May include a mode.

As shown in Fig. 4, the radio access technology according to the present invention is WCDMA. GSM. DCS1800 and PCS1900.

The frequency search cutoff identification field 460 is an identifier indicating whether the search for the frequency band corresponding to the corresponding radio access technology is blocked.

For example, when the value stored in the frequency search blocking identification field 460 is 'ON', this may mean that the frequency search for the corresponding radio access technology is valid.

On the other hand, when the value stored in the frequency search blocking identification field 460 is 'OFF', it may mean that the frequency search for the corresponding radio access technology is blocked.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, the present invention adds a function for recognizing a current mobile communication environment to a mobile terminal by using mobile country code information included in system information received from a base station, thereby searching for a frequency corresponding to an unnecessary wireless access method. It has the advantage of blocking.

In addition, since the present invention blocks unnecessary frequency search using only system information received from the mobile communication system, there is an advantage that the mobile communication system does not need to be changed.

Another object of the present invention is to prevent the mobile terminal from searching for unnecessary frequencies by only changing the software in the mobile terminal without changing the standard and the existing mobile communication system.

In addition, the present invention has the effect of minimizing battery consumption by blocking the mobile terminal from searching for unnecessary frequencies.

In addition, the present invention can exclude the radio access technology that does not require frequency searching from the search target, thereby reducing the initial cell search time.

Other objects of the present invention will be readily understood through the following description of the embodiments.

Claims (11)

In the method for searching a frequency in a mobile terminal, (a) searching for a cell according to a predefined frequency search order; (b) decoding system broadcast channels received from the found cells to obtain system information; (c) comparing a first mobile country code obtained from the system information with a second mobile country code preset in the mobile terminal; And (d) blocking the frequency search corresponding to the preset radio access technology and transitioning to the idle state if the comparison result is the same; Wherein the mobile terminal supports a plurality of radio access technologies. The method of claim 1, In the step (c), And if the first mobile country code and the second mobile country code are different from each other, performing steps (a) to (b) and transitioning to a dormant state. The method of claim 1, The system information includes a master information block (MIB), And wherein the first mobile country code is obtained from a public land mobile network identity included in the master information block (MIB). The method of claim 3, And wherein the public terrestrial mobile network identifier comprises at least one of a mobile country code and a mobile network code. The method of claim 1, The adaptive frequency searching method according to claim 1, wherein the frequency band corresponding to the blocked radio access technology is not searched when moving to the radio signal disconnection period in the dormant state. The method of claim 1, The information corresponding to the frequency search order is stored in advance in a predetermined nonvolatile recording medium. The method of claim 1, The system information includes a list of adjacent radio access technologies, The radio access technology blocked in the step (d) is a radio access technology that is not included in the neighbor radio access technology list. A storage unit which maintains information on frequency band information and frequency search order in the radio access technology; A radio frequency processor for transmitting and receiving radio frequency signals for a predetermined frequency band; A baseband processor for baseband processing the radio frequency signals received from the radio frequency processor to search for cells and to obtain system information from the found cells; And Control unit for controlling the frequency search by using the mobile country code and the neighbor radio access technology list information included in the system information A mobile terminal capable of adaptive frequency searching comprising a. The method of claim 8, The baseband processor is a mobile terminal capable of adaptive frequency search, characterized in that the baseband processing for a plurality of radio access technologies. The method of claim 8, If the mobile country code included in the system information is the same as the preset mobile country code, the controller blocks the frequency search corresponding to the radio access technology not included in the neighbor radio access technology list. Mobile terminal capable of frequency searching. The method of claim 8, And the control unit controls frequency searching according to the frequency search order when the mobile country code included in the system information is different from a preset mobile country code.

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