Abstract:
A mobile terminal has a communication unit for performing wireless communication, a plurality of modem units for performing modulation and demodulation in different communication methods, respectively, and a control unit for obtaining time information indicating a suspension of a wireless communication from a main modem unit in the plurality of modem units, for suspending the main modem unit from performing wireless communication via the communication unit, and for enabling the main modem unit to perform wireless communication via the communication unit on the basis of the time information, wherein, while the main modem unit suspending wireless communication, the control unit enables a sub modem unit in the plurality of modem units to measure a reception level via the communication unit in accordance with the obtained time information.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-254209, filed on Nov. 5, 2009, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present art relates to a mobile terminal, a method of controlling the mobile terminal, and a control apparatus. 
     BACKGROUND 
     A mobile terminal of related art includes a plurality of radio access technology (RAT) modules different from each other in wireless communication method and sharing a common antenna. Such a mobile terminal causes each RAT module (hereinafter simply referred to as RAT) to measure a reception level and assigns the antenna to a RAT providing high wireless communication quality. The RAT having the antenna assigned thereto performs wireless communications using the wireless communication method applied to the RAT. 
     The mobile terminal causes each BAT to measure a reception level as appropriate because the reception level of each RAT varies depending on a position of the mobile terminal. The RAT in operation may temporarily suspends wireless communications. During the communication suspension time band of the wireless communication active RAT, the mobile terminal causes another RAT to measure the reception level, and compares wireless communication qualities of the RATs. 
     More specifically, the mobile terminal causes the other RAT to acquire information of the communication suspension time band of the wireless communication active RAT. During the communication suspension time band of the wireless communication active RAT, the mobile terminal assigns the antenna to the other RAT, thereby causing the other RAT to measure the reception level. The mobile terminal then compares the communication qualities of the RATs. 
     Reference is made to Japanese Laid-open Patent Publication No. 2006-157546 for the above-described related art technique. 
     SUMMARY 
     According to an aspect of an embodiment, a mobile terminal has a communication unit for performing wireless communication, a plurality of modem units for performing modulation and demodulation in different communication methods, respectively, and a control unit for obtaining time information indicating a suspension of a wireless communication from a main modem unit in the plurality of modem units, for suspending the main modem unit from performing wireless communication via the communication unit, and for enabling the main modem unit to perform wireless communication via the communication unit on the basis of the time information, wherein, while the main modem unit suspending wireless communication, the control unit enables a sub modem unit in the plurality of modem units to measure a reception level via the communication unit in accordance with the obtained time information. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating a mobile terminal of a first embodiment; 
         FIG. 2  illustrates a mobile terminal of a second embodiment; 
         FIG. 3  illustrates a structure of a scheduler; 
         FIG. 4  is a sequence chart ( 1 ) illustrating a process flow of the mobile terminal of the second embodiment; 
         FIG. 5  is a sequence chart ( 2 ) illustrating a process flow of the mobile terminal of the second embodiment; 
         FIG. 6  illustrates a structure of each RAT and a scheduler according to a third embodiment; 
         FIG. 7  is a sequence chart illustrating a process flow of the mobile terminal of the third embodiment; 
         FIG. 8  illustrates a structure of each RAT and a scheduler according to a fourth embodiment; 
         FIG. 9  is a sequence chart illustrating a process flow of the mobile terminal of the fourth embodiment; 
         FIG. 10  is a diagram ( 1 ) illustrating an installation example of the scheduler; 
         FIG. 11  is a diagram ( 2 ) illustrating the installation example of the scheduler; 
         FIG. 12  illustrates a computer executing an assignment processing program; 
         FIG. 13  is a diagram ( 1 ) illustrating a related art technique; 
         FIG. 14  is a diagram ( 2 ) illustrating a related art technique; and 
         FIG. 15  is a diagram ( 3 ) illustrating a related art technique. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     As illustrated in  FIG. 13 , a method of the mobile terminal for causing the RAT to perform wireless communications is described.  FIG. 13  is a diagram ( 1 ) illustrating a related art technique. Referring to  FIG. 13 , the mobile terminal includes two RATs, one antenna, two radio frequency (RF) units that the two RATs respectively use for wireless communications, and an RF switch that assigns the antenna to one of the RATs. Each RAT includes a modem unit modulating or demodulating a radiowave signal received by the antenna, a codec unit coding or decoding information, a synchronization controller controlling synchronization between the RATs, and an interface connecting the two RATs. Each RAT performing modulation and demodulation. 
     If wireless communications are performed using a wireless communication method supported by the RAT # 1 , the mobile terminal assigns the antenna to the RF unit # 1 . The RAT # 1  performs wireless communications with a base station using the wireless communication method supported thereby. The RAT # 2 , having no antenna assigned thereto, does not performs wireless communication and waits on standby. 
     Referring to  FIG. 13 , methods of causing a standby RAT to acquire the information of the wireless communication suspension time band are described. In one method, the wireless communication active RAT notifies the standby RAT of the wireless communication suspension time band, and in another method, the standby RAT calculates the wireless communication suspension time band. In the discussion that follows, the RAT # 1  is active and the RAT # 2  is on standby. 
     The method in which the wireless communication active RAT notifies the standby RAT of the wireless communication suspension time band is described first. The active RAT # 1  notifies the standby RAT # 2  and the RF switch of the wireless communication suspension time via the interface # 1 . The RF switch assigns the antenna to the RF unit # 2  during the notified time band. The RAT # 2  then measures the reception level via the RF unit # 2  during the time band of which the RAT # 1  has notified the RAT # 2 . 
     The method in which the standby RAT calculates the time band of the wireless communication suspension is described. For example, the standby RAT # 2  has an algorithm to calculate the wireless communication suspension time band of the active RAT # 1 . The RAT # 2  calculates the wireless communication suspension time band of the RAT # 1  and notifies the RF switch of the calculated time band. The RF unit assigns the antenna to the RF unit # 2  during the notified time band. Through the RF unit # 2 , the RAT # 2  measure the reception level during the calculated time band. 
     To perform the method of notifying the standby RAT of the wireless communication suspension time band, one RAT in the mobile terminal needs an interface to communicate with each of the other RATs. This arrangement impairs independency of each RAT. When a new RAT is added, the new RAT needs an interface to each of all the existing RATs in the mobile terminal. Expandability of the mobile terminal is thus reduced. 
     The method of notifying the standby RAT of the wireless communication suspension time band impairs independency of each RAT and provides low system expandability. This problem is discussed with reference to  FIG. 14 .  FIG. 14  is a diagram ( 2 ) of the related art technique. The mobile terminal in  FIG. 14  includes n RATs. In the mobile terminal, one of the RATs # 1 -#n needs an interface to communication with each of the other RATs # 1 -#n. As a result, independency of each RAT is impaired. More specifically, impaired independency of RATs in the mobile terminal makes it difficult to develop and design the RATs separately from each other. If a new RAT #p is added to the mobile terminal, the new RAT #p needs interfaces with all the RATs # 1 -#n. Expandability of the mobile terminal is thus limited. Low expandability of the mobile terminal makes it difficult to add a new RAT. 
     In the other method in which the standby RAT calculates the wireless communication suspension time band, the mobile terminal has the algorithm to calculate the wireless communication suspension time band of each of the other RATs. Independency of each RAT is this impaired. When a new RAT is added, the mobile terminal needs an algorithm that causes the new RAT to calculate the wireless communication suspension time band of each of the other RATs. System expandability becomes low. 
     The method in which the standby RAT calculates the wireless communication suspension time band impairs independency of each RAT and provides low system expandability. This problem is discussed with reference to  FIG. 15 .  FIG. 15  is a diagram ( 3 ) of the related art technique. Referring to  FIG. 15 , the mobile terminal includes n RATs. Each of the RATs # 1 -#n in the mobile terminal having an algorithm to calculate the wireless communication suspension time bands of the other RATs # 1 -#n calculates the wireless communication suspension time bands of the other RATs # 1 -#n. Independency of the RAT is thus impaired. Impaired independency of the RATs in the mobile terminal makes it difficult to develop and design the RATs separately from each other. If a new RAT #x is added to the mobile terminal, the new RAT #x needs an algorithm to calculate the wireless communication suspension time bands of all the other RAT # 1 -#n. Expandability is thus low. Low expandability makes it difficult to add a new RAT onto the mobile terminal. 
     A mobile terminal, a communication control method, and a control apparatus related to the application are described below with reference to the accompanying drawings. 
     First Embodiment 
     A mobile terminal  6  as a first embodiment is described below. The mobile terminal  6  may be a cellular wireless terminal, for example. The mobile terminal  6  is a mobile communication terminal having at least a plurality of wireless communication units. 
     Referring to  FIG. 1 , the mobile terminal  6  of the first embodiment and a process thereof are discussed.  FIG. 1  is a block diagram illustrating the mobile terminal  6  of the first embodiment. 
     The mobile terminal  6  includes wireless communication unit A  1 , wireless communication unit B  2 , permit unit  4 , and wireless resource  5 . The wireless communication unit A  1  and the wireless communication unit B  2  perform wireless communications in different communication methods. The wireless resource  5  is needed for each of the wireless communication units  1  and  2  to perform wireless communications. If information regarding the wireless communication suspension time band is received from an active wireless communication unit, the permit unit  4  permits a standby wireless communication unit to use the wireless resource  5  during the wireless communication suspension time band, and then causes the standby wireless communication unit to measure a reception level. 
     As described above, the mobile terminal  6  of the first embodiment causes the permit unit  4  different from the wireless communication units  1  and  2  to acquire the information of the wireless communication suspension time band of the active wireless communication unit. The permit unit  4  then permits the standby wireless communication unit to use the wireless resource  5  during the time band, and causes the standby wireless communication unit to measure the reception level. The mobile terminal  6  is thus free from the need of an interface between the wireless communication units  1  and  2 , and an algorithm to calculate the wireless communication suspension time band. During the wireless communication suspension time band of one wireless communication unit, the mobile terminal  6  can cause the other wireless communication unit to acquire the reception level. As a result, the arrangement of the mobile terminal  6  increases expandability of the mobile terminal having a plurality of RATs. Since the mobile terminal  6  assures independency of each of the wireless communication units  1  and  2 , the wireless communication units  1  and  2  can be designed and developed independently with ease. Since expandability is assured, a new RAT can be easily added. 
     Second Embodiment 
     The mobile terminal  10  of a second embodiment is described below with reference to  FIG. 2 .  FIG. 2  illustrates the mobile terminal  10  of the second embodiment. 
     Mobile Terminal: 
     Elements of the mobile terminal  10  are described with reference to  FIG. 2 . Referring to  FIG. 2 , the mobile terminal  10  includes radio access technology (radio access technology (RAT))α  20  (wireless communication unit A), RATβ  30  (wireless communication unit B), scheduler  40  (permit unit), radio frequency (RF) unit  50  (wireless resource), and antenna  13 . 
     The RF unit  50  is a wireless resource working with each of the RATs  20  and  30  to perform wireless communications, and exchanges signals. More specifically, the RF unit  50  transfers a signal received by the antenna  13  to one of a modem unit  21  and a modem unit  31 . The RF unit  50  transmits a signal transferred from one of the modem unit  21  and the modem unit  31  to a base station A  11  or a base station B  12  via the antenna  13 . 
     The antenna  13  receives and transmits radiowaves to and from one of the base station A  11  and the base station B  12 . The antenna  13  is a wireless resource used for each of the RATs  20  and  30  to perform wireless communications. 
     The RATα  20  performs wireless communications in a communication method different from a communication method of the RATβ  30 . For example, the communication methods may include Global System for Mobile Communications/General Packet Radio Service (GSM/GPRS), Wideband Code Division Multiple Access (W-CDMA), Long Term Evolution (LTE). 
     More specifically, the RATα  20  performs wireless communications with the base station A  11  in a communication method applied thereto. To suspend wireless communications temporarily, the RATα  20  transfers to the scheduler  40  information of a wireless communication suspension time band. The phrase “To suspend wireless communications temporarily” refers to a compressed mode in W-CDMA or an idle frame in GSM, for example. 
     To measure a reception level, the RATα  20  requests the scheduler  40  to assign the RF unit  50  thereto. Also, upon receiving an interruption signal from the scheduler  40 , the RATα  20  measures the reception level via the antenna  13 . Upon receiving an interruption signal again from the scheduler  40 , the RATα  20  ends the measurement of the reception level. 
     The interruption signal is a pulse signal representing the start timing of wireless communications or the end timing of wireless communications. The interruption signal is generated by the pulse generator  45  to be discussed later. 
     The RATβ  30  performs wireless communications in a communication method different from the communication method of the RATα  20 . More specifically, the RATβ  30  communicates with the base station B  12  in the communication method applied thereto. To suspend wireless communications temporarily, the RATβ  30  transfers to the scheduler  40  information of the wireless communication suspension time band. 
     To measure the reception level, the RATβ  30  requests the scheduler  40  to assign the RF unit  50  thereto. Upon receiving an interruption signal from the scheduler  40 , the RATβ  30  measures a reception level via the antenna  13 . Upon receiving an interruption signal again from the scheduler  40 , the RATβ  30  ends the measurement of the reception level. 
     The scheduler  40  may retrieve the information of the wireless communication suspension time band from a wireless communication active RAT. The scheduler  40  then permits a wireless communication standby RAT to use the wireless resource during the wireless communication suspension time band and causes the wireless communication standby RAT to measure the reception level. More specifically, the scheduler  40  retrieves the information of the wireless communication suspension time band from the wireless communication active RAT using the wireless resource. If the information of the wireless communication suspension time band is retrieved, the scheduler  40  assigns the wireless resource to the wireless communication standby RAT during the wireless communication suspension time band. 
     The scheduler  40  transfers an interruption signal to the RAT assigned to the wireless resource, and causes the RAT to measure the reception level. To resume wireless communications, the scheduler  40  transfers an interruption signal to the RAT measuring the reception level, and causes the RAT to end the measurement of the reception level. 
     A process of the scheduler  40  is described below. In the discussion that follows, the RATα  20  is a wireless communication active RAT having the RF unit  50  assigned thereto and the RATβ  30  is a standby RAT having no RF unit  50  assigned thereto. 
     The scheduler  40  acquires the information of the wireless communication suspension time band from the RATα  20 . Upon receiving the wireless communication suspension time band from the RATα  20 , the scheduler  40  re-assigns the RF unit  50 , which has been assigned to the RATα  20 , to the RATβ  30  during the wireless communication suspension time band of the RATα  20 . 
     During the wireless communication suspension time band of the RATα  20 , the scheduler  40  transfers an interruption signal to the RATβ  30  to cause the RATβ  30  to measure the reception level. When the wireless communication suspension time band of the RATα  20  has elapsed, the scheduler  40  transfers an interruption signal again. 
     The elements of the RATα  20  and the RATβ  30  are described below. The RATα  20  includes modem unit  21 , codec unit  22 , synchronization controller  23 , counter  24 , and interruption processor  25 . Similarly, the RATβ  30  includes modem unit  31 , codec unit  32 , synchronization controller  33 , counter  34 , and interruption processor  35 . The elements  21 - 25  of the RATα  20  perform processes respectively identical to those of the elements  31 - 35  of the RATβ  30 . The processes of the elements  21 - 25  of the RATα  20  are described below, and the discussion of the processes of elements  31 - 35  of the RATβ  30  is thus omitted here. 
     The codec unit  22  encodes a signal to be transmitted to the base station A  11 . The codec unit  22  also decodes a signal received from the base station A  11 . The modem unit  21  modulates the signal to be transmitted to the base station A  11 . The modem unit  31  also demodulates the signal received from the base station A  11 . 
     The counter  24  generates a synchronization signal serving as a clock for the RATα  20 . More specifically, the counter  24  transfers the generated synchronization signal to the scheduler  40 . 
     When the RATα  20  suspends temporarily wireless communications, the synchronization controller  23  transfers the information of the wireless communication suspension time band of the RATα  20  to the scheduler  40 . More specifically, the synchronization controller  23  transfers to the scheduler  40  the information of the wireless communication suspension time band, RF setting information of the RATα  20 , and information indicating measurement period use application. If the RATα  20  measures the reception level, the synchronization controller  23  transfers to the scheduler  40  the information indicating the measurement target and the RF setting information in order to request the scheduler  40  assign to the RF unit  50  thereto. 
     The process of the synchronization controller  23  is described in detail. When the RATα  20  suspends temporarily wireless communications, the synchronization controller  23  generates the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application. The synchronization controller  23  then transfers to the scheduler  40  the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application. 
     The information of the wireless communication suspension time band represents a time band through which the RATα  20  suspends temporarily wireless communications. The RF setting information is stored on the RF unit  50  such that the RATα  20  performs wireless communications using the RF unit  50 . For example, the RF setting information indicates a frequency of a radiowave used in the wireless communication method applied to the RATα  20 . The information indicating the measurement period use application specifies a purpose of wireless communications performed by another RAT. For example, the synchronization controller  23  transfers to the scheduler  40 , as the measurement period use application information, information indicating a measurement of the reception level by the RAT to which W-CDMA is applied. 
     When the RATα  20  measures the reception level, the synchronization controller  23  transfers the information indicating the measurement target and the RF setting information to the scheduler  40  to request the scheduler  40  to assign the RF unit  50 . The information indicating the measurement target indicates the purpose of wireless communications. For example, the information indicating the measurement target indicates the measurement of the reception level by the RAT to which W-CDMA is applied. For example, when the RATα  20  measures the reception level, the synchronization controller  23  transfers to the scheduler  40  the information indicating the measurement of the reception level as the measurement target information and the RF setting information related to the RATα  20 . 
     In response to the reception of the interruption signal, the interruption processor  25  measures the reception level using the modem unit  21 . More specifically, the interruption processor  25  measures the reception level using the modem unit  21  if the interruption signal is acquired from the scheduler  40 . For example, if the interruption signal is acquired from the scheduler  40 , the interruption processor  25  retrieves from the scheduler  40  measurement period information to be discussed later. The interruption processor  25  also acquires TX (transmission)/RX (reception) signals from a base station using the modem unit  21  and measures the reception signal in response to the acquired TX/RX signals and the retrieved measurement period information. 
     If the interruption signal is received again, the interruption processor  25  ends the measurement of the reception signal. The measurement period information is used as a parameter for measuring the reception signal, and includes the wireless communication suspension time band, the RF setting information, and the information indicating the measurement period use application. For example, the measurement period information includes an average transmission and reception count as a parameter for measuring the reception level. 
     Scheduler: 
     The elements of the scheduler  40  are described below with reference to  FIG. 3 .  FIG. 3  illustrates a structure of the scheduler  40 . Referring to  FIG. 3 , the scheduler  40  includes selector A  41 , selector B  42 , selector C  43 , counter  44 , pulse generator  45 , register A  46 , register B  47 , controller  48 , and RF switch  49 . 
     The selector A  41  is connected to the counter  24  in the RATα  20 , the counter  34  in the RATβ  30 , the counter  44 , and the controller  48 . The selector B  42  is connected to the interruption processor  25  in the RATα  20 , the interruption processor  35  in the RATβ  30 , the pulse generator  45 , and the controller  48 . The selector C  43  is connected to the synchronization controller  23  in the RATα  20 , the synchronization controller  33  in the RATβ  30 , the register A  46 , the register B  47 , and the controller  48 . The controller  48  is connected to the counter  44 , the pulse generator  45 , the register A  46 , the register B  47 , the RF switch  49 , and the RF unit  50 . 
     The selector A  41  receives a synchronization signal transferred from the counter in a wireless communication active RAT, and transfers the received synchronization signal to the counter  44 . More specifically, the selector A  41  receives the synchronization signals transferred from the counter  24  in the RATα  20  and the counter  34  in the RATβ  30 . The selector A  41  then receives from the controller  48  a notification indicating a RAT selected by the controller  48 . The selector A  41  transfers to the counter  44  of the scheduler  40  the synchronization signal transferred from the RAT selected by the controller  48 . 
     If the RATα  20  is selected by the controller  48 , the selector A  41  receives from the controller  48  a notification indicating the RATα  20 . Upon receiving the notification indicating the RATα  20 , the selector A  41  transfers to the counter  44  in the scheduler  40  the synchronization signal transferred from the counter  24  in the RATα  20 . 
     The selector B  42  transfers to the interruption processor in a standby RAT the interruption signal generated by the pulse generator  45  in the scheduler  40 . More specifically, the selector B  42  receives from the controller  48  a notification indicating the RAT selected by the controller  48 . The selector B  42  transfers the interruption signal to the interruption processor in the RAT selected by the controller  48 . 
     If the RATβ  30  is selected by the controller  48 , the selector B  42  receives a notification indicating the RATβ  30 . Upon receiving the notification indicating the RATβ  30 , the selector B  42  transfers to the interruption processor  35  in the RATβ  30  the interruption signal received from the pulse generator  45 . 
     The selector C  43  receives information transferred from the synchronization controller in the wireless communication active RAT, and transfers the received information to the register A  46 . The selector C  43  receives information transferred from the synchronization controller in the standby RAT, and transfers the received information to the register B  47  in the scheduler  40 . 
     More specifically, the selector C  43  receives from the controller  48  the notifications indicating the wireless communication active RAT and the standby RAT. The selector C  43  also receives the information of the wireless communication suspension time band, the RF setting information, and the information indicating the measurement period use application transferred from the synchronization controller in the wireless communication active RAT, and transfers the received information to the register A  46  in the scheduler  40 . The selector C  43  also receives the information indicating the measurement target and the RF setting information transferred from the synchronization controller in the standby RAT, and transfers the received information to the register B  47  in the scheduler  40 . 
     If the RATα  20  is selected as a wireless communication active RAT by the controller  48 , the selector C  43  receives from the controller  48  a notification indicating that the wireless communication active RAT is the RATα  20 . When the notification that the wireless communication active RAT is the RATα  20  is received, the selector C  43  receives the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application transferred from the synchronization controller  23  in the RATα  20 . The selector C  43  then transfers the received information to the register A  46  in the scheduler  40 . 
     If the RATβ  30  is selected as the standby RAT by the controller  48 , the selector C  43  receives from the controller  48  a notification indicating that the standby RAT is the RATβ  30 . When the notification that the standby RAT is the RATβ  30  is received, the selector C  43  receives the information indicating the measurement target and the RF setting information of the RATβ  30  transferred from the synchronization controller  33  in the RATβ  30 . The selector C  43  then transfers the received information to the register B  47  in the scheduler  40 . 
     The counter  44  receives the synchronization signal via the selector A  41 , and establishes synchronization with the counter having transferred the synchronization signal, in response to the received synchronization signal. The controller  48  sets timer time on the counter  44 , and when the timer time is reached, the counter  44  notifies the controller  48  that the set time is reached. 
     The process of the counter  44  is specifically described. The counter  44  receives the synchronization signal transferred from the selector A  41 , and establishes synchronization with the RAT having transferred the synchronization signal in accordance with the received synchronization signal. More specifically, the counter  44  receives via the selector A  41  the synchronization signal transferred from the counter in the RAT to which the antenna  13  is assigned. In response to the received synchronization signal, the counter  44  establishes synchronization with the counter in the RAT to which the antenna  13  is assigned. 
     If the RAT having the antenna  13  assigned thereto is the RATα  20 , the counter  44  receives via the selector A  41  the synchronization signal transferred from the counter  24  in the RATα  20 . Using the received synchronization signal, the counter  44  synchronizes with the counter  24  in the RATα  20 . 
     When the timer time set on the counter  44  by the controller  48  is reached, the counter  44  so notifies the controller  48 . For example, if five seconds of timer time is set on the counter  44  by the controller  48 , the counter  44  immediately starts subtracting on the remaining time. At the 5 seconds after the timer setting, the counter  44  notifies the controller  48  of the timer out. 
     If the controller  48  issues a generation instruction of the interruption signal to the pulse generator  45 , the pulse generator  45  transfers the generated interruption signal to the selector B  42 . More specifically, upon receiving the generation instruction of the interruption signal from the controller  48 , the pulse generator  45  generates a pulse signal as the interruption signal and transfers the generated pulse signal to the selector B  42 . 
     The register A  46  stores information transferred from the synchronization controller in the wireless communication active RAT. More specifically, the register A  46  receives via the selector C  43  the information transferred from the synchronization controller in the wireless communication active RAT, and then stores the received information. When the RATα  20  performs wireless communications, the register A  46  stores via the selector C  43  the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application transferred from the synchronization controller  23  in the RATα  20 . 
     The register B  47  stores information transferred from the synchronization controller in the standby RAT. More specifically, the register B  47  receives via the selector C  43  the information transferred from the synchronization controller in the standby RAT and stores the received information. If the RATβ  30  is on standby, the register B  47  stores via the selector C  43  the measurement period information and the RF setting information transferred from the synchronization controller  33  in the RATβ  30 . The register B  47  stores the measurement period information that is generated by the controller  48 , based on the information stored on the register A  46 . For example, the register B  47  stores the measurement period information that is generated from the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application transferred from the RATα  20 . 
     The RF switch  49  assigns the RF unit  50  to the RAT selected by the controller  48 . More specifically, the RF switch  49  is notified of the wireless communication active RAT by the controller  48 . The RF switch  49  transfers to the RF unit  50  a signal transferred from the RAT of which the controller  48  has notified the RF switch  49 , and transfers a signal transferred from the RF unit  50  to the RAT of which the controller  48  has notified the RF switch  49 . 
     If the RATα  20  is selected by the controller  48 , the RF switch  49  receives from the controller  48  a notification indicating the RATα  20 . Upon receiving the notification indicating the RATα  20 , the RF switch  49  transfers a signal from the RATα  20  to the RF unit  50 , and a signal from the RF unit  50  to the RATα  20 . 
     The controller  48  controls elements  41 - 47  and  49  in the scheduler  40 . More specifically, the controller  48  selects a wireless communication active RAT and notifies the selector A  41  of the selected RAT. The controller  48  also selects a standby RAT, and notifies the selector B  42  of the selected RAT. The controller  48  notifies the selector C  43  of the wireless communication active RAT and the standby RAT. The controller  48  also selects a standby RAT and notifies the RF switch  49  of the selected RAT. 
     If the information of the wireless communication suspension time band is stored on the register A  46 , the controller  48  determines that the wireless communication active RAT is to suspend temporarily wireless communications. The controller  48  retrieves the information stored on the register A  46 . If the information indicating the measurement target and the RF setting information transferred from the standby RAT is stored on the register B  47 , the controller  48  determines that the standby RAT has requested the RF unit  50  to be assigned thereto. 
     In response to the information of the wireless communication suspension time band retrieved from the register A  46 , the controller  48  sets to the counter  44  timer time to the start of the wireless communication suspension time band of the wireless communication active RAT. If the counter  44  notifies the controller  48  of timer out of the time to the wireless communication suspension time band, the controller  48  timer-sets time to the resumption of wireless communications of the RAT having suspended wireless communications, based on the information of the wireless communication suspension time band. 
     In response to a timer out notification of the time until the wireless communication suspension from the counter  44 , the controller  48  selects a RAT that is to measure the reception level, and then notifies the RF switch  49  of the selected RAT. In response to the timer out notification of the time until the wireless communication suspension from the counter  44 , the controller  48  sets the RF unit  50  based on the RF setting information stored on the register B  47 . 
     In response to the timer out notification of the time until the wireless communication suspension from the counter  44 , the controller  48  generates the measurement period information and stores the generated measurement period information on the register B  47 . In response to the timer out notification of the time until the wireless communication suspension from the counter  44 , the controller  48  instructs the pulse generator  45  to generate the interruption signal. 
     In response to a timer out notification from the counter  44  of the time until the resumption of wireless communications of the RAT having suspended wireless communications, the controller  48  instructs the pulse generator  45  to generates the interruption signal. In response to the timer out notification from the counter  44  of the time until the resumption of wireless communications of the RAT having suspended wireless communications, the controller  48  sets the RF unit  50  using the RF setting information stored on the register A  46 . In response to the timer out notification from the counter  44  of the time until the resumption of wireless communications of the RAT having suspended wireless communications, the controller  48  selects a RAT that is to resume wireless communications, and notifies the RF unit  50  of the selected RAT. 
     A process of the controller  48  controlling elements  41 - 47  and  49  is specifically described. In the discussion that follows, the RATα  20  is a wireless communication active RAT having the RF unit  50  assigned thereto, and the RATβ  30  is a wireless communication standby RAT having no RF unit  50  assigned thereto. The following discussion is also based on the premise that the RATα  20  starts suspending temporarily wireless communications 5 seconds after the transmission of the information of the wireless communication suspension time band, and that the RATα  20  resumes wireless communications 15 seconds after the transmission of the information of the wireless communication suspension time band. 
     The controller  48  selects a wireless communication active RAT, and notifies the selector A  41  of the selected RAT. For example, the controller  48  selects a wireless communication active RATα  20  and notifies the selector A  41  that the RATα  20  has been selected. 
     The controller  48  selects a wireless communication standby RAT and notifies the selector B  42  of the selected RAT. For example, the controller  48  selects a standby RATβ  30  and notifies the selector B  42  that the RATβ  30  has been selected. 
     The controller  48  also notifies the selector C  43  of the wireless communication active RAT and the wireless communication standby RAT. For example, the controller  48  notifies the selector C  43  that the RATα  20  has been selected as a wireless communication active RAT and that the RATβ  30  has been selected as a standby RAT. 
     The controller  48  selects the wireless communication active RAT and notifies the RF switch  49  of the selected RAT. For example, the controller  48  notifies the RF switch  49  that the RATα  20  has been selected as the wireless communication active RAT. 
     If the information of the wireless communication suspension time band is stored on the register A  46 , the controller  48  determines that the wireless communication active RAT is to suspend temporarily wireless communications and acquires the information from the register A  46 . For example, if the information of the wireless communication suspension time band is transferred from the synchronization controller  23  in the RATα  20  and stored on the register A  46 , the controller  48  determines that the RATα  20  is to suspend temporarily wireless communications. The controller  48  then retrieves the information of the wireless communication suspension time band, the RF setting information of the RATα  20 , and the information indicating the measurement period use application, stored on the register A  46 . 
     If the information indicating the measurement target and the RF setting information transferred from the standby RAT is stored on the register B  47 , the controller  48  determines that the standby RAT has requested the RF unit  50  to be assigned thereto. For example, if the information indicating the measurement target and the RF setting information transferred from the synchronization controller  33  in the RATβ  30  is stored on the register B  47 , the controller  48  determines that the RATβ  30  has requested the RF unit  50  to be assigned thereto. If the information indicating the measurement target transferred from the synchronization controller  33  in the RATβ  30  indicates the measurement of the reception level, the controller  48  determines that the RATβ  30  has requested the reception level to be measured. 
     Using the information of the wireless communication suspension time band retrieved from the register A  46 , the controller  48  timer-sets on the counter  44  time lasting until the start of the temporary suspension of wireless communications of the wireless communication active RAT. For example, the controller  48  identifies 5 seconds as the time lasting until the start of the temporary suspension of wireless communications of the RATα  20 , from the information of the wireless communication suspension time band retrieved from the register A  46 . The controller  48  then timer-sets 5 seconds on the counter  44 . Upon being timer set, the counter  44  immediately starts subtracting on the set time. 
     In response to the timer out notification of the time lasting until the wireless communication suspension from the counter  44 , the controller  48  timer-sets the time to the resumption of wireless communications of the RAT having suspended wireless communications, in response to the information of the wireless communication suspension time band. For example, upon receiving the timer out notification from the counter  44  of the time lasting until the start of the wireless communication suspension of the RATα  20 , the controller  48  timer-sets on the counter  44  10 seconds as the time lasting until the resumption of wireless communications of the RATα  20 . 
     In response to the timer out notification from the counter  44  of the time lasting until the wireless communication suspension, the controller  48  selects a RAT that is to measure the reception level, and notifies the RF switch  49  of the selected RAT. For example, in response to the timer out notification from the counter  44  of the time lasting until the start of the wireless communication suspension of the RATα  20 , the controller  48  selects the RATβ  30  that is to measure the reception level, and notifies the RF switch  49  that the RATβ  30  has been selected. 
     Upon receiving the timer out notification of the time lasting until the wireless communication suspension from the counter  44 , the controller  48  sets the RF unit  50  using the RF setting information stored on the register B  47 . For example, upon receiving the timer output notification from the counter  44  of the time lasting until the start of the wireless communication suspension of the RATα  20 , the controller  48  retrieves the RF setting information of the RATβ  30  stored on the register B  47 . The controller  48  sets the RF unit  50  based on the retrieved RF setting information of the RATβ  30 . 
     Also in response to the timer out notification of the time lasting until the wireless communication suspension from the counter  44 , the controller  48  generates the measurement period information and stores the generated measurement period information on the register B  47 . For example, in response to the timer out notification from the counter  44  of the time lasting until the start of the wireless communication suspension of the RATα  20 , the controller  48  generates the measurement period information from a variety of information of the RATα  20  stored on the register A  46 . The controller  48  stores the generated measurement period information on the register B  47 . 
     Also upon receiving the timer out notification of the time lasting until the wireless communication suspension from the counter  44 , the controller  48  instructs the pulse generator  45  to generate the interruption signal. For example, the controller  48  instructs the pulse generator  45  to generates the interruption signal in response to the timer out notification from the counter  44  of the time lasting until the start of the wireless communication suspension of the RATα  20 . 
     Upon receiving the timer out notification of the time lasting until the resumption of wireless communications from the counter  44 , the controller  48  instructs the pulse generator  45  to generate the interruption signal. For example, the controller  48  instructs the pulse generator  45  to generate the interruption signal in response to the timer out notification from the counter  44  of the time lasting until the resumption of wireless communications of the RATα  20 . The interruption signal is thus transferred to the interruption processor  35  in the RATβ  30 . The interruption processor  35  in the RATβ  30  starts measuring the reception level. 
     Upon receiving the timer out notification of the time lasting until the resumption of wireless communications from the counter  44 , the controller  48  sets the RF unit  50  using the RF setting information stored on the register A  46 . For example, the controller  48  sets the RF unit  50  using the RF setting information of the RATα  20  stored on the register A  46 , in response to the timer out notification from the counter  44  of the time lasting until the resumption of wireless communications of the RATα  20 . 
     The controller  48  also selects the RAT that is to resume wireless communications and notifies the RF unit  50  of the selected RAT in response to the timer out notification of the time lasting until the resumption of wireless communications from the counter  44 . For example, the controller  48  selects the RATα  20  and notifies the RF switch  49  that the RATα  20  has been selected, in response to the timer out notification from the counter  44  of the time lasting until the resumption of wireless communications of the RATα  20 . In response, the RATα  20  can resume wireless communications. 
     Electrical circuits may be employed for the RF unit  50 , the modem unit  21 , the modem unit  31 , the codec unit  22 , the codec unit  32 , the synchronization controller  23 , the synchronization controller  33 , the counter  24 , the counter  34 , the interruption processor  25 , and the interruption processor  35 . The counter  44 , the pulse generator  45 , and the RF switch  49  are also electronic circuits. The electronic circuits may be an integrated circuit such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a central processing unit (CPU) or a micro processing unit (MPU). 
     The selector A  41 , the selector B  42 , and the selector C  43 , as electronic circuits, employ, for example, a pass transistor having an on-off switching function to select a destination of a signal. 
     Process of the Mobile Terminal: 
     The process flow of the mobile terminal  10  is described below with reference to  FIGS. 4 and 5 . Described below with reference to  FIGS. 4 and 5  are an initial setting process, a counter synchronization process, and a process of receiving a measurement request from a standby RAT performed by the mobile terminal  10 .  FIG. 4  is a sequence chart ( 1 ) illustrating the process flow of the mobile terminal  10  of the second embodiment. 
     Referring to  FIG. 4 , the RATα  20  is a wireless communication active RAT having the RF unit  50  assigned thereto and the RATβ  30  is a standby RAT having no RF unit  50  assigned thereto. The hardware (HW) resource illustrated on the top right corner of each of  FIGS. 4 and 5  refers to the RF unit  50  and the antenna  13 . 
     The process flow of the initial setting process for the RATα  20  to perform wireless communications is described below. The controller  48  in the scheduler  40  selects the wireless communication active RATα  20  and notifies the selector A  41  that the RATα  20  has been selected (step S 101 ). The controller  48  in the scheduler  40  selects the standby RATβ  30  and notifies the selector B  42  that the RATβ  30  has been selected (step S 102 ). 
     The controller  48  in the scheduler  40  notifies the selector C  43  that the RATα  20  has been selected as a wireless communication active RAT (step S 103 ). The controller  48  in the scheduler  40  notifies the selector C  43  that the RATβ  30  has been selected as a standby RAT (step S 104 ). 
     The controller  48  in the scheduler  40  notifies the RF switch  49  that the RATα  20  has been selected as the standby RAT (step S 105 ). The modem unit  21  in the RATα  20  exchanges TX/RX signals with the RF unit  50 , thereby performs wireless communications (step S 106 ). 
     The counter synchronization process for synchronizing the counter  24  in the RATα  20  with the counter  44  in the scheduler  40  is described below. Since the controller  48  selects the RATα  20  in the process step in step S 101 , the selector A  41  in the scheduler  40  transfers to the counter  44  in the scheduler  40  the synchronization signal transferred from the counter  24  in the RATα  20  (step S 107 ). 
     The counter  44  in the scheduler  40  establishes synchronization with the counter  24  in the RATα  20  (step S 108 ) using the synchronization signal. The counter  44  establishes synchronization with the RATα  20  every constant period. 
     The process of the RATβ  30  requesting the RF unit  50  to be assigned thereto to measure the reception level is described below. The synchronization controller  33  in the RATβ  30  transfers the information indicating the measurement of the reception level as the measurement target and the RF setting information of the RATβ  30  to the register B  47  via the selector C  43  in the scheduler  40  to store these pieces of information on the register B  47  (step S 109 ). In response to the variety of information stored on the register B  47 , the controller  48  in the scheduler  40  determines that the RATβ  30  has requested the reception level to be measured (step S 110 ). 
     A control process performed during a TX/RX suspension period is discussed with reference to  FIG. 5 . The control process includes assigning the RF unit  50  to the standby RAT and causing the standby RAT to measure the reception level during the wireless communication suspension time band of the wireless communication active RAT.  FIG. 5  illustrates a sequence chart ( 2 ) explaining the process flow of the mobile terminal  10  of the second embodiment. As illustrated in  FIG. 5 , the RF unit  50  is assigned to the RATβ  30  during the wireless communication suspension time band of the wireless communication active RATα  20 . 
     The synchronization controller  23  in the RATα  20  transfers to the register A  46  in the scheduler  40  the information of the wireless communication suspension time band, the RF setting information, and the information indicating the measurement period use application to store these pieces of information on the register A  46  (step S 111 ). The controller  48  determines from the variety of information stored on the register A  46  that the RATα  20  is to suspend temporarily wireless communications, and retrieves the variety of information from the register A  46  (step S 112 ). 
     Using the information of the wireless communication suspension time band stored on the register A  46 , the controller  48  in the scheduler  40  timer-sets on the counter  44  the time lasting until the start of the wireless communication suspension time band of the RATα  20  (step S 113 ). If the timer set time is reached, the counter  44  in the scheduler  40  notifies the controller  48  of the timer out (step S 114 ). 
     In response to the timer out notification from the counter  44 , the controller  48  in the scheduler  40  timer-sets the time lasting until the resumption of wireless communications by the RATα  20  having suspended wireless communications (step S 115 ). Also in response to the timer out notification from the counter  44 , the controller  48  in the scheduler  40  sets the RF unit  50  using the RF setting information of the RATβ  30  stored on the register B  47  (step S 116 ). 
     The controller  48  in the scheduler  40  notifies the RF switch  49  that the RATβ  30  has been selected (step S 117 ). The RF switch  49  in the scheduler  40  assigns the RF unit  50  to the RATβ  30  (step S 118 ). The modem unit  31  in the RATβ  30  acquires the TX/RX signals via the RF unit  50  (step S 119 ). 
     The controller  48  in the scheduler  40  generates the measurement period information and stores the generated measurement period information on the register B  47  (step S 120 ). The controller  48  in the scheduler  40  causes the pulse generator  45  to generate the interruption signal (step S 121 ). The interruption processor  35  in the RATβ  30  receives the interruption signal via the selector B  42  in the scheduler  40  (step S 122 ). 
     In response to the received interruption signal, the interruption processor  35  in the RATβ  30  retrieves the measurement period information stored on the register B  47  in the scheduler  40  via the synchronization controller  33  (step S  123 ). The interruption processor  35  in the RATβ  30  measures the reception level using the retrieved measurement period information and the TX/RX signals acquired in step S 119  (step S 124 ). 
     When the timer time set in S 112  is out, the counter  44  in the scheduler  40  notifies the controller  48  of the timer out (step S 125 ). If the time for the RATα  20  to resume wireless communications is reached, the counter  44  in the scheduler  40  notifies the controller  48  of the timer out. 
     In response to the timer out notification, the controller  48  in the scheduler  40  causes the pulse generator  45  to generate the interruption signal (step S 126 ). Upon receiving the interruption signal again, the interruption processor  35  in the RATβ  30  ends the measurement of the reception level (step S 127 ). 
     In response to the received timer out notification, the controller  48  in the scheduler  40  sets the RF unit  50  in accordance with the RF setting information of the RATα  20  retrieved in step S 112  (step S 128 ). The controller  48  in the scheduler  40  notifies the RF switch  49  that the RATα  20  has been selected (step S 129 ). In response to the received notification that the RATα  20  has been selected, the RF switch  49  assigns the RF unit  50  to the RATα  20  (step S 130 ). The RATα  20  resumes wireless communications using the modem unit  21  (step S 131 ). 
     Advantages of the Second Embodiment 
     The mobile terminal  10  of the second embodiment includes the scheduler  40 . The scheduler  40  assigns the RF unit  50  to the standby RAT during the wireless communication suspension time band of the wireless communication active RAT, and causes the standby RAT to measure the reception level. Without the need for the wireless communication active RAT to notify the standby RAT of the wireless communication suspension time band, the mobile terminal  10  can cause the standby RAT to acquire the reception level during the wireless communication suspension time band of the wireless communication active RAT. 
     Without the need for the interface between the RATs  20  and  30  and the algorithm calculating the wireless communication suspension time band, the mobile terminal  10  causes the other RAT to acquire the reception level during the wireless communication suspension time band of the wireless communication active RAT. As a result, the mobile terminal  10  has an improved expandability. For example, the mobile terminal  10  includes the RATs  20  and  30  having mutually independent to each other, and independent design and development of each of the RATs  20  and  30  are possible. With expandability assured, a new RAT can be easily added. 
     The mobile terminal  10  transfers the interruption signal to the standby RAT at the start of the wireless communication suspension time band of the wireless communication active RAT, and causes the standby RAT to measure the reception level. Without the need for the algorithm for one of the RATs  20  and  30  to calculate the wireless communication suspension time band of the other of the RATs  20  and  30 , the mobile terminal  10  measures the reception level during the wireless communication suspension time band. As a result, the mobile terminal  10  needs no algorithm to calculate the wireless communication suspension time band at each of the RATs  20  and  30 , and expandability of the mobile terminal  10  is increased. 
     The mobile terminal  10  causes the counter in the wireless communication active RAT to synchronize with the counter  44  in the scheduler  40 , and causes the standby RAT at the timing indicated by the counter  44 . The mobile terminal  10  is thus free from a mechanism for establishing synchronization between the counters in the RATs. This feature allows each RAT to be easily expanded, and expandability of the RAT is thus increased. 
     Third Embodiment 
     A mobile terminal  10   a  of a third embodiment performing a cancel process is described below. Referring to  FIG. 6 , the structure of the mobile terminal  10   a  performing the cancel process is discussed below.  FIG. 6  illustrates radio access technology (RAT) modules and a scheduler of the third embodiment. The mobile terminal  10   a  of the third embodiment is similar to the mobile terminal  10 . The discussion of the same process step as that of the second embodiment is omitted here. 
     Mobile Terminal: 
     As illustrated in  FIG. 6 , the mobile terminal  10   a  of the third embodiment includes RATα  20   a  and RATβ  30   a , scheduler  40   a , radio frequency (RF) unit  50 , and antenna  13 . The elements  20   a - 50  illustrated in  FIG. 6  have the same functions as those of the elements  20 - 50  of the second embodiment, respectively. The RATα  20   a  of the third embodiment further includes a cancel controller  26 . The RATβ  30   a  further includes a cancel controller  36 . 
     If a TX/RX process, which is to be performed with priority over performing the wireless communication suspension, during the wireless communication suspension time band, the RATα  20   a  of the third embodiment cancels the wireless communication suspension. More specifically, if a TX/RX process takes place, which is to be performed with priority over performing the wireless communication suspension, during the wireless communication suspension time band, the RATα  20   a  notifies the scheduler  40   a  information indicative of cancelling of the wireless communication suspension. 
     The scheduler  40   a  may assign the RF unit  50  to the RATα  20   a  after the RATα  20   a  has notified the scheduler  40   a  of the cancelling of the wireless communication suspension. The RATα  20   a  then resumes wireless communications. More specifically, the RATα  20   a  resumes wireless communications via the RF unit  50  reassigned thereto after notifying the scheduler  40   a  of the cancelling of the wireless communication suspension. 
     If the use permission of the antenna  13  provided by the scheduler  40   a  is canceled during the measurement of the reception level, the RATα  20   a  stops measuring the reception level. More specifically, upon receiving the interruption signal from the scheduler  40   a  during the measurement of the reception level, the RATα  20   a  stops measuring the reception level. 
     For example, if the RATβ  30   a  cancels the wireless communication suspension thereof, the RATα  20   a  in the middle of measuring the reception level receives the interruption signal from the scheduler  40   a . Upon receiving the interruption signal from the scheduler  40   a , the RATα  20   a  in the middle of measuring the reception level stops measuring the reception level. 
     When the RATα  20   a  stops measuring the reception level, the RATα  20   a  requests the scheduler  40   a  again to measure the reception level. More specifically, in response to the stopping of the measurement of the reception level, the RATα  20   a  transfers to the scheduler  40   a  the RF setting information and the information indicating the measurement target to request the scheduler  40   a  to measure the reception level. 
     If a TX/RX process, which is to be performed with priority over performing the wireless communication suspension, during the wireless communication suspension time band, the RATβ  30   a  of the third embodiment cancels the wireless communication suspension. More specifically, if a TX/RX process takes place, which is to be performed with priority over performing the wireless communication suspension, during the wireless communication suspension time band, the RATβ  30   a  notifies the scheduler  40   a  of information indicative of cancelling of the wireless communication suspension. 
     The scheduler  40   a  may re-assign the RF unit  50  to the RATβ  30   a  after the RATβ  30   a  has notified the scheduler  40   a  of the cancelling of the wireless communication suspension. The RATβ  30   a  then resumes wireless communications. More specifically, the RATβ  30   a  resumes wireless communications via the RF unit  50  reassigned thereto after notifying the scheduler  40   a  of the cancelling of the wireless communication suspension. 
     If the use permission of the antenna  13  provided by the scheduler  40   a  is canceled during the measurement of the reception level, the RATβ  30   a  stops measuring the reception level. More specifically, upon receiving the interruption signal from the scheduler  40   a  during the measurement of the reception level, the RATβ  30   a  stops measuring the reception level. 
     For example, if the RATα  20   a  cancels the wireless communication suspension thereof, the RATβ  30   a  in the middle of measuring the reception level receives the interruption signal from the scheduler  40   a . Upon receiving the interruption signal from the scheduler  40   a , the RATβ  30   a  in the middle of measuring the reception level stops measuring the reception level. 
     When the RATβ  30   a  stops measuring the reception level, the RATβ  30   a  requests the scheduler  40   a  again to measure the reception level. More specifically, in response to the stopping of the measurement of the reception level, the RATβ  30   a  transfers to the scheduler  40   a  the RF setting information and the information indicating the measurement target to request the scheduler  40   a  to measure the reception level. 
     To cause the RAT in a wireless communication suspended state to use the antenna during the measurement of the reception level, the scheduler  40   a  cancels the use permission of the antenna. More specifically, if the scheduler  40   a  acquires information indicating the cancelling of the wireless communication suspension from the RAT in a wireless communication suspended state, the scheduler  40   a  causes the RAT in the middle measuring the reception level to suspend the measurement of the reception level. The scheduler  40   a  re-assigns the RF unit  50 , assigned to the RAT having stopped measuring the reception level, to the RAT having canceled the wireless communication suspension. 
     The process of the scheduler  40   a  is specifically described below. In the discussion that follows, the RATα  20   a  cancels the wireless communication suspension subsequent to the start of the wireless communication suspension, and the RATβ  30   a  is in the middle of measuring the reception level. 
     When the RATα  20   a  temporarily suspends wireless communications, the scheduler  40   a  assigns the antenna  13  to the RATβ  30   a  and causes the RATβ  30   a  to measure the reception level. Upon receiving a notification of the wireless communication suspension from the RATα  20   a , the scheduler  40   a  transfers to the RATβ  30   a  the synchronization signal to cause the RATβ  30   a  to suspend the acquisition of the reception level. The scheduler  40   a  re-assigns the RF unit  50 , assigned to the RATβ  30   a , to the RATα  20   a.    
     The elements  21 - 25  in the RATα  20   a  and the elements  41 - 49  in the scheduler  40   a  of the third embodiment are described below. The elements  21 - 25  in the RATα  20   a  and the elements  31 - 35  in the RATβ  30   a  of the third embodiment perform the same processes as those of the elements  21 - 35  of the second embodiment, and the detailed discussion thereof is omitted here. 
     If a TX/RX process having priority over the wireless communication suspension occurs, the cancel controller  26  in the RATα  20   a  of the third embodiment notifies the scheduler  40   a  of information of the cancelling the wireless communication temporary suspension. More specifically, the cancel controller  26  transfers to the register A  46   a  the information indicating the canceling of the wireless communication temporary suspension via the synchronization controller  23  and the selector C  43  in the scheduler  40   a  to store the information on the register A  46   a.    
     If a TX/RX process having priority over the wireless communication suspension occurs, the cancel controller  36  in the RATβ  30   a  of the third embodiment notifies the scheduler  40   a  of information of the cancelling the wireless communication temporary suspension. More specifically, the cancel controller  36  transfers to the register A  46   a  the information indicating the canceling of the wireless communication temporary suspension via the synchronization controller  33  and the selector C  43  in the scheduler  40   a  to store the information on the register A  46   a.    
     Upon receiving the information indicating the canceling of the wireless communication temporary suspension from the synchronization controller of the RAT having temporary suspended wireless communications, the register A  46   a  of the third embodiment stores the received information. For example, if the register A  46   a  has received the information indicating the canceling of the wireless communication temporary suspension from the cancel controller  26  in the RATα  20   a , the register A  46   a  stores the received information. 
     If the information indicating the canceling the wireless communication temporary suspension is stored on the register A  46   a , the controller  48   a  in the scheduler  40   a  determines that the RAT has canceled the wireless communication temporary suspension. Upon determining that the RAT has canceled the wireless communication temporary suspension, the controller  48   a  stops timer counting set on the counter  44 . 
     Upon determining that the RAT has canceled the wireless communication temporary suspension, the controller  48   a  causes the pulse generator  45  to generate the interruption signal. The controller  48   a  notifies the RF switch  49  of the RAT having canceled the wireless communication temporary suspension. 
     The process of the controller  48   a  is specifically discussed. After temporarily suspending wireless communications, the RATα  20   a  cancels the wireless communication temporary suspension, and the RATβ  30   a  is in the middle of measuring the reception level. 
     If the information indicating the canceling of the wireless communication temporary suspension is stored on the register A  46   a , the controller  48   a  determines the RAT has canceled the wireless communication temporary suspension. For example, if the information indicating the canceling of the wireless communication temporary suspension is stored on the register A  46   a , the controller  48   a  determines the RATα  20   a  has canceled the wireless communication temporary suspension. 
     Upon determining that the RAT has canceled the wireless communication temporary suspension, the controller  48   a  stops the timer set on the counter  44 . For example, upon determining that the RATα  20   a  has canceled the wireless communication temporary suspension, the controller  48  stops the timer on the counter  44 . 
     Upon determining that the RAT has canceled the wireless communication temporary suspension, the controller  48   a  causes the pulse generator  45  to generate the interruption signal. For example, upon determining that the RATα  20   a  has canceled the wireless communication temporary suspension, the controller  48   a  causes the pulse generator  45  to generate the interruption signal. The interruption signal is transferred to the synchronization controller  33  in the RATβ  30  via the register B  47 . The controller  48   a  in the scheduler  40  in this way causes the RATβ  30   a  to suspend the measurement of the reception level. 
     The controller  48   a  notifies the RF switch  49  of the RAT having canceled the wireless communication temporary suspension. For example, the controller  48  notifies the RF switch  49  of the RATα  20   a  as the RAT having canceled the wireless communication temporary suspension. 
     The cancel controller  26  and the cancel controller  36  are electronic circuits. The electronic circuits include an integrated circuit such as ASIC or FPGA, or CPU or MPU. 
     Process of the Mobile Terminal: 
     Discussed with reference to  FIG. 7  is the process flow of the process performed when the RATα  20   a  of the third embodiment cancels the wireless communication temporary suspension.  FIG. 7  is a sequence chart illustrating the process flow of the mobile terminal  10   a  of the third embodiment. As illustrated in  FIG. 7 , the RATα  20   a  cancels the wireless communication temporary suspension after starting the wireless communication temporary suspension, and the RATβ  30   a  is in the middle of measuring the reception level. 
     The initial setting process for the RATα  20   a  to perform wireless communications and the process for causing the counter  24  in the RATα  20   a  to synchronize with the counter  44  in the scheduler  40   a  are identical to those illustrated in  FIG. 4 , and the discussion thereof is omitted here. The process for the RATβ  30   a  to request the RF unit  50  be assigned thereto to measure the reception level is identical to the process illustrated in  FIG. 4 , and the discussion thereof is omitted here. Steps S 211 -S 224  in  FIG. 7  are respectively identical to steps S 111 -S 124  in  FIG. 5 , and the discussion thereof is omitted here. 
     The RATα  20   a  temporarily suspends wireless communications, and the scheduler  40   a  assigns the RF unit  50  to the standby the RATβ  30  in response to information transferred from the RATα  20 , and causes the RATβ  30  to measures the reception level (steps S 211 - 224 ). When the RATα  20   a  cancels the wireless communication temporary suspension, the cancel controller  26  in the RATα  20   a  transfers to the register A  46  in the scheduler  40   a  the information indicating the canceling of the wireless communication temporary suspension (step S 225 ). If the information indicating the canceling of the wireless communication temporary suspension is stored on the register A  46   a , the controller  48   a  in the scheduler  40   a  determines that the RATα  20   a  is to cancel the wireless communication temporary suspension (step S 226 ). 
     Upon determining that the RATα  20   a  is to cancel the wireless communication temporary suspension, the controller  48   a  in the scheduler  40  stops the timer set on the counter  44  in step S 215  (step S 227 ). The controller  48   a  in the scheduler  40  causes the pulse generator  45  to generate the interruption signal (step S 228 ). In response to the received interruption signal (step S 229 ), the interruption processor  35  in the RATβ  30  ends the measurement of the reception level (step S 230 ). 
     Using the RF setting information of the RATα  20   a , the controller  48   a  in the scheduler  40  sets the RF unit  50  (step S 231 ). The controller  48   a  in the scheduler  40  notifies the RF switch  49  that the RATα  20   a  has been selected (step S 232 ). The modem unit  21  in the RATα  20   a  resumes wireless communications via the RF unit  50  (step S 233 ). 
     Advantages of the Third Embodiment 
     As described above, the mobile terminal  10   a  of the third embodiment suspends the measurement of the reception level by one RAT in the middle of the measurement of the reception level if another RAT cancels the wireless communication temporary suspension. The mobile terminal  10   a  then re-assigns the RF unit  50  to the RAT having canceled the wireless communication temporary suspension and causes the RAT to resume wireless communications. The mobile terminal  10   a  thus performs priority communication occurring in each of the RATs. As a result, the mobile terminal  10   a  not only increases expandability thereof but also assigns the RF unit  50  efficiently. 
     Fourth Embodiment 
     A fourth embodiment relates to a mobile terminal  10   b  that attaches to each RAT a priority to measure the reception level and causes the RAT to measure the reception level in accordance with the priority attached thereto. Discussed with reference to  FIG. 8  is a structure of the mobile terminal  10   b  that attaches to each RAT a priority to measure the reception level and causes the RAT to measure the reception level in accordance with the priority attached thereto.  FIG. 8  illustrates the structure of each RAT and a scheduler in accordance with the fourth embodiment. The discussion of elements in the mobile terminal  10   b  of the fourth embodiment, which are identical to those of the mobile terminal of the second and third embodiments, is omitted here. 
     The mobile terminal  10   b  includes a plurality of RATs  20 - 100 , one RF unit  50 , one scheduler  40 , and one antenna  13 . Each of the RATs  20 - 100  has the same function as that of the RATα  20  of the second embodiment or the RATα  20   a  of the third embodiment. Elements  103 - 106  in RATn  100  are identical in function to the elements  23 - 26 , respectively. 
     As the scheduler of the second and third embodiments, the scheduler  40   b  of the fourth embodiment includes elements  41 - 49 . The scheduler  40   b  includes a controller  48   b , and a priority storage unit  51 . The elements  41 - 49  in the scheduler  40   b  are identical in function to the elements  41 - 49  in the second and third embodiments, respectively. 
     If a wireless communication active RAT is to suspend temporarily wireless communications, the scheduler  40   b  permits each of the RATs  20 - 100  to use the RF unit  50  in response to the priority set for each of the RATs  20 - 100 . More specifically, the scheduler  40   b  sets a priority to each of the RATs  20 - 100  and stores the priorities set on the RATs  20 - 100 . The scheduler  40   b  also stores a cumulative value of a measurement count of the reception level of each of the RATs  20 - 100 . 
     If the RF unit  50  is assigned to a standby RAT, the scheduler  40   b  compares a cumulative value of a measurement count, at which each RAT requesting the RF unit  50  to be assigned thereto has measured the reception level, with the priority set at each RAT. The scheduler  40   b  assigns the RF unit  50  such that the ratio of the cumulative values of the measurement counts, at which the RATs requesting the RF unit  50  to be assigned thereto have measured the reception level, equals the ratio of the priorities set at the RATs. 
     An example of the process of the scheduler  40   b  is described below. The following discussion is based on the premise that the RATα  20  is to suspend wireless communications temporarily, that the RATs  20 - 100  measure the reception level once for each RAT, and that the same priority “1” is attached to each of the RATs  20 - 100 . If each of the RATs  30 - 100  requests the scheduler  40   b  to assign the RF unit  50  thereto, the scheduler  40   b  assigns the RF unit  50  to the RAT  100 , and causes the RAT  100  to measure the reception level. If the RATs requesting the RF unit  50  to be assigned thereto are only the RAT  100 , the scheduler  40   b  assigns the RF unit  50  to the RAT  100 . 
     The priority storage unit  51  in the scheduler  40   b  of the fourth embodiment stores the cumulative values of measurement counts of the RATs  20 - 100 . The priority storage unit  51  also stores the priorities set on the RATs  20 - 100 . 
     The controller  48   b  in the scheduler  40   b  of the fourth embodiment retrieves from the priority storage unit  51  the cumulative values of the measurement counts of the RATs  20 - 100  and the priorities set on the RATs  20 - 100 . The controller  48   b  compares the cumulative value of measurement count of each of the RATs  20 - 100  requesting the RF unit  50  to be assigned thereto with the priority of each of the RATs  20 - 100 . The controller  48   b  selects an RAT to assign the RF unit  50  thereto such that the cumulative values of the measurement counts of the reception levels by the RATs  20 - 100  have the same ratio as the ratio of the priorities set to the RATs  20 - 100 . The controller  48   b  updates the measurement count cumulative values of the reception level of the RATs  20 - 100  stored on the priority storage unit  51 . 
     A series of process steps of the controller  48   b  is described in detail below. In the discussion that follows, the RATs  30 - 1000  request the controller  48   b  to assign the RF unit  50  thereto during the wireless communication suspension time band of the RATα  20 , a priority “2” is set on the RATβ  30 , a priority “1” is set on the other RATs, and the measurement counts of the reception level of the RATs  20 - 100  are the same. 
     If the RATα  20  having the RF unit  50  assigned thereto suspends temporarily wireless communications, the controller  48   b  retrieves from the priority storage unit  51  the measurement counts of the reception level of the RATs  20 - 100  and the priorities set on the RATs  20 - 100 . The controller  48  compares the measurement counts of the reception level of the RATs  20 - 100  with the priorities set on the RATs  20 - 100 . The priority set on the RATβ  30  is “2” and is larger than a priority “1” set on the other RATs. The reception level measurement counts of the RATs  20 - 100  are all the same. 
     During the wireless communication suspension time band of the RATα  20  having the RF unit  50  assigned thereto, the controller  48   b  selects the RATβ  30  as a RAT to which the RF unit  50  is to be assigned. The controller  48   b  notifies the RF switch  49  that the RATβ  30  has been selected, and assigns the RF unit  50  to the RATβ  30 . The controller  48   b  then updates the reception level measurement count cumulative value of the RATβ  30  on the priority storage unit  51 . 
     The priority storage unit  51  may be a semiconductor memory such as RAM, ROM, or a flash memory, or a storage device such as a hard disk or an optical disk. 
     Referring to  FIG. 9 , the process of the mobile terminal  10   b  of the fourth embodiment is described below.  FIG. 9  is a sequence chart illustrating the process of the mobile terminal  10   b  of the fourth embodiment. Referring to  FIG. 9 , the RF unit  50  is assigned to a standby RAT  30  during the wireless communication suspension time band of the RATα  20 . 
     The detailed description of the initial setting process of the RATα  20  for wireless communications, and the process of establishing synchronization between the counters of the RATs  20 - 100  and the counter  44  in the scheduler  40   b  is omitted here. The description of the process of the RATs  30 - 100  that request the RF unit  50  to be assigned thereto to measure the reception level is also omitted here. 
     The scheduler  40   b  initializes the reception level measurement count cumulative value of each RAT stored on the priority storage unit  51  (step S 301 ). The scheduler  40   b  sets the priorities of the RATs  20 - 100  to be stored on the priority storage unit  51  (step S 302 ). 
     The scheduler  40   b  assigns the RF unit  50  to the RATα  20  which is to perform wireless communications and causes the RATα  20  to performs wireless communications. In order to measure the reception level, the RATs  30 - 100  request the scheduler  40   b  to assign the RF unit  50  thereto. If the RATα  20  suspends temporarily wireless communications, the RATα  20  transfers to the scheduler  40   b  the information of the wireless communication suspension time band. In response to the received information of the wireless communication suspension time band, the scheduler  40   b  determines that the RATα  20  is to suspend temporarily wireless communications. 
     Advantages of the Fourth Embodiment 
     If the information of the wireless communication suspension time band is retrieved from the RATα  20 , the scheduler  40   b  retrieves from the priority storage unit  51  the priority of the RAT having requested the RF unit  50  to be assigned thereto, and the cumulative value of the reception level measurement count of each RAT (step S 303 ). The scheduler  40   b  selects a RAT that causes the reception level measurement counts to have the same ratio as the ratio of the priorities, notifies the RF switch  49  of information indicating the selected RAT, and assigns the RF unit  50  to the selected RAT (step S 304 ). The scheduler  40   b  updates the cumulative value of the reception level measurement count of each of the RATs  20 - 100  (step S 305 ). 
     The mobile terminal  10   b  of the fourth embodiment assigns the RF unit  50  to each of the RATs  20 - 100  depending on the reception level measurement count of each of the RATs  20 - 100  and the priorities set on the RATs  20 - 100 , and causes the RAT having the RF unit  50  assigned thereto to measure the reception level. The mobile terminal  10   b  can effectively assign the RF unit  50  to the RATs  20 - 100 . As a result, the mobile terminal  10   b  has increased expandability, and assigns the RF unit  50  to each of the RATs in an appropriate time division manner. 
     If a wireless communication method applied to the RATβ  30  needs more frequent reception level measurements than the other wireless communication methods, the mobile terminal  10   b  sets on the RATβ  30  a priority higher than the priorities of the other RATs. The mobile terminal  10   b  in this way causes the RATβ  30  to measure the reception level at a higher frequency of occurrences than the other RATs. As a result, the mobile terminal  10   b  has increased expandability, and assigns the RF unit  50  to each of the RATs in an appropriate time division manner. 
     For example, if the RAT suspends temporarily wireless communications, the mobile terminal  10   b  assigns the RF unit  50  with priority to only a RAT that has requested the RF unit  50  to be assigned thereto to measure the reception level. The mobile terminal  10   b  can thus assign the RF unit  50  more appropriately. 
     Fifth Embodiment 
     The embodiments described above may be modified in a variety of arrangements described below. Such modifications are described below. 
     (1) Mobile Terminal: 
     In accordance with the first through third embodiments, the mobile terminal includes one antenna and one RF unit. In accordance with the first through fourth embodiments, the mobile terminal includes, as wireless resources, one antenna and one RF unit. The mobile terminal is not limited to this arrangement. The mobile terminal may includes a plurality of antennas, and a plurality of RF units, a plurality of RATS, and a scheduler that assigns the plurality of antennas and the plurality of RF units to a RAT. With reference to  FIGS. 10 and 11 , an example of the mobile terminal is described below.  FIG. 10  is a diagram ( 1 ) illustrating an installed example of the scheduler.  FIG. 11  is a diagram ( 2 ) illustrating another installed example of the scheduler. 
     The mobile terminal of  FIG. 10  includes one antenna, one scheduler, two RATs and two RF units respectively dedicated to the RATs. The scheduler assigns the antenna to the RF unit connected to the RAT  2  during the wireless communication suspension time band of the RAT  1 . 
     Referring to  FIG. 11 , the mobile terminal includes m RF units, m antennas, one scheduler, and n RATs where n&gt;m. Each RF unit has the antenna thereof. The scheduler assigns a couple of an RF unit and an antenna to each RAT. During the wireless communication suspension time band of an RAT  1 , the scheduler assigns an RF unit  2  and an antenna connected to the RF unit  2  to an RATn measuring a reception level. 
     As described above, the mobile terminal may include the scheduler which assigns the wireless resource to another RAT regardless of the number of wireless resources including antennas, RF units and RATs if the scheduler has received a notification of the wireless communication suspension time band. 
     (2) Measurement Period Use Application: 
     In the mobile terminals of the embodiments, a wireless communication active RAT transfers information of a measurement period use application to the scheduler, and specifies the purpose of the wireless communication to be performed by a standby RAT. For example, to specify the measurement of the reception level as the measurement period use application, the scheduler assigns the wireless resource to only the RAT that has requested the wireless resource to be assigned thereto to measure the reception level. The embodiments are not limited to this arrangement. The mobile terminal may not use the measurement period use application and may not limit the purpose of the wireless communication of the standby RAT. At least the scheduler of the mobile terminal may simply acquire the information of the wireless communication suspension time band of the wireless communication active RAT. 
     (3) Wireless Communication Method: 
     In accordance with the first through fourth embodiments, different communication methods are supported by the different RATs. The embodiments are not limited to this arrangement. For example, one wireless communication method may be supported by a plurality of RATs. An electronic circuit having the same function as the function of a plurality of RATs may be used. The electronic circuits may include an integrated circuit such as ASIC, or FPGA, or a CPU or a MPU. 
     The process steps of the mobile terminals of the above embodiments are not necessarily performed in the order specified here. A plurality of process steps may be concurrently performed. Steps S 101 -S 104  of  FIG. 4  may be concurrently performed. Steps S 115 -S 118  and steps S 126 -S 130  of  FIG. 5  may be concurrently performed. 
     (4) Program: 
     The mobile terminals of the second through fourth embodiments have a hardware structure to perform the variety of processes. The embodiments are not limited to this arrangement. A computer in the mobile terminal may perform the variety of processes by executing a program prepared beforehand. Described below is the computer executing a program having the same function as the function of the mobile terminal  10  of the first embodiment.  FIG. 12  illustrates an example of a computer  200  executing an assignment processing program. 
     The computer  200  of  FIG. 12  includes a random-access memory (RAM)  120 , a read-only memory (ROM)  130 , and a bus  170  connecting these elements. In the computer  200 , a central processing unit (CPU)  140  is interconnected via the bus  170 . The bus  170  also connects to an RF unit and an antenna as wireless resources via a connection terminal unit I/O  160 . 
     The ROM  130  pre-stores a permit program  134 . The CPU  140  reads the permit program  134  from the ROM  130 , and executes the permit program  134 . As illustrated in  FIG. 12 , the permit program  134  functions as a permit process  144 . The permit process  144  has the same function as the function of the permit unit  4  of  FIG. 1 . The permit process  144  can be designed to have the same function as that of the scheduler  40  of the second embodiment, and the scheduler of the third and fourth embodiment. 
     The permit program of the embodiment may be implemented by causing the program to run on a computer such as a personal computer or a workstation. The program may be distributed via a network such as the Internet. The program may be stored on computer readable recording media including a hard disk, a flexible disk (FD), a compact read only memory (CD-ROM), a magneto-optical disk (MO), and a digital versatile disk (DVD). The program may be executed by the computer that reads the program from the recording medium. 
     The technique disclosed in the application increases expandability of a mobile terminal having a plurality of RATs. 
     As mentioned above, the present art has been specifically described for better understanding of the embodiments thereof and the above description does not limit other aspects of the art. Therefore, the present art can be altered and modified in a variety of ways without departing from the gist and scope thereof. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.