JPH09149453A - Mobile terminal of mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a mobile terminal retrieve-receiving by plural frequencies and reducing power consumption in the state of the outside of a circle. SOLUTION: A base station transmits control information through the use of two frequencies as control carriers. When the mobile terminal shifts to the state of the outside of the circle, a control part 5 sets one of the two waves to a radio part 2 as a receiving carrier frequency. Then while a retrieve- receiving period measuring means 4 clocks a prescribed retrieve-receiving period X, a control part 5 makes the radio part 2 retrieve-receive by the set receiving carrier frequency. Until the shift to a stand-by state from the succeeding to retrieve-reception, whenever an outside-of-circle retrieving period measuring means 3 clocks an outside-of-circle retrieving period T, the control part 5 mutually sets the frequency of the two waves to the radio part 2 as a receiving carrier frequency and make the part 2 retrieve-receive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal of a mobile communication system such as a cordless telephone system handset terminal, and more particularly to a mobile terminal that attempts to receive control carriers on a plurality of frequencies.

[0002]

2. Description of the Related Art In recent years, mobile terminals of mobile communication systems such as PHS (Personal Handy Phone System) and car telephones, which are capable of talking while moving, are rapidly becoming popular. In addition to voice, these mobile communication systems can transmit various information such as image information such as fax and computerized information such as computer communication, and further development is expected.

In such a mobile communication system, a mobile terminal moves within a communicable service area composed of a plurality of base stations for communication. For this reason, when the mobile terminal is connected to the wireless communication network, position information indicating in which wireless communication area of the base station the mobile terminal exists is registered in the network database.

Here, the above line connection operation will be briefly described. Each base station in the system predefines control information (broadcast information) including the information of the base station necessary for connecting the line, such as radio channel information, method information, call information, regulation information, etc., for the control carrier in advance. At the specified frequency, intermittent transmission is performed at a constant cycle.

When the mobile terminal is powered on, it tries to receive the control information transmitted by the base station at the control carrier frequency. When the control information is received, the mobile terminal determines that it is within the service area of the base station, and the mobile terminal transmits its position information to the base station by the control carrier (position registration) and receives the received control information (base Station identification information, etc.) is stored. As a result, the mobile terminal is connected to the network via the base station and enters the standby state. The state in which the network is connected, including the standby state and the call state, corresponds to the in-range state described in the claims.

On the other hand, the mobile terminal shifts to the out-of-range state when it cannot receive the control information when the power is turned on or when it cannot receive the control information due to the movement to the outside of the service area. In the out-of-range state, the mobile terminal keeps a predetermined out-of-range search period T until receiving the control information.
Repeatedly search and receive with. This makes it possible to stop a circuit that consumes a large amount of power, such as a wireless unit, when the search is not being received, and reduce power consumption.

When the control information can be received by the intermittent search and reception, the mobile terminal performs location registration and the like based on the control information included in the received data, and again,
Move to standby mode.

By the way, it has been devised to use a plurality of frequency bands as control carriers in order to reliably transmit and receive the control information. For example, in the second-generation cordless telephone system standard (RCR STD-28) and the like. , It is described that a base station can multiplex carriers of two waves. On the basis of this, conventionally, in a self-employed digital cordless telephone system, a base station normally transmits two carriers of multiple waves, and a mobile terminal selects a carrier which can be received and waits. The self-employed mobile communication system refers to a mobile communication system other than the public one, such as home and office.

The operation of the mobile terminal in the out-of-service state will be described below with reference to the timing chart shown in FIG.

That is, when the mobile terminal enters the out-of-range state,
First, the reception of control information is attempted for a predetermined search reception period X at one frequency f1 of two predetermined carrier waves (the period from A to B in FIG. 4). When the search reception period X elapses while the mobile terminal cannot receive the desired carrier, the mobile terminal further performs search reception at the remaining frequency f2 during the search reception period X (the period from C to D in FIG. 4). ). Furthermore, if the search reception period X elapses without receiving the desired carrier,
The search reception is stopped to reduce the power consumption and maintain the out-of-range state (the period from D to E in FIG. 4). Out-of-range search cycle T
When the following period has elapsed (at time E shown in FIG. 4),
The mobile terminal searches and receives on each control carrier as in the above operation.

Therefore, the mobile terminal in the out-of-range state receives the search reception at the frequency f1 and the search reception at the frequency f2 at every predetermined out-of-range search cycle T until the mobile terminal receives the desired carrier and shifts to the standby state. repeat. The out-of-range search cycle T and the search reception period X
Is defined by the mobile communication system.

[0012]

However, since the conventional mobile terminal searches and receives twice in each out-of-range search cycle T, compared to the mobile terminal that searches and receives in one wave,
This causes a problem that the period for searching and receiving increases and power consumption in the out-of-range state increases. Since the mobile terminal is used by moving, the power supply capacity is severely limited, and the increase in power consumption has an extremely large effect.

The present invention has been made in view of the above problems, and an object thereof is substantially the same as the case where a mobile terminal capable of communicating with a plurality of control carriers performs search and reception with one wave of control carrier. To reduce the power consumption in the out-of-range state to the level of.

[0014]

In order to solve the above problems, a mobile terminal of a mobile communication system according to the invention of claim 1 has a base station which periodically transmits control information by a plurality of control carriers, When the control information of the base station cannot be received, the mobile terminal of the mobile communication system configured with the mobile terminal that moves to the out-of-range state and the mobile terminal that moves to the out-of-range state when the control information can be received is It is characterized by taking measures.

That is, when the mobile terminal is in the out-of-service area state, the control information is received by the specified control carrier during a predetermined search reception period at every predetermined out-of-service search cycle. Control for designating to the communication means an attempted communication means and a control carrier different from the control carrier designated to the communication means in the previous out-of-range search cycle from the control carriers transmitted by the base station for each out-of-range search cycle And carrier designating means.

In the above configuration, when the control information from the base station cannot be received, the mobile terminal shifts to the out-of-range state. In this out-of-range state, the control carrier designating unit designates the control carrier used by the communication unit for search and reception. The communication means searches and receives on a designated control carrier during a predetermined search reception period in a predetermined out-of-service search cycle.

If the mobile terminal can receive the control information by this search reception, it shifts to a standby state, and if it cannot receive the control information, it waits until the next out-of-range search cycle. As a result, the mobile terminal intermittently repeats the search reception every out-of-range search cycle until the control information can be received.

In the next out-of-range search cycle, the control carrier designating means designates the next control carrier as the communication means before the communication means searches and receives. When designating the next control carrier, a control carrier different from the control carrier designated in the previous out-of-range search cycle is selected.

Therefore, the mobile terminal can repeat search and reception on different control carriers for each out-of-range search cycle. Therefore, the search reception period for each out-of-range search cycle can be shortened as compared with the conventional mobile terminal in which all control carriers search and receive for each out-of-range search cycle. As a result, power consumption can be reduced and battery consumption can be suppressed.

In addition, when the mobile terminal returns to the service area, any control carrier succeeds in the search reception, so that the opportunity to shift to the standby state can be maintained in substantially the same manner as in the conventional case.

Further, in order to solve the above-mentioned problems, the mobile terminal of the mobile communication system according to the invention of claim 2 is the structure of claim 1, wherein the base station uses two control carriers of different frequencies. While transmitting control information by using the control carrier, the control carrier designating means designates a control carrier designated from the two-wave control carriers to the communication means.
It is characterized in that it is switched alternately every out-of-range search cycle.

Therefore, in the mobile terminal that communicates with the base station that transmits the two-wave control carrier, the power consumption can be reduced and the battery consumption can be suppressed while maintaining the opportunity to shift from the out-of-range state to the standby state. it can.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
The following is a description with reference to FIG. That is, the mobile communication system according to the present embodiment is, for example, a base station that regularly transmits control information on control carriers of two different frequencies, and for example, for receiving control information and for location registration. , A mobile terminal capable of communicating with a base station on each control carrier.

As shown in FIG. 1, the mobile terminal has a radio unit (communication means) 2 capable of communicating with the base station (not shown) via an antenna 1, and an out-of-range search for measuring a predetermined out-of-range search period T. A cycle measuring unit 3, a search receiving period measuring unit 4 for measuring a predetermined search receiving period X, and a control unit (control carrier) for controlling the entire mobile terminal by controlling the frequency and period for the wireless unit 2 to search and receive. (Designating means) 5. Further, the above-mentioned respective means are connected by a bidirectional control bus 6 and can transmit control signals and the like.

The out-of-range search period measuring means 3 starts timekeeping by an activation signal transmitted from the control section 5 via the control bus 6. Predetermined out-of-coverage period T since the start of measurement
When the time elapses, the out-of-range search cycle measuring unit 3 can detect this and notify the control unit 5 via the control bus 6. Similarly, the search reception period measuring means 4 receives the activation signal from the control unit 5, measures the search reception period X, and can notify the control unit 5 of the end of measurement. The out-of-range search cycle T and the search reception period X are set according to the mobile communication system configured by the mobile terminal.

The radio unit 2 can search and receive by each control carrier transmitted by the base station under the control of the control unit 5. The control unit 5 sets the frequency of the control carrier to be searched and received, that is, the reception carrier frequency of the radio unit 2. In the wireless unit 2 according to the present embodiment, the control unit 5 also controls the period for searching and receiving.

The control unit 5 detects the end of the search reception period X and the out-of-range search period T by the out-of-range search period measuring unit 3 and the search reception period measuring unit 4, and the radio unit 2
To start and stop search reception. When the control information cannot be received by the search reception, the control unit 5 can alternately switch and set the reception carrier frequency of the wireless unit 2 for each of the out-of-range search periods T.

As a result, when the mobile terminal is in the out-of-range state, the control unit 5 selects
Different control carriers are alternately selected for each predetermined out-of-range search period T, and the radio unit 2 can search and receive on the control carrier during a predetermined search reception period X.

Further, the control section 5 can judge whether or not the control information has been received. Specifically, during search reception, the wireless unit 2 transmits the received data to the control unit 5 via the control bus 6.
I am sending it to. The control unit 5 analyzes this received data,
It is possible to determine whether or not it is the data of the own system. When the data is the data of the own system, that is, when the control information can be received, the control unit 5 controls the wireless unit 2 and the like to perform a predetermined operation including location registration, and shifts the mobile terminal to a standby state. Let

In the above configuration, when the mobile terminal goes out of the service area of the base station due to movement of the mobile terminal,
The mobile terminal shifts to the out-of-service state according to a predetermined procedure. The operation of each unit of the mobile terminal in this out-of-range state will be described below step by step based on the flowchart shown in FIG.

That is, when the mobile terminal goes out of range,
First step 1 (hereinafter abbreviated as S1)
In, the control unit 5 sets the frequency of the reception carrier of the wireless unit 2 to f1.

The control section 5 also activates the search reception period measuring means 4. As a result, the search reception period measuring means 4
Starts timing of the search reception period X (S2). Similarly, the out-of-range search period measuring means 3 is activated based on an instruction from the control unit 5, and starts counting the out-of-range search period T (S).
3). Further, the control unit 5 causes the wireless unit 2 to start search reception at the preset reception carrier frequency (S4).

For example, in the first search reception after shifting to the out-of-range state, in S1, the reception carrier frequency is f1.
Therefore, the wireless unit 2 starts the search reception on the control carrier of the frequency f1 from the time point a shown in FIG.

If any data is received while the wireless unit 2 is performing search reception using the antenna 1, the wireless unit 2
Notifies the control unit 5 via the control bus 6. Control unit 5
Analyzes the received data and determines whether or not the received data is desired data, that is, data of its own system registered in advance in the mobile terminal (S5). If the data is not the desired data, the control unit 5 ignores the received data and continues the search and reception.

Further, the control unit 5 monitors the operation of the search reception period measuring means 4 in S6, and determines whether the search reception period X has elapsed (hereinafter referred to as timeout) or has not elapsed. judge. Specifically, when the search reception period X has elapsed, the search reception period measuring means 4
Notifies the control unit 5 that a time-out has occurred via the control bus 6, and based on this, the control unit 5 determines that the search reception period X has elapsed.

If the determination is negative in S5 and S6, the mobile terminal can repeat S5 and S6 to receive the data of its own system, or
The search reception is continued until the search reception period X has elapsed.

When the search reception period X has elapsed from the start of the search reception without receiving the control information, the control section 5 detects the timeout of the search reception period X in S6. Then, in S7, the control unit 5 instructs the wireless unit 2 to stop the search reception (at the time point b shown in FIG. 2).

Further, the control unit 5 monitors the operation of the out-of-range search period measuring means 3 in a manner substantially similar to S6, and waits until a time-out occurs in the measurement of the out-of-range search period T (S8). In this state, since the wireless unit 2 has not received the search and reception, the power consumption of the mobile terminal is kept low (the period from b to c shown in FIG. 2).

When the out-of-range search cycle measuring means 3 notifies the control section 5 of the timeout, the control section 5 determines whether or not the currently set reception carrier frequency is f1 (S1).
9). If the frequency is f1, the reception carrier frequency of the wireless unit 2 is set to f2 in S10, and then the process returns to S2 and the process of the next cycle is performed. On the other hand, when the frequency is f2, the process returns to S1, the reception carrier frequency of the radio unit 2 is set to f1, and the following process is executed.

For example, as shown in FIG. 2, at the time point c when the out-of-range search period T has passed since the mobile terminal moved to the out-of-range state, the reception carrier frequency set so far is f1. Therefore, the process of S10 is performed, and the control unit 5 sets the reception carrier frequency of the wireless unit 2 to f2.
Set to. Further, the processes of steps S2 to S4 are performed substantially at the same time, and the wireless unit 2 starts the search reception at the reception carrier frequency f2. Further, since the reception carrier frequency is set to f2 at the time point of d when the out-of-range search period T has further elapsed from the time point of c, the above S
The process 1 is performed, and a new reception carrier frequency f1 is set.

Steps S1 to S10 shown in FIG.
The search is performed every out-of-range search cycle T until the search is successfully received. Therefore, the mobile terminal performs the search reception period X with the reception carrier frequency set alternately every out-of-range search period T.
During that period, search reception is performed.

On the other hand, in S5, when the data of the own system can be received, the mobile terminal performs position registration and the like based on the control information included in the received data, and shifts to the standby state (S11).

In this embodiment, the case where the base station transmits the control information by the two control carriers is explained, but the present invention is not limited to this, and the control information may be transmitted by a plurality of control carriers. . If one search reception period X is set for each out-of-range search cycle T and a different reception carrier frequency is set for each cycle T, substantially the same effect as this embodiment can be obtained.

As described above, the mobile communication system according to the present embodiment is composed of the base station transmitting control carriers at a plurality of frequencies and the mobile terminal having the radio section 2 capable of searching and receiving at each of the above frequencies. ing. Further, the mobile terminal measures the control unit 5 for setting the reception carrier frequency of the radio unit 2, the out-of-range search period measuring means 3 for measuring the out-of-range search period T and transmitting the same to the control unit 5, and the search reception period X. Then, the wireless unit 2 is set under the control of the control unit 5 for each of the out-of-range search periods T for the search reception period X. It is configured to search and receive at different frequencies. The control unit 5 selects a different frequency for each out-of-range search cycle T from the plurality of frequencies and sets it in the wireless unit 2 as a reception carrier frequency.

Therefore, as compared with the conventional mobile terminal that searches and receives on all control carriers every out-of-range search cycle T, the time to search and receive every out-of-range search cycle T can be shortened. For example, when two-wave control carriers are used, in each out-of-range search cycle T, the time required for the conventional mobile terminal to search and receive is 2X.
become. On the other hand, in the mobile terminal according to the present embodiment, the search and reception time can be suppressed to X as in the case of using one-wave control carrier. As a result, power consumption can be reduced and battery consumption can be suppressed as compared with a conventional mobile terminal that searches and receives using a two-wave control carrier.

Further, the mobile terminal always searches and receives once every out-of-range search period T defined by the mobile communication system. Further, when returning to the service area, the mobile terminal can receive the control information on any of the reception carrier frequencies. Therefore, the opportunity to shift to the standby state can be maintained in substantially the same manner as in the conventional case.

Further, the control unit 5 sets the
Two predetermined frequencies are alternately set in the wireless unit 2. As a result, when two-wave control carriers are multiplexed, the power consumption can be reduced and the battery consumption can be suppressed while maintaining the opportunity of shifting from the out-of-service state to the standby state. Therefore, it can be suitably used for a self-employed digital cordless telephone system, for example.

[0048]

As described above, the mobile terminal of the mobile communication system according to the first aspect of the present invention, when the mobile terminal is in the out-of-coverage state, has a predetermined search reception period at a predetermined search reception period. , Communication means that tries to receive control information by searching and receiving on the specified control carrier, and communicates in the previous out-of-range search cycle from among multiple control carriers transmitted by the base station in each out-of-area search cycle. The control carrier designating means is configured to designate a control carrier different from the control carrier designated to the communication means to the communication means.

Therefore, the search reception period for each out-of-range search cycle can be shortened as compared with the conventional mobile terminal in which all control carriers search and receive for each out-of-range search cycle. Therefore,
In a mobile terminal capable of receiving control carriers at a plurality of frequencies, it is possible to reduce power consumption and suppress battery consumption while maintaining the opportunity of shifting from the out-of-range state to the standby state.

As described above, in the mobile terminal of the mobile communication system according to the invention of claim 2, in the configuration of the invention of claim 1, the base station uses two control carriers of different frequencies. While transmitting the control information, the control carrier designating unit is configured to alternately switch the control carrier designated from the two-wave control carrier to the communication unit for each out-of-range search cycle.

Therefore, in the mobile terminal communicating with the base station transmitting the two-wave control carrier, the power consumption can be reduced and the battery consumption can be suppressed while maintaining the opportunity to shift from the out-of-range state to the standby state. Produce an effect.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a block diagram showing a main configuration of a mobile terminal.

FIG. 2 is a waveform diagram showing a search reception window waveform in search reception performed when the mobile terminal is out of range.

FIG. 3 is a flowchart showing an operation of each unit of the mobile terminal when searching and receiving when out of service area.

FIG. 4 shows a conventional example, and is a waveform diagram showing a search reception window waveform in search reception performed when the mobile terminal is out of range.

[Explanation of symbols]

 1 antenna 2 radio unit (communication means) 3 out-of-range search period measuring means 4 search reception period measuring means 5 control unit (control carrier designating means) 6 control bus

Claims (2)

[Claims] 1. A base station that periodically transmits control information on a plurality of control carriers, and if the control information of the base station cannot be received, the system moves to an out-of-range state and the control information can be received. ,
In a mobile terminal of a mobile communication system composed of a mobile terminal that shifts to an in-range state, when the mobile terminal is in an out-of-range state, a specified out-of-range search cycle is specified during a certain search reception period. The communication means that tries to receive the control information by searching and receiving on the control carrier, and the control carrier transmitted by the base station at each out-of-range search cycle, are designated as the communication means in the previous out-of-area search cycle. A mobile terminal of a mobile communication system, comprising: a control carrier designating unit that designates a control carrier different from a control carrier to the communication unit. 2. The base station transmits control information using control carriers of two different frequencies, and the control carrier designating unit designates the control unit of the two waves to the communication unit. The mobile terminal of the mobile communication system according to claim 1, wherein the control carrier to be switched is alternately switched for each of the out-of-range search cycles.