JP4940935B2 - Wireless communication terminal and base station search method thereof - Google Patents

Description

  The present invention relates to a radio communication terminal and a base station search method thereof, and more particularly to a radio communication terminal having a function of changing a base station search cycle and a base station search method thereof.

  In general, when a wireless communication terminal moves away from a wireless base station that is in a synchronized in-service area state and the reception level decreases and shifts to a state outside the service area area, a method called all channel search The base station search is periodically performed, and the operation moves to the system service area of another base station to maintain a communicable state.

  In general, since the base station search needs to operate the reception detection circuit and control unit of the wireless communication terminal, power consumption becomes significant depending on the period, and the driving time of the wireless terminal is shortened. Thus, for example, a technique is known in which if the out-of-service state continues for a certain time, the base station search cycle is lengthened and the search interval is increased.

  If only the above method is used, the base station search cycle becomes long when the device is out of service for a long period of time, and the return to the system service range is delayed, and there is a case where incoming calls cannot be received. Therefore, Patent Document 1 proposes a wireless communication terminal that changes the base station search cycle according to the increasing / decreasing tendency of the reception level. Patent Document 1 describes that, for example, when the reception level tends to increase, it is estimated that the system service area is approaching, and the base station search period is returned to a normal short period to increase the reception performance. ing.

  Further, Patent Document 2 proposes to control the power supply interval to the receiving unit according to past usage conditions, paying attention to the bias in the day of the week and the time zone in which the wireless communication terminal is used for each user. ing.

Tokuma 2006-140912 Japanese Patent Laid-Open No. 2006-20021

  As described above, various timings for switching the base station search cycle have been proposed, but there is still a problem that a base station search cycle that does not match the actual situation of the wireless communication terminal is selected.

  For example, according to the method described in Patent Document 1, a short base station search cycle is adopted when approaching the system service area. However, if there is no actual incoming call, it is necessary to shorten the base station search cycle. It means no.

  The method of Patent Document 2 is also effective for users who use communication with a considerable frequency on the same day of the week or in the same time zone, but inappropriate for users with variations in the day of the week and time zone to be used. It is. Also, even for users who have a certain trend in the day of the week and time zone to use, such a trend does not always continue, because the base station search cycle is shortened for a specific day of the week and time zone, The power saving performance will drop.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to determine a base station search cycle in accordance with a use state of a terminal and optimize a balance between reception performance and power saving performance. An object of the present invention is to provide a base station search method that can be used, and a wireless communication terminal that has an execution function of the base station search method.

According to the first aspect of the present invention, the incoming call history recording unit that records the incoming call history, and the number of incoming calls in a predetermined period retroactive from the time when it is determined to be out of the service area of the base station is lower than a predetermined threshold value. In this case, there is provided a wireless communication terminal including a search cycle determination unit that changes to a base station search cycle longer than a normal base station search .

According to a second aspect of the present invention, there is provided a base station search method for a radio communication terminal, wherein the radio communication terminal records an incoming call history, and the radio communication terminal is out of a service area of the base station. And when the wireless communication terminal determines that the number of incoming calls in a predetermined period retroactive from the time point is lower than a predetermined threshold when it is determined that it is out of the service area of the base station , Changing to a base station search cycle longer than a normal base station search, and the wireless communication terminal performing a base station search using the changed base station search cycle, A base station search method is provided.

  According to the present invention, it is possible to perform control such that the base station search cycle is optimized and reception performance is increased only when necessary. The reason is that it is configured to refer to the past incoming call history and determine whether or not the base station search cycle needs to be changed each time.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a wireless communication terminal according to a first embodiment of the present invention represented by a mobile phone. Referring to FIG. 1, the radio communication terminal according to the present embodiment includes an antenna unit 10, a radio unit 20, a control unit 30, an incoming / outgoing call measurement unit 40, a search cycle determination unit 50, a storage unit 60, An external interface unit 70 is provided.

  The control unit 30 is means for controlling each unit of the wireless communication terminal. For example, the control unit 30 receives and demodulates signals such as broadcast information and call information transmitted from a radio base station (mobile phone base station) on which the radio communication terminal is waiting, and detects a signal error in the demodulated signal. The wireless unit 20 is caused to execute various processes necessary for voice communication and packet communication such as processing and base station search processing described later.

  The incoming / outgoing call measuring unit 40 measures incoming / outgoing calls under the control of the control unit 30. The measurement result is associated with the time information and recorded in the storage unit 60 for a predetermined time or a predetermined number of times as the incoming call history and outgoing call history.

The search cycle determination unit 50 is based on the incoming call history and outgoing call history recorded in the storage unit 60.
With reference to the frequency of outgoing / incoming calls within a predetermined time in the past, it is determined whether or not to extend the base station search cycle when out of service according to a predetermined rule.

  The external interface unit 70 represents a means for interfacing with the control unit 30 and a user interface (not shown) such as a key operation unit, a display unit, a microphone / speaker, and the like.

  For the sake of explanation, the incoming / outgoing call measurement unit 40 and the search cycle determination unit 50 will be described as being different functional blocks from the control unit 30, but may be configured to be included in the function of the control unit 30.

  Next, the operation of the wireless communication terminal according to the present embodiment will be described in detail with reference to the drawings. Hereinafter, for simplicity of explanation, it is assumed that the wireless communication terminal has two long and short base station search (reception detection) modes.

  FIG. 2 is a diagram for explaining the two base station search (reception detection) modes. FIG. 2A shows a first base station search mode in which a base station search (normal base station search) is performed with a period T1 shorter than the period T2 of FIG. FIG. 2B shows a second base station search mode in which a base station search (power-saving base station search) is performed with a period T2 longer than the period T1 of FIG. Ts in FIG. 2 represents the detection time required for the base station search by turning on the power of the radio unit 20 and tuning to the desired channel search frequency. Therefore, the difference between the above two search modes is that the lengths of the sleep periods T1a and T2a in which the radio unit 20 and the like are at rest (disabled) are different. Naturally, the second base station search mode with a long sleep period T2a consumes less power in a certain period of time and is superior in power saving.

  FIG. 3 is a flowchart showing the basic operation of the wireless communication terminal according to the present embodiment. Referring to FIG. 3, in a standby state (range) where transmission and reception are possible at any time within the service area, the control unit 30 of the wireless communication terminal records outgoing / incoming calls (step S001).

  When it is detected that the wireless communication terminal has shifted to the out-of-service-area state (YES in step S002), the control unit 30 refers to the outgoing / incoming data recorded in the storage unit 60 (step S003), and the power saving type It is confirmed whether or not a condition for shifting to the power saving mode for executing the base station search is satisfied (step S004).

  Here, the conditions for shifting to the power saving mode will be described. The condition for shifting to the power saving mode is set to be satisfied, for example, when the number of incoming calls in the most recent period from the current time to a predetermined time before is less than a predetermined threshold value. This is because, when the number of incoming calls is small, it is less necessary to immediately improve the reception performance compared to the case where the number of incoming calls is large.

  Further, for example, not only the number of incoming calls but also the number of outgoing calls can be added to the condition for shifting to the power saving mode. For example, the transition to the power saving mode can be performed when the total number of outgoing / incoming calls in the most recent period from the present time to a predetermined time before is smaller than a predetermined threshold value.

  When the above conditions for shifting to the power saving mode are satisfied, the control unit 30 shifts to the power saving mode in which the power saving type base station search illustrated in FIG. 2B is executed (step S005). On the other hand, when the condition for shifting to the power saving mode is not satisfied, the control unit 30 shifts to the normal mode in which the normal base station search illustrated in FIG. 2A is executed (step S006).

  Further, after shifting to the power saving mode, it is determined whether or not a predetermined power saving mode cancel condition is satisfied (step S007). For example, a power saving mode canceling condition for canceling the power saving mode when a user performs a transmission operation or a folding housing opening operation is set. The control unit 30 promptly returns to the normal mode after receiving the call operation or the like (to step S006). This makes it possible to quickly establish synchronization with the nearest base station.

  When a base station is found by either the power-saving base station search or the normal base station search, synchronization with the base station is established, and the mobile station moves into the service area and returns to the standby state (to step S001). .

  4 and 5 are diagrams showing the outgoing / incoming state recorded when the wireless communication terminal according to the present embodiment moves outside the system service area and the base station search mode to be selected. Both FIG. 4 and FIG. 5 define a power saving mode transition condition for shifting to the power saving mode when the number of incoming calls in the past fixed period Tm from the time Tk when the out-of-service area is detected to the time Tj retroactive is less than the threshold value. It shall be.

  FIG. 4 shows an example in which the number of incoming calls during the past certain period Tm is large. The incoming call is frequently made in the past fixed period Tm, and the reception capability of the wireless communication terminal should be kept high. In such a case, the radio communication terminal performs a base station search in a short cycle in the normal mode.

  FIG. 5 shows an example in which the number of incoming calls during the past certain period Tm is small. Although there are outgoing calls in the past certain period Tm, there are few incoming calls, and it can be said that there is little need to keep the reception capability of the wireless communication terminal high at all times. In such a case, the wireless communication terminal performs a base station search in a long cycle in the power saving mode with emphasis on power saving performance.

  As described above, by selecting an optimal base station search cycle according to the incoming call frequency, it is possible to achieve both reception performance capable of receiving a synchronization signal in a short time and power saving performance.

  The preferred embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the description of the above-described embodiments, and various types can be selected according to the specifications of the wireless communication terminal to be applied. It is possible to add a modification. For example, in the above-described embodiment, the configuration in which the base station search cycle in two stages of the normal mode and the power saving mode is switched has been described. However, the base station search cycle has three or more stages, and according to the incoming frequency or the like, A configuration in which the base station search cycle is changed in stages can also be adopted.

  Further, for example, in the above-described embodiment, the operation mode for executing the base station search with a short base station search cycle is set to the normal mode, and the base station search with a long base station search cycle is executed when the frequency of incoming calls in the past fixed period is low. The operation mode (power saving mode) has been described as switching to the normal mode, and the short base station search is performed when the operation mode for executing the base station search with a long base station search period is set to the normal mode and the frequency of incoming calls in the past certain period is high. It is also possible to switch to an operation mode (reception performance emphasis mode) in which a base station search based on a period is executed.

  In the above-described embodiment, the optimum base station search cycle is changed according to the number of incoming calls (or outgoing / incoming calls). It is also possible to change the station search cycle. In addition to the above, it is also possible to employ a configuration in which the change result of the base station search cycle is corrected by using information such as the time when out-of-service is detected, reception level, area information, and reception electric field level in combination.

  In the above-described embodiments, the present invention has been described with reference to an example in which the present invention is applied to a mobile phone. However, a wireless communication system that performs periodic base station search when out of service area such as an electronic mail terminal or a portable personal computer is adopted. Any wireless communication terminal can be applied in the same manner.

It is a block diagram showing the structure of the radio | wireless communication terminal which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating two base station search modes with which the radio | wireless communication terminal which concerns on the 1st Embodiment of this invention is equipped. 3 is a flowchart showing a basic operation of the wireless communication terminal according to the first embodiment of the present invention. It is a figure for demonstrating the operation | movement specific example of the radio | wireless communication terminal which concerns on the 1st Embodiment of this invention. It is another figure for demonstrating the operation | movement specific example of the radio | wireless communication terminal which concerns on the 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antenna part 20 Radio | wireless part 30 Control part 40 Incoming / outgoing call measurement part 50 Search period determination part 60 Memory | storage part 70 External interface part

Claims (6)

An incoming call history recording unit for recording incoming call history;
A search cycle determination unit that changes to a base station search cycle longer than a normal base station search when the number of incoming calls in a predetermined period retroactive from the time point determined to be out of the service area of the base station is lower than a predetermined threshold ; Having,
A wireless communication terminal characterized by the above. Furthermore, a transmission history recording unit for recording a transmission history is provided,
The search cycle determining unit refers to the transmission frequency in a predetermined period that is traced from the time when it is determined that the base station is out of the service area, and changes the base station search cycle.
The wireless communication terminal according to claim 1 . The search cycle determination unit shortens the base station search cycle when a predetermined terminal operation is performed in an operation state in which the base station search cycle is extended.
The wireless communication terminal according to claim 1 or 2 . A wireless communication terminal base station search method comprising:
The wireless communication terminal records an incoming call history;
Monitoring whether the wireless communication terminal is outside the service area of the base station;
When it is determined that the wireless communication terminal is out of the service area of the base station, if the number of incoming calls in a predetermined period retroactive from that time is lower than a predetermined threshold, the base station is longer than a normal base station search Changing to a search cycle ;
The wireless communication terminal performing a base station search using the changed base station search period,
A base station search method characterized by the above. Further, the wireless communication terminal includes a step of recording a call history,
The wireless communication terminal refers to the transmission frequency in a predetermined period retroactive from the time when it is determined that it is out of the service area of the base station, and changes the base station search cycle,
The base station search method according to claim 4 . Further, the wireless communication terminal shortens the base station search cycle when a predetermined terminal operation is performed in an operation state in which the base station search cycle is extended.
The base station search method according to claim 4 or 5 , wherein:

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