JP3780920B2 - Mobile communication terminal and computer program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile communication terminal such as a mobile phone configured to make a location registration request to a base station and a computer program executed by the mobile communication terminal.
[0002]
[Problems to be solved by the invention]
2. Description of the Related Art In recent years, mobile phones using a code division multiple access (CDMA) system have been provided as one of mobile communication terminals. By the way, in a mobile phone adopting this type of CDMA system, the mobile phone 1 is not connected to the base station as shown in FIG. 4 due to the influence of the position of the terminal itself and the surrounding environment (for example, the topography and the presence of buildings). 2, the mobile phone 1 can properly receive the signal (downlink signal) transmitted from the base station 2, but the base station 2 can receive the signal (uplink signal) transmitted from the mobile phone 1. It may not be able to receive properly. In such a case, when the mobile phone 1 makes a location registration request to the base station 2, the base station 2 can appropriately receive the uplink signal transmitted from the mobile phone 1 as described above. However, location registration with respect to the base station 2 fails, but the mobile phone 1 can properly receive the downlink signal transmitted from the base station 2, and therefore continues to request location registration with respect to the base station 2. Will be done.
[0003]
However, if the mobile phone 1 continues to make a location registration request to the base station 2 for a long time in this way, the transmission and reception of other mobile phones will be prevented accordingly, and the entire system will There is a problem that it becomes a factor that reduces the success rate of outgoing and incoming calls.
[0004]
The present invention has been made in view of the above-described circumstances, and the object of the present invention is to avoid making a location registration request for a base station continuously for a long time, and thereby the entire system. It is an object to provide a mobile communication terminal and a computer program that can increase the success rate of outgoing and incoming calls.
[0005]
[Means for Solving the Problems]
According to the mobile communication terminal described in claim 1, a base station is searched and acquired, and a group of base stations that can be acquired next is represented based on a neighboring base station list acquired from the acquired base station. A candidate base station is determined and a location registration request is made to the captured base station. Here, the control means determines whether or not there is a base station that has recently succeeded in location registration in the candidate base station, and if there is no base station that has recently succeeded in location registration in the candidate base station. The base station that has succeeded in location registration is added to the candidate base station, and one of the candidate base stations to which the base station that has recently succeeded in location registration has been added is captured. Request location registration to the base station.
[0006]
In this way, the mobile communication terminal determines whether or not a candidate base station has a base station that has recently succeeded in location registration, and the candidate base station has a base station that has recently succeeded in location registration. Otherwise, the base station that succeeded in location registration was added to the candidate base station, and one of the candidate base stations to which the base station that succeeded in location registration was added recently was captured. Therefore, adding a base station that has succeeded in location registration recently to a candidate base station also captures the base station that has recently succeeded in location registration, increasing the possibility of successful location registration for the base station. be able to. As a result, by succeeding in location registration for the base station, it is possible to avoid making a location registration request for the base station continuously over a long period of time. Can be increased.
[0007]
According to the mobile communication terminal described in claim 2, since the control means searches for and captures the base station for each different frequency, the base station is searched using one frequency. Regardless, even if the base station could not be acquired, by changing the frequency used to search for the base station from one frequency to another and searching for the base station using the other frequency The possibility that the base station can be acquired can be increased.
[0009]
According to the computer program according to claim 3, when the computer program is installed in the mobile communication terminal and executed, a procedure for searching for and capturing a base station, and a neighboring base acquired from the captured base station A procedure for determining a candidate base station representing a group of base stations that can be captured next based on the station list, and determining whether or not there is a base station that has recently succeeded in location registration, If there is no base station that has recently succeeded in location registration in the base station, a procedure for causing the candidate base station to add a base station that has recently succeeded in location registration to the base station, and a base that has succeeded in location registration recently. A procedure for acquiring any one of the candidate base stations added by the station and a procedure for requesting location registration for the acquired base station are executed. Since, it is possible to obtain the same effects as those described in the claims above. That is, by adding a base station that has recently succeeded in location registration to the candidate base station, it is possible to capture the base station that has recently succeeded in location registration, in the same manner as described in claim 1 above. Thus, the possibility of successful location registration for the base station can be increased.
[0010]
According to the computer program described in claim 4, when the computer program is installed in the mobile communication terminal and executed, a procedure for searching for a base station and capturing one of the base stations is executed for each different frequency. Therefore, the same effect as that described in claim 2 can be obtained. That is, even if the base station is not acquired even though the base station is searched using one frequency, the frequency used for searching the base station is changed from one frequency to another frequency. By changing and searching for the base station using other frequencies, the possibility of acquiring the base station can be increased.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which a mobile communication terminal of the present invention is applied to a mobile phone will be described with reference to the drawings.
FIG. 2 schematically shows a functional block and a periphery of the mobile phone. A cellular phone 11 is a CDMA radio that performs wireless processing in accordance with a code division multiple access (CDMA) system on a CPU (Central Processing Unit) 12 (control means in the present invention) mainly composed of a microcomputer. Unit 13, voice processing unit 16 that performs voice processing on the voice input by microphone 14 and the voice output by speaker 15, “call start” key, “call end” key, and “numbers” “0” to “9”. An operation unit 17 including a keypad in which a large number of keys such as keys are arranged, a display unit 18 including a liquid crystal display for displaying date / time, telephone number, and the like, a RAM (Random Access Memory), and a ROM (Read Only) Memory) 19 is connected.
[0014]
In this case, when the neighboring base station list is received and acquired by the CDMA radio unit 13 from the base station, the CPU 12 represents a group of base stations that can be captured next based on the acquired neighboring base station list. A base station is determined, and the determined candidate base station is stored in the storage unit 19. Then, when it is time to request location registration, the CPU 12 captures the base station with the strongest received electric field strength (pilot strength) of the pilot signal from the candidate base stations held in the storage unit 19 and captures the captured base station. A request for location registration is made to the base station.
[0015]
Specifically, as shown in FIG. 2, base station A to base station E are located around mobile phone 1, and base station A to base station D are determined as candidate base stations. If the received signal strength of the pilot signal of the base station B of the base station D is the strongest, the base station B having the strongest received signal strength of the pilot signal is captured, and the captured base station B A location registration request is issued to the user. The base station A to base station E are distinguished from each other by a PN (Pseudo Noise) offset.
[0016]
Next, the operation of the above-described configuration will be described with reference to FIGS. Here, FIG. 1 schematically shows the procedure of a computer program (execution program) that the CPU 12 reads from the storage unit 19 and executes.
[0017]
When it is time to supplement the base station, for example, when the mobile phone 11 is turned on, the CPU 12 first sets a counter value m representing the number of times the base station is changed (switched) and searched. Initialization is performed (the value of m is set to “0”) (step S1), and a frequency used for searching for a base station is selected (step S2). Then, the CPU 12 initializes a counter value n indicating the number of retries at the same frequency when the location registration for the base station fails (sets the value of n to “0”) (step S3).
[0018]
Next, the CPU 12 searches for a base station, acquires a base station having the strongest received electric field strength of the pilot signal (satisfying the predetermined condition referred to in the present invention) (step S4), and selects the neighboring base station from the acquired base station. A list is received and acquired (step S5). Then, the CPU 12 determines a candidate base station representing a group of base stations that can be captured next based on the acquired neighboring base station list (step S6).
[0019]
Here, the CPU 12 determines whether or not there is a base station that has recently succeeded in location registration in the determined candidate base station (step S7). Then, if there is no base station that has succeeded in location registration recently in the determined candidate base station (“NO” in step S7), the CPU 12 candidates the base station that has succeeded in location registration recently. Add to the base station (step S8). Specifically, as shown in FIG. 3A, the CPU 12 determines that the base station A to base station D are candidate base stations, and the base station that has recently succeeded in location registration is the base station A to base station. If it is a base station E different from D, there is no base station that has succeeded in location registration recently in the candidate base station. Therefore, as shown in FIG. The base station E that is a successful base station is added to the candidate base stations.
[0020]
Next, the CPU 12 shifts to a standby state (step S9) and determines whether or not a condition for starting a location registration request is satisfied (step S10). Then, when the condition for starting the location registration request is satisfied (“YES” in step S10), the CPU 12 makes a location registration request to the previously captured base station (step S11). Then, the CPU 12 determines whether the location registration for the base station has succeeded or failed (step S12).
[0021]
Here, if the location registration is successful (“YES” in step S12), the CPU 12 initializes the counter value m described above (step S13), and initializes the counter value n described above (step S14). ), The process returns to the above-described step S9, and steps after step S9 are executed.
[0022]
On the other hand, if the location registration fails (“NO” in step S12), the CPU 12 increments the counter value n described above (step S15), and increments the counter value n and the predetermined value N. Are compared (step S16). At this time, as the predetermined value N, an optimum value may be automatically set according to the system operation form, or may be arbitrarily set by the user.
[0023]
If the counter value n is equal to or smaller than the predetermined value N (“YES” in step S16), the CPU 12 removes the base station that failed in location registration from the candidate base stations (step S17), and the base station that failed in location registration The base station with the strongest received electric field strength of the pilot signal is captured from the candidate base stations from which is removed (step S18). Then, the CPU 12 returns to step S5 and executes step S5 and subsequent steps.
[0024]
Specifically, if the base station that has failed in location registration is the base station B, the CPU 12 determines that the base station B that has failed in location registration from the candidate base station, as shown in FIG. remove. Then, the CPU 12 captures the base station E, which is the base station having the strongest received electric field strength of the pilot signal, from among the candidate base stations from which the base station B that has failed in location registration has been removed, and the captured base station A request for location registration is made to E.
[0025]
On the other hand, if the counter value n is not equal to or smaller than the predetermined value N (“NO” in step S16), the CPU 12 increments the counter value m described above (step S19), and increments the counter value m and the predetermined value. M is compared (step S20). At this time, the predetermined value M is automatically set according to the operation mode of the system.
[0026]
If the counter value m is equal to or less than the predetermined value M (“YES” in step S20), the CPU 12 changes (switches) the frequency used to search for the base station (step S21), and returns to step S3 described above. Step S3 and subsequent steps are executed. On the other hand, if the counter value m is not equal to or smaller than the predetermined value M (“NO” in step S20), the CPU 12 prohibits the location registration request (step S22), and is in a standby state in which idle handoff, outgoing call and incoming call are possible. Is maintained (step S23), and counting of the predetermined time T is started (step S24). At this time, the predetermined time T may be automatically set to an optimum value according to the system operation mode, or may be arbitrarily set by the user.
[0027]
After starting to measure the predetermined time T, the CPU 12 monitors whether the idle handoff is successful (step S25), and monitors whether the received electric field strength of the pilot signal from the base station exceeds a predetermined level. (Step S26), and monitoring whether or not the measurement of the predetermined time T has been completed (Step S27). Then, CPU 12 succeeds in idle handoff (“YES” in step S25), or when the received electric field strength of the pilot signal from the base station exceeds a predetermined level (“YES” in step S26), or When the counting of the predetermined time T is completed (“YES” in step S27), the prohibition of the position registration request is canceled (step S28), the counter value m described above is initialized (step S29), and the description is made first. The counter value n is initialized (step S30), the process returns to step S5, and step S5 and subsequent steps are executed.
[0028]
By the way, as described above, a process of adding a base station that has recently succeeded in location registration to the candidate base station (a process of step S8), a process of removing a base station that has failed in the location registration from the candidate base station (a process of step S17), However, it is not always necessary to perform both of these processes, and only one of them may be performed.
[0029]
As described above, according to the present embodiment, in the mobile phone 11, if the location registration request to the base station is made and the location registration to the base station fails, the base stations that failed to register the location thereafter are selected as candidate base stations. Since the base station with the strongest received electric field strength of the pilot signal is captured from among the candidate base stations that have been removed from the station and the base station that failed in location registration has been removed, the base station that failed in location registration is selected as a candidate. By removing from the base station, the location registration request is not made again for the base station that failed to register the location first, that is, the location registration request is made to another base station. It is possible to increase the possibility of successful location registration for the station. As a result, it is possible to avoid making a location registration request to the base station continuously for a long time, and it is possible to increase the success rate of outgoing and incoming calls as a whole system.
[0030]
In addition, in the mobile phone 11, the base station that has succeeded in location registration recently is added to the candidate base station, and the received electric field strength of the pilot signal from among the candidate base stations to which the base station that has succeeded in location registration recently has been added. Since the strongest base station is acquired, adding the base station that has succeeded in location registration recently to the candidate base station also captures the base station that has succeeded in location registration recently. It is possible to further increase the possibility of successful location registration for.
[0031]
Furthermore, in the mobile phone 11, the base station is searched for each frequency different from each other, and the base station having the strongest received electric field strength of the pilot signal is captured, so the base station is searched using one frequency. Nevertheless, even if the base station cannot be acquired, the frequency used to search for the base station is changed from one frequency to another frequency, and the base station is searched using another frequency. By this, the possibility that the base station can be acquired can be increased.
[0032]
The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows.
The mobile communication terminal is not limited to the mobile phone adopting the CDMA method, but may be another terminal such as a portable information terminal having a communication function adopting the CDMA method.
[0033]
The computer program executed by the CPU is not limited to being installed in the mobile phone from the beginning, but may be downloaded and installed from the outside, such as a server or a memory card, as necessary.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an embodiment of the present invention. FIG. 2 is a diagram schematically showing functional blocks and surroundings of a mobile phone. FIG. 3 is a diagram showing transitions of candidate base stations. Schematic diagram of signals sent to and received from the telephone [Explanation of symbols]
In the drawing, 11 is a mobile phone (mobile communication terminal), and 12 is a CPU (control means).

Claims (4)

Search and capture a base station, determine a candidate base station representing a group of base stations that can be captured next based on a list of neighboring base stations obtained from the captured base station, and acquire the captured base station A mobile communication terminal comprising a control means for requesting location registration to a station,
The control means determines whether or not there is a base station that has recently succeeded in location registration in the candidate base station, and if there is no base station that has recently succeeded in location registration in the candidate base station. The base station that has succeeded in location registration is added to the candidate base station, and one of the candidate base stations to which the base station that has recently succeeded in location registration has been added is captured. A mobile communication terminal, which makes a location registration request to a base station. The mobile communication terminal according to claim 1, wherein
The mobile communication terminal characterized in that the control means searches for and acquires a base station for each different frequency. Mobile communication terminal
The procedure to search and acquire the base station,
Determining a candidate base station representing a group of base stations that can be acquired next based on a neighboring base station list obtained from the acquired base station;
It is determined whether or not there is a base station that has succeeded in location registration recently in the candidate base station, and if there is no base station that has succeeded in location registration recently in the candidate base station, A procedure for causing a candidate base station to add a base station that has successfully registered its location to
A procedure for capturing one of the candidate base stations to which a base station that has succeeded in location registration recently has been added,
A computer program for executing a procedure for making a request for location registration to the captured base station. The computer program according to claim 3, wherein
A computer program for executing a procedure for searching for and acquiring a base station for each different frequency.

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