JP3678393B2 - Base station selection processing method for mobile communication terminals - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a base station selection processing method in a mobile communication terminal, and more specifically to a base station selection processing method advantageously applied to, for example, a PHS terminal capable of 64 kbit / s bearer transmission.
[0002]
[Prior art]
As a mobile communication system, PHS (Personal Handy Phone System), which was commercialized in May 1995, is a digital cordless phone that has been designed in consideration of sharing with homes, offices, and the public. It is highly expected as the driving force for multimedia including personalization and data transmission.
[0003]
PHS currently communicates at a transmission rate of 32 kbit / s using one time slot, but in the future, it can communicate at a transmission rate of 64 kbit / s using two time slots. As described above, PHS is capable of high-speed data transmission as compared with other mobile communication systems, so that it will acquire many users in the future as a communication means including not only voice calls but also multimedia transmissions. I think that the.
[0004]
[Problems to be solved by the invention]
On the other hand, when the PHS can perform communication at a transmission rate of 64 kbit / s using two time slots in this way, the PHS terminal and the base station can also enjoy the service of 64 kbit / s transmission. The specification must be compatible. Therefore, even a PHS terminal capable of transmitting 64 kbit / s cannot perform 64 kbit / s communication if the base station performing the standby process is a base station with a transmission rate of 32 kbit / s.
[0005]
Thus, even if the PHS terminal can support 64 kbit / s, there is no guarantee that data communication or the like can be performed at a transmission rate of 64 kbit / s unless the PHS terminal distinguishes the base station. On the other hand, since it is possible to distinguish whether the base station is compatible with 64 kbit / s communication by interpreting the content of a message (second system information notification) broadcast on the control channel, the second system information notification is transmitted to the base station. It is possible to preferentially select a 64 kbit / s communication compatible base station by referring to it at the time of selection.
[0006]
However, if a base station corresponding to 64 kbit / s is searched at the time of call connection, there arises a problem that the time required for connection becomes long. This is because the number of base stations corresponding to 64 kbit / s is expected to be small at the beginning of the service, and this problem becomes more serious.
[0007]
In order to solve such a problem, the present invention provides a base having a desired transmission rate without delaying the call connection time in a communication system in which a first transmission rate and a second transmission rate lower than the first transmission rate are mixed. It is an object of the present invention to provide a base station selection processing method for a mobile communication terminal that can be preferentially connected to a station.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a first base station capable of communicating with a mobile communication terminal at a first transmission rate, and a second transmission rate that is lower than the first transmission rate. In a base station selection processing method for a mobile communication terminal in a mobile communication system in which at least a second base station capable of communicating with a mobile communication terminal is mixed, the first base station other than the base station currently performing standby processing The base station is searched for using the idle time, and the first base station searched using the idle time is stored in the memory as a candidate base station for the next standby process, and the current standby process is performed. When the received electric field level of a given base station falls below a predetermined value, the first base station having the highest received electric field level is selected as a new base station for performing standby processing from among the candidate base stations stored in the memory. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a base station selection processing method for a mobile communication terminal according to the present invention will be described in detail with reference to the accompanying drawings.
Referring to FIG. 2, there is shown a functional block diagram showing an embodiment when the mobile communication terminal according to the present invention is applied to a PHS terminal. The PHS terminal 10 according to the present embodiment is a TDMA mobile communication terminal capable of performing 64 kbit / s bearer transmission using two time slots.
[0010]
The PHS terminal 10 of the present embodiment also searches for neighboring base stations capable of 64 kbit / s bearer transmission as standby candidate base stations that perform standby reception processing in the intermittent reception gap during standby. The applicant of the present application has already filed Japanese Patent Application No. 8-316453 as a related technology of a PHS terminal capable of controlling two time slots.
[0011]
In FIG. 2, an antenna 12 receives radio waves transmitted from a base station and outputs them to radio units 14a and 14b, and radiates signals input from these radio units 14a and 14b into space. Each of the radio units 14a and 14b is a radio unit that processes a signal of one slot with a transmission rate of 32 kbit / s. That is, these radio units 14 amplify and frequency-convert the signal for one slot received from the antenna 12 and output the signal to the speech path control unit 16, and the voice modulation signal for one slot from the speech path control unit 16. Amplified and frequency-converted and output to the antenna 12.
[0012]
The communication path control unit 16 has functions such as switching control of a communication path of two 32 kbit / s time slots, channel codec, voice processing, modulation / demodulation, and the like.
[0013]
Specifically, the speech path control unit 16 demodulates and decodes the signal input from the radio unit 14 by the time slot according to the control of the call control unit 18, and after amplification, the signal is sent to the speaker 20 (or the data port 29) Output. Similarly, the signal input from the microphone 22 (or the data port 29) is amplified, encoded, modulated, and output to the radio unit 14.
[0014]
The call control unit 18 is a control unit that controls the entire PHS terminal 10 including protocol processing. The call control unit 18 includes a memory such as a ROM and a RAM therein, and operates according to a call processing program stored in the ROM. That is, when the LCD display unit 24 and the key operation unit 26 are connected and the call control unit 18 receives an incoming call request from the base station via the radio unit 14, the call control unit 18 receives a ring tone from the speaker 20 via the communication path control unit 18. And an incoming call display on the LCD display unit 24.
[0015]
When a response operation by the key operation unit 26 is detected, the speech path control unit 16 is controlled to set the speech path. Further, when a call operation is performed from the key operation unit 26, the input telephone number or the like is displayed on the LCD 24, and a call request is made to the base station that performs the standby process by controlling the radio unit 14. Do. Thus, when the called party terminal responds, the speech path control unit 16 is controlled to set the speech path.
[0016]
In addition, the call control unit 18 receives a control channel from a neighboring base station via the radio unit 14, and selects a base station and a standby candidate base station that perform standby processing. That is, in the present embodiment, the call control unit 18 is connected to the base station ID storage memory 28 and stores in the memory 28 peripheral base stations capable of 64 kbit / s bearer transmission other than the base station that performs standby processing.
[0017]
Specifically, the control unit 18 monitors the control channel in the intermittent reception gap that is on standby, and determines whether the base station is compatible with 64 kbit / s communication according to the content of the second system information notification in the notification information of the control channel signal. Is detected. If the base station is compatible with 64 kbit / s communication, the base station identification information (ID) and the received electric field level are stored in the base station ID storage memory 28 in the 64 kbit / s communication compatible base station table. Note that the 64 kbit / s communication compatible base station table of the memory 28 stores, for example, about 10 base stations for 64 kbit / s communication.
[0018]
The LCD display unit 24 is a display unit that performs various displays such as a telephone number, a message, or a received electric field level of a base station. The key operation unit 26 performs some action on the call control unit 18 such as a power key, an input key for inputting a telephone number or characters of a called party terminal, or a call connection key for performing call processing or response processing. It consists of various keys.
[0019]
FIG. 1 is a processing flow showing the operation of the base station selection processing method of the PHS terminal 10 shown in FIG. Hereinafter, the operation of the present embodiment will be described with reference to FIGS.
In FIG. 1, a base station 1 is a base station in which the PHS terminal 10 performs standby processing, and a period T indicates a battery saving period in which a control channel is intermittently received from the base station 1. By intermittently receiving the control channel signal 100 from the base station 1 with the period T, the call control unit 18 of the PHS terminal 10 monitors the call connection request and the received electric field level of the base station 1.
[0020]
In addition, the call control unit 18 intermittently receives the control channel signal 100 from the base station 1 as described above, and performs monitoring processing of peripheral base stations compatible with 64 kbit / s communication during the intermittent reception. Thus, for example, when the call control unit 18 receives the control channel signal 102 of the base station 2 as shown in FIG. 1, the call control unit 18 interprets the content of the second system information notification, and whether or not it is compatible with 64 kbit / s communication. Judging.
[0021]
As a result, if the base station 2 is a base station compatible with 64 kbit / s communication, the base station ID and the received electric field level are stored in the table of the base station ID storage memory 28 (104), and the base station 2 is awaited. It is assumed that the candidate base station performs processing. In this way, by storing in advance candidate base stations that perform standby processing, even if the received electric field level of the base station 1 falls below a predetermined value, it quickly waits for peripheral base stations that support 64 kbit / s communication. It can be selected as a base station for processing.
[0022]
By repeatedly performing the control channel monitoring process as described above, in the present embodiment, it is possible to grasp the status of peripheral base stations that support 64 kbit / s communication sequentially. Therefore, not only when the received electric field level of the base station 1 falls below a predetermined value, but also when a base station having a higher received electric field level than the base station performing the standby process is found, this 64 kbit / s communication It is also possible to select a corresponding peripheral base station as a new base station that performs standby processing.
[0023]
Although the present embodiment has been described in detail above, the present invention is not limited to the above embodiment, and variations or modifications that can be made by those skilled in the art without departing from the spirit of the present invention are within the scope of the present invention. include. That is, in the present embodiment, the present invention is applied to the PHS to which the present invention is advantageously applied. However, the present invention is not particularly limited to the PHS, and can be applied to communication systems of other systems.
[0024]
【The invention's effect】
As described above, according to the base station selection processing method of the mobile communication terminal of the present invention, it is necessary to switch the base station that performs the standby process by searching and storing in advance a base station that can provide a desired service. Even when it becomes, it becomes possible to select a desired base station promptly. Therefore, the capability of the mobile communication terminal can be fully utilized.
[Brief description of the drawings]
FIG. 1 is a processing flow showing an embodiment of a base station selection processing method of a mobile communication terminal according to the present invention.
FIG. 2 is a functional block diagram showing an embodiment when a base station selection processing method of a mobile communication terminal according to the present invention is applied to a PHS terminal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 PHS terminal 12 Antenna 14a, 14b Radio | wireless part 16 Call path control part 18 Call control part 20 Speaker 22 Microphone 24 LCD display part 26 Key operation part 28 Base station ID storage memory 29 Data port

Claims (3)

A first base station capable of communicating with a mobile communication terminal at a first transmission rate, and a second base station capable of communicating with a mobile communication terminal at a second transmission rate that is slower than the first transmission rate. In a base station selection processing method of a mobile communication terminal in a mobile communication system in which at least a base station is mixed,
Said non base station being currently waiting processing the first base station, searching by using the idle time between the intermittent reception is carried out the currently waiting process,
Stored in the memory as a candidate base station for the next waiting process said first base station searched by using the idle time,
When the received electric field level of the base station currently performing the standby process falls below a predetermined value , a new base station that performs the next standby process is selected from the candidate base stations stored in the memory. A base station selection processing method for mobile communication terminals. 2. The base station selection method according to claim 1, wherein the first transmission rate is 64 kbit / s, the second transmission rate is 32 kbit / s, and the mobile communication terminal is a PHS terminal. A base station selection processing method for mobile communication terminals. 2. The base station selection method according to claim 1, wherein when the received electric field level of a base station currently performing standby processing becomes weaker than that of the first base station searched using the idle time, Even if the received electric field level of the base station performing the processing does not drop to the received electric field level for switching the base station, the searched first base station is set as a base station that performs standby processing. Base station selection processing method for mobile communication terminals.

Images