JPH11308656A - Base station selection processing system for mobile communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station selection processing system for a mobile communication terminal capable of being connected preferentially to a base station at a desired transmission speed. SOLUTION: A communication terminal 10 intermittently receives a control channel signal 100 from a base station 1 and conducts monitoring processing of a peripheral base station, having provision for 64 kbit/s communication for the intermittent reception period. Thus, upon the receipt of a control channel signal 102 of the base station 2, a terminal 10 interprets contents of a 2nd system information to discriminate whether or not the information indicates provision for 64 kbit/s communication. When the base station 2 has a provision for the 64 kbit/s communication, the terminal 10 stores the ID of the base station and its received electric field strength in the table of a base station ID storage memory 28 (104) and selects the base station 2 to be an object base station for standby processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station selection processing method in a mobile communication terminal, more specifically, for example, 64k.
The present invention relates to a base station selection processing method which is advantageously applied to a PHS terminal capable of transmitting bit / s bearers.

[0002]

2. Description of the Related Art As a mobile communication system, a PHS (Personal Handy Phone) was commercialized in May 1995.
System) is a digital cordless telephone with a system designed in consideration of sharing of homes, offices, and the public, and is highly expected as a leader in multimedia including personalization of communications and data transmission.

At present, the PHS uses one time slot for communication at a transmission speed of 32 kbit / s, but in the future, it will use two time slots for 64 kbit / s.
Communication can be performed at a bit / s transmission rate.
As described above, PHS is capable of high-speed data transmission as compared with other mobile communication systems. Therefore, as a means of communication including not only voice communication but also multimedia transmission, PHS will acquire many user layers in the future. I think that the.

[0004]

On the other hand, if the PHS can communicate at a transmission rate of 64 kbit / s using two time slots as described above, 64 kbit / s is required.
In order to enjoy the bit / s transmission service, it is necessary that the PHS terminal and the base station also have specifications compatible with this. Therefore, PHS capable of transmitting 64 kbit / s
Even if it is a terminal, the number of base stations performing standby processing is 3
For a base station with a transmission rate of 2 kbit / s, 64 kb
It / s communication cannot be performed.

[0005] Thus, even if the PHS terminal is 64 kbi
Even if t / s can be supported, there is no guarantee that data communication or the like can be performed at a transmission speed of 64 kbit / s unless the PHS terminal side distinguishes the base station. On the other hand, 64 kbit /
Since it is possible to determine whether the base station is an s communication-compatible base station by interpreting the contents of a message (second system information notification) broadcast on the control channel, the second system information notification is referred to when a base station is selected. 64kbi preferentially
It is possible to select a base station compatible with t / s communication.

However, at the time of call connection, 64 kbit /
When searching for a base station corresponding to s, there is a problem that the time required for connection becomes longer. This is because the number of base stations corresponding to 64 kbit / s is expected to be small at the beginning of the service, so that this problem becomes more serious.

[0007] In order to solve such a problem, the present invention provides a communication system in which a first transmission rate and a second transmission rate lower than the first transmission rate coexist. An object of the present invention is to provide a base station selection processing method for a mobile communication terminal that can preferentially connect to a base station of a speed.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a first base station capable of communicating with a mobile communication terminal at a first transmission rate; In the base station selection processing method of the mobile communication terminal in the mobile communication system in which at least the second base station capable of communicating with the mobile communication terminal at a lower second transmission rate coexists, the current standby processing is performed. A first base station other than the base station performing the search is searched using the idle time during standby, and the first base station searched using the idle time is stored as a candidate base station to perform standby processing next. When the reception electric field level of the base station that is currently performing the standby process is lower than a predetermined value, the first base station having the highest reception electric field level among the candidate base stations stored in the memory is subjected to the standby process. I do It is selected as the Tana base station.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 a mobile communication terminal according to the present invention is applied to a PHS terminal. PHS terminal 10 according to the present embodiment is capable of performing TDM capable of performing 64 kbit / s bearer transmission using two time slots.
It is an A-type portable communication terminal.

[0010] The PHS terminal 10 of the present embodiment also searches for a nearby base station capable of transmitting 64 kbit / s bearers as a standby candidate base station for performing the next waiting reception process in the intermittent reception gap during standby. . The applicant of the present application has already filed a Japanese Patent Application No. 8-316453 as a related technique of a PHS terminal capable of controlling two time slots.

In FIG. 2, an antenna 12 receives a radio wave transmitted from a base station, outputs the radio wave 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 having a transmission speed 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 it to the channel control unit 16, and also convert the voice modulated signal for one slot from the channel control unit 16. The signal is amplified and frequency-converted and output to the antenna 12.

The communication path control unit 16 has two 32 kbits.
/ S time slot switching control, channel codec, voice processing, modulation / demodulation, and other functions.

More specifically, the channel control unit 16 demodulates and decodes the signal input from the radio unit 14 according to a time slot under the control of the call control unit 18, amplifies the signal, and then amplifies the signal from the speaker 20 (or data port). 29). Similarly, a signal input from the microphone 22 (or the data port 29) is amplified, encoded, modulated, and output to the radio unit 14.

The call control unit 18 is a control unit that controls the entire PHS terminal 10 including the processing of the protocol system. 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, the call control unit 18 controls the LCD display unit 2
4 and the key operation unit 26 are connected, and when receiving a call request from the base station via the radio unit 14, a ringtone is output from the speaker 20 via the communication path control unit 18 and
An incoming call is displayed on the CD display unit 24.

When a response operation by the key operation section 26 is detected, the communication path control section 16 is controlled to set a communication path. When a call operation is performed from the key operation unit 26, the input telephone number and the like are displayed on the LCD 24, and a call request is issued to the base station that is performing standby processing by controlling the wireless unit 14. Do. Thus, when the called terminal answers, the communication path control unit 16 is controlled to set the communication path.

Further, the call control unit 18 receives a control channel from a peripheral base station via the radio unit 14, and selects a base station for performing a standby process and a standby candidate base station. 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 transmitting 64 kbit / s bearers other than the base station performing the standby process.

Specifically, the control unit 18 monitors a control channel in a gap of intermittent reception during standby,
Based on the contents of the second system information broadcast of the broadcast information of the control channel signal, it is detected whether or not the base station is a 64 kbit / s communication compatible base station. If the base station is a 64 kbit / s communication compatible base station, the identification information (ID) of the base station and the received electric field level are stored in the 64 kbit / s communication compatible base station table of the base station ID storage memory 28. The 64 kbit / s communication-compatible base station table of the memory 28 stores, for example, about 10 base stations corresponding to 64 kbit / s communication.

The LCD display section 24 is a display section for performing various displays such as a telephone number, a message, or a received electric field level of a base station. The key operation unit 26 is a call control unit 1 such as a power key, an input key for inputting a telephone number or characters of a called terminal, or a call connection key for performing a calling process and a response process.
8 is composed of various keys for performing some action on the key 8.

FIG. 1 is a processing flow showing the operation of the base station selection processing method of the PHS terminal 10 shown in FIG. Less than,
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 a PHS terminal 10 performs a standby process, and a cycle T indicates a battery saving cycle for intermittently receiving a control channel from the base station 1. By intermittently receiving the control channel signal 100 from the base station 1 at a period T, the call control unit 18 of the PHS terminal 10 monitors a call connection request and the reception electric field level of the base station 1.

Further, the call control unit 18 intermittently receives the control channel signal 100 from the base station 1 as described above, and performs a monitoring process of a peripheral base station corresponding to 64 kbit / s communication during the intermittent reception. Thereby, when the call control unit 18 receives the control channel signal 102 of the base station 2 as shown in FIG. 1, for example, it interprets the content of the second system information broadcast and determines whether or not it is compatible with 64 kbit / s communication. Judge.

As a result, if the base station 2 is a base station supporting 64 kbit / s communication, the ID of the base station and the reception electric field level thereof are stored in the table of the base station ID storage memory 28 (104), and 2 is a candidate base station that performs standby processing. In this way, by storing in advance the candidate base stations for performing the standby process, even if the reception electric field level of the base station 1 drops below a predetermined value, 64 kb can be promptly obtained.
It is possible to select a peripheral base station that supports it / s communication as a base station that performs standby processing.

By repeatedly performing the control channel monitoring process as described above, according to the present embodiment,
It is possible to grasp the status of the peripheral base station that supports it / s communication. Therefore, not only when the reception electric field level of the base station 1 drops below a predetermined value, but also when a base station having a higher reception electric field level than the base station performing the standby process is found, the 64 kbit / s communication is performed. It is also possible to select a corresponding peripheral base station as a new base station for performing standby processing.

The embodiment has been described in detail above.
The present invention is not limited to the above embodiments, and variations or modifications that can be made by those skilled in the art without departing from the spirit of the present invention are included in the scope of the present invention. That is, in the present embodiment, the present invention is applied to a 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 a communication system of another system.

[0024]

As described above, according to the base station selection processing method of the mobile communication terminal of the present invention, a base station which can provide a desired service is previously searched for and stored, so that the base station which performs the standby processing can be obtained. It is possible to quickly select a desired base station even when station switching is required. 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 for 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 for a mobile communication terminal according to the present invention is applied to a PHS terminal.

[Explanation of symbols]

 Reference Signs List 10 PHS terminal 12 Antenna 14a, 14b Radio unit 16 Call path control unit 18 Call control unit 20 Speaker 22 Microphone 24 LCD display unit 26 Key operation unit 28 Base station ID storage memory 29 Data port

Claims (3)

[Claims] 1. A first base station capable of communicating with a mobile communication terminal at a first transmission rate, and communicating with a mobile communication terminal at a second transmission rate lower than the first transmission rate. In the base station selection processing method of the mobile communication terminal in the mobile communication system in which at least the second base station capable of performing the standby processing is present, the mobile station is waiting for the first base station other than the base station currently performing the standby processing. The first base station searched using the free time is stored in a memory as a candidate base station for performing a standby process next, and the first base station searched using the free time is stored in a memory. When the reception electric field level falls below a predetermined value, the first base station having the highest reception electric field level is selected as a new base station to perform a standby process from among the candidate base stations stored in the memory. Base station selection processing method of the mobile communication terminal to perform. 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. A base station selection processing method for a mobile communication terminal, being a terminal. 3. The base station selection method according to claim 1, wherein the reception electric field level of the base station currently performing the standby process is lower than that of the first base station searched using the idle time. In this case, even if the reception electric field level of the base station performing the standby processing has not decreased to the reception electric field level at which the base station is switched, the first base station searched is set as the base station performing the standby processing. A base station selection processing method for a mobile communication terminal.