JPH04241528A - Digital mobile communication terminal equipment - Google Patents

Abstract

PURPOSE:To shorten a time for executing reception operations, to reduce energy consumption, to update and register in a short time when moving to a different small radio zone and to correctly form a speech path with a communicating party when a call is terminated concerning the mobile communication terminal equipment of a digital mobile communication system to communicate the general terminal equipment of a public network while intermittently receiving radio waves from radio base station, then registering them as the communicatable small radio zones when the radio waves are higher than a certain level receive them. CONSTITUTION:A judgement circuit is provided to measure the electric field intensity of the radio waves from the radio base station and to judge it according to the change of the measured value with the passage of time whether the change of the said electric field intensity is increased or decreased, and a control circuit is provided to change the time interval of the intermittent reception according to the judged result of the said judgement circuit. Then, the interval of the intermittent reception is controlled to be short when the measured value of the electric field intensity is lower than a reference value and is decreased and to be long when the measured value of the electric field intensity is higher than the reference value and is increased.

Description

Detailed Description of the Invention [0001] The present invention relates to a digital mobile communication system that is connected to a general public network, is portable to any location, and is capable of making and receiving calls. In particular, the present invention relates to a method for controlling the time interval of so-called intermittent reception, in which a mobile communication terminal intermittently receives radio waves from a wireless base station. [0002] A digital mobile communication system has a plurality of radio base stations located within a service area and uses each small radio zone to cover the entire service area. It provides services such as making and receiving calls to terminals. FIG. 4 shows an example of the configuration of a digital mobile communication system using a plurality of small wireless zones. 11 to 13 are wireless base stations, and 11' to 13' are wireless small zones formed by the wireless base stations. 14 is a radio line control device that controls the radio base stations 11 to 13 and controls the mobile communication terminals 16,
17 and a general terminal of the public network via the exchange 15. In this digital mobile communication system, in order for a mobile communication terminal to receive a call correctly, it is inefficient to call the mobile terminal from all radio base stations of the system. A method is used in which it is registered which wireless sub-zone of which wireless base station exists, and the call is made only from that wireless base station. Conventionally, as a means of registration, in the explanatory diagram of the conventional example shown in FIG. The electric field strength of the radio wave is 200
A system is used in which when the measured value exceeds a certain level 300', it is recognized as being within the small wireless zone of that wireless base station and is registered. When a terminal moves to another small wireless zone, the radio wave strength from the previous wireless base station weakens beyond a certain level of 100', and the radio waves from another small wireless zone weakens beyond a certain level. When this happens, the mobile terminal recognizes that it has moved to a small wireless zone of a different wireless base station and updates its registration. [0005] The time interval of intermittent reception of conventional mobile communication terminals is constant as described above, and accordingly, the time interval of measurement of electric field strength is also constant. Also,
Since the electric field strength level used as a reference for registration renewal was set at a certain value, if the interval was set too long, the registration renewal would not be carried out immediately even though the user moved to a different wireless sub-zone, and calls would arrive during this time. There was a problem that a communication path with the other party could not be formed correctly in some cases. On the other hand, if this interval is shortened, the time during which reception operations are performed increases, resulting in a problem that the power consumption of the mobile terminal increases. The purpose of the present invention is to reduce power consumption by reducing the time spent in receiving operations in a digital mobile communication system, to update registration in a short time when moving to a different small wireless zone, and to prevent incoming calls from occurring. The object of the present invention is to realize a mobile communication terminal that can correctly form a communication path with the other party in the case of a mobile communication terminal. [Means for Solving the Problem] This object is to measure the electric field strength of received radio waves from a wireless base station and calculate the measured value with reference to the principle diagram of FIG. 1 showing the basic configuration of the present invention. A determination circuit 1 for determining the change in electric field strength determines whether the electric field strength tends to increase or decrease based on the temporal transition; and a time interval control circuit 2 that changes the intermittent reception interval based on the determination result of the determination circuit. When the measured value of electric field strength is lower than the reference value and tends to decrease, the interval of intermittent reception is shortened, and when the measured value of electric field strength is higher than the standard value and tends to increase, the interval of intermittent reception is lengthened. This is achieved by the digital mobile communication terminal of the present invention, which is configured to perform control so as to perform the following functions. [
[Operation] In the present invention, the circuit 1 for determining the change tendency of electric field strength
determines whether the field strength of the received radio waves from the radio base station is increasing or decreasing based on the temporal change in the measured value of the field strength of radio waves received from the radio base station, and the time interval control means 2 determines whether the field strength is increasing or decreasing based on the determination result of the determination circuit 1. The reception time interval is changed, and when the measured value of electric field strength is lower than the reference value and tends to decrease, the interval of intermittent reception is shortened, and when the measured value of electric field strength is higher than the standard value and tends to increase, the interval of intermittent reception is shortened. Control to lengthen the intermittent reception interval. Thereby, the digital mobile communication terminal of the present invention can correctly update the registration of the small wireless zone in which it is currently located, and can also reduce its power consumption. [Embodiment] FIG. 2 is a flowchart for explaining the operation of a digital mobile communication terminal according to an embodiment of the present invention.
FIG. 3 is a diagram showing the relationship between changes in electric field strength during movement and intermittent reception to explain the operation of this embodiment. In the flowchart of FIG. 2, the mobile communication terminal is controlled by, for example, a microcomputer, and is activated at an arbitrary intermittent reception timing. Then, in step 101, the field strength of radio waves from the wireless base station is measured. The measured output is input to the A/D converter built into the microcomputer and read digitally. This read value is then filtered by calculation to obtain an electric field strength value P. Next, in step 102, it is checked whether this electric field strength value P is greater than the registration update threshold Y or lower than the registration update threshold, and if it is lower than the registration update threshold, N
If so, the registration update sequence of step 103 is activated. If this electric field strength value P is larger than the registration update threshold Y in step 102, step 1
04, calculate P', which indicates an increasing/decreasing tendency, using the calculation dP/dt=P'. Furthermore, step 10
5, calculate t= f(
P, P'), determine the intermittent reception interval t. This intermittent reception interval t is a function of P and P', and this function is determined by system design requirements. Then, in step 106, this intermittent reception interval t is set in the microcomputer's built-in timer, and the next step 107
The wireless receiver circuit is turned off and the microcontroller is also moved to low power consumption mode. When the microcontroller's built-in timer times out and generates an interrupt, it returns to operating state. Then, in step 108, the microcomputer turns on the power to the wireless receiving circuit, returns to the first step 101, and repeats the measurement of the electric field strength again. The mobile communication terminal according to the embodiment of the present invention differs from conventional terminals in that the time interval of intermittent reception is controlled by the electric field strength and its increasing/decreasing tendency, which allows registration updates to be performed correctly. In addition, power consumption can be reduced. That is, according to the digital mobile communication terminal of the present invention, the time interval of intermittent reception is controlled by using both the strength/weakness of the electric field strength and the change tendency of its increase/decrease. As shown in the relationship diagram in Figure 3, if the electric field strength is weak and is decreasing, it indicates that the mobile terminal is moving to the outer periphery of the wireless small zone in which it is registered, so there is no need to update the registration. This is the case. In such a case, by controlling the reception interval to be short, the conditions for registration update are satisfied, registration can be updated quickly, and the possibility of incoming calls being lost is reduced. Conversely, if the electric field strength is strong and is increasing, this indicates that the mobile terminal is moving to the center of the wireless small zone in which it is registered, so there is no need to update the registration. In such a case, the power consumption of the mobile terminal can be reduced by controlling the reception interval to be longer. [0010] As explained above, according to the present invention, by controlling the time interval of intermittent reception based on the received electric field strength and its increasing/decreasing tendency, registration updates can be performed correctly and consumption can be reduced. Since the power consumption can be reduced, the communication quality of the digital mobile communication system can be improved and the operation can be made more convenient.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing the basic configuration of a digital mobile communication terminal of the present invention,

FIG. 2 is a flowchart for explaining the operation of the embodiment of the present invention;

FIG. 3 is a diagram showing the relationship between changes in electric field strength during movement and intermittent reception to explain the operation of the embodiment of the present invention;

[Figure 4]
Configuration diagram of a digital mobile communication system using small wireless zones,

FIG. 5 is an explanatory diagram of the operation of a conventional digital mobile communication terminal.

[Explanation of symbols]

Reference numeral 1 designates a circuit for determining the change tendency of the electric field strength, and reference numeral 2 represents a control circuit for the reception time interval.

Claims (1)

[Claims] Claim 1: A circuit (1) for determining a change in field strength, which measures the field strength of received radio waves from a wireless base station and determines whether the field strength tends to increase or decrease based on the time course of the measured value. and a time interval control circuit (2) that changes the intermittent reception interval according to the judgment result of the judgment circuit, and when the measured value of the electric field strength is lower than the reference value and tends to decrease, the intermittent reception interval is changed. A digital mobile communication terminal characterized in that the intermittent reception interval is controlled to be shorter, and when the measured value of the electric field strength is higher than a reference value and tends to increase, the intermittent reception interval is lengthened.