JP2991872B2 - Wireless mobile terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio mobile terminal used in a mobile communication system in which a radio base station is arranged in each radio zone and registers the position of a radio mobile terminal moving in a radio area comprising a plurality of radio zones. It is about.

[0002]

2. Description of the Related Art There is an automobile telephone as a method for realizing a location registration function of a conventional mobile communication system. In a mobile phone, a plurality of wireless base stations are combined to form a location registration area in order to reduce location registration traffic. That is, all the wireless base stations in the same area transmit the same location information, so that the location registration is not performed even if the wireless mobile terminal moves in a different wireless zone in the same location registration area. According to this method, the location registration traffic can be reduced as much as the location registration area is enlarged. However, at the time of an incoming call, a paging call is sent to a plurality of radio base stations constituting the wide location registration area and the incoming call information is transmitted. The traffic for incoming calls increases. Therefore, a method has been considered in which a plurality of wireless base stations are registered for each wireless mobile terminal, and a call is received to the registered wireless base station (Japanese Unexamined Patent Publication No. Sho 63).
175535 gazette).

[0003]

In this system, the condition for the wireless mobile terminal to execute location registration is to newly register the location when it becomes impossible to communicate with all the registered wireless base stations. If so, the loss of incoming and outgoing calls increases as the number of wireless base stations in which communication is impossible among the wireless base stations whose location is currently registered increases. In order to avoid this, all wireless mobile terminals, when at least one of the wireless base stations for which the current location is registered cannot communicate, is to perform new location registration. When a wireless mobile terminal holder who has a low frequency of traveling moves on a train, there is a possibility that location registration is frequently performed, and extra location registration traffic is generated. In particular, the influence becomes larger as the radius of the service zone managed by the radio base station becomes smaller.

As described above, in a mobile communication system in which a plurality of radio base stations are registered, if the location registration condition is the same for all the radio mobile terminals, a radio base station capable of performing a call required for each radio mobile terminal is provided. Despite the different numbers of
Since the location registration of the wireless base station that can talk under the same condition is performed, the location registration is performed inefficiently.

Accordingly, an object of the present invention is to provide a radio mobile terminal capable of performing position registration of a plurality of radio base stations and controlling the timing of position registration in order to perform position registration efficiently.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention transmits and receives signals to and from a plurality of radio base stations and detects an identification code for each radio base station transmitted from a plurality of radio base stations. Wireless transmitting and receiving means, electric field strength measuring means for measuring the electric field strength of a signal received from the radio base station, position registration memory means for storing an identification code corresponding to the radio base station whose position is registered, Location registration condition means storing conditions for executing, and determine whether communication is possible with the radio base station based on the electric field strength measured by the electric field strength measurement means, the number of radio base stations that can talk Control means for deciding whether or not to execute location registration based on the number of radio base stations registered for location and the number of radio base stations capable of talking among the registered radio base stations. Terminal.

[0007]

According to the present invention, the position is determined based on the number of wireless base stations capable of talking, the number of registered wireless base stations, and the number of wireless base stations capable of talking among the registered wireless base stations. By determining whether registration can be performed or not, it is possible to construct a communication system for efficiently performing location registration of a wireless mobile terminal.

[0008]

FIG. 1 is a block diagram showing one embodiment of a mobile communication system using a wireless mobile terminal according to the present invention. The wireless base stations 1a, 1b, 1c, 1d, and 1e are connected to the wireless control station 2 by wire lines. Radio base stations 1a, 1b, 1c,
The control channels transmitted from 1d and 1e contain different identification codes from each other.
b, 1c, 1d, and 1e are wireless zones 1A, 1
B, 1C, 1D, and 1E are formed. Wireless mobile terminal 4
Registration performed by the wireless base stations 1a, 1b, 1c, 1d,
1e and notified to the wireless control station 2 via a wired line, and registered in the position registration memory 3.

FIG. 2 is a block diagram showing one embodiment of the wireless mobile terminal 4 according to the present invention. A plurality of wireless base stations 1a, 1
The wireless transmission / reception unit 5 for detecting the identification code included in the control channels transmitted from b, 1c, 1d, and 1e is connected to the control unit 6. The electric field strength measurement unit 11 is connected to the radio transmission / reception unit 5 and receives the radio base station 1 received by the radio transmission / reception unit 5.
a, 1b, 1c, 1d, and 1e, which measure the electric field strength of the radio waves transmitted from them, and are connected to the control unit 6. A plurality of wireless base stations 1a, 1b, 1c, 1d, 1
The identification code of e is stored in the position registration memory 7. The control unit 6 that determines whether or not to execute the position registration is connected to the wireless transmission / reception unit 5, the electric field strength measurement unit 11, the position registration memory 7, and the position registration condition unit 8 that stores various conditions for executing the position registration. doing.

The operation of one embodiment of the wireless mobile terminal 4 according to the present invention will be described below. Radio base stations 1a, 1b, 1c,
The control unit 6 monitors the identification codes included in the control channels from 1d and 1e through the wireless transmission / reception unit 5. The control unit 6 controls the radio base stations 1a, 1a,
b, 1c, 1d, and 1e, the electric field intensity measuring unit 11
Get from. The control unit 6 calculates the number n of the communication-disabled state based on the electric field strength. When the ratio of the number n of identification codes registered in the position registration memory 7 to the number N _C exceeds the lower allowable fluctuation rate preset in the position registration condition section 8, a new position registration is performed. The control unit 6
Of the identification codes corresponding to the radio base stations 1a, 1b, 1c, 1d, and 1e monitored through the radio transmission / reception unit 5, the signal can be received from the corresponding electric field strength measured by the electric field strength measurement unit 11. The number N ₀ of the objects is calculated, and if the ratio of the number exceeding Nc (N ₀ −N _C ) to N _C exceeds the allowable fluctuation rate set in advance in the position registration condition unit 8, a new position registration is performed. Execute

When the location registration is newly executed, the location registration condition section 8 starts with the radio base station 1a, 1b, 1c, 1d, or 1e in the receivable state, which has a large electric field strength of the received radio wave of the control channel. With the stored maximum registration number as the maximum number, a position registration request signal to which a corresponding identification code is added is transmitted through the wireless transmission / reception unit 5 and stored in the position registration memory 7. The radio base stations 1a, 1b, 1c, 1d, and 1e transmitting the position registration request signal are, for example, those having the highest electric field strength of the received radio wave measured by the electric field strength measuring unit 11.

The upper allowable fluctuation rate, the lower allowable fluctuation rate, and the maximum number of registrations may be fixedly set in the form of a ROM or the like according to the expected frequency of incoming and outgoing calls.
It is also possible to provide a condition setting unit 9 as shown in FIG. 3 so that the user can set the condition.

In the case of the wireless mobile terminal 4 having a high moving speed, new wireless zones 1A1B, 1C, 1D,
As you move 1E, the frequency of performing location registration is
If the upper allowable fluctuation rate or the lower allowable fluctuation rate is the same, the number is larger than that of the moving speed that is low. Therefore, based on the electric field intensity measured by the electric field intensity measuring unit 11 shown in FIG. 4, the control unit 6 sets the upper allowable variation by the moving speed of the wireless mobile terminal 4 measured by the speed detecting unit 10 based on the temporal change. By automatically setting the rate, the allowable fluctuation rate, and the maximum number of registrations,
Location registration can be performed efficiently. The moving speed of the wireless mobile terminal 4 is measured at the wireless base stations 1a, 1b, 1c, 1d, and 1e based on the received electric field strength of the radio wave transmitted from the wireless mobile terminal 4, and the wireless base stations 1a, 1b
By transmitting control signals from b, 1c, 1d, and 1e, it is also possible to set the upper allowable fluctuation rate, the lower allowable fluctuation rate, or the maximum number of registrations in the position registration condition section 8.

Similarly, as shown in the block diagram of one embodiment of the wireless mobile terminal 5 shown in FIG. 5, a location registration condition section 8 is provided according to various conditions such as the current position and the current time of the wireless mobile terminal 4.
A configuration in which the control unit 6 automatically sets the upper allowable variation rate and the lower allowable variation rate recorded in the control unit 6 is also conceivable. Position measurement unit 1
In 3, the position where the wireless mobile terminal 4 is currently located is measured based on the electric field strengths of the plurality of radio base stations 1a, 1b, 1c, 1d and 1e measured by the electric field strength measuring unit 11, and the position information is controlled. It is transmitted to the unit 6. The time measuring unit 12 has a clock inside and is connected to the control unit 6. The control unit 6 automatically sets the upper allowable fluctuation rate, the lower allowable fluctuation rate, and the maximum number of registrations in the position registration condition section based on the current time obtained from the time measuring unit 12 and the position information obtained from the position measuring device 13. I do.

FIG. 6 shows a flowchart of an embodiment of a location registration process performed by the wireless mobile terminal based on the upper allowable variation rate and the lower allowable variation rate registered in the location registration condition section 8.
In the figure, in step 20, the number Nc of the radio base stations 1a, 1b, 1c, 1d, and 1e whose positions are currently registered is reset. The current call ready in step 21 the wireless base station 1a, 1b, 1c, 1d, counts the number of 1e (the number of counts to N _0). In step 26, Nc
It is determined whether it is 0. If Nc is 0, communication is possible
Wireless base stations 1a, 1b, 1c, 1d, and 1e
Register the maximum number of registrations in ascending order of field strength (Step 2
5). If Nc is not 0 in step 26, communication is possible
The number N of the wireless base stations 1a, 1b, 1c, 1d, and 1e whose positions are currently registered is counted (step 22). N is the case is below the radio base station 1a currently location registration, 1b, 1c, 1d, the number N _C of 1e compares the ratio of N _C -N for N _C and lower allowable variation rate ( Step 23). When the ratio exceeds the lower allowable fluctuation rate, the radio base station 1 in a communicable state is set.
The maximum registration numbers a, 1b, 1c, 1d, and 1e are registered in ascending order of electric field strength (step 25). In step 23 if (N _C -N) / N _C is not greater than the lower allowable variation rate, N ₀ is compared with the upper allowable variation rate ratio for the number of N _C which exceeds the N _C (step 24) . As a result, if the ratio of the number exceeds the maximum allowable fluctuation rate, the radio base stations 1a, 1b, 1c, 1d, and 1e in a communicable state are provided.
Are registered in the order of increasing electric field strength (step 25).

If the user can arbitrarily set the location registration conditions, if the upper allowable variation rate and the lower allowable variation rate are set small in all the wireless mobile terminals 4, location registration traffic increases in the entire system. Therefore,
Rather than allowing the user to arbitrarily set the location registration condition, the wireless control station 2 can set the location registration condition of each wireless mobile 4 based on the frequency of the location registration request of each wireless mobile terminal 4. It is also possible. In this case, the radio control station 2 is provided with means for calculating the frequency of the position registration request of each radio mobile terminal 4, and the lower permissible fluctuation rate, the upper permissible fluctuation rate, and the maximum number of registrations are determined in consideration of the position registration frequency of the entire system. decide.
The radio control station 2 sends the condition previously determined as the location registration control signal to the radio mobile terminal 4 to the radio base stations 1a, 1b, 1
Send out through c, 1d, 1e. The wireless mobile terminal 4 receives the position registration control signal at the wireless transmission / reception unit 5 and, based on the received lower permissible fluctuation rate, upper permissible fluctuation rate, and maximum registration number, the controller 6.
To change the contents of the location registration condition section 8. As described above, the location registration traffic can be controlled as the whole system.

[0017]

As described above, in the method of performing location registration of a plurality of radio base stations, the condition for performing location registration is set in the radio mobile terminal, so that the radio mobile terminal having a high outgoing / incoming call frequency can be used. On the other hand, by performing setting so as to respond to the change in the number of wireless base stations in a communicable state in a sensitive manner, the probability of occurrence of a call loss can be reduced. On the other hand, by setting the location registration not to be executed unless the number of wireless base stations in a communicable state greatly changes for wireless mobile terminals that are not frequently used, location registration traffic is reduced. You can do it. Also, by controlling the conditions for performing location registration on the radio control station side, location registration traffic can be controlled as a whole system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system using a wireless mobile terminal of the present invention.

FIG. 2 is a block diagram of an embodiment of a wireless mobile terminal according to the present invention.

FIG. 3 is a block diagram of an embodiment of a wireless mobile terminal according to the present invention.

FIG. 4 is a block diagram of an embodiment of a wireless mobile terminal of the present invention.

FIG. 5 is a block diagram of an embodiment of a wireless mobile terminal according to the present invention;

FIG. 6 is a flowchart of an embodiment of a process in the wireless mobile terminal of the present invention.

[Explanation of symbols]

1a-1e Wireless base station 1A-1E Wireless zone 2 Wireless control station 3 Location registration memory 4 Wireless mobile terminal 5 Wireless transmission / reception unit 6 Control unit 7 Location registration memory 8 Location registration condition unit 9 Condition setting unit 10 Speed detection unit 11 Electric field strength Measuring unit 12 Time measuring unit 13 Position measuring unit 20 to 26 steps

Claims (3)

(57) [Claims] 1. Radio transmission / reception means for transmitting / receiving a signal to / from a radio base station and detecting an identification code for each radio base station transmitted from a plurality of radio base stations, and an electric field of a signal received from the radio base station. Electric field strength measuring means for measuring the strength, position registration memory means for storing an identification code corresponding to the radio base station whose position is registered, position registration condition means for storing conditions for executing position registration, Based on the electric field strength measured by the electric field strength measuring means, it is determined whether communication with the radio base station is possible, and the number of radio base stations capable of talking and the number of radio base stations whose location is registered are registered. Control means for deciding whether or not to execute location registration based on the number of radio base stations capable of talking among the radio base stations. 2. The wireless mobile terminal according to claim 1, wherein the location registration condition is automatically set based on various conditions such as a moving speed, a current position, and a current time of the wireless mobile terminal. 3. The wireless mobile terminal receives a position registration request signal transmitted by the wireless mobile terminal at a wireless base station, and receives identification codes of a plurality of wireless base stations from the wireless base station via a wired line. In a mobile communication system having a radio control station having a function of managing the location of a mobile phone, a location registration condition control signal transmitted from the radio control station is received by a radio transmission / reception unit, and the location registration condition is transmitted through the control unit. Is changed according to the location registration condition control signal.