JPH099355A - Mobile communication system - Google Patents

Abstract

PURPOSE: To display in-zone and out-zone accurately when a mobile station whose position is registered in a base station moves to a service area of other base station. CONSTITUTION: An ID discrimination section 8 compares a just preceding base station ID stored in an ID memory 9 with a base station ID received at present and when they are different, that is, the mobile station is resident in a service area of a base station different from that whose position is registered precedingly, a communication enable discrimination level is received from the current base station and the level and the current reception level Lo are compared (level comparison section 3). When the reception level Lo is the reception level or over depending on the comparison result, in-zone notice (display) is conducted and when the reception level is less the discrimination level, out-zone notice (display) is conducted quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for effectively utilizing a frequency of a large capacity mobile communication system and economically realizing it.

[0002]

2. Description of the Related Art In order to realize a large-capacity mobile communication system in a limited frequency band, it is indispensable to improve the frequency utilization rate by repeatedly using frequencies locally.

Therefore, a method is used in which the service area is divided into small zones, base stations are arranged in the respective zones, and a plurality of radio channels are allocated in units of some base stations.

Conventionally, in a mobile communication system having such a small zone configuration, a control station is arranged to control a base station in order to cover a wide service area, and all mobile stations (also referred to as PS) are base stations. A centralized control system under the control of was used. Then, a control line for communication is provided between the control station and the base station and between the base stations, and when setting a communication channel, an unused wireless channel is fixedly allocated in advance in the base station. The method of allocating the channels was used.
However, the increase in the number of channels has led to an increase in the system cost of the base station.

On the other hand, unlike the centralized control method, the M using the distributed control method without such a central control station is used.
There are A cordless telephones. In this case, the service area is set in units of a calling station (which covers a plurality of base stations) compatible with a rosette or PBX,
Since it does not have a control function for location registration of mobile stations, it was not possible to realize a wide service area using a large number of calling stations.

Therefore, JP-A-62-179230 (H
04B 7/26), there is a location registration method for mobile radio communication. That is, the mobile communication system is provided with the location registration function, and the service can be used in any of the service areas of the plurality of base stations.

Specifically, when the mobile station enters the service area, the mobile station receives the ID transmitted from the base station covering the service area and compares it with the I degree stored up to that point. If it does not match, the ID code of the mobile station is transmitted to the base station to perform location registration,
The ID of the base station is stored in the mobile station.

This technology is based on, for example, a PDC (Personal Digital Cellular Telecommunicatio) based on the "digital system car telephone system standard" shown in RCR STD-27, which is the standard of the Radio System Development Center.
System) and PHS based on the "2nd generation cordless telephone system standard" shown in RCR STD-28.
Available for (Personal Handy / phone system).

Here, the callable area of the base station using the PHS system will be described. This base station has a communicability determination level (electric field strength level) as area information that defines the area where communication is possible for each base station.

This communication availability determination level may be the same in different base stations, different base stations may have different values, or a plurality of base stations may be set as a paging area within a service area of a calling station. They may be placed and have the same value.

The base station passes the data of the communication availability judgment level to the mobile station when the mobile station uses a communication channel (also referred to as TCH) such as at the time of location registration or during a call. Then, the delivered mobile station determines, based on the data, whether or not the current reception level is at or above the communication availability determination level indicated by the data, and only when it is at or above the communication level (communicable Area) and communicate with the base station. As a result, it is possible to always realize communication in an area with a good wireless condition.

The configuration of the mobile station for realizing this will be specifically described with reference to the circuit block of FIG.

The RF / IF unit 1 receives a radio signal from an antenna at the time of reception, converts a high frequency signal into an intermediate frequency band signal, and at the time of transmission converts an intermediate frequency band signal into a high frequency signal. To do. The reception level detector 2 detects the received level. The level comparison unit 3 compares the determination level from the level memory 4 that stores a preset communicability determination level with the reception level from the reception level detection unit 2 and notifies the result (display or sound notification). Output to the notification unit 5. Then, if the reception level is higher than the determination level, it is informed that the area is within the receivable area. This determination level is received from the base station that has registered the location, and may have a different value depending on the base station.

The modulation / demodulation unit 6 performs π / 4 shift four-phase QPSK modulation / demodulation on the IF band signal and performs digital signal processing such as TDMA processing. The ID discrimination unit 8 compares the base station ID of the data transmitted from the base station with the immediately preceding ID stored in the ID memory 9 of the mobile station, and if they do not match, the position registration as described above is performed. The position registration unit 7 performs the processing, and the level memory 4 stores the base station ID of the current service area. At the time of this location registration processing, the communication availability determination level is also changed and updated to the value from the base station. On the other hand, if they match, the location is not registered, the communication availability determination level is not changed, and the call can be performed as it is.

Next, this conventional example will be described with reference to the flow chart of FIG.

First, it is assumed that the mobile station is set in the out-of-range state. The power is turned on in step 101, and the out-of-range notification is performed in step 102 because the setting state is out of range. At that time, if it is detected whether the mobile station is in the area or has moved into the area, the reception level is detected in step 103. In step 104, the detected reception level and the judgment level LL registered in the mobile station are compared. In step 104, if the reception level is higher than the determination level LL, step 106 is entered; if it is smaller, step 105 is entered.
Move to

In step 105, when the reception level is lower than the determination level LL, the processing is performed, the notification (display) to the effect that it is out of the service area is made, and the process returns to step 103. This notification (display) information is maintained until the next different notification information. On the other hand, in step 106, if the reception level is higher than the determination level LL, the process is performed, and the notification (display) to the effect that the vehicle is within the range is performed, and the process proceeds to step 107. Step 10
7 is the I of the base station where the mobile station has this mobile station within range.
This is the part that receives D and extracts it.

The extracted base station ID is step 108.
The registered IDs registered in the mobile station are compared with each other to determine whether they are the same. If they are the same, the process proceeds to step 109, the range is continuously notified, and the process returns to step 103. If different, go to step 110,
Performs location registration processing. Then, in step 111, the communication availability determination level of the base station is detected, and in step 112 it is registered in the level memory 4. Then, the process returns to step 103, and the same process is repeated while the power is on.

Therefore, it is possible to recognize that the mobile station is in the service area of the predetermined base station by using the reception level and the communication availability judgment level from the base station, and even if the judgment level differs for each base station, The judgment level can be changed each time, and the user can use the device in any area without having to be aware of which area the user is in.

[0020]

In this prior art example, once it is recognized that the reception level exceeds the communicability determination level, it is considered that the communication area is within the communication area and the inside area is informed. Therefore,
When the mobile station P1 is moved from the base station A to the base station B as shown in FIG. 5A, the communicability determination level La of the previous base station A is compared with the current reception level Lo when the power is turned on, and La <Lo is satisfied.
Therefore, it is considered to be within the communication range, and a notification of the range is given.

However, the base station B has an ID different from that of the base station A, and the location registration process of the mobile station P1 is performed. Therefore, the base station B sets the level at which the electric field strength is higher than that of the base station A as the communicability determination level Lb, and the reception level Lo is Lb> Lo. Therefore, regardless of the fact that it was informed that it was within the communication range earlier, if the location was registered in this way, it would soon be out of the communication range, and that fact would be notified, causing the user to feel uncomfortable and uncomfortable. It is possible that it will end up.

On the other hand, when the mobile station P2 is moved from the base station C to the mobile station D as shown in FIG. 5B, the new base station D has the decision level of the base station C even though the mobile station P2 is in the communication range. As a result, the problem that the display remains out of the range occurs, and the user is confused.

[0023]

The present invention is capable of performing wireless communication with a plurality of base stations and within the service area where at least one of the plurality of base stations can serve. An identification signal transmitting means for transmitting an identification signal indicating the base station within at least the service area, and a reception electric field strength indicating the electric field strength for limiting the reception range preset by the base station. A reception level transmitting means for transmitting information; and a reception level detecting means for detecting the electric field strength from the base station, and a reception level detecting means for detecting the electric field strength from the base station, in which of the base stations the service area exists. When the identification memory stored in the identification signal of the corresponding base station, the identification signal stored in the identification memory, and the identification signal from the receiving base station are compared, and a negative output is obtained. Identification signal determination means for determining that the mobile station is in a service area of a base station different from the service area of the base station registered in the identification memory, and storing the received identification signal in the identification memory; At the time of the negative output of the signal discrimination means, the position registration means for registering that the mobile station is located in its service area to the base station where the mobile station is located, and the last position registration. Of the level memory storing the received electric field strength information of the, the received electric field strength information from the base station that has registered the position, and the received electric field strength information already stored in the level memory by the control of the position registration means. The level selecting means for selecting and outputting, the output from the receiving level detecting means, and the output from the level selecting means are compared, and as a result, the service area There is provided a mobile communication system comprising: the level comparing means for controlling the informing means for informing whether within or out of service, to the mobile station.

[0024]

According to the present invention, the mobile station uses the identification signal (I
Check D), and if it is different from the ID already stored in the mobile station, register a new ID and
A communication availability determination level at which communication with the base station can be reliably performed is acquired from the base station, and the availability of communication is determined using the level.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the block diagram of FIG. The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

Reference numeral 10 denotes a communicability determination level selection unit that receives the lowest level Lf set by the initial level setting unit 11 and sets the communication availability determination level to the lowest level Lf as an initial value.

The operation will be described with reference to this figure. RF / I
The F section 1 receives the radio signal from the base station, and the reception level detecting section 2 receives the reception level L at the point where this mobile station is located.
o is detected.

Then, the modulation / demodulation section 6 extracts the received data, and the base station ID transmitted from the base station therein,
ID of the base station ID stored in the ID memory 9 of the mobile station
The discrimination unit 8 compares and if they are the same, the communication is permitted as it is. In this case, the determination level LL stored in the level memory 4 is selected by the communicable determination level selection unit 10 and output to the level comparison unit 3.

However, if different, the ID discrimination unit 8 sends a command to the position registration unit 7, and the position registration unit 7 performs the position registration process to the base station via the RF / IF unit 1 and I
The base station I currently covering the mobile station in the D memory 9
D is stored. At that time, the communication availability determination level L1 of the base station is taken into the communication availability determination level selection unit 10. The determination level L1 is input to one input terminal of the level comparison unit 3 and stored in the level memory 4.

That is, the communicability determination level selection unit 10 stores the base station I storing the base station ID of the received signal.
If it is the same as D, the communication availability determination level LL stored in the level memory 4 is selected, and the base station I of the received signal is selected.
If D is different from the stored base station ID, the location registration unit 7 selects the communicability determination level L1 of the base station newly registered.

As a result, the set communicability determination level and the set reception level are compared with each other, and the information indicating that the vehicle is out of the service area or out of service is determined and notified.

Further, when the location registration is performed, a control signal from the location registration section 7 is used to determine the communicability determination level selection section 1
0 selects the decision level L1 and controls the level memory unit 4 to write the decision level L1.

Next, the flow of operation will be described with reference to the flowchart of FIG.

The power is turned on in step 1 and step 2
, The level L set in the initial level setting section
f is selected by the communicability determination level selection unit 10.

On the other hand, in step 3, the level of the reception level detector 2 is detected, and this reception level is the initial level Lf.
Is compared with (step 4), and if it is smaller, notification of the out-of-range is performed in step 14 and this is repeated. When the mobile station moves and the reception level becomes higher than the initial level Lf, the process proceeds to step 5 and the ID of the base station is detected.

Normally, in the same area, the ID of the base station
Does not change, it is judged that they are the same in this branch, and the judgment level LL stored in the level memory 4 is read (step 7). Then, in step 8, the reception level Lo
Is judged to be larger than the judgment level LL, and if larger than the judgment level LL, the inside of the area is notified, and if smaller than the judgment level LL, the outside of the area is notified (steps 9 and 10). Then, return to step 3 and repeat until the power is turned off.

However, if the base station with which the mobile station moves is changed and the ID of the base station is different, the process branches from step 6 to step 11, where the location registration unit 7 and RF are connected.
The position is registered in the ID memory 9 by wireless transmission / reception from the / IF unit 1.

Then, the communicability determination level L1 is extracted from the radio signal from the base station whose position has been registered (step 12), and the position registration unit 7 controls the communicability determination level L1 to be registered in the level memory 4. (Step 13). Then, the process proceeds to step 7 and is repeated.

With a series of these operations, the in-range or out-of-range notification is surely made, and the in-range notification and the out-of-range notification are continuously notified at the same position, and the user is not confused.

[0040]

According to the present invention, even when a mobile station moves between different base stations having different communication enable determination levels for each paging area composed of one base station or a plurality of base stations, power is turned on or communication is performed. When moving from outside the area to within the area, the area display (notification) according to the communication availability determination level of the new base station can be performed at any time without being limited to the communication availability determination level stored in the mobile station.

Further, when the power of the base station is turned on or when the base station moves from outside the communication area to within the communication area, an erroneous display (notification) is once made according to the communication availability determination level stored in the base station, and then the communication availability of a new base station is determined. Depending on the level, it is possible to solve the problem that a correct display (notification) is made, and it is possible to realize a display without a feeling of strangeness.

[Brief description of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3 is a system block diagram of a conventional example.

FIG. 4 is a flowchart of a conventional example.

FIG. 5 is a diagram showing a communication area between a base station and a mobile station.

[Explanation of symbols]

 1 RF / IF unit 2 Reception level detection unit 3 Level comparison unit 4 Level memory 5 Notification unit 6 Modulation / demodulation unit 7 Position registration unit 8 ID determination unit 9 ID memory 10 Communication possible determination level selection unit 11 Initial level setting unit

Claims (3)

[Claims] 1. A plurality of base stations, and a mobile station capable of performing wireless communication with the base station within a service area where at least one base station of the plurality of base stations can serve, Identification signal transmitting means for transmitting an identification signal indicating the base station, and reception level transmission for transmitting reception electric field strength information indicating electric field strength for limiting the reception range preset by the base station, at least within the service area. Means for the base station, the reception level detection means for detecting the electric field strength from the base station, the base station of the base station corresponding to which of the base stations the mobile station exists in the service area An identification memory stored as an identification signal, an identification signal stored in the identification memory, and an identification signal from the receiving base station are compared, and when the output is negative, the identification memory is stored in the identification memory. An identification signal determination means for determining that the mobile station is in a service area of a base station different from the service area of the recorded base station and storing the received identification signal in the identification memory; At the time of negative output, to the base station provided with the service area where the mobile station is located,
Position registration means for registering that the mobile station is located in its service area, level memory for storing received electric field strength information at the time of the last position registration, and the reception from the position-registered base station. Electric field strength information and received electric field strength information already stored in the level memory are selected by control of the position registration means,
A level selecting means for outputting, an output from the receiving level detecting means and an output from the level selecting means for comparison, and a level comparing means for controlling an informing means for informing whether the service area is within or out of the service area; , A mobile communication system comprising the mobile station. 2. The level memory stores the received electric field strength information of the registered base station when the location registration means operates and location registration processing is performed. Mobile communication system. 3. An initial level setting means for holding a preset initial level and outputting the initial level to the input of the level selecting means, and the level selecting means is provided when the power is turned on or when the service area is out of service area. 3. The movement according to claim 1, wherein the initial level is selected, the level comparison means compares the output level from the reception level detection means, and the result is used to control the notification means. Communications system.