JPH0373625A - Mobile communication system having hierarchical structure - Google Patents

Abstract

PURPOSE:To realize an economical system by constituting the service area with a small radio zone, a medium radio zone including small radio zones and a large radio zone including medium radio zones in a hierarchical way and deciding the location registration method among them and the call method based thereon. CONSTITUTION:The service area is constituted in a hierarchical way such as small radio zones, medium radio zones including the small radio zones and large radio zones including the medium radio zones. The position of a mobile terminal equipment is registered in a small zone area when it stays in the small radio zone and registered in a medium zone when the terminal equipment reaches the medium zone area at the outside of the small radio zone. However, no position registration is implemented even when the terminal equipment reaches a large radio zone at the outside of the medium zone area. An exchange station calls the zone in which the position of the terminal equipment is registered at the arrival of a call. If no reply comes from a small and a medium zone, a large zone is called to inform the arrival of the call to the mobile terminal equipment and the exchange station requests the mobile terminal equipment to move the medium or small zone area for its access. Then the user moves to the small zone or the medium zone and accesses the control station from the mobile terminal equipment.

Description

[Detailed Description of the Invention] [Industrial Field of Application] [Prior Art] Conventionally, in car telephones, etc., the service area is divided into multiple location registration areas, and the mobile terminal has to register the wireless channels currently being received. The electric field strength is constantly measured, and when the electric field strength deteriorates, a new wireless channel with a stronger electric field strength is searched for.
If the channel is a channel in a new location am zone, location registration is performed there.

This location registration information is stored in the exchange, and if a call is subsequently received, the call is made in that location registration area.

Further, the location registration area is covered by a plurality of radio base stations covering a radius of 3 to 5 i, so that calls can be received no matter where the mobile terminal is.

However, in future mobile phones, the radius of the service zone of a wireless base station may be several hundred meters from the viewpoint of effective frequency use. In such small zones, it is difficult to cover the entire service area with the same wireless base station zone.

That is, wireless base stations in small zones are installed only in downtown areas and around stations, and such small zones may not be installed in suburban areas. In other words, communication is impossible in suburban areas and the like.

[WII that the invention attempts to solve]

In the case of such a small zone wireless base station configuration, the present invention is important in providing a system that allows receiving calls even in areas where there is no small zone wireless base station.

[Means to solve the problem]

According to the invention, the above-mentioned advantages are achieved by the means set out in the claims.

That is, according to the present invention, zone Zi-+ is, in principle, Z that has a magnitude relationship that is included in zone Zi.

It consists of N types of paging zones from to ZN, and the mobile terminal is located at 1! When a mobile terminal receives a call after performing location registration in the smallest paging zone that can be registered, if the location registration has been performed in zone Z1, the control station first calls the mobile terminal in zone Zi and receives a response. If not, then zone Z
141, and if there is no response, Zone Zi
+2, Zi+3,...Zn, etc. The mobile communication system of the present invention has a hierarchical structure in which a call is made in successively larger zones, and a call is made in that zone depending on the mobile terminal's response. ) A wireless zone consists of a small zone and a larger zone that includes the small zone, and when the mobile terminal is in the small zone, it communicates in the small zone, and when it moves out of the small zone, it communicates in the larger zone.

(2) In principle, a mobile terminal registers its location in units of small zones, and if there is no small zone, it registers its location in a larger zone.

This is a communication method.

More specifically, in the present invention, the service area is configured hierarchically, for example, as a small wireless zone, a medium wireless zone including the zone, and an Okuma Line zone including the medium wireless zone.

That is, areas with heavy communication traffic are covered by small wireless zones, and the efficiency of frequency use is improved by repeatedly using the same 511#l channel.

On the other hand, areas with low communication traffic are covered by medium wireless zones to avoid an increase in the number of wireless base stations.

Furthermore, areas not covered by these wireless zones will be covered by large zones.

When a mobile terminal enters a small zone area, it registers its location in the small zone area, and when it leaves the small zone area and enters a medium zone area, it registers its location in the medium zone area. However, even if it leaves the medium zone area and enters the large zone, it does not register its location.

This is because the radius of a radio base station in a large zone is as large as several dozen, and the transmission power of a mobile terminal is small so that even if the mobile terminal registers its location, it will not reach the base station in the large zone.

When a call is received, the exchange calls in the zone where the location is registered, but if there is no response in the small or medium zone, it calls in the large zone, informs the mobile terminal that there is an incoming call, and moves to the medium or small zone area. and requests access from a mobile terminal.

Therefore, the user moves to a small zone or a medium zone and accesses the control station from the mobile terminal side.

By doing this, it is possible to repeatedly use wireless channels in areas with high traffic density due to the small zone configuration, and to avoid adding more wireless base stations in areas with low traffic, making it possible to configure an economical system.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG.
) is a diagram showing an example of a zone configuration, and (b) of the same diagram is a diagram showing a connection relationship between each radio base station, a control station, and a switching center.

This example is a zone configuration example in which the calling zone has three layers.
01 is a mobile terminal, 102 to 105 are small wireless zones (Z+
106 to 108 are non-M base stations (hereinafter referred to as "small wireless base stations") in the medium heat zone (corresponding to Zz). (also referred to as "base station" or simply "base station"), 109 is Daij!
It represents a wireless base station (hereinafter also referred to as a "large wireless base station" or simply "base station") in the Li-line zone (corresponding to Z).

Also, 110 is 5iIII1 station, 111 is mail, 1
12 is an exchange, and 113 is a telephone set.

Each of the base stations 102 to 109 has its own dedicated radio channel, and sends out paging data to each mobile terminal as well as its own base station identification code.

In Figure 1 (a), the solid line is the area of the small wireless base station zone, the dotted line is the area of the small wireless base station zone, and the dashed line is the area of the large wireless base station zone, and each area may be overlapping. For example, some have only medium and large zones, or only large zones.

First, location registration will be explained.

In FIG. 1(a), a mobile terminal 101 located at point a (a point marked with an x indicated by the symbol a, below, points with no marks are also expressed in the same way)
Although it constantly receives radio waves from the large zone radio base station 109, it also periodically receives radio waves from each radio channel in the small zone and each radio channel in the medium zone.

That is, the electric field strength of each wireless channel in the zone other than the wireless channel that the user always receives, in this example, the small zone and the medium zone, is measured at regular intervals. When the mobile terminal 101 enters point b within the zone of the base station 102, the electric field of the radio channel of the base station 102 is strongly detected. Then, the mobile terminal 101 refers to the contents of its waiting location registration memory, which stores the name or number of the wireless base station zone in which it previously registered its location, and if it is not the base station 102, it registers the location. The 0 location registration signal transmitted on the uplink radio channel of the base station 102 is received by the control station 110 via the radio base station 102,
A location registration reception completion signal is sent back from the control station 110 to the mobile vJJ terminal 101 if necessary.

Since the location registration signal includes the number of the mobile terminal 101, the control station 110 accesses the memory 111 and stores the radio base station 102 in the location registration area of the mobile terminal 101 number.
memorize the number.

FIG. 2 shows an example of a storage 7t mat of the location registration area for each mobile terminal in the memory 111.

201 is a storage area for mobile terminal numbers, 202 is a storage area for small wireless base station numbers, 203 is a storage area for small wireless base station numbers, 204 is a storage area for large wireless base station numbers, 2
05 is a storage area used for other controls.

The control station 110 searches the storage area 7 of 201 based on the mobile terminal number, and stores the number of the small zone wireless base station 102 in 202. At the same time, in the storage areas 203 and 204,
It has been decided in advance that the small wireless base station 102 will be included! The number of the 1IIa base station 106 and the number of the large wireless base station 109 are stored.

Next, a case where the mobile terminal at point b moves to point C will be explained.

When the mobile terminal 101 moves away from the wireless base station 102,
The electric field strength of the wireless channel of the wireless base station 102, which had been constantly receiving signals until then, deteriorates. Then, the mobile terminal 101 searches for another radio channel of the small radio base station and measures its electric field strength.

If there is a channel in which the field strength exceeds a predetermined value, location registration is performed in that zone; if not, each radio channel of the small wireless base station is searched and its field strength is measured.

In this example, the wireless channel of small wireless base station 106 is strongly received. Therefore, the mobile terminal 101 is connected to the small wireless base station 1.
At 06, a location registration signal is sent. In this case, the transmission power of the mobile terminal 101 needs to be higher than in the case of location registration in a small wireless base station zone. Small wireless base station 10
6, the control station 110 receives the location registration signal of the mobile terminal 101, accesses the number area of the mobile terminal 101 in the memory 111, and stores the number of the small wireless base station 106 in the storage area 203 of FIG. At the same time, the data in the storage area 202 is erased. In addition, the storage area 204
Needless to say, the number of the large wireless base station in which the small wireless base station zone is included is stored.

Next, a case will be described in which the mobile terminal at point C moves to point d.

When the mobile terminal 101 is at point C, the mobile terminal 101 always receives the radio channel of the small radio base station 106 and also periodically searches the radio channel of each small radio base station.
We are measuring whether there are small wireless base station channels with strong electric field strength.

If the electric field strength of the wireless channel of any small wireless base station is strong, even if the electric field strength of the wireless channel of the small wireless base station is strong,
I! register. The control in this case is the same as when moving from point a to point b.

That is, when the mobile terminal 101 moves away from the small wireless base station 106, the electric field strength of the wireless channel of the wireless base station 106, which has been constantly receiving signals, deteriorates. Then the mobile terminal 10
1 searches each radio channel of a small radio base station and measures its electric field strength. If there is a channel in which the field strength is greater than a predetermined value, location registration is performed in that zone. If not, then search each radio channel of the small radio base station and measure its electric field strength. If there is a channel in which the electric field strength exceeds a predetermined value, the location will be registered in that zone, or if there is not,
Next, each radio channel of the large radio base station is searched and its field strength is measured.

In this example, only the radio channel of large radio base station 109 is strongly received. Therefore, the normal operation of the mobile terminal 101 is to send a location registration signal to the large radio base station 109, but in this example, the large radio base station 109 is in the largest zone, and the mobile terminal 101 It is assumed that radio waves cannot reach the large radio base station 109* with the radio transmission output. Therefore, in this case, the mobile terminal 101 does not perform location registration, but simply constantly receives the radio channel of the radio base station 109 and periodically searches for the field strength of the radio channels of other radio base stations. FIG. 3 shows location registration control 70 for these mobile terminals.

However, if only this location registration control method were used, when a mobile terminal moves at high speed in a small wireless base station zone, location registration would be performed frequently. If you were to register your location every time you cross a small zone with a radius of 100 meters, you would need to register your location at least once every 12 seconds.

To avoid this, if the moving speed is fast, the location registration may be canceled or the location registration may be performed in the medium zone instead of the small zone.

In other words, it is desirable for a mobile terminal to measure its own moving speed from the 7 aging pitches of received radio waves, and if the speed is above a certain level, select a radio channel of a small radio base station and register its location there. In addition, location registration in small zones often only increases location registration traffic for users who move frequently; for such cases, location registration in small zones is not performed automatically. There is also a method.

In other words, it is conceivable that automatic location registration is normally performed in the middle zone, and manual location registration is performed only when the user rarely moves. If you use this method, you will be in a small zone, but
Location registration will be performed in the middle zone.

Next, the operation of calling a mobile terminal will be explained.

First, the case where the mobile terminal 101 is at point b in FIG. 1(a) will be described.

When the number of mobile terminal 101 is dialed from telephone 4f1113 from the general telephone network, the dial signal reaches control station 110 via exchange 112.

When the control station 110 searches the memory 111, the base station 102 is stored in the storage area 202 of the mobile terminal 101 shown in FIG.
, the number of the base station 106 is stored in the storage area 7203, and the number of the base station 109 is stored in the storage area 204.

Therefore, in order to make a call from the smallest zone, the control station 110 selects the base station 1 stored in the storage area 202.
02 calls the mobile terminal 101, and if there is a response, a radio channel for communication of the base station 102 is assigned and the communication is made.

When the mobile terminal 101 is at point 0 and has registered its location in the medium radio base station zone, nothing is written in the storage area 202 in FIG.
Since the mobile terminal 101 receives a response from the base station 106 by making a call from the base station 106 from the beginning, the mobile terminal 101 allocates the communication channel of the base station 106.
Make a call.

In addition, in a method that does not register location in a small zone, mobile terminal 1
Even if 01 is at 6 points, nothing is written in the storage area 202 in FIG. 2, and the medium radio base station 1 is written in the storage area 203.
The number 06 is written on it. In this case, the control station 110
makes a call from the medium radio base station 106, but the mobile terminal 1
01 is in the small wireless base station zone, so the small wireless base station 102 responds. Therefore, the control station 110 allows a call to be made using the communication channel of the small wireless base station 102.

When the mobile terminal 101 is at point a, there are various patterns.

If the mobile terminal 101 moves directly from the zone of the base station 102,
When moving to point ia, the number of base station 102 is stored in storage area 202 in FIG. 2, the number of base station 106 is stored in storage area 203, and the number of base station 109 is stored in storage area 204. It's in. When receiving a call from the exchange 112, the control station 110 accesses the memory 111.
Since the storage area 202 contains the base station number, if the call is made in the area of the base station 102, but the mobile terminal 1
Since 01 is at point a, the calling radio wave does not reach control station 1.
Since there is no response from the mobile terminal 101, the mobile terminal 10 calls again several times, but if there is still no response, the next zone written in the storage area 203, the base station 106, makes the call. Even a call from the base station 106 does not reach the mobile terminal 101, so there is no response.

The control station 110 calls again several times, and if there is still no response, the control station 110 next calls the base station 1 from the contents of the storage area 204.
09 number and makes a call at the base station 109. However, even if the mobile terminal 101 is called from the base R109, it can receive the signal but cannot transmit it.

Therefore, the control station 110 sends the mobile terminal 101 to the telephone a113.
The caller is not available to answer the call immediately, so the caller will be notified to hang up the phone and wait.

The number of the telephone 113 is stored in the storage area of the mobile terminal 101 of the memory 111, and the storage area 720b in FIG. 2 is used as the storage area for calling the mobile terminal 101 from the base station 109. The number of telephone 113 is
If it is an ISDN telephone network, it is easily recognized because it is transferred by the control station 110*. Furthermore, even if the network is not an 15DN network, calls can be easily transferred from the general telephone network by using a dialing method similar to automatic dial international calls or credit services.

Furthermore, if necessary, it is also possible to have the telephone 113 send out a push button signal. Mobile terminal 101
The call signal sent to the telephone includes a message indicating that there is a call request. The mobile terminal 101 that received this message learns from, for example, a lamp display on the mobile terminal 101 that transmission is not possible at its current location, and moves to the area of the base station 102.

Since the mobile terminal 101 periodically checks the electric field strength of the wireless channel in the small wireless base station zone and the wireless channel in the medium wireless base station zone, when it comes within the zone of the base station 102, it will be located at the previously mentioned position. When a location registration signal containing the number of the mobile terminal 101 for which registration is automatically performed comes to the control station 110 via the base station 106, the control station 110 stores the number in the memory 11.
1 and rewrites the memory for the above-mentioned location registration, and also looks at the storage area 205 in FIG.

Since the telephone number of the telephone 113 is written in the storage area 205, the control station 110 transfers the telephone 113 to the switching center 11.
2, the mobile terminal 101 is also called, the two are connected, and a conversation is made.

It's Sumeragi. If you can make a call, the phone number in storage area 205 will be deleted.

Here, we have described a method in which a response is performed at the same time as location registration, but there is also a method in which the user can manually perform this response instead of automatically.

That is, when the mobile terminal 101 enters the zone of the base station 102, the location registration is automatically performed, but the communication with the telephone 113 is not automatic, and the mobile terminal 101 is notified by a ringing sound and the like that it is in a zone where transmission is possible. After the user's instructions, such as pressing a specific button, the phone
This is a method of starting a connection with 113.

Although this requires a button press, it has the advantage that the call can be made when the user is in a suitable state.

Further, here, a response is assumed to be from the mobile terminal 101, but the response is not necessarily limited to one using a wireless base station.

For example, it is also possible to use a telephone set on the general telephone network. That is, by dialing a specific number from a telephone (not shown), the control station 110 receives the call and the mobile terminal 101 receives the call.
is transmitted end-to-end from the telephone to the sending control station, and the control station 110 accesses the memory 111 with the number of the mobile terminal 101, reads the number of the telephone 113, and connects both telephones. This is useful when there is no wireless base station nearby, but there are regular telephones.

Even if the mobile terminal 101 is at point a, if it goes from the middle zone 106 to point a without passing through the small zone, the contents of the memory 111 will be different, so the control will be slightly different.

That is, when the control station 110 learns of an incoming call from the telephone Ia 113 to the mobile terminal 101, it is difficult to read the memory 111, but the small wireless base station number is not stored in the storage area 7202 in FIG. The numbers of medium and large wireless base stations are stored only in and 204. Therefore, the control station 110 first calls the zone of the base station 106 written in the storage area 203, but the mobile terminal 101
Since there is no response from the base station 109, the next call is made from the base station 109 in the same manner as above.In this case, there will be fewer invalid calls than in the above case.

Of course, if the mobile terminal 101 is at point a from the beginning,
Since nothing is written in the storage areas 202 and 203 in Figure 2, it goes without saying that a call will be made in the large zone from the beginning. becomes less.

When the mobile terminal 101 is at point a, the control station 110 looks at the memory 111 and sends out a paging signal from the radio base station 102. However, if the paging signal does not reach the mobile terminal 101 due to 7 aging, etc., the control station 110 attempts retransmission several times, and then makes a call from the medium radio base station 106. However, if the mobile terminal 101 is not receiving the radio channel of the medium radio base station, the paging signal will not arrive.

The control station 110 continues to receive calls from the large wireless base station 109, but of course no signal is received from there either. In order to avoid such a situation, of course it is necessary to improve the transmission reliability of the paging signal, but instead of having the mobile terminal 101 receive the radio channel of the small radio base station 102, Station 106, big j! H
It is desirable to sequentially receive the radio channels of one base station 109.

Furthermore, in the above description, it is assumed that location registration and phone calls are also possible in the small wireless base station zone and the medium wireless base station zone, while only calling is possible in the large wireless base station zone. However, Is! in the wireless base station zone! IIl! However, there may be other zones in which calls cannot be made, but a confirmation signal in response to a call can be returned.

In other words, the transmission output of a mobile terminal is proportional to the size of the battery it has, but it cannot transmit at high output for a long time such as during a phone call, but if it is a confirmation signal for a call, it can transmit at a level of several millimeters to tens of millimeters. A second battery is sufficient, and it does not place a large load on the battery.

For example, assume that the medium radio base station 107 in FIG. 1 has only a control radio channel and no communication radio channel.

When the mobile terminal 101 receives a call from the telephone 1f1113,
The control station 110 looks at the memory 11. The small wireless base station number is not written in the storage area 202 of the mobile terminal 101 of the memory 11, and the medium wireless base station 10 is written in the storage area 203.
The number 7 is written on it. Since the control station 110 can also know that the radio base station 107 is a radio base station that has only a control channel, the control station 110 can call the mobile terminal 101 using the same control as the above-mentioned call from the large radio base station.
Sends a call signal to.

When a confirmation signal for the paging signal is returned from the mobile terminal 101, the control station 110 assigns the number of the telephone Ia 113 to the second
In addition to storing it in the storage area 205 in the figure, the phone m1i
Tell s to hang up the phone and wait.

The subsequent operations are the same as in the case of a call from a large wireless base station. Since there is a confirmation signal for the calling signal, it can be confirmed whether the calling has indeed reached the other party or not, thereby reducing unnecessary retransmissions, notifying the telephone 113 of the calling result, etc., and improving serviceability.

In addition, in the above explanation, control in a wireless base station zone without a communication channel is based on a method in which the telephone number of the called telephone 113 is stored in the memory of the control station, and the connection is automatically established in response to a response from the mobile terminal. However, it is also possible to send the telephone number of telephone 113 to the mobile terminal and display it on the mobile terminal. If the telephone number of the primary calling telephone 113 is displayed on the mobile terminal, the user sees it and dials it.
It is possible to receive calls on 3.

〔Effect of the invention〕

As described above, the present invention hierarchically configures a service area into a small wireless zone, a medium wireless zone including the zone, and a large wireless zone including the medium wireless zone, and provides a location registration method based thereon. An economical system was realized by defining the calling method.

In other words, in densely populated areas, a small wireless base station zone is set up to utilize multiple frequencies, and by registering a location in the small wireless zone, calls can be made in the small wireless zone, thereby increasing the efficiency of the wireless channel by using paging signals. We aimed to

In addition, areas with low population density are configured with medium zones to prevent an increase in the number of base stations and enable an economical system configuration. We are trying to make this happen.

Furthermore, in terms of service, in small and medium zone areas where mobile terminals are most frequently present, we have achieved the same service specifications as regular telephones, and even in areas outside the service area, only calls can be made. This service significantly expanded the service area by storing the telephone number of the telephone at the source and allowing the mobile terminal to make a call after moving to the transmission area.

By using this method, even in the future when everyone owns a mobile phone, it will be possible to use wireless channels for 911 calls and create a highly practical system with an economical wireless base station configuration. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a memory 1.
FIG. 3 is a diagram showing an example of storage area 7 of No. 11, and FIG. 3 is a diagram showing location registration control 70 of a mobile terminal. 101...Mobile terminal, 102-1
05 ... Wireless base station in small wireless zone (corresponding to Z), 106 to 108 ... Wireless base station in medium wireless zone (corresponding to Z)

Claims (1)

[Claims] Zone Z_i_-_1 basically consists of N types of paging zones from Z_1 to Z_N that are included in zone Z_1 and have a size relationship, and a mobile terminal performs location registration in the smallest paging zone in which location registration is possible, and When a call arrives at a terminal, if location registration is performed in zone Z_i, the control station first calls the mobile terminal in zone Z_i, and if there is no response, then calls in zone Z_i_+_1, and if there is no response, Zone Z_i_+_2, Z_i_
A mobile communication system that has a hierarchical structure in which calls are made in successively larger zones such as +_3, .