JPH02206929A - Mobile communication system - Google Patents

Abstract

PURPOSE:To miniaturize a terminal equipment by devising the terminal equipment such that it uses a control frequency of a zone in common to all zones so as to attain the implementation of connection, thereby eliminating the need for each circuit applying control channel selection and identification. CONSTITUTION:Upon the receipt of a 2 sets of connection request information or over from one and the same terminal equipment 103, a line controller 102 compares the sets of inputted information as to the measured electric field strength incorporated in them and returns line allocation information to only one base station sending the information of the maximum measured electric field strength among them. Thus, even when a zone control frequency is selected identically to zones 1001-100n, the signal collision in the terminal equipment 103 is prevented and only one route offering the best line quality is selected. Thus, each circuit implementing selection and identification of a control channel is not required the terminal equipment 103 is miniaturized.

Description

[Detailed Description of the Invention] [Summary] Regarding a mobile communication system using a multi-channel access system based on a small zone (micro cell) configuration,
The purpose of this is to prevent signal collisions when the frequencies are the same and thereby make terminals more compact.The service area is divided into multiple zones, a base station is placed in the center of each zone, and all Base station line 11t
A connection request input from a mobile terminal to the line control device via a predetermined base station of the zone using a predetermined control frequency of the zone in which the terminal is located. In a mobile communication system, communication is carried out between the terminal device that has made a connection request and the other party via the predetermined base station and the line (till II) device by allocating a line according to a signal. Each control frequency of each zone is set to the same frequency in all zones, and when each base station receives a connection request transmitted from the terminal at one control frequency of the zone, the received electric field strength at that time is set to the same frequency in all zones. The field strength is measured by a field strength measuring means, and the measured field strength is added to connection request information by a coder and transmitted to the line control device, and the line control device manually detects connection request information from two or more terminals. When this is the case, the line is allocated only to the one M other station that has transmitted the maximum measured field strength information based on the measured field strength information that has been received.

[Industrial application field]

The present invention relates to a mobile communication system, and more particularly to a mobile communication system using a multi-channel access system using a small zone (micro cell) configuration.

In mobile communication systems, the portability of mobile terminal devices is required, so it is necessary to further reduce the size and weight of the terminal devices.

[Conventional technology]

6th F! J shows a configuration diagram of an example of a conventional mobile communication system. In the figure, reference numerals 111, 112, 113 and 114 are base stations (BU: base units), and each is a small zone 12 with a radius of about 50 m, for example, centered on the base station.
+ , terminals in 122.123 and 724 <pu
:Personal unit). The base stations 111 to 114 have wireless carrier frequencies (zone control frequencies) used for wireless communication with terminals set to different frequencies.
Further, each of the base stations 11+ to 114 independently transmits the υ control frequency of the zone assigned to itself.

13 and 14 are the above-mentioned terminals, and are configured to be portable and mobile by the subscriber. Of these, terminal 13 is located in an area where zones 121 and 122 overlap, and terminal 14 is located in an area where zones 121 and 122 overlap, for example. is located within zone 123.

15 is a line control device, 16 is a subscriber file, 17 is a private branch exchange (PBX), and 18 is another communication network. The line υJ control device 15 controls all base stations (base units) 111 to 11.
It is connected to enable wired communication with PBX 17, and also enables verification of subscriber file 16 and communication with PBX 17.

Next, the operation of this conventional mobile communication system will be explained with reference to the connection procedure diagram of FIG. 7. When the terminal 13.14 wants to make a call with the other party on the other communication network 18, it first searches for the 1lJW frequency of the zone in which it is receiving, and if there is more than one (for the terminal t113, f+ and f '
z) is the sub-frequency with the highest received field strength, and when there is only one searched control frequency (f in the terminal 14).
3), a connection request is made to the base 8 (base unit) on the control channel (C-Ctl) using the IIJt[1 frequency.

As an example, a case will be explained in which a connection request is made from the terminal device 13 to the base unit 111. This connection request causes the base unit 111 to set the synchronization bit 20 as shown in FIG. Command bit 21 and PID (
A connection request signal consisting of a terminal ID code 22 is sent to the line control device 15 to perform file verification. Here, the above PID code 22 is a code unique to the terminal 13 sent from the terminal 13 when the terminal 13 makes a connection request, and the base unit 111 uses it as it is as the synchronization bit 20 and the connection request. It is added to the command bit 21 indicating the command and sent.

As shown in FIG. 7, upon receiving the above-mentioned connection request signal, the line control device 15 checks the subscriber file 16 to see if the terminal t1113 is a legitimate subscriber of its own system. If so, the line allocation information is transmitted to the base unit 11+.

In response to this, the base unit 111 notifies the terminal 13 of the line assignment via the control channel. As a result, the terminal device 13 transmits the dial number of the other party in the other communication 118 to the communication channel (S--) assigned to the base unit 111.
ch). This dial number is received by the base unit 11+, and is then input as dial data to the PBX 17 via the line IIJIll device f15. The P8X17 calls the other party based on this dial data, and when the other party responds, the line controller 1
5 to that effect, and from now on, the base unit 11
Terminal through 1! ! A response signal is sent to 113.

When the terminal W113 receives this response signal, the terminal W113 then transmits the base unit 1112 to the other party in the communication network 18.
Normal calls can be made via the line ll1m device f15 and PBX11.

When the call ends and the terminal 13 issues a disconnection request to the base unit 111, the base unit 111 returns a disconnection signal to the terminal 1113 and sends a disconnection notification to the @ line control bag W115. As a result, the line control device 15
The PBX 17 receives the notification and disconnects from the line control device 15.

Note that when the other party makes a call to, for example, the subscriber of the terminal 13, the line control device 115 transmits the PI of the terminal 13 to all of the base units 11+ to 114.
A D code is added and the connection request is sent on the l1111 channel. This causes the terminal 13 to accept this connection request as an I
When received at the IJID frequency f frequency 1, a response is made at the i#JII11 frequency, which has the higher received field strength. Thereafter, the telephone conversation is carried out in the same manner as above.

In this way, in this multi-channel access mobile communication system, the next day's wave numbers are made different for zone identification, so that the mobile terminal Ifi 13.14 can always communicate with other communication networks with optimal line quality. You can talk to the 18th person on the other end.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional mobile communication system, different control frequencies f1 to f4 are used for each zone 121 to 124 for adjacent zone identification, so the terminal device cannot detect its own In order to identify the zone in which the zone is located and communicate with the base unit of that zone, at least a circuit for searching the control frequency of the zone, a circuit for comparing the level of the electric field strength of one received control frequency to be searched, and all the zones. A circuit for transmitting and receiving a control frequency of 1 and a circuit for switching the control frequency for transmission and reception to a control frequency of -, which has the highest electric field strength, are required, which has been an impediment to the miniaturization of terminals.

Ta.

The present invention has been made in view of the above points, and an object of the present invention is to provide a mobile communication system that prevents signal collision when the control frequency of each zone is the same, and thereby reduces the size of terminals. do.

(Means for Solving the Problems) FIG. 1A shows a principle block diagram of the present invention, and FIG. 1B shows a principle block diagram of a base station 101 which is a main part of the present invention. ~100, is the zone,
1011 to 1011 are base stations, and 102 is a line control device. Base stations 1011-1011 are in zones 1001-1
00T+, and are commonly connected to the line control device i 102. A terminal 103 is a mobile object, and its connection request is transmitted to the base station using the control frequency of the zone in which the terminal 103 itself is located. Base station 1011~
101π, the base station that received this connection request sends a line connection request signal to the 11AtlJ'lBH location 102!
,;=Renyori@laljfirJH The station 102 allocates lines and enables communication between the other party and the terminal 103.

In a mobile communication system with such a configuration, the present invention provides zone 1
Each control frequency of 001 to 100t is the same frequency, and base 4101. ~1011 in Figure 1B.
01, electric field strength measuring means 104 and coder 10
5, and the line control device 102 is configured to perform a predetermined
The configuration is such that line allocation is performed for the base stations of -.

[Effect]

One of the factors that hindered the miniaturization of terminals in the conventional mobile communication system mentioned above is the circuit that searches the dust local wave number of the zone and the electric field strength of the searched control frequency. This requires a circuit to compare levels, a circuit to transmit and receive the 01W frequency of all zones, and a circuit to switch the transmission and reception control frequency to the local wave number with the highest electric field strength.
Set the zone control frequency to all zones 1001 to 100.
If the same frequency fG is set for each T+, each circuit for selecting and identifying the vI control channel described above becomes unnecessary, and the terminal can be made smaller.

However, if the zone control frequency is set to the station frequency f in all zones 1001 to 1'0OTl, the connection request from the terminal 103 will be sent to multiple base stations (1011 and 1012 in the example of FIG. 1A) at the same time. Since the signals are received at the same time, a collision of signals will occur.

That is, zones 10J to 100yl! 1Jtl1
If the frequencies are the same and the line allocation information is to be returned under any circumstances as long as the identification code of the terminal 103 that made the connection request is registered in the subscriber file, multiple base stations Different pieces of information will arrive at the same terminal 103 at the same time, and terminal W103 will not be able to receive any information due to the characteristics of the wireless device.

Therefore, as shown in FIG. 5, if a connection request from the terminal 103 is sent to the base station 101. , 1012. 101TI
, and thereby the base stations 1011 and 101
Connection request signals from z and 101T+ are sent to line I control device 1.
02 at the same time, after confirming that the identification code of the terminal 103 is registered in the subscriber file 10G, it is sorted in a preset priority order (for example, in descending order of line number). ), the line control device 102 returns line assignment information only to the earliest base station.
In this case, it is possible to prevent the collision of signals in the terminal 103 with extremely simple determination processing.

However, in this case, for example in FIG.
and the base stations 1011, 1012, and 101Tl, and each distance d+, dz, and dM, d+>dz>
Despite the relationship dTl, base stations 1011 and 1
012, and the route with the best line quality (the route of the base station 101η closest to the terminal 103) is not necessarily selected.

Therefore, in the present invention, each of the base stations 1011 to 101vl is configured as shown in FIG. 1B. In FIG. 1B, when a base station 101 (any one of 1011 to 1011) receives a connection request sent from a terminal 103 at a zone control frequency f, it measures the received electric field strength at that time. Measurement is performed by means 104 and the measurement result is supplied to coder 105.

The coder 105 adds the above-mentioned information on the measured electric field strength to the connection request information of the terminal 103 included in the above-mentioned reception request, and transmits it to the line control device 102 .

In the present invention, the line control device 102 is connected to the same terminal device 103.
When two or more pieces of connection request information are input, the measured electric field strength information input together with them is compared, and a line is allocated only to the one base station that sent out the highest measured electric field strength information. Send information back.

Therefore, in the present invention, the zone 1ldJl! Even when one frequency is the same frequency in each of the zones 1001 to 1001, terminal I! 103 can be prevented, and only one route with the best line quality can be selected.

【Example〕

FIG. 2 shows a block diagram of an embodiment of the main part of the present invention.

In the figure, the same components as in FIGS. 1A and 1B are denoted by the same reference numerals, and the explanation thereof will be omitted.

In FIG. 2, a base station (hereinafter also referred to as a base unit) 101 consists of an IIJWE channel transmitter/receiver section, an active 5 channel transmitter/receiver section 26. Control channel transmitter/receiver 2
5 is a receiving antenna 27. Reception lI28° Reception level detector 29. A/D converter 30. Loader 105. Transmitter 31
．． and a transmitting antenna 32. Receiver 2
i#J of zone received and transmitted by 8 and transmitter 31
The tl1 frequency is a single frequency f.

On the other hand, the communication channel transmitter/receiver 26 receives the anti-t33
, a receiving M'a 34, a sending Fs 35, and a sending my>tenna 36. A base station (base unit) 101 having such a configuration is used in place of the base stations 111 to 111 in the conventional mobile communication system shown in FIG. Further, the line control device 102 is used in place of the line 11w device 15 in FIG.

Next, the operation of this embodiment will be explained. The connection procedure of the mobile communication system having the base station 101 and the line control device 102 of this embodiment is essentially the same as the connection procedure shown in FIG. First, the terminal 103 is in zone 113111.
A connection request is made to the base station (base unit) 101 on the frequency (which is the same in each zone).

This connection request information includes a terminal identification code assigned to the terminal 103, a connection request code, and the like.

The above connection request information received by the receiver 28 via the receiving antenna 27 of the base station 101 is supplied to the coder 105, and the radio wave signal of the control channel extracted from a part of the receiver 28 at that time is received. The signal is supplied to a level detector 29, where the received electric field strength (reception level) is detected.

This detection level is an analog signal, which is converted into a digital signal by the A/D converter 30 at the next stage and then sent to the coder 105.
is supplied to As a result, the coder 105 generates a connection request signal in the signal format shown in FIG. 3 and sends it to the line control device 102.

The connection request signal shown in FIG. 3 is similar to the synchronization bit 20. of the conventional connection request signal shown in FIG. Command bit 21
and a BID code 38 which is a base unit identification code for identifying the base station 101 that sends out this connection request signal in the PID bit 22, and the A/D converter 30.
Field strength bit 3 based on detected reception level data from
9 is added to the signal format.

By inputting a connection request signal in such a signal format,
The line control device 102 operates according to the diagram shown in FIG. In Figure 4, line II I
When the above-mentioned connection request signal is input (connection request reception) in step 40, the II device 102 checks in step 41 whether the PID code 22 therein is that of a valid subscriber registered in the subscriber file. If it is determined that the PfD terminal 103 is registered, it is determined in step 42 whether or not the corresponding PfD terminal 103 is in use.

If it is determined that the terminal 103 is in a call, and in the file comparison in step 41, the input PID code 22
If it is not registered, the call cannot be made or the connection request is from an unauthorized subscriber, so line t, IJil device 1
02 rejects the line connection in step 43, but if it is determined in step 42 that the terminal 103 with the corresponding PID is not busy, the process proceeds to step 44 in FIG. 4, and the same PIDI code 22 is received from another route. Determine whether it is inside or not.

If the terminal 103 issues the connection request at a location where, for example, two zones 1001 and 1002 overlap, as shown in FIG. 1A, both base stations 1011 and 1012 in these two zones Since connection requests are received at the same time, a total of two connection request signals having the PiD code of the same terminal 103 are simultaneously supplied to the line IJ control device 102 from these two base stations 1011 and 1012. It turns out.

Therefore, in such a case, the line 11 JIII device 102
In addition, it is determined that the same-P[D code is being received from the root, and in the next step 45 in FIG. 4, a field strength list is created based on the field strength bit 39 in each input connection request signal, In step 46, the base unit (base station) with the maximum field strength is selected from the BIO code 38 in the connection request signal that is the same as the field strength bit indicating the maximum value in the list.

Thereafter, the line control device 102 returns line assignment information specifying a communication channel only to the base station (base unit) selected in step 46. Therefore, if a plurality of connection request signals having the same PID code are simultaneously supplied to the line control device 102, the terminal device 103
The communication channel is designated only to the one base station from which the connection request from the base station is received with the highest field strength.

In addition, in FIG. 4, if it is determined in step 44 that a PID code with the same value is not received from another route, the process immediately proceeds to step 47 without going through steps 45 and 46, and the same value as the received PID code is determined. A communication channel is designated to the base station indicated by the BID code 38 in the connection request signal.

From step 47 onwards, follow the same connection procedure as in Figure 7.
Transmission of a dialing signal using the designated call channel from the terminal R103 → response from the other party → call → call disconnection is performed by the call channel transmitting/receiving unit 26° line MlIl device 1 (1
2, via a PBX (corresponding to PBX 17 in FIG. 6).

Note that a call from the other party to the terminal 103 is made over the line tAm.
Apparatus 102. Send &t131. Transmission 7>rt32
It is done through. In response to this, when the response IIJwJ signal from the terminal 103 is received by the receiver 28 via the receiving antenna 27, the same operation as described above is performed between the - base station and the line control device that exhibits the maximum received field strength. 102
A call is then made with the other party via the PBX.

In this way, according to this embodiment, the terminal device 103 can make a connection request using the zone control frequency common to all zones, so the terminal device 103 can perform control channel selection and identification, which was necessary in the past. Each of the circuits for this purpose is unnecessary, and since only a small power supply capacity is required, the battery can be downsized, and as a result, the terminal device 103 can be made smaller and lighter than conventional devices.

Also, even if the control frequencies of the zones are the same, the terminal ill
103 does not occur, and it is possible to always select only the base station with the best line quality for communication.

〔Effect of the invention〕

As described above, according to the present invention, a terminal device can be made smaller and lighter than conventional devices, and there is no signal collision at the terminal device, and communication can always be performed via a base station with the best line quality. Also, since there is no need to sequentially search the control frequencies of the zones,
Since the time from when the terminal is activated to when it is possible to make a call can be shortened, the start operation when the terminal is in the holding state (repeat operation and pause at intervals)
It has features such as being able to increase efficiency and further reduce power consumption.

[Brief explanation of the drawing]

FIG. 1A is a configuration diagram of the present invention, FIG. 1B is a principle block diagram of the main part of the present invention, FIG. 2 is a block diagram of an embodiment of the main part of the present invention, and FIG. 3 is a connection request according to the present invention. A signal format diagram of one embodiment of the signal, FIG. 4 is a flowchart for explaining the operation of one embodiment of the line control device according to the present invention, and FIG. 5 is a diagram explaining problems when the control frequency of each zone is the same. , FIG. 6 is a block diagram of an example of a conventional system, FIG. 7 is an explanatory diagram of a connection procedure of a mobile communication system, and FIG. 8 is a signal format diagram of a connection request signal of a conventional system. In the figure, 100 to 10o1 are zones, 1(N, 1011 to 101?I are base stations (base units), 102 is a line l111!l device, 103 is a terminal, 104 is a field strength measuring means, and 105 is a coder shows.

Claims (1)

[Claims] The service area is divided into multiple zones (100_1 to 100_
n), place a base station (101_1 to 101_n) in the center of each zone (100_1 to 100_n), connect all base stations (101_1 to 101_n) to the line control device (102), and move A connection request input from a terminal (103), which is a network, to the line control device (102) via a predetermined base station of the zone using a predetermined control frequency of the zone in which the terminal (103) is located. In a mobile communication system in which communication is performed between the terminal (103) that has made a connection request and the other party via the predetermined base station and the line control device (102) by allocating a line according to a signal, Each control frequency of the plurality of zones (100_1 to 100_n) is the same frequency in all zones (100_1 to 100_n), and each of the base stations (101_1 to 101_n) is connected to the terminal device (103) using the control frequency of the zone. ), the received electric field strength at that time is measured by the electric field strength measuring means (104), and the measured electric field strength is added to the connection request information by the coder (105) to control the line. The line of sight control device (102) is configured to send data to the same terminal device (103).
When two or more pieces of connection request information are input from a base station, line allocation is performed only to the one base station that transmitted the highest measured field strength information based on the input measured field strength information. A mobile communication system characterized by