JPS5925530B2 - Line connection control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a line connection control method in a mobile communication system equipped with a control channel dedicated to line connections.

Generally, in mobile communication systems, many control methods are adopted in which lines are connected by separately providing a mobile station incoming connection control channel and a mobile station outgoing connection control channel in addition to a communication channel.

An example of a mobile communication system to which such a line connection control method is applied is shown in FIG. In the figure, the range that radio waves from radio base station 1 or 4 reach is defined as radio zone 2 or 5, respectively. A mobile station 3 located in a wireless zone 2 and equipped with a plurality of wireless channels and a base station 1 are connected wirelessly. The base stations 1 and 4 are connected by wire to a central office 6, and are further connected to regular telephone subscribers via a telephone exchange. Normally, the mobile station 3 sets a mobile station termination connection control channel (hereinafter referred to as P-CH) and waits for an incoming call to its own station. In addition, in this figure, the setting of multiple wireless zones means that even if all communication channels are busy in one wireless zone, communication channels are free in other wireless zones, so This is to enable connection processing with a mobile station within the zone or near the zone by issuing an incoming signal on the P-CH. FIGS. 2A and 2B are block diagrams showing specific configuration examples of the base stations 1 and 4, the central station 6, and the mobile station 3 in FIG. 1, respectively.

Note that here, in order to simplify the explanation, it is assumed that only the base station 1 is connected to the central station 6. There is one channel each for P-CH and mobile station originating connection control channel A-CH, and the base station 1 is equipped with a radio receiver 12 for P-CH.
4 and transmitter 128, radio receiver 125 for A-CH
and a transmitter 129, a radio receiver 12 for the communication channel.
6-1 to 126-n and transmitters 130-1 to 130-
It has n. Respective receivers 124, 125, 1
26-1 to n are connected to the transmitter/receiver duplexer 1 via the receiver duplexer 122.
It is connected to 21. In addition, each transmitter 128
, 129, 130-1 to n are also connected to the transmitter/receiver duplexer 121 via the transmitter/receiver duplexer 123. Then, the antenna 120 emits radio waves toward the mobile station 3, and
receive radio waves from. On the other hand, the mobile station 3 includes an antenna 1010, a duplexer 102, a control unit 108, a frequency synthesizer 104, a receiver 103, and a transmitter 105.
It also has functions 106, 107, 109, and 110 for transmitting and receiving data signals and tone signals from the central station 6. Furthermore, the central station 6 includes a data receiver 13 for P-CH.
2 and data generator 136, data receiver 133 and generator 137 for A-CH, signal receivers 134-1 to 134-n and signal generator 138- for communication channels.
1 to 138n. Then, the control unit 140 performs sequence control as shown below. Third
The figure shows the flow of mobile station incoming call connection control. The mobile station 3 is waiting on the P-CH, and when it receives an incoming call signal 21 on the P-CH from the central station 6 via the base station 1,
An incoming call response signal 22 is sent back. When the central station 6 receives this response signal 22, it sends out a channel designation signal 23 in order to allocate a vacant wireless channel as the communication channel for this mobile station 3. According to the channel designation from the central station 6, the mobile station 3 switches the frequency to the designated communication channel, and receives the loop check signal 24 from the central station 6.
When it receives the response signal 25, it notifies the central office 6 that the channel has been correctly switched. The central office 6 immediately sends a ringing signal 26 so that the mobile subscriber hears the ringing tone. When the mobile subscriber hooks off, a hook off signal 27 is sent to the central office 6 and the call begins. FIG. 4 shows the flow of mobile station origination connection control. When the mobile subscriber hooks off while the mobile station 3 is in standby on the P-CH, the mobile station origination connection control channel ( (hereinafter referred to as A-CH) and sends the outgoing signal 31 to the central station 6. When the central station 6 receives this signal, it sends a channel designation signal 32 to allocate a vacant communication channel (S-CH) as the communication channel for this mobile station. According to the channel designation from the central station 6, the mobile station 3 switches the frequency to the designated communication channel, and when it receives the loop check signal 33 from the central station 6, it returns the response signal 34, and thereby Then, the central station 6 confirms that the channel has been correctly switched. When the central office 6 sends a dialing signal sending command 35, the mobile station 3 sends a dialing signal 36 to the central office 6, and when the subscriber of the dialed number is answered, a call can be made. In this way, in a mobile communication system having a large number of communication channels, P-
By providing CH and A-CH separately and controlling incoming and outgoing calls respectively, line connections can be made error-free and efficiently.

However, since the number of call channels is finite, all call channels are often busy when a call is finalized.In such cases, if there is an urgent call request, the call channels that are already in use Forcibly end one of the
The call channel may be assigned for emergency calls. In such a case, in the conventional system, the A-CH is always used to notify the central office 6 of an urgent call.
I needed to leave it empty. This means that there are always at least two channels (P-CH (5
ACH), which had the disadvantage of not being able to efficiently utilize the small number of allocated radio frequencies. An object of the present invention is to provide a mobile communication system that allows emergency interruptions to be made without impairing the connection control function by transmitting a calling signal on the P-CH even when the A-CH is used as a communication channel. The purpose is to provide a line connection method for the system.

According to the present invention, in a mobile communication system that separately includes a mobile station terminating connection control channel (P-CH) and a mobile station originating connection control channel (A-CH) in addition to a large number of communication channels, all the communication channels When A becomes busy,
-CH is assigned as a communication channel to the next call that occurs, and for urgent mobile station-originated calls that occur while the A-CH is being used as a communication channel, P-CH is used to assign other mobile A line connection control system is obtained in which the outgoing signal is transmitted so as not to collide with the incoming call response signal of the station, and the P-CH is temporarily used for connection control of the mobile station outgoing call. Next, an actual example of the present invention will be described with reference to the drawings. FIG. 5 shows the timing of signals during line connection control on the P-CH, and in this case, the transmission and reception of signals is performed in the same manner as in FIG. 3.

For example, when a base station (BS) sends an incoming signal to the mobile station 201 at timing 41, the mobile station 201 returns an incoming response signal, which is slightly shorter than the incoming signal, at timing 42. Then, a channel designation signal (
(the same signal length as the incoming signal) is notified to the mobile station at timing 45. Furthermore, the incoming signal of the mobile station 202 is sent out at timing 43, and the incoming signal from the mobile station 202 is sent out at timing 44.
An incoming call response signal is returned, and a channel designation signal is sent to the mobile station 202 at timing 46. Then, the next incoming signal from the mobile station 203 is sent out at timing 47, and a response signal is returned at timing 48. In other words, even when many incoming signals are transmitted from the base station in a time-division manner and response signals are returned one after another, a channel designation signal is always inserted.
The idle time during which no incoming call response signal is sent from the mobile station is 5.
It can be seen that it exists as shown at 0.51. Therefore, as mentioned above, when the A-CH is used as a communication channel, a certain mobile station must send the outgoing signal to the central station immediately after receiving the channel designation signal of another mobile station. (The signal length is set to be slightly shorter than the incoming signal), the outgoing signal can reach the base station without colliding with incoming call response signals of other mobile stations. FIG. 6 shows an improvement to the central office 6 of FIG. 2A in accordance with the present invention. The data receiver and data generator of the central office 6 are conventionally constructed of shift registers and the like, of which the data receiver 132 functions as an incoming call response decoder, and the data receiver 133 functions as an outgoing signal decoder. The data generator 136 is composed of an incoming signal encoder 136a and a channel designation signal encoder 136b, which are switched by a switch S4, and the data generator 137 works as a channel designation signal encoder. The connection switching function by the switches Sl, S2 and S3 represents an improvement according to the present invention. In this circuit, when A-CH is used as a communication channel, S1 is switched from the receiver 125 side to the receiver 124 side, and the receiver 1 for P-CH is switched from the receiver 125 side to the receiver 124 side.
24 so that the data receiver 133 can receive the transmitted signal. Furthermore, the S3 is configured to transmit a channel designation signal for calling to the P-CH transmitter 128.
Switch to the side. In this way, when the A-CH is used as a communication channel, a mobile station that wants to make an emergency call can identify the channel designation signal of another station flowing on the PCH and, for example, P to Lotto 50
While transmitting the outgoing signal on the CH, the central office 6 can receive and decode this outgoing signal since the data receiver (outgoing signal decoder) 133 is connected to the P-CH. In response to this signal, the control unit 140 disconnects one of the communication channels in use, prepares it for the emergency mobile station, and also switches S2 to the A-CH data generator (channel) for the time slot 52. The mobile station connects to the specified signal encoder) 137, notifies the corresponding mobile station of the communication channel number, and thereafter performs the same processing as normal. After sending the channel designation signal, S2 is returned to the data generator 136 side and P
- Perform the original processing by CH. As a practical matter, when a mobile station transmits a transmission signal at time slot 50 in FIG. 5 and is received by central station 6, the channel designation signal for this mobile station is transmitted at time slot 47. Therefore, the incoming signal to mobile station 203 that should have entered time slot 47 will be delayed by one time slot. However, this degree of delay hardly poses a problem. As is clear from the above description, according to the present invention, even when the A-CH is used as a communication channel, the P-CH can be used to reduce the gap in the transmission timing of incoming call response signals of other mobile stations. By selectively transmitting a transmission signal, it becomes possible for the mobile station to interrupt in the event of an emergency, which has a significant effect on improving the efficiency of use of channel-allocated radio frequencies.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional example of a mobile communication system to which the present invention is applied; FIG. 2A is a block diagram showing a specific example of the configuration of the base station and central station in FIG. 1; B
is a block diagram showing a specific example of the configuration of the mobile station in FIG. 1, FIG. 3 is a diagram showing the flow of mobile station incoming connection control using PCH, and FIG. 4 is a flow diagram of mobile station originating connection control using A-CH. Figure 5 is a diagram showing the flow, and Figure 5 is a diagram showing signal timing in the case of mobile station incoming connection control by P-CH.
The figure is a block diagram showing the structure of a portion of the central office that has been improved according to the present invention. In the figure, 1 and 4 are radio base stations, 3 is a mobile station, 6 is a central station, 101 is a mobile station antenna, 102 is a transmitter/receiver duplexer, 103 is a receiver, 104 is a frequency synthesizer, 10
5 is a transmitter, 106 is a tone receiver, 107 is a data receiver, 108 is a control unit, 109 is a data generator, 110
1 is a tone generator, 111 is a handset, 120 is a radio base station antenna, 121 is a transmitting/receiving duplexer, 122 is a receiving duplexer, 123 is a transmitting duplexer, 124 is a P-CH receiver, 1
25 is an A-CH receiver, 126-1 to 126n are communication channel receivers, 128 is a P-CH transmitter, and 129 is an A-CH receiver.
CH transmitter, 130-1 to 130n are speech channel transmitters, 132 is P-CH data receiver, 133 is A-CH
Data receivers, 134-1 to 134-n are signal receivers for communication channels, 136 is a P-CH data generator, 13
7 is an A-CH data generator, and 138-1 to 138n are signal generators for communication channels.

Claims (1)

[Claims] 1. In a mobile communication system that separately includes a mobile station incoming connection control channel and a mobile station originating connection control channel in addition to a speech channel, the mobile station originating connection control channel is used as a speech channel because all the speech channels are busy. For calls originating from the mobile station that occur during the service, the mobile station terminating connection control channel selects a gap in the incoming connection control and transmits a mobile station originating signal, temporarily preventing the mobile station terminating connection. A line connection control method characterized in that a control channel is used for connection control of mobile station transmissions.