JPH06253356A - Mobile object communication network using satellite communication among base stations - Google Patents

Abstract

PURPOSE:To secure a redundant channel capacity economically between a radio base station and art exchange system equipment and to easily install a lot of base stations even in secluded places in mountains and crowded cities at a low cost by time division multiple accessing (TDMA) voice/data channels and base station control channels between a switchboard and a mobile station by satellite communication channels through a communication satellite. CONSTITUTION:The ground radio receiver 6(1) of as mobile object base station 1 is provided with a modem 14(1) and multiplexing/demultiplexing device 15(1) is provided between the modem 14(1) and a TDMA device 7(1). In the switchboard 2, the TDMA device 7(2) is provided and the multiplexing/demultiplexing device 15(2) is provided between a voice/data signal processor 9 and a base station controller 10 and the TDMA device 7(2). Then, the voice/data channels (a) and the base station control channels (b) between the TDMA device 7(2) of the switchboard 2 and the TDMA device 7(1) of the mobile object base station 1 are TDMA connected by the satellite communication channel 20 through the communication satellite 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multiple connection between a mobile communication base station and a switching center, and more particularly to connection by satellite communication.

[0002]

2. Description of the Related Art A conventional mobile communication network such as a cellular phone will be described with reference to FIG.

A control signal b for controlling the mobile station 4 '' and a line a for transmitting voice and data signals (hereinafter referred to as voice / data line) are referred to as a mobile base station 1 '' (hereinafter simply referred to as base station). It is wirelessly connected to the mobile station 4 ″ in the service area. In the base station 1 '', the voice / data line a and the base station control signal b are transmitted by the terrestrial radio transmitter / receiver 6
The signal is demodulated by the modulator / demodulator 14 (1) '' in (1) '', and further demultiplexed by the demultiplexer 15 (1) ''. On the other hand, in the exchange 2 '', the voice / data signal a is transmitted from the exchange 11 via the voice / data processor 9 '', and the base station control signal b for controlling the base station 1 '' and the mobile station 4 '' is transmitted. The signals are demultiplexed by the demultiplexers 15 (2) ″ via the base station controller 10 ″. The demultiplexers 15 (1) "and 15 (2)" of both the base station 1 "and the switching center 2" are, for example, 1.5 to 6.3 Mb such as electric wires, optical cables or 1: 1 micro lines.
ps high-speed digital multiplex line (digital highway)
Connected by 16.

[0004]

In the conventional mobile communication network described above, the above digital highway must be maintained even for base stations having an area with very few or no mobile stations. Therefore, there is a problem that the terminal capacity of the exchange is also wasted. Also, a large number of base stations are arranged every several kilometers for the operation of a small zone, but the cost of laying a digital highway for each is high. In addition, base stations are often installed in remote areas of the mountains. There is a problem that it takes a very large amount of money and time to lay the above-mentioned relay line from the remote area of the mountain to the exchange.

When such a fixed relay means is provided, the initial investment amount is further increased because the line capacity of the mobile station is secured redundantly in anticipation of an increase in mobile stations in the future, which is very uneconomical. Met.

In view of the above circumstances, the present invention provides a relay system that economically secures a redundant line capacity between a radio base station and a switching system device and, moreover, can easily and easily install a radio base station even in a remote area of a mountain. This is the purpose.

[0007]

Means for Solving the Problem and Its Action A mobile communication network of the present invention comprises a communication satellite (3); a mobile station (4);
A terrestrial radio transmitter / receiver (6 (1)) that performs radio communication with (4),
A mobile base station (1) having a TDMA device (7 (1)) for making a TDMA connection with the communication satellite (3); an exchange (11), a voice / data signal processing device (9), a base station control device ( 10) and the communication satellite
(3) and a switching center (2) having a TDMA device (7 (2)) for making a TDMA connection; a TDMA device 7 (2) of the switching center (2) and a TDMA device (7) of the mobile base station 1 The voice / data line a and the base station control line b with (1)) are connected by TDMA via the satellite communication line (20) via the communication satellite (3).

Inside the mobile base station (1) and the exchange (2)
The multiplex input / output of the TDMA devices 7 (1) and 7 (2) to the inside is a data highway of the primary group or secondary group transmission line type of the digital high araki used for the multiple connection line on the ground, and one of the highways. A time slot, that is, a data amount corresponding to 64 kbps is a unit of allocation of the line.

[0009] Further, the allocation division of the satellite communication line is (a) the voice / data line a and the base station control line b are mixedly accommodated by the demand assign system without being separated, and (b)
A demand assign operation part accommodating the voice / data line a and a pre-assign operation part accommodating the base station control line b are separately provided, or (c) a demand assign operation accommodating the voice / data line a. The operation part and the random access operation part for accommodating the base station control line b, monitoring the collision of data bursts, and performing retransmission control as necessary, and performing immediate transmission when a communication request occurs are provided separately. ,Is possible.

When the call requesting call is communication between mobile stations, the exchange performs only the connection control, and thereafter the voice / data line does not go through the exchange and the satellite line is used. It is also possible to directly connect the two moving bodies via the.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to FIG. The mobile base station 1 has a terrestrial radio transmitter / receiver 6 (1) having a radio transmission / reception function and a mobile station control function. For example, a plurality of in-vehicle phones, mobile phones, etc. existing in respective service areas by radio waves of 800 MHz are used. Mobile station 4
And line d is constructed between This wireless transceiver 6
In addition to transmitting and receiving radio waves, it has a function of instructing the power level and frequency of the radio wave used with the mobile station as a mobile station control function, and an appropriate modulation method such as π / 4
It has a modulator / demodulator 14 (1) that modulates and demodulates the radio wave by QPSK (π / 4 shift quadrature phase modulation) or the like. Modulation / demodulation equipment 14 (1) and time division multiple access (hereinafter referred to as TDMA) equipment 7
Demultiplexer (MUX / DEMUX) 15 (1) is installed between (1),
The voice / data line a and the base station control line b to / from the modulator / demodulator 14 (1) are connected to the primary or secondary group transmission line format of wired digital multiplex hierarchies, that is, a highway of 2 Mbps or 8 Mbps, for example. Is multiplexed to TDMA device 7 (1). (See Fig. 3) TDMA connection device 7
(1) is converted to the TDMA format of the satellite communication line and is connected to the communication satellite 3 (hereinafter simply referred to as satellite) via the satellite transceiver 8 by the satellite communication line 20 having a carrier of 14 GHz, for example. The satellite 3 which is a transponder
Switching back to the ground by a 12 GHz carrier,
It connects to the reference station 5 and another base station 1.

In the exchange 2, the exchange 11 connected to the fixed land network, the satellite transmitter / receiver 8 (2) for transmitting and receiving radio waves of the satellite communication line 20 with the satellite, and time division multiple access to the radio waves. A TDMA device 7 (2) for performing the above is provided, and a voice / data signal processing device 9 for processing a voice / data signal a and a base station control device 10 for controlling a mobile station call or the like are provided in parallel between them. It is provided in. A demultiplexing device 15 (2) is provided between the voice / data signal processing device 9, the base station control device 10 and the TDMA device 7 (2), and the voice / data signal from the voice / data signal processing device 9 is transmitted. The line a and the base station control line b from the base station control device 10 are connected in the same manner as described in the above base station by using a wired digital multiplex hierarchy primary or secondary group transmission line format, for example, 2 Mbps or 8 Mbps. Multiple connections to TDMA device 7 (2) by highway. (See FIG. 4) The highways of the base station and the exchange will be described in detail later. The TDMA device 7 (2) is the TDMA of the base station 1.
Similar to device 7 (1). In this manner, the TDMA devices 7 (1) of the plurality of base stations 1 and the TDMA device 7 (2) of the exchange station are TDMA-connected by the satellite communication line via the satellite 3.

The satellite TDMA reference station (hereinafter referred to as a reference station) 5 has a satellite line control device 12 for setting and opening the satellite line.
And a TDMA device that launches the signals and the line control signal received from the satellite line control device 12 as a reference burst while performing TDMA device synchronization control of each base station and switching station via the satellite.
7 (5) A satellite transmitter / receiver 8 (5) connected to the transit satellite 3 is provided.

In this way, the TDMA connection devices 7 (1), 7 (2), 7 (5) of the base station 1, the switching center 2, and the reference station 5 and the satellite channel control device 12 of the reference station are transmitted via the satellite 3. Standard TD
It constitutes the MA communication system. In the TDMA satellite communication system, the present invention is used for connection between the modulation / demodulation device 14 (1) of the base station 1, the voice / data signal processing device 9 of the switching center 2 or the base station control device 10. It uses a communication system.

In the present mobile communication network, there may be a base station 1 '' in which an exchange station and a mobile base station are multiply connected to each other by a land line 16 such as a wire, an optical fiber or a microwave. A case will be described as a second embodiment with reference to FIG. The base station 1 ″ is exactly the same except that the TDMA device 7 (1) and the satellite transceiver 8 (1) are removed from the base station 1 connected by satellite. The voice / data signal processing device 9 "and the base station control device 10" of the exchange 2 "are directly connected to the exchange 11 of the exchange 2 except that the TDMA device 7 and the satellite transceiver 8 are not provided. This is the same as the exchange 2 described above. Demultiplexer 15 (2) '' here and demultiplexer of base station 1 ''
15 (1) '' is directly connected by the primary or secondary group transmission line format of the digital communication hierarchy which is already standard in this industry, that is, 1.5 Mbps or 6.3 Mbps highway. ing. This transmission method is being standardized according to CCITT recommendations. The details are: 1st group 2nd group North America, Japan 24ch 1.544 Mbps 96ch 6.312 Mbps Europe, Japan 30ch 2.048 Mbps 120ch 8.448 Mbps.

Incidentally, for these one channel, that is, a unit slot, an 8 kHz synchronous 8-bit signal, that is, 64 kbps is usually used. 1 to 4, the voice / data signal and its line are indicated by a, the base station control signal and its line by b, the TDMA synchronization signal and line allocation control signal by c, and the terrestrial radio line with the mobile station by d. Shows.

As described above, according to the present invention, the unit slot of the primary or secondary group transmission line format of the digital multi-communication which is conventionally used between the base station and the switching station on the ground is used as the satellite communication line. It is used as a unit of line allocation when connecting to TDMA. The details of the satellite communication line connection procedure and the satellite communication line format are described below.

First, the reference station TDMA device 7 (5) in the reference station 5
To transmit the reference burst R in Fig. 5 (b). Exchange 2
The TDMA devices 7 (2) and 7 (1) in the TDMA device 7 (2) and the base station 1 (these may be referred to as slave stations in the future) receive this reference burst via the satellite to receive signals. Synchronization is established.

Next, the base station TDMA device 7 (5) carries out the procedure for establishing the transmission synchronization of the TDMA device of each slave station according to the information registered in advance in the satellite channel control device 12. At this time, each command for synchronization control is transmitted to the TDMA device of each slave station by the synchronization control signal channel in the reference burst. When the transmission synchronization establishment procedure is completed, each slave station starts transmitting slave station synchronization burst N shown in FIG. 5 (b).

Subsequently, the base station TDMA device 7 (5) operates in accordance with the information registered in the satellite line control device 12 for each slave station.
Assign communication bursts for control channels to TDMA devices. At this time, communication between the base station for setting the line and the slave is performed using the line allocation control signal channel in the reference burst R and the line allocation control signal channel in the slave synchronization burst N. The communication burst for the control channel for accommodating the base control line b is set between the exchange and the base station, and at least one burst per base station is bidirectionally allocated as described above. That is, when m is 1 or an integer larger than 1, 2 m bursts (here, 2 indicates an upward / downward bidirectional component), for example, 6 bursts (m = 3) are allocated.

In the TDMA device of the slave station, in accordance with the line assignment command notified from the satellite line control device 12 to the base station TDMA device 7 (5) via the satellite, the above communication burst is transmitted in the case of the ground connection described in the explanation of the exchange station. As in the above, it is connected to a commanded time slot on the highway of the Digital Hierarchy primary or secondary group, ie, 2.048 Mbps, for example. The line allocation method will be described in detail later.

By the above procedure, the base station control line b equivalent to the conventional ground line is completed between the base station 1 and the switching center 2. Next, the procedure for starting up the mobile station will be described. The base station controller 10 in the exchange 2 executes the common access channel activation procedure for the base station having the mobile station of the call destination. The instruction according to this procedure reaches the modulator / demodulator 14 (1) in the base station through the base station control line b . Modem 14
In (1), based on the instruction, transmission of the control channel for the mobile station at the specified frequency is started.

On the other hand, since the mobile station scans the frequencies of a plurality of perch channels stored in advance when its power source is turned on, it is necessary to detect the transmitted control channel from among them. Can be done. Simultaneously with the detection of the control channel, the scramble code is determined and the superframe synchronization is established. Further, by receiving the common access channel included in the plurality of control channels, the group number in the zone and the channel structure are recognized, and the corresponding channel (frequency) enters the standby state.

Here, for example, when a request for call connection (call origination) is generated from the mobile station 4 side, the mobile station transmits a call setup request using the common access channel within the control channel.
This call setting request signal is transmitted to the base station control device 10 in the exchange 2 through the base control line b and is further transmitted to the exchange 11. When the exchange 11 analyzes this call setting request information and finds the connection destination, the exchange 11 accommodates the voice / data line a between the exchange and the base station to the satellite line controller 12 in the base station 5. Request the communication line setting of.

The satellite line control device 12 gives an instruction for line setting,
This reference station TDMA device 7 (5) puts it on the reference synchronization burst, and from this reference station TDMA device 7 (5) through the satellite communication line, the (subordinate station) TDMA device 7 (2) in the exchange 2 and the base station 1 (Subordinate station) to the TDMA device 7 (1).

Receiving this, both slave stations' TDMA devices 7 (2), 7
According to the instruction, (1) starts additional transmission / reception processing of the communication burst on the satellite communication line and connects to the designated time slot on the digital highway in both stations. 5 to 7 show examples of the connection status of these communication bursts.

On the other hand, when the exchange receives the line setting completion notification from the satellite line control device 12, it proceeds with the call connection procedure.
First, the modulation / demodulation device 14 (1) of the base station is instructed to execute the communication channel activation procedure. The communication channel start-up procedure is to perform transmission synchronization time alignment control using a synchronization burst on the land line d. As a result, the control channel is switched to the communication channel on the wireless link between the mobile station and the base station. When the confirmation of the call setting response from the exchange is completed after the completion of the transfer to the communication channel, the call connection is completed. At this point, there is a burst for the base station control line and a burst for the voice / data line on the satellite communication line, and the former accommodates the radio line management information and the accompanying control channel in the communication channel, The latter contains information channels in the communication channel, that is, voice information and the like.

FIG. 4 shows the details of the structure of the digital highway in the exchange 2. As mentioned above, the TDMA for satellite communication is provided by a highway 2M HW of 2 Mbps, for example, which is compliant with the digital high araki used for terrestrial lines.
Up and down connections between the device 7 (2) and the demultiplexer 15 (2) are respectively n depending on the number of lines accommodated in the exchange.
It is composed of a book, and the voice / data signal a is multiplexed therein according to a predetermined order. Furthermore, this 2M HW n
The line b of the base station controller 10 is also accommodated on some predetermined time slots in the book.

The slave station TDMA devices 7 (1) and 7 (2) select a highway according to the line connection information from the satellite TDMA reference station 5, and select a highway according to a predetermined allocation method to establish a satellite communication line and a highway within the station on the ground. Although it has already been stated that the connections are performed while the time slots are exchanged in order, the method of assigning them will be described below.

A first example of a frame format of a digital multiplex signal used in the satellite communication line of the first embodiment will be described as a third embodiment with reference to FIG. Figure
5 (a) is the format of the highway in base station 1.
FIG. 5 (b) shows the format of the satellite communication line signal, and there is no distinction between the up line, the down line, the communication line a and the control line b.
Signals are stored by the widely known demand assign method. FIG. 5 (c) shows a highway signal format between the TDMA device 7 (2) and the demultiplexing device 15 (2) in the exchange 2. Since many highways are provided in the exchange, the highways are used exclusively for communication channels and control channels. However, a highway with both channels mixed may also be used. In each figure, T is a communication channel, C is a control channel, and x is a waiting or empty channel. The suffix number is the channel number, u
And d indicate up and down respectively. Here is the general
Similar to the TDMA satellite communication system, it has a reference burst and slave station synchronization burst, which are used for frame synchronization and line setting control.

The demand assign method is widely used as one method of TDMA connection, but its feature is that the voice / data line a and the base station control line b are accommodated in the satellite communication line without being separated. .

The procedure when a call is made from the mobile station or the land fixed station will be described. First, when a connection request is issued, the base station or switching center that receives the connection request requests the burst allocation for the control channel from the TDMA device 7 (1) or 7 (2) to the satellite channel reference station 5. . Then, after the call setting information is exchanged between the base station 1 and the exchange 2 using the assigned control channel, the exchange 11 sends it to the satellite line controller 12 of the base station as a communication burst for voice / data lines. Request the required amount directly. Base station 1
In the TDMA device 7 (1) of Fig. 5, while terrestrial time slots in Fig. 5 (a) are used as a unit, the arrangement order and the time slot order on the satellite line in Fig. 5 (b) are mutually converted as shown by arrows in the figure. Connecting. In the TDMA device 7 (2) of the exchange 2, the time slot order of the highway shown in FIG. 5 (c) is connected while mutually converting the time slot order on the satellite line of FIG. 5 (b). As a result of the demand assign method by the series of operations described above, it is possible to realize a system capable of operating the lines between a plurality of base stations and the switching center with a minimum line capacity.

A second example of a frame format of a digital multiplex signal used in the satellite communication line of the first embodiment will be described as a fourth embodiment with reference to FIG. The fourth embodiment is different from the third embodiment in that the base station control line is a widely used pre-assign system. When the connection request with the mobile station is issued, the burst for controlling the base station has already been allocated on the satellite line, so that the communication required for call setup can be started immediately between the base station and the exchange. The subsequent voice / data line allocation request procedure is essentially the same as that described in the demand assign method of the third embodiment.

According to the fourth embodiment, the satellite is used for call setup.
Since it is not necessary to perform the line setting procedure each time on the TDMA system and the base station control line can be used immediately, the time required for call connection can be greatly reduced. Further, the base station control line is suitable for pre-assignment operation because it is necessary to maintain the line even when there is no mobile station in the air area of the target base station.

A third example of the format of a digital multiplex signal used in the TDMA satellite line of the first embodiment will be described as a fifth embodiment with reference to FIG. The fifth embodiment is different from the above-mentioned embodiments in that the base station control line is a random access based on the widely used slotted Aloha method. When a connection request is issued from the mobile station and the packet data carrying the call arrives at the TDMA device 7 (1) of the base station via the base station control line b, the TDMA device 7 (1) detects it, Random access transmission is performed on the satellite link as a burst with destination information while performing collision control. The TDMA device of the other station constantly monitors this random access portion, and if it detects a burst addressed to itself, it immediately receives it. By repeating the above work, the communication required for call setup is executed between the base station and the exchange. Subsequent voice
The data line allocation request procedure and the like are the same as those in the third and fourth embodiments.

In the fifth embodiment, the base station control line needs to always secure a line, but in actual use, packet data may come and go from time to time, so that packets are transmitted to the TDMA device 7. Only if the satellite line is available when it arrives. As described above, if the satellite communication line is connected by the slotted Aloha method, it is possible to deliver the packet to the TDMA device of the other party in a relatively short time, and the instantaneous control of all base station control lines in the network. It is only necessary to secure a satellite line capacity sufficient to satisfy the communication capacity, and the satellite line utilization efficiency can be improved.

A sixth embodiment of the present invention will be described below with reference to FIG. The device configuration of this embodiment is the same as that of the first embodiment, but the line setting path for connecting the mobile station to the mobile station is different.

First, the exchange 2 receives a call request from the mobile station 4 on the calling side via the base control line b of the base station. The exchange 2 is a mobile station whose calling information belongs to the other base station 1 '.
When it is detected that it is destined for 4 ', at the same time as instructing the call connection preparation through the base station control line b'of the called side base station 1', And the call-side base station 1'to set up a voice / data line communication path. As a result, the voice / data line is directly connected from the calling base station 1 to the called base station 1'by the satellite without passing through the exchange even once.

In systems other than the sixth embodiment, there is a delay time of about 500 ms for two hops of the satellite section, that is, two round trips, since the mobile station-to-mobile station call once passes through the exchange. Although the conversation is inconvenient, according to the sixth embodiment, the delay is reduced to 250 ms for one hop, and the quality of the conversation is improved.

In the sixth embodiment described above, mobile stations communicating with each other belong to different base stations as an example. However, this embodiment also applies when these two mobile stations belong to the same base station. Needless to say, can be applied.

Now, consider the case where a new base station is added in the fourth embodiment. First, the identification information representing this base station is registered in the exchange, and the addition of the pre-assign burst of the base station control line is registered in the satellite line control device 12. As a result, a base station control line dedicated to the new base station is allocated, and various controls can be performed on the base station from the exchange. After that, when the call connection with the mobile station is actually performed, only the voice / data channel is requested from the exchange to the satellite line control device each time. Although this description has been given based on the fourth embodiment using the pre-assign burst for convenience of explanation, the procedure for adding a new base station is similarly performed for the demand assign method and the random access method. Needless to say.

[0042]

As is apparent from the above description, according to the present invention, since it is not necessary to fixedly allocate a line to a base station having a small number of mobile stations, essentially many base stations are required. In a cellular telephone system or the like, it is possible to greatly reduce waste of capacity redundancy of base connection lines and exchanges. Further, since the slot of the terrestrial multiplex line format is used as the slot of the satellite communication line, the ground station with a low construction cost is not affected by the completeness of the communication equipment of the existing ground station due to the commonality of the equipment, and Easy to configure. Also, a large number of wireless base stations can be easily and easily installed even in a remote area of a mountain or a dense urban area. It is also possible to install mobile switching units centrally in one place. Therefore, according to the present invention, it is possible to provide a mobile communication network in which a remarkable economic effect can be expected.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 Modulator / demodulator in mobile radio base station—TDMA
It is a connection diagram between devices.

FIG. 4 is a connection diagram between a TDMA device and a signal processing / base station control device in an exchange.

FIG. 5 is a diagram showing a format of a TDMA frame according to a third embodiment.

FIG. 6 is a diagram showing a format of a TDMA frame according to a fourth embodiment.

FIG. 7 is a diagram showing a format of a TDMA frame according to a fifth embodiment.

FIG. 8 is a configuration diagram of a sixth embodiment of the present invention.

[Explanation of symbols]

1 is a mobile base station, 2 is a switching station, 3 is a satellite, 4 is a mobile station, 5 is a satellite TDMA reference station, 6 is a terrestrial radio transmitter / receiver, and 7
Is a TDMA device, 8 is a satellite transmitter / receiver device, 9 is a voice / data signal processing device, 10 is a base station control device, 11 is an exchange, 12 is a satellite line control device, 14 is a modulator / demodulator, and 15 is a demultiplexer.

Claims (7)

[Claims] 1. A communication satellite (3); a mobile station (4); and a base station modulator / demodulator (14) for performing radio communication with the mobile station (4).
(1)) and a mobile base station (1) having a time division multiple access device (7 (1)) for performing time division multiple access with the communication satellite (3); an exchange (11), a voice / data signal A processor (9), a base station controller (10), and a switching center (2) having a time division multiple access device (7 (2)) for performing time division multiple access with the communication satellite (3);
Time-division multiple access device 7 (2) of switching center (2) and mobile base station
A satellite communication line (time-division multiple access) for connecting the voice / data line a and the base station control line b with the time division multiple access device (7 (1)) of (1) via the communication satellite (3). 20) A mobile communication network characterized by being provided. 2. A demultiplexer (15 (1)) between the modulator / demodulator (14 (1)) and the time division multiple access device (7 (1)) in the mobile base station (1), A demultiplexing device (15 (2)) is provided on the exchange (11) side of the time division multiple access device 7 (2) in the above switching center (2), and these time division multiple access devices (7)
(1)), (7 (2)) and these demultiplexers (15 (1)), (15 (2)) respectively, voice / data line (a) and base station control line (b) Is a data highway of the primary group or secondary group transmission line type of the digital high-speed line of the multiple connection line on the ground, and the unit of allocation of the satellite communication line is one time slot on the data highway. The mobile communication network according to claim 1. 3. The satellite communication line allocation procedure is a demand assign system, and the voice / data line a and the base station control line b are mixed and accommodated on the satellite communication line without separation. The mobile communication network according to claim 2. 4. The voice / data line a to the satellite communication line
3. The mobile communication network according to claim 2, wherein a demand assignment operation part for accommodating the base station control line and a preassignment operation part for accommodating the base station control line b are separately provided. 5. The voice / data line a to the satellite communication line
And a random access operation part for accommodating packet data using this unit while performing collision control on the base station control line b independently of this. The mobile communication network according to claim 2, wherein 6. The unit of allocation of the satellite communication line is 64 kbps
The mobile communication network according to claim 2, which is equivalent. 7. When the exchange (11) recognizes that the call requesting call is communication between mobile stations, the exchange sends only the base station control signal b to the mobile communication. For base station
The satellite communication line (20) between (1) and the switching center (2) is set, and the voice / data line a is a mobile base station accommodating the mobile station requesting the call and the called side. The mobile communication network according to any one of claims 1 to 5, wherein a satellite communication line is directly set between the mobile base stations accommodating the mobile stations.