JP3241589B2 - Mobile radio communication system, radio zone switching method and radio base station in the system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio communication system for realizing a public communication network using mobile communication terminals.

[0002]

2. Description of the Related Art A personal handy phone system (PH) conventionally considered as a kind of a mobile radio communication system.
S) is formed by each wireless base station, as described in `` Trends in Digital Cordless Telephones '' (Journal of the Institute of Electronics, Information and Communication Engineers, Vol.77 No.6, pp. 636-642). The size of the radio zone is extremely small, and each radio base station and mobile communication terminal are small, inexpensive,
Although it has the advantage of being able to achieve low power consumption, during communication during high-speed movement, handover processing for switching the wireless zone to which the mobile station belongs is frequent, and each time the call is interrupted for a few seconds, greatly affecting the communication quality degradation. was there.

[0003] Therefore, in a personal handy phone system for public communication, a call is automatically re-issued again in the destination wireless zone, so that a normal handover process is not performed on the network side and an ordinary call is made. There is known a recalling type handover processing method in which each mobile communication terminal autonomously implements a handover process only by call processing. In a personal handy phone system for public communication, the recalling type handover processing method is adopted, which is the second generation cordless telephone system standard version 1 (RCC) by the Radio System Development Center (RCR).
R STD-28). By adopting the recalling type handover processing method, switching of the assigned wireless zone can be realized only by normal calling processing without any special processing on the network side, thereby simplifying the handover processing. .

[0004] However, even in the recalling type handover processing method, each mobile communication terminal needs to make a new call in the destination wireless zone every time the mobile communication terminal performs the handover processing accompanying the movement. During the handover process, the communication is interrupted for several seconds for the time required for the re-call process. Since the size of the wireless zone of the personal handyphone system is extremely small, handover processing frequently occurs at a moving speed higher than the speed of slowing down of the vehicle, and the frequency of instantaneous call interruption accompanying it becomes a level that cannot be ignored. For example, when a mobile communication terminal is moving at a speed of 60 km / h, the wireless zone covered by one wireless base station has a diameter of 100 mm.
If the distance is set to about m, handover processing is performed approximately every 6 seconds, and the call is interrupted for about several seconds each time, so that there is a problem that accurate communication quality cannot be ensured.

FIG. 1 shows a configuration of a conventional personal handyphone system, a signal line (500) and a radio transmission path (300) by handover processing accompanying movement of a mobile communication terminal (100).
15 shows transition examples of communication slot positions on (a) to (300c).

That is, during communication, the mobile communication terminal (100) communicates with each wireless base station (400 a) to (400 c) in each wireless zone (200
If you move from a) to (200c) one after another,
(200a) to (200c) each time you enter
The handover process is realized by newly calling the mobile communication exchange (600) via the wireless base stations (400a) to (400c) forming the stations (00a) to (200c). Each time the mobile communication terminal (100) moves between the wireless zones (200a) to (200c), a new call is set, so the mobile communication terminal (100)
Of the signal line (500) and the wireless transmission path (30
0a) to (300c), the communication slot position is
0a) to (400c).

[0007] As another example of switching the belonging wireless zone without performing the handover process in accordance with the movement of the mobile communication terminal, there is another communication system of a public service for Shinkansen. In this system, the network side is a train system. Since movement between wireless zones is detected and switching of wireless zones is realized by control on the network side, it is necessary for the network side to have movement detection means and wireless zone switching control means. This is effective in a system having a relatively small number of wireless base stations or a system employing a centralized control method for wireless zone switching. However, there is a large number of wireless base stations, and a personal station in which each wireless base station performs wireless zone switching autonomously. The handy phone system has a problem that it is difficult to apply.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a problem in that a moving speed of a mobile communication terminal is reduced.
The wireless zone of each wireless base station is small compared to one communication moving distance determined from one communication required time, for example, in a mobile wireless communication system such as a personal handy phone system, a handover in a mobile communication terminal during mobile communication. A main object of the present invention is to suppress occurrence of processing, thereby reducing the occurrence of instantaneous call interruption, and ensuring accurate communication quality during high-speed movement in this type of mobile wireless communication system.

[0009]

In order to achieve the above object, according to the present invention, one mobile communication switch, a plurality of radio base stations, and the one mobile communication switch and a plurality of radio base stations are connected. In a mobile wireless communication system including a plurality of signal lines and a plurality of mobile communication terminals connected to the wireless stations via a wireless transmission path, the wireless base station is connected to any of the plurality of signal lines. And,
With the movement of the mobile communication terminal during the mobile communication, of the radio base stations installed along the movement path of the mobile communication terminal,
By providing a control function of sequentially switching the radio base station to which the mobile communication terminal connects while maintaining the signal line already selected by the adjacent radio base station and the slot position in the radio transmission path, high-speed control is provided. It is possible to reduce the frequency of occurrence of handover processing in a mobile communication terminal during mobile communication.

The means for solving the problems of the present invention will be described below in detail. According to the present invention, one mobile communication switch, a plurality of radio base stations, a plurality of signal lines connecting the one mobile communication switch and a plurality of radio base stations, and a radio transmission path with each of the radio stations. In a mobile radio communication system composed of a plurality of mobile communication terminals connected through the radio base station, each of the radio base stations is connected to any of the plurality of signal lines. A function of selecting a specific one from each of a signal line and a slot position in the radio transmission path, and the radio base station autonomously specifying a specific one according to an assumed value of a moving speed of a mobile communication terminal during mobile communication. By having the function of selecting the signal line and the slot position, a radio base station to which a mobile communication terminal performing mobile communication is connected is installed along a movement path of the mobile communication terminal performing mobile communication. Among the number of radio base stations, a mobile radio communication system sequentially switching in accordance with the movement direction of the mobile communication terminal in said movement is provided.

[0011] With this, the radio base station to which the mobile communication terminal performing the mobile communication is connected can be connected between the plurality of radio base stations installed along the moving direction of the mobile communication terminal performing the mobile communication on the network side. Switching can be performed autonomously sequentially without intervention of processing and without performing handover processing.

Further, according to the present invention, transmission delay control capable of variably setting a delay time of transmission timing when a signal is transmitted to a mobile communication terminal and a mobile communication exchange accommodated by each radio base station. By having a function, when transmitting a digital modulation signal from each radio base station to the mobile communication terminal, time-division multiplexed transmitted from the radio base station to the mobile communication terminal is placed on the radio transmission path Time-division multiplex channel slot phase of a digital modulation signal can be aligned between each radio base station, and
When transmitting a digital signal from each radio base station to the mobile communication switching system, a digital demodulated signal carried on the same signal line from a plurality of the radio base stations and transmitted to the mobile communication switching system is converted into a time-division multiplexed channel slot. The mobile radio communication system according to the above, which is capable of being transmitted to a mobile communication exchange as a time-division multiple access signal having the same phase.

[0013] Thus, when the mobile communication terminal moves between radio zones, it is possible to greatly reduce noise and the like generated due to synchronization deviation of communication slots.

Further, according to the present invention, there are provided a plurality of radio base stations accommodating a plurality of mobile communication terminals via a radio transmission path, and a mobile communication exchange and each radio base station are connected via a plurality of signal lines. In a mobile radio communication system in which a plurality of radio base stations are connected in parallel to each of the signal lines, each of the radio base stations starts communication of a mobile communication terminal under its own control. While selecting a specific one from the signal line and allocating a communication slot for a mobile communication terminal under its own control to a specific slot position on the signal line,
Allocate a communication slot for a mobile communication terminal under its own control to a specific slot position on a wireless transmission path of a specific frequency, and then, according to the elapse of a predetermined time calculated from a previously assumed moving speed of the mobile communication terminal during mobile communication, Each radio base station autonomously allocates the radio channel frequency and the time slot on the radio channel used by the mobile communication terminal under its control to the adjacent radio base station for the mobile communication terminal under its control, and A method for allocating a signal line and a communication slot on the signal line used by a mobile communication terminal under the control of an adjacent wireless base station for the mobile communication terminal under the control of the mobile communication terminal.

[0015] Thus, when the mobile communication terminal performing the mobile communication moves between a plurality of radio base stations installed along the moving direction of the mobile communication terminal performing the mobile communication, the handover process is performed. The assigned wireless zones can be sequentially switched without any trouble.

Further, according to the present invention, an antenna, a radio signal transmission / reception unit, a modulation / demodulation unit, and a digital signal addressed to a subordinate mobile communication terminal received from a mobile communication exchange are modulated by the modulation / demodulation function unit. A radio signal delay control unit for delaying transmission timing by a preset time when transmitting from the radio signal transmitting / receiving unit to the subordinate mobile communication terminal via the antenna, and transmitting / receiving a radio signal to / from the mobile communication terminal A radio channel assignment function unit for selecting a specific frequency as a radio transmission path to be assigned and allocating a communication slot for a mobile communication terminal under its control to a specific slot position on the radio transmission path, and a signal line for transmitting and receiving digital signals to and from a mobile communication exchange. A specific one of the plurality of signal lines is selected, and a communication slot for a mobile communication terminal under its control is placed at a specific slot position on the signal line. A radio base station in a mobile radio communication system including a signal line allocation function unit for allocating lots and a control unit for controlling the whole is provided.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments and examples.

FIG. 2 is a schematic diagram of a system configuration showing an embodiment of a mobile radio communication system according to the present invention. As shown in FIG. 2, the mobile radio communication system according to the present embodiment uses a radio zone (2) via radio transmission paths (300a) to (300c).
00a) to a plurality of mobile communication terminals (100a1) existing in (200c)
~ (100a3) to accommodate multiple wireless base stations (400a) ~ (400c)
And each wireless base station (400a) to (400c) has a plurality of signal lines.
It is connected to the mobile communication exchange (600) via (500).
Further, the plurality of mobile communication terminals (100a1) to (100a3) can support the plurality of wireless transmission paths (300a) to (300c).

Also, a plurality of radio base stations (400a) to (400c)
Has a function of transmitting and receiving radio signals to and from the plurality of mobile communication terminals (100a1) to (100a3), and a plurality of the mobile communication terminals (100a
1) to (100a3) a function of modulating and demodulating a wireless signal to be transmitted and received, and a function of performing delay control of a timing of transmitting a signal to the subordinate mobile communication terminals (100a1) to (100a3) and the mobile communication exchange (600), A function of selecting a signal line for transmitting and receiving a digital signal to and from the mobile communication exchange (600), and further comprising the mobile communication terminal (100) via wireless transmission paths (300a) to (300c).
a1) to (100a3), and the mobile communication terminals (100a1) to (10a).
0a3) and transmit and receive the modulated digital signal through a signal line (500) selected from a plurality of signal lines (500) connected to the mobile communication switch (600) and then have an appropriate delay. It has a function of transmitting and receiving to and from the mobile communication exchange (600).

Further, the mobile communication exchange (600) has a function of allocating time-division multiplex channel slots on the radio transmission lines (300a) to (300c) and the signal line (500), and a time-division multiplexing / multiplexing function according to the allocation. Separation processing function and wireless transmission path (3
00a) to (300c) Protocol processing function and ADPC
It has an M conversion function.

FIG. 3 shows an outline of the internal functional block configuration of the radio base station. The radio base station (400) includes an antenna (410),
Antenna selector (420) and wireless signal transmission / reception processing function unit
(430), a modulation / demodulation function unit (440), and a transmission delay control function unit (4
50) and a line selector (460).

The transmission delay control function section (450) modulates the digital signal addressed to the subordinate mobile communication terminal received from the mobile communication exchange by the modulation / demodulation function section (440), and selects the antenna (420) selected by the antenna selector (420). (410) via the radio signal transmission / reception function unit (430) to the subordinate mobile communication terminal, and from the subordinate mobile communication terminal via the antenna (410) selected by the antenna selector (420). When transmitting a digital signal received by the signal transmission / reception function unit (430) and demodulated by the modulation / demodulation function unit (440) to the mobile communication switching system, a function of giving an appropriate delay in transmission timing for each radio base station (400) Having. Line selector (460)
Is the antenna (410) selected by the antenna selector (420)
A signal line for transmitting / receiving a digital signal, which is transmitted / received to / from a mobile communication terminal via a wireless signal transmission / reception function unit (430) and transmitted / received to / from a mobile communication exchange via a modulation / demodulation function unit (440), is transmitted to / from a wireless base station (400) via It has a function of selecting from a plurality of signal lines (500) connected to the communication exchange. An outline of the processing operation of the system and the apparatus shown in FIGS. 2 and 3 will be described.

Now, for example, in a wireless zone (200a) formed by a wireless base station (400a), a mobile communication device in a communication state using a signal line 1 (500a) and a certain communication slot therein. Terminal (100a3) moves to another wireless zone (200b),
Further to another wireless zone (200c), the wireless zone (200a) to (2
00c) the mobile communication terminal when moving at high speed one after another
The destination wireless base station (400b) on the travel route of (100a3)
Then, in the wireless base station (400c), switching of the wireless base station is sequentially performed assuming the movement of the mobile communication terminal (100a3).

At this time, the destination radio base station (400b) and the radio base station (400c) also use the signal line 1 (500a) and use the communication slot (time division multiplex channel slot).
Also, switching control is performed so that the same communication slot occupied by the mobile communication terminal (100a3) at the time of transmission / reception on the wireless transmission path (300a) of the source wireless base station (400a) is used. This eliminates the need for the mobile communication terminal (100a3) to perform a recalling-type handover process when moving from the wireless zone (200a) that was originally present to a new wireless zone (200b). The switching movement of the communication line and the communication slot (time division multiplex channel slot) is performed by switching between the line selector (460) in the source wireless base station (400a) and the adjacent wireless base station (400b) as the destination. This is realized by switching control of the line selector (460).

Similarly, assuming the movement of the mobile communication terminal (100a3) between adjacent radio base stations on the movement path of the mobile communication terminal (100a3), the time-division multiplex channel slots are successively chained one after another. By performing the switching movement of the mobile communication terminal that is capable of communicating via the wireless base station of the destination one after another without having to perform a handover process associated with high-speed mobile communication, The occurrence frequency of handover in 100a3) is greatly reduced.

The mobile communication terminal during high-speed mobile communication
(100a3) For each radio base station (400) installed on the movement route, the transmission delay control function unit (450) provided in each radio base station (400), the radio base station ( 400) to the mobile communication terminal (100a3) during high-speed mobile communication, the timing of transmitting a digital modulation signal, and the respective radio base stations (40
0) to the mobile communication exchange (600) by controlling the delay time of the digital signal transmission, the radio base stations (400a) to (400a) to (400a) viewed from the mobile communication terminal (100a3) during high-speed mobile communication. 400c) from the wireless transmission path (300
a) to (300c) the timing phase of the time-division multiplex channel slot on (300c) and the time on the same signal line transmitted from each of the radio base stations (400a) to (400c) reaching the mobile communication switch (600) It can be realized that the timing phases of the division multiplex channel slots are all the same.

As described above, accurate communication quality can be ensured during high-speed movement. A specific processing operation in the radio base station of such a mobile radio communication system will be described below with reference to FIG. The table of FIG. 4 shows each radio base station (400a) to
(400e) shows an example of a time course of a signal line selected by a line selector provided in each of the radio base stations (400a) to (400e).

The mobile communication terminal A (100a) is connected to the radio base station 1 (40
0a) to the wireless base station 2 (400
b) A case will be described in which communication is performed while moving rapidly at high speed across the wireless zone formed by each of the wireless base station 3 (400c), the wireless base station 4 (400d), and the wireless base station 5 (400e). If the signal line occupied by the mobile communication terminal A (100a) in the wireless zone formed by the wireless base station 1 (400a) is the signal line 1 (500a), the mobile communication terminal A during high-speed mobile communication The wireless base station 2 (400b), the wireless base station 3 (400c), and the wireless base station 4 (4
00d), the radio base station 5 (400e) sequentially selects the signal line 1 (500a) at a timing assuming the movement of the mobile communication terminal A (100a) as shown by the arrow in the table of FIG. . Thereby, the mobile communication terminal A (100a) performing high-speed mobile communication
Can perform communication via a moving destination wireless base station one after another without having to perform a handover process associated with communication during high-speed movement.

The mobile communication terminal during high-speed mobile communication
Each wireless base station (400a) installed on the movement route of (100a) ~
(400e), for each of the radio base stations (400a) to (400e), a transmission delay control function unit provided in each of the radio base stations (400a) to (400e).
a) to (400e) from the mobile communication terminal (100
a) controlling the timing of transmitting the digital modulation signal to the mobile communication terminal and controlling the delay time of transmitting the digital signal from each of the wireless base stations (400a) to (400e) to the mobile communication switching system. (100a) seen from the respective radio base stations (400a) to (400e) timing phase of the communication slot (time division multiplex channel slot) on the radio transmission path transmitted from the (400e) and each of the radio base stations (400a) to (400e) )
, The timing phases of the time division multiplex channel slots transmitted on the signal line 1 are all aligned.

As described above, accurate communication quality can be ensured during high-speed movement. An operation flow of a specific process of the line selector provided in each of the radio base stations (400a) to (400e) of such a mobile radio communication system will be described with reference to FIG. The flow of FIG. 5 shows a processing operation flow in the case shown as an example in FIG.

For the sake of simplicity, it is assumed that mobile communication terminal A connects to radio base station 1 and a line selector provided in radio base station 1 selects signal line 1 for communication of mobile communication terminal A. A case where the mobile communication terminal A starts communication while moving at high speed via the radio base station 1 (F1) will now be described.

It is assumed that after the mobile communication terminal A starts communication during high-speed movement, the mobile communication terminal A moves at a specific speed v. Now, let t1 be the time at which the mobile communication terminal A is assumed to arrive in the wireless zone of the wireless base station 2 adjacent to the wireless base station 1, and always compare this time t1 with the current time T. (F2).

When the current time T reaches time t1, the line selector provided in the radio base station 1 deselects the signal line 1, and at the same time, the line selector provided in the radio base station 2 Select 1 (F3).

Next, assuming that the mobile communication terminal A moves at a specific speed v, a radio base station adjacent to the radio base station 2 on the moving path of the mobile communication terminal A during high-speed mobile communication. The time t2 at which the mobile communication terminal A is expected to arrive in the wireless zone by the station 3 is constantly compared with the current time T (F
Four).

When the current time T reaches time t2, the line selector provided in the wireless base station 2 deselects the signal line 1, and at the same time, the line selector provided in the wireless base station 3 Select 1 (F5).

The same procedure as described above is sequentially repeated between adjacent radio base stations installed on the moving path of the mobile communication terminal A during high-speed mobile communication.

If the actual moving speed of the mobile communication terminal A is different from the assumed specific speed v, a handover process will occur as the mobile communication terminal A moves.
The relative speed | v−v1 | of the actual moving speed v1 and the assumed speed v is
If the handover processing operation of the personal handy phone system is in the range from the walking speed of a person to the speed of slowing down the car, the frequency of handover processing can be suppressed to a level that can ensure accurate communication quality. it can.

Hereinafter, the present invention will be described more specifically with reference to examples. FIG. 6 is a system configuration of an embodiment of a personal handyphone system according to the present invention, and a signal line (500) and a wireless transmission path (300a) to (300c) by a handover process accompanying the movement of the mobile communication terminal (100). The example of transition of the communication slot position above is shown.

As shown in FIG. 6, the mobile radio communication system according to the embodiment includes mobile communication terminals (200a) to (200c) existing in radio zones (200a) to (200c) via radio transmission paths (300a) to (300c). 100a
1) to a plurality of radio base stations (400a) to (100a3)
c), each of the radio base stations (400a) to (400c) is connected in parallel to the mobile communication exchange (600) through a plurality of signal lines (500), and one of the signal lines Wireless base station (400a)
To (400c) are connected to each other.

More specifically, in the personal handyphone system shown as an embodiment, each of the plurality of radio base stations (400a) to (400c) includes a plurality of mobile communication terminals (100).
A function of transmitting / receiving a wireless signal to / from a plurality of mobile communication terminals (100), a function of modulating / demodulating a wireless signal transmitted / received to / from the plurality of mobile communication terminals (100), and a wireless transmission path (300a) to (300
c) a function of performing a delay control of a timing of transmitting a signal via the mobile communication terminal (100), and selecting a specific frequency as a radio transmission path (300a) to (300c) for transmitting / receiving a radio signal to / from the mobile communication terminal (100), A function of allocating a communication slot for the mobile communication terminal (100) under its own to a specific slot position on the road (300a) to (300c), and a plurality of signal lines (500) for transmitting and receiving digital signals to and from the mobile communication exchange (600). Said signal line
It has a function of selecting a specific one from (500) and allocating a communication slot for its own subordinate mobile communication terminal (100) to a specific slot position on the signal line (500).

In the personal handyphone system according to the present embodiment, the mobile communication terminal (100) moves between the wireless zones (200a) to (200c) by the wireless base stations (400a) to (400c) one after another during communication. In this case, each of the radio base stations (400a) to (400c) autonomously performs the mobile communication according to a predetermined time calculated from a previously assumed moving speed of the mobile communication terminal (100) during mobile communication. The wireless transmission path (300) used by the terminal (100) under the control of the adjacent wireless base stations (400a) to (400c) of the movement source.
a) to (300c) the frequency and the time slot on the wireless transmission path, within the wireless zone (200a) to (200c) under its
(100), and on the signal line (500) and the signal line (500) used by the mobile communication terminal (100) under the control of the adjacent base stations (400a) to (400c) of the movement source. Communication slots of the own radio base stations (400a) to (400c) and the mobile communication exchange (60
0) on the signal line (500) between the mobile communication terminal (100) and the signal line (500) used by the mobile communication terminal (100) as shown in FIG. Transmission line (3
The communication slot positions on (00a) to (300c) correspond to the respective radio base stations (4
00a) to (400c).

Thus, it is possible to realize switching of the assigned wireless zone without performing the handover process and without intervening the control process on the network side.

FIG. 7 shows an outline of the internal functional block configuration of the radio base stations (400a) to (400c). Wireless base stations (400a) to (4
00c) is an antenna (410), a radio signal transmitting and receiving unit (420),
Modulation / demodulation unit (430), wireless signal delay control unit (440), wireless channel assignment function unit (450), signal line assignment function unit (460)
And a control unit (470) for controlling the whole.

The radio channel assignment function unit (450) includes a control unit
Under the control of (470), a specific frequency is selected as a radio transmission path (300a) to (300c) for transmitting and receiving a radio signal to and from the mobile communication terminal (100), and on the radio transmission path (300a) to (300c) ) Has a function of allocating a communication slot for the mobile communication terminal (100) under its own control to a specific slot position.

The signal line allocation function unit (460) includes a control unit (470)
Control, a specific one of a plurality of the signal lines (500) is selected as a signal line (500) for transmitting / receiving a digital signal to / from the mobile communication exchange (600), and the signal line (5
(00) The mobile communication terminal under its own control at the specific slot position (100)
A function of allocating a communication slot for communication.

The radio signal delay control unit (440) modulates the digital signal addressed to the subordinate mobile communication terminal (100) received from the mobile communication exchange (600) by the modulation / demodulation function unit (430). When transmitting to the subordinate mobile communication terminal (100) via the antenna (410) by the (420), it has a function to delay the transmission timing by a set time.

An outline of the processing operation of this embodiment will be described with reference to FIGS. Now, as shown in FIG. 6, a mobile communication terminal (100) in a communication state in a wireless zone (200a) formed by a wireless base station (400a) is
0b), wireless zone (200c) to wireless zone (200c)
Let's consider a case of moving at high speed one after another. At the timing when the moving time of the mobile communication terminal (100) to the wireless zone (200b) elapses in advance, the source wireless base station (400
The frequency and communication slot occupied by the mobile communication terminal (100) at the time of transmission / reception on the wireless transmission path (300a) of (a) are changed to an adjacent wireless base station on the movement path of the mobile communication terminal (100).
Also on the wireless transmission path (300b) of (400b), it is allocated as a communication slot for the mobile communication terminal (100), and the mobile communication terminal (100) is subordinate to the source wireless base station (400a). The communication slot on the signal line (500) which is sometimes occupied is also used in the adjacent wireless base station (400b) on the moving route of the mobile communication terminal (100). At this time, in the source wireless base station (400a), the communication slot on the wireless transmission path (300a) and the communication slot on the signal line (500) occupied by the mobile communication terminal (100) are changed to another communication slot. Release for mobile communication terminals. The delivery of communication slots on the wireless transmission paths (300a) to (300c) between the wireless zones (200a) to (200c) is performed by the wireless channel assignment function unit (4) in the source wireless base station (400a).
50) and the processing of the radio channel assignment function unit (450) in the adjacent radio base station (400b) to which
The transfer of the communication slot on (500) between the radio base stations (400a) to (400c) is performed by the signal line allocation function unit (460) in the source radio base station (400a) and the adjacent radio base station as the destination. Bureau (40
This is realized by the processing of the signal line allocation function unit (460) in 0b).

In the above, the wireless zones (200a) to (200c)
It is advantageous that the assumed moving time between the mobile communication terminals (100) is set to a constant value suitable for the environment to which the personal handyphone system according to the present invention is applied as the moving speed of the mobile communication terminal (100). That is, the radio base station (4
From the installation intervals of 00a) to (400c) and the assumed value of the moving speed,
A specific fixed value is determined in advance as an assumed value of the travel time. For example, if the personal handyphone system according to the present invention is applied on a highway, a constant value of 80 km / h is assumed as the moving speed of the mobile communication terminal (100), and the radio base station (400a ) To (400c) are 200 m, the travel time between the wireless zones (200a) to (200c) is preliminarily calculated as 200 m ÷ 80 km / h = about 9 seconds.

As described above, the communication on the signal line (500) and the wireless transmission paths (300a) to (300c) is performed according to the assumed travel time between the wireless zones (200a) to (200c) of the mobile communication terminal (100). By performing the slot assignment process, the mobile communication terminal (10
(0), when moving from the originally existing wireless zone (200a) to the new wireless zone (200b), there is no need to perform a recalling-type handover process, and a control process by the network side is involved. There is no need to continue communication.

Thus, the mobile communication terminal (100)
Between adjacent wireless base stations (400a) to (400c) on the moving route of the mobile communication terminal (100), which are assumed in advance, according to the moving time to each wireless zone (200a) to (200c). The transfer of communication slots on the wireless transmission paths (300a) to (300c) between the wireless zones (200a) to (200c) and the signal line (50
0) By passing the upper communication slot between the wireless base stations (400a) to (400c), even in the communication state during high-speed movement, the wireless base station of the movement destination is successively changed without performing the handover process. Communication can be continued via the mobile communication terminal, and the frequency of occurrence of handover in the mobile communication terminal (100) during high-speed mobile communication is greatly reduced. Also, there is no need for any special control processing on the network side.

Next, synchronization of communication slots between the wireless zones (200a) to (200c) when the mobile communication terminal (100) moves one after another between the wireless zones (200a) to (200c) at high speed. explain.

The radio signal delay control unit (440) provided in each of the radio base stations (400a) to (400c) includes a mobile communication terminal (100)
When moving between the wireless zones (200a) to (200c), in order to reduce noise and the like generated due to the synchronization deviation of the communication slot, the wireless transmission path (300a) of the source wireless base station (400a) is reduced. And the adjacent wireless base station (4
00b) and the radio transmission path (300b) of the radio base station (400b) so as to be synchronized with the communication slot phase on the radio transmission path (300b).
Control is performed so that the communication slot phase on b) and the communication slot phase on the wireless transmission path (300c) of the adjacent wireless base station (400c) are synchronized. That is, each of the radio base stations (400a) to (400
c) provided in the wireless signal delay control unit (440), each of the wireless base stations (400a) ~ (400c) from each wireless transmission path (300
a) to (300c), by controlling the timing of transmitting a radio signal to each of the radio base stations (400a) to (400c) in accordance with a value set in advance, the mobile communication terminal during high-speed mobile communication ( 100), the communication slot phases on the wireless transmission paths (300a) to (300c) transmitted from the wireless base stations (400a) to (400c) can all be synchronized.

As described above, each of the wireless zones (200a) to (200a)
c), by synchronizing the communication slot phases on the wireless transmission paths (300a) to (300c), when the mobile communication terminal (100) moves between the wireless zones (200a) to (200c), the communication slot Noise and the like generated due to the synchronization deviation of the mobile communication terminal can be greatly reduced, and communication quality in the mobile communication terminal (100) moving at a high speed can be more accurately ensured.

The above-mentioned wireless zones (200a) to (200a)
c) When assuming the travel time between the mobile communication terminals (1) having a speed different from the speed assumed as the travel speed of the mobile communication terminal (100) (1).
(00), the transfer of communication slots on the wireless transmission paths (300a) to (300c) between the wireless zones (200a) to (200c), and between the wireless base stations (400a) to (400c). The conventional handover process will occur at the timing of the transfer of the communication slot on the signal line (500) in the above, but the relative speed | v-v1 | of the assumed moving speed v and the moving speed v1 of the mobile communication terminal is However, even in a conventional personal handy phone system, if the frequency of instantaneous call interruption due to handover occurrence is at a level that does not cause any problem, the communication quality due to instantaneous call interruption is low even if handover processing occurs. Deterioration is suppressed to a level at which accurate communication quality can be ensured.

For example, when the personal handyphone system according to the present invention is applied to a highway, a mobile communication terminal (10
Assuming a constant value of 80 km / h as the traveling speed of (0),
If the relative speed of the mobile communication terminal is less than or equal to the slow speed of the car, that is, if the slow speed of the car is about 30 km / h, the moving speed of the mobile communication terminal is 50 km / h to 110 km / h.
If it is below, accurate communication quality can be ensured.

FIG. 8 shows the time transition of the communication slot position for the mobile communication terminal (100) in each of the wireless zones (200a) to (200c) on the moving route of the mobile communication terminal (100). is there. In FIG. 8, in a wireless zone (200a) formed by a certain wireless base station (400a), as a communication slot for a mobile communication terminal (100), a wireless slot on a wireless transmission path (300a) having a frequency f1 is used.
In this example, two slots are allocated.

In this case, the adjacent radio base station (400b) installed at the destination of the mobile communication terminal (100) during high-speed mobile communication.
Then, the mobile communication terminal (100) is in the wireless zone (200a) to (200b)
Time assumed in advance as the time required to move between
At the time point (t1) at which T elapses, the mobile station (100) has been assigned to the wireless zone (200a) to which the mobile communication terminal (100) has been assigned on the wireless transmission path (300a) of the frequency f1 used by the mobile communication terminal (100). Is allocated for the mobile communication terminal (100) in the wireless zone (200b) under its own control.

At the timing (t2) after the elapse of the next time T, the next adjacent radio base station (400c) installed at the destination of the mobile communication terminal (100) has been assigned to the mobile terminal (100). The second slot on the wireless transmission path (300a) of the frequency f1 used by the mobile communication terminal (100) in the wireless zone (200b) that was Assign for terminal (100).

By performing similar processing in a chain along the movement route of the mobile terminal (100), the mobile communication terminal (100) performing high-speed mobile communication successively moves within the wireless zone of the movement destination. It is possible to occupy the same slot on the same frequency on the wireless transmission path.

When the mobile communication terminal (100) sequentially moves between the wireless zones (200a) to (200c) at a high speed, each of the wireless transmission lines (200a) to (200c) in each of the wireless zones (200a) to (200c). 300a)-(3
(00c) In order to synchronize all the communication slot phases above, the radio base stations (400a) to (400a) to (400c) are provided by radio signal delay control units (440) provided in the radio base stations (400a) to (400c). 400c)
The timing of transmitting a radio signal to each of the subordinate radio transmission paths (300a) to (300c) from the base stations (400a) to (4
00c) Control according to the value set for each. This allows
Radio transmission paths transmitted from the respective radio base stations (400a) to (400c) viewed from the mobile communication terminal (100) during high-speed mobile communication
The communication slot phases on (300a) to (300c) can all be synchronized.

FIG. 9 is a diagram showing the situation in each of the radio base stations (400a) to (400c) installed along the mobile light path of the mobile communication terminal (100).
9 shows an example of a time transition of the allocation status of a communication slot for the mobile communication terminal (100) on a signal line. Figure 9
Then, at a certain radio base station (400a), a mobile communication terminal (1
In this example, a second slot of line number 1 is assigned as a communication slot on the signal line (500) for (00).

In this case, the adjacent radio base station (400b) installed at the destination of the mobile communication terminal (100) during high-speed mobile communication
Then, the mobile communication terminal (100) is in the wireless zone (200a) to (200b)
Time assumed in advance as the time required to move between
At the time point (t1) at which T elapses, the second slot of the line number 1 used by the mobile communication terminal (100) in the radio base station (400a) to which the mobile terminal (100) has belonged, Used for the mobile communication terminal (100). At the timing (t2) after the elapse of the next time T, at the next adjacent wireless base station (400c) installed at the destination of the mobile communication terminal (100), the mobile terminal (100) has belonged so far. The second slot of line number 1 used by the mobile communication terminal (100) in the wireless base station (400b) is used for the mobile communication terminal (100).

By performing similar processing in a chain along the moving route of the mobile terminal (100), the mobile communication terminal (100) performing the high-speed mobile communication successively becomes a destination wireless base station. , It is possible to occupy the same slot on the same signal line.

As described above, the mobile communication terminal (100) performing high-speed mobile communication can move to the destination one after another without performing the handover process accompanying the high-speed movement without requiring any special processing control on the network side. Communication can be continued via the wireless base station, and all communication slot phases on the wireless transmission path transmitted from each wireless base station can be synchronized. Assures accurate communication quality with less noise contamination.

FIG. 10 shows a processing sequence between the mobile communication terminal and the radio base station when the mobile communication terminal switches the radio zone to which the mobile communication terminal belongs, according to the processing sequence (a) in the conventional personal handyphone system and the processing sequence according to the present invention. Processing sequence in personal handyphone system (b)
This is shown by comparing with.

As shown in FIG. 10, in the related art, a recalling-type handover process is required when the assigned wireless zone is switched, that is, a link channel is established between a mobile communication terminal and a destination wireless base station. Since each sequence of request, link channel assignment, call setup, call setup acceptance, and response is required, a call disconnection occurs during this time. In contrast, in the present invention, it is necessary to perform handover processing as described above. In addition, since the above-mentioned sequences associated with the handover process are not required, a call disconnection does not occur when the assigned wireless zone is switched.

FIG. 11 shows a flow of a specific processing operation of each radio base station in the personal handyphone system according to the present invention. This flow shows a processing operation flow in an arbitrary one of the plurality of wireless base stations installed along the moving direction of the mobile communication terminal.

The control unit in the radio base station controls the adjacent radio base station opposite to the moving direction of the mobile communication terminal, that is, the mobile communication terminal under the control of the adjacent radio base station from which the mobile communication terminal moves. About the radio transmission line frequency used and the communication slot position on the radio transmission line, and the signal line number and the communication slot position on the signal line, the signal line
Get information via (500). (G1) The time required for the mobile communication terminal to move between adjacent wireless zones, based on the assumed moving speed (specific constant value) of the mobile communication terminal and the installation interval of the wireless base stations (400a) to (400c).
(Specific constant value), and at the time when the assumed moving time elapses, communication for each mobile communication terminal on a wireless transmission path and a signal line for switching the wireless zone to which the mobile communication terminal belongs between the respective wireless base stations. Since the slots are transferred, the control unit in the wireless base station monitors the arrival of the wireless zone switching timing (elapse of a specific time).
(G2) When the wireless zone switching timing arrives, the control unit in the wireless base station controls the wireless channel assignment function unit and the signal line assignment function unit, and performs wireless transmission for mobile communication terminals that have been under their own control. The communication slot occupied on the road and the signal line is released. (G3) The radio channel assignment function unit is controlled by the control unit in the radio base station, and the radio channel frequency and the radio communication channel used by the mobile communication terminal under the adjacent radio base station on the source side acquired in (G1). According to the information on the communication slot position on the wireless transmission path, the same slot on the wireless transmission path of the same frequency is allocated as a communication slot for a mobile communication terminal that has moved under its control. (G4) The signal line assignment function unit is controlled by the control unit in the radio base station, and the signal line number and signal used by the mobile communication terminal under the control of the adjacent radio base station on the source side acquired in (G1) According to the information about the communication slot position on the line,
The same slot on the same signal line is occupied as a communication slot for a mobile communication terminal that has moved under its own control. (G5) When transmitting a communication slot for a mobile communication terminal that has moved under its control to the wireless transmission path by the wireless signal delay control unit in the wireless base station, the adjacent base station and the communication slot phase on the wireless transmission path are synchronized. As described above, the transmission timing is delayed by a time adjusted and set in advance. (G6) The wireless signal for the wireless transmission channel whose transmission timing has been adjusted for delay is modulated by the modulation / demodulation unit in the wireless base station, and transmitted to the wireless transmission channel information via the antenna by the wireless signal transmission / reception unit. (G7) Thereafter, the procedure returns to (G1), and the following procedures (G1) to (G7) are repeated.

[0069]

According to the present invention, it is possible to suppress occurrence of handover processing in a mobile communication terminal during high-speed mobile communication, thereby reducing occurrence of instantaneous call interruption due to handover processing. Accurate communication quality can be ensured during high-speed movement in the communication system.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration and a handover process of a conventional personal handyphone system.

FIG. 2 is a system configuration diagram of a personal handyphone system according to one embodiment of the present invention.

FIG. 3 is a functional block diagram of the wireless base station of FIG. 2;

FIG. 4 is a diagram showing an example of a processing operation in the wireless base station in FIG. 2;

FIG. 5 is a flowchart showing a processing operation example of a line selector in the wireless base station of FIG. 2;

FIG. 6 is a diagram showing a system configuration of an embodiment of a personal handyphone system and a processing example at the time of wireless zone switching.

FIG. 7 is a diagram showing an outline of an internal functional block configuration in the wireless base station of FIG. 6;

FIG. 8 is a diagram showing a time transition of a communication slot position for a mobile communication terminal on a wireless transmission path in each wireless zone in one embodiment.

FIG. 9 is a diagram illustrating a time transition of a communication slot occupation state for a mobile communication terminal on a signal line in each wireless base station according to the embodiment;

FIG. 10 is a diagram showing a processing sequence at the time of wireless zone switching by comparing a processing sequence (a) by the conventional system with a processing sequence (b) by the system of one embodiment.

FIG. 11 is a flowchart illustrating an example of a processing operation in the wireless base station according to the embodiment;

[Explanation of symbols]

100 ... mobile communication terminal, 200a, 200b, 200c ... wireless zone, 3
00a, 300b, 300c: Wireless transmission path, 400, 400a, 400b, 400c
... Wireless base station, 410 ... Antenna, 420 ... Wireless signal transmission / reception unit, 430 ... Modulation / demodulation unit, 440 ... Wireless signal delay control unit, 450 ...
Wireless channel assignment function unit, 460 ... Signal line assignment function unit, 470 ...
Control unit, 500 ... signal line, 600 ... mobile communication exchange

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenichi Aoyama 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Yokohama, Japan Inside the Information and Communication Division, Hitachi, Ltd. (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 7/24-7/26 113 H04Q 7/00-7/38

Claims (7)

(57) [Claims] 1. A mobile communication exchange, a plurality of radio base stations, a plurality of signal lines connecting the one mobile communication exchange and a plurality of radio base stations, and a radio transmission path with each of the radio stations. In a mobile radio communication system composed of a plurality of mobile communication terminals connected to each other, each of the radio base stations is connected to any of the plurality of signal lines, Accordingly, among the radio base stations installed along the moving path of the mobile communication terminal, the radio base station to which the mobile communication terminal connects is set to the signal line already selected by the adjacent radio base station and the radio transmission path within the radio transmission path. A mobile radio communication system characterized by having a control function of sequentially switching while maintaining the slot position. 2. A mobile communication exchange, a plurality of radio base stations, a plurality of signal lines connecting the one mobile communication exchange and a plurality of radio base stations, and a radio transmission path with each of the radio stations. In a mobile radio communication system including a plurality of mobile communication terminals connected to each other, each of the radio base stations is connected to any of the plurality of signal lines, and further, each of the plurality of signal lines is transmitted to each of the radio base stations. A function of selecting a specific one from a line and a slot position in the radio transmission path, and the radio base station autonomously specifying the specific one according to an assumed value of a moving speed of a mobile communication terminal during mobile communication. Having a function of selecting a signal line and a slot position, a plurality of wireless base stations connected to a mobile communication terminal performing mobile communication are installed along a moving path of the mobile communication terminal performing mobile communication. Between the radio base station, a mobile radio communication system characterized by sequentially switching in accordance with the movement direction of the mobile communication terminal in said mobile. 3. A transmission delay control function capable of variably setting a delay time of a transmission timing when transmitting a signal to a mobile communication terminal and a mobile communication exchange accommodated by each radio base station. When transmitting a digital modulation signal from each radio base station to a mobile communication terminal, the time division multiplexing of the time division multiplexed digital modulation signal transmitted from the radio base station to the mobile communication terminal is carried on a radio transmission path. The multi-channel slot phase can be aligned between the radio base stations, and when transmitting a digital signal from each radio base station to the mobile communication switching system, a plurality of radio base stations can carry the digital signal on the same signal line. The digital demodulated signal transmitted to the mobile communication exchange is converted to a time division multiplexed access signal having the same phase of the time division multiplexed channel slot. Mobile radio communication system according to claim 2, characterized in that makes it possible to transmit the 換機. 4. In a mobile radio communication system having a plurality of radio base stations accommodating a plurality of mobile communication terminals via a radio transmission path, a mobile communication exchange and each radio base station are connected via a plurality of signal lines. A plurality of radio base stations are connected in parallel to each signal line, and each radio base station selects a specific one from the plurality of signal lines and moves to a specific slot position on the signal line under its own control. A function of allocating a communication slot for a communication terminal and a function of allocating a communication slot for a mobile communication terminal under its control to a specific slot position on a wireless transmission path of a specific frequency are provided. The signal lines and signal lines that each of the radio base stations autonomously uses when the mobile communication terminal under its control is under the control of an adjacent radio base station as the predetermined time calculated from the assumed moving speed elapses The upper communication slot is allocated to the mobile communication terminal under its own control, and the radio transmission line frequency and the time slot on the radio transmission line used by the mobile communication terminal under its control under the control of the adjacent radio base station are assigned to the mobile communication terminal under its own control A mobile radio communication system characterized by having a function of allocating a mobile communication system. 5. A radio signal delay control function capable of variably setting a transmission timing delay time when a signal is transmitted to a mobile communication terminal accommodated by each radio base station. When transmitting a digital modulation signal from a station to a mobile communication terminal, a time-division multiplexed channel slot of a time-division multiplexed digital modulation signal placed on a radio transmission path from each of the radio base stations and transmitted toward the mobile communication terminal The mobile radio communication system according to claim 4, wherein the phases can be aligned between the respective radio base stations. 6. A wireless communication system comprising a plurality of radio base stations accommodating a plurality of mobile communication terminals via a radio transmission line, wherein a mobile communication exchange and each radio base station are connected via a plurality of signal lines. In each of the mobile radio communication system in which a plurality of radio base stations are connected in parallel, each radio base station, when starting communication of a mobile communication terminal under its own control, a specific communication from the plurality of signal lines Select one and assign a communication slot for the mobile communication terminal under its own to the specific slot position on the signal line, and allocate a communication slot for the mobile communication terminal under its own to the specific slot position on the wireless transmission path of the specific frequency After that, according to the elapse of a predetermined time calculated from the moving speed assumed in advance of the mobile communication terminal during the mobile communication, each of the radio base stations autonomously, and the mobile communication terminal under its control is connected to the adjacent radio base station. The radio transmission line frequency and the time slot on the radio transmission line used at the time of the control of the station are allocated to the mobile communication terminal under the control of the own station, and the signal lines and signals used by the mobile communication terminal under the control of the station under the control of the adjacent radio base station are allocated. A wireless zone switching method in a mobile wireless communication system, wherein a communication slot on a line is allocated to the mobile communication terminal under its control. 7. A modulation / demodulation function unit for modulating a digital signal addressed to a subordinate mobile communication terminal received from a mobile communication exchange, and modulating the antenna from the radio signal transmission / reception unit. A wireless signal delay control unit that delays the transmission timing by a preset time when transmitting to the mobile communication terminal under the control thereof, and a specific frequency as a wireless transmission path for transmitting and receiving a wireless signal to and from the mobile communication terminal. A radio channel allocation function unit for selecting and allocating a communication slot for a mobile communication terminal under its own control to a specific slot position on the radio transmission line; and a specific signal line from a plurality of signal lines as a signal line for transmitting and receiving digital signals to and from a mobile communication exchange. A signal line allocator that selects one and allocates a communication slot for its own mobile communication terminal to a specific slot position on the signal line A radio base station in a mobile radio communication system, comprising: an active unit; and a control unit that controls the entire unit.