JPH0879157A - Circuit management method for multi-beam mobile satellite communication system - Google Patents

Abstract

PURPOSE: To attain decentralized control and also to attain the dynamic channel assignment through a simple control by fixing the beam frequency in a corresponding area based on the instruction given from a base station and then deciding a feeder link frequency. CONSTITUTION: A base station controller 10 which controls the call of a beam area 18 assigns an idle radio communication circuit 16 to a corresponding mobile station 17 among those managed radio communication circuits. Under such conditions, a transceiver device 12 is instructed by the controller 10 to set a circuit in the area 18. The device 12 sets the assigned circuit frequency and the beam frequency in the fixed and variable states respectively and sets again this variable beam frequency in the area 18. Then the feeder link frequency is generated and a radio circuit is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line management method in a multi-beam mobile satellite communication system using a communication satellite for mobile communication.

[0002]

2. Description of the Related Art In recent years, mobile communication systems using communication satellites have come into use. Satellite systems in this mobile satellite communication system include a system using a single-beam satellite and a system using a multi-beam satellite. First, since the single-beam satellite covers a wide area with one beam, the effective radiation power (EIRP;
There is a problem that uivalent Isotropic Radiated Power) becomes low. On the other hand, the multi-beam satellite has an advantage that the EIRP can be increased by setting a small beam irradiation radius and covering a wide range with a plurality of beams, but if a fixed frequency band is set for each beam, traffic will be increased. However, there is a problem in that there is no tolerance when it is concentrated on one beam, and line division loss occurs.

As a means for solving these problems,
Multiple Porter Amplif (MPA)
The construction of a communication satellite using ier) has been proposed. The MPA distributes and amplifies received power of a communication satellite, and then performs synthesis again so that an output from a specific input terminal is transmitted from an output terminal corresponding to the output.

FIG. 5 shows a frequency of a line (hereinafter referred to as a service link) between a communication satellite and a mobile station and a line between the communication satellite and a base station in a multi-beam mobile satellite communication system using MPA. (Hereinafter referred to as feeder link)
The relationship with the frequency of is shown. That is, the satellite-mounted repeater 4
5 communicates with the entire beam area 46 of the satellite at a predetermined frequency 48 on the frequency axis of the service link, and between the satellite-mounted repeater 45 and the base station 47 has a predetermined frequency on the frequency axis of the feeder link. The communication is performed at the frequency 49. For details, see the paper "Multi-terminal Synthetic Multi-beam Transmission System".
IEICE Transactions (B), J69-B, No.2pp206〜212,198
In 6), it is described as a proposal for an active array multi-beam transmission system that can flexibly deal with traffic distribution or fluctuations when multi-beaming is performed.

However, such a hardware structure of MPA,
Although there have been studies on physical performance so far, there is no disclosure of technology regarding line management methods as operational technology.

Further, by using the MPA, it becomes possible to allocate all the radio lines to the respective beams as if the lines were allocated by a single beam. Generally, in order to realize this, (1) a method of collectively managing and controlling all the wireless lines by one base station controller,
(2) There are two possible methods: installing a line management device that manages only all wireless lines.

However, there is a problem in that a base station control device having an extremely high processing capacity is required to realize the method of performing all at once described in (1), and the line management described in (2). In the case of realizing the method by the device, there is a problem that the number of ladders is increased by one and the network configuration becomes complicated and the control becomes complicated.

[0008] Generally, as a line management method,
The line and the frequency are in one-to-one correspondence. Therefore,
One way to realize this is to manage the lines by associating them with all the feeder link frequencies.

However, in this case, a management table of (1) (number of lines used in service link) × (number of beams) is required, and the table size increases as the number of beams increases, (2) MPA As a result, all the bands on the feeder link are superposed on the same service link, so even if the frequency is different on the feeder link, it may be the same frequency on the service link. There is a problem that interference occurs.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and is a line in a multi-beam mobile satellite communication system capable of performing distributed control and realizing dynamic channel assignment with simple control. The purpose is to provide a management method.

[0011]

In order to achieve the above object, the first invention of the present application is such that when a base station control device has a free line in a radio communication line managed by the base station control device, the radio communication is performed. While assigning a line to a new call, the transceiver device is notified to set up a line in the called beam area of the called station, and the transceiver device fixes the assigned line frequency and sets the beam frequency. The gist is to set the corresponding beam area by the designation of the base station control device, determine the feeder link frequency, and set the line.

A second aspect of the present invention is the line management method in the multi-beam mobile satellite communication system according to claim 1, wherein when a call is generated in the beam area, the radio call is managed by the base station controller. When there is no free line in the line, the base station control device inquires of another base station control device whether or not there is a free line, and the base station control device receiving this inquiry has a free line. In this case, the wireless communication line is notified to the inquiring base station control device and the transmitting / receiving device of the wireless communication line is informed to set the wireless communication line in the corresponding beam area. The point is to determine the frequency and set the line.

A third aspect of the present invention is the line management method in the multi-beam mobile satellite communication system according to the first aspect, in which a mobile station that is in a call in a given beam area via a radio call line uses another beam. When moving to the area, the transmitting / receiving device notifies the base station control device that the mobile station has moved to another beam via the feeder link, and the base station control device notifies that the mobile station has moved to another beam area. When receiving from the transmitter / receiver, it is a gist to instruct the transmitter / receiver only to switch the beam frequency corresponding to the switch destination beam area to perform handover between the line switching beams during communication.

[0014]

In the line management method in the multi-beam mobile satellite communication system according to the first aspect of the present invention, the base station control device makes a new call to the wireless communication line when the wireless communication line managed by itself has an idle line. In addition to the allocation, the transmitter / receiver is notified to set a line in the called beam area of the called station. Upon receiving this notification, the transmission / reception device fixes the assigned line frequency, sets the beam frequency in the corresponding beam area, further determines the feeder link frequency, and sets the line.

The line management method in the multi-beam mobile satellite communication system according to the second invention of the present application is that the base station control device comprises:
When a call is made in the beam area, if there is no free line in the wireless communication line managed by itself, the other base station control device is inquired whether or not there is a free line. In response to this inquiry, the base station control device notifies the inquiring base station control device of the wireless communication line when there is a free line and secures it, and the corresponding beam is transmitted to the transmission / reception device of the wireless communication line. Notify the area to set up a wireless telephone line. The transmitter / receiver receiving this notification determines the feeder link frequency and sets the line.

The line management method in the multi-beam mobile satellite communication system according to the third aspect of the present invention is such that when a mobile station in a call moves to another beam area via a radio call line,
When the transmitting / receiving device detects this movement, it notifies the base station control device of the movement of this mobile station via the feeder link.
When the base station control device receives the movement of the mobile station from the transmitting / receiving device, it instructs the transmitting / receiving device only to switch the beam frequency corresponding to the switching destination beam area, and performs handover between the in-call line switching beams.

In the general mobile satellite communication system, the feeder link is composed of a single beam for one communication satellite, and the number of base stations is one or two. Further, in the present invention, the service link is composed of multiple beams, and the isolation of the MPA input terminal corresponding to each beam of this service link is normally provided with a feeder link frequency for each band corresponding to each beam. It is realized by changing the local frequency for each band. Further, according to the present invention, even if all the traffic is concentrated on a specific beam, it becomes possible to transmit all the lines to the beam.

In the base station controller, each radio line is managed as a local frequency corresponding to the beam and a frequency corresponding to each line of the service link, and a physical area controlled by another base station controller, that is, a beam is controlled. In the case of allocating the line, the line frequency can be changed by changing the local frequency of the allocated wireless line. In addition, the line management can be realized regardless of the number of beams, that is, the table size of the number of lines used in the service link,
It is possible to prevent the occurrence of interference by fixedly associating the line frequency with all the service link frequencies. Therefore, according to the channel management system in the multi-beam mobile satellite communication system of the present invention, sufficient distributed control is achieved, channel control is simplified, and 100% dynamic channel assignment is realized.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a frequency configuration example of each line in a base station control device and a transmission / reception device according to the present invention, and FIG. 2 is a block diagram showing a configuration example of a system to which the management method of the present invention is applied. First, referring to FIG. 1, the base station control device 1 includes a control unit 2 and a line management table 3. The transmitter / receiver 4 includes a beam frequency synthesizer 5, a modulator / demodulator 6, a line frequency synthesizer 7, and a beam frequency / line frequency coupling device 8. The exchange 9 in the system shown in FIG. 2 is connected to the transmitting / receiving device 12 via the base station control device 10 and is connected to the transmitting / receiving device 13 via the base station control device 11. Further, the transmitting / receiving device 12 is assigned to the mobile station 17 in the physical beam area 18 and is transmitted to the mobile station 1 via the communication line 16 managed by the base station control device 10.
Communicate with 7. At this time, a control line 14 for the beam area 18 is provided between the transceiver 12 and the beam area 18, and the transceiver 13 and the beam area 19 are provided.
A control line 15 for the beam area 19 is provided between and.

Next, the processing procedure in the line management method of this embodiment will be described with reference to FIGS. 1 and 2 by taking a case where a call occurs in the beam area 18 as an example. In the base station control device 10 that is performing the call control of the beam area 18, if the radio communication line managed by the base station control device 10 has a free space, the radio communication line 16 is connected to the corresponding mobile station 17
Assign to. At this time, the transmission / reception device 12 is notified by the base station control device 10 to set a line in the beam area 18. However, in the transmitter / receiver 12, the allocated line frequency is fixed, the beam frequency is made variable, and the beam frequency is reset in the beam area 18. Next, the feeder link frequency is generated and the wireless line is set.

Next, the base station controller 10 shown in FIG. 2 (the base station controller shown in FIG. 1, the base station controller 1 shown in FIG. 2)
1 is also the same).
Table 3 shows two frequencies, namely the line frequency fc
hi and beam frequency fbi (where i is 1, 2, ...,
n). For example, the frequency of a line is determined as a result of combining these two frequencies, ch # 1
It is a combination of fcf1 and fb1. Of these, the line frequency fchi
Is fixedly set, and the beam frequency fbi is dynamically determined according to the beam in the area.

When a mobile station 17 located in a certain beam area 18 makes a transmission request, the transmission / reception device 12 receives the transmission request via the control line 14. The transmission / reception device 12 manages that the control line 14 is set for the beam area 18 as data, and as a result, notifies the base station control device 10 of the information related to the beam area 18 together with the transmission request signal. To do. When the base station controller 10 selects a vacant line from the table 3 managed by the base station controller 10, it determines the beam frequency fbi corresponding to the beam area 18 for the beam frequency fbi of the line and instructs the transmitter / receiver 12 to do so. To specify the frequency.

The transmitter / receiver 4 shown in FIG. 1 (corresponding to the transmitter / receiver 12 shown in FIG. 2) is provided with two oscillators, that is, a beam frequency synthesizer 5 and a line frequency synthesizer 7, and a beam frequency synthesizer. 5
Corresponds to the beam frequency (line frequency fchi in Table 3) and line frequency synthesizer 7 corresponds to the line frequency (beam frequency fbi in Table 3). Therefore, the frequency of the line frequency synthesizer 7 is fixed.
Now, when the frequency corresponding to the beam area 18 is designated for the transmitter / receiver 4, the transmitter / receiver 4 extracts the beam frequency fbi and sets the frequency of the beam frequency synthesizer 5 to this. Beam frequency synthesizer 5
And the frequency of the line frequency synthesizer 7 are combined by the beam frequency / line frequency coupling device 8, and the frequency determined as a result is output from the beam frequency / line frequency coupling device 8.

FIG. 3 shows one pattern in the configuration of FIG. 2, and shows a case where a call is generated in the beam area 29 and there is no wireless line managed by the base station control device. Also, in the figure, a two-way arrow with a wavy line means a control line and an arrow with a solid line means a communication line. In FIG. 3, the switching center 20 is connected to the transmission / reception device 23 via the base station control device 21, and is connected to the transmission / reception device 24 via the base station control device 22. In addition, the transceiver 24
Communicates with the mobile station 28 via the communication line 27 assigned to the mobile station 28 within the physical beam area 29 and managed by the base station controller 22. At this time, the transmitter / receiver 2
A control line 25 for the beam area 29 is provided between the beam line 3 and the beam area 29, and a control line 26 for the beam area 30 is provided between the transceiver 24 and the beam area 30.

Next, the processing procedure will be described with reference to FIG. Here, a call occurs in the beam area 29,
A case where there is no wireless line managed by the base station controller 21 will be described. In this case, the base station control device 21 inquires of the base station control device 22 whether there is an available line. In response to this inquiry, the base station controller 22 responds to the wireless call line 2 if there is an available wireless line.
7 in response to the base station controller, reserves the corresponding wireless communication line 27, and notifies the transmitter / receiver 24 of the wireless communication line 27 to set the wireless communication line 27 in the beam area 29. The transmitter / receiver 24 generates the feeder link frequency and sets the wireless communication line 27 in the same manner as described above.

That is, although the call request is made on the control line and the communication line is set up in exactly the same manner as in FIG. 2, in the example shown in FIG. The case where a line under the control of the control device 22 is set is shown. The beam 29 is transmitted to the base station controller 22.
When the transmission request is transmitted from the transmitter / receiver 23 and the base station controller 21, the base station controller 22 specifies the beam frequency corresponding to the beam 29 to the transmitter / receiver 24, and as a result, Beam 29 from transmitter / receiver 24
The call line 27 is set up for.

Next, handover between beams will be described as an application example of the present invention with reference to FIG. In FIG. 4, during communication, the mobile station 38 moves from the beam area 42 to the beam area 43.
An example will be described in which the process shifts to and the handover is executed accordingly. Referring to FIG. 4, the base station control device 31 is connected to the amplifier / antenna unit 37 via the transmission / reception device 32. The configuration of the transmission / reception device 32 is the same as the configuration of the transmission / reception device 4 in FIG. 1, and includes a beam frequency synthesizer 33, a modulator / demodulator 34, and a line frequency synthesizer 35.
And a beam frequency / line frequency coupling device 36. Further, the amplifier / antenna unit 37 performs wireless communication with the communication satellite 44 via the feeder link 39 assigned to the mobile station 38. The service link 40 is assigned to the mobile station 38 in the physical beam area 42 and is a line before the switching of the call line, and the service link 41 is assigned to the mobile station 38 in the physical beam area 43 and is set to the call line. This is the line after switching.

The radio communication line 4 in the beam area 42
When the mobile station 38, which is in a call at 0, moves to the beam area 43, the transmitter / receiver 32 detects that the mobile station 38 has moved to the beam 43 by the feeder link 39. When the base station controller 31 receives from the transceiver 32 that the mobile station 38 has moved to the beam area 43, the transceiver 3
2 is instructed to switch the beam frequency synthesizer 34 corresponding to the switching destination beam area 43. In this case, since the service link frequency does not change, the mobile station 38 implements the handover without switching the frequency.

Further, as shown in the table of FIG. 1, the frequency of a certain line is composed of the line frequency fchi and the beam frequency fbi.
It is possible only by switching. For example, the beam frequency fbi is transmitted from the base station controller 31 to the transceiver 32.
When the switching is instructed, the frequency of the beam frequency synthesizer 33 corresponding thereto is switched, and the frequency synthesized by the beam frequency / line frequency coupling device 36 is changed. As a result, the communication line, which has been transmitted to the beam area 42 like the service link 40, is transmitted to the beam area 43 like the service link 41.

As described above, according to this embodiment,
Since each base station autonomously manages the assigned wireless lines, it is possible to assign the remaining wireless lines in the beam area with less traffic to the beam area with more traffic. Therefore, in an extreme example, it is possible for each base station to allocate all the wireless lines to one beam area, that is, to allocate all the lines to one beam in a concentrated manner. As a result, it is possible to eliminate the division loss of the wireless line and maximize the utilization efficiency.

Also, in call control during a call, since the line is managed by dividing it into the local frequency corresponding to the beam and the line frequency on the service link, the handover between the beams does not change the frequency of the mobile station but the base station. Only the frequency switching is performed, that is, the handover can be realized while the mobile station is not involved, and the frequency switching processing closer to the non-interruption can be performed.

[0032]

As described above, the present invention eliminates the division loss of the wireless line and maximizes the utilization efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing a frequency configuration example of each line in a base station control device and a transmission / reception device according to the present invention.

FIG. 2 is a block diagram showing a configuration example of an entire system to which the line management method of the present invention is applied.

FIG. 3 is a block diagram showing a configuration example of an entire system to which the line management method of the present invention is applied.

FIG. 4 is a block diagram showing the configuration of another embodiment according to the present invention.

FIG. 5 is a block diagram showing a relationship between a service link frequency and a feeder link frequency in MPA.

[Explanation of symbols]

1,10,11,12,22,31 Base station control device 2 Control unit 3 Line management table 4,12,13,23,24,32 Transmitter / receiver device 5,33 Beam frequency synthesizer 6,34 Modulator / demodulator device 7,35 Line frequency synthesizer 8,36 Beam frequency / line frequency coupling device 9,20 Switching station 14,15,25,26 Control line 16,27 Communication line 17,28,38 Mobile station 18,19,29,30,42 , 43 Physical beam area 37 Amplifier / antenna section 39 Feeder link of communication line 40 Service link before switching of communication line 41 Service link after switching of communication line 44 Communication satellite

Claims (3)

[Claims] 1. The base station control device allocates the radio communication line to a new call when the radio communication line managed by the base station control device has an empty line, and the called station to the transmitting / receiving device. Notifying that the line should be set in the existing beam area, the transmitting and receiving device sets the assigned line frequency to be fixed and sets the beam frequency in the corresponding beam area by the designation of the base station control device, and A line management method in a multi-beam mobile satellite communication system characterized by determining a feeder link frequency and setting a line. 2. When a call is generated in the beam area, and there is no idle line in the wireless communication line managed by the base station controller, the base station controller is provided with respect to another base station controller. Inquiring whether there is an available line, the base station control device that received this inquiry notifies the wireless communication line to the inquiring base station control device when there is an available line, and sends and receives the wireless communication line. 2. The device is informed to set a wireless communication line in a corresponding beam area, and the transmitting / receiving device determines a feeder link frequency and sets the line.
A line management method in the described multi-beam mobile satellite communication system. 3. When a mobile station in a call in a given beam area via a radio communication line moves to another beam area, the transmitting / receiving device confirms that the mobile station has moved to another beam via the feeder link. Notify the base station control device, and when the base station control device receives from the transceiver device that the mobile station has moved to another beam area, it only instructs the transceiver device to switch the beam frequency corresponding to the switching destination beam area. 2. The line management method in a multi-beam mobile satellite communication system according to claim 1, further comprising instructing and performing handover between the line switching beams during a call.