JP2966290B2 - Link management method in multi-beam mobile satellite communication 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 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, a mobile communication system using a communication satellite has been used. The satellite system in the mobile satellite communication system includes a system using a single beam satellite and a system using a multi-beam satellite. First, since a single beam satellite covers a wide area with one beam, the effective radiation power (EIRP; Eq
uivalent Isotropic Radiated Power). On the other hand, a multi-beam satellite has the advantage that the EIRP can be increased by setting a small beam irradiation radius and covering a wide area with a plurality of beams. However, if the used frequency band is fixedly set for each beam, the traffic becomes However, there is a problem in that there is no tolerance when the beam is concentrated on one beam, and a line division loss occurs.

[0003] As means for solving these problems,
Multiple Porter Amplif (MPA)
ier) has been proposed. In the MPA, an output from a specific input terminal is transmitted from an output terminal corresponding thereto by distributing and amplifying reception power of a communication satellite and then performing re-synthesis.

FIG. 5 shows the frequency of a line (hereinafter referred to as a service link) between a communication satellite and a mobile station and a line between a communication satellite and a base station in a multi-beam mobile satellite communication system using MPA. (Hereinafter referred to as feeder link)
Shows the relationship with the frequency. That is, the onboard satellite transponder 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 repeater 45 and the base station 47, a predetermined frequency 48 on the frequency axis of the feeder link. The communication is performed at the frequency 49. For details, see the paper "Multi-terminal combined multi-beam transmission system"
IEICE Transactions (B), J69-B, No.2pp206-212,198
6) describes a proposal for an active array multi-beam transmission system that can flexibly cope with traffic distribution or fluctuation in multi-beam conversion.

However, such a hardware configuration of the MPA,
Although there have been examples of studies on physical performance so far, there is no disclosure of technology on line management as an operational technology.

Further, the use of MPA makes it possible to allocate all radio lines to each beam as if a line were allocated by a single beam. In general, in order to realize this, (1) a method in which management and line control of all wireless lines are collectively performed by one base station controller,
(2) A method of installing a line management device that only manages all wireless lines can be considered.

However, there is a problem that a base station controller having extremely high processing capability is required to realize the collective method described in (1), and the line management described in (2) is required. When the method using the device is realized, there is a problem that the number of steps increases by one, the network configuration becomes complicated, and the control becomes complicated.

[0008] In general, line management methods include:
The line and the frequency are associated one-to-one. Therefore,
As a method for realizing the method, there is a method of associating lines with all of the feeder link frequencies and managing them.

However, in this case, (1) a management table of (the number of lines used in the service link) × (the number of beams) is required, and the table size increases as the number of beams increases. (2) MPA The effect of is that all the bands on the feeder link are superimposed on the same service link.Therefore, even if the frequencies are different on the feeder link, they may be the same on the service link. There is a problem that interference occurs.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problem. The purpose is to provide a management method.

[0011]

According to a first aspect of the present invention, there is provided a radio communication system, comprising the steps of: A line is allocated to a new call, and a transmission / reception device is notified to set a line in a serving beam area of a called station. The transmission / reception device fixes the allocated line frequency and changes the beam frequency. The gist is to set a corresponding beam area according to the specification of the base station controller, further determine a feeder link frequency, and set a line.

According to a second aspect of the present invention, in the line management method in the multi-beam mobile satellite communication system according to the first aspect, when a call is generated in the beam area, the radio communication managed by the base station controller is performed. When there is no vacant line, the base station controller inquires of another base station controller whether there is a vacant line. At the same time, the base station controller of the inquiry source is notified of the radio communication line, and the transmission / reception device of the radio communication line is notified to set the radio communication line in the corresponding beam area. The point is to determine the frequency and set the line.

According to a third aspect of the present invention, there is provided a line management method for a multi-beam mobile satellite communication system according to the first aspect, wherein a mobile station which is communicating via a radio communication line in an arbitrary beam area is connected to another beam. When moving to the area, the transmission / reception device notifies the base station controller that the mobile station has shifted to another beam via the feeder link, and the base station controller notifies the base station controller that the mobile station has moved to another beam area. The point is that when receiving from the transmitting / receiving apparatus, only the switching of the beam frequency corresponding to the switching destination beam area is instructed to the transmitting / receiving apparatus, and the handover between the line switching beams during the call is performed.

[0014]

According to the line management method in the multi-beam mobile satellite communication system of the first invention of the present application, when the base station controller has an idle line in the wireless communication line managed by itself, the base station controller sets this wireless communication line to a new call. In addition to this, it notifies the transmitting / receiving apparatus to set a line in the serving beam area of the called station. The transmitting / receiving apparatus that has received the notification sets the line frequency to be fixed, sets the beam frequency in the corresponding beam area, determines the feeder link frequency, and sets the line.

A line management method in a multi-beam mobile satellite communication system according to a second invention of the present application is a base station control device comprising:
When a call is generated in the beam area and there is no free line in the wireless communication line managed by itself, an inquiry is made to another base station controller as to whether there is a free line. In response to the inquiry, if there is a free line, the base station controller notifies the base station controller of the inquiry and reserves the wireless communication line, and further transmits the corresponding beam to the transmission / reception apparatus of the wireless communication line. Notify to set up wireless communication line in area. The transmitting / receiving device that has received the notification determines the feeder link frequency and sets the line.

A line management method in a multi-beam mobile satellite communication system according to a third aspect of the present invention is a method for managing a mobile station, which is communicating via a radio communication line, to another beam area.
Upon detecting this movement, the transmitting / receiving device notifies the base station controller of the movement of the mobile station via the feeder link.
When receiving the movement of the mobile station from the transmission / reception device, the base station control device instructs the transmission / reception device only to switch the beam frequency corresponding to the switching destination beam area, and performs handover between the line switching beams during a call.

In a general mobile satellite communication system, a feeder link is constituted by a single beam for one communication satellite, and one or two base stations are provided. Further, in the present invention, the service link is configured by a multi-beam, and the isolation of the MPA input terminal corresponding to each beam of the service link is generally provided by providing a feeder link frequency for each band corresponding to each beam. This is realized by changing the local frequency for each band. Further, according to the present invention, even when all traffic is concentrated on a specific beam, it is possible to transmit all 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, ie, a beam, is controlled. Can be performed by changing the local frequency of the radio line to be allocated. In addition, line management can be realized regardless of the number of beams, that is, with the table size of the number of lines used in the service link,
By fixedly associating the line frequency with all of the service link frequencies, it is possible to prevent the occurrence of interference. Therefore, according to the line management system in the multi-beam mobile satellite communication system of the present invention, sufficient dispersion control is performed, the line control is simplified, and 100% dynamic channel assignment is realized.

[0019]

An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of a frequency configuration 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 a 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 transmission / reception device 4 includes a beam frequency synthesizer 5, a modulation / demodulation device 6, a line frequency synthesizer 7, and a beam frequency / line frequency coupling device 8. The switching center 9 in the system shown in FIG. 2 is connected to the transmitting / receiving device 12 via the base station control device 10 and to the transmitting / receiving device 13 via the base station control device 11. The transmitting / receiving device 12 is connected to the mobile station 17 in the physical beam area 18 and is controlled by the mobile station 1 via the communication line 16 managed by the base station controller 10.
7 is communicated. At this time, a control line 14 for the beam area 18 is provided between the transmission / reception device 12 and the beam area 18, and the transmission / reception device 13 is connected to the beam area 19.
Between them, a control line 15 for the beam area 19 is provided.

Next, the processing procedure in the line management method of the present embodiment will be described with reference to FIGS. 1 and 2 by taking a case where a call is generated in the beam area 18 as an example. In the base station controller 10 that performs call control of the beam area 18, if there is a vacant radio communication line managed by the base station controller 10, the radio communication line 16 is changed to the corresponding mobile station 17.
Assign to At this time, the transmitting / receiving device 12 is notified by the base station control device 10 to set a line in the beam area 18. However, in the transmitting / receiving device 12, the assigned line frequency is fixed, the beam frequency is made variable, and the beam frequency is reset in the beam area 18. Next, a feeder link frequency is generated, and a wireless channel is set.

Next, the base station controller 10 shown in FIG. 2 (the base station controller shown in FIG. 1 and the base station controller 1 shown in FIG. 2)
The table 3 arranged in the same manner will be described.
Table 3 shows two frequencies: line frequency fc
hi and beam frequency fbi (where i is 1, 2,...,
n). For example, the frequency of a certain line is determined as a result of combining these two frequencies, and ch # 1 is
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.

Here, when there is a transmission request from the mobile station 17 located in a certain beam area 18, the transmission / reception device 12 receives the transmission request via the control line 14. The transmission / reception device 12 manages, as data, that the control line 14 is set for the beam area 18. As a result, the base station control device 10 is notified of information related to the beam area 18 together with a transmission request signal. I do. When the base station controller 10 selects a vacant line from the table 3 to be managed, the base station controller 10 determines a beam frequency fbi corresponding to the beam area 18 for the beam frequency fbi of the line, and To specify the frequency.

The transmitting / receiving device 4 shown in FIG. 1 (corresponding to the transmitting / receiving device 12 shown in FIG. 2) is provided with two oscillators, ie, 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 the 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 as the transmitting / receiving device 4, the transmitting / receiving device 4 extracts the beam frequency fbi from among them and sets the frequency of the beam frequency synthesizer 5 to this. Synthesizer for beam frequency 5
The frequency and the frequency of the line frequency synthesizer 7 are synthesized 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 controller. In the figure, a wavy double-headed arrow indicates a control line, and a solid arrow indicates a communication line. 3, the exchange 20 is connected to a transmitting / receiving device 23 via a base station control device 21 and to a transmitting / receiving device 24 via a base station control device 22. The transmitting / receiving device 24
Communicates with the mobile station 28 via the communication line 27 which is allocated to the mobile station 28 in the physical beam area 29 and managed by the base station controller 22. At this time, the transmitting / receiving device 2
A control line 25 for the beam area 29 is provided between 3 and the beam area 29, and a control line 26 for the beam area 30 is provided between the transmitting / receiving device 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 control device 21 will be described. In this case, the base station controller 21 inquires of the base station controller 22 whether or not there is a free line. In response to this inquiry, the base station control device 22 responds to the inquiry, if there is a free wireless line,
7 is returned to the base station controller to reserve the corresponding wireless communication line 27 and notify the transmitting / receiving device 24 of the wireless communication line 27 to set the wireless communication line 27 in the beam area 29. The transmission / reception device 24 generates a feeder link frequency in the same manner as described above, and sets the wireless communication line 27.

That is, although the outgoing call request is made on the control line and the communication line is set exactly as shown 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.
Is notified via the transmission / reception device 23 and the base station control device 21 that the transmission request is transmitted from the base station control device 22, the base station control device 22 specifies the beam frequency corresponding to the beam 29 to the transmission / reception device 24, and as a result, Beam 29 from transmitting / receiving device 24
The communication line 27 is set for.

Next, handover between beams will be described with reference to FIG. 4 as an application example of the present invention. FIG. 4 shows that the mobile station 38 moves from the beam area 42 to the beam area 43 during communication.
And an example in which a handover is executed in accordance with this. Referring to FIG. 4, the base station control device 31 is connected to an amplifier / antenna unit 37 via a 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. The amplifier / antenna unit 37 performs wireless communication with a communication satellite 44 via a feeder link 39 assigned to the mobile station 38. The service link 40 is allocated to the mobile station 38 in the physical beam area 42 and is a line before the switching of the communication line. The service link 41 is allocated to the mobile station 38 in the physical beam area 43 and This is the line after switching.

The radio communication line 4 in the beam area 42
When the mobile station 38 during a call moves to the beam area 43 at 0, the transmitting / receiving device 32 detects that the mobile station 38 has shifted to the beam 43 via the feeder link 39. When the base station controller 31 receives from the transmitting / receiving device 32 that the mobile station 38 has moved to the beam area 43, the transmitting / receiving device 3
2 is notified of a switching instruction of 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.
Only switching is possible. For example, the base station control device 31 sends a beam frequency fbi
Is switched, the corresponding frequency of the beam frequency synthesizer 33 is switched, and the frequency synthesized by the beam frequency / line frequency coupling device 36 is changed. As a result, the communication line previously transmitted to the beam area 42 as in the service link 40 is transmitted to the beam area 43 as in the service link 41.

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

In call control during a call, the line is managed by dividing the local frequency corresponding to the beam and the line frequency on the service link, so that the handover between the beams is performed without changing the frequency of the mobile 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 process that is almost instantaneous interruption can be performed.

[0032]

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

[Brief description of the drawings]

FIG. 1 is a diagram illustrating 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 illustrating a configuration example of an entire system to which a line management method according to the present invention is applied;

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

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

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

[Explanation of symbols]

1,10,11,21,22,31 Base station controller 2 Controller 3 Line management table 4,12,13,23,24,32 Transmitter / receiver 5,33 Beam frequency synthesizer 6,34 Modulator / demodulator 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 Talk line 17,28,38 Mobile station 18,19,29,30,42 , 43 Physical beam area 37 Amplifier / antenna unit 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 7/24-7/26 102 H04Q 7/00-7/38 H04B 7/14-7/195 H04B 7 /twenty two

Claims (3)

(57) [Claims] When a base station controller has a vacant line in a wireless communication line managed by the base station controller, the base station controller allocates the wireless communication line to a new call and sends a called station to the transmitting / receiving apparatus. Notify to set a line in the serving beam area of the, the transmitting and receiving device, fixed the line frequency assigned, and set the beam frequency in the corresponding beam area by the designation of the base station control device, further, A line management method in a multi-beam mobile satellite communication system, comprising determining a feeder link frequency and setting a line. 2. When a call is generated in a beam area and there is no free line in a wireless communication line managed by the base station control device, the base station control device makes a request to another base station control device. The base station controller receiving the inquiry asks whether there is an idle line. If there is an idle line, the base station controller notifies the inquiring base station controller of the wireless communication line and transmits / receives the wireless communication line. 2. The apparatus according to claim 1, wherein the apparatus notifies the apparatus to set a wireless communication line in a corresponding beam area, and the transmission / reception apparatus determines a feeder link frequency and sets the line.
A line management method in the multi-beam mobile satellite communication system described in the above. 3. When a mobile station that is talking via a wireless communication line in an arbitrary beam area moves to another beam area, the transmitting / receiving apparatus determines that the mobile station has shifted to another beam via a feeder link. Notify the base station controller, and when the base station controller receives from the transmitting / receiving apparatus that the mobile station has moved to another beam area, the base station controlling apparatus only performs switching of the beam frequency corresponding to the switching destination beam area to the transmitting / receiving apparatus. 2. The line management method according to claim 1, wherein a handover between the line switching beams during a call is performed by giving an instruction.