JPH104378A - Satellite communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a slave station equipment small and to economize the equipment by adopting a narrow frequency band for a frequency synthesizer of a slave station. SOLUTION: The system is made up of a base station consisting of a transmitter-receiver 1, each communication controller 3 belonging to communication system groups G1 to Gn, and a MODEM 2, and up of each slave station 11 belonging to each of the communication system groups G1 to Gn. An operating frequency band by the MODEM 2 designated by the communication controller 3 belonging to each of the communication system groups G1 to Gn and an operating frequency band of each slave station 11 are selected as one-unit band and the bands are not overlapped in the group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite communication system.

[0002]

2. Description of the Related Art A mobile satellite communication system will be described as an example of a satellite communication system. In a general mobile satellite communication system, a control signal called an outbound signal is transmitted in a broadcast mode in order to control all the slave stations from a base station. The frequency used for the outbound signal is often not one, and one of them is actually used. The slave station stores in advance the reception frequencies of these outbound signals, and attempts reception demodulation while searching for frequencies one by one. After the reception, for example, in the case of a child station call, a call request is output to the base station using one of the transmittable inbound signal frequencies included in the outbound signal.

[0003] After various protocols are completed, when bidirectional communication is finally permitted between the base station and the slave station, the slave station newly transmits and receives information for information communication (telephone, etc.). Assigned. The slave station performs communication by changing to a frequency for information communication for both transmission and reception. When the call ends, the receiver again tunes back to the original outbound frequency and the sender tunes back to the inbound frequency. In other words, the base station and each slave station exchange a common outbound / inbound signal for line control between the base station and each slave station, and a transmission / reception frequency dedicated to the line is allocated to information communication such as telephone. Become.

[0004]

The conventional problems are as described below. In a conventional satellite communication system,
It has been attempted to cover the entire range allocated to one communication system as a frequency band for transmission and reception by slave stations. For this reason, it is essential to increase the bandwidth of the frequency synthesizer, which has been a major obstacle to downsizing and economical use of the apparatus.

[0005]

According to the present invention, one communication system is divided into several communication system groups, or one communication system is constructed by stacking communication system groups. By narrowing the used frequency band per communication system group, the frequency synthesizer of the slave station is narrowed, and the slave station device is reduced in size and economical.

[0006]

For the two-way communication, there are frequency synthesizers for transmission and reception. Since the receiving synthesizer must be tuned to the outbound signal receiving frequency and the information signal receiving frequency, both need to be within one unit of frequency band. Since the transmitting synthesizer must tune to two frequencies, the inbound signal transmitting frequency and the information signal transmitting frequency, both need to be within one unit of frequency band.
A base station belonging to one communication system group manages the designation of a frequency to a slave station to be transmitted from its own station so as not to deviate from the restriction of a unique frequency range given by a system administrator.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows an example of the configuration of a base station apparatus using a satellite communication system according to the present invention.
(B) is an example of a slave station device configuration using the satellite communication system according to the present invention. The entire communication system is composed of several communication system groups, and each communication system group shares the transmission / reception device 1, and the modulation / demodulation device 2 and the communication control device 3 are individualized. Here, the frequency bands specified by the respective communication control devices 3 belonging to the respective communication system groups G1 to Gn are respectively FG1, FG2,.
..., FGn. Each slave station 11 is a respective slave station 11
Have usable frequency bands FG1, FG2,..., FGn.

For example, the communication control device 3 of the communication system group G 1 instructs the modem 2 on the outbound signal transmission frequency and the inbound signal reception frequency for line control for the communication system group G 1, and the gateway station 4 , And outgoing / incoming call information of each slave station connected via an outbound signal and an inbound signal are analyzed to control the line of the satellite line. In controlling the satellite link, the operating frequency between the base station and the slave station is selected from within a frequency band specified by the system administrator. The slave station 11 belonging to the communication system group, for example, the communication system group G1,
Outbound signal only. Therefore, the frequencies specified for inbound and information communication are also FG
Limited to one.

FIG. 2 shows an example of a used frequency band. The frequency bandwidths used by the communication system groups G1 to Gn are equalized for equalizing service / communication quality between the communication system groups. The slave station does not need to cover the entire band (FG1 + FG2 +... + FGn) for the entire communication system, but only needs to cover 1 / n, and can be easily realized, and can be reduced in size and economical.

[0010]

As described above, according to the present invention,
The frequency band used by the slave station has been narrowed, making the slave station smaller and smaller.
Economy becomes possible.

[Brief description of the drawings]

FIG. 1A is a configuration diagram of a base station in a satellite communication system according to the present invention, and FIG. 1B is a configuration diagram of a slave station in a satellite communication system according to the present invention.

FIG. 2 is a diagram showing an example of a used frequency band in the satellite communication system according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transceiver apparatus 2 Modulator / demodulator 3 Communication controller 4 Gateway station

Claims (3)

[Claims] 1. A base station comprising one transceiver, a communication control device and a modem device belonging to one or more communication system groups, and each slave station belonging to each communication system group. The frequency bands used by the modems designated by the communication control devices belonging to the system group and the frequency bands used by the slave stations belonging to the respective communication system groups are each one unit width, and are controlled so as not to overlap between the groups. Characteristic satellite communication system. 2. Each communication control device belonging to each of the communication system groups instructs the modem device on a line control outbound signal transmission frequency and an inbound signal reception frequency of the communication system group to which the communication control device belongs.
2. A line control of a satellite line by analyzing incoming / outgoing call information from a gateway station and outgoing / incoming call information of each slave station connected via said outbound signal and said inbound signal. A satellite communication system as described. 3. The satellite communication according to claim 2, wherein in controlling the line of the satellite line, a frequency used between the base station and the slave station is selected from a frequency band specified by a system administrator. system.