JP4748094B2 - Satellite communication method, slave station and master station - Google Patents

Description

  The present invention relates to a satellite communication method, a slave station, and a master station that perform voice and data communications of a terminal device including an IP telephone connected to a slave station by satellite communication of a request allocation multiple access method via a satellite. .

  Due to the recent development of Internet communication, data communication via the Internet has been actively performed, and voice communication via the Internet is also becoming widespread supported by IP telephone system construction technology. The voice communication over the Internet by this IP phone is different from the other data communication because of the simultaneity that the voice communication should have, and a protocol suitable for each signaling process of the start, change and end of the voice communication is necessary. is there. As a typical protocol, there is SIP (Session Initiation Protocol) defined in the RFC3261 standard and related standards, and various services such as an IP phone are provided by this protocol in the application layer. On the other hand, in the field of satellite communications, a request allocation multiple access scheme (hereinafter referred to as “DAMA scheme”) is used from the fixed scheme communication between one-to-one satellite communications apparatuses. DAMA is an abbreviation for Demand Assignment Multiple Access. )), And further communication by satellite mobile phones using CDMA or FDMA schemes such as the Iridium Project. Satellite communication has a history of technological development different from wired communication on the ground, from the viewpoint of wide area and publicity, and by pursuing the establishment of communication based on the speciality of remote wireless communication.

  The DAMA system in satellite communication is a system for effectively using a satellite communication line by a plurality of slave stations, and appropriately assigns a communication line used for communication between slave stations or between slave stations / parent stations. A communication line assignment request is issued from a slave station on a control line (referred to as a “CSC line”) different from the communication line, the master station receives the line assignment request, and the master station assigns the communication line. Is. In Patent Document 1, in a DAMA satellite communication system, when a telephone terminal is connected to a slave station and voice communication is performed by telephone between the slave stations, at least a part of a unique number of the telephone terminal is transmitted to the master station, For example, there is disclosed a conventional technique in which a slave station data file in which portions 03 (Tokyo) and 06 (Osaka) are associated with a relay station group number to be relayed is disclosed. According to this conventional technique, when a unique number of a partner telephone terminal is dialed from a telephone terminal connected to one slave station, the slave station uses at least a part of the unique number of the partner telephone terminal at the master station. Select the corresponding slave station from the data file and assign a satellite communication line between the slave station and the partner slave station, and specify the partner slave station when calling from the slave station There is no need to do so, and the operability is improved. Non-Patent Document 1 discloses a conventional technique for performing BOD (Bandwidth On Demand) control in a satellite communication system that performs satellite communication line control by DAMA. According to this prior art, the communication speed between the earth stations to which the satellite communication lines are assigned by the DAMA control can be changed in ten or more stages. Specifically, the traffic amount is monitored by a data transmission device provided in the slave station, and a request for changing the transmission rate according to the traffic amount is transmitted to the DAMA control station. In response to this change request, the DAMA control station performs line setting, transmits a line control signal to the slave station, and the received slave station sets a frequency channel and a transmission rate according to the line control signal.

JP-A-10-51370

"Development of IP communication satellite communication system" Toru Kikuta, 2004 Proceedings of the IEICE General Conference B-3-2, P.I. 330, March 22, 2004

  As described above, in voice communication using an IP telephone based on, for example, the SIP protocol, it is necessary to synchronize the communication and it is necessary to prevent the voice from being interrupted. However, the BOD disclosed in Non-Patent Document 1 is required. When the line is changed based on the increase / decrease of the data transmission amount by the control, there is a problem that the voice communication is interrupted during the line switching. In addition, when frequency hopping (reassignment) is performed in order to effectively use the communication band given in the master station, voice communication is also performed by disconnecting / connecting the communication line between slave stations accompanying the frequency hopping. There was a problem that was interrupted.

  The present invention has been made to solve the above-described problems, and is associated with BOD control and frequency hopping when performing communication using an IP telephone connected to a slave station in a DAMA satellite communication line. It is an object to obtain a satellite communication method, a slave station, and a master station that can suppress instantaneous interruption of voice communication.

According to a first aspect of the present invention, there is provided a satellite communication method in which a slave station requests a master station to allocate a channel to a partner slave station via a CSC channel via a satellite, the master station allocates a communication channel, and the slave station In a line assignment type satellite communication method for performing satellite communication between a remote station and a remote station,
IP phone start notification and IP phone end notification for notifying start and end of IP phone communication processing are configured to be transmitted / received via a CSC line, and connected to the slave station during data transmission on the assigned line . An IP telephone start notification is transmitted from the slave station to the master station via the CSC line based on a call signal from the IP telephone, and the slave station and the partner slave station are connected by the master station that has received the IP telephone start notification. Is changed to an IP telephone band that does not allow automatic frequency hopping of the master station.

The slave station according to the invention of claim 2 requests the master station to assign a channel to the partner slave station via a CSC channel via a satellite, and is assigned a communication channel by the master station. In a slave station that performs satellite communication between
The IP phone start notification and the IP phone end notification for notifying the start and end of the IP phone communication process are configured to be transmitted / received via the CSC line, and based on the call signal from the connected first IP phone, A satellite GW apparatus that generates an IP telephone start notification to be transmitted via a CSC line, and the IP telephone start notification generated by the satellite GW apparatus is transmitted to the parent station via the CSC line, and the parent station automatically And a satellite communication device that performs voice communication with a second IP telephone connected to the other slave station via a communication line assigned to a band for IP telephone that does not permit typical frequency hopping.

According to a third aspect of the present invention, a master station is a satellite which performs between a slave station and a partner slave station based on a line assignment request with the partner slave station transmitted from the slave station via a CSC channel via the satellite. In the master station that assigns the communication line of communication,
An IP phone start notification and an IP phone end notification for notifying the start and end of the IP phone communication process are configured to be transmitted / received via the CSC line, and are sent to the call signal from the first IP phone connected to the slave station. Based on the IP phone start notification, the master station satellite communication device that receives the IP telephone start notification transmitted from the slave station via the CSC line, and automatically establishes the communication line between the slave station and the partner slave station. And a DAMA control device that allocates to a band for IP telephones that does not allow for frequency hopping.

Slave station according to the invention of claim 4, requests a line allocation between Aiteko station to the master station by CSC line passing through the satellite, it allocated a communication line by the master station, and the Aiteko station In the slave station that performs satellite communication between
A satellite GW that transmits data from an IP terminal connected by an allocated line and generates a band change request signal for requesting increase / decrease of bandwidth to the master station via the CSC line based on increase / decrease of the data transmission amount A satellite communication device for transmitting data transmitted from the satellite GW device through the communication line assigned by the master station,
An IP phone start notification and an IP phone end notification for notifying the start and end of IP phone communication processing are transmitted and received through the CSC line, and the line is changed to the IP phone communication line.
The satellite GW apparatus generates an IP telephone start notification to be transmitted through the CSC line based on a call signal from the IP telephone, and stops generating the band change request signal during voice communication by the IP telephone.

The master station according to the invention of claim 5 is a satellite that performs between the slave station and the partner slave station on the basis of a line assignment request with the partner slave station transmitted from the slave station via the CSC channel via the satellite. In the master station that assigns the communication line of communication,
An IP phone start notification and an IP phone end notification for notifying the start and end of IP phone communication processing are transmitted and received through the CSC line, and the line is changed to the IP phone communication line.
A master station satellite communication device that receives, via the CSC line, an IP telephone start notification transmitted from the slave station based on a call signal from a first IP telephone connected to the slave station, and the slave station and the counterpart child A DAMA control device that identifies that the communication line with the station is in the IP telephone and excludes it from frequency hopping.

  According to the first to third aspects of the present invention, an IP phone start notification is transmitted from the slave station to the master station via the CSC line based on a call signal from the IP phone connected to the slave station, and the IP phone start is started. Since the communication station between the slave station and the partner slave station is changed to the IP telephone band by the master station that has received the notification, voice communication by IP telephone between the slave stations is prevented from being interrupted by frequency hopping. be able to.

  According to the fourth aspect of the present invention, since the IP telephone start notification to be transmitted through the CSC line is generated based on the call signal from the IP telephone, the generation of the band change request signal is stopped during the voice communication by the IP telephone. Voice communication by IP telephone can be prevented from being interrupted by BOD control.

  According to the fifth aspect of the present invention, the IP telephone start notification is transmitted from the slave station via the CSC line based on the call signal from the IP telephone connected to the slave station, and this is received by the master station. The communication line between the remote station and the remote station is identified as being IP telephone and is excluded from frequency hopping. Therefore, voice communication by IP telephone between the slave stations is prevented from being interrupted by frequency hopping. be able to.

Embodiment 1

  A satellite communication method, a slave station, and a master station according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a block diagram showing a configuration of a satellite communication system according to Embodiment 1 of the present invention. In FIG. 1, 1 is a master station, 2 is a slave station, 3 is a communication satellite, 4 is an uplink CSC line for transmitting a control signal from the slave station 2 to the master station 1 via the communication satellite 3, and 5 is This is a downlink CSC line for transmitting a control signal from the master station 1 to the slave station 2 via the communication satellite 3. The uplink CSC line 4 transmits a line assignment request signal for requesting communication line assignment from the slave station 2 to the master station 1, and the master station 1 assigns the communication line 6 between the slave stations. The line information of the assigned communication line 6 is transmitted from the master station 1 to the slave station 2 and the other slave station 2 as the communication partner as a line assignment response signal via the downlink CSC line 5. Communication is performed between the slave station 2 that has received this line assignment response signal and the partner slave station 2 via the communication line 6 via the communication satellite 3. This communication line 6 is also allocated for communication between the master station 1 and the slave station 2.

  Next, the configuration of the master station 1 and the slave station 2 will be described. FIG. 2 is a block diagram showing the configuration of the slave station and the master station according to Embodiment 1 of the present invention. In the master station 1 shown in FIG. 2, reference numeral 7 denotes a master station satellite communication device that performs radio wave transmission / reception, modulation / demodulation, and signal processing with the communication satellite 3, and 8 denotes a DAMA control device that performs DAMA line control. Control processing by a control signal received from the slave station 2 through the uplink CSC line 4 and generation of a control signal to be transmitted to the slave station 2 through the downlink CSC line 5 are performed. In the master station satellite communication device 7, 9 is a transmitter / receiver that transmits / receives radio waves to / from the communication satellite 3, and performs frequency conversion and amplification of signals. A CSC line modulation / demodulation unit 10 modulates / demodulates a control signal to be transmitted / received, and modulates / demodulates the control signal based on various modulation / demodulation methods such as PSK (phase shift modulation / demodulation). A signal processing unit 11 performs frame processing and error correction code processing of the transmission signal, error correction processing and frame processing of the reception signal.

  The configuration of the slave station 2 and the connected device shown in FIG. 2 will be described. Reference numeral 12 denotes an IP terminal, reference numeral 13 denotes an IP telephone, the IP terminal 12 is a device for mainly performing data communication with the IP terminal 12 connected to the other slave station 2, and the IP telephone 13 is another slave terminal. This is a device that mainly performs voice communication with the IP phone 13 connected to the station 2. The IP terminal 12 and the IP telephone 13 are devices that can perform packet communication according to the Internet protocol, and the IP terminal 12 can be provided with a voice communication function, and the voice communication function of the IP terminal 12 is the present invention. It shall be included in the IP phone. The slave station 2 is also connected to another external network 16 via an interface device 14 (hereinafter referred to as I / F 14), and this connection is generally made via a proxy server 15. In the slave station 2 shown in FIG. 2, 17 is a satellite communication device that performs transmission / reception of radio waves with the communication satellite 3, modulation / demodulation and signal processing, and 18 is a satellite of the slave station 2 for communication by the IP terminal 12 or IP phone 13. This is a satellite gateway device (hereinafter referred to as a satellite GW device) that performs transmission processing of data and audio data to be performed via the communication device 17. In the satellite communication device 17, reference numeral 19 denotes a transmitter / receiver that transmits / receives radio waves to / from the communication satellite 3, and performs signal frequency conversion, amplification, and the like. A CSC line modulation / demodulation unit 20 modulates / demodulates a control signal to be transmitted / received, and modulates / demodulates the control signal based on various modulation / demodulation methods such as PSK (phase shift modulation / demodulation). A communication line modulation / demodulation unit 21 modulates / demodulates a communication signal to be transmitted / received, and modulates / demodulates the communication signal based on various modulation / demodulation methods such as PSK (phase shift modulation / demodulation). A signal processing unit 22 performs frame processing and error correction code processing of the transmission signal, error correction processing and frame processing of the reception signal. Reference numeral 23 denotes a control unit that controls the transmission / reception frequency and band of the communication line modulation / demodulation unit 21 based on the line assignment response signal received by the CSC line modulation / demodulation unit 20. In the satellite GW apparatus 18, transmission control 24 identifies transmission data in communication by the IP terminal 12 or the IP telephone 13, and transfers transmission data between the satellite communication apparatus 17, the IP terminal 12, and the IP telephone 13. 25 is a BOD control unit that monitors the flow rate of transmitted data and requests a change in speed according to the flow rate.

  Although not shown in FIG. 2, a circuit unit corresponding to the communication line modulation / demodulation unit 21 in the satellite communication device 17 of the slave station 2 is provided in the master station satellite communication device 7 of the master station 1. There is a device corresponding to the satellite GW device 18 of the slave station 2, and an IP terminal or IP telephone connected to the master station 1 or another network device via the interface uses the master station 1 to establish a communication satellite. The communication line 6 can communicate with IP terminals connected to a plurality of slave stations. In the master station 1, a circuit and a device that perform a function provided to an IP terminal or the like may be considered to correspond to the slave station 2.

  Regarding the operations of the master station 1 and the slave station 2, the operation in the case of performing data communication via the communication satellite 3 between the IP terminals 12 connected to the slave station will be described first. The transmission control unit 24 transmits transmission data from the IP terminal 12 to the signal processing unit 22 while buffering, and the amount of transmission data that can be transmitted to the transmission control unit 24 and the signal processing unit 22 is allocated to the satellite communication device 17. Depending on the bandwidth of the selected communication line. When the slave station 2 needs data communication with the partner slave station 2, the slave station 2 transmits a line assignment request signal to the master station 1 through the uplink CSC line 4. This line allocation request signal includes information for identifying the partner slave station, is generated by the transmission control unit 24, is signal-processed by the signal processing unit 22, is modulated by the CSC line modulation / demodulation unit 20, and is transmitted and received by the transceiver 19. Sent. The master station 1 monitors the upstream CSC line 4, receives and demodulates the line assignment request signal, processes the signal, and reproduces it. The line allocation request signal reproduced by the signal processing unit 11 of the master station 2 is input to the DAMA control device 8, and the DAMA control device 8 is a free area in the system dedicated band (a usable frequency band given to the communication system). And allocating a communication line to a free area, and generating a line assignment response signal including information on the center frequency and bandwidth, and information identifying the slave station 2 and the partner slave station 2 that have requested the line assignment. And output to the signal processing unit 11. The channel assignment response signal is signal-processed by the signal processing unit 11, modulated by the CSC channel modulation / demodulation unit 10, and transmitted from the transceiver 9 through the downlink CSC channel 5. The slave station 2 and the partner slave station 2 monitor the downlink CSC line 5 and, upon receiving the line assignment response signal, demodulate and reproduce it, and set the communication line modulation / demodulation unit 21 to the assigned center frequency and bandwidth. Set to communicate between slave stations. The communication line assigned here is a transmission line from the slave station 2 to the partner slave station 2 and a transmission line from the partner slave station 2 to the slave station 2. When the communication between the slave stations 2 is completed, a transmission end signal is generated by the transmission control unit 24 of the slave station 2 and transmitted to the master station 2 via the uplink CSC line 4, and the master station 2 has assigned the communication line. To free space in the system dedicated band. When the master station 1 starts communication with the slave station 2, the line assignment is performed directly by the DAMA controller 8 of the master station 1, and a line assignment response signal is sent to the partner slave station 2 via the downlink CSC line 5. Just send it. Communication between the slave stations 2 is not only performed between a pair of IP terminals 12, but may be performed between a plurality of pairs of IP terminals 12 between the slave stations 2, and the number of pairs of IP terminals 12 is increased or decreased. The amount of data transmission increases or decreases.

  The data transmission amount is detected by the BOD control unit 25 of the satellite GW apparatus 18. The BOD control unit 25 can grasp the data transmission amount based on the amount of data buffered by the transmission control unit 24. When the detected data transmission amount increases or decreases, the BOD control unit 25 generates a band change request signal and transmits it via the uplink CSC line 4, receives the band change request signal at the master station 2, and receives the DAMA control device 8. BOD control is performed to reassign communication lines. The DAMA control device 8 of the master station 2 generates a line reassignment response signal and transmits it via the downlink CSC line 5, and the slave station 2 and the partner slave station 2 that have received this signal transmit the frequency of the communication line based on the line reassignment response signal. And change the bandwidth. Such reallocation of communication lines allows flexible operation of the system dedicated band. However, such line reassignment operation requires a disconnection operation of the communication line in use and a connection operation to the reassigned communication line, and a communication disconnection for a considerable time occurs due to these operations. To do.

  On the other hand, in the master station 2, as the communication line assignment between the slave stations 2 (including change assignment by BOD control) and the release thereof are repeated, free bandwidths with small bandwidths are scattered in the communication band. Can be. The existence of such a free band hinders effective use of the communication band allocated to the system. The master station 2 has a frequency hopping function for moving the communication line 6 allocated between the slave stations 2 to another band within the communication band. FIG. 3 is a schematic diagram showing band change of the communication line 6 by frequency hopping in the master station 2. FIG. 3 (a) shows the allocation state of communication bands before frequency hopping. The A band and the C band are vacant bands, but are divided by the communication line in the B band. In particular, the C band is a bandwidth. Becomes a narrow state, and a new communication line cannot be allocated to the C band, which is a useless area. FIG. 3B shows a state of communication band allocation after frequency hopping, in which the communication line in the B band before the frequency hopping is moved to the D band. As a result, the divided A band and C band are absorbed by the wide E band, and the line can be allocated to the original C band, and the frequency can be effectively used. Even with such frequency hopping operation, it is necessary to disconnect the communication line in use between the slave stations and connect to the reassigned communication line. Occurs.

  Next, the operation of the master station 1 and the slave station 2 will be described when voice communication is performed via the communication satellite 3 between the IP telephones 13 connected to the slave stations. The case where the protocol for performing voice communication is SIP will be described as an example, but the same operation is performed for other IP telephone communication protocols. FIG. 4 is a processing sequence diagram showing processing for an Invite message according to the SIP protocol. In FIG. 4, the IP data is transmitted from the IP terminal 12 in step S1, and the satellite GW apparatus 18 of the slave station 2 that receives the IP data generates a line allocation request signal. In step S2, the satellite communication apparatus 17 sends the uplink CSC line 4 Send by. The master station satellite communication device 7 receives the channel allocation request signal, the DAMA control device 8 allocates the communication channel 6 of the slave station 2 and the partner slave station 2, and transmits a channel allocation response signal through the downlink CSC channel 5 in step S3. . The slave station 2 and the partner slave station 2 that have received this line assignment response signal use the assigned communication line 6 to start communication in step S4. When the IP phone 13 connected to the slave station 2 makes a call to the IP phone 13 connected to the partner slave station 2, the Invite message as a calling signal is sent from the calling IP phone 13 to the satellite of the slave station 2 in step S5. It is sent to the GW apparatus 18 in step S5. When the transmission control unit 24 of the slave station 2 detects the Invite message, the Invite message is transmitted to the partner slave station 2 through the satellite communication device 17 via the communication line 6 with the partner slave station 2 in step S6. In step S7, the master station 2 is notified that voice communication by the IP phone is started. This notification is performed on the upstream CSC line 4, and the slave station 2 transmits an IP telephone start notification as a control signal. The partner slave station 2 that has received the Invite message transmitted in step S6 uses the partner IP phone 13 connected to the own station based on the unique information (SIP URI, IP address, etc.) of the partner IP phone included in the Invite message. Then, the Invite message is transmitted to the identified partner IP phone 13 in step S8. The DAMA control device 8 of the master station 1 that has received the IP telephone start notification changes the line to the IP telephone band so that the communication line 6 does not perform frequency hopping. FIG. 5 is a schematic diagram showing a line change by the master station 1. As shown in FIG. 5, it is assumed that the communication band is composed of a normal allocation band in which frequency hopping is possible and an IP telephone band in which automatic frequency hopping of the master station is not permitted. FIG. 5 (a) shows the line assignment status before the IP telephone start notification, and the communication line f3 from the slave station 2 to the partner slave station 2 and the communication line f4 from the partner slave station 2 to the slave station 2 are normally assigned. Assigned to bandwidth. In FIG. 5B, after the IP telephone start notification, the communication line from the slave station 2 to the partner slave station 2 is set to f5 in the IP telephone band, and the communication line from the partner slave station 2 to the slave station 2 is set to the IP telephone. The master station 2 changes the line to f6 in the band. Based on the line information after the change, the DAMA control device 8 of the master station 1 generates a line change signal and transmits it to the slave station 2 and the partner slave station 2 via the downlink CSC line 5 in step S9 of FIG. The slave station 2 and the partner slave station 2 that have received the line change signal switch the communication line, and in step S10, the change completion signal is transmitted to the master station 1 via the uplink CSC line 4, and data communication between the slave stations by the IP terminal is performed. And voice communication by IP phone. In step S10, after transmitting the change completion signal, the slave station 2 and the partner slave station 2 stop generating the band change request signal in the respective BOD control units 25.

  When the voice communication between the IP phone 13 and the partner IP phone 13 is completed, a Bye message indicating the end of the call is sent out in step S11 by the operation of placing the handset of the IP phone 13. The slave station 2 transmits a Bye message to the partner slave station 2 via the communication line (f5, f6) in step S12, and sends an IP telephone end notification indicating the end of voice communication by IP telephone to the master station 2 in step S13. Transmit via the CSC line 4. The partner slave station 2 transmits a Bye message to the partner IP phone 13 in step S14. Based on the received IP telephone end notification, the DAMA controller 8 of the master station 1 changes the communication line between the slave station 2 and the partner slave station 2 from the IP telephone band to the normal allocated band. A line change signal is generated on the basis of the line information and is transmitted to the slave station 2 and the partner slave station 2 via the downlink CSC line 5 in step S15. The slave station 2 and the partner slave station 2 that have received the line change signal switch the communication line, and in step S16, the change completion signal is transmitted to the master station 1 via the uplink CSC line 4, and data communication by the IP terminal between the slave stations is performed. I do. After step S <b> 16, the slave station 2 and the partner slave station 2 resume the generation of the band change request signal in the respective BOD control units 25.

  As described above, during the period in which voice communication by IP telephone is being performed, BOD control is stopped in the slave station 2 and the partner slave station 2, so that voice communication by IP telephone is momentarily interrupted by a line change by BOD control. Can be prevented. Also, since the communication line between the slave stations that have started voice communication by IP telephone is changed to the IP telephone band, voice communication by IP telephone is prevented from being interrupted by frequency hopping by the master station 1. Can do.

  In addition, even when the communication band is not managed separately into the normal allocation band and the IP telephone band, but only the normal allocation band, the communication line between the slave stations that started the voice communication by the IP telephone, The master station 1 may identify that it is in an IP phone, and the communication line in the IP phone may be excluded from the target of frequency hopping control. In this case, too, the communication line in the IP phone may be interrupted by frequency hopping. Can be prevented. Note that the DAMA control device 8 of the master station 1 sets a flag indicating that the corresponding communication line is in the IP phone based on the received IP phone start notification, and assigns it to the normal allocation band depending on the presence or absence of this flag. It is possible to identify that the communication line is not subject to frequency hopping.

  Furthermore, in the above example, the Invite message according to the SIP protocol is detected by the transmission control unit 24 of the slave station 2, and the IP telephone start notification is sent to the master station 1, but an RTP (Real-time Transport Protocol) packet is detected. Then, the notification of the start of the simultaneous (real-time) communication may be transmitted to the master station 1 in step S5 of FIG. 4, and the subsequent processing sequence in this case is performed in the same manner as in the case of the IP phone start notification. Also good.

  Further, when communication between IP terminals does not occur between the slave stations 2 and a communication line is not allocated, when the slave station 2 receives an Invite message of IP telephone, In order to receive the communication line assignment, a line assignment request signal is transmitted to the master station 1 via the uplink CSC line, and an identification code indicating that voice communication by IP telephone is started is attached to this line assignment request signal. You may do it. In the master station 1 that has received the line assignment request signal, the DAMA control device 8 assigns a communication line between the slave stations to the IP telephone band by detecting an identification code indicating the start of voice communication.

It is a block diagram showing the structure of the satellite communication system which concerns on Embodiment 1 of this invention. It is a block diagram showing the structure of the sub_station | mobile_unit which concerns on Embodiment 1 of this invention, and a master station. It is a schematic diagram showing the band change of the communication line by the frequency hopping in the master station. It is a process sequence diagram showing the process with respect to an Invite message. It is a schematic diagram showing the line change by the master station.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Master station 2 Slave station 3 Communication satellite 4 Uplink CSC line 5 Downlink CSC line 6 Communication line 7 Master station satellite communication apparatus 8 DAMA control apparatus 13 IP telephone 17 Satellite communication apparatus 18 Satellite GW apparatus

Claims (5)

The slave station requests the master station to assign a line to the partner slave station via the CSC line via the satellite, assigns the communication line by the master station, and performs satellite communication between the slave station and the partner slave station. In the line assignment type satellite communication method,
IP phone start notification and IP phone end notification for notifying start and end of IP phone communication processing are configured to be transmitted / received via a CSC line, and connected to the slave station during data transmission on the assigned line . An IP telephone start notification is transmitted from the slave station to the master station via the CSC line based on a call signal from the IP telephone, and the slave station and the partner slave station are connected by the master station that has received the IP telephone start notification. A satellite communication method characterized in that the communication line between the two is changed to an IP telephone band that does not allow automatic frequency hopping of the master station. In the slave station that requests the master station to assign a line to the partner slave station by the CSC line via the satellite, is assigned a communication line by the master station, and performs satellite communication with the partner slave station.
The IP phone start notification and the IP phone end notification for notifying the start and end of the IP phone communication process are configured to be transmitted / received via the CSC line, and based on the call signal from the connected first IP phone, A satellite GW apparatus that generates an IP telephone start notification to be transmitted via a CSC line, and the IP telephone start notification generated by the satellite GW apparatus is transmitted to the parent station via the CSC line, and the parent station automatically And a satellite communication device for performing voice communication with a second IP phone connected to the other slave station through a communication line assigned to a band for IP phone that does not allow typical frequency hopping. Slave station. In a master station that assigns a communication line for satellite communication performed between the slave station and the partner slave station based on a channel assignment request between the slave station and the counterpart slave station transmitted from the slave station via a CSC line via the satellite,
An IP phone start notification and an IP phone end notification for notifying the start and end of the IP phone communication process are configured to be transmitted / received via the CSC line, and are sent to the call signal from the first IP phone connected to the slave station. Based on the IP phone start notification, the master station satellite communication device that receives the IP telephone start notification transmitted from the slave station via the CSC line, and automatically establishes the communication line between the slave station and the partner slave station. And a DAMA control device that is allocated to an IP telephone band that does not allow for frequency hopping. Requesting line allocation between Aiteko station to the master station by CSC line passing through the satellite, allocated a communication line by the master station, the slave station for satellite communication with the Aiteko station,
A satellite GW that transmits data from an IP terminal connected by an allocated line and generates a band change request signal for requesting increase / decrease of bandwidth to the master station via the CSC line based on increase / decrease of the data transmission amount A satellite communication device for transmitting data transmitted from the satellite GW device through the communication line assigned by the master station,
An IP phone start notification and an IP phone end notification for notifying the start and end of IP phone communication processing are transmitted and received through the CSC line, and the line is changed to the IP phone communication line.
The satellite GW apparatus generates an IP telephone start notification to be transmitted through the CSC line based on a call signal from an IP telephone, and stops generating the band change request signal during voice communication by the IP telephone. A slave station. In a master station that assigns a communication line for satellite communication performed between the slave station and the partner slave station based on a channel assignment request between the slave station and the counterpart slave station transmitted from the slave station via a CSC line via the satellite,
An IP phone start notification and an IP phone end notification for notifying the start and end of IP phone communication processing are transmitted and received through the CSC line, and the line is changed to the IP phone communication line.
A master station satellite communication device that receives, via the CSC line, an IP telephone start notification transmitted from the slave station based on a call signal from a first IP telephone connected to the slave station, and the slave station and the counterpart child A master station comprising: a DAMA control device that identifies that a communication line with a station is in an IP telephone and is excluded from frequency hopping.

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