Signal processing device, signal processing system, and signal processing method

Abstract

Provided is a signal processing device that processes signals of an internet telephone using a communications satellite. The purpose of the present invention is to restrict the number of calls and ensure call quality without worsening congestion in the uplink direction from a terminal station to a base station when there are many call requests. A signal processing device 12 comprises a downlink signal identification unit 46 that identifies a user ID included in a call request from a partner terminal 24. When the relationship between a calling user count b and a simultaneous usage upper limit S satisfies b<S, a call information management unit 52 causes a downlink signal control unit 48 to permit the call of the user ID. However, if b≧S, the downlink signal control unit 48 is made to discard the call request, and a call management signal generation unit 58 is made to notify the partner terminal 24 corresponding to the user ID that the call is in a waiting state and also of the position in the wait sequence.

Description

[Technical Field]

[0001] The present disclosure relates to a signal processing device, a signal processing system, and a signal processing method suitable for carrying out Internet telephone communications using a communications satellite. [Background technology]

[0002] Fig. 1 shows an example of the configuration of a communication system using a communication satellite. In Fig. 1, a user terminal 10 such as a smartphone is connected to a terminal station 14 via a terminal station signal processing device 12. The terminal station 14 can establish communication with a base station 18 via a communication satellite 16. The base station 18 can establish a connection with a user terminal (hereinafter referred to as "partner terminal") 24 of a communication partner via a base station signal processing device 20 and the Internet 22.

[0003] 1, communication data can be transmitted and received in both the uplink direction from the terminal station 14 to the base station 18 and the downlink direction from the base station 18 to the terminal station 14. If a voice call application is installed in the user terminal 10 and the other terminal 24, calls via Internet telephone are also possible.

[0004] Internet telephony is a type of VoIP (Voice over Internet Protocol) telephony. It does not use a dedicated IP telephone network, but rather uses the Internet to enable calls using voice calling apps on social networking services (SNS). In this case, calls are not managed using telephone numbers.

[0005] In satellite communications, terminals often use devices with lower transmission power than base stations, emphasizing portability. As a result, communication speeds are asymmetric, as shown in Figure 1, and the communication system generally has an uplink speed slower than the downlink speed.

[0006] 2 shows an example of Internet telephone communication in a satellite communication system using a communication satellite 16. There are multiple user terminals 10 under the control of a terminal station 14. These user terminals 10 respond to incoming Internet telephone calls made at random times by a destination terminal 24.

[0007] The communication speed of Internet telephones using social networking apps such as LINE (registered trademark) phone varies depending on the app, but the average speed is approximately 50 kbps. On the other hand, communication speeds in satellite sections are generally slow, with upload speeds often even slower than download speeds. For example, Non-Patent Document 1 discloses a disaster response satellite communication system in which the download speed is 1.5 Mbps and the upload speed is 384 kbps. If more than seven user terminals 10, each with a communication speed of 50 kbps, use the system simultaneously, the upload speed will exceed its limit, even if there is sufficient downlink speed. As a result, upload data may be randomly discarded.

[0008] If communication data is discarded in this way, the quality of Internet telephone calls for all users will deteriorate. Therefore, in order to prevent deterioration of telephone quality, it is necessary to prevent data discarding.

[0009] To prevent data from being discarded, it is effective to reduce the number of user terminals 10 that are used simultaneously. However, it is difficult to control the actual number of user terminals 10 in use. Therefore, a method can be considered in which the terminal station signal processing device 12 recognizes a user ID, such as an IP address, assigned to each user terminal 10, and sets an upper limit on the number of upstream users that are allowed to access simultaneously.

[0010] An example of this operation is shown in Figure 3. In the example shown in Figure 3, the terminal station signal processing device 12 recognizes user IDs and sets an upper limit on the number of users that can be used simultaneously. If the number of users that can be used simultaneously exceeds a preset upper limit, the communication data of the user IDs that exceed the upper limit is discarded. This operation makes it possible to fit the amount of data in uplink communication from the user terminal 10 within the communication capacity of the satellite section, and ensures the quality of communication data that is permitted for use. [Prior art documents] [Non-patent literature]

[0011] [Non-Patent Document 1] "Quality Evaluation of SNS in Disaster Management Satellite Communication Systems," Mitsuru Nishino, Fumiaki Nagase, Koichi Harada, Daiki Shibayama, Fumihiro Yamashita, Nippon Telegraph and Telephone Corporation, NTT Access Network Service Systems Laboratories, 2021 Institute of Electronics, Information and Communication Engineers General Conference, Proceedings of the IEICE Communications Conference 1, p. 221, March 9, 2021 Summary of the Invention [Problem to be solved by the invention]

[0012] However, if an upper limit is set on the number of permitted simultaneous users and control is exercised to ensure that the number does not exceed the upper limit, a remote terminal 24 that requests a call when the number of users exceeds the upper limit will be unable to start the call because the terminal station signal processor 12 discards data. In this case, the user of the remote terminal 24 on which the usage restriction is imposed does not necessarily give up on the call request and wait. Rather, the user on whom the usage restriction is imposed is likely to repeatedly request a call until the call is available. As a result, the traffic volume in the downlink direction (base station → terminal station) will further increase, and in response, the data volume in the uplink direction (terminal station → base station) will also increase, which is likely to worsen the congestion state in the uplink direction.

[0013] 4 shows an example of a case where congestion worsens in the uplink direction from terminal station 14 to base station 18. Let a be the number of call requests from destination terminal 24, b be the number of users currently in conversation, and S be the upper limit for the number of users allowed to simultaneously use the Internet telephone. Call request a from destination terminal 24, a-(Sb), is dropped. The dropped user cannot make the call. If the user of destination terminal 24 of dropped call a-(Sb) makes a new call without giving up, the number of call requests will increase, further worsening the congestion.

[0014] The present invention has been made in consideration of the above-mentioned problems, and its primary object is to provide a signal processing device that limits the number of calls and ensures call quality when the number of call requests from the destination terminal increases in Internet telephone calls using a communications satellite, without causing worsening congestion in the uplink direction (terminal station → base station) that may occur due to an increase in call volume in the downlink direction (base station → terminal station).

[0015] A second object of the present invention is to provide a signal processing system that limits the number of calls and ensures call quality when the number of call requests from the destination terminal increases in an Internet telephone call using a communications satellite, without causing congestion in the upstream direction (terminal station → base station) that may occur due to an increase in the volume of calls in the downstream direction (base station → terminal station).

[0016] Furthermore, a third object of the present invention is to provide a signal processing method for limiting the number of calls and ensuring call quality when the number of call requests from the destination terminal increases in Internet telephone calls using a communications satellite, without causing worsening congestion in the upstream direction (terminal station → base station) that may occur due to an increase in call volume in the downstream direction (base station → terminal station). [Means for solving the problem]

[0017] In order to achieve the above object, a first aspect is a signal processing device for processing signals for Internet telephone using a communication satellite, a process of identifying a user ID included in a call request received from a remote terminal via the communication satellite; When the relationship b < S holds between the number of users b in a call and the upper limit S of concurrent usage, the process of permitting a call to the user ID, and When the relationship b ≥ S holds between b and S, the process of discarding the call request and notifying the partner terminal corresponding to the user ID that it is in a call waiting state and the waiting order, and When the relationship b < S holds, the process of notifying the partner terminal corresponding to the user ID located at the head of the call waiting list that it can receive a call request, and It is desirable to be configured to execute.

[0018] Further, a second aspect is a signal processing system that provides an Internet phone using a communication satellite, and a signal processing device, and a partner terminal capable of communicating with the signal processing device via the communication satellite, and The signal processing device identifies the user ID included in the call request received from the partner terminal, and When the relationship b < S holds between the number of users b in a call and the upper limit S of concurrent usage, the process of permitting a call to the user ID, and When the relationship b ≥ S holds between b and S, the process of discarding the call request and notifying the partner terminal corresponding to the user ID that it is in a call waiting state and the waiting order, and When the relationship b < S holds, the process of notifying the partner terminal corresponding to the user ID located at the head of the call waiting list that it can receive a call request, and It is desirable to be configured to execute.

[0019] Further, a third aspect is a signal processing method for providing an Internet phone using a communication satellite, and a step in which a signal processing device identifies the user ID included in a call request received from a partner terminal capable of communicating with the signal processing device via the communication satellite, and When the relationship of b < S holds between the number of users b during a call and the upper limit S of the number of concurrent users, the step of permitting a call to the user ID; When the relationship of b ≥ S holds between the b and the S, the step of discarding the call request and notifying the counterpart terminal corresponding to the user ID that it is in a call waiting state and the waiting order; When the relationship of b < S holds, the step of notifying the counterpart terminal corresponding to the user ID located at the head of the call waiting queue that it can receive a call request; It is desirable to include.

Effect of the Invention

[0020] According to the first to third aspects, when the number of call requests from the counterpart terminal increases in an Internet phone using a communication satellite, it is possible to limit the number of calls without causing deterioration in congestion in the uplink (terminal station ⇒ base station) direction that may occur due to an increase in the downlink (base station ⇒ terminal station) traffic volume. Therefore, according to these aspects, the call quality of an Internet phone using a communication satellite can always be kept good.

Brief Description of the Drawings

[0021] [Figure 1] Shows a configuration example of a communication system using a communication satellite. [Figure 2] Shows a communication example of an Internet phone in a satellite communication system using a communication satellite. [Figure 3] In a satellite communication system, shows an operation example when an upper limit is set for the number of counterpart terminals that the terminal station signal processing device permits simultaneous access. [Figure 4] In a satellite communication system, shows an example when the congestion state in the uplink direction from the terminal station to the base station deteriorates due to an increase in downlink call requests from the base station to the terminal station. [Figure 5] It is a diagram for explaining the configuration of the signal processing system according to Embodiment 1 of the present disclosure. [Figure 6A]1 shows an example of an active call list used in the first embodiment of the present disclosure. [Figure 6B] 1 shows an example of a call waiting list used in the first embodiment of the present disclosure. [Figure 7] 1 is a flowchart illustrating a processing flow in the first embodiment of the present disclosure. [Figure 8] 10 is a flowchart illustrating a processing flow according to a second embodiment of the present disclosure. [Figure 9] FIG. 10 is a diagram illustrating the configuration of a signal processing system according to a third embodiment of the present disclosure. [Figure 10] 10 is a timing chart for explaining a modified example in which SIP messages are used for call management of Internet telephone calls. DETAILED DESCRIPTION OF THE INVENTION

[0022] Embodiment 1 [Configuration of the First Embodiment] The first embodiment of the present disclosure can be used in the satellite communication system described with reference to Fig. 1. Fig. 5 is a block diagram for explaining a configuration unique to the system of the first embodiment of the present disclosure. In Fig. 5, elements common to elements shown in Fig. 1 are assigned the same reference numerals.

[0023] As shown in Fig. 5, the system of this embodiment includes a user terminal 10. The user terminal 10 can communicate with a terminal station 14 via a terminal station signal processing device 12. The terminal station 14 can communicate with a remote terminal 24 via a satellite network 30. The satellite network includes the communication satellite 16 and base station 18 shown in Fig. 1. By using this system, the user terminal 10 can establish wireless communication with the remote terminal 24 in both uplink and downlink directions.

[0024] The user terminal 10 is a terminal located on the side of the terminal station 14 as viewed from the satellite network 30. The user terminal 10 includes a transmitter 32 and a receiver 34. The terminal station signal processing device 12 includes an uplink receiver 36 that receives signals input from the transmitter 32 of the user terminal 10, an uplink signal identifier 38 that identifies the uplink signal, an uplink signal controller 40 that controls the uplink signal, and an uplink transmitter 42 that sends the controlled uplink signal to the remote terminal 24 via the terminal station 14. The terminal station signal processing device 12 also includes a downlink receiver 44 that receives downlink signals from the remote terminal 24 via the terminal station 14, a downlink signal identifier 46 that identifies the downlink signal, a downlink signal controller 48 that controls the downlink signal, and a downlink transmitter 50 that transmits the controlled downlink signal to the receiver 34 of the user terminal 10.

[0025] The terminal station signal processing device 12 further includes a call information management unit 52 that manages call information. The call information management unit 52 includes an active call list 54 and a call waiting list 56. More specifically, the call information management unit 52 includes storage that stores the active call list 54 and the call waiting list 56. The terminal station signal processing device 12 includes a call management signal generation unit 58 that can access the storage.

[0026] The call management signal generation unit 58 generates a call management signal by referring to the active call list 54 and the call waiting list 56 stored in the storage. The call management signal generation unit 58 can provide the generated call management signal to the destination terminal 24 via the upstream transmission unit 42.

[0027] The remote terminal 24 includes a remote terminal receiving unit 60 and a remote terminal transmitting unit 62. The remote terminal receiving unit 60 can receive signals from the terminal station signal processing device 12 via the terminal station 14 and the satellite network 30. The remote terminal transmitting unit 62 can transmit signals to the terminal station signal processing device 12 via the satellite network 30 and the terminal station 14.

[0028] An example of the traffic control operation in this embodiment will be described below with reference to the same figure. In FIG. 5, when a call request signal is input from the partner terminal 24 to the terminal station signal processing device 12, the downstream signal identification unit 46 identifies the user ID of the partner terminal 24. Then, the downstream signal identification unit 46 notifies the call information management unit 52 of the occurrence of the call request and the user ID.

[0029] Upon receiving the above notification, the call information management unit 52 checks the in-call list 54 and the call waiting list 56.

[0030] FIG. 6A shows an example of the in-call list 54 stored in the call information management unit 52. As shown in the figure, here, the user ID of the calling partner terminal 24, the user ID of the called user terminal 10, and the confirmation time of the call start signal are recorded in consecutive numbers.

[0031] FIG. 6B shows an example of the call waiting list 56 stored in the call information management unit 52. As shown in the figure, here, the user ID of the call request source partner terminal 24 and the confirmation time of the call request signal are recorded in consecutive numbers.

[0032] The call information management unit 52 compares the number b of users in the call with the upper limit number S that allows simultaneous use. When b < S, it instructs the downstream signal control unit 48 to pass a signal requesting a call. As a result, the partner terminal 24 becomes in a state where a call can be started.

[0033] After that, when the downstream signal identification unit 46 detects a call start signal of the corresponding user ID, it notifies the call information management unit 52 of the user ID in the call. The call information management unit 52 registers the user ID in the call in the in-call list 54 and adds 1 to the number b of users in the call.

[0034] After that, when the downstream signal identification unit 46 detects an end call signal of the corresponding user ID, it notifies the call information management unit 52 of the user ID that ended the call. Upon receiving this notification, the call information management unit 52 deletes the user ID that ended the call from the in-call list 54 and subtracts 1 from the number b of users in the call.

[0035] When the call information management unit 52 receives a notification of the occurrence of a call request from the downlink signal identification unit 46 and the condition of b≧S is satisfied, it instructs the downlink signal control unit 48 to discard the request signal for starting communication, and registers the corresponding user ID at the end of the call waiting list 56. Further, the call information management unit 52 instructs the call management signal generation unit 58 to notify the corresponding partner terminal 24 of the state of being in the call waiting state and the information indicating the waiting order. The call management signal generation unit 58 notifies the partner terminal 24 of the corresponding user ID via the uplink transmission unit 42 with the signal generated in response to the instruction.

[0036] The in-call list 54 and the call waiting list 56 synchronize information as appropriate. For example, if the user ID located at the head of the call waiting list is added to the in-call list 54, the user ID is deleted from the call waiting list 56. The call information management unit 52 periodically acquires the latest information from those lists, and checks whether the corresponding user ID can make a call request. That is, it checks whether the relationship of b<S holds and whether the corresponding user ID is located at the head of the call waiting list 56. When it is confirmed that a call request is possible, the call information management unit 52 instructs the call management signal generation unit 58 to notify the corresponding partner terminal 24 that the call request can be received, and deletes the corresponding user ID from the call waiting list. The call management signal generation unit 58 notifies the partner terminal 24 of the corresponding user ID via the uplink transmission unit 42 with the signal generated in response to the instruction.

[0037] Note that even when the corresponding user ID cannot make a call request, the partner terminal 24 may be periodically notified of the call waiting state and the information representing the waiting order.

[0038] In this embodiment, the user of the partner terminal 24 determines the timing of transmitting a call request signal based on his or her own judgment based on the information such as the call waiting state and the waiting order transmitted from the call management signal generation unit 58. Therefore, if the user does not make a call request even after the partner terminal 24 of the corresponding user ID receives the notification, the call is not started. And if the user issues a call request again, the user will go to the end of the waiting queue.

[0039] [Operation of Embodiment 1] FIG. 7 is a flowchart showing the flow of the above-described processing executed in the terminal station signal processing apparatus 12 of the present embodiment. As shown in the figure, when the terminal station signal processing apparatus 12 confirms a call request signal from the partner terminal 24 (step 100), it acquires the latest information from the in-call list 54 (step 102), and compares the number of users b in the call with the upper limit S of the simultaneous use number (step 104).

[0040] If the latest b acquired from the in-call list 54 satisfies the relationship b < S, the call request signal is passed through (step 106). Thereafter, when a call start signal is confirmed (step 108), the user ID in the call is registered in the in-call list 54, and the value of b is incremented by 1 (step 110).

[0041] Thereafter, the in-call state is continued until an end call signal is confirmed. When the end call signal is confirmed (step 112), the user ID of the ended call is deleted from the in-call list 54, and the value of b is decremented by 1 (step 114).

[0042] On the other hand, in step 104 above, when it is determined that the relationship b ≥ S holds for the latest b, the call request signal is discarded, and the corresponding user ID is registered at the end of the call waiting list 56. Further, it is notified to the partner terminal 24 of the corresponding user ID that it is in the call waiting state and the information of the order (step 116).

[0043] Thereafter, the latest information is periodically acquired from the list (step 118), and it is confirmed that the corresponding user ID is call requestable, that is, b < S holds, and the corresponding user ID is at the head of the call waiting list 56 (step 120). When that state can be confirmed, it is notified to the partner terminal 24 of the corresponding user ID that the call request can be received, and the corresponding user ID is deleted from the call waiting list 56 (step 122).

[0044] As described above, even if the user ID is not available for a call request, the other party's terminal 24 may be periodically notified that it is in a call waiting state and information regarding the order of waiting.

[0045] As described above, in this embodiment, by recognizing the user ID of the destination terminal 24, it is possible to create a busy list 54 that manages the number of active users b and their user IDs, and a waiting list 56 that manages the number of waiting users and their user IDs. Using the information in these lists, the user can be notified of a waiting call status and information indicating the waiting order. Upon receiving such notification, the user of the destination terminal 24 can appropriately control downstream traffic to avoid unnecessary repeated call re-attempts. Furthermore, if the number of downstream call re-attempts is not increased unnecessarily, further deterioration of upstream congestion can be avoided. Therefore, according to the system of this embodiment, in an Internet telephone system using a communication satellite 16, when the number of call requests from user terminals 10 increases, it is possible to appropriately limit the number of calls and ensure good call quality without worsening upstream congestion.

[0046] In the first embodiment described above, the user ID is managed for each remote terminal 24, but the present disclosure is not limited to this. For example, the user ID may be managed for each internet telephone call, that is, for each call. This also applies to the other embodiments described below.

[0047] Furthermore, in the above-described first embodiment, when b≧S, the call information management unit 52 registers the corresponding user ID in the call waiting list 56 without checking the status of the call waiting list 56, but the present disclosure is not limited to this. For example, when b≧S, it may be possible to check whether the corresponding user ID is already registered in the call waiting list 56 before registering the corresponding user ID in the call waiting list 56. If the corresponding user ID is not already registered, the corresponding user ID may be registered at the end of the call waiting list. On the other hand, if the corresponding user ID is already registered, the registration may be deleted first, and then the corresponding user ID may be registered at the end of the call waiting list 56.

[0048] Embodiment 2 Next, a second embodiment of the present disclosure will be described with reference to Fig. 8 in addition to Fig. 1 and Fig. 5. Similar to the first embodiment, the second embodiment of the present disclosure can be used in the satellite communication system described with reference to Fig. 1. The system of this embodiment can be realized by causing the terminal station signal processing device 12 shown in Fig. 5 to execute processing in accordance with the flowchart shown in Fig. 8 instead of the flowchart shown in Fig. 7 above.

[0049] In the first embodiment described above, when the call information management unit 52 determines that b≧S, it registers the corresponding user ID in the call waiting list 56 without checking the status of the call waiting list 56. In contrast, in the present embodiment, when it determines that b≧S, it checks whether the corresponding user ID is already registered in the call waiting list 56 before registering the corresponding user ID in the call waiting list 56. If the corresponding user ID is not already registered, it registers the ID at the end of the call waiting list, whereas if the corresponding user ID is already registered, it temporarily deletes the registration and then registers the corresponding user ID at the end of the call waiting list 56.

[0050] Fig. 8 is a flowchart for explaining the flow of processing executed by the terminal station signal processing device 12 in this embodiment to realize the above-mentioned functions. In Fig. 8, the same steps as those shown in Fig. 7 are denoted by the same reference numerals, and their explanations are omitted or simplified.

[0051] 8, when it is determined in step 104 that b≧S, the call request signal is discarded as in the first embodiment, and the corresponding user ID is checked against the call waiting list 56 (step 130). If the corresponding user ID has already been registered in the call waiting list 56 (step 132), the registration is deleted (step 134), and the corresponding user ID is registered again at the end of the call waiting list 56 (step 136).

[0052] If a user of the destination terminal 24 in a call waiting state were to be put at the end of the waiting queue every time he or she requests a call, the user would be urged to avoid making unnecessary call requests. In other words, according to this embodiment, the user can be encouraged to refrain from making further requests until notified that the call request can be accepted. Therefore, according to this embodiment, it is possible to more efficiently avoid worsening of the congestion state compared to the first embodiment, and it is possible to provide the user with even better call quality.

[0053] Embodiment 3 Next, a third embodiment of the present disclosure will be described with reference to Fig. 9 together with Fig. 1. Similar to the first embodiment, the third embodiment of the present disclosure can be used in the satellite communication system described with reference to Fig. 1.

[0054] Fig. 9 is a block diagram for explaining a configuration unique to the system according to the second embodiment of the present disclosure. In Fig. 9, elements corresponding to those explained with reference to Fig. 5 are given the same reference numerals, and their explanation will be simplified or omitted.

[0055] As shown in FIG. 9 , in the system of this embodiment, the remote terminal 24 includes a terminal call management application 64. The terminal call management application 64 has a function of recognizing information on the call waiting state and the waiting order transmitted from the call management signal generation unit 58 of the terminal station signal processing device 12, and autonomously issuing a call request signal at an appropriate timing. More specifically, upon receiving a signal indicating that the call request can be accepted from the call management signal generation unit 58, the terminal call management application 64 promptly retransmits the communication request. Therefore, in this embodiment, it is possible to initiate a call with the remote terminal 24 of the corresponding user ID at an appropriate timing, thereby freeing the user from the hassle of having to voluntarily issue a re-request at an appropriate time.

[0056] [Modifications of the First to Third Embodiments] FIG. 10 is a timing chart for explaining a technique for using SIP (Session Initiation Protocol) messages to manage calls over the Internet. SIP is generally used to manage calls over the Internet. In this case, SIP messages can be used as the user IDs and the like used in the first to third embodiments. Specifically, for example, the IP address information included in (0) REGISTER can be used as the user ID. (1) INVITE can be used as a call request signal. Also, (4) ACK can be used as a call start signal. Furthermore, (7) 200 OK following (6) BYE can be used as a call termination signal.

[0057] Furthermore, in the above-described first to third embodiments, a specific user is permitted to continue a call for a long period of time, but the present disclosure is not limited to this. For example, by using the call start signal confirmation time recorded in the call in progress list 54, if a certain period of time has elapsed, frames may be forcibly discarded and the call for the corresponding ID may be terminated. [Explanation of symbols]

[0058] 10 User terminal 12 Terminal station signal processing device 14 Terminal Station 16. Communications satellites 18 base station 24 Remote terminal 52 Call information management department 54 Call List 56 Call waiting list 58 Call management signal generation section 64 Device call management app

Claims

1. A signal processing device for processing signals for Internet telephone using a communication satellite, a process of identifying a user ID included in a call request received from a remote terminal via the communication satellite; A process of permitting a call to be made to the user ID when a relationship b<S is established between the number of users currently on a call b and the maximum number of simultaneous users S; a process of discarding the call request when a relationship of b≧S is established between the b and the S, and notifying the other terminal corresponding to the user ID that a call is waiting and the order of waiting; When the state where the relationship b≧S is satisfied changes to the state where the relationship b<S is satisfied, a process of notifying the other party's terminal corresponding to the user ID located at the head of the call queue that the call request can be accepted; a process of waiting for a call request from the other terminal that provided the notification, in the same way as for call requests from other other terminals, after notifying that the call request can be accepted; configured to run It has storage for a call waiting list, a tail registration process for registering the user ID included in the discarded call request at the tail of the call waiting list if b≧S; a process of deleting the user ID that has been notified that the call request can be accepted from the call waiting list; A process of reading the waiting order of the user ID from the information of the call waiting list; and further configured to perform The last registration process is a process of determining whether the user ID included in the discarded call request has been registered in the call waiting list; If the user ID is already registered in the call waiting list, the registration is deleted and the user ID is registered at the end of the call waiting list; A signal processing device comprising:

2. A storage device storing a list of active calls, a process of adding 1 to the serial number of the busy list when a call start signal from the other terminal is confirmed; a process of subtracting 1 from the serial number of the busy list when a call-ending signal from the other terminal is confirmed; A process of reading the call number b from the serial number of the busy call list; The signal processing apparatus of claim 1 further configured to perform:

3. A signal processing system for providing internet telephone using a communications satellite, comprising: a signal processing device; a counterpart terminal capable of communicating with the signal processing device via the communication satellite, The signal processing device includes: A process of identifying a user ID included in a call request received from the other terminal; A process of permitting a call to be made to the user ID when a relationship b<S is established between the number of users currently on a call b and the maximum number of simultaneous users S; a process of discarding the call request when a relationship of b≧S is established between the b and the S, and notifying the other terminal corresponding to the user ID that a call is waiting and the order of waiting; When the state where the relationship b≧S is satisfied changes to the state where the relationship b<S is satisfied, a process of notifying the other party's terminal corresponding to the user ID located at the head of the call queue that the call request can be accepted; a process of waiting for a call request from the other terminal that provided the notification, in the same way as for call requests from other other terminals, after notifying that the call request can be accepted; configured to run It has storage for a call waiting list, a tail registration process for registering the user ID included in the discarded call request at the tail of the call waiting list if b≧S; a process of deleting the user ID that has been notified that the call request can be accepted from the call waiting list; A process of reading the waiting order of the user ID from the information of the call waiting list; and further configured to perform The last registration process is a process of determining whether the user ID included in the discarded call request has been registered in the call waiting list; If the user ID is already registered in the call waiting list, the registration is deleted and the user ID is registered at the end of the call waiting list. Signal processing system.

4. 1. A signal processing method for providing Internet telephony using a communications satellite, comprising: a step of identifying a user ID included in a call request received by a signal processing device from a partner terminal that can communicate with the signal processing device via the communication satellite; a step of allowing the user ID to make a call when a relationship of b<S is established between the number of users currently in communication b and the maximum number of simultaneous users S; a step in which the signal processing device discards the call request when a relationship b≧S is established between the b and the S, and notifies the other party's terminal corresponding to the user ID that a call is waiting and the order of waiting; a step in which the signal processing device notifies a destination terminal corresponding to a user ID located at the head of a call queue that a call request can be accepted when the state where the relationship b≧S is satisfied changes to a state where the relationship b<S is satisfied; a step of waiting for a call request from the other terminal that provided the notification of being able to accept the call request in the same way as for call requests from other other terminals; Including, the signal processing device includes a storage device storing a call waiting list; a tail registration step in which the signal processing device registers the user ID included in the discarded call request at the tail of the call waiting list when b≧S; the signal processing device deleting the user ID that has been notified that the call request can be accepted from the call waiting list; the signal processing device reading the waiting order of the user ID from the information of the call waiting list; Further comprising: The last registering step determining whether the user ID included in the discarded call request has been registered in the call waiting list; If the user ID is already registered in the call waiting list, deleting the registration and registering the user ID at the end of the call waiting list. Signal processing methods.

Images