JP4911238B2 - Packet communication system, packet communication method, transmission apparatus, and computer program - Google Patents

Description

  The present invention relates to a packet communication system, a packet communication method, a transmission apparatus, and a computer program that transmit packets by connecting to a communication network, and in particular, a packet communication system and packet that improve real-time communication quality such as VoIP and stream distribution. The present invention relates to a communication method, a transmission device, and a computer program.

  In recent years, the use of real-time applications such as VoIP (Voice Over Internet Protocol) and stream distribution for transmitting and receiving data such as audio and video between devices via a communication network is increasing. When a real-time application is used, the reproduction quality when reproducing data such as audio and video received by the application is affected by the state of the communication network. Therefore, when newly introducing a real-time application, it is necessary to grasp the state of the communication network in order to further improve the reproduction quality.

  However, VoIP calls are between the same bases, and even for a plurality of calls using the same route, the call quality may differ depending on the traffic load of the call route. This is because the traffic load density is periodically biased when a large amount of traffic having a predetermined period is superimposed on the transmission interval of VoIP packets. When the transmission interval of VoIP packets coincides with a cycle with a high load density, delay is likely to occur or packet loss is likely to occur, and it becomes difficult to maintain high call quality.

  Therefore, for example, Patent Documents 1 and 2 disclose a VoIP voice packet transmission method in which a packet transmission interval, a voice CODEC, and the like are changed, and a transmission interval and a transmission size are changed in conjunction with each other. By controlling the transmission interval so as to coincide with a cycle in which the load density is as low as possible, it is possible to maintain high call quality.

JP 2003-046563 A JP 2005-252665 A

  However, in the VoIP voice packet transmission method disclosed in Patent Document 1, it is necessary to perform call control between the transmission device and the reception device, and the packet transmission interval changed by the transmission device and the change are interlocked. There is a problem that it is necessary to change the setting of the receiving apparatus in accordance with the packet size, which makes communication control complicated.

  Further, in the VoIP voice packet transmission method disclosed in Patent Document 2, when the voice packet transmission interval is changed, the call control setting of the receiving apparatus is changed to perform call connection with the receiving apparatus, and then the change is made. It is necessary to transmit voice packets at the specified transmission interval. Therefore, it is necessary to set the communication environment in conjunction with the receiving apparatus as well as the transmitting apparatus, and there is a problem that the control becomes complicated.

  The present invention has been made in view of such circumstances, and a packet communication system, a packet communication method, a transmission device, and the transmission capable of improving communication quality only by controlling the packet transmission interval on the transmission device side. It is an object to provide a computer program used in an apparatus.

  Further, the present invention acquires the density distribution of the communication load within the transmission interval of the transmission packet by transmitting the load detection packet or by acquiring it from an external detection device, thereby transmitting in a transmission time zone with a small traffic. It is an object of the present invention to provide a packet communication system, a packet communication method, a transmission apparatus, and a computer program used in the transmission apparatus that can transmit a packet. Note that the density distribution of the communication load means a change in the amount of the communication load with respect to a change with time. The communication load density distribution may be extremely biased due to factors such as periodic communication load fluctuations.

  In order to achieve the above object, a packet communication system according to a first aspect of the present invention is a packet communication system comprising: a transmission device connected to a communication network and transmitting a packet; and a reception device connected to the communication network and receiving a packet. The device calculates the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum in the packet transmission interval based on the communication quality information related to the quality of communication returned in response to the transmitted packet. A transmission start time setting means for setting a packet transmission start time at the calculated timing, and a means for starting packet transmission at the set transmission start time.

  A packet communication system according to a second aspect of the present invention is a transmitter that connects to a communication network and transmits packets, and a communication device that connects to the communication network and transmits and receives load density detection packets that detect the density of the communication load. In a packet communication system including a communication load density detection device for detecting, the transmission device receives a timing at which a delay based on load density detection from the communication load density detection device is minimum and / or a timing at which an erasure rate is minimum. And a means for receiving transmission quality information, a transmission start time setting means for setting a packet transmission start time at the received timing, and a means for starting packet transmission at the set transmission start time.

  According to a third aspect of the present invention, there is provided a packet communication method using a transmission device that connects to a communication network and transmits packets, and a packet communication method that uses a reception device that connects to a communication network and receives packets. Based on the communication quality information relating to the quality of the communication returned in response, the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum in the packet transmission interval is calculated, and the packet is calculated at the calculated timing. The transmission start time is set, and packet transmission is started at the set transmission start time.

  According to a fourth aspect of the present invention, there is provided a packet communication method for transmitting a packet connected to a communication network, and transmitting and receiving a load density detection packet connected to the communication network for detecting a communication load density to reduce the communication load density. In the packet communication method using the communication load density detection device to detect, the transmission device receives a timing at which a delay based on load density detection from the communication load density detection device is minimum and / or a timing at which the disappearance rate is minimum. The communication quality information is received, the packet transmission start time is set at the received timing, and the packet transmission is started at the set transmission start time.

  According to a fifth aspect of the present invention, there is provided a transmitting apparatus for transmitting a packet by connecting to a communication network, based on communication quality information relating to the quality of communication returned in response to the transmitted packet. Means for calculating the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum; transmission start time setting means for setting the transmission start time of the packet at the calculated timing; and packets at the set transmission start time Means for initiating transmission.

  According to a sixth aspect of the present invention, there is provided a computer program that can be executed by a transmitting apparatus that transmits a packet by connecting to a communication network, and the communication quality returned by the transmitting apparatus in response to the transmitted packet. Based on the communication quality information regarding, a means for calculating a timing at which the delay is minimum and / or a timing at which the loss rate is minimum in the packet transmission interval, transmission for setting the packet transmission start time at the calculated timing It is characterized by functioning as start time setting means and means for starting packet transmission at the set transmission start time.

  In the first invention, the third invention, the fifth invention, and the sixth invention, a transmitting device that connects to a communication network and transmits a packet and a receiving device that connects to the communication network and receives a packet are used. Based on the communication quality information related to the communication quality returned in response to the packet, the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum is calculated in the packet transmission interval, and the calculated timing is calculated. The packet transmission start time is set with, and packet transmission is started at the set transmission start time. Thereby, it is possible to calculate the distribution of the density of the communication load at a predetermined transmission interval, for example, the transmission interval of the VoIP packet, from the communication quality information returned from the receiving device in response to the packet transmitted by the transmitting device, By setting the transmission timing so that the packet is transmitted at a timing when the communication load density is low, the communication quality can be kept high.

  In the second invention, the fourth invention, the fifth invention, and the sixth invention, a transmission device connected to the communication network and transmitting packets, and a load density detection packet connected to the communication network and detecting the density of the communication load are transmitted and received. Then, the communication load density detection device that detects the density of the communication load is used, and the transmission device uses either the timing when the delay based on the load density detection from the communication load density detection device is minimum and / or the timing when the disappearance rate is minimum. Communication quality information is received, packet transmission start time is set at the received timing, and packet transmission is started at the set transmission start time. As a result, the external load density detection device transmits a load density detection packet, thereby acquiring communication quality information regarding the packet delay and / or loss rate. By receiving communication quality information from an external load density detection device, the transmission device can calculate the distribution of communication load density at a predetermined transmission interval, for example, the transmission interval of VoIP packets, and the communication load density is small. By setting the transmission timing so that the packet is transmitted at the timing, it is possible to maintain high communication quality.

  According to the first invention, the third invention, the fifth invention, and the sixth invention, the transmission device transmits the load density detection packet, so that the density of the communication load in a predetermined transmission interval, for example, the transmission interval of the VoIP packet, is increased. The distribution can be calculated, and by setting the transmission timing so that the packet is transmitted at a timing at which the communication load density is small, the communication quality can be maintained high.

  According to 2nd invention, 4th invention, 5th invention, and 6th invention, the external load density detection apparatus transmits the packet for load density detection, so that the communication quality relating to packet delay and / or loss rate is one of them. Get information. By receiving communication quality information from an external load density detection device, the transmission device can calculate the distribution of communication load density at a predetermined transmission interval, for example, the transmission interval of VoIP packets, and the communication load density is small. By setting the transmission timing so that the packet is transmitted at the timing, it is possible to maintain high communication quality.

It is a block diagram which shows the structure of the packet communication system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the transmitter used with the packet communication system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the receiver used with the packet communication system which concerns on Embodiment 1 of this invention. It is a figure which shows the packet transmission timing in the conventional packet communication method. It is a figure which shows the packet transmission timing in the packet communication method which concerns on Embodiment 1 of this invention. It is an illustration figure of the structure of the RR packet prescribed | regulated by RTCP. It is a flowchart which shows the process sequence of the control means of the transmission apparatus used with the packet communication system which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the VoIP packet transmission process of the control means of the transmission apparatus used with the packet communication system which concerns on Embodiment 2 of this invention. It is a figure which shows the packet transmission timing in the packet communication method which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the packet communication system in the case of providing a communication load density detection apparatus separately.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a packet communication system according to Embodiment 1 of the present invention. In FIG. 1, a transmission apparatus 1 is connected to a communication network 3 such as the Internet, and transmits a packet to a reception apparatus 2 that is also connected thereto. The communication network 3 receives stream data transmitted from a plurality of transmission devices 1, 1,..., And transmission devices 1, 1,. Are connected. The communication network 3 includes a plurality of relay devices 4, 4,... Such as Internet routers, and the transmission device 1 passes through a communication path constituted by unspecified relay devices 4, 4,. The packets are transmitted from 1,... To the receiving devices 2, 2,.

  FIG. 2 is a block diagram showing a configuration of transmitting apparatus 1 used in the packet communication system according to Embodiment 1 of the present invention. The transmission apparatus 1 includes a control unit 11 such as a CPU that controls the entire apparatus, a computer program 101 that can be executed by the transmission apparatus 1 according to Embodiment 1 of the present invention, and a CD-ROM that records various information such as data. An auxiliary storage unit 12 such as a CD-ROM drive for reading various information from the recording medium 102 and a recording unit 13 such as a hard disk for recording various information read by the auxiliary storage unit 12 are provided. Then, the computer program 101 according to the present invention and various types of information such as data are read from the recording unit 13 and stored in the storage unit 14 such as a RAM for temporarily storing the information, and various procedures included in the computer program 101 are controlled by the control unit 11. The computer operates as the transmission device 1 according to the present invention. The transmission apparatus 1 further includes a communication unit 15 that transmits a packet, a clock unit 16 that acquires time, an input unit 17 such as a mouse and a keyboard, and an output unit 18 such as a monitor. The first embodiment assumes an IP telephone system that performs a telephone call using a PC. Therefore, it is possible to use a dedicated terminal such as an IP telephone. In this case, auxiliary storage means 12 such as a CD-ROM or CD-ROM drive, and input means 17 other than a telephone function such as a mouse and a keyboard are provided. It goes without saying that it is not included.

  FIG. 3 is a block diagram showing a configuration of receiving apparatus 2 used in the packet communication system according to Embodiment 1 of the present invention. The receiving device 2 includes a control means 21 such as a CPU that controls the entire device, a computer program 201 that can be executed by the receiving device 2 according to Embodiment 1 of the present invention, and a CD-ROM that records various information such as data. Auxiliary storage means 22 such as a CD-ROM drive for reading various information from the recording medium 202, and a recording means 23 such as a hard disk for recording various information read by the auxiliary storage means 22 are provided. Then, the computer program 201 according to the present invention and various types of information such as data are read from the recording unit 23 and stored in the storage unit 24 such as a RAM for temporarily storing the information, and various procedures included in the computer program 201 are controlled by the control unit 21. The computer operates as the receiving apparatus 2 according to the present invention. The receiving apparatus 2 further includes a communication unit 25 that receives a packet, a clock unit 26 that acquires time, an input unit 27 such as a mouse and a keyboard, and an output unit 28 such as a monitor. The first embodiment assumes an IP telephone system that performs a telephone call using a PC. Therefore, it is also possible to use a dedicated terminal such as an IP telephone. In this case, auxiliary storage means 22 such as a CD-ROM or CD-ROM drive, and input means 27 other than a telephone function such as a mouse and a keyboard are provided. It goes without saying that it is not included.

  A packet communication method using the transmission apparatus 1 and the reception apparatus 2 configured as described above will be described. FIG. 4 is a diagram showing packet transmission timing in the conventional packet communication method. In the following description, the transmission interval Ts of VoIP packets is 20 ms. The transmission interval Ts is not limited to 20 ms.

  For example, in call A, a VoIP packet (voice packet) 42 is always transmitted at the timing of the latter half of the transmission interval Ts of VoIP packets. On the other hand, for example, in call B, a VoIP packet (voice packet) 42 is always transmitted at the timing of the first half of the transmission interval Ts of VoIP packets. When there are many transmission timing calls such as the call A, the communication traffic increases at the timing of the latter half of the VoIP packet transmission interval Ts, and the communication load 41 is periodically biased. The period of bias of the communication load 41 is the transmission interval Ts of VoIP packets. Therefore, when the VoIP packet 42 is transmitted at the transmission timing as in the call A, there is a high possibility that the VoIP packet 42 will be delayed or lost, and the call quality will be low.

  Therefore, in the first embodiment, by periodically changing the transmission interval of VoIP packets in a plurality of calls, the periodic bias generated in the communication load 41 is leveled and the communication load is reduced. FIG. 5 is a diagram showing packet transmission timing in the packet communication method according to Embodiment 1 of the present invention.

  As shown in FIG. 5, the transmission timing of VoIP packets in a plurality of calls is changed by randomly changing the transmission interval by generating random numbers, for example, VoIP of calls A, B, C, D, E,. Packets 42, 43, 44, 45, and 46 (solid line portions) are transmitted at different transmission timings (broken line portions). Since the transmission interval Ts of each VoIP packet fluctuates according to the random number, the communication load distribution 51 is less biased than the normal communication load 41, and any VoIP packet is transmitted at any transmission timing. The traffic is substantially uniform, and it is possible to suppress variations in call quality.

  Note that, for the VoIP packet transmitted from the transmission device 1 to the reception device 2, a packet defined by a communication protocol for transmitting and receiving voice and moving images in real time such as RTP is used.

  FIG. 6 is an exemplary diagram of a configuration of an RR (Receiver Report) packet defined by a report packet RTCP (RTP Control Protocol) received as information such as a loss rate of a VoIP palette as communication quality. In the case of RTCP, the header information is included in the data portion of the IP packet, and various information related to the packet defined by RTCP is written. The meaning of the written information will be described below.

  V (Version) indicates the version of RTCP. P (padding) indicates the presence / absence of padding data for adjusting the packet length. RC (reception report count) indicates the number of blocks of the received report. PT (packet type) indicates the type of RTCP packet, and is set to “201” in the case of an RR packet. SSRC_1 indicates the first SSRC identifier and is used for identifying the transmission source of the SR packet. The fraction_lost indicates the position where the partial loss of the RTP packet has occurred, and the cumulative number of packets lost is the cumulative value of the number of lost packets. The extended highest sequence number (extended highest sequence number received) indicates the maximum sequence number received in the RTP packet, and the inter- nal jitter indicates an evaluation value of fluctuation within the response time of the RTP packet. LSR (last SR timestamp) indicates the time stamp of the recently received RTCP packet, and DLSR (delay since last SR) indicates the delay of the recently received RTCP packet.

  The format and content of the report packet may be other than the RTCP RR packet, and even in the case of other formats and content, if information necessary for grasping the communication status is acquired from a predetermined position in the packet, good.

  FIG. 7 is a flowchart showing a processing procedure of the control means 11 of the transmission apparatus 1 used in the packet communication system according to Embodiment 1 of the present invention. The control means 11 of the transmission apparatus 1 acquires the transmission interval Ts of VoIP packets (step S701). The transmission interval Ts of VoIP packets may be received via the input unit 17 of the transmission device 1 or may be received from the external device via the communication unit 15.

  The control unit 11 acquires the maximum value ΔT of the fluctuation range of the transmission interval of the VoIP packet using a random number (step S702). The maximum value ΔT of the fluctuation range of the transmission interval of the VoIP packet may be received via the input unit 17 of the transmission device 1 or may be received from the external device via the communication unit 15. Note that the maximum value ΔT of the fluctuation range of the transmission interval of the VoIP packet is preferably equal to or less than the transmission interval Ts of the VoIP packet when a random number r described later is 0 ≦ r ≦ 1. In this way, packet transmission start timings can be distributed substantially evenly within the range of the VoIP packet transmission interval Ts, and the unevenness of communication load can be leveled.

  The control means 11 generates a random number r (0 ≦ r ≦ 1) (step S703). The generation method of the random number r is not particularly limited, and any known random number generation method may be used.

  The control unit 11 adds the transmission interval variation r · ΔT to the transmission interval Ts to obtain a new transmission interval Ts ′ (step S704), and the control unit 11 determines whether or not the transmission interval Ts ′ has elapsed. However, if the control unit 11 determines that the transmission interval Ts ′ has not elapsed (step 705: NO), the control unit 11 enters a standby state until it elapses. When the control unit 11 determines that the transmission interval Ts' has elapsed (step S705: YES), the control unit 11 transmits a packet (step S706). After the control unit 11 transmits the packet, the control unit 11 determines whether or not the transmission of the VoIP packet is completed (step S707).

  When the control unit 11 determines that the transmission of the VoIP packet is not completed (step S707: NO), the control unit 11 returns the process to step S703 and repeats the above-described process. When the control unit 11 determines that the transmission of the VoIP packet is completed (step S707: YES), the control unit 11 stops the transmission of the VoIP packet and ends the process.

  As described above, according to the first embodiment, the distribution of communication loads is leveled by randomly changing the transmission interval of VoIP packets, packet loss is suppressed, and the occurrence of delay is suppressed. Therefore, the difference in communication quality due to the difference in transmission timing can be suppressed, and the communication quality can be improved.

(Embodiment 2)
Hereinafter, a communication load density measurement system according to Embodiment 2 of the present invention will be described with reference to the drawings. Since the configuration of the communication load density measuring system according to the second embodiment is the same as that of the first embodiment, detailed description thereof is omitted by attaching the same reference numerals. In the second embodiment, the load density detection packet is transmitted to grasp the density distribution of the communication load of the communication network 3, and the transmission start timing is set so that the packet is transmitted at a transmission timing with a low communication load. This is different from the first embodiment. Also in the second embodiment, as in the first embodiment, the period of communication load bias, that is, the transmission interval Ts of VoIP packets is set to 20 ms.

  FIG. 8 is a flowchart showing a procedure of VoIP packet transmission processing of the control means 11 of the transmission apparatus 1 used in the packet communication system according to Embodiment 2 of the present invention. FIG. 8 illustrates a method for specifying a transmission timing with a low communication load density based on the loss information of the load density detection packet. Note that the communication load density is not limited to the determination based on the loss information of the load density detection packet, and the same processing procedure may be used even if the communication load density is determined based on the delay information of the load density detection packet. Needless to say.

  The control means 11 of the transmission apparatus 1 acquires the transmission interval Ts of VoIP packets and the unit variation width d of the transmission timing (step S801). The transmission interval Ts of VoIP packets and the unit variation width d of the transmission timing may be received via the input unit 17 of the transmission device 1 or may be received from the external device via the communication unit 15. Further, the unit variation width d of the transmission timing is assumed to be smaller than the transmission interval Ts of VoIP packets.

  The control means 11 receives an RTCP (RTP Control Protocol) RR (Receiver Report) packet received as correction variation width T of the transmission timing, the number of lost packets loss (T) at each transmission timing, and communication quality information indicating the communication quality. Is set to an initial value “0” (step S802). Note that the maximum value N of the number of received RTCP (RTP Control Protocol) RR (Receiver Report) packets is set to a predetermined value, for example, N = 5.

  The control unit 11 transmits one VoIP packet at the transmission timing T (step S803), and determines whether or not an RTCP RR packet is received (step S804). Here, the transmission of the VoIP packet at the transmission timing T means that the VoIP packet is transmitted after T time has elapsed from the time when the VoIP packet should be originally transmitted. When the control unit 11 determines that the RR packet has not been received (step S804: NO), the control unit 11 returns the process to step S803. When the control unit 11 determines that the RR packet has been received (step S804: YES), the control unit 11 extracts the value of the header item fraction_lost of the RR packet and sets the packet loss number loss (T) at each transmission timing. Accumulate (step S805). That is, it can be determined that a transmission timing with a large value of loss (T) has a large communication traffic and a high communication load density, and a transmission timing with a small value of loss (T) has a small communication traffic and a high communication load density. Can be judged low.

  The control means 11 increments the received number n of RR packets by “1” (step S806), and determines whether or not it is less than the maximum value N of the received number of RR packets, eg, “5” (step S807). When the control unit 11 determines that the received number of RR packets is smaller than the maximum value N (step S807: YES), the control unit 11 returns the process to step S803 and repeats the above-described process.

  When the control unit 11 determines that the number of RR packets received is greater than or equal to the maximum value N (step S807: NO), the control unit 11 increments the transmission timing unit variation width d to the transmission timing T (step S808). ), It is determined whether or not the calculated transmission timing T is smaller than the VoIP packet transmission interval Ts (step S809). When the control unit 11 determines that the calculated transmission timing T is smaller than the VoIP packet transmission interval Ts (step S809: YES), the control unit 11 sets the reception number n of RR packets to an initial value “0”. (Step S810), the process returns to Step S803, and the above-described process is repeated.

  When the control unit 11 determines that the calculated transmission timing T is equal to or longer than the VoIP packet transmission interval Ts (step S809: NO), the control unit 11 has the smallest number of lost packets (T) for each transmission timing. A certain transmission timing T is calculated (step S811), and thereafter, the VoIP packet is continuously transmitted at the calculated transmission timing T (step S812).

  FIG. 9 is a diagram showing packet transmission timing in the packet communication method according to Embodiment 2 of the present invention. For example, even in the second embodiment, the communication load 91 has a periodic bias. The period of bias of the communication load 91 is a transmission interval Ts of VoIP packets, for example, 20 ms.

  In this state, for example, in calls A, B, and C, VoIP packets (voice packets) 92, 93, and 94 are always transmitted in the latter half of the transmission interval Ts of VoIP packets. Therefore, the calls A, B, and C transmit the VoIP packets 92, 93, and 94 at the transmission timing 96, which is a timing when there is a lot of communication traffic, and there is a possibility that the VoIP packet is delayed or the VoIP packet is lost. High, call quality is low.

  When it is determined that the transmission timing 97 is a timing when there is little communication traffic by using the load density detection packet, the transmission device 1 sets the transmission timing so that the VoIP packet 95 is transmitted at the transmission timing 97. Therefore, it is unlikely that the VoIP packet is delayed or lost, and the call quality can be maintained high.

  As described above, in the second embodiment, the transmission device 1 can transmit the load density detection packet to calculate the distribution of the communication load density at a predetermined transmission interval, for example, the transmission interval of the VoIP packet. By setting the transmission timing so that the VoIP packet is transmitted at a timing when the communication load density is low, the communication quality can be maintained high.

  Further, it is not limited to calculating the optimum transmission timing by transmitting a load density detection packet from the transmission device 1, for example, a communication load density detection device that separately detects the communication load density, The transmission timing of the VoIP packet may be changed by acquiring the detection result by the communication load density detection device. FIG. 10 is a block diagram showing a configuration of a packet communication system when a communication load density detection device is separately provided. In FIG. 10, a transmitting apparatus 1 is connected to a communication network 3 such as the Internet, and transmits a packet to a receiving apparatus 2 that is also connected thereto. The communication network 3 receives stream data transmitted from a plurality of transmission devices 1, 1,..., And transmission devices 1, 1,. Are connected. The communication network 3 includes a plurality of relay devices 4, 4,... Such as Internet routers, and the transmission device 1 passes through a communication path constituted by unspecified relay devices 4, 4,. The packets are transmitted from 1,... To the receiving devices 2, 2,.

  The transmission-side communication load density detection device 5 is also connected to a communication network 3 such as the Internet, and transmits a load density detection packet to the reception-side communication load density detection device 6 that is also connected. The transmitted load density detection packet passes from the transmission side communication load density detection device 5 to the reception side communication load density detection device 6 via a communication path constituted by unspecified relay devices 4, 4. Sent.

  The communication load density detection device may be a separate device on the transmission side and the reception side as shown in FIG. 10, or may be an integrated device having a transmission port and a reception port in one housing. Further, the procedure for calculating the optimum transmission timing T in the communication load density detecting device is the same as steps S801 to S810 of the processing procedure of the transmitting device 1 shown in FIG. The transmission apparatus 1 can obtain the same effect by acquiring the optimal transmission timing T from the communication load density detection apparatus and transmitting the VoIP packet at the acquired transmission timing T.

  Regarding the above first and second embodiments, the following additional notes are disclosed.

(Appendix 1)
In a packet communication system including a transmission device that transmits a packet by connecting to a communication network,
The transmitter is
Random number generating means for generating a random number;
An interval setting means for setting a packet transmission interval based on the generated random number, and
A packet communication system, wherein packets are transmitted at a set transmission interval.

(Appendix 2)
The interval setting means includes
The packet communication system according to appendix 1, wherein a transmission interval based on the random number is set to be smaller than an upper limit value of a ratio to a packet transmission interval.

(Appendix 3)
In a packet communication system including a transmission device connected to a communication network and transmitting a packet, and a reception device connected to the communication network and receiving a packet,
The transmitter is
Means for calculating a timing at which the delay is minimum and / or a timing at which the erasure rate is minimum in the packet transmission interval based on communication quality information related to the quality of communication returned in response to the transmitted packet; ,
Transmission start time setting means for setting the transmission start time of the packet at the calculated timing;
Means for starting packet transmission at a set transmission start time.

(Appendix 4)
The receiving device is:
The packet communication system according to supplementary note 3, comprising means for returning, when a packet is received, the communication quality information relating to the packet as a response to the transmission device.

(Appendix 5)
A packet having a transmission device connected to a communication network and transmitting a packet, and a communication load density detection device connected to the communication network and detecting a communication load density by transmitting and receiving a load density detection packet for detecting a communication load density In a communication system,
The transmitter is
Means for receiving communication quality information including the timing when the delay based on load density detection is minimum and / or the timing when the disappearance rate is minimum from the communication load density detection device;
A transmission start time setting means for setting a packet transmission start time at the received timing;
Means for starting packet transmission at a set transmission start time.

(Appendix 6)
In a packet communication method using a transmission device that transmits a packet by connecting to a communication network,
The transmitter is
Generate random numbers,
Based on the generated random number, set the packet transmission interval,
A packet communication method characterized by transmitting a packet at a set transmission interval.

(Appendix 7)
The packet communication method according to appendix 6, wherein a transmission interval based on the random number is set to be smaller than an upper limit value of a ratio to a packet transmission interval.

(Appendix 8)
In a packet communication method using a transmitting device connected to a communication network and transmitting a packet, and a receiving device connected to the communication network and receiving a packet,
The transmitter is
Based on the communication quality information related to the quality of the communication returned in response to the transmitted packet, calculate the timing at which the delay is minimum and / or the timing at which the loss rate is minimum in the packet transmission interval,
Set the packet transmission start time at the calculated timing,
A packet communication method characterized by starting packet transmission at a set transmission start time.

(Appendix 9)
The receiving device is:
9. The packet communication method according to appendix 8, wherein, when a packet is received, the communication quality information regarding the packet is returned as a response to the transmitting apparatus.

(Appendix 10)
A packet that uses a transmission device that connects to a communication network and transmits a packet, and a communication load density detection device that connects to the communication network and detects a communication load density by transmitting and receiving a load density detection packet for detecting a communication load density. In the communication method,
The transmitter is
Receiving communication quality information including a timing at which the delay based on load density detection is minimum and / or a timing at which the loss rate is minimum from the communication load density detection device;
Set the packet transmission start time at the reception timing,
A packet communication method characterized by starting packet transmission at a set transmission start time.

(Appendix 11)
In a transmission device that transmits a packet by connecting to a communication network,
Random number generating means for generating a random number;
An interval setting means for setting a packet transmission interval based on the generated random number, and
A transmission apparatus characterized by transmitting packets at a set transmission interval.

(Appendix 12)
The interval setting means includes
The transmitting apparatus according to appendix 11, wherein a transmission interval based on the random number is set to be smaller than an upper limit value of a ratio to a packet transmission interval.

(Appendix 13)
In a transmission device that transmits packets by connecting to a communication network,
Means for calculating a timing at which the delay is minimum and / or a timing at which the erasure rate is minimum in the packet transmission interval based on communication quality information related to the quality of communication returned in response to the transmitted packet; ,
Transmission start time setting means for setting the transmission start time of the packet at the calculated timing;
Means for starting packet transmission at a set transmission start time.

(Appendix 14)
In a computer program that can be executed by a transmission device that connects to a communication network and transmits a packet,
The transmitting device;
Random number generating means for generating random numbers,
A computer program that functions as interval setting means for setting a packet transmission interval based on a generated random number, and means for transmitting a packet at a set transmission interval.

(Appendix 15)
The interval setting means;
15. The computer program according to appendix 14, wherein the computer program functions as means for setting a transmission interval based on the random number to be smaller than an upper limit value of a ratio to a packet transmission interval.

(Appendix 16)
In a computer program that can be executed by a transmission device that connects to a communication network and transmits a packet,
The transmitting device;
Means for calculating the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum in the packet transmission interval based on the communication quality information relating to the quality of the communication returned in response to the transmitted packet;
A computer program that functions as transmission start time setting means for setting a packet transmission start time at a calculated timing, and means for starting packet transmission at a set transmission start time.

DESCRIPTION OF SYMBOLS 1 Transmission apparatus 2 Reception apparatus 3 Communication network 4 Relay apparatus 5 Transmission side communication load density detection apparatus 6 Reception side communication load density detection apparatus 101, 201 Computer program 102, 202 Recording medium

Claims (6)

In a packet communication system including a transmission device connected to a communication network and transmitting a packet, and a reception device connected to the communication network and receiving a packet,
The transmitter is
Means for calculating a timing at which the delay is minimum and / or a timing at which the erasure rate is minimum in the packet transmission interval based on communication quality information related to the quality of communication returned in response to the transmitted packet; ,
Transmission start time setting means for setting the transmission start time of the packet at the calculated timing;
Means for starting packet transmission at a set transmission start time. A packet having a transmission device connected to a communication network and transmitting a packet, and a communication load density detection device connected to the communication network and detecting a communication load density by transmitting and receiving a load density detection packet for detecting a communication load density In a communication system,
The transmitter is
Means for receiving communication quality information including the timing when the delay based on load density detection is minimum and / or the timing when the disappearance rate is minimum from the communication load density detection device;
A transmission start time setting means for setting a packet transmission start time at the received timing;
Means for starting packet transmission at a set transmission start time. In a packet communication method using a transmitting device connected to a communication network and transmitting a packet, and a receiving device connected to the communication network and receiving a packet,
The transmitter is
Based on the communication quality information related to the quality of the communication returned in response to the transmitted packet, calculate the timing at which the delay is minimum and / or the timing at which the loss rate is minimum in the packet transmission interval,
Set the packet transmission start time at the calculated timing,
A packet communication method characterized by starting packet transmission at a set transmission start time. A packet that uses a transmission device that connects to a communication network and transmits a packet, and a communication load density detection device that connects to the communication network and detects a communication load density by transmitting and receiving a load density detection packet for detecting a communication load density. In the communication method,
The transmitter is
Receiving communication quality information including a timing at which the delay based on load density detection is minimum and / or a timing at which the loss rate is minimum from the communication load density detection device;
Set the packet transmission start time at the reception timing,
A packet communication method characterized by starting packet transmission at a set transmission start time. In a transmission device that transmits packets by connecting to a communication network,
Means for calculating a timing at which the delay is minimum and / or a timing at which the erasure rate is minimum in the packet transmission interval based on communication quality information related to the quality of communication returned in response to the transmitted packet; ,
Transmission start time setting means for setting the transmission start time of the packet at the calculated timing;
Means for starting packet transmission at a set transmission start time. In a computer program that can be executed by a transmission device that connects to a communication network and transmits a packet,
The transmitting device;
Means for calculating the timing at which the delay is minimum and / or the timing at which the erasure rate is minimum in the packet transmission interval based on the communication quality information relating to the quality of the communication returned in response to the transmitted packet;
A computer program that functions as transmission start time setting means for setting a packet transmission start time at a calculated timing, and means for starting packet transmission at a set transmission start time.

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