WO2016103676A1

WO2016103676A1 - Data distribution system, data distribution device, data distribution method and recording medium for data distribution

Info

Publication number: WO2016103676A1
Application number: PCT/JP2015/006373
Authority: WO
Inventors: 貴弘城島
Original assignee: 日本電気株式会社
Priority date: 2014-12-22
Filing date: 2015-12-22
Publication date: 2016-06-30
Also published as: JP6677171B2; JPWO2016103676A1

Abstract

Provided are a data distribution system, a data distribution device, a data distribution method and a recording medium for data distribution, which enable effective utilization of a non-communication time that temporarily occurs. In this data distribution method, Retransmission Time Out (RTO) is calculated on the basis of information relating to the size of a packet the transmission of which can be delayed with respect to a packet to be normally transmitted, from among the packet to be normally transmitted and the packet the transmission of which can be delayed, and the RTO is updated.

Description

DATA DISTRIBUTION SYSTEM, DATA DISTRIBUTION DEVICE, DATA DISTRIBUTION METHOD, AND DATA DISTRIBUTION RECORDING MEDIUM

The present invention relates to a data distribution system, a data distribution device, a data distribution method, and a data distribution recording medium, and in particular, a data distribution system, a data distribution method, and a data distribution recording medium between devices via a base station on a wireless network. About.

The use of the Internet on the move is increasing, and along with this, the number of terminals that support high-speed mobile communication is increasing in mobile terminals such as mobile phones and smartphones. As a standard for realizing such high-speed mobile communication, W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed Packet Access), LTE (Long Term Evolution) and the like have been proposed. Furthermore, it is standardized by the standardization project (3GPP) of the third generation mobile communication system and used in each mobile terminal. Here, WCDMA is a registered trademark and 3GPP is a registered trademark.

Since each mobile terminal communicates with server devices on the Internet, it can communicate with the Internet by exchanging radio signals with base stations installed in various locations and exchanging packets with the base stations as radio signals. To do.

Each base station manages mobile terminals that are within reach of the radio waves from its own station, and when receiving a packet from each mobile terminal, the mobile network (core network) intervenes between the base station and the Internet. Send to the Internet via Alternatively, communication between the mobile terminal and the Internet is enabled by transmitting a packet received from the Internet via the core network to the mobile terminal.

When a packet is relayed from the Internet to a plurality of mobile terminals, the base station schedules in what order each packet is transmitted to the mobile terminal. As the schedule method, a round robin method, a proportional fair method, or the like is used, and the packet transmission order is determined by the packet transmission interval of each terminal and the radio wave quality between the terminal and the base station.

The communication specifications in the mobile network are defined in 3GPP, and a virtual communication connection called a bearer is formed between the mobile terminal, the base station, and the core network, and each packet passes through this bearer through the mobile terminal and the Internet. Transferred between. A priority can be set for each bearer, and when a packet is scheduled at the base station, the order can be controlled according to the priority. Further, since packets are exchanged between the base station and the mobile terminal via radio, the transfer speed depends on the quality of radio waves. In order to keep up with fluctuations in the transfer rate, the base station stores the packets once in the base station buffer when sending packets to the mobile terminal, and converts them into radio waves after being ordered based on the radio wave status and the scheduling described above. And transmitted to the mobile terminal.

In addition, users using mobile terminals often operate the terminal from evening to night, and communication occurs from the mobile terminal in response to the operation. To do. Also, spatially concentrated communication occurs because there are many people operating mobile terminals in places where there are many traffic such as in front of stations in large cities.

When communication is concentrated in this way, the packet processing capacity that can be transferred by the base station is exceeded, and the packet is lost without being transferred. The time that the packet stays in the base station buffer and reaches the mobile terminal. Problems such as delays occur. However, whether an application running on a mobile terminal requires a packet from the Internet immediately depends on the processing contents. For example, application update data is rarely required to be real-time, but Web content displayed by a Web browser operated by the user is often required to be real-time. When communication concentrates on the base station, it is possible to reduce the concentration of communication by delaying packets to applications that do not require real-time performance. Patent Document 1 proposes a method in which data communication that does not require real-time performance is stopped during the day, and communication is performed during a time zone where the communication load is low, such as at night.

Also, as a communication method between the mobile terminal and the server device, generally, TCP / IP (Transmission Control Protocol / Internet Protocol) protocol is used. In the TCP / IP protocol, packet arrival confirmation and retransmission control are performed by a confirmation response in order to guarantee the arrival of the packet at the transmission destination. When a TCP / IP packet is received at the packet transmission destination, an acknowledgment packet called an Ack packet (Acknowledgement packet) is returned to the transmission source. When the Ack packet is received at the transmission source, the TCP / IP packet corresponding to the Ack packet is considered to have arrived at the transmission destination.

However, when a TCP / IP packet or an Ack packet corresponding to the TCP / IP packet is lost due to some failure, the packet transmission source receives an Ack packet for a time indicated by a timer called RTO (Retransmission Time Out). Wait for. When the Ack packet indicating normal reception of the packet is not returned from the packet transmission destination after waiting for reception of the Ack packet, it is determined that the packet has been lost during transfer, and the transmission source transmits the same packet again.

RTO is calculated by RTT (round trip time) from when a packet is transmitted until the Ack packet of that packet is returned. In a network with a large fluctuation in delay, the round trip time measured when the transmission delay is small becomes a small value, so the RTO value becomes small. Thereafter, when the transmission delay suddenly increases, packet retransmission due to a small RTO frequently occurs.

In Patent Document 2, when a transmitting terminal sends a packet at a frequency of a certain frequency or more, the receiving terminal does not immediately return an Ack packet, and after a while, the RTT is increased by returning the Ack packet. As a result, the RTO on the transmission side is constantly increased, thereby reducing packet re-transmission due to RTO progress.

JP-A-9-200334 JP 2006-229955 A

However, the data distribution method described above has the following problems.

In a base station where communication is concentrated, the time during which communication is performed and the time during which communication is not performed (no communication time) are mixed in a short time. This is because communication is interrupted when the user using the mobile terminal moves to a different place (under a different base station) or stops the operation and reads the terminal screen. In Patent Document 1, only communication time can be controlled by a time zone, and such a temporarily generated no-communication period cannot be effectively used.

Also, it is difficult to predict in advance when the temporary no-communication time will occur and for how long no communication will occur. For this reason, it is necessary to store packets to be transmitted to the base station using a temporary non-communication time in advance, and to immediately transmit the accumulated packets when no communication time occurs.

Although the transmission interval until the packet accumulated in advance is transmitted becomes longer or shorter depending on the frequency of occurrence of no-communication time, in TCP / IP, when the transmission interval suddenly increases, retransmission of the packet by RTO Occurs multiple times and the same packet is transmitted many times. On the other hand, if the accumulation time is suddenly shortened, when the RTO remains long and the packet is lost, the time until the retransmission becomes longer and the packet does not arrive at the mobile terminal. If Patent Document 2 is used, it is possible to prevent retransmission of a plurality of packets, but the RTO remains long and appropriate packets cannot be retransmitted.

Accordingly, an object of the present invention is to provide a data distribution system, a data distribution device, a data distribution method, and a data distribution recording medium that can effectively use a temporarily generated no communication time.

In order to achieve the above object, a data distribution system according to the present invention relays a server device that distributes data to a mobile terminal, a base station that wirelessly communicates with the mobile terminal, and communication from the server device to the mobile terminal. A gateway device,
The server device is
Communication means for transmitting packets;
RTO (Retransmission Time) based on information on the size of a packet that can be delayed in transmission among the normally transmitted packet and the packet that can be delayed in transmission relative to the normally transmitted packet. RTO calculating means for calculating (Out), and updating the RTO based on the information on the size of the packet whose transmission can be delayed.

The data distribution device according to the present invention delays the transmission among a communication unit that transmits a packet, a packet that is normally transmitted, and a packet that can delay transmission with respect to the packet that is normally transmitted. RTO calculating means for calculating RTO (Retransmission Time Out) based on information on the size of a packet that can be transmitted,
The RTO is updated based on the information regarding the size of the packet whose transmission can be delayed.

According to the data distribution method of the present invention, the size of the packet that can delay the transmission among the normally transmitted packet and the packet that can delay the transmission with respect to the normally transmitted packet. RTO (Retransmission Time Out) is calculated on the basis of the information on the RTO and the RTO is updated.

A recording medium for data distribution according to the present invention is a computer-readable recording medium in which a program for distributing data to another communication device is recorded via a base station,
On the server device,
Based on the information regarding the size of the packet that can delay the transmission among the normally transmitted packet and the packet that can delay the transmission with respect to the normally transmitted packet, the RTO (Retransmission RTO calculation processing for calculating (Time Out) and processing for updating the RTO are executed.

According to the present invention, it is possible to retransmit an appropriate packet, and it is possible to realize data distribution that effectively uses a temporarily generated no communication time.

FIG. 1 is a conceptual diagram for explaining data distribution by a high-level data distribution device of the present invention. FIG. 2 is a block diagram showing a data distribution system according to an embodiment of the present invention. 3A and 3B are data formats showing an example of a packet according to an embodiment of the present invention, and FIG. 3C is a data format showing an example of a layout of identifier information. FIG. 4 is a flowchart for explaining packet transmission processing from the server apparatus 2 to the base station 3 according to the embodiment of the present invention. FIG. 5 is a flowchart for explaining packet transmission processing of the scheduling unit 303 of the base station 3 according to the embodiment of this invention. FIG. 6 is a flowchart for explaining packet transfer processing from the mobile terminal 1 to the server device 2 according to the embodiment of the present invention. FIG. 7 is a block diagram showing a data distribution device according to another embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the direction of the arrow in a drawing shows an example and does not limit the direction of the signal between blocks. In the present invention, for example, data that does not need real-time characteristics that need only be transmitted during no-communication time is determined, and a special accumulation unit that accumulates packets related to data that does not require real-time performance is installed, and no communication time occurs. In this case, the packet stored in the storage unit is transmitted. Thereby, the no-communication time is used effectively. Further, it is possible to prevent unnecessary packet retransmission by estimating the time accumulated in the accumulation unit in TCP / IP as needed and appropriately setting the RTO. In the following description, the size of a packet that can delay the transmission is referred to as a “delayed packet size”. In a more specific embodiment, an example of “delay packet size” is referred to as “delay buffer size”.

FIG. 1 is a conceptual diagram for explaining data distribution by a data distribution device of a superordinate concept of the present invention. The data distribution device 12 in FIG. 1 is, for example, an update data distribution server, identifies a partner that needs updating, and distributes update data to the partner through a wireless network by packet communication. The data distribution device 12 in FIG. 1 includes a TCP communication unit 22 as an example of a TCP communication unit that transmits a TCP packet, and an RTO calculation unit 23 as an example of an RTO calculation unit that calculates an RTO. The RTO calculating unit 23 is information regarding the size of the packet that can delay the transmission among the normally transmitted packet and the packet that can delay the transmission compared to the normally transmitted packet. RTO is calculated based on the above.

In the data distribution by the data distribution device 12, it is determined whether to transmit a retransmission packet to the mobile terminal 11, which is an example of the other party, based on the RTO calculated by the RTO calculator 23. When the calculated RTO is large, if a packet is lost, a retransmission packet is not transmitted unless a long time indicated by the RTO has elapsed. When the calculated RTO is small, if a packet is lost, a retransmission packet is transmitted in a short time indicated by the RTO. By such control, it becomes possible to retransmit an appropriate packet, and the no-communication time temporarily generated can be used effectively. Hereinafter, more detailed embodiments of the present invention will be described.

[First Embodiment]
First, a data distribution system, a data distribution device, a data distribution method, and a data distribution recording medium according to a first embodiment of the present invention will be described. FIG. 2 is a block diagram showing a data distribution system according to an embodiment of the present invention. FIG. 4 is a flowchart for explaining packet transmission processing from the server apparatus 2 to the base station 3 according to the embodiment of the present invention. FIG. 5 is a flowchart for explaining packet transmission processing of the scheduling unit 303 of the base station 3 according to the embodiment of this invention. FIG. 6 is a flowchart for explaining packet transfer processing from the mobile terminal 1 to the server device 2 according to the embodiment of the present invention.

(Constitution)
The data delivery system of this embodiment performs data delivery to a plurality of mobile terminals 1 operated by a plurality of users. The data distribution system according to the present embodiment includes a server device 2 that provides a service to a user in cooperation with the mobile terminal 1, a base station 3 that communicates with the mobile terminal 1 by radio, and a mobile device from the server device 2. And a gateway device 4 that relays communication to the terminal 1.

Generally, a plurality of base stations 3 are arranged according to the reach of radio waves. The mobile terminal 1 monitors radio waves from a plurality of base stations 3 and is automatically connected to the base station 3 with good radio quality. The gateway device 4 is often installed in a core network and connected to a plurality of base stations 3, but the gateway device 4 and the base station 3 may be mounted on the same device.

The server apparatus 2 of the data distribution system includes an application unit 201 that provides an arbitrary service, a TCP communication unit 202, and an RTO calculation unit 203. The TCP communication unit 202 receives a packet transmission request from the application unit 201 and exchanges it with the mobile terminal 1 as a packet on the TCP / IP protocol. The RTO calculation unit 203 determines whether or not a packet sent to the mobile terminal 1 has been lost based on time. The RTO calculation unit 203 recalculates the RTO using the delayed packet size added to the header portion of the TCP packet returned from the mobile terminal 1. The application unit 201 in the server device 2 may operate on another device connected via a network instead of on the server device 2.

The base station 3 of the data distribution system includes a normal storage unit 301 as an example of a normal storage unit, a delay storage unit 302 as an example of a delay storage unit, and a scheduling unit 303 as an example of a scheduling unit. The normal storage unit 301 stores packets to be transmitted at normal timing. The delay accumulation unit 302 accumulates packets that can be delayed in transmission compared to packets transmitted at normal timing accumulated in the normal accumulation unit 301. The packets stored in the delay storage unit 302 can be stored until no communication time occurs. The packet stored in the delay storage unit 302 may be a packet that rarely requires real-time characteristics, such as application update data. The scheduling unit 303 transfers the packet of the normal storage unit 301 when there is a packet in the normal storage unit 301, and extracts the packet from the delay storage unit 302 and transfers it to the mobile terminal 1 when there is no packet in the normal storage unit 301.

The gateway device 4 of the data distribution system includes a delayed packet identification unit 401 as an example of a delayed packet identification unit, a buffer size transcription unit 402 as an example of a buffer size transcription unit, and a packet transfer unit 403 as an example of a packet transfer unit. And including. The delayed packet identification unit 401 determines whether the packet received from the server device 2 is a packet that can be delayed. In other words, the delayed packet identifying unit 401 identifies whether the packet received from the server device 2 is a packet that may be delayed. When receiving a packet from the base station 3, the buffer size transcription unit 402 acquires the buffer size of the base station 3 described in the packet, and confirms the delay buffer size added to the packet. Then, the buffer size transfer unit 402 transfers the delay buffer size to the packet by a method defined by the protocol on TCP / IP. When the delay buffer size is added to the packet and not added to the header part of the TCP packet, the buffer size transfer unit 402 transfers the delay buffer size to the header part of the TCP packet.

The packet transfer unit 403 transfers the packet received from the server device 2 to an appropriate base station 3 and transfers the packet received from the base station 3 to the server device 2.

(Operation)
Next, the operation of the data distribution system according to the present embodiment will be described with reference to FIGS. Although communication between the mobile terminal 1 and the server device 2 will be described based on the TCP / IP protocol, this method is not limited to the TCP / IP protocol. That is, any protocol can be applied as long as it is a protocol in which retransmission is performed when communication between the mobile terminal 1 and the server device 2 is lost and the retransmission is controlled by a timer. Further, the communication between the gateway device 4 and the base station device 3 is not limited to the TCP / IP protocol, and a protocol other than the protocol used between the mobile terminal 1 and the server device 2 may be used. .

First, the application unit 201 passes the communication content for a specific mobile terminal 1 to the TCP communication unit 202 at an arbitrary timing. The communication destination and the communication source are identified by information defined by an IP address and a port number in TCP / IP. The TCP communication unit 202 divides the communication content into packets, and transfers the packets to the packet transfer unit 403 of the gateway device 4 via the network. That is, the TCP communication unit 202 transmits the communication content as a TCP packet (step S201). At this time, the TCP communication unit 202 may set a flag indicating a delayable communication packet in the header of the TCP packet based on an instruction from the application unit 201.

3A and 3B are data formats showing an example of a packet according to an embodiment of the present invention, and FIG. 3C is a data format showing an example of a layout of identifier information. FIG. 3B is a data format showing an example of a packet to which identifier information indicating that delay is possible is added. FIG. 3A is a data format showing an example of a normally transmitted packet to which such identifier information is not added. The identifier information shown in FIG. 3B includes an ID (Identifier) area and a flag indicating a communication packet that can be delayed as shown in FIG.

The packet transfer unit 403 of the gateway device 4 passes the received packet to the delayed packet identification unit 401. The delayed packet identification unit 401 determines whether the received packet is a packet that can be delayed (step S202). As a determination method, a packet source or destination IP address or a port number may be used. As an example, a TCP packet with a port number of 20 is FTP (File Transfer Protocol) communication, and it is determined that it may be delayed. Further, when a flag indicating that the communication packet can be delayed is set in the header of the TCP packet as shown in FIG. 3B, it is determined that the packet may be delayed.

The delayed packet identification unit 401 adds a delay transfer flag indicating that the packet can be delayed (step S203). This flag may be a flag using a header portion of an IP packet indicating that a bearer set for transmission / reception of a delayed packet is used, for example. Alternatively, a special header may be added to the header portion of the TCP packet for transmission. Moreover, you may add to the protocol uniquely set for communication between the gateway apparatus 4 and the base station 3. FIG.

Next, the packet transfer unit 403 determines the base station 3 to transfer the packet, and transfers the packet to the scheduling unit 303 of the base station 3 via the network (step S204).

The scheduling unit 303 of the base station 3 that has received the packet determines whether a delayed transfer flag is added to the received packet (step S205). If the delay transfer flag is added, the packet is stored in the delay storage unit 302 (step S206). If the delay transfer flag is not added, the packet is stored in the normal storage unit 301 (step S207).

The scheduling unit 303 of the base station 3 transmits a packet to the mobile terminal 1 using radio. If a packet is stored in the normal storage unit 301 of the base station 3 (Y in step S301), the packet is extracted from the normal storage unit 301 and transmitted to the mobile terminal 1 (step S302). If no packet is accumulated in the normal accumulation unit 301 of the base station 3 (N in step S301), the packet is extracted from the delay accumulation unit 302 and transmitted to the mobile terminal 1 (step S303).

When the packet is returned from the mobile terminal 1 to the scheduling unit 303 (step S401), the scheduling unit 303 sets the size based on the total size of the packets stored in the delay storage unit 302 in the header of the reply packet. Append. That is, the scheduling unit 303 adds the delay buffer size to the reply packet (step S402). As the added delay buffer size, the total size of the packets stored in the delay storage unit 302 is used. Here, other information may be added to the delay buffer size. The additional information includes a fixed value set in advance separately, the amount of packets received or received by the scheduling unit 303 per unit time, and a value calculated based on those amounts. The header part to which the delay buffer size is added may be, for example, an IP packet or a TCP packet header part. Or you may add to the protocol uniquely set for the communication between the gateway apparatus 4 and the base station 3. FIG.

Next, the scheduling unit 303 transfers the packet to the packet transfer unit 403 of the gateway device 4 (step S403).

The packet transfer unit 403 of the gateway device 4 passes the packet to the buffer size transcription unit 402. The buffer size transcription unit 402 confirms the delay buffer size added to the packet. In other words, the buffer size transcription unit 402 confirms whether the delay buffer size is added to other than the header portion of the TCP packet (step S404). Here, when the delay buffer size is added to the packet and not added to the header portion of the TCP packet (Y in step S404), the delay buffer size is transferred to the header portion of the TCP packet (step S405). ).

Next, the packet transfer unit 403 transfers the packet to the TCP communication unit 202 of the server device 2 (step S406).

Next, the TCP communication unit 202 confirms whether or not the delay buffer size is added to the header part of the TCP packet. When the delay buffer size is added to the header of the TCP packet (Y in step S407), the delay buffer size is passed to the RTO calculation unit 203. The RTO calculation unit 203 recalculates the RTO using the passed delay buffer size. As a result of the RTO recalculation, if necessary, the RTO is corrected based on the delay buffer size (step S408). An example of the RTO calculation method at this time is shown by the following (Equation 1).

The throughput indicates the size per unit time of the packet transferred from the TCP communication unit 202. Α is an arbitrary constant.

In this RTO calculation, if the delay buffer size is large, it indicates that it takes a long time until a deferrable packet is transmitted to the mobile terminal 1, and thus the RTO becomes large. In this case, even if the packet accumulated in the delay buffer is transmitted to the terminal for a long time, the time until the sender determines that the packet has been lost and retransmits the packet also increases. Do not send by mistake.

Also, if the delay buffer size is small, it indicates that the time until a packet that can be delayed is transmitted to the mobile terminal is short, and thus the RTO is small. In this case, if a packet is lost, a retransmission packet can be transmitted immediately.

Next, when the communication content is included in the packet, the TCP communication unit 202 passes the packet to the application unit 201, and the application unit 201 performs processing based on the communication content. That is, the application unit 201 processes the packet (step S409).

(effect)
According to the above-described embodiment of the present invention, the accumulated packet can be transmitted immediately when no communication time occurs.

In a network with severe delay variation, the measured RTO is small when the transmission delay is small, so the RTO value is small. Thereafter, when the transmission delay suddenly increases, packet retransmission due to a small RTO frequently occurs.

On the other hand, according to the above-described embodiment of the present invention, the delay buffer size is added to the header of the packet returned from the mobile terminal 1, and the RTO calculation unit 203 uses the RTO (RTO) based on this delay buffer size. Retransmission Time Out) is calculated. Further, it is determined whether or not to send a retransmission packet to the mobile terminal 1 based on the RTO thus calculated. Whether or not to send a retransmission packet is determined in consideration of the size of the packet stored in the delay storage unit 302. Thereby, it is possible to solve the problem that the retransmission of the packet by RTO occurs a plurality of times and the same packet is transmitted many times. Also, if the storage time is suddenly shortened, the problem that the RTO remains long and the packet is lost, the time until the retransmission is increased and the packet does not arrive at the mobile terminal can be solved.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. Each component of the present invention can also be realized by a function of each component or a program that executes processing by each component. For example, the RTO calculation unit 203 and the TCP communication unit 202 of the server device 2 perform an RTO calculation process for calculating the RTO and a determination process for determining whether to send a retransmission packet to the other party based on the calculated RTO. It can also be realized by a program to be executed.

[Other Embodiments]
FIG. 7 is a block diagram showing a data distribution device 12 according to another embodiment of the present invention. The data distribution device 12 of FIG. 7 includes a CPU (Central Processing Unit) 25 and a memory 26 as an example of a processing unit. The data distribution device 12 in FIG. 7 reads into the memory 26 a program for executing an RTO calculation process for calculating an RTO and a determination process for determining whether or not to transmit a retransmission packet to the other party based on the calculated RTO. . Further, the CPU 25 executes RTO calculation processing and TCP communication processing. This program is a data distribution recording medium, for example, a general-purpose semiconductor recording device such as CF (Compact Flash (registered trademark)) and SD (Secure Digital), a magnetic recording medium such as a flexible disk, or the like. It can be distributed in the form of an optical recording medium such as a CD-ROM (Compact Disc Read Only Memory). The functions of the present embodiment may be realized in software by reading a program recorded in such a recording medium and causing the server apparatus 2 to execute an RTO calculation process and a determination process. It goes without saying that various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Additional remark 1) It is possible to delay the transmission among the communication means for transmitting the packet, the packet that is normally transmitted, and the packet that can delay the transmission with respect to the packet that is normally transmitted. RTO calculating means for calculating RTO (Retransmission Time Out) based on information on the size of the packet, and data distribution for updating the RTO based on the information on the size of the packet capable of delaying transmission machine.
(Supplementary note 2) The data distribution device according to supplementary note 1, wherein the RTO calculation unit calculates the RTO based on information on a size of a packet whose transmission can be delayed.
(Appendix 3) A server device that distributes data to a mobile terminal, a base station that wirelessly communicates with the mobile terminal, and a gateway device that relays communication from the server device to the mobile terminal, the server device including: Information on the size of a packet that can delay transmission among communication means for transmitting a packet, a packet that is normally transmitted, and a packet that can delay transmission with respect to the packet that is normally transmitted RTO calculation means for calculating RTO (Retransmission Time Out) based on the data, wherein the server device updates the RTO based on the information on the size of the packet whose transmission can be delayed. Distribution system.
(Supplementary Note 4) The base station includes normal storage means for storing the normally transmitted packet, and delay storage means for storing a packet capable of delaying transmission with respect to the normally transmitted packet. The data distribution system according to attachment 3, further comprising:
(Supplementary Note 5) When the base station transmits a packet to the mobile terminal, if the packet is stored in the normal storage unit, the base station extracts the packet and transmits it to the mobile terminal, and the packet is stored in the normal storage unit If not, the data distribution system according to appendix 4, wherein the packet is extracted from the delay storage means and transmitted to the mobile terminal.
(Supplementary note 6) The RTO calculation means of the server device calculates the RTO based on information on the size of a packet that can be delayed in transmission, accumulated by the delay accumulation means of the base station. Or the data distribution system according to appendix 5.
(Supplementary Note 7) The gateway device adds identification information indicating that transmission can be delayed to a packet whose transmission can be delayed, transmits the packet to the base station, and The data distribution system according to any one of appendix 4 to appendix 6, wherein the base station accumulates the received packet in the normal accumulation unit or the delay accumulation unit based on the identification information.
(Supplementary Note 8) The gateway device checks the delay buffer size added to the packet, and if the delay buffer size is added to the packet and is not added to the header of the packet, the gateway The data distribution system according to any one of appendix 4 to appendix 7, further comprising buffer size transcribing means for transcribing the size to the header of the packet.
(Additional remark 9) Based on the information regarding the size of the packet which can delay transmission among the packet transmitted normally and the packet which can delay transmission with respect to the packet transmitted normally A data delivery method for calculating RTO (Retransmission Time Out) and updating the RTO.
(Supplementary note 10) The data distribution method according to supplementary note 9, wherein the normally transmitted packet and the packet whose transmission can be delayed with respect to the normally transmitted packet are stored separately.
(Additional remark 11) When transmitting the packet to the other party, if the normally transmitted packet is accumulated, the packet is taken out and transmitted to the other party, and if the normally transmitted packet is not accumulated. The data delivery method according to appendix 9 or appendix 10, wherein a packet capable of delaying transmission is extracted and transmitted to the destination.
(Supplementary note 12) The data distribution method according to Supplementary note 10 or Supplementary note 11, wherein the RTO is calculated based on the stored information relating to a size of a packet capable of delaying transmission.
(Additional remark 13) The identification information which shows that transmission can be delayed is added with respect to the packet which can delay transmission, The received packet is accumulate | stored based on the said identification information The data delivery method according to any one of 10 to Supplementary Note 12.
(Supplementary note 14) The delay buffer size added to the packet is confirmed, and if the delay buffer size is added to the packet and is not added to the header of the packet, the delay buffer size is set to the packet header. 14. The data distribution method according to any one of appendix 10 to appendix 13, wherein the data is transferred to a section.
(Supplementary Note 15) A computer-readable recording medium in which a program for distributing data to another communication device is recorded via a base station, and a packet normally transmitted to a server device and the normal transmission RTO calculation processing for calculating RTO (Retransmission Time Out) based on information on the size of the packet that can delay transmission among packets that can delay transmission with respect to the transmitted packet; A computer-readable recording medium in which a program for executing the process of updating the RTO is recorded.
(Additional remark 16) The said RTO calculation process is a computer-readable recording medium of Additional remark 15 which calculates the said RTO based on the information regarding the size of the packet which can delay transmission.

The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above-described embodiment. That is, the present invention can apply various modes that can be understood by those skilled in the art within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2014-259005 filed on Dec. 22, 2014, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1,11 Mobile terminal 2 Server apparatus 3 Base station 4 Gateway apparatus 12 Data distribution apparatus 201 Application part 22, 202

TCP communication part

23, 203 RTO calculation part 25 CPU
26 Memory 301 Normal accumulation unit 302 Delay accumulation unit 303 Scheduling unit 401 Delay packet identification unit 402 Buffer size transcription unit 403 Packet transfer unit

Claims

Of the communication means for transmitting a packet, the normally transmitted packet, and the packet capable of delaying the transmission with respect to the normally transmitted packet, the size of the packet capable of delaying the transmission RTO calculation means for calculating RTO (Retransmission Time Out) based on the information,
A data distribution device that updates the RTO based on the information on the size of a packet whose transmission can be delayed.
A server device that distributes data to a mobile terminal, a base station that wirelessly communicates with the mobile terminal, and a gateway device that relays communication from the server device to the mobile terminal,
The server device
Communication means for transmitting packets;
RTO (Retransmission Time) based on information on the size of a packet that can be delayed in transmission among a normally transmitted packet and a packet that can be delayed in transmission relative to the normally transmitted packet. RTO calculating means for calculating (Out), and updating the RTO based on the information on the size of a packet whose transmission can be delayed.
The base station comprises: normal storage means for storing the normally transmitted packet; and delay storage means for storing a packet capable of delaying transmission with respect to the normally transmitted packet. 2. The data distribution system according to 2.
When the base station transmits a packet to the mobile terminal, if the packet is stored in the normal storage unit, the base station extracts the packet and transmits it to the mobile terminal, and if the packet is not stored in the normal storage unit The data distribution system according to claim 3, wherein a packet is extracted from the delay storage means and transmitted to the mobile terminal.
The RTO calculation unit of the server apparatus calculates the RTO based on information on a size of a packet that can be delayed in transmission accumulated by the delay accumulation unit of the base station. 4. The data distribution system according to 4.
The gateway device adds identification information indicating that transmission can be delayed to a packet whose transmission can be delayed, and transmits the packet to the base station.
The data distribution system according to any one of claims 3 to 5, wherein the base station accumulates the received packet in the normal accumulation unit or the delay accumulation unit based on the identification information.
The gateway device checks the delay buffer size added to the packet. If the delay buffer size is added to the packet and is not added to the header of the packet, the gateway device sets the delay buffer size of the packet. The data distribution system according to any one of claims 3 to 6, further comprising buffer size transfer means for transferring to the header portion.
Based on information on the size of the packet that can be delayed in transmission among the normally transmitted packet and the packet that can be delayed in transmission relative to the normally transmitted packet, RTO (Retransmission A data distribution method for calculating (Time Out) and updating the RTO.
The data distribution method according to claim 8, wherein the normally transmitted packet and the packet whose transmission can be delayed with respect to the normally transmitted packet are stored separately.
A computer-readable recording medium recorded with a program for distributing data to other communication devices via a base station,
On the server device,
Based on information on the size of the packet that can be delayed in transmission among the normally transmitted packet and the packet that can be delayed in transmission relative to the normally transmitted packet, RTO (Retransmission A computer-readable recording medium on which a program for executing RTO calculation processing for calculating (Time Out) and processing for updating the RTO is recorded.