JP2009141466A - Video stream receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a video reception terminal for receiving a video stream from a video server via a network cannot detect by itself whether or not a radio LAN section is present in a section up to the video server in a condition that missing packets never occur continuously or in a condition that the LAN section has stable communication condition. <P>SOLUTION: In the network in which video content is distributed from a terminal to a server via a router, the terminal requests the server to transmit video streams, transmits a Ping packet to the router while the terminal is receiving the video streams transmitted from the server, and records a first response time as a response time thereof. The terminal requests the server to stop transmission of the video streams, retransmits the Ping packet to the router and records a second response time as a response time thereof. The first response time is compared with the second response time to judge whether or not the radio LAN section is present. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication system using a network, and in particular, in stream communication in which continuous packet transmission / reception is performed, a communication system capable of identifying whether a network is a wireless LAN or a wired LAN, and video stream reception Related to the machine.

  In stream communication for transmitting large-capacity data such as video data from a server to a terminal using an IP network at a certain timing, if there is a wireless LAN section in the communication path from the server to the terminal, Transmission delay may occur.

  In stream communication, when a communication packet is lost or a transmission delay occurs, the quality of data displayed on the terminal is degraded. For example, when video data is transmitted from a server to a terminal by stream communication, a missing communication packet or a transmission delay is recognized as a video disturbance.

  When video disturbance is observed at a terminal, when the cause is investigated, the cause is quickly investigated by determining whether a wireless LAN section exists in the communication path from the server to the terminal. be able to.

  Patent Document 1 describes a method for determining whether a wireless LAN section exists in a communication path from a server to a terminal.

The terminal and server are provided with IP network identification means for identifying whether a wireless LAN or wired LAN communication means is used, and data exceeding the amount of data that the terminal can receive in one transfer is received from the server side. Then, it is divided into a plurality of packets and transmitted for a predetermined time. Sequential sequence numbers are assigned to the packets to be transmitted on the server side. The terminal receives the packet and confirms the sequence number of each packet. When a phenomenon in which sequence numbers are continuously lost is observed on the terminal side, it is determined that a wireless LAN is being used.
JP 2005-223471 A

  In the prior art described in the above-mentioned Patent Document 1, since it is determined that the wireless LAN is simply observed when a phenomenon in which packets are continuously dropped is observed, the packets are continued due to other factors such as router overload. May be misjudged if missing. Further, when the communication state is stable, there is a case where the presence of the wireless LAN cannot be detected because no packet is lost.

  An object of the present invention is to detect the presence of a wireless LAN section in a section from a terminal to a server even in a situation where continuous packet loss does not occur or a communication state of the wireless LAN section is stable. .

In order to solve the above-described problem, the present invention provides a video stream receiver for receiving video data from a video server via a router, and a packet from the router during a period of receiving video data from the video server. If the difference between the reception time and the packet reception time from the router during a period when video data is not received from the video server is greater than a predetermined value, the video stream receiver and the router The video stream receiver is characterized in that it is determined that a half-duplex communication wireless section exists between them.
In order to solve the above-mentioned problems, the present invention provides a method for confirming network communication quality in a video stream receiver that receives video data from a video server via a router, from the video server to the video stream receiver. A first step for confirming that a video stream is not transmitted; and after execution of the first step, a plurality of response request packets of a predetermined number or more are transmitted to the router, and the plurality of response request packets are transmitted from the router. A second step of recording a first response time that is an average response time until receiving a plurality of response packets that are packets for a response request packet; and a video stream from the video stream receiver to the video server A third step for requesting transmission of the video stream, and after execution of the third step, the video stream receiver While receiving a video stream transmitted from the image server, a plurality of response request packets of a predetermined number or more are transmitted to the router, and a plurality of response packets that are packets for the plurality of response request packets are received from the router A fourth step of recording a second response time that is an average response time until the first response time is compared with the first response time and the second response time, and the difference in response time is greater than a predetermined value A network communication quality observation method including: a fifth step of determining that a half-duplex wireless section exists between the video stream receiver and the router.

  In order to solve the above problems, the present invention provides a video stream receiver for receiving video data from a video server via a router, a network interface capable of transmitting and receiving video data, and the video stream from the video server. After confirming that no video stream is transmitted to the receiver, a plurality of response request packets of a predetermined number or more are transmitted to the router, and a plurality of response packets that are packets for the plurality of response request packets from the router The first response time which is an average response time until receiving the video stream is recorded, the video stream receiver requests the video server to transmit a video stream, and the video stream receiver receives the video server from the video server. While receiving a video stream to be transmitted, a plurality of response requests of a predetermined number or more to the router A packet response time measuring unit that records a second response time that is an average response time until a packet is transmitted and a plurality of response packets that are packets for the plurality of response request packets are received from the router, The packet response time measurement unit compares the first response time with the second response time, and if the difference in response time is greater than a predetermined value, the packet response time measurement unit The video stream receiver is characterized in that it determines that there is a half-duplex communication wireless section.

  As described above, according to the present invention, in a communication system using a network, it is possible to detect the presence of a wireless LAN section in a transmission path from a server to a video stream receiver that is a terminal. When the video displayed on the screen is distorted, the cause of the distorted video can be quickly investigated.

(Embodiment)
An embodiment according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a video stream receiver according to the present embodiment.
In FIG. 1, a network 101 is an IP network that transmits IP packets. For example, Ethernet (registered trademark).
The video stream receiver 100 includes a network interface 102 capable of transmitting and receiving IP packets, a video stream receiving unit 103 that extracts video data from IP packets storing video data received by the network interface 102, and a video stream receiving unit. A decoding unit 104 that decodes the output video data and a packet response time measurement unit 105 are included.
FIG. 2 is an explanatory diagram showing an embodiment of a communication system using an IP network.
In this communication system, the video stream receiver 100 described with reference to FIG. 1 is connected to the wireless base station 202 via a wired LAN, for example, a 100Base-TX standard wired LAN. The wireless base station 202 performs bidirectional communication with another wireless base station 203 using a wireless LAN. The home router 204 connects the home network including the video stream receiver 100, the wireless base station 202, and the wireless base station 203 to the wide area network 205. The video server 206 transmits a video stream to the video stream receiver 100 via the wide area network 205 using UDP (User Datagram Protocol).
Hereinafter, the operation of the entire communication system according to the present embodiment will be described in detail with reference to FIG. 1, FIG. 2, and FIG.
The video stream receiver 100 transmits a Ping packet from the packet response time measurement unit 105 to the home router 204 before receiving the video stream (S302).
The Ping packet is sent to the wireless base station 202 via the network interface 102. The wireless base station 202 converts the transmission medium, and the Ping packet is transmitted to the wireless base station 203 by a wireless signal. The wireless base station 203 converts the transmission medium again, and the Ping packet is transmitted to the home router 204 by a packet on the wired LAN. At this time, according to the 802.11n standard, which is a wireless LAN standard, in the wireless transmission section, communication is performed by half-duplex communication, so that transmission and reception are not performed simultaneously.
The home router 204 that has received the Ping packet transmits to the video stream receiver 100 a Ping response packet that is a response packet to the Ping packet. The Ping response packet passes through the path to the video stream receiver 100 and arrives at the video stream receiver 100.
In the video stream receiver 100, the Ping response packet is received through the network interface 102 and input to the packet response time measuring unit 105. The packet response time measuring unit 105 measures the response time from when the Ping packet is transmitted until it receives the Ping response packet, and stores it in an internal memory (not shown) (S303).
S302 and S303 are repeated N times (N is a natural number) (S304), and the average value of the response times obtained in S303 is obtained and held as the first response time in the internal memory (S305).
Next, the video stream receiver 100 requests the video server 206 to transmit a video stream (S306). The request for the video stream is made using means such as RTSP (Real Time Streaming Protocol), and the video server 206 transmits the video stream to the video stream receiver 100 using UDP (User Datagram Protocol). The video stream transmitted from the video server 206 arrives at the video stream receiver 100 via the wireless base stations 203 and 202.
The video stream transmitted from the video server 206 is received through the network interface 102 of the video stream receiver 100. The received UDP packet is processed by the video stream receiving unit 103 to extract video data. The extracted video data is input to the decoding unit 104 to decode the video data (S307).
At this time, while receiving the video data, the video stream receiver 100 transmits the Ping packet N times from the packet response time measuring unit 105 to the home router 204 before the reception of the video stream is completed. To do. N is sufficiently large. For example, the accuracy increases when transmission is performed continuously about 500 times. Further, each Ping packet is transmitted at a time interval in which a plurality of UDP packets transmitted from the video server 206 can be stored (S308).
The Ping packet is sent to the wireless base station 202 via the network interface 102 as in S303. The wireless base station 202 converts the transmission medium, and the Ping packet is transmitted to the wireless base station 203 by a wireless signal.
At this time, since communication in the wireless section is performed in half duplex, the video stream transmitted from the wireless base station 203 to the wireless base station 202 is interrupted, and a Ping packet is transmitted from the wireless base station 202 to the wireless base station 203. The
At this time, since the wireless base stations 202 and 203 cannot simultaneously transmit a Ping packet from 202 to 203 and a video stream from 203 to 202, the wireless base stations 202 and 203 perform an operation of frequently switching the communication direction. For this reason, the response time of the Ping packet observed by the video stream receiver 100 has a response time longer than the response time measured in S303. The Ping response packet is received by the video stream receiver 100 by the network interface 102 and input to the packet response time measuring unit 105. The packet response time measurement unit 105 measures the response time from the time when the Ping packet is transmitted until the reception of the Ping response packet, and stores the response time in the internal memory (S309).
The response time is measured for each of the Ping packets transmitted N times (S310), the average of the response times measured in S310 is taken, and held as the second response time in the internal memory (S311).
The packet response time measurement unit 105 compares the first response time and the second response time calculated in S305 and S311 respectively (S312), and the difference between the second response time and the first response time is a predetermined value. If it is larger than the range, it is determined that a wireless LAN section exists (S313). If it can be determined that the difference in response time is a measurement error within a predetermined range, it is determined that there is no wireless LAN section.
As described above, according to this embodiment, in a communication system using an IP network, it is possible for a video receiving terminal to detect whether or not a wireless LAN section exists in a transmission path from a server to a terminal. .
In the above embodiment, the response time is measured using the Ping packet. However, any packet can be used as long as it can return a response packet such as a Ping response packet that is a response to the Ping packet. .

  The present invention relates to a communication system using a network, in particular, in a stream communication in which continuous packet transmission / reception is performed, a communication system capable of identifying whether a network is a wireless LAN or a wired LAN, and a video stream receiver Useful for.

The block diagram which shows the structure of the video stream receiver concerning embodiment of this invention 1 is a block diagram showing a video distribution system using an IP network according to an embodiment of the present invention. Flowchart showing determination operation in the video distribution system shown in FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Video stream receiver 101 Network 102 Network interface 103 Video stream receiving part 104 Decoding part 105 Packet response time measurement part 106 Wireless LAN determination part 201 Video stream receiver 202 Wireless base station 203 Wireless base station 204 Home router 205 Wide area network 206 Video server

Claims (3)

A video stream receiver for receiving video data from a video server via a router,
The difference between the packet reception time from the router during the period when the video data is received from the video server and the packet reception time from the router during the period when the video data is not received from the video server is compared. A video stream receiver characterized in that if it is larger than a predetermined value, it is determined that a half-duplex wireless section exists between the video stream receiver and the router. A method for checking network communication quality in a video stream receiver that receives video data from a video server via a router,
A first step of confirming that no video stream is transmitted from the video server to the video stream receiver;
After execution of the first step, an average of transmission of a plurality of response request packets of a predetermined number or more to the router and reception of a plurality of response packets that are packets for the plurality of response request packets from the router A second step of recording a first response time that is a response time of
A third step of requesting transmission of a video stream from the video stream receiver to the video server;
After the execution of the third step, while the video stream receiver is receiving a video stream transmitted from the video server, a plurality of response request packets of a predetermined number or more are transmitted to the router, and the router A fourth step of recording a second response time, which is an average response time until receiving a plurality of response packets that are packets for the plurality of response request packets;
When the first response time is compared with the second response time, and the difference in response time is greater than a predetermined value, a half-duplex wireless section is provided between the video stream receiver and the router. A fifth step of determining that it exists;
Of network communication quality including A video stream receiver for receiving video data from a video server via a router,
A network interface capable of sending and receiving video data;
After confirming that no video stream is transmitted from the video server to the video stream receiver, a plurality of response request packets of a predetermined number or more are transmitted to the router, and the router responds to the plurality of response request packets. Recording a first response time that is an average response time until receiving a plurality of response packets, and requesting the video server to transmit a video stream from the video stream receiver; While receiving a video stream transmitted from the video server, the receiver transmits a plurality of response request packets of a predetermined number or more to the router, and a plurality of packets corresponding to the plurality of response request packets from the router. A packet response that records a second response time that is an average response time until the response packet is received. And a between measurement unit,
The packet response time measurement unit compares the first response time with the second response time, and if the difference in response time is greater than a predetermined value, the packet response time measurement unit A video stream receiver characterized in that it determines that there is a half-duplex communication wireless section.

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