KR20150075132A - Apparatus and method for transmitting network packet, and device for receiving network packet - Google Patents

Abstract

The present invention relates to a network apparatus for transmitting a packet input through a broadband network to a device, comprising: a broadband communication unit for receiving a packet through a broadband network; and a video packet determination unit for determining whether the packet is a video packet or not; a buffering unit for storing, if the packet is the video packet, the packet in a buffering database; and a short-range communication unit for transmitting the packet to a device through a short-range communication network, wherein the short-range communication unit transmits the packet stored in the buffering database to the device when retransmission of the packet is requested from the device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a network device and method for transmitting a packet, and a device for receiving a packet.

An apparatus and method for transmitting a packet input through a network to a device, and a device for receiving a packet.

In general, an IPTV system may include a broadcasting server for transmitting media content to an IP network, and a set-top box for receiving and reproducing media contents from an IP network. In the IPTV system, the live TV service or the real-time broadcast service can access the multicast stream and watch the broadcast according to the protocol. In the case of the VOD service, the content may be requested according to the protocol and then received and viewed in a unicast manner.

However, in the IPTV system, when the packetized media contents are lost or damaged in the transmission process, a request for retransmission of the problematic part may be required. In the case of the live broadcast TV service or the real-time broadcast service, only the unidirectional transmission from the server to the terminal is possible due to the characteristic of the multicast transmission. In the case of the VOD service, Time may become longer and server complexity may increase. Korean Patent Publication No. 2006-0005092 discloses a method of retransmitting media in connection with a method of retransmitting media.

The wireless network device attempts to buffer a certain amount of IPTV signals. When a set-top box detects a lost or damaged packet and requests retransmission, the network device attempts to retransmit only the requested portion. It is desired that the wireless set-top box be provided with stable IPTV service. It is to be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may be present.

According to an aspect of the present invention, there is provided a wireless communication system including a broadband communication unit for receiving a packet through a broadband network, a video packet determination unit for determining whether the packet is a video packet, And a local communication unit for transmitting the packet to the device via the local area communication network. The local area communication unit is configured to transmit the packet stored in the buffering database to the device, when receiving a packet retransmission request from the device, And transmits the packet to the device via the broadband network.

According to another embodiment of the present invention, there is provided a method for receiving a packet, comprising: receiving a packet through a broadband network; determining whether the packet is a video packet; storing the packet in a buffering database if the packet is a video packet; There is provided a method for transmitting a packet input through a broadband network to a device, the method including transmitting a packet to a device through a network, requesting retransmission of a packet from the device, and transmitting the packet stored in the buffering database to the device can do.

Further, in another embodiment of the present invention, there is provided a video packet decoding apparatus comprising: a receiver for receiving a video packet from a network device via a short-range communication network; a video packet determiner for determining whether a loss or corruption corresponding to the video packet exists; A transmission unit for transmitting a request message to a network device, a transmission unit for transmitting the request message to the network device, a playback unit for playing back the video using the received video packet and the video packet re-received from the network device, Wherein the replayed video packet is a packet stored in the network device among a plurality of packets input to the network device via the broadband network.

The above-described task solution is merely exemplary and should not be construed as limiting the present invention. In addition to the exemplary embodiments described above, there may be additional embodiments described in the drawings and the detailed description of the invention.

According to any one of the above-mentioned problems, the wireless network device can buffer a predetermined amount of IPTV signals. When a set-top box detects a lost or damaged packet and requests retransmission, the network device can retransmit only the requested portion. The set-top box connected wirelessly can provide stable IPTV service. By supporting the retransmission function of the IPTV RTP traffic through a simple change of the wireless network device, stable image reproduction can be performed even when the set-top box is wirelessly connected, even in the case of loss and damage.

1 is a configuration diagram of an IPTV system according to an embodiment of the present invention.
2 is a configuration diagram of a network device according to an embodiment of the present invention.
3 is a configuration diagram of a device according to an embodiment of the present invention.
4 is a flowchart illustrating an operation of a network device according to an exemplary embodiment of the present invention.
5 is a flowchart illustrating a method of transmitting a packet according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

In this specification, the term " part " includes a unit realized by hardware, a unit realized by software, and a unit realized by using both. Further, one unit may be implemented using two or more hardware, or two or more units may be implemented by one hardware.

In this specification, some of the operations or functions described as being performed by the terminal or the device may be performed in the server connected to the terminal or the device instead. Similarly, some of the operations or functions described as being performed by the server may also be performed on a terminal or device connected to the server.

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

1 is a configuration diagram of an IPTV system according to an embodiment of the present invention. Referring to FIG. 1, an IPTV system includes an IPTV broadcast server 30, a network device 10, and a device 20. However, since the video conference system shown in FIG. 1 is only one embodiment of the present invention, the configuration of the present invention is not limited to those shown in FIG.

Each of the configurations shown in FIG. 1 can be generally connected through a network. The network refers to a connection structure in which information can be exchanged between each node such as terminals and servers. One example of such a network is a 3rd Generation Partnership Project (3GPP) network, a Long Term Evolution (LTE) , A WIMAX (World Interoperability for Microwave Access) network, the Internet, a LAN (Local Area Network), a wireless LAN (Local Area Network), a WAN ) Networks, satellite broadcast networks, analog broadcast networks, and the like.

The IPTV broadcasting server 30 can provide the IPTV service to the device 20. [ For example, the IPTV broadcast server 30 may provide a real-time broadcast service to the user's device 20 based on the EPG information or the program schedule table. In another example, the IPTV broadcast server 30 may provide the real- To the device 20, the requested VOD content.

The device 20 may receive the video packet from the network device 10 over the local area network and may determine whether a loss or corruption exists in the video packet. For example, the device 20 may receive a video packet for VOD content received from a network device and determine whether there is a corruption in the received video packet.

The device 20 generates a request message related to the retransmission of the video packet and transmits it to the network device 10 and transmits the received video packet and the video packet re-received from the network device 10 So that the video can be played back.

The device 20 may include a mobile terminal capable of wireless communication, and may further include various types of devices. For example, the device 20 may be a TV device, a computer, or a portable terminal capable of connecting to a remote server via a network. Here, an example of the TV apparatus includes a smart TV, an IPTV set-top box, and the like. Examples of the computer include a notebook computer, a desktop computer, a laptop computer, One example of the terminal includes a Personal Communication System (PCS), a Global System for Mobile Communications (GSM), a Personal Digital Cellular (PDC), a Personal Handyphone System (PHS) Assistant, IMT (International Mobile Telecommunication) -2000, Code Division Multiple Access (CDMA) -2000, W-Code Division Multiple Access (W-CDMA), Wibro (Wireless Broadband Internet) terminals, smart phones, And the like may be included in the present invention. However, the device 20 is not limited to the illustrated form of FIG. 1 or to those illustrated above.

The operation of such a device 20 will be described later in FIG.

The network device 10 receives a packet through the broadband network and determines whether the packet is a video packet. If the input packet is a video packet, the network device 10 may store the received packet in the buffering database. For example, the network device 10 may receive packets for real-time broadcasting contents from the IPTV broadcasting server 30 through a broadband network, and may store packets for the received real-time broadcasting contents in a buffer or a buffering database.

The video signal transmitted from the IPTV broadcasting server 30 through the IP network is a bit stream encoded according to a compression method such as MPEG4 or H.264. In the case of real-time broadcast contents or live broadcast TV service, And may be transmitted to the network device 10 in a unicast manner according to the RTSP protocol in case of VOD content.

The network device 10 may transmit a packet received via the local area network to the device 20 and may receive the packet stored in the buffering database into the device 20 when receiving a retransmission request for the packet from the device 20. [ Lt; / RTI > In one example, the network device 10 may transmit video packets over the Wi-Fi to the device 20 connected to the network device 10 and may receive a request for retransmission of a portion of the video packets transmitted from the device 20 The network device 10 may retransmit the corresponding video packet of the video packets stored in the buffer to the device 20. [ The network device 10 includes a router, a hub, a wireless access point (AP), and the like, but is not limited thereto.

The operation of the network device 10 will be described in detail below with reference to FIG.

2 is a configuration diagram of a network device 10 according to an embodiment of the present invention. 2, the network device 10 includes a broadband communication unit 101, a video packet determination unit 102, a buffering unit 103, a short range communication unit 104, and a packet storage determination unit 105. However, the configuration of the network device 10 shown in FIG. 2 is not limited to those described above.

The broadband communication unit 101 receives a packet through a broadband network. For example, the broadband communication unit 101 can receive media content from the IPTV broadcast server 30 according to a normal IP communication procedure. The broadband communication unit 101 may receive the packetized media content in the RTP format from the IPTV broadcast server 30. The broadband communication unit 101 receives a real-time transport protocol (RTP), an internet group management protocol (IGMP), or a real-time streaming protocol (RTSP) from the IPTV broadcast server 30 Streaming Protocol). ≪ / RTI >

The video packet determination unit 102 may determine whether the received packet is a video packet. In this case, the video packet determination unit may determine whether the packet is a video packet based on the video transmission communication protocol or compression method of the packet. The video packet transmitted from the IPTV broadcasting server 30 is generally a bit stream encoded according to a compression scheme such as MPEG4 or H.264. The real-time broadcasting contents can be transmitted through the multicast stream according to the IGMPv2 protocol, Content can be transmitted according to the RTSP protocol. At this time, the video packet determination unit 102 may determine whether the packet received from the IPTV broadcast server 30 is a video packet transmitted according to the above-described method. At this time, the video packet may further include an audio packet related to the audio, and may be differently described as a traffic generated in association with a media packet or an IPTV content transmission.

When the received packet is a video packet, the buffering unit 103 stores the packet in the buffering database. The buffering unit 103 may store the received packet in a buffering database if the received packet is a video packet and the packet corresponds to a video transmission communication protocol. On the other hand, when the storage state of the buffering database is full, the buffering unit 103 deletes at least one of the plurality of packets stored based on the sequence number of each of the plurality of packets stored in the buffering database , And store the received packet in the buffering database. At this time, the buffering unit 103 can delete the packet having the lowest sequence number among the plurality of packets stored in the buffering database.

For example, the buffering unit 103 may store a video packet received in accordance with the RTP protocol from the IPTV broadcast server 30 in a buffer. If the buffer or the buffer memory is full, And can store newly received video packets.

The short-range communication unit 104 transmits a packet to the device 20 via the local area network. When receiving a packet retransmission request from the device 20, the local communication unit 104 transmits a packet corresponding to the request among the packets stored in the buffering database to the device 20 Lt; / RTI > The local area communication unit 104 can transmit a video packet to the device 20 connected to the network device 10 using Wi-Fi wireless communication, If a retransmission request is made, the packet stored in the buffer can be retransmitted to the device 20. The device 20 can check whether the IPTV RTP traffic is lost or erroneous by checking the continuity of the RTP sequence number or the like. If there is a problem, the device 20 requests retransmission of the packet, The packet can be requested again to the network device 10 by inputting the sequence number of the packet to be re-requested to the portion corresponding to the IP option in the packet header with the IP address of the device 10 as the destination address. At this time, the sequence number may be designated as a range type such as WX to YZ, and multiple packets may be requested at a time.

When the retransmission of a packet is requested from the device 20, the packet storage determination unit 105 can determine whether the packet is stored in the buffering database. If the packet is stored, the packet storage determination unit 105 determines whether the packet is stored in the local communication unit 104 The packet can be transmitted to the device 20, and if the packet is not stored in the buffering database, a notification message can be transmitted to the device 20. On the other hand, when the retransmission requested packet is transmitted to the device 20, the buffering unit may delete another packet having the previous sequence number of the sequence number of the retransmitted packet.

The packet storage determination unit 105 may determine whether a packet is stored based on the sequence number of the packet requested to be retransmitted from the device 20. [ When a plurality of packets are requested to be retransmitted from the device 20, the short range communication unit 104 can transmit the packet stored in the buffering database to the device 20 based on the sequence number. If the packet is not stored in the buffering database , The broadband communication unit 101 can request the IPTV broadcast server 10 to transmit a packet that is not stored in the buffering database.

Such a network device 10 can transmit a media packet transmitted from the IPTV broadcast server 30 to the device 20 and store the media packet in a buffer in the network device 10. [ Thereafter, when a retransmission request for a lost packet is received from the device 20, the retransmission request packet of the packets stored in the buffer is transmitted to the device 20, and the retransmission requested packet is transmitted to the packet or the previous sequence number Can be deleted. The network device 10 may also receive the packet from the IPTV broadcast server 30 and transmit it to the device 20 when the packet requested to be retransmitted is not stored in the buffer.

3 is a configuration diagram of a device 20 according to an embodiment of the present invention. The device 20 illustrated in FIG. 3 may operate through data transmission / reception with the network device 10 described with reference to FIGS. Therefore, contents which are not explained with respect to the device 20 of FIG. 3 can be deduced from the contents of the network device 10 explained with reference to FIG. 1 and FIG. 2, so that redundant or detailed contents are omitted.

Referring to FIG. 3, the device 20 includes a receiving unit 201, a video packet receiving unit 202, a message generating unit 203, a transmitting unit 204, and a reproducing unit 205. However, the configuration of the device 20 of FIG. 3 is not limited to those shown above.

The receiving unit 201 can receive a video packet from the network device 10 based on the local area communication network. The local area network may include, but is not limited to, Wi-Fi communication. For example, the receiving unit 201 can receive video packets for VOD contents encoded according to the MPEG4 or H.264 compression scheme via Wi-Fi.

The video packet determination unit 202 may determine whether a loss or a corruption exists in the video packet. For example, the video packet determination unit 202 may check the continuity of the RTP sequence number with respect to the IPTV RTP traffic to determine whether the video packet is lost or erroneous. However, there may be various methods for determining whether a video packet is lost or damaged in the video packet determination unit 202. FIG. For example, the video packet determination unit 202 may determine whether the data of the video packet itself is damaged or not by checking whether the data is damaged.

The message generating unit 203 may generate a request message related to retransmission of a video packet when a lost or damaged packet exists. For example, if the received packet has a problem and needs to be re-requested, the message generating unit 203 sets the IP address of the network device 10 as the destination address in the header of the packet, A request message related to retransmission of the packet can be generated by inputting the sequence number of the packet. The sequence number can be specified in a range form such as WX to YZ to request a plurality of packets at once.

The transmitting unit 204 can transmit the generated request message to the network device 10 and the reproducing unit 205 can reproduce the video using the received video packet and the video packet re-received from the network device 10 . The re-received video packet may be a packet stored in the network device 10 among a plurality of packets input to the network device 10 via the broadband network.

4 is a flow chart illustrating an operation of the network device 10 according to an embodiment of the present invention. Referring to FIG. 4, the network device 10 may receive traffic for real-time broadcast or VOD content from the IPTV broadcast server 30 (S401). When the received traffic is a wide area network (WAN) traffic (S402) and the RTP traffic (S403) provided by the IPTV service, the network device 10 stores the corresponding traffic in a buffer and then transmits the traffic to the set- To the representative device 20 (S404). If the stored traffic exceeds the size of the buffer, the lowest data of the sequence number can be deleted. If the received traffic is not the traffic based on the WAN traffic (S402) or the RTP protocol provided by the IPTV service, an operation similar to a general access point (AP) can be performed (S405). On the other hand, when the received traffic is a LAN (Local Area Network) rather than the WAN traffic S402 and there is no retransmission request (S406) of the device 20, the network device 10 performs the same operation as a normal AP (S405 )can do. In addition, if the network device has a request for retransmission of the device 20 and the requested packet is stored in the buffer (S407), the network device transmits the requested packet to the device 20 (S408). If not, It is possible to return to the device 20 that there is no data or packet to be transmitted (S409). The network device determines that all the data before the requested sequence number are normal and deletes the data before the sequence number (S410).

4 is only one of various embodiments of the present invention and is not so limited. In the above description, steps S401 to S410 may be further divided into additional steps, according to an embodiment of the present invention, Can be combined in fewer steps. Also, some of the steps may be omitted as necessary, and the order between the steps may be changed.

5 is a flowchart illustrating a method of transmitting a packet according to an embodiment of the present invention. The method of transmitting the packet shown in FIG. 5 includes operations that are processed in a time-series manner in the network device 10 described in FIGS. Therefore, even if omitted in the following description, the operation of the network device 10 explained with reference to Figs. 1 and 2 is also applied to Fig.

Referring to FIG. 5, the network device 10 receives a packet through a broadband network (S501) and determines whether the received packet is a video packet (S502). Whether or not the video packet is a video packet is determined based on whether the received packet is a video packet related to broadcasting or not. The packet is decoded using MPEG4 or H.264, which is a media compression scheme, or a video transmission protocol such as RTP, IGMP or RTSP Whether or not it is possible to make a decision.

If the received packet is a video packet, the network device 10 stores the packet in the buffering database (S503), and transmits the packet to the device 20 via the local area communication network (S504). Thereafter, when the network device 10 receives a request for retransmission of a packet from the device 20 (S506), the network device 10 may transmit the packet stored in the buffering database to the device 20 (S507).

In the above description, steps S501 to S507 may be further divided into further steps, or combined in fewer steps, according to an embodiment of the present invention. Also, some of the steps may be omitted as necessary, and the order between the steps may be changed.

The method of transmitting a packet described with reference to FIG. 5 may also be implemented in the form of a recording medium including instructions executable by a computer such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media.

In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

10: Network device
20: Device
30: IPTV broadcast server

Claims (16)

A network apparatus for transmitting a packet input through a broadband network to a device,
A broadband communication unit for receiving packets through the broadband network;
A video packet determination unit for determining whether the packet is a video packet;
A buffering unit for storing the packet in a buffering database when the packet is a video packet; And
And a local communication unit for transmitting the packet to the device through a local area network,
Wherein the short-range communication unit transmits a packet stored in the buffering database to the device when receiving a request for retransmission of the packet from the device.
The method according to claim 1,
Wherein the video packet determination unit determines whether the packet is a video packet related to broadcasting.
The method according to claim 1,
Further comprising a packet storage determination unit for determining whether the packet is stored in the buffering database when a request for retransmission of the packet is received from the device,
Wherein the local communication unit transmits a packet stored in the buffering database to the device when the packet is stored in the buffering database,
And the short-range communication unit transmits a notification message to the device if the packet is not stored in the buffering database.
The method of claim 3,
Wherein the packet storage determination unit determines whether the packet is stored based on the sequence number of the packet requested to be retransmitted.
The method of claim 3,
Wherein the buffering unit deletes another packet having a previous sequence number of the sequence number of the packet requested to be retransmitted.
The method according to claim 1,
Wherein the short-range communication unit transmits a first packet stored in the buffering database among the plurality of packets to the device when receiving a request for retransmission of a plurality of packets from the device,
Wherein the broadband communication unit requests a broadcast server to transmit a second packet not stored in the buffering database among the plurality of packets.
The method according to claim 1,
Wherein the video packet determination unit determines whether the packet is a video packet based on a video transmission communication protocol or a compression scheme of the packet.
The method according to claim 1,
Wherein the buffering unit stores the packet in a buffering database if the packet is a video packet and the packet corresponds to a first video transmission communication protocol.
9. The method of claim 8,
The first video transmission communication protocol may be any one of Real-time Transport Protocol (RTP), Internet Group Management Protocol (IGMP), or Real-time Streaming Protocol (RTSP) / RTI >
8. The method of claim 7,
Wherein the compression scheme is MPEG4 or H.264.
The method according to claim 1,
Wherein the buffering unit deletes at least one of the stored plurality of packets based on a sequence number of each of a plurality of packets stored in the buffering database when the storage state of the buffering database is full, And store the packet in a buffering database.
12. The method of claim 11,
Wherein the buffering unit deletes the packet having the lowest sequence number among the plurality of packets stored in the buffing database.
The method according to claim 1,
Wherein the retransmission request includes an address of the device, an address of the network device, and a sequence number of the retransmitted requested packet.
The method according to claim 1,
The device device is a set top box,
Wherein the network device is a wireless access point device.
A method for transmitting a packet input through a broadband network to a device,
Receiving a packet through the broadband network;
Determining whether the packet is a video packet;
Storing the packet in a buffering database if the packet is a video packet;
Transmitting the packet to the device via a local area network;
Receiving a request for retransmission of the packet from the device; And
And transmitting the packet stored in the buffering database to the device.
A device for receiving a packet from a network device,
A receiver for receiving a video packet from the network device via a local area network;
A video packet determination unit for determining whether there is a loss or a corruption corresponding to the video packet;
A message generating unit for generating a request message related to retransmission of the video packet when the loss or damage exists;
A transmitting unit for transmitting the request message to the network device; And
And a playback unit for playing back video using the received video packet and a video packet re-received from the network apparatus,
Wherein the replayed video packet is a packet stored in the network device among a plurality of packets input to the network device via the broadband network.

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