KR101744680B1 - System and method for retransmitting broadcasting packet based on error correction in wireless lan, access point therefor - Google Patents

Abstract

The present invention relates to an error correction based broadcast packet transmission system and method, and an access point for the same. More particularly, the present invention relates to a broadcast service apparatus that transmits a broadcast packet to an access point of a sub network by a unicasting method, A packet for recovery is generated by recognizing a packet received through a specific port as a broadcast packet, and a broadcast packet and a packet for restoration are transmitted to a user terminal of the corresponding sub network by multicasting / broadcasting, The transmission efficiency can be increased.

Description

Technical Field [0001] The present invention relates to an error correction based broadcast packet transmission system and method, and an access point for the same. [0001] The present invention relates to a system and method for transmitting a broadcast packet based on error correction in a wireless local area network (WLAN)

The present invention relates to an error correction based broadcast packet transmission system and method, and an access point for the same. More particularly, the present invention relates to a broadcast service apparatus that transmits a broadcast packet to an access point of a sub network by a unicasting method, A packet for recovery is generated by recognizing a packet received through a specific port as a broadcast packet, and a broadcast packet and a packet for restoration are transmitted to a user terminal of the corresponding sub network by multicasting / broadcasting, The present invention relates to an error correction based broadcast packet transmission system and method, and an access point therefor.

2. Description of the Related Art Generally, a wireless LAN (WLAN) is an access point (AP) corresponding to a hub of a wired LAN and provides a LAN service to a wireless terminal such as a smart phone or a notebook equipped with a wireless LAN card Network environment. It can be considered that the wired section between the hub and the user terminal in the conventional Ethernet system is replaced with the wireless section between the access point and the NIC (Network Interface Card) such as the wireless LAN card.

Meanwhile, recently, a data broadcasting service for transmitting the same advertisement and information video as well as internet service to a plurality of user terminals in a public place such as a coffee shop, a large discount mart, an airport, a department store and a hotel through a wireless LAN is provided.

Broadcast packets in the wireless LAN do not support MAC (Media Access Control), so the loss of packets is much higher in the upper layers than in unicast packets. Therefore, on the user terminal side decoding the broadcast stream, not only a part of the contents of the received packet but also an error that the whole packet is lost may occur frequently.

In order to solve this problem, an error recovery technique based on an error correction method in a packet transmission has been developed. The error correction scheme adds redundancy to the character or frame to be transmitted by the broadcasting service apparatus on the transmission side and transmits error detection and error correction to the additional information when the receiving user terminal detects an error .

This error correction method is mainly used in a place where there is one broadcast service apparatus on the transmission side and a plurality of user terminals on the reception side, where the feedback of the user terminal is difficult to be retransmitted or returned and the channel environment is poor or high reliability is required . In addition, since the error correction method can perform error correction without requesting retransmission even if an error occurs, there is an advantage that real-time processing and high throughput can be provided.

Meanwhile, in order to provide a multicasting / broadcasting service using the error correction method, a broadcast service apparatus generates broadcast packets and recovery packets together and transmits them to the access point. Then, the access point receives both the broadcast packet and the recovery packet from the broadcast service apparatus and transmits it to the user terminal.

Such a recovery packet increases the amount of packet transmission, that is, traffic, between the broadcast service apparatus and the access point. That is, the network load between the broadcasting service apparatus and the access point increases. Thus, there is a problem that the transmission efficiency between the broadcast service apparatus and the access point is low.

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above problems, and it is an object of the present invention to provide a broadcast service apparatus which transmits a broadcast packet to an access point of a sub network by a unicasting method, A restoration packet is generated and the broadcast packet and the restoration packet are transmitted to the user terminal of the corresponding sub network by the multicasting / broadcasting method, thereby reducing the amount of packets transmitted between the broadcasting service apparatus and the access point, An error correction based broadcast packet transmission system and method in a wireless LAN, and an access point therefor.

To this end, the system according to the first aspect of the present invention is a system for allocating a broadcast packet to a predetermined port of the access point by designating a subnetwork to which a broadcast packet is to be transmitted and using the access point address of the designated subnetwork, A service device; And recognizing the packet received through the predetermined port as a broadcast packet, generating a recovery packet for the recognized broadcast packet, multicasting / broadcasting the recognized broadcast packet and the generated recovery packet, To the access point.

According to a second aspect of the present invention, there is provided an apparatus comprising: a packet receiver for receiving a packet from a broadcast service apparatus through a predetermined port; A packet recognition unit for recognizing a packet received through the predetermined port as a broadcast packet; A recovery packet generating unit for generating a recovery packet for the recognized broadcast packet; And a packet transmission unit for transmitting the recognized broadcast packet and the generated recovery packet to a user terminal in a subnetwork.

The apparatus further comprises a packet combining unit for combining the recognized broadcast packet and the generated recovery packet, and the packet transmitting unit transmits the combined broadcast packet and the recovery packet to the user terminal .

And the packet receiving unit receives a packet transmitted from the broadcast service apparatus through the unicasting method through the predetermined port.

The recovery packet generation unit may generate a recovery packet for the recognized multicasting / broadcasting packet by a forward error correction (FEC) method.

According to a third aspect of the present invention, there is provided a method comprising: receiving a packet through a predetermined port from a broadcast service apparatus; A packet recognition step of recognizing a packet received through the predetermined port as a broadcast packet; A recovery packet generation step of generating a recovery packet for the recognized broadcast packet; And a packet transmission step of transmitting the recognized broadcast packet and the generated recovery packet to a user terminal in a subnetwork.

The method may further include a packet combining step of combining the recognized broadcast packet and the generated recovery packet, wherein the packet transmission step transmits the combined broadcast packet and the recovery packet to the user terminal .

The packet receiving step receives a packet transmitted from the broadcast service apparatus through the unicasting method through the predetermined port.

And the recovery packet generation step generates a recovery packet for the recognized multicasting / broadcasting packet by a forward error correction method.

According to the present invention, a broadcast service apparatus transmits a broadcast packet to an access point of a sub network by a unicasting method. The access point recognizes a packet received through a specific port as a broadcast packet to generate a recovery packet, By transmitting the recovery packet to the user terminal of the corresponding subnetwork in multicasting / broadcasting mode, the amount of packets transmitted between the broadcasting service apparatus and the access point is reduced, thereby increasing the transmission efficiency.

In addition, according to the present invention, a broadcast service apparatus transmits a broadcast packet to an access point located in a plurality of subnetworks in a unicasting manner, so that a broadcast service can be provided to a plurality of subnetworks There is an effect that can be provided.

1 is a block diagram of an error correction based broadcast packet transmission system in a wireless LAN according to an embodiment of the present invention.
2 is a detailed configuration diagram of an access point for transmission of an error correction based broadcast packet in a wireless LAN according to an embodiment of the present invention;
3 is a diagram illustrating an error correction based broadcast packet transmission process in an access point according to an embodiment of the present invention.
4 is a flowchart illustrating an error correction based broadcast packet transmission method in a wireless LAN 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. The configuration of the present invention and the operation and effect thereof will be clearly understood through the following detailed description. Before describing the present invention in detail, the same components are denoted by the same reference symbols as possible even if they are displayed on different drawings. In the case where it is judged that the gist of the present invention may be blurred to a known configuration, do.

1 is a block diagram of an error correction based broadcast packet transmission system in a wireless LAN according to an embodiment of the present invention.

Referring to FIG. 1, a broadcast packet transmission system according to an embodiment of the present invention includes a broadcast service apparatus 100, an access point (AP) 300, and a plurality of user terminals 400. Here, the broadcast service apparatus 100 is connected to an access point 300 located in each sub-network. The subnetwork includes an access point 300 and a plurality of user terminals 400.

 The broadcasting packet transmission system according to the embodiment of the present invention transmits a packet in a unicasting manner to the access point 300 through the broadcast service apparatus 100 and transmits the multicasting / To provide broadcast packets to a plurality of user terminals (400).

The broadcast service apparatus 100 for this purpose specifies a sub-network to which broadcast packets are to be transmitted. That is, the broadcast service apparatus 100 designates a subnetwork to which a broadcast packet (e.g., multimedia streaming data) is transmitted, and collects the IP address of the access point 300 located in the designated subnetwork.

The broadcast service apparatus 100 transmits the broadcast packet to a predetermined port of the access point 300 using the IP address of the collected access point 300. Here, the broadcast service apparatus 100 transmits a broadcast packet to the access point 300 in a unicasting manner. In this case, the broadcast service apparatus 100 can transmit broadcast packets through a specific port of a plurality of access points 300 without being located in each sub-network. A specific port means a port for receiving a broadcast packet, not a general packet. Broadcast packets may be encoded in various formats, including MPEG-1, MPEG-2, MPEG-4, and H.264.

The communication network 200 refers to a network that provides a service by communicating between the broadcasting service apparatus 100 and a plurality of user terminals 400 by wired / wireless communication. That is, the communication network may be a wired Internet network and may include a wireless data network (Internet network, IMS, etc.) connected through a mobile communication network (CDMA, W-CDMA, etc.). The communication network 200 is connected to the access point 300 and provides a path through which a plurality of user terminals 400 can transmit and receive a packet to and from the broadcasting service apparatus 100 through the access point 300 do.

The access point 300 is installed in an area such as a hot spot and is connected to the communication network 200 through a wireless LAN such as Wi-Fi. In the embodiment of the present invention, it is assumed that the access device is connected to the wireless LAN through Wi-Fi, and has IP address information unless otherwise noted.

The access point 300 receives a packet from the broadcast service apparatus 100 and recognizes the packet as a broadcast packet for multicasting / broadcasting when a packet is received through a specific port designated for broadcast. In this case, the access point 300 generates a packet for Forward Error Correction (FEC) recovery to recover the packet. Then, the access point 300 combines the generated FEC recovery packet with the broadcast packet and transmits it to the user terminal 400. The detailed configuration will be described in detail with reference to FIG.

In the embodiment of the present invention, the recovery packet is not limited to the FEC, and it means a recovery packet for error correction to be applied for recovering the packet in a large concept.

The plurality of user terminals 400 receive the broadcast packets through the access point 300 and provide the received broadcast packets to the user. For example, if the broadcast packet is a video packet, the plurality of user terminals 400 confirms whether there is an error or a lost frame when decoding a packet received at the time of reproduction. When the error is confirmed, the plurality of user terminals 400 recover the error packet using the FEC recovery packet for the frame in which the error occurs. The user terminal 400 can be applied to any type of terminal provided that a LAN card capable of interfacing with the access point 300 can be interfaced with the access point 300 and can reproduce and recover the packet. For example, a mobile terminal, a PDA, a notebook, a navigation, a PMP, a smart phone, an electronic dictionary, and an MPS.

2 is a detailed configuration diagram of an access point for transmission of an error correction based broadcast packet according to an embodiment of the present invention.

Specifically, the access point 300 according to the embodiment of the present invention relays packet transmission between the broadcast service apparatus 100 and the plurality of user terminals 400, and generates a packet for FEC recovery according to the FEC function A packet receiving unit 310, a packet recognizing unit 320, a restoring packet generating unit 330, a packet combining unit 340, and a packet transmitting unit 350.

The packet receiving unit 310 accesses the communication network 200 and receives packets from the broadcasting service apparatus 100 in a unicasting manner. Here, the packet receiving unit 310 can receive a packet through a specific port designated for broadcasting in advance.

The packet recognizing unit 320 recognizes, as a broadcast packet, a packet received through a predetermined port among the packets received through the packet receiving unit 310. [ Here, a broadcast packet means a broadcast packet transmitted through a multicasting / broadcasting scheme. On the other hand, the packet recognizer 320 recognizes a packet received through a port other than the specific port as a packet for transmitting general data. That is, the packet recognizer 320 can distinguish whether the packet is a broadcast packet for multicasting / broadcasting or a packet for transmitting general data through a predetermined port number. For example, in the case of telnet, the packet is received at port number 23, and in the case of FTP, the packet is received at port number 21. Thus, if the port number 1988 is set as a broadcast packet for multicasting / broadcasting, the packet recognizer 320 can recognize a packet received at port number 1988 as a broadcast packet.

The recovery packet generation unit 330 generates a recovery packet for the broadcast packet recognized by the packet recognition unit 320. [ The recovery packet generating unit 330 may generate the FEC-based recovery packet from the recovery packet. Here, as the packet amount of the FEC recovery packet increases, the probability that the original broadcast packet can be recovered through the FEC recovery packet is increased. The recovery packet generation unit 330 transmits the generated FEC recovery packet to the packet combining unit 340. The recovery packet generation unit 330 can generate a packet for FEC recovery of the original broadcast packet by using its own FEC modulation function.

The packet combiner 340 combines the original broadcast packet and the FEC recovery packet for broadcast packet transmission. The packet combining unit 340 may combine the original broadcast packet and the corresponding FEC recovery packet so that they are adjacent to each other. In addition, the packet combining unit 340 may combine the original broadcast packet with the broadcast packet, and combine the FEC recovery packet with the FEC recovery packet.

The packet transmitter 350 transmits the original broadcast packet and the FEC recovery packet, which are combined in the packet combiner 340, to the plurality of user terminals 400 by multicasting or broadcasting. At this time, the method of transmitting to the plurality of user terminals 400 may be set according to the type of the broadcast packet. That is, when transmitting to all of the plurality of user terminals 400 included in the subnetwork, the packet transmitting unit 350 may transmit the combined packets to the plurality of user terminals 400 in a broadcast manner. In addition, when transmitting to a plurality of user terminals 400 belonging to a group of subnetworks, the packet transmitting unit 350 may transmit the combined packets to the plurality of user terminals 400 of the group by multicasting .

3 is a diagram illustrating an error correction based broadcast packet transmission process according to an embodiment of the present invention.

As shown in FIG. 3, the broadcast service apparatus 100 transmits a broadcast packet to the access point 300 in a unicasting manner. For example, the broadcasting service apparatus 100 may be a moving picture streaming apparatus that transmits moving picture packets, and may be located in an external network rather than a local network. When the broadcast service apparatus 100 is located in an external network, the broadcast service apparatus 100 can transmit a broadcast packet to the IP address of the access point 300 through the communication network 200.

The access point 300 receives a broadcast packet from a broadcast service apparatus 100 located in a local network or an external network through a specific port predetermined in advance. The access point 300 generates a packet for FEC recovery for a broadcast packet received via a specific port. Then, the access point 300 combines the broadcast packet and the FEC recovery packet.

Then, the access point 300 transmits the combined broadcast packet and the FEC recovery packet to the user terminal 400 in a broadcasting or multicasting manner.

4 is a flowchart illustrating an error correction based broadcast packet transmission method in a wireless LAN according to an embodiment of the present invention.

The packet receiving unit 310 of the access point 300 receives the packet from the broadcast service apparatus 100 (S100).

Then, the packet recognizing unit 320 determines whether the port of the received packet is a specific port designated for broadcasting (S110).

As a result of the check (S110), when a packet is received through a predetermined port, the packet recognizing unit 320 recognizes the received packet as a broadcast packet (S120).

On the other hand, if it is determined in step S110 that the packet is received through a port other than the predetermined port, the packet recognizing unit 320 recognizes the received packet as a packet for transmitting general data, To the user terminal 400 (S130).

The recovery packet generating unit 330 generates an FEC recovery packet for the broadcast packet recognized in the step " 120 " (S140).

The packet combiner 340 combines the original broadcast packet and the FEC restoration packet (S150).

Thereafter, the packet transmitting unit 350 transmits the original broadcast packet combined with the user terminal 400 in the sub-network in a broadcasting or multicasting manner, and a packet for FEC recovery in operation S160.

Meanwhile, in the present invention, the error correction-based broadcast packet transmission method described above can be implemented as a software program and recorded on a computer-readable recording medium.

For example, the recording medium may be a hard disk, a flash memory, a RAM, a ROM, or the like embedded in each reproduction apparatus, or an external optical disk such as a CD-R or a CD-RW, a compact flash card, a smart media, have.

In this case, a program recorded on a computer-readable recording medium may include a packet receiving process for receiving a packet through a predetermined port from the broadcast service apparatus, a packet recognition process for recognizing a packet received through the predetermined port as a broadcast packet The method includes generating a recovery packet for the recognized broadcast packet, and transmitting the recognized broadcast packet and the generated recovery packet to a user terminal in the subnetwork, Lt; / RTI >

The foregoing description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed according to the following claims, and all the techniques within the scope of equivalents should be construed as being included in the scope of the present invention.

A broadcast service apparatus transmits a broadcast packet to an access point of a sub network by a unicasting method. The access point recognizes a packet received through a specific port as a broadcast packet to generate a recovery packet, By transmitting the packet to the user terminal of the corresponding subnetwork in the multicasting / broadcasting scheme, the amount of packets transmitted between the broadcasting service apparatus and the access point can be reduced to increase the transmission efficiency. In this respect, it is not only the use of the related technology but also the possibility of commercialization or operation of the applied device, as it exceeds the limit of the existing technology.

100: broadcasting service apparatus 200: communication network
300: access point 400: user terminal
310: packet receiver 320: packet receiver
330: Recovery Packet Generation Unit 340: Packet Combination Unit
350: Packet transmission unit

Claims (10)

delete A packet receiving unit for receiving packets from a broadcast service apparatus by unicasting from a preset port for broadcasting;
A packet recognition unit for recognizing the packet as a broadcast packet;
A recovery packet generation unit for generating a recovery packet corresponding to the broadcast packet using a self-contained recovery modulation function; And
And for transmitting the broadcast packet and the recovery packet to the user terminal in the sub-network by multicasting / broadcasting,
Based access point in a wireless LAN. 3. The method of claim 2,
Further comprising a packet combining unit for combining the broadcast packet and the recovery packet,
Wherein the packet transmission unit transmits the combined broadcast packet and the recovery packet to the user terminal. delete 3. The method of claim 2,
Wherein the recovery packet generating unit comprises:
And generates the recovery packet by using a forward error correction (FEC) method. A packet receiving step of receiving packets from a broadcast service apparatus by unicasting from a preset port for broadcasting;
A packet recognizing step of recognizing the packet as a broadcast packet;
A recovery packet generation step of generating a recovery packet corresponding to the broadcast packet using a self-contained recovery modulation function; And
A packet transmission step of multicasting / broadcasting the broadcast packet and the recovery packet to a user terminal in a subnetwork
And transmitting the error correction-based broadcast packet to the access point. The method according to claim 6,
Further comprising a packet combining step of combining the broadcast packet and the recovery packet,
And the packet transmission step transmits the combined broadcast packet and the recovery packet to the user terminal. delete The method according to claim 6,
Wherein the recovery packet generation step comprises:
And the recovery packet is generated using the forward error correction method. A computer-readable recording medium storing a program for executing the steps according to any one of claims 6, 7, and 9.

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