KR101080079B1 - Efficient video distribution method over wireless networks - Google Patents

Abstract

The present invention relates to an efficient video distribution method in a wireless network, comprising: a step 110 of a receiver requesting a sender to transmit a video; and a step 120 of sending a broadcaster to a broadcaster for a video transmission request received from the receiver. In step 130, the receiver calculates a loss rate every 100 ms for a frame received through a broadcast, and reports the loss rate to the sender. The sender compares the loss rate reported in step 130 to the target MAC address of the video frame. In operation 140, the receiver transmits the lost frame to the receiver having the highest loss rate, and the receiver receives the lost frame using the injecting method for the frame transmitted in the operation 140. Therefore, in the present invention, since a receiver receiving a video receives similarly to a broadcast by using a promiscuous mode, data generated by watching the same video by using retransmission of a unicast. The efficiency of frame transmission is increased by reducing redundant transmission.

Video Distribution, Rate, Wireless Networks, Unicast, IEEE 802.11

Description

Efficient video distribution method over wireless networks

The present invention relates to an efficient video distribution method on a wireless network, and more particularly, to an efficient video distribution method on a wireless network that improves the frame rate of video in a wireless network standard (IEEE 802.11 WLAN) environment.

With the development and popularization of wireless communication technologies such as IEEE 802.11a / b / g / WLANs, cdma2000, UMTS, and WiBro, home networks and wireless Internet are widely used, and video streaming is expected as a killer application of these services. In particular, as a broadcasting system such as DMB (Digital Multimedia Broadcasting) is being built, the importance of video transmission in wireless communication is emerging.

The promiscuous mode of the IEEE 802.11 standard receives a packet regardless of the destination of the frame, and thus, even if a single transmission is transmitted to one person, it is effective to send to a large number.

In IEEE 802.11, a beacon frame is one of the 802.11 management frames. It informs the existence of a wireless network and periodically transmits the mobile station to find the network (802.11 scanning) and join the network.

There are two methods of transmitting video in a wireless environment, a single transmission (unicast) to each requesting individual and a broadcast (broadcast).

However, in a wireless network standard (IEEE 802.11 WLANs) environment, since the packet loss rate is increased compared to the wired, the broadcast without retransmission cannot be used as it is. In addition, the packet loss rate decreases when unicast is used when multiple people watch the same video.However, as the receiver increases, transmission efficiency decreases, and when broadcasting, the frame loss is large due to the absence of retransmission. There is a problem.

In order to solve the above problems, in the present invention, in order to simultaneously increase the reliability and efficiency of video transmission in wireless network standard (IEEE 802.11 WLAN) environment, MAC (Medium Access) It is an object of the present invention to provide an efficient video distribution method in a wireless network which improves the efficiency of frame transmission by using a method of mixing a single transmission and a broadcast in a control step.

In order to achieve the object, in step 110, a receiver requests video transmission from a sender, and in step 120, the sender sends a broadcast to a video transmission request received from the receiver. In step 130, a loss rate is calculated every 100 ms for the frame received through a broadcast) and reported to the sender, and the sender compares the loss rate reported in step 130 to determine a target MAC address of the video frame having the highest loss rate. In step 140, the receiver transmits a single transmission, and the receiver receives a lost frame by using a method of listening to the frame transmitted in the step 140.

As described above, the present invention receives a video similarly to a broadcast by using a promiscuous mode, so that the same video can be viewed by using retransmission of a unicast. This reduces the redundant transmission of data and increases the efficiency of frame transmission.

1 is a reference diagram showing a frame transmission method between a sender and a receiver according to the present invention, FIG. 2 is a flowchart illustrating an efficient video distribution method in a wireless network according to the present invention, and FIG. FIG. 4 is a structural diagram of a beacon frame for transmitting a loss rate according to the present invention, and FIG. 5 is a diagram for describing a process of a sender processing a job according to the present invention. 6 is a flowchart illustrating a process of processing a job by a receiver according to the present invention.

Hereinafter, the components will be described with reference to the drawings.

1 is a reference diagram illustrating a frame transmission method between a sender and a receiver according to the present invention, in which a receiver requests transmission to a sender when video transmission is required, and the sender calls its number if the video is existing and a new video. Establishes a connection by sending a new number to the receiver. The sender then sends a video frame and the receiver reports the loss rate to the sender every 100 ms.

FIG. 2 is a flowchart illustrating an efficient video distribution method in a wireless network according to the present invention. In step 110, a receiver requests a sender to transmit a video, and the sender receives a video transmission request from the receiver. Step 120 of transmitting to a broadcast (S120), the receiver calculates a loss rate every 100 ms for the frame received through the broadcast to the sender (130) (S130), and the sender (130) (S130) In step 140, the receiver transmits the target MAC address of the video frame to the receiver having the highest loss rate by comparing the loss rate reported in the step S140, and the receiver listens to the frame transmitted in the step S140. A 150th step S150 of receiving a lost frame using the technique is included.

In step 120 (S120), the sender broadcasts a corresponding video frame of the existing table when the video is being transmitted to the receiver's transmission request, and registers a new video frame in the existing table when the video is not being transmitted. It includes broadcasting.

In addition, in step 120 (S120), a serial number is assigned to each requested video so that each group can identify whether the video is requested by the group, and in the Type and Subtype areas of the Frame control area in the existing MAC header. A maximum of 16 videos are classified using 11, a subtype of 0000-1111, which is not currently used, and when a receiver requests video transmission, the sender receives a type value of 11 and a subtype value in the frame control area. The video number is transmitted, and the receiver includes receiving a frame corresponding to the video number requested by the receiver while receiving the frame through a promiscuous mode.

Step 130 (S130) obtains the entire frame number through the serial number of the beginning and end of the transmission, calculates the loss rate by obtaining the received frame number by storing the serial number of the received frame in an array, and in accordance with the IEEE 802.11 WLANs standard The loss rate is included in the existing beacon frame, and the receiver includes managing the loss rate and the MAC address pair in the beacon frame.

In the 150th step S150, when a transmitter receives a frame transmitted by a single transmission, if a frame having the same video number as the video number lost in the 130th step S130 is received, the frame is transmitted to a higher layer. It includes.

3 is a structural diagram of a MAC header for identifying a group of viewing the same video according to the present invention, and includes a Type and Subtype field in a frame control area in order to confirm whether a video frame requested by a receiver is included.

4 is a structural diagram of a beacon frame for transmitting a loss rate according to the present invention, and includes a type1, length1, value1 (Loss Ratio) field in a frame body region to include loss rate information.

5 is a flowchart illustrating a process in which a sender processes a job according to an embodiment of the present invention, in which a frame loss of step 141 (S141) and step 141 (S141) determines whether a frame is received from a receiver. If it is a report frame, the loss rate of the corresponding MAC address is updated in the loss rate table, and if the frames of step 142 (S142) and step 141 (S141) returning to step 141 (S141) are a transmission request frame of the receiver, it is previously Step 143 (S143) of checking whether the frame is being transmitted or not (144) (S144) and (143) of transmitting the video number found in the table to the receiver if the frame is currently being transmitted as a result of the check of step 143 (S143). If it is determined that the frame is not being transmitted, the new number is registered in the table and the video number is transmitted to the receiver (S145). 44) or step 146 (S146) after transmitting the video number in step 145 and receiving the number confirmation complete frame of the receiver, changing the target MAC address of the video frame to the receiver having the highest loss rate (S146). If there is no frame to be transmitted after the transmission in step 146 (S146), the method returns to step 141 (S147).

FIG. 6 is a flowchart illustrating a process of processing a job by a receiver according to the present invention. In step 151 (S151) of listening to a frame transmitted from a sender using a listening method, there is a video transmission request from an upper application. Step 152 (S153) of transmitting a video transmission request frame to the sender; receiving a video numbering frame from the sender, transmitting a number confirmation completed frame to the sender, and returning to step 151 (S151) (S153). It includes.

The step 151 (S151) includes receiving a video frame and delivering the frame to the upper layer if the video number of the frame is the same (S154) (S155), and returning to the step 151 (S151) if different.

In addition, step S151 may include receiving a video frame and transmitting a loss rate report frame to a sender every 100 ms (S156).

Therefore, in the present invention, since a receiver receiving a video receives similarly to a broadcast by using a promiscuous mode, data generated by watching the same video by using a retransmission of a unicast. The efficiency of frame transmission can be improved by reducing redundant transmission of.

Although the present invention has been shown and described with respect to specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Anyone who can afford it will know.

1 is a reference diagram showing a frame transmission method between a sender and a receiver according to the present invention.

2 is a flowchart illustrating an efficient video distribution method in a wireless network according to the present invention.

3 is a structural diagram of a MAC header for identifying a group of viewing the same video according to the present invention.

4 is a structural diagram of a beacon frame for transmitting a loss rate according to the present invention.

5 is a flowchart illustrating a process of a sender processing a job according to the present invention.

6 is a flowchart illustrating a process of processing a job by a receiver according to the present invention.

Claims (9)

In the efficient video distribution method on a wireless network, A step S110 in which the receiver requests video transmission from the sender; Step 120 (S120), wherein the sender transmits a video frame through a broadcast in response to a video transmission request received from the receiver; Step 130, in which the receiver calculates a loss rate every 100 ms for the video frame received through broadcast and reports it to the sender (S130); The sender comparing the loss rate reported in step 130 (S130) to change the target MAC address of the video frame to a receiver having the highest loss rate (S140); The receiver includes a 150th step (S150) of receiving a lost video frame by using a method of listening to a single transmitted video frame in the 140th step (S140), The 150th step S150 is performed when the sender receives a video frame transmitted by a single transmission, and receives a video frame having the same video number as the video number lost in the 130th step S130. Efficient video distribution method in a wireless network, characterized in that for transmitting. The method of claim 1, In step 120 (S120), the sender broadcasts a corresponding video frame of the existing table when the video is being transmitted to the receiver's transmission request, and registers a new video frame in the existing table when the video is not being transmitted. Efficient video distribution method over a wireless network, characterized in that for broadcasting. The method of claim 1, In step 120 (S120), a maximum of 16 videos are classified by using 11 of a type that is not currently used in a type and a subtype area of a frame control area in a conventional MAC header, and 0000 to 1111 of a subtype. Efficient video distribution method in a wireless network, characterized in that the frame is transmitted only once to the requesting recipients. The method of claim 1, In step 130 (S130), the entire video frame number is obtained by using the serial number of the beginning and the end of the transmission, the serial number of the received video frame is stored in an array, and the received video frame number is calculated to calculate a loss rate. Efficient video distribution method in a wireless network, characterized in that the area to put the loss rate in the beacon frame existing in the WLANs standard, and the receiver manages the loss rate and MAC address pairs. delete The method of claim 1, The step 140 (S140) comprises receiving a frame from the receiver and determining what kind of frame (S141); Step 142 (S142) of updating the loss rate of the corresponding MAC address in the loss rate table if the frame of the step S141 is a loss rate report frame, and returning to the step 141 (S141); Step 143 (S143) checking whether the frame of the step 141 (S141) is a frame currently being transmitted if the transmission request frame of the receiver; A step 144 of transmitting the video number found in the table to the receiver if the frame is being transmitted in the previous step as a result of checking in the step 143 (S143); If it is determined that the frame is not being transmitted, the new number is registered in the table and the video number is transmitted to the receiver (S145); In step 144 (S144) or 145 (S145), after transmitting the video number and receiving the number confirmation complete frame of the receiver, the target MAC address of the video frame is changed to the receiver having the highest loss rate (146). S146); If there is no frame to be transmitted after the transmission of the step 146 (S146), the method returns to the step 141 (S141) of the efficient video distribution method on a wireless network, characterized in that it comprises. The method of claim 1, The 150th step (S150) may include a 151st step (S151) of listening to a video frame transmitted from a sender using a listening method; A step 152 in which there is a video transmission request from a higher application and a video transmission request frame is transmitted to the sender; And step 153 (S153) of receiving a video numbering frame from the sender, transmitting a number confirmation complete frame to the sender, and returning to step 151 (S151). The method of claim 7, wherein The step 151 may include receiving a video frame and transferring the video frame to a higher layer if the video number of the video frame is the same (S154) (S155), and returning to the step 151 (S151) if different. An efficient video distribution method on a wireless network. The method of claim 7, wherein The step 151 (S151) includes receiving a video frame and transmitting a loss rate report frame to a sender every 100 ms (S156).

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