KR20120040642A - Method and apparatus of transmitting a packet in communication system - Google Patents

Abstract

PURPOSE: A packet transmission method in a communication system and apparatus thereof are provided to improve transmission efficiency in a communication system by reducing protocol overheads. CONSTITUTION: A first apparatus requests permission to use a compressed packet before a second apparatus transmits a message(S210). The second apparatus transmits a specific preamble with the message for approving the usage of the compressed packet(S220). When the detection preparation of the specific preamble is completed, the first apparatus requests the packet to the second apparatus(S230). The second apparatus transmits the compressed packet by using the specific preamble(S240).

Description

Method and apparatus for transmitting a packet in a communication system

The present invention relates to packet transmission in a communication system, and more particularly, to a packet transmission method using header compression and an apparatus supporting the same.

In order to improve the data transmission efficiency required by users in wired and wireless communication systems, it has been an important technology for a long time. In particular, with the rapid increase in wireless data demand, the use of efficient frequency resources is becoming more important.

The types of packets in a general communication system can be broadly divided into user data packets and control packets. The user data packet refers to a packet generated in a user application and intended for use by an actual communication system. The control packet refers to a packet that controls the operation of a communication device such as error correction or flow control so that a user data packet can be transmitted smoothly. How efficiently these packets are transmitted also affects communication user data transmission efficiency.

Among these control packets, the ARQ-related packet is a packet that is continuously transmitted when transmitting user data. The efficient transmission of this packet has a significant effect on user data transmission efficiency.

In the related art, Go-back-N ARQ, Selective-repeat ARQ, or Adaptive ARQ is widely used to reduce the number of control packet transmissions in order to reduce the overhead caused by such a packet.

An object of the present invention is to provide a packet transmission method and apparatus in a communication system. A method of mapping header information in header compression using a preamble is provided.

In one aspect, a packet transmission method in a communication system includes a request message receiving step of receiving a compressed packet use request message from a receiver, and a compressed packet transmission step of generating a specific preamble and transmitting a compressed packet to the receiver, The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header.

The receiving of the request message may further include transmitting a compressed packet use approval message to the receiver in response to the compressed packet use request message.

The transmission of the compressed packet may be made in response to the compressed packet request message of the receiver.

The specific preamble may be obtained based on the bit string of the preamble and the device ID of the sender.

The specific preamble may be obtained based on the bit string of the preamble and the connection ID of the sender.

The specific preamble may be obtained based on the bit string of the preamble and the compressed header information.

In another aspect, a packet transmission method in a communication system includes a request message transmission step of transmitting a specific preamble use request message to a receiver, and a compression packet transmission step of generating a specific preamble and transmitting a compressed packet to the receiver. The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header.

In another aspect, a packet transmission method in a communication system includes a request message transmission step of transmitting a specific preamble use request message to an administrator, and a specific preamble use approval message in response to the specific preamble use request message from the administrator. And a compressed packet transmission step of generating a specific preamble and transmitting a compressed packet to the receiver, wherein the compressed packet omits information of a duplicate frame header among frames to be transmitted, and information of the omitted frame header. It is created by pasting a specific preamble including.

The receiver may receive the specific preamble use approval message sent by the manager.

In another aspect, a packet transmitter in a communication system includes a transceiver configured to transmit and receive a compressed packet, and a processor operatively coupled to the transceiver, the processor receiving a compressed packet use request message from a receiver; And generating a specific preamble and transmitting a compressed packet to the receiver. The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header. do.

By reducing the size of the packet to be transmitted in the communication system, the user can transmit more user data packets by the reduced size, and reduce the probability of packet transmission error. In addition, by reducing the time required to process the control message, the inter-frame space can be reduced as a result. By reducing the protocol overhead due to packet loss, communication system transmission efficiency can be improved.

1 illustrates an example of a frame structure applicable to a communication system.
2 shows a packet transmission method according to an embodiment of the present invention.
3 shows a packet transmission method according to another embodiment of the present invention.
4 shows a packet transmission method according to another embodiment of the present invention.
5 is a block diagram illustrating an example of a compressed packet according to an embodiment of the present invention.
6 shows examples of a method of generating a specific preamble.
7 shows a specific example of generating a specific preamble by mapping information to a preamble.
8 is a block diagram showing an ACK packet of IEEE 802.11.
FIG. 9 illustrates a packet obtained by compressing the packet illustrated in FIG. 8 into a specific preamble according to an embodiment of the present invention.
10 is a block diagram illustrating a packet transmission apparatus in which an embodiment of the present invention is implemented.

In the packet transmission method proposed by the present invention, in order to transmit the control message, the preamble of each packet can be distinguished from the purpose of synchronization as well as the synchronization purpose as in the conventional method, so that the control message can be replaced by only preamble detection. do. At this time, each message or header information should be changed to a specific preamble and delivered. At this time, each message or header information must be mapped to a preamble.

Hereinafter, in describing the present invention, a preamble according to an embodiment of the present invention obtained by mapping each message or header information into a preamble is called a specific preamble. The specific preamble means a preamble that can be dynamically allocated. That is, the specific preamble means a preamble that can be allocated and retrieved as needed according to the type of device or stream. The specific preamble may be selected from two or more preamble sets or may be determined in a random manner.

Hereinafter, with reference to the drawings will be described in more detail.

1 illustrates an example of a frame structure applicable to a communication system.

In a typical frame-based network, a frame structure includes a preamble 110, a frame header 120, and a payload 130.

The preamble 110 refers to an area attached to the front of the header of each frame for frame synchronization in frame units. In the case of Ethernet, the preamble continues more than 56 bits, repeating 1s and 0s, like 101010, with the primary purpose of non-synchronizing to match speed between transmit and receive. In the case of wireless mobile communication, the preamble is used for timing estimation of an initial symbol using a continuously transmitted signal.

SFD (Start of Frame Delimiter, 111) is a 1-byte bit string consisting of 10101011 attached immediately after the preamble near the beginning of the Ethernet frame. From the SFD bit string, it is a bit string for frame synchronization indicating that it is configured in byte units.

The frame header 120 includes a destination address (DA) 121, a source address (SA) 122, and a len / type 123.

In Len / Type 123, Length refers to the maximum size that can be carried in one frame, and Type indicates which protocol the encapsulated data corresponds to.

In various wired / wireless communication systems, control data and user data are transmitted / received using a frame structure similar to the frame structure illustrated in FIG. 1. The present invention can be applied to a wired / wireless communication system that transmits / receives data using a frame structure. The frame shown in the following specific embodiments may be modified and used according to the communication system to be actually applied. That is, while being specifically applied to each communication system, a name, an order of each field constituting the frame, etc. may be adjusted according to an existing frame structure used in each communication system, and necessary control information may be further included.

Hereinafter, the compressed packet is a packet in which the preamble is replaced with a specific preamble according to an embodiment of the present invention in the conventional frame structure. When another specific preamble is applied to an embodiment of the present invention, the content of a repeated header may be omitted. For example, in the case of a video stream, the frame header may include a source address, a destination address, a header type, and the like. If all the information of the frame header is duplicated for a certain time, all of the frame header information can be omitted. However, when only part of the frame header information is overlapped, only the overlapped part may be omitted, thereby improving transmission efficiency in communication.

If there is no repeated content in the frame header information or if the repeated time is short, the general preamble may be allocated to perform communication as in a general frame-based communication method. The general preamble can be dynamically allocated in a similar manner to a specific preamble, and can be assigned to a fixed value.

When the redundant frame header information is omitted, the length of the frame data is relatively shorter than the length of the general frame data. When all the information in the frame header information is duplicated, all of the frame header information can be omitted.

The compressed packet transmission method using a specific preamble according to the present invention may be utilized as a method of allocating a specific preamble for each video stream in a data transmission in which header contents do not change for a predetermined time such as a video streaming service.

In one example of generating a specific preamble, the transmitter may extract a content of a repeated frame header and generate a specific preamble mapped to omitted frame header information. The transmitter transmits the frame header information and the preamble, which are omitted, to the receiver to share information on the specific preamble. A detailed procedure for notifying the generation and application of this specific preamble will be described in more detail below with reference to FIGS. 2 to 4.

2 shows a packet transmission method according to an embodiment of the present invention.

In the following example, the device 1 (10) and the device 2 (20) is a communication device for transmitting / receiving a packet may be called various names such as a terminal, subscriber equipment, station, mobile terminal, etc. according to the communication system. Device 2 (20) is a transmitter or source station that transmits a packet to device 1 (10), and device 1 (10) is a receiver or destination station that receives the packet. to be. The transmission / reception concepts of the device 1 10 and the device 2 20 are relative, and as the data flows, the roles of the transmitter and the receiver may be replaced with each other.

The device 1 (20), which is a message receiver, requests the use of a compressed packet before the device 2 (20) transmits the message (S210).

Receiving the compressed packet use request from the device 1 (10), the device 2 (20) in response to the request to use the compressed packet, when accepting the use of the device compression packet, the specific device to use for the compressed packet with a message for the approval of the compressed packet use The preamble is transmitted (S220). In this case, the usage approval and the specific preamble may be transmitted together in one packet as in the example of FIG. 2 or may be transmitted in separate packets according to the embodiment. When the device 1 (10) receiving the specific preamble is ready to detect the specific preamble, the device 2 20 is notified of this (packet request, S230), and the device 2 20 uses the specific preamble. The compressed packet can be transmitted (S240). In this case, the step S230 of requesting the packet to the device 2 20 by the device 1 10 may be omitted. According to an embodiment, when the device 1 (10) requesting the use of the compressed packet without the packet request step (S230) of the device 1 (10) is approved for use of the compressed packet and receives the specific preamble from the device 2 (20), the device 2 20 may transmit a compressed packet using a specific preamble without requesting packet transmission.

2 illustrates an example of a process in which a message receiver (device 1) requests the use of a compressed packet to map compressed information to a specific preamble, but the request for using the compressed packet may be performed by the message sender.

3 shows a packet transmission method according to another embodiment of the present invention.

Unlike the example of FIG. 2, the message sender requests the use of a compressed packet to map the compressed information to a specific preamble. The device 2 (20), which is a message sender, requests the use of a specific preamble to the device 1 (10), which is a message receiver, before transmitting the message (S310). The specific preamble usage request message informs the device 1 10 that the device 2 20 will transmit a compressed packet using the specific preamble later, or the device 1 10 may accept the compressed packet using the specific preamble. It can be used to verify that it has the capability.

According to an embodiment, when the device 2 (20) knows that the device 1 (10) is capable of accepting the compressed packet using the specific preamble, the compressed packet using the specific preamble is subsequently added to the specific preamble use request message. It is possible to transmit the compressed packet using the specific preamble without the procedure (S320) to inform that it will be transmitted and receive the specific preamble use approval message of the device 1 (10). In this case, steps S320 and S330 may be omitted in the example of FIG. 3.

In response to the specific preamble use request message, the device 1 10 approves this (S320) and prepares for detecting a specific preamble to be transmitted later. Thereafter, when the packet request is made (S330), the device 2 (20) transmits the compressed packet using the specific preamble to the device 1 (10) (S340). In this case, the step of requesting the packet to the device 2 (20) by the device 1 (10) can be omitted as described in the embodiment of FIG.

4 shows a packet transmission method according to another embodiment of the present invention.

The example of FIG. 4 is an example in which a third device, which is neither a sender nor a receiver of a message, maps compressed information and a specific preamble. That is, a method of mapping a specific preamble using a third apparatus that does not transmit or receive a compressed packet is shown. The third device may be an administrator who is not directly involved in the transmission or reception of the compressed packet between the sender and receiver of the compressed packet. For example, in an IEEE 802.11 system, when a sender and a receiver set up a direct link to transmit / receive data frames through a direct link, the third device is involved only in the direct link setup process and the direct link after the direct link setup. It may also be referred to as a device that performs a function such as an access point (AP) that is not involved in frame transmission / reception through the AP. When the example described below is applied in an IEEE 802.11 system, the following devices 1 and 2 are stations that perform a direct link setup (DLS) procedure, and the device 3 may be replaced by an AP, and a specific preamble The use request and use approval procedure can be done together in the DLS setup procedure.

Device 2 20 informs device 3 30 that it wants to send a compressed packet to device 1 10 using a particular preamble (S410). In this case, the device 3 30 notifies the device 1 10 and the device 2 20 that the device 2 20 intends to transmit data using a specific preamble (S420-1, S420-2). In this case, the device 1 10 prepares to detect a specific preamble. When the device 1 10 is ready to detect a specific preamble, the device 2 20 is notified of this (packet request, S430). In response, the device 2 20 transmits a compressed packet using a specific preamble (S440). At this time, the device 1 (10) does not send a packet request message to the device 2 (20), and the device 2 (20) is specified after a specific time (eg, interval between specific frames, expiration of the period specified in the timer) by using a timer or the like. The compressed packet using the preamble may be transmitted.

5 is a block diagram illustrating an example of a compressed packet according to an embodiment of the present invention.

Frame 510 in FIG. 5 is an example of a general transport packet. Frame 520, frame 530 and frame 540 are diagrams showing packets when a general transport packet 510 is compressed through a specific preamble.

Among the control messages, there may be a packet without payload in a general transmission packet 510. Frame 520, frame 530, and frame 540 compress these packets through a specific preamble. Indicates. The specific preamble may be generated randomly or may be generated with basic information about the device and the traffic.

6 shows examples of a method of generating a specific preamble.

The specific preamble may generate a specific preamble by combining the compressed header information, the device ID, and the connection ID. Each of the apparatuses 610, 620, and 630 generating a specific preamble of FIG. 5 shows an example of generating a specific preamble by combining the original preamble with the compressed header information, the device ID, or the connection ID.

7 shows a specific example of generating a specific preamble by mapping information to a preamble.

An example of generating a specific preamble by mapping the compressed header information, the device ID, or the connection ID illustrated in FIG. 6 to the preamble. In the example of FIG. 7, the mapping method illustrates a case of using an exclusive OR (XOR) operation.

8 is a block diagram showing an ACK packet of IEEE 802.11.

The ACK packet of FIG. 8 briefly illustrates a PPDU including an ACK frame transmitted by a station receiving a data frame in a WLAN system to a transmission acknowledgment.

FIG. 9 illustrates a packet obtained by compressing the packet illustrated in FIG. 8 into a specific preamble according to an embodiment of the present invention.

FIG. 9 shows an ACK message in which the packet shown in FIG. 8 is compressed using this invention. At this time, the effect of the compression depends on the length of the specific preamble. Similarly to the one used in FIG. 8, when the 96-bit preamble is used, the packet length can be reduced to about 2/5 of the original size.

10 is a block diagram illustrating a packet transmission apparatus in which an embodiment of the present invention is implemented. The device 1000 may function as a sender or a receiver in the above-described embodiment.

The packet transmitter 1000 includes a processor 1010, a memory 1020, and a transceiver 1030. The transceiver 1030 may have a plurality of network interface cards (NICs). The processor 1010 is functionally connected to the transceiver 1030 and configured to generate a specific preamble, generate a compressed packet, and process the received compressed packet according to the method proposed by the present invention. The processor 1010 and / or transceiver 1030 may include an application-specific integrated circuit (ASIC), other chipset, logic circuit, and / or data processing device. The memory 820 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage device. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The module may be stored in the memory 1020 and executed by the processor 1010. The memory 1020 may be inside or outside the processor 1010 and may be connected to the processor 1010 by various well-known means. The apparatus 1000 may operate as a terminal for wired / wireless communication according to a wireless communication protocol and a setting implemented in the processor 1010.

The above-described embodiments include examples of various aspects. While it is not possible to describe every possible combination for expressing various aspects, one of ordinary skill in the art will recognize that other combinations are possible. Accordingly, it is intended that the invention include all alternatives, modifications and variations that fall within the scope of the following claims.

Claims (15)

In the packet transmission method in a communication system,
A request message receiving step of receiving a compressed packet use request message from a receiver; And
And a compressed packet transmission step of generating a specific preamble and sending a compressed packet to the receiver.
The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header. The method according to claim 1,
The receiving of the request message may further include sending a compressed packet use approval message to the receiver in response to the compressed packet use request message. The method according to claim 1,
And the transmission of the compressed packet is in response to the compressed packet request message of the receiver. The method according to claim 1,
The specific preamble is obtained based on the bit string of the preamble and the device ID of the sender. The method according to claim 1,
The specific preamble is obtained based on the bit string of the preamble and the connection ID of the sender. The method according to claim 1,
The specific preamble is obtained based on the bit string of the preamble and the compressed header information. In the packet transmission method in a communication system,
Transmitting a request message for transmitting a specific preamble use request message to a receiver; And
And a compressed packet transmission step of generating a specific preamble and sending a compressed packet to the receiver.
The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header. The method of claim 7, wherein
The transmitting of the request message may further include receiving a specific preamble use approval message from the receiver in response to the specific preamble use request message. The method of claim 7, wherein
And the transmission of the compressed packet is in response to the compressed packet request message of the receiver. The method of claim 7, wherein
The specific preamble is obtained based on the bit string of the preamble and the device ID of the sender. The method of claim 7, wherein
The specific preamble is obtained based on the bit string of the preamble and the connection ID of the sender. The method of claim 7, wherein
The specific preamble is obtained based on the bit string of the preamble and the compressed header information. In the packet transmission method in a communication system,
Transmitting a request message for transmitting a specific preamble use request message to an administrator;
Receiving a specific preamble use approval message in response to the specific preamble use request message from the manager; And
And a compressed packet transmission step of generating a specific preamble and sending a compressed packet to the receiver.
The compressed packet is generated by omitting information of a duplicate frame header among frames to be transmitted and attaching a specific preamble including information of the omitted frame header. The method of claim 13,
And the receiver receives the specific preamble use approval message sent by the administrator. A transceiver configured to transmit and receive a compressed packet; And
Including a processor functionally connected with the transceiver,
The processor is
Receive a compressed packet usage request message from a receiver,
Generate a specific preamble and send a compressed packet to the receiver;
The compressed packet is generated by attaching a specific preamble including information of the omitted frame header and omitting overlapping frame header information among frames to be transmitted.

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