KR101238325B1 - A throughput enhancement method in multiple infrastructure-based wireless networks using directional antenna - Google Patents

Abstract

PURPOSE: A throughput improving method using a directional antenna in a wireless network environment based on a plurality of infrastructures is provided to enable each AP(Access Point) and each node to include a sector with four directions for transmission based on OFDM(Orthogonal Frequency Division Multiplexing). CONSTITUTION: Transmission sequence information for data of nodes is generated. AP-1 transmits the generated transmission sequence information with a notification frame(S3). Each node gradually transmits data for the transmission sequence information to AP-1(S4). A reception process for sequential data is completed by AP-1. AP-1 changes a sector direction by executing a sector switching process(S5). [Reference numerals] (AA) Start; (BB) End; (S1) AP-1 transmits a beacon frame unless detecting a signal during MTT and SIFS; (S2) Connection requiring node of beacon frame received nodes transmits an association request frame to the AP-1 and allocates a transmission alarm channel in case of the conclusion of the association; (S3) Data transmission requiring node transmits a have frame through the transmission alarm channel; (S4) Node successively transmits data including the association success information of the AP-1, the allocated transmission notification information, and transmission sequence information according to notification frame transmission; (S5) AP-1 notifies the change of a section in a different direction to an AP-2 by switch frame transmission

Description

Throughput enhancement method in multiple infrastructure-based wireless networks using directional antenna

The present invention relates to a method for improving throughput using a directional antenna in a plurality of infrastructure based wireless network environments. More specifically, in Orthogonal Frequency Division Multiplexing (OFDM) based transmission, the configuration of wireless networks The present invention relates to a throughput improvement method using a directional antenna in a wireless infrastructure environment based on a plurality of infrastructures for improving overall network throughput by reducing interference and increasing frequency spatial reuse between data transmission and reception between units.

Infrastructure-based wireless networks have brought many benefits to real life.

As the use of smartphones increased, the number of access points increased exponentially. However, as the number of APs using the same frequency increases, wireless networks suffer from performance degradation due to interference.

Directional antennas have been developed as innovative devices to increase frequency spatial reuse. However, directional antennas suffer from the chronic problem of deflection problem because they have directional limitations in detecting other signals.

Therefore, if used in infrastructure-based wireless network without solving this problem, it may cause serious interference problem.

Accordingly, in the technical field, there is a demand for technology development to solve not only a performance degradation problem caused by interference between a plurality of APs, but also a problem of deflection of a directional antenna.

[Related Technical Literature]

1. Directional Antenna
Orthogonal Frequency Division Multiplexing Based Spread Spectrum Multiple Access System (Patent Application No. 10-2000-0012078)

2. Smart antenna system for signal processing in frequency domain and transmitting and receiving device and method of mobile terminal and base station therefor (Patent Application No. 10-2006-0023742)

The present invention has been made to solve the above problems, while using the directional antenna in a plurality of infrastructure-based wireless network environment to address the deficiency problem and to present a directional media approach applicable to a plurality of infrastructure-based wireless network at the same time It is to provide a method for improving throughput.

In addition, the present invention in Orthogonal Frequency Division Multiplexing (OFDM) -based transmission, each AP and the node has a four-way sector, reducing the interference between each other when transmitting and receiving data between the configuration unit of the wireless network It is to provide a throughput improvement method using a directional antenna in a plurality of infrastructure-based wireless network environments to improve overall network throughput by increasing frequency spatial reuse.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environments according to an embodiment of the present invention includes a maximum transmission time after AP-1 is switched to a predetermined sector. transmitting a beacon frame when no signal is detected during a transmission time (MTT) and a short interframe space (SIFS); Each of the nodes receiving the beacon frame among at least one node randomly selects a contention channel provided by the AP-1, and selects an association request frame through the selected contention channel. The second step of returning to 1; The AP-1 completes the assignment of a transmission alarm channel to a node with which an agreement is concluded according to the analysis of the agreement request frame, and the data of data for a node with data to be transmitted among nodes with which the agreement is concluded. Generating a transmission order information and including the same in a notification frame for transmission; A fourth step in which each node having the data to be transmitted sequentially transmits data to the AP-1 based on the transmission order information; And a fifth step of the AP-1, after the AP-1 completes reception of the sequential data, performs a sector switching process from the preset sector to another sector to switch the sector direction; It includes.

According to another embodiment of the present invention, a throughput improving method using a directional antenna in a plurality of infrastructure-based wireless network environments, in the first step, the beacon frame is a contention channel for concluding agreement according to the contention channel selection (contention channel) candidates information and network ID information of the AP-1 is preferably included to enable transmission and reception between the at least one node and the AP-1.

According to another aspect of the present invention, a method for improving throughput using a directional antenna in a plurality of infrastructure-based wireless network environments includes, in the second step, when the AP-1 receives and analyzes the agreement request frame. It is preferable not to enter into an agreement when there is a node selected to overlap the contention channel among nodes that transmit the agreement request frame.

According to another aspect of the present invention, in a method for improving throughput using a directional antenna in a plurality of infrastructure-based wireless network environments, in the third step, each node having the data to be transmitted may be configured through the allocated transmission notification channel. It is preferable to transmit a have frame so that the transmission order information is generated by the AP-1.

In a method for improving throughput using a directional antenna in a plurality of infrastructure-based wireless network environments according to another embodiment of the present invention, in the third step, when the AP-1 generates the notification frame, the transmission order In addition to the information, it is preferable to form by including the agreement success information and the transmission notification channel assignment information.

In a method for improving throughput using a directional antenna in a plurality of infrastructure-based wireless network environments according to another embodiment of the present invention, in the fifth step, the AP-1 may be configured in a specified order of each node having the data to be transmitted. When the data transmission is completed, it is preferable to transmit a switch frame for the last transmitted data to notify that the sector in the other direction has been switched.

In a method for improving throughput using a directional antenna in a plurality of infrastructure based wireless network environments according to another embodiment of the present invention, the AP-2 performed between the first to fifth steps may change direction of a sector. Switching to another sector if network usage of the AP-1 is detected during a later maximum transmission time and a short frame interval; It is preferable to further include.

The throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environments according to an embodiment of the present invention is different through an agreement between the directional antenna-based AP and nodes in an infrastructure-based wireless network using the same frequency. Provides the effect of reducing interference with the AP.

In addition, the throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environment according to another embodiment of the present invention, in Orthogonal Frequency Division Multiplexing (OFDM) based transmission, When transmitting and receiving data between components, it is possible to reduce interference with each other and increase frequency-space reuse to improve network throughput.

1 is a diagram illustrating a system in which a throughput enhancement method using a directional antenna is implemented in a plurality of infrastructure based wireless network environments according to an embodiment of the present invention.
2 is a flowchart illustrating a method for improving throughput using a directional antenna in a plurality of infrastructure based wireless network environments according to an embodiment of the present invention.
3 is a diagram illustrating a channel structure allocated by AP-1 10 of FIG.
4 is a view for explaining a specific example of the throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environment according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the present specification, when any one element 'transmits' data or signals to another element, the element can transmit the data or signal directly to the other element, and through at least one other element Data or signal can be transmitted to another component.

1 is a diagram illustrating a system 1 in which a throughput enhancement method using a directional antenna is implemented in a plurality of infrastructure based wireless network environments according to an embodiment of the present invention. Referring to FIG. 1, a system 1 in which a throughput enhancement method is implemented includes an AP-1 10, node-1 to node-m (N-1 to Nm: 20-1 to 20-m, and m is 7 or more). Natural numbers), and AP-2 (30).

In this case, the AP-1 10 includes a directional antenna, has four sectors based on Orthogonal Frequency Division Multiplexing (OFDM), and sector switching between sectors can be performed.

More specifically, AP-1 (10) is a node connected to itself without being interfered by AP-2 (30), which is another AP for OFDM-based Node-1 to Node-m (N-1 to Nm) This is a system configuration unit that is set up to transmit data first. It is named "AP-1" for convenience of description, but it is not limited to a name. Hereinafter, a method of improving throughput using a directional antenna in a wireless network environment formed by such a system configuration unit will be described in detail.

2 is a flowchart illustrating a method for improving throughput using a directional antenna in a plurality of infrastructure based wireless network environments according to an embodiment of the present invention. 1 and 2, the interference avoidance process of step S1 is largely performed to improve the throughput, and the agreement process for connection between the AP-1 10 and the nodes, which is step S2, is step S3. A data notification process, a data transmission / reception process in step S4, and a sector switching process in step S5 are performed. Hereinafter, each process will be described in detail.

The AP-1 10 transmits a beacon frame when no signal is detected after detecting the signal of another AP during the maximum transmission time (MTT) and short interframe space (SIFS). By doing so (S1), interference with the AP-2 30 which is another AP can be avoided.

In this case, the AP-1 10 may beacon a frame to configure a channel (see FIG. 3) for connection with specific nodes among the Node-1 through Node-m (20-1 through 20-m). Contention channel candidate information for the agreement and the network ID information of the AP-1 10 are transmitted. Here, the network ID information is an identifier for enabling transmission and reception of signals and data between the Node-1 through Node-m (20-1 through 20-m) and the AP-1 (10).

After the step S1, each node that receives the beacon frame among the node-1 to node-m 20-1 to 20-m randomly selects contention channel candidate information from among the contention channel candidates. When the association request frame is returned to the AP-1 10 through the channel, the AP-1 10 transmits a separate transmission notification channel to the node to which the agreement is concluded or the node to which the agreement is previously concluded. alarm channel) (S2).

After step S2, if there is data to be transmitted among the nodes that have completed agreement with the AP-1 10 through the transmission alarm channel assignment, the corresponding node is assigned a transmission alarm channel (transmission alarm channel). A have frame is transmitted through a channel (S3).

On the other hand, since the AP-1 10 receives each half frame on an OFDM basis, the AP-1 10 can simultaneously receive the association request frame and transmit the transmission alarm frame in step S2. .

After step S3, the AP-1 10 transmits a notification frame so that data is sequentially transmitted by a node having data to be transmitted (S4).

Here, the notification frame includes "contract success information" that is information allowing connection, "transmission alarm channel information" assigned to each node, and "transmission order information" of a node having data to be transmitted. Include.

After the step S4, the AP-1 10 performs a sector switching process in the other direction, thereby completing the process of the AP 10 switching to another direction sector (S5). At this time, the AP-1 10 transmits the switch frame when the reception of the last transmitted data is completed according to the transmission order information. Notify that the switch has been made.

3 is a diagram illustrating a channel structure allocated by AP-1 10 of FIG. 1. 4 is a diagram illustrating a specific example of a throughput enhancement method using a directional antenna in a plurality of infrastructure based wireless network environments according to the present invention.

1, 3, and 4, the direction is set to the 3 o'clock sector of the AP-1 10 and the 9 o'clock sector of the AP2 30, and the AP-1 10 is a node-1. 20-1 and Node-2 20-2 are already connected. Meanwhile, node-1 20-1 and node-2 20-2 have a transmission alarm channel assigned to them, and node-3 20-3 and node-4 20 -4), Node-5 (20-5) is in a state that wants to connect with the AP-1 (10). It is also assumed that node-6 20-6 is already connected to AP-2 30.

Hereinafter, a practical example of a throughput enhancement method using a directional antenna in a plurality of infrastructure based wireless network environments under these conditions will be described.

The AP-1 10 switches to the 3 o'clock sector, detects a signal between a predefined maximum transmission time (MTT) and a short interframe space (SIFS), and then detects any signal. If not, send a beacon frame.

Here, the beacon frame transmitted by the AP-1 10 includes contention channel candidate information and network ID information of the AP-1 10.

Accordingly, as shown in FIG. 1, node-1 20-1, node-2 20-2, node-3 20-3, and node-4 that have received a beacon frame. (20-4), and Node-5 (20-5) each initiates action.

As shown in FIG. 4, since the node-1 20-1 and the node-2 20-2 have data to be transmitted (Data1 and Data2), the node-1 20-1 and the node-2 20-2 transmit data presence or absence through the transmission alarm channel assigned thereto. do.

And Node-3 20-3, Node-4 20-4, and Node-5 20-5 randomly select one of the contention channel candidates to negotiate with AP-1 10. Select to transmit an association request frame through the selected contention channel.

The AP-1 10 receives an association request frame at the same time as the Node-3 20-3, the Node-4 20-4, and the Node-5 20-5. Since -4 (20-4) and node-5 (20-5) cannot be interpreted as a duplicate channel selection problem, they are ignored and only connections to node-3 (20-3) are allowed.

The AP-1 10 transmits the agreement success information according to the permission of the connection, the transmission order information determined to be transmitted by the node-2 20-2 after the node-1 20-1, and the node-1 20-. 1) and transmission alarm channel information allocated to the node 20-1 are included in the notification frame and transmitted.

When each node 20-1 to 20-5 receives a notification frame, the nodes 20-1 to 20-5 may recognize whether the agreement is made using the agreement success information and recognize the order of transmission using the transmission order information. Done.

After the transmission of the data Data1 of the node-1 20-1 and the transmission of the data Data2 of the node-2 20-2 are completed in the specified order, the AP-1 10 finally ends. By transmitting a switch frame instead of an ack frame for the transmitted data Data2, a notification is made that sectors in the other direction are switched.

Accordingly, the AP-2 30 detects the network usage of the AP-1 10 between the maximum transmission time (MTT) and the short frame interval (SIFS) at any time and switches to the next sector. Potential interference with (10) can be avoided.

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored.

Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device and the like, and also implemented in the form of a carrier wave (for example, transmission over the Internet) .

The computer readable recording medium may also be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers skilled in the art to which the present invention pertains.

As described above, preferred embodiments of the present invention have been disclosed in the present specification and drawings, and although specific terms have been used, they have been used only in a general sense to easily describe the technical contents of the present invention and to facilitate understanding of the invention , And are not intended to limit the scope of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: AP-1
20-1 to 20-m: node-1 to node-m
30: AP-2

Claims (7)

A beacon frame when no signal from another AP is detected during the maximum transmission time (MTT) and short interframe space (SIFS) after the AP-1 switches to a preset sector. A first step of transmitting;
Each node that receives the beacon frame among at least one node randomly selects a contention channel provided by the AP-1, and selects an association request frame through the selected contention channel. The second step of returning to 1;
The AP-1 completes the assignment of a transmission alarm channel to a node with which an agreement is concluded according to the analysis of the agreement request frame, and the data of data for a node with data to be transmitted among nodes with which the agreement is concluded. Generating a transmission order information and including the same in a notification frame for transmission;
A fourth step in which each node having the data to be transmitted sequentially transmits data to the AP-1 based on the transmission order information; And
A fifth step of the AP-1, after the AP-1 completes reception of the sequential data, performing a sector switching process from the preset sector to another sector to switch the sector direction; Throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environment comprising a.
The method according to claim 1, wherein in the first step,
The beacon frame includes contention information about contention channel candidates for entering into an agreement according to contention channel selection, and network ID information of the AP-1 to enable transmission and reception between the at least one node and the AP-1. Throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environment comprising a.
The method according to claim 1, wherein in the second step,
When the AP-1 receives and analyzes the agreement request frame, if there is a node selected to overlap the contention channel among nodes that transmit the agreement request frame, a plurality of infrastructures are not concluded. Throughput Enhancement Method Using Directional Antenna in Wireless Network Environment.
The method according to claim 1, wherein in the third step,
Each node having the data to be transmitted transmits a have frame through the allocated transmission notification channel so that the transmission order information is generated by the AP-1. Throughput Enhancement Method Using Directional Antenna in Network Environment.
2. The method of claim 1,
When generating the notification frame, the AP-1 further includes not only the transmission order information but also agreement success information and transmission notification channel allocation information. Throughput Enhancement Method Using Directional Antenna.
The method according to claim 1, wherein the fifth step,
When the AP-1 completes data transmission in the designated order of each node having the data to be transmitted, the AP-1 transmits a switch frame for the last transmitted data to notify that the sector in the other direction is switched. Throughput enhancement method using a directional antenna in a plurality of infrastructure-based wireless network environment, characterized in that the.
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