KR100703747B1 - Apparatus and method for relaying data using plural channels - Google Patents

Abstract

The present invention relates to an apparatus and a method for relaying data using a plurality of channels, wherein the bandwidth of a selected channel among a plurality of channels provided is changed according to a bandwidth of a station transmitting or receiving data on a wireless network. An apparatus and method for relaying data using a plurality of channels for transmitting and receiving.

An apparatus for relaying data using a plurality of channels according to an embodiment of the present invention includes a receiver for receiving data through one channel among a plurality of channels, and a channel including a receiving station with reference to information of stations stored for each channel. And a control unit for transmitting the data to the receiving station through the identified channel.

Wireless network, channel, bandwidth, multiple antenna

Description

Apparatus and method for relaying data using plural channels}

1 is a diagram illustrating a semi-duplex wireless network using a transmission request and a transmission clear.

2 is an exemplary diagram illustrating a system for relaying data using a plurality of channels according to an embodiment of the present invention.

3 is a block diagram illustrating an apparatus for relaying data using a plurality of channels according to an embodiment of the present invention.

4 is a table showing information of a station according to an embodiment of the present invention.

5 is an exemplary diagram illustrating relaying data using a plurality of channels according to an embodiment of the present invention.

6 is an exemplary diagram illustrating relaying data according to bandwidth using a plurality of channels according to an embodiment of the present invention.

7 is an exemplary diagram illustrating load management between channels using channel switching according to an exemplary embodiment of the present invention.

8 is a flowchart illustrating a process of relaying data using a plurality of channels according to an embodiment of the present invention.

9 is an example of the data transmission and reception performance according to an embodiment of the present invention and the data transmission and reception performance results according to 802.11n.

10 is an experimental example showing the results of data transmission / reception performance and 802.11n data transmission / reception performance of the relay apparatus of the present invention according to the mixing ratio of bandwidths.

<Explanation of symbols on main parts of the drawings>

410: receiver 420: transmitter

430: storage unit 440: channel management unit

450: controller 460: buffer

The present invention relates to an apparatus and method for relaying data using a plurality of channels, and more particularly, to a bandwidth of a selected channel among a plurality of channels provided according to a bandwidth of a station transmitting or receiving data on a wireless network. The present invention relates to an apparatus and method for relaying data by using a plurality of channels for transmitting and receiving data by changing.

1 is a diagram illustrating a semi-duplex wireless network using a transmission request and a transmission clear.

In general, a wireless network uses a half-duplex method that cannot transmit and receive at the same time. A half-duplex method uses a request to prevent collisions with media occupancy when accessing a wireless medium. The Send signal and the Clear To Send signal are used.

The transmitting station having the frame to be transmitted starts the transmission procedure by first transmitting a transmission request signal, and all the stations in the vicinity of receiving it stop generating radio waves. When the receiving station receives the transmission request signal, the receiving station responds with a transmission clear signal. The transmission clear signal also stops generation of radio waves of all the stations in the vicinity. The transmitting station receiving the transmission clear signal transmits a frame and receives an acknowledgment signal from the receiving station receiving the transmission clear signal.

Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA), a Media Access Control (MAC) algorithm commonly used in wireless networks, is provided by the Distributed Coordination Function (DCF). As with Ethernet, the distributed coordination function checks that the radio link is clean before the station transmits a frame, and uses a random back-off at the end of each frame to avoid collisions with other stations.

Carrier sensing is used to determine if a medium is available and is classified into physical carrier sensing and virtual carrier sensing. Physical carrier detection is provided by the physical layer and depends on the medium and modulation scheme used. The virtual carrier detection is provided by a network allocation vector (NAV), which is a timer indicating time information when a medium is reserved. Here, the network allocation vector is included in the frame header of the transmission request signal and the transmission clear signal and transmitted, and the transmitting station and the receiving station set a time required to complete the operation in the network allocation vector to prevent the use of the medium by another station.

The basic building block of the network for data communication between stations is called a basic service set, which is an independent basic service set (Independent BSS) and an infrastructure basic service set (Infrastructure BSS) according to its characteristics. Are classified as).

In an independent basic service set, a station in a communication area is characterized by direct communication with another station, which is used for short service life and small network configuration. Meanwhile, the infrastructure basic service set is distinguished from the independent basic service set by using an access point. The access point is used in all communication processes including communication of the mobile station in the same service area. Therefore, since all communication is transmitted by the access point, the corresponding basic service area in the infrastructure basic service set is defined as an area capable of receiving a signal from the access point.

In order to replace the existing wireless mobile communication system, which mainly focuses on voice service and mainly relies on channel coding to overcome channel deterioration, the demand for high-quality multimedia service that can always talk with anyone, anywhere, anytime Next-generation wireless transmission technology is required to move the central axis around the service and to transmit more data with lower error probability. As a result, 802.11a, 802.11b, and 802.11g have been developed, including the initial 802.11 standards, and 802.11n, which supports data rates above 100 Mbps, is being standardized.

802.11n improves transmission speed and transmission quality by using multiple input multiple output antenna technology and orthogonal frequency division multiplexing.

Here, the multiple transmit / receive antenna technology transmits different data simultaneously using multiple antennas to a transmitter and a receiver, thereby transmitting data at higher speed or transmitting the same data from multiple transmit antennas without increasing the bandwidth of the system. Increase In addition, the orthogonal frequency division multiplexing method divides one wide frequency band channel into several sub-channels, transmits data through each sub-channel, and multiplexes all low-speed sub-channels into one fast synthesis channel. That's the way.

Under this background, U.S. Patent Application Publication No. 2003-171116 discloses a method for fast channel conversion for one or more stations in the area of a basic service set or infrastructure basic service set of a wireless network, but this only covers most of the band. As a method of reducing or eliminating occupying the occupied station, it cannot be a fundamental method of improving transmission speed, and a technique for more effective use of bands and channels is required.

An object of the present invention is to relay data between stations in regions of different channels using a plurality of channels.

In addition, an object of the present invention is to relay data by changing the bandwidth of a selected channel among a plurality of channels provided according to the bandwidth of a station transmitting or receiving data.

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

In order to achieve the above object, an apparatus for relaying data using a plurality of channels according to an embodiment of the present invention refers to a receiver for receiving data through one of a plurality of channels, and information of stored stations for each channel. And a control unit for identifying a channel including a receiving station and a transmitting unit for transmitting the data to the receiving station through the identified channel.

The method for relaying data using a plurality of channels includes receiving data through one of a plurality of channels, checking a channel including a receiving station by referring to information of a station for each channel, and checking the data. Transmitting the data to the receiving station over a established channel.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

2 is an exemplary diagram illustrating a system for relaying data using a plurality of channels according to an embodiment of the present invention, in which the system relays each channel using a plurality of antennas (hereinafter relaying). Device) and stations in the area of each channel.

802.11n proposes a 40/20 MHz channel, which supports channel widths of 20 MHz and 40 MHz. The 40 MHz channel consists of two 20 MHz channels in close proximity, providing more than twice the current data rate of 54 Mbps and enabling up to 125 Mbps.

The relay device 200 of the present invention also provides a 40/20 MHz channel where each channel can relay data between stations using a channel bandwidth of 20 or 40 MHz. Stations exist in the region of each channel formed by the physical antenna, and each station may transmit or receive data to another station through a channel bandwidth suitable for its bandwidth. At this time, the relay device 200 serves to relay data through a channel bandwidth suitable for the bandwidth of the transmitting station and the receiving station.

Therefore, a plurality of channel networks are formed according to the number of antennas provided in the relay device 200, and stations included in each channel network can transmit data to stations existing in the same channel network or different channel networks.

For this purpose, the relay device 200 is preferably provided with a predetermined buffer, the buffer serves to temporarily store data received from one station. The temporarily stored data is managed by a separate memory allocation algorithm and transmitted to the receiving station according to the network usage algorithm.

In order to relay data between channels, it is preferable that information of a station is stored in a storage of the relay device. When an external station joins one channel network among a plurality of channel networks, information on the station is created and stored in the storage unit. Preferably, the station information includes a channel including the station, an address, and a bandwidth that can be supported. The relay device 200 checks a receiving station by referring to data stored in a buffer and refers to station information of the confirmed receiving station. Relays the data through the corresponding channel according to the bandwidth. Here, the channel including the station means a channel included in the region among the plurality of channels, and corresponds to one or a plurality of channels. For example, in the relay device configuring the first channel network and the second channel network, if the station participates to be included only in the region of the first channel network, the channel of the participating station becomes the first channel, and the first channel network. If a station participates to be included in both the region of the network and the second channel, the channel of the participating station becomes the first and second channels.

In addition, the bandwidth of the station may be 20 or 40 MHz, and a variable bandwidth of 20 and 40 MHz may be set depending on whether the station is implemented.

For reference, a semi-duplex wireless network using a transmission request and a transmission clear is implemented in each channel, and the operation of one channel does not affect the operation of other channels. In other words, data transmission and reception in each channel is performed independently, and data transmission and reception may be simultaneously performed in each channel.

If data transmission and reception through a specific channel network among a plurality of channel networks is concentrated, network resources may be wasted. Accordingly, in this case, the relay apparatus 200 may change the channel of the station included in the common channel network with reference to the information of the station stored in the storage unit, and relay the data through the changed channel.

3 is a block diagram illustrating an apparatus for relaying data using a plurality of channels according to an embodiment of the present invention. The relay device 200 includes a receiver 410, a transmitter 420, a channel manager 440, a storage 430, a controller 450, and a buffer 460.

The receiving unit 410 serves to receive data transmitted by the transmitting station through one of a plurality of channels. The relay device 200 includes a plurality of antennas and forms a plurality of channel networks, and the receiver 410 receives data from a station included in each channel network.

The storage unit 430 stores information of stations for each channel. The station information is preferably created and stored when an external station joins one of the channel networks. The information of the station preferably includes a channel including the station, an address, and a bandwidth that can be supported. In this case, the channel including the station means a channel included in the region among a plurality of channels. Yes. In other words, if the participating station is included in one channel network, the channel of the station is one, and if it is included in the plurality of channel networks, all channel networks including the station may correspond.

In addition, the address of the station is preferably an IP address or a hardware address of the station, and the bandwidth of the station means a frequency bandwidth supported by the station.

The controller 450 determines a channel including a reception station with respect to data received by the receiver 410 by referring to information of a station for each channel stored in the storage 430. The header of the data transmitted by the transmitting station includes the address of the receiving station. The control unit 450 extracts an address matching the address of the receiving station included in the header of the data from the information of the station stored in the storage unit 430. And check the channel accordingly.

The buffer serves to temporarily store the data received by the receiver 410. Each channel transmits and receives data through a semi-duplex wireless network process using a transmit request and a transmit clear. Accordingly, the data received by the receiver 410 is temporarily stored in the buffer 460, and then extracted and transmitted by the controller 450. In this case, the controller 450 may allocate and manage the size of the data stored in the buffer 460 and the memory according to the corresponding channel.

The channel manager 440 manages a channel to allow a part of the load to be processed through another channel when a load processed through a specific channel among a plurality of channels exceeds a predetermined threshold. For example, when the first channel and the second channel are formed, if the amount of data transmitted and received through the first channel is more than twice the amount of data transmitted and received through the second channel, the transmission and reception through the first channel Some of the data to be transmitted and received through the second channel.

To this end, the channel manager 440 refers to the information of the station stored in the storage 430 because the load transfer can be performed only for the stations commonly included in the region of the first channel and the second channel. to be.

The transmitter 420 transmits data to a receiving station through a channel determined by the controller 450.

4 is a table showing information of a station according to an embodiment of the present invention.

As described above, when the external station participates in one of the plurality of channels, the relay device 200 creates and stores the information of the station including the address, channel, and bandwidth of the station in the storage unit 430. .

The address of the station may be an IP address or a hardware address. Using this, the controller 450 may identify a channel matching the address of the receiving station included in the header of the received data. There may be one or more channels of the station depending on the area of the channel network including the participating station. At this time, the station having a plurality of channels transmits and receives data through a flexible channel by the channel manager. The bandwidth of the station may be 20, 40 MHz or a variable bandwidth for 20 and 40 MHz, the control unit 450 processes the data using the bandwidth selected according to the bandwidth of the transmitting station and the receiving station.

5 is an exemplary diagram illustrating relaying data using a plurality of channels according to an embodiment of the present invention, wherein the first, second, and third stations of the first, second, third, and fourth stations are included in a first channel network. 3, 4, and stations are included in the second channel network, and the relay device 200 relays data transmission between stations.

Zones A and C in the figure represent data transmission and reception on the same channel, and zone B represents data transmission and reception between channels.

The data transfer process in zones A and C is as follows. After the network is initialized by the Beacon packet, when the first station transmits data a with the second station as the receiving station, the relay device 200 receives the data a and receives the address of the receiving station included in the header. Check and transmit data a to the second station since the receiving station is the second station. Data b transmitted by the second station to the receiving station by the second station is transferred in the same process, and data e is transmitted in the same process between the third station and the fourth station in the C zone.

Meanwhile, data movement is performed between channels in the zone B. When the third station included in the second channel network transmits the data c to the receiving station, the relay device 200 determines that the receiving station included in the data c is located. The information of the station stored in the storage unit 430 is searched using the address. Thus, it is confirmed that the address of the receiving station is the second station, and after confirming the channel, data c is transmitted to the second station through the corresponding channel network. The same process applies to the data d.

6 is an exemplary diagram illustrating relaying data according to bandwidth using a plurality of channels according to an embodiment of the present invention. The first station supporting bandwidths of 20 and 40 MHz and the bandwidth supporting 20 MHz Two stations, a third station supporting a bandwidth of 40 MHz and a relay device 200 supporting bandwidths of 20 and 40 MHz are shown.

Here, the first, second, and third stations may include the same channel or different channel networks, and in case of being included in different channel networks, data may be transmitted / received through the relay channel described above with reference to FIG. 5.

After the network is initialized by the beacon packet, the first and second stations may respectively receive data a, c and data b, d from the relay device 200 through a bandwidth of 20 MHz, and the first station may receive the second. It is also possible to transmit data e to the station.

In addition, the third station supporting the 40 MHz bandwidth may receive the data f from the relay device 200 through the channel bandwidth of 40 MHz, and the first station may also switch the channel to 40 MHz to receive the data f. Can be.

In the figure, Self-CTS and CF-End represent the self-transmission clear and the end packet broadcast by the relay device 200 to the stations included in each channel network, and the NAV is a network allocation vector as a transmitting station and a receiving station. The data occupies the network according to the time set in the network allocation vector and transmits and receives data.

FIG. 7 is an exemplary diagram illustrating load management between channels using channel switching according to an exemplary embodiment of the present invention, in which first, second, third, and fourth stations transmit and receive data through first and second channel networks.

In the figure, the box represents data transmitted and received through each channel network, and the number in the box represents the number of the transmitting station.

As shown in the figure, it can be seen that data of the first, second, and third stations are concentrated in the first channel before the channel switching time. Accordingly, the data transmitted through the first channel network may be delayed according to the load and transmitted to the transmitting station. On the other hand, since the second channel network transmits the data by one station, waste of the channel network may occur. appear.

Accordingly, the channel manager 440 of the relay device 200 compares the load of the first channel with the load of the second channel within a predetermined time, and the difference is greater than or equal to a predetermined threshold (for example, 2 times or 3 times). In this case, data of one or more stations included in a channel having a high load is transmitted through another channel.

At this time, the channel manager 440 performs channel switching by referring to the information of the station included in the storage 430, and selects a station to be channel switched by referring to the amount of data of a specific station included within a predetermined time. have.

8 is a flowchart illustrating a process of relaying data using a plurality of channels according to an embodiment of the present invention.

When the receiver 410 receives data from a transmitting station through one of a plurality of channels (S810), the data is transmitted to the controller 450 through the channel manager 440. At this time, the channel manager updates the load of the corresponding channel.

The controller 450 receiving the data identifies the receiving station and the corresponding channel that match the address of the receiving station included in the header of the data by referring to the information of the station stored in the storage 430 (S815). Then, the bandwidth of the station is checked (S820) and the data is transmitted to the channel manager 440 to transmit data according to the bandwidth through the corresponding channel.

Accordingly, the channel manager 440 checks the load of each channel and the load of the channel including the receiving station (S825), checks whether the load exceeds a threshold (S830), and confirms that the load of the corresponding channel is different. If the threshold value is less than the channel load, data is transmitted through the corresponding channel (S845). If the threshold value is larger than the threshold value, it is checked whether channel switching for the receiving station is possible (S835). Thus, if channel switching is possible for the receiving station, channel switching is performed (S840), and data is transmitted to the receiving station through the changed channel network (S845). However, if channel switching is not possible for the receiving station, it is checked whether channel switching of another station using the corresponding channel is possible (S850). If the channel switching of the other station is possible, the channel switching is performed (S855). .

9 is an experimental example showing data transmission and reception performance according to an embodiment of the present invention and data transmission and reception performance according to 802.11n, using 20 and 40 MHz using a channel supporting data rates of 24, 36, and 54 Mbps. Table shows the rates of data transmitted and received through two channels with channel bandwidth. Here, the usage rates of the 20 MHz and 40 MHz channel networks are the same.

As shown in the figure, it can be seen that the data transmission speed by the relay apparatus 200 of the present invention is improved over 802.11n. The extent of improvement depends on the usage rates of 20 MHz and 40 MHz channel networks, and as the usage rate of 20 MHz increases, so does the extent of improvement.

10 is an experimental example showing the results of data transmission / reception performance and 802.11n data transmission / reception performance of the relay apparatus of the present invention according to the mixing ratio of bandwidths.

Data transmission and reception performance of the relay device 200 of the present invention for the data transmission and reception performance of 802.11n depends on the 20 MHz channel usage. As shown in the figure, while the 20 MHz channel usage increases, the data transmission / reception performance of 802.11n decreases, whereas the relay apparatus 200 of the present invention performing channel management through channel switching has the same performance regardless of the usage of the 20 MHz channel. Indicates.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the apparatus and method for relaying data using a plurality of channels of the present invention as described above, there are one or more of the following effects.

First, there is an advantage in that data of a plurality of stations can be processed using a few access points by relaying data between stations in regions of different channels using a plurality of channels.

Second, according to the bandwidth of the station for transmitting or receiving data, there is an advantage of providing a high data transmission rate by changing the bandwidth of the selected channel among the plurality of channels provided to relay the data.

Claims (12)

A receiver which receives data through one channel of the plurality of channels; A control unit for identifying a channel including a receiving station by referring to information of a station for each channel; A channel manager configured to process a part of the load through another channel when a load processed through a specific channel among the plurality of channels exceeds a predetermined threshold; And Apparatus for relaying data using a plurality of channels including a transmitting unit for transmitting the data to the receiving station through the identified channel. The method of claim 1, Apparatus for relaying data using a plurality of channels further comprising a buffer for temporarily storing the received data. The method of claim 1, The controller relays data using a plurality of channels for receiving or transmitting the data by changing the bandwidth of the channel according to the bandwidth supported by the station. The method of claim 1, The information of the station for each channel relays data using a plurality of channels including the channel, the address and the bandwidth supported by the station. delete The method of claim 1, And the channel manager relays data using a plurality of channels for transmitting and receiving data of a station included in an area of the specific channel through the other channel. Receiving data through one of the plurality of channels; Identifying a channel including a receiving station by referring to information of a station for each channel; If a load processed through a particular channel of the plurality of channels exceeds a predetermined threshold, causing a portion of the load to be processed through another channel; And And transmitting the data to the receiving station through the identified channel. The method of claim 7, wherein And relaying data using a plurality of channels, the method further comprising temporarily storing the received data. The method of claim 7, wherein The checking of the channel may include changing a bandwidth of the channel according to a bandwidth supported by the station to receive or transmit the data. The method of claim 7, wherein The information of the station for each channel is a method for relaying data using a plurality of channels including the channel, the address and the bandwidth supported by the station. delete The method of claim 7, wherein Processing a portion of the load through the other channel may include transmitting and receiving data of a station included in an area of the specific channel through the other channel. .

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