KR0181567B1 - Data transceiving method - Google Patents

Abstract

When installing a microwave wireless system, the MPDU format received in relaying between wireless LAN stations to enable transmission and reception in certain environments where the distance between the access point and the station or between the station and the station is far away or obstructive After inputting the signal, the address is analyzed to confirm whether the network ID is the ID of the wireless repeater, the source address and the destination address are the jurisdiction of the wireless repeater, and the relay function is performed to perform the relay function. Data transmission / reception method using wireless repeater for extending cell area of LAN.

Description

Data transmission / reception method using wireless repeater

1 is a state diagram of a wireless LAN using a conventional infrared repeater.

2 is a state diagram using a wireless LAN using a wireless repeater of the present invention.

3 is a state diagram of a wireless LAN using a user station instead of a wireless repeater according to another embodiment of the present invention.

4 is a schematic diagram of a microwave wireless repeater of the present invention.

* Explanation of symbols for main parts of the drawings

1: Access Point (AP) 2: Station

3: infrared repeater 4: user station

5 wireless repeater 6 software algorithm processing unit

7: digital signal processing unit 8: microwave RF processing unit

9: frame buffer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless repeater for extending a cell area of a microwave wireless LAN using a multipath characteristic, and particularly, between an access point and a station in a special environment in which wired installation is difficult. The present invention relates to a data transmitting / receiving method capable of precise transmission and reception by installing a wireless repeater between stations and analyzing an address and identifying a source and a destination.

Conventional wireless repeater technology is an infrared (Infra Red) LAN repeater, there is a problem that the signal is not transmitted when there is an obstacle in the optical path due to the linearity and non-transmittance of the infrared. In particular, when used in shipyards, steel mills, etc., where a large number of moving objects exist, transmission / reception disconnections frequently occur and the amount of wire wiring required increases. Therefore, a repeater, which is a device for shaping, amplifying, and relaying a signal flowing on a LAN transmission medium, is used to connect segments, thereby extending the transmission distance and increasing the degree of freedom of wiring. In this case, the LAN standard has a transmission distance of 1 segment (for example, 500m with 10 bases 5). However, even if the repeater is used, if the terminal exists in the distance where a large transmission delay occurs, packet collision detection is impossible and the transmission distance cannot be extended indefinitely.

This is why the maximum transmission distance of one network to 10 bases 5 is limited to 2.5 km. In addition, there are some relay delays, and the number of relay stages is also defined as four.

1 shows a conventional Infra Red LAN repeater, which shows the installation of an infrared relay 3 between an access point 1 and a station 2, and uses infrared light to relay a signal. At this time, the external repeater 3, when there is an obstacle between the access point 1 and the station 92 due to the directivity and impermeability of the infrared ray, the signal is not transmitted. In particular, in a workplace where a large number of moving objects exist, the above-described transmission / reception disconnection frequently occurs when the infrared repeater 3 is installed. Therefore, in this case, it is necessary to pay special attention to the installation of the infrared repeater 3, and the amount of wire wiring required is also increased.

The present invention can avoid the interruption of transmission and reception by using a microwave LAN repeater having a certain degree of permeability and multipath characteristics to solve the above problems and to expand the cell area of the wireless LAN, and also MPDU (MAC Protocol Data Unit) Amplification of unnecessary signals can be prevented by using a reswitching method, and a buffer can be used to perform a buffering function when the traffic volume of the target access point (or station) to which the repeater belongs is temporarily increased. .

In order to achieve the above object, the present invention provides a method for transmitting wireless data to a wireless repeater in the form of MPDU in a user station of a wireless LAN, and the network ID of the data received in the wireless repeater matches the cell to which the wireless repeater belongs, If the source address is an access point or station in a first jurisdiction of a wireless repeater and the destination address is an access point or station in a second jurisdiction, storing the received data in a buffer of the wireless repeater; And retransmitting data in a second jurisdiction in the form of MPDU to a point or destination station. In addition, the wireless repeater receives the data in the form of MPDU from the access point or the destination station, the network ID of the received data matches the jurisdiction to which the repeater belongs, the source address is an access point in the second jurisdiction Or a station, and if the destination address is a station in a first jurisdiction, storing the received data in a buffer in a wireless repeater; and receiving, by the user station, MPDU type data from the wireless repeater. A data receiving method is featured.

Hereinafter, the present invention will be described in more detail with the accompanying drawings.

2 is a diagram showing a state of use of a wireless LAN using the wireless repeater of the present invention, wherein the wireless repeater 5 between the access point 1 and the user station 4 attached to the wired backbone is converted into a microwave LAN repeater. When used, it may have some degree of permeability and multipath characteristics. At this time, the communication method uses a collision avoidance method, CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) and MPDU (MAC Protocol Data Unit), where the MPDU is composed of RTS (Request To Send) and CTS (Clear). To Send) and Data and Ack (Acknowledge) frames.

Here, in the data transmission method, first, when an input that requires on-line terminal processing is generated at the source station and a processing request is made to the central processing unit, the RTS is delivered to the destination station and the destination station receiving the request transmits the CTS to the source station. The data is sent from the source station to the destination station. The ACK then sends an ACK to the source station stating that data has been received at the destination station (see Table 1).

The format of the MPDU frame is as follows (see Table 2).

3 is a diagram showing a state of use of a wireless LAN using a user station instead of a wireless repeater according to another embodiment of the present invention, in which a user station equipped with a network card is equipped with an operating system capable of multi-processing and When the program is installed in the form of a process, the user station can be used as a wireless repeater. Here, the address consists of a network ID, a source address, and a destination address. RTS, CTS, and ACK are additional procedures for accurately transmitting and receiving data in a wireless environment. Next, when using the wireless repeater of the present invention, a transmission and reception procedure centering on a user station in an Ad Hoc B cell is as follows.

In the transmission procedure, the user station 4 transmits data in the form of MPDU to the wireless repeater 5. Thereafter, the network ID of the received data matches the cell to which the wireless repeater 5 belongs, the source address is an Ad Hoc B cell (first jurisdiction), and the destination address is an access point in an A cell (second jurisdiction). Or if it is a station, store it in a buffer. The wireless repeater then retransmits the data in cell A in the form of MPDU to the access point (or destination station).

In the reception procedure, the radio repeater 5 receives data in the form of MPDU from the access point (or destination station). Thereafter, the network ID of the received data matches the cell to which the radio repeater 5 belongs, and the address is stored in the buffer if the address is an access point (or station) in the A cell and the destination address is a station in the Ad Hoc B cell. The user station then receives data in MPDU form from the wireless repeater.

4 is a schematic diagram of a microwave wireless LAN repeater of the present invention. When using a conventional user station as a repeater, the digital signal processor 7 and the microwave RF processor 8 can be processed by a wireless network interface card. Only the software algorithm processing section 6 is configured to exist as one process under the multipurpose operating system.

That is, in the case of the conventional infrared method, due to the non-transmittance and straightness of the infrared ray, if there is a fixed obstacle on the relay path is not transmitted and received, there are many points to be noted at the time of installation, and the transmission and reception may be disconnected when a protruding movement obstacle occurs. However, the present invention uses a wireless repeater to expand the cell area of the microwave WLAN, by using the transmission and multipath characteristics to avoid the interruption of transmission and reception, and the environment of the wall or partition of a material such as wood and a number of fixed and It can be used well in special environments such as factory hospitals where moving obstacles exist.

In addition, the MPDU re-switching scheme prevents unnecessary signal amplification compared to passive repeaters that amplify all signals in the band, and uses a buffer to temporarily increase the traffic volume of the target access point (or station) to which the repeater belongs. This has the advantage of being able to perform buffering functions.

Claims (5)

Transmitting, in a user station of a wireless LAN, MPDU data to a wireless repeater, a network ID of the data received on the wireless repeater matches a cell to which the wireless repeater belongs, and a source address of the wireless repeater to the first jurisdiction; Storing the received data in a buffer of the wireless repeater if the access point or station in an area and the destination address is an access point or station in a second jurisdiction, and the wireless repeater in the form of MPDUs to the access point or destination station Transmitting data including retransmitting data to a second jurisdiction, wherein the wireless repeater receives the data in MPDU form from an access point or destination station, and the network ID of the received data belongs to the repeater. Matches the cell, and the source address If the access point or station is within a jurisdiction and the destination address is a station within a first jurisdiction, storing the received data in a buffer in a wireless repeater, and the user station stores the MPDU data from the wireless repeater. Method of transmitting and receiving data comprising the step of receiving. The digital repeater of claim 1, wherein the wireless repeater includes a software algorithm processing unit having a frame buffer therein, a digital signal processing unit receiving a signal from the software algorithm processing unit and processing the signal into a digital signal, and the digital signal processing unit. Microwave RF processing unit for receiving and processing the signal of the data transmission and reception method comprising the. The data transmitting / receiving method according to claim 1, wherein a network interface card and a multiprocess operating system are mounted in a user station in place of the wireless repeater, and an input program is mounted in a process form. The method of claim 2 or 3, wherein the software algorithm processing unit is one process under a multi-process operating system. The method of claim 2 or 3, wherein the digital signal processor and the microwave RF processor are wireless network interface cards.