KR20050002269A - Apparatus for communicating Wireless LAN and method for communicating Wireless LAN using the same - Google Patents

Abstract

PURPOSE: A wireless LAN communication device and a wireless LAN communication method using the communication device are provided to maintain a continuous fragment transmission method by receiving retransmission information through a Bluetooth device, thereby obtaining an improved data rate. CONSTITUTION: Wireless LAN devices(11,21) decide whether errors are produced by fragment with regards to receiving data, transmit information on a fragment having an error to Bluetooth devices(12,22), and transmit transmission data by loading the data on continuous fragments. The wireless LAN devices(11,21) receive information on the fragment having the error, and retransmit the information with the transmission data. The Bluetooth devices(12,22) receive the information on the fragment having the error to transmit the received information in Bluetooth way. If fragment information on an error is received from a public network, the Bluetooth devices(12,22) transmit the received information to the wireless LAN devices(11,21).

Description

Wireless communication device and wireless LAN communication method using the same {Apparatus for communicating Wireless LAN and method for communicating Wireless LAN using the same}

The present invention relates to wireless LAN communication, and more particularly, to a wireless LAN communication apparatus and a wireless LAN communication method using the same, enabling high-speed wireless LAN communication by simultaneously using a wireless LAN and Bluetooth.

Wi-Fi, also called Wi-Fi, means that wireless networks can be used as easily as hi-fi audio. Internet is available. Since it uses radio frequency, no telephone line or dedicated line is required, but PDA or notebook computer should be equipped with wireless LAN card.

In the early stages, the radio range was only 10m, but in the 2000s, it increased to 50-200m. Its transmission speed is 4 ~ 11Mbps, and it can send and receive large amount of multimedia information. It is cheap to use even for a long time, and it has mobility and security. It is very useful for temporary network installation in department stores, hospitals, museums, exhibitions, seminars, construction sites, etc., where wired connections are complicated.

In addition, with the recent increase in multimedia services, the demand for high-speed data transmission is increasing. Accordingly, devices satisfying 802.11b, which is a wireless LAN (LAN) standard of the 2.4 GHz band, are widely used.

The WLAN device uses a carrier sense multiple access / collision avoidance (CSMA / CA) scheme. In this method, several WLAN devices share a channel while using a channel.

The method of using a channel is divided into a Point Coordination Function (PCF) method in which wireless LAN devices have no contention for using a channel, and a Distributed Coordination Function (DCF) method in which wireless LAN devices compete with each other to use a channel.

In the 802.11b specification, DCF is the default, and PCF is optional.

In the case of PCF, an access point (AP) grants channel use rights to clients. This means that you can continue to get channel usage rights at regular intervals. In other words, the use of PCF can guarantee the use of the channel to a certain level or more, thereby improving the quality of service, but most wireless LAN devices do not currently support PCF.

Therefore, in the case of the DCF wireless LAN device, in order to use a channel, the contention must be competing with each other, and thus, the channel cannot be continuously used for a predetermined time. In this case, real-time transmission data may not be sent, and quality of service (QoS) guarantee may be difficult.

When the WLAN device obtains a right to use a channel, the WLAN device continuously transmits data by using fragmentation. At this time, the size of data that can be transmitted is limited by a variable called maximum transmission survival time (aMaxTransmitMSDULifetime).

When the timer reaches this time limit, all remaining untransmitted data is lost. In other words, all continuous data must be transmitted within the time limit.

After that, you have to compete again to use the channel.

During the fragmentation process, the data to be sent is made into several fragments and transmitted.

For transmission of each fragment, the receiving device is to send an Acknowledge (ACK) signal.

This acknowledgment signal should be transmitted for every fragment, and a time called a short inter-frame space (SIFS) is required before and after the acknowledgment signal.

SIFS is precisely timed during the WLAN device manufacturing process. The above described fragmentation operation process will be described with reference to the accompanying drawings.

1 is a view for explaining a data transmission and reception method using a wireless LAN device according to the prior art.

First, the source transmits a ready to send (RTS) indicating a transmission request to a destination, and then receives several fragments of data to be transmitted when a clear to send (CTS) indicating that transmission is possible from the receiver. Send to (Fragment 0, ... Fragment N).

In the DCF data transmission / reception method using the WLAN apparatus according to the prior art, two SIFS and one ACK time are required for each number of fragments.

At this time, even if the wireless LAN device can monopolize the channel through the fragmentation (Fragmentation) to share the channel, the fragment transmission time is limited, so it must compete to use the channel again. This is done through a back off process.

As described above, the current 802.11b standard has a disadvantage in that the transmission rate is reduced by the ACK and SIFS as well as the transmission period is limited during fragment transmission.

Although the transmission rate is lower than the case in which only fragments can be transmitted, this method is used because several WLAN devices must share a channel.

However, in the situation where most wireless LAN devices do not support PCF, it can be said to be modified to support real-time service while using DCF. In other words, there is a need to add a device for real-time service as a kind of option in the DCF.

Therefore, the present invention has been made to solve the above problems, a wireless LAN communication device and wireless using the same to improve the transmission speed of the wireless LAN communication by connecting a Bluetooth device of the wireless LAN connection standard to the wireless LAN device The purpose is to provide a LAN communication method.

1 is a view for explaining a data transmission and reception method using a wireless LAN according to the prior art

2 is a block diagram illustrating a wireless LAN communication apparatus according to the present invention.

3 is a view for explaining a data transmission and reception method using a wireless LAN communication apparatus according to the present invention.

4 is a view for explaining an embodiment of a data transmission and reception method using a wireless LAN communication apparatus of the present invention.

* Description of the symbols for the main parts of the drawings *

10: first wireless LAN communication apparatus 11: transmitting side wireless LAN apparatus

12. Sending side Bluetooth device 20: Second wireless LAN communication device

21: receiving side wireless LAN device 22: receiving side Bluetooth device

The wireless LAN communication apparatus according to the present invention for achieving the above object, and determines whether there is an error for the received data, and transmits information about the fragment in which the error occurred to the Bluetooth device, the transmission data to the continuous fragment A wireless LAN device for receiving and transmitting information about a fragment in which the error occurs among the transmission data from a Bluetooth device, and retransmitting the fragment in which the error occurs together with the transmission data; and the error is generated from the wireless LAN device. Receiving the information about the fragmentation and transmits the received information to the air by Bluetooth method, and if the received fragment information from the air from the air including a Bluetooth device for transmitting the received information to the wireless LAN device; It is composed.

Preferably, the presence or absence of the error is determined for each fragment.

According to another aspect of the present invention for achieving the above object, the step of transmitting the transmission data to the receiving side WLAN device in a continuous fragment through the transmission channel in the transmitting side WLAN device, and the receiving side Detecting a fragment in which an error occurs among received data in a wireless LAN device, transmitting the detected error information to a receiving Bluetooth device, and transmitting the detected error information in the receiving Bluetooth device to the transmitting WLAN device; Transmitting to the transmitting side Bluetooth device connected to the transmitting side, receiving the error information from the transmitting side Bluetooth device, and transmitting the received error information to the transmitting side wireless LAN device; And retransmitting the fragment with an error through the transport channel.

Advantageously, in the step of transmitting said transmission data via said successive fragments, said transmitting side WLAN device comprises a short inter-frame space (SIFS) between said fragments and an actuating from said receiving side WLAN device. (ACK) Transmits continuously regardless of reception.

Preferably, the transmitting side wireless LAN apparatus transmits the continuous fragment using a maximum size defined according to a variable of the maximum fragment threshold, and if the transmission data remains after the continuous fragment transmission, the reception A transmission request (RTS) is sent to the wireless LAN apparatus to reoccupy the transmission channel.

Preferably, in the WLAN communication method, pipeline processing is used for the error detection, the Bluetooth transmission / reception, and the retransmission.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Recently, wireless devices are increasingly embedded with Bluetooth devices, which are suitable for transmitting and receiving control information of a small capacity rather than transmitting a large amount of data.

The Bluetooth device can operate at a transmission rate of up to 723 Kbps, and the present invention proposes a method of increasing the transmission rate by using the Bluetooth device together in a wireless LAN communication.

In the case of using a conventional wireless LAN device and a Bluetooth device together, performance degradation caused by mutual interference has been raised (Nada Golmie, "Interference in the 2.4GHz ISM Band: Impact on the Bluetooth Access Control Performance", IEEE 2001). But. In recent years, studies on this have been actively conducted and methods for not interfering with relative signal components have emerged (Jim Lansford, "Wi-Fi (802.11b) and Bluetooth: Enabling Coexistence", IEEE Network, September / October 2001).

As a simple example, there is a method to prevent the Bluetooth device from invading the frequency band used by the WLAN device. This is possible by modifying the hopping order of the Bluetooth device.

Hereinafter, a WLAN communication apparatus and a WLAN communication method using the same according to the present invention will be described with reference to the accompanying drawings.

2 is a block diagram for explaining a wireless LAN communication apparatus according to the present invention, Figure 3 is a view for explaining a data transmission and reception method using a wireless LAN communication apparatus according to the present invention.

The WLAN communication apparatus according to the present invention uses a WLAN device and a Bluetooth device for providing short-range wireless communication. As shown in FIG. 2, the first WLAN communication device 10 and the second WLAN communication device 20 are used. The wireless LAN device 11 and 21 and the Bluetooth device 12 and 22, respectively.

As shown in FIG. 2, the WLAN communication apparatus according to the present invention determines whether an error exists for each fragment of received data, and transmits information about a fragment in which an error occurs to a Bluetooth device, and the transmission data is a continuous fragment. The wireless LAN devices 11 and 21 which receive information on fragments in which the error occurs among the transmission data from the Bluetooth device and retransmit together with the transmission data, and from the wireless LAN devices 11 and 21. Receives information on the fragment in which the error occurs, and transmits the received information to the air by Bluetooth method, and when the fragment information in error is received from the air, the received information is transmitted to the wireless LAN apparatus (11, 21) It is configured to include a Bluetooth device 12,22 for transmitting to.

Herein, the wireless LAN apparatuses 11 and 21 of the present invention are used to transmit data, and a method of continuously transmitting data between fragments and fragments regardless of SIFS or ACK from the destination. use.

The Bluetooth devices 12 and 22 of the present invention transmit information of fragments in which an error occurs among the received fragments (data) to the source WLAN apparatuses 11 and 21.

In this case, when the transmitter for transmitting data is referred to as the first WLAN communication apparatus 10, the embedded WLAN side 11 transmits a function to the first WLAN communication apparatus 10, and a flag to be retransmitted. Receiving the information of the fragment (Fragment) is the main reception function of the sending Bluetooth device 12.

And extends the time to send a fragment by sending a fragment between the fragment and the fragment without SIFS and without an ACK from the receiving side. That is, the wireless LAN apparatuses 11 and 21 can monopolize the channel without competing for channel use during the time required for real-time service.

In the present invention as described above it is possible to improve the transmission rate of the wireless LAN device using a Bluetooth device mounted in the same product or using an external Bluetooth module.

In the data transmission / reception method using the wireless LAN communication apparatus according to the present invention, first, a source and a reception are performed by using a ready to send (RTS) signal indicating a transmission request and a clear to send (CTS) signal indicating a transmission possibility. By occupying the transmission channel between destinations, the rest of the wireless LAN devices are set not to use the channel for a certain period of time. In this case, the remaining WLAN devices cannot use the channel for a certain period of time due to duration information included in the RTS and the CTS.

Subsequently, after the transmission channel is occupied, the transmission source (Source) continuously transmits a fragment (Fragment 0, Fragment 1, ..., Fragment N).

Each fragment uses a maximum size defined according to a variable called a fragmentation threshold.

After the successive fragments (Fragment0, Fragment 1, ..., Fragment N) are transmitted, the RTS is sent to the destination at the SIFS interval again. This is because wireless LAN devices enter a race to use a channel when waiting for a distributed inter-frame space (DIFS) interval. If there is still data to be transmitted, the transmitting side again occupies the transmission channel by sending the RTS back to the receiving side. Here, the interval of RTS is determined by the maximum transmission survival time (aMaxTransmitMSDULifetime).

As described above, in the present invention, the fragments are continuously transmitted, and by reusing the RTS / CTS signal to extend the channel occupancy, the transmission rate of fragments to be transmitted is increased, and the channel usage time for real time transmission is extended. It is possible.

As a result, instead of receiving an ACK for each fragment, it checks whether the fragment is sent after continuously sending fragments, and based on the information of the fragment to be retransmitted. Send (Fragment) again.

Bluetooth is used to obtain such retransmission information.

The receiving WLAN device 21 that receives data in units of a fragment should determine whether an error exists. Check whether there is an error in units of fragments, arrange fragment information that needs to be retransmitted, and transmit the fragment information to the receiving Bluetooth device 22. This information is periodically sent to the sending Bluetooth device 12.

In this case, three operations should be largely defined in the communication method of the present invention.

First, it is necessary to determine whether there is an error among the fragments (Fragment) received in the wireless LAN device, which is the basic of the 802.11b standard, no additional circuit design is required. At this time, the information on the fragment in which the error occurs should be arranged.

Second, information on the fragment in which the error occurs must be transmitted to the Bluetooth device in the form of data. The receiver-side Bluetooth device must periodically send this information to the transmitter-side Bluetooth device. The function of periodic transmission is important here because it is related to the delay time that can be caused by fragments that are retransmitted.

Third, a fragment that needs to be retransmitted is inserted into the fragment to be transmitted using this information and then transmitted. Through the above process, a continuous fragment transmission is performed between the WLAN devices, and at the same time, refraction of the fragment may be performed. It is important to group them in functional units to reduce the delay of fragments that are retransmitted. In this case, a method of classifying operations using a pipeline is used.

4 is a view for explaining an embodiment of a data transmission and reception method using a wireless LAN communication device of the present invention.

4 is a view illustrating a pipeline operation in which fragments are bundled in functional units in order to reduce delay of fragments retransmitted in the data transmission / reception method using the wireless LAN communication apparatus of the present invention. Make

Detecting a fragment in which an error occurs in the wireless LAN device on the receiver side is called Error Fragment Detection. It is called (Bluetooth Tx / Rx). Lastly, the insertion of retransmission fragments between fragments to be transmitted by the transmitter-side wireless LAN apparatus is called fragment alignment.

This process is done continuously by constructing a pipeline.

In FIG. 4, two fragments are allocated to each section of the pipeline, and the number of fragments may vary depending on the system speed.

In FIG. 4, fragment 2 between fragment 8 and fragment 9 is retransmitted and is sent. Fragment 2 is inserted while fragments are continuously transmitted.

The important thing here is the delay time for retransmission. The longer this delay, the worse it is for real-time services. The number of fragments per section of the pipeline is determined according to the experience or the experiment in consideration of the allowable delay time and the size of the data buffer of the transmitting and receiving side.

These two variables can be applied in various ways depending on the performance and configuration of each transceiver system.

By using the device and method configured as described above, the transmission rate of the WLAN device can be improved.

As described above, the present invention is a method of using continuous fragment transmission in a wireless LAN device. This is a method of receiving retransmission information through a Bluetooth device and continuing to maintain continuous fragment transmission. This eliminates time loss of SIFS and ACK signals that occur during normal fragment transmission. As a result, an improved data rate can be obtained.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (6)

Determining whether there is an error on the received data and transmitting information on the fragment in which the error occurred to the Bluetooth device, and transmits the transmission data in a continuous fragment, and transmits the error of the fragment in the transmission data from the Bluetooth device A wireless LAN device which receives information and retransmits the fragment in which the error occurred together with the transmission data; Receives information on the fragment in which the error occurs from the WLAN device and transmits the received information to the air in a Bluetooth manner, and if received fragment information from the air, the received information is transmitted to the WLAN. Wireless communication device comprising a Bluetooth device for transmitting to the device. The wireless LAN communication apparatus of claim 1, wherein the error is determined for each fragment. Transmitting transmission data in a continuous fragment through a transmission channel in a transmitting WLAN device to the receiving WLAN device; Detecting, by the receiving wireless LAN device, a fragment in which an error occurs in the received data, and transmitting the detected error information to a receiving Bluetooth device; Transmitting the detected error information by the receiving Bluetooth device to a transmitting Bluetooth device connected to the transmitting WLAN device; Receiving the error information at the transmitting Bluetooth device and transmitting the received error information to the transmitting WLAN device; And retransmitting the fragment in which the error occurred in the transmitting WLAN apparatus through the transmission channel according to the error information. 4. The wireless LAN apparatus of claim 3, wherein in the transmitting of the transmission data through the consecutive fragments, the transmitting side wireless LAN apparatus comprises a short inter-frame space (SIFS) between the fragments and the receiving side wireless LAN apparatus. Wireless communication method, characterized in that the continuous transmission regardless of the reception (ACK) from. The method of claim 3, wherein The transmitting WLAN device transmits the continuous fragment using a maximum size defined according to a variable of the maximum fragment threshold value, and if the transmission data remains after the continuous fragment transmission, the receiving side wireless LAN And re-occupying the transmission channel by sending a transmission request (RTS) to a LAN apparatus. The method of claim 3, wherein In the wireless LAN communication method, the error detection, the Bluetooth transmission / reception, and the retransmission use a pipeline processing.