1. Field of the Invention
The present invention relates to a method for transmitting frames at a high rate, and more particularly to a method for transmitting frames at a high rate in a wireless Local Area Network (LAN).
2. Description of the Related Art
A LAN was developed as a wired network system in its initial stage. The LAN has been rapidly developed mainly by small and medium sized companies. Along with the rapid development of wireless communication technology, the LAN has been combined with wireless technology to develop a wireless LAN, which is currently in widespread use in a variety of areas.
The wireless LAN allows terminals to be used within a specified area no matter where they are located due to the fact they are wireless. The wireless LAN will now be described in detail with reference to FIG. 1.
FIG. 1 is a block diagram showing the configuration of a wireless LAN. In the wireless LAN, wireless terminals 110, 120, 130, 140 and 150 are located around an Access Point (AP) 100. The AP 100 can be connected to other networks. The wireless terminals 110 to 150 can communicate with each other inside the wireless LAN directly or via the access point 100. The wireless terminals 110 to 150 can communicate with external networks only through the access point 100.
Because they are wireless, each of the wireless terminals 110 to 150 is not always located in the same place. In other words, the locations of the wireless terminals 110 to 150 may be continually changed. As shown in FIG. 1, the wireless terminals 110 to 150 are located apart from the access point 100 by distances R1, R2, R3, R4 and R5, respectively. The distances R1 to R5 of the terminals 110 to 150 are different from each other. In the wireless environment, the wireless terminals 110 to 150 generally have different transfer rates depending on the distances R1 to R5. A wireless terminal with a shorter distance from the access point 100 has a higher transfer rate than a wireless terminal with a longer distance therefrom. Although the calculation of the transfer rate is not based only on the distance, the transfer rate generally decreases as the distance increases.
As described above, the first wireless terminal ST1 110 located at an initial distance of R1 may move to a location ST1 110-1 where it is at a distance of R−1. After moving to the location of distance R−1, the ST1 100-1 has a different transfer rate from its transfer rate before the movement. Accordingly, when a mobile terminal is in communication with the access point 100, the terminal must always report its transfer rate to the access point 100 and carry out data transmission based on the reported transfer rate.