Patent ID: 9537981
Date: 2017-01-03
CPC Classifications: H04L

Claim:
1. A method of transmitting a frame according to a channel environment, the method comprising: receiving, by an access point(AP), long training field (LFT) configuration information from a station, wherein the LTF configuration information includes information related to a maximum velocity of the station, a Doppler frequency due to a moving of the station and an additional LTF; receiving, by the AP, channel delay information for determining guard intervals to be used upon a transmission of a frame from the station; determining, by the AP, a period of an additional LTF and a location of the additional LTF based on the LTF configuration information; determining, by the AP, the guard interval based on the channel delay information, wherein if a value of a channel delay is larger than a predetermined threshold, the guard interval is determined to be a long guard interval (LGI), wherein if the value of the channel delay is smaller or equal to the predetermined threshold, the guard interval is determined to be a short guard interval (SGI); generating, by the AP, the frame including an LTF, a first split data field, the additional LTF and a second split data field based on the LTF configuration information and the channel delay information; and transmitting, by the AP, the frame to the station by using the determined guard interval, wherein the LTF is located ahead of the first split data field, and wherein the additional LTF is located between the first split data field and the second split data field.