The invention discloses a sending method of terminal front in a time division duplexing
system. An RACH channel only requires less
guard time to reach the coverage area of the RACH channel. The method comprises the following steps: firstly, when a
system is configured, determining the total
guard time TGT of the
random access RACH channel, and dividing a
cell into a plurality of circular or annular areas according to the distance between the
cell and a
base station; secondly, when the front is sent by a terminal, judging the area of the terminal, and determining the front sending time corresponding to the area; and thirdly, sending the front by using the terminal at the determined sending time. By adopting the method, the method for sending the starting point of a
preamble at a terminal side is determined according to the position range of the terminal in the
cell; and the larger coverage area can be supported under the condition that the total length of the
guard time is definite without estimating the distance between the range and the
base station accurately.