Random Access Method for Multi-cell OFDMA Networks

1. Technical Field of the invention defined in the claims The invention will be particularly relates to a random access method according to the uplink access method in a mobile communication system that is based on (Orthogonal Frequency Division Multiplexing Access) OFDMA. 2. The invention attempts to solve the technical challenges The invention that is the object to provide a random access method in the multi-cell OFDMA network which can be used efficiently by considering the frequency reuse rate in a network system having OFDMA-based multiple cells. 3. Resolution of the subject matter of the invention, The present invention provides a random access method in OFDMA networks, each network unit is a first step of randomly selecting a channel of the uplink random access channels, if a random access request to the OFDMA network; If a conflict does not occur in the selected channel a second step of connecting through the channel; A third step wherein, if a crash occurs in the selected channel, the selected channel to the selected number of attempts a random one channel of equal to or less than a predetermined value, the uplink random access channel is set in advance to determine whether the collision; If no collision is confirmed result of the third step of generating a fourth step of connecting through a finally selected channel; And if the check result of the collision of the third step of generating, including a fifth step of proceeding to the third step. 4. An important use of the invention, The invention yiyongdoem like an OFDMA system. OFDMA, random access, and Rate of