A method is provided for allocating initial ranging opportunities in a series of frames. According to the method, a number of initial ranging opportunities are allocated in frame N that occurs after a triggering event, and k frames after frame N the number of initial ranging opportunities is selectively reduced. The triggering event is one of system startup and broadcast of an Uplink Channel Descriptor message. Also provided is a base station that includes a controller for allocating a number of initial ranging opportunities in frame N that occurs after a triggering event. The controller selectively reduces the number of initial ranging opportunities k frames after frame N. The triggering event is one of system startup, broadcast of an Uplink Channel Descriptor message, broadcast of a page message, or broadcast of a signature for an overhead configuration message.