Patent ID: 9713171
Date: 2017-07-18
CPC Classifications: H04W

Claim:
1. A method for a startup of a base station to communicate with a terminal station, comprising the steps, in the sequence set forth, of: (a) selecting a frequency channel from a plurality of predetermined frequency channels; (b) receiving preambles under the frequency channel, wherein in response to the base station receiving preambles at a cycle of a length of a frame under the frequency channel, a base station changes the frequency channel; (c) transmitting preambles at a cycle of n-times a length of a frame under the frequency channel, wherein n is an integer 2 or greater; (d) in response to the base station not receiving ranging signals under the frequency channel, the base station changes the frequency channel, and returns to step (b); and (e) communicating with the terminal station using preambles at the cycle of the length of the frame under the frequency channel.