The present invention relates to an opportunistic
frequency spectrum access method based on
collision probability restriction, and belongs to the technical field of
wireless mobile communication. The method comprises the following steps: setting a
collision probability restriction value zeta, and setting the parameter of
frequency spectrum disengagement time
length distribution function f(t) to arbitrary values; circulating the following steps: continuously perceiving until the
frequency spectrum is free; if the frequency spectrum is free, using zeta, f(t) and v for calculating the optimal
access time point x and optimal
access time length T, if the free time length is smaller than x, perceiving the frequency spectrum, otherwise continuously accessing the frequency spectrum until the
access time length is larger than T or collision generation; if the access time length is larger than T, continuing perceiving until the frequency spectrum is busy, and if the frequency spectrum is busy, calculating and storing the
busy time length and
idle time length, estimating the parameter of f(t) and v for entering the next circulation; and if the collision is generated, calculating and storing
busy time length and free time length, estimating the parameter of f(t) and v for entering the next circulation. The method of the invention can optimally use the free frequency spectrum resource and simultaneously satisfies the
collision probability restriction which can be tolerated by the master subscriber.