This paper presents the classical ALOHA algorithm in detail and estimates the real-time number of tags according to the collision so as to change the length of the frame dynamically.

• 文章介绍了经典的防冲突算法-ALOHA算法，根据冲突情况，从数学角度对动态时隙ALOHA算法的标签数作出实时估计，动态地改变帧长；