To accommodate more users with limited spectrum, the radius of new cellular will be much smaller, the factor of spectrumreuse will be more tight.
为了在有限频谱范围内满足更多的用户需要，通信系统的蜂窝半径越来越小，频率复用密度越来越高。
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Andrea Goldsmith: There's not enough spectrum to assign every phone in the world its own dedicated channel so we have to reuse the channels and that causes interference between users.