Measuring for the beat error (frequency error) : Numerical display in milliseconds. Resolution is 0.1 milliseconds; the measuring range is 0-9.9 ms.

偏振(频率错误)测量：数值以毫秒显示。分辨率是0.1毫秒，测量范围是0—9.9毫秒。

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High resolution is achieved by measuring motion rather than radio frequency signals as wifi does, and is based on where and how the person moves through an environment over time.

BBC: Technology that works behind closed doors