信号传播的物理学理论

In radio-frequency engineering, a transmission line is a specialized cable or other structure designed to conduct alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account.

Transmission Delay 与 Propagation Delay

$100ns = 1 \times 10 ^ {-7}s = \frac{1}{10000000}$

$t_{3} = t_{1} + t_{2}$

以太网的速率

• 如果一个以太网是使用集线器或总线连接的共享网络，那么它有CMSA/CD机制避免冲突，实际上的速率是标注值除以共享网络的人数。
• 如果一个以太网不是共享的（比如用交换机连接），那么它的速率和标注值一致。