局域网中使用的传输介质有双绞线、同轴电缆和光纤等。10BASE-T采用3类UTP，规定从收发端到有源集线器的距离不超过(44)m。100BASE-TX把数据传输速率提高了10倍，同时网络的覆盖范围(45)。假设tPHY表示工作站的物理层时延，c表示光速，s表示网段长度，tR表示中继器的时延，在IOBASE-5最大配置的情况下，冲突时槽约等于(46)。光纤分为单模光纤和多模光纤，与多模光纤相比，单模光纤的主要特点是(47)，为了充分利用其容量，可使用(48)技术同时传输多路信号。

(82)

(81)

(79)

(80)

(71) In the strength of the carrier signal is varied to represent binary 1 or 0.

  (72) is a system that can map a name to an address and conversely an address to an name.

  (73) is a three-way handshaking authentication protocol that it's packets are encapsulated in the point-to-point protocol

  (74) is an approach that enables an ATM Switch to behave like a LAN switch.

  (75) is an guided media which is made of glass or plastic and transmits signals in the form. of light.

(76)

(77)

(74)

(75)

(72)