第10題： 正在發(fā)展的第四代無(wú)線通信技術(shù)推出了多個(gè)標(biāo)準(zhǔn)，下面的選項(xiàng)中不屬于4G標(biāo)準(zhǔn)的是（ ）。
A.LTE
B.WiMAXII
C.WCDMA
D.UMB
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第11題：

下面是家庭用戶安裝ADSL寬帶網(wǎng)絡(luò)時(shí)的拓樸結(jié)構(gòu)圖，圖中左下角的x是（1）設(shè)備，為了建立虛擬撥號(hào)線路，在用戶終端上安裝（2）協(xié)議。

（1）A.DSLAM
B.HUB
C.ADSL Modem
D.IP Router
（2）A.ARP
B.HTTP
C.PPTP
D.PPPoE

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第12題： 網(wǎng)絡(luò)系統(tǒng)設(shè)計(jì)過程中，物理網(wǎng)絡(luò)設(shè)計(jì)階段的仟?jiǎng)?wù)是（ ）。
A.依據(jù)邏輯網(wǎng)絡(luò)設(shè)計(jì)的要求，確定設(shè)備的具體物理分布和運(yùn)行環(huán)境
B.分析現(xiàn)有網(wǎng)絡(luò)和新網(wǎng)絡(luò)的各類資源分布，掌握網(wǎng)絡(luò)的狀杰
C.根據(jù)需求規(guī)范和通信規(guī)范，實(shí)施資源分配和安全規(guī)劃
D.理解網(wǎng)絡(luò)應(yīng)該具有的功能和性能，最終設(shè)計(jì)出符合用戶需求的網(wǎng)絡(luò)
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第14題： Let us now see how randomization is done when a collision occurs . After a (1), time is divided into discrete slots whose length is equal to the worst-case round-trip propagation time on ether. To accommodate the longest path allowed by Ethernet, the slot time has been set to 512 bit times, or 51.2us.
After the first collision, each station waits either 0 or 1 (2) times before trying again. If two stations collide and each one picks the same random number, they will collide again. After the second collision, each one picks either 0,1,2 or 3 at random and waits that number of slot times. If a third collision occurs (the probability of this happening is 0.25), then the next time the number of slots to wait is chosen at (3) from the interval 0 to 23-1.
In general, after I collisions, a random number between 0 and 2i -1 is chosen, and that number of slots is skipped. However, after ten collisions have been reached, the randomization (4) is frozen at a maximum of 1023 slots. After 16 collisions, the controller throws in the towel and reports failure back to the computer. Further recoveries up to (5) layers.

（1）A.datagram
 B.collision
 C.connection
D.service
（2）A.slot
 B.switch
 C.process
 D.fire
（3）A.rest
 B.random
 C.once
 D.odds
（4）A.unicast
 B.multicast
 C.broadcast
 D.interval
（5）A.local
 B.next
 C.higher
 D.lower

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