第
9題: 物聯(lián)網(wǎng)中使用的無線傳感網(wǎng)絡(luò)技術(shù)是( )。
A.802.15.1藍(lán)牙個域網(wǎng)
B.802.11n無線局域網(wǎng)
C.802.15.3 ZigBee微微網(wǎng)
D.802.16m無線城域網(wǎng)
答案解析與討論:
www.jycxcx.com/st/2344422058.html第
10題: 正在發(fā)展的第四代無線通信技術(shù)推出了多個標(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
答案解析與討論:
www.jycxcx.com/st/2344516479.html第
11題:
下面是家庭用戶安裝ADSL寬帶網(wǎng)絡(luò)時的拓樸結(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
答案解析與討論:
www.jycxcx.com/st/2344620749.html第
13題: 下列關(guān)于網(wǎng)絡(luò)核心層的描述中,正確的是( )。
A.為了保障安全性,應(yīng)該對分組進(jìn)行盡可能多的處理
B.將數(shù)據(jù)分組從一個區(qū)域高速地轉(zhuǎn)發(fā)到另一個區(qū)域
C.由多臺二、三層交換機(jī)組成
D.提供多條路徑來緩解通信瓶頸
答案解析與討論:
www.jycxcx.com/st/2344811789.html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
答案解析與討論:
www.jycxcx.com/st/2344912465.html