第9题： 物联网中使用的无线传感网络技术是（ ）。
A.802.15.1蓝牙个域网
B.802.11n无线局域网
C.802.15.3 ZigBee微微网
D.802.16m无线城域网
答案解析与讨论：www.cnitpm.com/st/2344422058.html

第10题： 正在发展的第四代无线通信技术推出了多个标准，下面的选项中不属于4G标准的是（ ）。
A.LTE
B.WiMAXII
C.WCDMA
D.UMB
答案解析与讨论：www.cnitpm.com/st/2344516479.html

第11题：

下面是家庭用户安装ADSL宽带网络时的拓朴结构图，图中左下角的x是（1）设备，为了建立虚拟拨号线路，在用户终端上安装（2）协议。

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

答案解析与讨论：www.cnitpm.com/st/2344620749.html

第13题： 下列关于网络核心层的描述中，正确的是（ ）。
A.为了保障安全性，应该对分组进行尽可能多的处理
B.将数据分组从一个区域高速地转发到另一个区域
C.由多台二、三层交换机组成
D.提供多条路径来缓解通信瓶颈
答案解析与讨论：www.cnitpm.com/st/2344811789.html

第14题： 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

答案解析与讨论：www.cnitpm.com/st/2344912465.html