计算机与通信网络实验报告

1、精选优质文档-倾情为你奉上计算机与通信网络实验报告 戴妍实验一 隐终端和暴露终端问题分析 一、实验设定：基本参数配置：仿真时长100s；随机数种子1；仿真区域2000x2000；节点数4。 节点位置配置：本实验用1 、2、 3 、4共两对节点验证隐终端问题。节点1、2距离为200m，节点3、4距离为200m，节点2、3距离为370m。  业务流配置：业务类型为恒定比特流CBR。1给2发，发包间隔为0.01s，发包大小为512bytes；3给4发，发包间隔为0.01s，发包大小为512bytes。 二、实验

2、结果： Node: 1, Layer: AppCbrClient, (0) Server address: 2Node: 1, Layer: AppCbrClient, (0) First packet sent at s: 0.Node: 1, Layer: AppCbrClient, (0) Last packet sent at s: 99.Node: 1, Layer: AppCbrClient, (0) Session status: Not closedNode: 1, Layer: AppCbrClient, (0) Total number of bytes sent

3、: Node: 1, Layer: AppCbrClient, (0) Total number of packets sent: 10000Node: 1, Layer: AppCbrClient, (0) Throughput (bits per second): Node: 2, Layer: AppCbrServer, (0) Client address: 1Node: 2, Layer: AppCbrServer, (0) First packet received at s: 0.Node: 2, Layer: AppCbrServer, (0) Last packet rece

4、ived at s: 99.Node: 2, Layer: AppCbrServer, (0) Average end-to-end delay s: 0.Node: 2, Layer: AppCbrServer, (0) Session status: Not closedNode: 2, Layer: AppCbrServer, (0) Total number of bytes received: Node: 2, Layer: AppCbrServer, (0) Total number of packets received: 9718Node: 2, Layer: AppCbrSe

5、rver, (0) Throughput (bits per second): Node: 3, Layer: AppCbrClient, (0) Server address: 4Node: 3, Layer: AppCbrClient, (0) First packet sent at s: 0.Node: 3, Layer: AppCbrClient, (0) Last packet sent at s: 99.Node: 3, Layer: AppCbrClient, (0) Session status: Not closedNode: 3, Layer: AppCbrClient,

6、 (0) Total number of bytes sent: Node: 3, Layer: AppCbrClient, (0) Total number of packets sent: 10000Node: 3, Layer: AppCbrClient, (0) Throughput (bits per second): Node: 4, Layer: AppCbrServer, (0) Client address: 3Node: 4, Layer: AppCbrServer, (0) First packet received at s: 0.Node: 4, Layer: App

7、CbrServer, (0) Last packet received at s: 99.Node: 4, Layer: AppCbrServer, (0) Average end-to-end delay s: 0.Node: 4, Layer: AppCbrServer, (0) Session status: Not closedNode: 4, Layer: AppCbrServer, (0) Total number of bytes received: Node: 4, Layer: AppCbrServer, (0) Total number of packets receive

8、d: 10000Node: 4, Layer: AppCbrServer, (0) Throughput (bits per second): 通过仿真结果可以看出，节点2无法收到数据。由于节点3是节点1的一个隐终端，节点1无法通过物理载波检测侦听到节点3的发送，且节点3在节点2的传输范围外，节点3无法通过虚拟载波检测延迟发送，所以在节点1传输数据的过程中，节点3完成退避发送时将引起冲突。 三、课后思考 1、RTS/CTS能完全解决隐终端问题吗？如果不能，请说明理由。 答：能。对于隐发送终端问题，2和3使用控制报文进行握手（RTS-CTS），听到回应握手信号的3知

9、道自己是隐终端，便能延迟发送；对于隐接受终端问题，在多信道的情况下，3给4回送CTS告诉4它是隐终端，现在不能发送报文，以避免4收不到3的应答而超时重发浪费带宽。 2、如何设计仿真场景来验证暴露终端问题？ 答：只需更改业务流配置：业务类型为恒定比特流CBR。2给1发，发包间隔为0.01s，发包大小为512bytes；3给4发，发包间隔为0.01s，发包大小为512bytes。观察在2给1发送数据的同时，3给4 发送数据会不会被影响。 3、如何设计协议使暴露终端场景下的流实现并发？ 答：至少要使用两个信道资源，在数据信道上进行RTS-CTS握手，

10、在数据信道上发送数据报文。在2给1发送数据报文时，3也想向4发送数据报文，通过控制信道向4发送RTS，4也从控制信道向3回送CTS，这样3就不会因为2的数据信号和4的回应信号产生碰撞而听不到4的回应了。这样就可以实现并发了。 实验二 无线局域网DCF协议饱和吞吐量验证1、 实验设定基本参数配置：仿真时长100S随机数种子1仿真区域150x150节点数100。业务流配置：业务类型为CBR，发包大小为512bytes，发包间隔为0.01S，分别测出5、 10、 15 、 20 、 25 、 30 、 35 、 40 、 45 、 50 条流的吞吐量。二、实验结果：5条：Node: 1,

11、Layer: AppCbrClient, (4) Server address: 55Node: 1, Layer: AppCbrClient, (4) First packet sent at s: 0.Node: 1, Layer: AppCbrClient, (4) Last packet sent at s: 99.Node: 1, Layer: AppCbrClient, (4) Session status: Not closedNode: 1, Layer: AppCbrClient, (4) Total number of bytes sent: Node: 1, Layer:

12、 AppCbrClient, (4) Total number of packets sent: 10000Node: 1, Layer: AppCbrClient, (4) Throughput (bits per second): Node: 1, Layer: AppCbrClient, (3) Server address: 54Node: 1, Layer: AppCbrClient, (3) First packet sent at s: 0.Node: 1, Layer: AppCbrClient, (3) Last packet sent at s: 99.Node: 1, L

13、ayer: AppCbrClient, (3) Session status: Not closedNode: 1, Layer: AppCbrClient, (3) Total number of bytes sent: Node: 1, Layer: AppCbrClient, (3) Total number of packets sent: 10000Node: 1, Layer: AppCbrClient, (3) Throughput (bits per second): Node: 1, Layer: AppCbrClient, (2) Server address: 53Nod

14、e: 1, Layer: AppCbrClient, (2) First packet sent at s: 0.Node: 1, Layer: AppCbrClient, (2) Last packet sent at s: 99.Node: 1, Layer: AppCbrClient, (2) Session status: Not closedNode: 1, Layer: AppCbrClient, (2) Total number of bytes sent: Node: 1, Layer: AppCbrClient, (2) Total number of packets sen

15、t: 10000Node: 1, Layer: AppCbrClient, (2) Throughput (bits per second): Node: 1, Layer: AppCbrClient, (1) Server address: 52Node: 1, Layer: AppCbrClient, (1) First packet sent at s: 0.Node: 1, Layer: AppCbrClient, (1) Last packet sent at s: 99.Node: 1, Layer: AppCbrClient, (1) Session status: Not cl

16、osedNode: 1, Layer: AppCbrClient, (1) Total number of bytes sent: Node: 1, Layer: AppCbrClient, (1) Total number of packets sent: 10000Node: 1, Layer: AppCbrClient, (1) Throughput (bits per second): Node: 1, Layer: AppCbrClient, (0) Server address: 51Node: 1, Layer: AppCbrClient, (0) First packet se

17、nt at s: 0.Node: 1, Layer: AppCbrClient, (0) Last packet sent at s: 99.Node: 1, Layer: AppCbrClient, (0) Session status: Not closedNode: 1, Layer: AppCbrClient, (0) Total number of bytes sent: Node: 1, Layer: AppCbrClient, (0) Total number of packets sent: 10000Node: 1, Layer: AppCbrClient, (0) Thro

18、ughput (bits per second): Node: 51, Layer: AppCbrServer, (0) Client address: 1Node: 51, Layer: AppCbrServer, (0) First packet received at s: 0.Node: 51, Layer: AppCbrServer, (0) Last packet received at s: 99.Node: 51, Layer: AppCbrServer, (0) Average end-to-end delay s: 0.Node: 51, Layer: AppCbrServ

19、er, (0) Session status: Not closedNode: 51, Layer: AppCbrServer, (0) Total number of bytes received: Node: 51, Layer: AppCbrServer, (0) Total number of packets received: 9966Node: 51, Layer: AppCbrServer, (0) Throughput (bits per second): Node: 52, Layer: AppCbrServer, (1) Client address: 1Node: 52,

20、 Layer: AppCbrServer, (1) First packet received at s: 0.Node: 52, Layer: AppCbrServer, (1) Last packet received at s: 99.Node: 52, Layer: AppCbrServer, (1) Average end-to-end delay s: 0.Node: 52, Layer: AppCbrServer, (1) Session status: Not closedNode: 52, Layer: AppCbrServer, (1) Total number of by

21、tes received: Node: 52, Layer: AppCbrServer, (1) Total number of packets received: 9966Node: 52, Layer: AppCbrServer, (1) Throughput (bits per second): Node: 53, Layer: AppCbrServer, (2) Client address: 1Node: 53, Layer: AppCbrServer, (2) First packet received at s: 0.Node: 53, Layer: AppCbrServer,

22、(2) Last packet received at s: 99.Node: 53, Layer: AppCbrServer, (2) Average end-to-end delay s: 0.Node: 53, Layer: AppCbrServer, (2) Session status: Not closedNode: 53, Layer: AppCbrServer, (2) Total number of bytes received: Node: 53, Layer: AppCbrServer, (2) Total number of packets received: 7668

23、Node: 53, Layer: AppCbrServer, (2) Throughput (bits per second): Node: 54, Layer: AppCbrServer, (3) Client address: 1Node: 54, Layer: AppCbrServer, (3) First packet received at s: 0.Node: 54, Layer: AppCbrServer, (3) Last packet received at s: 0.Node: 54, Layer: AppCbrServer, (3) Average end-to-end

24、delay s: 0.Node: 54, Layer: AppCbrServer, (3) Session status: Not closedNode: 54, Layer: AppCbrServer, (3) Total number of bytes received: 22016Node: 54, Layer: AppCbrServer, (3) Total number of packets received: 43Node: 54, Layer: AppCbrServer, (3) Throughput (bits per second): 1761Node: 55, Layer:

25、 AppCbrServer, (4) Client address: 1Node: 55, Layer: AppCbrServer, (4) First packet received at s: 0.Node: 55, Layer: AppCbrServer, (4) Last packet received at s: 0.Node: 55, Layer: AppCbrServer, (4) Average end-to-end delay s: 0.Node: 55, Layer: AppCbrServer, (4) Session status: Not closedNode: 55,

26、 Layer: AppCbrServer, (4) Total number of bytes received: 22016Node: 55, Layer: AppCbrServer, (4) Total number of packets received: 43Node: 55, Layer: AppCbrServer, (4) Throughput (bits per second): 176110、15、20、25、30、35、40、45、50条省略各发送节点发包间隔较大，当网络中发送节点较少时，网络还未饱和。逐渐往网络中增加负载，网络总吞吐量逐渐增大，之后，网络吞吐量逐渐趋向于平稳

27、，此时，网络即达到了饱和状态。三、课后思考1 、总结IEEE 802.11DCF协议饱和吞吐量和哪些因素有关。 任选一个时隙，网络中有节点在发送数据的概率 当有节点在发送数据包时，数据包发送成功的概率 数据包发送成功和发送失败所需的时间2 、为什么在数据包长度较长时，采用 RTS/CTS 模式更合理？ "隐藏终端"多发生在大型单元中（一般在室外环境），这将带来效率损失，并且需要错误恢复机制。当需要传送大容量文件时，尤其需要杜绝"隐藏终端"现象的发生。3 、本实验中提出的马尔科夫链模型只适用于单跳模型，若应用到多跳网络中时，需如何改进？

28、于定长时隙的多跳ad hoc网络DCF协议马尔可夫链模型 实验三 动态源路由协议路由选择验证 一、实验设定 基本参数配置：仿真时长100S；随机数种子1；仿真区域2000x2000；节点数5。 节点位置配置：用节点1-5来验证DSR路由协议的路由发现过程。1和2、2和3、3和4、3和5、4和6、5和6之间距离为200m。  设置业务流：1给2发，发包间隔0.01s，发包大小512Bytes。 设置节点移动性：节点1为移动节点，仿真过程中绕网格拓扑转一圈。二、 实验结果： Time(s): 1.,

29、 Node: 1, Route path: 2Time(s): 2., Node: 1, Route path: 2Time(s): 3., Node: 1, Route path: 2Time(s): 4., Node: 1, Route path: 2Time(s): 5., Node: 1, Route path: 2Time(s): 6., Node: 1, Route path: 2Time(s): 7., Node: 1, Route path: 2Time(s): 8., Node: 1, Route path: 4-2Time(s): 9., Node: 1, Route pa

30、th: 4-2Time(s): 10., Node: 1, Route path: 4-2Time(s): 11., Node: 1, Route path: 4-2Time(s): 12., Node: 1, Route path: 4-2Time(s): 13., Node: 1, Route path: 4-2Time(s): 14., Node: 1, Route path: 4-2Time(s): 15., Node: 1, Route path: 4-2Time(s): 16., Node: 1, Route path: 4-2Time(s): 17., Node: 1, Rout

31、e path: 4-2Time(s): 18., Node: 1, Route path: 4-2Time(s): 19., Node: 1, Route path: 4-2Time(s): 20., Node: 1, Route path: 4-2Time(s): 21., Node: 1, Route path: 4-2Time(s): 22., Node: 1, Route path: 4-2Time(s): 23., Node: 1, Route path: 4-2Time(s): 24., Node: 1, Route path: 4-2Time(s): 25., Node: 1,

32、Route path: 4-2Time(s): 26., Node: 1, Route path: 4-2Time(s): 27., Node: 1, Route path: 4-2Time(s): 28., Node: 1, Route path: 4-2Time(s): 29., Node: 1, Route path: 4-2Time(s): 30., Node: 1, Route path: 4-2Time(s): 31., Node: 1, Route path: 4-2Time(s): 32., Node: 1, Route path: 4-2Time(s): 33., Node:

33、 1, Route path: 4-2Time(s): 34., Node: 1, Route path: 4-2Time(s): 35., Node: 1, Route path: 4-2Time(s): 36., Node: 1, Route path: 4-2Time(s): 37., Node: 1, Route path: 4-2Time(s): 38., Node: 1, Route path: 5-4-2Time(s): 39., Node: 1, Route path: 5-4-2Time(s): 40., Node: 1, Route path: 5-4-2Time(s):

34、41., Node: 1, Route path: 5-4-2Time(s): 42., Node: 1, Route path: 5-4-2Time(s): 43., Node: 1, Route path: 5-4-2Time(s): 44., Node: 1, Route path: 5-4-2Time(s): 45., Node: 1, Route path: 5-4-2Time(s): 46., Node: 1, Route path: 5-4-2Time(s): 47., Node: 1, Route path: 5-4-2Time(s): 48., Node: 1, Route

35、path: 5-4-2Time(s): 49., Node: 1, Route path: 5-4-2Time(s): 50., Node: 1, Route path: 5-4-2Time(s): 51., Node: 1, Route path: 5-4-2Time(s): 52., Node: 1, Route path: 5-4-2Time(s): 53., Node: 1, Route path: 5-4-2Time(s): 54., Node: 1, Route path: 5-4-2Time(s): 55., Node: 1, Route path: 5-4-2Time(s):

36、56., Node: 1, Route path: 5-4-2Time(s): 57., Node: 1, Route path: 5-4-2Time(s): 58., Node: 1, Route path: 5-4-2Time(s): 59., Node: 1, Route path: 5-4-2Time(s): 60., Node: 1, Route path: 5-4-2Time(s): 61., Node: 1, Route path: 5-4-2Time(s): 62., Node: 1, Route path: 5-4-2Time(s): 63., Node: 1, Route

37、path: 5-4-2Time(s): 64., Node: 1, Route path: 5-4-2Time(s): 65., Node: 1, Route path: 5-4-2Time(s): 66., Node: 1, Route path: 5-4-2Time(s): 67., Node: 1, Route path: 5-4-2Time(s): 68., Node: 1, Route path: 3-2Time(s): 69., Node: 1, Route path: 3-2Time(s): 70., Node: 1, Route path: 3-2Time(s): 71., N

38、ode: 1, Route path: 3-2Time(s): 72., Node: 1, Route path: 3-2Time(s): 73., Node: 1, Route path: 3-2Time(s): 74., Node: 1, Route path: 3-2Time(s): 75., Node: 1, Route path: 3-2Time(s): 76., Node: 1, Route path: 3-2Time(s): 77., Node: 1, Route path: 3-2Time(s): 78., Node: 1, Route path: 3-2Time(s): 79

39、., Node: 1, Route path: 3-2Time(s): 80., Node: 1, Route path: 3-2Time(s): 81., Node: 1, Route path: 3-2Time(s): 82., Node: 1, Route path: 3-2Time(s): 83., Node: 1, Route path: 3-2Time(s): 84., Node: 1, Route path: 3-2Time(s): 85., Node: 1, Route path: 3-2Time(s): 86., Node: 1, Route path: 3-2Time(s)

40、: 87., Node: 1, Route path: 3-2Time(s): 88., Node: 1, Route path: 3-2Time(s): 89., Node: 1, Route path: 3-2Time(s): 90., Node: 1, Route path: 3-2Time(s): 91., Node: 1, Route path: 3-2Time(s): 92., Node: 1, Route path: 3-2Time(s): 93., Node: 1, Route path: 2Time(s): 94., Node: 1, Route path: 2Time(s): 95., Node: 1, Route path: 2Time(s): 96., Node: 1, Route path: 2Time(s): 97., Node: 1