Description: 水下ns2 UnderWaterMiracle: Underwater Channel, PHY and MAC for NS-MIRACLE .-UnderWaterMiracle: Underwater Channel, PHY and MAC for NS-MIRACLE .
escription: we have developed a module for ns-miracle that allows a fully detailed simulation of the underwater channel, including frequency-dependent attenuation and noise, and the impact of temperature, salinity and depth on the propagation speed of acoustic waves.
Included in this model are also two underwater PHY models: one providing the maximum theoretical bitrate according to Shannon s theorem, and the other implementing a BPSK modulation scheme. Other PHY layer implementations can easily be developed.
Thanks to the PHY/MAC API included in Miracle, it is possible and also very easy to develop and test different MAC layers on top of the underwater PHY. Currently provided MAC protocols are ALOHA and FDMA.
The module can be downloaded here below. Please note that nsmiracle version 1.2.0 or above is required for the module to run. Platform: |
Size: 328704 |
Author:geful |
Hits:
Description: 本文着重研究网络中使用的MAC协议对语音传输过程的影响，以及无线传
感器网络中适用的语音编码算法。本文首先综述了现有无线传感器网络中常用
的MAC协议，对这些协议进行了分析比较。提出了一种新的基于TDMA的MAC
协议VR-TDMA，为了测试提出的协议性能，在NS2仿真平台上对该协议进行
了仿真，结果证明该协议具有良好的实时性能。然后研究了几种常用语音编码
算法的性能，通过比较研究，认为ADPCM语音编码算法的性能符合无线传感
器网络应用的要求，并对该算法进行了简化，减少了算法运行的计算量。实际
测试表明，算法具有良好的性能。
-In this paper,we concentrate on the mac protocols of wireless sensor networks，
especially the impact imposed on speech transmition．We also want to find a speech
coder which is fit for wireless sensor networks．Firstly,we intorduce the existing mac
protocol，such aS IEEE802．1 1，SMAC protocol，TRAMA protocol，DMAC protoc01．
Moreover we analyse and make comparison of them．Secondly，we propose a new
mac protocol named VR-TDMA．Simulation in NS2 proves that this protocol Canhave pleasing performance in real．time application．Thirdly,we
make a comparison
of some famous speech encoders．The result indicates that ADPCM(Adaptive
Di脏rential Pulse Code Modulation)is simpler than advanced low bit。rate VOICe
coding techniques and doesn’t require as heavy caculations．In this work，We simplify
the algorithm in order tO make it fit for the networks beaer．Actual tests prove that
this simplified algorithm work well in wireless sensor networks． Platform: |
Size: 3294208 |
Author:曾晓丽 |
Hits:
Search - mac protocols for ns2