Coding and Error Control Review/Recap - Lecture 25File Edit View lerminal Tabs tjelp [zulkiflỡvmmachine ns-2.3O]$ ./validate (Validation can take 1-30 hours to run.) Fri Feb 1 12:22:21 PKT 2008 *** ./test-all-simple Tests: tahoel tahoelBytes tahoelRED tahoelREDbytes tahoe2 tahoe3 tahoe3RED tahoe 4 no_bug bug renol reno reno.A reno2 reno3 reno4 reno4a reno5 reno5_nobug telnet delayed phase pha...
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Software Defined Radio - Lecture 31Applications: OpenBTS+GnuRadio+USRP Entrepreneurs mostly emphasize their businesses and infrastructures in settled and developed areas. Low cost, low power, reconfigurable and flexible communication model for those Entrepreneurs ROI (Return on Investment) for MNO's (Mobile Network Operators) GSM to Voice over IP (GSM-2-VoIP), GSM to Conventiona...
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Coding and Error Control Review/Recap - Lecture 24Example – Modulo-2 Arithmetic Method Given D = 1 0 1 0 0 0 1 1 0 1 P = 1 1 0 1 0 1 Find the FCS field Solution: First we note that: The size of the data block D is k = 10 bits The size of P is (n – k + 1) = 6 bits Hence the FCS length is n – k = 5 Total size of the frame T is n = 15 bits Example – Modulo-2 Arith. Method Solution (cont...
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Cellular Wireless Networks GSM - Lecture 30Analogy: Multiplexing Lectures at a learning institute: Frequency Division: takes place in different rooms Time Division: taking turns in a single room Code Division: lectures on different subjects. GSM Location Services 1. Call made to mobile unit (cellular phone) 2. Telephone network recognizes number and gives to gateway MSC 3. MSC can...
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Coding and Error Control - Lecture 23Error Detection Process Transmitter For a given frame, an error-detecting code (check bits) is calculated from data bits Check bits are appended to data bits Receiver Separates incoming frame into data bits and check bits Calculates check bits from received data bits Compares calculated check bits against received check bits Detected error ...
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Wireless and Mobile Computing ns-2 Architecture - Lecture 29Maths Support classes [ns-2.29/tools/] class Integrator Simple linear interpolation integrator class Samples Tracks set of sample points (count, sum, sum2, mean, var) class Random,
RandomVariable Wrapper around RNG Uniform, exponential, pareto, normal, lognormal generators class RNG Implementation of pseudo-random number generator... 88 trang | Chia sẻ: thucuc2301 | Ngày: 23/11/2020 | Lượt xem: 554 | Lượt tải: 0
Cellular Wireless Networks - Lecture 28OFDM Quadrature Phase Shift Keying (QPSK) symbol represents 2 bits Example of OFDM/QPSK scheme: occupies 6 MHz made up of 512 individual carriers, with a carrier separation of a little under 12kHz data are transmitted in bursts bursts consist of a cyclic prefix followed by data symbols cyclic prefix absorbs burst transients waveform from mul...
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Spread Spectrum Review/Recap - Lecture 22CDMA Q:- What is CDMA? Ans:- CDMA allows multiple users to transmit over the same wireless channel using spread spectrum. Each user uses a different spreading code. The receiver picks out one signal by matching the spreading code. Summary Relationship between bandwidth of a signal (before and after and encoding SS) Benefits of SS FHSS Slow a...
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Wireless and Mobile Computing Simulations - Lecture 27Bug-Fixing Questions What is the expected behaviour of the network? Have I connected the network right? Am I logging trace information at the right level? Can I change it to narrow down on the problem? Has anyone else out there had the same problem? Is there something similar in examples that I can look at, and build upon? Does the code reall...
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Spread Spectrum - Lecture 21Advantages of Spread Spectrum Reduced crosstalk interference Better voice quality/data integrity and less static noise Lowered susceptibility to multipath fading Inherent security: Co-existence Longer operating distances Hard to detect Hard to intercept or demodulate Harder to jam Summary Spread Spectrum (SS) SS Techniques: FHSS DSSS...
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