Netw 360

Week 1 iLab Report

DeVry University

NETW360: Wireless Technologies and Services

OPNET Preparation and Spread Spectrum Transmission Comparison

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Professor:

Date: 7/10/2014

OPNET Preparation

Spread Spectrum Transmission Comparison

Introduction to Spread Spectrum Transmission

Guidelines

* What is it? Why is it important? What issues are addressed? How does it work?

There are two dominate radio frequency modulation techniques, narrowband and spread spectrum transmissions. A narrowband transmission is as the name describes. Narrowband transmits a strong signal over a narrow portion of the spectrum. However, spread spectrum transmits a weaker signal but it covers a wider portion of the spectrum. It is important because it provides more resistance to outside interference. This is due to the large area of the spectrum it comes, so when there is interference it only covers a small portion of the spread spectrum area. Spread spectrum uses different procedures when transmitting, so it less likely to have interference with other spread-spectrum transmissions. Also, spread spectrum requires less power to transmit the signal, because it is sending out a weaker signal. Spread spectrum offers better security because receivers intercept the transmissions and categorize them as noise. The receiver then ignores the spread spectrum transmission because it thinks it is noise. A final important feature of spread spectrum is that it can send more information than narrowband. In order to transmit it signal, the spread spectrum uses three methods: frequency-hopping spread spectrum, direct sequence spread spectrum, and orthogonal frequency division multiplexing (Ciampa, M.,2013).

Frequency Hopping Spread Spectrum (FHSS)

Guidelines

* What is it? How does it work? What issues are addressed? Why is it important?

Frequency hopping does not transmit using a single frequency. It will jump around a range of frequencies. The range of frequencies is...