Ilab1 Netw360

Week 1 iLab Report

DeVry University

NETW360: Wireless Technologies and Services

OPNET Preparation and Spread Spectrum Transmission Comparison

Submitted to:

Professor: Arias

Date: 1/11/15

OPNET Preparation

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?

Spread Spectrum techniques are methods by which a signal generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. Spread Spectrum establishes secure communication, increasing resistance to natural interference, noise and jamming, to prevent detection. It’s important in military applications when protecting communications.

Frequency Hopping Spread Spectrum (FHSS)

Frequency hopping is one of two basic modulation techniques used in spread spectrum signal transmission. It is the repeated switching of frequencies during radio transmission, often to minimize the effectiveness of "electronic warfare" - that is, the unauthorized interception or jamming of telecommunications. I use this technique often in the miltary

Direct Sequence Spread Spectrum (DSSS)

In telecommunications, direct-sequence spread spectrum (DSSS) is a modulation technique. As with other spread spectrum technologies, the transmitted signal takes up more bandwidth than the information signal that is being modulated.

Comparison between FHSS and DSSS

Technique | Advantages | Disadvantages |

FHSS | easy to implement | Throughput/ less secure |

DSSS | provides maximum security | interfering signals |

Conclusion

The radio technology on which WLANs are based is known as Spread Spectrum modulation and has its origins in the military. Spread Spectrum systems can coexist with other radio systems, without being disturbed by their presence and without disturbing their activity.

References

Ciampa, M....