Lesson 11: Spread Spectrum Technology

Which of the following networks or products use spread spectrum technologies?

Wireless local area networks (WLAN), Bluetooth, and global positioning systems (GPS). Wireless local area networks (WLAN), Bluetooth, and global positioning systems (GPS). Wireless local area networks (WLAN), digital subscriber links (DSL), and global positioning systems (GPS). Wireless local area networks (WLAN), personal communications systems (PCS), and satellite radio. Wireless local area networks (WLAN), digital subscriber links (DSL), and digital cellular telephony (code division multiple access [CDMA]).

The Federal Communications Commission (FCC) rules regarding power output for frequency-hopping spread spectrum (FHSS) state that a maximum output to the intentional radiator (IR) with 5 megahertz (MHz) of carrier frequency bandwidth must be which one of the following?

125 milliwatts (mW). 125 milliwatts (mW). 100 milliwatts (mW). 1 watt (W). 150 milliwatts (mW).

What is the width of direct sequence spread spectrum (DSSS) channels and how far apart are their center frequencies spaced?

22 megahertz (MHz) wide and 5 MHz apart. 11 megahertz (MHz) wide and 5.5 MHz apart. 72 megahertz (MHz) wide and 11 MHz apart. 5 megahertz (MHz) wide and 2.5 MHz apart. 22 megahertz (MHz) wide and 5 MHz apart.

How does spread spectrum technology reduce the probability of signal jamming?

By transmitting over a wide frequency spectrum. By transmitting over a wide frequency spectrum. By spreading the signal over a range of narrow frequency bands. By increasing the power level during jamming. By transmitting an anti-jamming signal along with the intelligence.

Although there are many different implementations of spread spectrum technology, what are the only types specified by the Federal Communications Commission (FCC) in the Codes of Federal Regulation (CFR), Volume 47, Part 15?

Direct Sequencing Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS). Direct Sequencing Spread Spectrum (DSSS) and Frequency Agile Spread Spectrum (FASS). Direct Sequencing Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS). Direct Structure Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS). Direct Sequencing Spread Spectrum (DSSS) and Frequency Holding Spread Spectrum (FHSS).

Why is direct sequence spread spectrum (DSSS) the most widely known and the most used of the spread spectrum types?

Its ease of implementation and high data rates. It is the most secure spread spectrum technology. Its ease of implementation and high data rates. It requires the least amount of power and frequency spectrum. It is the most resistant of all the spread spectrum technologies to narrowband interference.

The ratio of the chipping code to data bits for a direct sequence spread spectrum (DSSS) signal is called which of the following?

Processing gain. Data integrity threshold. Compression algorithm. Overhead. Processing gain.

Why is spread spectrum technology used in applications such as Bluetooth wireless personal area networks (WPAN)?

Spread spectrum technology allows wireless networking to create a short range, personal communications network. Spread spectrum technology makes efficient use of precious frequency spectrum. Spread spectrum technology sends data in short bursts, allowing multiple users to share the network by transmitting at different times. Spread spectrum technology can be used without paying royalty fees to the patent owners. Spread spectrum technology allows wireless networking to create a short range, personal communications network.

Which component of frequency hopping spread spectrum (FHSS) system creates more overhead than any similar component in a direct sequence spread spectrum (DSSS) system?

The interframe spacing. Co-location. The interframe spacing. The noise floor. The frame size.

In a frequency-hopping spread spectrum (FHSS) system that uses 10 frequencies across a 12 megahertz (MHz) frequency band, what happens if narrowband interference occurs at only one of the 10 frequencies?

The spread spectrum signal remains intact. Instead of being lost, the data on the interfered frequency is retransmitted on one of the other nine frequencies. The spread spectrum signal remains intact, but approximately 10 percent of the transmitted data is lost. The spread spectrum signal remains intact. Instead of being lost, the data on the interfered frequency is retransmitted on one of the other nine frequencies. The spread spectrum signal remains intact, but to compensate, the system automatically extends the dwell time for the remaining nine frequencies, thus sending more data on each. The spread spectrum signal remains intact, but the system abandons the frequency with narrowband interference and automatically switches to an open and available frequency for transmission.