Which four options are the characteristics of the original 802.11 protocol? (Choose four.)
A.
Defined DSSS and FHSS as possible methods for modulation
B.
Designed to operate in the 5 GHz ISM frequency spectrum
C.
The most common deployment is three non-overlapping channels that are 20 MHz wide
D.
The protocol sets the maximum throughput at 1 Mb/s or 2 Mb/s
E.
Defined FHSS and OFDM as possible methods for modulation
F.
The most common deployment is three non-overlapping channels that are 22 MHz wide
G.
Designed to operate in the 2.4 GHz ISM frequency spectrum
H.
The protocol sets the maximum throughput at 1 Mb/s
FHSS is still described in the original 802.11, but another technique is preferred and later adopted: Direct Sequence Spread Spectrum.
Instead of small channels and a jumping sequence, the information is sent over a wider channel. This channel is 22 Mhz wide and does not move, no hopping and direct sequence.
Then, over this 22 Mhz channel, several bits are sent in parallel. If a source of interference affects part of the channel, it will prevent only the bits sents in that frequency from reaching the server.
802.11b and 802.11g use the 2.4 GHz ISM band, operating in the United States under Part 15 of the U.S. Federal Communications Commission Rules and Regulations.
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In the telecommunications, direct-sequence spread spectrum (DSSS) is a spread spectrum modulation technique.
Frequency Hopping Spread Spectrum (FHSS) is a method of transmitting radio signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver
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dsss – 1 – 22 – 2.4
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The 802.11 family consists of a series of half-duplex over-the-air modulation techniques that use the same basic protocol. 802.11-1997 was the first wireless networking standard in the family, but 802.11
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