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31 Cards in this Set
- Front
- Back
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The 900 MHz ISM band is ____ wide and spans from _______ to _________ |
26 MHz, 902 MHz to 928 MHz |
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The most common band used for wireless networking communications. |
2.4 GHz band |
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How wide is the 2.4 GHz band? |
100 MHz and spans from 2.4 to 2.5 GHz. |
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What wireless radios use the 2.4 GHz band?
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802.11 (FHSS or DSSS radios) 802.11b (HR-DSSS radios) 802.11g (ERP radios) 802.11n (HT radios) |
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How wide is the 5.8 GHz ISM band? This band spans from what to what? |
150 MHz wide and spans from 5.725 from 5.875 GHz. |
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The IEEE 802.11a amendment designated WLAN transmissions within the frequency space of the three 5 GHz band, each with four channels. These frequency ranges are known as what? |
Unlicensed National Information Infrastructure (U-NII) bands. |
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Wi-Fi radios that currently transmit in the 5 GHz U-NII bands include radios that use what technologies? |
OFDM radios (802.11a) HT radios (802.11n) VHT radios (802.11ac) |
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This band used to be restricted to indoor use only but as of 2014 is available. Has a total of four 20 MHz channels. |
U-NII-1 band |
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This band spans from 5.150 to 5.250 GHz and is 100 MHz wide. |
U-NII-1 or the lower U-NII band |
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This band spans from 5.250 to 5.350 GHz and is 100 MHz wide. |
U-NII-2 or the middle U-NII band |
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This band has a total of 4 20 MHz channels and radios that operate in this band must support dynamic frequency selection (DFS). |
U-NII-2 or the middle U-NII band |
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This band has a total of twelve channels and spans from 5.470 to 5.725 GHz. This band is also 255 MHz wide. |
U-NII-2 Extended band |
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This band is 125 MHz wide and spans from 5.725 to 5.850 GHz. This band is used for outdoor point-to-point communications but is not limited to only indoor use. |
U-NII-3 or the upper U-NII band |
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The two primary radio frequency transmission methods are? |
Narrowband and spread spectrum |
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This technology uses more bandwidth than what is necessary to carry its data. This technology takes the data that is to be transmitted and spreads it across the frequencies that it is using. |
spread spectrum |
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This type of technology is prone to intentional jamming or unintentional interference. This technology uses a higher power to transmit signals. The ______ signals take up a single or very narrow band of frequencies. |
narrowband |
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This occurs when a reflected signal arrives at the receiving antenna after the primary signal. |
multipath |
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What standard takes advantage of multipath? |
802.11n and 802.11ac |
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Used in the original 802.11 standard this technology provided 1 and 2 Mbps RF communications using the 2.4 GHz ISM band for legacy radios. |
Frequency Hopping Spread Spectrum (FHSS) |
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This technology transmits data by using a small frequency carrier space, then hops to another small frequency carrier space and transmits data, then to another frequency, and so on. |
Frequency Hopping Spread Spectrum (FHSS) |
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This technology was originally specified in the 802.11 standard and provides 1 and 2 Mbps RF communications using the 2.4 GHz ISM band. This technology is set to one channel and does not jump between frequencies. |
Direct Sequence Spread Spectrum (DSSS) |
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DSSS uses this to add additional redundant information to data. This is done because of the unbounded medium that signals travel across have a huge potential for RF interference. This additional redundant information will minimize data corruption. |
Processing gain |
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The process of converting a single data bit into a sequence is called what? |
spreading or chipping |
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To provide faster speeds of HR-DSSS this code is used. It uses an 8 chip PN along with using different PNs from different bit sequences. |
Complementary Code Keying (CCK) |
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A modulation technique that supports data rates of 5.5, 11, 22, and 33 Mbps. |
Packet Binary Convolutional Code (PBCC) |
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Used in both wired and wireless communications this technology uses high power and more bandwidth than necessary to carry data. |
Orthogonal Frequency Divison Multiplexing (OFDM) |
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The center frequency of channel 4 in the 2.4 GHz band is |
2.427 |
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HR-DSS uses what type of encoding |
Complementary Code Keying (CCK) |
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In FHSS a measurement of the amount of time it takes for the transmitter to change from one frequency to another is called what? |
Hop time |
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OFDM in 802.11a/g/n/ac standards, the frequency width used by an OFDM channel is how wide? |
20MHz |
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The amount of time that the FHSS system transmits on a spcecific frequency before it switches to the next frequency in the hop set is called what? |
Dwell time |
