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18 Cards in this Set
- Front
- Back
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3-82M1
What term describes a wide-bandwidth communications system in which the RF carrier frequency varies according to some predetermined sequence? |
Spread spectrum communication
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3-82M2
Name two types of spread spectrum systems used in most RF communications applications? |
Direct Sequence and Frequency Hopping
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3-82M3
What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels? |
Frequency hopping
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3-82M4
A TDMA radio uses what to carry the multiple conversations sequentially? |
Separate time slots
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3-82M5
Which of the following statements about SSB voice transmissions is correct? |
They normally use J3E emissions, which consists of one sideband and a suppressed carrier
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3-82M6
What are the two most-used PCS (Personal Communications Systems) coding techniques used to separate different calls? |
CDMA and GSM
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3-83M1
What is a CODEC? |
A coder/decoder IC or circuitry that converts a voice signal into a predetermined digital format for encrypted transmission
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3-83M2
The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications? |
Regular-Pulse Excited (RPE)
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3-83M3
Which of the following codes has gained the widest acceptance for exchange of data from one computer to another? |
ASCII
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3-83M4
The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. What level is responsible for the actual transmission of data and handshaking signals? |
The physical layer
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3-83M5
What CODEC is used in Phase 2 P25 radios? |
IWCE
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3-83M6
The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. The _______ level arranges the bits into frames and controls data flow. |
Link layer
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3-84M1
What is a SDR? |
Software Defined Radio
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3-84M2
What does the DSP not do in a modern DSP radio? |
Control SWR
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3-84M3
Which statement best describes the code used for GMDSS-DSC transmissions? |
A 10 bit error correcting code starting with bits of data followed by a 3 bit error correcting code
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3-84M4
Which is the code used for SITOR-A and -B transmissions? |
Each character consists of 7 bits with 4 “zeros” and 3 “ones”
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3-84M5
Which of the following statements is true? |
The Idle Signal (a) (0000111) is used for FEC Phasing Signal 1.
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3-84M6
What principle allows multiple conversations to be able to share one radio channel on a GSM channel? |
Time Division Multiplex
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