Cellular systems and PCS systems are widely used in U.S.
Choose one answer.
a. Both cellular and PCS operate around 800 MHz |
b. Both cellular and PCS operate around 2 GHz |
c. Cellular systems operate around 800 MHz; PCS systems operate around 2 GHz |
d. Cellular systems operate around 2 GHz; PCS systems operate around 800 MHz |
Received signal power P decreases with increased distance d
Choose one answer.
a. in free space and urban area, P is proportional to d^-4 |
b. in free space and urban area, P is proportional to d^-2 |
c. in free space, P is proportional to d^-4; in urban area, P is proportional to d^-2 |
d. in free space, P is proportional to d^-2; in urban area, P is proportional to d^-4 |
Frequency reuse is achieved through cell/cluster structures
Choose one answer.
a. A service provider typically limits its operation within one cell |
b. A service provider typically limits its operation within one cluster |
c. A service provider typically operates in multiple clusters |
d. None of the above statement is correct |
Handoff occurs when a mobile station moves from one cell to another
Choose one answer.
a. If handoff occurs too early, call dropping rate may increase |
b. If handoff occurs too early, handoff rate may increase |
c. If handoff occurs too late, call dropping rate may decrease |
d. If handoff occurs too late, handoff rate may increase |
Cochannel interference is due to
Choose one answer.
a. Signal power attenuation |
b. Out-of-band user interference |
c. High noise level |
d. Frequency reuse |
Cell-splitting and sectoring increase system capacity
Choose one answer.
a. Cell-splitting reduces cochannel interference |
b. Cell-splitting increases the number of base stations required |
c. Sectoring increases the number of base stations required |
d. None of the above statement is correct |
In wireless channels, propagation mechanisms include reflection, diffraction and scattering
Choose one answer.
a. Reflection occurs when the signal propagates around curved surface |
b. Diffraction occurs around rough surfaces |
c. Scattering occurs along a smooth surface |
d. None of the above statement is correct |
Rayleigh fading versus Rician fading
Choose one answer.
a. Rayleigh fading is a special case of Rician fading |
b. Rician fading is a special case of Rayleigh fading |
c. Both Rayleigh fading and Rician fading characterize long-term fading |
d. Both Rayleigh fading and Rician fading characterize propagation without LOS |
FEC versus ARQ
Choose one answer.
a. ARQ typically requires more redundancy in coding |
b. ARQ requires feedback |
c. FEC requires feedback |
d. FEC is a reactive scheme for error recovery |
Different ARQ schemes have different efficiencies
Choose one answer.
a. SW is more efficient than GBN |
b. GBN is more efficient than SR |
c. SR is more efficient than SW |
d. None of the above statement is correct |
There are various multiple access schemes
Choose one answer.
a. Different users use different time slots in FDMA |
b. Different users use different frequency channels in TDMA |
c. Different users use different orthogonal codes in CDMA |
d. None of the above statement is correct |
Pure Aloha versus slotted Aloha
Choose one answer.
a. Pure Aloha has higher throughput |
b. Slotted Aloha is easier to implement |
c. Pure Aloha and slotted Aloha reach their peak throughput under the same traffic load |
d. None of the above statement is correct |
There are various versions of CSMA
Choose one answer.
a. In non-persistent CSMA, the terminal does not sense the channel |
b. In 1-persistent CSMA, the terminal stops sensing the channel when the channel is busy |
c. In p-persistent CSMA, the terminal sends packet immediately when channel becomes idle |
d. None of the statements are correct |
Wireless system capacity is limited by many factors. It is
Choose one answer.
a. bandwidth-limited because of channel fading |
b. range-limited because of cochannel interference |
c. interference-limited because of frequency reuse |
d. None of the above statement is correct |
Open-loop versus close-loop power control
Choose one answer.
a. In open-loop power control, MS determines its transmit power based on BS command |
b. In open-loop power control, MS determines its transmit power based on its received power level |
c. In close-loop power control, MS determines its transmit power based on its received power level |
d. None of the above statement is correct |
In radio resource management, QoS can be achieved through
Choose one answer.
a. transmitting higher power level |
b. reducing transmit data rate |
c. prioritizing real-time traffic over non-real-time traffic |
d. None of the above statement is correct |