CCNP Wireless FAQ: Solving Noise and Interference Problems
Q1. For reliable network operation, signal strength is more important than SNR. True or false?
Q2. A reliable wireless link needs a line-of-sight path and an unobstructed Fresnel zone. True or false?
Q3. Will the noise level always be low in a rural area?
Q4. How many nonoverlapping 2.4 GHz channels are available for use in the United States?
Q5. The consequence of a low SNR is reduced network throughput. True or false?
Q6. Reusing a DSSS frequency at the same AP location requires how many decibels of antenna isolation?
Figure: Frequency Plan
Answer: Reusing the same frequency in the same location requires approximately 121 dB of antenna isolation.
Q7. To avoid interference, collocated FHSS sectors should use different hopping sequences and different hopping sets. True or false?
Q8. When is the SNR highest at an AP?
Q9. When the percentage of retransmitted packets reaches 20 percent, you should start looking for the cause of the network slowdown. True or false?
Q10. Explain why it is necessary to write down the results of your noise-reduction efforts.