inversely proportional

inversely proportional

Suppose, that in an attempt to increase range, cordless telephone manufacturers double the power output of their transmitters. Assume, that in the cluttered in-house environment, power density is inversely proportional to the fourth power of distance.
(a) Suppose the usable range, limited by signal strength without interference, was 50 m before the power increase. What is it after the increase?
(b) What effect will the power increase have on interference from other portable telephones?
(i) operating at the old (low) power level?
(ii) operating at the new (high) power level?
(c) What can you conclude from your answer about the effect of increasing power in an environment where transmission range is limited by
(i) signal-to-noise ratio? (ii) signal-to-interference ratio?

inversely proportional