A sighnal must be transmitted over distance L. You can use aguided (attenuating) medium, like a coaxial cable, or radiation(dissipating) from an antenna. Testing the two media reveals: (a)on the coaxial, transmit power = 20 dBm, which attenuates at 10dB/km and (b) using anttena, received power = 20 dBm when the receiving antenna is 1m from the transmiter. Over what range of L does each medium out perform the other?