Telephony and broadband need innovative spectrum management,
says Shyam Ponappa. Twenty years ago, "spectrum" implied the
colours of the rainbow. Now, we understand that spectrum also
relates to mobile phones. We encounter spectrum daily, in TV
remote controls, microwave ovens, even sunlight. So, what
exactly is spectrum, and how do government and commercial
decisions on this scientific phenomenon affect public facilities
and costs? "Spectrum" is short for "electromagnetic spectrum",
the range of radiated energies that envelop the Earth. This
electromagnetic radiation (EMR) is primarily from the sun, and
secondarily from the stars/cosmos, radioactive elements in soil,
rock and gases... One section of EMR is visible light; another
is radio frequency (RF) spectrum. There are many other
"wavelengths" in EMR with different characteristics and effects,
such as infrared and ultraviolet rays. All countries have the
same RF spectrum in equivalent areas. How is spectrum used? The
length of a wave, its associated frequ