Sentence:  Current 3G technologies can send roughly 1 bit of data - a one or a zero - per second over each 1 Hz of <WSD>spectrum</WSD> that the operator owns. 
Meaning of the word marked with <WSD> tags:  Specifically, a range of colours representing light (electromagnetic radiation) of contiguous frequencies; hence electromagnetic spectrum, visible spectrum, ultraviolet spectrum, etc. (from later 17th c.)