bandwidth

noun [C usually singular]
1 the amount of information that can be sent between computers, through a telephone wire, etc:
The system will handle not only telephone calls and data messages but other signals that need high bandwidth, for instance those that encode TV pictures.
high bandwidth services/applications

2 the range of frequencies used to send information over a distance using telephone wires

3 in radio, the width of a particular waveband

(from Cambridge Advanced Learner's Dictionary)