# Why do mobile phone transmissions come in pulses?

We are all familiar with the phenomenon that mobile phones induce in amplifiers and loudspeakers. The bip bip-da-bip bip-da-bip which happens just before you get a call, or if the phone is just feeling chatty.

I understand how the sound is produced, I don't understand why it has that particular pattern. Why a series of pulses?

I thought at first it might be an attempt to avoid interference, but of course that's nonsense: two x-millisecond transmissions are just as likely to become corrupted as one 2x-millisecond transmission.

So why the pule? Why not send the packet all at once? (Or send several packets in succession without a gap? Same difference -- the expected number of resends is surely the same.)