Many wireless operators use the analog network as a fallback for digital customers.
The techniques use the current analog network but with a digital information stream.
Digital phones also have their own type of networks, which were built after the old analog networks.
Most of the older cell phones use analog networks.
All three services send digital data over analog networks.
But sending data over the cellular analog network can be a clunky process.
The analog network was to be switched off in June 2012.
OnStar's decision to use analog networks made sense a decade ago when the service was started because they were the most pervasive and reliable.
It may be used in analog cellular networks as well.
But in nearly every case, those on the sending and receiving ends must first go through the old-fashioned analog network.