Originally Posted by Turkish_Leprechaun
Also, for the network, non of the towers are connected via T1, if they're not on fiber then they're on copper, 1.5 Mbps is not fast enough to support a tower by itself, a single digital voice call alone uses over 50 kbps.
Sprint phones use either 13kbps or 8kbps EVRC codecs depending on the age and manufacturer of the phone.
Cell sites use T1 lines. In areas of high bandwith use they may have several. In areas where T1 service is unavailable there are other alternatives (like microwave links), however these are very rare and do not offer optimal performance.
CDMA is a technology that allows each call to be encoded with a unique PR
code and spread across the available frequency. It does not require a fixed amount of bandwith held open for the duration of a call. As the bandwith used aproaches maximum soft capacity limits will kick in to degrade the quality of all users calls equally and allow even more traffic in times of high usage. Various methods Code division multiple access - Wikipedia, the free encyclopedia
I am not a network engineer so I am not able to provide much more detail then that.