The web is agog at the return of unlimited data plans for the iPhone, thanks to Sprint (s s) confirming today that it will offer unlimited plans for the upcoming iPhone 4S (s aapl). Those unlimited plans won’t come with throttling, either confirms a Sprint spokeswoman. But, while we’re pretty confident that Sprint’s network can handle that, will consumers be able to handle Sprint’s network?
Sprint operates a 3G network using CDMA technology, which currently delivers theoretical downlink speeds of between about 3 Mbps and 700 kbps. And thanks to having less coverage in some areas it means that the iPhone experience on Sprint might be slightly worse than the iPhone experience on Verizon (s vz) and actually a lot slower than the experience for folks using AT&T’s upgraded HSPA+ network. That’s because while the CDMA radio inside the phone is stuck using the much slower CDMA speeds, the GSM radio is tuned to take advantage of HSDPA with theoretical downlink speeds of 14.4 Mbps.
So for those users, there’s a big difference in how fast a YouTube clip loads (and how fast you’ll go through that data cap.) The trade-off on AT&T is that all voice and data traffic goes over the same network, which is what initially helped drive the poor voice experience for AT&T. Verizon and Sprint’s CDMA networks separate voice and data which is why the calling quality was never the issue it was for Ma Bell.
It may be that Verizon will be the bigger loser here as Sprint can take those who care more about price and data away from the Big Red, while those who are ready to sacrifice their hard-earned cash for a faster web experience run to AT&T.