With the iPhone 4S having the preorders starting today, you might be thinking about just how great this new phone is going to be working for those who buy it. But there is still an issue with the 4S that is a carry over from the iPhone 4 and is not being resolved on the Verizon and now the Sprint wireless networks in the US. That issue is the fact that with the iPhone 4S, you cannot do both Voice and Data access at the same time. This is a known issue and has not been resolved with the latest phone.
With the latest release of the iPhone, one might expect this problem to be corrected, but thus far, there has been nothing stated that would point to a correction to the limitation up to this point. If the iPhone 4S was correcting this, Verizon would most certainly have made it a point to communicate that to potential customers. In the past, it was something lacking called SVDO and that technology would allow for Voice and Data to function at the same time on Verizon’s network. Since that is not there, we can plan on not seeing the capabilities for the iPhone 4S.
You still have the ability to do simultaneous Voice and Data if your data connection is over WiFi. Unless there is an announcement from Apple or Verizon that they have resolved the issues and the iPhone 4S is now capable of providing simultaneous Voice and Data, you are stuck. The same is going to apply to Sprint as they are a CDMA provider the same as Verizon.
AT&T has been advertising that they have the capability to allow for having both a Voice and Data connection at the same time on their network and those ads have been going on ever since Verizon got the iPhone. We can expect that they will be continuing to air those ads because it shows a difference between themselves as compared to Verizon and Sprint.
Since LTE is the next technology leap for speed and capacity, there is not really much incentive for Sprint and Verizon to make any changes to their network. With LTE, they will be able to run both Voice and Data connections at the same time, though that will be with the next iPhone, not the current models. There is no incentive for Verizon or Sprint to make changes to their networks to provide for both Voice and Data, which would in reality increase congestion on their 3G networks. No point in providing something that would hinder service.
Since it is going to be about a year before Apple produces the next iPhone, you will not have both Voice and Data at the same time until that time and must be considered. For some, that may be the deciding issue as Verizon continues to roll out their LTE network and more new phones are being released which are LTE capable and thus capable for simultaneous Voice and Data. It makes for a touch decision.