According to the latest news on the Web, wireless carrier AT&T might face some difficulties when it comes to providing the necessary support for the upcoming iPhone 3G S. It seems that the handset includes some functionalities that the operator is not ready to support just yet, such as multimedia messaging and “tethering” options, due to network limitations, at least this is what Roger Entner, head of telecom research for Nielsen, is reported to have stated.

While the list of worldwide carriers that offer support for Tethering (a wireless device that can be used as a broadband modem for over-the-air support for laptops) and MMS (video clips, audio files, pictures that can be attached to text messages) is a long one, AT&T is not on it. As many of you might already know, AT&T is the only operator that sells the iPhone 3G S in the US and, while the phone will become available on Friday, the carrier said that MMS would be offered “by the end of the summer.”

There are no exact details on when the MMS support will come to iPhone users from AT&T, nor on when tethering will be supported. “Tethering will be available at some point,” is what AT&T spokesman Mark Siegel is reported to have stated. At the same time, we should also mention that iPhone 2G users won't be able to enjoy MMS with the upcoming OS 3.0, which means that they will have to upgrade to a newer version in case they would like to have it.

On the other hand, AT&T seems to be aware of the fact that iPhone users eat up more network capacity than the rest, and it announced plans to upgrade the network to HSPA. According to the carrier, the upgrade should be completed by 2011, which means that iPhone 3G S owners will be able to benefit from faster speeds and more stability. Given the large number of iPhone users it has, namely around 7 million according to estimations, the network is heavily loaded, yet once the upgrade will be deployed, people will have to acquire the new model to enjoy it, as the 3G iPhone won't support it.