The new iPhone 4S has three important wireless networking enhancements that its predecessor lacked, including dual-network world phone capabilities.

But more important to many would-be buyers, however, may be that it comes with unique technology that switches a radio signal between its two exterior antennas to provide better reception.

Antennagate

Those two antennas were behind the 'Antennagate' brouhaha that erupted last year after the iPhone 4 launched and users found that holding the device a certain way led to dropped calls. With the iPhone 4S, Apple seems to have come up with an internal fix for the "death grip" issue, analysts said.

Apple officials only briefly mentioned the new antenna design in their presentation, and an Apple statement about the new phone, which goes on sale October 14, was succinct: "Improving on the innovative stainless steel external dual-antenna design of iPhone 4, iPhone 4S is the first phone to intelligently switch between two antennas to send and receive."

Apple didn't respond to a request to more details. But Gartner analyst Michael Gartenberg said the company probably tweaked the new phone's hardware and software to eliminate reception problems that plagued some iPhone 4 devices.

"Apple didn't go into details of what they are doing, but they were clearly laying to rest early on the issues over reception seen in iPhone 4," Gartenberg said. "Since the iPhone 4S exterior design is relatively unchanged from iPhone 4, people were obviously wondering if there would be any issues with the antenna again, call it 'Antennagate' or whatever."

A world phone

The new iPhone 4S also functions as a world phone that works with both CDMA and GSM networks.

That means that customers of Sprint and Verizon, which have CDMA networks, will have to use GSM networks if they travel abroad, since GSM is widely deployed globally. And they will also be subject to roaming policies and will have to pay rates that can be quite high, analysts noted.

"The world phone is a big thing, especially for a lot of users who travel internationally," Burden said.

Both Gartenberg and Burden noted that Apple benefits from having both GSM and CDMA inside the iPhone 4S, because it can simplify future updates to one model. "You will have one phone for multiple carriers," Burden said.

HSDPA means fast downloads

Apple boasted that the iPhone 4S supports download speeds of up to 14.4Mbps with HSDPA (High Speed Download Packet Access) technology. Burden said that capability will work on many GSM networks globally, including AT&T in the US.

However, Apple included a footnote in its press release noting that "HSDPA availability and network speeds are dependent on carrier networks."

In fact, only AT&T will support HSDPA. On Sprint and Verizon networks, download performance is governed by the CDMA/1x EV-DO rev. A standard, so speeds will reach up to 3Mbps at best, according to industry standards.

Additionally, AT&T will only have the faster 14.4Mbps downloads where it has provisioned HSDPA. And that download speed is considered a theoretical maximum, in reality the average user in a crowded tower zone won't experience that level of performance.

Gartenberg said the network improvements are not what he considers the best new features in the iPhone 4S. Instead, he pointed to the faster dual-core A5 processor, the 8 megapixel enhanced camera and speech recognition capability using Siri.

The fact that Apple stuck with the same exterior design as the iPhone 4 isn't going to be a problem, he contended. "People like that design and it sold incredibly well," Gartenberg said. "It makes sense to keep it."