We tested 3G and 4G wireless data transfer speedsindoors and outfor ATT, Sprint, TMobile, and Verizon, at multiple locations in 13 major cities. Here. Verizon made it official today it will be getting the iPhone, ending years of ATT exclusivity in the U. S. Improve coverage in your home or small business with the Network Extender. Learn what it is, how to set it up, troubleshooting tips and more. Whats the Difference Between AT T and Verizons 3. G Networks Verizon made it official today it will be getting the i. Phone, ending years of AT T exclusivity in the U. S. With the Verizon i. Phone a reality, there is one question that millions of i. Phone owners are now asking themselves should I switch carriersAfter years of frustration with dropped calls and spotty 3. G connectivity, we understand why so many i. Verizon 3G Speed' title='Verizon 3G Speed' />Explore Verizons full selection small and medium business solutions including FiOS, high speed internet, phone, and TV service. Find great deals for Apple iPad 2 16GB, WiFi 3G Verizon, 9. Black. Shop with confidence on eBay Verizon is killing off its 3G network to add more capacity for 4G smartphones and tablets. Phone users are eager to become Verizon customers. In our reader poll, 2. Mashable readers said theyre switching to Verizon ASAP, while another 1. A lot of people have been asking us about whether switching is a good idea. More specifically, they want to understand the differences between the AT T i. Phone, a UMTSGSM device, and the Verizon i. Nascar Thunder 2004 Pc Full. Phone, a CDMA gadget. Verizon 3G Speed' title='Verizon 3G Speed' />What exactly is CDMA Is it better or worse than UMTS Why is it impossible to to talk and browse the web at the same time on a Verizon i. Shortcut Key To Switch Between Programs In Windows. Phone To answer your questions, we wrote a short guide on the subject of CDMA, UMTS and the differences between AT T and Verizons 3. G networks The Basics on CDMA, GSM and UMTSThe primary difference between the AT T i. Phone and the Verizon i. Phone is the technology each uses for 3. G connectivity. AT T employs the Universal Mobile Telecommunications System in its network. UMTS is built upon concepts from the Global System for Mobile Communications GSM standard, the basis for EDGE Enhanced Data rates for GSM Evolution. Because of this shared architecture, most UMTS devices support GSM and EDGE, including the AT T i. Phone. GSM and UMTS technology is widely used worldwide. UMTS phones can be easily moved from one UMTS network to another, making them ideal for international use. Verizon, on the other hand, uses code division multiples access CDMA, a form of spread spectrum signaling that utilizes bandwidth more effectively than most other solutions its often considered more spectrally efficient. CDMA also utilizes soft handovers of phone calls, so instead of switching directly from one tower to the next hard handover, CDMA devices can receive a signal from multiple towers simultaneously. That makes the shift between towers less detectable, and it decreases the rate of dropped calls. On the other hand, UMTS devices arent as efficient at soft handovers. CDMA technology does have several disadvantages, though. It cant use a SIM card, making it far more difficult to switch handsets. More important is that UMTS networks tend to upload and download data faster than CDMA. A test last year by PCWorlddemonstrated that AT T has the fastest 3. G network by a healthy margin. There is, of course, great variation in network speeds depending on location, population density and other factors, but in general youre going to get a faster 3. G connection on AT T UMTS than you will on Verizon CDMA. One of the other big disadvantages of CDMA is its inability to carry voice and data simultaneously. AT T phones can browse the web while on a phone call. Verizon phones dont have that capability, although the network is working on that feature. Whats the Bottom Line In the end, your phone is going to work essentially the same on both networks, and the truth is that the vast majority of users wont notice any difference. Here are some key points to remember, though Calls In general, Verizon will drop less calls. Its unclear what impact the i. Phone will have on its network, but we dont expect it to be as bad as AT T was in its early years. Verizons network has proven itself to be more robust. Speed In general, AT T has the faster 3. G network, and in some cases its a great deal faster than Verizon. Simultaneous voice and data Only AT T is capable of talking on the phone and surfing the web at the same time, but Verizon is working on a solution, saying the fix might be implemented by the end of this year. The latter point may become a nonissue soon, though. According to The Wall Street Journal, a solution to carry voice and data simultaneously on CDMA networks is coming later this year The inability to multitask can be traced to a decision years ago by the engineers developing CDMA to split voice and data traffic into separate signals, so they cant run both at once. Now, theyre working to overcome it. A solution that will allow CDMA networks to carry voice and data simultaneously will become commercially available in the first half of 2. Brad Shewmake, spokesman for the CDMA Development Group, an industry organization. This argument between CDMA and UMTS may become a moot point in the next few years, though, as 4. G networks overtake 3. G technology. Wi. Max and LTE are the primary 4. G standards. Both AT T and Verizon are utilizing LTE as a standard for their 4. G networks. LTE is a GSM based technology, so its no surprise AT T would embrace it. Verizons decision to utilize LTE though could make the argument between the two networks moot, though. They are using the same technology, meaning that the effectiveness of their 4. G implementations will determine how fast and reliable they are. Because its GSM based, it will also support simultaneous voice and data. For now, its smart to at least know the advantages and disadvantages of CDMA and UMTS. It will change in the next few years, though.