Of all the confusing technology terms used in consumer marketing today, perhaps the most opaque is '4G,' used to describe a new, much faster generation of cellular data on smartphones, tablets and other devices. It sounds simple, but there are many varieties of 4G and conflicting claims.
AT&T claims 'The nation's largest 4G network,' and T-Mobile says it has 'America's largest 4G network.' Verizon Wireless boasts 'America's fastest 4G network,' and Sprint says it had the first 4G network.
Yet the technology used by T-Mobile, and mostly comprising AT&T's 4G network, isn't considered 'real' 4G at all by some critics, and the one used by Sprint has proven to be a dead end and is being abandoned. The flavor being used by Verizon is now being adopted by its rivals, but won't be interoperable among them.
It's a headache for consumers to grasp. So here's a simplified explainer to some of the most common questions, based on interviews with top technical officials at all four major U.S. wireless carriers.
What is 4G?
It's the fourth and latest generation technology for data access over cellular networks. It's faster and can give networks more capacity than the 3G networks still on most phones. There's a technical definition, set by a United Nations agency in Europe, and a marketing definition, which is looser, but more relevant to most consumers.
Who needs 4G?
It's mostly for people with smartphones, tablets and laptops who often need fast data speeds for Web browsing, app use and email when they're out of the range of Wi-Fi networks. It can give you the same or greater data speeds as home or office Wi-Fi when you're in a taxi. In hotels and airports, it's often faster than public Wi-Fi networks.
How does 4G differ from another term being advertised,'LTE'?LTE, which stands for 'Long Term Evolution.' is the fastest, most consistent variety of 4G, and the one most technical experts feel hews most closely to the standard set by the U.N. In the U.S., it has primarily been deployed by Verizon, which offers it in over 200 markets. AT&T has begun deploying it, offering LTE in 28 markets so far. Sprint and T-Mobile are pivoting to LTE, though they have no cities covered by it yet.
What are these other versions of 4G?
Sprint uses a technology called WiMax. T-Mobile and AT&T deployed a technology called HSPA+, a faster version of 3G that they relabeled as 4G, and which many technical critics regard as a 'faux 4G.' Sprint will begin switching to LTE later this year, and T-Mobile in 2013.
How fast is 4G?
Claims vary and performance depends upon the type of device, location, and time. In my tests, 4G phones, tablets and data modems for laptops typically deliver from three to 20 times the download speeds of 3G devices. The speed king is LTE. The LTE devices I've used have typically averaged download speeds of between 10 and 20 megabits per second, with frequent instances of over 30 megabits per second. The other forms of 4G have generally produced download speeds well under 10 mbps in my tests. But all of these are better than 3G, which in my tests on all networks and many devices, averages download speeds of under 2 mbps.
Who has the biggest 4G network in the U.S.?
Even if you accept all the carriers' definitions of 4G, it's hard to tell. Carriers measure their networks differently -- sometimes by the number of people to whom it is theoretically available, and sometimes by the number of cities and markets, which can be defined differently. Verizon has the largest LTE network. Both AT&T and T-Mobile claim the biggest 4G network, but the first has a limited LTE deployment and the second has none.
Does LTE work overseas?
Yes, but there is less LTE rollout going on overseas than in the U.S. So, in most countries, your shiny new American LTE device may wind up falling back to slower networks.
