What is 4G?4G, short for fourth generation, is the fourth generation of mobile telecommunications technology succeeding 3G. A 4G system, in addition to usual voice and other services of 3G system, provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to smartphones, and to other mobile devices. Even though 4G is a successor technology of 3G, there can be signification issues on 3G network to upgrade to 4G as many of them were not built on forward compatibility. Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, 3D television, and cloud computing.
Why do we need 4G?4G will support bandwidth hungry applications like video watching, video conferencing, downloading, etc
Where has 4G been deployed?Two 4G candidate systems are commercially deployed: the Mobile WiMAX standard (first used in South Korea in 2006), and the first-release Long Term Evolution (LTE) standard (in Oslo, Norway and Stockholm, Sweden since 2009). It has however been debated if these first-release versions should be considered to be 4G or not, as discussed in the technical definition section below.
In the United States, Sprint (previously Clearwire) has deployed Mobile WiMAX networks since 2008, and MetroPCS was the first operator to offer LTE service in 2010. USB wireless modems have been available since the start, while WiMAX smartphones have been available since 2010, and LTE smartphones since 2011. Equipment made for different continents is not always compatible, because of different frequency bands. Mobile WiMAX is currently (April 2012) not available for the European market.
What is the Difference Between 3G and 4G?As a rule, provided that you’re on the same carrier, a 4G connection will be faster than a 3G one. However, that doesn’t necessarily mean that a 4G network of one carrier will always be faster than the 3G network of another.
To be advertised as 3G, a network is required to meet a set of technical standards for speed and reliability, and must offer peak data transfer rates of at least 200 kilobits per second. The first networks that met this standard rolled out in the U.S. around 2003, and as smartphones began to gain more widespread use, demand for faster mobile broadband access saw a corresponding rise. In just a few short years, this push for faster data rates drove the standard forward, and today 3G networks can be anywhere from 200 kbps to dozens of times that fast.
To be advertised as 4G, a network must offer peak data rates of at least 100 megabits per second for high mobility communication (users in cars, trains, etc.), and at least 1 Gigabit per second for low mobility communication (pedestrians and stationary users). Not all 4G networks are created equal though – they come in a variety of different flavors, and some are faster and more widely deployed than others. The most common deployments are LTE, WiMAX, and HSPA+, but LTE is undoubtedly the most widely used amongst major US carriers.
It’s also worth noting that each new generation of wireless broadband typically requires your cell phone provider to make upgrades on their towers, and therefore requires you to upgrade your phone so that it can send/receive signals through the new infrastructure. A 3G phone cannot communicate through a 4G network, but newer generations of phones are practically always designed to be backward compatible, so a 4G phone can communicate through a 3G or even 2G network.