3G ,4G Service Of Mobile Phone

3G ,4G Service Of Mobile Phone

3g and 4g service

3G, short form of third generation, is the third generation of mobile telecommunications technology.This is based on a set of standards used for mobile devices and mobile telecommunications use services and networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. 3G finds application in wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV.

3G telecommunication networks support services that provide an information transfer rate of at least 200 kbit/s. Later 3G releases, often denoted 3.5G and 3.75G, also provide mobile broadband access of several Mbit/s to smartphones and mobile modems in laptop computers. This ensures it can be applied to wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV technologies.

A new generation of cellular standards has appeared approximately every tenth year since 1G systems were introduced in 1981/1982. Each generation is characterized by new frequency bands, higher data rates and non–backward-compatible transmission technology. The first 3G networks were introduced in 1998 and fourth generation "4G" networks in 2008.

First things first, the "G" stands for a generation of mobile technology, installed in phones and on cellular networks. Each "G" generally requires you to get a new phone, and for networks to make expensive upgrades. The first two were analog cell phones (1G) and digital phones (2G). Then it got complicated.

Third-generation mobile networks, or 3G, came to the U.S. in 2003. With minimum consistent Internet speeds of 144Kbps, 3G was supposed to bring "mobile broadband." There are now so many varieties of 3G, though, that a "3G" connection can get you Internet speeds anywhere from 400Kbps to more than ten times that.

New generations usually bring new base technologies, more network capacity for more data per user, and the potential for better voice quality, too.

4G phones are supposed to be even faster, but that's not always the case. There are so many technologies called "4G," and so many ways to implement them, that the term is almost meaningless. The International Telecommunications Union, a standards body, tried to issue requirements to call a network 4G but they were ignored by carriers, and eventually the ITU backed down. 4G technologies include HSPA+ 21/42, the now obsolete WiMAX, and LTE (although some consider LTE the only true 4G of that bunch, and some people say none of them are fast enough to qualify.)

There's a big difference between 4G LTE and other technologies called "4G" though, and it's most visible in upload speeds. If you upload a lot of data - posting photos or videos, for instance - you'll find LTE's upload speeds are far better than those on HSPA.

There are many different ways to implement LTE, too, so you can't assume all LTE speeds are the same. Carriers with more available radio spectrum for LTE can typically run faster networks than carriers with less spectrum, for instance.

This confusion is why we run our annual Fastest Mobile Networks story, which tests 3G and 4G networks in 30 cities nationwide. In this year's tests, we generally found that on speed alone Verizon's 4G LTE network was the fastest, followed by T-Mobile LTE, AT&T LTE, T-Mobile HSPA+, Sprint LTE, AT&T HSPA, Verizon 3G and finally Sprint 3G. 

When to Go For 4G?

In 2015, almost everyone should have a 4G phone. Verizon now has nationwide 4G LTE coverage. T-Mobile and MetroPCS have nationwide HSPA+ 42 and growing LTE networks. AT&T has broad LTE coverage. Sprint is still building out LTE, but by next year the carrier aims to be comprehensive.

If you like to surf the Web and especially stream video, 4G can be heaven. If you connect a laptop to your mobile link, 4G makes a huge difference. In general, anything involving transferring large amounts of data gets a big boost from 4G. Watch out for the data limits on your service plan, though; it's easy to use up a lot of data very quickly with 4G.

If you have a 3G phone and you've been frustrated with slow data, 4G may be the solution. 4G won't solve any dropped call problems, though, as all calls will be made over older networks until carriers switch to voice-over-LTE during the next few years.

Finally, if you want to future-proof yourself, get a 4G phone. 4G coverage is only going to get better, and that's where the carriers are spending most of their money right now. You can assume that all 4G phones also support your carrier's 3G and 2G networks as well.

Should You Even Consider 3G?

There are a few reasons you might still settle for a 3G phone.

If your phone is mostly for voice use, you have no need for 4G data. Save money and save battery life by choosing a device without the high-speed network.

If you live in an area that doesn't have 4G coverage, there's no advantage to a 4G phone. In fact, you'll have serious battery life problems if you buy an LTE phone and don't disable 4G LTE, as the radio's search for a non-existent signal will drain your battery quickly.

If you're strapped for cash and buying a phone off contract, you may have to settle for 3G to save money. In that case, make sure to get the fastest 3G phone possible. On Verizon and Sprint, you want to check that it supports "EVDO Rev A." On T-Mobile and AT&T, you want the highest class of HSPA+ possible: if not 42 or 21, then 14.4.

Features

Data rates

ITU has not provided a clear[citation needed][vague] definition of the data rate that users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the rates it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum data rate of 2 Mbit/s for stationary or walking users, and 384 kbit/s in a moving vehicle," the ITU does not actually clearly specify minimum required rates, nor required average rates, nor what modes[clarification needed] of the interfaces qualify as 3G, so various[vague] data rates are sold as '3G' in the market. Compare with 3.5G and 4G.

Security

3G networks offer greater security than their 2G predecessors. By allowing the UE (User Equipment) to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator. 3G networks use the KASUMI block cipher instead of the older A5/1 stream cipher. However, a number of serious weaknesses in the KASUMI cipher have been identified.

In addition to the 3G network infrastructure security, end-to-end security is offered when application frameworks such as IMS are accessed, although this is not strictly a 3G property.

Applications of 3G

The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users. Some of the applications are:

Global Positioning System (GPS)

Location-based services

Mobile TV

Telemedicine

Video Conferencing

Video on demand

Evolutiont

Both 3GPP and 3GPP2 are working on extensions to 3G standard that are based on an all-IP network infrastructure and using advanced wireless technologies such as MIMO. These specifications already display features characteristic for IMT-Advanced (4G), the successor of 3G. However, falling short of the bandwidth requirements for 4G (which is 1 Gbit/s for stationary and 100 Mbit/s for mobile operation), these standards are classified as 3.9G or Pre-4G.

3GPP plans to meet the 4G goals with LTE Advanced, whereas Qualcomm has halted development of UMB in favour of the LTE family.

On 14 December 2009, Telia Sonera announced in an official press release that "We are very proud to be the first operator in the world to offer our customers 4G services." With the launch of their LTE network, initially they are offering pre-4G (or beyond 3G) services in Stockholm, Sweden and Oslo, Norway.