We’ve heard that the latest iPhone is really “only” 3G. And what about the move of the iPhone to Verizon? Will it be as fast as the iPhone on AT&T, or an Android? What about all those new phones shown at Comdex? What does this all mean? Most people know that the G stands for the generation of cellular wireless standards. But what can 4G do that 3G could not?
3G and 4G are standards for mobile telecommunications. Standards specify how the airwaves must be used for transmitting information (voice and data). 3G (or 3rd Generation) was launched in Japan in 2001. As recently as mid-2010, the networks for most wireless carriers in the U.S. were 3G. 3G networks were a significant improvement over 2G networks, offering higher speeds for data transfer. The AT&T “EDGE” network, that your iPhone sometimes resorts to, is a 2G network.
Both 2G and 3G networks were designed primarily for voice communications rather than data. On the other hand, 4G is designed especially for data transmission rather than voice. So 4G offers faster access to data using mobile phones. For example, streaming video works better with 4G, with less stuttering and a higher resolution. Similarly, video conferencing and multi-player online games work better with the faster data transmission offered by 4G.
Speed requirements for 4G service set the peak download speed at 100 Mbit/s for high mobility communication (such as from trains and cars) and 1 Gbit/s for low mobility communication (such as pedestrians and stationary users). Considering that my home network is a 1Gbit/s Ethernet, the idea that my cell phone network will match my home, wired network is amazing. Pardon me while I drool.
The International Telecommunication Union (ITU), formerly known as the CCIR — Comité consultatif international pour la radio, "Consultative Committee on International Radio" or "International Radio Consultative Committee" — was founded in 1927. The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication. Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunications systems with the objective of ensuring the effective use of the spectrum.
Pre-4G technologies such as mobile WiMAX and first-release 3G Long Term Evolution (LTE) have been on the market since 2006 and 2009 respectively, and are often branded as 4G. The current versions of these technologies did not fulfill the original ITU-R requirements of data rates approximately up to 1 Gbit/s for 4G systems. Yet, marketing materials use 4G as a description for Mobile-WiMAX and LTE in their current forms.
IMT-Advanced compliant versions of the above two standards are under development and called “LTE Advanced” and “WirelessMAN-Advanced” respectively. ITU has decided that “LTE Advanced” and “WirelessMAN-Advanced” should be accorded the official designation of IMT-Advanced. On December 6, 2010, ITU announced that current versions of LTE, WiMax and other evolved 3G technologies that do not fulfill "IMT-Advanced" requirements could be considered "4G", provided they represent forerunners to IMT-Advanced and "a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed." In other words, the standards body has approved the marketing hype — well at least partial hype.
In all suggestions for 4G, the CDMA spread spectrum radio technology used in 3G systems and IS-95 is abandoned and replaced by OFDMA and other frequency-domain equalization schemes. This is combined with MIMO (Multiple In, Multiple Out), for example, multiple antennas, dynamic channel allocation and channel-dependent scheduling. (If the last paragraph made any sense to you at all, then I assume you have a subscription to Radio-Electronics magazine, a soldering iron on your desk, and a plastic pocket protector — I know I do!)
It is against this technical background that Verizon, the largest cell phone carrier in the US, has announced their LTE network. It is the fastest in the land, and, once again, makes Verizon the premiere cell phone carrier in the US. Verizon is actually the fourth US carrier to call its network 4G, after T-Mobile, Sprint, and MetroPCS. With LTE, Verizon chose a truly forward-looking 4G technology. AT&T, Cricket, and MetroPCS have all committed to going to LTE, and it is shaping out as the dominant technology for advanced cell phone data networks. However, the four carriers use very different technologies, none of which are technically 4G. Sprint has a WiMAX network, T-Mobile's network is HSPA+ and MetroPCS's is LTE, but a much slower variant than Verizon is using.
Verizon's LTE network currently covers 38 major metro areas and more than 60 airports, about a third of the U.S. population. The carrier has said it will have complete nationwide coverage by 2013.
Sprint has more metro areas covered — in the sixties — but covers less of some of them. While the two carriers' coverage areas around Chicago are equivalent, for example, Verizon covers more suburban counties in the New York City area. T-Mobile is the 4G coverage leader, covering 96 percent of the U.S. population with its HSPA+ 21 technology. (That’s some justification for the pretty girl in the poka-dot dress.)
To me, more importantly, Verizon has a stronger reputation for providing even coverage within cities. Although I think Verizon has a misleading online coverage map — it doesn't show signal strength, they are a definite coverage leader — well ahead of AT&T. While Sprint's WiMAX system tends to be spotty and variable, more consistent results have been reported than from Verizon's network.
Verizon promises 5-12Mbps down and 2-5Mbps up. Considering the carrier's 3G EVDO system offers 1Mbps down on average, that's a huge improvement. It's faster than some home connections.
LTE had no problem with even the most demanding Internet applications. Skype audio and video calls are clear. YouTube videos play in 720p HD without a problem. Netflix and Hulu Plus stream easily. Download a 350MB file through BitTorrent in about ten minutes. There may be some problems with multiplayer gaming; you may have a slight problem with lag. Although LTE's average ping of 67ms was much faster than WiMax and HSPA+ (which were at 100-120ms), wired connections are typically around 30ms. (With this data, lower numbers are better.)
Verizon LTE was launched in December, and Verizon promises that, in subsequent years, an aggressive growth plan will result in full nationwide coverage in 2013. The company’s 4G LTE network ultimately will connect a full range of electronics devices and machines to each other. Let’s hope that they can follow through on that promise. For those planning to purchase the iPhone on the Verizon network and those waiting for the 4G iPhone to be available on this new carrier, I wish you luck.
I wish you luck
I hope you get what you deserve
I wish you luck
I hope you catch before the curve
I wish you luck
I hope you make it to the end
I wish you luck
Originally written on February 1, 2011.
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