The Approach of 4G

The next-generation mobile network will offer bigger, better, faster bandwidth and is being promoted as enabling "anytime, anywhere, anything" in terms of content. How will this type of connectivity actually come to pass and what does it mean for mobile-device displays?

by Jenny Donelan

EVERY TECHNOLOGY has its Next Big Thing, and in the world of mobile communications, 4G is clearly a contender for the title. Service providers such as Sprint/ Clearwire and Verizon have announced rollout plans for the next generation of mobile service, which is by definition a mobile Internet service. With 4G fully deployed, users wielding the appropriate devices will be able to download and watch movies, share photos, browse the Web, and, in general, conduct any type of electronic business imaginable in near real time – wherever they like. With 4G, users will be able to loosen their ties to home or office computers and enter a world of limit-less connectivity and entertainment on demand.

Such is the promise of the next-generation network. And judging from the popularity of Apple's iPhone and other smart mobile devices, the service will be feeding at least a specific sector of the public that is increasingly hungry for mobile data. But how soon 4G will become reality depends on several factors – the carriers' ability to build out the 4G infrastructure, the devices' ability to handle the content, and the desire of a large-enough base of users (beyond early adapters and teenagers) to actually employ mobile devices in these ways.

4G Definitions

To begin with, what actually is 4G? In plainest terms, it stands for the fourth generation of wireless communication, with 1G being analog mobile phones, 2G the first digital generation, and 3G the network capabilities that we are supposedly enjoying right now. However, although 4G is also often referred to as the "next generation," most users are not even using third-generation technology yet, so 4G is, for the majority of us, the "generation after the next generation."

A precise definition of 4G's benefits is equally difficult to pin down. According to a recent Sprint press release, it is "… a turbo-charged mobile broadband experience with wireless connectivity 3–5 times faster than today's 3G from any carrier." ¹ Many industry experts agree that the term is somewhat nebulous. "4G is not well-defined," says Barry Young, Managing Director for the OLED Association, "although it will enable a whole new set of devices and capabilities." Perhaps the best way to view 4G is in holistic terms. The organizers behind the first 4G World Conference and Expo, held in Chicago in September of this year, describe their event as "dedicated to the entire landscape of next-generation mobile networks from infrastructure to devices, applications, and content" (www.4gworld.com). Viewed this way, 4G is a sort of ecosystem of the future of mobile Internet.

One thing is definite: 4G will be fast. How fast is hard to say, but certainly faster than the wireless Internet most of us experience today. While 3G's data-transmission speeds are between 600 kbps and 1.4 Mbps, 4G speeds start at around 2 Mbps and may at some point reach 10 times that speed. This should enable faster, smoother file sharing and downloading – even high-definition movies would become feasible as content. 4G networks are also designed for distance, offering service in terms of square miles instead of feet (as is the case with most Wi-Fi networks today). The official coverage range for a typical 4G access point, for example, is about 30 square miles. Due to the bandwidth used, the equipment, and other considerations, the actual range will probably be considerably less, but wider than current Wi-FI by far.

Several specific technologies or platforms have been developed to realize the 4G eco-system. Of these, the two major players at present are Worldwide Interoperability for Microwave Access (WiMAX) and Long-Term Evolution (LTE). Each has been developed to move data rather than or as well as voice, and each forms the basis for an IP network based on orthogonal frequency-division multiplexing (OFDM) technology, which is a digital multi-carrier modulation method. And each has its proponents. Sprint's 4G network is based on WiMAX, as is its business partner Clearwire's. Verizon and AT&T have chosen LTE. (For more description, see the Sidebar "WiMAX and LTE.")

As stated above, these platforms are similar at the core. In fact, some observers predict a convergence in years to come. In general, though, WiMAX is farther along commercially than LTE, whereas LTE is thought to have more powerful backers and more backwards compatibility with existing networks (at least in Europe). LTE is also faster, but WiMAX is working on a new standard that will make it comparable.

When Will It Arrive?

Citizens of Moscow and St. Petersburg, Russia, were introduced to 4G from Cisco early this year. The rest of Europe and Korea have also been in the vanguard compared to the U.S. Sprint piloted a 4G network in Baltimore last year. Otherwise, in the U.S., for those living in Atlanta, Las Vegas, or Portland, Sprint's 4G network has recently come to your town. Sprint and other carriers have announced 4G rollouts in several other U.S. cities before the end of 2009. So it would seem that 4G is poised to become a reality.

Yes and no – it will be used as a broadband Internet service before it becomes the mobile device platform of choice. The first 4G-enabled device that Sprint has offered for sale is not a mobile phone but a modem (Fig. 1). Currently, there are no 4G phones on the market in the U.S. Nokia and LG are rumored to have prototypes of 4G devices, but photos of those are few and far between and have appeared only in unofficial blog postings.

It is also possible that users are not ready for 4G. According to Richard Murphy, research analyst in the Wireless and Mobile Communications group at IDC. "Right now, in the U.S., there are approximately 278 million mobile-phone users. And for all the emphasis on 4G these days, only 25–30% are even using 3G."

Are users going to be willing to make the leap from second generation straight to fourth generation, he asks. "And how much are they going to be willing to pay for 4G?" AT&T discovered with Apple's iPhone, he continues, that the top per-month price consumers seemed to be willing to pay for the privilege of using the device was $90–100. Even so, while it is a great convenience to be able to look up restaurant reviews and directions in a strange city (to cite some of the more popular and useful applications for these devices), how many people are willing to pay for the convenience, let alone for more content at perhaps an even higher premium? "The average user," says Murphy, "is not at a point where streaming TV or even surfing the Web is a primary driver. Data revenue is still about 25% [of total] for carriers."

4G Devices

That said, there was a time when experts said that TVs were a passing fad – why would anyone want to watch something on a small screen at home when they could go to the movies? So it behooves display makers to make preparations for the Next Big Thing. And, in fact, they are already doing so, though they are probably not seeking 4G solutions specifically – they just want larger, sharper, more-colorful displays that use less power, regardless of the platform.

When Information Display asked various entities in the display business how 4G was likely to affect R&D, the answers varied. The OLED Association's Barry Young said "4G is not likely to have a leading-edge kind of impact on OLEDs." But, he added, the fact that users will be doing more video could lead to a more OLED-friendly device environment. "What we're seeing now is displays getting bigger and bigger," says Young. "And one could envision that in a 4G device you could have the equivalent of a DVD player." That could be a good opportunity for OLED technology's vibrant color, low energy drain, and ability to handle motion, he notes.

Jim Cathey, Vice-President of Business Development at Qualcomm (and author of an article in this issue), believes that the additional applications that 4G could bring about may well have some kind of an impact on display technology. "Your handset could become a DVR for high-definition video," he says. "For example, I travel a lot, and I would love to have my shows taped and then play them on the handset or connect them to a display in my hotel room." Similar to OLED technology, his company's MEMs-based mirasol displays might be a good choice for this type of application, he says, but again, it's along the direction his company is already pursuing.

However, it is good to keep in mind that the conundrum raised by 4G – devices will have larger, thinner displays capable of showing color and moving imagery, which will compel people to use the devices for longer periods while viewing content that is power hungry by its very nature, which will drain batteries faster than ever – is the same conundrum faced by display makers today. So, the emergence of 4G is not likely to cause an explosion on the display scene because the display-size vs. battery-drain situation already exists and is, in fact, the subject of most of the articles in this issue of Information Display.

Coming (Somewhat Soon) to a Mobile Phone Near You

"4G is something that many people are excited about," says IDC's Murphy. But it's still a ways off. We could be 5 years off. The network still has to be built." As it is, the 3G network itself has to get up to speed. In early September, The New York Times⁴ ran an article about how intensive iPhone use in particular geographic areas can overload a network. The author even compared the iPhone to a Hummer (among cell phones), noting that excessive numbers of the devices in use in a particular area clog the information highway and lead to dropped calls and spotty service. The carrier involved was AT&T, and other carriers are quick to claim that they do not, or will not, have such problems. Only time will tell. However, it is probably safe to say that the displays in mobile devices are not going to be any kind of gating factor for 4G's adoption. Says Paul Semenza, analyst with DisplaySearch, "The bandwidth is kind of catching up to the displays."

Fig. 1: This print advertisement from Sprint shows its first 4G/3G mobile broadband device – a modem. Image courtesy Sprint.

This is a fact that has not gone unnoticed by carriers. In fact, the whole infrastructure issue is one of the selling factors of 4G. Nokia's literature, for example, refers to the need for increased capacity in light of growing demand. A plus for its LTE 4G platform, it notes, is "the reduced capital and operating expenditures it requires over previous 3G networks. A key aspect of LTE is its simplified, flat network architecture, derived from it being an all-IP packet-based network, and the use of new techniques to obtain high volumes of data through a mobile network." ³

Sprint, on its part, is saying that its roll-out is going to enable a better, more dependable experience for users. "What we're doing for 4G is building an entire network from the ground up," says spokesperson Stephanie Vinge-Walsh.

Whenever it does arrive, and whether it is based on WiMAX or LTE or something else, 4G's increased speed, bandwidth, and distance capability should eventually bring about a new type of connectivity. These days, for example, if you want to check your e-mail at the airport or in a city, "You have to hunt around for a hotspot," says Vinge-Walsh. But 4G can be deployed across a much larger area. To explain WiMAX, she says, she tells people, "You'll have a hotspot the size of a city. That really kind of resonates."

References

¹http://community.sprint.com/baw/community/ sprintblogs/buzz-by-sprint/announcements/blog/2009/08/20/sprint-4g-blazes-into-atlanta-las-vegas-and-portland

²http://newsroom.clearwire.com/phoenix.zhtml?c=214419&p=irol-newsArticle&ID= 1331811&highlight=

³http://www.nokia.com/NOKIA_COM_1/Press/Press_Events/Nokia_Technology_Media_Briefing/LTE_Press_Backgrounder.pdf

⁴http://www.nytimes.com/2009/09/03/technology/companies/03att.html?_r=1&scp=1&sq=iphone%20overload&st=cse •