Electronic Design

Wireless Technology Makes Waves In All Directions

Nothing is hotter now than the cell-phone business, which is driving semiconductor sales. And while cell phones are the biggest contributor to electronics growth, many other wireless technologies keep expanding as we drive toward a totally wireless society.

In 2007, annual cell-phone sales exceeded 1 billion handsets for the first time. Experts say 2008 will see 1.4 billion sales. The total number of U.S. subscribers passed 250 million in 2007, but the market is nearing saturation.

Despite this impressive number, the U.S. is small potatoes. China saw about 400 million handset sales in 2007, and that is only a fraction of the potential there. India is another growing customer, second to China in volume.

3G Rollout
Third-generation (3G) cell phones based on the ITU UMTS WCDMA standards set by the Third Generation Partnership Project (3GPP) are slowly but surely being bought and deployed, especially in the larger cities of Asia, Europe, and the U.S. The U.S. 3G rollout is going more slowly. But Qualcomm’s cdma2000 EV-DO technology, which is used by Sprint Nextel and Verizon, is helping it along.

The Rev. A and B versions of EV-DO are even faster and becoming more widely deployed in cell phones and notebook data cards. Some High Speed Packet Access (HSPA) 3G technology that boosts WCDMA connection speeds to more than 3 Mbits/s are also coming online. While 3G adoption is roughly only 50% of what it could be worldwide (even less in the U.S.), it is expected to ramp up as the carriers build out their networks and add services and as new phones become available.

Progress In 4G
The development of fourth-generation (4G) cell-phone technologies continues to progress, with the Long Term Evolution (LTE) standard apparently well in the lead for future adoption. LTE is still under development in the 3GPP, but is expected to be ratified in 2009.

This is the upgrade path that current GSM/EDGE/ WCDMA carriers like AT&T and T-Mobile will adopt in the future. It uses orthogonal frequency-division multiple access (OFDMA) and promises data speeds to 100 Mbits/s.

Qualcomm’s Ultra Mobile Broadband technology is also 4G and uses OFDMA. It is the 4G upgrade path for cdma2000 EV-DO carriers. But LTE now has the support of cdma2000 EV-DO carrier Verizon and has just about clinched the title of 4G winner.

The "Open" Movement
U.S. cell-phone carriers only offer the products and services they want you to have in their so-called “walled gardens.” Many experts say this limits their possible applications. Google wants to change this approach, intending to enter the cell-phone business and provide open products and services.

With the real possibility of Google becoming a buyer of spectrum in the forthcoming FCC auction and thus competing in the wireless business, the big carriers have beat Google to the punch. Verizon and more recently AT&T announced that they would immediately open their systems, giving subscribers a chance to buy other phones and use other applications.

Meanwhile, Google’s recent announcement of its Android Linux-based operating system software for developing open applications has generated lots of interest in developing third-party software and applications for cell phones.

The Femto Phenomenon
A recent upsurge in interest in femtocells will further roil the cell-phone business. A femtocell is a home basestation that is designed to bring superior cell coverage inside homes (see the figure). With over 50% of all cellular calls coming from inside buildings and homes, many customers have discovered just how unreliable wireless can be with multiple walls and other obstructions.

The femtocell is a full-blown basestation, but operates at low power to prevent spillover into the marco network or into your neighbor’s home. It connects to your DSL or cable TV high-speed Internet connection for backhaul to the carrier. There’s lots of interest, with carriers studying it and preparing network changes to accommodate it. While 2008 is expected to be a year of study and development, look for real femto-cell products and services in 2009.

A Widely Wi-Fi World
Wi-Fi has reached the ubiquitous stage, and more is on the way. The Wi-Fi Alliance, an industry association with more than 300 members, says that more than 4000 products had received the Wi-Fi Alliance certification of “guaranteed” compatibility and interoperability as of November. One current area of certification activity is with the 802.11n standard. The Alliance is certifying draft 2.0 products before the final 802.11n standard is ratified by the IEEE.

Over 140 draft 2.0 11n products have already been blessed, meaning that draft 2.0 is pretty much the final version. Final ratification is expected in July. Nevertheless, users are already enjoying the more than 100-Mbit/s performance promised by this standard. And speaking of higher speeds, the IEEE 802.11 VHT Study Group is already at work examining standards for potentially higher data rates to 1 Gbit/s.

Other developments in Wi-Fi include slower rollout of municipal Wi-Fi networks in cities around the country. Hundreds of cities already have broad Wi-Fi coverage for citizens, but other cities are backing out of the muni trend as they discover the high operational and maintenance costs.

Another major development is the rapid incorporation of Voice over Wi-Fi or Voice over Wireless LAN. Well over 100 cell-phone models now incorporate Wi-Fi, meaning they can provide Internet connectivity or VoWi-Fi phone calls. The Apple iPhone and RIM BlackBerry both incorporate Wi-Fi but not VoWi-Fi. Others include Wi-Fi as an alternative for voice when cellular coverage is poor.

Dual-mode phones that hand off between cellular basestations and Wi-Fi access points are becoming popular in the enterprise as companies look for economies in telecom. This is all part of the fixed mobile convergence (FMC) movement, in which a single phone can become the employee’s only phone. The employee uses the cellular mode off campus while using the WLAN network to make calls at the office.

Cellular provider T-Mobile now offers dual-mode phones. Its [email protected] Home service permits Wi-Fi phone calls. Dual-mode phones are expected to continue to grow in popularity as consumers expect communications alternatives in different environments.

Meanwhile, new chip sets with very low power consumption are becoming available, suiting them for dual-mode phone service. They will also find homes in some low-power applications previously denied to Wi-Fi because of their inherent power-hungry characteristics. Low-power 802.11b/g chips now suit some wireless sensor networks and other industrial monitoring and control applications.

Some of the latest 802.11 standards developed by the IEEE include 802.11p, which provides for Wi-Fi usage in the 5.8-GHz range between vehicles and between vehicles and roadside services at speeds to 200 km/s at up to 1000 feet. The 802.11s standard provides for mesh Wi-Fi networks, while 802.11y implements Wi-Fi-like operation in the 3650- to 3700-MHz band.

Wimax On It's Way
WiMAX is the wireless broadband standard for implementing metropolitan-area networks (MANs). Based on the IEEE 802.16 standard, this new wireless service is available in fixed (802.16-2004) and mobile (802.16e-2005) forms.

The fixed form is for implementing wireless broadband services that can provide high-speed backhaul for other wireless services as well as Internet in areas where there’s no cable or DSL service.

The mobile version will provide a higher-speed alternative to Wi-Fi in laptops in a mobile environment. It could be used for cell phones because of its handoff capability, but it isn’t expected to be successful in that application.

With fully ratified standards and many chip suppliers and new equipment vendors, WiMAX is truly ready for action. Sprint Nextel recently announced its Xohm WiMAX service in Baltimore, Washington, D.C., Chicago, Dallas, and Austin, Texas, which is expected to go online in 2008. A nationwide buildout is also anticipated. Clearwire, another WiMAX service provider, already offers the service in selected areas, with more coverage and buildout to continue this year.

Intel eventually will offer combined Wi-Fi/WiMAX chip sets for laptops, giving users several connection options depending on their location. The IEEE also is working on improved versions of the WiMAX standards. Of particular interest is the 802.16m standard, which will offer wider bandwidth options with speeds to 100 Mbits/s mobile and 1 Gbit/s fixed.

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