Topping Today's Power

The industry has big plans for future wireless devices. Handset vendors are proclaiming amazing feats of voice, data, Internet, video, television and telematics. But before eager patrons succumb to the hype, the industry must develop viable ways to fuel the functions touted in these new devices.

Phone manufacturers are designing more efficient and less power-hungry handsets. Battery manufacturers are offering longer-lasting, rechargeable batteries and promise that evolutionary power sources are just around the corner. Are these steps enough to future-proof tomorrow's devices?

Wanted: More Power

Although today's phones boast hours of talk time and up to a week of standby time, current power capabilities fall short of meeting future power needs, said Phil Asmundson, Deloitte Consulting analyst.

"People already worry about battery life and not being able to use their phones because the battery isn't working," he said.

Duane Rabe, Motorola vice president of advanced technology and product platform group, said today's phones consume 0.5W to 3W of power, depending on usage patterns. As additional functions are added, consumption levels will increase.

Vassilis Keramidas, Bellcore senior scientist, said the power demands of enhanced display screens pose a considerable challenge for wireless handset designers, much as they did for the laptop computer designers a few years ago. As computers became smaller and more efficient, manufacturers incorporated high-resolution, color-intensive displays as a selling point. With fast processors and high-end screens, power requirements reached current highs of approximately 50W.

"The same thing will happen with wireless devices that happened with the laptop computers," Keramidas said. "Currently, people focus on functionality -- e-mail access and so forth. But as you put more functionality into a device, they will require a visual image to communicate, and a color device will replace the gray-and-black screen. When that happens, the power requirement will skyrocket, just like it did on the laptop computer."

Rainer Kuhn, Colorado Micro-Display marketing director, said a monochrome display and backlight requires 10mW of power and up to 750mW for electro-luminescent displays with greater temperature tolerance. For manufacturers to offer a larger screen size and to add color and a higher resolution to support web browsing and other data applications adequately, Kuhn said the power demand would jump to between 4.5W and 6W.

Doug Fults, Geoworks software architect, said powering the CPU for more data-intensive applications or software can require an additional 15 to 60 million instructions per second (MI/S) -- each MI/S the equivalent of approximately 1mW. Although this demand diminishes when phones are idle, extended use such as navigating the Internet can affect operation significantly.

"Web browsing is one of the more intense activities less than the radio side, but if you keep it active, it will further drain the power," Fults said.

Adopting other advanced functions into wireless devices will pose similar challenges. GPS and location-based applications, video and digital imaging, speakerphone, video games and a host of other potential applications could appear on the market within the next few years.

"All of those things are going to be challenges for power," said Larry Paulson, Nokia vice president and general manager of business development.

Responding to Future Power Needs

Much of the progress in power has come from handset advances, where manufacturers have developed smaller, more advanced devices that require significantly less power.

"We have made a lot of progress in that area," said David McCartney, Bosch vice president of sales and marketing. "Take the first Motorola phones on the market remember the bricks? Look at how big that battery was, and it would only talk for a few hours. Compare that to the little 6100 from Nokia. That is a 3V device, and look at the talk time (195 minutes) on that."

Digital technology inherently allows for improvements, but much of this progress also is a result of chip and component consolidation. Vendors are putting more functionality into the fundamental chipsets, said Peter Skarzynski, Samsung vice president of sales and marketing. As chips become more powerful, engineers can design the circuit board more efficiently because they don't need as many components or separate connections on the board.

Emerging display technologies could support graphic-intensive applications at substantially less power than larger versions of existing monochrome and LCD screens. Colorado MicroDisplay and Displaytech have developed dynamic nematic liquid crystal on silicon and ferro-electric liquid crystal technologies as a low-consumption alternative for future display screens. These miniature, high-resolution color displays could support text, multimedia and full-motion video capability at 90mW to 120mW.

Paulson said that adopting the networking concept used in many office environments also should reduce the amount of power required to store data and operate web browsers and other software applications. Remote servers could assume the computing responsibility and free the handset of power-hungry operating functions.

"It is simply going back to a desktop and network environment," Paulson said. "The handset will perform a lot of functions, but it won't necessarily be controlling all of the network or all of the requirements to do that."

McCartney predicted Bluetooth technology will reduce power requirements further and still provide much of the functionality expected in future devices. Consumers could place a small transponder in a pocket and drive peripherals when needed.

"When we ultimately get into that kind of configuration, the requirements for battery technology and current drain are going to be lower, because you will have more devices with smaller power requirements," McCartney said. "What we have to do is figure out how to have a single chipset and supply a battery that is going to be very small and lightweight in nature."

Taking Charge

The battery industry also is striving to keep pace with the power requirements of next-generation products. Li-Ion batteries offer a thinner and lighter-weight alternative that boasts a higher energy density, operating voltage, life cycle and lower self-discharge rates compared with NiCd or NiMH batteries. A Bellcore study predicts more than 80% of wireless phones will feature Li-Ion batteries by 2000.

Ian Irving, Battery Engineering executive vice president, labels Li-Ion polymer batteries as the future solution. These batteries provide a higher-energy density than alternatives and can be manufactured as thin as 2mm -- well below the current industry minimum of 5.5mm. It is the ability to move beyond cylindrical cells and actually mold Li-Ion polymer into a desired shape that holds the most promise. This trait provides greater leeway in unit design and battery placement. Irving said the same potential could be incorporated into wireless handsets, permitting smaller devices or greater battery volume to increase available power substantially.

"(Polymer) technology provides you with the ability to triple or quadruple the time of operation," Keramides said. "Or you can place a 6-inch by 10-inch battery in the back of the display, free up all the space that was taken up in the body of the computer and make the body half as thick as it is now."

Keramides said vendors likely will move away from the traditional battery-cavity limitations and incorporate new designs with lithium polymer batteries by late 1999 or early 2000.

Zinc-air technology offers comparable performance to some Li-Ion products at less expense, a lighter weight and with fewer disposal concerns. Currently, developers are addressing performance issues because zinc-air products fall to half capacity around the 50th discharge. But Electric Fuel said initial products could be available this year.

Bellcore is working to increase power capabilities by re-examining the materials used in battery- manufacturing processes and is seeking less-expensive alternatives with comparative performance levels. One possibility is doped manganese oxy-fluoride, a new material that Keramides said could provide comparable performance to lithium cobalt-dioxide-based batteries at one-fifth of the cost.

"(Improvements) are coming," Keramides said. "We believe that the capability exists now and more so in the future that as power consumption becomes more and more power hungry, we will be able to meet that demand."

How Much Is Enough?

Future-proofing tomorrow's wireless devices will require a combination of all of these efforts. But how much power is enough?

Skarzynski said most consumers demand a full business day of use and a couple of days of standby. Others said the demand for power should transcend an 8- or 12-hour workday and reach ubiquity with wireline.

"People want to use handsets almost as a wireline replacement, and it does them no good if the battery runs out," said Roger Berg, Sony vice president of product engineering. "(Consumers) want something almost to the point when you don't know when your battery runs out -- you just place it back into its charger after three days or five days or a week."

Asmundson agreed. "Everyone in the wireless industry says they want parity with their wireline phone, but I don't have to recharge my wireline phone. You need to make recharging my wireless phone as painless and as invisible as possible. The way to do that is to expand its strengths."

Asmundson expects battery technology will emerge to allow wireless to reach near-parity with wireline eventually.

"Equipment manufactures are extremely talented," Asmundson said. "They are going to figure out a way not only to increase battery strength, but to decrease or more efficiently use power in the handsets themselves. I think it will be in the near future all of this is moving truly at Moore's Law speed."

Those improvements remain the key to success.

"Everyone demands continual improvements," Irving said. "That is just the nature of the beast."