Subject: [NEXTEL-1] Smart Antennas for the Customer Premises

From: Marcel <[email-masked]>
Date: Tue, 25 Feb 2003 12:42:25 -0500

Smart Antennas for the Customer Premises

By Shane Young 
& Steve Adams, Spotwave Wireless, Inc. 

February, 2003

If you were allowed just one word to describe the future of wireless, that word would
surely have to be MORE … more people using more wireless services and devices in more
places and more often. Whether it's business or personal, people want and need to
communicate. 

The enormous success of wireless technology has raised expectations of 'anytime, anywhere'
connectivity. While the macro network has extended to provide ever-increasing coverage,
users are impatiently demanding that the network reach inside their buildings. The
increased reliance on wireless communication has created a new expectation, that phones
can be used in buildings large and small; at work and at home; in public spaces and
private buildings.

Delivering on this promise remains one of the greatest challenges facing the wireless
industry.
Most people have experienced the frustration of poor in-building wireless reception
resulting in dropped calls or spotty reception, and have had to move quickly to the
nearest window to improve reception and avoid losing the call. Elevators, underground
parking garages, boardrooms, offices, warehouses and retail stores. These are all areas
where wireless reception can suffer or be non-existent. While dead zones were tolerated in
the past, today's tech-savvy wireless device users demand clear, readily available
in-building wireless coverage.

Providing in-building coverage solutions to all needed areas is a significant challenge.
Expansion of the macro network is neither economical, nor effective, as building
construction blocks the penetration of signals. While large buildings like airports and
casinos might justify expensive and complex distributed antenna systems, over 95 percent
of all US commercial buildings are less than 25,000 square feet. Deploying personal
coverage solutions in homes and small offices means that millions of locations need to be
covered.

Effective in-building wireless solutions must meet three key criteria:
1. They must be easily installed by consumers, with no network knowledge or 
special tools;
2. They must continuously adapt to the changing network environment without 
manual intervention; and
3. They must be low cost.

Those who are familiar with smart antenna technology applications in large phased arrays
or digital beam-forming networks at the base station might not immediately recognize its
application to low cost, easily deployable in-building applications. Years of seemingly
esoteric academic research, coupled with recent commercialization efforts, have resulted
in a new generation of smart antennas - effective, inexpensive and easy to deploy. These
antennas bear little resemblance to the base station deployments, nor to traditional yagi
antennas. 

Smart antennas provide two key benefits in in-building deployments: they automatically
seek out the optimal base station signal; and they continuously adapt to changes.

Deploying a traditional yagi antenna requires the installer to know where all the base
stations are (for both wanted and other carriers), and to use a spectrum analyzer to
ensure correct alignment. Clearly, consumers and enterprises cannot deploy systems using
yagi antennas.

Smart antennas can automatically scan across the spectrum, looking at both wanted signals
and potential interference from unwanted signals. The optimal location can be indicated to
the installer through simple LEDs and graphical displays - guiding the installer to
correct placement, and alignment, of the antenna. The determination of the optimal
location is based on a knowledge-based algorithm, which considers factors like signal
strength, dominant pilots and control channels. This eliminates the need for specialized
tools and network knowledge.

The network environment is dynamic, and a successful system needs to automatically react
to network changes. Signals change due to growth in the network, ongoing network
optimization and tuning, and the introduction of new services such as GPRS and 1xRTT. It
is critical that the system respond automatically because, unlike the network
infrastructure, most customer premise equipment is not remotely managed - the equipment
needs to adapt to changes on its own, with no manual intervention.

Smart antennas enable this adaptive behavior. Continuously monitoring the environment, the
smart antenna analyzes changes, and decides whether (and how) to change its behavior. If
the signal from the base station were to disappear (during maintenance, for example), the
smart antenna will automatically shift to the best available signal. When the original
signal is restored, the system can return to its initial state. Conversely, as new base
stations are deployed, the smart antenna can adaptively shift to align to the new,
stronger signal.

Commercialization of smart antennas dictates continuous tradeoffs. The antenna pattern
must be wide enough to be able to detect new base stations while narrow enough to reduce
CDMA pilot pollution. The system must be able to instantly switch to a new signal when the
original disappears, while intelligent enough to ignore momentary ups and downs.

And What About the Future? 
Research is driving the commercialization of smart antennas in three new ways:

· Including active adaptive interference canceling techniques for robust deployment 
   in isolation limited environments (typical in small spaces);
· Deploying smart antennas in vehicles to reduce dropped calls, increase call 
   quality and improve data rates while traveling at high speed.
· Incorporating beam-steering capabilities for automatic alignment.

Summary

While smart antenna technology has traditionally been used in base stations, they are now
critical in the development of intelligent in-building coverage solutions, and provide key
capabilities that are essential to today's commercial products. Expanding the application
of smart antennas in end-user devices will help enable the wireless vision of 'anytime,
anywhere' communications.

Shane Young is the president, CEO and a co-founder of Spotwave Wireless. He has more than
16 years of technical and management experience in the high-tech industry, with a
particular focus on wireless communications. Shane is an expert in the field of adaptive
antennas and is the co-inventor of an interference canceller for CDMA with patents pending
in Canada, the US and Japan.

Steve Adams is the vice president of marketing and product management at Spotwave. He has
extensive experience in creating and marketing new products and expanding high-tech
organizations. He has also worked with such companies as Crosskeys Corp., Corel Corp. and
Nortel, and is a graduate of the University of Waterloo and the Ivey School of Business.

http://www.antennasonline.com/ast_newsletter_2-03.htm#feature1

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