Within the last two decades, communication advances
have reshaped the way we live our daily lives. Wireless communications has
grown from an obscure, unknown service to an ubiquitous technology that serves
almost half of the people on Earth. Whether we know it or not, computers now
play a dominant role in our daily activities, and the Internet has completely
reoriented the way people work, communicate, play, and learn.
However severe the changes in our lifestyle may seem
to have been over the past few years, the convergence of wireless with the
Internet is about to unleash a change so dramatic that soon wireless ubiquity
will become as pervasive as paper and pen. WiMax—which stands for Worldwide
Interoperability for Microwave Access—is about to bring the wireless and
Internet revolutions to portable devices across the globe. Just as broadcast
television in the 1940’s and 1950’s changed the world of entertainment,
advertising, and our social fabric, WiMax is poised to broadcast the Internet
throughout the world, and the changes in our lives will be dramatic. In a few
years, WiMax will provide the capabilities of the Internet, without any wires,
to every living room, portable computer, phone, and handheld device.In its simplest form, WiMax promises to deliver the
Internet throughout the globe, connecting the “last mile” of communications
services for both developed and emerging nations.
Introduction
Broadband wireless sits at the confluence of two of
the most remarkable growth stories of the telecommunications industry in recent
years. Both wireless and broadband have on their own enjoyed rapid mass-market
adoption. Wireless mobile services grew from 11 million subscribers worldwide
in 1990 to more than 2 billion in 2005 . During the same period, the
Internet grew from being a curious academic tool to having about a billion
users.
This staggering growth of the
Internet is driving demand for higher-speed Internet-access services, leading
to a parallel growth in broadband adoption. In less than a decade, broadband
subscription worldwide has grown from virtually zero to over 200 million.
Will combining the convenience of wireless with the rich performance of
broadband be the next frontier for growth in the industry? Can such a
combination be technically and commercially viable? Can wireless deliver
broadband applications and services that are of interest to the end-users? Many
industry observers believe so. Before we delve into broadband wireless, let us
review the state of broadband access today. Digital subscriber line (DSL) technology, which delivers
broadband over twisted-pair telephone wires, and cable modem technology, which delivers over coaxial cable TV
plant, is the predominant mass-market broadband access technologies today. Both
of these technologies typically provide up to a few megabits per second of data
to each user, and continuing advances are making several tens of megabits per
second possible. Since their initial deployment in the late 1990s, these
services have enjoyed considerable growth. The United States has more than 50
million broadband subscribers, including more than half of home Internet users.
Worldwide, this number is more than 200 million today and is projected to grow
to more than 400 million by 2010. The availability of a wireless solution
for broadband could potentially accelerate this growth. What are the applications
that drive this growth? Broadband users worldwide are finding that it
dramatically changes how we share information, conduct business, and seek
entertainment. Broadband access not only provides faster Web surfing and
quicker file downloads but also enables several multimedia applications, such
as real-time audio and video streaming, multimedia conferencing, and
interactive gaming. Broadband connections are also being used for voice
telephony using voice-over-Internet Protocol (VoIP) technology.
More advanced broadband access systems, such as
fiber-to-the-home (FTTH) and very high data rate digital subscriber loop (VDSL),
enable such applications as entertainment-quality video, including
high-definition TV (HDTV) and video on demand (VoD). As the broadband market
continues to grow, several new applications are likely to emerge, and it is
difficult to predict which ones will succeed in the future.
So what is broadband wireless? Broadband wireless is
about bringing the broadband experience to a wireless context, which offers
users certain unique benefits and convenience. There are two fundamentally
different types of broadband wireless services. The first type attempts to
provide a set of services similar to that of the traditional fixed-line
broadband but using wireless as the medium of transmission. This type, called fixed wireless broadband, can be
thought of as a competitive alternative to DSL or cable modem. The second type
of broadband wireless, called mobile
broadband, offers the additional functionality of portability,
nomadicity,1 and mobility.
