Subject: [NEXTEL-1] The End of Spectrum Scarcity

From: Marcelrf <[email-masked]>
Date: Sun, 07 Mar 2004 10:02:01 -0500

The End of Spectrum Scarcity 

New technologies and regulatory reform will bring a bandwidth bonanza 

By Gregory Staple
& Kevin Werbach

Radio spectrum may be one of the most tightly regulated resources of all
time. From cellphones to police scanners, from TV sets to garage-door
openers, virtually every wireless device depends on access to the radio
frequency wireless spectrum. But access to spectrum has been chronically
limited ever since RF transmissions were first regulated in the early
20th century. Now that's all about to change. New technologies that use
spectrum more efficiently and more cooperatively, unleashed by
regulatory reforms, may soon overcome the spectrum shortage. 

Since the 1920s, regulators have assumed that new transmitters will
interfere with other uses of the radio spectrum, leading to the
"doctrine of spectrum scarcity." As a result, every wireless system has
required an exclusive license from the government. With virtually all
usable radio frequencies already licensed to commercial operators and
government entities, the upshot has been, in the words of former U.S.
Federal Communications Commission (FCC) chair William Kennard, a
"spectrum drought." We've become accustomed to seeing every new
commercial service, from satellite broadcasting to wireless local-area
networks, compete for licenses with numerous existing users, including
the government—all of which guard their spectrum jealously. Cellular
phone service, for example, was demonstrated in the lab in 1949 but not
deployed until the 1980s, largely because of licensing delays. 

That world is coming to an end. At least in the United States, new
technologies and regulatory reforms may soon free up enough RF capacity
to transform wireless-industry economics, especially for popular mobile
telephony and wireless Internet services. In fact, there's every reason
to think we're on the cusp of a spectrum explosion—one that will trigger
major shifts in investment, business models, and services. 

In the spectrum-rich future, wireless connections for new voice, music,
and video services should abound, benefiting consumers and businesses
alike. In our homes, devices such as TVs, stereos, DVD players, and PCs
will come with built-in high-capacity wireless links to swap
information. Outside, new networks will let movies and other huge
multimedia files zip across town or across the country. Billions, or
perhaps trillions, of wireless sensors will be embedded virtually
everywhere. Wireless data, voice, and video connections will be
increasingly available when we are on the move, in cars, trains, and
perhaps planes, too. New services—everything from personal music
channels to video-on-demand to mobile computing utilities and, yes, to
the latest in ever-profitable adult entertainment—will flourish. So,
too, will the markets for the hand-held devices needed to deliver these
services. 

These scenarios do not require infinite bandwidth. Relatively modest
capacity increases—from either new spectrum allocations or new
technologies—can have dramatic consequences. Today, satellite radio is
delivering scores of new music choices to millions of listeners
nationwide using just 25 megahertz of spectrum, about the same bandwidth
as four analog television channels. Personal communications services
have sparked a sea change in data services delivered to cellphones,
using about 90 MHz. The Wi-Fi (the popular name of the IEEE 802.11
standard) revolution in wireless local-area networking was started with
only 84 MHz. Now imagine more new spectrum made available simultaneously
in the next few years than is now used by the satellite TV, PCS, and
Wi-Fi industries combined . 

The era of future abundance will be as foreign to us as our world today
would have been to Marconi and Tesla, whose early spark-gap radios
occupied the entire usable spectrum for each individual Morse code
message. The U.S. government's first tables of spectrum allocation, in
the 1920s, extended only to 60 MHz, with frequencies above 23 MHz
labeled "experimental." The bands of spectrum covered by international
treaties were similarly limited. In contrast, our current allocation
tables regulate spectrum up to 300 000 MHz (300 gigahertz), with the
vast majority of services operating above the 60 MHz that was once the
top of the chart, beginning with the FM radio band (88108 MHz). 

Before we look further at what it means to live in an age of spectrum
abundance, let's look more closely at the two main reasons for the past
era of scarcity: the state of available radio technologies and
government policies. What's extraordinary about the present period is
that both these historical constraints are simultaneously going through
radical change. Let's start with technology. 

To understand the impact new radio technologies are having on spectrum
availability, it is helpful first to address a common misconception:
that spectrum is a concrete and finite resource. Not so. Radio waves do
not pass through some ethereal medium called "spectrum"; they are the
medium. What's licensed by governments is not a piece of a finite pie
but simply the right to deploy transmitters and receivers that operate
in particular ways. 

Moreover, interference is not some inherent property of spectrum. It's a
property of devices. A better receiver will pick up a transmission where
an earlier one heard only static. Whether a new radio system
"interferes" with existing ones is entirely dependent on the equipment
involved. Consequently, the extent to which there appears to be a
spectrum shortage largely depends not on how many frequencies are
available but on the technologies that can be deployed. Many regulations
intended to promote harmony of the airwaves have instead, by putting
artificial limits on technology, created massive inefficiency in
spectrum utilization. 

Last year, a Spectrum Policy Task Force, organized by the FCC,
recognized that much of the spectrum already licensed is not really in
short supply. If you scan portions of the radio spectrum, even premium
frequencies below 3 GHz in dense, revenue-rich urban areas, you will
find that most bands are quiet most of the time. One study found that
only four of 18 UHF television channels were used in Washington, D.C.
Sometimes that's by design, as with "guard bands"—spectral equivalents
of highway shoulders, in which no radio signals are permitted. Fifty
years ago, when TV sets still used vacuum tubes, guard bands were the
only way those sets could distinguish signals on adjacent channels. In
some other cases, an apparent lack of spectrum use reflects system
design, as with cellular-phone towers, which transmit actively only when
communicating with a nearby handset. 

That's why what's happening now is so exciting. New radio transmission
and networking technologies can squeeze more and more capacity out of
the same spectrum. Some of the improvement comes from the shift from
analog to digital transmission. For example, at least five digital TV
shows can be broadcast on the same frequencies that a single analog
channel now occupies. Similarly, digital cellular systems now carry
three times as many phone calls as their analog predecessors. 

Even greater improvements in spectrum usage will come from a family of
technologies that use the computational intelligence of today's wireless
devices to allow multiple systems to "share" the same spectrum. The
first of these, spread spectrum, replaces ancient high-power,
undifferentiated narrowband transmissions with modern low-power, coded
wideband signals  [see figure, "What's the Frequency?"
http://www.spectrum.ieee.org/WEBONLY/publicfeature/mar04/0304scarf2.html].
First described during World War II, spread-spectrum technology is
already used in many cellular phone networks and in Wi-Fi, but newer
systems promise even greater capacity improvements. 

A newly permitted method of using spectrum, ultrawideband, takes spread
spectrum to its logical conclusion, operating at such low power that,
subject to appropriate safeguards, it can underlie existing licensed
services. That is, preexisting users of the same spectrum bands won't
even know the ultrawideband transmissions are there. It will be as if we
figured out a way for freight trains to travel on highways, with cars
being none the wiser. Standards work is already under way to make
ultrawideband the core technology for home entertainment networks,
transferring video, audio, and photos among home PCs, stereos,
high-definition televisions, and DVD players. 

And this is only the beginning. Another recent innovation, smart
antennas, can focus adaptively to "lock into" a directional signal.
Instead of radiating a signal in all directions equally, they figure out
where a user is located and direct the radiation accordingly, reducing
effective interference with other transmitters. Now, too, novel coding
algorithms can take factors that traditionally hampered transmission,
such as physical obstacles and motion, and use them to generate
information that increases capacity. 

Perhaps the greatest technological gain in wireless capacity, however,
will come from systems that work cooperatively. In a network
architecture called a mesh, each RF receiver also acts as a transponder,
retransmitting data sent by other devices in the network. In other
words, every new device uses some of the network's capacity but also
adds capacity back. Because a device in a mesh no longer needs to send
information all the way to its ultimate destination (such as a cell
tower), it can use less power. That allows the network to add more
devices without any noticeable increase in interference. The approach
resembles the distributed architecture of the Internet, in which every
router can move traffic along an efficient path. 

Software radios are a key enabler for all these advances. A software
radio can receive and transmit across a broad range of frequencies;
because it processes signals in software, it is far more adaptable than
a traditional radio. In principle, a software radio originally used for
cellular telephony could, for example, download new software and begin
to receive broadcast television signals, or, more likely, access a
network that uses a new cellular transmission protocol. Even more
sophisticated "cognitive radios" would work cooperatively, analyzing
other nearby radios and adapting on the fly to avoid other
transmissions. 

The spectrum "dividends" possible from these new technologies have not
been lost on regulators. Traditional spectrum licenses were technology-
and service-specific, precluding most of the capacity-enhancing
mechanisms described above. Led by FCC chair Michael Powell, the U.S.
government has embarked on a historic effort to update the way spectrum
is managed. It has three main strands: 

1) Spectrum reallocation: the reallocation of bandwidth from government
and other long-standing users to new services, such as mobile
communications, broadband Internet access, and video distribution.
 
2) Spectrum leases: the relaxation of the technical and commercial
limitations on existing spectrum licenses by, for example, permitting
existing licensees to use their spectrum for new or hybrid (for example,
satellite and terrestrial) services and granting most mobile radio
licensees the right to lease their spectrum to third parties.
 
3) Spectrum sharing: the allocation of an unprecedented amount of
spectrum that could be used for unlicensed or shared services. 

Spectrum reallocation

The FCC's reallocation of 120 MHz of spectrum for third-generation (3-G)
mobile services has probably received the greatest media attention. It
stemmed, in part, from a landmark 2002 agreement with the U.S. military
to free at least 45 MHz of government spectrum. What's more, as part of
the digital television transition, the FCC is reclaiming and auctioning
approximately 85 MHz of UHF broadcast spectrum, which might be used for
mobile communications services in the future. 

Once TV stations commence all-digital broadcasting on their newly
assigned channels—perhaps as early as 2007—the FCC will also reclaim a
huge cache (approximately 290 MHz) of "beachfront" spectrum, assigned
for analog broadcasting since the 1940s. Germany, which switched off
analog broadcasting in Berlin this year and is now enjoying
smooth-running all-digital broadcasting, shows just how fast this
transition can occur. 

Since 1999, the FCC has also authorized more than a dozen new
high-powered satellite systems to use at least 5001000 MHz of spectrum
for broadband video and data services in the 26.540-GHz band (known as
the Ka band). And in 2000, the commission authorized the reuse of 500
MHz of spectrum for a novel tower-based video and data service that
shares spectrum with existing satellite television. 

This new scheme, first envisioned by Northpoint Technology Ltd., of
Portsmouth, N.H., and known as the multichannel video distribution and
data service (MVDDS), takes advantage of the fact that in the northern
hemisphere, satellite TV dishes all face south—the satellites themselves
orbit over the equator. So the service would send customers about 100
channels of digital television programming—and throw in high-speed
Internet access as well—by transmitting southward to north-facing dishes
from lower, tower-based radios. 

Taken together, these and other FCC actions may increase the available
bandwidth for video services by over 1500 MHz and the bandwidth for
mobile wireless services by at least 300 MHz. By comparison, from 1985
to 2000 the total allocation for analog and digital cellular telephony,
plus specialized mobile radio services, was just 195 MHz. 

Spectrum leases

These spectrum reallocation decisions are complemented by a May 2003 FCC
decision to relax the conditions under which spectrum can be leased to
another party. Before then, licensees could neither sell nor "sublet"
their spectrum to another party. 

Economists have long urged the FCC to make spectrum licenses more
flexible and to authorize secondary markets through which licensees
could lease some or all of their rights to others who could use the
spectrum more efficiently. Such changes also would get the FCC out of
the impossible task of deciding ahead of time what spectrum is worth and
how it should be used. 

The agency's May 2003 order endorses this idea, but only in part. It
permits most two-way wireless communications services, such as cellular
voice and data licensees, to lease some or all of their spectrum. But
UHF operators and other broadcasters are not covered by the new rules,
even though most licensed UHF television channels are simply not used.
In addition, the wireless licensees that are covered can lease their
spectrum only for services of the same type as their own. A group of
paging operators, for example, probably could not pool their spectrum
and lease it for two-way mobile telephony. 

Spectrum sharing

The dramatic growth of Wi-Fi in the unlicensed or shared 2.4-GHz band
has been one of the few unequivocal telecommunications success stories
in recent years. From fledgling sales in 1999, the market for Wi-Fi
equipment grew to US $2 billion in 2002 and will exceed $4 billion in
2005, according to a projection by In-Stat/MDR, in Scottsdale, Ariz. 

The unlicensed bands are not unregulated. The FCC still sets aside
specific frequencies for unlicensed use, imposes power limits on
transmission equipment, and provides some basic technical rules for
receivers. However, once these requirements are set, any company can
build and deploy compliant radio equipment, for any use, without needing
further permission from the FCC or a spectrum licensee. A combination of
sophisticated coding techniques, powerful signal processing, and widely
adopted technical standards allows a cacophony of unlicensed devices,
from Wi-Fi to garage-door openers, to coexist without any operator or
government deciding what can be deployed. 

Wi-Fi's success helped convince the United States to support the
worldwide addition of 255 MHz of unlicensed spectrum in the 5-GHz range
and to persuade other governments at the 2003 World Radiocommunication
Conference in Geneva, Switzerland, last summer to make this new
allocation a global reality. As a result, in the years ahead, the 5-GHz
band could well provide a home for more high-speed Wi-Fi devices (which
use IEEE Standard 802.11a, as opposed to 11b or 11g). That same band
could be used by new metropolitan-area networks, which offer Internet
access from cellular-like towers [see "The Wireless Last Mile," IEEE
Spectrum, September 2003]. 

In the future, the type of spectrum sharing that the FCC permits in
unlicensed bands may also be possible in licensed bands through the use
of spectrum underlays and cognitive radios, described above. 

The technical and regulatory developments surveyed here suggest that we
are beginning an entirely new era—an era of spectrum abundance. Because
these changes have largely occurred piecemeal, few participants seem to
have recognized their collective impact. Every segment of the
communications industry cares intensely about its own spectrum
allocations but pays less attention to policy developments affecting
other frequency bands and services. 

To be sure, not all spectrum is created equal. The commercial value of
any frequency band depends on its propagation characteristics and the
current deployment environment. But, in today's world of digital
convergence where almost every electronic service can be linked to via
the Internet, most customers will be unconcerned which band of RF
spectrum is used to deliver the content they want or to provide
communications. Bits are bits, and spectrum is spectrum, as long as it
connects. 

Clearly, in the decade ahead, spectrum access will become more like a
commodity—widely affordable for almost any purpose the user desires.
While it may be too early to identify specific winners and losers, we
can venture some general observations about the impact of a
post-scarcity regime. 

When spectrum seems scarce, service providers must focus all their
energy on acquiring and husbanding spectrum access rights. But when
spectrum seems more like a commodity, investors will shift their funds
from those that are best at protecting spectrum to those best at using
it: content and service providers. Likewise, economic power will shift
from government spectrum gatekeepers to consumers, and from companies
able to obtain licenses to those that offer useful devices, content, and
service packages. 

Incumbent mobile operators and broadcasters will almost certainly face
greater competitive pressures from both licensed and unlicensed
alternatives. The spectrum portfolios of incumbent operators, especially
the large cellular phone companies, may be the first to be devalued.
Manufacturers, on the other hand, may see an enormous stimulus from the
new spectrum environment. If nothing else, lower entry barriers mean
that more service providers will want their equipment. Greater demand,
in turn, may stimulate price reductions for devices and other equipment. 

As spectrum becomes more abundant, content providers will benefit, too.
Indeed, consumers seem to have always-open wallets when it comes to new
mobile applications. Cellphones are the device of choice for almost
everything now—music, AM/FM radio, and mobile games, especially
interactive ones, and even Web-based news, sports, and weather. 

We really don't know yet how the coming age of spectrum abundance will
reshape the market for communications services. But it's tempting to
speculate that as spectrum becomes ever cheaper, the wireless data and
mobile phone markets will begin to look more like the computer industry.
Both, after all, benefit from Moore's Law. 

In this new world, services may be driven more by the cycle of new
receiver technologies than by access to spectrum licenses, more by
engineers and entrepreneurs than by lawyers. The broadcasting business
might change in a similar fashion, with content becoming more like
network applications, available for a price anytime and anywhere, rather
than at a fixed time on one channel. And in a world of spectrum
abundance, regulators will be much less important. Spectrum users
themselves will play a bigger role in mitigating potential conflicts and
in putting spectrum to its highest and best use. At long last, the epoch
of spectrum scarcity will be over. 

To Probe Further
 
The FCC's radio spectrum home page is http://www.fcc.gov/oet/spectrum/.

The International Telecommunication Union in Geneva sells a number of
useful publications; see 
http://www.itu.int/publications/main_publ/frequency.html. 

An online chart of the entire radio spectrum is at
http://www.alvarion.com/Runtime/Materials/KnowledgePoolFiles/C1_FCC_freq_chart.pdf. 

The IEEE Communications Society annually holds an international
symposium on advanced radio technologies.
"ISART 2004" is held 2-4 March in Boulder, Colo. 

http://www.spectrum.ieee.org/WEBONLY/publicfeature/mar04/0304scar.html

http://www.spectrum.ieee.org/WEBONLY/publicfeature/mar04/0304scarf1.pdf

http://www.spectrum.ieee.org/WEBONLY/publicfeature/mar04/0304scart1.html

-- 
    "NEXTEL-1 IT'S NOT JUST NEXTEL"
  Note The New address 
Subscribe to Nextel-1: http://www.groups.yahoo.com/subscribe/NEXTEL-1

  "NEXTEL2 FOR iDEN SOFTWARE DEVELOPERS"
Subscribe to Nextel2: http://www.groups.yahoo.com/subscribe/NEXTEL2

  "WIRELESS FORUM HOMELAND SECURITY GROUP"
     The Complete Resource for Wireless Homeland Security.
Subscribe to WFHSG:  http://www.groups.yahoo.com/subscribe/WFHSG

Yahoo! Groups Links

<*> To visit your group on the web, go to:
     http://groups.yahoo.com/group/NEXTEL-1/

<*> To unsubscribe from this group, send an email to:
     [email-masked]

<*> Your use of Yahoo! Groups is subject to:
     http://docs.yahoo.com/info/terms/