Carrier Channel: ‘WIDER-FI’ FILLS GAP FOR LOW-CO$T BACKHAUL

Posted: 8/2003

‘WIDER-FI’ FILLS GAP FOR LOW-CO$T
BACKHAUL

By Khali Henderson

As part of the evolution toward
carrier-class Wi-Fi, metro broadband wireless is being groomed for lower-cost
backhaul as well as traditional first-mile fiber replacement.

Critical to this evolution is the
emergence earlier this year of the IEEE’s 802.16a WirelessMAN standard, which
supports licensed and exempt spectra between 2GHz and 11GHz — frequencies that
are suited to residential and small business applications using
non-line-of-sight links.

Roger Marks, chairman of the 802.16
working group, says 802.16 base stations are candidates for wirelessly linking
802.11x hotspots to the Internet.

Larry Brilliant, vice chairman of
Wi-Fi wholesaler Cometa Networks Inc., agrees. In a keynote address at
SUPERCOMM’s one-day wireless networking event, he predicted an overlay of
802.16a to provide the backhaul — more cheaply and quickly than current
wireline methods.

Brilliant describes the 802.11b and
802.16a growth pattern using an analogy from his other career as an
epidemiologist. Bacteria growth in a Petri dish placed in a warm environment
first sprouts and spreads and then grows in all dimensions, forming a canopy
over the dish. In this same way, he expects Wi-Fi and wireless MAN to grow and
spread.

"If the canopy effect occurs,
it will force virtually every telecom provider to rethink their
businesses," he says, explaining it could be a complement or an alternative
to most incumbent providers, including IXCs, RBOCs, mobile wireless network
operators, CLECs and cablecos.

Intel Corp., a partner in Cometa
Networks, is backing 802.16a and is working on chipsets, says Alan Menezes, vice
president of marketing for Aperto Networks Inc., a founding member of the WiMAX
(Worldwide Interoperability for Microwave Access) Forum, the industry group
established in April to promote adoption of the standard. Intel also is a
member. The group announced in June the addition of 18 members to the original
10. Menezes says WiMAX plans compatibility testing for early 2004 with compliant
product being rolled out in the second half of next year.

Research firm Visant Strategies Inc.
projects the market for WiMAX equipment will exceed $1.6 billion by 2008.
"We see WiMAX playing a key role in the wide-scale proliferation of
wireless broadband for the extension of hotspots, the deployment of outdoor and
private networks, non-line-of-sight backhaul applications and eventually as a
migration path to 4G," says Visant Strategies’ analyst Andy Fuertes.

Menezes adds that 802.16a is
"the next step beyond Wi-Fi" because it is designed with greater
capacity and range required in the MAN. Aperto Networks’ technology, for
example, covers up to 30 miles (e.g., eight miles at 5GHz and 18 to 20 miles at
2.5 GHz).

"It’s more cost-effective than
T1 and faster to provision," Menezes says. Aperto Networks’ base station is
$30,000 with subscriber units supporting up to 1,000 users available for as low
as $700.

Yankee Group Inc. analyst Lindsay
Schroth writes in a recent report the research firm predicts WiMAX technologies
will not compete with cable and DSL in the near term, but will steal market
share from the T1, fractional T1 and frame relay markets.

With the exact intention of
eliminating recurring leased-line costs associated with wireline T1 and
backhaul, Redline Communications Inc., debuted at SUPERCOMM its AN-30T
long-range, non-line-of-sight broadband wireless product.

Keith Doucet, Redline’s vice
president of marketing, says depending on the configuration, the AN-30T costs
about $10,000 to $12,000. Significantly, he says, it doesn’t need wave guides
(metallic conduit that keep water out) or expensive heliax cables. Rather, it
uses standard RG6 cables that are available at computer supply stores. "It
opens the doors in terms of enabling nontraditional players to get into [the
broadband wireless business]."

Doucet says that the biggest hurdle
its technology overcomes is changes in line of sight. The company’s
mathematicians spent three years developing the solution, which is based on
orthogonal frequency division multiplexing (OFDM). "OFDM is not new, but
what is new is to put it into a cost-effective package," Doucet says,
explaining that OFDM divides a single carrier into multiple paths that must be
synchronized. "It’s so precise that it needs expensive components. We
figured out a way to overcome the instability of using cheaper components."

The result, he says, is that AN-30T
provides 72mbps throughout over the air in the unlicensed 5.8GHz spectrum at a
range of more than 50 miles. It offers connectivity for up to four TDM links and
enables simultaneous transport of data and voice traffic. Doucet claims all its
initial trials have turned into sales. The company is working with enterprises
as well as an unnamed U.S. carrier and a Canadian carrier.

Redline, one of WiMAX’s new members,
supports the 802.16a standard. However, not all broadband wireless providers are
on board.

Bjorn Kirchdorfer, executive vice
president of commercial operations for Navini Networks Inc., for example, says
his company is leaning more toward 802.20, an emerging standard for mobile
broadband wireless access that supports mobile users traveling at speeds as
great as 250km per hour. Mobility is possible already in some of the company’s
deployments with international operators, Kirchdorfer says, adding that he
expects a deployment to be feasible this year and hinted at an upcoming operator
announcements planned for Wireless Communications Association International
trade show this month.

A spokesperson for Motorola Inc.
says the company is participating in standards making, but has not embraced
either standard — primarily because it seeks to preserve its RF interference
mitigation techniques which it claims to be the best in the industry at a
minimum of 3dB carrier to interference (C/I). Motorola’s Canopy system uses the
unlicensed UNII bands (5.25-5.35GHz or 5.725-5.825GHz). Its point-to-multipoint
range is 10 miles; point-to-point is 35 miles.

Standards aside, Navini Networks and
Motorola are shopping their broadband wireless technologies for similar
applications — backhaul and last-mile replacement. "We can be
complementary to wireless LAN. We can be a backhaul network," says
Kirchdorfer, who notes Navini uses 2.6GHz, or MMDS, spectrum for backhaul. The
price per user, he says, is $300 to $450, which is "cost-competitive with
DSL."

He says the reduced costs and the
improvements in the technology are why broadband wireless is making a
resurgence. "Getting from the WLAN to the WAN, the last mile is a problem
operators have to be able to solve," he adds.