New Orleans -- Wireless cable companies' hookups with
long-distance carriers are spurring technology developments that promise to overturn
previous assumptions about broadband-wireless platforms.
In the past, cable's hybrid fiber-coaxial topology
stood alone as a ubiquitous broadband link to the mass market. But now, new means of
integrating once-disparate wireline- and fixed-wireless-access systems into a single local
platform could make such systems a far more potent force.
These new technology developments lend credibility to
assertions last week by executives from MCI WorldCom Inc., Sprint Corp. and America Online
Inc. that they could compete effectively using a portfolio of access technologies -- none
of which in and of itself matches the delivery power of cable.
"We intend to accomplish our local service goals using
a patchwork of overlapping networks, including DSL [digital subscriber line], fiber,
wireless, cable or other means," MCI vice president of strategic development Robert
AOL, which is already working with MCI's UUNet on
trials of DSL technology, could also be a customer for MCI's new wireless-broadband
platform. Finch outlined service plans that would include wholesaling transport to
Internet-service providers, much as MCI wholesales long-distance capacity and other
AOL senior vice president George Vradenburg made it clear
to attendees at the Wireless Communications Association International (WCA) conference
here last week that wireless cable's multichannel-multipoint-distribution-system
capacity is part of the provider's strategy.
"As we look at broadband, we're looking at a
tapestry of network platforms," Vradenburg said, noting, "The promise for
wireless broadband is just beginning."
But in order to successfully use many platforms to provide
ubiquitous coverage for AOL's broadband data and its upcoming "AOL TV"
service, different access technologies need to "work together," he added.
With cable limiting access to its own ISP affiliates,
wireless broadband is especially important as a complement to DSL in filling out the
coverage for broadband-data services, Vradenburg noted. "Get into this
business," he urged the crowd.
The wireless cable industry is awaiting the completion of
the Federal Communications Commission's reconsideration of its September 1998 ruling
authorizing two-way communications, which officials said would come shortly.
But it was clear that once the complex engineering
certifications on noninterference are completed, the industry will be able to aggressively
move forward with rollouts of two-way data, thanks to the availability of new technical
systems on display here that will support such services.
In fact, People's Choice TV Corp. (PCTV) has already
moved quietly ahead with a launch of two-way data services in Phoenix, after several
months of testing a system supplied by modem-maker Hybrid Networks Inc. and antenna
manufacturer Conifer Corp., PCTV chairman Matthew Oristano said.
After one year of operating data service using telco
return, the company had 2,500 subscribers. Four months later, unpublicized availability of
the two-way version has jumped its subscriber base by 60 percent, counting backlogs,
"Two-way will transform our business," he said,
adding that PCTV has also tested IP-voice (Internet protocol) communications over the
Hybrid system, using IP phones supplied by Selsius Systems Inc. Using a gateway connection
to the public switched network, PCTV has activated high-quality voice on a plug-and-play
basis, Oristano said.
Vendors reported that Sprint and MCI are already shopping
for solutions in the fixed-wireless arena at the MMDS 2.5-gigahertz spectrum tier that
will allow them to integrate what was once a one-way wireless cable platform into the
two-way broadband mesh of the future.
This includes a move from the single-transmitter-per-market
design to cellularization, in which several transmitters would reuse bandwidth.
"We will break the serving areas up into smaller cell
sizes," Finch said, acknowledging that this would add substantial costs to the
approximately $1 billion that MCI is spending to acquire the wireless cable properties of
CAI Wireless Systems Inc. and Prime One.
Sprint chief technology officer Marty Kaplan, in an
interview, also made it clear that cellularization is a likely step in his company's
efforts to maximize the use of the relatively small amount of bandwidth -- about 200
megahertz -- that comes with MMDS, versus the 1.15 GHz used by local multipoint
"I doubt that we'll put just one stick up in an
area," Kaplan said, adding that Sprint is also looking at the use of
"intelligent waveguide" technology as a means of expanding bandwidth efficiency.
Vendors are responding to the need to maximize the
efficiency of MMDS spectrum, and several have introduced sectorized transmitter systems.
Sectorization divides the serving area into 90-degree or smaller slices, thereby greatly
increasing the total available bandwidth from a given transmitter.
Thomcast Communications Inc. -- a new firm comprised of
various units of Thomson-CSF -- introduced a four-quadrant, two-way MMDS-transmission
system, using 64 QAM (quadrature amplitude modulation) downstream and QPSK (quadrature
phase shift key) modulation upstream. This translates into delivering 30 megabits per
second, per 6-MHz channel, in the downstream per sector.
"We're operating in the 1.8- to 3.6-GHz bands to
accommodate use of the system in markets outside of the United States," Thomcast area
sales manager Goerge Moura said.
The highest level of sectorization achieved so far in the
MMDS sphere was on display from Spike Technologies Inc., which subdivides the coverage
area into 22 sectors and reuses bandwidth with every other sector. This nets out to 11
channels of 10-mbps throughput for each 6 MHz of frequency, Spike sales manager Mark
Sprint also wants to integrate services delivered by both
wireless and DSL in any one service area, Kaplan said. "Where we can get to the
household, our preference is wireless broadband, but we'll use DSLAMs [DSL-access
multiplexers] to provide connections where there are problems with line of sight," he
Tight integration of multiple delivery platforms at the
base-station transmitter location is a key selling point of a new system introduced by
Newbridge Networks Corp., which recently signed an agreement to acquire Stanford
Telecommunications Inc. as a step in its efforts to create extremely compact systems.
The company's "MainStreetXpress" ATM
(asynchronous transfer mode) switch is designed to aggregate a variety of access platforms
-- including LMDS, MMDS, DSL and, eventually, cable -- at a local service node that also
serves as the wireless base station. The company is also developing a voice-over-DSL
Repurposing MMDS and integrating it with other access
platforms is just beginning. It will take a while before companies like MCI and Sprint can
fully realize their goals in the local-access market. "The bonanza is not just around
the corner," Finch noted.
Finch called on the wireless industry to think about
standardizing its advanced-service platform, much as cable has done with its data system.
"We'd encourage you to think of coordination and cooperation," he said.