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Smart antennas, mesh networks,
ad hoc
architectures, and ultra-wideband transmission are all on the
development horizon. Smart antennas are already in use in some
locations, and mesh networks are beginning to appear. Ad hoc
architecture and ultra-wideband transmission are still in
preliminary stages, but, alone or in combination with any of the
four, each of these technologies could have a major impact on
communication capabilities.
Common base station antennas broadcast
in all directions, and utilize a narrow segment of the radio
spectrum to avoid interfering with other cells. Smart antennas
use directional broadcasting and frequency controls to achieve a
much more efficient use of the radio spectrum, thus increasing
the capacity of the system.
Mesh networks depend upon the creation
of a wireless base station in a neighborhood, with a high speed
Internet connection via traditional means. Wireless devices
within range of this station can then communicate with the
internet at high speed. This is the same approach, but on a
larger scale, as the currently available wireless network that
anyone can create in his home or office. What sets the mesh
network apart is the ability for each device in the network to
act as a relay for other devices that are beyond the range of
the neighborhood access point.
Current trial versions of this approach
utilize a small, weatherproof pods or smart antennas mounted on
the outside of each subscribers home. These devices relay the
signals from the neighborhood access point and create multi-node
networks within the neighborhood.
This ability to create new networks "on
the fly", is the principle of the third technology, ad hoc
networks. This technology can allow rescue workers in a
catastrophe to communicate with one another over a network that
exists on the units that they each carry into the area. Another
approach that may have already been used in military
applications is to "seed" an area with small units, perhaps
distributed from the air, that serve as routers for the
network. This would allow the "network" to move ahead of the
users so as to be in place when they arrive.
"Bluetooth" is a short range and limited
version of this approach, and is currently in use in Europe to
allow cell phones to communicate with one another and with other
nearby computers. In some instances, this technology provides a
mobile wallet, as the user can utilize his or her mobile phone
to pay merchants, or even buy soft drinks from a vending
machine.
Finally, ultra wideband ("UWB")
transmission offers dramatic increases in transmission
capabilities of 100 megabits per second, compared to the current
wireless capability of 11 mbps in smaller network
configurations, or 384 bps for longer range wireless
transmission. UWB sends its signals out in short, low power
pulses over a wide range of frequencies simultaneously.
Existing wireless utilizes a single designated radio frequency.
As The Economist concludes, "one thing
is clear: it is still very early days for wireless data."
The full article is available for
purchase from The Economist: search for
"Watch this airspace."
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