Chipsets from startup Engim which allow one Wi-Fi access
point to carry data on multiple channels may end up in networks
optimised for high-density environments, including multipurpose
wireless infrastructures on airliners.
The company will introduce its new generation of both silicon
and access points for suppliers to incorporate into wireless Lan
offerings.
Engim's EN-3001 Wideband Wireless Lan chipset and access point
reference designs for 802.11b and 802.11g are designed to use three
channels at once, allowing more clients within a single area to
simultaneously use Wi-Fi, according to Scott Lindsay,
vice-president of marketing at Engim.
Engim is adding to its lineup a thin access point, priced to
system makers at about $100, in which the processing of packets
takes place in the chipset rather than on a separate processor.
Also new is a feature in Engim's radio chip called "transmit
cancellation", which can prevent interference that an access
point's transmitting antenna can cause to the same access point's
receiving antenna, Lindsay said. The feature subtracts the transmit
antenna's interfering signals for the receiving antenna.
At the heart of Engim's approach is multichannel capability. The
802.11b and 802.11g standards use spectrum in the 2.4GHz band that
offers at least 11 bands, but generally only three of those can be
used because of interference from channel overlap. Each access
point typically can only use one of those channels, and simply
putting three access points in one location with each on a
different channel - or just building an access point with three
chips on different channels - will not provide good performance
because they will interfere with each other, Lindsay said.
That means the zone covered by an access point, typically about
300ft, can only be served by one channel, leaving two channels
unused, said analyst Craig Mathias, founder of Farpoint Group. That
is a waste of spectrum, he said, one that is not a big problem
today but is likely to become one in the future.
Engim built the silicon for three channels into a single chip,
with technology that can find the interference on a channel and
subtract it out for a clear signal, Lindsay said. A radio for
802.11a, due in two or three months, will allow the use of three
802.11a channels simultaneously.
One of the dense environments that may benefit from Engim's
approach is airliner cabins, according to Jim Pristas, founder and
chief executive officer of Matrx Aerospace Broadband
Technologies.
Matrx is using Engim's chipset in the demonstration unit of an
in-flight wireless infrastructure it is developing, called Galaxy.
Matrx plans to work with airlines, aircraft manufacturers and other
partners to install the systems, Pristas said. Matrx was founded in
2001, and is backed by a major aerospace company, although he would
not identify the company.
Galaxy will be able to use multiple wireless bands as well as
multiple channels within each band, according to Pristas.
The company aims to start out in late 2005 with a version geared
primarily to passenger web access and e-mail over Wi-Fi. Those
services are already offered on some airlines, but because Galaxy
will be built specifically for airplane cabins, it will offer
better performance, in part because of the multichannel capability,
Pristas said.
A second version of Galaxy, aimed for 2006, would offer a wider
range of services through a system that could include proprietary
wireless systems in addition to Wi-Fi, Pristas said.
The system might also be used for surveillance cameras, crew
communication, handheld point-of-sale devices and other
applications. The performance advantages of the purpose-built
system could also serve another future application, in-flight
wireless phone calls, he said.
Prices for the EN-3001 chipset will vary based on volume and the
customer's development needs. The chipset, as well as the AP-310
All Services Access Point at about $120 (£65) and the AP-320 Thin
All Services Access Point at about $100, are available immediately
to system suppliers.
Stephen Lawson writes for IDG News Service