Click to See Complete Forum and Search --> : How much data throughput can a mulit-channel chip like Engim's really deliver?


dbeberman
04-16-2003, 09:13 AM
Engim has just announced their multi-channel chip.
They are making claims of massive amounts of data throughput, 594 Mbps.
to be exact.

If 4 of Engim chipsets are bundled into a single AP, and the 3, 2.4 Ghz
channels along with the 8, 5.8 Ghz channels are used simultaneously for this
one AP, then the total raw modulated data rate does equal 594 Mbps. This
is not 594 Mbps. of data throughput however. If there is a small enough
number of devices so that only a few devices can be allocated to each channel,
(assuming there is an ability to control which channel a device decides to use),
and all of the devices are close enough to this one AP (approx. 40 feet),
then all the devices can enjoy 54 Mbps. of raw data rate.
The overhead of the 802.11 protocols and the upper layer protocols
will still limit the real application data throughput.
In the rare and unusual circumstances that only one AP is need for the
entire enterprise, this design should deliver good throughput.

The coverage of an AP can extend to a radius of approximately 250 feet.
As the distance increases, as is likely in a corporate enterprise network,
the data rates drop. 802.11a will drop to a low and almost useless minimum
of 6 Mbps. shared data rate. The expected data throughput drops to about 2.5 Mbps.
With all 8 channels the total application data throughput reaches about 20 Mbps.
A multi-channel AP does offer an advantage in that the devices near the AP can use
one channel at a higher data rate while the far devices use another channel at a
lower data rate. This is essentially a software and management issue for any
multi-channel AP, not something specific to Engim's chipset.

(continued in next message)

dbeberman
04-16-2003, 09:15 AM
However, if the needs of the enterprise require more than one AP, each
additional AP will cause co-channel interference and hidden node interference,
further reducing the application data throughput,
thus far a serious problem no multi-channel chip manufacturer has addressed.

Corporate WaveNet, (CWN), has focused on solutions for enterprise-scale application
data throughput. The result is a technology that offers reliable, dependable
data throughput comparable to that of wired LANs. CWN's technology, TRUErate,
enables all WLAN users to enjoy maximum data rates throughout the enterprise, while
also enabling channel reuse, providing scalability to cover any sized corporate
office space. TRUErate can provide 1 Gbps. or more user application data
throughput, enough data throughput to satisfy the MIS department of virtually
any corporate enterprise. For more information, visit CWN at www.corporatewavenet.com