[ILUG] Wireless ethernet

[Brady, Padraig]

> -----Original Message-----
> From: Colm Buckley [mailto:colm at tuatha.org]
> Sent: 09 November 2000 10:50
> To: ilug at linux.ie
> 
> > I have done nothing myself but there are projects started in my
> > class using Bluetooth for that purose. I can let you know how they
> > get on if you remind me around feb/mar 01.
> 
> Bluetooth isn't really a LAN system, and it's definitely not
> Ethernet.  The range of Bluetooth devices is only a couple of metres
> in general (this is all it's *meant* to be), and the bandwidth isn't
> anything to write home about - Bluetooth is meant to be a
> moderate-bandwidth short-range adhoc networking protocol; the real
> wireless LAN standard is IEEE802.11b, which covers distances of up to
> 100m with bandwidth of 2 to 11Mb/s.
> 
>          Colm

You are mostly correct. Bluetooth originally designed as just a short range 
(10m) point to point interoperability standard. I.E you can connect
laptop<->palm
<->phone<->... without the hassles, deficiencies and incompatabilities of
IR. 
They extended the standard a bit to support simultaneous communication of
up to 8 devices (called a piconet), and these piconets can be connected
together
in "scatter nets". However the data rates are around 400Kb so you wouldn't
use
this for traditional LAN applications. Note bluethooth can operate @ up to
100m 
but @ lower data rates. 

Another important point is that bluetooth & IEEE802.11b share the same
frequency 
range (the globally available 2.4GHz) and will interfere with each other! 
A new 802.11a standard will be the basis for wireless LAN speeds of 50 Mbps
and 
higher and will probably use the 5GHz band to get around the interference
problems.

Just to complete this diatribe there is another short range wireless
standard that also uses (interferes with) the 2.4GHz range. It's called
Shared Wireless Access Protocol (SWAP) and defined by the HomeRF working
group.
It was derived from DECT but designed to carry data (1-2 Mbps) in addition
to voice.
It supports up to 127 devices over a range of 40 meters.

Padraig.