|
|
|
| Authored by: jesse on Friday, May 24 2013 @ 03:13 PM EDT |
http://en.wikipedia.org/wiki/ALOHAnet
Ethernet uses wires to broadcast signals in the same way wireless networks are
configured. The original use of coax confined the required broadcast power,
allowing communications directly to nodes within 500 meters along the coax.
There was a requirement (due to the resonant frequency of the cable) that the
minimum distance was 2 meters.
The key is that it is broadcast. This was derived from the ALHOHAnet, which used
UHF transmissions during experiments in Hawaii where wired connections just
didn't exist at the time.
Using wireless today is just a replacement of the ethernet transmitter and
cable.
Interesting experiments (not necessarily legal for all use) have been made to
see how far communication can be made. The common "Pringles potato chip
antenna"
http://www.networkworld.com/columnists/2001/1105gearhead.html
Using such oddball antennas extend the range from about 300 feet (a bit over 91
meters), to about 2 miles (a bit over 3 Km) in a line in good conditions. The
key is that instead of broadcasting in a circle pattern it is focused in a
direction.
Using dish antennas has gotten the directed range up to around 50 miles (only in
ideal weather conditions), depending on the dish used (I believe the record was
using two surplus 3 meter radar dishes).[ Reply to This | Parent | # ]
|
|
|
|
|
