Forum

What I think is more amusing is that it was token ring!!!

Ive come across quite a bit of 802.11 1-2Mb stuff usually ripping it out though. Mainly warehouse with Symbol kit I think it is

Yes, FHSS was the father of modern 802.11 systems. The concept was brought to us by one of the world's most beautiful women and a flamboyant artist.

Their incredible ground-breaking work set the foundation for secure military communications and Wi-Fi. It took years before they were finally recognized for their magnificent efforts.

She was regarded by so-called "experts" as what would know be nowadays known as an "air head". That couldn't have been farther from the truth. Sharp as a whip she was:

[ About half way down for FHSS ]:

http://en.wikipedia.org/wiki/Hedy_Lamarr

http://people.seas.harvard.edu/~jones/cscie129/nu_lectures/lecture7/hedy/lemarr.htm

Dave

I'm going to show that to my wife, she is an electrical engineer.

http://www.women-inventors.com/Hedy-Lammar.asp

Dave

Damn Dave, that Harvard page on Hedy is fantastic. Thanks a lot for that I know a bunch of people am going to show it to now.

Nowadays FHSS seems "so old fashioned", but at the time it was an incredible breakthrough. It should remembered that at the time, the best engineers and scientists on both sides of the Atlantic [ tens of thousands of them ] were desperately trying to solve the torpedo/flying bomb problem. The Atlantic Convoys from the U.S. to the UK were vitally important during the war. Hitler wanted to have his long range Condor aircraft be able to drop flying bombs far enough away from the ships that the aircraft wouldn?t be hit by anti-aircraft fire, yet close enough that ?unjammable? radio links could be used to keep the torpedos on target.

http://www.youtube.com/watch?v=rqOVXnNUcYo&feature=related
http://www.ctie.monash.edu.au/hargrave/rpav_germany_hr.html
http://www.youtube.com/watch?v=5K-isY-nhQU&feature=related

Not many people are aware of what Hitler?s main goal was. His scientists had developed the V1 and V2 long range rockets and flying bombs. They were very close to developing a very long range rocket that he hoped would be able to target the eastern seaboard of the U.S. If the war had lasted another year, he could have have had nuclear capability. The problem for him was that the rocket could not hit the States from any of the occupied countries. However, if he could invade Britain and then Ireland, the rockets could reach the U.S. from Ireland.

http://www.youtube.com/watch?v=IN4M1p_tTKU
http://www.theotherside.co.uk/tm-heritage/background/v1v2.htm
http://www.youtube.com/watch?v=R-GhqhUKRVU

If the Atlantic convoys had suffered much more losses than they did, Britain?s supply of raw materials [ especially oil ] would have been cut off. The RAF with a few hundred Spitfires and Hurricanes turned back attacks from the Luftwaffe during the Battle of Britain. This was done thanks to the bravery of the pilots [ They were known as ?The Few?] ,but also due to the radar systems developed by Sir Watson Watt which directed the planes.

http://www.youtube.com/watch?v=TK6uNQoBAGY

If Britain had fallen, Hitler planned to bombard the U.S. constantly to force it?s withdrawal from the war. This is the main reason Churchill said [ referring to those RAF pilots ] ?Never in the field of human conflict was so much owed by so many to so few?. He wasn?t just referring to the possible loss of Britain, but to what it would mean for the rest of the world. Hitler would have been unstoppable if he had gotten those rocket launch sites built in Ireland.

http://sciencestage.com/v/5839/w.-churchill-never-in-the-field-of-human-conflict-was-so-much-owed,-by-so-many,-to-so-few..html

http://www.presentationmagazine.com/winston_churchill_speech_fight_them_on_beaches.htm

http://spoken-gems.com/2008/11/26/winston-churchill-we-shall-fight-on-the-beaches/

The planes seen in the following were of the type used to try and bombard Britain into submission:

http://www.youtube.com/watch?v=cNVVoH9-QH0&feature=related

http://www.youtube.com/watch?v=hjz8pAGRvsg&feature=related

http://en.wikipedia.org/wiki/Battle_of_Britain

Had the Germans been able to come up with a torpedo guidance system that was difficult to jam, the war could have taken a different course.

The technology that was used to develop radar produced much of the electronic circuitry and equipment [ especially oscillators and mixers ] that is used in modern Access Points and WLC?s. The propagation models involved and the practical data recorded helped engineers with link budget development. With the continuing development of radar, phased array radar systems were constructed, which lead to the development of transmit beamforming in 802.11n.
There is very, very little in modern 802.11 Wi-Fi systems that ?just suddenly appeared? . Technology from electronic circuitry to antennas to encryption systems to spread spectrum to link budgets to point to point bridging links came from technology used during WW2.

What Hedy Lamarr the movie star did, was without exaggeration, the technical equivalent of Sandra Bullock announcing that she had invented something called Ethernet. FHSS was the building block for all Wi-Fi systems as we know them.

http://www.youtube.com/watch?v=YAuXz0prMYw

You can see Hedy and George?s patent below:

http://www.ncafe.com/chris/pat2/index.html

Dave

Thanks Dave. She is now one of my most favorite geeks of all time. I love that too; [quote]the technical equivalent of Sandra Bullock announcing that she had invented something called Ethernet[/quote]
Really puts into perspective what an accomplishment it was.

Dave,

That was all very interesting.

I had never heard of the "Ireland connection" before, nor that the Arms mfgr. she had been married to worked for the Axis.

Your post and the links you included definitely filled in a lot of historical "holes".

Big thanks.

The 1997 completion of the IEEE 802.11 standard for wireless LANs (WLANs) was a first important step in the evolutionary development of wireless networking technologies. The standard was developed to maximize interoperability between differing brands of wireless LANs as well as to introduce a variety of performance improvements and benefits. On September 16, 1999, the 802.11 ratified a revision of the 802.11 standard, called 802.11 High Rate, that provides much higher data rates, while maintaining the 802.11 protocol.

In addition to providing high performance and robust systems, 802.11 also promises multi-vendor interoperability amongst product with the same PHYs. This means that customers are freer to mix and match vendors to meet their requirements for each given application. Furthermore, standardization also delivers lower cost components, which will translate into lower prices for users. Because of this, almost all WLAN vendors have moved to IEEE compliance. With the upcoming announcement of the new high-speed specification, most of these vendors will be announcing High Speed 802.11 compliant products as well.

The standard specifies a choice of different physical (PHY) layers. Vendor's implementations have either used Direct Sequence Spread Spectrum (DSSS) or Frequency Hopping Spread Spectrum (FHSS), both Radio Frequency (RF) based.

In 802.11, the DSSS PHY specifies a 2-Mbps-peak data rate with optional fallback to 1-Mbps in very noisy environments. The standard defines the FHSS PHY to operate at 1 Mbps and allows for optional 2-Mbps operation in very clean environments.

Tks

When Churchill referred to ?The Few? [ the RAF pilots who turned back the enemy onslaught and prevented those rocket launching sites being built ], it is though that he took the line from the St Crispin?s Day speech by Henry V, from Shakespeare.

Henry?s men were going into battle against a vastly larger enemy. He gave the speech to bolster their spirits. It?s also the speech from which Steven Spielberg took the title ?Band of Brothers?

We few, we happy few,
we band of brothers...
And gentlemen in England now a-bed
Shall think themselves accursed they were not here,
And hold their manhoods cheap whiles any speaks
That fought with us upon Saint Crispin's day

http://movieclips.com/watch/henry_v_1989/saint_crispins_day/

Dave