On 9/4/2012 11:43, Patrick Elliott wrote:
> On 9/3/2012 1:07 PM, Darren New wrote:
>> On 9/2/2012 17:28, Patrick Elliott wrote:
>>> The same identical, save in electronic form,
>>> technology is at the center of cell tower systems.
>>
>> Well, no, not really.
>>
> Odd then that, a few years back, she was recognized, finally, for having
> invented the idea, and it was attributed as one of the key features that
> make cell phone networks possible.
>
> http://en.wikipedia.org/wiki/Hedy_Lamarr
>
> "Lamarr's and Antheil's frequency-hopping idea serves as a basis for modern
> spread-spectrum communication technology, such as Bluetooth, COFDM used in
> Wi-Fi network connections, and CDMA used in some cordless and wireless
> telephones."


Spread spectrum and frequency hopping are two different things. Frequency 
hopping is only one possible way of doing spread spectrum.

In CDMA, everyone is transmitting on the same frequencies, in both 
directions, at different baud rates, all the time. There's no frequency 
hopping involved: every phone and every tower uses the entire frequency band.

-- 
Darren New, San Diego CA, USA (PST)
   "They're the 1-800-#-GORILA of the telecom business."

Post a reply to this message