Reply #25: Altitude and Speed duh..

[zforce]

http://www.privateline.com/Cellbasics/AirCell.pdf

.5G 3G

AT&T Service
Sprint Service
Verizon Service

Personal Cell Phone Use Inflight

WAEA TC Presentation - Updated 11/12/02


Pros & Cons for Airborne Use

CON-

Poor rural coverage (1)
Requires complex and expensive airborne system
Doppler limited (speed)
Receive/Transmit (RT) timing limited (distance)
No air-to-ground network to match these technologies
More difficult issues for Electro Magnetic Interference (EMI)
Fractured market, no one format is emerging as dominant
finite life, 2-3 more evolutions before 3G interoperability(2)
Market presence only 12% (digital-only phones)


(1) Not an airborne issue



Pro-
Good urban coverage - high growth, pervasive (1)
Spectrally efficient (high capacity)
Market presence of 67% (dual-mode phones, all types)
Multiple levels for transmit power



http://www.cellular-news.com/story/8727.shtml

"Generally, wireless operating equipment can only work below a height of 4,000 meters. China Mobile is the first carrier to bring wireless applications to a level above 5,100 meters." (they put a tower on MT. Everest)

http://telephonyonline.com/wireless/mag/wireless_final_contact/

Final Contact - using cell phones on September 11, 2001
Wireless Review, Nov 1, 2001 by Betsy Harter
Excerpt:
"Calling From 30,000 Feet"

Because wireless networks are designed for terrestrial use, the fact that so many people were able to call from the sky brings into question how the phones worked from such altitudes.

Alexa Graf, AT&T spokesperson, said systems are not designed for calls from high altitudes, suggesting it was almost a fluke that the calls reached their destinations.



Z: Funny how rational people understanding of cell phone technology will bend their technological(scientific) understanding just because of something being repeatedly told to them by the media and government, isn't it?

BOTTOM-LINE___________they don't work.