10-08-2012, 12:06 PM
The Future of Wireless Technologies
[attachment=30909]
Disclaimer
This presentation made direct and indirect quotes
from books, articles and other publications
including contents available on the Internet. The
presenter has taken great pains to acknowledge all
sources. Links are provided to the pertinent web
sites in the appropriate sections of the presentation.
Any omission to acknowledge any source is
unintentional. Some views expressed in the
presentation are the personal opinion of the
presenter.
The History
• Maxwell’s 1864 work was known around the
world. Created a lot of excitement.
• Thomas Edison (circa 1875), while working on
“acoustical telegraphy” generated
electromagnetic sparks from a “vibrator
magnet
• David Hughes (circa 1879-1886),
London born freelance inventor. He
discovered radio waves. He was
incorrectly told that he had discovered
no such thing. He was discouraged. He
abandoned radio work. He was the first
person to take a call on a mobile phone.
At 26 he designed the printing
telegraph. Like Edison, he worked as a
contractor for Western Union.
Developed the first true microphone,
and (independently) a radio transmitter.
• Professor Heinrich Hertz of Bonn Germany (circa
1888) reliably produced and detected radio waves.
• Other inventors (e.g., Tesla, Branly, Stubblefield,
Jagadis G. Bose, Marconi) reproduced/validated
Hertz’s experiments and advanced the practical use of
radio.
• Lars M. Ericsson and wife Hilda (circa 1910-)
worked on the first car telephone.
• The US radio Act (1912) assigned spectrum blocks
and gave operator licenses.
• Mobile radios were being operated in the 2 MHz by
1921.
• The Federal Radio Commission was created in 1927
to bring order to radio-related legal and operational
chaos . FRC became the Federal Communications
Commission (FCC) in 1934.
• The first voice based radio mobile system went
operational on April 7, 1928.
The First Handheld Cellphone
• On October 17, 1973, Motorola
filed a patent entitled 'Radio
telephone system.' It outlined
Motorola's cellular radio system
and was given US Patent Number
3,906,166 when it was granted on
September 16,1975. Inventors on
the patent were Martin Cooper,
Richard Dronsuth, Albert J.
Mikulski, Charles N. Lynk, Jr.,
James J. Mikulski, John F.
Mitchell, Roy A. Richardson, and
John H. Sangster. This came a
year after the Bell System patent
was approved.
How a Cellphone Works
• Each cell site has a base station with a
computerized 800 or 1900 megahertz
transceiver (transmitter + receiver) and an
antenna. This radio equipment provides
coverage for an area that's usually two to ten
miles in radius. The coverage area size
depends on such factors as topography,
population, and traffic.
When you turn on your phone the mobile switch determines
what cell will carry the call and assigns a vacant radio channel
within that cell to take the conversation. It selects the cell to
serve you by measuring signal strength, matching your mobile
to the cell that has picked up the strongest signal. Managing
handoffs or handovers, that is, moving from cell to cell, is
handled in a similar manner. The base station serving your call
sends a hand-off request to the mobile switch after your signal
drops below a handover threshold. The cell site makes several
scans to confirm this and then switches your call to the next
cell. You may drive fifty miles, use 8 different cells and never
once realize that your call has been transferred.
Wireless Bytes
• 545: Number of New York customers (in 1976) who
had Bell System mobiles.
• 3,700: NY customers on the waiting list.
• 44,000: Number of Bell AT&T US mobile
subscribers.
• 20,000: Number on waiting list that lasted 5-10 years.
• 37: Years it took (from the introduction of mobile
phones) for cellular technology to be commercialized.
[attachment=30909]
Disclaimer
This presentation made direct and indirect quotes
from books, articles and other publications
including contents available on the Internet. The
presenter has taken great pains to acknowledge all
sources. Links are provided to the pertinent web
sites in the appropriate sections of the presentation.
Any omission to acknowledge any source is
unintentional. Some views expressed in the
presentation are the personal opinion of the
presenter.
The History
• Maxwell’s 1864 work was known around the
world. Created a lot of excitement.
• Thomas Edison (circa 1875), while working on
“acoustical telegraphy” generated
electromagnetic sparks from a “vibrator
magnet
• David Hughes (circa 1879-1886),
London born freelance inventor. He
discovered radio waves. He was
incorrectly told that he had discovered
no such thing. He was discouraged. He
abandoned radio work. He was the first
person to take a call on a mobile phone.
At 26 he designed the printing
telegraph. Like Edison, he worked as a
contractor for Western Union.
Developed the first true microphone,
and (independently) a radio transmitter.
• Professor Heinrich Hertz of Bonn Germany (circa
1888) reliably produced and detected radio waves.
• Other inventors (e.g., Tesla, Branly, Stubblefield,
Jagadis G. Bose, Marconi) reproduced/validated
Hertz’s experiments and advanced the practical use of
radio.
• Lars M. Ericsson and wife Hilda (circa 1910-)
worked on the first car telephone.
• The US radio Act (1912) assigned spectrum blocks
and gave operator licenses.
• Mobile radios were being operated in the 2 MHz by
1921.
• The Federal Radio Commission was created in 1927
to bring order to radio-related legal and operational
chaos . FRC became the Federal Communications
Commission (FCC) in 1934.
• The first voice based radio mobile system went
operational on April 7, 1928.
The First Handheld Cellphone
• On October 17, 1973, Motorola
filed a patent entitled 'Radio
telephone system.' It outlined
Motorola's cellular radio system
and was given US Patent Number
3,906,166 when it was granted on
September 16,1975. Inventors on
the patent were Martin Cooper,
Richard Dronsuth, Albert J.
Mikulski, Charles N. Lynk, Jr.,
James J. Mikulski, John F.
Mitchell, Roy A. Richardson, and
John H. Sangster. This came a
year after the Bell System patent
was approved.
How a Cellphone Works
• Each cell site has a base station with a
computerized 800 or 1900 megahertz
transceiver (transmitter + receiver) and an
antenna. This radio equipment provides
coverage for an area that's usually two to ten
miles in radius. The coverage area size
depends on such factors as topography,
population, and traffic.
When you turn on your phone the mobile switch determines
what cell will carry the call and assigns a vacant radio channel
within that cell to take the conversation. It selects the cell to
serve you by measuring signal strength, matching your mobile
to the cell that has picked up the strongest signal. Managing
handoffs or handovers, that is, moving from cell to cell, is
handled in a similar manner. The base station serving your call
sends a hand-off request to the mobile switch after your signal
drops below a handover threshold. The cell site makes several
scans to confirm this and then switches your call to the next
cell. You may drive fifty miles, use 8 different cells and never
once realize that your call has been transferred.
Wireless Bytes
• 545: Number of New York customers (in 1976) who
had Bell System mobiles.
• 3,700: NY customers on the waiting list.
• 44,000: Number of Bell AT&T US mobile
subscribers.
• 20,000: Number on waiting list that lasted 5-10 years.
• 37: Years it took (from the introduction of mobile
phones) for cellular technology to be commercialized.