When San Francisco sounded the call for ideas this summer on how to bring cheap, wireless Internet connections to the entire city, technology industry giants responded with one answer -- mesh networks.
The city's project has put a spotlight on this emerging technology, which supporters say can cheaply turn the city's 49 square miles into one big wireless Internet hot spot like you'd find at Starbucks.
That means anyone in San Francisco could log on to the Internet from a park bench, from their living room, or even from the 20th floor of a skyscraper, provided their computer has a special card to pick up the signal. And they could do it without any cords or wires.
Such major companies as Google, Motorola, Earthlink, Nortel, Cisco and others have all proposed installing a mesh network that would make this happen. Google grabbed headlines for proposing to do it for free, but Mountain View's MetroFi, a much smaller company with a proven track record in mesh networking locally, is also offering to build a free network.
Mayor Gavin Newsom launched the search for ideas in August. A city panel is reviewing the 26 responses from companies and will make a recommendation to Newsom by the middle of next month on whether to start a formal bidding process -- requiring companies to submit more detailed proposals -- or enter into direct negotiations with a company.
The major tech companies that responded believe mesh networking can meet all of the city's demands, which include: 95 percent Internet coverage outdoors; 90 percent coverage indoors; 1 megabit-per-second data transfer speed, comparable to ``wired'' connections through DSL; Internet connections for residential, business and government customers; and the ability for someone to remain connected to the Internet even while in motion.
A mesh network can be likened to an invisible fishing net laid over the city, with each knot a radio transmitter. The transmitters all communicate with each other via silent radio signals, hence the ``mesh.'' Data travels along those mesh links to and from the Internet to reach customers on their computers.
Experts say the technology has many advantages, including being vastly cheaper than installing a network of underground wires. Supporters also tout the fact that mesh networks are ``self-healing.'' That means if one of the transmitters conks out, it doesn't stop the entire network. Data just hops to other transmitters.
But WiFi networks also have their limitations. Signals from the transmitters can't penetrate deep indoors without the help of additional equipment to strengthen the signal, experts say. And because of the physical nature of radio waves, transmitter signals also can't penetrate hills or thick cement walls. Additionally, radio signals from other sources, such as existing WiFi ``hotspots,'' could potentially interfere with or diminish the mesh signals.
``There are already a huge number of hotspots and access points being used by businesses, homeowners and hotspot providers in this spectrum,'' independent industry analyst Andrew Seybold wrote in a newsletter earlier this month. ``There will be speed fluctuations, service outages and `bandwidth hogs.' ''
San Francisco also represents a particularly stiff challenge with its hilly landscape and dense urban areas.
Problems solvable
Yet the companies promoting mesh say most of those problems can be solved simply by installing additional, specially designed equipment indoors and out.
Many in the tech world are curious about the details of Google's proposal because it could offer clues to the company's overall business strategy. But the Internet search giant has made only a small excerpt of its proposal public.
MetroFi, which already operates mesh networks in Santa Clara and Cupertino, made a detailed proposal public. It provides a good example of how mesh systems work.
The company proposes installing 1,400 transmitters throughout the city, mounted on light poles. The transmitters would be powered by the pole's electricity and would communicate with one another via radio signals. The transmitters could also wirelessly connect to any laptop up to 500 feet away, using radio waves to ferry data to and from the Internet.
For every 17 MetroFi light-pole transmitters, there would be one ``gateway'' radio device installed on a building. The transmitters would send and receive data, again by radio waves, to and from the gateway radio. The company refers to this collection of a gateway radio and its 17 feeder transmitters as a ``microcell.'' There would be 81 gateway radios -- and thus 81 microcells -- spread throughout the city.
These gateway radios, in turn, would send data to one of eight larger ``hub'' transmitters, which would send signals to one central microwave receiver on a tower connected to an underground network of fiber-optic cables. The fiber cables carry the signals to and from the Internet.
Indoor modem
To connect from the light-pole transmitter deeper into a home 300 to 500 feet away, residents would have to install a special indoor modem near the front of their house that would strengthen the signal.
People living farther than 500 feet from a light-pole transmitter would need to install a special, 8-inch outdoor antenna to amplify the WiFi signals.
Moreover, a light-pole transmitter wouldn't create a strong enough signal to bring the Internet to someone above the third story of a building, said Chuck Haas, MetroFi's chief executive. To get coverage to a high-rise building, MetroFi would install a special transmitter focused vertically on the building, rather than outward in all directions.
As far as costs go, residents could gain access to the Internet for free under the MetroFi plan if they are willing to keep a window in the corner of their computer screens playing advertising during their Web surfing. For a subscription fee of about $15 per month, customers could get online without the ads. Both options would bring data speeds of 1 megabits per second.
http://news.yahoo.com/s/sv/20051031/tc_siliconvalley/_www13043832;_ylt=AqQ_sNzm5KeQPZ6.s4NSxhAjtBAF;_ylu=X3oDMTA5aHJvMDdwBHNlYwN5bmNhdA--
The city's project has put a spotlight on this emerging technology, which supporters say can cheaply turn the city's 49 square miles into one big wireless Internet hot spot like you'd find at Starbucks.
That means anyone in San Francisco could log on to the Internet from a park bench, from their living room, or even from the 20th floor of a skyscraper, provided their computer has a special card to pick up the signal. And they could do it without any cords or wires.
Such major companies as Google, Motorola, Earthlink, Nortel, Cisco and others have all proposed installing a mesh network that would make this happen. Google grabbed headlines for proposing to do it for free, but Mountain View's MetroFi, a much smaller company with a proven track record in mesh networking locally, is also offering to build a free network.
Mayor Gavin Newsom launched the search for ideas in August. A city panel is reviewing the 26 responses from companies and will make a recommendation to Newsom by the middle of next month on whether to start a formal bidding process -- requiring companies to submit more detailed proposals -- or enter into direct negotiations with a company.
The major tech companies that responded believe mesh networking can meet all of the city's demands, which include: 95 percent Internet coverage outdoors; 90 percent coverage indoors; 1 megabit-per-second data transfer speed, comparable to ``wired'' connections through DSL; Internet connections for residential, business and government customers; and the ability for someone to remain connected to the Internet even while in motion.
A mesh network can be likened to an invisible fishing net laid over the city, with each knot a radio transmitter. The transmitters all communicate with each other via silent radio signals, hence the ``mesh.'' Data travels along those mesh links to and from the Internet to reach customers on their computers.
Experts say the technology has many advantages, including being vastly cheaper than installing a network of underground wires. Supporters also tout the fact that mesh networks are ``self-healing.'' That means if one of the transmitters conks out, it doesn't stop the entire network. Data just hops to other transmitters.
But WiFi networks also have their limitations. Signals from the transmitters can't penetrate deep indoors without the help of additional equipment to strengthen the signal, experts say. And because of the physical nature of radio waves, transmitter signals also can't penetrate hills or thick cement walls. Additionally, radio signals from other sources, such as existing WiFi ``hotspots,'' could potentially interfere with or diminish the mesh signals.
``There are already a huge number of hotspots and access points being used by businesses, homeowners and hotspot providers in this spectrum,'' independent industry analyst Andrew Seybold wrote in a newsletter earlier this month. ``There will be speed fluctuations, service outages and `bandwidth hogs.' ''
San Francisco also represents a particularly stiff challenge with its hilly landscape and dense urban areas.
Problems solvable
Yet the companies promoting mesh say most of those problems can be solved simply by installing additional, specially designed equipment indoors and out.
Many in the tech world are curious about the details of Google's proposal because it could offer clues to the company's overall business strategy. But the Internet search giant has made only a small excerpt of its proposal public.
MetroFi, which already operates mesh networks in Santa Clara and Cupertino, made a detailed proposal public. It provides a good example of how mesh systems work.
The company proposes installing 1,400 transmitters throughout the city, mounted on light poles. The transmitters would be powered by the pole's electricity and would communicate with one another via radio signals. The transmitters could also wirelessly connect to any laptop up to 500 feet away, using radio waves to ferry data to and from the Internet.
For every 17 MetroFi light-pole transmitters, there would be one ``gateway'' radio device installed on a building. The transmitters would send and receive data, again by radio waves, to and from the gateway radio. The company refers to this collection of a gateway radio and its 17 feeder transmitters as a ``microcell.'' There would be 81 gateway radios -- and thus 81 microcells -- spread throughout the city.
These gateway radios, in turn, would send data to one of eight larger ``hub'' transmitters, which would send signals to one central microwave receiver on a tower connected to an underground network of fiber-optic cables. The fiber cables carry the signals to and from the Internet.
Indoor modem
To connect from the light-pole transmitter deeper into a home 300 to 500 feet away, residents would have to install a special indoor modem near the front of their house that would strengthen the signal.
People living farther than 500 feet from a light-pole transmitter would need to install a special, 8-inch outdoor antenna to amplify the WiFi signals.
Moreover, a light-pole transmitter wouldn't create a strong enough signal to bring the Internet to someone above the third story of a building, said Chuck Haas, MetroFi's chief executive. To get coverage to a high-rise building, MetroFi would install a special transmitter focused vertically on the building, rather than outward in all directions.
As far as costs go, residents could gain access to the Internet for free under the MetroFi plan if they are willing to keep a window in the corner of their computer screens playing advertising during their Web surfing. For a subscription fee of about $15 per month, customers could get online without the ads. Both options would bring data speeds of 1 megabits per second.
http://news.yahoo.com/s/sv/20051031/tc_siliconvalley/_www13043832;_ylt=AqQ_sNzm5KeQPZ6.s4NSxhAjtBAF;_ylu=X3oDMTA5aHJvMDdwBHNlYwN5bmNhdA--
