The word on just about every Internet user's lips these days is "broadband." We have so much more data to send and download today, including audio files, video files and photos, that it's clogging our wimpy modems. Many Internet users are switching to cable modems and digital subscriber lines (DSLs) to increase their bandwidth. There's also a new type of service being developed that will take broadband into the air.

Photo courtesy Angel Technologies This diagram shows how the HALO Network will enable a high-speed wireless Internet connection

At least three companies are planning to provide high-speed wireless Internet connection by placing aircraft in fixed patterns over hundreds of cities. Angel Technologies is planning an airborne Internet network, called High Altitude Long Operation (HALO), which would use lightweight planes to circle overhead and provide data delivery faster than a T1 line for businesses. Consumers would get a connection comparable to DSL. Also, AeroVironment has teamed up with NASA on a solar-powered, unmanned plane that would work like the HALO network, and Sky Station International is planning a similar venture using blimps instead of planes.

We've already seen satellites used for broadband Internet access. In this article, you'll learn about the future of the airborne Internet. We'll take a look at the networks in development, the aircraft and how consumers may use this technology in their homes.

The Net Takes Flight
The computer most people use comes with a standard 56K modem, which means that in an ideal situation your computer would downstream at a rate of 56 kilobits per second (Kbps). That speed is far too slow to handle the huge streaming-video and music files that more consumers are demanding today. That's where the need for bigger bandwidth -- broadband -- comes in, allowing a greater amount of data to flow to and from your computer. Land-based lines are limited physically in how much data they can deliver because of the diameter of the cable or phone line. In an airborne Internet, there is no such physical limitation, enabling a broader capacity.

Several companies have already shown that satellite Internet access can work. The airborne Internet will function much like satellite-based Internet access, but without the time delay. Bandwidth of satellite and airborne Internet access are typically the same, but it will take less time for the airborne Internet to relay data because it is not as high up. Satellites orbit at several hundreds of miles above Earth. The airborne-Internet aircraft will circle overhead at an altitude of 52,000 to 69,000 feet (15,849 to 21,031 meters). At this altitude, the aircraft will be undisturbed by inclement weather and flying well above commercial air traffic.

Networks using high-altitude aircraft will also have a cost advantage over satellites because the aircraft can be deployed easily -- they don't have to be launched into space. However, the airborne Internet will actually be used to compliment the satellite and ground-based networks, not replace them. These airborne networks will overcome the last-mile barriers facing conventional Internet access options. The "last mile" refers to the fact that access to high-speed cables still depends on physical proximity, and that for this reason, not everyone who wants access can have it. It would take a lot of time to provide universal access using cable or phone lines, just because of the time it takes to install the wires. An airborne network will immediately overcome the last mile as soon as the aircraft takes off.

The airborne Internet won't be completely wireless. There will be ground-based components to any type of airborne Internet network. The consumers will have to install an antenna on their home or business in order to receive signals from the network hub overhead. The networks will also work with established Internet Service Providers (ISPs), who will provide their high-capacity terminals for use by the network. These ISPs have a fiber point of presence -- their fiber optics are already set up. What the airborne Internet will do is provide an infrastructure that can reach areas that don't have broadband cables and wires.

Photo courtesy Angel Technologies Airborne-Internet systems will require that an antenna be attached to the side of your house or work place.

In the next three sections, we will take a look at the three aircraft that could be bringing you broadband Internet access from the sky.

A HALO Over Head
One the three companies developing an airborne Internet network is Angel Technologies. Its HALO Network may be ready for deployment at the end of 2003 and in place over 10 cities by 2006. The centerpiece of this network is the Proteus plane, which will carry wireless networking equipment into the air.

Photo courtesy Angel Technologies The Proteus plane will carry the network hub for the HALO Network.

The Proteus plane was developed by Scaled Composites. It is designed with long wings and the low wing loading needed for extended high-altitude flight. Wing loading is equal to the entire mass of the plane divided by its wing area. Proteus will fly at heights of 9.5 and 11.4 miles (15.3 and 18.3 km) and cover an area up to 75 miles (120.7 km) in diameter. The plane still needs to receive approval from the Federal Aviation Administration.

Proteus Aircraft
Weight	9,000 pounds at takeoff 5,900 pounds empty
Wingspan	77 ft 7 inches (23.7 m) Expandable to 92 feet (28 m)
Length	56.3 ft (17.2 m)
Height	17.6 ft (5.4 m)
Engines	2 turbofan engines 2,300 pounds of thrust
Range	18 hours
Speed	65 knots (75 mph/120.7 kph) to 250 knots (288 mph/463.5 kph)

At the heart of Angel's Proteus planes is the one-ton airborne-network hub, which is what allows the plane to relay data signals from ground stations to your workplace and home computer. The airborne-network hub consists of an antenna array and electronics for wireless communication. The antenna array creates hundreds of virtual cells, like mobile-phone cells, on the ground to serve thousands of users. The payload is liquid-cooled and operates off of about 20 kilowatts of DC power. An 18-foot dish underneath the plane is responsible for reflecting high-speed data signals from a ground station to your computer.

Each city in the HALO Network will be allotted three piloted Proteus planes. Each plane will fly for eight hours before the next plane takes off. Angel CEO Marc Arnold says his company has identified 3,500 airports in the United States that can meet HALO's operational needs. After takeoff, the Proteus plane will climb to a safe altitude, above any bad weather or commercial traffic, and begin an 8-mile loop around the city. Each plane will accommodate two pilots, who will split flying duties during their eight-hour flight.

Floating On Air
Sky Station International is counting on its blimps to beat Angel to the punch in the race to deliver high-speed Internet access from high altitudes. Sky Station calls its blimps lighter-than-air platforms, and plans to station these airships over at least 250 cities worldwide, one over each city. Each station would fly at an altitude of 13 miles (21 km) and provide wireless service to an area of approximately 7,500 square miles (19,000 square km).

Sky Station Blimp
Diameter	203 ft (62 m)
Length	515 ft (157 m)
Width	approx. 300 ft (91 m)
Power	Solar and fuel cells

Each blimp will be equipped with a telecommunications payload to provide wireless broadband connections. The blimps will be able to carrying payloads of up to about 2,200 pounds (1,000 kg). Sky Station believes it can have its first blimp deployed by 2002. Each blimp will have a life span of about five to 10 years. Sky Station says that its user terminals will enable broadband connections of between 2 and 10 megabits per second (Mbps).

NASA's Sub-space Plans
Not to be left out of the high-flying Internet industry, NASA is also playing a role in a potential airborne Internet system being developed by AeroVironment. NASA and AeroVironment are working on a solar-powered, lightweight plane that could fly over a city for six months or more, at 60,000 feet, without landing. AeroVironment plans to use these unmanned planes as the carrier to provide broadband Internet access.

Photo courtesy NASA The Helios aircraft will be equipped with telecommunications equipment and stay airborne for six months straight.

Helios is currently in the prototype stage, and there is still a lot of testing to be done to achieve the endurance levels needed for AeroVironment's telecommunications system. AeroVironment plans to launch its system within three years of receiving funding for the project. When it does, a single Helios airplane flying at 60,000 feet will cover a service area approximately 40 miles in diameter.

Helios Aircraft
Weight	2,048 pounds (929 kg)
Wingspan	247 ft (75.3 m)
Length	12 ft (3.7 m)
Wing Area	1,976 square ft (183.6 m2)
Propulsion	14 brushless, 2-horsepower, direct-current electric motors
Range	1 to 3 hours in prototype tests 6 months when fully operational
Speed	19 to 25 mph (30.6 to 40.2 kph)

The Helios prototype is constructed out of materials such as carbon fiber, graphite epoxy, Kevlar and Styrofoam, covered with a thin, transparent skin. The main pole supporting the wing is made out of carbon fiber, and is thicker on the top than on the bottom in order to absorb the constant bending during flight. The wing's ribs are made of epoxy and carbon fiber. Styrofoam comprises the wing's front edge, and a clear, plastic film is wrapped around the entire wing body.

The all-wing plane is divided into six sections, each 41 ft (12.5 m) long. A pod carrying the landing gear is attached under the wing portion of each section. These pods also house the batteries, flight-control computers and data instrumentation. Network hubs for AeroVironment's telecommunications system would likely be placed here as well.

It seems that airborne Internet could take off in the very near future. If and when those planes and blimps start circling to supplement our current modes of connection, downloading the massive files we've come to crave for entertainment or depend on for business purposes will be a snap -- even if we live somewhere in that "last mile."