Broadband is a transmission medium which enables high speed Internet access. Broadband service is always on, and much faster than dial-up access. The speed of transmission is defined by the FCC, who categorizes broadband into various service tiers based on these speeds. Basic broadband service is defined as data transmission speeds of at least 4 megabits per second in the download direction, and 1 megabit per second in the ulpoad direction. Broadband is transmitted by various technologies, including: DSL, Cable Modem, Fiber Optics, Wireless, Satellite, WiMax, and White Space. A description of these methods for delivering high speed broadband access follows.
Digital Subscriber Line (DSL) broadband service leverages existing copper telephone lines already installed in most businesses and homes to deliver broadband. Likewise, cable modem broadband service allows cable providers to deliver broadband using coaxial cables which deliver cable TV service to many consumers.Fiber Optic Broadband
Fiber optic technology converts electrical signals carrying data to light and sends the light through very narrow transparent glass fibers. The main advantage to fiber data transmissions is the speed at which it travels. Fiber optic broadband speeds far exceed current DSL or cable modem speeds. The actual speeds users experience is dependent on many factors, including proximity to the service provider, and how the connection is configured. Fiber optic technology is more expensive than other broadband delivery methods.
The various kinds of fiber optic technology available depend on how far the fiber is installed. Fiber to the home (FTTH) runs the fiber all the way to the customer's home or business. Fiber to the node (FTTN) runs fiber to a neighborhood, where pre-existing copper telephone deliver broadband service to the customer's home or business.
To demonstrate how fast fiber broadband service really is, Internet giant Google plans to build, high speed broadband networks in a small number of communities in the United States. Google's Fiber to the Community project promises Internet speeds of 1 gigabit per second to homes in the winning communities.
Wireless broadband uses a radio link between the user's location and the service provider's facility. Wireless technologies are beneficial in providing broadband service in rural or sparsely populated areas where DSL, cable modem, or fiber broadband service would be too costly to provide. Wireless broadband speeds are very similar to DSL and cable modem. Wireless broadband Internet providers can provide permanent Internet access solutions to customers (often in rural areas) who do not have access to wireline services. They can also extend the reach of other "last-mile" wireline broadband connections. This type of wireless broadband access is provided by Wireless Local Area Networks (WLANs), and is often used for public Internet access at "hot spots" in hotels, airports, convention centers, and city parks.WiMAX Broadband
Worldwide Interoperability for Microwave Access, (WiMAX) service is another form of wireless broadband technology designed primarily as an alternative to satellite, or for mobile broadband applications. The range of WiMAX is much longer than WiFi, providing broadband wireless access up to 30 miles using fixed and mobile base stations.Satellite Broadband
Satellite broadband service is useful in rural areas where wired service would be difficult to install. Satellite service is generally more expensive than other means, and does experience problems with latency which can affect speed. Weather conditions can also affect the delivery of service and connection speeds. However, speeds are often much higher than those with dial-up access, and satellite is sometimes the only way to deliver broadband to extremely remote areas.White Space
Since wireless spectrum is a limited resource, broadband service providers have been exploring innovative ways to wring more bandwidth from existing spectrum. One way to accomplish this is by using the "white space" in between television broadcast channels. Proponents of this technology say that this will bring affordable broadband to users who need it the most. With the transition from analog to digital television devices much of the spectrum previously used for television broadcast stations now remains unused.
Broadband Internet Speed Requirements
|Personal Communications, Instant Messengers||300 to 9,600 bits/sec or higher|
|E-mail transmissions||2,400 to 9,600 bits/sec or higher|
|Remote control programs||9,600 to 56 Kbits/sec|
|Digitized voice phone call||64,000 bits/sec|
|Database query||Up to 1 Mbit/sec|
|Digital audio||1 to 2 Mbits/sec|
|Access images||1 to 8 Mbits/sec|
|Compressed video||2 to 10 Mbits/sec|
|Medical Transmissions||Up to 50 Mbits/sec|