Broadband Internet Access

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Broadband Internet Access refers to a service that allows an internet user to access the World Wide Web at a data rate much higher than dial-up internet access. Dial-up internet access typically reaches a maximum of 56 kilobits per second (kbps) only, whereas broadband access is defined as internet access having download data transfer rates of at least 256 kbps.

This definition of broadband access is subject to debate and change as rapid technology advances make maximum data transfer rates obsolete in a short time. In fact, as of this writing, the US FCC already defines broadband access as one that has a download data transfer rate of 768 kbps while some other entities even define it as having a transfer rate of 2.1 Mbps. Note that data rates are measured in terms of maximum download because some broadband systems (such as the ADSL) are asymmetric in nature, i.e., its maximum upload rate is much lower than its maximum download rate. There are many ways to achieve broadband internet access, as discussed below.

The most common broadband services at present include those that utilize DSL and cable modem technologies. Other technologies used for broadband internet access include fiber-optic connections, wireless networks (of which there are many kinds), and satellite systems. Prior to DSL, cable, and wireless connections commonly used today, the ISDN (Integrated Services Digital Network) is a common technology used for digital broadband access to the internet (circa 1990's). Some broadband access technologies are described below.

DSL, which stands for "Digital Subscriber Line", is basically a technology that uses an ordinary telephone line to achieve high download data transfer rates for broadband access. The most popular consumer-ready DSL is assymetric DSL, or ADSL, so named because its download rate is faster than its upload rate. Unlike dial-up access, DSL doesn't interfere with the use of the telephone even if they're sharing the same line because it operates at much higher frequencies (25 kHz and above) than those used by the phone (4 kHz and below).

Another technology used for broadband access is commonly referred to as "T-1" (although it also has other names). T1 is a highly-regulated and relatively expensive line service intended for businesses. Sometimes likened to a 'leased line' for internet access, it was designed originally for voice communications. T-1 can provide data transfer rates of up to 1.544 Mbps.

Wireless internet service providers (WISP's) are now another common alternative for broadband access. WISP's use high-power radio transceiver systems and/or 802.11 Wi-Fi systems with special antennas to provide broadband access to their subscribers. Wi-Fi may also be employed to further distribute broadband access from a wireless ISP to multiple users within a facility.

Cellular phone broadband access is now widely available in the market, thanks to the extensive deployment of cellphone towers today. 3G technology, which is needed for cellular broadband access, is now commonplace around the world. 3G networks use various technologies such as HSDPA, EVDO, and UMTS to achieve high data transmission rates. A USB cellular modem is all that's needed by laptops and desktop PC's to gain broadband internet access through a cellular phone.

Satellites in geostationary orbit are also used to provide broadband internet access to subscribers. Although an expensive alternative that is not viable for many locations, satellite internet is useful in isolated areas where it is the only option. Nonetheless, satellite internet costs are going down and may soon be competitive with other broadband alternatives. One problem with satellite internet is the delays introduced by the long distances traveled by the satellite signals to and from Earth. This is an inherent problem that has no solution, making satellite internet less suitable for real-time interactions with other internet users.

A new broadband access service is known as 'Broadband over Power Lines', or BPL. As its name implies, it allows broadband internet access through power lines. The obvious advantage of this method is its 'reuse' of the ubiquitous power lines, which takes care of a big part of its infrastructure requirements. Unfortunately, sending internet signals over the power lines is not easy because power lines are inherently noisy. The noise and harmonics present on the power lines can result in internet access disruptions. Also, the high-frequency internet signals traversing the power lines can interfere with amateur radio communications. Security risks may also be an issue since the internet signals may be radiated outward by the unshielded power lines.