Bandwidth is the amount of data that can be transmitted over a network in a certain amount of time. Bandwidth is measured in Mbit/s (megabits per second), Kbit/s (kilobits per second), or bit/s (bits per second). If the bandwidth of a network is 1 Mbit/s, then 1 megabit of data can be transmitted over that network in 1 second. The actual rate of transfer of data will vary depending on the equipment of the ISP, the type of Internet connection, and the number of people using the same connection at a single point in time.
You can use various types of technologies, such as dial-up and cable modems, to connect to the Internet. Each technology supports a different bandwidth. Sometimes, you may connect to the Internet by using more than one type of connection. For example, at some airports, you can use a wireless connection to connect to a cable modem. In such a case, the connection speed is only as fast as the slower of the connections. The following describes the various types of Internet connections.
Dial-up Internet access establishes a connection to an ISP via telephone lines using the facilities of the public switched telephone network (PSTN). Today, dial-up connections allow data transfer rates up to 56.6 Kbit/s.
Digital Subscriber Line (DSL) connection
DSL provides digital data transmission over the wires of a local telephone network. Asymmetric Digital Subscriber Line (ADSL) connection is the most common type of DSL connection. To use an ADSL connection, you must have a special ADSL modem. The data transfer rate of DSL Internet connection is 384 Kbit/s to 30 Mbit/s.
Cable modem connection
A cable modem is primarily used to deliver broadband Internet access in the form of cable Internet. If you have a cable TV connection, you can obtain a high-speed Internet connection from the cable TV provider. By using this type of connection, you can be connected to the Internet at all times. This connection supports data transfer rates of 4 Mbit/s.
T1 lines provide a dedicated phone line connection to connect to the Internet and are a popular option for businesses today. This connection supports data transfer rates of 1.544 Mbit/s. T1 connections can be bought in multiples and added together to give more bandwidth
Wireless connections help you to connect to the Internet by using the wireless technology and then connecting you to wired connections such as a cable modem. Although you may connect to a high-speed cable connection, this type of connection may not provide you the full data transfer rates of the wired connection. A popular wireless networking technology is Wi-Fi. It uses radio waves to provide high-speed Internet and network connections. The data transfer rates of wireless Internet connections can range from 11 Mbit/s to 54 Mbit/s. Some wireless connections support a bandwidth of several gigabits per second (Gbit/s).
Cellular Web connection
A cellular Web connection provides you access to e-mail, instant messaging, mobile banking, weather and travel information, and other services anytime and anywhere. The transfer rates for a cellular Web connection depend upon the technologies you use for the connecting device. These technologies include 3G, EDGE, and GPRS.
3G can provide download data rates up to 56 Mbit/s and upload data rates up to 22 Mbit/s. EDGE can provide data rates up to 236.8 Kbit/s while GPRS can provide data rates up to 171.2 Kbit/s.
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