In its original sense, bandwidth refers to the range of fre-quencies that a communications medium can effectively transmit. (At either end of the bandwidth, the transmission becomes too attenuated to be received reliably.) For a stan-dard voice telephone, the bandwidth is about 3kHz.
In digital networks, bandwidth is used in a rather differ-ent sense to mean the amount of data that can be transmit-ted in a given time—what is more accurately described as the information transfer rate. A common measurement is Mb/sec (megabits per second). For example, a fast Ethernet network may have a bandwidth of 100 Mb/sec while a home phone-line network might have a bandwidth of from 1 to 10 Mb/sec and a DSL or cable modem runs at about 1 Mb/sec. (By comparison, a typical dial-up modem connection has a bandwidth of about 28–56 kb/sec, roughly 20 times slower than even a slow home network.)
The importance of bandwidth for the Internet is that it determines the feasibility of delivering new media such as sound (MP3), streaming video, and digital movies over the network, and thus the viability of business models based on such products. The growth of high-capacity access to the Internet (see broadband) is changing the way people use the network.
In digital networks, bandwidth is used in a rather differ-ent sense to mean the amount of data that can be transmit-ted in a given time—what is more accurately described as the information transfer rate. A common measurement is Mb/sec (megabits per second). For example, a fast Ethernet network may have a bandwidth of 100 Mb/sec while a home phone-line network might have a bandwidth of from 1 to 10 Mb/sec and a DSL or cable modem runs at about 1 Mb/sec. (By comparison, a typical dial-up modem connection has a bandwidth of about 28–56 kb/sec, roughly 20 times slower than even a slow home network.)
The importance of bandwidth for the Internet is that it determines the feasibility of delivering new media such as sound (MP3), streaming video, and digital movies over the network, and thus the viability of business models based on such products. The growth of high-capacity access to the Internet (see broadband) is changing the way people use the network.
No comments:
Post a Comment