Universal Serial Bus – what is it?

The USB has a port connection often located at the rear of the computer and these days there are one or two provided on the front of the cabinet. Most computers have a USB port that is used to connect various types of peripherals to the computer system. USB brings Plug and Play capabilities to peripherals connected outside the PC. These peripherals are automatically configured when attached to the USB port and a reboot is not necessary to use the component. A few examples are the portable hard disks, the pen drive or flash drive, net connect cards provided by Internet service providers etc.

Example of USB Ports



Theoretically, you can daisy chain (connect various devices to each other in series) 127 devices to each USB port. However, in reality any more than five devices require a USB hub. The current USB specification, version 2.0, supports a data transfer rate of 480 Mb/sec. Version 2.0 is backward compatible with earlier versions 1.1 and 1.0 that used 12 Mb/sec. and 1.5 Mb/sec. rates.

USB is a continually evolving technology, as evidenced by the announcement of USB 3.0. USB 3.0 increases the speed rating of external devices by ten times that of USB 2.0, transferring data at 4.8 Gb/sec. USB 3.0 will be fully compatible with 2.0 and 1.1 devices.

In addition to wired USB solutions, there are recent innovations in Wireless USB (WUSB). WUSB allows for USB 2.0 speeds to devices within three meters of a computer. Wireless USB works similarly to Bluetooth, but features a reduced range to support higher transfer speeds.

We cannot imagine a system without an USB port these days! I personally use an USB port to transfer photographs from my digital camera, for synchronizing data between the internal hard disk and the external hard disk, occasional use of pen drive, to insert the Bluetooth dongle, wireless modem, the mouse and the keyboard, etc.