An introduction to USB technology
What is a USB?
Universal Serial Bus “USB” 3.0 is the latest specification of the USB standard established by Intel. It was released in August 2008 by a group of developers led by Intel. The technology supports data transfer at very high speeds, from 625 megabytes per second to 5 gigabits per second, which is actually ten times faster than USB 2.0. When USB technology was first introduced, it was considered to be one of the best things to have happened in the field of personal computing, and was enthusiastically welcomed by PC users. Over the years, USB technology has continued to evolve, becoming more and more efficient and popular. Manufacturers have designed and developed many variants of interface connectors to support the technology and link various peripheral devices to the PC system. Originally developed to be used by modems and routers, USB now supports a large number of external devices, which can be connected with the PC mainly for data transfer purposes. However, most devices communicate with PCs via USB, including keyboards, mice, printers, etc. Fundamentally, USBs help to interconnect or “bind” external devices or peripherals with PCs.
Devices that use USB technology
The devices that help us to interact with the PC are called human interface devices. USB can help these devices to connect with PC through special sockets specially designed to support its interface. Human interface devices such as mice and keyboards require very low bandwidths for communication purposes and are even compatible with USB 1.0. However, external peripheral devices such as printers, fax machines, scanners, hard drives, and backup devices require higher versions of USB technology. Devices such as cell phones, digital cameras, game boards, and personal digital assistants (PDAs) also communicate over USB.
USB versions and speed transfer rates
USB technology has evolved over the years, and with each new version, the data transfer rate has steadily increased:
• USB 1.0 low speed compliant up to 1.5 Mbps
• USB 1.1 compatible with maximum speed up to 12 Mbps
• USB 2.0 compatible with high speed up to 480 Mbps
• USB 3.0 compatible with super speed up to 5 Gbps
USB 3.0 compatibility with version 2.0
USB 3.0 achieves its exceptionally high transfer rates by incorporating four additional wires inside its data cable, a total of six wires. It supports full-duplex communication protocol (ability to send and receive data simultaneously over the same medium) and uses negligible electrical power. It is backward compatible with USB 2.0 devices. However, to achieve the full benefit of USB 3.0, the use of devices compatible with the latest version of USB and its special cable is required.