A History of the USB Standard

Universal Serial Bus (USB) is a serial bus standardease-of-use of wireless technology. It can be used
for connecting peripherals to a host. It wasin devices including game controllers, printers,
designed to allow peripherals to be connectedscanners, digital cameras, digital music players,
using a single standardized interface and tohard disks and flash drives. It can also transfer
improve plug and play capabilities by allowingparallel video streams.
peripherals to be connected or disconnectedIt is capable of sending date at a rate up to 480
without having to reboot the computer or turnMbps at a 3 meter distance and up to 110 Mbps
the device off. This bus can connect devicesup to 10 meters. It was designed for the 3.1 to
including mice, keyboards, gaming controllers,10.6 GHz frequency range. The Wireless
scanners, digital cameras, printers, digital mediaarchitecture allows up to 127 devices to connect
players, flash drives and external hard drives. USBdirectly to a host. With the elimination of wires, a
has become the standard connection method forhub is not needed. An upcoming Wireless 1.1
the majority of consumer electronic devices. Tospecification will increase data transfer speed to
date, billions of these devices have been1.0 Gbps per second.
introduced into the consumer electronics market.USB 3.0
The USB Implementers Forum, Inc. (USB-IF) is aIn November 2008, the USB 3.0 Promoter Group
non-profit corporation founded by leadingannounced the completion of the 3.0 specification.
companies in the computer and electronicsIt delivers transfer rates up to 10 times faster
sectors. The organization was formed to providethan USB 2.0 through the utilization of a 5.0 Gbps
a support group and forum for the advancementdata rate. Additionally, it has optimized power
and adoption of USB technology. The Board ofefficiency, sync-n-go technology that minimizes
Directors is currently comprised of the followinguser wait-time and backward compatibility with
companies: Hewlett-Packard Company, IntelUSB 2.0. SuperSpeed USB devices interoperate
Corporation, LSI Corporation, Microsoftwith 2.0 platforms and SuperSpeed USB hosts
Corporation, NEC Corporation and ST-Ericsson.support Hi-Speed legacy devices.
USB 1.0 and 1.1NEC Electronics recently announced the first USB
The USB 1.0 specification was introduced in 19943.0 host controller (part number
with two data rates, Low-Speed (1.5 Mbps) andµPD720200). With its high-speed data
Full-Speed (12 Mbps). It was designed to replacetransfer capability, the new SuperSpeed host
the myriad of connectors at the back of PCs andcontroller will require only 70 seconds to transfer
simplify software configuration of communication25 GB of HD video content, the equivalent of a
devices. The 1.1 specification was released in 1998Blu-Ray disc. Transferring the same content would
and was the earliest revision to be widelytake upwards of 14 minutes with Hi-Speed USB.
adopted.Advances in USB technology will lead to a new
USB 2.0generation of high-performance, consumer
The USB 2.0 specification was released in 2000electronic products. For assistance with
and was standardized by the USB-IF in 2001.SuperSpeed product development, the
Several companies led the initiative to develop aSuperSpeed USB Platform Integration Lab (PIL) is
higher data transfer rate of 480 Mbps, about 40now open for USB-IF members. The SuperSpeed
times faster than the 1.1 specification. Also knownUSB PIL provides 3.0 developers with the
as Hi-Speed USB, 2.0 expanded the range ofopportunity to test host and device
external devices that could be used on ainteroperability. For more information, visit the PIL
computer. And, offered backward compatibilitytesting page.
with previous generations.USB Connectors
USB On-The-GoUSB connectors are designed for ease-of-use.
Many USB devices are portable, and there is anGenerally, the trident logo on the connector should
increasing need for devices to communicatebe facing up when plugging into a port. The
directly with each other without a computer. Theconnectors are designed to be durable and easy
On-The-Go Supplement makes it possible forto insert/remove. Different types of connectors
peripherals to communicate directly with eachserver different functions. The Standard-A plug is
other. On-The-Go features include:frequently on cables permanently attached to
- Limited host capability to communicate withdevices, such as computer keyboards or mice.
selected USB peripheralsThe Standard-B plug typically plugs into devices
- A small connector appropriate for the mobilewith removable cables, such as a printer. USB
formdevice connectors have evolved and become
- Low power requirements for preserving batterysmaller as consumer electronic devices have also
lifebecome smaller in size. The current standard
- Ability to be either host or peripheral and toconnector for small devices such as mobile
dynamically switch between the two.phones and cameras is the Micro-B connector.
Wireless USBUSB logos
Wireless USB is a short-range, high-bandwidthFor a company to use a USB logo, its product
wireless radio communication technology originallymust be compliant as demonstrated by passing
developed by the Wireless USB Promoter Groupthe Compliance Test Program. Companies must
and subsequently managed by the USB-IF.also execute a Trademark License Agreement to
Designed from the ground up to addressbe eligible for logo use. When a certified logo
challenges of wireless communications andappears on a product, consumers know the
personal networking, this standard combines theproduct has passed the standards set by the
speed and security of wired technology and theUSB-IF.