What is IEEE 1394?
What Is IEEE 1394?
IEEE 1394 is a high speed internet cable standard developed by Apple specifically for its FireWire brand of connector cables. IEEE 1394 cables are compatible with other USB cables, but they are not used as often as USB cables.
The Different Versions of IEEE 1394
IEEE standard 1394, first released in 1994, originally covered cables that handled data rates up to 50 megabytes per second. Version IEEE 1394A, first published in 2000, covers cables that handle speeds up to 400 megabytes per second.
IEEE 1394B was published in 2002. IEEE 1394B covers speeds up to 800 megabytes per second. IEEE std 1394C was released in 2007.
Each version of the IEEE 1394 standard is backward compatible. For example, IEEE 1394B cables are designed to be compatible with IEEE 1394A and IEEE 1394 cables. IEEE 1394C cables are compatible with 1394A ports as well as 1394B ports.
The Many Names of the IEEE 1394 Standard
FireWire is the term used for Apple cables manufactured to the IEEE 1394 standard. Sony uses the name iLINK. Texas Instruments uses the term Lynx. IEEE 1394 is called the standard for high performance serial bus. IEEE 1394 is similar to Universal Serial Bus or USB, but they are considered competing standards.
IEEE 1394 cables, regardless of name, are covered by several patents. Anyone who manufactures IEEE 1394 ports must pay a royalty; this may be why many computers come with a standard USB port, though IEEE 1394 / USB adapters are available on the market.
Uses of IEEE 1394 Cables
IEEE 1394 serial bus cables link devices to computers and devices to each other for high speed data transfers. IEEE 1394 allows several dozen devices to be linked directly without a hub.
FireWire connections can link devices to each other as well as to computers. When an iPod is connected to a personal computer or a smart phone connects to a Blackberry, an IEEE standard 1394 cable is used.
FireWire / i.LINK cables can also connect a video camera to a computer or digital video recorder. When video from a digital camcorder is sent directly to a digital television, an IEEE 1394 cable is being used. IEEE 1394 cables may be used to link digital VCRs to TVs or DVD players. IEEE 1394 cables may be used to connect computers to each other, though adapter cards may need to be used. IEEE 1394 cables generally work with parallel buses.
The Impact of IEEE 1394 on Cable Design
The IEEE 1394 standard included two types of cables. The first type of cable contains two pairs of wires with three wires in each strand. When six wires are used in the cable, one wire in each twisted wire pair can be used to carry power while the other two in each strand carry data. When your digital cable lets you download songs while recharging the device, it contains six wires within the cable.
The second type of cable built to IEEE 1394 standards contains two pairs of wires with two wires in each strand. Connectors that only allow for data uploads and downloads contain two twisted wire pairs and four wires.
The number of wires within the cable is also indicated by the number of pins. Wires that terminate in a four pin connection do not provide power. Three pin connectors can deliver power while transferring data.
Both types of IEEE 1394 cables are allowed to be up to 4.5 meters or 15 feet long. Cables and cable chains can be connected using a bus bridge that is even longer.
Related IEEE Standards
IEEE standard 1394.1 outlines the standard for high performance serial bus bridges. These bridges link separate buses or cable networks.
IEEE 1394.3 outlines the data communication protocol for peer-to-peer data transport. This covers the method of two devices sharing information without using a computer as an intermediary, such as when images from a camera are sent directly to a printer.