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What is P1394b?
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The first technological specifications for 1394 digital links were complete in 1987. These specifications were approved as IEEE 1394 standard (IEEE 1394-1995) in 1995. Currently, there are several devices available with 1394 interfaces already installed; for example, storage devices for digital camcorders, digital video decks, DVD, printers, and hard disk drives, as well as 1394 ICs and other devices such as connectors, cables, evaluation devices, development tools, and software. Furthermore, 1394a, the addition/expansion standard for the 1394 interface standard was accepted in 2000 as the 1394a-2000.
The following specifications were added to 1394a-2000.
Addition of a 4 pin connector
Stabilization of the bus reset operation
Addition of short bus reset (feature to shorten the bus reset time)
PHY low electric power consumption (addition of a suspend mode)
In addition, changing to a network that allows for even higher speeds and longer distances(1). Studies are proceeding on higher speeds and longer distances with another standardization group, the 1394b. Features added in the 1394b is the following:
Higher Speeds (800Mbps ~ 3.2Gbps)
Longer distances (up to 100m)
Addition of transmission media (quartz fiber, plastic fiber, UTP)
Addition of specifications for optical fiber (initialization methods, coding methods)
(1)
"Higher speeds" refers to capacities greater than the S400 (400Mbps) stipulated in the 1995 standards, such as S800 (800Mbps) and S1600 (1.6Gbps). Also, "longer distances" refer to transmissions that exceed the 4.5m stipulated in the 1995 standards. Evaluations have been completed, and it is expected to finish processing and be accepted during 2001.
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Activities by Mitsubishi Rayon concerning 1394.b
This low-speed, long-distance solution has always received attention from the start as a solution to maintain the low-cost of 1394, while expanding the 1394 standards further (extending distances to 50m or greater). Mitsubishi Rayon has recommended and promoted this technology, and worked actively in the development of devices since its proposal in 1995. Mitsubishi Rayon is pressing forward with standardization and distribution activities, and, as one of the core corporations involved in this standardization, has taken the lead in low-cost and long-distance solutions. The current POF specification draft was determined on the basis of the ESKAMEGA, upgraded in 1997.
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MITSUBISHI RAYON CO., LTD.
Optical Fiber Department
6-41, Konan 1-chome, Minato-ku, Tokyo 108-8506, JAPAN
Phone: +81 3 5495 3060
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