1394 Trade Association
has introduced a new version of the 1394 multimedia standard. The new specification is called 1394b, and it supplements the exist standard used by Macs called FireWire.
1394b incorporates bandwidth improvements — while the interface in its current implementation on the Mac is limited to a still-hefty 400Mbps, IEEE 1394b knocks the standard up to 3.2Gbps using plastic optical fiber. Audio and video transfer on plastic optical fiber up to 50 meters at 200Mbps, up to 100 meters at 5Mbps, and up to 3.2Gbps over glass optical fiber.
A new bus arbitration scheme called BOSS (Bus Owner Supervisor Selector) has also been incorporated, enabling overlapped, pipelined arbitration that runs in parallel with data transmission. Hybrid bus operation also provides backward compatibility with 1394-1395 and 1394a variants.
Two types of transmission are supported on 1394b — the “beta” mode, which is the pure 1394b spec, and the “bilingual” mode, which guarantees backward compatibility by supporting data-strobe signaling.
Zayante CTO Michael Johas Teener says that costs of 1394b-enabled products are expected to be cheaper than previous versions, too. Gate counts for integrated circuits designed for 1394b are going to double, but the analog design is simpler, since the 1394b variant uses unidirectional arbitration signaling rather than common mode signaling. This improves efficiency and reduces voltage.
Max Bassler of Molex Inc. is the 1394 Trade Association’s chairman. He says that the new interface — which is currently in re-circulation for final approval by committee members — is ideal for home networking, industrial applications, and new peripherals. Bassler also expects 1394b to make inroads in installation as the network bus for new consumer electronics systems in passenger vehicles.
Bassler says the industry expects to see the first 800Mbps devices in circulation this summer, with new development happening by autumn. TI, NEC, Panasonic and Agere are all purportedly working on 1394b devices. Apple has not yet made any announcements regarding adoption of the standard, but the company is a member of the 1394 Trade Association and sits on its board of directors.