For the user and consumer, 1394 has been designed to simplify the many technical issues involved as data is streamed for viewing on a DTV. The user makes random inputs. The network configuration may be changed at any time by adding or deleting new applications. Different types of content are involved, all with their own characteristics, including Internet protocol (IP) from the web; MPEG data for DTV; digital video (DV) data from the camcorder; content-sensitive information like pay-per-view movies; and non-content sensitive data such as still image transfer from a camera. Top

In addition to these technical issues, there are user considerations, focused on guaranteed delivery and service quality. For example, how long it takes to change from one channel to another, or whether the stream will be disturbed when reconfiguring for a new application, possibly interrupting a viewer who’s watching a movie. Top

First, general architectural concepts included in the 1394 standard govern data flow. A key differentiator for 1394 compared with other buses is that the data flow between 1394 nodes is segmented into asynchronous and isochronous channels. Asynchronous channels are used for command and control functions of the bus as well as transfer of bulk data (ie. IP files) between applications of the network. Isochronous channels are targeted at streaming audio and streaming video. Data streaming must be reliable and well organized so they assure user satisfaction; out of order data packets can destroy a viewing experiences quickly. The channels have been designed to ensure bandwidth and
stability throughout any of the numerous scenarios that might occur. 1394 is one of the only interfaces that provides both isochronous and asynchronous capabilities. Top

This leads to another key concept: 1394 is “plug and play”, meaning the network continues to operate as devices are connected or detached. Also, 1394 is peer-to-peer, which means, in effect, that the intelligence for using the network is present in each node/system. As a result, users need not worry about the order in which systems are connected. They are not burdened by the need to complete complex network setups for addressing or configuration. So, 1394 delivers a high-speed network capable of connecting a wide range of diverse equipment with a minimum of complexity. Top

There are legal issues, too. Movie studios insist on control over their content to prevent illegal pirating and unauthorized commercial use -- especially when an unreleased or first-run film in initial distribution is involved. These concerns must be measured against the increasing number of consumers who want the right to duplicate, or copy, content for personal use. Top

Authors and editors of the 1394 standard have resolved these issues, using complex but reliable data flow, bus arbitration, and copy protection guarantees encompassed in the Digital Transmission Content Protection (DTCP) or ‘5C’ protocols. Defined by a leading group of technology companies from three continents, the copy protection scheme has been endorsed by many leading US studios and is becoming accepted as a highly reliable system designed to protect content from illegal re-use. Top

1394 interoperability

Interoperability involves the correct and proper functioning of systems that share applications, and to offer one network for the increasing number of complex applications that can be linked through 1394. Generally, each application has its own requirements so there are specific protocols and guidelines created to support each. Top

For example in 1394, there are protocols in place to support the AV transmission of sensitive content (i.e., first-run movies). These include IEC 61883 for AV streaming and DTCP for copy protection of the content. When two nodes are discovered on the network, they first use 1394 network specifications. Once they find that they share an application, they utilize the necessary rules and guidelines for transmitting data. Top

If no application is shared between two systems nothing will occur. It’s important to note that the network will still be maintained and that nodes will continue network communication, but no application data will be shared. An example: a DTV connected to a printer. Nothing will occur if the DTV is speaking IEC61883 and DTCP while the printer is looking for SBP3. This represents the proper functioning of the 1394 bus. Top

Complete Network Application Enabled

Transporting digital data is a relatively straightforward process. But, specific applications and user requirements can make it more complex. For example, a network must manage data in situations where a set-top box is streaming a program to a Digital TV at the same time channels can be changed. Now, at the same time the streaming and channel changing occurs, a user needs to output another program to DVHS for recording, while taking part in an Internet session on his or her PC. Add a camcorder connected to the PC for video editing and it makes up a complex network scenario. With IEEE 1394, it can all be done at the same time, efficiently. Top

Other Key Benefits

The arrival of the digital age has created a complex web of technologies, audio systems, and video products with broad appeal to consumers and users worldwide. The ability to take still or moving pictures, edit them, and ship them out via the Internet using a personal computer and a modem line is compelling. So is the ability to download a full, feature length movie onto a small hard drive, then upload it again for viewing on a large, high definition television panel. There are many other business and consumer applications just emerging – along with others not yet conceived. Top

The key technology for this digital traffic is the IEEE 1394 multimedia bus, the most reliable, cost-effective, and efficient way to move audio and video data. Known commercially as FireWire in the computer community and as i.LINK among most consumer electronics providers in Japan, IEEE 1394 has been designed for transporting and networking multiple types of digital data between users and systems, simply and with a quality that users expect. It also has been constructed to move data to or through systems that are busy with other tasks and applications – without disruptions. As the digital revolution continues, this kind of performance enables huge new and exiting opportunities in and for networks populated with every conceivable digital consumer and computer device from storage to printing to display products. Top

As a comprehensive example: a 1394 network at present can include a personal computer, digital TV, digital set-top box, printer, DVD player, external disk drive, and camcorder. Because 1394 has been built to support up to 63 nodes in one network, it can easily handle requirements of all of these products and systems at the same time. Also, multiple 1394 networks can be connected together, so -- theoretically -- more than 1,000 systems can communicate together in a super network, which is still just an idea. But it will not be long in arriving. Top