Overview of Desk Area Network (DAN)

A Desk Area Network (DAN) is a specialized network architecture designed for multimedia workstations that enables direct connection of multimedia devices and peripherals to the network. DAN uses Asynchronous Transfer Mode (ATM) technology to provide high-speed, reliable communication between multimedia devices, workstations, and peripheral equipment without requiring data to pass through the central workstation.

Before DAN, multimedia devices like cameras, audio equipment, and displays had to communicate through the workstation, creating bottlenecks and reducing performance. DAN eliminates this limitation by allowing devices to connect directly to the network infrastructure.

Architecture of DAN

The DAN architecture consists of several key components working together through ATM technology. ATM transmits all information in small, fixed-size packets called ATM cells, which provide predictable performance for multimedia applications requiring consistent bandwidth and low latency.

The CPU node contains an ARM 600 processor with 256KB additional cache memory, providing high-performance processing capabilities while connecting directly to the ATM fabric for efficient data handling.

Key Components

• Audio/Video Machines Handle multimedia content processing including audio and video streams.

• Presentation Nodes Display and present multimedia content to users through monitors, projectors, or other display devices.

• DSP Node Digital Signal Processing node with additional processors and memory for enhanced multimedia processing performance.

• CPU Node Central processing unit with ARM 600 processor and dedicated cache memory connected to the ATM fabric.

• DAN Cache Controller Manages cache operations and facilitates ATM cell movement between devices and the network interconnect.

How DAN Works

DAN operates through direct device-to-device and device-to-CPU connections using ATM technology. When data needs to be transmitted, it is packaged into fixed-size ATM cells that travel directly to their destination without intermediate processing by the workstation.

The network establishes connection-oriented communication paths, providing both routing information and data context at endpoints. This eliminates the need for devices to specify detailed addressing information they only need to specify the required service type and quality level.

Advantages

• High Performance ATM technology provides guaranteed bandwidth and low latency for multimedia applications.

• Direct Connectivity Devices communicate directly without workstation bottlenecks, improving overall system performance.

• Resource Sharing Multimedia devices can share resources directly across the network without CPU intervention.

• Simplified Interface Connection-oriented design simplifies network configuration and management.

Limitations

Conclusion

Desk Area Network (DAN) provides an efficient solution for multimedia workstation connectivity by using ATM technology to enable direct device communication. While facing challenges in cost and standardization, DAN offers significant performance benefits for multimedia applications requiring high bandwidth and low latency communication.