1. Background Report 1394b:Optoelectronic Data Communications ECE 4006C Tiffany Lovett Tornya Moore Mareisha Winters January 31, 2002

2. Key features of 1394? It is a hardware and software standard for transporting data at 100, 200, or 400 Mbps It is a digital interface - no need to convert digital data into analog It is physically small and can replace larger, more expensive interfaces It is easy to use

3. Key features of 1394? It is hot pluggable - users can add or remove 1394 devices while the bus is active It is inexpensive It is a scaleable architecture - can mix 100, 200, and 400 Mbps devices on a bus It has a flexible topology It is non-proprietary - there is no licensing problem to use for products.

4. 1394 Cable Is a small, thin serial cable Contains six wires: two of the wires carry power; the remaining four wires are grouped into two twisted signal pairs

5. How 1394 Works Supports both asynchronous and isochronous data transfers 1394 device requests control of the physical layer Asynchronous: The address if the sender & receiver is transmitted by the packet data. Once the receiver accepts the packet, an acknowledgement is returned to the original sender Isochronous: The sender requests an isochronous channel with a specific bandwidth. Isochronous channel IDs are transmitted followed by the packet data. The receiver monitors the incoming data’s channel ID

6. Why 1394b? 1394b is a revision of the initial 1394 standard 1394b is twice the speed, and allows for longer distances It provides new connection options such as Plastic Optical Fiber, Glass Optical Fiber and UTP-S. Previously 1394 could only be connected via copper cabling 1394b is a prime choice for connecting personal computers with digital devices (i.e. cameras, DVD players, and camcorders)

7. Photodetectors Optoelectronic device that senses and measures the output of a typical light source There are three steps in the photodetection process: (1) absorption of optical energy and generation of carriers (2) transportation of the photogenerated carriers across the absorption region (3) carrier collection and generation of a photocurrent The three main types are photoconductors, PIN photodiode, and Avalanche photodiodes For high-speed applications the PIN photodiode is the best choice because it has no internal gain and can attain very large bandwidths.

8. Emitters Three types are LEDs, Edge emitting lasers, and VSCELs LEDs produce light by a process known as spontaneous emission, resulting in incoherent light Lasers produce light by stimulated emission, which results in coherent light For high-speed applications VCSELs are superior to LEDs and Edge emitting lasers because they achieve high data rates easier and they are less expensive

9. Project Goals Investigate and purchase of PIN photodiodes and VSCELs available that meet the 1394b specifications Implement optoelectronic portion of the 1394b test bed with evaluation boards Verify functionality of PIN photodiodes and VSCELs as receivers and transmitters for 1394b Implement own version of 1394b test bed and verify functionality