An area related to broadband access is the issue of how interactive multimedia services can easily, reliably, and usefully be distributed and networked among consumer electronics equipment in the home. The growth rates of such equipment, which includes large-screen and stereo TVs, video recording and playback devices, personal computers (PCs), video games, faxes, and printers, is very high. The concept of a network for the home has been considered in Europe for some time and in the United States recently. Such a network also solves recently discovered problems with existing home wiring, such as reflections, EMI ingress, and signal leakage.
Although all but one company with which the JTEC panel discussed this topic are specifically not working on residential networks, panel hosts at Toshiba say they are important, and hosts at Matsushita say they are "under discussion." Only Sharp is developing a stand-alone residential network for monitoring alarms and controlling appliances, but its network is not capable of distributing or networking video or other broadband or multimedia services. It is interesting that Panasonic Technologies in Princeton, NJ, has published papers on broadband residential networks (Burroughs 1993, and Hofmann 1994), and NEC C&C Research Laboratories, also in Princeton, has begun research in this area.
A "home information system" such as those described above can utilize copper wiring (coaxial cable, telephone pairs, power lines), wireless, infrared, or fiber. (In the United States, the Electronics Industry Association's "CEBus" accommodates all these media.) This, then, raises interesting questions with regard to multimode silica fiber and high-bandwidth plastic optical fiber (POF), low-bandwidth versions of which are already available for certain consumer electronics equipment.
Because of the focus in Japan on lightwave transmission, manufacturers there have a strong commitment to single-mode silica fiber. In Europe and the United States, interest occasionally resurfaces in using graded-index multimode fiber for subscriber access networks, in order to reduce costs for connecting, splicing, and coupling fibers to devices. Multimode fiber is also used in the United States in LAN applications such as fiber-distributed data interface (FDDI). No significant role for multimode silica fiber was acknowledged by the panel's hosts in any of its visits in Japan, except in light-emitting diode (LED)-based data links (see next section).
Interestingly, several Japanese companies anticipated no significant role for the new graded-index plastic optical fiber (GI-POF) invented at Keio University, even though it, too, might be useful for LANs and residential networks, and it leverages off the current progress in visible laser diodes. GI-POF has a distance x bandwidth product of approximately 2 GHz-km, similar to the highest-performance multimode silica fiber. Recently, transmission experiments were performed at 2.5 Gbit/s over distances of 100 m by NEC in collaboration with Keio University (Yamazaki et al. 1994). The panel learned recently that Keio University has licensed Mitsubishi Rayon and Boston Fiber Optics to begin production of the new graded-index POF.
Residential premises networks have potential for future importance. Although U.S. efforts are currently more focused on TV distribution plus low-bit-rate control of appliances, there are growing numbers of R&D activities in the area of residential networking, and in this sense, Japan is behind. On the other hand, Japan is ahead in enabling technologies such as low-cost LAN components, plastic fiber, visible lasers, and LEDs.