The introduction of networks providing Internet-like services such as the Open Computer Network (OCN) by NTT and others like it will lead to higher level demands by users. For example, users will be asking for higher quality, greater functionality, and lower charges for high-speed, high-throughput data transfer. To respond effectively to the wishes of sophisticated and varied users, technological development must be pursued from the user's point of view. For this reason, research and development is being performed on middleware to open up network functions and make it possible for the user and network to cooperate with each other. This paper discusses the development of major technologies for achieving an enhanced internetworking that should become a catalyst for the future multimedia network, and presents a future vision for the network.

Intensity noise reduction effects by superimposed pulse modulation are theoretically analyzed for LD inherent noise, feedback light noise, and modal noise. It is shown that noise spectrum spreading effects due to LD mode partition noise are very effective to reduce mode hopping noise and modal noise, that a short pulse width completely suppress beat noise and mode hopping noise based on submode structures constructed by feedback light, and that modal noise is effectively reduced by LD longitudinal mode linewidth broadening effect as long as a fiber bandwidth is sufficiently narrow compared with the broadened LD linewidth. It is also shown that LD quantum intensity noise increases for LD multimode operation, and that feedback light noise based on injection locking effect can not be suppressed without system parameter adjustment.