This letter shows an architectural approach for analyzing real-time aspects of distributed multimedia processing systems. The results of this letter are 1) to propose the concept real-time supporting environments which consist of real-time traffic management/control environment and real-time application environment and 2) to analyze the real-time requirements of such environments.

Key aspects and technologies of future satellite communications are discussed toward multimedia era. Onboard processing called the switchboard in the sky and networking taking full advantage of features peculiar to satellite communications are pointed out as essential technologies to overcome a variety of big challenges for realizing future satellite communications. Several experimental and commercial systems are introduced as the first step toward multimedia era.

We propose an architecture of a high-speed internetworking device using central control method. Co-operations of hardware and software is required to realize high relay performance. For the hardware, we have designed an original bus arbitration control method to achieve a high throughput of a data bus. For the software, we have devided a normal relay processing from other processing and built it as a basic function of the monitor. By this method, relay perfomance improves dramatically, because of a multiple effect of the reduction of software overheads and the improvement of cache hit ratio. We have developed the prototype device and confirmed the effects of the proposed method.

This paper discusses key technologies for intelligent radio transmissions and intelligent network constitution techniques for advanced wireless communication systems. In the former part, this paper discusses the intelligent radio transmission techniques, in which the adaptive modulation techniques are mainly introduced because it is very effective to intelligently assign radio resources to each terminals as well as to intelligently control radio transmission parameters under dynamically changing traffic, required quality of services (QOS), and channel conditions. In the latter part, this paper discusses intelligent networking techniques, in which autonomous radio networking techniques and IP address control techniques for mobile host in the Internet are introduced to obtain suggestions for future intelligent and robust networking technologies.