|Budget Amount *help
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
This research project aims at establishing the basic technologies associated with the following three technical issues to realize ubiquitous computing networks the environment-adaptive personal communications architecture, the context-aware information delivery network architecture and systems, and the privacy protection technologies.
(1)An environment-adaptive personal communications (EAPEC) system
An environment-adaptive personal communications (EAPEC) system is proposed that accepts communications from senders, automatically selects the most appropriate communications device, medium, and service for the receiver, converts the sender's message into the selected form, and forwards the converted message to the receiver. The EAPEC can easily be implemented by adding functional components of five types to the 3GPP-based all IF network: The EAPEC architecture is evaluated in terms of call-setup times by theoretical analysis and simulation. Performance analysis indicates that the performance
of application servers and degrees of server utilization greatly affects the call-setup times while the IP-network delay does not have much effect under practical conditions.
(2)Context-aware information delivery network architecture and systems
Context-aware computing is a requisite to achieve "invisibility" in ubiquitous computing, where user context such as the user's location, time, activity status, activity history, and preferences are automatically captured and analyzed by computers to provide users with relevant content and services. Two types of network architectures are proposed that use. UMTS Release 5 architecture and wireless LAN suitable for context-aware information delivery services. The first type of network architecture is the NCA (network-centric architecture) and the second is the ECA (end-user-centric architecture). The two architectures are modeled with a queuing network and their response times are compared through theoretical analysis and simulation. The results indicate that with low-performance servers, the response times of the ECA are generally shorter or almost the same as those if the NCA. However, with high-performance servers, the response times of the NCA are generally shorter except during high server utilization.
(3)Privacy protection technologies
A mobile agent-based privacy model characterized by two basic ideas is proposed. First, the model encapsulates personal data and the associated user's preferences into a privacy capsule. The purpose of encapsulation is to hide the data and prohibit it from flowing to the world outside of the capsule and to check the user's preferences for the personal data every time it is accessed. As a second feature, the model allows mobile agents to migrate into the privacy capsule, to execute necessary processes referring to the personal data, and to generate execution results to be utilized by the outside world. The mobile agent mechanism provides a robust and effective solution for enabling service execution while keeping the personal data hidden inside the privacy capsule. Less