Michiharu Takemoto

A service-composition and service-emergence framework for ubiquitous-computing environments

While new network technologies bring ubiquitous-computing environments ever closer, methods to provide suitable services within such environments remain immature. We describe the ubiquitous service-oriented network (USON) architecture, a new service-provision architecture, covering the basic concept, components and their roles, and the service-provision mechanism. A USON provides services in two phases, a service-composition phase in which service elements (SEs) are combined on the basis of service templates (STs), and a service-emergence phase in which a new ST is obtained on the basis of the history of usage of SEs and STs. A USON can handle various types of SEs, representing Web services, computer resources, and sensor devices. The establishment of USON technologies on networks provides various services within ubiquitous-computing environments.

Advanced peer-to-peer network platform for various services-SIONet (Semantic Information Oriented Network)

This paper describes an advanced peer-to-peer (P2P) platform called the Semantic Information Oriented Network (SIONet). This is a meta-network that delivers user events based on semantic information (meta-data) and searches for specific entities dynamically in the network. SIONet consists of Semantic Information (SI) Switch (SI-SW), which compares the meta-data of each event with the receivers conditions, SI-Router (SI-R), which routes events between two SI-SWs, Event Place (EP), which is a logical subnet constructed by SI-SW and SI-R, and SI-Gateway (SI-GW), which connects EPs. These elements are self-organizing as needed, making possible a secure and scalable P2P network.

Method of creating web services from web applications

Web 2.0 is becoming popular among people who are interested in creating or providing more useful services on the Internet. Mashup is one of the most important methods in Web 2.0, which creates services by combining components on the Internet, such as Web services. Mashup enables many people to create various services easily and use services created by many other people. To create such a variety of useful services, we need a large number of components, but there are not so many components available on the Internet yet. We describe an effective method of creating wrappers that make Web applications usable as Web services. The method extracts important segments, such as search results of a hotel search application, from an HTML document generated by the web application and generates extraction rules for the wrappers. This extraction is performed by using the characteristic depth of each tag in the HTML document.

Designing Overlay Networks for Handling Exhaust Data in a Distributed Topic-based Pub/Sub Architecture

To provide event-driven services in IoT, scalable methods of topic-based pub/sub messaging are indispensable. Methods using structured overlay networks are promising candidates. However, existing methods have the problem of wasting network resources, because they lack adaptivity to “exhaust data,” which have low or no value most of the time. The problem contains two aspects. One is that each publisher node continues to forward data to a relay node even if there are no subscribers. The other is that excessively large multicast trees are constructed for low value data, which will be received by only a small number of subscribers. In this paper, we formulate the desirable design of overlay networks by defining a property called “strong relay-free” as an expansion of relay-free property. The property involves publishers and subscribers composing connected subgraphs to enable detecting the absence of subscribers and autonomously adjusting the tree size. We also propose a practical method satisfying the property by using Skip Graph, and evaluate it through simulation experiments. We confirmed that the proposed method can suspend publishing adaptively, and shorten the path length on multicast trees by more than 75% under an experimental condition with 100,000 nodes.

A Context-Aware Content-Provision Service Based on a Ubiquitous Service-Oriented Network Framework

As emerging technologies are being developed, a ubiquitous computing environment will be established in the near future. Researches on service provisions for users over the ubiquitous computing environment have been started. The implementation method of an actual service, based on our proposed service-provision framework, is described in this paper. The service is a context-aware content-provision service. Through the implementation experience of the service, three issues are reported in this paper that are generally important for services in a ubiquitous computing environment. The first issue is that there is a difficulty in handling information in the community in ubiquitous computing environments unlike traditional Internet-based communities. The second issue is that the context-handling mechanism is important in ubiquitous computing environments. The third issue is that the system designer must consider the dynamic device-allocation facilities in the system.

Service elements and service templates for adaptive service composition in a ubiquitous computing environment

Service elements (SEs) and service templates (STs) are the basic elements for service-provision in a ubiquitous computing environment, which will be achieved by the new network technologies of peer-to-peer (P2P) and nomadic communication. An SE is a component for a service, and an ST is a design or flow-diagram of a service. In the ubiquitous computing environment, there are so many elements (SEs and STs) available that it is difficult to create services suitable for the users. Also, users require fully or well customized services. Thus, a new technology for providing autonomous service will need to be established. SEs and STs behave (move, combine, replicate, etc.) autonomously in the network and provide a suitable service for users and the situation. This paper describes SEs and STs and how STs are provided.

Service composition architecture for programmability and flexibility in ubiquitous communication networks

This paper addresses a new service composition method suitable for the forthcoming ubiquitous computing era. The latest developments in network computer technology have made various entities connected to the Internet, such as Web services, sensors, and home information appliances, accessible to those who want to create their own service capabilities. The architecture we have thus far proposed is a key to achieving the ubiquitous concept, but approaches that spread the use of the architecture are required. We establish the architecture more widely usable in mobile Internet environments and suggest applicable domains for two types of proxy servers to compensate for the shortage of mobile terminal capacities. Practical service examples and business models are also discussed

P2P platform implementation on PDAs organizing ad hoc wireless network

This paper describes P2P platform implementation on PDAs. Recent progress of P2P and mobile technologies is promoting P2P platform on mobile devices which enables mobile devices to behave autonomously as peers within either hotspot or ad hoc wireless network. The implementation on PDAs requires new techniques quite different from those on PCs because of so poor resources. In view of this, we describe issues, solutions and evaluation results on the implementation of P2P platform on PDAs based on actual development. This result is expected to be useful for the implementation of P2P platforms on mobile devices hereafter.

A Network Architecture to Easily Control Devices

Recently, many works on ubiquitous computing have been reported. Many of them assume a closed system such as a Smart Home. In this paper, we consider assumptions in ubiquitous computing environments and discuss requirements for those environments. In addition, we propose and discuss network architecture for reducing the spatial limitations when controlling devices. Moreover, we show the current implementation of our prototype system.

P2P applications using the semantic information oriented network

This paper describes P2P applications using an advanced P2P platform called SIONet. Based on its metadata-based routing and easy communication creation capabilities, various kinds of P2P applications can be constructed. Effective discovery, P2P content delivery with digital rights management, semi-active information exchanging community, and P2P ad hoc community are constructed. These are expected to be bases for next generation ubiquitous applications.