Shiro Tanabe

CHORUS: a framework for scalable collaboration in heterogeneous networks with cognitive synergy

We propose a unified framework called Collaborative Harmonized Open Radio Ubiquitous System (CHORUS) that can jointly optimize heterogeneous wireless networks. To support large-scale collaboration, cognitive synergy is exploited to collect the status of multiple radios and layers, namely the network state information (NSI). Based on cognition results, resource virtualization and harmonious collaboration control are applied to optimize the global performance. We present the architecture, design challenges, and key technologies of CHORUS through our initial research efforts. We illustrate how to use cognition to interact with collaboration among multiple base stations (BSs), between BSs and relays, and among heterogeneous networks so as to save the network energy consumption. We also provide examples of cognition design across communication and broadcast networks based on traffic load and service contents information.

A hyper-distributed switching system architecture for B-ISDN

A hyper-distributed switching system architecture is proposed for a large-scale asynchronous transfer mode (ATM) switching system to handle heterogeneous traffic and sophisticated services for B-ISDN. The system consists of a non-intelligent module with small capacity ATM switches allocated separately at a single stage, and many independent modules have call processing. The same architecture from a small-scale system can be used in a large-scale system by connecting the ATM links among the regularly allocated ATM switches. Also proposed are a nonblocking switching configuration, efficient intermodule connection, concentrated quality control, state dependent intermodule routing, and virtual channel assignment to decrease the label conversion table size in the hyper-distributed switching system.<<ETX>>

CHORUS: Collaborative and harmonized open radio ubiquitous systems

In this paper, we first briefly review the collaborative communication technology, and indicate that current intrasystem collaboration mainly focuses on collaboration of limited fields and cognition of some specific aspects, while inter-system collaboration has been simply used to provide access flexibility. This motivates the design of a more generalized framework: namely Collaborative HarmOnic Radio Ubiquitous network System (CHORUS). This framework is designed to achieve optimized performance gain and environmental friendliness by cognitive synergetics in the ubiquitous radio network environment. The idea of cognition is generalized by inspecting the status and parameters of multiple network scales and layers. Based on the cognitive result, harmonic control of collaborative and ubiquitous radio network systems can be applied to globally optimize the network performance. We present the detailed architecture and key aspects of CHORUS, and also provide several examples of the technical solutions of CHORUS.

Context-aware quality of service control in session based IP networks

Context-aware QoS control in session-based IP networks is proposed. This work proposed the basic architecture and algorithm of context-aware SIP-QoS server that can control QoS for each session or media stream, based on context information including IP flow information, media type, user presence, and user preference. QoS applications with context-aware QoS control in session based networks are also proposed.

Scalability and Performance Analysis of Multi-Level Hierarchy in IP Micro-Mobility Management

This paper presents a study on the benefits of multi-level hierarchy for scalable mobility management in the wireless mobile IP context. Micro-mobility management is considered. The analysis took advantage of the locality in movement and call activities of mobile users. It was discovered that whether multi-level hierarchy is beneficial or not depends on the type of address management employed in the mobility management. When hierarchical addressing structure is used in a micro-mobility region, the system scales with more levels of hierarchy, but if the address structure used is not hierarchical, multi-level hierarchy is less scalable because the root node presents a bottleneck to the system.

A large scale ATM switching system architecture for multimedia communications

1 . Introduction Multimedia communications are having a great impact on switching system architecture . The Asynchronous Transfer Mode (ATM) is the predominant technique used to obtain a B-ISDN with a universal interface . Next-generation switching using this technique must have a flexible architecture to handl e the heterogeneous traffic and sophisticated services multimedia communications will provide . To adapt to the increase of B-ISDN subscribers, we propose a hyper-distributed switching system architecture composed of a non-intelligent module and independent modules with call processing functions . To multiplex burst traffic , ATM shared buffer memory switches are used as the unit switches in both modules .

A real intercontinental mobile IPv6 demonstration between China and Japan for mobility enhancement

Mobile IPv6 is considered to be one of the key technologies for realizing mobile Internet which enables seamless communication between fixed line and wireless access networks. In this paper, we introduce the basic concept of mobile IPv6 and describe the detail procedure of handoff of mobile terminal. We analyze its effectiveness of mobile IPv6 handoff by using network simulator 2 and constructed mobile IPv6 testbed based on wireless LAN IEEE802.11b. Finally, we connect two mobile IPv6 testbeds and test video transmission each other. This is the first test that three nodes of the mobile IPv6 located separately in China and Japan.

Broadband network system toward the 21th century

Broadband communications have a great impact on network architecture. ATM is becoming a key technology for networking infrastructure of a whole range of communications from legacy telephone networks to broadband integrated services digital network (B-ISDN). This paper describes Hitachis view of network systems architecture toward the 21th century. Based on this concept, we introduce our network technology, switching technology, operation support, and service operation as key issues to be resolved.