Seishi Hanaoka

Testbed System of Inter-Radio System Switching for Cognitive Radio

The cognitive radio system consists of multiple wireless access systems that cover overlapping areas and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we describe the architecture of the cognitive radio system and the inter-system handover protocols. In the architecture, each cognitive terminal, which can access multiple radio systems, operates with a single local IP address. The control sequence and packet format are designed to achieve fast handover among the radio systems. Based on the architecture, we have developed a testbed system. On this system, we demonstrate that data can be delivered continuously and radio systems can be switched correctly without any packet loss. In addition, we present the result of the evaluation of the end-to-end latency on the testbed system. These testbed results demonstrate the system architecture described in the paper can achieve a cognitive radio system.

Platform for Load Balancing and Throughput Enhancement with Cognitive Radio

The cognitive radio system consists of multiple wireless access systems that cover overlapping areas and cognitive terminals that use one or more of the wireless access systems simultaneously. In this paper, we describe the system architecture of a platform for load balancing and throughput enhancement with cognitive radio system. In our platform, each terminal, which can access multiple radio systems, operates with a single local IP address. Based on our platform, we have developed both simulator and testbed system. Through the simulation of and the testing of a testbed system, we prove that systems load balance was achieved between WiMAX and wireless LAN, and total user throughput was increased with the proposed platform. Moreover, load balance to satisfy both real time service and best effort service. These results demonstrate the platform described in the paper can achieve a convergence with plural wireless systems.

Evaluation of inter base station handover for cognitive radio

Cognitive radio system consists of multiple wireless accesses that cover overlapping area, and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we present the architecture of the cognitive radio system that we proposed. In the proposed architecture, each cognitive terminal, that has multiple radio systems, operates with a single local IP address. Based on the proposed architecture, we have developed a simulator with EVDO, WiMAX and wireless LAN, and evaluated inter cognitive base station handover. From a result of simulation, it was found that it took 66 msec for the beginning of handover to the end.

Simulation and Basic Experiment of Inter Radio System Handover for Cognitive Radio

Cognitive radio system consists of multiple wireless accesses that cover overlapping area, and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we propose the architecture of the cognitive radio system, and the inter-system handover protocols. In the proposed architecture, each cognitive terminal, that has multiple radio systems, operates with a single local IP address. The control sequence and packet format are designed to achieve fast handover among the radio systems. Based on the proposed architecture, we have developed both a simulator and a testbed system with WiMAX and wireless LAN. Through simulation and testbed, we have proved that stream data can be delivered continuously without any effects of the handover. Also, we present the evaluation result of the end-to-end latency on the testbed system.

Basic Simulation Result of Inter System Handover for Cognitive Radio

Cognitive radio system consists of multiple wireless accesses that cover overlapping area, and cognitive terminals that use one or more of the wireless accesses simultaneously. We had proposed the architecture of the cognitive radio system, the inter-system handover protocols and packet format designed to achieve fast handover among the radio systems. Based on the proposed architecture, we have developed a simulator that supports EVDO, WiMAX and wireless LAN, and we have simulated the inter system handover where one cognitive base station covered. Through the simulation, we have proved that the system changes with following the movement of cognitive terminal and that the transmission data can be delivered continuously regardless the system handover.

A practical approach for network fault detection

Todays fault detection in commercial networks is still done in an inefficient way with alarms and threshold violations that treat measured indexes separately. To provide a practical network fault detection approach for the actual network operation, we investigate many actual network fault occurrences, and discover that many network faults can be characterized by unbalanced variation among measured network indexes that occur prior to or during an network fault occurrence. According to this general model of network fault, we propose a practical method for network fault detection that automatically extracts the unbalanced variation among measured indexes without the necessity of recognizing the physical meaning of them. Our evaluation shows that the proposed approach is applicable for the majority of measured indexes in the commercial networks, is efficient and scalable in performance, and with acceptable detection accuracy.

Proposal of new generation mobile system cooperating with virtualized network

In this paper, we discuss the functionality of mobile systems in a new generation network. Our goal is to provide mission-critical services using the mobile systems in the fields such as energy, disaster prevention, and medical care. It is necessary to guarantee both reliability and quality of communication for these services. We show that the future mobile systems should have three functions for cooperating with virtualized backbone networks and applications. We show the system architecture for achieving the functions, and preliminary evaluation on a testbed environment.

Proposal and Testbed System of Inter Radio System Switching for Cognitive Radio

Cognitive radio system consists of multiple wireless accesses that cover overlapping area, and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we propose the architecture of the cognitive radio system, and the inter-system handover protocols. In the proposed architecture, each cognitive terminal, that has multiple radio systems, operates with a single local IP address. The control sequence and packet format are designed to achieve fast handover among the radio systems. Based on the proposed architecture, we have developed a testbed system. On this system, we have proved that data can be delivered continuously and radio systems can be switched correctly without any packet loss. Also, we present the evaluation result of the end-to-end latency on the testbed system.