Kazunori Ueda

Proposal of an Initial Route Establishment Method in Wireless Mesh Networks

Hybrid wireless mesh protocol (HWMP) is consists of on demand routing protocol RM-AODV and pro-active routing based on tree-base routing. When a mesh portal exists as a gateway of a wireless mesh network, tree-based routing is very efficient in fixed mesh deployments. However, with the distance vector routing method, all mesh points need route metrics based on the network topology and many packets are consumed to build the topology. To solve these problems, we define a new address space based on the link state and propose an initial route establishment method with greedy forwarding by using addresses as positional information. From simulations results, we confirmed that the proposed routing method can build the routing topology before the entire wireless mesh network is constructed and reduce the number of control packets for routing, and it also has scalability.

A Method for Establishing Routes and IPv6 Addressing Based on the Estimated Distance from Neighboring Nodes in Wireless Mesh Networks

As networks for providing wireless access easily and inexpensively with high robustness against network node failures, wireless mesh networks have been expected in recent years. However, wireless mesh networks consume numerous control packets to establish transmission routes and the number of control packets greatly exceeds that of conventional wireless network environments. Opportunities for packet collision will therefore increase as a result. Our research group has made progress in research based on the locations of mesh points to decrease the number of control packets needed to establish routes. This information about the locations of mesh points is offered to neighboring mesh points. We define a virtual space and an IPv6 address specification including information of each mesh point location. In this paper, we introduce a method for establishing routes and an IPv6 addressing specification in detail.

Peer-to-Peer contents distribution system using multiple peer clusters

Peers search contents with information of contents such as keywords in many peer-to-peer contents sharing systems. In many peer-to-peer contents search architectures, queries are forwarded to peers which belong to clusters related with the keywords. Since clusters are basically constructed regardless of physical network topology, a peer receives contents from peers that are located far from the peer in some cases. To solve this problem, the authors proposed an architecture in which clusters were constructed on multiple logical layers. And furthermore, the authors verified effects of switching clusters.

Cooperation P2P Web Proxy to Reduce Resource Usage

In this paper, we propose a P2P Web Proxy system where each peer does not need to consume resources such as data storage or network bandwidth when caching content. In this system, Web servers manage a list of the peers that are downloading content and a candidate list is provided for P2P Web Proxy nodes. If a peer finishes downloading the content, the peer is removed from the list and they leave the P2P network. Thus, the peer does not need to make its resources available. Furthermore, an interface is implemented to show the progress of data downloading.

Routing Method Based on Relationships between Neighboring Nodes in Wireless Mesh Networks

Wireless mesh networks (WMN) enable easy construction and management of wireless network environments. In WMNs, access points communicate wirelessly and establish routes to other access points autonomously. This technology is useful in serious situations, such as natural disasters, because access points do not require wired connections to establish appropriate communication routes. However, the communication of routing information consumes significant network bandwidth. We propose a new routing method for WMNs that is based on the relationships between access points. Simulation results show that the proposed routing method reduces the number of communication control packets generated by each access point.

Design and Implementation of a Cache-less P2P Web Proxy

In recent years, large-volume Web applications have become common, such as video streaming or sharing. However, these applications generate high volumes of Internet traffic, which is a very important issue. Therefore, P2P Web proxy technologies have been developed to distribute this increased Web traffic. However, current P2P Web proxy technologies (or systems) have problems because they consume high bandwidth during the uploading and storage of the transferred content. This study proposes a method that can solve these problems by eliminating the contents cache used by P2P Web proxies.

Asymmetric DHT based on performance of peers

Recently, a distributed hash table (DHT) has been used to construct peer-to-peer (P2P) overlay networks. DHT has high scalability for the number of peers, and peers can efficiently retrieve contents from the overlay network. Since DHT algorithms are used to construct symmetric network models, the communication cost of maintaining the routing table is low for peers that have a large computing or network resource and vice versa. We propose an asymmetric DHT network model that can be used to allocate appropriate jobs to a peer according to its performance.

Performance Evaluation of Peer–to–Peer Network Applications on Multiple Overlay Networks

A peer–to–peer (P2P) network applications support peers or contents search based on overlay networks constructed by considering several criteria. Since overlay networks are constructed based on profiles of peers, overlay networks enable to search contents by each peer effectively. In case of overlay network based on trend of contents peers have, each peer does not always select a peer that is the closest to the searching peer. On the other hand, in case of overlay network based on network distance between peers, it takes a long time to search rare contents or a lot of search packets are transmitted. In this paper, we reported experimental results by contents distribution system implemented on the agent platform PIAX in order to verify effectiveness of system that switches overlay networks.

Peer-to-Peer Network System and Application Design on Multiple Virtual Networks

The increase in network traffic has recently become a problem. Therefore, we attempt to solve it using peer-to-peer (P2P) technology. This research proposes a system design to reduce the traffic of P2P applications by switching between multiple overlay networks according to content ratings. The multiple overlay networks are constructed as virtual networks on physical networks using Software-Defined Networking (SDN) techniques. The overlay networks are mapped into slices of SDN, and the proposed system switches between multiple slices according to the content rating. Two slices are used in the prototype of the proposed system. One of the slices is an overlay network based on the network distance, and the other is an overlay network based on content trends. The network distance-based slice is constructed by clustering based on Round Trip Time (RTT). When a peer searches for content, a region of the content search is expanded little by little. The peer can then receive the content from a peer close to it in terms of network distance. The content trend-based slice is constructed according to contents of each node. Specifically, nodes that have similar content are close to each other. As a result, peers can obtain content by minimizing the number of hops when any node obtains that content. The prototype of the proposed system will be demonstrated and experiments will be performed in a testbed specialized for P2P agent platforms. In the demonstration and experiments, the slices will be implemented as conventional overlay networks.

Improvement of WMNs routing method for the purpose of reduction of control communications

We propose the multiple branch collection routing (MBCR), a routing method for wireless mesh networks (WMNs), and the main purpose of which is to reduce control communications. The virtual address of a node is generated when the node joins a network through MBCR. Nodes that join the network can obtain necessary information only from their neighboring nodes. When data are transmitted to a destination node, each node uses information of its virtual address, and the virtual addresses of its neighboring and destination nodes. However, MBCR does not include a method to retrieve a destination virtual address.