Miae Woo

An Enhanced Gnutella for Ad-Hoc Networks

In recent years, Internet has witnessed the introduction of many peer-to-peer systems designed to implement large scale resource sharing. These systems exhibit interesting features like self configuration, self-healing and complete decentralization, which make the systems appealing for deployment in ad hoc environments as well. This paper enhances Gnutella with peer-node hierarchy to achieve better performance with less overhead in the ad hoc network. The proposed system introduces ultrapeer selection scheme based on the metric values and a proactive communication mechanism among ultrapeers. According to the simulation results, the proposed system gives better performance than Gnutella in terms of query success rate, query response time, and overhead.

A study on the seamless transmission of an uplink constant streaming data over wireless LANs and cellular networks

Recently, with the advent of the wireless Internet, IPv6, and P2P communications, the seamless transmission of a constant streaming data through wireless Internet has been widely accepted as a new research area. In this paper, we address a seamless transmission of constantly generated streaming data from a moving object to a remote site. We divide the whole wireless communication environments into an indoor environment, where the main communication method is the WLAN and an outdoor, where the main communication method is CDMA cellular Network and assume that the mobile server is able to move anywhere. We develop algorithms, implement them on a PDA-based hardware platform, and show some of the results. We think that, with some improvement of the performances, this work can be applied to many services such as P2P communication, file sharing services such as Napster or Soribada, and constant monitoring of the mobile objects.

A Power-Aware Peer-to-Peer System for Ad-Hoc Networks

Recently, many peer-to-peer (P2P) systems have been introduced to implement large scale resource sharing systems. Such P2P systems exhibit interesting features like self configuration, self-healing and complete decentralization, which make the systems appealing for deployment in ad hoc environments as well. This paper proposes a power-aware peer-to-peer system specially designed for the ad-hoc networks based on Gnutella with hierarchical structure. The objectives of this paper is to enhance performance as well as to prolong the lifespan of the participating P2P nodes. To pursue the objectives, the proposed system chooses ultrapeers which can serve the overlay network better, by considering battery power, connectivity with other peers and commitment level of each node. It also introduces proactive approach for distributing ultrapeer information to reduce P2P overheads. According to the simulation results, the proposed system provides higher query success rate, shorter query response time, less overhead and extended lifespan of peers.

A new multicast group management scheme for IP mobility support

As the number of portable devices roaming across the Internet increases, the problem of routing packets to mobile hosts generates increasing research and commercial interest. To support mobility more effectively for seamless provision of various applications, many multicast-based localized mobility support schemes have been proposed to achieve better performance than the basic solutions provided by the IETF, such as Mobile IP and Mobile IPv6. However, any multicast-based scheme inherently introduces significant bandwidth wastage at the wireless access network due to long leave latency. In this paper, we propose a new multicast group managment scheme that is tailored for managing multicast groups used to support host mobility. It has been shown by simulation that the proposed scheme achieves extremely short leave latency and eliminates bandwidth wastage in the wireless links.

An Adaptive Mobility Management Scheme to Support Internet Host Mobility

To cope with the Internet host mobility in a cellular network environment, we proposed an adaptive mobility management scheme that can compensate drawbacks of Mobile IP. Our proposed scheme determines foreign agent care-of addresses adaptively according to user mobility. Consequently, it is different from other proposals for micro mobility, which statically assign the gateway in the domain as a foreign agent. Using such a scheme, it is possible to effectively meet the users demands for different service qualities in the various environments considered in the cellular network and to reduce signaling overhead due to frequent handovers occurred in Mobile IP. The performance of the proposed scheme is examined by simulation. The results of simulation show that the proposed scheme can provide relatively stable points of attachment to the mobile node.