Kyung-Sook Lee

Design and Evaluation of a Dynamic Continuous Media Streaming Supporting Method on the Basis of Logical Grid Hierarchy for MANETs

As wireless connectivity is integrated into many handheld devices, streaming multimedia content among mobile ad-hoc peers is becoming a popular application. In this paper, we propose a dynamic service replication algorithm for providing guaranteed continuous streaming services to all nodes in mobile ad-hoc networks (MANETs). First, a MANET is comprised of logical grid hierarchy, and a streaming service is replicated to a lower server region of the logical grid hierarchy by considering the link availability between a mobile node and the streaming server within a server region or the popularity of the streaming service. We evaluate analytically the performance of the proposed algorithm, and compared with that of existing Qins algorithm. Evaluation results show that our algorithm can achieve better streaming performance than Qins algorithm. Therefore, the proposed algorithm not only improves the sharing availability of replicated streaming services but also controls efficiently the number of streaming service replications.

Design and Evaluation of a Dynamic Anomaly Detection Scheme Using the Age of User Profiles

The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents a dynamic anomaly detection scheme that can effectively identify a group of especially harmful internal attackers - masqueraders in cellular mobile networks. Our scheme uses the trace data of wireless application layer by a user as feature value. Based on this, the use pattern of a mobiles user can be captured by rough sets, and the abnormal behavior of the mobile can be also detected effectively by applying a roughness membership function with both the age of the user profile and weighted feature values. The performance of our scheme is evaluated by using a simulation.

A weighted-dissimilarity-based anomaly detection method for mobile networks

Mobile wireless networks continue to be plagued by theft of identity and intrusion. Both problems can be addressed in two different ways, either by misuse detection or anomaly-based detection. In this paper, we propose a weighted-dissimilarity-based anomaly detection method that can effectively identify abnormal behavior such as mobility patterns of mobile wireless networks. In the proposed algorithm, a normal profile is constructed from normal mobility patterns of mobile nodes in mobile wireless networks. From the constructed normal profile, the dissimilarity is computed by a weighted dissimilarity measure. If the computed dissimilarity value is greater than the dissimilarity threshold that is a system parameter, an alert message is occurred. The performance of the proposed method is evaluated through a simulation. From the result of the simulation, we know that the proposed method is superior to the performance of anomaly detection methods using other dissimilarity measures.

A Pointer Forwarding Scheme for Fault-tolerant Location Management in Mobile Networks

One of the main challenges in personal communication services(PCS ) Is to locate many mobile terminals that nay move from place to place frequently. This kind of system operation is called location management. This task entails sophisticated signaling traffic and database queries. Several strategies have been proposed to improve the efficiency of location management. These strategies use location register databases to store the current locations of mobile terminals, and are vulnerable to failure of the location register databases. In this paper, we propose a fault-tolerant pointer forwarding scheme with distributed home location register in order to tolerate the failure of location registers. The performance of the proposed scheme is evaluated analytically by simulation, and Is compared with Biaz`s bypass forwarding strategy and two-path forwarding strategy.