University of Houston
Department of Computer Science

In partial fulfillment of the Requirements for the Degree of
Master of Science

Eunjung Lee
will defend her thesis

A DYNAMIC MOBILITY MANAGEMENT SCHEME FOR VoIP SERVICES

Abstract
Voice over IP (VoIP) uses the Internet Protocol (IP) to transmit real-time data as packets over an IP network. It is likely to be an important way in which voice and data communications networks that use IP, like IP-based Internet and mobile cellular networks, may 'converge' into a single communication network. For VoIP to become popular, some key issues need to be resolved. One of the most important issues is enabling mobility in IP networks. There are two well-known approaches to support mobility for VoIP services, namely Mobile IP and Session Initiation Protocol (SIP). Unfortunately, both approaches suffer from their own limitations, because they are not originally developed for mobile VoIP applications. Hence, we need to extend them employing a more efficient mobility management scheme.

In order to provide seamless VoIP service in the mobile wireless environment, we need an efficient scheme to minimize the disruption time to process a handoff of an ongoing VoIP call. There are several schemes focusing on this issue. While the schemes were found to be efficient in terms of disruption time, we need to point out that they require a lot of signaling message exchanges, resulting in exposures of confidential information of the mobile nodes in network. We propose a Dynamic Shadow Registration scheme eliminating these disadvantages. Our simulation results show our scheme can significantly reduce the message overhead with maintaining the almost same handoff delay with other schemes. Our scheme can be applied to both Mobile IP and SIP.

Date: Tuesday, July 19, 2005
Time: 12:00 PM
Place: 550-PGH

Faculty, students, and the general public are invited.
Thesis Advisor: Dr. Shou-Hsuan Stephen Huang