M.Sc Thesis

M.Sc StudentLavi Nadav
SubjectSupporting Groupware in Mobile Networks
DepartmentDepartment of Electrical and Computer Engineering
Supervisors PROFESSOR EMERITUS Israel Cidon
PROF. Idit Keidar


This thesis presents MaGMA, a novel architecture for group management in mobile networks interconnected via the global Internet. MaGMA provides a comprehensive solution for the mobile world, addressing aspects such as scalable group management, mobility, handoff, and QoS provision. We believe that such a solution will be an inherent part of 3G and B3G cores. We are not aware of any previous comparable solution for mobility support in groupware applications.

MaGMA's architecture consists of a collection of mobile group managers (MGMs), which manage group membership and may also implement a multicast overlay for data delivery. Each mobile node (MN) is served by an MGM proximate to it. Developing a fully distributed group management and mobility solution that is both efficient and scalable is technically challenging. In this paper, we address this challenge.

In this thesis we offer two group management approaches in the context of  MaGMA: The first is a subscription model, in which the servers (MGMs) support group management only, and MNs can obtain the list of group subscribers in order to transmit data to them without the servers' intervention. The second is the multicast overlay model, where the servers implement the group multicast service. The first approach is appropriate for small groups and light servers, whereas the latter is more appropriate for large groups and clients with battery power constrains. We devise protocols for both approaches, and evaluate both solutions using the ns2 network simulator. We validate our simulation results through mathematical analysis. In addition we prove the correctness of the main group-membership protocol under several assumptions. As a proof-of-concept, we also build a SIP-based prototype running groupware applications over WiFi network with iPAQ MNs.