SHOW: Symmetric Design for Hybrid Handoff Scheme in Wireless Networks

Speaker:	Dr. Shih-Yu CHANG
		National Tsing Hua University,
		Taiwan

Title:		"SHOW: Symmetric Design for Hybrid Handoff Scheme in
		 Wireless Networks"

Date:		Monday, 13 September 2010

Time:		4:00pm - 5:00pm

Venue:		Lecture Theatre F (near lifts 25.26), HKUST

Abstract:

Handoff of mobile users is one challenge task to be faced in realizing
heterogeneous networks. Hard handoff (HHO) and soft handoff (SHO) are two
basic schemes to perform handoff. Seldom works are dedicated to study a
hybrid handoff method by combining these two basic handoff schemes in
order to gain both advantages from them. In this paper, we propose a
hybrid handoff method by allocating frequency bands usage to HHO and SHO
judiciously based on two combinatorial design approaches, symmetric design
(SD) and quasi-semisymmetric design (QSSD), respectively. Due to the nice
property of the  intersection number of bands between each pair of cells
from block design theory, the ratio of common frequency bands (CFB)
reserved for SHO between each pair of cells can be guaranteed regardless
the users mobility. Hence, the proposed hybrid scheme is proper to be
adopted in high mobility network environments specially. Besides, two
performance measures, the new call blocking probability and the handoff
call blocking probability, are also derived to measure the performance of
the proposed hybrid handoff scheme. Accordingly, optimization problems to
minimum these probabilities are formulated and solved based on generic
algorithm (GA) by considering the implementation cost and the block design
constraints. Finally, numerical and simulation results are studied
extensively to verify the proposed hybrid handoff scheme.

*****************
Biography:

Shih Yu CHANG received his Ph.D. from the University of Michigan, Ann
Arbor, in 2006. Since then he has been at the National Tsing Hua
University, where he is an Assistant Professor of Department of Computer
Science.

His research interests are mainly in Wireless Communication Systems,
Wireless Network Performance Analysis and Modeling. Analytical Research
and Algorithm Development in Digital Signal Processing,