Abstract

IEEE 802.11-based networks are likely to become popular as
replacements for cordless phones, particularly in enterprise settings,
and as a way to fill in cellular coverage inside buildings and
homes. However, using 802.11a/b/g for VoIP poses a number of
challenges, including how to make hand-offs transparent, how to
maximize capacity and how to limit the number of concurrent calls to
avoid quality degradation. In the IRT Lab at Columbia University, we
have proposed and investigated a number of techniques that address
these issues. In addition, measurements of 802.11 networks illustrate
some of the operational and modeling challenges. We also describe a
new signaling protocol addressing the needs of QoS-sensitive
applications, developed as part of the IETF NSIS effort.


This is joint work with Ashutosh Dutta, Andrea Forte, Sangho Shin and
Kenta Yasukawa.


Speaker Bio

Prof. Henning Schulzrinne received his undergraduate degree in
economics and electrical engineering from the Darmstadt University of
Technology, Germany, his MSEE degree as a Fulbright scholar from the
University of Cincinnati, Ohio and his Ph.D.  degree from the
University of Massachusetts in Amherst, Massachusetts.  He was a
member of technical staff at AT&T Bell Laboratories, Murray Hill and
an associate department head at GMD-Fokus (Berlin), before joining the
Computer Science and Electrical Engineering departments at Columbia
University, New York.  He is currently chair of the Department of
Computer Science.

He is editor of the "IEEE/ACM Transactions on Networking", the "ACM
Transactions on Multimedia Computing", the "ComSoc Surveys &
Tutorials" and the "IEEE Internet Computing Magazine", and a former
editor of the "IEEE Transactions on Image Processing" and "Journal of
Communications and Networks." 

He has been a member of the Board of Governors of the IEEE
Communications Society and is vice chair of ACM SIGCOMM, former chair
of the IEEE Communications Society Technical Committees on Computer
Communications and the Internet and has been technical program chair
of Global Internet, Infocom, NOSSDAV and IPtel and was General Chair
of ACM Multimedia 2004.  He also has been a member of the IAB
(Internet Architecture Board).