PI: Ramesh Rao, Prof, Jacobs School of Engineering;
UCSD Division Director, Calit2
Funding: Ericsson, UC Discovery Grant Division:
Corporate Partner: Ericsson Wireless
Start Date: August 2002
Wireless users may be surrounded by half a dozen or more wireless
"bubbles"-competing cell-phone networks, short-range Bluetooth,
local area 802.11b (Wi-Fi) high-speed data service, or, in many
cities, so-called third-generation (3G) coverage such as CDMA2000
networks. But as wireless systems and standards proliferate, how
can these technologies work for consumers-not just confuse them?
With $2.7 million in funding from the UC Discovery Grant program
and Ericsson, a team of up to 20 researchers from Calit2
and the UCSD Jacobs School of Engineering is undertaking a four-year
project to enhance wireless connectivity. "Adaptive systems" would
permit seamless interoperability among various network infrastructures
to maintain constant-and the most powerful-connection to the Internet
for mobile users using both licensed (e.g., cellular networks) and
unlicensed (e.g., 802.11b) spectrum. Users would be switched invisibly
and seamlessly between wireless networks based on whichever is the
optimal connection at the time, hence the project's nickname, "Always
Best Connected" (ABC).
about the options facing a wireless user. The consumer needs
to send packets of information from point A to point B and can
choose among a variety of networks at different times of day.
But to take advantage of alternatives, you need a way to prioritize.
It’s like the airlines, which have figured out how to
get planes off the ground, when to land them, and how to price
- Ramesh Rao, UCSD Division Director, Calit2
The ABC project
is part research, part deployment. On the UCSD campus, researchers
have already installed hardware and software that allow user devices
to roam among four network access technologies: 802.11b, GPRS, CDMA2000
1xRTT, and CDMA2000 1xEVDO, as well as local-area Ethernet. These
networks vary in speed, and some are always-on. Capacity alone can
be a major problem if you are dealing with multimedia and switching
from high-bandwidth Wi-Fi to cellular access.
One major research focus is the job of encoding, delivering, and
dealing with errors across systems. These tasks are usually designed
around the particular characteristics of one system. But if you're
going to run your application across five different systems, you
have to adapt much more dynamically than before to the underlying
characteristics. You have to adapt not only to channel conditions,
but also to the user's conditions-how much battery power the device
has, what type of display, and whether it's a color screen or not.
One goal is to figure out the smart thing to do at the level of
the mobile device. But ABC researchers are also investigating the
smartest way to architect the system. There is also huge potential
to develop new services that will be broadly available whatever
your access technology. Co-PIs on this project are Pamela Cosman,
Rene Cruz, Sujit Dey, and Geoff Voelker.
Contact: Ramesh Rao