SAN DIEGO-An engineering professor and a graduate student at the University of California at San Diego have developed software that makes Wi-Fi roaming easier by reducing the hand-off time between Wi-Fi networks.
Professor Stefan Savage of the Jacobs School of Engineering and graduate student Ishwar Ramani have applied for a patent for the basic invention behind their SyncScan process.
“Wi-Fi offers tremendous speeds if you stay in one place or at least within 100 meters of the same access point,” said Savage, an assistant professor in the Computer Science and Engineering department and academic participant in the California Institute for Telecommunications and Information Technology. “SyncScan is a handoff algorithm, which can cut the time it takes to switch from one Wi-Fi access point to another by a factor of a hundred over existing solutions.
“This is a requirement for demanding applications like Voice over Wi-Fi, where even short interruptions can disrupt the illusion of continuous connectivity.”
SyncScan also allows mobile devices to make better handoff decisions, improving signal quality overall, said Savage.
The SyncScan solution overcomes the typical delay caused when an access-point signal weakens and Wi-Fi device begins to query the network for nearby access points. The delay of up to one second can cause packets to be lost. SyncScan continuously monitors the proximity of nearby 802.11 access points.
“Today most Wi-Fi users accept being tethered to a single location in exchange for the broadband speeds that Wi-Fi offers,” said Ramani. “But increasingly they want to be able to make VoIP phone calls or stream multimedia while commuting or on the move, and a one-second disruption can seem like an eternity.”
