THE vast data centers that process information for the Facebooks and Amazons of the Web work at a brisk clip. But even so, they can’t always keep up.

During sudden bursts of activity, bottlenecks occur as traffic moves among dense clusters of servers. Typically, the servers are stacked one on top of another in rack after rack — and are connected by switches, routers and cables.

To better handle the congestion, researchers are testing a shortcut that doesn’t involve costly rewiring. They are experimenting with wireless links, mounted atop the server racks, to supply extra bandwidth for moving data along at crunch times.

Researchers in the field, as well as data center administrators, initially were skeptical about the idea of applying wireless technologies inside data centers, which have stringent requirements for reliability and security, says Victor Bahl, director of the mobile computing research center at Microsoft Research in Redmond, Wash. His group began trying the links to supplement wired systems three years ago.