Researchers at the US Defence Advanced Research Projects Agency (DARPA) have successfully demonstrated an ad-hoc-networking technology that allows several users to occupy the same time and frequency slot.

DARPA strategic technology office programme manager, Bruce Fette, said that during the demonstration of DARPA Interference Multiple Access (DIMA), five mobile transmitters delivered signals at a speed of up to 60 miles per hour over 5MHz of spectrum to a single transmitter.

“The DIMA system could track real-time artefacts of mobility with multiple vehicles operating in an urban environment and receive multiple signals at the same time on the same frequencies,” Fette said.

The system also achieved maximum data-throughput rates of 5.2Mbps in the demonstration, which can be further increased, according to Fette.

DARPA’s wireless network after next (WNaN) features ad-hoc networking between cognitive radios that automatically find usable spectrum, which serve as nodes to route voice and data information to each other, reports

In October 2009, DARPA conducted a WNaN demonstration using a ten-node network and is scheduled to conduct another demo using 50 network nodes by this month, Fette said.