Beamnet One was one of the most ambitious projects of the immediate pre-collapse period. It hinged on what is now called Ansible Type Three: a hybrid of recently discovered alien stargate and wormhole technology to produce a multipurpose transportation system. The principle was simple: if a mass is imploded by using the proper style of stabilization and activation array, and a second mass of the same size is imploded at the proper time (about a week per light-year later) at the destination, the two arrays are linked. This allows for several kinds of connection- the three main types were respectively designed for people, power lasers, and communications lasers. Larger sizes were possible, to a point, but transmission of vehicles never worked out well- possibly due to issues in the arrays' power sources.
Beamnet One was quickly expanded from its initial test station on the old antimatter power beaming centre close to the star Tiorasav across the Ecumene- while it was slower than starships, it was faster than any other communications method and could power worlds on its own. The distribution network would be hierarchical for better control- thus allowing certain favored systems to recieve local main stations, and others to recieve subsidiary ones. The system was rolled out within a decade- some of the furthest systems of the Ecumene even recieved the order to construct a station while the activation pulse was on its way to them. Soon, many of the new appliances, tools, and even vehicles (though starship movement would make power transmission choppy at best, so nearly no starships carried them) in the Ecumene depended on tiny wormholes for power.
The issue that helped bring on the fall of the Ecumene occured a century in. In the power beaming centre, a thruster jostled one of the antimatter delivery systems- causing a remarkably small implosion that destabilized the central alien technology keeping the system together. Within the next hour, every beamnet station in Tiorasav system was burned out- with millions of devices either running on auxilliary power or without power entirely. Luckily, the slow speed of the delivery network worked in the Ecumene's favor- nearly all other systems were able to collapse their delivery networks in time... though a few systems were not notified of the fact that all gates in the network would shut down in a hierarchical manner. This eventually denied power to all of the systems relying on the beamnet throughout the Ecumene. When several systems petitioned the central-ish government for permission to restart their beamnets, it was denied- making the beamnet failure one of the events that spurred on the collapse of the Ecumene. Beamnets are considered absurdly slow for transport or ansible today, though similar technologies do provide auxilliary power to devices and cities in several areas of the Ecumene.