Old US Spy Planes to Act As Flying Wi-Fi Hotspots
Published on: 14th Apr 2014
By: Ian Mansfield
The US military is considering reusing its old military spy planes to deliver Wi Fi hotspots to conflict areas for its own communications.
A project by the research arm, DARPA is building and demonstrating a scalable, mobile millimeter-wave communications backhaul network mounted on small unmanned aerial vehicles (UAVs) and providing a 1 Gb/s capacity.
DARPA performers recently completed the first of three phases in which they developed and tested key technologies to be integrated into a complete system and flight tested in subsequent phases.
"We're pleased with the technical achievements we've seen so far in steerable millimeter-wave antennas and millimeter-wave amplifier technology," said Dick Ridgway, DARPA program manager. "These successes -- and the novel networking approaches needed to maintain these high-capacity links -- are key to providing forward deployed units with the same high-capacity connectivity we all enjoy over our 4G cell-phone networks."
The steerable millimeter-wave antennas are essential to enable the formation of a high-capacity backhaul network between aerial and ground platforms.
Performers also demonstrated an advanced low-noise amplifier (LNA), which boosts the desired communications signal while minimizing unwanted noise. The prototype achieved the record for the world's lowest noise millimeter-wave LNA at about half the noise figure of a typical LNA.
Efficient millimeter-wave amplification is required to achieve the long ranges (> 50 km) desired in the Mobile Hotspots program. During Phase 1, performers demonstrated output power exceeding 1 watt and 20% power added efficiency (PAE) from a single gallium nitride (GaN) chip operating at E-Band frequencies (71 GHz to 86 GHz). Output powers exceeding 20 watts and approaching 20% PAE were also achieved using power-combining techniques.
Phase 2 of the program began March 2014.
Two performers, L-3 Communications and FIRST RF, were chosen to lead teams comprising several Phase 1 performers. Phase 2 goals include the integration of the selected Phase 1 technologies into Shadow-compatible aerial pods and ground vehicles. Phase 2 will conclude with a ground demonstration of at least four Shadow-compatible pods, two ground vehicles and a fixed ground node.
A planned third phase will encompass field testing of the Mobile Hotspot systems on networks of multiple SRQ-7 Shadow UAVs and mobile ground vehicles.