Penn State engineers have developed an economical way to more efficiently manage radio spectrum use and prevent interference on wireless broadband systems for high-speed Internet access – potentially bringing down costs for consumers. Dr. Mohsen Kavehrad, director of Penn States Center for Information and Communications Technology Research (CICTR), says, "With this technique, service providers could offer quality service to more homes using only a limited span of the radio spectrum. And, if providers can squeeze more customers onto the available bandwidth, it could translate into lower costs for the consumer." In addition, the approach promises equipment cost savings since simulations show that the new scheme maintains performance at top industry standards with more economical components.
The new approach is detailed in a paper, "Co-Channel Interference Reduction in Dynamic-TDD Fixed Wireless Applications Using Time Slot Allocation Algorithms," published in the October issue of the IEEE Transactions on Communications. The authors are Wuncheol Jeong, doctoral candidate in electrical engineering, and Kavehrad.
Kavehrad explains that, currently, high speed Internet access capable of carrying MP3 files, video, or teleconferencing is available primarily over wired networks. However, wireless local loops are being introduced as broadband alternatives in some test markets. These new wireless networks are facing serious obstacles in competing for bandwidth; sometimes, having to share bands with cordless phones or even microwave ovens. Even when the wireless providers use licensed bands, they face the prospect of many customers simultaneously uplinking and downlinking information across the net, creating co-channel interference.
Barbara Hale | EurekAlert!
Stable magnetic bit of three atoms
21.09.2017 | Sonderforschungsbereich 668
Drones can almost see in the dark
20.09.2017 | Universität Zürich
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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