Featured Research

from universities, journals, and other organizations

First Responders: Random Antenna Arrays Boost Emergency Communications

Date:
March 11, 2009
Source:
National Institute of Standards and Technology
Summary:
First responders could boost their radio communications quickly at a disaster site by setting out just four extra transmitters in a random arrangement to significantly increase the signal power at the receiver, according to theoretical analyses, simulations and proof-of-concept experiments.

First responders could boost their radio communications quickly at a disaster site by setting out just four extra transmitters in a random arrangement to significantly increase the signal power at the receiver, according to theoretical analyses, simulations and proof-of-concept experiments performed at the National Institute of Standards and Technology (NIST).

The NIST work may provide a practical solution to a common problem in emergency communications. The vast amount of metal and steel-reinforced concrete in buildings and rubble often interferes with or blocks radio signals. This was one factor in the many emergency communications difficulties during the response to the attacks on the World Trade Center on Sept. 11, 2001.

Antenna arrays have been studied and used for years, but the latest NIST work provides several new twists. Unlike the typical case in which antenna arrays boost signals to or from a distant target, a first responder’s radio would be relatively close to the portable transmitters, ideally within the perimeter of the array. More importantly, since disaster sites rarely allow for niceties of design, NIST studied the benefits of a fast and imprecise technique—randomly placed antennas combined with coarse signal matching. The signals produced by the radio and portable transmitters need to operate at the same frequency and roughly in phase, such that the radio waves are fairly well synchronized and thus build on each other. Phase-matching was performed manually in the experiments but might eventually be possible remotely.

The NIST experiments covered a range of communications scenarios, using up to eight transmitters at different locations as well as objects such as concrete blocks that scatter radio waves. Across all experimental scenarios, researchers observed at least a 7 decibel median power gain—roughly a five-fold increase in the median received power—when splitting the power among four in-phase transmitting antennas, compared to using just a single transmitter. More important, researchers observed a 2.5 to 4-fold increase in the median signal at the radio receiver when using four in-phase transmitters instead of four randomly phased transmitters. More than four extra transmitters offered diminishing returns. (Unlike conventional repeaters, which re-send signals to maintain transmission strength across long-distance networks, the antennas in the NIST scenarios transmit the same signal at the same time to multiply its strength.)

Project leader Chris Holloway envisions portable transmitter devices shaped like hockey pucks, incorporating a small antenna and phase-shifting electronics, which could be thrown on the ground or stuck on a wall with the antenna always upright. “The idea is that someone, or even a robot, would have a bag of these things and would drop them off as they go through a building,” Holloway says. Other authors include a guest researcher from Sandia National Laboratories and a collaborator from the University of Colorado at Boulder. The work was funded in part by the Office of Community-oriented Policing Services of the U.S. Department of Justice.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. W.F. Young, E.F. Kuester and C.L. Holloway. Measurements of randomly placed wireless transmitters used as an array for receivers located within the array volume with application to emergency responders. IEEE Transactions on Antennas and Propagation, (in press)

Cite This Page:

National Institute of Standards and Technology. "First Responders: Random Antenna Arrays Boost Emergency Communications." ScienceDaily. ScienceDaily, 11 March 2009. <www.sciencedaily.com/releases/2009/02/090225151337.htm>.
National Institute of Standards and Technology. (2009, March 11). First Responders: Random Antenna Arrays Boost Emergency Communications. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2009/02/090225151337.htm
National Institute of Standards and Technology. "First Responders: Random Antenna Arrays Boost Emergency Communications." ScienceDaily. www.sciencedaily.com/releases/2009/02/090225151337.htm (accessed August 20, 2014).

Share This




More Matter & Energy News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins