radio relay communication line
31Amateur Radio Emergency Communications — (AREC), formerly the Amateur Radio Emergency Corps , is a service provided by the New Zealand Association of Radio Transmitters (NZART) which provides trained radio communicators and communication systems for emergency situations.Mission… …
32Amateur radio repeater — An amateur radio repeater is an electronic device that receives a weak or low level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. Many repeaters are… …
33Alabama Public Radio — Infobox Radio station name = WUAL FM city = Tuscaloosa, Alabama area = slogan = branding = Alabama Public Radio frequency = 91.5 MHz HD Radio repeater = WQPR 88.7 (Muscle Shoals) WAPR FM 88.3 (Selma) airdate = share = 2.3 share as of = FALL 2007… …
34BMT Canarsie Line automation — The New York Metropolitan Transportation Authority (MTA) has plans to upgrade the entire New York City Subway system with communication based train control (CBTC) technology, that will control the speed and starting and stopping of subway trains …
35Microwave transmission — The atmospheric attenuation of microwaves in dry air with a precipitable water vapor level of 0.001 mm. The downward spikes in the graph correspond to frequencies at which microwaves are absorbed more strongly, such as by oxygen molecules… …
36Communications satellite — A communications satellite (sometimes abbreviated to COMSAT) is an artificial satellite stationed in space for the purpose of telecommunications. Modern communications satellites use a variety of orbits including geostationary orbits, Molniya… …
37telecommunications media — Introduction equipment and systems metal wire, terrestrial and satellite radio, and optical fibre employed in the transmission of electromagnetic signals. Transmission media and the problem of signal degradation Every… …
38Parabolic antenna — A parabolic satellite communications antenna at Erdfunkstelle Raisting, the biggest facility for satellite communication in the world, in Raisting, Bavaria, Germany. It has a Cassegrain type feed. A parabolic antenna is an antenna that uses a… …
39Computer network — Computer networks redirects here. For the periodical, see Computer Networks (journal). Datacom redirects here. For other uses, see Datacom (disambiguation). Internet map. The Internet is a global system of interconnected computer networks that… …
40Media and Publishing — ▪ 2007 Introduction The Frankfurt Book Fair enjoyed a record number of exhibitors, and the distribution of free newspapers surged. TV broadcasters experimented with ways of engaging their audience via the Internet; mobile TV grew; magazine… …
