tag:blogger.com,1999:blog-14298569442064552462024-03-07T21:35:47.119-08:00Telephone Systems - HistoryQuick view to telephone techologyAnonymoushttp://www.blogger.com/profile/16216458546247998886noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-1429856944206455246.post-14550022311546867772012-09-18T19:04:00.002-07:002012-10-19T19:32:59.394-07:00<br />
My journey through Telephone Technology begun 33 years ago when I took my first couse at <a href="http://www.etb.com.co/">E.T.B,</a> the colombian largest telephone provider. I was a 18 years old and had just received my High School degree as Electronics Techincian when got my first job with ETB. These are the technologies I have worked with:<br />
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1. <strong>Manual systems.</strong> A phone call is iniciated by turning the magnet which sends a electical signal over a pair of wires. The alternate current travel along the circuit and alerts the operator located at the switching center. The connection was enterely manual controlled by a human operator.<br />
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<strong>1. Ericsson AGF.</strong> This was my first couse, learnend how the operator was replaced by a electro-mechanical devices that emulates the movement made by the operator's arm. <br />
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<strong>2. Ericsson ARF.</strong> Relays replaced most of the mechanical parts AGF systems had. This system was able to perform some intelligent actions like number analys. <br />
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<strong>3. Motorola MTS.</strong> First mobile telephone system. Designed in the 70's. 120 wats radio-base station covered a circular area about 20 km radius. The control center was based in a electro-mechanical system similar to a ARF system. Mobile units had heavy Radio unit usually installed in a car trunk. The control head had a phone dial disk.<br />
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<strong>4. NAMTS</strong>. NEC Advanced mobile telephone system. Also known as a pre-cellualr system. A NEAX-61 was the Mobile Control Center (MCC) which controlled a number of Radio Base Stations. All electronics was basically TTL and 8 bit microcontrollers were used in several control cards.<br />
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<strong>5. FUJITSU FETEX-150.</strong> Digital Telephone system.<br />
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<strong>6 FUJISTU CDMA</strong>. Cellular system. <br />
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<strong>7 UMTS 4G 2012.</strong> I'm just learning the basics of LTE technologyAnonymoushttp://www.blogger.com/profile/16216458546247998886noreply@blogger.com0