Glossary: E |
E1 |
European version of first level multiplexing (2.048 Mbps w/ 30 channels)
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E1 (CEPT T1) |
A rate of 2.048 Mbps in the European digital transmission hierarchy defined by CEPT. TS0 is used for framing and maintenance. TS16 is optionally used for signaling. TS1 is assigned as channel one.
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E3 |
A CEPT signal which carries four multiplexed E2 circuits and overhead. Effective rate is 34.368 Mbps.
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Echo return loss (ERL) |
"The difference in dB |
Echo suppressor |
A device that detects speech signals transmitted in either direction on a four-wire circuit. This device suppresses echoes by introducing loss in the opposite direction of speech transmission.
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EDD |
Envelope Delay Distortion
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EDSX-1 |
"Electronic Digital Signal Cross-connect |
EDSX-3 |
"Electronic Digital Signal Cross-connect |
eDTAU |
See Enhanced DS1 Test Access Unit.
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EFS |
See Error Free Second.
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EIA |
Electronic Industries Association
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EIA Interface |
"One of a set of signal characteristics set up by the Electronic Industries Association for standardization. These characteristics include time |
Elapsed bits |
The number of bits that have elapsed since the beginning of a timed test.
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Elapsed time |
The time that has elapsed since the beginning of a timed test interval.
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EM+ |
Enhanced Monitor Plus
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EM/MU |
Enhanced Monitor/Matrix Unit
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EMC |
Electromagnetic Compatibility
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EML |
Element Management Layer
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EMR |
Errored Message Ratio
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Enhanced DS1 Test Access Unit (eDTAU) |
A subset of digital access and test equipment included in Hekimian's DTAS product line. This equipment provides split and hitless monitor access to T1 lines for maintenance and testing and also provides full-time performance monitoring.
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Enhanced Monitor/Matrix Unit (EM/MU) |
An optional component in either a DTAU or Mini-DTAU. This unit performs extensive scanned monitoring of T1 lines.
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EPN |
External Point Name
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Equalizer |
A network which corrects a circuit's transmission characteristics. It may correct for gain-slope (non-linear frequency response) or for delay distortion.
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Error event |
(DS3): A second with one or more frame format coding violation events and no OOF or AIS events.
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Error-free second (EFS) |
A second that does not contain any error events. These seconds are calculated as 100 x [1 - errored seconds/measurement period]. Circuit quality is usually expressed in percentage of EFS.
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ESF |
See Extended Superframe.
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ETSI |
European Telecommunications Standards Institute
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Extended superframe format (ESF) |
"A framing format that extends DS1 framing from 12 to 24 frames so that an 8-kbps F-bit pattern can be used for three separate functions: framing |
EXZ |
See Excessive Zeros (also EZ).
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EZ |
See Excessive Zeros (also EXZ). |