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Cordless Telephony » History » Revision 8

Revision 7 (eloy, 03/22/2024 04:56 PM) → Revision 8/10 (eloy, 03/22/2024 06:21 PM)

h1. Cordless Telephony 

 Over the years several standards for cordless telephones have come and gone: 

 | Name | Year | Frequencies | Info | 
 | CT0 | N/A | N/A | Retronym for non-standardized earlier versions| 
 | CT1 | 1984 | 40 ch @25kHz 
 UL 914–915 MHz 
 DL 959–960 MHz 
 overlaps GSM channels 120-124 | Analog CEPT standard, specified in _CEPT Recommendation T/R 24-03_ and _I-ETS 300 235_ . The former is the original standard from 1984, the latter is an updated version from ETSI released in 1994 which contains some updates. 
 Operation no longer allowed since 1998 in Germany / 2005 in Austria | 
 | CT1+ | | 80 ch @25kHz 
 UL 885–887 MHz 
 DL 930–932 MHz | Used in Belgium, Germany, Luxembourg and Switzerland 
 Operation no longer allowed since 2008 in Germany | 
 | [[CT2]] | 1985 | 864–868 MHz | British standard MPT1375, later adopted by other countries 
 Operation no longer allowed since 2008 in Germany | 
 | CT3 | | | Only available as prototype, first presented at a CEPT conference in Lund, 1987. Became the basis for DECT. (source: DECT Today, May 2016) | 
 | DECT | 1992 | 10 ch @1728 kHz * 24 timeslots 
 1880–1900 MHz 
 1900–1980 MHz optional 
 2010–2025 MHz optional 
 2400–2480 MHz optional 
 1920–1930 MHz USA 
 | Originally _Digital European Cordless Telephony_, later _Digital Enhanced Cordless Telecommunications_ 
 Digital standard using G.726 as voice CODEC 
 DECT only defines the radio interface. 
 Later DECT-GAP (Generic Access Profile) specified basic functions (call setup / tear-down) ensuring interoperability between vendors | 
 | CAT-iq | 2006 | see DECT | _Cordless Advanced Technology – internet and quality_ 
 Superset of DECT ensuring more interoperability and adding G.722 as mandatory voice CODEC |
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