Editing CDMA2000 (section)

==1X==
{{List of mobile phone generations}}
'''CDMA2000 1X (IS-2000)''', also known as '''1x''' and '''1xRTT''', is the core CDMA2000 wireless air interface standard. The designation "1x", meaning ''1 times radio transmission technology'', indicates the same [[radio frequency]] (RF) bandwidth as [[IS-95]]: a [[duplex (telecommunications)|duplex]] pair of 1.25&nbsp;MHz radio channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the [[forward link]], [[orthogonality|orthogonal]] to (in [[Quadrature phase|quadrature]] with) the original set of 64. The 1X standard supports packet data speeds of up to 153&nbsp;[[Kilobit per second|kbit/s]] with real world data transmission averaging 80–100&nbsp;kbit/s in most commercial applications.<ref>{{cite web|url=http://www.cdg.org/technology/cdma20001x.asp|title=CDG : Technology : CDMA2000 1X|website=CDMA Development Group|access-date=July 28, 2017|archive-date=August 2, 2010|archive-url=https://web.archive.org/web/20100802011151/http://www.cdg.org/technology/cdma20001x.asp|url-status=dead}}</ref> IMT-2000 also made changes to the [[data link layer]] for greater use of data services, including medium and link access control protocols and [[quality of service]] (QoS). The IS-95 data link layer only provided [[best-effort delivery]] for data and circuit switched channel for voice (i.e., a voice frame once every 20 ms).