Editing UMTS (section)

==== Rationale for W-CDMA ====
W-CDMA transmits on a pair of 5&nbsp;MHz-wide radio channels, while CDMA2000 transmits on one or several pairs of 1.25&nbsp;MHz radio channels. Though W-CDMA does use a [[direct-sequence spread spectrum|direct-sequence]] CDMA transmission technique like CDMA2000, W-CDMA is not simply a wideband version of CDMA2000 and differs in many aspects from CDMA2000. From an engineering point of view, W-CDMA provides a different balance of trade-offs between cost, capacity, performance, and density{{citation needed|date=November 2011}}; it also promises to achieve a benefit of reduced cost for video phone handsets. W-CDMA may also be better suited for deployment in the very dense cities of Europe and Asia. However, hurdles remain, and [[cross-licensing]] of [[patent]]s between Qualcomm and W-CDMA vendors has not eliminated possible patent issues due to the features of W-CDMA which remain covered by Qualcomm patents.<ref>{{cite web|url=https://www.infoworld.com/article/2205181/qualcomm-says-it-doesn-t-need-nokia-patents-2.html|title=Qualcomm says it doesn't need Nokia patents}}</ref>

W-CDMA has been developed into a complete set of specifications, a detailed protocol that defines how a mobile phone communicates with the tower, how signals are modulated, how datagrams are structured, and system interfaces are specified allowing free competition on technology elements.