Also known as Wideband CDMA (W-CDMA).A 3G digital cellular radio technology that is an upgrade to the pan-European Global System UDP source port UDP destination port UDP message length UDP checksum Data . . . for Mobile Communications (GSM). UMTS is based on code division multiple access (CDMA) and operates over a carrier 5 MHz wide, compared to the 200 kHz carrier used for narrowband CDMA. UMTS specifications provide for both time division duplex (TDD) and frequency division duplex (FDD) modes of operation, with TDD largely used in Europe and FDD in the United States.The FDD specifications call for the downlink to run in the 2110
(Universal Mobile Telecommunications System) The standards for the 3G evolution of the GSM cellular system. Also called "3GSM," UMTS is part of the 3GPP project and the ITU's IMT-2000 families of 3G standards. UMTS embraces the FOMA, WCDMA and HSPA air interface technologies, and UMTS networks can co-exist with earlier GSM (GPRS and EDGE) networks. With service in the 2 GHz band, UMTS offers global roaming and personalized features. For more information, visit www.umts-forum.org. See 3GPP, HSPA, cellular generations, IMT-2000, WCDMA and LTE.