The important competitor to UMTS is CDMA2000 (IMT-MC), which is mature by the 3GPP2. Dissimilar UMTS, CDMA2000 is an evolutionary designate to an existing 2G criterion, cdmaOne, and is competent to control within the assonant cardinal allocations. This and CDMA2000's narrower bandwidth requirements work it easier to deploy in existing spectra. In whatever, but not all, cases, existing GSM operators only soul sufficiency spectrum to oblige either UMTS or GSM, not both. For instance, in the US D, E, and F PCS spectrum blocks, the total of spectrum visible is 5 MHz in apiece instruction. A canonic UMTS system would saturate that spectrum. Where CDMA2000 is deployed, it usually co-exists with UMTS. In more markets yet, the co-existence publicize is of younger relevancy, as legislative hurdles survive to co-deploying two standards in the unvarying licensed cut of spectrum.
Added competitor to UMTS is Furnish (IMT-SC), which is an evolutionary advance to the 2G GSM system, investment existing GSM spectrums. It is also overmuch easier, quicker, and substantially cheaper for wireless carriers to "bolt-on" Border functionality by upgrading their existing GSM coefficient instrumentality to argue Supply than having to put nearly all brand-new equipment to deport UMTS. Still, beingness mature by 3GPP vindicatory as UMTS, Bounds is not a confessedly competitor. Instead, it is misused as a temporary root above UMTS roll-out or as a hands for countrified areas. This is facilitated by the fact that GSM/EDGE and UMTS spec are collectively mature and rely on the like set scheme, allowing dual-mode procedure including plumb handovers.
Dishware's TD-SCDMA classical is often seen as a competitor, too. TD-SCDMA has been intercalary to UMTS' Achievement 4 as UTRA-TDD 1.28 Mcps Low Cut Appraise (UTRA-TDD LCR). Unequal TD-CDMA (UTRA-TDD 3.84 Mcps Great Scrap Judge, UTRA-TDD HCR) which complements W-CDMA (UTRA-FDD), it is eligible for both micro and macro cells. However, the want of vendors' backing is preventing it from beingness a historical competitor.
While DECT is technically susceptible of competing with UMTS and new cancellous networks in densely-populated, urban areas, it has only been deployed for internal cordless phones and semiprivate in-house networks.
All of these competitors fuck been recognised by ITU as concept of the IMT-2000 ancestry of 3G standards, along with UMTS-FDD.
On the Cyberspace accession sidelong, competing systems allow WiMAX and Flash-OFDM.