The 3G (UMTS and CDMA2000) research and development projects started in 1992. In 1999, ITU approved five radio interfaces for IMT-2000 as a part of the ITU-R M.1457 Recommendation; WiMAX was added in 2007.[4]
There are evolutionary standards (EDGE and CDMA) that are backward-compatible extensions to pre-existing 2G networks as well as revolutionary standards that require all-new network hardware and frequency allocations. The cell phones utilise UMTS in combination with 2G GSM standards and bandwidths, but do not support EDGE.[5] The latter group is the UMTS family, which consists of standards developed for IMT-2000, as well as the independently developed standards DECT and WiMAX, which were included because they fit the IMT-2000 definition.
| ITU IMT-2000 compliant standards | common name(s) | bandwidth of data | pre-4G upgrade | duplex | channel | description | historical areas | |
|---|---|---|---|---|---|---|---|---|
| TDMA Single‑Carrier (IMT‑SC) | EDGE (UWC-136) | EDGE Evolution | likely discontinued | FDD | TDMA | evolutionary upgrade to GSM/GPRS[nb 1] | worldwide, except Japan and South Korea | |
| CDMA Multi‑Carrier (IMT‑MC) | CDMA2000 | EV-DO | UMB[nb 2] | CDMA | evolutionary upgrade to cdmaOne (IS-95) | Americas, Asia, some others | ||
| CDMA Direct Spread (IMT‑DS) | UMTS[nb 3] | W-CDMA[nb 4] | HSPA | LTE | family of revolutionary upgrades to earlier GSM family. | worldwide | ||
| CDMA TDD (IMT‑TC) | TD‑CDMA[nb 5] | TDD | Europe | |||||
| TD‑SCDMA[nb 6] | Mainland China only | |||||||
| FDMA/TDMA (IMT‑FT) | DECT | none | FDMA/TDMA | short-range; standard for cordless phones | Europe, US, Canada | |||
| IP‑OFDMA | WiMAX (IEEE 802.16) | OFDMA | worldwide, except mainland China | |||||
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