With 4G LTE and WiMAX on the rise, the GSMA (which represents GSM mobile operators) wants to see 50MHz of the 2.6GHz band held for WiMAX use, while LTE would get 340Mhz of the band (which ranges from 2.5GHz-2.69GHz). In the mean time, the International Telecommunications Union has come up with 3 options for allocating bands for Frequency Division Duplex and Time Division Duplex. With FDD, one set of frequencies is used for the up-link, while a separate set is used for the down-link, which is currently how 3G and 4G LTE will work. Though TDD, which is what WiMAX uses, only uses one set of frequency, where the base-station and mobile device takes turns to transmit. With the three options for spectrum allocation on the table, the GSMA would like to see option 2 implemented, however option 3 would be the most flexible. The downside with this is that it has TDD and FDD all using the same frequencies, which may cause problems and might not work well with neighboring countries. Because of this, the GSMA has now recommended option 1, but it leaves 50MHz open, which they'd like used for WiMAX. But to their dismay, some counties, such as the US and Canada, have already allocated spectrum before an international agreement was reached. Furthermore, the 2.6GHz auction in the UK was to be done 18 months ago, but got delayed by legal actions taken by the operators, and is now part of the Digital Britain project.