TDD or FDD is used more in the world, and how many countries are using it

1.The main equipment and terminals of the base station are more mature than TD-LTE, and at present, TD-LTE has not yet launched a mobile phone terminal, only data cards and applications that convert to WiFi signals.

Global roaming is guaranteed by large-scale global deployment, and FDD's good interoperability with existing 2G 3G networks protects effective investment in existing networks and smooth network transitions.

3.On the one hand, the possibility of TDD technology to be promoted on a larger scale in the world is increased by splicing spectrum, but it is also difficult to solve the problems of base station asynchronicity, long-distance base station co-channel interference, and different interference in adjacent frequency slots of the same frequency band.

4.Multi-antenna is an important feature of TDD, on the one hand, it can achieve shaping gain and improve the signal coverage at the edge of the cell, but on the other hand, multi-antenna also faces the problems of occupying more roof, larger and heavier equipment, and more interfaces, which causes great resistance to the implementation of the project.

5.The above are all technical comparisons, compared with technology, what is really related to the fate of TD-LTE is the industrial scale of TD-LTE. In the communications industry, the success of a technology is often determined not by the technology itself, but by the cost.

Which technology can be supported by a larger industrial chain, the lower its cost can be, so it will also gain heavier weight in the competition, as is the case with the decline of WiMAX in the LTE competition.

If the deployment scale of TD-LTE continues to expand, it is believed that a bunch of immature TD-LTE can find a way out, but choosing TD-LTE requires huge risks and time costs.

TDD and FDD refer to the two duplex communication modes in the third generation of mobile communication technology (3G).

TDD (Time-Division Duplex) mode refers to the time division duplex mode, which is used by TD-SCDMA in the 3G standard.

TDD is a duplex mode of communication system, which is used to separate the receiving and transmitting channels (or uplink and downlink) in mobile communication systems. In the TDD mode mobile communication system, the reception and transmission are separated by the same frequency channel, that is, the carrier in different time slots, and the receiving and transmitting channels are separated by guaranteed time.

FDD (Frequency-Division Duplex) mode refers to the frequency division dual-mode mode, which is used by WCDMA and CDMA2000 in the 3G standard.

The receiving and transmitting of the FDD mode mobile communication system is on two separate symmetrical frequency channels, and the guaranteed frequency band is used to separate the transmission channel between the receiving and Yanbian Town.