LTE TDD means

LTE-FDD implies that downlink and uplink transmission take place in different, sufficiently separated, frequency bands, while TDD implies that downlink and uplink transmission take place in different, non overlapping time slots.

Most of the 3G UMTS networks use a frequency division duplex scheme where uplink and downlink transmit simultaneously and use different frequencies. However time division duplex, TDD where uplink and down link use the same frequency but transmit at different times has some distinct advantages in some circumstances .

LTE is able to utilise both frequency division and time division, FDD & TDD (TD-LTE) forms of duplex to accommodate the uplink and downlink. LTE can utilise both FDD – frequency division duplex and TDD – time division duplex, often referred to as TD-LTE.

FDD LTE stands for Frequency-Division Duplexing LTE . Both TDD and FDD differ in the way they treat data. Duplexing means a phone can transmit and receive simultaneously. TDD means the “receive” and “transmit” channels divide the time between them on the same frequency band.

Here, there first EN-DC deployments that will use 4G LTE as an anchor will use 5G in the TDD variant first . For those network operators deploying 5G in 3. x GHz, 3GPP band n78 will be used, which is TDD. And for those network operators going for mmWave, TDD is also the only option.

TDD means the transmission and reception occur on the same frequency , but each only for a split second, alternating between the two. That’s great for mobile Internet use, because you can use more of the bandwidth available for either downloading or uploading, whichever you happen to be doing.2 Ağu 2013