UpPTS Uplink Pilot Time Slot
In LTE , the radio frame structure type 2 is used for TDD operation and consists of two half-frames with a duration of 5ms each and containing each 8 slots of length 0.5ms and three special fields ( DwPTS , GP and UpPTS) which have configurable individual lengths and a total length of 1ms. The DwPTS and UpPTS both provide time which enables downlink/uplink switching to be performed.
