5.1 Frame structure
25.2213GPPPhysical channels and mapping of transport channels onto physical channels (TDD)Release 17TS
The TDMA frame has a duration of 10 ms and is subdivided into 15 time slots (TS) of 2560*Tc duration each. A time slot corresponds to 2560 chips. The physical content of the time slots are the bursts of corresponding length as described in subclause 5.2.2.
Each 10 ms frame consists of 15 time slots, each allocated to either the uplink or the downlink (figure 2). With such a flexibility, the TDD mode can be adapted to different environments and deployment scenarios. In any configuration at least one time slot has to be allocated for the downlink and at least one time slot has to be allocated for the uplink with the exception of no uplink timeslots when the entire carrier is dedicted to MBSFN
Figure 2: The TDD frame structure
Examples for multiple and single switching point configurations as well as for symmetric and asymmetric UL/DL allocations are given in figure 3.
Multiple-switching-point configuration (symmetric DL/UL allocation)
Multiple-switching-point configuration (asymmetric DL/UL allocation)
Single-switching-point configuration (symmetric DL/UL allocation)
Single-switching-point configuration (asymmetric DL/UL allocation)
10 ms
Entire carrier dedicated to MBSFN
Figure 3: TDD frame structure examples