Why second Slot in all subframe is not using, why only one slot only using in all subframes ?

Question

As per radio resource Allocation grid, we do having two slots in each subframe and each slot contains 12 sub carriers and 7 ofdm symbols in normal CP .

But when scheduling of Data or control especially in schedulers they talk only about one slot .. why not doing for 2 slots ??

If my understanding is wrong ... please explain me how it happening clearly ? I have lot of confusiion about this .

Answer 1

Hi,

Actually For L2 there are only one slot is allowed to schedule, In 20 Mhz Max RB is 100, Suppose if you schedule all 100 Rb's for some UE, but you need to send control information but you don't have enough Rb's because you have consumed all 100 Rb's . Now PHY will use both slot to send control information (MIB,PCFICH,PHICH,PDCCH ,PSS,SSS,CSRS) and data. Also PHY has to do coding for the scheduled data, if you send 1500 bytes PHY will do coding and it will add still more data to that, so to compensate all these it will use both slot.