Why PCCH logical channel is separately mapped PCH transport channel for paging ? Why can't it be mapped to DL-SCH

4G LTE
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1

Why PCH transport channel is separately designed for paging in LTE? like CCCH ,DCCH logical channel information are mapped to DL-SCH transport channel , so why can’t we map PCCH also to DL-SCH

2

Because PCCH follows DRX

3

Hi @O.B ,

Could you please elaborate further.

Thanks in advance

4

The classification of the channels into Transport channels depends on the characteristics of transmission

DL-SCH is characterized by link adaptation and HARQ that cannot be used for the logical PCH.

PCCH is characterized by support of idle mode DRX (only transmit when UE is not in sleep cycle) and broadcast to the whole cell (conservative mod and coding) because exact location is not known so link adaptation cannot be used

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5

Thanks for info @O.B

6

Paging use TM - transparent mode, no need feedback.
DL-SCH for AM - ack mode with harq.
So, pcch is not mapped to dl-sch.

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7

Thanks for info @Hainm