if required.

Parameters $A$ and $E$ are bounded according to the channel used, obviously having $A \leq E$. In the uplink, $12 \leq A \leq 1706$, while for $A\le11$ different block codes are used. The agreed codeword length range is $18 \leq E \leq 8192$, however the payload length $G$ can be larger since $G \leq 16384$: in this case, the information bits may be divided into two polar codewords through segmentation. In the downlink, $A$ is upper bounded by 140 for PDCCH, however in this case if $A \le 11$ the message is padded with zeros to reach $A = 12$. Due to the presence of the CRC, $E$ is lower bounded by 25, while $E \leq 8192$ as for uplink. For PBCH, only one code is accepted with parameters $A = 32$ and $E = 864$. The flags $I_{IL}$ and $I_{BIL}$ refer to the activation of the input bits interleaver and the channel interleaver, respectively. The number of the two types of assistant PC bits are given by $n_{PC}$ and $n_{PC}^{wm}$ (see Section \[subsec:subch\] for details). Table \[tab:sched\_chan\] summarizes the encoding chain parameters, while Figure \[fig:U\_D\_leng\] shows with a line pattern the rate matching scheme and mother polar 