What is meaning of PHICH Config present in MIB ??

Question

In RRC Message MIB there is an IE PHICH config whcih consist of PHICH Duration and PHICH Resource

    PHICH-Config ::= SEQUENCE { 
    phich-Duration ENUMERATED {normal, extended},
     phich-Resource ENUMERATED {oneSixth, half, one, two} }
    }

What is the importance of these two IEs ???

Answer 1

PHICH = Physical Hybrid-ARQ Indicator Channel

The PHICH duration is configurable by higher layers according to Table 6.9.3-1 TS 36.211 Click here for Specification TS 36.211 .

The duration configured puts a lower limit on the size of the control region signaled by the PCFICH (Physical Control Format Indicator Channel).

PHICH Resource : - The PHICH carries the hybrid-ARQ ACK/NAK. Multiple PHICHs mapped to the same set of resource elements constitute a PHICH group, where PHICHs within the same PHICH group are separated through different orthogonal sequences.
A PHICH resource is identified by the index pair (PHICH group number and orthogonal Sequence index within the group).

For your refrence:
It is specified in 36.211 (Page no. 60)

Comments

What is the duration normal/extended signifies ???
What is the  phich-Resource 1/6, 1/2 ,1 ,2 signifies ???