Understanding 5G NR SLIV for PDSCH and PUSCH Resource Allocation

This page describes the 5G NR SLIV definition. SLIV stands for Start and Length Indicator Value. SLIV values for PDSCH and PUSCH are also mentioned along with PDSCH and PUSCH time domain resource allocation.

What is SLIV?

The starting symbol S relative to the start of the slot, and the number of consecutive symbols L counting from the symbol S allocated for the PDSCH are determined from the start and length indicator (SLIV).

The formula for SLIV is as follows. It is defined in 3GPP TS 38.214 document.

It is used for time domain allocation for PDSCH and PUSCH. It defines start symbol and number of consecutive symbols for the respective allocation.

Following table mentions valid S and L combination values used for SLIV for PDSCH.

Following table mentions valid S and L combination values used for SLIV for PUSCH.

5G NR SLIV for PDSCH and PUSCH IEs

Following structures for SLIV used for PDSCH and PUSCH are defined in 3GPP TS 38.331 RRC specification document.

Following are the values used in “PDSCH-TimeDomainResourceAllocationList” information element (IE).

PDSCH-TimeDomainResourceAllocation ::= SEQUENCE {
k0 INTEGER(0..32)
mappingType ENUMERATED {typeA, typeB},
startSymbolAndLength INTEGER (0..127)
}

Following are the values used in “PUSCH-TimeDomainResourceAllocation” information element(IE).

PUSCH-TimeDomainResourceAllocation ::= SEQUENCE {
k2 INTEGER(0..32)
mappingType ENUMERATED {typeA, typeB},
startSymbolAndLength INTEGER (0..127)
}