SearchSpace
SearchSpace is an RRC information element of 3GPP TS 38.331 (38331), the 5G NR Radio Resource Control (RRC) protocol.
Definition
The IE SearchSpace defines how/where to search for PDCCH candidates. Each search space is associated with one ControlResourceSet . For a scheduled SCell in the case of cross carrier scheduling, except for nrofCandidates , all the optional fields are absent (regardless of their presence conditions). For a scheduled SpCell in the case of the cross carrier scheduling, if the search space is linked to another search space in the scheduling SCell, all the optional fields of this search space in the scheduled SpCell are absent (regardless of their presence conditions) except for nrofCandidates .
SearchSpace ::= SEQUENCE {
searchSpaceId SearchSpaceId,
controlResourceSetId ControlResourceSetId OPTIONAL, -- Cond SetupOnly
monitoringSlotPeriodicityAndOffset CHOICE {
sl1 NULL,
sl2 INTEGER (0..1),
sl4 INTEGER (0..3),
sl5 INTEGER (0..4),
sl8 INTEGER (0..7),
sl10 INTEGER (0..9),
sl16 INTEGER (0..15),
sl20 INTEGER (0..19),
sl40 INTEGER (0..39),
sl80 INTEGER (0..79),
sl160 INTEGER (0..159),
sl320 INTEGER (0..319),
sl640 INTEGER (0..639),
sl1280 INTEGER (0..1279),
sl2560 INTEGER (0..2559)
} OPTIONAL, -- Cond Setup4
duration INTEGER (2..2559) OPTIONAL, -- Need S
monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL, -- Cond Setup
nrofCandidates SEQUENCE {
aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},
aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}
} OPTIONAL, -- Cond Setup
searchSpaceType CHOICE {
common SEQUENCE {
dci-Format0-0-AndFormat1-0 SEQUENCE {
...
} OPTIONAL, -- Need R
dci-Format2-0 SEQUENCE {
nrofCandidates-SFI SEQUENCE {
aggregationLevel1 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel2 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel4 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel8 ENUMERATED {n1, n2} OPTIONAL, -- Need R
aggregationLevel16 ENUMERATED {n1, n2} OPTIONAL -- Need R
},
...
} OPTIONAL, -- Need R
dci-Format2-1 SEQUENCE {
...
} OPTIONAL, -- Need R
dci-Format2-2 SEQUENCE {
...
} OPTIONAL, -- Need R
dci-Format2-3 SEQUENCE {
dummy1 ENUMERATED {sl1, sl2, sl4, sl5, sl8, sl10, sl16, sl20} OPTIONAL, -- Cond Setup
dummy2 ENUMERATED {n1, n2},
...
} OPTIONAL -- Need R
},
ue-Specific SEQUENCE {
dci-Formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1},
...,
[[
dci-Formats-MT-r16 ENUMERATED {formats2-5} OPTIONAL, -- Need R
dci-FormatsSL-r16 ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1, formats3-0, formats3-1,
formats3-0-And-3-1} OPTIONAL, -- Need R
dci-FormatsExt-r16 ENUMERATED {formats0-2-And-1-2, formats0-1-And-1-1And-0-2-And-1-2}
OPTIONAL -- Need R
]],
[[
dci-FormatsNCR-r18 ENUMERATED {formats2-8} OPTIONAL, -- Need R
dci-FormatsSL-PRS-r18 ENUMERATED {formats3-2, formats3-0-And-3-2, formats3-0-And-3-1-And-3-2,
formats3-1-And-3-2} OPTIONAL -- Need R
]]
}
} OPTIONAL -- Cond Setup2
}Candidate change requests of v18.2.0
The CRs whose title or cover names this change, strong and likely matches only.
- CR 4832 r1 (likely): Rapp RRC CR for MC enhancement
- CR 4799 r2 (likely): Miscellaneous non-controversial corrections Set XXI
- CR 4689 r3 (likely): Correction on MBS search spaces configuration for (e)Redcap [RedCapMBS_Bcast]
Fields (48)
| Field | Description |
|---|---|
| searchSpaceId SearchSpaceId | Identity of the search space. SearchSpaceId = 0 identifies the searchSpaceZero configured via PBCH (MIB) or ServingCellConfigCommon and may hence not be used in the SearchSpace IE. The searchSpaceId is unique among the BWPs of a Serving Cell. In case of cross carrier scheduling, search spaces with the same searchSpaceId in scheduled cell and scheduling cell are linked to each other. The UE applies the search space for the scheduled cell only if the DL BWPs in which the linked search spaces are configured in scheduling cell and scheduled cell are both active. For an IAB-MT, the search space defines how/where to search for PDCCH candidates for an IAB-MT where each search space is associated with one ControlResearchSet and for a scheduled cell in the case of cross carrier scheduling, except for nrofCandidates, all the optional fields are absent. |
| controlResourceSetId ControlResourceSetId · OPTIONAL Cond SetupOnly | The CORESET applicable for this SearchSpace. Value 0 identifies the common CORESET#0 configured in MIB and in ServingCellConfigCommon . Values 1.. maxNrofControlResourceSets-1 identify CORESETs configured in System Information or by dedicated signalling. The CORESETs with non-zero controlResourceSetId are configured in the same BWP as this SearchSpace except commonControlResourceSetExt which is configured by SIB20. If the field controlResourceSetId-r16 is present, UE shall ignore the controlResourceSetId (without suffix). |
| monitoringSlotPeriodicityAndOffset CHOICE { · OPTIONAL Cond Setup4 | Slots for PDCCH Monitoring configured as periodicity and offset. For SCS 15, 30, 60, and 120 kHz and if the UE is configured to monitor: - DCI format 2_1, only the values 'sl1', 'sl2' or 'sl4' are applicable. - DCI format 2_0, only the values ′sl1′, ′sl2′, ′sl4′, ′sl5′, ′sl8′, ′sl10′, ′sl16′, and ′sl20′ are applicable (see TS 38.213 [13], clause 10). - DCI format 2_4, only the values 'sl1', 'sl2', 'sl4', 'sl5', 'sl8' and 'sl10' are applicable. For SCS 480 kHz and if the UE is configured to monitor: - DCI format 2_0, only the values 'sl4', 'sl8', 'sl16', 'sl20', 'sl32', 'sl40', 'sl64', and 'sl80' are applicable. - DCI format 2_1, only the values ′sl4′, ′sl8′, and ′sl16′ are applicable. - DCI format 2_4, only the values 'sl4', 'sl8', 'sl16', 'sl20', 'sl32', 'sl40' are applicable. For SCS 960 kHz and if the UE is configured to monitor: - DCI format 2_0, only the values 'sl8', 'sl16', 'sl32', 'sl40', 'sl64', 'sl80', 'sl128', and 'sl160' are applicable. - DCI format 2_1, only the values ′sl8′, ′sl16′, and 'sl32' are applicable. - DCI format 2_4, only the values 'sl8', 'sl16', 'sl32', 'sl40', 'sl64', 'sl80' are applicable. For SCS 480 kHz and SCS 960 kHz, and the configured periodicity and offset are restricted to be an integer multiple of L slots, where L is the configured length of the bitmap provided by monitoringSlotsWithinSlotGroup-r17 , i.e. for a given periodicity, the offset has a range of {0, L, 2L, …, LFLOOR(1/L(periodicity-1))}. For IAB-MT, If the IAB-MT is configured to monitor DCI format 2_1, only the values 'sl1', 'sl2' or 'sl4' are applicable. If the IAB-MT is configured to monitor DCI format 2_0 or DCI format 2_5, only the values ′sl1′, ′sl2′, ′sl4′, ′sl5′, ′sl8′, ′sl10′, ′sl16′, and ′sl20′ are applicable (see TS 38.213, clause 10). If monitoringSlotPeriodicityAndOffset-v1710 is present, any previously configured monitoringSlotPeriodicityAndOffset is released, and if monitoringSlotPeriodicityAndOffset is present, any previously configured monitoringSlotPeriodicityAndOffset-v1710 is released. |
| sl1 NULL | |
| sl2 INTEGER (0..1) | |
| sl4 INTEGER (0..3) since v15.1.0 | |
| sl5 INTEGER (0..4) | |
| sl8 INTEGER (0..7) since v15.1.0 | |
| sl10 INTEGER (0..9) | |
| sl16 INTEGER (0..15) since v15.1.0 | |
| sl20 INTEGER (0..19) | |
| sl40 INTEGER (0..39) since v15.2.0 | |
| sl80 INTEGER (0..79) since v15.2.0 | |
| sl160 INTEGER (0..159) since v15.2.0 | |
| sl320 INTEGER (0..319) since v15.2.0 | |
| sl640 INTEGER (0..639) since v15.2.0 | |
| sl1280 INTEGER (0..1279) since v15.2.0 | |
| sl2560 INTEGER (0..2559) since v15.2.0 | |
| duration INTEGER (2..2559) · OPTIONAL Need S since v15.2.0 | Number of consecutive slots that a SearchSpace lasts in every occasion, i.e., upon every period as given in the periodicityAndOffset . If the field is absent, the UE applies the value 1 slot, except for DCI format 2_0. The UE ignores this field for DCI format 2_0. The maximum valid duration is periodicity-1 (periodicity as given in the monitoringSlotPeriodicityAndOffset ). For SCS 480 kHz and SCS 960 kHz, duration-r17 is used, and the configured duration is restricted to be an integer multiple of L slots and smaller than periodicity, where L is the configured length of the bitmap monitoringSlotsWithinSlotGroup-r17 . If duration-r17 is absent, the UE assumes the duration in slots is equal to L. The maximum valid duration is periodicity-L. For IAB-MT, duration indicates number of consecutive slots that a SearchSpace lasts in every occasion, i.e., upon every period as given in the periodicityAndOffset . If the field is absent, the IAB-MT applies the value 1 slot, except for DCI format 2_0 and DCI format 2_5. The IAB-MT ignores this field for DCI format 2_0 and DCI format 2_5. The maximum valid duration is periodicity-1 (periodicity as given in the monitoringSlotPeriodicityAndOffset ). |
| monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) · OPTIONAL Cond Setup | The first symbol(s) for PDCCH monitoring in the slots configured for (multi-slot) PDCCH monitoring (see monitoringSlotPeriodicityAndOffset and duration ). The most significant (left) bit represents the first OFDM in a slot, and the second most significant (left) bit represents the second OFDM symbol in a slot and so on. The bit(s) set to one identify the first OFDM symbol(s) of the control resource set within a slot. If the cyclic prefix of the BWP is set to extended CP, the last two bits within the bit string shall be ignored by the UE or IAB-MT. For DCI format 2_0, the first one symbol applies if the duration of CORESET (in the IE ControlResourceSet ) identified by controlResourceSetId indicates 3 symbols, the first two symbols apply if the duration of CORESET identified by controlResourceSetId indicates 2 symbols, and the first three symbols apply if the duration of CORESET identified by controlResourceSetId indicates 1 symbol. See TS 38.213 [13], clause 10. For IAB-MT: For DCI format 2_0 or DCI format 2_5, the first one symbol applies if the duration of CORESET (in the IE ControlResourceSet ) identified by controlResourceSetId indicates 3 symbols, the first two symbols apply if the duration of CORESET identified by controlResourceSetId indicates 2 symbols, and the first three symbols apply if the duration of CORESET identified by controlResourceSetId indicates 1 symbol. See TS 38.213 [13], clause 10. |
| nrofCandidates SEQUENCE { · OPTIONAL Cond Setup | Number of PDCCH candidates per aggregation level. The number of candidates and aggregation levels configured here applies to all formats unless a particular value is specified or a format-specific value is provided (see inside searchSpaceType ). If configured in the SearchSpace of a cross carrier scheduled cell, this field determines the number of candidates and aggregation levels to be used on the linked scheduling cell (see TS 38.213 [13], clause 10). |
| aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} | |
| aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} | |
| aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} | |
| aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} | |
| aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} since v15.1.0 | |
| searchSpaceType CHOICE { · OPTIONAL Cond Setup2 | Indicates whether this is a common search space (present) or a UE specific search space as well as DCI formats to monitor for. |
| common SEQUENCE { | Configures this search space as common search space (CSS) and DCI formats to monitor. |
| dci-Format0-0-AndFormat1-0 SEQUENCE { · OPTIONAL Need R since v15.1.0 | If configured, the UE monitors the DCI formats 0_0 and 1_0 according to TS 38.213 [13], clause 10.1. |
| dci-Format2-0 SEQUENCE { · OPTIONAL Need R since v15.1.0 | If configured, UE monitors the DCI format 2_0 according to TS 38.213 [13], clause 10.1, 11.1.1. |
| nrofCandidates-SFI SEQUENCE { since v15.1.0 | The number of PDCCH candidates specifically for format 2-0 for the configured aggregation level. If an aggregation level is absent, the UE does not search for any candidates with that aggregation level. The network configures only one aggregationLevel and the corresponding number of candidates (see TS 38.213 [13], clause 11.1.1). For a search space configured with freqMonitorLocations-r16 , only value ′n1′ is valid. |
| aggregationLevel1 ENUMERATED {n1, n2} · OPTIONAL Need R since v15.1.0 | |
| aggregationLevel2 ENUMERATED {n1, n2} · OPTIONAL Need R since v15.1.0 | |
| aggregationLevel4 ENUMERATED {n1, n2} · OPTIONAL Need R since v15.1.0 | |
| aggregationLevel8 ENUMERATED {n1, n2} · OPTIONAL Need R since v15.1.0 | |
| aggregationLevel16 ENUMERATED {n1, n2} · OPTIONAL Need R since v15.1.0 | |
| dci-Format2-1 SEQUENCE { · OPTIONAL Need R since v15.1.0 | If configured, UE monitors the DCI format 2_1 according to TS 38.213 [13], clause 10.1, 11.2. |
| dci-Format2-2 SEQUENCE { · OPTIONAL Need R since v15.1.0 | If configured, UE monitors the DCI format 2_2 according to TS 38.213 [13], clause 10.1, 11.3. |
| dci-Format2-3 SEQUENCE { · OPTIONAL Need R since v15.1.0 | If configured, UE monitors the DCI format 2_3 according to TS 38.213 [13], clause 10.1, 11.4 |
| dummy1 ENUMERATED {sl1, sl2, sl4, sl5, sl8, sl10, sl16, sl20} · OPTIONAL Cond Setup since v15.3.0 | This field is not used in the specification. If received it shall be ignored by the UE. |
| dummy2 ENUMERATED {n1, n2} since v15.3.0 | This field is not used in the specification. If received it shall be ignored by the UE. |
| ue-Specific SEQUENCE { | Configures this search space as UE specific search space (USS). The UE monitors the DCI format with CRC scrambled by C-RNTI, CS-RNTI (if configured), and SP-CSI-RNTI (if configured) |
| dci-Formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1} since v15.1.0 | Indicates whether the UE monitors in this USS for DCI formats 0-0 and 1-0 or for formats 0-1 and 1-1. |
| dci-Formats-MT-r16 ENUMERATED {formats2-5} · OPTIONAL Need R since v16.1.0 | Indicates whether the IAB-MT monitors the DCI formats 2-5 according to TS 38.213 [13], clause 14. |
| dci-FormatsSL-r16 ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1, formats3-0, formats3-1, formats3-0-And-3-1} · OPTIONAL Need R since v16.0.0 | Indicates whether the UE monitors in this USS for DCI formats 0-0 and 1-0 or for formats 0-1 and 1-1 or for format 3-0 or for format 3-1 or for formats 3-0 and 3-1. If this field is present, the field dci-Formats is ignored and dci-FormatsSL is used. |
| dci-FormatsExt-r16 ENUMERATED {formats0-2-And-1-2, formats0-1-And-1-1And-0-2-And-1-2} · OPTIONAL Need R since v16.0.0 | If this field is present, the field dci-Formats is ignored and dci-FormatsExt is used instead to indicate whether the UE monitors in this USS for DCI format 0_2 and 1_2 or formats 0_1 and 1_1 and 0_2 and 1_2 (see TS 38.212 [17], clause 7.3.1 and TS 38.213 [13], clause 10.1). This field is not configured for operation with shared spectrum channel access in this release . |
| dci-FormatsNCR-r18 ENUMERATED {formats2-8} · OPTIONAL Need R since v18.0.0 | Indicates whether the NCR-MT monitors the DCI formats 2-8 according to TS 38.213 [13], clause 20. |
| dci-FormatsSL-PRS-r18 ENUMERATED {formats3-2, formats3-0-And-3-2, formats3-0-And-3-1-And-3-2, formats3-1-And-3-2} · OPTIONAL Need R since v18.2.0 | Indicates whether the UE monitors in this USS for DCI formats 3-2 or for formats 3-0 and 3-2 or for formats 3-0 and 3-1 and 3-2 or for formats3-1 and 3-2. If this field is present, the field dci-Formats is ignored and dci-FormatsSL-PRS is used. |