Idle Mode Mobility
Measurements in LTE
LTE Measurements
Intra LTE measurements ( from LTE to LTE)
• UE measurements
– CQI measurements
– Reference Signal Received Power (RSRP)
– Reference Signal Received Quality (RSRQ)
• eNB measurements
– Non standardized (vendor specific): TA, Average RSSI, Average SINR, detected PRACH
preambles, transport channel BLER
– Standardized: DL RS Tx Power, Received Interference Power, Thermal Noise Power
Measurements from LTE to other systems
• UE measurements are mainly intended for handover.
– UTRA FDD: CPICH RSCP, CPICH Ec/No and carrier RSSI
– GSM: GSM carrier RSSI
– UTRA TDD: carrier RSSI, RSCP, P-CCPCH
– CDMA2000: 1xRTT Pilot Strength, HRPD Pilot Strength
UE Measurements: RSRP & RSRQ
RSRP (Reference Signal Received Power)
• Average of power levels (in [W]) received across all Reference Signal symbols within the considered
measurement frequency bandwidth.
• UE only takes measurements from the cell-specific Reference Signal elements of the serving cell, this makes
RSRP results load and MIMO/diversity independent.
If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRP of
any of the individual diversity branches
Received Signal Strength Indicator (RSSI)
• RSSI comprises the linear average of the total received power (in [W]) observed only in OFDM symbols
containing reference symbols for antenna port 0, in the measurement bandwidth, over N number of resource
blocks by the UE from all sources, including co-channel serving and non-serving cells, adjacent channel
interference, thermal noise etc.
RSRQ (Reference Signal Received Quality)
• Defined as the ratio N×RSRP/(E-UTRA carrier RSSI), where N is the number of RBs of the E-UTRA carrier
RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the
same set of resource blocks
Cell Selection
Cell Selection Procedure
1) UE creates a candidate list of potential cells to camp on. Two possible search procedures:
• Initial Cell Selection: UE scans all RF channels to find a suitable cell. On each carrier, the UE searches for the strongest
cell and reads information. Once the UE has found the suitable cell for the selected PLMN, the UE creates a candidate list
consisting of this cell and its neighboring cells as received in measurement control information.
• Stored Information Cell Selection (optionally) This procedure requires information stored from previously received
measurement control information elements (cell parameters, carrier frequencies, etc.). After the UE has found a suitable cell
for the selected PLMN, candidate list is created same as the initial cell selection process.
2) Each cell on the candidate list is evaluated according to the selection criteria S
3) After selecting a suitable cell (S criterion fulfilled) for camp on, UE
reports this event to NAS for registration procedures. If the registration
is successful, the UE enters into "camped normally“ state.
Initial Selection
- Carrier 1:
strongest cell
- Carrier 2:
strongest cell
- Carrier i …..
Stored Information
Selection
- Previous information
- Previous detections
S – Criterion Cell Selection
UE selects a eUTRA cell if the S (selection) criteria is fulfilled: Srxlev > 0
Srxlev = Qrxlevmeas – (Qrxlevmin* + Qrxlevminoffset**) - Pcompensation
UE measurement
(RSRP)
SIB1 Parameter
SIB1 Parameter
Pcompensation = max (PEMAX*** – PUMAX, 0) (dB)
SIB1 Parameter
qrxlevmin
* Qrxlevmin = LNCEL: qrxlevmin
** Qrxlevminoffset = LNCEL: qRxLevMinOffset (used
only when camped in VPLMN)
*** PEMAX = LNCEL: pMaxOwnCell
PUMAX is UE class specific max. UL Tx power
Minimum required RSRP level
LNCEL; -140…-44dBm; 2dBm; -
qRxLevMinOffset
Affects minimum required RSRP level
LNCEL; 2..16 dB; 2dB; -
pMaxOwnCell
Used to calculate Pcompensation
LNCEL; -30..34dBm; 1dBm; *PUMAX: UE class specific max. UL Tx power; 23 dBm
S – Criterion Cell Selection
Cell size defining parameters:
• Qrxlevmin
I am
outside
☺
I am inside,
but have not
enough
power
pMaxOwnCell
Used to calculate Pcompensation
LNCEL; -30..33dBm; 1dBm; -
Pcompensation = max(P_MAX_OWN_CELL – PUMAX, 0)
*PUMAX: UE class specific max. UL Tx power; 23 dBm
S – Criterion Parameter
Parameter
QRxLevMin
QRxLevMin Offset
PEMAX
Huawei
Nokia
Parameter Name
Parameter Name
[CellSel] QRxLevMin
[LNCEL] qrxlevmin
[CellSel] QRxLevMinOffset [LNCEL] qRxLevMinOffset
[CellResel] PMax
[LNCEL] pMaxOwnCell
EID
Parameter Name
[EUtranCellFDD] qRxLevMin
[EUtranCellFDD] qRxLevMinOffset
[EUtranCellFDD] pMaxServingCell
ZTE
Parameter Name
[EUtranReselection] selQrxLevMin
[EUtranReselection] qrxLevMinOfst
Recommended
Value
[EUtranReselection] intraPmax
23 dBm
-124 dBm
0 dB
Cell Reselection
Nokia Parameter Objects Structure for Reselection
LNBTS
Reselection has different
parameter for different
neighbor type:
- Intra Frequency LTE
- Inter Frequency LTE
- UTRAN
- GERAN
- CDMA2000
LNCEL
IAFIM
CDFIM
IRFIM
GFIM
UFFIM
GNFL
IAFIM = Intra Frequency Idle Mode
IRFIM = Inter Frequency Idle Mode
UFFIM = UTRAN FDD Idle Mode
GFIM = GERAN Frequency Idle Mode
GNFL = GERAN Neighbor Frequency List
CDFIM = CDMA2000 Frequency Idle Mode
Reselection Process Overview
Measurements trigger
UE is measuring the neighbor cells only when the RSRP signal level is
below some threshold.
The measurements trigger is based primarily on absolute priorities.
In case of equal priority additional thresholds are defined
Evaluate cell reselection criteria “R”
For the reselection there are different cases depending on priorites of
the neighbour frequency Layers (for inter-frequency and inter-RAT)
Execute cell reselection
Priority Layer Concept in LTE
•
•
•
Cell reselection between different LTE frequencies and different RATs is based on priorities
Priorities could be configured for each LTE frequency (including serving cell) and for each
frequency of each RAT
Priorities are provided to UE via system information
• eUTRAN : SIB3, SIB5, SIB6, SIB7, SIB8
• UTRAN: SIB19
• GERAN: SI2quater
RAT_4 f_2
RAT_3 f_1
•
•
Equal priorities are not applicable for inter-RAT cell reselection
UE performs only cell reselection evaluation for inter-LTE frequency and inter-RAT carriers for
which the UE has a priority
•
•
The range of absolute priorities is 0..7 (0 is the lowest priority)
Priorities can also be signaled directly within RRC connection release message; RRC Timers
control validity of prio information
• eUTRAN: T320; UTRAN: T322; GERAN: T3230
LNCEL: cellReSelPrio
Absolute priority of the serving cell
IRFIM: eutCelResPrio
Absolute priority of EUTRA carrier frequency
UFFIM: uCelResPrio
Absolute priority of the UTRA carrier frequency
GNFL: gCelResPrio
Absolute priority of the GERAN carrier frequency
CDFIM: hrpdCResPrio
Absolute priority of the CDMA2000 HRPD carrier frequency
CDFIM: rttCResPrio
Absolute priority of the CDMA2000 1xRTT carrier frequency
RAT_2 f_2
RAT_2 f_1
RAT_1 f_2
RAT_1 f_1
Measurements Trigger - Intra Frequency
• When to trigger the measurements of neighbor cells?
• UE is not continuously measuring neighbor cells in search of a better cell to camp on
• UE only performs intra frequency measurements when:
Intra - Frequency:
sIntrasearch
LNCEL; 0..62dB; 2dB; -
Srxlev <= Sintrasearch
→ Qrxlevmeas ≤ Qrxlevmin + Sintrasearch
qrxlevmin
Minimum required RSRP level
LNCEL; -140…-44dBm; 2dBm; -
(assuming that qRxLevMinOffset is not used)
sIntrasearch broadcasted
on SIB3
Reselection Intra Frequency Start Measurement Parameter
Category
Selection
(S - Criteria)
ReSelection
Start Measurement
Huawei
Nokia
EID
ZTE
Parameter Name
Parameter Name
Parameter Name
Parameter Name
QRxLevMin
[CellSel] QRxLevMin
[LNCEL] qrxlevmin
[EUtranCellFDD] qRxLevMin
QRxLevMin
Offset
[CellSel]
QRxLevMinOffset
[LNCEL]
qRxLevMinOffset
PEMAX
[CellResel] PMax
[LNCEL] pMaxOwnCell
[EUtranCellFDD]
qRxLevMinOffset
[EUtranCellFDD]
pMaxServingCell
[CellResel]
SIntraSearch
[LNCEL] sIntrasearch
[SIB3] sIntraSearch
Parameter
sIntraSearch
[EUtranReselection]
selQrxLevMin
[EUtranReselection]
qrxLevMinOfst
Recommended
Value
-124 dBm
0 dB
[EUtranReselection] intraPmax
23 dBm
[EUtranReselection]
sIntraSearch
62 dB
Measurements Trigger – Inter-frequency and Inter-RAT (1/2)
• In the case of inter-frequency and inter-RAT reselection the measurements trigger depends primarily
on the absolute priorities of the serving & non-serving layer
• UE should always measure higher priority layers
• Therefore UE searches for higher priority layers at least once every (60xNlayers) seconds
• Nlayers is the total number of higher priorities LTE and 3G layers
• Nlayers is increased by 1 if there is one or more groups of GSM frequencies with higher priority.
IF cellReSelPrio(inter-f or inter-RAT) > cellReSelPrio(serving)
THEN the measurements of the neighbor cell are mandatory
IF cellReSelPrio(inter-f or inter-RAT) <= cellReSelPrio(serving)
THEN the measurements are performed when RSRP of the serving cell is below some threshold:
Srxlev <= Snonintrasearch
sNonIntrsearch
→ Qrxlevmeas ≤ Qrxlevmin + Snonintrasearch
(assuming that qRxLevMinOffset is not used)
LNCEL; 0..62dB; 2dB; -
Measurements Trigger – Inter-frequency and Inter-RAT (1/2)
sNonIntrsearch
LNCEL; 0..62dB; 2dB; -
sNonIntrasearch broadcasted on
SIB3
Reselection Inter Freq & Inter RAT Start Measurement
Parameter
Category
Selection
(S - Criteria)
Parameter
QRxLevMin
QRxLevMin Offset
PEMAX
sIntraSearch
ReSelection Start
Measurement
sNonIntraSearch
Huawei
Parameter Name
Nokia
Parameter Name
EID
Parameter Name
[CellSel] QRxLevMin
[LNCEL] qrxlevmin
[EUtranCellFDD] qRxLevMin
[CellSel]
QRxLevMinOffset
[LNCEL] qRxLevMinOffset
[EUtranCellFDD]
qRxLevMinOffset
[CellResel] PMax
[CellResel]
SIntraSearch
[CellResel]
SNonIntraSearch
[LNCEL] pMaxOwnCell
[EUtranCellFDD]
pMaxServingCell
[LNCEL] sIntrasearch
[SIB3] sIntraSearch
[LNCEL] sNonIntrsearch
[EUtranCellFDD]
systemInformationBlock3_sNonI
ntraSearch
ZTE
Parameter Name
[EUtranReselection]
selQrxLevMin
[EUtranReselection]
qrxLevMinOfst
[EUtranReselection]
intraPmax
[EUtranReselection]
sIntraSearch
[EUtranReselection]
snonintrasearch
Default Value
-124 dBm
0 dB
23 dBm
62 dB
10 (-114 dBm)
Reselection Process Overview
Measurements trigger
UE is measuring the neighbor cells only when the RSRP signal level is
below some threshold.
The measurements trigger is based primarily on absolute priorities.
In case of equal priority additional thresholds are defined
Evaluate cell reselection criteria “R”
For the reselection there are different cases depending on priorites of
the neighbour frequency Layers (for inter-frequency and inter-RAT)
Execute cell reselection
R Criterion – Cell Reselection
Intra-frequency Case (1/2)
•
Once the measurements for neighbor cells have been triggered the UE will rank the measured
cells which fulfill the S- Criterion according to the R- Criterion
qHyst
• Cell ranking criterion:
LNCEL; 0dB (0),…,24dB (15); Rs = Qmeas,s + Qhyst,s
qOffsetCell
Rn = Qmeas,n – Qoffset,n
IAFIM; -24 dB (0),…,24 dB (30); - ; 0
dB(15)
Rn > Rs ⇒“cell reselection“
tReselEutr
LNCEL; 0…7s; 1s; -
Where: Qmeas,s & Qmeas,n = RSRP
• The UE shall reselect the new cell, if the following conditions are met:
• 1. The new cell is better ranked than the serving cell during a time interval tReselection
• 2. More than 1 second has elapsed since the UE has camped on the current serving cell
Note:
s – indicates the serving cell
n – indicates the candidate neighbour cell.
R Criterion – Cell Reselection
Intra-frequency Case (2/2)
Qmeas
Rs = Qmeas,s + Qhysts
Rn = Qmeas,n - Qoffsets,n
Rn > Rs =>
„cell reselection“
qHyst
Qmeas,n
LNCEL; 0dB (0)… 24dB (15); -
Rn
Qmeas,s
Qhysts
qOffsetCell
IAFIM; -24 dB (0)… 24 dB (30); - ; 0 dB(15)
Rs
Qoffsets,n
Treselection
tReselEutr
LNCEL; 0…7s; 1s; -
Time
R – Criterion Intra Frequency Parameter
Huawei
Parameter Name
Nokia
Parameter Name
EID
Parameter Name
[CellSel] QRxLevMin
[LNCEL] qrxlevmin
[EUtranCellFDD] qRxLevMin
QRxLevMin Offset
[CellSel]
QRxLevMinOffset
[LNCEL] qRxLevMinOffset
PEMAX
[CellResel] PMax
[LNCEL] pMaxOwnCell
[CellResel] SIntraSearch
[LNCEL] sIntrasearch
[CellResel]
SNonIntraSearch
[LNCEL] sNonIntrsearch
Category
Selection
(S - Criteria)
Parameter
QRxLevMin
sIntraSearch
ReSelection Start
Measurement
sNonIntraSearch
qHyst
ReSelection R-Criteria qOffset Cell
Intra Freq
tReselect Eutran
[CellResel] Qhyst
[EutranIntraFreqNCell]
CellQoffset
[CellResel] TReselEutran
[LNCEL] qHyst
[IAFIM] qOffsetCell
[LNCEL] tReselEutr
[EUtranCellFDD]
qRxLevMinOffset
[EUtranCellFDD]
pMaxServingCell
ZTE
Parameter Name
[EUtranReselection]
selQrxLevMin
[EUtranReselection]
qrxLevMinOfst
Default Value
-124 dBm
0 dB
[EUtranReselection] intraPmax
23 dBm
[SIB3] sIntraSearch
[EUtranReselection]
sIntraSearch
62 dB
[EUtranCellFDD]
systemInformationBlock3_sNonI
ntraSearch
[EUtranReselection]
snonintrasearch
10 (-114 dBm)
[EUtranReselection] qhyst
4 dB
[EUtranRelation] qofStCell
0 dB
[EUtranReselection]
tReselectionIntraEUTRA
2s
[SIB3] qHyst
[EUtranCellRelation]
qOffsetCellEUtran
[EUtranFreqRelation]
tReselectionEutra
R Criterion – Cell Reselection
Inter-frequency Equal Priority Case
• Similar to intra-frequency case
• An additional frequency offset to control the reselection is introduced:
LTE f2
Rs = Qmeas,s + Qhyst
Rn = Qmeas,n – Qoffset
Rn > Rs ⇒“cell reselection“ offset = 0 dB
LTE f1
• Where:
Qmeas,s & Qmeas,n = RSRP
Qoffset = qOffCell,n + Qoffsetfrequency
qOffCell
Cell specific offset
IRFIM; -24..24; 1; - dB
qOffFrq
Frequency specific offset for
equal priority EUTRAN
frequencies
IRFIM; -24..24; 2; 0 dB
LTE f2
offset = -2 dB
LTE f1
R Criterion – Cell Reselection
Reselection to a Higher Priority LTE frequency
• The reselection to a higher absolute priority LTE layer is performed if:
SnonServingCell > Threshx,high
• Where:
interFrqThrH
Threshx,high
IRFIM; 0..62dB; 2dB; -
SnonServingCell = Qrxlevmeas – Qrxlevmin - Pcompensation
qRxLevMinInterF
Min. coverage criteria
• Qrxlevmeas = RSRP of the LTE frequency layer
IRFIM;-140..-44dBm; 2dB; • Qrxlevmin specified by the parameter qRxLevMinInterF
→ Qrxlevmeas(nonServingCell) > qRxLevMinInterF + interFrqThrH
(Assuming Pcompensation = 0)
• The criteria above must be satisfied for a time period equal to
Treselection
interTResEut
Reselection timer
IRFIM; 0..7s; 1s; -
R Criterion – Cell Reselection
Reselection to a Lower Priority LTE frequency
• Reselection to a lower priority LTE Layer is performed if:
interFrqThrL
SservingCell < Thresoldserving,low AND
SNonServingCell > Threshx,low
Threshx,low
IRFIM; 0..62dB; 2dB; -
threshSrvLow
• Which means:
Thresholdserving,low
LNCEL; 0..62dB; 2dB; -
→ Qrxlevmeas(ServingCell) < qRxLevMin + thresholdSrvLow
AND
Qrxlevmeas(NonServingCell) > qRxLevMinInterF + interFreqThrL
(assuming that qRxLevMinOffset is not used and Pcompensation = 0)
qrxlevmin
qRxLevMinInterF
Minimum required RSRP level
Min. coverage criteria
LNCEL; -140…-44dBm; 2dBm; -
IRFIM;-140..-44dBm; 2dB; -
Threshx,high > Threshx,low > Thresserving,low
R – Criterion Parameter
Category
Selection
(S - Criteria)
Parameter
QRxLevMin
QRxLevMin Offset
PEMAX
sIntraSearch
ReSelection Start
Measurement
sNonIntraSearch
qHyst
ReSelection R-Criteria
qOffset Cell
Intra Freq
tReselect Eutran
qOffset Cell
qOffset Freq
Threshold Serving Low
ReSelection R-Criteria
qRxLevMin InterFreq
Inter Freq
InterFreq Thres High
InterFreq Thres Low
tReselect Inter Freq
qRxLevMin utran
ReSelection R-Criteria Utran Thres High
Inter RAT
Utran Thres Low
tReselection Utran
Huawei
Nokia
EID
ZTE
Parameter Name
[CellSel] QRxLevMin
[CellSel]
QRxLevMinOffset
[CellResel] PMax
[CellResel] SIntraSearch
Parameter Name
[LNCEL] qrxlevmin
Parameter Name
[EUtranCellFDD] qRxLevMin
Parameter Name
[EUtranReselection] selQrxLevMin
[LNCEL] qRxLevMinOffset
[EUtranCellFDD] qRxLevMinOffset
[EUtranReselection] qrxLevMinOfst
0 dB
[LNCEL] pMaxOwnCell
[LNCEL] sIntrasearch
[EUtranReselection] intraPmax
[EUtranReselection] sIntraSearch
23 dBm
62 dB
[CellResel]
SNonIntraSearch
[LNCEL] sNonIntrsearch
[EUtranReselection] snonintrasearch
10 (-114 dBm)
[LNCEL] qHyst
[EUtranCellFDD] pMaxServingCell
[SIB3] sIntraSearch
[EUtranCellFDD]
systemInformationBlock3_sNonIntraSea
rch
[SIB3] qHyst
[EUtranReselection] qhyst
4 dB
[IAFIM] qOffsetCell
[EUtranCellRelation] qOffsetCellEUtran
[EUtranRelation] qofStCell
0 dB
[LNCEL] tReselEutr
[EUtranFreqRelation] tReselectionEutra
[EUtranReselection]
tReselectionIntraEUTRA
2s
[IRFIM] qOffCell
[EUtranCellRelation] qOffsetCellEUtran
[EUtranRelation] qofStCell
0 dB
[IRFIM] qOffFrq
[EUtranFreqRelation] qOffsetFreq
[EUtranReselection]
eutranRslPara_qOffsetFreq
[LNCEL] threshSrvLow
[EUtranCellFDD] threshServingLow
[EUtranReselection] threshSvrLow
[IRFIM] qRxLevMinInterF
[EUtranFreqRelation] qRxLevMin
[IRFIM] interFrqThrH
[EUtranFreqRelation] threshXHigh
[IRFIM] interFrqThrL
[EUtranFreqRelation] threshXLow
[IRFIM] interTResEut
[EUtranFreqRelation] tReselectionEutra
[UFFIM] qRxLevMinUtra
[UtranFreqRelation] qRxLevMin
[UFFIM] utraFrqThrH
[UtranFreqRelation] threshXHigh
[UFFIM] utraFrqThrL
[UtranFreqRelation] threshXLow
[CellResel] Qhyst
[EutranIntraFreqNCell]
CellQoffset
[CellResel] TReselEutran
[EutranInterFreqNCell]
CellQoffset
[EutranInterNFreq]
QoffsetFreq
[CellResel]
ThrshServLow
[EutranInterNFreq]
QRxLevMin
[EutranInterNFreq]
ThreshXhigh
[EutranInterNFreq]
ThreshXlow
[EutranInterNFreq]
EutranReselTime
[UtranNFreq]
QRxLevMin
[UtranNFreq]
ThreshXHigh
[UtranNFreq]
ThreshXLow
[UFFIM] tResUtra
[EUtranReselection]
eutranRslPara_interQrxLevMin
[EUtranReselection]
eutranRslPara_interThrdXHigh
[EUtranReselection]
eutranRslPara_interThrdXLow
[EUtranReselection]
eutranRslPara_tReselectionInterEUTRA
[UtranReselectionFDD]
utranRslPara_qRxLevMin
[UtranReselectionFDD]
utranRslPara_threshXHigh
[UtranReselectionFDD]
utranRslPara_threshXLow
Default Value
-124 dBm
-112 dBm
-124 dBm
2s
-115 dBm
Mobility States
Mobility States
• Possible mobility states are: high, medium & normal mobility speed UE’s.
• For faster moving UEs the procedure alters - speed dependent scaling rules are applied.
tEvaluation
• UE state detection:
nCellChgHigh
LNCEL; 1..16; 1; -
LNCEL; 30s (0), 60s (1), 120s
(2), 180s (3), 240s (4) ; -
– If the number of (different cells) cell reselections during the past time period tEvalulation exceeds
nCellChgHigh, high mobility has been detected.
– If the number exceeds nCellChgMed, and not nCellChgHigh, medium mobility has been detected.
– Else Normal Mobility is considered
– REMARK: Mobility could be further applied separately for intra, inter frequency, inter-RAT
scenarios
.
nCellChgMed
LNCEL; 1..16; 1; -
Mobility States
• For High & medium mobility states, cell ranking criteria will be modified to
consider a scaling factor:
qHystSfHigh
LNCEL; -6 dB (0), -4 dB (1),
-2 dB (2), 0 dB (3); -
• High mobility:
•
Multiply Qhyst by "Speed dependent ScalingFactor for Qhyst for high mobility state“ (qHystSfHigh)
•
Multiply tReselection by "Speed dependent ScalingFactor for TreselectionRAT for high mobility state for RAT
cells. (RAT = EUTRAN, UTRAN, GERAN). (celResTiFHM)
celResTiFHM
qHystSfMed
•Medium mobility:
LNCEL; -6 dB (0), -4 dB (1),
-2 dB (2), 0 dB (3); -
LNCEL; 0.25 (0), 0.5 (1),
0.75 (2), 1 (3); -
•
Multiply Qhyst by "Speed dependent ScalingFactor for Qhyst for medium mobility state“ (qHystSfMed)
•
Multiply tReselection by "Speed dependent ScalingFactor for TreselectionRAT for medium mobility state for
RAT cells. (RAT = EUTRAN, UTRAN, GERAN). (celResTiFMM)
celResTiFMM
LNCEL; 0.25 (0), 0.5 (1),
0.75 (2), 1 (3); -
Intra LTE Mobility
Intra Frequency Mobility
Inter Frequency Mobility
Idle Mode Mobility LTE Intra-Frequency (1/4)
•
Broadcast of SIB 4 is optional – no need to broadcast any intrafrequency neighbor cells
– UE is able to complete cell re-selection with SIB3 information
•
eUTRAN SIB4 informs about LTE idle mode neighbors
– Physical Cell Identifier (PCI) of neighbor cell can be broadcast
– cell (neighbor) individual re-select offset can be broadcast
•
SIB4 also informs about blacklisted cells (BC)
– A UE is not allowed to re-select a blacklisted cell
– Up to 16 groups of cells (PCIs) can be blacklisted
– UE will not measure BC cells in connected mode
•
UE will never be instructed from eNB to handover to a blacklisted cell
physCellIdNcl
PCI is a unique cell identification
in a neighboring cell list
IAFIM; 0…503; 1; -
qOffsetCell
IAFIM; -24 dB(0)… 24 dB (30); 0dB (15)
Idle Mode Mobility LTE Intra-Frequency (2/4)
Black Listed Cells –> the feature prohibit UE to camp on group of cells
–
–
–
–
–
–
UE shall not consider Black Listed Cells to camp on
Operator can control Black Cell List
Range of blacklisted cells must be consecutive
Range can be defined with parameter IAFIM: rangeIntraPci
Start of range can be defined with parameter IAFIM: startIntraPci
PCI is Physical Cell Identifier
Black Cell List
startIntraPci
rangeIntraPci
IAFIM; n4 (0), n8 (1), n12 (2), n16
(3), n24 (4), n32 (5), n48 (6), n64
(7), n84 (8), n96 (9), n128 (10),
n168 (11), n252 (12), n504 (13),
Not Used (14) ;-
0
rangeIntraPci
IAFIM; 0…503; 1; -
startIntraPci
PCI Range
503
Idle Mode Mobility LTE Intra-Frequency (3/4)
SIB 4
Parameter structure of IAFIM Object:
– IAFIMId Identifies IAFIM managed object
– intrFrBCList
(structure: 2 parameters)
rangeIntraPCI Indicates the number of PCIs in the range
startIntraPCI Indicates the lowest PCI in the range
– intrFrNCList
x 16
Black Cell
List
(structure: 2 parameters)
x 16
physCellIdNcl The Physical Cell Identifier is a unique cell
identification in a Neighboring Cell List
qOffsetCell The parameter defines a cell-specific offset (in dB)
that is used in the cell reselection procedure.
IAFIM = Intra Frequency Idle Mode Parameters
Idle Mode Mobility LTE Intra-Frequency (4/4)
Neighbor cell list – copy from eNB SCF file
8 PCIs are blacklisted
1 regular intra-frequency neighbors defined
Idle Mode Mobility LTE Inter-Frequency (1/2)
SIB5
IRFIM Object Parameters
• irfimId
8 frequency layers could be defined
• dlCarFrqEut f2 Frequency number
• eutCelResPrio relative cell prio for ranking
x8
• intFrBCList (structure: 2 parameters per neighbor)
– rangeInterPci
– startInterPci
x 16
• intFrNCList (structure: 2 parameters per neighbor)
– physCellIdNcl
– qOffCell
• interFrqThrH
• interFrqThrL
x 16
Idle Mode Mobility LTE Intra-Frequency (2/2)
SIB5
IRFIM Object Parameters
e.g.
interTResEut
• interPresAntP Antenna port 1 used*
• interTResEut
• measBdw
f2 Bandwidth
• pMaxInterF
• qOffFrq
Frequency specific offset
• qRxLevMinInterF minimum coverage criteria
• tResEutSF (structure: 2 parameters)
– eutResTiFHM
– eutResTiFMM
* True ⇒ all neighbor cells are applying at least 2 cell specific Antenna Ports
E-UTRA Cell Reselection Timer
IRFIM; 0 – 7s; 1; -
measBdw
Max. allowed BW for neighbors
IRFIM; 6, 15, 25, 59, 75, 100 mbw; -
pMaxInterF
Pmax to be used in neighb. EUTRA cells on this frequency
IRFIM; -33..33; 1; -
THANK YOU