The LTE3264: Additional PRS Subframe Configurations feature introduces support for additional subframe configurations for the positioning reference signal (PRS)
transmission. The support of location services (LCS) allows to determine the position of a UE within the RAN. The UEs are able to detect the PRS and derive measurements, based on the PRS.
3.15.1 LTE3264 benefits
The LTE3264: Additional PRS Subframe Configurations feature provides the following benefit:
• In markets where customers have a mix of AirScale/FSMF equipment, the observed time difference of arrival (OTDOA) feature runs using positioning reference signal (PRS) transmission on the subframes, thus allowing for a more adaptive and diverse deployment.
3.15.2 LTE3264 functional description
Functional overview
The feature allows Nokia equipment to operate in market regions already committed to sending PRS symbols in predetermined subframes.
The following additional subframe configurations are supported for the PRS transmission:
• FDD (5, 10, 15, and 20 MHz)
7, 14, 27, 47, 67, 87, 107, 127 and 147 with a repetition = 1 and a periodicity of 160 ms. In addition, the 5-MHz cell bandwidth supports a repetition = 2.
• TDD UL/DL configuration 1 (10 and 20 MHz)
49, 69, 129, 149 with a repetition = 1 and a periodicity of 160 ms.
• TDD UL/DL configuration 2 (10 and 20 MHz)
28, 48, 68, 108, 128, 148 with a repetition = 1 and a periodicity of 160 ms.
The UE is informed about the PRS configuration via the LTE positioning protocol (LPP).
The LPP is a protocol defined between the UE and the enhanced serving mobile location centre (E-SMLC). It communicates the PRS settings of the network to the UEs as well as the OTDOA measurements (also called a reference signal time difference (RSTD)) from the UEs to the E-SMLC. The LPP protocol entities are transparent to the eNBs, and the computation of the UE positions is done in the E-SMLC. The operator needs to provide PRS settings of the network and antenna positions of eNBs to the E-SMLC.
3.15.3 LTE3264 system impact
Interdependencies between features
The LTE3264: Additional PRS Subframe Configurations feature is an extension of the LTE495: OTDOA feature.
The LTE3264: Additional PRS Subframe Configurations feature is enabled together with the LTE495: OTDOA.
The LTE3264: Additional PRS Subframe Configurations feature impacts the following features:
• LTE1117: LTE MBMS
The operator has additional choices on where to position the PRS subframes. FDD-specific MBMS subframe patterns now support prsConfigurationIndex parameter values of 7, 14, 27, 47, 67, 87, 107, 127, 147.
• LTE3199: Support for Multiple MBSFN and Synchronization Areas
This feature is a follow-up to the LTE1117: eMBMS feature, in which a cell can support multiple MBSFN areas, and an eNB can provide eMBMS services on multiple carriers.
• LTE3200: Dynamic Allocation of eMBMS Resources
This feature is a follow-up to the LTE1117: eMBMS feature, in which an active number of eMBMS sessions will dynamically adjust the number of eMBMS
subframes allocated. New subframes that can be used for OTDOA must be excepted from MBMS usage.
• LTE1891: eNode B Power Saving – Micro DTX
If the LTE3264: Additional PRS Subframe Configurations feature is activated, micro DTX has to consider that OFDM symbols used for OTDOA are found in different locations.
• LTE2085: SIB Reception with Parallel Measurement Gaps
The list showing the subframe usage for various functions has to be updated.
The current SIB timing allows new PRS locations.
• LTE1987: Downlink Adaptive Closed Loop SU MIMO (4x4)
• LTE1709: Liquid Cell
• LTE1543: 8x2 SU MIMO with TM9
• LTE3128: LTE-M
This feature needs to adapt the pattern of valid subframes.
• LTE2120: TDD SIB Reception with Parallel Measurement Gaps
DL scheduler has to handle the collision between the new PRS configurations and SIB scheduling subframes when LTE2120 is activated.
Impact on interfaces
The LTE3264: Additional PRS Subframe Configurations feature has no impact on interfaces.
Impact on network management tools
The LTE3264: Additional PRS Subframe Configurations feature has no impact on network management tools.
Impact on system performance and capacity
The LTE3264: Additional PRS Subframe Configurations feature has no impact on system performance or capacity.
3.15.4 LTE3264 reference data
Requirements
Table 65 LTE3264 hardware and software requirements System Multiradio 10
BTS
AirScale BTS Flexi Zone Micro BTS
Flexi Zone Access Point
FDD LTE17 not supported FL17 FL17 FL17 FL17
Flexi Zone Controller
OMS UE NetAct MME SAE GW
FL17 - 3GPP R8 UE
capabilities
NetAct 17.2 -
-Alarms
There are no alarms related to the LTE3264: Additional PRS Subframe Configurations feature.
BTS faults and reported alarms
There are no faults related to the LTE3264: Additional PRS Subframe Configurations feature.
Commands
There are no commands related to the LTE3264: Additional PRS Subframe Configurations feature.
Measurements and counters
There are no measurements or counters related to the LTE3264: Additional PRS Subframe Configurations feature.
Key performance indicators
There are no key performance indicators related to the LTE3264: Additional PRS Subframe Configurations feature.
Parameters
Table 66 Existing parameters related to LTE3264
Full name Abbreviated name Managed object
Parent structure
Max phase drifting maxPhaseDrifting BTSSCL
-PRS activation actOtdoa LNCEL
-PRS Tx diversity activation
actPrsTxDiv LNCEL
-PRS bandwidth prsBandwidth LNCEL
-Table 66 Existing parameters related to LTE3264 (Cont.) Full name Abbreviated name Managed
object
Parent structure
PRS configuration index prsConfigurationI ndex
LNCEL
-PRS muting prsMuting LNCEL
-PRS muting info prsMutingInfo LNCEL prsMuting PRS muting info pattern
length
prsMutingInfoPatt ernLen
LNCEL prsMuting
PRS Number of DL frames prsNumDlFrames LNCEL -PRS power boost prsPowerBoost LNCEL -SI window length siWindowLen LNCEL -DRX on duration timer drxOnDuratT LNCEL -Downlink channel
bandwidth
dlChBw LNCEL
-Network synchronization mode
btsSyncMode BTSSCL
-Activate supercell configuration
actSuperCell LNCEL
-Activate liquid cell configuration
actLiquidCell LNCEL
-Activate LPPa support for OTDOA
actLPPaOtdoa LNCEL
-Activate support for MBMS
actMBMS LNCEL
-MBSFN EARFCN mbsfnEarfcn MBSFN
-MBSFN downlink channel bandwidth
mbsfnDlChBw MBSFN
-Activation ETWS support actETWS LNBTS -Activation CMAS support actCMAS LNBTS -Twofold transmission of
SIBs per SI window
sib2xTransmit SIB
-Activate enhanced
inter-cell interference coordination
actEicic LNCEL
-CSI-RS subframe configuration
csiRsSubfrConf LNCEL
-Parameter relationships:
• If btsSyncMode is set to PhaseSync, maxPhaseDrifting must be configured.
• If actOtdoa is set to true:
– siWindowLen must be set appropriately, depending on the individual PRS configuration. For details on appropriate values, see the siWindowLen parameter in Reference documentation.
– configuration of the following parameters is required: prsPowerBoost, prsConfigurationIndex, prsBandwidth, prsNumDlFrames, actPrsTxDiv.
• If numOfTxPorts is set to 1, actPrsTxDiv must be set to false.
If actPrsTxDiv is set to true:
– drxProfile2-drxOnDuratT must be greater than 3.
– drxProfile3-drxOnDuratT must be greater than 3.
• The range of the prsBandwidth parameter depends on dlChBw. For parameter descriptions, see LTE Radio Access Operating
Documentation/Reference/Parameters.
Sales information
Table 67 LTE3264 sales information
Product structure class License control Activated by default Application software (ASW) Pool license No
3.15.5 Activating LTE3264
Before you start
The LTE3264: Additional PRS Subframe Configurations feature is enabled as long as the LTE495: OTDOA feature is enabled.
3.15.6 Deactivating LTE3264
Before you start
The LTE3264: Additional PRS Subframe Configurations feature is deactivated when the LTE495: OTDOA feature is deactivated.