3.8.4 2445 reference data
3.10 LTE2479: 256QAM in Downlink
Benefits, functionality, system impact, and reference data of the feature.
The LTE2479: 256QAM in Downlink feature introduces 256 quadrature amplitude modulation (QAM) for a dynamic data scheduling in the physical downlink shared channel (PDSCH).
3.10.1 LTE2479 benefits
The LTE2479: 256QAM in Downlink feature provides the following benefits:
• Increased spectral efficiency depending on the 256QAM area probability
• Higher downlink peak rates depending on the user equipment (UE) categories
3.10.2 LTE2479 functional description
If the LTE2479: 256QAM in Downlink feature is enabled in the cell and the user
equipment (UE) is 256QAM-capable, the evolved Node B (eNB) configures the UE and applies a dedicated table for the channel quality indicator (CQI) and the modulation and
coding scheme (MCS) index in downlink (DL) link adaptation. The eNB indicates the applicability of the CQI table to the UE in the reconfiguration procedure in case of an initial context setup (ICS), handover (HO), re-establishment, or addition of a secondary cell (SCell). Reconfiguration to the 256QAM-specific CQI and MCS table requires a transient phase where all data scheduling are done based on the legacy table
(conservative approach) and can impact the data rates. Hybrid automatic repeat request (HARQ) retransmissions use the same transport format and MCS in the initial
transmission to maintain the same transport block size (TBS).
g
Note: In a bad channel quality, the coarser granularity of the 256QAM-specific MCS-to-TBS mapping can reduce data rates and lower the transmission efficiency.The radio frequency (RF) power offset that depends on the hardware variant should be applied to meet the 3GPP error vector magnitude (EVM) requirements for DL 256QAM.
Corresponding RF power offsets are configured via Cell power
reduce (dlCellPwrRed) LNCEL parameter. For more information about the recommended power offset per radio unit, see Flexi Multiradio BTS RF Module and Remote Radio Head Description.
In case of carrier aggregation (CA) scenarios, the applicability of 256QAM is decided on a per-component-carrier (CC) basis and depends on the feature activation and UE capabilities.
3.10.3 LTE2479 system impact
LTE2479: 256QAM in Downlink impact on features, system performance and capacity.
Interdependencies between features
The LTE2479: 256QAM in Downlink feature can be enabled together with the LTE2531:
FDD Downlink Carrier Aggregation 4CC feature to facilitate a downlink peak data rate of up to 780 Mbps.
The LTE2479: 256QAM in Downlink feature impacts the following features:
• LTE1117: LTE MBMS
The 256QAM is not supported for the multimedia broadcast/multicast service (MBMS)-related signaling.
• LTE2275: PCell Swap
The modulation and coding scheme (MCS)-related signaling are updated.
• LTE819: DL Inter-cell Interference Generation
This feature is not included in the operation and maintenance (O&M) consistency check from the simultaneous operation with 256QAM.
Impact on interfaces
The LTE2479: 256QAM in Downlink feature has no impact on interfaces.
Impact on network management tools
The LTE2479: 256QAM in Downlink feature has no impact on network management tools.
Impact on system performance and capacity
The LTE2479: 256QAM in Downlink feature impacts system performance and capacity as follows:
• Increased UE peak throughput
• Increased downlink peak data rates of up to 780 Mbps with 4CC carrier aggregation
3.10.4 LTE2479 reference data
LTE2479: 256QAM in Downlink requirements, measurements and counters, parameters, and sales information.
Requirements
Table 45 LTE2479 hardware and software requirements System Multiradio 10
BTS
Nokia AirScale BTS
Flexi Zone Micro BTS
Flexi Zone Access Point
FDD-LTE 16A Not supported FL16A Not supported Not supported Not supported
Flexi Zone Controller
OMS UE NetAct MME SAE GW
Not supported Support not required
3GPP R12 UE capabilities
NetAct 16.8 Support not required
Measurements and counters
Table 46 New counters introduced by LTE2479
Counter ID Counter name Measurement
M8010C116 UE Reported CQI Level 00 for 256QAM configured UEs
LTE Power and Quality DL
M8010C117 UE Reported CQI Level 01 for 256QAM configured UEs
LTE Power and Quality DL
M8010C118 UE Reported CQI Level 02 for 256QAM configured UEs
LTE Power and Quality DL
M8010C119 UE Reported CQI Level 03 for 256QAM configured UEs
LTE Power and Quality DL
M8010C120 UE Reported CQI Level 04 for 256QAM configured UEs
LTE Power and Quality DL
M8010C121 UE Reported CQI Level 05 for 256QAM configured UEs
LTE Power and Quality DL
M8010C122 UE Reported CQI Level 06 for 256QAM configured UEs
LTE Power and Quality DL
M8010C123 UE Reported CQI Level 07 for 256QAM configured UEs
LTE Power and Quality DL
M8010C124 UE Reported CQI Level 08 for 256QAM configured UEs
LTE Power and Quality DL
Table 46 New counters introduced by LTE2479 (Cont.)
Counter ID Counter name Measurement
M8010C125 UE Reported CQI Level 09 for 256QAM configured UEs
LTE Power and Quality DL
M8010C126 UE Reported CQI Level 10 for 256QAM configured UEs
LTE Power and Quality DL
M8010C127 UE Reported CQI Level 11 for 256QAM configured UEs
LTE Power and Quality DL
M8010C128 UE Reported CQI Level 12 for 256QAM configured UEs
LTE Power and Quality DL
M8010C129 UE Reported CQI Level 13 for 256QAM configured UEs
LTE Power and Quality DL
M8010C130 UE Reported CQI Level 14 for 256QAM configured UEs
LTE Power and Quality DL
M8010C131 UE Reported CQI Level 15 for 256QAM configured UEs
LTE Power and Quality DL
M8011C196 PDSCH transmission using QPSK of 256QAM configured UE
LTE Cell Resource
M8011C197 PDSCH transmission using 16QAM of 256QAM configured UE
LTE Cell Resource
M8011C198 PDSCH transmission using 64QAM of 256QAM configured UE
LTE Cell Resource
M8011C199 PDSCH transmission using 256QAM of 256QAM configured UE
LTE Cell Resource
M8011C200 PDSCH transmission nacks using QPSK of 256QAM configured UE
LTE Cell Resource
M8011C201 PDSCH transmission nacks using 16QAM of 256QAM configured UE
LTE Cell Resource
M8011C202 PDSCH transmission nacks using 64QAM of 256QAM configured UE
LTE Cell Resource
M8011C203 PDSCH transmission nacks using 256QAM of 256QAM configured UE
LTE Cell Resource
M8011C204 Failed PDSCH transmission using QPSK of 256QAM configured UE
LTE Cell Resource
M8011C205 Failed PDSCH transmission using 16QAM of 256QAM configured UE
LTE Cell Resource
M8011C206 Failed PDSCH transmission using 64QAM of 256QAM configured UE
LTE Cell Resource
M8011C207 Failed PDSCH transmission using 256QAM of 256QAM configured UE
LTE Cell Resource
M8012C175 MAC PDU volume PDSCH using QPSK of 256QAM configured UE
LTE Cell Throughput
M8012C176 MAC PDU volume PDSCH using 16QAM of 256QAM configured UE
LTE Cell Throughput
M8012C177 MAC PDU volume PDSCH using 64QAM of 256QAM configured UE
LTE Cell Throughput
Table 46 New counters introduced by LTE2479 (Cont.)
Counter ID Counter name Measurement
M8012C178 MAC PDU volume PDSCH using 256QAM of 256QAM configured UE
LTE Cell Throughput
Key performance indicators
There are no key performance indicators related to the LTE2479: 256QAM in Downlink feature.
Parameters
Table 47 New parameters introduced by LTE2479
Full name Abbreviated name Managed
object Activate modulation scheme DL actModulationSchemeDl LNCEL
Table 48 Existing parameters related to LTE2479
Full name Abbreviated name Managed
object
Initial MCS in downlink iniMcsDl LNCEL
PCell swap configuration pcellSwapConfig LNCEL Threshold for a SCell detected
- bad channel quality
scellBadChQualThr LNCEL
Threshold for a SCell detected - good channel quality
scellGoodChQualThr LNCEL
Threshold for a not detectable Scell
scellNotDetectableThr LNCEL
CQI threshold for fallback to MIMO diversity
mimoOlCqiThD LNCEL
CQI threshold for activation of OL MIMO SM
mimoOlCqiThU LNCEL
CQI threshold for fallback to CL MIMO 1 CW mode
mimoClCqiThD LNCEL
CQI threshold for activation of CL MIMO 2 CW mode
mimoClCqiThU LNCEL
Sales information
Table 49 LTE2479 sales information
Product structure class License control Activated by default Application software (ASW) Pool license No