256-QAM Downlink Contents 1
Introduction
1.1
Basic Characteristics
1.2
Benefits
1.3
<"Additional Information" optional section>
2
Feature Operation
2.1
Network Requirements
2.2
<"Feature Operation Sequence Diagram" optional section>
2.3
<"Process Steps" optional section>
3
Parameters
3.1
Feature Configuration Parameters
3.2
Affected Parameters
3.3
<"Parameters Affecting the Feature" optional section>
4
Network Impact
4.1
<"Capacity" optional section>
4.2
<"Coverage" optional section>
4.3
<"Mobility" optional section>
4.4
<
optional section>
5
Associated Features and Affected Functions
5.1
Prerequisite Features
5.2
Affected Features
5.3
Affected System Functions
6
Performance
6.1
KPIs
6.2
Counters
6.3
Events
7
O&M Information
7.1
Activate and Deactivate Feature
1 Introduction This document describes the 256-QAM Downlink feature and its main benefits and impacts in the LTE RAN.
1.1 Basic Characteris Characteristics tics
This section describes the basic characteristics of the feature. Feature name:
256-QAM Downlink
Product identity:
DU-based node, see Feature Overview.
Baseband-based node, see Licensed Feature Overview. Replaces:
N/A
Dependencies
This feature requires the following RAN features to be active:
This feature can affect the following RAN features:
1.2 Benefits The feature provides higher users peak rate. The user peak rate (MAC layer) is i ncreased from 150 Mbps to approximately 195 Mbps for a 20 MHz carrier. With carrier aggregation of three 20 MHz carriers, the user peak rate is i ncreased from 450 Mbps to 587 Mbps. For UEs that are not capable of 256-QAM, or UEs that are capable of 256-QAM with low link quality, the user date rate is not impacted. The main benefits of 256-QAM Downlink are:
The user peak rate is increased by about 30% when the 256-QAM capable UE uses a high quality DL link. The 256 QAM HARQ BLER can be calculated from new pm counters. The CQI and rank distributions for 256-QAM capable UEs can be obtained from pm counters.
1.3 <"Additional Information" optional section> More information about this feature and related topics can be found i n the following 3GPP documentation:
TS36.211 TS36.213 TS36.331 TS36.306
2 Feature Operation The 256-QAM Downlink feature supports dynamic switch between two modes:
legacy mode in which 256 QAM is not allowed higher order modulation (HOM) mode in which 256 QAM i s supported
Radio can be configured on a mode to provide good throughput performance for 256-QAM. This feature is supported in:
FDD and TDD TM mode 1, 2, 3 and 4 FDD carrier aggregation (CA), TDD CA, and mixed FDD-TDD CA
2.1 Network Requirements This is a licensed feature. This means that for the feature to be operational, a valid li cense key must be installed and the feature must b e explicitly activated by setting a MOM attribute. See Section 7.1 for more details. The feature can be enabled or disabled through MOM attribute dl256QamEnabled on cell level. The following must be fulfill ed at feature activation:
The license is enabled and activated, AND The attribute dl256QamEnabled is set to TRUE
2.2 <"Feature Operation Sequence Diagram" optional section> 2.3 <"Process Steps" optional section> This section describes the main process steps for the feature flow. 2.3.1
2.3.2
3 Parameters This section describes configuration parameters for the feature and parameters affected by activating the feature.
3.1 Feature Configuration Parameters Table 1 describes the feature parameters.
Table 1
Feature Parameters
Parameter
MO Class
dl256QamEnabled
EUtranCellFDD/ Enable or disable 256 QAM support in DL. EUtranCellTDD
radioTransmitPerformanceMode SectorCarrier dl256QamStatus
Description
A radio transmit operating mode, which is tailored to achieve good throughput.
EUtranCellFDD/ Indication if 256 QAM in DL is supported in the cell. EUtranCellTDD
3.2 Affected Parameters Table 2 describes the parameters affected by the feature. Table 2
Affected Parameters
Parameter
Description
3.3 <"Parameters Affecting the Feature" optional section> Table 3 describes parameters that affect the feature. Table 3
Parameters Affecting the Feature
Parameter
Description
4 Network Impact This section describes how the feature impacts the network functions and capabilities.
4.1 <"Capacity" optional section> This section provides information on the impact of the feature on n etwork capacity.
4.2 <"Coverage" optional section> This section provides information on the impact of the feature on n etwork coverage.
4.3 <"Mobility" optional section> This section provides information on the impact of the feature on mobi lity.
4.4 < optional section> This section provides information about <...>.
5 Associated Features and Affected Functions This section describes how the feature affects other features and functions.
5.1 Prerequisite Features Table 4 lists prerequisite features to the feature, that is, they must be active prior to introducing the feature. Table 4
Prerequisite Features
Feature
Description
5.2 Affected Features Table 5 lists features that are affected by the feature. Table 5
Affected Features
Feature
Description
5.3 Affected System Functions Table 6 lists functions affected by the feature. Table 6
Affected System Functions
Function
Description
6 Performance This section describes performance indicators, counters, and events associated with the feature.
6.1 KPIs Table 7 lists the main Key Performance Indicators (KPIs) associated with the feature. Table 7
KPIs
KPI
Description
6.2 Counters Table 8 lists the counters associated with the 256-QAM Downlink feature. Table 8
Counters
Counter
Description
pmMacHarqDlAck256qam
The total number of successful HARQ transmissions in the DL direction using a 256QAM modulation.
pmMacHarqDlNAck256qam
The total number of unsuccessful HARQ transmissions in the DL direction using a 256QAM modulation.
pmMacHarqDlDtx256qam
The total number of occasions when DL HARQ feedback for a transport block using 256QAM modulation was not received from a UE, and DTX is considered the reason.
pmRadioHomUeRepCqiDistr
The reported CQI value from UEs in higher order modulation (HOM) mode (which supports 256 QAM) in a distribution.PDF ranges:[0]: CQI = 0[1]: CQI = 1[2]: CQI = 2[3]: CQI = 3[4]: CQI = 4[5]: CQI = 5[6]: CQI = 6[7]: CQI = 7[8]: CQI = 8[9]: CQI = 9[10]: CQI = 10[11]: CQI = 11[12]: CQI = 12[13]: CQI = 13[14]: CQI = 14[15]: CQI = 15
pmRadioHomUeRepCqi2Distr
The reported CQI values related to rank 2 transmissions from UEs in higher order modulation (HOM) mode (which supports 256 QAM) in a distribution.PDF ranges:[0]: CQI = 0[1]: CQI = 1[2]: CQI = 2[3]: CQI = 3[4]: CQI = 4[5]: CQI = 5[6]: CQI = 6[7]: CQI = 7[8]: CQI = 8[9]: CQI = 9[10]: CQI = 10[11]: CQI = 11[12]: CQI = 12[13]: CQI = 13[14]: CQI = 14[15]: CQI = 15
pmRadioHomUeRepRankDistr
The reported rank distribution indicates the rank of UEs that are in a Open and Closed Loop Spatial Multiplexing mode (where rank is reported), and are also in higher order modulation (HOM) mode which supports 256 QAM.PDF ranges:[0]: Rank = 1[1]: Rank = 2[2]: Rank = 3[3]: Rank = 4
pmUeCategoryDistr
A distribution of the UE capability parameter UeCategory for established UE contexts.PDF ranges:[0]: ueCategory = 1[1]: ueCategory = 2[2]: ueCategory = 3[3]: ueCategory = 4[4]: ueCategory = 5[5]: ueCategory = 6[6]: ueCategory = 7[7]: ueCategory = 8[8]: ueCategory = 9[9]: ueCategory = 10[10]: ueCategory = 11[11]: ueCategory = 12
More information about counters can be found in Managed Object Model (MOM).
6.3 Events Table 9 lists the events associated with the 256-QAM Downlink feature.
Table 9
Events
Event
Event Parameter
Description
More information about events can be found in PM Event List (DU-based node) or Lists (Baseband-based node).
7 O&M Information This section provides Operation and Maintenance (O&M) information for the feature.
7.1 Activate and Deactivate Feature Activating the feature requires that the corresponding license is installed. When the li cense is installed, an MO instance Dl256Qam is automatically created. Table 10
Feature MO Instance
Node type
MO instance
DU-based node
MO instance is OptionalFeatureLicense= Dl256Qam
Baseband-based node
MO instance is FeatureState= Dl256Qam
Feature activation and deactivation are described in Manage Licenses.
