C HAPTER 1 C ONTEXT AND R ESEARCH P ROBLEM
1.2. Objetivos de la investigación
Before you start
Restart of the eNB is not required after deactivation of this feature.
The Activation of uplink group hopping (actUlGrpHop) parameter is used to deactivate the feature. Modification of this parameter requires object locking.
Procedure
1 Follow the general procedure described in section Activating and deactivating LTE features using BTS Site Manager.
In Step 3 (Modify the feature-specific eNB configuration settings) of the general procedure, perform the steps described in this procedure.
2 Go to the Radio Network Configuration page.
a) Expand the MRBTS object.
b) Expand the LNBTS object.
c) Select the LNCEL object corresponding to the cell where the LTE801: Group hopping for UL reference signal feature will be deactivated.
d) Set the Activation of uplink group hopping (actUlGrpHop) parameter value to false.
3 Send the parameters to the eNB according to the procedure described in section Activating and deactivating LTE features using BTS Site Manager.
Expected outcome
The LTE801: Group hopping for UL reference signal feature is deactivated in the cell.
4.6 LTE874: CSFB to CDMA/1xRTT for dual RX Ues 4.6.1 Description of LTE874: CSFB to CDMA/1xRTT for dual RX
Ues
Introduction to the feature
The LTE874: CSFB to CDMA/1xRTT for dual RX Ues feature introduces service continuity for CS voice.
4.6.1.1 Benefits
End-user benefits
This feature does not affect the end-user experience.
Operator benefits
This feature benefits the operator by redirecting call setup for voice calls
4.6.1.2 Requirements
Software requirements
The table lists software required for this feature.
Table 23 Software requirements
System release Flexi Multiradio BTS Flexi Multiradio 10 BTS
OMS
RL60 LBTS6.0 LBTS6.0
-UE NetAct MME SAE GW
3GPP R9 UE capabilities NetAct8 EP1 -
-Hardware requirements
This feature requires no new or additional hardware.
4.6.1.3 Functional description
The Flexi Multiradio BTS supports the RRC-release-based Circuit Switched Fallback (CSFB) to CDMA/1xRTT for dual receiver multimode UEs and for single radio UEs emulating dual receiver mode. With the feature, UE supporting dual Rx 1xCSFB stays attached to CDMA/1xRTT network to perform idle mode mobility procedures and to listen paging also while being in RRC-connected state to the LTE network. When voice call is initiated or received on CDMA/1xRTT system by the UE, the eNB releases the RRC connection to allow voice call setup on CDMA.
The eNB indicates with the SIB 8 the related capabilities to the UE.
The following scenarios are supported:
• Mobile-originated CSFB with an Initial context setup (UE in IDLE prior to CSFB)
• Mobile-originated CSFB with a UE context modification (UE in RRC-connected prior to CSFB)
• Mobile-terminated CSFB with an Initial context setup (UE in IDLE prior to CSFB)
• Mobile-terminated CSFB with a UE context modification (UE in RRC-connected prior to CSFB)
• Mobile-originated CSFB with a UE in RRC IDLE
• Mobile-terminated CSFB with a UE in RRC IDLE
The MME triggers in all cases the CSFB procedure at the eNB by sending the IE CS Fallback Indicator within the S1AP:UE Context Modification Request (RRC connected cases) or Initial context setup request (RRC idle cases) message to the eNB. The eNB performs upon the CSFB trigger an RRC connection release without redirect information for UEs.
There is no need for redirect information or measurements as the UE is already attached to CDMA/1xRTT. Towards MME, the eNB will send S1AP: UE context release request with cause value “Redirection towards 1xRTT” (though terminal still gets an RRC release without actual redirection). The eNB indicates within the SIB8 the capability to support dual receiver UEs.
The following performance counters are supported.
The following existing PM counters under LNCEL are updated:
• CS Fallback attempts with redirection via RRC Connection Release (M8016C11)
• CS Fallback attempts (UE in Connected Mode) with redirection via RRC Connection Release (M8016C12)
• CS Fallback attempts for emergency call reason with redirection via RRC Connection Release (M8016C13)
The following existing PM counters under LNCEL are reused:
• UE Context modification attempts (M8000C23)
• UE Context modification failures (M8000C25)
• UE Context modification attempts because of to CS Fallback (M8000C31) The operator can enable/disable the functionality per cell by O&M setting.
Emergency session
The eNB is able to determine whether an Emergency Session is active for the feature LTE874: CSFB to CDMA/1xRTT for dual RX Ues. An Emergency Session is active for a UE if:
• feature LTE874: CSFB to CDMA/1xRTT for dual RX Ues is activated in the eNB (actDualRx1xCsfb)
• AND
– RRC establishment cause for this UE has been set to “emergency” AND the INITIAL UE MESSAGE has not been sent yet
or
– Initial Context Setup Request has been received with “CS Fallback Indicator” =
“CS Fallback High Priority”, RRCConnectionRelease message has not been sent yet and the Initial Context Setup Request is not rejected by the eNB.
or
– UE Context Modification Request has been received with “CS Fallback Indicator”
= “CS Fallback High Priority”, and RRCConnectionRelease message has not been sent yet and the UE Context Modification Request is not rejected by the eNB.
4.6.1.4 System impact
Interdependencies between features
The following features introduce CSFB to GERAN/UTRAN. When LTE874: CSFB to CDMA/1xRTT for dual RX Ues is active, these features need to be deactivated.
• LTE562: CSFB to UTRAN or GSM via redirect
• LTE22: Emergency call handling
• LTE736: CS Fallback to UTRAN
The following features have also impact to LTE874: CSFB to CDMA/1xRTT for dual RX Ues:
• LTE1441: Enhanced CS fallback to CDMA/1xRTT (e1xCSFB)
LTE1441: Enhanced CS fallback to CDMA/1xRTT (e1xCSFB) could be activated parallel with LTE874: CSFB to CDMA/1xRTT for dual RX Ues, eNB will make 1xCSFB decision according to UE capability:
– in case that both LTE874: CSFB to CDMA/1xRTT for dual RX Ues and LTE1441:
Enhanced CS fallback to CDMA/1xRTT (e1xCSFB) are activated, if UE have dual receiver but not support R9 e1xCSFB, then eNB will execute Dual Rx 1xCSFB option; otherwise, the R8/R9 (e)1xCSFB options defined in LTE1441:
Enhanced CS fallback to CDMA/1xRTT (e1xCSFB) are attempted.
– in case that LTE874: CSFB to CDMA/1xRTT for dual RX Ues is deactivated but LTE1441: Enhanced CS fallback to CDMA/1xRTT (e1xCSFB) is activated, the eNB will perform the legacy R8/R9 (e)1xCSFB
• LTE807: Idle mode mobility LTE to CDMA/1xRTT
LTE807: Idle mode mobility LTE to CDMA/1xRTT introduces the broadcast of SIB8.
LTE807: Idle mode mobility LTE to CDMA/1xRTT is not a precondition for LTE874:
CSFB to CDMA/1xRTT for dual RX Ues. SIB8 broadcasting is enabled automatically if LTE874: CSFB to CDMA/1xRTT for dual RX Ues is activated
• LTE426: System time broadcast for SIB8
This feature introduces the CDMA system time support from the GPS timing. The CDMA system time is broadcasted together with other SIB8 parameters. Enabling of LTE874: CSFB to CDMA/1xRTT for dual RX Ues implicitly enables LTE426: System time broadcast for SIB8 automatically.
• LTE1074: Multimedia priority services
LTE1074: Multimedia priority services feature introduces the priority-controlled admission and pre-emption of RRC connections and active UEs as well as paging priority handling. When both LTE874: CSFB to CDMA/1xRTT for dual RX Ues and LTE1074: Multimedia priority services are activated, LTE874: CSFB to CDMA/1xRTT for dual RX Ues will not have any special handling for high priority call except the case of receipt of Initial Context Setup Request/UE Context Modification Request with CS Fallback High Priority indicator, which will be treated as emergency call during 1xCSFB procedure.
• LTE572: IMS emergency sessions
LTE572: IMS emergency sessions introduces IMS emergency session. This feature could be active in parallel with LTE874: CSFB to CDMA/1xRTT for dual RX Ues. But for one specific UE, only LTE572: IMS emergency sessions or LTE874: CSFB to CDMA/1xRTT for dual RX Ues could happen.
In small cell bandwidth (1.4 MHz/3 MHz) configuration, LTE874: CSFB to CDMA/1xRTT for dual RX Ues is supported while other CDMA interworking features are still not supported.
• LTE116: Cell Bandwidth - 3 MHz
• LTE117: Cell Bandwidth - 1.4 MHz
These features can be activated with LTE874: CSFB to CDMA/1xRTT for dual RX Ues in parallel (no feature dependency rule is defined in eNB between these features and LTE874: CSFB to CDMA/1xRTT for dual RX Ues).
• LTE56: Inter RAT handover to WCDMA
• LTE442: Network Assisted Cell Change
• LTE898: TDD inter-RAT handover to TD-SCDMA
• LTE873: SRVCC to GSM
• LTE908: ANR Inter-RAT UTRAN - Fully UE based
For (de-)configuration of SCell RRC Connection Reconfiguration procedures are started without any eNB external triggering event. During such an RRC Reconfiguration no other RRC procedure may be performed to avoid inconsistent configuration in the UE.
Therefore, RRC: RRCConnectionRelease for LTE874: CSFB to CDMA/1xRTT for dual RX Ues might have to be delayed if an SCell addition/release is ongoing.
• LTE1089: Downlink carrier aggregation - 20 MHz
• LTE1558: TDD Downlink carrier aggregation
• LTE1830: TDD downlink carrier aggregation enhancement
Impact on interfaces
This feature impacts interfaces as follows:
• S1–Interface
– S1AP: INITIAL CONTEXT SETUP REQUEST and S1AP: UE CONTEXT MODIFICATION REQUEST -> reuse field “CS Fallback indicator”
• RRC – Interface:
– RRC: UECapabilityInformation -> reuse and newly support EUTRA Capability: rx-Config1xRTT
– RRC: RRCConnectionRelease -> reuse
– RRC: SIB8 -> add csfb-SupportForDualRxUEs support
Impact on network and network element management tools
This feature has no impact on network management or network element management tools.
Impact on system performance and capacity
This feature has no impact on system performance or capacity.
4.6.1.5 LTE874: CSFB to CDMA/1xRTT for dual RX Ues management data
Alarms
There are no alarms related to this feature.
Measurements and counters
The table lists counters which are updated or reused with this feature.
Table 24 Counters
Counter ID Counter name Measurement
M8016C11 CS Fallback attempts via RRC Connection Release
8016 - LTE Inter System Handover (WBTS) M8016C12 CS Fallback attempts (UE in Connected
Mode) via RRC Connection Release
8016 - LTE Inter System Handover (WBTS) M8000C23 UE Context modification attempts 8000 - LTE S1AP (WBTS) M8000C25 UE Context modification failures 8000 - LTE S1AP (WBTS) M8000C31 UE Context modification attempts due to
CS Fallback
8000 - LTE S1AP (WBTS)
Key performance indicators
There are no key performance indicators related to this feature.
Parameters
There is only one new parameters related to this feature.
Table 25 New parameter
Full name Abbreviated name Managed object
Activate CSFB to CDMA 1xRTT for dual Rx UEs
actDualRx1xCsfb LNBTS
The table lists parameters which are updated or reused with this feature.
Table 26 Updated or reused parameters
Full name Abbreviated name Managed object
Activate CS Fallback Via Redirection actCSFBRedir LNBTS
Activate Emergency Call Via Redirection actEmerCallRedir LNBTS
Activate CS Fallback with PS-HO to UTRA
actCsfbPsHoToUtra LNBTS
System Information Scheduling List sibSchedulingList SIB
Table 26 Updated or reused parameters (Cont.)
Full name Abbreviated name Managed object
SIB Type siMessageSibType SIB
Naming attribute of MOC CDFIM cdfimId CDFIM
4.6.1.6 Sales information
Table 27 Sales information
BSW/ASW License control in network element
License control attributes
Activated by default
ASW SW Asset Monitoring No