http://www.linkedin.com/pub/ray-khastur/36/965/b7a
LTE Feature Performance
4G LTE Feature Performance| Page 2
Beam Forming
4G LTE Feature Performance| Page 3
Beamforming Increase Capacity
2R
8T Single &Dual flow adaptive BF
UE
1
2
3
4
S UES
Single-flow BF 11
21
31
41
UE1222
32
42
S2
S1
S1
S2
Single user dual-flow BF
4T Single-flow BF
4T Dual-flow BF
Cell A
Cell B
Cell C
DL 4*2 BF: Single &Dual flow adaptive
DL 2*2 MIMO
15% Increase
Average Throughput Edge-User Throughput
25% Increase
* Based on Huawei system simulation
15% Increase
28% Increase
DL 8*2 BF: Single &Dual flow adaptive
Thro
ugh
pu
t (M
bp
s)
BF with better SINR Benefits
BF significantly improve downlink system throughput and coverage performance and also provide good user experience by offering higher data rates.
4G LTE Feature Performance| Page 4
MIMO & Beamforming Adaptation
Adaptive MIMO
DL Scheme
Open Loop Utilize CSI
SFBC/TM2 SM/TM3 Single layer
/TM7,TM8
Dual layer,MU-BF
/TM8
Low speed move UE High speed move UE
Cell edge Cell center Cell edge Cell center
MIMO mode and Beamforming are adaptive
according to channel condition and users velocity
Scenario of low speed and low channel correlation
Scenario of high speed
4G LTE Feature Performance| Page 5
IRC
4G LTE Feature Performance| Page 6
IRC to reduce UL interference
Gain of 7dB at 10-1 FER in interference limited environment
MMSE: Minimum Mean Square Error IRC: Interference Rejection Combination ICE: Ideal Channel Estimate RCE: Real Channel Estimate MRC: Maximum Ratio Combination IRC: Interference Rejection Combination
Signal Interference
Cell1
Cell2
Cell3
Noise Evaluated antenna 1
antenna 2 Noise
Evaluated
combining
+
=
=
-
-
When Uplink inter-cell interference arise
IRC uses the spatial characteristics of
inter-cell interference.
Consider interference correlation.
Evaluate the power of interference and
remove it.
Enhance Coverage and capacity in interference
limited scenario.
4G LTE Feature Performance| Page 7
Comparison Static ICIC and Dynamic ICIC
4G LTE Feature Performance| Page 8
Inter-Cell Interference Coordination
1
2
3
6
5
7
4 1
2
3
6
5
7
4
Frequency
Cell 1 Power
Frequency
Cell 2,4,6 Power
Frequency
Cell 3,5,7 Power
DL Load DL ICIC Gain (dB) UL ICIC Gain (dB)
100% 2 0.3
70% 1.5 0.2
50% 0.5 0.1
30% 0 0
0% 0 0
Increase the coverage Increase cell edge data rate Link Cell edge 5% user
DL ICIC OFF Benchmark
DL ICIC ON 36.2%
UL ICIC OFF Benchmark
UL ICIC ON 13.9%
ICIC reduces the inter-cell interference, improves cell edge users throughput
4G LTE Feature Performance| Page 9
Content
1 Overview of SFR & ICIC Feature on TD-LTE
2 Coverage Prediction of TD-LTE with SFR
3 Summary
Adaptive ICIC: Improve 30% Cell Edge Throughput
Adaptive ICIC switch on / off
Support cell edge frequency
reuse (1, 1/3, 1/6).
Frequency: reuse=1 Frequency: reuse=3
Cell Edge
Interference
High
Cell edge interference lead
to low throughput
Unique cell edge frequency reuse 6 in telecom
industry
Adaptive ICIC:
Cell Edge
Throughput
Low Cell Edge Interference
Low
Cell Edge
Throughput
30% improved
eCoordinator
4G LTE Feature Performance| Page 11
Content
1 Overview of SFR & ICIC Feature on TD-LTE
2 Coverage Prediction of TD-LTE with ICIC
3 Summary
SINR Coverage with Adaptive ICIC
SINR Coverage without ICIC
Comparison of Implementation ICIC - SINR
In TD-LTE configuration 1x3x1 all sector using same resource carrier, the disadvantage of using single frequency is in the cell edge, end user equipment will deteriorate of signal quality due to UE receive same frequency that will impact as interferer. In this simulation UE using Smartphone in the outdoor case.
Adaptive ICIC is the most powerful feature to minimize interference in the cell edge, this type of SFR will divided BW in 6 style of cell edge. In the center of cell SINR size better than using static ICIC.
SINR Coverage with Static ICIC
SINR Coverage without ICIC
In TD-LTE configuration 1x3x1 all sector using same resource carrier, the disadvantage of using single frequency is in the cell edge, end user equipment will deteriorate of signal quality due to UE receive same frequency that will impact as interferer. In this simulation UE using Smartphone in the outdoor case.
By using SFR (Soft Frequency Reuse), same like FFR (Fractional Frequency Reuse) in WiMAX technology. The Bandwidth divided into 3 style of edge, which 1/3 BW will be used in cell edge then 2/3 BW will be used in the center of cell. This method to minimize interference and improve the cell edge throughput.
Comparison of Implementation ICIC - SINR
Without ICIC With Static ICIC
With Adaptive ICIC
Comparison of Implementation ICIC - SINR (Animation)
Comparison of Implementation ICIC SINR Statistic
There is SINR improvement with using ICIC feature, Adaptive ICIC show the best improvement than Static ICIC
Radio Bearer Coverage with Static ICIC
Radio Bearer Coverage without ICIC
Comparison of Implementation ICIC Radio Bearer
TD-LTE modulation coding scheme without implementing ICIC is much degraded in the cell edge, especially in the inner city. End User in the cell edge will get QPSK as the highest MSC that serving their UE.
After implementing AFP function in U-Net for static ICIC we get better improvement in the cell edge area. Bur on the center of coverage cell radius of MCS 64 QAM will be reduce.
Radio Bearer Coverage with Adaptive ICIC
Radio Bearer Coverage without ICIC
Comparison of Implementation ICIC Radio Bearer
TD-LTE modulation coding scheme without implementing ICIC is much degraded in the cell edge, especially in the inner city. End User in the cell edge will get QPSK as the highest MSC that serving their UE.
After conduct AFP with adaptive ICIC, the cell edge is better than static ICIC. And the cell radius of MCS 64 QAM is more longer than static ICIC.
Comparison of Implementation ICIC Radio Bearer (Animation)
Without ICIC With Static ICIC With Adaptive ICIC
DL Throughput Coverage with Static ICIC
DL Throughput Coverage without ICIC
Comparison of Implementation ICIC DL Throughput
In TD-LTE without activating ICIC, we can see much of area in the inner city with low DL Throughout due to impact of interference from same frequency that receive by UE.
After implementing static ICIC, there are much improvement for DL Throughput than before. End user experience will be increase while interference impact decrease.
DL Throughput Coverage with Adaptive ICIC
DL Throughput Coverage without ICIC
Comparison of Implementation ICIC DL Throughput
In TD-LTE without activating ICIC, we can see much of area in the inner city with low DL Throughout due to impact of interference from same frequency that receive by UE.
After implementing adaptive ICIC, cell edge DL Throughput are better than static ICIC, really recommend to using this feature to manipulate lack of customer BW resource.
Without ICIC
Comparison of Implementation ICIC DL Throughput (Animation)
With Static ICIC With Adaptive ICIC
Comparison of Implementation ICIC DL Throughput Statistic
This graphic show the cumulative of DL Throughput from all coverage, even the cumulative of TD-LTE without ICIC is better, but the this is just focus on center of center of cell coverage. The cell edge throughput is better after implementing of ICIC
4G LTE Feature Performance| Page 23
Content
1 Overview of SFR & ICIC Feature on TD-LTE
2 Coverage Prediction of TD-LTE with SFR
3 Summary
4G LTE Feature Performance| Page 24
Summary
Frequency: reuse=6
eCoordinator
Adaptive frequency reuse pattern selection: The system automatically
selects an appropriate edge frequency allocation pattern for each cell.
The patterns for allocating cell edge frequencies are as follows:
Reuse1, Reuse3, and Resue6. These patterns can be flexibly used in
different scenarios. For example, reuse1 is used in the low interference
scenario, reuse3 is used in medium interference scenario and reuse6
is used in the high interference with mass neighbor cells scenario.
Static ICICcell center use 2/3 bandcell edge use 1/3 bandso, in cell edge, frequency reuse 3, different cell edge use different frequency. Tx power in cell center lower than cell edge Tx power to control interference.
4G LTE Feature Performance| Page 25
Self Optimization Network : ANR
4G LTE Feature Performance| Page 26
ANR Classification
Based on neighbor relations, ANR is classified into intra-RAT ANR and inter-RAT ANR.
Based on the methods of measuring neighboring cells, ANR is classified into event-triggered ANR and fast ANR (also known as periodic ANR).
4G LTE Feature Performance| Page 27
ANR Feature Benefit and influence Benefit
ANR is a self-optimization function. It automatically maintains the integrity and effectiveness of
neighbor cell lists (NCLs) and neighbor relation tables (NRTs) to increase handover success
rates and improve network performance. In addition, ANR does not require manual
intervention, which reduces the costs of network planning and optimization.
Event ANR
Find the missing neighbor cells when handover measurement is reported, handover success rate and
call drop rate can be improved.
Fast ANR
Choose some UE to measure neighbor cells and report periodically, the neighbor cell relations can be
convergent more faster.
4G LTE Feature Performance| Page 28
ANR Feature Benefit and influence Influence
Event ANR
CGI report process will introduces extra delays in handovers of the UEs that meet the handover
conditions.
Fast ANR
In fast ANR processes, UE will report PCI periodically and read CGI when the neighbor cell is unknown.
In intra-frequency scene, periodical PCI reporting does not impact system performance, whereas CGI
reading interrupts UE services.
In inter-frequency and inter-RAT scene, periodical PCI reporting impacts UE throughput, and CGI
reading interrupts UE services.
4G LTE Feature Performance| Page 29
Relation between ANR and others
Intra-RAT ANR
Intra-RAT ANR needs UE to support Long DRX cycle and ANR-related measurement. If
ANR measurements need to be performed, a temporary dedicated DRX cycle needs
to be configured for the UE. During this cycle, the UE obtains the CGIs of neighboring
cells in dormancy periods.
Intra-RAT ANR has an impact on Feature PCI Collision Detection & Self-Optimization.
When neighboring cell information changes because of intra-RAT ANR, PCI conflict
detection is triggered.
Inter-RAT ANR
Inter-RAT ANR needs UE to support Long DRX cycle and ANR-related measurement.
If ANR measurements need to be performed, a temporary dedicated DRX cycle
needs to be configured for the UE.
Relation between ANR and others
4G LTE Feature Performance| Page 30
Intra-RAT Event ANR - Missing Neighbor Detection
By UE Measurement
1. The source eNodeB delivers the intra/inter-frequency measurement configuration to the UE, instructing the UE to measure neighboring cells that work on the frequencies specified in the measurement configuration.
2. The UE detects that the PCI of cell B meets the measurement requirements, and reports the PCI to the source eNodeB.
3. The source eNodeB checks whether its intra-RAT NCL includes the PCI of cell B. If so, the procedure ends. If not, the source eNodeB sends the measurement configuration to the UE, instructing the UE to read the ECGI, tracking area code (TAC), and PLMN ID list of cell B.
4. The source eNodeB allows the UE to read these parameters over the broadcast channel (BCH).
5. The UE reports the obtained parameter values to the source eNodeB.
4G LTE Feature Performance| Page 31
Intra-RAT Event ANR - Missing Neighbor Detection
Source Cell
(Cell A)
Target Cell
(Cell B)
M2000
2.Handover response
1.Handover request
3.Report cell A ECGI
Information query
4.Send info to cell B
By UE UE History Information 1. The source eNodeB sends a Handover Request
message to the target eNodeB including UE
history information.
2. The target eNodeB obtains the UE history
information from the message. If the target
eNodeB detects that the ECGI of the last visited
cell (that is, cell A, the source cell) does not exist
in the NCL of the target cell (cell B), cell A is
considered as a new neighboring cell of cell B.
3. The target eNodeB reports the ECGI of cell A to
the M2000.
4. The M2000 queries the PCI, TAC, and PLMN ID list
of cell A based on the reported ECGI and sends
the parameters to the target eNodeB.
5. The target eNodeB adds cell A to the intra-RAT
NCL of cell B.
4G LTE Feature Performance| Page 32
Inter-RAT Event ANR
1. The source eNodeB delivers the inter-RAT measurement configuration (including target RATs and ARFCNs) to the UE, activates the measurement gap mode, and instructs the UE to measure the neighboring cells that meet the measurement requirements.
2. The UE detects that cell B meets the measurement requirements and reports its scrambling code to cell A. If the NCL of cell A does not include the scrambling code of cell B, the source eNodeB proceeds to the next step.
3. The source eNodeB requests the UE to read the parameters of cell B. If cell B is a GERAN or UTRAN cell, the parameters to
be read are the CGI, location area code (LAC), and routing area code (RAC).
If cell B is a CDMA2000 cell, only the CGI is to be read. 4. The source eNodeB schedules appropriate measurement
gaps to allow the UE to read the CGI and other parameters of cell B over the BCH.
5. The UE reports the CGI and other parameters of cell B to the source eNodeB.
4G LTE Feature Performance| Page 33
Intra & Inter-RAT Fast ANR
In order to reduces the impact of event-triggered UE measurements on handover performance, system supports period measurement.
Period measurement report
4G LTE Feature Performance| Page 34
Intra & Inter-RAT Fast ANR
Periodic UE measurements have a negative impact on the uplink throughput of the network. Therefore, fast ANR restricts the number of concurrent UEs involved in periodic measurements by several mechanisms.
When current UE number involved in fast ANR achieve the threshold, eNodeB stop selecting new UE for fast ANR When the specific UE measurements achieve the threshold, the UE stop fast ANR report
When the total Ue number involved in fast ANR achieve the threshold in the certain period, the eNodeB will get into the state of monitoring or start a new FastAnr Period .
4G LTE Feature Performance| Page 35
Neighbor Relations MaintenanceNRT/NCL Maintenance
Added to NRT / NCL
Period calculation
Adjust the list of NRT
Result analysis
Removed from NRT / NCL
Kept in NRT / NCL
4G LTE Feature Performance| Page 36
Self Optimization Network : CSFB
4G LTE Feature Performance| Page 37
CSFB: Architecture and functionalities
S1-MME
S1-U
S11
E-UTRAN
MME
S-GW
S5
SGSN
HSS/HLR
S6a
S4
S3
S12
Iu-ps
Gb
PDN-GW
SGi
S7
MSC/VLR
A
Iu-cs
Gr
SGs
G/U/L handset
Multi-mode G/U/L
CSFB capable
Support of procedures:
Combined EPS/IMSI
Attach, Update, Detach.
Deriving a VLR number and LAI
from the TAI of the current cell, or
using a default VLR number and LAI.
Maintaining SGs association with
MSC/VLR for EPS/IMSI Attached UE
Triggering paging to eNodeB (when
MSC-S pages the UE)
Initiating IMSI Detach at EPS
Detach
GERAN
UTRAN
Need to be R8 ready
Maintaining SGs
association with MME
Forwarding paging request for CS
domain to the UE.
Directing the UE to the target CS
capable cell. (PS HO/redirection
with or without SIBs).
C/D
PCRF
Rx
Internet / intranet /
Operators & 3rd
Party Applications
Gs
for the mobility
management and
paging procedures
between EPS and
CS domain.
4G LTE Feature Performance| Page 38
CSFB: Mobile Originating call
Page 38
CSFB MO procedure:
A: Voice service request is activated from UE;
B: MME indicates UE fall back to GERAN/UTRAN for voice service via eNodeB, UE sends service request to GERAN/UTRAN; in the mean time,
MME informs GSM/UMTS CS Core to prepare resource;
C: When resource in GSM/UMTS network is allocated, UE falls back to GERAN/UTRAN for voice service; And then UE will initiate the CS voice
call, MCS processes the UEs calling request and sends IAM(Initial Address Message) to CS core.
Phase Flows
A 1.Ext Service Request (CSFB indicator)
B
2.S1 AP Message (CSFB indicator)
3.Optional measurement
4.PS HO or PS redirection
5.eNodeB direct the UE to G/U
C 6. Resource located, UE initiate CS call
7. MSC processes UEs calling(IAM)
NodeB RNC
eNodeB SAE-GW
MSC-VLR
SGs
HSS/HLR
MME
SGSN
1
5
2
3
4
6
UMTS
LTE
1
4
7
Inte
r-syste
m c
han
ge
4G LTE Feature Performance| Page 39
CSFB: Mobile Terminating call
3
NodeB RNC
eNodeB SAE-GW
UMTS
LTE
MSC-VLR
SGs
2
HSS/HLR
Inte
r-syste
m c
han
ge
9
MME
1
SGSN
5 7
2 3
4 6
Phase Flows
A 1.IAM: Initial Address Message
B
2.Paging Request (Domain indicator: CS)
3.Ext Service Request (CSFB indicator)
4.S1AP Message (CSFB indicator)
5.Measurement
6.PS HO or PS Redirection
7.eNodeB direct the UE to G/U
8.Paging Response
C 9.Voice Call establishment
CSFB MT procedure:
A: GSM/UMTS MSC initiates CS paging to the called party (LTE UE), voice service is requested by LTE UE;
B: MME indicates UE fall back to GERAN/UTRAN for voice service via eNodeB, UE sends service request toGERAN/UTRAN; in the mean time,
MME informs GSM/UMTS CS Core to prepare resource;
C: When resource in GSM/UMTS network is allocated, UE falls back to GERAN/UTRAN for voice service;
4G LTE Feature Performance| Page 40
CSFB to UMTS (PS HO)
MMERNCeNodeBUE MSC SGSN
Handover
Command
1. Extended Service Request
(containing a CS Fallback Indicator)
Handover Command
S1-AP Response Message
3. Optional measurement report
4. PS handover preparation phase
5.CS call establishment procedure with LAU or combined RAU/LAU
6.PS handover execution phase
2. S1-AP Message
(containing a CS Fallback Indicator)
MMERNCeNodeBUE MSC SGSN
3. S1-AP message with CS Fallback indicator
2.Extended Service Request
(containing a CS Fallback Indicator)
Service
Request
S-GW
P-GW
Paging
1.Paging Request
4. Subsequent procedure similar to that in a mobile-originated case, with the CS
call establishment procedure replaced with a Paging Response message
MO call MT call
4G LTE Feature Performance| Page 41
CSFB to UMTS (PS RRC Redirection w/o RIM)
MO call (R8: without RIM)
MMERNCeNodeBUE MSC SGSN
2.S1-AP Message with CS Fallback Indicator
1.Extended Service Request
(containing a CS Fallback Indicator)
S1-AP Reponse Message
3.Optional measurement report
5. LAU, combined RAU/LAU, or RAU and LAU
6.CS call establishment procedure
S1 UE context release
4. RRC Connection Release with UTRAN frequency
MMERNCeNodeBUE MSC SGSN
2.S1-AP Message with CS Fallback Indicator
1.Extended Service Request
(containing a CS Fallback Indicator)
S1-AP Reponse Message
3.Optional measurement report
5. LAU, combined RAU/LAU, or RAU and LAU
6.CS call establishment procedure
S1 UE context release
4. RRC Connection Release with UTRAN
frequency\cell id\cell System information
MO call (R9: with RIM)
*MT calls procedure is same.
PS Suspend PS Suspend
4G LTE Feature Performance| Page 42
CSFB to GERAN (PS HO)
MO call MT call MMEBSCeNodeBUE MSC SGSN
Handover
Command
1. Extended Service Request
(containing a CS Fallback Indicator)
Handover Command
S1-AP Response Message
3. Optional measurement report
4a. PS handover preparation phase
4b.Suspend
5.CS call establishment procedure with LAU or combined RAU/LAU
6.PS handover execution phase
S-GW
P-GW
Update
Bearers
2. S1-AP Message
(containing a CS Fallback Indicator)
MMERNCeNodeBUE MSC SGSN
3. S1-AP message with CS Fallback indicator
2.Extended Service Request
(containing a CS Fallback Indicator)
Service
Request
S-GW
P-GW
Paging
1.Paging Request
4. Subsequent procedure similar to that in a mobile-originated case, with the CS
call establishment procedure replaced with a Paging Response message
BSC
In case GERAN or UE cant support DTM (Dual transfer Mode) the PS service will be suspended
4G LTE Feature Performance| Page 43
CSFB to GERAN (PS RRC Redirection w/o RIM)
MMEBSCeNodeBUE MSC SGSN
2.S1-AP Message
(containing a CS Fallback
Indicator)
1.Extended Service Request
(containing a CS Fallback Indicator)
S1-AP Reponse Message
3.Optional measurement report
6.Suspend
5.LAU, combined RAU/LAU, or RAU and LAU
7.CS call establishment procedure
S1 UE context release
4. RRC Connection Release with GERAN frequency group
MMEBSCeNodeBUE MSC SGSN
2.S1-AP Message
(containing a CS Fallback Indicator)
1.Extended Service Request
(containing a CS Fallback Indicator)
S1-AP Reponse Message
3.Optional measurement report
6.Suspend
5.LAU, combined RAU/LAU, or RAU and LAU
7.CS call establishment procedure
S1 UE context release
4. RRC Connection Release with GERAN frequency
group\Cell id\Cell system information
MO call (R8: without RIM) MO call (R9: with RIM)
4G LTE Feature Performance| Page 44
CSFB to GERAN (CCO w/o RIM)
MO call (w/o RIM)
MMEBSCeNodeBUE MSC SGSN
4. MobilityFromEUTRACommand
(CCO optionally with NACC)
2.S1-AP Message
(containing a CS Fallback Indicator)
1.Extended Service Request
(containing a CS Fallback Indicator)
S1-AP Response Message
3.Optional measurement report
7.Suspend
6.LAU, combined RAU/LAU, or RAU and LAU
8.CS call establishment procedure
5. S1 UE context release
In case GERAN or UE cant support DTM (Dual transfer Mode) the PS service will be suspended
4G LTE Feature Performance| Page 45
CSFB to UTRAN: Three mechanisms
R8 PS Handover: base on the
inter-RAT PS handover procedures
R8 PS redirection: RRC release with
redirectedCarrierInfoIE to UE
R9 PS redirection: RRC release with a
carrier frequency and UTRAN cells SIBs
acquired by RIM procedures before CSFB.
4G LTE Feature Performance| Page 46
CSFB to GERAN: Four mechanisms
R8 PS Handover: base on the
inter-RAT PS handover procedures
R8 PS redirection: RRC release with
redirectedCarrierInfoIE to UE
R9 PS redirection: RRC release with a
carrier frequency list and cells SIBs
acquired by RIM procedures before CSFB.
R8 CCO with NACC: HandoverCommand
With target cell and SI
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