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1 Lte Eran6.0 Icic Feature Issue 1.00
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www.huawei.com
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
LTE eRAN6.0 ICIC Feature
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Objectives
Upon completion of this course, you will be able to:
Describe basic concepts of ICIC, such as CCU,
CEU, etc.
Describe the ICIC A3/A6 event and related
parameters
Describe downlink and uplink ICIC procedures
Perform enable/disable ICIC functions
Describe the deployment strategy of ICIC
List the main parameters of ICIC
Page3
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page4
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Overview of ICIC
ICIC: Inter Cell Interference Coordination
Function:
Increase the cell edge user experience (throughput)
Increase the cell capacity
Page5
Huawei interference mitigation solutions
Interference Rejection Combining (IRC) :applied at the physical layer
Inter-Cell Interference Coordination (ICIC):applied at the MAC layer
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Types of ICIC
Page6
ICIC
Static ICIC
Dynamic ICIC
ICIC
DL ICIC
UL ICIC
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User
Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page7
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Cell Center User and Cell Edge User (CCU/CEU) identification To implement ICIC, the eNodeB must first identify
CCUs and CEUs correctly.
In the LTE system, UEs in the center of a cell usually
enjoy favorable radio conditions and do not require
ICIC. These UEs are called Cell Center Users (CCUs).
UEs at the edge of a cell, however, are affected by
interference from neighboring cells and therefore
require interference mitigation. These UEs are called
Cell Edge Users (CEUs).
Page8
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Cell Center User and Cell Edge User (CCU/CEU) identification (Cont.) When initially accessing a network, an UE is recognized as
a CCU
After a handover, the UE is recognized as a CEU
After a short period following the initial access or
handover, the eNodeB starts to use event A3 or A6 for ICIC
(referred to as ICIC event A3 or A6) to determine
whether the UEs are CEUs or CCUs.
If an ICIC A3/A6 report contains the measurement about
the serving cell only, the eNodeB treats the UE as a CCU
If an ICIC A3/A6 report contains the measurement result
about at least one neighboring cell, the eNodeB treats the
UE as a CEUPage9
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page10
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Mode Assignment
DL: ICIC operating band = system band of PDSCH
UL: ICIC operating band = system band - PUCCH
band (PUSCH)
The center band is mainly allocated to CCUs, and the
edge band is mainly allocated to CEUs.
Assignment of different edge bands to neighboring
cells must be planned, in Huawei eNodeB as
MODE1, MODE2 and MODE3.
Page11
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
PRB
Edge band mode assignment
Edge band adjustment
CEU/CCU identificationICIC A3 Event
Power Control
MAC Scheduling
Power Control
MAC Scheduling
CEU CCU
Cell #N
PRB
Edge band mode assignment
Edge band adjustment
CEU/CCU identificationICIC A3 Event
Power Control
MAC Scheduling
Power Control
MAC Scheduling
CEU CCU
Cell #2
UE
PRB
Edge band mode assignment
Edge band adjustment
CEU/CCU identificationICIC A3 Event
Cell #1
Power Control
MAC Scheduling
Power Control
MAC Scheduling
CEU CCU
UL/DL grant
Edge Band Mode Assignment (Cont.)
Page12
PRB for edge band
PRB for center band
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Mode Assignment (Cont.)
MODE1 MODE2 MODE3
Page13
MODE3
MODE2
MODE1
PDSCH/PUSCH
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Mode Assignment (Cont.)
Page14
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Mode Assignment (Cont.)
Page15
No ICIC ICIC
f (x)
Pow
e r
edge band
center band-
1.77dB66% of
RS power
0dB
-6dB25% of RS power
-3dB50% of RS power
f (x)
Pow
e r
0dB reference signal
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page16
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
ICIC Event A3/A6 Based on RSRP Measurement
ICIC event A3 is used for reporting RSRP (Reference Signal
Received Power) measurement reports, based on which
DL ICIC and UL ICIC can determines the type of a UE in the
serving cell.
ICIC event A3 is reported in event-triggered periodical
reporting mode.
Entering condition:
Leaving condition:
ICIC event A6 is reported in event-triggered periodical
reporting mode.
Entering condition:
Leaving condition:
ICIC event A3 is reported only if either the entering
condition or leaving condition for ICIC event A3 is met for
a period of time
Page17
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Entering Condition for ICIC Event A3 Entering condition:
Page18
OffOcsOfsMsHysOcnOfnMn
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Leaving Condition for ICIC Event A3 Leaving condition:
Page19
OffOcsOfsMsHysOcnOfnMn
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
More Parameters of ICIC Event A3
Page20
MaxReportCellNum parameter: the maximum number of reported neighboring cells
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Related MML of ICIC Event A3
MOD CELLDLICICMCPARA
Page21
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Related MML of ICIC Event A3 (Cont.) MOD CELLULICICMCPARA
Page22
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
ICIC Event A3 Parameters Setting
A3Offset ↑=> CEU Number ↓
Hysteresis ↑=> probability of Ping-Pong ICIC A3↓
TimeToTrigger ↑ => probability of Ping-Pong ICIC
A3↓
ReportInterval ↑ => frequency of sending
measurement reports ↓ & UE info updated in time ↓
ReportAmount ↑ => UE power consumption ↑ &
CEU throughput improved by dynamic UL ICIC ↑
Note: TriggerQuantity only support RSRP now
Page23
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page24
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Adjustment
If the static ICIC is used, edge bands sizes remain
unchanged and during the higher load, overlapping
PRBs may cause inter-cell interference.
Page25
X X X
Y Y Y Y
Collision
Neighboring cell
Serving cell
X: cell edge PRBs occupied in the neighboring cell
Y: cell edge PRBs occupied in the current cell
cell edge PRBs defined in static ICIC
cell center PRBs defined in static ICIC
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Edge Band Adjustment (Cont.)
Only dynamic ICIC adjusts edge bands.
Page26
X X X
Y Y Y
Neighboring cell
Serving cell
X: cell edge PRBs occupied in the neighboring cell
Y: cell edge PRBs occupied in the current cell
cell edge PRBs defined in static ICIC
cell center PRBs defined in static ICIC
Expanding
Shrinking
Y
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC2.1 Static DL ICIC
2.2 Dynamic DL ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page27
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Static DL ICIC
The major techniques used in Static DL ICIC are DL
band division activated by DlIcicSwitch to
DlIcicStaticSwitch_ON_ENUM value and UE type
determination based on previously explained
techniques.
Page28
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Dynamic DL ICIC
If dynamic DL ICIC is enabled, the eNodeB allocates
an initial DL edge band to each cell based on the cell
bandwidth and edge band mode.
Then, the eNodeB periodically triggers adjustments
of the DL edge band.
Dynamic DL ICIC adjusts DL edge bands for cells
based on the interference and load information
exchanged between the cells.
Page29
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Dynamic DL ICIC (Cont.)
Huawei-defined message includes: ID of the source cell
ID of the target cell
Coordination request indication
Load status of the source cell
Edge band status of the source cell
Page30
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Dynamic DL ICIC (Cont.)
If the edge band of the cell is adjusted, during the
dynamic ICIC procedure, this cell notifies
neighboring cells of this adjustment. Based on this
information neighboring cells either expand or
shrink their edge bands.
Page31
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
DL ICIC Algorithm Switch MML
MOD ENODEBALGOSWITCH
Page32
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC2.1 Static UL ICIC
2.2 Dynamic UL ICIC
8. ICIC Deployment Strategy
Page33
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Static UL ICIC
The major techniques used in Static UL ICIC are DL
band division activated by UlIcicFreqSwitch to
STATIC and UE type determination based on similar
techniques as with DL ICIC.
Page34
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Dynamic UL ICIC
If dynamic UL ICIC is enabled, the eNodeB allocates
an initial UL edge band to each cell based on the cell
bandwidth and edge band mode.
The eNodeB triggers adjustments of the UL edge
band based on the edge band mode and High
Interference Indicator (HII) messages from
neighboring cells, containing:
ID of the source cell:
ID of the target cell:
Interference information
Page35
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Dynamic UL ICIC (Cont.)
If the difference between the PRB number actually
used by CEUs and PRBs reserved for the edge band
is excessively large for a cell, the eNodeB triggers an
edge band adjustment. If the edge band of the cell is
adjusted, the cell transmits the updated HII
messages to its neighboring cells.
Neighboring cells then expand or shrink their edge
bands.
Page36
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
UL ICIC Algorithm Switch MML
MOD ENODEBALGOSWITCH
Page37
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Neighboring Cell List Management Neighboring cell lists for UL ICIC are classified into
two levels: UE level and cell level.
A UE-level neighboring cell list, which records the
information about neighboring cells, is created on the
basis of an RSRP measurement report sent from the
UE. The list is updated on the basis of the
subsequent RSRP measurement reports from the UE.
A cell-level neighboring cell list contains the
information about the interfering cells indicated in
the RSRP measurement reports from all the CEUs in a
cell. Page38
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
OI Message Processing
An OI message provides information that the
average interference caused to all RBs in a cell is
large. It also provides the level of interference
caused to each RB.
An OI message contains the following information:
ID of the source cell
Interference indication
Page39
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Overview of ICIC
2. Cell Center User and Cell Edge User Identification
3. Edge Band Mode Assignment
4. ICIC Event A3/A6
5. Edge Band Adjustment
6. Downlink ICIC
7. Uplink ICIC
8. ICIC Deployment Strategy
Page40
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
DL ICIC Deployment Strategy (1/3) DL ICIC is not recommended if any of the following
situations occurs:
Operators have high requirements for cell capacity but
low requirements for cell coverage.
The total load of cells is high but the edge load is low.
There are only a few UEs in cells, and therefore the
system throughput is low after ICIC is enabled because
of limited power or frequency band.
The system bandwidth is less than 3 MHz.
Page41
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
DL ICIC Deployment Strategy (2/3) When the load of neighboring cells is approximately
balanced and the edge load is relatively low, static
DL ICIC can be used to allocate mutually orthogonal
edge bands to different cells for inter-cell
interference mitigation.
Dynamic DL ICIC can be used when the load of
neighboring cells is not evenly distributed. It adjusts
the edge bands of different cells dynamically and
thus mitigates inter-cell interference.
Page42
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
DL ICIC Deployment Strategy (3/3) When the inter-cell interference is very high and
neither static DL ICIC nor dynamic DL ICIC can
achieve expected ICIC effects, the Reuse3 mode can
be used to allocate mutually orthogonal bands to
different cells for interference mitigation. In this
mode, however, the system capacity decreases
accordingly because only 1/3 of the ICIC operating
band is used in each cell.
Page43
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
UL ICIC Deployment Strategy (1/4) UL ICIC is not recommended if any of the following
situations occurs:
Operators have high requirements for cell capacity but
low requirements for cell coverage.
Cells are not interfered or UEs are insensitive to
interference, for example, most UEs are located in the
cell center.
The edge load of most cells is low, that is, CEUs have a
relatively low RB usage or interference level.
The system bandwidth is 1.4 MHz, and therefore only a
few RBs are available. In this situation, UL ICIC affects
scheduling.Page44
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
UL ICIC Deployment Strategy (2/4) Static UL ICIC is recommended if any of the following
situations occurs:
The load of neighboring cells is approximately
balanced.
Most cells have relatively low edge load, that is, the RB
usage of CEUs is not higher than one third of the
system RB usage.
Page45
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
UL ICIC Deployment Strategy (3/4) Dynamic UL ICIC is recommended if the following
situations occur:
The load of neighboring cells is not balanced.
The RB usage of CEUs in cells with high edge load is
higher than one third of the system RB usage.
The RB usage of CEUs in cells with low edge load is
lower than one third of the system RB usage.
Page46
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
UL ICIC Deployment Strategy (4/4) Time-domain ICIC is applicable to intra-eNodeB cells,
which are time synchronized. If the frequency
resources cannot meet the requirements of CEUs in
intra-eNodeB neighboring cells with heavy edge
load, time-domain UL ICIC can be applied to improve
the effect of UL ICIC.
Page47
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
ICIC Related MML Review
MOD ENODEBALGOSWITCH, switching on/off ICIC
algorithm
MOD CELLDLICICMCPARA, setting DL ICIC A3
parameters
MOD CELLDLICIC, setting DL ICIC band mode
MOD CELLULICICMCPARA, setting UL ICIC A3
parameters
MOD CELLULICIC, setting UL ICIC band mode
Page48
Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.
Summary
The basic concepts of ICIC, such as CCU, CEU, Center
Band, etc.
The ICIC A3/A6 event (entering and leaving) and related
parameters
The downlink and uplink ICIC procedures
The deployment strategy of ICIC
MML to enable/disable ICIC functions
MML to setting ICIC bandmode
MML to seeting ICIC A3/A6 event
Page49
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