Load Control
Short Description
Load Control...
Description
WCDMA Load Control www.huawei.com
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Objectives z
Upon completion of this course, you will be able to:
Know the load control principles
Know the load control realization methods in WCDMA system
Know The load control parameters in WCDMA system
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Load Definition z
Load: the occupancy of capacity
z
Two kinds of capacity in CDMA system
Hard capacity
Code channels
Hard ware resource: Transport resource, NodeB processing capability (CE)
Soft capacity
Interference (UL)
Power (DL)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Uplink Load Definition z
Cell Load Factor: ηUL
1 = 1− noise rise
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
RTWP noise rise = PN
Downlink Load Definition Common Measurement in Node B UL Load
Cell Load Factor (based on RTWP) RTWP (Received Total Wideband Power)
Scenario R99 load control
Transmitted carrier power of all codes not used for HS-PDSCH or HS-SCCH
R99 load control
transmission DL Load
Total Carrier Power (TCP)
R99 and HSDPA load control
HS-DSCH Required Power
HSDPA load control
HS-DSCH Provided Bit Rate
HSDPA load control
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
The Objectives of Load Control z
Keeping system stable
z
Maximizing system capacity while ensuring the coverage and QoS
PUC
• LDR • OLC
• CAC • IAC
1. Before UE access 2. During UE access
3. After UE access
PUC: Potential User Control CAC: Call Admission Control IAC: Intelligent Admission Control LDR: Load Reshuffling
OLC: Overload Control
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Time
Load Control Algorithms NodeB transmit power (noise) Icons for different load levels
Cell load OLC starts: to reduce the TFs of BE subscribers, and release some UEs forcibly
No Load control
CAC or IAC: to prevent new calls into cells with heavy load DRD starts: to enable rejected UEs to retry neighboring cells or GSM cells PUC starts: to enable UEs in idle mode to camp on cells with light load LDR starts: to check and release initial congestion in cells
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Load Measurement z
The objectives of LDM (LoaD Measurement)
Measure the system load
Filter the measured data according to the requirement of different load control algorithms
z
Major Measurement Quantities
Uplink Received Total Wideband Power (RTWP)
Downlink Transmitted Carrier Power (TCP)
TCP of all codes not used for HSDPA transmission
Power Requirement for Guaranteed Bit Rate (GBR) on HS-DSCH
Provided Bit Rate (PBR) on HS-DSCH
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDM procedure
z
Smooth Window Filtering on the RNC Side
P ( n) =
N −1
N : the size of the smooth window
i =0
Pn : the reported measurement value
∑ Pn−i N
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDM (1) z
CHOICERPRTUNITFORULBASICMEAS /CHOICERPRTUNITFORDLBASICMEAS (Time unit for UL/DL basic meas rprt cycle)
Value Range: TEN_MSEC, MIN
Recommended value: TEN_MSEC, means the time unit is 10ms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDM (2) z
TENMSECFORULBASICMEAS/TENMSECFORDLBASICMEAS (UL/DL basic meas rprt cycle, Unit:10ms)
z
Value Range: 1~6000
Recommended value: 20, namely 200ms
MINFORULBASICMEAS/MINFORDLBASICMEAS (UL/DL basic meas rprt cycle, Unit: min)
Value Range: 1~60
Recommended value: none
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDM (3) z
ULBASICCOMMMEASFILTERCOEFF / DLBASICCOMMMEASFILTERCOEFF (UL/DL basic common measure filter coeff)
Value Range: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19
Recommended value: D6
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDM (4) z
The parameters for smoothing filter window Value Range
Recommend Value
PucAvgFilterLen
1–32
32
UL LDR moving average filter length
UlLdrAvgFilterLen
1–32
25
DL LDR moving average filter length
DlLdrAvgFilterLen
1–32
25
UL CAC moving average filter length
UlCACAvgFilterLen
1–32
3
DL CAC moving average filter length
DlCACAvgFilterLen
1–32
3
UL OLC moving average filter length
UlOLCAvgFilterLen
1–32
25
DL OLC moving average filter length
DlOLCAvgFilterLen
1–32
25
Parameter Name
Parameter ID
PUC moving average filter length
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for HSDPA LDM (1) z
CHOICERPRTUNITFORHSDPAPWRMEAS (Time unit of HSDPA need pwr meas cycle)
z
Value Range: TEN_MSEC, MIN
Recommended value: TEN_MSEC, means the time unit is 10ms
CHOICERPRTUNITFORHSDPARATEMEAS (Time unit of HSDPA bit rate meas cycle)
Value Range: TEN_MSEC, MIN
Recommended value: TEN_MSEC, means the time unit is 10ms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for HSDPA LDM (2) z
z
TENMSECFORHSDPAPWRMEAS (HSDPA need pwr meas cycle,Unit:10ms)
Value Range: 1~6000
Recommended value: 10, namely 100ms
TENMSECFORHSDPAPRVIDRATEMEAS (HSDPA bit rate meas cycle,Unit:10ms)
Value Range: 1~6000
Recommended value: 10, namely 100ms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for HSDPA LDM (3) z
MINFORHSDPAPWRMEAS (HSDPA need pwr meas cycle, Unit: min)
z
Value Range: 1~60
Recommended value: none
MINFORHSDPAPRVIDRATEMEAS (HSDPA bit rate meas cycle, Unit: min)
Value Range: 1~60
Recommended value: none
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for HSDPA LDM (4) z
z z
HSDPANEEDPWRFILTERLEN (HSDPA need power filter len)
Value Range: 1~32
Recommended value: 1
HSDPAPRVIDBITRATEFILTERLEN (HSDPA bit rate filter len) Value Range: 1~32
Recommended value: 1
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Priority z
The service of user with low priority will be affected by the load control algorithms first
z
Three kinds of priority
User Priority
User Integrate Priority
RAB Integrate Priority
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
User Priority z
There are three levels of user priority (1, 2, and 3)
gold (high), silver (middle) and copper (low) user
User priority
Gold
Silver
Copper
Uplink
128kbps 64kbps 32kbps
Downlink
128kbps 64kbps 32kbps
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gold user
Pay $100 for 3G services
User Priority z
The relationship between user priority and ARP is configurable
The typical relationship as follow:
ARP
1
2
3
4
5
6
7
8
9
10 11 12 13 14
User Priority
1
1
1
1
1
2
2
2
2
2
3
3
3
3
The relationship can be configured through SET USERPRIORITY, and queried through LST USERPRIORITY
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
RAB Integrate Priority z
The values of RAB Integrate Priority are set according to the following parameters
PRIORITYREFERENCE (Integrated Priority Configured Reference)
Value range: ARP, TrafficClass
Recommended value: ARP
CARRIERTYPEPRIORIND (Indicator of Carrier Type Priority)
Value range: DCH, HSDPA
Recommended value: DCH
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Example for RAB Integrate Priority Based on ARP, HSDPA priority is higher Service ARP ID Services attribution in the cell Service ARP ID
Traffic Class
Bear type
A
1
Interactive
DCH
B
1
Interactive
HSDPA
C
2
Conversational
DCH
D
2
Background
DCH
Traffic Class
Bear type
B
1
Interactive
HSDPA
A
1
Interactive
DCH
C
2
Conversational
DCH
D
2
Background
DCH
Based on Traffic Class, HSDPA priority is higher Service ID
Traffic Class
ARP
Bear type
C
Conversational
2
DCH
B
Interactive
1
HSDPA
A
Interactive
1
DCH
D
Background
2
DCH
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
User Integrate Priority z
For multiple-RAB users, the integrate priority of the user is based on the service of the highest priority. User integrate priority is mainly used to select different users during LDR/OLC.
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
PUC Principles Light load Freq1
Modify System Info SIB3,11,12
1.Hard to trigger reselection 2.Easy to camp on the cell Increase the POTENTIAL load
Normal load Stay System Info SIB3,11,12
Heavy load
Freq2 1.Easy to trigger reselection
2.Easy to select light load Inter-freq neighbor Cell
Modify
Decrease the POTENTIAL load
System Info SIB3,11,12
Idle state
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CCH state
PUC Realization z
PUC can modify inter-frequency cell reselection parameters to control the user distribution between cells.
Sintersearch: when the load of a cell is “Heavy”, PUC will increase this parameter; when the load of a cell is “Light”, PUC will decrease this parameter.
QOffset1sn and QOffset2sn: when the load of a cell is “Heavy”, PUC will decrease these parameters; when the load of a cell is “Light”, PUC will increase these parameters.
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for PUC Algorithm Switch z
NBMSWITCH (Cell algorithm switch)
Value Range:
z
PUC
Default status: OFF
PUCPERIODTIMERLEN (PUC period timer length)
Value Range:6s~86400s
Default status: 1800, namely 1800 seconds, i.e. 30 minutes
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for PUC (1) z
z
z
SPUCHEAVY (Load level division threshold 1)
Value Range: 0 to 100%
Recommended value: 70, namely 70%
SPUCLIGHT (Load level division threshold 2)
Value Range: 0 to 100%
Recommended value: 45, namely 45%
SPUCHYST (Load level division hysteresis)
Value Range: 0 to 100%
Recommended value: 5, namely 5%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for PUC (2) z
z
OFFSINTERLIGHT (Sintersearch offset 1)
Value Range: -10 to 10
Physical Value Range: -20 to 20dB, step 2dB
Recommended value: -2, namely -4dB
OFFSINTERHEAVY (Sintersearch offset 2)
Value Range: -10 to 10
Physical Value Range: -20 to 20dB, step 2dB
Recommended value: 2, namely 4dB
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for PUC (3) z
z
OFFQOFFSET1LIGHT (Qoffset1 offset 1)
Value Range: -20 to 20
Physical Value Range: -20 to 20dB, step 1dB
Recommended value: -4, namely -4dB
OFFQOFFSET2LIGHT (Qoffset2 offset 1)
Value Range: -20 to 20
Physical Value Range: -20 to 20dB, step 1dB
Recommended value: -4, namely -4dB
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for PUC (4) z
z
OFFQOFFSET1HEAVY (Qoffset1 offset 2)
Value Range: -20 to 20
Physical Value Range: -20 to 20dB, step 1dB
Recommended value: 4, namely 4dB
OFFQOFFSET2HEAVY (Qoffset2 offset 2)
Value Range: -20 to 20
Physical Value Range: -20 to 20dB, step 1dB
Recommended value: 4, namely 4dB
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Why we need CAC? z
WCDMA is an interference limited system, after a new call is admitted, the system load will be increased
z
If a cell is high loaded, a new call will cause ongoing user dropped
z
We must keep the coverage planed by the Radio Network Planning
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Flow chart of CAC
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CAC Code Resource Admission z
For handover services
The current remaining code resource should be enough for the service
z
For other R99 services
RNC shall ensure the remaining code does not exceed the configurable thresholds after admission of the new service
z
For HSDPA services
The code resource admission is not needed
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Code Resource Admission z
DLHOCECODERESVSF (DL HandOver Credit and Code Reserved SF)
Value Range:0, 1, 2, 3, 4, 5, 6, 7
Physical value Range: SF4, SF8, SF16, SF32, SF128, SF256, SFOFF
Recommended value: SF32
Configuration Rule and Restriction:
[Dl HandOver Credit and Code Reserved SF] >= max ([Dl LDR Credit SF reserved threshold], [Cell LDR SF reserved threshold])
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CAC Power Resource Admission z
Algorithm 1: based on UL/DL load measurement and load prediction (RTWP and TCP)
The algorithm is easy to implement, but it is affected by the result of RTWP and TCP measurement
z
Algorithm 2: based on Element Number of User (ENU)
The algorithm is no need to measure RTWP and TCP, but the calculation is more complex
z
Algorithm 3: loose call admission control algorithm
Similar to algorithm 1, but the prediction of needed power of a new call will be set to zero
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Uplink CAC Algorithm 1 - Load Prediction Admission request
ηUL
Get current RTWP, and calculate the current load factor
Δη
Get the traffic characteristic, and estimate the increment of load factor
ηUL _ predicted = ηUL + Δη
Calculate the predicted load factor
Y
Smaller than the threshold?
admitted
PN = 1− RTWP
N
rejected
End of UL CAC Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Downlink CAC Algorithm 1 - Load Prediction Admission request
P(N )
Get current TCP Get the traffic characteristic, and estimate the increment of TCP
ΔP
P( N ) + ΔP
Calculate the predicted TCP
Y
Smaller than the threshold?
admitted
N
rejected
End of DL CAC Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Uplink and Downlink CAC Algorithm 2 - ENU Admission request Get current total ENU
ENU
Get the traffic characteristic, and estimate the increment of ENU
Smaller than the threshold?
admitted
(N ) =
∑ ENU i =1
i
ENU new
ENU total ( N + 1) = ENU total ( N ) + ENU new
Calculate the predicted ENU
Y
total
N
N
ENULoad = ENU total ( N + 1) / ENU max
rejected
End of UL/DL CAC Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Typical equivalent number of users Service
Equivalent Number of User (ENU) For Already Existing Users
For New Incoming Call
3.4 kbit/s SIG
0.2669
0.4569
13.6 kbit/s SIG
0.4531
1.2131
3.4 + 12.2 kbit/s
0.7662
1.3210
3.4 + 8 kbit/s (PS)
0.5106
0.6325
3.4 + 16 kbit/s (PS)
0.9215
1.0472
3.4 + 32 kbit/s (PS)
2.1319
2.2680
3.4 + 64 kbit/s (PS)
3.2479
3.4188
3.4 + 128 kbit/s (PS)
6.2219
6.4143
3.4 + 144 kbit/s (PS)
6.9731
7.1888
3.4 + 256 kbit/s (PS)
11.2941
11.5245
3.4 + 384 kbit/s (PS)
17.0178
17.1897
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission Algorithm Switch z
NBMULCACALGOSELSWITCH (Uplink CAC algorithm switch)
Value Range:
ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, and ALGORITHM_THIRD
z
NBMDLCACALGOSELSWITCH (Downlink CAC algorithm switch)
Value Range:
ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, and ALGORITHM_THIRD
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Load Prediction (1) z
CELLENVTYPE (Cell environment type)
Value Range:
z
TU: typical urban district
RA: rural area
Default value: TU
BACKGROUNDNOISE (Background noise)
Value Range: 0 to 621
Physical Range: -112 to -50dBm, step: 0.1
Recommended value: 71, namely -105dBm
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HT: hill terrain
Parameters for Load Prediction (2) z
z
ULINTERFACTOR (UL neighbor interference factor )
Value Range: 0 to 200
Physical Range: 0 to 2, step: 0.01
Recommended value: 60, namely 0.6
NONORTHOFACTOR (DL Nonorthogonality factor)
Value Range: 0 to 1000
Physical Range: 0 to 1, step: 0.001
Recommended value: 400, namely 0.4
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (1) z
z
ULCCHLOADFACTOR (UL common channel load factor)
Value range: 0 to 100%
Recommended value: 0, namely 0%
DLCCHLOADRSRVCOEFF (DL common channel load reserved coefficient)
Value range: 0 to 100%
Recommended value: 0, namely 0%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (2) z
z
ULCONVAMRTHD (UL threshold of Conv AMR service)
Value range: 0 to 100%
Recommended value: 75, namely 75%
ULCONVNONAMRTHD (UL threshold of Conv non_AMR service)
Value range: 0 to 100%
Recommended value: 75, namely 75%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (3) z
z
ULOTHERTHD (UL threshold of other services)
Value range: 0 to 100%
Recommended value: 60, namely 60%
ULHOTHD (UL handover access threshold)
Value range: 0 to 100%
Recommended value: 80, namely 80%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (4) z
z
DLCONVAMRTHD (DL threshold of Conv AMR service)
Value range: 0 to 100%
Recommended value: 80, namely 80%
DLCONVNONAMRTHD (DL threshold of Conv non_AMR service)
Value range: 0 to 100%
Recommended value: 80, namely 80%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (5) z
z
DLOTHERTHD (DL threshold of other services)
Value range: 0 to 100%
Recommended value: 75, namely 75%
DLHOTHD (DL handover access threshold)
Value range: 0 to 10%
Recommended value: 85, namely 85%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Power Resource Admission (6) z
z
ULTOTALEQUSERNUM (UL total equivalent user number)
Value range: 1 to 200
Recommended value: 80, namely UL ENUmax = 80
DLTOTALEQUSERNUM (DL total nonhsdpa equivalent user number)
Value range: 1 to 200
Recommended value: 80, namely DL ENUmax = 80
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CAC Credit Resource Admission z
Credit resource admission is similar with code resource admission
z
For handover services
The current remaining credit resource should be enough for the service
z
For other R99 services
RNC shall ensure the remaining code does not exceed the configurable thresholds after admission of the new service
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Credit Resource Admission (1) z
DLHOCECODERESVSF (DL HandOver Credit and Code Reserved SF)
Value Range:0, 1, 2, 3, 4, 5, 6, 7
Physical value Range: SF4, SF8, SF16, SF32, SF128, SF256, SFOFF
Recommended value: SF32
Configuration Rule and Restriction:
[Dl HandOver Credit and Code Reserved SF] >= max ([Dl LDR Credit SF reserved threshold], [Cell LDR SF reserved threshold])
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Credit Resource Admission (2) z
ULHOCERESVSF (Ul HandOver Credit Reserved SF)
Value Range:0, 1, 2, 3, 4, 5, 6, 7
Physical value Range: SF4, SF8, SF16, SF32, SF128, SF256, SFOFF
Recommended value: SF16
Configuration Rule and Restriction:
[Ul HandOver Credit Reserved SF] >= Ul LDR Credit SF reserved threshold
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Why we need IAC? z
z
The disadvantage of CAC:
For PS NRT (Non-Real Time) services, CAC is not flexible
No consideration about the priority of different users
No consideration about Directed Retry after CAC rejection
“Intelligent” means the algorithm can increase admission successful rate
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Flow chart of IAC
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
IAC – Rate negotiation z
Iu QoS Negotiation: based on the UE capability
Maximum allowed bit rate •384kbps
Physical layer capability
Transport channel capability
RLC capability
•256kbps •128kbps z
Initial / Target data rate •64kbps
RAB Downsizing: based on system load
Channelization codes
Iub transmission resources
Radio resources
•32kbps
Scenarios: RAB setup，RAB modify, SRNSR request, reconfiguration Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
IAC – Direct Retry based on service z
Data service can be retry to HSDPA cells for better QoS
Data service Frequency A
CELL2 R99
CELL 1
R99
Frequency B CELL A
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HSDPA
IAC – Preemption z
The user with high priority can preempt the resource of users with low priority
z
Triggering resource for Preemption
Power (or ENU), SF (spreading factor), Iub transmission resource, NodeB CE High priority Preempting resource Low priority
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
IAC – Queuing z
After CAC rejection, UE can wait a moment and queue, then try to admit again
z
Queuing priority: Pqueue = Tmax – Telapsed
Tmax is the maximum time in the queue, default value is 5s
Telapsed is the time has queued
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
IAC – Directed Retry based on Load Balance z
Service will be set up to the cell with lightest load
z
The advantages
Keeping the load of the network balanced
Supporting higher data rate for the user Cell 1 Cell 2
Cell 1 Cell 2
RRC Connection
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
RAB
Parameters for IAC Algorithm Switch (1) z
z
IU_QOS_NEG_SWITCH (Switcher for IU QoS Negotiation)
Value range: 0 (close), 1 (open)
Default value: 0
RAB_DOWNSIZING_SWITCH (RAB Downsizing Switch)
Value range: 0 (close), 1 (open)
Default value: 1
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for IAC Algorithm Switch (2) z
z
PREEMPTALGOSWITCH (Preempt algorithm switch)
Value range: On, Off
Default value: Off
QUEUEALGOSWITCH (Queue algorithm switch)
Value range: On, Off
Default value: Off
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for RAB Downsizing z
ULBETRAFFINITBITRATE (Uplink initial access rates) & DLBETRAFFINITBITRATE (Downlink initial access rates)
Value range: D8, D16, D32, D64, D128, D144, D256, D384, D768, D1024, D1536, D2048
Physical Value range: 8, 16, 32, 64, 128, 144, 256, 384, 768, 1024, 1536, 2048, Unit: kbps
Default value: D64, namely 64kbps
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Queuing (1) z
z
QUEUELEN (Queue length)
Value range: 5 to 20
Recommended value: 10
POLLTIMERLEN (Poll timer length)
Value range: 1 to 6000
Physical value range: 10 to 60000 ms step: 10ms
Recommended value: 50, namely 500 ms
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Queuing (2) z
MAXQUEUETIMELENx (Max queuing time length 1~12)
Value range: 1 to 60s
Recommended value: 5, namely 5 seconds
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for DRD (1) z
DRMAXUMTSNUM (Max inter-frequency direct retry number)
Value range: 0 to 5
Recommended value: 2
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for DRD (2) z
z
R99CSSEPIND (R99 CS separation indicator)
Value range: FALSE (no separation), TRUE (separation)
Recommended value: FALSE
R99PSSEPIND (R99 PS separation indicator)
Value range: FALSE (no separation), TRUE (separation)
Recommended value: FALSE
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Load%
LCC (Load Congestion Control) 100%
Overload state: OLC will be
section A
THOLC
used 1
2
section B
Basic congestion state: LDR
THLDR
will be used section C
Normal state: Permit entry
Times Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR (Load Reshuffling) z
Reasons
When the cell is in basic congestion state, new coming calls could be easily rejected by system
z
z
Purpose
Optimizing cell resource distribution
Decreasing load level, increasing admission successful rate
Triggering of LDR
Power resources, code resource, Iub resources or Iub bandwidth, NodeB Credit resource
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Turn on LDR algorithm switch
LDR Procedure
Mark "current LDR state = uncongested" Start LDM congestion indication report
Mark "current action = first LDR action" Clear "selected" mark of all UE LDR actions Congestion state indication
Wait for congestion indication
Current LDR state = congested?
Inter-freq load handover
Succeed?
N
Y
N Code reshuffling
Succeed?
Y
N BE rate reduction
Succeed?
Y
N Sequence of actions can be configured (current action is taken firstly)
Inter-system handover in CS domain Inter-system handover in CS domain
AMR rate reduction
Succeed?
Y
N Succeed?
Y
Mark "current action = successful action"
N Succeed?
Y
N
QoS renogiation on Iu interface
Succeed?
Y
N MBMS power reduction
Succeed?
Y
N No related action can be found
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Mark "current action = first LDR action"
Wait time for LDR action duration
LDR Actions - Inter-frequency Load Handover z
Target cells
Load difference between current load and the basic congestion trigger threshold of target cell is larger than “UL/DL Inter-freq cell load handover load space threshold”
z
Target users
z
Based on user priority and the current service rate
Result
The load of two cells is lower than the basic congestion trigger threshold
The user with low priority hand over to the “Light load” cells
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - BE Rate Reduction z
Candidate RABs
z
The data rate of BE service is larger than GBR
Target RABs
Rank the candidate RABs by the integrate priority, the low priority RABs reduce BE rate first
z
Result
Cell load is decreased under basic congestion trigger threshold
The BE service rate of low priority RABs is limited in GBR
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - Uncontrolled Real-time QoS Renegotiation z
Target RABs
Rank the candidate RABs by the integrate priority, the service with lowest priority and current data rate higher than GBR will be selected
z
Result
Cell load is decreased under basic congestion trigger threshold
The data rate of low priority service is reduced to GBR
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - Inter-system Handover In the CS/PS Domain z
Target user
Based on the integrate priority, sorting the UEs in descending order. The top CS/PS services are selected GSM cell WCDMA cell
z
Result
Cell load is decreased under basic congestion trigger threshold
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - AMR Rate Reduction z
Target user (downlink e.g.)
Candidate RABs: users accessing the AMR services (conversational) and with the bit rate higher than the GBR
Rank the candidate RABs by the integrate priority, the AMR service with lowest priority will be selected
z
Result
Cell load is decreased under basic congestion trigger threshold
The AMR user with low priority is reduced to low voice rate mode
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - Code Reshuffling z
Purpose
Cell load is decreased under basic congestion trigger threshold
Sufficient code resources can be reserved for subsequent service
SF=4 SF=8
SF=16
7
SF=32 SF=64
C
3 1
2
4
A
5 6
B
SF=128
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LDR Actions - MBMS Power Reduction z
Purpose
The downlink power load can be reduced by lowering power on MBMS traffic channels
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Algorithm Switch z
NBMLdcAlgoSwitch (Cell algorithm switch)
Value Range:
ULLDR, DLLDR, CELL_CODE_LDR, CELL_CREDIT_LDR
Default status: OFF
Most of the LDR actions (except inter-frequency load handover) affect QoS
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Algorithm Priority z
Priority for load reshuffling
Value Range:
IUBLDR(Iub load reshuffling), CREDITLDR(Credit load reshuffling), CODELDR (Code load reshuffling), UULDR (Uu load reshuffling)
Default status:
LdrFirstPri = IUBLDR
LdrSecondPri = CREDITLDR
LdrThirdPri = CODELDR
LdrFourthPri = UULDR
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Triggering of Power Resource (1) z
z
ULLDRTRIGTHD (UL LDR trigger threshold)
Value range: 0 to 100%
Recommended value: 55, namely 55%
ULLDRRELTHD (UL LDR release threshold)
Value range: 0 to 100%
Recommended value: 45, namely 45%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Triggering of Power Resource (2) z
z
DLLDRTRIGTHD (DL LDR trigger threshold)
Value range: 0 to 100%
Recommended value: 70, namely 70%
DLLDRRELTHD (DL LDR release threshold)
Value range: 0 to 100%
Recommended value: 60, namely 60%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Triggering of Code Resource and Credit Resource z
z
CELLLDRSFRESTHD (Cell LDR SF reserved threshold)
Value Range:0, 1, 2, 3, 4, 5, 6, 7
Physical value Range: SF4, SF8, SF16, SF32, SF128, SF256
Recommended value: SF8
UL (DL) LDRCREDITSFRESTHD (UL/DL LDR Credit SF reserved threshold )
Value Range:0, 1, 2, 3, 4, 5, 6, 7
Physical value Range: SF4, SF8, SF16, SF32, SF128, SF256
Recommended value: SF8
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Period z
LDRPERIODTIMERLEN (LDR period timer length)
Value range: 1 to 86400 unit: second
Recommended value: 10, namely 10s
Not less than 8s
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Action Sequence z
UL (DL) LDRFIRSTACTION (UL/DL LDR First action) ~
UL (DL) LDRSIXTHACTION (UL/DL LDR Sixth action)
Value range: NOACT, INTERFREQLDHO, BERATERED, QOSRENEGO, CSINTERRATLDHO, PSINTERRATLDHO, AMRRATERED, MBMSDECPOWER, CODEADJ
Default value: UlLdrFirstAction or DlLdrFirstAction is CODEADJ, UlLdrSecondAction or DlLdrSecondAction is INTERFREQLDHO UlLdrThirdAction or DlLdrThirdAction is BERATERED，the other is NOACT
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Code Reshuffling z
MAXUSERNUMCODEADJ (Max user number of code adjust)
Value range: 1 to 3
Recommended value: 1
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Inter-Frequency Load Handover (1) z
ULINTERFREQHOCELLLOADSPACETHD (UL Inter-freq cell load handover load space threshold)
z
Value range: 0 to 100%
Recommended value: 20, namely 20%
DLINTERFREQHOCELLLOADSPACETHD (DL Inter-freq cell load handover load space threshold)
Value range: 0 to 100%
Recommended value: 20, namely 20%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Inter-Frequency Load Handover (2) z
ULINTERFREQHOBWTHD (UL Inter-freq cell load handover maximum bandwidth)
z
Value range: 0 to 400000bps
Recommended value: 200000, namely 200kbps
DLINTERFREQHOBWTHD (DL Inter-freq cell load handover maximum bandwidth)
Value range: 0 to 400000bps
Recommended value: 200000, namely 200kbps
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for LDR Other Actions z
UL (DL) LDRBERATEREDUCTIONRABNUM, UL (DL) LDRPSRTQOSRENEGRABNUM, UL (DL) LDRCSINTERRATHOUSERNUM, UL (DL) LDRPSINTERRATHOUSERNUM, ULLDRAMRRATEREDUCTIONRABNUM
Value range: 1 to 10
Default value
UL (DL) LDRBERATEREDUCTIONRABNUM:
1
UL (DL) LDRPSRTQOSRENEGRABNUM:
1
UL (DL) LDRCSINTERRATHOUSERNUM:
3
UL (DL) LDRPSINTERRATHOUSERNUM:
1
UL (DL) LDRAMRRATEREDUCTIONRABNUM:
3
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents 1. Load Control Overview 2. Basic Load Control Algorithms 2.1 PUC (Potential User Control) 2.2 CAC (Call Admission Control) 2.3 IAC (Intelligent Admission Control) 2.4 LDR (Load Reshuffling) 2.5 OLC (Overload Control)
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
OLC (Over Load Control) z
Reasons
z
In overload state, system is not stable
Purpose
Ensuring the system stability and making the system back to the normal state as soon as possible
z
Triggering of OLC
Power resources only
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
OLC Procedure
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
OLC Actions - TF Control z
Target user
Rank the candidate users by the integrate priority, the low priority user will be selected
z
Execution
Send the control message to UE (downlink: TF control indication, uplink: Transport format combination control) to restricts the TFC selection
After the congestion is released, the BE service rate will be recovered
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
OLC Actions - Release of Some UEs z
Target user (downlink e.g.)
Rank the candidate users by the integrate priority, the low priority user will be selected
z
Execution
Releasing the service of the selected user
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC Algorithm Switch z
NBMSWITCH (Cell algorithm switch)
Value Range:
ULOLC, DLOLC
Default status: OFF
OLC actions affect QoS heavily
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Triggering of Overload (1) z
z
ULOLCTRIGTHD (UL OLC trigger threshold)
Value range: 0 to 100%
Recommended value: 95, namely 95%
ULOLCRELTHD (UL OLC release threshold)
Value range: 0 to 100%
Recommended value: 85, namely 85%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for Triggering of Overload (2) z
z
DLOLCTRIGTHD (DL OLC trigger threshold)
Value range: 0 to 100%
Recommended value: 95, namely 95%
DLOLCRELTHD (DL OLC release threshold)
Value range: 0 to 100%
Recommended value: 85, namely 85%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (1) z
OLCPERIODTIMERLEN (OLC period timer length)
Value range: 100 to 86400000, unit: ms
Recommended value: 3000, namely 3s
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (2) z
z
ULOLCFTFRSTRCTTIMES (UL OLC fast TF restrict times)
Value range: 0 to 100
Recommended value: 3
DLOLCFTFRSTRCTTIMES (DL OLC fast TF restrict times)
Value range: 0 to 100
Recommended value: 3
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (3) z
z
ULOLCFTFRSTRCTRABNUM (UL OLC fast TF restrict RAB number)
Value range: 1 to 100
Recommended value: 3
DLOLCFTFRSTRCTRABNUM (DL OLC fast TF restrict RAB number)
Value range: 1 to 100
Recommended value: 3
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (4) z
RATERSTRCTCOEF (DL OLC fast TF restrict data rate restrict coefficient)
Value range: 1 to 99%
Recommended value: 68, namely 68%
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (5) z
RATERSTRCTTIMERLEN (DL OLC fast TF restrict data rate restrict timer length)
z
Value range: 1 to 65535, unit: ms
Recommended value: 3000, namely 3s
RATERECOVERTIMERLEN (DL OLC fast TF restrict data rate recover timer length)
Value range: 1 to 65535, unit: ms
Recommended value: 5000, namely 5s
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Parameters for OLC (6) z
z
ULOLCTRAFFRELRABNUM (UL OLC traff release RAB number)
Value range: 0 to 10
Default value: 0
DLOLCTRAFFRELRABNUM (DL OLC traff release RAB number)
Value range: 0 to 10
Default value: 0
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Thank You www.huawei.com
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
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