WCDMA Radio Network Coverage Planning
Objects After completing this course, you should be able to learn :
Content and flow of network planning Uplink budget and the meaning of its elements Downlink budget and the meaning of its elements Coverage enhancement technology
Table of Contents
Chapter 1 WCDMA Network Planning Flow Chapter 2 Uplink Budget Chapter 3 Downlink Budget Chapter 4 Coverage Enhancement Technology Chapter 5 Example ofTraining.huawei.com Link Budget
WCDMA Network Planning Flow
Section 1 Concept of Huawei Radio Network Planning
Section 2 Radio Network Planning Flow
Concept of Huawei Radio Network Planning Minimizing integrated network construction cost Radio network planning construction runs through the entire lifetime of the network. Early planning must consider demands for the subsequent development to reduce integrated network construction cost.
Optimizing profitable service coverage 3G networks feature multiple service. Network resources should be allocated among services. Therefore, it is necessary to determine which service is profitable and its requirements for coverage quality, as well as plan cell radius and coverage schemes. During the early 3G network construction, targeting at high speed data service will waste lots of resources (such as too many sites) because there is no enough services.
Concept of Huawei Radio Network Planning Maximizing resource capacity The capacity of 3G radio networks is mainly restricted by interference. Reasonable parameter planning can reduce interference within and between cells, increase cell capacity and utilize limited resources to the greatest extent. Huawei realize reliable and efficient power control and radio resource management algorithm with a variety of actual test data and advanced simulation means, which are verified in many customer pilots globally. Besides, Huawei accumulates abundant experience.
Optimizing core service quality Core services have an long-term effect on network development. Although they cannot make a profit in the short term, they can attract users and speed up service development, such as high speed data service. Therefore, optimize the quality of core service coverage in areas where it is available so as to present superiority of 3G radio network in service and performance and improve the operator’s brand.
WCDMA Network Planning Flow
Section 1 Concept of Huawei Radio Network Planning
Section 2 Radio Network Planning Flow
Overview of Radio Network Planning Flow
Radio Network Dimension Perform initial planning for future networks at the early project planning. Output the configuration and dimensioning of RAN NEs for early communication of projects and cost estimation in the process of making a contract.
Radio Network Preplanning In the middle-stage project planning, perform farther detailed planning for future networks based on Dimension output to determine more precise network dimensioning and theoretical site location. Output preplanning reports for project communication at the middle stage and cost estimation in the process of signing a contract.
Overview of Radio Network Planning Flow
Radio network cell planning In the later project planning, survey and verify all selected site on the spot to determine cell engineering parameters related to various types of network planning for engineering construction, according to outputs of preplanning. If they are greatly different from preplanning results, it is still required to verify cell parameters setting and planning effects through simulation. The output report is the final radio network planning scheme to guide engineering construction.
Overview of Radio Network Planning Flow Relationship among various flows
Output information
Ÿ Site position ŸEngineering parameters
Output information
Radio network cell planning
Input information
ŸCoverage objectives ŸSearch radius
Input information
ŸTheoretical site ŸSearch radius
Radio network preplanning
ŸDimension result ŸSpare site
Input information ：
ŸBS configuration
Output information ：
Radio network estimation
of network ŸObjectives construction
Ÿ BS numbers
Cost of network
Ÿconstruction
Radio Network Dimension
Radio network Dimension is a simplified analysis of future networks. Purposes: Acquire the network construction dimensioning (including BSs and BS configuration). Acquire construction cycle, economic cost and human resources cost estimation. Methods: Select a proper propagation model, user mobility, distribution behavior, and traffic model. Estimate sites, cells, coverage area and capacity roughly required.
Radio Network Dimension Input
Coverage related Coverage area Coverage probability Capacity related Traffic model Service model User density Quality related QoS requirements GoS requirements Demodulation threshold
Output
Coverage design
Capacity design
System dimensioning Number of sites System configuration Sector structure Number of carriers Cost on network construction Site cost Equipment cost
Radio Network Preplanning
Based on network estimation, network preplanning further determines the following parameters, including BS initial layout, BS theoretical location, BS location , antenna installation (height), network architecture, transmit power, antenna type, mounted height, direction and downtilt, transmit power and orthogonal factor of common and traffic channels, as well as cell scramble.
Coverage range under an unloaded condition
BS
Coverage range under a lightly-loaded condition
Coverage range under a heavily-loaded condition
Radio Network Cell Planning
Cell planning flow Radio network preplanning report
Yes Radio network preplanning report
Noise test
Site survey
2G site or not Site survey report
Noise test report
Output Search Rings
Site list
Site selection
New site or not (name prefix) ） NewSite
No
Yes
N
Obtain spare site
No
Confirm site conditions or not
No
Site survey No
System simulation
Meet design objectives or not
Radio network planning report
Yes
Noise test
Noise test report
Site survey report
Meet site requirements or not
Yes
Review Questions
1. 2. 3. 4.
How many processes are there in radio network planning? What is the concept of Huawei radio network planning? What is radio network preplanning oriented to? What are output from radio network estimation?
Summary
This chapter introduces: Category of radio network planning Concept of Huawei radio network planning Difference between GSM and WCDMA radio network planning Main flows of radio network planning Input and output requirements for radio network preplanning
Table of Contents
Chapter 1 WCDMA Network Planning Flow Chapter 2 Uplink Budget Chapter 3 Downlink Budget Chapter 4 Coverage enhancement Technology Chapter 5 Example of Link Budget Training.huawei.com
Capacity-Coverage-Quality
Relationship among WCDAM capacity, coverage and quality Since the WCDMA system is self-interference, capacity, coverage and quality are closely related. Capacity-coverage – When the design load increases, capacity and interference increase but coverage decrease. Capacity-quality – Improve system capacity by decreasing quality requirements for parts of connections. Coverage-quality – Improve coverage capability by decreasing quality requirements for parts of connections. 容量
质量
覆盖
Coverage Dimension Flow Create link budget
Max. path loss
Obtain cell radius
Min. cell radius
Planning area environment correlation Site capacity Indoor coverage degree Coverage probability Propagation model Equipment performance
Calculate site area Max. site coverage area
Specify area sites Required sites=Planning area/site coverage area
Basic Principle of Uplink Budget NodeB TX
Ga_BS
budget:
Pout_BS Lf_BS
Estimate system Feeder PL
Lc_BS Combined duplexer
Link
L _D
_ PL UL
RX
coverage capacity to acquire the maximum propagation loss the link allowed under a certain communication
Ga_UE UE TX
quality by observing Shadow fading marginMf
Pout_UE
affecting forward and reverse signal
Combined duplexer Body loss
RX
various factors
Lb
Building penetration loss Lp
propagation of the system.
Algorithm Introduction Uplink (Reverse) PL_UL=Pout_UE +Ga_BS+Ga_UE –Lf_BS+Ga_SHO –Mpc– Mf – MI – Lp – Lb – S_BS – PL_DL: downlink maximum propagation loss – Pout_UE: maximum transmit power of BS traffic channel – Lf_BS: feeder loss – Ga_BS: BS antenna gain; Ga_UE: UE antenna gain – Ga_SHO: soft handoff gain – Mpc: fast power control margin – Mf: slow fading margin (related to propagation environment) – MI: interference margin (related to system design capacity) – Lp: penetration loss of building (used when indoor coverage is required) – Lb: body loss – S_BS: sensitivity of the receiver (related to service and multipath conditions)
WCDMA Uplink Budget Elements 1.
Max Power of TCH
13.
2.
Body Loss
3.
Gain of UE Tx Antenna
14.
4.
EIRP
15.
5.
Gain of BS Rx Antenna
16.
6.
Cable Loss
7.
Noise Figure (BS)
8.
EbvsNo Required (BS)
9.
Sensitivity of BS Receiver
10.
UL Cell Loading
11.
Interference Margin
12.
Background Noise Level
17. 18. 19. 20. 21.
Margin for Background Noise SHO Gain over Fast Fading Fast Fading Margin Minimum Signal Strength Required Penetration Loss Std. dev. of Slow Fading Edge coverage Probability Slow Fading Margin SHO Gain over Slow Fading
WCDMA Uplink Budget Elements 1. Max Power of TCH (dBm) The maximum transmit power of the UE on each TCH usually refers to the rated total transmit power. In commercial networks, reasonably set this parameter during link budget, according to specifications on main commercial UEs on the market and operator’s suggestions
Power level of UE （ TS 25.101 v3.7.0 （ 200106 ） 6.2.1 Power Class
Nominal maximum output power
Tolerance
1
+33dBm
+1/-3dB
2
+27dBm
+1/-3dB
3
+24dBm
+1/-3dB
4
+21dBm
+2/-2dB
WCDMA Uplink Budget Elements 2. Body Loss (dB) Body loss for speech services is 3dB. Body loss for data services is 0dB because data services are mainly read and watched and the UE is faraway from the human body.
3. Gain of UE Tx Antenna (dBi) Usually suppose the antenna gain of the UE is 0dBi (receiving and transmitting are the same)
4. EIRP
(dBm)
UE EIRP (dBm) = UE Tx Power (dBm) - Body Loss (dB) + Gain of UE Tx Antenna (dBi)
WCDMA Uplink Budget Elements 5. Gain of BS Rx Antenna (dBi) Kathrein 741794
Kathrein 741790
1710~2170MHz (dual band for DCS and UMTS)
Frequency range
1920~2170MHz
Polarization
Vertical
Gain
11dBi
Polarization
+45○, -45○
HPBW
Vertical: 7○
Gain
18.5dBi
Electrical tilt
Fixed, 0○
HPBW (1920~2170MHz)
Horizontal: 63○ Vertical:6.5○
Dimension (Height)
1387 mm
Electrical tilt
Fixed, 2○
Weight
5kg
Side lobe suppression for 1st side lobe above horizon
>14dB
Front-to-back ratio, copolar
>30dB
Dimension (Height / Width / Depth)
1302 mm / 155 mm / 69 mm
Weight
6.6kg
Frequency range
WCDMA Uplink Budget Elements 6. Cable Loss (dB) Include loss of all feeders and connectors between set top and antenna connector – – – – –
Bottom jumper Connector Cable Top jumper Etc.
Loss except for cable loss is relatively fixed. Suppose the loss of the 0.8dB cable is about 2GHz. – 7/8-inch cable 6.1dB / 100m – 5/4-inch cable 4.5dB / 100m
WCDMA Uplink Budget Elements 7. Noise Figure (dB) Noise figure is an index to evaluate whether noise performance of the amplifier is good. It is expressed by NF and defined as the ratio of input Signal-toNoise ratio (SNR) and output Signal-to-Noise ratio (SNR) of the amplifier. NF
= SNRi / SNRo = (Si / Ni) / (So / No)
Floor noise of the receiver (within each bandwidth): – PN = K×T×BW×NF
= -174 (dBm/Hz) + 10lg(3.84MHz / 1Hz) + NF(dB) = -108 (dBm/3.84MHz) + NF (dB)
WCDMA Uplink Budget Elements 8. EbvsNo Required (dB) It is obtained through link simulation, related to the following factors: – Receive diversity configuration – Multipath channel conditions – Bearer type
9. Sensitivity of BS Receiver (dBm) Sensitivity of Receiver (dBm) = -174 (dBm/Hz) + NF (dB) + 10lg(3.84MHz/1Hz) + EbvsNo required (dB) - 10lg[3.84MHz/Rb(kHz)] = -174 (dBm/Hz) + NF (dB) + 10lg[1000 * Rb (kHz)] + Eb/No (dB)
WCDMA Uplink Budget Elements 10.
Uplink Cell Loading Uplink load factor is an index of cell uplink load level. The higher the load factor is, the greater the uplink interference is. Uplink interference increases to an infinite value and the corresponding capacity is called limit capacity when uplink load nears 10%.
N
N
1
1
UL 1 i L j 1 i
1 1 W 1 1 EbvsNo j R j v j
WCDMA Uplink Budget Elements 11. Uplink Interference Margin (dB)
NoiseRise
I TOT PN
1 N
1 Lj
1 1 UL
1
50% load — 3dB 60% load— 4dB 75% load ---6dB
WCDMA Uplink Budget Elements 12. Background Noise Level (dBm) Source of external electromagnetic interference: – Radio transmitter （ GSM, microwave, radar and TV station…) – Autocar ignition – Lightning – … Relevant reports show that average electromagnetic interference is -104dBm and the standard deviation is 2.9dB in 2GHz frequency band. Estimate interference level of a specific planning area with a noise test.
WCDMA Uplink Budget Elements
13. Margin for Background Noise (dB) Suppose the noise floor of equipment (NodeB or UE) is X dBm and external interference power is Y dBm, external interference margin should be: – Margin for Background Noise = 10log (10^(X /10 )+ 10^(Y /10 )) dBm- X dBm
WCDMA Uplink Budget Elements 14. SHO Gain over Fast Fading (dB) SHO gain consists of the following two parts: – Gain resulting from decreased demands for slow fading margin due to multiple irrelated SHO branches － multi-cell gain – SHO gain over link demodulation performance － macro diversity combining gain SHO gain over fast fading refers to macro diversity combining gain. Obtain this value through simulation and the typical value is 1.5dB.
WCDMA Uplink Budget Elements 15. Fast Fading Margin (dB) In the link budget, the required demodulation performance of the receiver is estimated by the link-level simulation with the assumption of perfect power control. In the actual system, however, introduce imperfect factors to closed loop power control since transmit power at the transmitting end is limited.
Effect of power control margin on uplink demodulation performance: – The simulation result shows: EbvsNo target value set by outer loop power control nears the estimated value under perfect power control when HeadRoom is large. EbvsNo increases gradually with the decrease in power margin. Finally, the corresponding EbvsNo increases by 1dB when power margin decreases by 1dB. It is impossible to guarantee demands for BER/BLER when there is almost no power control performance.
WCDMA Uplink Budget Elements 16. Minimum Signal Strength Required (dBm) Demodulate required signal strength correctly after considering various interference factors and performance deterioration factors － can be understood as the sensitivity of the receiver in the running of actual networks. Minimum Signal Strength Required = Sensitivity of Receiver (dBm) - Gain of Antenna (dBi) + Body Loss (dB) + Interference Margin (dB) + Margin for Background Noise (dB) - SHO Gain over fast fading (dB) + Fast Fading Margin (dB)
WCDMA Uplink Budget Elements 17.
Penetration Loss (dB) Indoor penetration loss is the difference of average signal strength outside the exterior wall close to the building and that on the first floor of the building. Penetration loss is related to the specific building type and reference angle of electric wave. Suppose penetration loss follows logarithmic normal distribution in the link budget, adopt average value and standard deviation of penetration loss (logarithmic value). Realize better indoor coverage adopting specific indoor coverage solutions instead of outdoor BS. During actual commercial network construction, penetration loss margin is uniformly specified by operators to compare planning results of various manufacturers.
WCDMA Uplink Budget Elements 18. Std. dev. of Slow Fading (dB) Calculating standard deviation of indoor slow fading: – Suppose the standard deviation of outdoor path loss and penetration loss is XdB and YdB respectively, the standard deviation of path loss of indoor users is sqrt (X^2 + Y^2 )
WCDMA Uplink Budget Elements 19. Edge coverage Probability If the UE transmit power reaches the largest but path loss still cannot be overcome, this link is disconnected when the lowest received level is realized. For the UE d away from the BS , its link interruption probability is: Pr_ outage( d ) Pr{Pmax _ UE PL( d ) S min } Pr{Pmax _ UE 10 lg(d ) S min } Pr{Pmax _ UE S min 10 lg(d ) } Pr{ ( d ) }
ρ(d) = Pmax_UE – S_min – 10γlg(d) ， it is physically the difference between the average value of path loss of the UE d away the BS and maximum path loss allowed to remain connection. Its average value takes zero and standard deviation takes σ to obey slow fading margin in logarithmic normal distribution.
WCDMA Uplink Budget Elements 20. Slow Fading Margin (dB) Core content: logarithmic normal distribution SF x dnorm x 0
SF_M x pnorm x 0 1 0.9 0.8
0.06
0.7
SF( x 8)
SF_M ( x 8)
0.6
SF( x 10) 0.04
SF_M ( x 10) 0.5
SF( x 12)
SF_M ( x 12) 0.4 0.3
0.02
0.2 0.1
0
30
20
10
0 x
10
20
30
0
20
16
12
8
4
0
4
8
x
Slow Fading Margin (dB) = NORMSINV (Edge Coverage Probability)× Std. dev. of Slow Fading (dB)
12
16
20
WCDMA Uplink Budget Elements 21.
SHO Gain over Slow Fading (dB) As stated in the previous slide, SHO gain consists of the following two parts: – Gain resulting from decreased demands for slow fading margin due to multiple irrelated SHO branches － multi-cell gain – SHO gain over link demodulation performance － macro diversity combining gain
SHO gain over slow fading refers to multi-cell gain. Acquire this value through simulation.
WCDMA Uplink Budget Elements
Summary: cell edge path loss Based on maximum path loss the link allows, calculate mid-value of path loss at the cell edge, considering Slow Fading Margin, SHO gain and Penetration Loss in the case of indoor coverage required to meet a certain edge/area coverage probability. Path Loss (dB) = [ EiRP (dBm) - Minimum Signal Strength Required (dBm) ]- Penetration Loss (dB) - Slow Fading Margin (dB) + SHO Gain over Slow Fading (dB)
Table of Contents
Chapter 1 WCDMA Network Planning Flow Chapter 2 Uplink Budget Chapter 3 Downlink Budget Chapter 4 Coverage Enhancement Technology Chapter 5 Example of Link Budget Training.huawei.com
Basic Principle of Downlink Budget NodeB TX
Ga_BS
budget:
Pout_BS Lc_BS
Lf_BS
Estimate system coverage capacity
Feeder PL
Combined duplexer
Link
L _D
_ PL UL
RX
to acquire the maximum propagation loss the link allowed under a certain communication
Ga_UE UE TX
quality by observing Slow fading margin Mf
Pout_UE
affecting forward and reverse signal
Combined duplexer Body loss Lb RX
various factors
Penetration loss of the buildingLp
propagation of the system.
Algorithm Introduction Downlink (Forward) PL_DL=Pout_BS – Lf_BS+Ga_BS+Ga_UE +Ga_SHO –Mpc– Mf – MI – Lp – Lb – S_UE – – – – – – – – –
PL_DL: downlink maximum propagation loss Pout_BS: maximum transmit power of BS traffic channel Lf_BS: feeder loss Ga_BS: BS antenna gain; Ga_UE: UE antenna gain Ga_SHO: soft handover gain Mpc: fast power control margin Mf: slow fading margin (related to propagation environment) MI: interference margin (related to system design capacity) Lp: penetration loss of the building (used when indoor coverage is required) – Lb: body loss – S_UE: sensitivity of UE receiver (related to service and multipath conditions
WCDMA Downlink Budget Elements 1.
Max Power of TCH
13.
2.
Cable Loss
14.
3.
Gain of BS Tx Antenna
15.
4.
EIRP
16.
5.
Gain of UE Rx Antenna
6.
Body Loss
7.
Noise Figure (UE)
19.
8.
EbvsNo Required (UE)
20.
9.
Sensitivity of UE Receiver
21.
10.
DL Cell Loading
11.
Interference Margin
12.
Background Noise Level
17. 18.
Margin for Background Noise SHO Gain over Fast Fading Fast Fading Margin Minimum Signal Strength Required Penetration Loss Std. dev. of Slow Fading Edge coverage Probability Slow Fading Margin SHO Gain over Slow Fading
WCDMA Downlink Budget Elements
10. Downlink Cell Loading Downlink cell loading can be defined in the following two ways: Define downlink cell loading at the receiving end:
Rj DL 1 j i j EbvsNo j v j W 1 N
It has similar characteristics with uplink cell loading, such as – The higher downlink cell loading is, the greater cell transmit power is and the higher the interference at the receiving end is. – The corresponding capacity is called downlink “limit capacity” when the downlink cell loading reaches 10%. Define downlink cell loading at the transmitting end: ratio between the current cell transmit power and BS maximum transmit power capability In this way, downlink cell loading owns the following characteristics: – The higher downlink cell loading is, the greater the cell transmit power is. In addition, it is related to service type, UE receiver performance, cell size, and BS capability.
WCDMA Downlink Budget Elements
11. Downlink Interference Margin (dB) Downlink interference increases at the UE receiving end : [ ]
I TOTj No j fj P TX0/CL0, j No No N [ j fj ] CL0, n P CCH 1 CIR_Txn 1 DL CL0, j No n1 CL0, j
NoiseRisej
If defining downlink cell load at the transmitting end, the above formula can be simplified as follows: NoiseRise( j ) 1 [ ( j ) f ( j )] DL
Pmax N o CL (0, j )
In link budget tools, select the following typical value for parameters in the above formula: – Orthonormalized factor at the edge of a cell α(j): obtained through simulation, related to environment type and cell radius – Interference factor at the edge of a cell f(j) ： 1.78
Table of Contents
Chapter 1 WCDMA Network Planning Flow Chapter 2 Uplink Budget Chapter 3 Downlink Budget Chapter 4 Coverage Enhancement Technology Chapter 5 Example of Link Budget Training.huawei.com
OTSR
Tx
Rx
Rx
Rx
BB
Capacity of OTSR is close to that of the omnidirectional cells. Therefore, OTSR is applicable to areas requiring small capacity but large coverage at the early stage. Cell radius of OTSR is 1.5 times of that of omnidirectional BS, so sites can be reduced by 40~50%.
Tower Mounted Amplifier
Adopting a TAM (Low Noise Amplifier) can improve uplink receiver sensitivity and strength uplink coverage.
Four-Antenna Receiving Diversity
Relative to two-antenna receive diversity, four-antenna receive diversity can realize lower Eb/No . Gain effect of four-antenna receive diversity is as follows, compared with two-antenna receive diversity.
Area
Channel
Eb/N0 improved
Capacity gain
Coverage gain
Dense urban
TU3
2.4
1.73
1.37
Urban
TU3
2.4
1.73
1.37
Suburban
RA120
2.5
1.77
1.39
Rural
RA120
2.5
1.77
1.39
MUD (Multiuser Detection)
Single cell: Increase capacity by 70 ~ 100%
Multi-cell: Increase capacity by 40~60%
Decrease UE transmit power Decrease transmit power by 2 ~ 3 dB averagedly. Add standby times
SA (Smart Antenna)
SA can improve system capacity and coverage uplink/downlink and decrease requirements for transmitted power. Test results of SA gain are as follows: Downlin Area Uplink k 1x4
2x2
2x4
1x4
Capacity gain
1.85
1.70
3.37
3.54
Coverage gain
1.42
1.35
2.02
2.07
Review Questions
1. 2. 3.
4.
What are main technologies to enhance coverage? What are main technologies to enhance capacity? How much UE transmitted power can be reduced by MUD technology? How many times is the OTSR cell radius than that of the omnidirectional cell?
Table of Contents Chapter 1 WCDMA Network Planning Flow Chapter 2 Uplink Budget Chapter 3 Downlink Budget Chapter 4 Coverage Enhanced Technology Chapter 5 Example of Link Budget Training.huawei.com
Example of Link Budget Analysis scenario setting
Transmitter
Example of Link Budget Receiver
Example of Link Budget Calculating Path Loss
Calculating Cell Radius
Coverage Estimation － Example
Suppose Planning target area is 80km^2 Maximum path loss is 151dB in the case of 50% cell load (3dB). Path loss is reduced to 131dB considering 20dB of penetration loss and slow fading margin. Path loss model is :L ＝ 137 ＋ 35logR dB Therefore, R=0.674 km can be obtained .
Coverage Estimation － Example
Coverage area of the three-sector site is: S ＝ 1.95R^2 ＝ 0.88km^2
The required site numbers are ： N ＝ 80/0.88 ＝ 90
Namely, require 90 sites (270 sectors)
Review Questions
1. 2.
What elements are included in uplink budget? What is the process of coverage estimation?
Summary
This chapter describes Elements in radio uplink budget Effect of each element on cell radius calculation Basis of value of each element Calculation methods for coverage-based site numbers
Thank you
