WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-1
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-2
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-3
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-4
Capacity–coverage (typical case: downlink load balance)
Capacity–quality (typical case: lowering BLER through outer loop power control)
Coverage–quality (typical case: lowering the data rate of the connections with
much path loss through AMRC)
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-5
3G radio network planning can be divided into three phases. They are shown in
above figure, and consist of dimensioning, pre-planning and cell planning.
According to the above figure, the output result of radio network dimensioning
stage serves as the input condition of the pre-planning, and the pre-planning is
based on the network dimensioning and also checks the network dimensioning
result. The site quantity can be adjusted according to the pre-planning result in
order to obtain the reasonable sites. If the existing sites are considered in the
selection of theoretical sites during the pre-planning, the pre-planning result will
be more practical, thus facilitating the cell planning.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-6
Radio Network Dimensioning is a simplified analysis for radio network
Dimensioning provides the first and most rapid evaluation of the network element
number as well as the associated capacity of those elements. The target of
dimensioning phase is to estimate the required site density and site configurations
for the area of interest. Dimensioning activities include radio link budget and
coverage analysis, capacity evaluation and final estimation of the amount of
NodeB hardware and E1, cell average throughput and cell edge throughput.
Objective:
To obtain the network scale ( approximate NodeB number and
configuration)
Method:
Select a proper propagation model, traffic model and subscriber
distribution, and then estimate the NodeB number, coverage radius, E1
number per site, cell throughput, cell edge throughput and so on.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-7
The service distribution, traffic density, traffic growth estimates and QoS
requirements are already essential elements in dimensioning phase. Quality is
taken into account here in terms of blocking and coverage probability.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-8
Wireless network dimensioning intends to obtain the approximate UTRAN scale.
Based on the network dimensioning, geography and traffic distribution, the
network is pre-planned in detail by using planning software and digital map.
Based on the network dimensioning and site information, the initially selected
WCDMA site is imported into the planning software, and coverage is estimated by
parameters setting. Then an analysis is made to check whether the coverage of
the system meet the requirements. If necessary, the height and tilt of the antenna
and the NodeB quantity are adjusted to optimize the coverage. And then the
system capacity is analyzed to check whether it meets the requirement.
Implementation parameters, such as antenna type / azimuth / tilt / altitude /
feeder type / length …
Cell parameters, such as transmission power of traffic channel and common
channel, orthogonal factor, primary scrambling code…
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-9
Based on the network dimensioning and site information, the initially selected
WCDMA BS is imported into the planning software, and coverage is estimated by
setting the cell parameters and engineering parameters. Then an analysis is made
to check whether the coverage of the system meet the requirements. Then the
system capacity is analyzed to check whether it meets the requirement. If
necessary, the height and tilt angle of the antenna and the BS quality are adjusted
to optimize the coverage.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-10
These graphs are prediction results of Huawei planning tool: U-Net
For the result of coverage prediction, focus on the distribution of best servers and
pilot level. For the small areas with unqualified level, adjust the azimuth and
down tilt to improve the coverage. For the large areas with weak coverage,
analyze whether the site distance is over large:
If yes, add sites to improve coverage.
If no, check whether the configuration of parameters related to coverage
prediction is correct.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-11
We should consider other factors when we select the backup sites
Commercial factor: rent
Radio propagation factor: situation / height / surrounding /
Implementation factor: space / antenna installation / transmission / power
supply
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-12
Simulation is oriented to simulate the running situation of networks under the
current network configuration so as to facilitate decision-making adjustment.
Now there are two system simulation classes: static simulation and dynamic
simulation.
Static simulation focus on user behavior such as browsing Internet, call. It would
gain the performance of radio network based on “snapshot”.
Dynamic simulation focus on detail of user behavior such as duration and data
rate of browsing. It would gain the performance of radio network based on
analysis of mobile subscribers. But it requires higher precision of e-map.
At present, Static simulation is in common use. Monte Carlo simulation is one
type of static simulation.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-13
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-14
Some UEs or terminals are distributed based on a certain rule (such as random
even distribution) at each “snapshot”
It is required to consider the possibility of multiple connection failure
(uplink/downlink traffic channel maximum transmit power, unavailable channels,
low Ec/Io and uplink/downlink interference
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-15
These graphs are prediction results (based on simulation) of Huawei planning tool:
U-Net
The previous predictions (Coverage by transmitter, Coverage by signal level,
Overlapping zones) are based on coverage, the predictions in this slide are based
on simulation.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-16
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-17
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-18
In the coverage dimensioning, the link is estimated according to elements such as
planned area, network capacity, and equipment performance in order to obtain
the allowed maximum path loss. The maximum cell radius is obtained according
to the radio propagation model and allowed maximum path loss. And then the
site coverage area is calculated. Finally, the site quantity is calculated. Of course,
the site quality is only for the ideal cell status, and some additional sites will be
needed in actual terrain environment.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-19
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-20
Link dimensioning intends to estimate the system coverage by analyzing the
factors of the propagation channels of the uplink signal and downlink signal. It is
the link analysis model.
If the parameters such as transmit signal power, gain and loss of the transmitter
and receiver, and quality threshold of received signal are known or estimated, the
allowed maximum path loss used for ensuring the quality of received signal can
be calculated.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-21
In network planning, the value should be set according to the UE capacity with
lowest power grade in the commercial network of the operator.
Note that it is possible that a UE supporting high-speed uplink data service
(higher than 64kbps) has a higher power grade than a UE supporting only voice
and low-speed data services, for example, power grade 3dBm ~ 24dBm.
With a higher maximum power rating, the maximum path loss is increased accordingly.
This allows the operator to plan cells with a relatively larger coverage.
The UE cable loss, connector loss, and combiner loss are quite negligible, hence a
0 dB loss is assumed here。
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-22
The 0 dBi antenna gain is considered here with respect to the internal antenna of
mobile phones.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-23
The penetration loss is related to building type, incidence angle of
the radio wave and so on. In the link budget, assume that the
penetration loss obey the Log-Normal distribution. The penetration
loss is related to mean value of penetration loss and standard
deviation
When indoor coverage is required to coverage by outdoor macro NodeBs,
building penetration loss needs to be considered. Building penetration loss is
related to such factors as incidence angle of the radio wave, the building
construction (the construction materials and number and size of windows), the
internal building layout and frequency. Building penetration loss is highly
dependent on specific environment and morphology and varies greatly. For
instance, the wall thickness in Siberian tends to be larger than that of Singapore
in order to resist coldness and hence the former’s building penetration loss is
correspondingly larger.
In addition, sometimes vehicular coverage may be required and consequently
vehicular penetration loss also needs to be included in link budget process. typical
vehicular penetration loss is around 8dB.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-24
Antenna gain: It refers to the ratio of the square of the actual field of an antenna
at a point in the space to the square of the field of an ideal radiation unit at the
same point in the space, namely power ratio. It is the gain in the main transmit
direction. In general, the gain is related to the antenna pattern. If the central lobe
is narrow and the back lobe and side lobe are small, the gain is high. If the
transmit direction is centralized, the antenna gain is high. For an omnidirectional
antenna, the gain in all the directions is the same.
Front-to-back ratio: It refers to the ratio of the maximum gain in the principal
direction to the gain in the reverse direction. It describes the directing feature. If
it is high, the directed receive performance of the antenna is high.
Beam width: It refers to the separation angle between the main transmit direction
of the power and the point with 3 dB of transmit power reduced, and the area is
called an antenna lobe. Tilt: It refers to the tilt angle of a directional plate
antennal. It is used to control interference and improve coverage.
Polarization: The vector direction of the electrical field in the direction with the
highest radiation. A dual polarized antenna can provide diversity over a single
antenna, thus saving one antenna.
In general, there are two or more lobes in an antenna pattern. The largest lobe is
the central lobe, and others are side lobes. The separation angle between the two
half-power points of the central lobe is the lobe width of the antenna pattern,
namely, half-power (angle) lobe width. If the central lobe is narrow, the directivity
is high, and the anti-interference capability is high.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-25
Radio propagation in the land mobile channel is characterized by multiple
reflections, diffractions and attenuation of the signal energy. These are caused by
natural obstacles such as buildings, hills, and so on, resulting in so-called multi-
path propagation. Furthermore, with the moving of a mobile station, the signal
amplitude, delay and phase on various transmission paths vary with time and
place. Therefore, the levels of received signals are fluctuating and unstable and
these multi-path signals, if overlaid, will lead to fading i.e. short term fading. The
mid-value field strength of Rayleigh fading has relatively gentle change and is
called “Slow fading” i.e. long term fading. And it conforms to lognormal
distribution.
Long term fading– the variation of signal level is slow and smooth.
Short term fading– the variation of signal level is fast and poignant
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-26
Slow Fading --- Signal levels obey Log-Normal distribution
Propagation models predict only mean values of signal strength , the mean value of
signal strength fluctuates. The deviation of the mean values has a nearly normal
distribution in dB, The variation in mean values is called log-normal fading.
Probability that the real signal strength will exceed the average one on the cell border is
around 50%,for higher than 50% coverage probability an additional margin has to be
introduced. The margin is called slow fading margin.
Slow Fading Margin (SFM) is related with coverage probability in cell edge and standard
deviation of slow fading. The equation is described as following:
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-28
Soft Handover --- handover between different NodeBs
Softer Handover --- handover between cells in a NodeB
SHO gain over slow fading is also known as the Multi-Cell gain because in soft
handover more than 1 branch exists and hence the coverage probability increases
which would result in the decreasing of required slow fading margin.
Suppose that soft handover has 2 branches, and the orthogonality of the two
radio link branches on slow fading is 50%. We can calculate the slow fading
margin required with soft handovers based on the former assumptions, and
compare it with the slow fading margin required without soft handover to get the
SHO gain over slow fading.
SHO gain over slow fading is dependent on the required area coverage probability,
the propagation path loss slope and the STD. The following table gives the
calculated SHO gain over slow fading and the propagation path loss slope equals
to 3.59.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-29
Fast power control
to enhance weak signal caused by Rayleigh fading
to mitigate interference and enhance the capacity
to promote power utilization efficiency
In WCDMA, user signals should be received at the NodeB with equal power all the
time and for downlink the transmitted TCH power should be as small as possible
while maintaining the required Qos. This implies that fast fading are compensated
by the power control algorithm, which requires additional headroom at both UE
and NodeB in order to let UE and NodeB following the power control commands
at cell edge.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-30
Because of the macro diversity combination, the soft handover reduces the
required Eb/No by a single radio link, which results in additional macro diversity
gain.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-31
Interference margin is the required margin in the link budget due to the noise rise
caused by system load (the noise rise due to other subscribers). The higher the
system load is, the larger the interference margin should be.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-32
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-33
If the W=1Hz, Nth=-174dBm/Hz
If the W=200kHz, Nth=-121dBm/200kHz
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-34
Typical noises are: external sky and electric noise, vehicle start-up noise, heat
noise from inside systems, scattered noise of transistor during operation,
intermodulation product of signal and noise.
Noise figure is used for measuring the processing capability of the RF component
for small signals, and is usually defined as: output SNR divided by unit input SNR.
NF
Si
Ni
So
No
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-35
For common services, the bit rate of voice call is 12.2kbps, the bit rate of video
phone is 64kbps, and the highest packet service bit rate is 384kbps(R99). After
the spreading, the chip rate of different service all become 3.84Mcps.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-36
For instance:
Service BLER Channel Model Uplink Eb/N0 Downlink Eb/N0
AMR12.2k 1.00% TU3 5.4dB 7.8 dB
RA120 4.5 dB 8.3 dB
CS64k 0.10% TU3 2.8 dB 6.3 dB
RA120 2.8 dB 6.8 dB
CS64k 1.00% TU3 2.5 dB 5.4 dB
RA120 2.3 dB 6 dB
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-37
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-38
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-39
In case of multi-path propagation, certain energy will be detected by the
RAKE receiver, and become interference signals. We define the orthogonal
factor to describe this phenomenon. It is obtained through simulation, and
related to environment type and cell radius.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-40
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-41
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-42
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-43
Continuous coverage target service requirement with specific coverage probability
should be given for R99
Cell edge throughput requirement with specific coverage requirement should be
given for HSDPA
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-44
The cell total transmit power is the constant resources. The DL power consists of
the following three parts:
Power of the HSPA DL physical channel (HS-PDSCH, and HS-SCCH)
Common channel power
DPCH power
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-45
Fast power control
For R99, power control margin should be considered
For HSDPA, the maximum transmission power for HS-PDSCH is the
remaining power excluding R99 power and power margin, and no power
control margin
SHO gain
For R99, SHO gain should be considered
For HSDPA, only hard handover, no SHO gain
HSDPA related parameters should be configured when simulation
Max number of HS-PDSCH channel
Min number of HS-PDSCH channel
HSDPA power allocation, dynamic or fixed
HS-SCCH power allocation, dynamic or fixed
Max number of HSDPA users
Scheduling Algorithm
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-46
Single carrier for HSDPA and R99
Advantages
Maximum resource utilization efficiency
Save cost
Disadvantages
Handover between HSDPA cell and R99 cell
Two carriers for HSDPA and R99
Advantages
Fewer inter-frequency handover for HSDPA user
Disadvantages
High cost
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-47
If operator wants to upgrade HSDPA from R99, R99 should be met first, and
HSDPA should not affect the R99.
If operator setups R99 and HSDPA directly, R99 and HSDPA requirement should
be met at the same time.
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-48
DL Coupling Loss :
PL_DL: Downlink path loss
Lf_BS: cable loss of NodeB
Ga_antenna: Gain of UE antenna and NodeB antenna
Lb: Body loss
SFMNSHO: Slow fading margin without soft handover
Lp: Penetration loss
Cell edge Ec/No:
PHS-DSCH : total power of HS-DSCH channel
: non-orthogonality factor
: neighbor cell interference factor
: downlink load factor including R99 and HSDPA service
Pmax : max transmission power of downlink
Nt : thermal noise power spectral density , typical value is -108.16dB
NF : receiver noise figure of UE, typical value is 7dB
f
DL
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-49
The theoretical maximum throughput is decided by the number of HSDPA codes.
For HSDPA , soft handover gain and fast fading margin should not be considered
in link budget , since neither power control nor soft handover in HS-PDSCH
channel
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-50
The step is present below:
According to the Cell Radius comes from R99 dimensioning, the Downlink
Path Loss can be calculated
According to the Downlink Path Loss , the Downlink Coupling Loss can be
calculated
According to the Downlink Coupling Loss and HS-DSCH Power, Cell Edge
Ec/No can be calculated
According to the Cell Edge Ec/No and simulation result, Cell Edge
Throughput can be calculated
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-51
The step is present below:
According to the Cell Edge Throughput and simulation result, Cell Edge
Ec/No can be calculated
According to the Cell Edge Ec/No and HS-DSCH Power, the Downlink
Coupling Loss can be calculated
According to the Downlink Coupling Loss, the Downlink Path Loss can be
calculated
According to the Downlink Path Loss and and Propagation Model, HSDPA
Cell radius can be calculated
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-52
The step is present below:
According to the Cell Radius comes from R99 dimensioning, the Downlink
Path Loss can be calculated
According to the Downlink Path Loss , the Downlink Coupling Loss can be
calculated
According to the Cell Edge Throughput and simulation result, Cell Edge
Ec/No can be calculated
According to the Downlink Coupling Loss and Cell Edge Ec/No , HS-DSCH
Power can be calculated
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-53
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-54
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-55
WCDMA Radio Network Coverage Planning
Confidential Information of Huawei. No Spreading Without Permission
N-56