03 WCDMA Site Survey

7/28/2019 03 WCDMA Site Survey

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

HUAWEI Confidential

Internal

WCDMA Site Survey


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HUAWEI TECHNOLOGIES CO., LTD. HUAWEI Confidential Page 2

During WCDMA network construction, the

survey on NodeB is intended to provide

detailed construction solutions for theimplementation of network construction to

guide goods preparation, engineering

construction, installation and debugging, and

so on.

The survey results may affect the quality and

smooth implementation of a whole project.


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After studying this course, you will be able to:

Be familiar with the process of NodeB survey.

Master the rules of selecting a NodeB site.

Understand the design of the antenna system.

Know the output documents during NodeB survey.


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Chapter 1 Definition of Roles in NodeB

Survey

Chapter 2 NodeB Survey Process

Chapter 3 NodeB Survey Report


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Definition of Roles in NodeB Survey

Role definition

Radio network planning manager: is responsible for the overall

planning result as a general organizer for network planning.

Network planning survey personnel: completes field survey

including spectrum test and site survey under the guidance of theradio network planning manager, and outputs the Site Survey Report

and Spectrum Test Report.

Engineering survey personnel: cooperates with the network

planning survey personnel to complete site survey.


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Survey




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Does the sitemeet the

requirement?

NodeB Survey Process

ideal sites list

Are the sites shared

with 2G sites?

No

Output search

rings

Obtain the

alternative

sites

Perform site

survey

Output a

survey

report

Yes

No

Ye

s


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Coordination Meeting for NodeB Survey

Before the survey starts, notify relevant personnel to participate in the

coordination meeting for survey preparation and complete the following

tasks:

Know the local electromagnetic background and conduct a spectrum test

if necessary.

Determine and dispatch the survey and cooperation personnel.

Prepare necessary vehicles and devices.

Work out a survey plan and determine the survey route. If the area to besurveyed is large, divide it into different parts and survey them at the

same time.

Work out preliminary solutions for transmission and power supply.

Communicate with the operator to determine the band, antenna azimuth

and tilt angle of the existing antenna system in the shared site.

After fully communicating with the operator, make sure that the areas the

operator focuses on are within the coverage of the local site. Know these

major coverage areas before the survey.


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Preparations for NodeB Survey

After knowing the general situation of the project, try your best to

collect various types of information related to the project,including:

Engineering file

Background information

Situation of the existing network Local map marked with ideal sites

Contract configuration list

Latest NodeB survey form for network planning


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Preparations for NodeB Survey

Get in touch with the marketing personnel or the relevant

personnel in the Engineering Department, and record thephone number of the regional office, operators address,

contacts phone number of the operator, as well as how to

arrive at the site.

Prepare relevant tools and ensure that they are available

before departure. The tools include:

Digital camera

GPS satellite receiver

Compass

Tape/laser rangefider

Portable computer

Telescope


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Precautions on Selecting a NodeB Site

The network planning personnel need to have an overall understanding of the coverage

area and determine the ideal sites.

The survey personnel select and survey the preplanned sites one by one. When none of

the sites meet the requirement, the network planning personnel need to determine

alternative sites.

For complicated coverage areas, the actual propagation test is sometimes needed to

check whether the candidate site can meet the coverage requirement.

After confirming an ideal site, you need to communicate with the landlord or the land

owner to buy or rent it.

If no alternative site meets the requirement, you need to re-select a NodeB or change

the coverage requirement till a site selection plan meeting the actual coverage

requirement is available.


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Principles for Selecting a NodeB Site

Specific principles for site selection are as follows:

a. The site should be located in the ideal position of the

regular mesh. An alternative site should be selected

from the R/4 search ring.

Theoretical

site position


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b. In the case that the layout of NodeB is not affected, try to select the existing facilities to reduce

construction cost and shorten the construction period.

c. Avoid selecting a site on the mountain peak of a high altitude (100 m to 300 m higher than the

altitude of the urban areas) at the edge of urban areas or in the suburban areas. This facilitates

you to control the coverage range and reduces the difficulty of engineering construction, thus

realizing convenient maintenance.

d. Build a NodeB in the place with convenient transportation, available mains, secure environment

and few arable lands occupied.

e. Avoid building a site near a large-power radio transmitter, a radar station or other interference

sources.

f. Build a NodeB in the place far away from the woods to avoid fast fading of the received signals.

g. Consider the impact of signal reflection and time dispersion when selecting a site in the

mountainous areas, in steep or dense lake areas, in highland cities, or in environment with high-

storey metal buildings.


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h. Flexibly use the height of buildings when selecting a site among buildings in the urban areato realize network hierarchy.

i. When there are a few NodeBs at the initial phase of network construction, ensure that the

major areas of the selected sites are well covered.

j. Avoid setting the cell edge in the dense user area. Good coverage means that there is only

one primary coverage cell.

k. The first Fresnel zone of the antenna should be free from obstructions.

l. Consider construction on a long-term basis.m. If a site is selected based on capacity expansion of the existing network, consider the

compatibility with the NodeB in the existing network during site selection.


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Typical Problems During Site Selection

Unreasonable cell layout imposes a

great impact on network

performance, which is more

remarkable in the WCDMA network.

1. Weak signal zone and signalblind zone: Too long inter-

NodeB distance, building

obstruction and insufficient

indoor coverage will cause weak

signal zones and signal blind

zones.


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2. Too large overlapped coverage zone:

When there are too many NodeBs, too

short inter-NodeB distance, improper

forward power allocation and bad

control over cell coverage will make the

inter-NodeB overlapped zone too largeand cause a high softer handover ratio.

Too many strong pilot signals will result

in pilot pollution, BLER and even call

drop.


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3. Overreach coverage: Overreachcoverage may occurs when you

construct a NodeB on the high

mountains in the urban or

suburban areas or on the too high

buildings. After you determine the

site and the direction of the main

lobe of the antenna and feeder,

overreach coverage also occurs if

the cell direction is consistent with

the direction of such clutters with

the waveguide effect as the streetsand rivers.


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Detailed NodeB Survey

Shooting the site

After arriving at a site, take one to two photos of the overall structure of the entry

to the alternative site, the relevant building or the tower.

Collecting the longitude and latitude information of the NodeB

Before collecting the longitude and latitude information using GPS on the top of a

building, set the coordinate format of the GPS to WGS-84 and the display format

of the longitude and latitude to XX.XXXX. If the operator has other formats, set

them as required by the operator.

Fill in Network Planning Survey Form for XXX Site in XXX Projecton the site

after getting the longitude and latitude information.


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Propagation environment surrounding the NodeB

Beginning with the North, record the height and the distance to the local NodeB

of the buildings or natural barriers that have the same height as the antenna or

are higher than the antenna in various directions within 500 m of the NodeB.

Shoot the surrounding radio propagation environment on the antenna

installation platform: beginning with 0 (namely the North), shoot the

surrounding radio propagation environment clockwise with the step of 30 from

12 directions. On each photo, you need to mark the shooting position anddirection on the finished schematic diagram of the roof plane.

Observe whether there are antenna systems of other operators near the site

and record them if any.

Others

Correctly fill in Network Planning Survey Form for XXX Site in XXXProjecton the site.


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Taking photos and drawing a sketchof the geographical location

When taking photos, record the angle

information of photos for future archiving.


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Taking photos and drawing a sketch of the geographical location

Save the photos in the format that is as small as possible under thecondition that they can be viewed clearly.


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Roof information Not constructed sites: On the

roof diagram, mark the installation

position of the antenna and the

basic direction of the cabling rack.

Constructed sites: The

installation position of an antenna

is restricted by many factors. The

spatial position information of the

antenna installation platform and

the antenna and feeder

parameters of the co-site

heterogeneous systems affect the

installation position of the antenna

to a great extent.


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Survey and Design of the Antenna

System

As an important part of the NodeB

system, the antenna system refers to

the channel part from the antenna to

the top of the cabinet. It consists of the

antenna, feeder, jumper, tower-

mounted amplifier, lightning arrester,grounding clip, feeder clip, feeder

window, and so on.

Solution to the antenna system

Grounding facility

Jumper for the antenna and feeder

Fixing facility

Grounding facility

Indoor jumper

Tower for the antennas and feeders NodeB

Feeder


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Survey and Design of the Antenna System

Tower mounted amplifier (TMA) is installed on a tower and is near to the

antenna. A jumper of 2m to 3m long is used to connect the TMA and

antenna. The received signal from the antenna can be amplified by the TMA

with a small attenuation. The TMA can improve system sensitivity and uplink

coverage. In addition, it can also reduce the Tx power of the user equipment

(UE) and noise interference within the system, thus improving conversation

quality.

Tower mounted amplifier

Feed current ofthe towermountedamplifier

Filter for

transmitted signals

Filter forreceived

signals

Bypass

Low noiseamplifier

Antenna

Filter forreceived

signals

S d D i f th A t


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Survey and Design of the Antenna

System Classification of Antennas

By the radiation direction:

Directional antenna and omni-directional antenna

By the appearance:

Panel antenna, cap antenna, whip antenna and aperture antenna

By polarization:

Single polarization antenna and dual polarization antenna



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Selection of Antennas Selecting an antenna for the dense urban and urban NodeB

The directional antenna with a horizontal half-power angle ranging from

60to 65is usually selected to realize 3 sectors.

Intermediate gain antenna (about 15 dBi) for low frequency band (UMTS

900MHz), High gain antenna (18 dBi) for high frequency band( UMTS

2000Mhz).

The antenna downtilt should be designed according to site situations,

normally from 4to 10with suitable height. Electr ic t i l t angle antenna (ranging from 2to 6) is recommended and

antenna supported should realize 0to 15

A dual p olar izat ion antennais recommended.

The main beam of antenna should be direct to high traffic area, import

buildings or regions (airport, emporium, gym, government, hotel, etc) Installed antenna locations should be far away to other system

transm it ter (l ike GSM, CDMA, TV tower and o ther RF transm it ter)

to guarantee the isolation and without obv ious obstac le to block

or ref lect.



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y g y

Selection of Antennas Selecting an antenna for the suburban NodeB

Select a directional antenna with a horizontal half-power angle

ranging from 65or 90according to the actual situation.

The intermediate or high gain antenna of15dB ito 18dB iis

selected according to frequency band and NodeB density.

The antenna downtilt should be designed according to site situations,

normally from 0to 6with suitable height.

Generally,preset tilt antenna is unnecessary.

Both dual and v ert ical po lar izat ion antennascan be used.

The main beam of antenna should be direct to high traffic area,

import buildings or regions

Installed antenna locations should be far away to oth er systemtransm it ter (l ike GSM, CDMA, TV tow er and o ther RF

transmit ter)to guarantee the isolation and without obv ious

obs tacle to block or ref lect.



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y g y

Selection of Antenna

Selecting an antenna for the rural NodeB

Select a direct ional antenna or an omnidirect ional antenna of 90or 120according to the actual situation and requirement.

The gain of the selected directional antenna is usually high (about

18dBi).

Generally, the antenna with a preset tilt angle is not selected and

dow nt i l t was set as 0. Electr ic t i l t angle antenna (ranging from 0to

10) can be used in special scenery (high mountain site) The nul l f i l l ing antennais preferred in the high NodeB (higher than

400m for directional antenna and 200m for omni antenna).

A vertical polarization antenna is recommended.

Installed antenna locations should be far away to other sys tem

transm itter (like GSM, CDMA, TV tower and o ther RF transm itter)

to guarantee the isolation and wi thout obv ious obstac le to b lock orref lect.



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Selecting an antenna for the NodeB on the road

Usually, the direct ional antenna with a narrow beam and hig h gain

(21~22dBi)is selected. The 8-shaped an tenna (14dBi),om nidirect ional and deformed omn idirect ional antenna (12dBi)

can also be selected according to the actual situation.

The antenna with a preset tilt angle is usually not selected and

dow nt i l t was set as 0. because the NodeB on the road has a highrequirement for the coverage distance.

A vert ical polarizat ion antennais recommended . The front-back ratio of the selected directional antenna should not be

too high.

Installed antenna locations should be far away to other system

transm itter (l ike GSM, CDMA, TV tower and oth er RF transm itter)

to guarantee the isolation and wi thout obv ious obstac le to b lock or

ref lect.

S d D i f th A t S t


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Selecting an antenna fortunnels

For tunnels shorter than two kilometers

The 10-12dBi Yagi/ log p eriodic antenna/panel antennaisrecommended. You are usually recommended to install them at the

tunnel entrance to cover road tunnels shorter than 2 km.

For tunnels longer than two kilometers

The leaky cables, coaxial cables and distributed fiber systems arerecommended.



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Selecting an indoor antenna Omnidirectional antenna

Small, vert ic al pol arizat ion, and cap or cup antennas with thegain of2dBiare recommended. Such antennas are of good

appearance and easy to install.

Directional antenna

Vertical polarization directional antennas with the horizontalhalf-power angle of 90and the gain of7dBiare recommended.



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Installation of Antenna

Installation environment is divided into environment near the antenna

and environment near the NodeB. For environment near the antenna,you need to consider the antenna isolation and the impact of the

tower and the floor. For environment near the NodeB, you need to

consider the impact of the buildings within 500 m on radio propagation.

Requirements for antenna

installation against the wall

Clearance

requirements

surrounding the

antenna



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When installing the NodeB antenna, we need to consider whether

the antenna will cause a large shadow in its coverage area. Inaddition, we also need to install the antenna in the place away from

the barriers. For example, antennas should be installed along the

edge of the building top to prevent the roof from obstructing radio

signals.

Distance (m) from the

antenna to the edge of the

building

Height (m) from the bottom

of the antenna to the roof of

the building



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You can analyze mutual interference between the GSM BTS and the NodeBfrom the following aspects:

Blocking of the GSM BTS on the NodeB

Spurious impact of the GSM BTS on the reception band of the NodeB

Blocking of the NodeB on the GSM BTS

Spurious impact of the NodeB on the GSM reception band

Usually, to meet the isolation requirement for blocking and spurious

emission, antenna isolation is required to exceed 30 dB when the WCDMA,

GSM and DCS share a site.

Survey and Design of the Antenna system


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Antenna Installation Spacing

In space diversity, the spacing between two Rx antennas should range from 12 to

18 . 1 is equal to 0.15 m (2 GHz). The higher the antenna is installed, the larger the horizontal spacing of antenna

diversities is. Usually, the horizontal spacing of diversity antennas is 0.11 time as

much as the valid height of the antenna.

To reach the same diversity effect, the vertical diversity spacing must be five to six

times as much as the horizontal diversity spacing.

To reduce mutual impacts

between two antennas, the

horizontal spacing of diversity

antennas need to exceed 3 m

no matter what the valid height

of the antenna is.

Diversity distance

of the directional

antenna


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Survey



S D t


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Survey Documents

WCDMA NodeB Survey Report

Involves the network construction background, pre-planning solution,

NodeB engineering parameter list, NodeB distribution diagram, and so on.

WCDMA NodeB Survey Form during Network Planning

Involves the antenna installation position, engineering parameters of

various sectors, surrounding environment of the antenna, and so on.

Survey Memo

WCDMA Engineering Parameter List


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