01_Introduction to Radio Network Planning

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Introduction to Radio Network Planning Siemens

MN1790EU02MN © 2006 Siemens AG

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Contents

1 Course Objectives 3

2 Radio Network Planning Objectives 5

3 Radio Network Planning Constraints 7

4 Radio Network Planning Steps 9

4.1 Customer Requirement Analysis 10

4.2 Provision of Digital Maps 10

4.3 Tuning of Radio Wave Propagation Models 11

4.4 Nominal Cell Plan 12

4.5 Site Survey and Site Selection 13

4.6 Final Cell Plan 14 4.7 Determination of Database Parameters 16

4.8 Rollout of Equipment and Initial Tuning 17

4.9 Acceptance and Optimization Cycles 18

Introduction to Radio Network Planning



Siemens Introduction to Radio Network Planning

MN1790EU02MN

© 2006 Siemens AG

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1 Course Objectives

Due to the fast growing GSM network, the efficient basic planning process continuesto have an important role. For existing GSM network systems which are influenced bychanging and increasing usage, the continuous optimization is an additionalpermanent challenge.

Accordingly, in addition to the introduction to the basics of radio network planning andits system and hardware dependencies, this course offers in a supplementarychapter detailed possibilities for network optimization. Subjects such as planning andoptimization of coverage, capacity, allocation of frequencies and network IDs will beexplained.

After the course the participants will know about and understand the background ofradio network planning. The participant will be able to make sound decisions for thepossible usage of software tools. This course teaches knowledge and techniqueswhich are relevant for planning and which are independent of certain planning tools.

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Fig. 1 Course objectives




MN1790EU02MN

© 2006 Siemens AG

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2 Radio Network Planning Objectives

Networkplanning

Goodquality S

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a c i t y

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i e n t

c o v e r a g e

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e f f e c t i v i t y

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n d i b i l i t

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Fig. 2 Radio network planning objectives




MN1790EU02MN

© 2006 Siemens AG

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The objectives of Radio Network Planning are:

• Provision of sufficient coverage (radio aspect):

An important requirement in cellular networks is the contiguous coverage of theservice areas without noticeable holes. Furthermore an adequate depth ofcoverage (i.e. outdoor or indoor, 2 W or 8 W mobiles) is necessary to meet theoperator’s marketing plans.

• Provision of satisfactory network capacity (traffic aspect):

The operator has to provide traffic in the busy hour with only a low probability ofblocking (congestion) in order to avoid complaints of the subscriber.

• Provision of good network quality (frequency aspect):

Since the number of frequencies a network operator can use is limited the

frequencies must be re-used. In order to receive a good quality radio networkplanning is trying to separate the cells with equal frequencies as much asnecessary.

• Accommodation of network growth (forecast development):

This includes extension of coverage to new areas for the case that an operatordoes not start with country-wide coverage and expansion of the network capacityso that the quality of service is maintained at all times. A provident planning is animportant issue since network operators start with only a few subscribers.

• A cost effective design:

Cost effectivity means lowest possible cost over the life of the network whilemeeting the quality targets.





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3 Radio Network Planning Constraints

Marketingrequirements

Radiofundamentals

GSM systemSpecifications

Budget

ManufacturerSpecifications

Licenseconditions Radio

NetworkPlanning

Fig. 3 Radio network planning constraints




MN1790EU02MN

© 2006 Siemens AG

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The objective of radio planning is a technical realization of the marketingrequirement, taking into account of the following constraints:

• Technical requirements from the license conditions

• GSM system-specific parameters (e.g. GSM Rec. 45.005)

• Manufacturer-specific features and parameters

• Radio communication principles and fundamentals

• Budgetary factors.

A license from a regulatory authority could be associated with technical requirements.An example of this could be:

• Coverage requirement:

MS class 2 coverage of 75% of the population 12 months from commercial launch

MS class 2 coverage of 95% of the population 36 months from commercial launch

• Quality of coverage

Service to be available in 90% of the declared area and for 90% of the time

• GOS (Grade Of Service)

Endeavour to achieve 5% or better

• Frequency allocation:

50 frequencies in the frequency band 1800 MHz





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4 Radio Network Planning Steps

Requirement

analysis

Provision of

digital maps

Tuning of thepropagation

model

Nominal

cell plan

Site survey

Final

cell plan

Determinationof DB

parameters

Rollout of

equipmentInitial tuning

Acceptance

Optimization

cycles

Fig. 4 Radio network planning steps




MN1790EU02MN

© 2006 Siemens AG

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4.1 Customer Requirement Analysis

Network planning follows a very simple principle, the GIGO principle:

Garbage In results in Garbage Out.

Therefore a planning process can only be started when there are clear requirementswhat the network should offer. This includes:

• Network coverage:

Which areas shall be covered?

What is the coverage probability, i.e. the probability to have sufficient signalstrength at a certain place?

Where can the BTS be located?

• Network capacity:

How many subscribers are expected to use the network?

How often and how long do the subscribers use the network?

Which services do the subscribers use?

How is the geographical and the time distribution of the traffic?

What is the blocking probability for the subscribers?

• Network quality:

Which interference levels can be accepted?

Which frequencies are available?

Which features can be used?

4.2 Provision of Digital MapsDigital terrain databases are an essential input for all further planning activities. Theyshould not only contain roads and buildings, but also contain information aboutterrain height and morphology.





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4.3 Tuning of Radio Wave Propagation Models

The propagation of radio waves is described with mathematical formalisms either inempirical or semi-empirical manner. These propagation models are developed forvery precisely defined environments and do normally not correspond to realsurroundings. Therefore propagation models bear the danger that cells are notplanned accurately that a mobile at the edge of the cell may have no coverage.

The planner places a test transmitter at certain sites and collects measurement data.These data are now compared with the theoretical predicted values and the modelscan be tuned to fit real environments.

TestBTS

Set-up of a test transmitter Collecting measurement data

Analysis of predicted versusmeasured data

Adaptation of standard modelto local environment

Fig. 5 Tuning of radio wave propagation models




MN1790EU02MN

© 2006 Siemens AG

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4.4 Nominal Cell Plan

The nominal Cell plan includes:• a design of the sites that meets coverage and capacity targets (which is

calculated with the help of a computer tool)

• a feasibility verification of meeting service requirements

• the possibility of a frequency plan for the design

• an estimation of equipment requirements and costs

• a development of implementation and resource plans (including personnelrequirements)

• a radio plan that will provide input to fixed network planning

Fig. 6 Nominal cell plan





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4.5 Site Survey and Site Selection

Once the nominal cell plan has been provided the radio network planner has tosearch for site candidates (towers, high buildings, poles, etc.) and to evaluate thesites concerning building height, obstacles, etc.

Afterwards he has to evaluate this site with the prediction tool and by measurementsafter having installed a test transmitter.

Then he selects the candidate site if:

• it is appropriate due to the RF capabilities

• a contract for renting the location can be signed to a low price

• the security aspects are met

• the technical assessment is positive (power supply, construction, antennas, etc…).

?

Fig. 7 Site survey and site selection




MN1790EU02MN

© 2006 Siemens AG

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4.6 Final Cell Plan

In order to provide the final cell plan cellular radio network planning tools are used.Such Radio network planning tools are used for:

• Coverage Planning (Measurement data input, Prediction of coverage and trafficmodel tuning)

• Interference analysis and automatic frequency allocation

• Production of coverage plots

• Parameter planning and optimization: O&M interface (parameters, statistics).

They are essential for effective optimization and for planning network growth.

• Graphical user interface

• Use digital map information

• User definable propagation models• Tuning of propagation models by radio survey analysis

• Traffic analysis and calculation

• Interference analysis

• Handover considerations

• Automatic frequency planning

Fig. 8 Cellular radio network planning tools





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The final cell plan includes:

• Coverage predictions with tuned model

• Usage of contracted sites (check site acquisition)

• Determination of antenna configuration

• Capacity calculation

• Required TRX per cell

• Frequency planning and assignment

• Graphical presentation (e.g. C/I plot)

• Documentation.

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Fig. 9 Final cell plan




MN1790EU02MN

© 2006 Siemens AG

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4.7 Determination of Database Parameters

Determination of parameters such as:

– Cell Parameters (CI, BSIC, LAC)

– Neighbour List (Adjacent Cells)

– Handover Parameters

– Power Control Parameters

– ……

Fig. 10 Definition of database parameters





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4.8 Rollout of Equipment and Initial Tuning

At this stage of the planning process the rollout of the radio network equipment canstart. But the job of the planner is by no means done yet, because once theequipment is installed and powered on, the basic commissioning test will beperformed. Drive tests will check

• the DB parameters,

• if the receive level and quality meet the requirements,

• if call setup procedures as well as handovers work properly.

Furthermore OMC performance measurements are carried out to revealshortcomings of the system.

A visual check of the site construction follows.

In case of shortcomings first corrections are made, like:

• Changes of installation (e.g. Alignment of antennas)

• Changes of DB (e.g. addition of neighbour relationships, change of frequencies).

• Drive Tests to check:

– RXLEV, RXQUAL

– Handovers

– Call setup procedures

– DB settings

• OMC statistics analysis

• Visual check of site construction

• Changes of installation

(Alignment of antennas (tilt, azimuth))

• Changes of DB

(add neighbours, change Frequencies, etc…)

Fig. 11 Initial Tuning




MN1790EU02MN

© 2006 Siemens AG

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4.9 Acceptance and Optimization Cycles

If all requirements are met the sites are accepted and released for the subscriber.Now different input from performance measurements, refined traffic models,customer needs, network expansion decisions, feature changes a.s.o. will lead to theendless optimisation cycle.





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01_Introduction to Radio Network Planning

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