WCDMA RNP Neighboring Cell Planning Guidance

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Huawei Technologies Co. Ltd.

Product version Confidentialitylevel

V100R001 For internal useonly

Product name: WCDMA RNP Total pages: 20

WCDMA RNP Neighboring Cell Planning

Guidance

For internal use only

Prepared by URNP-SANA Date 2003-05-10

Reviewed by Date

Reviewed by Date

Approved by Date

Huawei Technologies Co., Ltd.

All rights reserved


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WCDMA RNP Neighboring Cell Planning Guidance For internal use only

2004-07-1910 All rights reserved Page 2 , Total20

Revision Record

Date Revision

version

Description Author

2003/5/10 1.00 Initial transmittal Zhu Ailin

2003/5/20 1.00 Verification and revision for first draft Xu Dengyu


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Table of Contents

1 Overview ................................................................................................................................. 6

1.1 Objective............................................................................................................................. 61.2 Principles for Neighboring Cell Planning ........................................................................... 6

2 Preparations for Planning ..................................................................................................... 7

2.1 Checking PLMN Network ................................................................................................... 72.2 Checking BSs Setup and Cell Distribution ......................................................................... 82.3 Checking whether 3g Carrier is Set up and Added to Cell ................................................ 92.4 Checking Cell Coverage Prediction ................................................................................. 10

3 Operation Process of Neighbor Planner Tools ................................................................. 11

3.1 Setting Cell Range for Planning ....................................................................................... 11

3.2 Automatic Planning of Intra-carrier neighboring cells ...................................................... 123.2.1 Step 1 ......................................................................................................................... 123.2.2 Step 2 ......................................................................................................................... 133.2.3 Step 3 ......................................................................................................................... 133.2.4 Step 4 ......................................................................................................................... 15

3.3 Automatic Planning of Inter-carrier Neighboring Cells ..................................................... 173.3.1 Step 1 and Step 2 ..................................................................................................... 173.3.2 Step 3 ......................................................................................................................... 173.3.3 Step 4 ......................................................................................................................... 18

4 Advices on Neighboring Cell Planning .............................................................................. 18


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List of Figures

FIGURE 1PLMNSITE DATABASE.................................................................................................................................... 8FIGURE 2NODEB&CELLS DISTRIBUTION .......................................................................................................................... 9FIGURE 3CARRIERS................................................................................................................................................... 10FIGURE 4COVERAGE PREDICTOR ................................................................................................................................. 11FIGURE 5FILTERS ..................................................................................................................................................... 12FIGURE 6NEIGHBOUR PLANNER SELECT VIEW ................................................................................................................. 13FIGURE 7NEIGHBOUR PLANNER FILTER.......................................................................................................................... 13FIGURE 8INTRA-CARRIER NEIGHBOUR PLANNER PARAMETER SETTING ........................................................... ...................... 14FIGURE 9NEIGHBOUR PLANNER REPORT....................................................................................................................... 16FIGURE 10WORDPAD REPORT .................................................................................................................................... 17FIGURE 11INTER-CARRIER NEIGHBOUR PLANNER PARAMETER SETTING......................................................... ...................... 18


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WCDMA RNP Neighboring Cell Planning Guidance

Key words: WCDMA RNP, neighboring cell

Abstract: This describes how to plan neighboring cell in tools or in handwork.

List of abbreviations:


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1 Overview

1.1 Objective

The WCDMA system is a self-interference system. Its frequency reuse coefficient is 1, and

the same frequency can be used in different sectors. Controlling the interference between

sectors , including power control, load control, etc is an effective method to increase network

capacity and improve system efficiency,. Good neighboring cell planning is also one of the

effective methods to control the interference between cells.

This document is to guide engineers to carry out the neighboring cell planning with the

planning software ENTERPRISE, so as to make preparation for the subsequent scrambling codeplanning and soft handover planning.

1.2 Principles for Neighboring Cell Planning

In the WCDMA system, the cells which have interference to the primary cell are called as

adjacent cells. Any cell can be the primary cell with adjacent cells. Neighboring cells exist in the

adjacent cells of the primary cell. The cell border is determined according to UE access level. In

terms of primary cell, it can receive pilot signals from other intra-frequency cells at the border of

the cell. These pilot signals may be stronger or weaker than that of UE access level. If the pilot

signal at the border of the primary cell is stronger than the access level, this cell is (or probably is)

the neighboring cell of the primary cell. And there is a soft handover area between two

neighboring cells, whose size is determined by handover margin. The following three kinds of

handover may take place between neighboring cells:

Soft handover If the neighboring cells are intra-frequency cells, the UE can

communicate with the network through multiple radio links;

Softer handover It takes place between two intra-frequency cells of the same NODEB;

Hard handover (It takes place between any two cells regardless of frequencydistribution) It means that the UE disconnects the communication with the original cell at

first and then access the network from a new one. In order to assist the neighboring

cells data compiling, the hard handover mentioned here is the one taking place between

inter-frequency cells.

Note: Cells with different frequencies can be configured as inter-frequency neighboring

cells.

Follow these principles when configuring neighboring cell relation:

Cells being neighbor geographically are usually configured as neighboring cells;


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Neighboring cells are usually required to be neighbor to each other. That is, the

carrier frequency of sector A regards B as its neighboring cell, and B should regard A as its

neighboring cell too. However, on some special occasions, unidirectional neighboring cell

configuration is required. If the BSs of some areas adopt f1 and f2 configurations and if the BSs

of other surrounding areas adopt single carrier f1 configurations, it is necessary to configure the

unidirectional neighboring cell relation from f2 to f1 only.

For dense urban and mean urban, the distance between two sites is relatively short

(say 0.5 to 1.5 km), so more neighboring cells should be planned. At present, a maximum of 32

neighboring cells can be configured. When configuring the neighboring pilot, you should mind the

number of neighboring pilots. In order to avoid occupying the cells in the neighboring cell list and

causing interference by putting the real neighboring pilot out of the MS neighbor list, only those

with real neighbor relation should be configured and the irrelative ones should be removed. Atthe same time, configuring too many neighboring cells will affect the MS s pilot searching time

and accuracy. So it is required to configure necessary neighboring cells only, avoiding too many

neighboring cells in the actual network.

For BSs in suburban and rural areas, although the distance between sites is long, the

cells being neighbors geographically must be configured as the neighboring cells to ensure the

prompt handover and avoid call drop.

Because there is no order between the WCDMA neighboringcells, and the detection

cycle is relatively short (32 intra-carrier neighboring cells only require a measurement cycle of320ms), it is only required to avoid missing neighboring cells, and unnecessary to sequence the

neighboring cells according to signal strength.

2 Preparations for Planning

When using the tools provided by ENTERPRISE4.0 to make neighboring cell planning, we

should check whether the following works have been prepared in advance or not.

2.1 Checking PLMN Network

Select the 3g->Database->Site menu as shown in the following window, check whether the

PLMN network exists, and whether BSs and cells have been set up in this network.

The parameter description part in each schematic diagram only presents the parameters

related to neighboring cell planning. For the complete parameter configuration analysis, please

refer to [1].


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Figure 1PLMN Site database

2.2 Checking BSs Setup and Cell Distribution

Select the3g->View->New 2D view menu and select a map in the pull-down box (note:

If the terrain is not displayed, please click the button and then to configure the display elements). In window below ,check whether BSs and cells exist in

the map. (Note: the map is imported by setting the relevant contents of the coordinate system

and the maximum and minimum values of the latitude and longitude of the map in the ModifyProject window. At the same time, the antenna data should also be imported. For detailed

operation, refer to (2).


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Figure 2NodeB&Cells distribution

2.3 Checking whether 3g Carrier is Set up and Added to Cell

Select the 3g->Options->Carriers menu as shown in the following window, check whether

3g carrier is configured or not, and whether the carrier is added to the cell as shown in figure 3.


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Figure 3Carriers

2.4 Checking Cell Coverage Prediction

Select the 3g->Tools->Coverage Predictormenu to checking whether the cell coverage is

created or not.


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Figure 4Coverage predictor

3 Operation Process of Neighbor Planner Tools

3.1 Setting Cell Range for Planning

Select the 3g->Database->Filters menu as shown in the following window, and add Filter,

and then set the cells to be allocated in this Filter.


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Figure 5Filters

3.2 Automatic Planning of Intra-carrier neighboring cells

3.2.1 Step 1

Select the 3g->Tools->Neighbour Planner menu as shown in the following window,

select the cells to be planned, and then click :


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Figure 6Neighbour planner select view

3.2.2 Step 2

Select the filters where those cells to be planned and their neighboring cells locate, then

click , as shown in the window below:

Figure 7Neighbour planner filter

3.2.3 Step 3

Set the parameters that should be considered in neighboring cell planning and click ,


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as shown in the following window:

Figure 8Intra-carrier neighbour planner parameter setting

The relevant parameters are described as follows:

Override Handover Margin [dB]: The pilot power difference between two cells within

the handover area should be smaller than or equal to the handover margin value

set here. The default value is 3dB, indicating that two cells have the possibility of

becoming neighboring cells only when the terminal receiving signal strength

difference the two cells is smaller than or equal to 3dB. Please note that this

value is valid only in the intra-carrier neighboring cell planning.

Explanation: This value is proportional to the size of Interfering Area. For

Enterprise 4.0 sets neighboring cells according to Interfering Area principle.,so the

bigger this value is , the more possibility of becoming neighboring cells will be.

However, this parameter does not affect the number of neighboring cells the

software plans.

Carrier: It is the carrier used by neighboring cells.

Resolution[m]: It refers to the precision of the digital map, for example, 20m.

Minimum Interfering Area [km2

]: it is the minimum value of neighboring cell s

interfering area . The default value is 0.00. This parameter means that the cell may

become a neighboring cell only when the interfering area is larger than this value.

The purpose of this parameter is to avoid too many neighboring cells and avoid

adding unnecessary cells to the neighboring cell list, which results in resources

wasting.


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Explanation: It is for Interfering area calculation. For intra-frequency cells, itcalculates the area of all points where the signal strength received from

neighboring cells is Handover Margin smaller than the signal strength of this cell.

For inter-frequency cells, it calculates the area of all points where the requirement

for the parameter Ec/Io Threshold is met. (Note that the interfering area

calculated from the cells with bi-directional neighboring cell relation may be

different.) The value of this parameter directly influences the number of

neighboring cells.

Standard Deviation [dB]: It indicates the Eb/No measurement standard difference

of UE, and it controls Eb/No distribution achieved by UE. The default value is 10.

The setting of this parameter is mainly related to the accuracy of propagation

model. If the local propagation model has already been revised and if it is very

close to the actual condition, this standard difference can be set to a very small

value, for example 1. Note: the value of this parameter, which is not proportional to

the size of Interfering Area, does not affect the number of neighboring cells.

Number of neighboring cells: It refers to the maximum number of neighboring cells

each cell can have. The default value is 6. If this value is too large, it will result in

many unnecessary neighboring cells; if it is too small, it is likely to miss some cells

and result in frequent call drop. It is recommended to set different values for

different locations. For example, set it to a large value for central cells, and a smallvalue for margin cells, set more for intra-frequency cells and less for

inter-frequency cells.

Explanation: The value of this parameter will affect the number of neighboring cells.

The planning software uses this value to sequence the cells, and select ones with

larger Interfering Area as neighboring cells.

3.2.4 Step 4

As shown In the following window, Generate the neighboring cell planning report and

analyze it. If the neighboring cell planning results meet the requirements, click or

to the complete neighboring cells planning.


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Figure 9Neighbour Planner Report

Cell name: Cell name, name of the cell to be planned. For example, dayawanC.

Neighbours: List of neighboring cells. Select the cell on the left frame, and its

neighboring cells will be listed on the Neighbours frame.

Carriers: It refers to the carrier used by the neighboring cells.

Interfering Area: It refers to the Interfering Area between the selected cell and its

neighboring cells.

Replace existing UMTS neighbours with same and Replace existing UMTS

neighbours with difference: It indicates whether to replace the existing neighboring

cell data with the generated neighboring cells data which are the same or different

from the existing neighboring cell data of this project (if the database of this

project has neighboring cell data).

In addition, the result report of neighboring cell planning can be in the format of WordPad. In

the above window, you can click button to generate report format as shown below:


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Figure 10WordPad Report

3.3 Automatic Planning of Inter-carrier Neighboring Cells

3.3.1 Step 1 and Step 2

The operations in Step1 and Step 2 are the same as those of intra-carrier neighboring cell

planning.

3.3.2 Step 3

In the following window set the parameters to be considered for neighboring cells planning,

and click :


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Figure 11Inter-Carrier neighbour planner parameter setting

The relevant parameters are described as follows:

Ec/Io Threshold [dB]: It is the Ec/Io threshold in neighboring cell planning. In

inter-carrier neighboring cell planning, only the service cells connected with the

terminal or other cells whose the Ec/Io value is larger than or equal to this thresholdcan become neighboring cells. The default value is -18dB.

Carrier: It is the carrier used by the cell.

the descriptions of Resolution[m], Minimum Interfering Area[km2

], Standard

Deviation [dB] and Number of Neighboring Cells are ditto

3.3.3 Step 4

This step is the same as Step 4 in the intra-carrier neighboring cells planning.

4 Advices on Neighboring Cell Planning

When using Enterprise 4.0 to carry out intra-frequency and inter-carrier neighboring cell

planning, it is recommended to follow the principles below:

When planning intra-carrier neighboring cells, you can expand the Interfering Area

through increasing Handover Margin. Because the interfering area of the cells with

true neighboring cell relation expands more quickly than that of the cells without

actual neighboring cell relation. Next, you need to filter unnecessary cells by setting

suitable Minimum Interfering Area (At this time, you can export the neighboring cell


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report to decide what value of Minimum Interfering Area should be set to, and

then use this value to filter the unnecessary neighboring cells). The parameters of

Handover Margin and Minimum Interfering Area should be set based on the

data accuracy of the project interested (such as propagation model data, electronic

map information, etc.). If these data are inaccurate, the neighboring cells planned

by the neighbour planner function of ENTERPRISE provide no reference meaning.

Similar to the planning of intra-carrier neighboring cells, you can also expand

Interfering Area by decreasing Ec/Io threshold. Then you need to filter

unnecessary neighboring cells by setting Minimum Interfering Area and Number

of Neighboring Cells properly. Please note that UMTS CELL is for cells instead of

sectors in multi-carrier BS; otherwise, the BS will lose inter-carrier neighboring

cells.

When planning neighboring cells, it is recommended to select the suitable areas

instead of all areas, which will lead to inaccurate result of neighboring cells

planning. Since the calculation result of interfering area of the cells at the edge of

network is obviously larger than that of the cells at the network center, and these

parameters related to neighboring cell planning are uniformly used for the cells in

selected filter. Therefore, it is recommended to set different filters according to

different BS distributions. For example, set separate filters for cells in city,

suburban and rural respectively, and then plan neighboring cells according to eachfilter. The parameters set for neighboring cell planning for these filters may be

different.

Whats more, to carry out neighboring cell planning among too many BSs

simultaneously will result in the lack of memory, thus the planning cannot continue

at all.

When carrying out inter-carrier neighboring cell planning, it is likely to encounter

unreasonable unidirectional neighboring cells relation. This problem is resolving. At

present, you can generate bi-directional neighboring cells relation through relevant

tools (such as GSM bi-directional neighboring cell planning tool) to avoid it.


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List of reference:

[1] Yao Jianqing, WCDMA RNP Technology Research on Special Topics -- ENTERPRISE

Parameter Analysis Report, 2003/01/04

[2] Chen Jing, WCDMA RNP ENTERPRISE V4.0 Planning Software Usage Guide V1.0,2002/07/30.

[3] Chen Qi, WCDMA RNP Cell Primary Scrambling Code Planning Guide V1.0, 2003/04/24

WCDMA RNP Neighboring Cell Planning Guidance

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