Comparison of Asset and Atoll Cellular Planning tools for LTE Network Planning.pdf

Comparison of Asset and Atoll Cellular Planning tools for LTE Network Planning Hormoz Parsian 85014K Department of Communication and Networking

Supervisor: Prof. Jyri Hämäläinen Instructor: Dr. Kimmo Mäkeläinen This Master’s thesis was conducted at

Nokia Siemens Networks 5/22/2012

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Outline of the work: •

Introduction   

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Propagation Models   

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Analysis of Number of Covering Cells in Asset Interference Analysis for Outdoor Users Interference Analysis for Indoor Users

Capacity Analysis   

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Coverage Analysis with original constant term in Atoll propagation model Coverage Analysis with optimum constant term in Atoll propagation model

Interference Analysis   

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Hata Models Standard Propagation Models in the Tools Deriving Equivalent Parameters

Coverage Analysis  

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Background Research question Methodology

Capacity Analysis of LTE services Capacity Analysis for MIMO modes Capacity Analysis of Scheduling Algorithms

Conclusions and Future Works

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Introduction • Backgrond • Software for network planning:  Astoll of Forsk  Asset of Aircom  Planet of Mentum

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Planning tool manufacturers design their tools independently of each other • Users do not know before testing whether different planning tools produce comparable performance estimates for a given network • Sometimes a network is planned or investigated in two different planning tools • Companies often change from one planning tool to another 

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Planning results of the first tool have to be reproduced in the second one

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Introduction • Research Question • Comparing two planning tools, Atoll of Forsk and Asset of Aircom with respect to LTE network planning  Not trying to find out which of the tools is better than the other one  Trying to investigate whether they provide comparable performance measures in the test network

• Tools’ performance can be close to each other if two investigated network configurations and other configurations like propagation models are equal to each other. • Finding equal parameters mean they produce same performance estimates AND it necessary does not mean numerically equal parameters • LTE input parameters for Asset and Atoll, prepared by NSN to give equal performance estimates

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Introduction • Methodology • To compare the tools different testing scenarios and network configurations are analyzed.     

Propagation Models Number of Transmitting and receiving Antennas Services used MIMO configurations Scheduling methods

• Planning tools are compared in terms of three performance estimates:  Coverage  Interference  Traffic capacity

• For radio propagation prediction digital map is required.  Digital map of Helsinki with 10 m resolution

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Propagation Models • Hata Model • All computed coverage, interference and capacity results in the cellular network planning tools are based on losses between base stations ad points on the digital map that computed from propagation prediction models • Standard propagation models in Asset and Atoll are based on OkumuraHata models • Hata model is derived from Okumura’s measurement reports  The reports are obtained from four different environments in and around Tokyo  The measurements are for limited parameter ranges e.g. frequency, distance and height.  In Hata model frequency, distance, base (BS) and mobile station (MS) antenna heights are limited.  150 MHz < Frequency < 1500 MHz  1 km < Distance < 20 km  30 m < BS Antenna Height < 200 m  1 m < MS Antenna Height < 10 m

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Propagation Models • Hata Model • Hata model was extended to frequencies higher than 1500 MHz but less than 2000 MHz • Also it was extended for distances between 20 km and 10 0km

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Propagation Models • Standard Propagation Models (SPM): • SPM in Asset is presented below: 𝒑𝒂𝒕𝒉𝒍𝒐𝒔𝒔

𝑳𝑱𝑲

𝒅𝑩 = 𝑨 + 𝑩 𝐥𝐨𝐠 𝟏𝟎 𝒅 + 𝑪𝒎

Where: 𝑨 = 𝒌𝟏 + 𝒌𝟑 𝑯𝑴𝑺 + 𝒌𝟒 𝐥𝐨𝐠 𝟏𝟎 𝑯𝑴𝑺 + 𝒌𝟓 𝐥𝐨𝐠 𝟏𝟎 𝑯𝒆𝒇𝒇 𝑩 = 𝒌𝟐 + 𝒌𝟔 𝐥𝐨𝐠 𝟏𝟎 𝑯𝒆𝒇𝒇 𝑪𝒎 = 𝒌𝟕 𝑫𝒊𝒇𝒇𝒓𝒂𝒄𝒕𝒊𝒐𝒏 𝑳𝒐𝒔𝒔 + 𝑪𝒍𝒖𝒕𝒕𝒆𝒓 𝑳𝒐𝒔𝒔

• In Asset distances between BS and MS are in kilometers.

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Propagation Models • Standard Propagation Models (SPM): • SPM in Atoll is presented below: 𝑳𝒅𝑩 𝒅𝑩 = 𝑨 + 𝑩 𝐥𝐨𝐠 𝟏𝟎 𝒅 + 𝑪𝒎 Where 𝑨 = 𝑲𝟏 + 𝑲𝟑 𝐥𝐨𝐠 𝟏𝟎 𝑯𝑻𝑿𝒆𝒇𝒇 + 𝑲𝟔 𝑯𝑹𝑿𝒆𝒇𝒇 + 𝑲𝟕 𝐥𝐨𝐠 𝟏𝟎 𝑯𝑹𝑿𝒆𝒇𝒇

𝑩 = 𝑲𝟐 + 𝑲𝟓 𝐥𝐨𝐠 𝟏𝟎 𝑯𝑻𝑿𝒆𝒇𝒇 𝑪𝒎 = 𝑲𝟒 𝑫𝒊𝒇𝒇𝒓𝒂𝒄𝒕𝒊𝒐𝒏 𝑳𝒐𝒔𝒔 + 𝑲𝒄𝒍𝒖𝒕𝒕𝒆𝒓 𝒇 𝒄𝒍𝒖𝒕𝒕𝒆𝒓 + 𝑲𝒉𝒊𝒍𝒍,𝑳𝑶𝑺

• In Atoll distances between BS and MS are in meters. • Thus coefficients of the terms in models of the tools containing distance parameter have to be modified.

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Propagation models • Deriving Equivalent Parameters • SPM in Asset is based on Okumura-Hata model. • To achieve equivalent propagation models, corresponding terms in the tools have to be equated. • The tests are carried out at frequency of 2100 MHz. • Equivalent coefficient in the tools are given in the table:

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Asset coefficients

Atoll coefficients

k1= 158.92 dB

K1= k1 – 3k2 = 24.22

k2 = 44.9

K2 = k2 = 44.9

k3 = 0

K3 = k5 – 3k6 = 5.83

k4 = 0

K4 = k7 = 0.8

Asset coefficients

Atoll coefficients

k5 = -13.88

K5 = k6 = -6.55

k6 = -6.55

K6 = k 3 = 0

k7 = 0.8

K7 = k 4 = 0

--

Kclutter = 1

--

Khill.LOS = 0

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Propagation Models • Deriving Equivalent Parameters • Correction Factors in Asset and Atoll • Propagation models in the tools have additional terms as correction factors to take into account terrain height, clutter losses and diffraction losses. • Equivalent algorithms for antenna height corrections, diffraction corrections and clutter corrections are chosen in tools.

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Propagation Models • Deriving Equivalent Parameters • Verifying the derived propagation models • Derived propagation models are tested using point analysis • LTE cell coverage is determined using Reference Signal Received Power which is reported in form of Energy Per Resource Element of Reference Signal (RS EPRE) in the tools. • Discrete points at different distances were considered in point analysis • Systematically Asset gives 1 - 2dB higher RS EPRE values than Atoll does • Such differences in models should not cause significant errors in coverage, interference and capacity analysis.

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Coverage Analysis • Coverage Analysis with Original Constant Term in Atoll • Equivalent propagation models and path losses do not guarantee equivalence of coverage results. • Comparing coverage distribution of predicted RS EPRE intervals • RS EPRE range of -55 to -130 dBm in steps of -5 dB are investigated. RS EPRE Interval (dBm)

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% Coverage Area in Asset (k1=

% Coverage Area in Atoll (K1=

158.92)

24.22)

-60.00