TE 4103 SISTEM KOMUNIKASI BERGERAK Modul 13

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TE 4103 SISTEM KOMUNIKASI BERGERAKModul 13
14. Perencanaan System CellularCase Study 3G
System Design
Jurusan Teknik Elektro Program Studi S1 SEKOLAH
TINGGI TEKNOLOGI TELKOM 2006
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Conditions of 3G Planning

• Planning should meet current standards and
  demands and also comply with future requirements.
• Uncertainty of future traffic growth and service
  needs.
• High bit rate services require knowledge of
  coverage and capacity enhancements methods.
• Real constraints
• Coexistence and co-operation of 2G and 3G for old
  operators.
• Environmental constraints for new operators.
• Network planning depends not only on the coverage
  but also on load.

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Objectives of the Planning

• Traffic Forecasting
• To measure the demand on targeted marked so as to
  allow an appropriate growth of the Network.
• Coverage
• To obtain the ability of the network ensure the
  availability of the service in the entire service
  area.
• Capacity
• To support the subscriber traffic with
  sufficiently low blocking and delay.
• Quality
• Linking the capacity and the coverage and still
  provide the required QoS.
• Costs
• To enable an economical network implementation
  when the service is established and a controlled
  network expansion during the life cycle of the
  network.

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Business Planning

• Marketing is responsible the revenue side and
  must also produce a traffic forecast.
• The engineering model must translate the traffic
  forecast into a network plan and generate the
  capex and opex numbers to be passed to the
  financial model.
• The financial model takes in information from
  marketing, including key metrics, revenue
  forecast, acquisition costs and capex, opex from
  the engineering model.

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Financial model

• Capturing all the detail of the customer base
  dynamics, the financial model allows the most
  comprehensive and rigorous approach to
  forecasting the cost base and ultimately a
  valuation.
• The financial model outputs are those used by
  decision makers at board level and the financial
  community.
• The presentation pack produced by the financial
  model provides a complete business case, which
  takes the reader from an analysis of the
  population through to a range of valuations.
• The valuation of the business case is the
  ultimate objective of the suite of models.

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The model combines inputs from the marketing and
the engineering models with operating cost
assumptions to forecast the financial statements
and free cash flow.
Engineering Models Network Opex and Capex
Forecasts
Market Forecast Model
Operational Structure, Distribution Channels,
Staffing etc.
Customers and Revenue Forecasts
Business Planning Model
Operating Cost Assumptions
Network Capex and Opex Forecast
All figures in Nominal Local Currency
Free Cash Flow in Nominal Local Currency
(Operating Cash Flow less Capital Expenditure)
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Marketing Model
What kind of Services do we offer?
Revenue Forecast
How many customers do we have?
How much are they willing to spend?
Traffic Forecast
What are our tariffs?
Essentially the question is how many customers
are there and what does the mobile operator has
to deliver for the money paid by those customers.
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Cost and Revenue Structure
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The Diversity of 3G Applications and Sources of
Billing
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3G Tariff Dimensions for different Services
Packages
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Tariff Plans to Suit Market Segments and
Applications.
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Pendahuluan
Implementasi suatu jaringan telekomunikasi di
suatu wilayah disamping berhadapan dengan
regulasi telekomunikasi, juga akan berhadapan
dengan situasi pasar yang harus dipelajari dengan
seksama untuk mengantisipasi berbagai
kemungkinan. Di bawah ini adalah 3 tugas besar
yang harus dikerjakan seorang analis pasar ...
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Siklus Perencanaan Sistem Cellular
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Apa sesungguhnya peranan seorang engineer ?
Setelah menerima laporan dari analis ekonomi yang
meneliti kelayakan ekonomi, tugas seorang
engineer untuk mewujudkan jaringan yang andal
dari sisi kapasitas, kualitas dengan biaya
seefisien mungkin
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Lalu..
Sebelum merencanakan sistem, seorang engineer
harus memiliki pengetahuan yang mendalam mengenai
dasar-dasar teknologi selular, yang meliputi
struktur sel, channel asignment, cell splitting,
sistem sel overlay, pemrosesan panggilan, konsep
propagasi radio , dan berbagai prinsip lainnya.
Seperti yang sudah dijelaskan dimuka, bahwa
langkah pertama desain jaringan telekomunikasi
selalu berdasar tentang estimasi apa yang akan
terjadi pada masa datang terhadap jaringan yang
hendak direncanakan. Dalam hal ini prediksi
trafik telekomunikasi merupakan hal penting yang
pertamakali akan dilakukan. Filosofi umum dari
desain jaringan telekomunikasi adalah mendapatkan
performansi terbaik dengan minimal cost.
Performansi radio meliputi kualitas kanal fisik
untuk kontrol / signalling dan juga kanal fisik
suara. Dalam kaitan ini, ukuran dari kualitas
transmisi adalah S/(IN) atau biasa disebut RF
signal to impairement ratio. Seorang RF
enginner harus menganalisis 2 macam kondisi
(1), Pada kondisi yang terburuk, dan (2), Pada
kondisi rata-rata yang dicapai oleh jaringan yang
didesain. Dalam hal ini, kondisi performansi
rata-rata akan menunjukkan ukuran persepsi
pelanggan mengenai kualitas yang akhirnya
bermuara pada kepuasan pelanggan. Sedangkan
analisis kondisi terburuk adalah untuk mencegah
berbagai kasus terburuk yang mungkin akan
terjadi.
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Adalah cukup sulit untuk mencapai performansi
yang diharapkan pada lingkungan komunikasi
mobile yang sangat kompleks. Karena itu
diharapkan seorang engineer memiliki berbagai
pengetahuan untuk melakukan optimalisasi sistem
yang nantinya akan melibatkan berbagai solusi
kompromi dari berbagai kondisi trade off yang
nantinya akan dihadapi. Berbagai metoda
optimalisasi jaringan komunikasi bergerak seluler
ini diberikan pada bagian selanjutnya.
Tujuan Perencanaan Jaringan Selular...

• Kapasitas
• Coverage
• Kualitas

Goal
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Tujuan dari Perencanaan
Perencanaan jaringan dimulai dari alokasi lebar
pita frekuensi yang diberikan pemerintah kepada
suatu operator seluler. Alokasi lebar pita
frekuensi inilah yang digunakan oleh operator
untuk memberikan layanan komunikasi dengan
kualitas komunikasi yang sebaik-baiknya dan untuk
sebanyak-banyaknya user.
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Diagram Alir Perencanaan Sel
START
Kapasitas
Prediksi trafik yang dibutuhkan sampai dengan
beberapa tahun ke depan (Analisis statistik
demand)
Analisa kapasitas yang dibutuhkan Atot
(Erlang) Kapasitas sistem dari BW yang
dialokasikan Asel (Erlang / sel)
END
Kualitas
Yes

• OPTIMASI
• Threshold handover
• Daya Pancar
• Noise Figure, dll

KUALITAS OKE ?
No
Jumlah sel Atot /Asel (sel)
Analisa Pathloss Analisa Link Budget Perhitungan
Daya Frequency Planning
Coverage
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Traffic Forecasting
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Proses Cell Planning

• Proses sell planning dapat menggambarkan
  semua kegiatan yang digunakan dalam proses
  perencanaan cellular,dan mengkonfigurasikannya
  sehingga sesuai dengan kondisi yang sebenarnya .
• Cell planning dimulai dari menganalisa
  trafik dan daerah cakupan yang dinginkan dengan
  cara terlebih dulu mengetahui kondisi geografinya
  serta jumlah yang dibutuhkan untuk mengcover
  pelanggan.
• Data yang dibutuhkan diantaranya
• Biaya
• Kapasitas
• Daerah cakupan
• Grade Of service (GoS)
• Frekuensi
• Speech Quality Index (SQI)
• System growth capability
• Kebutuhan traffic menggambarkan kondisi
  dalam mendesain system yang ingin dirancang dan
  mengkonfigurasikannya sehingga sesuai dengan
  kondisi geografis dari daerah yang sebenarnya
  tersebut.
• Hal-hal yang perlu diperhatikan dalam hal
  perkiraan kondisi geografis adalah
• Jumlah penduduk
• Jumlah Pelanggan Telephone
• Level keuntungan
• Land usage data
• Pengguna telephone
• Dan faktor lainnya seperti harga ponsel

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Traffic Forecasting

• Penetration total subscribers
• Customers, gross adds, churn
• Voice, data and other source of revenues
• User growth joint up to maturity of the network.
• As initial works to measure the required capacity

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Demographic Anatomy of Targeted Market (i-th
year!)
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Propensity to Adopt Mobile Comm. by Age example
from Western European country Age is an
important discriminator.
A Western European country, sample 1,000
interviews 1997
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Correlation between propensity to adopt mobile
income example lower income country Income
matters.
A Far Eastern country, sample 1,500 interviews
1996
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Penetration Growth

• The potential demand assumptions should be linked
  to changing demographic patterns and changes in
  income.
• The potential demand sets a penetration ceiling,
  conceptually the maximum potential penetration is
  the level at which the service life cycle curve
  reaches its upper limit.

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Growth of Subscribers
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Traffic Growth

• e.g voice traffic/user 27 mErl which comprises
  80 of total traffic, Data traffic/user 10 mErl
  which is the rest of total traffic. Combined
  average generated traffic per user is 23.1 mErl.

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The Traffic Data from the Marketing Model Drives
Network Dimensioning.

• Because the model is intended to be used in the
  business-planning phase, it is essential that a
  range of scenarios can be evaluated rapidly.
• The impact of varying, for example, different
  tariffs can be calculated instantly.
• The engineering model can run completely in the
  background so that business planners can run
  scenarios without recourse to engineering.

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The Engineering Model covers Capex and Opex for
2G and 3G Networks.

• The capex and opex part of the 3G Mobile Toolkit
  covers the technical aspects, including capital
  and operational expenditures.
• The scope of the 3G engineering model includes
  dimensioning and costing for the following
  elements
• Radio network
• Core network interconnect
• Server network

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ENGINEERING MODEL
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Whats New on 3G

• Multiservice environment
• Highly sophisticated radio interface.
• Bit rates from 8 kbit/s to 2 Mbit/s, also
  variable rate.
• Cell coverage and service design for multiple
  services
• different bit rate
• different QoS requirements.
• Various radio link coding/throughput adaptation
  schemes.
• Interference averaging mechanisms
• need for maximum isolation between cells.
• Best effort provision of packet data.
• Intralayer handovers

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Whats New on 3G

• Air interface
• Capacity and coverage coupled.
• Fast power control.
• Planning a soft handover overhead.
• Cell dominance and isolation
• Vulnerability to external interference

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Whats New on 3G

• 2G and 3G
• Co-existence of 2G and 3G sites.
• Handover between 2G and 3G systems.
• Service continuity between 2G and 3G.

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3G (WCDMA) Radio Network Planning Process
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1st. Coverage

• coverage regions
• area type information
• Dense Urban, Urban, sub-urban, or rural
• propagation conditions
• Indoor, outdoor

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Radio Link Budgets (WCDMA)

• There are some WCDMA-specific parameters in the
  link budget that are not used in a TDMA-based
• Interference margin
• it is needed due to the traffic loading of the
  cell. The more loading is allowed, the larger is
  the interference margin needed in the uplink, and
  the smaller is the coverage area. Typical values
  for the interference margin are 1.03.0 dB,
  corresponding to 2050 Cell loading.
• Fast fading margin (power control headroom)
• Some headroom is needed in MS TX power for
  maintaining adequate closed loop fast power
  control to be able to effectively compensate the
  fast fading. Typical values for the fast fading
  margin are 2.05.0 dB for slow-moving MS.
• Soft handover gain
• Soft handover gives an additional macro diversity
  gain against fast fading by reducing the required
  Eb/No relative to a single radio link. The soft
  handover gain is assumed between 2.0 and 3.0 dB

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RLB Assumptions for MS and BS
MS
BS
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Example of WCDMA RLB for Voice
Link budget of AMR 12.2 kbps voice service (120
km/h, in-car users, Vehicular A type channel,
with soft handover)
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Example of WCDMA RLB for Data
Link budget of 144 kbps real-time data service (3
km/h, indoor user covered by outdoor BS,
Vehicular A type channel, with soft handover)
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Cell range calculation
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RLB Okumura-Hatta Model

• The propagation model describes the average
  signal propagation in an environment, and it
  converts the maximum allowed propagation loss in
  dB on the row u to the maximum cell range in
  kilometres.

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Maximum and Average Path Loss in Macro Cells
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Cell Range

• From the RLB above, the cell range R can be
  calculated. e.g with the OkumuraHata propagation
  model for an urban macro cell with base station
  antenna height of 30 m, mobile antenna height of
  1.5 m and carrier frequency of 1950 MHz
• L 137.4 35.2 log10 (Rkm) ..Urban
• L 129.4 35.2 log10 (Rkm) Sub-Urban

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Cell Range

• From RLB above, MAPL for 12.2 kbps voice service
  is 141.9 dB
• Urban Rcell 1.34 km
• Sub-urban Rcell 2.27 km
• For 144 kbps data service with MAPL 133.8 dB
• Urban Rcell 0.79 km
• Sub-urban Rcell 1.33 km

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2nd. Capacity

• Spectrum availability
• Subscriber growth forecast
• Traffic density information to estimate the
  amount of supported traffic per base station
  site.

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3th. Quality of Service

• Area location probability (coverage
  probability)
• Blocking probability
• End user throughput.

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3G W-CDMA Capacity (1)
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3G W-CDMA Capacity (2)
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Uplink Load Factor

• Load Factor

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Downlink Load Factor
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Noise Rise Capacity

• The load equation predicts the amount of noise
  rise over thermal noise due to interference.
• The noise rise is equal to -10log10(1 hUL).
• The interference margin on row i in the link
  budget must be equal to the maximum planned noise
  rise.

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Example (DL) Load Factor Calculation

• Assume the required aggregate cell throughput in
  kbps. Through-put is equal to the number of users
  Nx(bit rate R)x(1 - BLER).
• Calculate load factor DL from Equation above.
• Calculate average path loss from RLB.
• Calculate maximum path loss by adding 6 dB.

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Maximum Path Loss Calculations for Data
Transmission
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Capacity vs Coverage
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Base Station Transmission Power

• The minimum required transmission power for each
  user is determined by the average attenuation
  between base station transmitter and mobile
  receiver, L, and the mobile receiver sensitivity,
  in the absence of multiple access interference
  (intra- or inter-cell). Then the effect of noise
  rise due to interference is added to this minimum
  power and the total represents the transmission
  power required for a user at an average
  location in the cell. Mathe-matically, the total
  base station transmission power can be expressed
  by the followingequation

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Effect of BS TX Power to DL Capacity and Coverage
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Capacity per Subscriber

• Capacity depends on AMR rate (voice) and data
  rate for the associated Eb/No.
• e.g. 5 MHz W-CDMA carrier capacity is 800
  kbps/cell or 80 voice channels/cell, Downlink
  Packet Access (HSDPA) carrier capacity is 2000
  kbps/cell.
• Cell capacity utilisation is 80 during busy
  hours
• Busy hour carries 20 of daily traffic.
• 1000 subscribers per site
• 3 sectors per site, 2 carrier (i.e 10MHz),
  Config. 222

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Capacity per Subscriber

• Uplink
• Equivalent with 1725 minutes/Subc./month
• Downlink Packet Access
• 650 MB/Subc./Month
• With split 50/50, we get 325 MB 862
  min/subc./month

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Typical Capacity of W-CDMA

• Capacities per km2 with macro and micro layers
  in an urban area

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Iteration of Capacity and Coverage Calculations
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Case Study Planning in Espoo, Finland

• Please refer to
• Hari Holma Antti Toskala, WCDMA for UMTS,
  3rd Ed., John Wiley Son, 2004, p.210 214.
• Course Work Make a resume from that section!
  Submit due to the end of Semester (before UAS).

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Network Optimisation

• Network optimisation is a process to improve the
  overall network quality as experienced by the
  mobile subscribers and to ensure that network
  resources are used efficiently. Optimisation
  includes
• Performance measurements.
• Analysis of the measurement results.
• Updates in the network configuration and
  parameters.

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Network Optimisation Process
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Network Performance Measurements
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Network Tuning with Antenna Tilts
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GSM - WCDMA Co-Planning

• Utilisation of existing base station sites is
  important in speeding up WCDMA deployment and in
  sharing sites and transmission costs with the
  existing GSM networks. The feasibility of sharing
  sites depends on the relative coverage of the
  existing network compared to WCDMA. Typical
  maximum path losses with existing GSM and with
  WCDMA

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Co-siting of GSM and WCDMA

• Since the coverage of WCDMA typically is
  satisfactory when reusing GSM sites, GSM site
  reuse is the preferred solution in practice.
• The co-siting of GSM and WCDMA is taken into
  account in 3GPP performance requirements and the
  interference between the systems can be avoided.
• Co-sited WCDMA and GSM systems can share the
  antenna when a dual band or wideband antenna is
  used. The antenna needs to cover both the GSM
  band and UMTS band. GSM and WCDMA signals are
  combined with a diplexer to the common antenna
  feeder.
• The shared antenna solution is attractive from
  the site solution point of view but it limits the
  flexibility in optimising the antenna directions
  of GSM and WCDMA independently.
• Another co-siting solution is to use separate
  antennas for the two networks. That solution
  gives full flexibility in optimising the networks
  separately.

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Co-siting of GSM and WCDMA