KFUPM COE 543 Mobile and Wireless Networks Course Project

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KFUPMCOE 543 Mobile and Wireless NetworksCourse
Project

• Capacity Evaluation for UMTS Integrated-service
  Network
• design and Simulation
• By Raed Mesmar

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Presentation Layout

• What is UMTS
• Services Offered
• Network Architecture
• Frequency Bands Modulation Techniques
• Channels Frames
• The Common Packet Channel (CPCH) Operation
• Capacity Study Simulation
• END

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What is UMTS

• Universal Mobile Telecommunications System
• Evolution of the GSM 2G to 3G
• Partly based on the GSM
• Main feature of UMTS is higher user bit rates
• circuit-switched connections 384 kbps
• packet-switched connections up to 2 Mbps
• One of several proposals by IMT-2000
• Accepted by the ITU
• SDO developed these proposals
• The UMTS is being developed by the
  Third-Generation Partnership Project (3GPP).
• It has been introduced in phases to gain global
  acceptance
• The most recent releases are release 99 and
  release 2000

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Services Offered

• UMTS system has been designed with information
  services in mind
• Bearer characteristics are most appropriate for
  carrying information
• The bearer properties could be changed during a
  session
• This is done either by the application or the
  network
• Four classes of services are defined
• Conversational
• Streaming
• Interactive
• Background classes

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Services Offered contd

• Conversational
• The most delay sensitive class serving voice
  calls
• The quality of service is measured by the maximum
  allowable delay
• 400ms end-to-end
• The traffic is symmetric or almost symmetric
• AMR speech rate
• Adaptive Multi-Rate Technique
• The multi-rate speech coder is a single
  integrated speech codec with eight source rates
  12.2 (GSM-EFR), 10.2, 7.95, 7.40 (IS-641), 6.70
  (PDC-EFR), 5.90, 5.15 and 4.75 kbps
• video telephony services
• This class is designed to serve multimedia
  applications

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Services Offered contd

• Streaming
• data can be transferred and then processed as if
  it is a steady stream
• i.e. multimedia files could be displayed before
  being fully downloaded
• traffic type is asymmetric
• delay is tolerable
• more jitter in the transmission can be
  accommodated
• Interactive
• characterized by the request response pattern of
  the end-user
• The application depends directly on the end-user
  response
• end user could either be a human or a machine
• Human end user application
• web browsing
• server access
• Machine end-user application
• automatic database enquiry

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Services Offered contd

• Background classes
• destination is not expecting the data within a
  certain window of time
• data has to be received error free
• E-mail delivery
• SMS
• database downloading
• Terminal Classes
• 32 kbps class speech service AMR some limited
  data rate capabilities up to 32 kbps 
• 64 kbps class speech and data service
  simultaneous data and AMR speech capability
• 128 kbps class video telephony or various other
  data services 
• 384 kbps class being further enhanced from 128
  kbpshas multi-code capability which
• 768 kbps class an intermediate step between 384
  kbps and 2 Mbps class
• 2 Mbps class the state of the art class and has
  been defined for downlink direction only

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Network Architecture

•  
•  
•   NB
•  
•  
• NB
• 
  RNC
•  
• UE
• NB
• UU
  IU
  CN
•  
• NB
•  
• 
  RNC
•  
• NB
•  

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Frequency Bands
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Frequency Bands contd

• UTRA-FDD
• Uplink 1920-1980 MHz
• Downlink 2110-2170 MHz
• duplex spacing 190 MHz
• 12 channels, each 5 MHz
• UTRA-TDD
• 1900-1920 MHz
• 2010-2025 MHz
• 5 MHz channels
• Constant chipping rate of 3.84 Mchip/s
• Different user data rates supported via different
  spreading factors

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Channels Structures

• 13 total Physical Channels
• 3 common channels
• 1 uplink channel
• 11 downlink channels
• 1 uplink/downlink channel

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Channels Structures contd

• DPCH (Dedicated Physical Channel)
• DL UL channel
• carries user information or control information
  to the UE
•  
• PRACH (Physical Random Access Channel)
• DL channel
• carries control information to the UE or short
  user packets,
•  
• PCPCH (Physical Common Packet Channel)
• UL common channel
• DSMA-CR
• carries short and medium size user packets
•  
• CPICH (Common Pilot Channel)
• DL channel
• Fixed rate
• carries a predefined bit/symbol sequence

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Channels Structures contd

• P-CCPCH (Primary Common Control Physical
  Channel)
• DL common channel
• 90 duty cycle operation
• broadcasts the system and cell specific
  information
•  
• S-CCPCH (Secondary Common Control Physical
  Channel)
• DL channel
• carries FACH and PCH transport channel
•  
• SCH (Synchronization Channel)
• DL channel
• consists of two sub-channels Primary and
  secondary SCH
• used for cell search
•  
• PDSCH (Physical Downlink Shared Channel)
• DL channel
• carries DSCH transport channel

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Channels Structures contd

• AICH (Acquisition Indicator Channel)
• DL channel
• fixed rate
• carries access preamble acquisition indicators
  for random access procedures
• AP-AICH (Access preamble acquisition Indicator
  Channel)
• DL channel
• fixed rate
• carries access preamble acquisition indicators of
  CPCH 
• PICH (Paging Indicator Channel)
• DL channel
• fixed rate
• carries paging indicators to indicate the
  presence of a page message on the PCH
•  
• CSICH (CPCH Status Indicator Channel)
• DL channel
• fixed rate
• carries CPCH status information

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Channels Structures contd

• CD/CA-ICH (Collision-Detection/Channel Assignment
  Indicator Channel)
• DL common channel
• fixed rate
• carries the CD indicator only if the CA is not
  active,
• or carries the CD/CA indicator if the CA is
  active

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The Common Packet Channel (CPCH)

• designed for the transfer of user packet data
• supports two types of services
• non-real time services
• E-mail (SMTP)
• web browsing (HTTP)
• file transfer (FTP)
• real time services
• video and the voice over IP (H323)
• operates at variable rate that could reach up to
  960 ksps
• maximum possible packet length over the CPCH
  channel is 64 frames (640 ms)

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CPCH elements

• UL-CPCH implements implements Digital Sense
  Multiple Access with Collision Resolution DSMA/CR
• uplink burst consists of four elements
• Access Preamble Element (APE)
• used to request for a CPCH from the UMTS network
• Collision Resolution Element (CRE)
• used to resolve collision
• Power Control Preamble Element (PCPE)
• carries the power control from the UE
• Message Element (ME)

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CPCH Access Procedures

• 16 CPCH channels operating at 8 different data
  rates are offered
• CPCH has one Access Preamble (AP) signature
  associated with one data rate
• Two modes of operation are supported
• UE channel selection
• UTRAN channel selection
• The access procedures consists of four phases
• Access Phase (AP)
• Collision Resolution Phase (CRP)
• Pre-Data Power Control Phase (PDPCP)
• Message Transmission Phase (MTP)

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CPCH Access Procedures contd

• Access Phase (AP)
•  
• aims at gaining access to one free CPCH channels
• CPCH channel information is broadcasted over the
  Broadcast Channel
• UE periodically monitors the Status Broadcast
  Channel
• UE randomly picks up a signature associated with
  a free CPCH
•  UE increases its preamble access power till its
  acknowledged by the network
• There are 15 equally spaced access slots in 20
  broadcast channels
• The access slot is 1.33 ms long and the signature
  is 1 ms long
• signature ramp up process 
• UE transmits a signature and waits for a response
  in the next 3-to-4 access slots
• If no response UE transmits another preamble at a
  higher power until positive acquisition
  indication
• AP-AICH carries the response to the UE

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CPCH Access Procedures contd

• Collision Resolution Phase (CRP)
• aims at securing one CPCH to one UE at a given
  time
• Many UEs could pick up the same signature for
  the same CPCH
• This is due to randomness in selecting the
  signature
• Thus collision has to be resolved first before
  granting access to any UE
• UE picks up one of available NCD collision
  Detection signatures
• NCD 16
• One UE randomly picks up 1 of the NCD signatures
• The Base Node transmits the selected CD
  signatures over the CD/CA indication channel
  (CD/CA-ICH)
• probability that two UEs pick up the same NCD is
  1/16
• Thus CRP minimizes collision probability but does
  not bring it zero!
• a MAC-based Back-Off mechanism occurs under
  collision conditions

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CPCH Access Procedures contd

• Pre-Data Power Control Phase (PDPCP)
•  
• aims at setting the appropriate power levels to
  start transmission
• Duration 0-to-5 ms
• It helps the inner loop power control to
• converge
• correct any error in the open loop power control
  estimation.

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CPCH Access Procedures contd

• Message Transmission Phase (MTP)
• The last phase in the access procedure
• Aims at uploading the message
• A dedicated downlink control channel (DPCCH)
  associated with the uplink Common Packet Channel
  (CPCH) sent during the phase
• (DPCCH) provide power control, and pilot
  information
• dedication provides security against any false
  UE
• If the UE detects loss of DL-DPCCH during
  transmission of the power control preamble or the
  packet data then the UE
• halts UL-CPCH transmission,
• aborts the access attempt
• sends a failure message to the MAC layer

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CPCH Access Procedures

• DL
  acknowledgement CR acknowledgement
• 
  AP-AICH CD-AICH
• 
  
  DL-PC DL-DPCCH
• DL
• 
  
  UL-PC UL-Packet
• UL
• 
  AP Contention Resolution
• Power Ramp
  Preamble

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Capacity Study Simulation

• Aims at
• Determining SIR behavior under increasing number
  of MS
• Tracking the adaptive modulation behavior of the
  UMTS network
• Determining the system throughput
• General Assumptions
• Cluster of 19 cells
• sectorized cell, 6 sectors per cell gt 1
  interfering BS
• 95 successfull covarege fringe is targeted
• cell radius 2 Km
• Max Power TX by BS 20 W gt 10log10(20000)
  43.01 dBm 43 dBm
• Pilot Power TX by BS 1 W gt 10log10(1000)
  30 dBm
• power transmitted by Active Set MS 2 mW gt
  10log10(2) 3dBm
• power transmitted by Down Loading MS 125 mW gt
  10log10(125) 21dBm

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Simulation setup

• For the same PASS the number of MS is fixed and
  assumed stationary
• At the beginning of the simulation all MS are at
  Active Set Mode
• PASMS 3dBm
• Initial system SIR is calculated, Background
  noise SYS-SIR !
• One MS at a time switches to Down Loading Mode
• PDLMS 21dBm
• Thus the SYS_SIR is recalculated every time a MS
  switches between modes
• For simplicity all MSs switch in one direction
  DLMS
• If min(SYS_SIR) drops below a threshold, BS power
  is ramped up
• This condition could be alternatively applied!
• The Modulation rate is selected based on SIR at
  MS location
• Capacity is calculated based on the Modulation
  Rate
• A second Pass is tried with a different MS number

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Running the Simulation

• Random MS location assignment
• Background SYS_SIR
• MS switching from ASMS to DLMS
• SYS_SIR recalculation
• Reason why?
• By altering Path Loss Model for MS to MS
  interference the SYS_SIR changes significantly
• Power assignments of system
• Path Loss Model
• ?

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Results

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References

• 1 3G Mobile Communication Technologies, March
  2001 Throughput of High Speed DOWNLINK PACKET
  ACCESS FOR UMTS, T J Moulsley
• 2 The International Engineering Consortium,
  UMTS Protocols and Protocol Testing
• 3 Mobile Computing and Communications Review,
  Volume4, Number3, GPRS and UMTS Release 2000
  ALL-IP option, Jonne Soininen
• 4 IEEE 2000, Transport Architecture Evolution
  in UMTS/IMT-2000 Cellular Networks, Barani
  Subbiah
• 5 Technical Overview of UMTS Natalia V.
  Rivera - presentation
• 6 Mobile Communications Cahpter 4 Wireless
  Telecommunications Systems Prof. Dr.-Ing. Jochen
  Schiller, http//www.jochenschiller.de/ MC SS02 -
  presentation
• 7 Rysavy Research Data Capabilities for GSM
  Evolution to UMTS Peter Rysavy
• 8 forum, UMTS Services and Applications Jouni
  Salonen, Antti Toskala and Harri Holma
• 9 White paper! An Overview of Common Packet
  Channel in 3GPP W-CDMA System Method,
  Performance Simulations, Benefits and
  Applications Kourosh Parsa, GBT, Emmanuel
  Kanterakis, GBT, Nader Bolourchi, Motorola,
  Inhyok Cha, Lucent, Saied Kazeminejad, SBC
  Technology Resources
• 10 IEEE 2002, Capacity Benefits of Node B
  Power Sharing in a Homogenous Circuit Switched
  UMTS Network Davood Molkdar and Jonathan
  Wallington
• 11 ETSI Telecomunicaci?n, Ciudad Universitaria,
  28040 Madrid, Spain Quality of Service Support
  in the UMTS Terrestrial Radio Access Network
  Ana-Belén Garc?a, Manuel Alvarez-Campana, Enrique
  V?zquez, Julio Berrocal
• 12 2000 IEEE Harmonization of Global
  Third-Generation Mobile Systems M. Zeng,
  Motorola Inc. A. Annamalai, Virginia Polytechnic
  Institute State University Vijay K. Bhargava,
  University of Victoria

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END !