3g project
DESCRIPTION
WCDMA for UMTSTRANSCRIPT
Design and Performance Analysis for radio planning
network
SupervisorsSupervisorsAssistant Prof.. Sherif Elsayed
KishkEng. Fahmy A. Khalifa
By /Eng Ahmed Hamed
Department of Electronics and Department of Electronics and CommunicationCommunication
Faculty of Engineering Faculty of Engineering Mansoura UniversityMansoura University
20082008
Contents
Project Motivation. UMTS Architecture. UMTS Issues. System Model and Assumptions. Uplink Admission and Handoff Procedure. Simulation Results. summary.
Project Motivation
UMTS system is considered as one of the most common 3G standards.
UMTS capacity is interference based , so its important to reach optimum design to get best performance.
Project Motivation
Project Motivation (cont’d)
Objective:How to build the program to design and simulate radio planning system.
Performance Metrics:The total system capacity.Probability of ongoing calls being dropped.Probability of incoming calls being blocked.
UMTS Architecture
UMTS Architecture
• System Features The UMTS operates in two modes FDD and
TDD.
UMTS Architecture (cont’d)• The UMTS architecture at the very highest level:
– User Equipment (UE).– UMTS Terrestrial Radio Access Network (UTRAN).
– Core network.
UMTS Architecture (cont’d) UMTS Subscriber Identity
Module (USIM) . Mobile Terminal (ME). Node B. Radio Network Controller (RNC). Mobile Switching Center (MSC). Home Location Register (HLR). Visitor Location Register (VLR).
Equipment Identity Register (EIR).
Authentication Center (AUC). GGSN (Gateway GPRS Support
Node). SGSN (Serving GPRS (General
Packet Radio Service) Support Node).
Gateway MSC.
User Equipment (UE)UE consist of two parts: Mobile Terminal (Handset)
_max output power of 2W. UMTS Subscriber Identity
Module (USIM) is a smart card that stores information about the subscriber such as:
MSISDN: Mobile Station Integrated Service Data Network.
IMSI: International Mobile Subscriber Identity.
TMSI: Temporary Mobile Subscriber Identity.
IMEI: International Mobile Equipment Identity.
UMTS Terrestrial Radio Access Network (UTRAN)
Radio Network Controller (RNC)
Serving and Drift RNCs
Core Network Architecture
Interfaces• A InterfaceThis interface exists between the MSC and the BSC and it is a pure GSM interface.
• Iu InterfaceThis interface connects the core network and the UMTS Radio Access Network.• Iub InterfaceThis interface is situated between the RNCand the Node B in the UTRAN.
• Iur InterfaceThe Iur interface connects two radio network controllers.• Gb InterfaceThe Gb interface connects the packet-
switched core network to the GSM network.
Interfaces cont.
MAP InterfacesTypes of MAP Interfaces:
Gf : fraud interface. Gp : PLMN interfaceGn : node interface . Gb : base interface.Gi :Internet interface. Gc : context interface.
UMTS Issues
Channels Types
Power Control
Handoff
Physical ChannelsPhysical Channels
Dedicated ChannelsDedicated Channels Common ChannelsCommon Channels
UMTS ChannelsUMTS Channels
transport Channelstransport Channels
Physical Channels:Physical Channels:carrier frequency, code, relative phase
Main 3G Requirements on Physical Layer:Main 3G Requirements on Physical Layer:
High bit rates up to 2 MbpsBandwidth-On-Demand = Flexible variable bit rateHigh spectral efficiency, especially in downlink
Tasks of physical layer:Error protection and detection.Control soft handover and power control.Mapping transport ch to physical ch.
Uplink Physical Channels
Dedicated uplink physical channels Common Uplink physical channels
Downlink physical channel
Dedicated physical channels Common physical channels
Frame Structure for Uplink DPDCH/DPCCH
PRACH – Physical Random-Access Channel. PRACH is used to carry RACH.
Access Slots
Frame Structure for Downlink DPCH
DPCH – Dedicated physical channels
CCPCH – Primary Common Control Physical Channel
Frame Structure for primary Common Control physicalChannel
Frame Structure for Secondary Common Control physical Channel
CCPCH – secondary Common Control Physical Channel
This channel is used by mobile stations for cell search. There are two synchronization channels _the primary and the secondary.
The primary synchronization channel transmits a modulated code, called the primary synchronization code.Every cell in a UTRAN uses the same primary synchronization code.The secondary SCH is constructed by repeating a sequence of modulated codes of 256 chips and is transmitted in parallel with the primary SCH.
Transport Channel to physical Channel Mapping
Transport channels:Transport channels:They are defined on the basis of the types of
information they transfer and how it is transferred
on the radio interface.
Dedicated Transport Channels:-DCH – Dedicated Channel DCH
Full douplex channel.carry control information between the network and mobile station .It controls (call setup, billing, handover, power,……)
SDCCH – Stand-Alone Dedicated Control Channel Full douplex channel.Used for service requests.Initiate call setup.
DTCH – Dedicated Traffic ChannelFull douplex channel
During call setup the network takes the SDCCH and gives the DTCH to the subscriber to can send speech or data.
Common Transport Channels:-Broadcast Channel (BCH) :
D.L transport channel. cell-specific parameters such as random access codes, access slots in a cell, or diversity types used. carries UTRAN system.
Paging Channel (PCH):D.L transport channel .To inform the subscriber of an incoming call.
Random Access Channel (RACH):U.L transport channel, available only in the FDD mode. Used to request a channel for a connection.
Forward Access Channel (FACH):D.L transport channel.It carries control information to terminals known to be located in the given cell .(Ack)
Other Transport Channels:-
Common Packet Channel (CPCH)uplink transport channel .carry packet data from a user.
Downlink Shared Channel (DSCH)downlink transport channel.carries user data and control information.
Uplink Shared Channel (USCH)only used in the TDD mode. carry both control and user data.
Power Control in UMTSPower control is very important for UMTS :Power control is very important for UMTS :• Minimize the interference in the system.• All signal arrives at base station’s receiver with the same signal power.• Solve Near-far problem.
Near-far effect in the up link direction
Power Control in UMTS
Types of power control:Types of power control:A. Open loop power control
B.B. Closed loop power control
C.C. Inner loop power control
Handover
Is the process in which a cellular phone is handed from one cell to the next in order to maintain a radio connection with the network. Types of Handover:
• Hard Handover (GSM).• Soft Handover (UMTS).• Softer Handover (Sectors).
Admission Control (AC)
• Admission Control occurs when new connection is set up as well as handover.
• Ac needs to check that admittance will not sacrifice the planned coverage area or existing connection.
Admission Control (AC)Ac algorithm estimates the load that the
establishment of the bearer would cause in the network.
Load Control (Congestion Control)
• It’s important to ensure that system is not overloaded and remains stable.• The possible load control actions in order to reduce load• DL fast load control (deny DL power up
command).• UL fast load control (reduce the Eb/No
target). • Handover to another WCDMA carrier.• Decrease bit rates of real time UE’s.
Load Control (Congestion Control)
HSPA
• High Speed Downlink Packet Access.• High Speed Uplink Packet Access. • HSOPA.
Technological approach
Reasons to deploy HSDPA:• Saturated voice
communication market• Growing demand and user
expectation for the data services like broadband internet access, streaming, gaming, etc.
• Competing High Speed wireless technologies:
- WLAN - WiMAX
Shorter time transmission interval (TTI)• HSDPA introduces short TTI concept,
where TTI=2ms.• Advantages: -Less probability of an error due to the
change of the channel conditions . -More efficient when packet retransmission
is necessary. -Decreased buffer size.• ARQ mechanism is placed in RNC(Rel’99): -Disadvantage: latency time up to 100 ms! -Solution: move it to node B. -Profit: latency below 10 ms• Scheduling is controlled by RNC(Rel’99): -Disadvantage: important channel
measurement information can be delayed. -Solution: move scheduling close to the air
interface. -Profit: rescheduling is made within a short
time.
Adaptive Modulation and Coding (AMC)
• Main principle –to dynamically modify Signal modulation and Coding scheme to compensate the variations in cannel conditions.
• Benefits: -Increased average cell
throughput -Reduced interference
variation -Higher data rates for users
in favourable positions.
HARQ
H-ARQ-type-IIIH-ARQ-type-II
Channel
Category Max. no of codes
Modulation Max. data rate[Mbit/s]
1 5 QPSK & 16-QAM 1.2
2 5 QPSK & 16-QAM 1.2
3 5 QPSK &16-QAM 1.8
4 5 QPSK &16-QAM 1.8
5 5 QPSK &16-QAM 3.6
6 5 QPSK &16-QAM 3.6
7 10 QPSK &16-QAM 7.3
8 10 QPSK &16-QAM 7.3
9 15 QPSK &16-QAM 10.2
10 15 QPSK &16-QAM 14.4
11 5 QPSK only 0.9
12 5 QPSK only 1.8
HSUPA
• To enhance the uplink performance.
• The key difference between uplink and downlink is the handling of the total transmission power resource.
• The power control cannot be abandoned in the case of continuous uplink transmission due to the near–far problem.
HSOPA
• OFDM divides the signal into several narrow-band sub-carriers which are designed to be narrower than the coherence bandwidth of the wireless propagation channel.
• Uses Orthogonal Frequency Division Multiplexing (OFDM) and multiple-input multiple-output (MIMO) antenna.
• Flexible bandwidth usage with 1.25 MHz to 20 MHz bandwidths. By comparison, W-CDMA uses fixed size 5 MHz chunks of spectrum.
• HSOPA will use OFDMA for the down-link and Single Carrier FDMA (SC-FDMA) for the up-link, WiMAX/802.16e-2005 uses OFDMA for both the up and down links.
• For WiMax, HSDPA serves as a form of competition that's not as fast. WiMax promises speeds of up to 70Mbps, but much more mobile.
• HSDPA will allow to increase downlink throughput and, in turn, offer advanced quality of service (QoS) capabilities and speeds that rival those delivered by cable modem and DSL service providers.
Simulation
system considerations The program is initiated by a number of
usersRandom uniform velocity distribution Vt , Uniform random directions 0→2π, Uniform random locations (X,Y), Uniform random call duration Ct Number of the serving base station and
the corresponding path gain PgThe call arrival rate to the system is considered
to be a Poisson distributed random variable with mean (L)
System model
Cell membershipPath Gain Criterion.
Users select the base station to Users select the base station to which it has the largest path gainwhich it has the largest path gain
Cell Load CriterionUsers select the base station with Users select the base station with
the smallest number of users.the smallest number of users.
System model
Each cell supplies coverage and service to a specific number of users.
Users (MS) are uniformly distributed within the unit areas.
Only the uplink is considered.The system performance is determined
by a constraint on the Signal-to-Interference Ratio (SIR) at all BSs.
A threshold value of SIR for all users in the system is required to maintain the acceptable QoS.
System model Each user in the environment is processed
by only one BS.
Cell membership is determined according to the path gain.
The system employ perfect uplink power control
(That is mean the received signal power from all users in the system is the same
Uplink Performance
n
trd
dokPP
Propagation Model
Simplified Propagation Model
010 4
log20)(d
dBk
Uplink Performance
outcellincellP
Gr
IIN
PSSIR
bG R
W
atedata
ratechipP
r
The uplink SIR
Where Sr is the received signal power. PG is the system processing gain. Np is Background Noise power
Iincell is the in-cell interferenceIoutcell is the out-of-cell interference
Uplink admission and handoff
Users select base station according to a predefined path gain criteria
New call requests as well as the handoff requests are queued (one second length queue)
A new user will be admitted as long as its SIR is above the systems’ SIRmin and those of all users are also above the minimum threshold
Handoff requests are prioritized than new call requests
[Flowchart]
Simulation result
System capacity
Blocking of new user