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Soc Classification level Presentation / Author / Date 1 © Nokia Siemens Networks
3G BASIC THEORY
Soc Classification level Presentation / Author / Date 2 © Nokia Siemens Networks
WHAT IS 3G?WHAT IS 3G?
- stands for THIRD GENERATION mobile technology
- NTC clarified it viewed 3G as enhancement and improvement of the 2nd Generation Technology
- it is a wireless technology designed to allow a certain device to access to voice, video and data services at much faster rates than can be achieved today
Soc Classification level Presentation / Author / Date 3 © Nokia Siemens Networks
OBJECTIVE:OBJECTIVE:To EXPLORE:
- The History and roadmap of mobile Telecommunication
- 3G Basic Technology
- 3G Basic Network Architecture
- 3G Basic Nature and Behavior
Soc Classification level Presentation / Author / Date 4 © Nokia Siemens Networks
The mobile communications industry has evolved in three stages:
Voice call Voice call,fax, data and text messaging
1G 2G – 2.5 G 3G
High speed data transfer.
New video, audio and Mobile TV,Internet browsing and Music download
Soc Classification level Presentation / Author / Date 5 © Nokia Siemens Networks
Soc Classification level Presentation / Author / Date 6 © Nokia Siemens Networks
3G SERVICES 3G SERVICES
Soc Classification level Presentation / Author / Date 7 © Nokia Siemens Networks
3G – 3rd Generation: Digital Cellular –
1) Feature: – Wide band code division multiple access (WCDMA)
technology– digital signal– Broadband (5Mhz Bandwidth)– integrated service system integrating all current mobile
telephone system functions providing multiple services– large capacity
2) Radio Frequency Spectrum (UHF – Ultra high Frequency)– frequency spectrum around 2000MHz or 2GHz – Data rate up to 2000kbps or 2Mbps
Soc Classification level Presentation / Author / Date 8 © Nokia Siemens Networks
What triggered them to implement 3G?What triggered them to implement 3G?
Voice services currently account for more than 90 percent of income, but by the year 2005 it has been forecasted that data and other non-voice services will generate 50 percent of operator income.
Soc Classification level Presentation / Author / Date 9 © Nokia Siemens Networks
What is IMT-2000What is IMT-2000
"International Mobile Telecommunications – 2000 (IMT-2000)
represents the global standard for meeting the emerging needs of
mobile telecommunications in the 21st century whereby mobile
telecommunications subscribers will be able to access voice, data,
Internet, and multimedia services at any time and at any place."
Soc Classification level Presentation / Author / Date 10 © Nokia Siemens Networks
The Goal of IMT 2000
- Higher transmit rate 2Mbps
- Rich and colorful service
- Good voice quality
- Larger capacity
- Lower cost
- Good security performance
- High frequency efficiency
- Increased Mobility
- Easy to transition from 2G
Soc Classification level Presentation / Author / Date 11 © Nokia Siemens Networks
U101 11
IMT-2000 Candidate Harmonization
A number of technologies were submitted many of which had distinct similarities
Of course operators were generally keen on a single standard to allow global roaming and economies of scale• Operators Harmonization Group (OHG)
This led to two partnership projects being set up:• 3rd Generation Partnership Project (3GPP)
– Dealing with WCDMA (Also Known as Universal Mobile Telephone Systems UMTS) and related candidate technologies
• 3rd Generation Partnership Project 2 (3GPP2)– Dealing with cdma2000 and related candidate
technologies
Soc Classification level Presentation / Author / Date 12 © Nokia Siemens Networks
IMT 2000 Roadmap
HSDPA HSUPA
3GPP 3GPP23rd Generation Partnership Project
Soc Classification level Presentation / Author / Date 13 © Nokia Siemens Networks
Where is Philippines?Where is Philippines?
Soc Classification level Presentation / Author / Date 14 © Nokia Siemens Networks
1920M1920M 1980M1980M
( Uplink : 1920-1980 )
2110M2110M 2170M2170M
( Downlink : 2110-2170 )
1920-1980 2110-2170
Uplink Downlink
NTC Spectrum Allocation for WCDMA
Soc Classification level Presentation / Author / Date 15 © Nokia Siemens Networks
1920M
1920M
1980M
1980M
( Uplink : 1920-1940 )
2110M
2110M
2170M
2170M
( Downlink : 2110-2130 )
1920-1940 2110-2130
Uplink Downlink
NTC Allocated for GLOBE 3G (WCDMA)
1960M
1960M
1980M
1980M
( Uplink : 1960-1980 )
2110M
2110M
2170M
2170M
( Downlink : 2110-2170 )
1960-1980 2150-2170
Uplink Downlink
Soc Classification level Presentation / Author / Date 16 © Nokia Siemens Networks
RADIO FREQUENCIES
Where IS GLOBE 3G ?Where IS GLOBE 3G ?
Soc Classification level Presentation / Author / Date 17 © Nokia Siemens Networks
Globe needs these 3G frequency spectra to upgrade its current CMTS (Cellular Mobile Telephone System) services to 3G.
Globe will remit the corresponding spectrum user fees and post a performance bond equivalent to P300 million to the NTC to comply with the rules on the allocation of 3G radio frequency bands.
Soc Classification level Presentation / Author / Date 18 © Nokia Siemens Networks
HIERARCHICAL CELL STRUCTURES
Pico Cell
Few meters to 100
Micro cell
200 -500 meter range
Macro Cell
Few meters to 100
Soc Classification level Presentation / Author / Date 19 © Nokia Siemens Networks
HIERARCHICAL CELL STRUCTURESMacro Cells - carry the faster-moving wide-area traffic.
Micro Cells carry the higher-data-rate pedestrian traffic.
Pico Cells are deployed to cover ‘hot spots’ to relive capacity bottlenecks such as in offices or airports where user density is particularly high.
Soc Classification level Presentation / Author / Date 20 © Nokia Siemens Networks
WHAT IS WCDMA?
- stands for Wide-Band Code Division Multiple Access
- is a type of Cellular Network
- it is the higher speed transmission protocol used in the UMTS (Universal Mobile Telephone Systems)
Soc Classification level Presentation / Author / Date 21 © Nokia Siemens Networks
W-CDMA is a wideband spread-spectrum mobile
Air-interface that utilizes the direct-sequence spread
Spectrum method of asynchronous code division
multiple access to achieve higher speeds and
support more users compared to the implementation
of time division multiplexing (TDMA) used by
2G GSM networks.
Soc Classification level Presentation / Author / Date 22 © Nokia Siemens Networks
What is Bandwidth?
Bandwidth is the difference between the upper and lower cutoff frequencies, and is typically measured in hertz
Soc Classification level Presentation / Author / Date 23 © Nokia Siemens Networks
What is the Bandwidth?
1920M1920M 1930M1930M
5Mhz
Soc Classification level Presentation / Author / Date 24 © Nokia Siemens Networks
What is Code?
A code is a rule for converting a piece of information (for example, a letter, word, phrase, or gesture) into another form or representation (one sign into another sign), not necessarily of the same type.
Soc Classification level Presentation / Author / Date 25 © Nokia Siemens Networks
Example of a Code?
Soc Classification level Presentation / Author / Date 26 © Nokia Siemens Networks
• Scrambling Codes – Are used to separate cells and terminals from each other rather than
purely channels
A UE is surrounded by Base Stations, all of them transmitting on the same CDMA Frequency.
A UE must be able to discriminate between different Sectors of different Node B’s.
The Downlink Scrambling Codes can be used in 512 different ways in a CDMA system. Each one of them constitutes a mathematical code which can be used to identify a particular sector.
.
A BCode ChannelsScrambling Code 1
Code ChannelsScrambling Code 2
WCDMA CODE Scrambling Code
Soc Classification level Presentation / Author / Date 27 © Nokia Siemens Networks
What is Multiple Access?
Imagine you are in a cocktail party…
Now imagine you are trying to talk to somebody
If you are trying to listen to somebody you need to be able to pick out their speech from everybody else’s speech
Everybody is using the same medium to talk – the air in the room
There are a number of different Multiple Access strategies…
Simultaneous private use of a transmissionmedium by multiple, independent users.
Soc Classification level Presentation / Author / Date 28 © Nokia Siemens Networks
What is Channel?
An individually-assigned, dedicated pathwaythrough a transmission medium for one user’s information.
Soc Classification level Presentation / Author / Date 29 © Nokia Siemens Networks
What is Transmission Medium
The transmission medium is a resource that can be subdivided into individual channels according to the technology used.
Each pair of users enjoys a dedicated,
private circuit through the transmission
medium, unaware that the other users exist.
Transmission
Medium
Soc Classification level Presentation / Author / Date 30 © Nokia Siemens Networks
Types of Multiple AccessA. FDMA Frequency Division Multiple Access• Each user on a different frequency• A channel is a frequency
Soc Classification level Presentation / Author / Date 31 © Nokia Siemens Networks
Types of Multiple AccessB. TDMA Time Division Multiple Access• Each user on a different window period in time (“time slot”)• A channel is a specific time slot on a specific frequency
Soc Classification level Presentation / Author / Date 32 © Nokia Siemens Networks
Types of Multiple AccessC. CDMA Code Division Multiple Access• A channel is a unique code pattern• Each user uses the same frequency all the time, but
mixed with different distinguishing code patterns
Soc Classification level Presentation / Author / Date 33 © Nokia Siemens Networks
CDMA Code Division Multiple Access
Frequency reuse factor is 1;network design and expanding become much easier
Frequency reuse factor is 1;network design and expanding become much easier
CDMA
5 MHz
1
1
11
1
11
11
1
11
1
1
Typical Frequency Reuse N=1
Soc Classification level Presentation / Author / Date 34 © Nokia Siemens Networks
TRADITIONAL COMMUNICATION SYSTEM
TRADITIONAL COMMUNICATIONS SYSTEM
SlowInformation
Sent
TX
SlowInformationRecovered
RX
NarrowbandSignal
Traditional technologies try to squeeze the signal into the minimum required bandwidth
Soc Classification level Presentation / Author / Date 35 © Nokia Siemens Networks
WCDMA COMMUNICATION SYSTEM
Spread spectrum systems mix their input data with a fast spreading sequence and transmit a wideband signal
The spreading sequence is independently regenerated at the receiver and mixed with the incoming wideband signal to recover the original data
.
SPREAD-SPECTRUM SYSTEM
FastSpreadingSequence
SlowInformation
Sent
TX
SlowInformationRecovered
RX
FastSpreadingSequence
Wideband Signal
Soc Classification level Presentation / Author / Date 36 © Nokia Siemens Networks
SPREAD SPECTRUM SYSTEM HISTORY
Soc Classification level Presentation / Author / Date 37 © Nokia Siemens Networks
What is SPREAD SPECTRUM SYSTEM?
Spread Spectrum techniques are methods by which more frequency bandwidth is deliberately used than motivated by the actual information rate (spectrum spreading). On one hand, this implies a certain waste of valuable frequency spectrum; but on the other hand,these techniques have advantages such as increasing the resistance to interference,jamming and interception.
Soc Classification level Presentation / Author / Date 38 © Nokia Siemens Networks
Spread Spectrum Principles
Shannon's FormulaShannon's Formula
C=B*log2(1+S/N)
Where, C is capacity of channel, b/s B is signal bandwidth, Hz S is average power for signal N is average power for noise
Claude Shannon is the Father of Information Theory. It was entirely new that information of any kind-- whether for use on a telegraph, telephone, radio, or television-- could be decomposed into zeros and ones, encoded, transmitted, and decoded at the other end which is called the Mathematical Theory of Communication. He went on to present the concept of the maximum rate of transmission on a channel-- the capacity or "Shannon limit"-- which provides the benchmark against which all codes and modulations are measured.
Claude Shannon is the Father of Information Theory. It was entirely new that information of any kind-- whether for use on a telegraph, telephone, radio, or television-- could be decomposed into zeros and ones, encoded, transmitted, and decoded at the other end which is called the Mathematical Theory of Communication. He went on to present the concept of the maximum rate of transmission on a channel-- the capacity or "Shannon limit"-- which provides the benchmark against which all codes and modulations are measured.
Soc Classification level Presentation / Author / Date 39 © Nokia Siemens Networks
SPREAD SPECTRUM SYSTEM ILLUSTRATION
5 MHz12.2 KHz
Power is “Spread” Over a Larger Bandwidth
MATHHAMMER
MATHHAMMER
Soc Classification level Presentation / Author / Date 40 © Nokia Siemens Networks
SPREAD SPECTRUM SYSTEM
I. Frequency-Hopping Spread Spectrum (FH-SS)
The SS technique Frequency-Hopping Spread Spectrum (FH-SS) involves transmitting a signal with a “normal” bandwidth over a carrier frequency that rapidly changes within a wider frequency spectrum.
To decode the signal, thereceiver in the FH-SS system needs to know the frequency-hopping sequence – the“code.”
FH-SS was first developed by scientist Nicola Tesla around 1900
Soc Classification level Presentation / Author / Date 41 © Nokia Siemens Networks
SPREAD SPECTRUM SYSTEM
II. Direct Sequence Spread Spectrum (DS-SS)
It is SS principle wherein the carrier frequency stays the same, but instead the signal to be transmitted is multiplied with a high bandwidth signal.
On the receiving end, the reproducible high bandwidth signal – the “code” – is multiplied with the received signal to recover the original signal.
Soc Classification level Presentation / Author / Date 42 © Nokia Siemens Networks
U101 42
Tx Bit Stream
Rx Bit Stream
Code Chip Stream (Spreading Code)
Air Interface Chip Stream
1
-1X
X
Spreading
Despreading
Spread
SPREADIND AND DESPREADING
1
-1
Code Chip Stream (Spreading Code)
Soc Classification level Presentation / Author / Date 43 © Nokia Siemens Networks
What is CHIP?
It is a pulse of a direct-sequence spread spectrum (DSSS) Code
WCDMA CHIP RATE: 3.84 Mcps
1
-1
pseudo-noise code sequence
Soc Classification level Presentation / Author / Date 44 © Nokia Siemens Networks
WCDMA Architecture
Iu
Iur
RNC
RNC: RadioNetwork
ControllerSGSN
GGSN
AuCHLREIR
VLR
G-MSC
MSC
cellcell
cellcell
cellcell
cellcell
cell
Uu
US
IMU
SIM
US
IM
FDD modeonly
UE: User Equipment N
od
e BN
od
e BN
od
e B
RNS: Radio Network Subsystem
RNS
CN: Core Network
IuCS
IuPSIub
Gc
Gr
Gs Gf
D
B
F C
PSTN
EE
GiGn
Gp
ME
ME
ME
Soc Classification level Presentation / Author / Date 45 © Nokia Siemens Networks
WCDMA - GSM Architecture
A-bis
Iub
Interface
Interface
Soc Classification level Presentation / Author / Date 46 © Nokia Siemens Networks
UTRAN (Universal Terrestrial Radio Access Network) Structure
RNS RNS
NodeB NodeBNodeB NodeB
RNC
CN
RNC
Iu Iu
Iur
Iub IubIub Iub
UE
UuUTRAN UTRAN
Soc Classification level Presentation / Author / Date 47 © Nokia Siemens Networks
WCDMA Architecture
The system consists of:
• UTRAN
UTRAN performs all the functions related to wireless communication;
• CN (Core Network)
CN switches and routes voice and data services to connect them to the external network.
• UE (User Equipment)
The UE (User Equipment) is connected to the UTRAN through the air interface standard.
Soc Classification level Presentation / Author / Date 48 © Nokia Siemens Networks
Functional Units
UE (User Equipment):
As the wireless terminal that performs wireless communication via the Uu interface, it contains an intelligent card, which records the user ID, performs the authentication algorithm, and stores information such as authentication information and keys.
Node B:
Transmits data streams between the Iub and the Uu interfaces, participating in radio resource management.
RNC (Radio Network Controller): Owns and controls the radio resources under its
administration. The RNC is the service access point provided by the UTRAN for the CN.
Soc Classification level Presentation / Author / Date 49 © Nokia Siemens Networks
INTERFACE
Uu interface:
Serves as the air interface of the WCDMA system to connect a UE to a Node B.
Iu interface: Connects the UTRAN and the CN. It is similar to the A
interface (circuit switching) and the Gb interface (packet switching) in GSM.
Iur interface:Allows soft handover between the RNC equipment of
different manufacturers as an open interface.
Iub interface:
Connects the Node B and the RNC.
Soc Classification level Presentation / Author / Date 50 © Nokia Siemens Networks
WCDMA Basic Nature and Behavior - Cell Breathing
Breath effect of cell
• With the increase of activated
terminals, interference increase
• the increase of high speed service,
the increase of interference
• The shrink of cell coverage area
• Coverage blind spot occurs
• Drop of call will happen at the edge of cell
Coverage and capacity are
relative
backback
Soc Classification level Presentation / Author / Date 51 © Nokia Siemens Networks
Coverage/capacity vs Data Rate
>12.2 kbps
>64 kbps
>384 kbps
>144 kbps
Coverage decrease
Subscriber num increase
Higher rate needs higher power
High data rate transmission is only available nearby the station
Soc Classification level Presentation / Author / Date 52 © Nokia Siemens Networks
Multipath Propagation
Received SignalReceived Signal
TimeTime
StrengthStrength
00
TransmitTransmit
Soc Classification level Presentation / Author / Date 53 © Nokia Siemens Networks
Multipath Propagation
Soc Classification level Presentation / Author / Date 54 © Nokia Siemens Networks
RAKE Receiving
RAKE improve receive capability
receiver
Single receiving
Single receiving
Single receiving
searcher calculate
combining
tt
s(t) s(t)
signal
Soc Classification level Presentation / Author / Date 55 © Nokia Siemens Networks
Use handoff: minimize drop-call rateUse handoff: minimize drop-call rate
WCDMA Behavior: HANDOVER
sssssssss
Handover is the process of shifting a mobile device’s connection from one Node B to another
Soc Classification level Presentation / Author / Date 56 © Nokia Siemens Networks
TYPES OF HANDOVER
I. Intra-System (WCDMA) Handover a. SOFTER HANDOVER Mobie Station handover within one node B between different sectors –
b. SOFT HANDOVER - Mobile Station handover between different Node B.
c. Hard HANDOVER - Mobile Station handover between different frequencies
II. Inter-System HandoverHandover between WCDMA <--> GSM (Hard)
Handover between WCDMA/FDD <--> TDD (Hard)
Soc Classification level Presentation / Author / Date 57 © Nokia Siemens Networks
WCDMA Power ControlWhy need Power Control?
- All User Equipment transmit on the same frequency
- UE with low path loss will cause large interference
- Removes Near –Far Effect – Variation of power level and interference due to distance and fading
Soc Classification level Presentation / Author / Date 58 © Nokia Siemens Networks
WCDMA Power Control
•Goal: Adjust transmit power so that all mobile terminals are received with approximately the same power
•Set PTX,1 and PTX,2 so that PRX,1 ~ PRX,2
Soc Classification level Presentation / Author / Date 59 © Nokia Siemens Networks
WCDMA Power Control
Open loop power control (No feed Back from the Node B)
If received signal is stronger,then UE can transmit lowerIf received signal is weaker,then UE can transmit stronger
To provide a course initial power setting of the mobile station at the beginning of a connection.
Closed Loop - With feed back from the Node B. Base station informs mobile unit to increase or decrease the power level