Dar es Salaam Institute of Technology (DIT)
ETCT 06204
Digital Cellular Network
Ally, J
jumannea@gmail.com
DIT
3G and 3.5G Networks
3G Evolution
◼
Proposal of 3G
❑
IMT-2000: the general name of third
generation mobile communication system
❑
The third generation mobile communication
was first proposed in 1985，and was renamed
as IMT-2000 in the year of 1996
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Commercialization: around the year of 2000
Work band : around 2000MHz
The highest service rate :up to 2000Kbps
DIT
Improvement Beyond Voice Only
Core of 3G- CDMA Technology
WCDMA
Core network: MAP and GPRS-based
network
Radio transmission technology:
WCDMA－FDD/TDD
CDMA2000
Core network: ANSI 41 and MIP
networktechnology:
Radio transmission
CDMA2000
3G
mechanism
TD-SCDMA
Core network: MAP-based
Radio transmission
network technology:
TD-SCDMA
CDMA technology is the core of 3G.
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Mobile Multimedia Services by 3G
◼
◼
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High-speed packet communication
Audio/Visual communication (ex. Video
phone)
Location service (ex. Navigation)
Mobile e-Commerce
Multi-call service (Voice+Packet+…)
International roaming
Contents distribution (Video, Music,
Game, Map, etc.)
DIT
3G Objectives
3G is developed to achieve:
◼
Universal frequency band for standard and seamless global
coverage
◼
High spectral efficiency
◼
High quality of service with complete security and reliability
◼
◼
Easy and smoothly transition from 2G to 3G, compatible
with 2G
Provide multimedia services, with the rates:
❑
Vehicle environment: 144kbps
❑
Walking environment: 384kbps
❑
Indoor environment: 2Mbps
What is UMTS/WCDMA?
An IMT-2000 standard – 3G mobile wireless solution (also known as
UMTS/WCDMA)
◼ Compliments GSM/GPRS/EDGE services
◼ High Voice Capacity:
❑ 51 to 83 Erlangs/sector/5 MHz (62 to 95 TCH/sector/5 MHz)
❑ Voice quality rated as excellent
◼ Always On Packet Data Rates:
❑ 384/384kbps (DL/UL) peak data rate in initial (Release 99)
commercial deployments
❑ Up to 14.4 Mbps peak downlink data rate with HSDPA (Release 5)
❑ Up to 5.8 Mbps peak Uplink data rate with HSUPA (Release 6)
❑ Evolution to HSPA+ (Release 7)
◼ Up to 28 Mbps downlink peak data rate
◼ Up to 11.5 Mbps uplink peak data rate
❑ Evolution to HSPA+ (Release 8)
◼ Up to 42.2 Mbps downlink peak data rate
◼ Up to 11.5 Mbps uplink peak data rate
DIT
WCDMA Bands Used
◼
Main bands
❑
◼
Supplementary bands: different country maybe
different
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1920 ~ 1980MHz / 2110 ~ 2170MHz
1850 ~ 1910 MHz / 1930 MHz ~ 1990 MHz (USA)
1710 ~ 1785MHz / 1805 ~ 1880MHz (Japan)
890 ~ 915MHz / 935 ~ 960MHz (Australia) . . .
Frequency channel number＝central frequency×5,
for main band:
❑
❑
UL frequency channel number ：9612～9888
DL frequency channel number : 10562～10838
DIT
UMTS (Universal Mobile Telecommunication
System) R99 Network Architecture
MSC/VLR
Other PLMN
PSTN,ISDN
GMSC
GSM /GPRS BSS
BSC
HLR/AUC
BTS
PCU
SCE
SS7
RNC
SMS
NodeB
SCP
GPRS
backbone
UMTS
UTRAN
Internet,
Intranet
SGSN
GGSN
CG
BG
Other PLMN’s
GPRS network
DIT
UMTS R4 Network Architecture
IP/ATM Backbone
MGW
Other PLMN
PSTN,ISDN
MGW
GSM /GPRS BSS
BSC
VMSC Server
GMSC Server
HLR/AUC
BTS
PCU
SCE
SS7
RNC
SMS
NodeB
SCP
GPRS
backbone
UMTS
UTRAN
Internet,
Intranet
SGSN
GGSN
CG
BG
Other PLMN’s
GPRS network
Page 11
UMTS Elements Definition
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The Mobile Equipment (ME) is the radio terminal used
for radio communication over the Uu interface.
The UMTS Subscriber Identity Module (USIM) is a
smartcard that holds the subscriber identity, performs
authentication algorithms, and stores authentication
and encryption keys and some subscription information
that is needed at the terminal.
The Node B converts the data flow between the Iub
and Uu interfaces. It also participates in radio resource
management.
The Radio Network Controller (RNC) owns and
controls the radio resources in its domain (the Node Bs
connected to it).
Home Location Register (HLR) is a database located
in the user’s home system that stores the master copy
of the user’s service profile.
DIT
Network Elements Definitions (2)
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Mobile Services Switching Centre/Visitor Location
Register (MSC/VLR) is the switch (MSC) and
database (VLR) that serves the UE in its current
location for Circuit-Switched (CS) services.
Gateway MSC (GMSC) is the switch at the point
where UMTS PLMN is connected to external CS
networks. All incoming and outgoing CS
connections go through GMSC.
Serving General Packet Radio Service (GPRS)
Support Node (SGSN) functionality is similar to that
of MSC/VLR but is typically used for PacketSwitched (PS) services.
Gateway GPRS Support Node (GGSN)
functionality is close to that of GMSC but is in
relation to PS services.
DIT
WCDMA Network Architecture
DIT
WCDMA Network Architecture (2)
◼
WCDMA including the RAN (Radio Access Network) and the CN
(Core Network).
❑
❑
The RAN is used to process all the radio-related functions.
The CN is used to process all voice calls and data connections within
the UMTS system, and implements the function of external network
switching and routing.
◼
Logically, the CN is divided into the CS (Circuit Switched) Domain
and the PS (Packet Switched) Domain.
◼
UTRAN, CN and UE (User Equipment) together constitute the
whole UMTS system
◼
A RNS (Radio Network Sub-system) is composed of one RNC and
one or several Node Bs.
◼
The Iu interface is used between RNC and CN while the Iub
interface is adopted between RNC and Node B.
DIT
WCDMA Network Architecture (3)
◼
Within UTRAN, RNCs connect with one another
through the Iur interface.
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The Iur interface can connect RNCs via the direct
physical connections among them or connect them
through the transport network.
◼
RNC is used to allocate and control the radio
resources of the connected or related Node B.
◼
Node B serves to convert the data flows between the
Iub interface and the Uu interface, and at the same
time, it also participates in part of radio resource
management.
DIT
CDMA Concepts – Multiple Access Methods
1-to-1 Frequency Re-Use
◼
◼
CDMA eliminates frequency planning and
achieves higher system capacity.
This requires good radio planning, as is true for
FDMA/TDMA systems.
Common Frequency Channel
Power Control
Power Control compensates for:
- Near/Far Problem
- Path Loss
- Fading
Handover
Soft Handover
◼ Soft handover allows the mobile to establish a connection
with a new Node B before breaking the connection with the
previous serving cell.
◼ In a WCDMA system, a mobile can be “in soft handover” with
two or more cells for an extended period of time. This is a
desirable state as it provides path diversity.
◼ If the path to one cell experiences a temporary fade, the
communication link through the other path or paths may not
be affected.
Hard Handover
◼ A hard handover occurs when all existing radio links must be
dropped before a new link is established.
◼ This causes a brief interruption in voice or data
communication, while making the transition from the old
serving link to the new.
Hard Handover Versus Soft Handover
Advantages of Soft Handover
➢ Reduces
interference and transmit power required
➢ Increases capacity
➢ Maintains call continuity and reduces dropped calls
➢ Improves voice quality
Channel Mapping
◼
In the new WCDMA Access Stratum, radio bearers are mapped onto
logical channels, then onto transport channels, and eventually physical
channels.
UMTS Channels
Broadcast Channel
◼
Broadcast Channel (Downlink)
❑ Broadcast Control Channel
(BCCH)
❑ Broadcast Channel (BCH)
❑ Primary Common Control
Physical Channel (PCCPCH)
❑ First channel to be decoded by
UE after acquisition
❑ Carries system information such
as system ID, cell ID, neighbor
cell information, system frame
number, etc.
Paging Channel
◼
Paging Channel (Downlink)
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Paging Control Channel
(PCCH)
Paging Channel (PCH)
Secondary Common Control
Physical Channel (SCCPCH)
Page Indicator Channel
(PICH)
Monitored by UE in Idle
Mode, CELL_PCH, and
URA_PCH
Carries Paging messages
Random and Forward Access Channels
◼
Random Access Channel (Uplink)
Common Control Channel (CCCH)
❑ Random Access Channel (RACH)
❑ Physical Random Access Channel
(PRACH)
❑ Transmitted by UE to access the
system
Forward Access Channel (Downlink)
❑ Common Control Channel (CCCH)
❑ Forward Access Channel (FACH)
❑ Secondary Common Control
Physical Channel (SCCPCH)
❑ Acquisition Indication Channel
(AICH)
❑ Carries UTRAN messages to UE in
Idle mode
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Dedicated Channels
◼
Dedicated Channels
(Uplink/Downlink)
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Dedicated Control
Channel (DCCH)
Dedicated Traffic
Channel (DTCH)
Dedicated Channel
(DCH)
Dedicated Physical Data
Channel (DPDCH)
Dedicated Physical
Control Channel
(DPCCH)
Carries signaling and
user data
HSDPA and HSUPA
What are the drivers and motivations for HSDPA and HSUPA?
✓Data Rate
➢Demand for high data rate
multimedia services
➢Demand for higher peak data
rates
✓Throughput/Capacity
➢Cost per megabyte
✓Coverage
➢ Higher data rates available
over a larger cell footprint
✓Delay
➢Lower Latency
DIT
HSDPA
(High Speed Downlink Packet Access )
◼
What is HSDPA?
❑ Enhancement of 3GPP W-CDMA specification
❑ Targeting throughput enhancement and delay
reduction
❑ Providing peak data rate up to 14.4 Mbps
◼
Technologies
❑ Use of downlink shared channel
❑ Both QPSK and 16QAM transmission
❑ Adaptive Modulation and Coding (AMC)
❑ Hybrid ARQ (Automatic Repeat request)
❑ Effective packet scheduling algorithm
DIT
Quadrature Amplitude Modulation
16QAM
QPSK
i1
i2
10
11
q2
00
10
i2
1011
1001
0001
0011
1010
1000
0000
0010
1110
1100
0100
0110
1111
1101
0101
0111
q1
q2
Same amount
of noise
2 bits per symbol
Robust
4 bits per symbol
Requires high S/N
DIT
Radio Channel Quality
Adaptive Modulation and Coding (AMC)
Modulation &
Coding
Channel Quality Indicator
(CQI)
QPSK
16 QAM
time (mS)
Use high level modulation and coding rate when
channel condition is good
Data Throughput can be increased
05/17/17
DIT
Scheduling
• In each time slot, the terminals
which have good downlink
condition are selected. (Multiuser diversity)
• Date queue for each terminal is
monitored. NodeB schedules
the downlink according to the
queue length.
NodeB
MS1
MS2
MS4
MS3
Data Queue
at NodeB
Balance
➢fairness
➢throughput
➢delay
Downlink Scheduling
time
DIT
HSDPA Scheduling and Retransmissions
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Scheduling
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Done at the Node B
No interaction with the RNC
Based on Channel Quality Feedback from the
UE
Retransmissions
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H-ARQ (link level retransmissions)
Based on UE feedback (ACK/NAK)
Done at the Node B
Soft combining at the UE
DIT
HSDPA Channels
DIT
HSDPA Performance Summary
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Maximum Theoretical Data Rate:
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14.4 Mbps
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Practical Peak User Data Rate:
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10.0 Mbps
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Virtually impossible to obtain in the field.
Full capability UE
Good RF conditions (High Cell Geometry)
Single UE
Dedicated HSDPA carrier
Significant Performance Gains over Release 99
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Peak Data Rate
Cell Throughput
DIT
HSUPA
(High Speed Downlink Packet Access )
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What is HSUPA?
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Enhancement of 3GPP W-CDMA specification
Targeting throughput enhancement (Uplink)
Providing peak data rate up to 5.76 Mbps
Upload of photo/movie, on-site live reporting, etc.
Technologies (Similar to HSDPA, under control of NodeB)
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Use of Uplink shared channel
QPSK transmission
QAM Rele.7
Adaptive Modulation and Coding (AMC)
Hybrid ARQ
Effective packet scheduling algorithm
DIT
HSUPA Channels
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HSUPA Uplink Channels
Enhanced Uplink Dedicated Channel (E-DCH)
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E-DCH Dedicated Physical Data Channel (E-DPDCH)
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Downlink Physical Channel
E-DCH Absolute Grant Channel (E-AGCH)
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Uplink Control Channel
HSUPA Downlink Channels
E-DCH Hybrid ARQ Indicator Channel (E-HICH)
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Uplink Physical Channel
E-DCH Dedicated Physical Control Channel (E-DPCCH)
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Uplink Transport Channel
Downlink Physical Channel
E-DCH Relative Grant Channel (E-RGCH)
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Downlink Physical Channel
DIT
HSUPA Channel Mapping
DIT
HSDPA/HSUPA Summary
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HSDPA and HSUPA offer Significant Performance
Gains over Release 99
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Peak Data Rate
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Cell Throughput
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Theoretical Maximum: 14.4/5.74 Mbps
(Downlink/Uplink)
Improved Spectral Efficiency
Fast Scheduling and Improved Link Adaptation
Delay
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Reduced Latency
DIT
Goals For HSPA+ In Release 7
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Enhancements in Release 7 will enable:
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Reduced latency
Higher user throughput
Higher system capacity
Extended talk time
Faster call setup
It is important to achieve these goals with minimal changes to software,
hardware, and network architecture, ensuring backward compatibility.
DIT
HSPA+ Advantages
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Cost effective upgrade
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Can be selectively deployed in areas with high demand
for data and for voice
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HSPA is being widely deployed. HSPA+ can leverage
existing assets:
◼ Cell Sites, UTRAN, and Core Network.
Deployment of HSPA+ will provide an edge in terms of time
to deploy.
Selective deployment based upon needs can be easily
achieved.
Backward Compatibility
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Backward compatible with existing UTRA.
◼ No dedicated spectrum needed.
R99, R5/R6, HSPA, and HSPA+ devices operate on the
same network.
DIT
Evolution of HSPA Maximum Peak Bit Rate
DIT
DIT