Transcript Wireless Standards Landscape

LTE Technology Overview and
Radio Performance Issues Focus On IBS
Hani Al-Hadidi
Regional Technical Manager
Comba-Middle East
PMP, BSc (EE)
[email protected]
Outline
1
LTE Overview Technology Evolution
2
Why Do We Need LTE?
3
LTE Market Status
4
LTE Network Architecture and Air Interface
5
Key LTE Radio Technology (OFDM)
6
Quality of Service (QoS) Focus on IBS
7
2
LTE Performance Issues Focus on IBS
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1
LTE Overview Technology Evolution
Wireless Network Standards Landscape
4
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3GPP Roadmap
Standards Developing Organizations
(Japan)
(USA)
(Europe)
(China)
(Korea)
5
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Voice vs. Data
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3G Looking Ahead
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•
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The next step in the evolution of the Third Generation Partnership
Project (3GPP) was the LTE:
Designed to meet the high speed data and multimedia transport
needs of operators
Benefits of users include:
Higher data rates
New added services
Business services and mobile commerce
Truly mobile broadband
Extra capacity and increase connection speeds (even @ peak
times)
Richer multimedia experience
More efficient social networking
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2
Why Do We Need LTE?
Limiting Factors of the 3G
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Wishing List of the 4G
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Design Goals
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LTE Promising
 Dr. Michael Schopp defines the that main
benefit of LTE is that it can deliver services
at fixed line quality with cost of IP
technologies
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Mobile Data Rate Growth
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Application Download Times
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LTE Features
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LTE Features
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LTE Looking Ahead
3GPP Release 10
You are here
3G/LTE
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4G/LTE-Advanced
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3
18
LTE Market Status
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Global WCDMA Map
 400 WCDMA networks are commercially
launched in 161 countries
 398 WCDMA operators launched HSPA in 160
countries
 99.5% of commercial WCDMA operators
have launched HSPA
 632m WCDMA subscribers including 342m
HSPA was reported (Q4 2010)
 173 HSPA+ network commitment , 123
HSPA+ launched
 23 Commercial 42 Mbps DC-HSPA+ networks
+ 36 commitments

19
150 HSPA+ Commercial by end of 2011
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Global LTE Map
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LTE Commitments
 196 operators in 75 investing in
the LTE
 140 network commitments in
56 countries + 56 precommitments
 The strong wireless data traffic
and revenue growth with HSPA
reported by most operators
around the world
 3071 devices launched by 262
suppliers include 144 HSPA+
 722 devices introduced in the
past 12 months
 68% networks and 61% devices
support the 7.2 Mbps DL
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LTE Coverage Example
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4
23
LTE Network Architecture and Air
Interface
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LTE Architecture Goals
 LTE uses the same principal
as HSPA for scheduling of
shared channel data and
fast link adaption which
enables the network to
optimize cell performance
dynamically .
 No dedicated channel
carrying data to specific
user , it is based entirely on
shared and broadcast
channels (more efficient air
interface according to the
real time demand)
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GSM/UMTS Network Architecture
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LTE Network
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Architecture Evolution
LTE designed to support only the PS services
Seamless IP connectivity between UE and PDN considering the
disruption during mobility
Together SAE and LTE form the EPS (Evolved Packet System)
EPS includes:
 Radio Access Network: Evolved UTRAN (E-UTRAN)
 System Architecture: Evolved Packet Core (EPC)
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Evolved Packet System
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E-UTRAN
Wideband OFDMA
Freq. Selective Scheduling
Interoperability with the 3GPP, 3GPP2, WiMAX, WiFi
All IP, Redundant Architecture
OFDMA DL and SC-FDMA UL
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5
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Key LTE Radio Technology (OFDM)
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OFDM Principle
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Different Multiple Access Techniques
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OFDM
Assigning subcarriers to multiple users at the same time
Resource block define group of subcarriers
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Quality of Service (QoS) Focus on IBS
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Bearer/Trestle
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LTE Main KPI’s
Unit of KPI’s
•
percentage
•
time interval (second or millisecond)
•
Erlang
•
kbit/s
1. Accessibility: probability for an end-user to be provided with an ERAB at request
2. Retainability: shows how often an end-user abnormally looses an
E-RAB during the time the E-RAB is used
3. Integrity (E-UTRAN IP Throughput): shows how E-UTRAN impacts
the service quality provided to an end-user
4. Latency: shows how E-UTRAN impacts on the delay experienced
by an end-user
5. Availability: shows Availability of E-UTRAN Cell
6. Mobility:shows how E-UTRAN Mobility functionality is working
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LTE Performance Issues Focus on IBS
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The new air Interface
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Multi-Antenna Transmission Schemes
 MISO: Multiple Inputs Single
Output
 SIMO: Single Input Multiple
Output
 MIMO: Multiple Input Multiple
Output
 All mentioned Diversity or
Spatial Multiplexing (This
means that different data is
sent from the two antennas
increasing bit rates
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Service Sensitivity and Coverage
Throughput
60
Highest data rate service
50
Data Rate 1
has the smallest coverage
Data Rate 2
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High data rates require
30
higher tx power due to
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reduced sensitivity
10
In order successfully decode data,
0
Range
1 2 3 4 5 6 7 8 9 10 11 12
The received signal strength (RSSI) needs to
be greater than noise interference by a certain amount (Higher bps
require higher SINR, Signal strength decreases with increased range)
Antenna placement depends on location of high data rate users
Planned Cell Coverage
PS128 UL / 384 DL Cell coverage
UL Voice Cell coverage
CPICH coverage
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Release 7 (R7) HSPA+ Performance
Up to 21.6 Mbps (with only 64QAM modulation) and
28.8 Mbps (with 2x2 MIMO and 16QAM modulation).
20 dB isolation needed
to achieve 21 Mbps
Dedicated HSPA
carrier with 15
SF16 codes
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LTE Performance
9
Spectral Efficiency b/s/Hz
8
7
SISO
6
SIMO
SFC
Spatial Multiplexing MIMO
JC
5
4
3
Diversity MIMO can increase the link
quality through diversity and array
gain, but there is no data rate
improvement compared to SISO.
2
1
0
-10
-5
0
5
10
15
20
G-Factor [dB]
42
25
30
35
40
JC: Joint Coding (Spatial Multiplexing)
SFC: space-frequency coding (Diversity)
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Outdoor Interference
Coverage varies along height of
buildings due to:
•
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Shadow effect from other
buildings in lower floors
Direction of the main lobe of
outdoor antenna
Typically, sites are more
down tilted
•
a lower coverage is
expected in upper floors
Upper floors of tall buildings
receive signals of similar level
from several cells
43
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Degraded Throughput at
Building Peripheral
Mbps
8
Cell Throughput
vs G-Factor (C/I)
4
dB
25+
44
20 15
10
5
2
-3
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Minimum Coupling Loss (MCL)
UE
DAS
Node B
Path Loss
1m
DAS Loss
30 dB
38 dB
40 dB (2100 MHz)
32 dB (900 MHz)
3GPP Specs:
• UE Rx input power level: max -25 dBm
• Node B Rx input power level: max -73 dBm
Assume 1 meter minimum distance between antenna and UE
• we will get 40 dB of worst case coupling loss (2100MHz).
To provide 70 dB of total minimum path loss, we need another
30 dB of DAS losses between antenna and Node B input.
On downlink,
• Antenna total EIRP = 43 – 30 = 13 dBm for 3G
• EIRP for pilot level (10% CPICH allocation) = 3 dBm
• Total EIRP of 13 dBm and 40 dB downlink path loss means
13-40 = -27 dBm maximum input power to UE
• 3GPP states < -25, so downlink is also OK
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Thank You
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