Transcript Positioning_EDGE

POSITIONING EDGE IN THE
MOBILE NETWORK EVOLUTION
TIK-109.551 Research Seminar on
Telecommunications Business II
12.3.2003
[email protected]
[email protected]
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Positioning EDGE in the mobile
network evolution
• GSM evolution towards 3G
• Introduction to GSM EDGE (Rel’99)
• EDGE performance in theory
• GERAN Rel’5
• EDGE services
• EDGE investments for an operator
• EDGE network planning
• EDGE performance in real life networks
• What is the future of GSM EDGE?
• Conclusions
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GSM Evolution paths towards
3G
GSM
9.6kbps
UMTS
<2Mbps
HSCSD
57.6kbps
GPRS
115kbps
EDGE
384kbps
1999
2000
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2001
2002
2003
What is GSM EDGE ?
• EDGE = Enhanced Datarates for GSM Evolution
– GSM2+ specification accepted 3G standard by 3GPP and ITU
– GSM/EDGE RAN = GERAN
– GERAN Rel’5: In the future common 3G core with same Iu- interfaces for
multiradio GSM/EDGE/WCDMA RAN
• Improved GSM air-interface performance
–
–
–
–
–
8-PSK modulation method
New modulation & coding schemes (1-9)
Incremental Redundancy (IR)
Link Adaptation (LA) Enhancements
In the near future: AMR
(d(3k),d(3k+1),d(3k+2))=
(0,0,0)
(0,1,0)
(0,1,1)
(0,0,1)
(1,1,1)
(1,0,1)
(1,1,0)
(1,0,0)
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EDGE performance in theory (1)
Spectral efficiency
Kbps / MHz
350
EDGE
300
250
200
WCDMA
150
100
50
•
•
•
•
GPRS
Assuming
CS1&2
Average C/I from
tested networks
(-> 11,5 kbps/TS)
BCCH re-use 12
TCH re-use 3
•
•
•
•
Assuming
MCS5-8
Average C/I from
tested networks
(-> 34,2 kbps/TS)
BCCH re-use 12
TCH re-use 3
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•
•
•
•
Assuming
Max load of 75%
Orthgonality of 0,6
15% of DL power to
CCCHs
Frequency re-use
efficiency of 60%
EDGE performance in theory (2)
Modulation 1 TS
Method
(kbps)
GMSK
8,8
GMSK
11,2
GMSK
14,8
GMSK
17,6
8-PSK
22,4
8-PSK
29,6
8-PSK
44,8
8-PSK
54,4
8-PSK
59,2
MCS-1
MCS-2
MCS-3
MCS-4
MCS-5
MCS-6
MCS-7
MCS-8
MCS-9
4 TS’s
(kbps)
35,2
44,8
59,2
70,4
89,6
118,4
179,2
217,6
236,8
8 TS’s
(kbps)
70,4
89,6
118,4
140,8
179,2
236,8
358,4
435,2
473,6
60
Kbps/ TS
50
40
30
20
E-GPRS
GPRS CS 1-4
GPRS CS 1-2
Average
3- 4 x
10
0
8 10 12 14 16 18 20 22 24 26 28 30
C/I
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In theory EDGE offers
• 3-4 x higher data bit rates for
end-users than GPRS
• Improved voice capacity via
enhanced data capabilities (+
later AMR)
EDGE performance in theory (3)
Incremental redundancy
– Incremental Redundancy gives additional 2-3 dB to radio link
– IR adjusts the code rate of the transmission to true channel conditions
with incremental transmissions of the redundant information until the
decoding is successful
– Utilises ARQ protocol
Link Adaptation
– Link Adaptation is used to select the best MCS for the radio link
conditions
– LA algorithms compare the estimated channel quality to threshold
values -> optimised throughput
– In EDGE LA works more effectively than in GPRS, because of IR
gives better re-transmission performance
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GERAN Rel’5 Goals
Performance enhancements for existing services.
Adoption of the UMTS Iu interface and UMTS quality of
service (QoS) architecture
– Enable GERAN to the same 3G CN (core network) as UTRAN
– Enable GERAN to provide the same set of services as UTRAN
– Support for conversational and streaming service classes as defined for
WCDMA
 First steps towards efficient resource optimizations in multi-radio networks
 Making the radio technology invisible to the end-user, while allowing
operators to efficiently manage the available spectrum.
 Significant modifications to the existing GERAN radio
protocols
– increases the complexity of radio interface protocols.
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GERAN Rel’5 Features
Enhancements for speech and data services:
–
–
–
–
–
–
–
Iu interface (GERAN can be directly connected to IMS)
Header adaptation mechanism (RTP/UDP/IP)
Wideband AMR (quality)
Half-rate 8-PSK (capacity)
Fast power control for speech
Location service enhancements for Gb and Iu
Network assisted cell change (NACC)
Rel´5 supports
– A true multi-vendor environment
– Backward compatibility (support of services for Release 99 terminals)
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GERAN Rel’5 Architecture
GERAN
BSS
Iur-g
MS
MS
A
BTS
BSC
Um
Gb
Iu
BTS
Iur-g
UTRAN
RNC
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GSM/WCDMA
Core Network
(Halonen et al 2002)
Network elements of combined UMTS
and GSM EDGE networks
GPRS/EDGE Radio Network
EDGE BS
BTS
Network Subsystem
BSC
MSC/VLR
HLR
UTRAN
BTS
PSTN
RNC
GPRS-backbone
BTS
RNC
UMTS Radio Network
SGSN
GGSN
Core Network
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IP Network
EDGE Services (1)
No significant changes in achievable services before GERAN
Rel’5 -> Iu interface and UMTS QoS classes
QoS classes for UMTS and EDGE Rel´5
Traffic class
Example of application
Fundamental characteristics
Conversational
Voice and video
Preserve time relation between
class
telephony
information elements, low delay
Streaming
Real time
Preserve time relation between,
class
streaming video
low level retransmission
Interactive Web browsing and real
Preservation of content,
class
time control channels retransmission, "request response"
Background
Downloading of files
Delay insensitive, preservation of
class
and email
content, retransmission
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EDGE Services (2)
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Service QoS Requirements for Bearers, Data rates and Services 2003 [Auramo 2002]
Global EDGE Status
US+Canada:
EDGE roll-outs
on the way
and EDGE will
be deployed
during 2003
Latin America:
Will eventually
follow US.
Europe:
WCDMA
technology
commitment.
Strong need
for delaying
UMTS roll-outs
Growing
interest
towards
EDGE, but no
public
commitments
yet.
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APAC:
Market follows global
trends. “Ongoing
technology standard
war”. Also public
commitments to EDGE
China:
Political
commitments
to every
technology.
No rush to
3G. No
public EDGE
commitments
yet
EDGE from network investments
point of view (1)
• In the current market situation Operators have to decide
how to divide their network investments between WCDMA
and EDGE
• European 3G -market could be divided as follows:
Heavily influenced by
the UMTS delays and
availability of
EDGE/UMTS terminals
2H2002
1H2003
2H2003
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1H2004
2H2004
2005
EDGE from network investments
point of view (2)
What’s required to go for EDGE?
GSM BS
What’s required to go for WCDMA?
Depending on the age and
manufacturer of the GSM BS:
• EDGE TRX:s must
be introduced
• EDGE BSS/NSS software acquired
• Possible baseband units obtained
• In worst case new EDGE compatible
BS:s introduced
• Transmission
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A complete
Radio Access Network…
and possible updates to
GPRS core
+ transmission
EDGE from network investments
point of view (3)
Compared to WCDMA the investments in EDGE are
smaller for an operator with moderate traffic growth
Traffic ~1 Mbps*
per base station
Traffic ~2 Mbps**
per base station
The feasibility of EDGE
depends on the amount
of traffic :
EDGE
WCDMA
• With moderate traffic,
EDGE is clearly
more cost efficient
EDGE
• With higher traffic
WCDMA becomes
more feasible
WCDMA
network CAPEX
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* Equals
approx.
4+4+4 GPRS
thrput
** Equals
approx.
1+1+1
WCDMA
thrput (2,4Mbps)
EDGE from network investments
point of view (4)
• Total CAPEX, EDGE vs WCDMA
Point of equal CAPEX for
both technologies to support
the required traffic
WCDMA
EDGE
Traffic (kbps/ site)
250
500
750
1000
1250
1500
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2000
2500
3000
EDGE from network investments
point of view (5)
• The cheapest way to implement EDGE is to replace or add one
(or several) GSM TRXs with EDGE TRXs in most feasible site
locations.
The needed
amount of EDGE
TRXs increase
as the required
traffic grows
Only one EDGE
TRX needed per
site to support
the required traffic
EDGE TRX
CAPEX
per site (k€)
100
Feasibility of replace
strategy depends
on the amount of
EDGE
capable BSs
80
60
Replacing more
than one
TRX is more
complex
40
20
250
500
750
1000
1250
1500
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2000
2500
3000
Traffic
(kbps/ site)
EDGE from network investments
point of view (6)
• When compared to investments needed for WCDMA to support
the same amount of traffic per site…
CAPEX
per site (k€)
Significantly higher
investments
needed
for WCDMA
Assumed only EDGE TRX
costs and total WCDMA
site CAPEX
100
80
Assumed total EDGE site
CAPEX after more than one
EDGE TRX must be
implemented
60
WCDMA
EDGE
40
20
250
500
750
1000
1250
1500
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Traffic
(kbps/ site)
EDGE from network investments point of
view (7) – investment strategies
EDGE as a
stepping stone
to UMTS
EDGE as a
complementary
solution to WCDMA:
Different Coverage areas
EDGE and WCDMA
co-exist but for different
user segments
• EDGE to provide ”3G like” data
services prior to large scale
WCDMA deployment
• ”US style” mobile evolution
• Provide more cost-effective coverage
in wide area
• WCDMA focus on urban areas and
license requirements
• Minimal service differentitation
between GSM and UMTS network ->
services easier to plan
• Both WCDMA and EDGE
deployed in cities and EDGE
also elsewhere
• EDGE positioned clearly to
different market segment than
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EDGE from network planning
perspective (1)
• As GPRS, EDGE performance is dependent on the
achievable C/I (and RXlev) in the network
• The most effective means to gain this is to
come up with a optimised frequency plan
TRX
requirements
Propagation
estimations
Coverage
Analysis
Interference
matrix
• co-channel
• adjacent
channel
Help from automation in large networks required
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Frequency
plan
Separation
constraints
EDGE from network planning
perspective (2)
• Frequency plan optimisation can make a significant
difference for the achievable throughput
• Example case from a live network, EDGE throughput
measured based on network C/I and Rxlev:
29,9 kbps
Average throughput
per TS over the network
with “old” frequency plan
34,7 kbps
Average throughput
per TS over the network
with optimised frequency plan
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EDGE from network planning
perspective (3)
• EDGE deployment doesn’t bring dramatical changes
to radio network planning with GPRS
• Main concerns the allocation of capacity and steering
of traffic to wanted layer/cell/TRX
• Features such as LA should be utilised optimally
• Upcoming 2G/2,5G/3G parameterisation challenges
• Changes to transmission capacity will be needed, if
larger scale EDGE deployment per cell/area is done
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EDGE from network planning
perspective (4)
• The easiest way to implement EDGE from network
planning point of view is the TRX replacing strategy
new frequency plan not mandatory
• The replacing can be done for every 1-3rd site
E.g. hotspots or rural can be selected for EDGE, but
limited amount of data throughput
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EDGE from network planning
perspective (5)
Higher data amounts with EDGE can be offered if it is implemented by
• Bringing an additional EDGE TRX dedicated to data usage to (some of)
the cells in the network
• Reserving more timeslots for the use of EDGE data users from the
TRXs (-> decrease in the GoS experienced by the speech users )
• In real life these actions are not always possible to perform and they will
require significant amount more implementation and planning work
• In order to utilise EDGE performance in full, a totally new frequency plan
and possibly new GSM cell structure are required
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EDGE performance in live networks (2)
European small/medium and larger size GSM networks
Achievable EDGE throughput per TS versus GPRS
(DL in kbit/s)
Throughput per TS (kbit/s)
35
30
25
Approx. 2,5
times higher
throughput
to end users
20
15
10
5
0
GPRS
EDGE
GPRS
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EDGE
The future of EDGE
• How has the GPRS traffic
evolved in the network ?
• Traffic growth
• UMTS timetable
• How does the GSM
capacity respond to this ?
• EDGE terminals
• Do we believe in short
term mobile data take off ?
• Operator business cases
• EDGE capable infrastructure
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The future of EDGE
• Traffic growth
• What is the operators
strategic/ financial UMTS
commitment ?
• Launch dates are
postponed in Europe
• UMTS timetable
• How ready is the UMTS
infrastructure ?
• EDGE terminals
• Operator business cases
• EDGE capable infrastructure
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• Would EDGE offer
competitive advantage
before UMTS is widely
deployed ?
• When to start utilising the
enormous capacity of
WCDMA ?
The future of EDGE
• Traffic growth
• E2002 in US, but when in
Europe ?
• Classical chicken-andegg problem again
• UMTS timetable
• Asian EDGE commitment
will guarantee EDGE
terminals to 900/1800
bands ?
• EDGE terminals
• Operator business cases
• EDGE capable infrastructure
• What is the vendors’
commitment and ability to
take risks ?
• Multimode UMTS/EDGE
terminals the best bet ?
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The future of EDGE
• When will the saturation
point of current network
technology be reached ?
• Traffic growth
• UMTS timetable
• How should the network
investments be planned for
next 5 years ?
• EDGE terminals
• Operator business cases
• Roll-out strategy for
EDGE and UMTS
• EDGE capable infrastructure
• Service strategy for
EDGE and UMTS
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The future of EDGE
• Traffic growth
• What is the EDGE
capability of current
network infrastructure ?
• UMTS timetable
• How is that capability
spread over the network ?
• EDGE terminals
• Operator business cases
• Capacity extensions
done with EDGE HW ?
• EDGE capable infrastructure
• Geographical swap ?
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Conclusions
• EDGE would be the best network evolution for GSM operators on the
road to UMTS (as in US)
• The needed investments are a lot smaller than in WCDMA
• Planning/deployment complexity is a fraction of that of WCDMA
• EDGE provides ~2,5 times the performance of GPRS and enables
similar services than UMTS
• EDGE is been specified by the 3GPP to fully meet UMTS QoS in the
future with Iu-interface + common 3G core network
• The feasibility of EDGE is network specific
EDGE will live alongside of WCDMA, but who is ready to
drive the market and set the role of EDGE in 3G field for the future?
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The scale of EDGE deployment is highly
Thank you!
[email protected]
[email protected]
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