Istanbul, 01.-03. April.2014 GSM-R Packet Switched Technology
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Transcript Istanbul, 01.-03. April.2014 GSM-R Packet Switched Technology
GSM-R Packet Switched Technology
Introduction of GPRS/EGPRS for ETCS
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(1) Packet Mode for ETCS
Motivation
Status GSM-R Air-Interface
Capacity
Track
High Density Area
Stations
High Density Area-Border Region
Germany
France
Switzerland
Circuit ModeDedicated
Channel
Packet ModeShared
Channel
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
ETCS data application widely used in
low density areas (track)
What about high density areas like
stations?
Voice capacity demand increases!
ETCS in stations demands
additional Circuit Mode channels!
Border regions have to share the
limited number of frequencies
Capacity demand conflicts with the
limited GSM-R(EIRENE) frequency
band resources
Increase radio channel multiplexing –
keep QoS requirements transition
towards packet switched mode
Istanbul, 01.-03. April.2014
(2) GSM-R ETCS Bearer
Circuit Switched (CS) versus Packet Switched
Circuit Mode (CS-Mode)
CS
CS
Dedicated transmission resource
per ETCS session
Sufficient transmission robustness
(Radio Network design)
Low traffic channel capacity utilisation
(10-20%)
ETCS
ETCS
CS
ETCS
CS
PS
Packet Mode (PS-Mode GPRS/EDGE)
ETCS
ETCS
PS
ETCS
PS
ETCS
PS
ETCS
Shared transmission resource(s) between
several ETCS sessions
Bearer Service bandwidth depends on:
Channel Coding (more/less robust against
transmission errors caused by Doppler and Delay
spread)
Radio Network design
Improved protection algorithms against
transmission errors
Multiplexing of several ETCS sessions
improves resource utilisation
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(3) GSM-R ETCS Bearer
Circuit (CS) versus Packet Switched (PS) Mode
Radio Resource
Allocation/Release
Mobility
• CS-Mode
• Handover (Network commanded)
• dedicated resources in source
and target cell
• End User resource demand
• End User release resource
• PS-Mode
Release
Demand
• PS-Mode
• Cell Change (Reselection)
Mobile self sustaining with/without
Network assistance
• Traffic resources between target
cell and origin cell (Planning Task)
• Handover (Network commanded)
(Neither in Public-GSM nor in
GSM-R Network/Mobile available)
• End User demand
• Network release
Demand
• CS-Mode
• CS-Mode
• Dedicated transmission resource
- allocation – ranking by preemption!
• PS-Mode
• ETCS application
• typical machine to machine
interaction (location measurement
to get track segment permission)
• stringent and low delay real
time treatment
Applications
Other «Best Effort»
CS-Mode
Resource
PS-Mode
Resource
Application - Priority
based resource
allocation
Release
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
ETCS - «LOW» Delay
Istanbul, 01.-03. April.2014
(4) GSM-R GPRS/EDGE
Test Cases(O-3023v0.73)
•
•
Radio Resources Allocation
respecting ETCS application
Mobility behaviour (Cell Change)
Ensure ETCS application precedence
over non-ETCS traffic
CS-Mode and
GPRS/EDGE coexistence
Variation of Radio
Channel Conditions
(Optimum 320km/h)
User Area - ETCS traffic emulation
Traffic Model 1 - Limit
• Reflects high radio traffic channel utilisation
• Message frequency
every 3 seconds Train RBC
every 6 seconds RBC Train
Traffic Model 2 - Typical
• Reflects medium traffic channel utilisation
• Message frequency
every 6 seconds Train RBC
every 20 seconds RBC Train
Mixed Traffic – Application dependent
bandwidth allocation
•
Test Case Focus
Variation in ETCS Session
quantity sharing one Radio
Traffic Channel
•
Variation of Radio Traffic
Channel quantity
GSM System
3GPP Features to improve PS-Mode:
Specific
Test Conditions
Variation of Channel Coding
(GPRS/EDGE)
Boundary Test Conditions
GSM Feature Gain
GPRS/EDGE
robustness
Multiplexing Gain
of one Radio
Traffic Channel
IP-performance
for transport layer
parameterization
Traffic Model 1/2 + non-ETCS data
Network Registration
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(5) GPRS/EDGE Bearer
Optimisation - Testing Procedure
Track
Measurement
LAB Phase 1
LAB Phase 2
(Ø 50km/h up to 320km/h
(Optimum Radio)
(Optimum Radio)
Tool
Control of min.
Final-LAB
Robustness
Performance
Feature Gain
4 concurrent
Parameter
Parameter
Reference
IP-Performance
Mobile Modules
Timer
Timer
“Best Effort”
Radio Access
Technology
GSM
GSM
Tool
Independent
Feature
Feature
Qualification
Traffic Model
Activation
Qualification
Emulation
ETCS Traffic Model
Timestamp
• Traffic Model 1
generation
• Traffic Model 2
Transfer Delay
Automated Cell Change
Computation
Mixed Traffic
(ETCS/Non-ETCS)
Reporting
Finished
Finished
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(6) GSM-R GPRS/EDGE
Results: Feature Gain
Demand
PS-Mode
Resource
Applications
Other «Best Effort»
Release
ETCS - «LOW» Delay
Radio Resource
Allocation/Release
Features:
• Delayed-Downlink-TBF (Network)
• Extended-Uplink-TBF
(Network/Mobile)
•(TBF -Temporary Block Flow)
Mobility
Feature:
• Network Assisted Cell Change
(Network/Mobile)
System Feature Gain Ø
45%
40%
System Feature Gain Ø
35%
35%
20%
30%
10%
5%
0%
up to
•(GBR Guaranteed Bit Rate)
System Feature Gain Ø
33%
15%
0%
17%
-28%
-10%
-20%
25%
20%
Reference feature inactive
10%
0%
40%
25%
15%
Feature:
• Packet Flow Context
(Network/Mobile)
20%
43%
30%
Application - Priority
based resource
allocation
up to
-5%
up to
GBR 2kbps
GBR 3kbps
GBR 4kbps
-30%
-40%
10%
5%
0%
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(7) GPRS/EDGE - ETCS Bearer
/
Robustness
Transmission
Transfer Delay
Impact
Circuit
Packet Mode
Multiplexing Gain
one GSM-R
Traffic Channel
Results:
• 4 concurrent ETCS sessions
@320km/h
• 6 concurrent ETCS sessions
under static conditions
• Co-existence guaranteedmatter of GSM-R capacity
planning
• Requires min. one dedicated
Packet Mode Traffic Channel
PS
ETCS
PS
ETCS
PS
ETCS
PS
ETCS
PS
ETCS
PS-Mode
CS-Mode
CS
ETCS
• 3GPP GSM features improves
transfer delay significantly
• (TTD) equal/better than
Circuit Mode for ETCS
• Recovery of erroneous packets
faster than in Circuit Mode
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014
(8) GPRS/EDGE - ETCS Bearer
PS-Mode
Engineering
• Operation of the required
features
• Planning recommendation
(Min. Packet Switched capacity,
Channel Coding)
• 3GPP GSM feature specification
MRM/Network
• PS-Mode functions
• Full Qualified Domain Name(s)
RBC / OBU Identification
• IP Addressing Scheme
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
400
200
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140
200
260
350
500
560
620
680
740
800
860
950
1200
1800
• Transport Channel qualification
Transfer Delay
(Transmission Interference –
Transport Protocol impact)
• Multiplexing Gain –New!
EIRENE SRS/FRS
Subset093
Bearer Service QoS
Related Documents
Transfer Delay
subset093 95%
subset093 99%
1 Traffic Channel
GPRS CS2 EGPRS MCS2
2 Traffic Channel
GPRS CS2 EGPRS MCS2
Requirements
Istanbul, 01.-03. April.2014
(9) GPRS/EDGE - ETCS Bearer
Conclusion(s)
Transformation
Best Effort “QoS Transmission System ”
3GPP Features
Standard features are sufficient
to fulfil application QoS requirements
Robustness
Faster detection and retransmission
of erroneous radio blocks with less impact
to higher layers
PS-Mode (GPRS/EDGE) provides
a capacity improvement especially in
high density - railway traffic areas!
Radio Access Technology Independent Measurement Tool
ETCS / non-ETCS Traffic Emulation
Transport Channel – System Qualification (i.e. Transfer Delay/Multiplexing Gain)
GSM-R Packet Switched Technology
Ingo Wendler / UIC Project Manager - ETCS over GPRS
Istanbul, 01.-03. April.2014