GEO-NETWORKING MEDIA-DEPENDENT
FUNCTIONALITY FOR ITS-G5- ETSI STF 447 Presentation -
Presented by Jan de Jongh, TNO ETSI ITS Workshop Feb 5th-6th, Vienna, Austria
© ETSI 2013 All rights reserved
Contents
ETSI STF-447 and its ToR
Architecture
Congestion and Awareness Control
Traffic-Class MappingTraffic-Class Mapping
Conclusions
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ETSI STF 447
ETSI created a Specialist Task Force STF 447 to address Media-dependent GeoNetworking, in particular DCC aspects at Network Layer.
• STF 447 Members:1. Tessa Tielert – KIT2. Katrin Sjöberg – Volvo Technologies
3. Jérôme Härri – EURECOM3. Jérôme Härri – EURECOM4. Jan de Jongh – TNO
5. Dieter Smely – Kapsch
6. Andreas Festag – NEC Europe
• STF Documents:• ETSI TS 102 636-4-2• ETSI TR 103 110 (beyond contract; WI DTR/ITS 0030039)
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STF447 Terms of Reference
Media-dependent functionality of GeoNetworking for ITS-G5
ITS G5 interfaces “Access” <-> “Network & Transport” layer.
Objectives:
TS 102 636-4-2specification for:
• Network-layer congestion control ;• Network-layer congestion control ;
• Network-layer multi-channel operation support.
Change Requests to related standards
• Analyze other standards of the Minimum Set of Standards, which have interdependencies with the GeoNetworking standards series;
• Resolve the dependencies among standards.
TR 103 110• Structure of Decentralized Congestion Control;
• Background for TS 102 636-4-2.4
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ETSI DCC – Architecture
WI
DTS/ITS-0010021
STF395A
STF420
STF447WITS 103 175
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DTS/ITS-0020046
STF447 – GeoNetworking Context
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Congestion and Awareness Control
Prevent the wireless channel from becoming overloaded and useless;
Various means available in ITS-G5:• Modulation (‘Datarate’) – fixed @ 6 Mbps
• Transmit Power (STF-447)
• Transmission Rate (STF-447)
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• Transmission Rate (STF-447)
• Sensitivity Control (‘CCA Threshold’) – fixed -95 dBm
• Channel (STF-420)
• EDCA Access Category (‘priority’; ‘queue’; STF-420)
Transmit Power Control alone has limitations; combination with Transmit Rate Control performs better.
Treating all ITS Stations equally is not a good idea in general.
Awareness Control versus
Congestion Control
Slow vehicle in traffic jam
� Low dynamics
� Low Tx power and rate
Fast vehicle about to change lanes
� High dynamics
� High Tx power (to reach relevant vehicles)
� High Tx rate (to account for change of direction)
Conclusion: Same safety benefit does not
necessarily mean using the same share of bandwidth
Congestion and Awareness Control
Three approaches discussed with increasing complexity:• Adjust Tx Power to load (given CAM rate). Currently
drafted in Draft EN 302 663 – 4 – 2.
• Adjust Tx Power, but incorporate safety benefit (‘awareness control’) -> Requires input from Facilities
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• Adjust Tx Power, but incorporate safety benefit (‘awareness control’) -> Requires input from Facilities on ‘Range’ and ‘Rate’.
• Adjust both Tx Power and Rate (requires further discussion with WG-1 and others).
All: Use measure of network congestion status; not just link congestion status. (See TS for details.)
STF447 – Traffic Class Mapping
A Traffic Class defines a ‘traffic type’ is assigned at the Facilities layer
A Traffic Class maps onto• Facilities Control Parameters
• Transmit Rate
• GeoNetworking Control Parameters• GeoNetworking Control Parameters• Transmit Range -> Tx Power
• [Transmit Rate] -> Transmit Rate
• ITS G5A Control Parameters through a DCC Profile ID:• Channel
• EDCA queue
• [max tx power, max tx rate – STF 420]
Mappings may depend on DCC State
[Still, partially, under discussion.]
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TC Mapping @GeoNetworking
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TC ID DCC_load output
1 Relax DP_0, TX_power, (TX_rate)
2 Relax DP_1, TX_power, (TX_rate)
3 Activated DP_3, TX_power, (TX_rate)
… … …
STF447 – Conclusions
Stable draft Network Congestion Control
• Uses range/tx power as control parameter
• Modified Fallah et al. algorithm
Extensions to trade-off “range” versus “rate”.Extensions to trade-off “range” versus “rate”.
Discussions with WG-1 on awareness control
(CAM rate).
Shaping ideas on Multi-Channel Operations.
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STF447 – TC Mapping in Detail
Functions to be defined at DCC_facilities
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DCC_Net functionalities
