overview of 5g c-v2x standard5gvs.org/pdf/5g summit 자료_서한별.pdf · 2020. 11. 27. · 3gpp...
TRANSCRIPT
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Hanbyul Seo
LG Electronics
Overview of 5G C-V2X standard
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Vehicle-to-everything (V2X)
V2X is a set of services enabled by vehicular communications.
– V2V: Vehicle-to-Vehicle
– V2P: Vehicle-to-Pedestrian
Handheld terminal carried by a pedestrian, cyclist, driver or passenger
– V2I: Vehicle-to-Infrastructure application
RSU (Roadside Unit) is the transportation infrastructure entity.
– V2N: Vehicle-to-Network
Communication with application servers
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Why V2X is necessary?
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One of the main enabler of highly automated driving
– International transport forum, “Automated and Autonomous Driving”, 2015
“Vehicle-to-X connectivity (V2X): Connectivity is an important element of the automated vehicles especially secure V2X communication requiring low latency. V2X technologies encompass the use of wireless technologies to achieve real-time two-way communication among vehicles (V2V) and between vehicles and infrastructure (V2I). The convergence of sensor-based solutions (current advanced driver assistance - ADAS) and V2X connectivity will promote automated driving.”
V2X allows information collection othersensors cannot do.
– Can know the situation even whenthe line-of-sight is blocked.
– Less impacted by the circumstance,e.g., weather, light, …
– Even allows collecting invisible information such as the intended maneuver in the future
Radar
Camera
Lidar
Ulatrasonic
V2X
3D HD Map
Precise positioning
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Basic V2X services – Day 1
4
Electric emergency brake light
Control loss warningEmergency vehicle alert
Road hazard warning
Curve speed warning
Forward collision warning
Vulnerable user safety
(may be a part of
advanced services)
Signal phase and timing
Traffic flow control
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Advanced V2X services – Day 2
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From http://www.sarte-project.eu
(1)
(2)
From 3GPP TR 22.886
Collective perception
Maneuver coordination Platooning & group start
Tele-operated driving
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V2X service requirements
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Main performance metrics
– Latency: Upper bound of message transmission latency is of more importance.
– Reliability: Typically in terms of the probability of failure in delivering the messages to the target receiver(s).
– Data rate: Peak data rate as well as the average data rate
• Predictable message generation• Small message size• Relaxed latency & reliability requirements
• Unpredictable message generation• Large message size• Stringent latency & reliability requirements
Day-1 Day-2
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C-V2X standards
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Cellular V2X (C-V2X) is V2X based on cellular technology such as LTE and NR.
– Uu and PC5 interfaces for C-V2X
Sidelink (used for PC5 interface) Uplink & downlink (used for Uu interface)
Pros - Shorter latency- Local communication with spatial resource reuse- Operation even outside network coverage
- Larger coverage- Reuse existing infrastructure (V2I or V2N)- More efficient centralized control
Cons - Limited coverage- Limitation in controlling multiple devices
- Longer latency in V2V and V2P- No support for out-coverage operations
Sidelink (D2D)
Control may be provided by the
network.
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C-V2X standards
Multiple phases for evolution of C-V2X technologies.
– Started from LTE-based V2X standards
– Initial release of 5G NR based V2X standards are completed.
Non-compatible PHY format is used, but device-level compatibility and coexistence can be supported.
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3GPP V2X phase 2 based on LTE
3GPP V2X phase 1 based on LTE
Backward compatible
Non-backward compatible
3GPP V2X evolution path
3GPP V2X phase 3 based on NR
5GLTE Evolution
New RadioTight Integration
March 2017 June 2018
Rel-15Rel-14
June 2020
Rel-16
March 2022 (TBD)
Rel-17
3GPP V2X phase 4 based on NR
Backward compatible
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C-V2X standards
Vehicle communications in 3GPP releases
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LTE Uu(V2N service)
LTE Uu(basic safety)
LTE PC5(basic safety)
Release 8, 9, …, 13
Release 14
5G
LTE PC5(improvement for
basic safety)NR Uu
(high bandwidth, low latency)
LTE Uu(basic safety)
LTE PC5(basic safety)
NR Uu (enhanced URLLC)
LTE Uu(basic safety)
NR PC5(advanced V2X
support)
Release 15
Release 16
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Highlights of Rel-16 NR sidelink
Flexible radio design
– Can cover low-mid frequency bands as well as mmWave spectrum
Operation in a wider band is supported (e.g., 10, 20, 30, 40 MHz in 5.9 GHz)
– Can adapt the physical layer structure
Subcarrier spacing, overhead of reference signals, …
Higher spectral efficiency
– MIMO multi-layer transmissions
– Channel status information feedback for link adaptation
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Control
Time
Frequency
Data
Reference signal
Control
Data
Reference signal
Control
Data
Reference signal
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Highlights of Rel-16 NR sidelink
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Hybrid automatic repeat request (HARQ) feedback
– A packet can be retransmitted until it is received by all the intended receivers.
Efficient handling of unpredicted packet generations
– Re-evaluation of the resource reservation and pre-emption for high priority packets
Time
Frequency
Low priority from device 1
High priority from device 2
Resource reservation
Cancel the reserved resource and select an
alternative
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Highlights of Rel-16 NR sidelink
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Efficient coexistence with LTE sidelink
– When a device is equipped with both LTE and NR sidelinks
– Radio selection for each generated message
– NR sidelink can be synchronized with LTE sidelink.
NR sidelink can avoid interfering with an important operation in LTE sidelink, and vice versa.
APP Layer
V2X Layer
LTE
sidelink
Message
NR
sidelink
Basic safety message
Advanced use cases message
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Thank you!