Vehicular Communications via Cellular Networks

Joachim Sachs | IEEE VTS Workshop on Wireless Vehicular Communications | © Ericsson AB 2015 | 2015-11-11

Vehicular communications via cellular networks

Dr. Joachim SachsPrincipal Researcher, Ericsson Research


› Introduction into 4G LTE

› Automotive communication and Cooperative ITS

› Cellular connectivity for C-ITS, the early research

› Evolved LTE: embracing vehicular communication

› The path to 5G – what is next

› Summary

Outline

Introduction into 4G LTE

Outline

• Introduction into 4G LTE

• Automotive communication and Cooperative ITS

• Cellular connectivity for C-ITS, the early research

• Evolved LTE: embracing vehicular communication

• The path to 5G – what is next

• Summary


LTE – worldwide standard for mobile broadband

Early concepts from ~2002

Standardization 2005-2008 (first release)

Early trials ~2007

Commercial operation from 2009

Continuous evolution since 2008 with regular new standard releases

High data rates

300 Mbit/s DL, 75 Mbit/s UL initially

4 Gbit/s DL, 1.5 Gbit/s UL currently

Low latency– 5 ms user plane, 50 ms control plane


Global Convergence

GSM WCDMA HSPA

TD-SCDMA HSPA/TDD

IS-95 cdma2000 EV-DO

D-AMPS

WiMAX

3GPP

3GPP2

IEEE

› LTE is the technology for mobile broadband– Convergence of 3GPP and 3GPP2 technology tracks– Convergence of FDD and TDD into a single technology track

PDCPDC

LTEFDD and TDD


LTE networks

Sources: LTEmaps.org (April, 2015)


Spectrum Flexibility

› Operation in differently-sized spectrum allocations– Core specifications support any bandwidth from 1.4 to 20 MHz– Radio requirements defined for a limited set of spectrum allocations

6 RB (|1.4 MHz)

100 RB (|20 MHz)

› Support for paired and unpaired spectrum allocations

timeFDD

timeHalf-duplex FDD(terminal-side only)

timeTDD

10 MHz 15 MHz 20 MHz3 MHz 5 MHz1.4 MHz

with a single radio-access technology ¨ economy-of-scale


Transmission Scheme

Downlink – OFDM› Parallel transmission on large number of

narrowband subcarriers

Uplink – DFTS-OFDM› DFT-precoded OFDM

› Benefits:– Avoid own-cell interference– Robust to time dispersion

› Main drawback– Power-amplifier efficiency

› Tx signal has single-carrier properties@ Improved power-amplifier efficiency– Improved battery life – Reduced PA cost– Critical for uplink

› Equalizer needed @ Rx Complexity– Not critical for uplink

Cyclic-prefixinsertion

OFDM modulatorDFT precoder

DFT IFFTIFFT Cyclic-prefixinsertion


Time-domain Structure

› FDD– Uplink and downlink separated in frequency domain

ULDL

One radio frame, Tframe = 10 ms

One subframe, Tsubframe = 1 ms

fUL

fDL

Subframe #0 #1 #2 #3 #4 #5 #6 #7 #8 #9

UL

DL

DwPTS GP UpPTS

fDL/UL

(special subframe) (special subframe)

› TDD– Uplink and downlink separated in time domain ¨ ”special subframe”– Same numerology etc as FDD ¨ economy of scale


data1data2data3data4

User #1 scheduled

User #2 scheduled

Time-frequency fading, user #1

Time-frequency fading, user #2

Frequency-selective Scheduling

› LTE – channel-dependent scheduling in time and frequency domain


Protocol Architecture

UE eNodeB

RR

C

RRC

RR

C

RRC

IP IP

PDCP PDCP

RLC RLC

MAC MAC

PHY PHY



UE eNodeB

RR

C

RRC

RR

C

RRC

IP IP

PDCP PDCP

RLC RLC

MAC MAC Adaptive Coding, Modulation Power control Multi-antenna processing 24 bit CRC

PHY PHY



UE eNodeB

RR

C

RRC

RR

C

RRC

IP IP

Multiplexing and scheduling of radio bearers

Hybrid ARQ with incremental redundancy

PDCP PDCP

RLC RLC

MAC MAC

PHY PHY



UE eNodeB

RR

C

RRC

RR

C

RRC

IP IP

Segmentation/concatenation RLC retransmissions (if configured)

Sliding Window Selective Repeat ARQ

In-sequence delivery

PDCP PDCP

RLC RLC

MAC MAC

PHY PHY



UE eNodeB

RR

C

RRC

RR

C

RRC

IP IP

Header compression to reduce overhead

Ciphering for security Lossless inter-eNB handover by

data forwarding

PDCP PDCP

RLC RLC

MAC MAC

PHY PHY


Quality of service in LTE

LTE RAN TRANSPORT GATEWAYDEVICE

Service flow separation by UL/DL Packet Filters at the network edges(gateway and device)

ClientApplication(s)

Service 1

Service 2

Service 3

QoS parameters (QCI, ARP, MBR, GBR)• Prioritize in scheduling and retention• Possibly resources reservationEnabled throughout the entire network domain


Multi-antenna techniques

Diversity for improved system peformance

Beam-forming for improved coverage(less cells to cover a given area)

SDMA for improved capacity(more users per cell)

Multi-layer transmisson (”MIMO”) for higher data rates in a given bandwidth

The multi-antenna technique to use depends on what to achieve


MBSFN OperationRel-9

› Multicast-Broadcast Single Frequency Network– Synchronized transmission from multiple cells– Seen as multipath propagation by terminal ¨ combining gain ‘for free’

› MBSFN for content known to have many viewers– News, sport events, …

On demandPersonalized content

Big eventsKnown in advance to have many users


Carrier AggregationRel-10

› What?– Multiple component carriers in parallel

› Why?– Exploitation of fragmented spectrum– Higher bandwidth ¨ higher data rates

Frequency band A Frequency band B

Intra-band aggregation, contiguous component carriers


Intra-band aggregation, non-contiguous component carriers


Inter-band aggregation


LTE – Major Evolution Trends

Spectrum FlexibilityCarrier Aggregation, New Frequency Bands, …

Multi-antenna techniquesMIMO, CoMP, …

New scenariosDevice-to-Device Communication, Machine-type communications, …

DensificationLocal-area access, Heterogeneous deployments, …

Device EnhancementsReceiver improvements,…

Multi-RAT coordinationWiFi interworking, inter-RAT RRM, …

LTERel-8/9

Rel-11

Rel-12

Rel-10

Automotive communicationand Cooperative ITS

Outline






• Summary

Joachim Sachs | IEEE VTS Workshop on Wireless Vehicular Communications | © Ericsson AB 2015 | 2015-11-11 23

The Connected Vehicle

ABI Research: 2017 60% of cars globally and 80% in US and Western Europe will be “connected cars”(ABI Research 2012-07-03)

IEEE prediction: 2040 75% of cars will be driverless. Most promising form of intelligent transportation. (IEEE 2012-09-05)

US Secretary of Transpotation A. Foxx: Driverless cars common in 2025 (FAZ 2015-09-19)

Ford CEO M. Fields: Fully autonomous cars appear 2020(Forbes 2015-02-05)

Mobile network technology is ready for the Connected Car


The connected car

Congestion

fees

“Pay-As-You-Drive”

- Insurance

Fees & ChargesRemote Diagnostics

and SW Updates

Vehicle interaction

Service Calls

Charging support

for Electric Cars

Advertisement

and Points Of Interest

InfotainmentPersonal

Information MgmtIn-car entertainment

Travel

Planning

Traffic Efficiency

Traffic

alerts

Traffic Safety

eCallRoad

Hazard warnings

Alco-lock

IntelligentSpeed

Adaptation

Traffic

Mgmt

Eco Driving

Road Usage

Charging


Similarly for other vehicles

Access control

Fees & ChargesFees & ChargesRemote Diagnostics

and SW Updates

Vehicle interactionVehicle interaction

Service planning

Advertisementand Points Of Interest

InfotainmentInfotainment

In-bus entertainmentRoutemanagement

Traffic Efficiency Traffic Efficiency

Traffic alerts

Safety Safety

eCallTraffic Hazard

warnings

Driver authorities

IntelligentSpeed

Adaptation

Bus stop info

Eco Driving

PassengerTicketing

Alco-lock

Interiorsurveillance

InfotainmentInfotainment

Personal Information MgmtIn-car entertainment

Remote Diagnostics and SW Updates


Service Calls

Fleet ManagementRemote Diagnostics and SW Updates


Service Calls

Fleet Management

Traffic Safety Traffic Safety

eCallTraffic Hazard

Warnings

Alco-lock

IntelligentSpeed

Adaptation

Traffic Safety Traffic Safety

eCallTraffic Hazard

Warnings

Alco-lock

IntelligentSpeed

Adaptation

Travel Planning


Traffic Alerts

Traffic Mgmt

Eco Driving

Travel Planning


Traffic Alerts

Traffic Mgmt

Eco Driving

Congestion Fees

“Pay-As-You-Drive”- Insurance

Fees & ChargesFees & ChargesRoad Usage

Charging

Congestion Fees

“Pay-As-You-Drive”- Insurance

Fees & ChargesFees & ChargesRoad Usage

Charging

Goods MgmtGoods MgmtGoods

Condition Mgmt

GoodsTracking

CustomsDeclaration

GoodsSecurity

Goods MgmtGoods MgmtGoods

Condition Mgmt

GoodsTracking

CustomsDeclaration

GoodsSecurity

The connected bus The connected truck


Services of the connected Vehicle

› Wide range of possible services with economicvalue, enabling new business models and innovations

› Basic wide-area internet connectivity (V2I) is typically sufficient –as already provided by e.g. LTE today

› Some services have high communicationsdemands (e.g. cooperative collision avoidance)– Research to evolve communication systems

OEM XYZ insurance traffic center


Car communication & traffic safety

› Constant decrease despite increasing traffic volumes

Billion kilometers per yearFatalities

Source: German Federal Statistical Office


Car communication & traffic safety

› Next big step in vehicle safety through communication

Passive Safety

Feel

See

Communicate

Seat belts

AirbagsABS

ESP

ACCLane assist


ETSI standardization

› C-ITS – Cooperative Intelligent Transport Systems– Goals, e.g.:

› Improved traffic efficiency› Increased road safety

› Automotive Messaging Types– CAM – Cooperative Awareness Message– DEN – Decentralized Environmental Notification


Cooperative awareness message CAM - use cases

Use Case Min frequency (Hz) Max latency (ms)

Emergency Vehicle Warning 10

100

Intersection Collision Warning 10Collision Risk Warning 10Slow Vehicle Indication 2Motorcycle Approaching Indication 2Traffic Light Optimal Speed Advisory 2Speed Limits Notification 1 to 10

Intersection assistance • Sent by vehicle or roadside unit

• Periodically transmitted

• Vehicle information (position, direction, velocity, …)

• Destination: immediate surrounding


Decentralized environmental notification DEN – use casesUse Case Triggering condition Terminating condition Latency (s)

Emergency electronic brake light

Hard braking of a vehicle Automatically after the expiry time 0.2

Collision risk warning Detection of a turning/crossing/merging collision by

roadside unit

End of collision risk 0.2 - 1 s

Stationary vehicle – accident eCall triggering Vehicle involved in accident is removed

< 5

Stationary vehicle – vehicle problem

Vehicle breakdown or vehicle with activated warnings

Vehicle is removed from the road < 5

Traffic jam warning Traffic jam detection End of traffic jam < 5Road work warning Signalled by fixed or moving

roadside stationEnd of road work > 1 min

Precipitation Detection of a heavy rain or snow (activation of windscreen wrappers)

Detection of the end of the heavy rain or snow situation

< 5

Road adhesion Detection of a slippery road condition (ESP activation)

Detection of end of the slippery road condition

< 5


Decentralized environmental notification DEN – use casesUse Case Triggering condition Terminating condition Latency (s)

Emergency electronic brake light

Hard braking of a vehicle Automatically after the expiry time 0.2

Collision risk warning Detection of a turning/crossing/merging collision by

roadside unit

End of collision risk 0.2 - 1 s

Stationary vehicle – accident eCall triggering Vehicle involved in accident is removed

< 5

Stationary vehicle – vehicle problem

Vehicle breakdown or vehicle with activated warnings

Vehicle is removed from the road < 5

Traffic jam warning Traffic jam detection End of traffic jam < 5Road work warning Signalled by fixed or moving

roadside stationEnd of road work > 1 min

Precipitation Detection of a heavy rain or snow (activation of windscreen wrappers)

Detection of the end of the heavy rain or snow situation

< 5

Road adhesion Detection of a slippery road condition (ESP activation)

Detection of end of the slippery road condition

< 5

• Main usage Road Hazard Warnings

• Sent when road hazard is detected

• event based (road hazard exists)

• periodic repetition and continuous broadcast (until expiry or termination message)

• Distribution to all vehicles within a relevance area

Cellular connectivity for C-ITS- the early research

Outline






• Summary


Car-to-car using dedicated short range radio (802.11p)

› 802.11p in 5.9 GHz– Roadside equipment

every 500-1000 meters

› Highway networks– US: 76.000 km– Germany: 13.000 km– Sweden: 2.000 kmRural and urban roads not included

TrafficManagementCenter

!

Why not use cellular?availability, coverage and performance


Cooperative cars projects› Cooperative Cars (CoCar, 2006-2009)

– Basic research on cellular car-to-car communication usingUMTS and HSPA

– Reference case: Road Hazard Warnings

› Cooperative Cars eXtended (CoCarX, 2009-2011)– LTE, session management, heterogeneous approach


Car-to-car over cellular

NodeB

!

!

!

!

Core NetworkInfrastructure

Filtering/GeoMessaging

Hazard Warningaccident, emergency breaking, bad road condition, road works, slow vehicle

Traffic Information updatestraffic condition & warnings

TrafficManagementCenter


› Overlay map with a grid› Cars are only aware of their own tile

› When a car leaves a tile– Car sends the position to the Geo Messaging

Server (GPS)– GMS updates tile information database– GMS sends new tile to the car

› Service content is tagged with distribution area

› Geomessaging server distributes to vehicles in distribution area and marked for the service type

GeomessagingTraffic

Management Control GeoMessaging

See also ETSI TR 102 962 V1.1.1 (2012-02). Intelligent Transport Systems (ITS); Framework for Public Mobile Networks in Cooperative ITS (C-ITS)


Cellular car-to-car delay

UM

TS 2009

HS

PA 2011

LTE 2011

AS

WAN

Core


Cellular car-to-car delay

UM

TS 2009

HS

PA 2011

LTE 2011

AS

WAN

CoreDelay requirements can be metwith LTE (and largely with HSPA)


How about system capacity ?


LTE capacity evaluationmethodology

› LTE radio network simulations– Full protocol stack and mobility simulated

› Network size: 9 cells, 3 sites› System bandwidth: 5 MHz for UL and DL› Intersite-distance (ISD) and carrier frequency

– A: 500 m at 2 GHz– B: 6 km at 800 MHz

› Tx / Rx antennas: 1 / 2 (SIMO)› Over 5000 cars simulated› User speed: 13.9 m/s = 50 km/h› Message sizes based on ETSI DENM/CAM (120 byte)› No other traffic


LTE capacity evaluationmethodology

› LTE radio network simulations– Full protocol stack and mobility simulated

› Network size: 9 cells, 3 sites› System bandwidth: 5 MHz for UL and DL› Intersite-distance (ISD) and carrier frequency

– A: 500 m at 2 GHz– B: 6 km at 800 MHz

› Tx / Rx antennas: 1 / 2 (SIMO)› Over 5000 cars simulated› User speed: 13.9 m/s = 50 km/h› Message sizes based on ETSI DENM/CAM (120 byte)› No other traffic

Note

• Typicaly carrier bandwidths 10 or 20 MHz

• Typically min. 2x2 MIMO

• No broadcast (MBMS) considered


LTE capacity evaluationcase 1: periodic messages

1. Sender behavior– All cars sending CAM, 2 Hz and 10 Hz compared

2. Message distribution– CAM to all receivers in same cell immediately congests network – Regional filtering modeled

› CAM distributed to 10 or 40 vehicles in the vicinity

Mobile Network

CoCarX Backend

Direct communication using pWLAN broadcast Communication through network infrastructure and backend

1. 2.


CAM V2V delayurban vs. rural environment

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Avera

ge ve

hicle-

to-ve

hicle

delay

[s]

2 GHz, 500 m ISD

Average number of vehicles per cell

10 Hz, 40 neighbors10 Hz, 10 neighbors 2 Hz, 40 neighbors 2 Hz, 10 neighbors

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6800 MHz, 6 km ISD

Avera

ge ve

hicle-

to-ve

hicle

delay

[s]



› V2V delays < 100 ms

Scenario Nvehicles per cell

UL+DL 10 Hz40 neighbors

urban ≈ 13rural ≈ 9







› Bottleneck: PDSCH


CAM V2V delayurban vs. rural environment

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Avera

ge ve

hicle-

to-ve

hicle

delay

[s]

2 GHz, 500 m ISD



0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1.0

1.2

1.4


Avera

ge ve

hicle-

to-ve

hicle

delay

[s]




Scenario Nvehicles per cell









Downlink capacity quickly reached(5MHz spectrum)

reduce transmit frequencyreduce # neighbors



LTE capacity evaluationcase 2: warning messages (DENM)

1. Sender behavior– 1, 10, 20, 40 cars per cell sending DENM with average 1 Hz

2. Message distribution– Simple GeoMessaging abstraction used– DENM sent to all vehicles in same cell (easy to implement)– Substantial potential for optimization (e.g. duplicate filtering in backend)

Mobile Network

CoCarX Backend

Direct communication using pWLAN broadcast (with routing through multiple hops)

Communication through network infrastructure and backend

1. 2.


DEN V2V delayurban vs. rural environment


0 100 200 300 400 500 6000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Avera

ge ve

hicle-

to-ve

hicle

delay

[s]

2 GHz, 500 m ISD


40 incidents20 incidents10 incidents 1 incident

0 100 200 300 400 500 600 7000

0.2

0.4

0.6

0.8

1.0

1.2

1.4


Avera

ge ve

hicle-

to-ve

hicle

delay

[s]



Scenario Ncars per cell

UL+DL 1 Hz 1 incident

urban 2500

rural 2250

UL+DL 1 Hz10 incidents

urban 550

rural 400

UL+DL 1 Hz20 Incidents

urban 280

rural 200


urban 140

rural 100



DEN V2V delayurban vs. rural environment


0 100 200 300 400 500 6000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Avera

ge ve

hicle-

to-ve

hicle

delay

[s]

2 GHz, 500 m ISD



0 100 200 300 400 500 600 7000

0.2

0.4

0.6

0.8

1.0

1.2

1.4


Avera

ge ve

hicle-

to-ve

hicle

delay

[s]



Scenario Ncars per cell

UL+DL 1 Hz1 incident

urban 2500

rural 2250


urban 550

rural 400

UL+DL 1 Hz20 Incidents

urban 280

rural 200


urban 140

rural 100

More than 100-2000 cars per cell withdelay <200ms

Temporary load



Conclusion› CAM can in theory be supported up to modest vehicle densities by LTE networks

– Tremendous traffic load for limited new information– High opportunity costs for an operator (sacrifice one carrier for ITS)

› DENM can efficiently be supported by LTE networks– Warning essential to increase road safety– Delay requirements can be met– Capacity only needed in case of incident temporary effect

› Possible capacity improvements– Solution using Multimedia Broadcast Multicast Service– More advanced LTE features improve performance (MIMO, D2D/V2V, …)

› Other important vehicular communication use cases well supported by LTE– Remote diagnostics, road traffic management, …


Cellular communication Ad-hoc communication

Intersection assistant

Hazard warnings

Infotainment

Software download

Remote Diagnostics

Lane changeassistantCooperative

traffic lights

Traffic information

Remote Navigation

2G (EDGE)

3G (HSPA)

4G (LTE)

802.11p (ad-hoc)

Collisionavoidance

Complements: LTE 802.11p

(LOS)(NLOS)


Objective› Develop Converge Car2X System

Network– Safe and secure– Privacy protection via pseudonymization– Open to variety of participants and

services– Operator agnostic– Builds on international standards

› http://www.converge-online.de/

COmmunication NetworkVEhicle Road Global Extension

(2012-2015)

Source: Converge presentations http://www.converge-online.de/

http://www.converge-online.de/



Partners

Public Institutions Science Public Authority

Vehicle Manufacturers Suppliers Cellular Solutions




› Communication technologies for vehicles– Mobile networks (LTE)– ITS G5 (DSRC)

› Communication can be via either of ITS G5 or LTE, or via both

› Coordinated Hybrid Communication– Clustering: connect clusters to communication infrastructure via LTE and distribute

messages within cluster via ITS G5– Methods for clusterhead selection developed– Performance benefits of clustering has been demonstrated

Hybrid Communication


› Multiple service providers, e.g.– Traffic Management Center – Vehicle Manufacturer– Road Operator

› Service creation / provisioning– Extendable service creation– Service registration in Service Directory– Services agnostic on how data is

disseminated / communication technologies– Integrated security

Service Management




› Extension of CoCarX geomessaging solution› Geomessaging proxy

– Operator- and network-agnostic– Enables transmission over multiple networks– Works for multi-country operation

› Geomessaging server– Included into communication networks– Can be different type of networks, e.g.

› Mobile network› ITS-G5 based ITS road-side stations

– Enables geomessaging within the network› E.g. unicast or broadcast

Layered Geomessaging

GEOMProxy

GEOMServerMNO GEOM

ServerIRS

SPOEM

SPRoad Auth

Area A Area BSource: Converge presentations http://www.converge-online.de/



› Road side unit detects misbehaving vehicle via CAM› Warning distribution via Converge Car2X System Network

Converge Validation

Source: Converge presentations and pictures http://www.converge-online.de/





Hazard warnings

Infotainment

Software download

Remote Diagnostics


traffic lights

Traffic information

Remote Navigation

2G (EDGE)

3G (HSPA)

4G (LTE)

802.11p (ad-hoc)

Collisionavoidance

Complements: LTE 802.11p

(LOS)(NLOS)

Evolved LTE: embracing vehicular communication

Outline






• Summary


LTE – Some recent Features

LTERel-8/9

Rel-11

Rel-12

Rel-10

Rel-13

Rel-14

• Device-to-Device

• Licensed Assisted Access

• V2X

• (Latency Reductions)

Today


› Unlicensed spectrum used as performance booster in small cells– Accompanied by a licensed carrier– Carrier aggregation between licensed and unlicensed spectrum– Specified for 5 GHz ISM band

– Fair co-existence with WiFi has been demonstrated and standardization is ongoing› WiFi performance not more affected

than by other WiFi system› Performance at least as good as WiFi

LTE in unlicensed spectrumLicensed-Assisted Access (Rel-13)

UL DL

Primary CarrierLicensed Spectrum

Secondary CarrierUnlicensed Spectrum


› LTE enables direct communication between devices since Rel-12(proximity services, ProSe)

› Main use cases– Public safety (NSPS)

› Push to talk in out of coverage scenarios– Commercial

› Discovery services building on UEs in close proximity

LTE Device-to-Device (D2D)

D2Dsidelink(PC5)

Uplink /downlink

(Uu)

References

D2D in 3GPP TS 36.300, TS 23.303, TR 36.843.


› D2D can be operated overlaid to cellular spectrum or on dedicated bands

› For FDD spectrum, D2D operated on UL carrier– Some additional receiver implementation required

› For TDD spectrum, D2D operated on UL subframes

› Rel-12/13 focus on licensed spectrum› D2D UE are considered half-duplex (Rel-12/13)

D2D Spectrum

D2Dsidelink(PC5)

Uplink /downlink

(Uu)


D2D Services

D2D

Cellularaccess

D2D

Cellularaccess

D2D

In coverage

Partial coverage

Out of coverage

D2D Communication

From Rel-12

D2D Discovery

From Rel-12

From Rel-13


› D2D communication is unicast or broadcast– No closed-loop link control or (H)ARQ– Blind re-transmissons with soft combining– QoS via per packet priority (Rel-13)– UE-to-network relaying (Rel-13)

› Resource allocation modes for D2D transmission– Mode 1 (network scheduled)

› UE requests resources and eNB schedules– Mode 2 (autonomous)

› eNB configures D2D resource pool› UE selects autonomously D2D resources from the pool

D2D communication

D2Dsidelink(PC5)

control


› D2D Discovery models– Model A: ”Here I am, I am a xyz” announcement– Model B: ”Here I am; I am looking for xyz” request

› Type 2 (Network scheduled)– D2D resources for discovery for a UE are scheduled by eNB

› Type 1 (Autonomous)– UE selects D2D resources for discovery from indicated resource pool– eNB configures D2D resource pool

D2D discovery

D2Dsidelink(PC5)

control


› Common time reference needed for efficient D2D

› Local synchronization is achieved by a distributed synchronization protocol, which includes relayed distribution

› Multiple synchronization sources with different priorities coexist

Synchronization for D2D

D2Dsidelink(PC5)

Uplink /downlink

(Uu)


› Large buildout and high performance of LTE networks and interest by automotive industry in connected cars

› Strong interest in China for LTE-based V2X– First feasibility studies and spectrum considerations by CCSA

LTE based V2X communication(Rel-13)

D2D V2V

CCSA - China Communications Standards Association


› SA1 Study on LTE support for V2X services [SP-150051]– Approved in SA#67 (March 2015)– The study use cases and identify requirements for

V2V, V2I, V2P and V2N based on LTE› For safety and non-safety services

– LTE-D2D and LTE-unicast/multicast/broadcast to be considered

› SA2 Study in prepraration

LTE based V2X communicationV2V

V2I

V2P

V2N

CCSA - China Communications Standards Association

http://www.3gpp.org/ftp/tsg_sa/TSG_SA/TSGS_67/Docs/SP-150051.zip


LTE V2x Radio Requirements (from 3GPP#SA1)

Table A.1: Example parameters for V2X Services

Effective range*

Absolute velocity of a UE supporting V2X Services

Relative velocity between 2 UEs supporting V2X Services

Maximum tolerable latency

Minimum radio layer message reception reliability (probability that the recipient gets it within 100ms)

Example Cumulative transmission reliability***

#1 (suburban) 200m 50kmph 100kmph 100ms 90% 99%

#2 (freeway) 320m 160kmph 280kmph 100ms 80% 96%

#3 (autobahn) 320m 280kmph 280kmph 100ms 80% 96%

#4 (NLOS / urban)

150m 50kmph 100kmph 100ms 90% 99%

#5 (urban intersection**)

50m 50kmph 100kmph 100ms 95% -

#6 (campus/ shopping area)

50m 30kmph 30kmph 100ms 90% 99%

Note*: Effective range is greater than range required to support TTC=4s at maximum relative velocity. This is such that multiple V2X transmissions are required to increase the cumulative (overall, effective, or final) transmission reliability.

Note**: This scenario represents the scenario where a new incident presents itself at a short range, requiring a high level of reliability for short range radio transmissions to ensure timely message delivery, thus a cumulative transmission reliability may not be appropriate.

Note***: Example shown for 2 transmissions, for the statistical assumptions leading to a probability of 1 – (1-p)2, where p is the probability of reception at the radio layer. V2X application layer requires a consecutive packet loss no more than 5%. If probability that a single V2X application layer message is lost is less than 20%, the requirement of less than 5% consecutive packet loss is met. Due to PHY retransmissions and the rapid cadence of application layer transmissions, the reliability as viewed from the application layer will be increased from the numbers as stated in this column.

20ms is also mentioned in the document

3GPP TR 22.885 V0.3.0 (2015-08), “Study on LTE Support for V2X Services”


› RAN1 study item: Feasibility Study on LTE-based V2X Services [RP-151109]– Finalization date: RAN#72 – June 2016

– Scope› LTE-based V2X with or without network coverage› Shared LTE carrier (mixed service) or dedicated licensed LTE-V2X ITS carrier

– Objectives› Define evaluation methodology› Improved V2X via D2D sidelink (PC5)› Improved V2X via cellular link (Uu)

RAN Standardization LTE-V2X

V2Vsidelink(PC5)

Uplink /downlink

(Uu)

http://www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_68/Docs/RP-151109.zip


› LTE enhancements for both direct mode (PC5) and cellular mode (Uu)› Some PC5 (D2D) enhancement areas:

– L1 enhancements and synchronization for high Doppler spread– Revised frame structure and radio protocol design for V2X traffic– Improved resource allocation with sensing– Traffic management for different V2X services

› Some Uu (cellular) enhancement areas:– MBMS for V2X traffic– Scheduling optimizations for efficient DRX and overhead– Mobility

› General enhancements:– Specification of Road Side Units in

architecture (as RSU-UEs or RSU-eNB)

LTE Radio Enhancement Areas for V2X

V2Vsidelink(PC5)

Uplink /downlink

(Uu)


› Demodulation reference symbols (DMRS) interleaved with data– efficient channel estimation and channel tracking

even at high Doppler frequency

› Modified SC-OFDM transmission

Sidelink V2V PHY Format

AG

C S

ettli

ng

GP

1ms

6 su

bcar

riers

(90

kHz)

Proposal:

Ericsson, “Physical Layer Format for V2X over PC5,” R1-157365, 3GPP TSG RAN WG1 Meeting #83, Anaheim, USA, 15th - 22nd November 2015

V2Vsidelink(PC5)


› Pre-established MBMS bearers enables cellular V2X communication– Max delay <90 ms

› Capacity of unicast and multicast options investigated for rural and urban traffic scenarios

› Multicast has typically better capacity for CAM-like transmission

Broadcast for V2I2VProposal:

Ericsson, “MBMS latency and capacity analysis for V2X,” R2-156639, 3GPP TSG RAN WG2 Meeting #92, Anaheim, USA, 16th - 20nd November 2015


› eNB assigned V2V resource allocations– Can be semi-persistent or dynamically allocated– Should consider requirements of different V2X services– UEs report status of radio environment

› Autonomous resource allocation– More sophisticated resource allocation needed than in D2D ProSe

(due to higher traffic load and mobility)– Radio environment should be considered in resource selection– Separate resource pools should be considered for different V2X services– UE reports to eNB shall enable configuration of suitable sidelink resource pools

V2V Resource allocationProposal:

Ericsson, “Resource Allocation in V2X,” R2-156634, 3GPP TSG RAN WG2 Meeting #92, Anaheim, USA, 16th - 20nd November 2015

V2Vsidelink(PC5)

control




Hazard warnings

Infotainment

Software download

Remote Diagnostics


traffic lights

Traffic information

Remote Navigation

2G (EDGE)

3G (HSPA)

4G (LTE)

Collisionavoidance

Hybrid LTE: Cellular D2D

(LOS)(NLOS)

LTE D2D

The path to 5G

Outline






• Summary


wireless access generations

The foundation of

mobile telephony

The foundation of mobile broadband

Mobile telephony

for everyone

The evolution of mobile broadband

Non-limiting access anywhere, anytime, anyone, anything

~1980 ~1990 ~2000 ~2010 ~2020


5G – Beyond Mobile Broadband

Broadband experienceeverywhere anytime

Smart TransportInfrastructureand vehicles

Remote controlledmachines

Mass market personalized

media and gaming

Human–machineinteraction

P

Meters, sensors,“Massive MTC”

And much morebeyond thecrystal bowl

Wide range of use cases – wide range of requirements


Wide Range of Requirements

Data rates Traffic Volume Density

Device Density

Latency

ReliabilityEnergy EfficiencySource: Draft ITU-R M.[IMT.VISION] recommendation July 15, 2015


Example: Ultra-reliable low latency communiction

Factory Automation≤ 1 ms

Motion Control≤ 1 ms

Smart Grid3-5 ms

Process Automation100 ms

Intelligent Transportation Systems5 ms

Tactile Internet1 ms

Automated Guided Vehicle15-20 ms

Numbers are examples, requirements vary within one application area

Remote Control5-100 ms


One Network – Multiple Industries

From dedicated physical networks and resources for different applications…

NWn

fn

NW1

f1

NW2

f2

S1 S2 Sn

…to a “network factory” where new networks and architectures are “manufactured by SW”

Physical Resources(Access, Connectivity, Computing, Storage, ..)

Service n

HealthRobotic communication

MediaMBB Basic


5G Radio Access ~2020

“NX”No compatibility constraints

“Existing” spectrum

Below 6 GHz

Tight interworking

“New” spectrum

Above 6 GHzNew spectrum below 6 GHz

LTE Evolution

1 GHz 3 GHz 10 GHz 30 GHz 100 GHz 1 GHz 3 GHz 10 GHz 30 GHz 100 GHz

Gradual migration


Standardization Plan

› Phase 1 – early commercial deployments› Phase 2 – full IMT-2020 compliance

SI: CM > 6 GHz

SI: 5G req.

SI: NX

NX Phase 1 NX Phase 2

LTE evo LTE evo LTE evo

SI: self-evaluation

2015 2016 2017 2018 2019 2020

NX evo

LTE evo

SI: NX enh.

IMT-2020 requirements IMT-2020 proposals IMT-2020 spec

Rel-13 Rel-15Rel-14 Rel-16 Rel-17

3GPP


› New use cases with much more challenging requirementsthan ”100ms C-ITS CAM” envisioned(references: METIS, White Paper ”5G Automotive Vision”)– Collective perception via distribution of multiple sensory data

› Bird’s eyes view of a intersection› See through driving› Platooning with close driving vehicles

– Fast exchange and computation of vehicle trajectories– Offloading real-time complex processing from vehicles to the cloud

(e.g. augmented reality, …)› Enables state-of-the-art computing for vehicles with longer product

lifecycles

› Today’s wireless technology (cellular or DSRC) insufficient

Emerging V2X services beyond C-ITS

Reference:5G-PPP, “5G Automotive Vision,” https://5g-ppp.eu/white-papers

https://5g-ppp.eu/white-papers


› Toughest identified requirements for emergingvehicular services:– Latency

› 10ms with 10-5 reliability (automated overtake, high density platooning)

– Positioning accuracy› 10 cm (vulnerable road user discovery)

or 20 cm (high density platooning, automated overtake, cooperative collision avoidance)

– Date rates› 50 Mb/s with 50 ms latency (bird's eye view)

or 10 Mb/s with 50 ms (“see trough” vision)– Only indicative. Be prepared for the future.

Future V2X services requirements

Reference:5G-PPP, “5G Automotive Vision,” https://5g-ppp.eu/white-papers

https://5g-ppp.eu/white-papers


Concepts› Network assisted clustering

– Network provided resource assignments to clusters for cluster separation

– Cluster head allocates resources within cluster› Availability Indication

– Configuration and feedback of transmission reliability and delay

› D2D optimization

5G / METIS (2012-2015)› Test Case: “Traffic Safety and Efficiency”

–road platooning (vehicle-2-vehicle)–traffic safety, including pedestrians & cyclists(vehicle-2-vehicle, vehicle-2-infrastructure,vehicle-2-device)

–integration of wide-area connectivity with D2D and DSRC–guaranteed e2e delay of 5ms–transmission reliability of 99.999%–relative velocities up to 500 km/h

› Use case driver: .

Intelligent Transport Systems5G research

Service / application

Availability estimation & indication

Reliable transmission

Summary

Outline






• Summary


› Vehicular communications remains an interesting and dynamic field

› There is a huge variety of vehicular services– Many are ”in the cloud” and require vehicular-to-network connectivity

› Often state-of-the-art cellular network connectivity is sufficient

– Localized real-time communication is needed for Cooperative ITS and its’ evolution› Many services are still to emerge

(may be triggered by the availability of suitable connectivity)

Vehicular communications


› LTE – Standardized since 2005, first release (Rel-8) in Dec. 2008– First commercial deployments in Dec. 2009

› Today widely deployed globally– Continuously evolving with several features per release

› 6th LTE release (Rel-13) to be finished Q1 2016› From Rel-13: V2X via D2D and/or cellular transmission

› 5G standardization is starting– Higher capabilities also addressing V2X and

ultra-reliable low latency communication– Accelerate cellular network feature evolution

› Cellular D2D may obsolete 802.11p

Wireless access for V2X and C-ITS

› IEEE 802.11p– Standardized from 2004-2010– Based on 802.11a (1999)– Only test deployments

– No standard revision planned– What’s next? Future proofness?

Make V2X research relevant for future deployed wireless networks

Complementary hybrid usage is possible


› E. G. Ström, P. Popovski, J. Sachs, “5G Ultra-Reliable Vehicular Communication,” submitted for publication, available at http://arxiv.org/abs/1510.01288

› 5G-Infrastructure-Association, “5G Automotive Vision,” October 20, 2015. Available at https://5g-ppp.eu/white-papers/.

› G. Gehlen, F. Ramme, S. Sories and G. Jodlauk, “Cooperative Cars – Using Cellular Communications for Co-operative Automotive Applications”, ITS World Congress 2007, Beijing, China, October 2007.

› S. Sories, J. Huschke and M.-A. Phan, “Delay Performance of Vehicle Safety Applications in UMTS”, ITS World Congress 2008, New York City, USA, November 2008.

› G. Jodlauk, R. Rembarz, Z. Xu: 'An Optimized Grid-Based Geocasting Method for Cellular Mobile Networks', ITS World Congress 2011, Orlando, Florida, October 2011

› M. Phan, R. Rembarz, S. Sories: 'A Capacity Analysis for the Transmission of Event and Cooperative Awareness Messages in LTE Networks', ITS World Congress 2011, Orlando, Florida, October 2011

› O. N. C. Yilmaz, Z. Li, K. Valkealahti, M. A. Uusitalo, Martti Moisio, P. Lundén, C. Wijting, "Smart mobility management for D2D communications in 5G networks", IEEE WCNC 2014, April 6-9, 2014, Istanbul, Turkey.

› G. Fodor, D. D. Penda, M. Belleschi, and M. Johansson, "A Comparative Study of Power Control Approaches for Device-to-Device Communications", IEEE International Conference on Communications (ICC), Budapest, Hungary, June 2013.

References

http://arxiv.org/abs/1510.01288


› A. Pradini. G. Fodor, and M. Belleschi, "Near Optimal Practical Power Control Schemes for D2D Communications in Cellular Networks", European Conference on Networks and Communications (EuCNC), Bologna, Italy, June 23-26, 2014.

› W. Sun, D. Yuan, E. G. Ström, F. Brännström, "Resource Sharing and Power Allocation for D2D-based Safety-Critical V2X Communications", IEEE ICC 2015, June 8-12, 2015, London, UK.

› J. M. B. da Silva Jr, G. Fodor, T. F. Maciel, "Performance Analysis of Network Assisted Two-Hop D2D Communications", 10th IEEE Broadband Wireless Access Workshop, Austin, TX, USA, December 2014.

› A. Abrardo, G. Fodor, B. Tola, "Network Coding Schemes for D2D Communications Based Relaying for Cellular Coverage Extension", IEEE Signal Processing Advancements for Wireless Communications (SPAWC), Stockholm, June 2015.

› ETSI TS 102 637-3: “Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic Service”.

› ETSI TS 102 637-2: “Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service.

› ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".

› ETSI TR 102 962, Intelligent Transport Systems (ITS) - Framework for Public Mobile Networks in Cooperative ITS (C-ITS), technical report, Feb. 2012

› ETSI TS 103 084, Geomessaging Enabler, draft technical specification, Oct. 2012

References


› E. Dahlman, S. Parkvall, J. Skold, “4G LTE/LTE-Advanced for Mobile Broadband,” Academic Press, 1st edition, May 10, 2011

› E. Dahlman, G. Mildh, S. Parkvall, J. Peisa, J. Sachs, Y. Selén and J. Sköld, "5G Wireless Access: Requirements and Realization," IEEE Communications Magazine, vol. 52, no. 12, Dec. 2014.

› Ericsson, “5G - key component of the Networked Society,“ RWS-150009, 3GPP RAN Workshop on 5G Phoenix, AZ, USA, September 17 –18, 2015 http://www.3gpp.org/ftp/workshop/2015-09-17_18_RAN_5G/Docs/RWS-150009.zip

› O. N. C. Yilmaz, Y.-P. E. Wang, N. A. Johansson, N. Brahmi, S. A. Ashraf and J. Sachs, “Analysis of Ultra-Reliable and Low-Latency 5G Communication for a Factory Automation Use Case,” in IEEE International Conference on Communication (ICC), London, Jun. 2015.

› N. A. Johansson, Y.-P. E. Wang, E. Eriksson and M. Hessler, “Radio Access for Ultra-Reliable and Low-Latency 5G Communications,” in IEEE International Conference on Communication (ICC), London, Jun. 2015.

› J. Sachs, P. Popovski, A. Höglund, D. Gozalvez-Serrano and P. Fertl, “Machine-Type Communications,” book chapter in “5G Mobile and Wireless Communications Technology,” ISBN 9781107130098, to appear

› S. A. Ashraf, F. Lindqvist, B. Lindoff, R. Baldemair, "Control Channel Design Trade-offs for Ultra-Reliable and Low-Latency Communication System", IEEE Globecom Workshop on Ultra-Low Latency and Ultra-High Reliability in Wireless Communication, San Diego, USA, December, 2015.

› N. Brahmi, O. N. C. Yilmaz, K. W. Helmersson, S. A. Ashraf, J. Torsner, "Deployment Strategies for Ultra-Reliable and Low-Latency Communication in Factory Automation", IEEE Globecom Workshop on Ultra-Low Latency and Ultra-High Reliability in Wireless Communication, San Diego, USA, December, 2015.

References

http://www.3gpp.org/ftp/workshop/2015-09-17_18_RAN_5G/Docs/RWS-150009.zip

Vehicular Communications via Cellular Networks

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Transcript of Vehicular Communications via Cellular Networks