Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7...

82
Distributed Embedded Systems Group – CCS Towards the Tactile Internet: Low Latency Communication for Connected Cars 1 Falko Dressler Towards the Tactile Internet: Low Latency Communication for Connected Cars

Transcript of Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7...

Page 1: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Distributed EmbeddedSystems Group – CCS

Towards the Tactile Internet: Low Latency Communication for Connected Cars1

Falko Dressler

Towards the Tactile Internet: Low Latency Communication for Connected Cars

Page 2: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars2

n Coordinated Automated Driving

n Towards the Tactile Internet

n Vehicular Networking

n Beaconing and Vehicular Ad Hoc Networks

n Case Study: Platooning

n Performance Evaluation

Outline

Page 3: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars3

Coordinated Automated Driving

Page 4: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards Autonomous Driving

Towards the Tactile Internet: Low Latency Communication for Connected Cars4

Page 5: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Inter-Vehicle Networking for Situation Awareness

Illustrations: C2C-CC

Towards the Tactile Internet: Low Latency Communication for Connected Cars5

Page 6: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars6

n Many communication channels availablen Which to pick when?

Towards Heterogeneous Vehicular Networks

Wi-Fi

DSRC

cellular

?“Technology2020”

mmWAVE

SoftwareDefinedRadio

VLC

Page 7: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars7

n Dedicated spectrum for inter-vehicle communicationin Europe (5.9 GHz), the US (5.9 GHz), and Japan (700 MHz)

n IEEE DSRC/WAVE, ETSI ITS G5, ARIB T109n Both build upon IEEE 802.11p

n Situation awareness as major year-one-applicationn ETSI DCC (Decentralized Congestion Control)

n But many fundamental research questions still unansweredn Scalability, real-time capabilities, use of heterogeneous networks

n Dagstuhl seminar series identified key challengesn Falko Dressler, Hannes Hartenstein, Onur Altintas and Ozan K. Tonguz, "Inter-Vehicle

Communication - Quo Vadis," IEEE Communications Magazine, vol. 52 (6), pp. 170-177, June 2014.

Standardization and Open Research

Page 8: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars8

Towards the Tactile Internet

Page 9: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars9

n Via Della Conciliazione

Towards 5GHuge Data Rates

Source: http://www.spiegel.de/panorama/bild-889031-473266.html and http://www.spiegel.de/panorama/bild-889031-473242.html

2005/4/4 2013/3/12

Page 10: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars10

Towards 5GThe evolution…

Source: http://de.slideshare.net/qualcommwirelessevolution/qualcomm-5g-vision-presentation

Page 11: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars11

n 7 billion devices in 2014 à 500 billion devices in 2022

Towards 5GHuge Data Rates

G. Fettweis, “5G: And Its Impact on Electronics”, 5G Lab Germany

Page 12: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars12

Towards 5GThe Internet of everything

Page 13: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars13

Towards 5GThe evolution…

Source: http://de.slideshare.net/qualcommwirelessevolution/qualcomm-5g-vision-presentation

Page 14: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars14

The New Challenge:Delays in the Order of a Millisecond

Page 15: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars15

Towards 5G and the Tactile InternetHaptics and remote control as a game changer

Source: http://ostsee-spezial.de/?p=148

Page 16: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars16

n 10 cameras @ 100Hz frame rate à 100Gb/s Latency @ <10ms

Towards 5G and the Tactile InternetLatencies in the low milliseconds

Source: http://baumgartnerfl.lima-city.de/stadion.html

Page 17: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars17

Towards 5G and the Tactile InternetDistributed Real-Time Control Systems

Page 18: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars18

Towards 5G and the Tactile InternetNetworked Control

4G:Content and

communications5G:

Networked Control

Page 19: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars19

Towards 5G and the Tactile InternetNew Challenges

The Tactile Internet

Page 20: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars20

n IEEE COMSOC Subcommittee “Tactile Internet”n Involved in a new standards family P1918.X

Towards 5G and the Tactile InternetStandardization

Architecture, Terminology and

Assumptions(IEEE P1918.X)

Codecs for Tactile Internet

(IEEE P1918.X.1)

AI for Tactile Internet(IEEE P1918.X.2)

MAC(P1918.X.3)

Page 21: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Vehicular Networking

Towards the Tactile Internet: Low Latency Communication for Connected Cars21

Page 22: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n WAVEn IEEE 1609.1: “Core System”

n IEEE 1609.2: Security

IVC Specific Protocols: DSRC/WAVE

[1] Jiang, D. and Delgrossi, L., "IEEE 802.11p: Towards an international standard for wireless access in vehicular environments," Proceedings of 67th IEEE Vehicular Technology Conference (VTC2008-Spring), Marina Bay, Singapore, May 2008

[2] Uzcátegui, Roberto A. and Acosta-Marum, Guillermo, "WAVE: A Tutorial," IEEE Communications Magazine, vol. 47 (5), pp. 126-133, May 2009

TCP / UDP

WAVE PHY

WAVE MAC and Channel Coordination

IPv6WSMP

Man

agem

ent

Secu

rity LLC

802.

11p 16

09.4

1609

.3

1609

.2

WAVE PHY

n IEEE 1609.3: Network Services

n IEEE 1609.4: Channel Management

Towards the Tactile Internet: Low Latency Communication for Connected Cars22

Page 23: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n PHY layer almost identical to IEEE 802.11an OFDM using 16 QAMn Reduced inter symbol interference

(multipath effects and Doppler shift)n Doubled timing parametersn Channel bandwidth (10 MHz instead of 20 MHz)n Reduced throughput (3 ... 27 Mbit/s instead of 6 ... 54 Mbit/s)n Communication range of up to 1000 mn Vehicles’ velocity up to 200 km/h

n MAC layer with extensions to IEEE 802.11an Randomized MAC addressn QoS (Priorities, see IEEE 802.11e, ...)n Support for multi channel and multi radion New ad hoc mode

IEEE 802.11p

Towards the Tactile Internet: Low Latency Communication for Connected Cars23

Page 24: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n New: 802.11 WAVE mode, now called OCB moden Main mode for all WAVE nodes

n Suggests the use of “Wildcard-BSS” in transmitted packets

n Every node is required to receive all packets using a wildcard BSS

n Inherently allows simultaneous transmission from and to a BSS

n Membership management just by using a BSS

IEEE 802.11 Basic Service Set (BSS)

BSSSSID “A”

BSSSSID “B”

Towards the Tactile Internet: Low Latency Communication for Connected Cars24

Page 25: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Use of EDCA equivalent to IEEE 802.11e EDCA n DCF -> EDCA (Enhanced Distributed Channel Access)n Definition of four Access Categories (AC)

n AC0 (lowest) to AC3 (highest priority)n Introduction of AIFS (Arbitration Inter-Frame Space)

n ACs define...n CWmin, CWmax, AIFS, TXOP-Limit (max. continuous channel use)

n Management data are transmitted using DIFS instead of an AIFS

Access Control and QoS in WAVE

Medium busy Data

Data

Data

Towards the Tactile Internet: Low Latency Communication for Connected Cars25

Page 26: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n WAVE uses a dedicated frequency range in the 5.9 GHz bandn Exclusive for V2V and V2I communication

n Strictly regulated but no license costs

n In the US, FCC reserved 7 channels a 10 MHz (“U.S. DSRC”)

n 1 control and 4 service channels to be used by applications

n In Europa, ETSI reserved 5 channels a 10 MHz

Channel Management

[1] ETSI ES 202 663 V1.1.0 (2010-01) : Intelligent Transport Systems (ITS); European profile standard for the physical and medium access control layer of Intelligent Transport Systems operating in the 5 GHz frequency band

CriticalSafety of

Life

ch 1725.860GHz

SCH

ch 1745.870GHz

SCH

ch 1765.880GHz

ControlChannel(CCH)

ch 1785.890GHz

SCH

ch 1805.900GHz

SCH

ch 1825.910GHz

Hi-PowerPublicSafety

ch 184 5.920GHz

SCH

ch 1725.860GHz

SCH

ch 1745.870GHz

SCH

ch 1765.880GHz

SCH

ch 1785.890GHz

CCH

ch 1805.900GHz

Towards the Tactile Internet: Low Latency Communication for Connected Cars26

Page 27: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Channel Managementn Management and safety information on the Control Channel (CCH)

à single radios have to switch to the CCH at known times

n Two-way communication on the Service Channel (SCH)

n Slot managementn Synchronization using GPS

n Standard: 100ms sync interval including 50ms on the CCH

n Slots start with a guard interval

Channel Management

[1] IEEE Vehicular Technology Society, "IEEE 1609.4 (Multi-channel Operation)," IEEE Std, November, 2006

CCHinterval

CCHinterval

“SCH”interval

“SCH”interval

t = n × 1s

Towards the Tactile Internet: Low Latency Communication for Connected Cars27

Page 28: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Beaconing and Vehicular Ad Hoc Networks

Towards the Tactile Internet: Low Latency Communication for Connected Cars28

Page 29: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Fully distributed approach

n No communication infrastructure needed

n No data loss in fragmented networks

n No unique node identifiers mandated

n No network topology assumed, created, or maintained

n SOTIS: local knowledge bases + beaconing

n Aggregate all sensed data + received data

n Periodic broadcast of entries (beaconing)

n Ex.: one beacon every five seconds

n No congestion control in the wireless network

The SOTIS Approach

<!><!>

Towards the Tactile Internet: Low Latency Communication for Connected Cars29

Page 30: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

SOTIS

Towards the Tactile Internet: Low Latency Communication for Connected Cars30

Page 31: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

<!><!>

<!>

<!>

<!>

<!>

<!>

<!>

idle send

rcvdup

n Flooding (Multi-Hop Broadcast)n Simplest protocol: „Smart Flooding“:

n Problem: Broadcast Storm

n Superfluous re-broadcasts overload channel

Broadcast Storm Problem

Towards the Tactile Internet: Low Latency Communication for Connected Cars31

Page 32: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Estimate distance to sender as 0 ≤ ρij ≤ 1

n GPS based

n RSS based

Broadcast Suppression

[1] Wisitpongphan, Nawaporn and Tonguz, Ozan K. and Parikh, J. S. and Mudalige, Priyantha and Bai, Fan and Sadekar, Varsha, "Broadcast Storm Mitigation Techniques in Vehicular Ad Hoc Networks," IEEE Wireless Communications, vol. 14 (6), pp. 84-94, December 2007

Towards the Tactile Internet: Low Latency Communication for Connected Cars32

Page 33: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Beacon interval: measure of channel quality and message prioritiesn Infrastructure elements: RSUs of different capabilities can be included

n Lightweight SSUs (service support unit)

n Interconnected RSUs

Fully Distributed: Adaptive Traffic Beacon (ATB)

[1] Christoph Sommer, Ozan K. Tonguz and Falko Dressler, "Traffic Information Systems: Efficient Message Dissemination via Adaptive Beaconing," IEEE Communications Magazine, vol. 49 (5), pp. 173-179, May 2011

[2] Christoph Sommer, Ozan K. Tonguz and Falko Dressler, "Adaptive Beaconing for Delay-Sensitive and Congestion-Aware Traffic Information Systems," Proceedings of 2nd IEEE Vehicular Networking Conference (VNC 2010), Jersey City, NJ, December 2010, pp. 1-8

Challenging questions• How frequently can the beacons be sent?• How frequently should the beacons be sent?• Which information should be included into the beacon?

Towards the Tactile Internet: Low Latency Communication for Connected Cars33

Page 34: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Adaptive selection of beacon interval ΔI

n Consider message utility P

n Consider channel quality C

n Choose interval from range Imin to Imax

n Use factor wI to increase weight of C (ex. wI=0.75)

n ΔI = ((1 – wI) × P2 + (wI × C 2)) × (Imax – Imin) + Imin

Adaptive Traffic Beacon (ATB)

00.20.40.60.81

00.250.5

0.751

0 0.2 0.

4 0.6 0.8 1

P

I

C

Towards the Tactile Internet: Low Latency Communication for Connected Cars34

Page 35: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Adaptive selection of beacon interval ΔI

n Calculation of message utility P based on metrics of (ex.)

n A: age of information

n De: distance to source of information

n Dr: distance to closest Road Side Unit (RSU)

n B: ratio of beacon contents received from Road Side Unit (RSU)

n Calculation of channel quality C based on metrics of (ex.)

n N: (estimated) number of neighbors (à future)

n S: (observed) signal-to-noise ratio (à present )

n K: (measured) collisions on channel (à past )

Adaptive Traffic Beacon (ATB)

P = A+De +Dr

3×B C = N +wC (S +K ) / 2

1+wC

Towards the Tactile Internet: Low Latency Communication for Connected Cars35

Page 36: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

State of the Art: Adaptive Beaconing

n First proposed in Adaptive Traffic Beacon (ATB) protocol

[1] Christoph Sommer, Ozan K. Tonguz and Falko Dressler, "Traffic Information Systems: Efficient Message Dissemination via Adaptive Beaconing," IEEE Communications Magazine, vol. 49 (5), pp. 173-179, May 2011

10s 3s 1s 300ms 100ms 30ms ATB

1020

3040

5060

Beacon interval

Em

erge

ncy

msg

del

ay in

s

Page 37: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

State of the Art: Adaptive Beaconing

n Later introduced in standardizationn ETSI ITS-G5 developed DCC (Decentralized Congestion Control) with TRC

(Transmit Rate Control)

n bt is the “busy ratio” of the channel

n Rather coarse grained measurement intervals

[1] Werner, Marc and Lupoaie, Radu and Subramanian, Sundar and Jose, Jubin, "MAC Layer Performance of ITS G5 - Optimized DCC and Advanced Transmitter Coordination," Proceedings of 4th ETSI TC ITS Workshop, Doha, Qatar, February 2012

1 . . .

. . . n

active

relaxed restrictive

bmin,1 s ≥ 15 % bmin,1 s ≥ 40 %

bmax,5 s < 15 % bmax,5 s < 40 %

Page 38: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Maybe we all overlooked some issues!

n Antenna characteristicsn Radio signal shadowing

Problem Solved?

Towards the Tactile Internet: Low Latency Communication for Connected Cars38

Page 39: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Experimental Validation

[1] Christoph Sommer, David Eckhoff, Reinhard German and Falko Dressler, "A Computationally Inexpensive Empirical Model of IEEE 802.11p Radio Shadowing in Urban Environments," Proceedings of 8th IEEE/IFIP Conference on Wireless On demand Network Systems and Services (WONS 2011), Bardonecchia, Italy, January 2011, pp. 84-90

[2] David Eckhoff, Christoph Sommer, Reinhard German and Falko Dressler, "Cooperative Awareness At Low Vehicle Densities: How Parked Cars Can Help See Through Buildings," Proceedings of IEEE Global Telecommunications Conference (GLOBECOM 2011), Houston, TX, December 2011

Towards the Tactile Internet: Low Latency Communication for Connected Cars39

Page 40: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Models allow taking into consideration(a) static and(b) moving obstacles

n Research question: What is their impact on beaconing?

Establishment of New Models

Towards the Tactile Internet: Low Latency Communication for Connected Cars40

Page 41: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n DynB – Dynamic Beaconing

n Considering all the radio shadowing effects to adapt very quickly to the current channel quality

n Main idea: continuously observe the load of the wireless channel to calculate the current beacon interval

n I = Imin + r (Imax – Imin)

with Imax = (N+1) Imin (N is the number of neighbors)and r = (bt / bdes) - 1 clipped in [0, 1]

Towards new Beaconing Concepts

[1] Christoph Sommer, Stefan Joerer, Michele Segata, Ozan K. Tonguz, Renato Lo Cigno and Falko Dressler, "How Shadowing Hurts Vehicular Communications and How Dynamic Beaconing Can Help," Proceedings of 32nd IEEE Conference on Computer Communications (INFOCOM 2013), Mini-Conference, Turin, Italy, April 2013

Towards the Tactile Internet: Low Latency Communication for Connected Cars41

Page 42: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Assuming a payload of l = 512 bit (at 18 Mbit/s),we obtain

tbusy = Tpreamble + Tsignal + Tsym [(16 + l + 6) / NDBPS] = 104 µs

n Using a minimum AIFS and an average initial backoff counter, we get a maximum bt

bt = tbusy / (tbusy + taifs + tidle) = 0.64

n With some maximum collision probability of 0.05, we get a maximum bt

bt = 0.25

How Busy Can/Should the Channel Be?

Towards the Tactile Internet: Low Latency Communication for Connected Cars42

Page 43: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Assuming two larger clusters of vehicles meeting spontaneously (e.g., at intersections in suburban or when two big trucks leave the freeway)

Handling Dynamics in the Environment

Towards the Tactile Internet: Low Latency Communication for Connected Cars43

Page 44: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Temporary network fragmentation

Remaining Problems

Towards the Tactile Internet: Low Latency Communication for Connected Cars44

Page 45: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Idea: detect current scenario, switch between protocols

n Check for fragmented networkn Network connected à perform broadcast suppression

n Network fragmented à perform Store-Carry-Forward

DV-CAST

<!>

Towards the Tactile Internet: Low Latency Communication for Connected Cars45

Page 46: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Mechanismn Nodes periodically send Hello beacons containing position, speedn Nodes maintain 3 neighbor tables

n Same direction, aheadn Same direction, driving behindn Opposite direction

n Messages contain source position and Region of Interest (ROI)

n For each message received, evaluate 3 Flags:n Destination Flag (DFlg):

Vehicle in ROI, approaching sourcen Message Direction Connectivity (MDC):

neighbor driving in same direction, further away from sourcen Opposite Direction Connectivity (ODC):

neighbor driving in opposite direction

DV-CAST

[1] Tonguz, Ozan K. and Wisitpongphan, N. and Bai, F., "DV-CAST: A distributed vehicular broadcast protocol for vehicular ad hoc networks," IEEE Wireless Communications, vol. 17 (2), pp. 47-57, April 2010

Towards the Tactile Internet: Low Latency Communication for Connected Cars46

Page 47: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Algorithm

DV-CAST

Towards the Tactile Internet: Low Latency Communication for Connected Cars47

Page 48: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Simulation results

DV-CAST

Towards the Tactile Internet: Low Latency Communication for Connected Cars48

Page 49: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Temporary network fragmentation

n Undirected message dissemination

Remaining Problems

Towards the Tactile Internet: Low Latency Communication for Connected Cars49

Page 50: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n TO-GOn “Topology-Assisted Geo-Opportunistic Routing”

n Nodes periodically send Hello beacons; Contents:

n Number of neighbors

n Bloom filter of neighbor IDs

n IDs of neighbors furthest down the road/roads

n Thus, nodes know about all 2-hop neighbors

Geocast

[1] Lee, K.C. and Lee, U. and Gerla, M., "Geo-Opportunistic Routing for Vehicular Networks," IEEE Communications Magazine, vol. 48 (5), pp. 164-170, May 2010

Towards the Tactile Internet: Low Latency Communication for Connected Cars50

Page 51: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Bloom Filtern Idea:

n Bloom filter is a bit field X

n Hash functions h1 to hk map input data x à one bit (each) in X

n Insertion of x: Set X[hi(x)] ← 1 i [1..k]

n Test for x X: Check X[hi(x)] 1 i [1..k]

n Probabilistic test for “x X”

n Possible results: no / maybe (à chance of false positives)

n Allows for very compact representation of X

Geocast

[1] Bloom, Burton H., "Space/time trade-offs in hash coding with allowable errors," Communications of the ACM, vol. 13 (7), pp. 422-426, 1970

0 1 0 0 0 1 0 1

“foo”

h1 h2 h3

Towards the Tactile Internet: Low Latency Communication for Connected Cars51

Page 52: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n TO-GOn Find best next hop (Target Node, T)

n Find N: Furthest neighbor towards destination

n Find J: Furthest neighbor towards destination, currently on junction

n Find NJ: Furthest neighbor towards destination, as seen by J

n if N, NJ are on the same road (and running in greedy mode),pick Nelse, pick J

Geocast

N

NJ

J

Towards the Tactile Internet: Low Latency Communication for Connected Cars52

Page 53: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Case Study: Platooning

Towards the Tactile Internet: Low Latency Communication for Connected Cars53

Page 54: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars54

n A specific application: platooningn solve traffic congestion problems

n decrease pollution

n increase safety

n decrease severe injuries/deaths

n Avoid wasting driving time

n Research questionsn Impact of platooning on network (and vice versa)

n Develop protocols to better support platooning

Distributed ControlPlatooning as one of the most challenging applications

Page 55: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars55

n Manual driving (Dist: 2s ~ 50m @ 100km/h)

n ACC – Radar based (Dist: 1s ~ 28m @ 100km/h)

n Simple CACC – Radar + IVC (Dist: 0.6s ~ 16m @ 100km/h)

Automated Car Following

BrakeReactionPerception

BrakeRadar

BrakeComm

Page 56: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars56

n Cooperative CACC (Dist: 0.2s ~ 5m @ 100km/h)

CACC / Platooning Controller

Michele Segata, Bastian Bloessl, Stefan Joerer, Christoph Sommer, Mario Gerla, Renato Lo Cigno and Falko Dressler, "Towards Communication Strategies for Platooning: Simulative and Experimental Evaluation," IEEE Transactions on Vehicular Technology, vol. 64 (12), pp. 5411-5423, December 2015.

BrakeComm BrakeComm

Page 57: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

57

n Permit detailed simulation ofn Communications

n Road traffic

Simulation Framework

Michele Segata, Stefan Joerer, Bastian Bloessl, Christoph Sommer, Falko Dressler and Renato Lo Cigno, "PLEXE: A Platooning Extension for Veins," Proceedings of 6th IEEE Vehicular Networking Conference (VNC 2014), Paderborn, Germany, December 2014, pp. 53-60.

Towards the Tactile Internet: Low Latency Communication for Connected Cars

Page 58: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Platooning Braking – Minimum Distance

1 2 3 4 5 10 20

01

23

45

1 .33 .2 .1 .05.5 .25

minim

um

distance

(m)

beacon frequency (Hz)

inter-message delay (s)

2 m/s2

4 m/s2

6 m/s2

8 m/s2

Towards the Tactile Internet: Low Latency Communication for Connected Cars58

Page 59: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

59

n Develop and test 4 different protocolsn Random transmission (static beaconing)

n Synchronized transmission (slotted beaconing)

n Both w/ and w/o transmission power control

Communication Protocols

Towards the Tactile Internet: Low Latency Communication for Connected Cars

Page 60: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Protocol Performance for 640 Cars

Towards the Tactile Internet: Low Latency Communication for Connected Cars60

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

00.2

0.4

0.6

0.8

1safe

timeratio

delay requirement (s)

StbPSlbPStbSlbDynBDCC

Page 61: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Emergency Braking Requirements

Towards the Tactile Internet: Low Latency Communication for Connected Cars61

WE CAN USE ADYNAMIC APPROACH!

Page 62: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars62

n Main idea:n the more constant the system, the lower the requirement

n send updates only when needed, use prediction otherwise

n Problems:n awareness: we can’t simply stop beaconing

n what does it mean “constant”?

Jerk: The Concept

Michele Segata, Falko Dressler and Renato Lo Cigno, "Jerk Beaconing: A Dynamic Approach to Platooning," Proceedings of 7th IEEE Vehicular Networking Conference (VNC 2015), Kyoto,Japan, December 2015, pp. 135-142.

Page 63: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars63

n Jerk:n physical quantity measuring variation of acceleration over time

n using an estimation of jerk we compute the beacon interval

n tunable parameters:

n minimum beacon interval

n maximum beacon interval

n sensitivity

Jerk Beaconing

Page 64: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Jerk Beaconing

Towards the Tactile Internet: Low Latency Communication for Connected Cars64

Page 65: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars65

n Problem:n (dynamically) undersampling a system à risk in case of losses

n Solution: couple with a reliable delivery mechanismn send packets in a chained fashion

n use transmit power control to increase spatial re-use

n static assignment

n piggyback acknowledgements

n ensure delivery OR

n try again OR

n notify application about failure (stop simulation and log outcome)

n re-propagate leader information (most important)

Jerk Beaconing: Reliability

Page 66: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Protocol Performance for 640 Cars – Harsh scenario

Towards the Tactile Internet: Low Latency Communication for Connected Cars66

3 m

45 %

4 m

17 %

Page 67: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Towards the Tactile Internet: Low Latency Communication for Connected Cars67

n There’s life after static beaconing even for platooning, butn jerk beaconing still a heuristic proof of conceptn can we theoretically link control requirements, beacon interval, and inter-

vehicle gap? à optimal beacon rate for target requirementn how can we handle network failures?

n More Options: Getting Heterogeneousn Communication between platoon lead and all followers: radio broadcastn Communication between succeeding cars: visual light communication

(VLC)

n Simple VLC model:n Constant (processing) delayn 20% packet loss

Next Steps

Michele Segata, Renato Lo Cigno, Hsin-Mu Tsai and Falko Dressler, "On Platooning Control using IEEE 802.11p in Conjunction with Visible Light Communications," Proceedings of 12th IEEE/IFIP Conference on Wireless On demand Network Systems and Services (WONS 2016), Cortina d'Ampezzo, Italy, January 2016, pp. 124-127.

Page 68: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n LED transmitter, CCD receiver

Impact of Using VLC

8 - 11p 8 - vlc 160 - vlc 320 - vlc 640 - vlc

0

1

2

3

4

5

6

distance

(m)

scenario

bad

great

Towards the Tactile Internet: Low Latency Communication for Connected Cars68

Page 69: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Protocol Performance with VLC

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

00.2

0.4

0.6

0.8

1safe

timeratio

delay requirement (s)

802.11p only, 8 vehicles802.11p/VLC (leader/front), 8 vehicles802.11p/VLC (leader/front), 160 vehicles802.11p/VLC (leader/front), 320 vehicles802.11p/VLC (leader/front), 640 vehicles

Towards the Tactile Internet: Low Latency Communication for Connected Cars69

Page 70: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Performance Evaluation

Towards the Tactile Internet: Low Latency Communication for Connected Cars70

Page 71: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Real-world experimentsn Outline only limited information about the feasibility and the performance

à experiments with roughly 400 cars are planned in a German project

n Performance evaluation for 2%, 10%, 50%,… penetration?

n Simulationn Usually using standard network simulation methods

n ns2/ns3, OMNeT++, GloMoSim, OPNET, …

n Detailed network layers, simple “support” modules

n Appropriate for VANETs?

n Research challenge: appropriate mobility modeling

Evaluation

Towards the Tactile Internet: Low Latency Communication for Connected Cars71

Page 72: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Early approachesn Random Waypoint

n Manhattan Grid

n Traces

n Road traffic microsimulationn Simulation of individual cars

n Exact modeling of streets, speed limits, etc.

n Coupling with network simulationn Pre-computation (or on-demand simulation) of road traffic

n Incorporation of computed traces into network simulators(can be used for real-world traces as well)

Mobility Modeling

[1] C. Sommer and F. Dressler, "Progressing Towards Realistic Mobility Models in VANET Simulations," IEEE Communications Magazine, vol. 46 (11), pp. 132-137, November 2008

[2] J. Yoon, M. Liu, and B. Noble, "Random waypoint considered harmful," Proceedings of 22nd IEEE Conference on Computer Communications (IEEE INFOCOM 2003), vol. 2, San Francisco, CA, March 2003, pp. 1312-1321

[3] V. Naumov, R. Baumann, and T. Gross, "An evaluation of inter-vehicle ad hoc networks based on realistic vehicular traces," Proceedings of 7th ACM International Symposium on Mobile Ad Hoc Networking and Computing (ACM Mobihoc 2006), Florence, Italy, March 2006, pp. 108-119

Towards the Tactile Internet: Low Latency Communication for Connected Cars72

Page 73: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Unidirectional coupling: models road traffic without any optimization through TIS information

n Bidirectional coupling is important to analyze effects of IVC on road traffic and vice versa

Coupling Approaches

[1] Christoph Sommer, Reinhard German and Falko Dressler, "Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis," IEEE Transactions on Mobile Computing, vol. 10 (1), pp. 3-15, January 2011

[2] M. Treiber, A. Hennecke, and D. Helbing, "Congested Traffic States in Empirical Observations and Microscopic Simulations," Physical Review E, vol. 62, pp. 1805, 2000

Network Simulation Road Traffic Simulation

B. Real-world traces

A. Random node movement C. Micro-

simulation

D. Bidirect. coupling

Towards the Tactile Internet: Low Latency Communication for Connected Cars73

Page 74: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Veins – Vehicles in Network Simulationn http://veins.car2x.org/

n Based on tools that are well-acceptedin their respective communitiesn OMNeT++ for network simulation

n SUMO for road traffic microsimulation

n Objectivesn Bidirectionally coupled simulation of VANETs

n Incorporation of real-world street maps

n Flexible and fast(!) simulation

Veins

[1] Christoph Sommer, Reinhard German and Falko Dressler, "Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis," IEEE Transactions on Mobile Computing, vol. 10 (1), pp. 3-15, January 2011

Towards the Tactile Internet: Low Latency Communication for Connected Cars74

Page 75: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Veins System Architecture

Towards the Tactile Internet: Low Latency Communication for Connected Cars75

[1] Christoph Sommer, Reinhard German and Falko Dressler, "Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis," IEEE Transactions on Mobile Computing, vol. 10 (1), pp. 3-15, January 2011

http://veins.car2x.org

Page 76: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Evaluation metrics: traveling time vs. CO2 emissionn Quite accurate gas consumption / emission models available

n E.g., EMIT

Further Challenges

[1] A. Cappiello, I. Chabini, E. Nam, A. Lue, and M. Abou Zeid, “A statistical model of vehicle emissions and fuel consumption,” 5th IEEE International Conference on Intelligent Transportation Systems (IEEE ITSC), pp. 801–809, 2002

[2] C. Sommer, R. Krul, R. German, and F. Dressler, "Emissions vs. Travel Time: Simulative Evaluation of the Environmental Impact of ITS," Proceedings of 71st IEEE Vehicular Technology Conference (VTC2010-Spring), Taipei, Taiwan, May 2010

Towards the Tactile Internet: Low Latency Communication for Connected Cars76

Page 77: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Traveling Time vs. CO2 Emission

Towards the Tactile Internet: Low Latency Communication for Connected Cars77

Page 78: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Accuracy of technically optimal solutions and imperfect driver behavior

Further Challenges

[1] R. König, A. Saffran, and H. Breckle, “Modelling of drivers’ behaviour,” in Vehicle Navigation and Information Systems Conference, Yokohamashi, Japan, August/September 1994, pp. 371–376.

[2] W. Barfield, M. Haselkorn, J. Spyridakis, and L. Conquest, “Commuter Behavior and Decision-Making: Designing Motorist. Information Systems,” in 33rd Human Factors and Ergonomics Society Annual Meeting, Santa Monica, CA, 1989, pp. 611–614.

[3] P. C. Cacciabue, Ed., Modelling Driver Behaviour in Automotive Environments: Critical Issues in Driver Interactions with Intelligent Transport Systems. Springer, 2007.

[4] F. Dressler and C. Sommer, "On the Impact of Human Driver Behavior on Intelligent Transportation Systems," Proceedings of 71st IEEE Vehicular Technology Conference (VTC2010-Spring), Taipei, Taiwan, May 2010

Towards the Tactile Internet: Low Latency Communication for Connected Cars78

Page 79: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Driver Behavior – Results

[1] F. Dressler and C. Sommer, "On the Impact of Human Driver Behavior on Intelligent Transportation Systems," Proceedings of 71st IEEE Vehicular Technology Conference (VTC2010-Spring), Taipei, Taiwan, May 2010

Towards the Tactile Internet: Low Latency Communication for Connected Cars79

Page 80: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Conclusions

Towards the Tactile Internet: Low Latency Communication for Connected Cars80

Page 81: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

Today, we studied

n Challenges and opportunities of using connected cars conceptsn Capability to connect everyone and everything

n Can be seen as a big data storage

n Help improving our daily road traffic experience and safety

n Not discussedn Security issues: Strong debate about privacy vs. security

… as can be seen, there are many open challenges and questions for another decade of interesting research JJ

Conclusions

Towards the Tactile Internet: Low Latency Communication for Connected Cars81

Page 82: Towards the Tactile Internet: Low Latency Communication for Connected Cars · 2017-10-27 · 7 Towards the Tactile Internet: Low Latency Communication for Connected Cars n Dedicated

n Vehicular Networking (Cambridge University Press)

More Information?

Towards the Tactile Internet: Low Latency Communication for Connected Cars82