Vehicle to Vehicle Communication Presented at PATH Conference 2001

1
Vehicle to Vehicle CommunicationPresented at
PATH Conference 2001

• Raja Sengupta, Asst. Professor, CEE Department,
  UC Berkeley
• Joint work withDuke Lee, Ruchira Datta, Mustafa
  Ergen, Jeff Ko, Roberto Attias, Anuj Puri,
  Stavros Tripakis, Paul Xu, Pravin Variaya

2
PATH LAB Wireless Overview

• Research Strategy
• Networks for Asynchronous Messaging
• Networks for Synchronous Communication
• Summary
• Future Work

3
ITS Wireless is Developing Rapidly

• We are cognizant of the substantial efforts by
  both government and non-government entitites to
  develop, in response to Congress transportation
  legislation, a national ITS plan and Architecture
  addressing ways of using communication
  technologies to increase the efficiency of the
  nations transportation infrastructure. The
  record in this proceeding overwhelmingly supports
  the allocation of spectrum for DSRC based ITS
  applications to increase traveler safety, reduce
  fuel consumption and pollution, and continue to
  advance the nations economy.
• FCC Report and Order, October 22, 1999, FCC
  99-305

4
Current DSRC National Standards Activities

• Developing usage rules and licensing procedure
  recommendations for the FCC
• Expect to submit FCC rule recommendations in
  October 2000
• Developing the first draft of the Physical and
  MAC Layer Standards
• Expected standard completion is early 2002

5
5.9 GHz DSRC TECHNOLOGY
Proposal Originated by CALTRANS/TCFI/PATH

• The first round selection has been made by the
  ASTM E17.51 DSRC Standards Writing Group on
  August 24, 2001
• FIRST ROUND WINNER - IEEE 802.11a/RA Physical
  Layer and the IEEE 802.11 Medium Allocation (MAC)
  Layer
• IEEE 802.11a/RA is a modified version of IEEE
  802.11a with 10 MHz wide channels instead of 20
  MHz channels and half the data rate
• The SECOND ROUND of Voting will occur in
  September and will include the Larger ASTM E17.51
  subcommittee
• It is expected that the subcommittee will confirm
  the writing groups selection

6
Public Safety and Private Applications Share the
Band
PUBLIC SAFETY
PRIVATE

• PROBE DATA COLLECTION
• TRAFFIC INFORMATION
• TOLL COLLECTION
• IN-VEHICLE SIGNING
• WORK ZONE WARNING
• HIGHWAY/RAIL INTERSECTION WARNING
• ROAD CONDITION WARNING
• INTERSECTION COLLISION AVOIDANCE
• VEHICLE TO VEHICLE
• VEHICLE STOPPED or SLOWING WARNING
• VEHICLE-VEHICLE COLLISION AVOIDANCE
• ROLLOVER WARNING
• LOW BRIDGE WARNING
• MAINLINE SCREENING
• BORDER CLEARANCE
• ON-BOARD SAFETY DATA TRANSFER
• DRIVERS DAILY LOG
• VEHICLE SAFETY INSPECTION
• TRANSIT VEHICLE DATA TRANSFER (gate)

• ACCESS CONTROL
• GAS PAYMENT
• DRIVE-THRU PAYMENT
• PARKING LOT PAYMENT
• DATA TRANSFER (IDB, J1708, J1939, PCI, etc.)
• ATIS DATA
• DIAGNOSTIC DATA
• REPAIR-SERVICE RECORD
• VEHICLE COMPUTER PROGRAM UPDATES
• MAP and MUSIC DATA UPDATES
• RENTAL CAR PROCESSING
• UNIQUE CVO FLEET MANAGEMENT
• CVO TRUCK STOP DATA TRANSFER
• LOCOMOTIVE FUEL MONITORING
• LOCOMOTIVE DATA TRANSFER

Courtesy Broady Cash ARINC Inc
ATIS - Advanced Traveler Information Systems CVO
- Commercial Vehicle Operations EV - Emergency
Vehicles IDB - ITS Data Bus THRU - Through
ITALIC - Primarily 915 MHz Applications REGULAR
- Currently 134 kHz DL 903 MHz UL BOLD -
Primarily 5.9 GHz Applications BOLD - Both 915
MHz and 5.9 GHz Applications GREEN - One-Way
Communication from RSU to OBU
7
PATH LAB Strategy

• Safety-critical Vehicle-Roadside and
  Vehicle-Vehicle Communications is important in
  the DSRC agenda
• Unique experience
• Ten years of experience in safety-critical
  wireless communication over 802.11 hardware
• Key role in national DSRC standards process
• Maintaining leadership through several projects
• AHS (P.O. 4224)
• Merge (P.O. 4224)
• Cooperative Cruise Control (DARPA MOBIES)
• Intersection Decision Systems (USDOT IVI)

8
What is the Traveler Safety Problem?

• Our research impacts REC, Intersection, LCM

Source Report to Congress on NHTSA ITS Program,
January 1997 USDOT
9
Two kinds of Networks

• Asynchronous messaging
• Applications
• Stopped vehicle warning
• Lead Vehicle Decelerating warning
• Merge warning
• Delivered with high probability within delay
  bounds
• Synchronous communication
• Applications
• Platooning
• Automated Vehicle Merging
• Control data delivered periodically with high
  probability

10
Asynchronous Messaging
ICC Car
Entering!

• Send roadside information to vehicle
• Signage, dynamic advice
• SVRD, ICC
• Send vehicle information to vehicle
• Cybernetic brake lights
• Stopped Vehicle Warning
• Turn signals
• FCWS, ICC, LCAS
• Using 802.11
• DSSS

Braking!
11
A Protocol for Asynchronous V-V Messaging

• Events generate messages
• Events Stopping, Hard braking, Merging, etc.
• To be useful the message must be received within
  D sec
• For hard braking D 50 ms (Sengupta etal. 1997)
• Vehicle puts its own position and event code in
  the message and broadcasts
• Event codes Hard braking, merging, entering
  intersection, etc.
• Receivers accept or discard message based on
  position of the sender and the event code
• Example It this is a hard braking message from
  the vehicle in front of me then give this message
  to my Cooperative Cruise Control
• Sender may broadcast the message more than once
  in time D to increase the probability of it being
  received
• After D the message is discarded

12
A Broadcast Protocol for Vehicle-to-Vehicle
Communication
Brake event
50 ms

• Scheme 1 Transmit on the first slot only
• Scheme 2 Pick n slots randomly out of 50 and
• transmit in each of them

13
Performance of the Protocol

• 200 bytes per point-to-point message exchange
• 6 brakings per minute for each vehicle

14
Synchronous CommunicationWireless Token Ring
Protocol

• Vehicles transmit control data in turn every 20
  ms
• Vehicles change
• Requirements
• On-time packets
• Small packet loss
• Not handled by 802.11, etc.

15
Wireless Token Ring Protocol
T
Data
PS (C) B NS (C) A
C
T
Data

• Forms a ring from any topology (regardless of
  hidden terminals)
• The ring adapts dynamically to configuration
  changes
• Gives all stations regular on-time access with a
  fair share of the bandwidth
• Completely distributed No super administrator!
• IEEE 802.11 compliant implementation
• Very different network but built on hardware in
  the market

T
Data
B
PS (B) A NS (B) C
A
PS (A) C NS (A) B
16
Performance Analysis
3 FTP Flow
Token Rotation Time
Rotation number
17
PerformanceThroughput comparison with 802.11

• 802.11 DCF
• No MAC level
• retransmission
• In WTRP

18
PATH LAB Summary

• Networks for Asynchronous Messaging
• Protocol design
• Mathematical Analysis
• Networks for Synchronous Communication
• Token Ring Protocol Design
• Simulation Analysis
• Implementation and Experimental Evaluation
• Key participation in federal and California ITS
  DSRC Effort

19
PATH LAB Future

• Protocols for position based addressing and
  filtering
• Roadside Vehicle Networks
• Intersection Decision Systems
• Experimental work on 802.11a/RA hardware as it
  develops
• Corporate gift of OFDM hardware from Wi-LAN Inc.
• Continued participation in national DSRC with
  emphasis on California
• Continued development of diversified wireless
  program

20
DSRC CAPABILITIES
(in the designated ITS RADIO SERVICE bands)
902 - 928 MHz Band
PARAMETERS
5850 - 5925 MHz Band
SPECTRUM USED DATA RATE COVERAGE ALLOCATIO
N STATUS INTERFERENCE POTENTIAL MAXIMUM
RANGE CHANNEL CAPACITY POWER (Downlink) POWER
(Uplink)
75 MHz 6 Mbps - 27 Mbps (7 channels) Overlap
ping communication zones needed and
allowed Primary Status (high protection) Sparse
ly located Military Radars, Very Sparsely located
Satellite Uplinks 1000 m ( 3000 ft) 7
channels 44.77 dBm (30 W) up to 15 dBm (lt
32mW) (See Note)
12 MHz (909.75 to 921.75 MHz) 0.5 Mbps Large
distances between communication zones No
protection Many 900 MHz Phones, Many Rail Car
AEI Readers, Many Spread Spectrum Devices, Wind
Profile Radars 300 ft 1 to 2 channels 44.77
dBm (30 W) up to 6 dBm (lt 4mW)
ITS RADIO SERVICE is the FCC Part 90 designation
for the 915 MHz and 5.9 GHz DSRC spectrum Note -
As a special case 44.77 dBm (30 W) may be use for
the signal preemption uplink on a unique channel.
21
5.9 GHz COMMUNICATIONS SYSTEM BASIC OPERATING
FACTORS

• PUBLIC SAFETY and PRIVATE APPLICATIONS share the
  band
• INTEROPERABILITY
• PUBLIC SAFETY INSTALLATION PRIORITY
• NON-MUTUAL EXCLUSIVITY FOR PRIVATE INSTALLATIONS
• LIMITED RANGE FOR PRIVATE OPERATIONS
• FREQUENCY COORDINATOR USED TO ASSIGN LICENSES

22
Assumptions of Analysis

• The distribution of braking for each individual
  vehicle is a Poisson process
• The braking distributions for different vehicles
  are identically independent
• Therefore the braking distribution of all
  vehicles is also a Poisson process with the rate
  equal to the sum of the rates of all vehicles

23
Result of AnalysisProbability of Failure for a
braking message

• n is the number of transmission for each braking
  (1lt n lt 49)
• m is the total number of slots in the 50 ms (m
  50)
• is the arrival rate of brakings of all
  vehicles
• ( 0.1 /sec (number of vehicles))
• is the length of time a vehicle buffers the
  braking message ( 0.05 second)

24
Wireless Token Ring Protocol (WTRP)A Medium
Access Control Protocol for Wireless Networks in
Intelligent Transportation Systems.
Duke Lee, Ruchira Datta, Mustafa Ergen, Jeff Ko,
Roberto Attias, Anuj Puri, Raja Sengupta,
Starvros Tripakis, and Pravin Variaya
25
Berkeley WOW Network Stack
TCP/UDP/WTP
Transport Layer
Mobility Management
Geographic routing, DSDV, QOS
Network Layer
Data Link
Token ring, bluetooth 802.11
MAC
Physical Layer
Network provides a socket type interface to
applications --- send (DestinationName, message)
Illustrated by Anuj Puri
26
Merge Lane

• Distributed solution
• Need wireless QOS
• Admission control

27
Motivations for WTRP

• Quality of service (real time applications)
• Distributed solution (robust against a single
  node failure)
• Flexible topology (token ring can be created with
  Pico cells)
• Safety critical applications (need fast recovery
  from failure)
• No need for clock synchronization (compared to
  TDMA)
• Partial connectivity (hidden terminal problem)

28
Motivations for WTRP

• Quality of service (real time applications)
• Distributed solution (robust against a single
  node failure)
• Flexible topology (token ring can be created with
  Pico cells)
• Safety critical applications (need fast recovery
  from failure)
• No need for clock synchronization (compared to
  TDMA)
• Works on partial connectivity (no hidden terminal
  problem)

29
Motivations for WTRP

• Quality of service (real time applications)
• Distributed solution (robust against a single
  node failure)
• Flexible topology (token ring can be created with
  Pico cells)
• Safety critical applications (need fast recovery
  from failure)
• No need for clock synchronization (compared to
  TDMA)
• Works on partial connectivity (no hidden terminal
  problem)

centralized (802.11 PCF, Bluetooth)
distributed (token ring)
30
Motivations for WTRP

• Quality of service (real time applications)
• Distributed solution (robust against a single
  node failure)
• Flexible topology (token ring can be created with
  Pico cells)
• Safety critical applications (need fast recovery
  from failure)
• No need for clock synchronization (compared to
  TDMA)
• Works on partial connectivity (no hidden terminal
  problem)

1
4
3
1
2
TDMA
31
Motivations for WTRP

• Quality of service (real time applications)
• Distributed solution (robust against a single
  node failure)
• Flexible topology (token ring can be created with
  Pico cells)
• Safety critical applications (need fast recovery
  from failure)
• No need for clock synchronization (compared to
  TDMA)
• Works on partial connectivity (no hidden terminal
  problem)

32
Additional Challenges From Wireless Medium

• Partial connectivity (unable to hear all nodes in
  a ring)
• Support for multiple rings
• Self-managed admission control
• Frequent packet loss, corruption

33
Solutions Unique Ring Address

• Each ring has unique ring id based on unique MAC
  address of one of the stations of the ring.

34
Solutions Connectivity Table

• Each node builds and updates connectivity table
  that contains information of all stations in its
  reception range, and transmission order of the
  nodes in its ring

35
Solutions Connectivity Table

• Each node builds and updates connectivity table
  that contains information of all stations in its
  reception range, and transmission order of the
  nodes in its ring

36
Ring Recovery

• B fails or moves out of range.
• A tries to transmit to its successor (B) a
  specified number of tries and determine that
  communication link to B is bad.

C
A
B
37
Solutions Unique Priority of Token

• Based on ring address and generation sequence
  number pair.
• Station only accept token that has higher
  priority than the last token that the station has
  accepted.

ring address
generation sequence

38
Token Recovery (Multiple Tokens Resolution)
1
1
2
2
1
1
6
6
39
Token Recovery (Multiple Tokens Resolution)
2
2
1
2
1
6
6
6
40
Token Recovery (Multiple Tokens Resolution)
2
2
2
6
6
1
6
6
41
Token Recovery (Multiple Tokens Resolution)
6
6
2
6
2
2
6
6

• At next step
• Delete token with generation sequence number 2
  since the next node has seen token with
  generation sequence number 6

42
Token Recovery (Multiple Tokens Resolution)
6
6
6
6
2
6
6
43
Token Recovery (Multiple Tokens Resolution)
6
6
6
6
6
6
6
44
Token Recovery (Multiple Tokens Resolution)
6
6
6
6
6
7
7
Token refreshed by owner
45
Token Recovery (Multiple Tokens Resolution)
6
6
6
6
7
7
7
46
Token Recovery (Ring Address Resolution)
6
6
6
6
6
6
7
47
Token Recovery (Ring Address Resolution)
6
6
6
6
8
7
8
This node detects that the owner is down and
claims the token
48
Token Recovery (Ring Address Resolution)
6
6
8
8
6
8
7
49
Token Recovery (Ring Address Resolution)
8
8
6
8
6
8
7
50
User Interaction
High Priority Applications (6)
Low Priority Applications (6,3)
Wireless Token Ring Protocol (10)
51
User Interaction
High Priority Applications (6)
Low Priority Applications (6,3)
Wireless Token Ring Protocol (4)
52
User Interaction
High Priority Applications (6)
Low Priority Applications (6,3)
Wireless Token Ring Protocol (4)
53
User Interaction
High Priority Applications (6)
Low Priority Applications (6,3)
Wireless Token Ring Protocol (1)
54
WTRP Deliverables (2001)
55
UDP Instant Messenger Application
56
UDP Video Streaming
57
Simulation Front End
58
(No Transcript)
59
Token Rotation Time Vs. Rotation
A
3
A
A
1
2
B
B
B
60
Throughput Comparison With 802.11 DCF
61
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

62
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

63
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

64
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

65
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

66
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

67
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.

68
Conclusions

• The wireless token ring protocol (WTRP) is a
  medium access control protocol for wireless
  networks in intelligent transportation systems.
• It supports quality of service in terms of
  bounded latency and reserved bandwidth.
• WTRP is efficient in the sense that it reduces
  the number of retransmissions due to collisions.
  
• It is fair in the sense that each station takes a
  turn to transmit and is forced to give up the
  right to transmit after transmitting for a
  specified amount of time.
• It is a distributed protocol that supports many
  topologies since not all stations need to be
  connected to each other or to a central station.
  
• It can be used with an admission control agent
  for bandwidth or latency reservations.
• WTRP is robust against single node failure.
  WTRP is designed to recover gracefully from
  multiple simultaneous faults.
• It has applications to inter-access point
  coordination in ITS DSRC, vehicular platooning,
  and safety-critical vehicle-to-vehicle
  networking.