1. DSRC & WAVE

2. Overview DSRC WAVE IEEE 802.11p Dedicated Short-Range Communications
ASTM Standard E , based on a
ITS communications on 5.9/5.8GHz band
WAVE
Wireless Access in Vehicular Environments
Mode of operation used by IEEE devices to operate in the DSRC band
IEEE p
Based on ASTM Standard E
Currently draft
DSRC technology for ITS applications is working in the 5.9 GHz band (U.S.) or 5.8 GHz band (Japan, Europe). Former standard used the 915 MHz band.
ASTM (American Society for Testing and Materials)
ASTM Standard E

3. Comparisons DSRC/WAVE Wi-Fi Cellular Mobile WiMAX5 Data rate 3-27Mbps
Mobility
>  60 mph
< 5mph
> 60 mph
Nominal Bandwidth
10MHz
20MHz
< 3MHz
< 10MHz
Operating Band
GHz (ITS-RS)
2.4GHz, 5.2GHz (ISM)
800MHz, 1.9GHz
2.5 GHz
IEEE std.
802.11p
(WAVE)
802.11a
N/A
802.16e

4. IEEE WAVE Standards
Figure from IEEE Trial-Use Standard

5. IEEE P1556
Standard for Security and Privacy of Vehicle/Roadside Communication Including Smart Card Communication
Is now replaced by IEEE

6. IEEE P1609/WAVE IEEE P1609 family are standards for WAVE
Defines…for vehicular wireless communication
Architecture, Communications model, Management structure, Security mechanisms, Physical access
Architectural components
On Board Unit (OBU)
Road Side Unit (RSU)
WAVE interface

7. IEEE P1609/WAVE CCH & SCH
WAVE devices shall be able to accommodate an architecture that supports a Control Channel (CCH) and multiple Service Channels (SCH)
CCH
Transmit WAVE Short Messages (WSM)
Announce WAVE services
SCH
Application interactions/transmissions

8. Synchronization
To make sure all devices are monitoring CCH during CCH interval
IEEE Security
Single-channel device
Must have Coordinated Universal Time (UTC)
Ex: GPS pulse per second (PPS)
Or it shall continuously monitoring CCH
Multi-channel device
Monitor CCH
Ex: Timestamp field of IEEE

9. IEEE 1609 Sync Tolerance
Guard interval is used for synchronization

10. IEEE 1609/WAVE IEEE 1609.1 IEEE 1609.2 IEEE 1609.3 IEEE 1609.4
Resource Manager
IEEE
Security Services for Applications and Management Messages
IEEE
Networking Services
IEEE
Multi-Channel Operations
* IEEE P Standard for Wireless Access in Vehicular Environments (WAVE) - Resource Manager specifies the services and interfaces of the WAVE Resource Manager application. It describes the key components of the WAVE system architecture and defines data flows and resources at all points. It also defines command message formats and data storage formats that must be used by applications to communicate between architecture components, and specifies the types of devices that may be supported by the On Board Unit (OBU) resident on the vehicle or mobile platform.
* IEEE P Standard for Wireless Access in Vehicular Environments (WAVE) - Security Services for Applications and Management Messages defines secure message formats and processing. This standard also defines the circumstances for using secure message exchanges and how those messages should be processed based upon the purpose of the exchange.
* IEEE P Standard for Wireless Access in Vehicular Environments (WAVE) - Networking Services defines network and transport layer services, including addressing and routing, in support of secure WAVE data exchange. It also defines Wave Short Messages, providing an efficient WAVE-specific alternative to IPv6 (Internet Protocol version 6) that can be directly supported by applications. Further, this standard defines the Management Information Base (MIB) for the WAVE protocol stack.
* IEEE P Standard for Wireless Access in Vehicular Environments (WAVE) - Multi-Channel Operations provides enhancements to the IEEE Media Access Control (MAC) to support WAVE operations.

11. IEEE Protocol Stacks WME: WAVE Management Entity
MIB: Management Information Base
MLME: Mac Sublayer Management Entity
PLME: PHY Sublayer Management Entity
WSMP: WAVE Short Message Protocol
LLC: Logic Link Control

12. IEEE 1609.3 Data Services Logical Link Control (LLC) IPv6 UDP & TCP
WAVE short message (WSM) and protocol (WSMP)

13. IEEE 1609.3 Management Services
Application Registration
Register application to WAVE Management Entity (WME) so service flow can map to correct IP address & port
WAVE Basic Service Set (WBSS) management
WBSS actions
Ex: Joining & ending a WBSS
WBSS parameters management
Ex: SSID, MAC address, SCH number, Timestamp

14. IEEE 1609.3 Management Services
Channel usage monitoring
Ex: QoS, avoid using congested channel
IPv6 configurations
Received channel power indicator (RCPI) monitoring
Ex: provide RCPI for applications
Management information base (MIB) maintenance
Management parameters

15. IEEE 1609.4 User Priority (UP)
Use IEEE e EDCA mechanism
Mapping UP to Access Category Index (ACI)
EDCA: Enhanced Distributed Channel Access

16. IEEE 1609.4 UP on CCH & SCH CCH SCH
AIFS: Arbitration Inter-Frame Space, an EDCA parameter, the minimum time interval between the wireless medium
becoming idle and the start of transmission of a frame
CW: Contention Window, an EDCA parameter, an interval from which a random number is drawn to implement the
random back-off mechanism
TXOP: Transmit Opportunity, an EDCA parameter, the maximum time duration (in milliseconds) for which a
station can transmit after obtaining a TXOP. If the TXOP limit is 0, the transmit opportunity only
permits the transmission of a single MSDU

17. IEEE 1609.4 Channel Coordination
CCH: Control Channel
SCH: Service Channel
ACI: Access Category Index
AIFS: Arbitration Inter-Frame Space, an EDCA parameter, the minimum time interval between the wireless medium
becoming idle and the start of transmission of a frame
CW: Contention Window, an EDCA parameter, an interval from which a random number is drawn to implement the
random back-off mechanism
TXOP: Transmit Opportunity, an EDCA parameter, the maximum time duration (in milliseconds) for which a
station can transmit after obtaining a TXOP. If the TXOP limit is 0, the transmit opportunity only
permits the transmission of a single MSDU

18. IEEE 1609.4 Channel Coordination
Channel coordination requires synchronization
A guard interval is at the beginning of each synchronization interval
Media busy is declared during guard interval

19. IEEE p
Define enhancements to required to support ITS applications
Lower layer of WAVE
Supports two different stacks
IPv6
only on SCHs (not CCH)
WAVE Short Message Protocol (WSMP)
can be sent on any channel
allows applications to directly control physical characteristics
allows applications to directly control physical characteristics: channel number and transmitter power

20. IEEE 802.11p Communication between 802.11 STAs …
Without becoming a member of a BSS is possible
Direct & Immediate
Avoid the latency caused by BSS association
May use a dedicated frequency band
STA = Station
BSS = Basic Station Set
IEEE p 的設計允許讓station可以直接連接溝通而不需要成為同個BSS的成員，
這個直接、快速立即連線的設計可以省下與BSS的association時間，
不過可能要使用特殊的頻帶來傳輸這類的通信訊號。

21. IEEE p MAC
DCF – CSMA/CA
IBSS & Infrastructure
Communication outside BSS
HCF contention-based channel access (EDCA)
EDCA is an enhanced variant of DCF
EDCA parameters
Outside BSS: default
Inside BSS: given by associated BSS or AP
DCF = Distributed Coordination Function
CSMA/CA = Carrier Sense Multiple Access With Collision Avoidance
IBSS = Independent Basic Service Set
HCF = Hybrid Coordination Function
EDCA = Enhanced Distributed Channel Access
AP = Access Point
IEEE p在MAC主要有兩種方式：DCF與EDCA。
在每個節點上，包括與BSS連線、運作在infrastructure模式的節點，以及直接連線不經過BSS，都必須要有DCF的設計。
可以不經過BSS直接連線是802.11p的特點。
EDCA是一種DCF的加強版。有關EDCA的連線參數，在運作於BSS之下時是由BSS或AP提供，在直接連線不經BSS時，則使用一套預設的參數設定。

22. DSRC Worldwide - ISO
ISO (International Organization for Standardization)
Working Group 15
Upper layer
Working Group 16
Lower layer

23. DSRC Worldwide - Europe
CEN (European Committee for Standardization)
EN 12253:2004 Dedicated Short-Range Communication - Physical layer using microwave at 5.8 GHz (review)
EN 12795:2002 Dedicated Short-Range Communication (DSRC) - DSRC Data link layer: Medium Access and Logical Link Control (review)
EN 12834:2002 Dedicated Short-Range Communication - Application layer (review)
EN 13372:2004 Dedicated Short-Range Communication (DSRC) - DSRC profiles for RTTT applications (review)
EN ISO 14906:2004 Electronic Fee Collection - Application interface

24. DSRC Worldwide - Japan
ARIB (Association of Radio Industries and Businesses, 電波產業會)
STD-T55: Electronic Toll Collection System
STD-T75: Dedicated Short-Range Communication System
STD-T88: DSRC Application Sub-Layer

25. The lead organization is ASTM
DSRC Worldwide - US
The lead organization is ASTM
Old – 915MHz
New – 5.9GHz
Range < 30 meters
Data rate = 0.5 mbps
Designed for ETC, but can be used for other applications
Single unlicensed channel
Requires special (custom) chip set & software
Vehicle to roadside
Command-response
Range to 1000 meters
Data rate 6 to 27 mbps
Designed for general internet access, can be used for ETC
7 licensed channels
Uses open off-the-shelf chip set & software
Vehicle to roadside & vehicle to vehicle
Command-response & peer to peer
ASTM (American Society for Testing and Materials)

26. US DSRC Spectrum 75 MHz band has been allocated by FCC at 5.9 GHz
Initial band use rules accepted
No auction expected
Band allows both safety and commercial applications to coexist

27. US DSRC Channel Plan
IEEE a/RA WB - 52 carrier OFDM /w 48 data carriers, 10 MHz channels
Control Channel
Optional 20 MHz
US Spread Spectrum Allocation
Optional 20 MHz
Uplink
Downlink
Ch 172
Ch 174
Ch 176
Ch 178
Ch 180
Ch 182
Ch 184
Canadian Special License Zones*
5.825
5.830
5.835
5.840
5.845
5.850
5.855
5.860
5.865
5.870
5.875
5.880
5.885
5.890
5.895
5.900
5.905
5.910
5.915
5.920
5.925
Frequency (GHz)
* - The channels overlapping these zones may be restricted in some locations in Canada. In these cases use channels 1, 2, and 3 in their place.

28. US DSRC Performance Envelope~ ~ 33 30
Data Transfer and Internet Access Services 27
MHz Band
Performance Envelope 24
Data Rate (Mbps)
(Approximate) 21 18 12
Emergency Vehicle Services
Safety Message Services 9 6
3000ft↓ 3
Toll and Payment Services
MHz Band Performance Envelope
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
0.5 Mbps
Range (ft)

29. Specific Applications
Private and Public Safety - Short Range
ALL VEHICLES
Private and Public Safety - Short Range
CVO
ACCESS CONTROL
PROBE DATA COLLECTION
TRAFFIC INFORMATION
TOLL COLLECTION
GAS PAYMENT
DRIVE-THRU 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
MAINLINE SCREENING
BORDER CLEARANCE
ON-BOARD SAFETY DATA TRANSFER
UNIQUE CVO FLEET MANAGEMENT
DRIVER’S DAILY LOG
VEHICLE SAFETY INSPECTION
TRANSIT VEHICLE DATA TRANSFER (gate)
TRANSIT VEHICLE REFUELING
LOCOMOTIVE FUEL MONITORING
ROLLOVER WARNING
LOW BRIDGE WARNING
Private and Public Safety - Large Zone
CVO = Commercial Vehicle Operations
Mainline screening: 在路上可能會用掃描技術測量車載重，以決定車輛是否需要進入過磅站或檢查哨。
Vehicle signal priority: 某些車間通訊的訊息可能具有較高的優先權，例如警車、救護車等。
Public Safety - Extended Range
TOLL COLLECTION
TRANSIT VEHICLE DATA TRANSFER (yard)
LOCOMOTIVE DATA TRANSFER
CVO TRUCK STOP DATA TRANSFER
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
Public Safety - Intersection and Emergency
EMERGENCY VEHICLE SIGNAL PREEMPTION
TRANSIT VEHICLE SIGNAL PRIORITY
EMERGENCY VEHICLE VIDEO RELAY
EMERGENCY VEHICLE APPROACH WARNING

30. Illustrations of some US DSRC APPs
Roadside Unit Placement
Good News/ Bad News
General Internet Access
On-Demand/Dynamic Navigation
Traffic Advisories
Use Vehicles as Traffic Probes
Travel Assistant
Relayed & Delayed Transmission
Information or Transaction Request
Information Requested over Internet
Data Downloaded Later
Pictures of these applications are selected from Lee Armstrong’s DSRC introduction website

31. Roadside Unit Placement
Sometimes someplace instead of everywhere always

32. Good News/ Bad News
Can be targeted to specific lanes, directions of travel but not for wide area coverage

33. General Internet Access

34. On-Demand/Dynamic Navigation

35. Traffic Advisories

36. Use Vehicles as Traffic Probes

37. Travel Assistant

38. Relayed & Delayed Transmission
Information or Transaction Request
Information Requested over Internet
Data Downloaded Later

39. Information or Transaction Request

40. Information Requested over Internet

41. Data Downloaded Later