1. Dedicated Short Range Communication

2. What is DSRC? A short to medium range communications service Aimed as a replacement to the 802.11 wireless standards –802.11 a – Operates at 5 GHz –802.11 b/g – Operates at 2.4 GHz – Bandwidth of (11 / 52 Mbps respectively) – Interference with Microwave/Bluetooth Older DSRC systems such as toll tags operate in the 900 MHz spectrum –No standard, several proprietary systems are in place FCC has authorized 75 MHz of spectrum from 5.850 to 5.925 GHz for DSRC (incl. Canada and Mexico) –Standardization, Interoperability –Europe and Japan use the 5.8 GHz spectrum –European organization – CEN – Different Physical and MAC layer standards –Japan – ARIB T55

3. DSRC Overview Supports both Public Safety and Private operations Both roadside to vehicle and vehicle to vehicle communication environments Meant to be a complement to cellular communications –provides very high data transfer rates and minimal latency –Range – upto 1000 m –Data Rate – 6 to 27 Mbps –Channels – 7 Licensed Channels

4. DSRC Key Issue – QoS – Prioritization of Safety messages If a neighboring car is in the middle of a streaming movie application, and I need to communicate about an accident, how to prioritize the message? DSRC has 1 control channel and other service channels. Safety messages are expected to use the control channel

5. DSRC Overview ASTM 17.51 – the DSRC Standards Committee Underlying radio technology for DSRC applications –802.11a – Originally proposed standard –802.11p – aka Wireless Access for the Vehicular Environment (WAVE) defines enhancements to 802.11 required to support Intelligent Transportation Systems (ITS) applications Formal standard is scheduled to be published in Jan 2007

6. Alternatives to 802.11p 802.20 - http://www.ieee802.org/20/http://www.ieee802.org/20/ –Different Frequency band – 3.5 Ghz –Designed for mobile broadband wireless access systems –Optimized for IP-data transport –Supports mobility upto 250 kmph –Peak data rate per user > 1 Mbps 802.16 – WiMAX – MAN (Point to Multipoint) 802.15 – PANs (Bluetooth, ZigBee)

7. ISO TC204 WG16 CALM M5 Architecture

8. DSRC Protocol Stack P1609.1, Resource Manager P1609.2, Application Services P1609.3, IP Network Services P1609.4, Medium Access Control (MAC) Extension Services [Vehicle Safety Data Dictionary/Message Sets (SAE)]

9. IEEE P1609.1 Scope Modified version of the Resource Manager standard originally defined in IEEE Std 1455-1999 P1609 Resource Manager supports DSRC applications using the IEEE 802.11a communication technology

10. IEEE P1609.2 Scope An Application Services (Layer 7) standard for 5.9 GHz DSRC applications Supports several protocol stacks, including one representing traditional DSRC systems, TCP/IP, and streaming audio/video Describes interfaces with the lower layer standards being developed by ASTM

11. IEEE P1609.3 Scope Defines interfaces between the multiple communication stacks and the lower layer services of ASTM 2213-02 (IEEE 802.11a R/A) Support multiple protocol stacks, one for the traditional DSRC, one for streaming audio/video, and another for TCP/IP The North American DSRC Architecture is evolving

12. IEEE P1609.4 Scope Standard for the Media Access Control Extension sub-layer (Layer 2) that defines interfaces between these multiple applications and communication stacks that interface with ASTM 2213-02 (IEEE 802.11a) Interface with the public safety applications community through National Public Safety Telecommunication Council (NPSTC) NPSTC cooperation is expected to result in potential use of the ITS Radio (DSRC) by ITS and public safety

13. IEEE DSRC DD/MST Standardization of the Data Dictionary and Message Set (DD/MS) definitions DD/MST was present in IEEE Standard 1455-1999, being ported to 5.9 GHz DSRC standards Auto manufacturers - on-board vehicle safety messages – need for standardization

14. References DSRC http://www.leearmstrong.com/DSRC/DSRCHomeset.htm IEEE 802.11 Task Group status http://grouper.ieee.org/groups/802/11/Reports/tgp_update.htm AMI-C http://www.ami-c.org NPSTC http://www.npstc.org

15. Brake-light communication system Related work –Performance Evaluation of Safety Applications over DSRC Vehicular Ad Hoc Networks, VANET 2004. Based on simulations, no real hardware.Performance Evaluation of Safety Applications over DSRC Vehicular Ad Hoc Networks –Few other papers from PATH, Europe, etc.