CAMP
Vehicle Safety Communications 3
Intelligent Transportation Systems
CAMP VSC3 Model Deployment DSRC
Device Minimum Performance Requirements
Overview
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
1
Model Deployment (MD) BSM Minimum Performance
Requirements (MPR) Scope
• Providing minimum performance requirements to V2V
safety applications based on VSC-A implementation
• Requirements are based on testing and simulation analysis
• The requirements are subject to change
• Will be refined with post-Model Deployment data analysis
• Reference 3 different device categories:
• OEM integrated vehicles (IV)
• Vehicle Awareness Device (VAD)
• Aftermarket Safety Device (ASD)
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
2
Table 4 Minimum Set of Data Elements with Meaningful Value to Be Included in a BSM for Vehicle Safety Application Use
MD MPR 1
• Dedicated Channel Usage: Channel (CH) 172 for BSM mainly
•
•
All three device categories that conform to the requirements shall use CH 172
for BSM transmission
Under consideration: may allow Signal Phase and Timing (SPaT) and
intersection map messages (GID) to be sent on CH 172 instead of being sent
on other channels
• Congestion Mitigation
•
•
Congestion mitigation is expected to be applied to all three device categories
Congestion mitigation requirements are expected to be published after V2V-I
project completion
• Transmission Power Requirements
•
•
Will be based on the result of scalability testing in V2V-I project
Currently the default power level requirement is 18 dBm
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
3
Table 4 Minimum Set of Data Elements with Meaningful Value to Be Included in a BSM for Vehicle Safety Application Use
MD MPR 2
•Security and Privacy Requirements:
The Security and Privacy requirements for the integrated vehicles,
VAD and ASD are being defined in conjunction with the V2V-I project
•GPS configuration Requirements - WAAS/SBAS configuration
Each GPS receiver in the Model Deployment program shall be
configured to use WAAS corrections.
•Data Frame/Element Accuracy and Latency Definition
• The accuracy shall be measured at the sensor output point
• The latency of a data element/frame is defined as the maximum age of
the data in the outgoing BSM, from the time the data is obtained from
the sensor source
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
4
Table 4 Minimum Set of Data Elements with Meaningful Value to Be Included in a BSM for Vehicle Safety Application Use
MD MPR 3- BSM Transmission Interval Requirements
BSM Transmission Interval Requirements
•The BSM consists of two parts: Part I and Part II. Part I contains some
basic vehicle state information such as the message ID, vehicle ID,
vehicle latitude, longitude, speed and acceleration. MD MPR Part II
contains two data frames: VehicleSafetyExtension and VehicleStatus
•The default BSM transmission interval is set to 100ms; The device is
required to be capable of sending BSM at 50ms interval to accommodate
potential pre-crash situation
• Some of the Part II data are required to be transmitted at the same
interval as Part I’s, such as PathHistory and PathPrediction, while other
Part II data is required to be sent based on needs (e.g. EventFlag)
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
5
Table 4 Minimum Set of Data Elements with Meaningful Value to Be Included in a BSM for Vehicle Safety Application Use
MD MPR 5 - BSM Data-Element-Level Requirements Detail
•
•
•
Provide accuracy, latency and other requirements for each of the BSM data elements used in
Model Deployment
The requirement values are expected to be adjusted after Model Deployment data analysis
Some of the examples are:
•
•
•
•
TempID shall be randomized periodically and shall be re-randomized if the same ID was detected to be
used by another device
•
The above description may be suitable for J2945 draft
•
To meet MD data collection & processing needs, TempID randomization may be implemented
differently in MD
The positional data shall be at least 1.5 m accurate, under certain environments/conditions
For non-integrated vehicles, a data element such as TransmissionState, that cannot be populated by
VADs, shall be transmitted using “not available” value
Some data elements shall be sent when needed, such as EventFlags being sent when at least one
event is active
•
Each event has its own requirements. E.g. Transmission of Hard Brake Event requires that the
brake threshold be met
•
SAE J2735 Path History Type 4 is specified as the Path History being used for V2V safety in
Model Deployment with maximum 23 points allowed
•
The maximum number of points needed may be discussed further
* In J2735 there are many PathHistory types defined to accommodate various needs therefore
PathHistory type needs to be specified in this document
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
6
Influence to SAE J2945.1 BSM Communication MPR
• MD MPR is based on CAMP field testing and simulation
results
• MD MPR will continue being adjusted and refined through
MD program
• The recommended MD requirements for actual deployment
will be ported to SAE J2945.1 document for publishing
• In addition to BSM, other messages defined in SAE J2735
are expected to have their specific SAE J2945.X
performance requirements documents
March 12, 2012
-- CAMP - VSC3 Consortium Proprietary --
7