SAE J 2313 : 1999

1 Scope
2 References
      2.1 Application Documents
             2.1.1 SAE Publications
             2.1.2 ISO Publications
      2.2 Related Publications
             2.2.1 Other Publications
3 Definitions
4 Overview of Message Set Standard
      4.1 System Architecture
      4.2 Message Information Flow
      4.3 Relationships with National Architecture Flows
      4.4 Additional Requirements Imposed by Commercial,
             Hazmat, and Medical Needs
      4.5 Use of Location Referencing Methods of ITS
      4.6 Structure of the Document
5 The Message Protocol
      5.1 Message Protocol Flow
      5.2 State Time-Out and Transition Requirements
      5.3 Third Party message Protocol Flow
             Considerations
6 The Message Frames
      6.1 General Message Frame Elements
      6.2 The Data_Msg Frame Elements
      6.3 The Init_Msg Frame Elements
      6.4 The Req_Msg Frame Elements
      6.5 The Ack_Msg Frame Elements
7 The Message Types
      7.1 Collections of Data Elements into Related
             Message Types
      7.2 Message Type Definitions
      7.3 Message Type: Current_Position
      7.4 Message Type: Prior_Position
      7.5 Message Type: Start_Position
      7.6 Message Type: Position_History
      7.7 Message Type: Position_Text
      7.8 Message Type: Last_DRSC
      7.9 Message Type: Vehicle_Info
      7.10 Message Type: Vehicle_Details
      7.11 Message Type: Vehicle_Sensor_Info
      7.12 Message Type: Vehicle_SRS
      7.13 Message Type: Vehicle_Security
      7.14 Message Type: Cargo_Info
      7.15 Message Type: Occupant_Info
      7.16 Message Type: Occupant_SRS
      7.17 Message Type: Text_Info
      7.18 Message Type: Proprietary_Info
      7.19 Message Type: Message Sets
      7.20 Message Type: Request Data
      7.21 Message Type: Acknowledge Data
      7.22 Message Type: Position_LRMS
8 The Data Elements
      8.1 Data Element: Message Frame Header
      8.2 Data Element: Sequence Number
      8.3 Data Element: Frame Word Count
      8.4 Data Element: Sender Flags
      8.5 Data Element: Sender Status
      8.6 Data Element: Message Type
      8.7 Data Element: Message Word Count
      8.8 Data Element: Location-Long
      8.9 Data Element: Location-Lat
      8.10 Data Element: Location-Alt
      8.11 Data Element: Velocity
      8.12 Data Element: Heading
      8.13 Data Element: Time-Minutes
      8.14 Data Element: Beacon-ID
      8.15 Data Element: Location-Tech
      8.16 Data Element: Identity-Name
      8.17 Data Element: Identity-Number
      8.18 Data Element: Identity-ESN
      8.19 Data Element: Identity-DL-Number
      8.20 Data Element: Identity-VIN
      8.21 Data Element: Identity-Plate
      8.22 Data Element: Identity-Carrier-ID
      8.23 Data Element: Vehicle-Sensor-Identifier
      8.24 Data Element: Data-Sensor
      8.25 Data Element: Data-Cargo
      8.26 Data Element: Data-Proprietary
      8.27 Data Element: Data-Door-Status
      8.28 Data Element: Occupant-Sensor-Identifier
      8.29 Data Element: Sensor-Status
      8.30 Data Element: Message-Bit-Fields
      8.31 Data Element: Ack
      8.32 Data Element: Data Text
      8.33 Data Element: Identity-Plate-Origin
      8.34 Data Element: Identity-Plate-Type
      8.35 Data Element: Location-Quality
      8.36 Data Element: CRC
9 Implementation of a Rudimentary MAYDAY System over
      the IDB
      9.1 Overview of the IDB
      9.2 An illustrative MAYDAY System Using the IDB
      9.3 IDB MAYDAY Components on the Bus
             9.3.1 Cellular Phone
             9.3.2 GPS Set
             9.3.3 Display Console with Buttons
             9.3.4 Central Processor Resource
             9.3.5 Gateway into the Vehicle Electronics
10 Physical Layer Interface Issues
      10.1 Requirements for MAYDAY System over AMPS
             Cellular Networks
      10.2 Physical Layer Specifications for MAYDAY
             Systems
      10.3 Discussion of Other Communication Technologies
             10.3.1 CDPD Technologies
             10.3.2 Two-Way Paging Technologies
             10.3.3 TDMA Technologies
             10.3.4 CDMA Technologies
             10.3.5 Satellite Communications Technologies
             10.3.6 SMR Technologies
11 MAYDAY Message Set Testing
Figure 1 - Overall Operational Concept
Figure 2 - Generic MAYDAY System Diagram Model
Figure 3 - MAYDAY Functional Flows from the National
           Architecture
Figure 4 - Detailed MAYDAY Message Flows
Figure 5 - Typical Protocol Exchange
Figure 6 - Typical Three Frame Protocol Exchange
Figure 7 - Example of Extended Protocol Exchange
Figure 8 - Exchange Initiated by Status Change
Figure 9 - Example of Data from the Dispatch Center
Figure 10 - General Sending Message State Flow
Figure 11 - General [Waiting for &] Receiving Message State
            Flow
Figure 12 - Example of Device Communications Driver Layer
Figure 13 - A Three Party Protocol Exchange
Figure 14 - Message Frame Contents
Figure 15 - An Example of the Passenger Airbag Status in a
            Message Frame
Figure 16 - Typical IDB Bus (Figure Taken from SAE J2366)
Figure 17 - Example of Devices on Bus Needed for MAYDAY

This SAE Standard describes the interface between an on-vehicle Mayday detection, reporting system and the off-vehicle response center that will manage the response to the vehicle's call for assistance.