SSEM

Version

Look for the current version via the link in the table at the message-type introduction page

caution

As of mid november 2024, Mobilidata has changed version regarding AMQP headers (version 0.9 to 1.0). This is caused by changes in the C-Roads (TF4 spec release 2.1.0) specification.

Description

The Signal Status Message (SSM) is a message sent by a RoadSide Unit (RSU) in a signalized intersection. It is used to relate the currentstatus of the signal and the collection of pending or active preemption or priority requests acknowledged by the controller. It is also used to send information about preemption or priority requests which were denied. This in turn allows a dialog acknowledgmentmechanism between any requester and the signal controller. The data contained in this message allows other users to determine their "ranking" for any request they have made as well as to see the currently active events. When there have been no recently receivedrequests for service messages, this message may not be sent. While the outcome of all pending requests to a signal can be found in theSignal Status Message, the current active event (if any) will be reflected in the SignalPhaseAndTiming (SPAT) message contents.

Usage

As this message is related to SREM messages, see SREM description.

Attributes

"Ssm": {
  ...
  "Status":[
        {
          "SequenceNumber": 102,
          "Id": {
            "Region": 4001,
            "Id": 191
        },
          ...
  ]
}

The Status object contains an array and every object has the information on the intersection in the Id object. The Id object contains the Region and Id of the intersection.

"Ssm": {
  ...
  "Status":[
        {
          ...
          "SigStatus": {
            "Requester":
              {
                ...
                "TypeData": {
                  "Role": 6,
                  "Subrole": 5,
                  ...
                }
              }
            ...
        },
      ...
  ]
}

The Requester attribute contains information on the requester. See the SREM message for more information on these fields.

caution

Data packages are encoded/decoded to ASN.1 standard, using the 'UPER' encoding rules.

Example

SSEM AMQP Header example

{
    "id": ",4001-222,",
    "quadTree": ",120202123030001300,",
    "timestamp": "1733317395498",
    "messageType": "SSEM",
    "publisherId": "BE00004",
    "publicationId": "BE00004:SSEM_03",
    "carolTimestamp": "2024-12-04T13:03:14Z",
    "baselineVersion": "2.1.0",
    "protocolVersion": "SSEM:1.3.1",
    "originatingCountry": "BE",
    "custom-mobilidata-baselineVersion": "D",
    "custom-mobilidata-dtapEnvironment": "production",
    "custom-mobilidata-origin-timestamp": "173331739"
}

SSEM Example Message

ASN.1

020a0fa100be6679974bf2cc03343e8402fc0b8c1c3e7f3ec83203293679975a98fde820

JSON

{
    "Header": {
    "ProtocolVersion": 2,
    "MessageID": 10,
    "StationID": 262209726
},
    "Ssm": {
    "Timestamp": 424343,
    "Second": 19442,
    "SequenceNumber": 102,
    "Status": [
{
    "SequenceNumber": 102,
    "Id": {
    "Region": 4001,
    "Id": 191
},
    "SigStatus": [
{
    "Requester": {
    "Id": {
    "EntityID": null,
    "StationID": 118464463
},
    "Request": 178,
    "SequenceNumber": 6,
    "Role": null,
    "TypeData": {
    "Role": 6,
    "Subrole": 5,
    "Request": null,
    "ISO3883": null,
    "HpmsType": null,
    "Regional": null
}
},
    "InboundOn": {
    "Lane": 0,
    "Approach": 3,
    "Connection": 0
},
    "OutboundOn": null,
    "Minute": 424343,
    "Second": 23192,
    "Duration": 65000,
    "Status": 2,
    "Regional": null
}
    ],
    "Regional": null
}
    ],
    "Regional": null
}
}