Home > UPER Encoding/Decoding
UPER (Unaligned Packed Encoding Rules) is a binary encoding format used in C-ITS messages, including DENM and IVIM. It optimizes message size while ensuring efficient encoding and decoding processes.
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Data Structure Definition: Each message type (e.g., DENM, IVIM) defines its data structure using ASN.1 (Abstract Syntax Notation One).
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Mapping to ASN.1 Types: ASN.1 types (e.g., INTEGER, OCTET STRING) are mapped to corresponding data elements in the message structure.
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UPER Encoding: Data elements are encoded using UPER rules, which involve:
- Breaking down data into smaller components
- Encoding each component according to predefined rules
- Packing encoded components into binary format
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Bit-Level Optimization: UPER optimizes the use of individual bits within bytes to minimize message size without sacrificing data integrity.
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Binary Input: The encoded message in binary format is received by the decoder.
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UPER Decoding: The decoder interprets the binary stream according to UPER rules, which involves:
- Unpacking binary data into individual components
- Decoding each component based on its predefined rules
- Reconstructing the original data structure
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ASN.1 Mapping: Decoded components are mapped back to their corresponding ASN.1 types and data elements.
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Output: The decoded message is then available for further processing or display within C-ITS applications.
UPER encoding and decoding ensure efficient and reliable communication of C-ITS messages while minimizing bandwidth usage and processing overhead.
11004c01204000800050010003db00009400000000000000adbed407f974b8e6f952f45d000d000e7974b8e67952f45d000a00000000000007d200000201012fd537c78097ea9b81ed9f2d8fa1a3c7cb63e868f2f19a1e6649cc65d17917900018b5010546001f3056c1c0061000dff8480e018d841196eac3e4a01c780c518d3261453f0077e000
{
"gbcGacHeader":{
"basicHeader":{
"version":1,
"nextHeader":1,
"reserved":0,
"lifeTime":{
"multiplier":19,
"base":0
},
"remaingHop":1
},
"commonHeader":{
"nextHeader":2,
"reserved1":0,
"headerType":4,
"headerSubType":0,
"traficClass":{
"scf":false,
"channelOffload":false,
"tcID":0
},
"flags":{
"mobile":true,
"reserved":0
},
"payloadLength":80,
"maxHopLimit":1,
"reserved2":0
},
"sequenceNumber":987,
"reserved1":0,
"sopv":{
"address":{
"configuration":"manual",
"stationType":5,
"reserved":0,
"mid":{
"lsb":0,
"msb":0
}
},
"tst":2914964487,
"latitude":2037692646,
"longitude":2035479645,
"pai":false,
"speed":-16370,
"heading":14
},
"geoArea":{
"lat":-109791002,
"long":-112004003,
"distanceA":10,
"distanceB":0,
"angle":0
},
"reserved2":0
},
"btpb":{
"destinationPort":2002,
"destinationPortInfo":0
},
"denm":{
"header":{
"protocolVersion":2,
"messageID":1,
"stationID":19911991
},
"denm":{
"management":{
"actionID":{
"originatingStationID":19911991,
"sequenceNumber":987
},
"detectionTime":1071266991390,
"referenceTime":1071266991390,
"eventPosition":{
"latitude":-109791002,
"longitude":-112004003,
"positionConfidenceEllipse":{
"semiMajorConfidence":377,
"semiMinorConfidence":377,
"semiMajorOrientation":0
},
"altitude":{
"altitudeValue":1200,
"altitudeConfidence":"alt-000-02"
}
},
"relevanceDistance":"lessThan50m",
"relevanceTrafficDirection":"allTrafficDirections",
"validityDuration":86400,
"transmissionInterval":500,
"stationType":5
},
"situation":{
"informationQuality":3,
"eventType":{
"causeCode":14,
"subCauseCode":0
},
"linkedCause":{
"causeCode":97,
"subCauseCode":0
},
"eventHistory":[
{
"eventPosition":{
"deltaLatitude":-123,
"deltaLongitude":897,
"deltaAltitude":20
},
"eventDeltaTime":1706733817,
"informationQuality":1
},
{
"eventPosition":{
"deltaLatitude":456,
"deltaLongitude":789,
"deltaAltitude":10
},
"informationQuality":2
}
]
},
"location":{
"eventSpeed":{
"speedValue":1300,
"speedConfidence":127
},
"eventPositionHeading":{
"headingValue":14,
"headingConfidence":127
},
"traces":[
[
]
]
}
}
}
}Intelligent Transport Systems
ItsPduHeader
protocolVersion: 2
messageID: denm (1)
stationID: 19911991
DecentralizedEnvironmentalNotificationMessage
management
actionID
originatingStationID: 19911991
sequenceNumber: 987
detectionTime: 2037-12-11 22:09:46.390 (1071266991390)
referenceTime: 2037-12-11 22:09:46.390 (1071266991390)
eventPosition
latitude: 10°58'44.761"S (-109791002)
longitude: 11°12'1.441"W (-112004003)
positionConfidenceEllipse
semiMajorConfidence: 3.77m (377)
semiMinorConfidence: 3.77m (377)
semiMajorOrientation: wgs84North (0)
altitude
altitudeValue: 12.00m (1200)
altitudeConfidence: alt-000-02 (1)
relevanceDistance: lessThan50m (0)
relevanceTrafficDirection: allTrafficDirections (0)
validityDuration: 24:00:00 (86400)
transmissionInterval: Unknown (500)
stationType: passengerCar (5)
situation
informationQuality: Unknown (3)
eventType
causeCode: wrongWayDriving (14)
wrongWayDrivingSubCauseCode: unavailable (0)
linkedCause
causeCode: collisionRisk (97)
collisionRiskSubCauseCode: unavailable (0)
eventHistory: 2 items
Item 0
EventPoint
eventPosition
deltaLatitude: 0°0'0.044"S (-123)
deltaLongitude: 0°0'0.323"E (897)
deltaAltitude: 0.20m (20)
eventDeltaTime: 17067338.17s (1706733817)
informationQuality: lowest (1)
Item 1
EventPoint
eventPosition
deltaLatitude: 0°0'0.164"N (456)
deltaLongitude: 0°0'0.284"E (789)
deltaAltitude: 0.10m (10)
informationQuality: Unknown (2)
location
eventSpeed
speedValue: 13.00m/s = 46.8km/h (1300)
speedConfidence: unavailable (127)
eventPositionHeading
headingValue: 1.4° (14)
headingConfidence: unavailable (127)
traces: 1 item