IoT Gateway

Operations

Gateway -> Device

• SendControlMessage : Index -> Format -> Data -> Success

Device -> Gateway

• SendSensorUpdate : Index -> Format -> Data

Controller -> Gateway

• GetSensors : [ DeviceId, Index, CRC ] -> [ DeviceId, Index, CRC, Data ]
• SendControl : [ DeviceId, Index, Format, Data ] -> Success

Attach device

• AttachRequest : DeviceId -> [D:Format] -> [C:Format]
• AttachConfirm : same as SendControlMessage with pre-defined control format
• User and controller may be involved in accepting an new device

Security

• Encryption key kan be installed at factory or installed once at attach

Cloud Gateway Data Structures

TBD

Edge Gateway Data Structures

Lookup table for control data : intermediate data towards devices

• [ Device ID, SegmentIndex, DataIndex, ControlFormatId, CRC ] : static element size
  • DeviceIndex specify number if multiple control segements are supported
• [ Data ] : variable element size where element start is at DataIndex
• [ ControlFormatId, ControlFormatSpec ]

Lookup table for sensor data : latest sensor data from devices

• [ Device ID, SegmentIndex, DataIndex, SensorFormatId, CRC ] : static element size
  • DeviceIndex specify number if multiple control segements are supported
• [ Data ] : variable element size where element start is at DataIndex
• [ SensorFormatId, SensorFormatSpec ]

Data format spec

• [ Name, Type ]

Device Data Structures

Sensor data is stored in C code structires which can be translated to binary air protocol

• [ SegmentIndex, ControlData ]
• [ SegmentIndex, SensorData ]

TODO

References

• PubSubAlternative
• GatewayDesign

Tags: IoT, MQTT, Gateway

This site is maintained by Peter Ljung using the powers of OpenBSD, Ruby, Sinatra combined as WebFactory