In this article let’s explore the role of devices, gateways in IoT and also understand how data management takes place in an IoT system.
Device
The device management assigns ID and address for each device:
ID: Each device is assigned an unique ID which is used for source and destination address
Addressing: Header fields add the destination address and port number of the application
Device Management
Device management involves provisioning of device ID or address, activation, configuration, registration and deregistration, attachment and detachment.
Device management also includes accepting or requesting subscription for its resources on topic(s). Device fault-management includes actions and guidelines to be followed in case of a fault.
OMA-DM standard model suggests the use of a DM server.
Gateway functions for device management are as follows:
- Forwarding function between DM server and device.
- Protocol conversion when device and DM server use distinct protocols.
- Act as a proxy in case an intermediate pre-fetch (caching) is required in LLNs.
Gateway
A gateway accepts data from devices, manages the data and performs data enrichment and consolidation for communication over the Internet.
A gateway consist of the following functions:
- Data management and consolidation.
- Connected device management.
- Communication over the Internet.
Data Management at Gateway
Data characteristics, formats and structures:
- Data characteristics can be temporal data, spatial data, real-time data, real-world data, proprietary data, and big data.
- Various data formats are XML, JSON, TLV, MIME, etc.
- Data structure refers to how the data is arranged (bits, bytes, or a sequence of bytes).
Transcoding:
- Involves adaptation, conversion and changes using software which renders the web responses and messages in various formats acceptable at an IoT device.
- Transcoding involves formatting, data and code conversion from one end to another.
- Transcoding also involves filtering, compression or decompression.
- A transcoding proxy has conversion, computational and analysing capabilities.
Data gathering involves data acquisition from the device. Four modes of data gathering are:
- Polling fetches the data from a device by addressing the device.
- Event-based gathering refers to the data sought from the device on an event.
- Scheduled interval refers to the data sought from a device at selected intervals.
- Continuous monitoring refers to the data sought from a device continuously.
Data enrichment and data consolidation
- Involves adding value, security, and usability of data.
- Initial three steps for data enrichment before data is disseminated to the network are:
- Aggregation: refers to the process of joining together present and previously received frames after removing redundant or duplicate data.
- Compaction means making information short without changing the meaning or context.
- Fusion means combining data received over several frames, formatting it and presenting it.
Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.
He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.
He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.
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