Enterprise Interoperability: Smart Services and Business Impact of Enterprise Interoperability

20 Semantic Interoperability for the IoT: Analysis of JSON for Linked Data

Recently a number of IoT platforms have been developed to cope with the big data generated and consumed by sensors and actuators. Some IoT platforms achieve syntactic interoperability by adopting JavaScript Object Notation (JSON) to represent the message payload produced by devices. Usually, semantic interoperability of IoT solutions is also required. JSON for Linked Data (JSON-LD) is a syntax to serialize RDF and, therefore, can provide semantic interoperability to IoT solutions. Although JSON-LD is designed to be lightweight, it causes an increase of the size of messages if compared to native JSON, due to the additional metadata. This paper presents an empirical performance analysis of JSON-LD compared to JSON in common IoT scenarios. Event data produced by a sensor are serialized as JSON and JSON-LD and the total transaction time is compared in request/reply and publish/subscribe architectures. The results indicate that JSON-LD is adequate.

20.1. Introduction

Current IoT solutions follow the event-driven architecture for data exchange among IoT devices, networks and applications through RESTful web services with JSON as a data exchange format [DIA 16]. JSON for Linked Data (JSON-LD) is a lightweight syntax to serialize RDF as a structured JSON, representing a way to semantically enrich conventional JSON messages [JAN 16]. JSON-LD is a W3C standard [W3C 18] recommended by schema.org and Google. ...