INTER-LAYER - Device to Device (D2D) Interoperability

Currently applications and platforms are tightly coupled, preventing their interaction with other applications and platforms, sensors and actuators communicate only within one system, certain platforms do not implement some important services (i.e. discovery), or do so in an incompatible way. Roaming elements can be missing or inaccessible. IoT Device software is never platform independent as companies create proprietary software. These facts present enormous difficulties for the achievement of interoperability. At the device level, D2D solution will allow the seamless inclusion of novel IoT devices and their interoperation with already existing ones (legacy). D2D interoperability will allow a fast growth of smart objects ecosystems. As a potential solution INTER-IoT proposes a D2D gateway that allows any type of data forwarding, making the device layer flexible by decoupling the gateway into two independent parts: a physical part that only handles network access and communication protocols, and a virtual part that handles all other gateway operations and services. When connection is lost, the virtual part remains functional and will answer the API and Middleware requests. The gateway will follow a modular approach to allow the addition of optional service blocks, to adapt to the specific case.

Proposed solution

The following factors illustrate the need to implement an interoperability solution at the device layer:

  • Applications and platforms are tightly coupled, preventing them from interacting with other applications/platforms.

  • Sensors and actuators communicate only within one system.

  • Certain platforms do not implement some important services (i.e. discovery), or do so in an incompatible way.

  • Roaming elements can be lost or inaccessible.

  • IoT Device software is never platform independent, since companies produce proprietary/closed solutions for economical reasons. This makes interoperability hard or impossible.

Interoperability at the device level implies that heterogeneous IoT devices are able to interact with each other. IoT devices can be accessed/controlled through a unifying interface and integrated into any IoT platform.

This interoperability solution at device level is achieved through a Device to Device Gateway (D2D Gateway, or sometimes simplified as Gateway or GW in this document). There are two approaches for the implementation of this Gateway: physical and virtual.

The physical implementation of the Gateway is oriented towards hardware with medium computational capacities and storage. The virtual implementation is meant for hardware with low computational capacities and storage. In this implementation only the south part of the Gateway (network and protocol capabilities) is processed in hardware while all the other Gateway functionalities are shifted to the virtual Gateway with more computational power.

For this reason, the Gateway will be developed in Java using the OSGi framework. All components of the Gateway will be packaged as OSGi bundles and the OSGi framework will be utilized to control the bundles that will be needed depending on the chosen implementation mode.