  The proliferation of the Internet of Things (IoT) has since seen a growing
interest in architectural design and adaptive frameworks to promote the
connection between heterogeneous IoT devices and IoT systems. The most widely
favoured software architecture in IoT is the Service Oriented Architecture
(SOA), which aims to provide a loosely coupled systems to leverage the use and
reuse of IoT services at the middle-ware layer, to minimise system integration
problems. However, despite the flexibility offered by SOA, the challenges of
integrating, scaling and ensuring resilience in IoT systems persist. One of the
key causes of poor integration in IoT systems is the lack of an intelligent,
connection-aware framework to support interaction in IoT systems. This paper
reviews existing architectural frameworks for integrating IoT devices and
identifies the key areas that require further research improvements. The paper
concludes by proposing a possible solution based on microservice. The proposed
IoT integration framework benefits from an intelligent API layer that employs
an external service assembler, service auditor, service monitor and service
router component to coordinate service publishing, subscription, decoupling and
service combination within the architecture.
