# Middleware Technologies for Cloud of Things - a survey

## TL;DR

This survey reviews middleware technologies for Cloud of Things, highlighting their features, architectures, and challenges in managing heterogeneous IoT devices within cloud environments.

## Contribution

It provides a comprehensive overview of middleware solutions for CoT, analyzing their architectures, service domains, and current challenges in design and implementation.

## Key findings

- Middleware addresses heterogeneity in IoT devices.
- Various middleware architectures support CoT platforms.
- Challenges include scalability, security, and interoperability.

## Abstract

The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.