# Embracing the Future Internet of Things +
## 6 Challenges and Open Issues  
We have performed a trend analysis based on the reports from International Data Corporation (IDC) [33], Gartner [34] and our estimations [3]. In addition, 11.4 billion \"things\" were installed in  
Figure 8: IoT platform experiments: (**a**) performance impact of the federation of IoT platforms; (**b**) scalability of IoT platforms’ federation. 2014 and 13.7 billion in 2015 with a 20.8% increase. Even if the numbers are forecast to continue increasing, the rate will gradually decrease to 11.5% in 2020, with an estimation of 28.1 billion \"things\". Consequently, the generated data volume will grow by an order of magnitude (10\(\times\)) from 2015 to 2020 [35]. This exceptional growth of IoT is due to the promised financial benefits. Smart cities and smart homes are, amongst the others, the most advanced field where many businesses compete to earn a share of the market. In the smart cities field, a big push was made by the governments that gradually increased investments, whereas the change in the way of people thinking about everyday life, always more digitalized, opens great business opportunities in the smart homes area. According to [33; 34; 3], the market share of smart homes and smart cities is forecast to be the 25% over the total IoT market, by 2020. These vast numbers of connected \"things\" and large data volumes are only possible with new technologies and standards. The unprecedented increase in \"things\" coming together with big data brings many new challenges and problems in connectivity, processing, memory, sensing, and actions that require enabling of the future IoT platform capabilities and 5G in order to lead the aforementioned expectations into a reality. Based on this observation, we point out some open issues in the future IoT as follows:  
1. _Data ownership management_: For a future IoT where data is globally accessible and discoverable, special attention should be paid in order to assure that the producer of the data (or the owner of the observed things) keeps ownership of the data, especially for privacy-sensitive data. A study of the International Data Space Association (IDSA) [36; 37], where more than 200 companies have been interviewed regarding data exchanged with other companies, states that one of the major concerns that blocks a company from sharing data with another peer is the uncertainty of losing control over the data once the data has been released, and thus losing the \"sovereignty\" of the data. A first issue is to state \"who is the owner of the data\"--for instance, we are keen to think that the owner of the IoT deployment is the owner of the data; for example, a public transportation company deploying sensors on its buses is the owner of such data. However, in other situations, the owner of the data is the observed thing; this is the case of health sensors deployed by the health care system at home of a patient where the patient is the \"thing\" observed and the owner of the data. In addition, another open issue is \"how to control the data migration to other users and services\". Often, users are requested to sign agreements on processing their data, as specified on common data regulations (e.g., General Data Protection Regulation-GDPR [38], but, afterwards, there is not an easy way to control if those agreements are respected. In addition, the data owners should be capable to visualize where, how, by whom and why their data are accessed. Moreover, usage terms might dynamically change over time due to new regulations, changing of the mind of the data owner, or other factors (e.g., expiration of a time period). An automatic system of managing these data access rights' dynamism is a clear challenge. 2. _Privacy and security_: With the realization of the presented capabilities, the future IoT will encounter new security and privacy threats. Every IoT layer, from application to devices, has peculiarities on the security risks and possible attacks.