# Moving Towards Body-to-Body Sensor Networks for Ubiquitous Applications: A Survey
## 4 BBN Design Challenges and Open Issues
### Storage and Privacy of Health Data in IoT/Cloud Environment  
The communication and cooperation between a group of WBANs are driven by the continuous expansion of the IoT infrastructures and cloud-computing market. Yet, BBNs could benefit from the data storage capabilities of the existing infrastructures, but should pay special attention to the related privacy issues. Already, in [101], the idea of including WBANs to extend the infrastructures coverage area, had been tackled. WBAN packets are expected to be translated into IP datagrams by the WBAN coordinator, that could be a smartphone able to transmit over multiple network interfaces, to ensure the connectivity of the WBAN with the outside world. Existing technologies such as short message services (SMS), general packet radio services (GPRS), email, Bluetooth personal area networking, IPv6 over low power wireless personal area networks (6 LoWPAN), and IP for smart objects (IPSO), are expected to enhance and speed up the data transfer. Today, it will be possible to ensure this task by creating a new type of ad hoc network, where network users themselves are used as ad hoc base stations, able to forward real-time information among co-located persons carrying body sensors. Then, with the emergence of the IoT, ubiquitous healthcare, WBAN data storage, and other management services could be performed remotely by a powerful computing platform at a distant location (Figure 8).  
In [102; 103], it is argued that the standardization of the technologies in IoT is important and urgent, in order to ensure the interactions among the networked things and help accelerate the spread of IoT technology. Yet, to deal with the lack of IoT standardization, global collaboration between existing standards is necessary. The objective, in the long term, is to ensure the integration of objects with sensors in the cloud-based Internet, and then the fusion of sensing and Internet, where all of the networked devices should be autonomous and smart enough to support the ubiquitous services. The other major requirement to enable the integration of WBANs within an IoT platform would be the security of health data storage and transmissions across the networked objects [22; 104]. [PERSON] et al. in [22] proposed a cloud-enabled WBAN architecture to transmit vital sign data using joint cloud resource allocation and cloud data security, along with an energy-efficient routing. The integration of WBANs and mobile cloud computing (MCC), in order to provide and facilitate pervasive healthcare services, is driven in the scope of the cloud-enabled WBAN platforms (wMCC). Data storage encryption, data partitioning, access control, user diversity, scalability and mobile access are the more challenging constraints to be held to enable wMCC services. These security issues are also investigated in [30], especially to ensure secure access control and distributed data storage for sensitive medical data. The goal is to overcome the weaknesses of classical key management approaches, for example the shared public keys should be centralized in a trusted server outside the cloud, or decentralized/distributed among users, rather than centralized in the cloud provider. Besides, in [104], IoT security and resilience challenges are analyzed in order to ensure the IoT - Cloud convergence in the context of Smart City deployment.  
Another example of applications using WBANs in a cloud environment is proposed in [105], and consists of a cloud health management system which includes six subsystems; electronic health record, health information collection, health risk assessment, health intervention, health education and telemedicine system, that are all assisted by an Android mobile phone application. In general, an adequate storage solution solution must be robust, secure, compatible with existing infrastructures and low cost.