Smart Objects and the Internet of Things provide unparalleled means for connecting the physical world with the digital world, thus enabling important applications such as Smart Infrastructures or Smart Cities. At the same time, we can observe a rapid large- scale expansion of smartphones that are becoming sources of measures collected by mobile users—a trend called crowd-sensing. For instance, commuters or Smart City services may be interested in various information on mobility patterns or traffic intensity as well as other information about the environment. Such applications can use different types of networks for data collection: cellular networks or sensor oriented technologies such as low rate long distance radio networks currently being developed by SigFox. However, such approaches are suited for only one type of sensor devices and we observe the lack of a unifying technology that will make use of existing and future access networks to gather data from all types of devices: smartphones, smart objects, cars etc.

The DataTweet project proposes to explore the idea of a ubiquitous public data service for transmitting short messages in a similar way to Twitter. Any user of the service or a data source will be able to send a short message at a very low rate to some destination address over various access networks: open 802.11 hotspots, base stations of LTE, car-to-infrastructure stations of 802.11p. The user or a device sends its message to the nearest wireless network at hand (for instance a 802.11 hotspot) that will forward it in a multihop way to the destination by the elements of the infrastructure network.

In a similar way to the Water Cycle, crowds of devices and mobile users may generate data sent to the Cloud through nearest access points like water evaporating to the sky to form clouds. Collected data become useful information in the Cloud, because of all the meaning and interpretation that we can attach to raw data. Then, the Cloud can shower the users and devices with the information transmitted in short messages in target areas.

The DataTweet service requires carefully designed support for security and privacy. The simplicity of the communication mode stems from a lightweight operation without association with access points and with simple authorization of groups of users. Nevertheless, the content of a message should be encrypted and authenticated to guarantee confidentiality and authentication at several levels allowing plain or partial access to the content based on groups of users. The payload security is orthogonal to the data plane and will be supported off-line. The project will address the problems of privacy through anonymization techniques and information hiding. A message may include some metadata describing the content.

DataTweet can support several types of applications. It can easily gather data from users and vehicles on a large-scale for improving traffic prediction and congestion management in Smart Cities. It can also provide a means for conveying data from deployed sensors or to a larger extent, from the Internet of Things to become an interconnection infrastructure.

We aim at two applications to drive our work: Smart Traffic and Smart Home that will benefit from the deployed service. We see experimental validation and evaluation as critical to the success of the project. Therefore, we will extensively rely on prototype deployment in the City of Grenoble. This gives a solid base for evaluation in realistic conditions and environments.