# My Smartphone tattles: Considering Popularity of Messages in Opportunistic Data Dissemination
## 2 Background and Application Scenarios
### Real Implementations  
Very few real-world implementations exist currently, but their number increases constantly. Implementing OppNets on real user devices, especially on smartphones, is not trivial and often forces the developers to \"root\" the devices. This section describes some well-known current applications and frameworks in the area of device-to-device technologies and, if known, describes the underlying technologies.  
_FireChat_ and the underlying framework _MeshKit_ by OpenGarden ([[https://www.opengarden.com](https://www.opengarden.com)]([https://www.opengarden.com](https://www.opengarden.com))) is one of the well-known solutions. The communication is based on Bluetooth and WiFi, and does not require Internet connectivity, but the details are not known as the source code is not publicly available. The SMARTER project ([[http://www.smarter-projekt.de](http://www.smarter-projekt.de)]([http://www.smarter-projekt.de](http://www.smarter-projekt.de))) from Darmstadt, Germany, aims at ad-hoc communication in emergency scenarios. A demonstrator app was developed and tested to communicate during a disaster without cellular infrastructure. However, the application requires rooting the phones and is not available on the market. _BLEMeshChat_ ([[https://github.com/chrisballinger/BLEMeshChat](https://github.com/chrisballinger/BLEMeshChat)]([https://github.com/chrisballinger/BLEMeshChat](https://github.com/chrisballinger/BLEMeshChat))) is a chat application for iOS and Android based on BLE beacons and does not require Internet connectivity. Unfortunately, it has not been active since February 2015.  
It is interesting to note that most of the applications above are targeting destination-less scenarios. There exist also many applications, which do not require a central server, but rely on an Internet connection, e.g., _Tox_ ([[https://tox.chat](https://tox.chat)]([https://tox.chat](https://tox.chat))) and _BRIAR_ ([[https://briarproject.org](https://briarproject.org)]([https://briarproject.org](https://briarproject.org))). These are peer-to-peer applications, as opposed to device-to-device applications.  
Figure 1: Taxonomy of OppNets Applications in terms of the destination of messages.  
Apple and Google, the main companies behind the mobile phone operating systems--iOS and Android--offer frameworks to communicate with devices in proximity. Apple's _MultipeerConnectivity_ ([[https://developer.apple.com/documentation/multipeerconnectivity](https://developer.apple.com/documentation/multipeerconnectivity)]([https://developer.apple.com/documentation/multipeerconnectivity](https://developer.apple.com/documentation/multipeerconnectivity))) framework is only available for iOS devices and uses Bluetooth and WiFi to establish connection between devices. Here, no Internet is required. _Nearby_ ([[https://developers.google.com/nearby](https://developers.google.com/nearby)]([https://developers.google.com/nearby](https://developers.google.com/nearby))) is the name of the counterpart by Google. It uses a variety of technologies to connect to devices in proximity. It does not require Internet access for Android devices, but offers an Internet-based approach to connect to iOS-based devices.  
Most of the above-mentioned frameworks and applications use a flooding or Epidemic-like data forwarding approach. This is another motivation for us to compare our work against Epidemic.