"The Smart Phone Ad-Hoc Networks (SPAN) project reconfigures the onboard Wi-Fi chip of a smartphone to act as a Wi-Fi router with other nearby similarly configured smartphones, creating an ad-hoc mesh network. These smartphones can then communicate with one another without an operational carrier network. SPAN intercepts all communications at the Global Handset Proxy (see figure at right) so applications such as VoIP, Twitter, email etc., work normally.
The source from the Linux Wireless Extension API was merged into the Android kernel source and compiled. The modified version of Android was used to root specific models of Android smartphones to expose and harness the ad-hoc routing features of the onboard Wi-Fi chip to enable this intercept."