The NFC Forum recently released the Generic Control Record Type Definition (RTD) and Connection Handover specifications. The two specifications stipulate the requesting of actions and the activation of alternative data transfers technologies between NFC enabled devices. The Generic Control RTD specification provides a simple way to request a specific action, such as starting an application or setting a mode on an NFC enabled device (destination device) from another NFC device, tag or card (source device) through NFC communication. The Connection Handover specification defines the structure and sequence of interactions that enable two NFC-enabled devices to establish a connection using other wireless communication technologies, such as WiFi or Bluetooth. Both specification are available for download.
Connection Handover makes it possible to deploy applications that offer the best of both worlds by combining the simple, one-touch set-up of NFC with the high-speed communication of Bluetooth or WiFi. With this capability, users of Bluetooth mobile phones can quickly transfer even large data files to one another simply by touching their phones together. The specification enables developers to choose the carrier for the information to be exchanged. If matching wireless capabilities are revealed during the negotiation process between two NFC-enabled devices, the connection can switch to the selected carrier.
The Connection Handover specification also covers static handover, in which the connection handover information is stored on a simple NFC Forum Tag that can be read by NFC-enabled devices. Static mode is used in applications in which the negotiation mechanism or on-demand carrier activation is not required. In both negotiated and static handover, communication is established between the devices using the NFC touch paradigm.
More info: NFC Forum Specifications