Portable storage devices for storing digital data are known in the art. A portable storage device typically comprises a memory and an interface through which the portable storage device can be releasably plugged in a terminal, such as for instance a PC, a mobile phone, a digital photo-frame, a set-top box, etc.
A very common type of portable storage device is the so-called “USB drive”, which typically includes a non volatile memory (e.g. a flash memory of NAND type) and a USB (“Universal Serial Bus”) interface. Storage capacity of a USB drive typically ranges from 64 MB to 64 GB and more, and may allow up to 1 million re-writing cycles.
When a portable storage device is plugged in a terminal, the terminal typically presents the content of the portable storage device as a file system additional to its local one. Accordingly, the user may access and possibly modify the content of the portable storage device, as if such content were stored in a local memory of the terminal. For instance, if the portable storage device stores audio files, the user may listen to them by suitable audio output means (e.g. a speaker) of the terminal. On the other hand, if the portable storage device stores image files, the user may view them by using suitable output means (e.g. a screen) of the terminal. On the other hand, if the portable storage device stores text files, the user may read and modify them by using suitable output means (e.g. a screen) and input means (e.g. a keyboard or a mouse) of the terminal.
US 2007/0294457 discloses a USB device that includes a USB interface and mimics the operation of a typical USB drive. The USB device provides identification information through its USB interface indicating that it is a storage device. In reality, the USB device does not include a USB drive or storage but rather a communication interface, such as a wired or wireless network interface, that allows the USB device to autonomously connect to and/or map a networked drive. This allows the USB device to establish a communication link to a remote storage device over the communication interface. Thus, the USB device allows a terminal to transparently connect to a remote network drive via a USB port, while the remote network drive appears as a local USB drive to the terminal.